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9746 lines
235 KiB
9746 lines
235 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* ring buffer based function tracer |
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* |
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* Copyright (C) 2007-2012 Steven Rostedt <[email protected]> |
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* Copyright (C) 2008 Ingo Molnar <[email protected]> |
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* |
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* Originally taken from the RT patch by: |
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* Arnaldo Carvalho de Melo <[email protected]> |
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* |
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* Based on code from the latency_tracer, that is: |
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* Copyright (C) 2004-2006 Ingo Molnar |
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* Copyright (C) 2004 Nadia Yvette Chambers |
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*/ |
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#include <linux/ring_buffer.h> |
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#include <generated/utsrelease.h> |
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#include <linux/stacktrace.h> |
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#include <linux/writeback.h> |
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#include <linux/kallsyms.h> |
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#include <linux/security.h> |
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#include <linux/seq_file.h> |
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#include <linux/notifier.h> |
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#include <linux/irqflags.h> |
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#include <linux/debugfs.h> |
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#include <linux/tracefs.h> |
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#include <linux/pagemap.h> |
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#include <linux/hardirq.h> |
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#include <linux/linkage.h> |
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#include <linux/uaccess.h> |
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#include <linux/vmalloc.h> |
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#include <linux/ftrace.h> |
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#include <linux/module.h> |
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#include <linux/percpu.h> |
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#include <linux/splice.h> |
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#include <linux/kdebug.h> |
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#include <linux/string.h> |
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#include <linux/mount.h> |
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#include <linux/rwsem.h> |
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#include <linux/slab.h> |
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#include <linux/ctype.h> |
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#include <linux/init.h> |
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#include <linux/poll.h> |
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#include <linux/nmi.h> |
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#include <linux/fs.h> |
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#include <linux/trace.h> |
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#include <linux/sched/clock.h> |
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#include <linux/sched/rt.h> |
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#include <linux/fsnotify.h> |
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#include <linux/irq_work.h> |
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#include <linux/workqueue.h> |
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|
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#include "trace.h" |
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#include "trace_output.h" |
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|
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/* |
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* On boot up, the ring buffer is set to the minimum size, so that |
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* we do not waste memory on systems that are not using tracing. |
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*/ |
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bool ring_buffer_expanded; |
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|
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/* |
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* We need to change this state when a selftest is running. |
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* A selftest will lurk into the ring-buffer to count the |
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* entries inserted during the selftest although some concurrent |
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* insertions into the ring-buffer such as trace_printk could occurred |
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* at the same time, giving false positive or negative results. |
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*/ |
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static bool __read_mostly tracing_selftest_running; |
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|
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/* |
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* If boot-time tracing including tracers/events via kernel cmdline |
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* is running, we do not want to run SELFTEST. |
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*/ |
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bool __read_mostly tracing_selftest_disabled; |
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|
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#ifdef CONFIG_FTRACE_STARTUP_TEST |
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void __init disable_tracing_selftest(const char *reason) |
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{ |
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if (!tracing_selftest_disabled) { |
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tracing_selftest_disabled = true; |
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pr_info("Ftrace startup test is disabled due to %s\n", reason); |
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} |
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} |
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#endif |
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|
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/* Pipe tracepoints to printk */ |
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struct trace_iterator *tracepoint_print_iter; |
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int tracepoint_printk; |
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static DEFINE_STATIC_KEY_FALSE(tracepoint_printk_key); |
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|
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/* For tracers that don't implement custom flags */ |
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static struct tracer_opt dummy_tracer_opt[] = { |
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{ } |
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}; |
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static int |
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dummy_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set) |
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{ |
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return 0; |
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} |
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|
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/* |
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* To prevent the comm cache from being overwritten when no |
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* tracing is active, only save the comm when a trace event |
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* occurred. |
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*/ |
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static DEFINE_PER_CPU(bool, trace_taskinfo_save); |
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|
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/* |
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* Kill all tracing for good (never come back). |
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* It is initialized to 1 but will turn to zero if the initialization |
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* of the tracer is successful. But that is the only place that sets |
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* this back to zero. |
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*/ |
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static int tracing_disabled = 1; |
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|
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cpumask_var_t __read_mostly tracing_buffer_mask; |
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|
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/* |
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* ftrace_dump_on_oops - variable to dump ftrace buffer on oops |
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* |
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* If there is an oops (or kernel panic) and the ftrace_dump_on_oops |
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* is set, then ftrace_dump is called. This will output the contents |
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* of the ftrace buffers to the console. This is very useful for |
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* capturing traces that lead to crashes and outputing it to a |
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* serial console. |
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* |
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* It is default off, but you can enable it with either specifying |
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* "ftrace_dump_on_oops" in the kernel command line, or setting |
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* /proc/sys/kernel/ftrace_dump_on_oops |
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* Set 1 if you want to dump buffers of all CPUs |
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* Set 2 if you want to dump the buffer of the CPU that triggered oops |
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*/ |
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enum ftrace_dump_mode ftrace_dump_on_oops; |
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|
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/* When set, tracing will stop when a WARN*() is hit */ |
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int __disable_trace_on_warning; |
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#ifdef CONFIG_TRACE_EVAL_MAP_FILE |
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/* Map of enums to their values, for "eval_map" file */ |
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struct trace_eval_map_head { |
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struct module *mod; |
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unsigned long length; |
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}; |
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union trace_eval_map_item; |
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struct trace_eval_map_tail { |
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/* |
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* "end" is first and points to NULL as it must be different |
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* than "mod" or "eval_string" |
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*/ |
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union trace_eval_map_item *next; |
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const char *end; /* points to NULL */ |
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}; |
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static DEFINE_MUTEX(trace_eval_mutex); |
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/* |
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* The trace_eval_maps are saved in an array with two extra elements, |
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* one at the beginning, and one at the end. The beginning item contains |
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* the count of the saved maps (head.length), and the module they |
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* belong to if not built in (head.mod). The ending item contains a |
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* pointer to the next array of saved eval_map items. |
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*/ |
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union trace_eval_map_item { |
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struct trace_eval_map map; |
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struct trace_eval_map_head head; |
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struct trace_eval_map_tail tail; |
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}; |
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static union trace_eval_map_item *trace_eval_maps; |
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#endif /* CONFIG_TRACE_EVAL_MAP_FILE */ |
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int tracing_set_tracer(struct trace_array *tr, const char *buf); |
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static void ftrace_trace_userstack(struct trace_array *tr, |
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struct trace_buffer *buffer, |
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unsigned int trace_ctx); |
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#define MAX_TRACER_SIZE 100 |
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static char bootup_tracer_buf[MAX_TRACER_SIZE] __initdata; |
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static char *default_bootup_tracer; |
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|
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static bool allocate_snapshot; |
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static int __init set_cmdline_ftrace(char *str) |
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{ |
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strlcpy(bootup_tracer_buf, str, MAX_TRACER_SIZE); |
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default_bootup_tracer = bootup_tracer_buf; |
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/* We are using ftrace early, expand it */ |
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ring_buffer_expanded = true; |
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return 1; |
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} |
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__setup("ftrace=", set_cmdline_ftrace); |
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|
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static int __init set_ftrace_dump_on_oops(char *str) |
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{ |
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if (*str++ != '=' || !*str) { |
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ftrace_dump_on_oops = DUMP_ALL; |
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return 1; |
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} |
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if (!strcmp("orig_cpu", str)) { |
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ftrace_dump_on_oops = DUMP_ORIG; |
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return 1; |
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} |
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return 0; |
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} |
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__setup("ftrace_dump_on_oops", set_ftrace_dump_on_oops); |
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static int __init stop_trace_on_warning(char *str) |
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{ |
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if ((strcmp(str, "=0") != 0 && strcmp(str, "=off") != 0)) |
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__disable_trace_on_warning = 1; |
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return 1; |
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} |
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__setup("traceoff_on_warning", stop_trace_on_warning); |
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static int __init boot_alloc_snapshot(char *str) |
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{ |
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allocate_snapshot = true; |
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/* We also need the main ring buffer expanded */ |
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ring_buffer_expanded = true; |
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return 1; |
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} |
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__setup("alloc_snapshot", boot_alloc_snapshot); |
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static char trace_boot_options_buf[MAX_TRACER_SIZE] __initdata; |
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static int __init set_trace_boot_options(char *str) |
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{ |
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strlcpy(trace_boot_options_buf, str, MAX_TRACER_SIZE); |
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return 0; |
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} |
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__setup("trace_options=", set_trace_boot_options); |
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static char trace_boot_clock_buf[MAX_TRACER_SIZE] __initdata; |
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static char *trace_boot_clock __initdata; |
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static int __init set_trace_boot_clock(char *str) |
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{ |
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strlcpy(trace_boot_clock_buf, str, MAX_TRACER_SIZE); |
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trace_boot_clock = trace_boot_clock_buf; |
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return 0; |
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} |
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__setup("trace_clock=", set_trace_boot_clock); |
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static int __init set_tracepoint_printk(char *str) |
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{ |
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if ((strcmp(str, "=0") != 0 && strcmp(str, "=off") != 0)) |
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tracepoint_printk = 1; |
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return 1; |
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} |
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__setup("tp_printk", set_tracepoint_printk); |
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unsigned long long ns2usecs(u64 nsec) |
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{ |
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nsec += 500; |
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do_div(nsec, 1000); |
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return nsec; |
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} |
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static void |
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trace_process_export(struct trace_export *export, |
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struct ring_buffer_event *event, int flag) |
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{ |
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struct trace_entry *entry; |
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unsigned int size = 0; |
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if (export->flags & flag) { |
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entry = ring_buffer_event_data(event); |
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size = ring_buffer_event_length(event); |
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export->write(export, entry, size); |
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} |
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} |
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static DEFINE_MUTEX(ftrace_export_lock); |
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static struct trace_export __rcu *ftrace_exports_list __read_mostly; |
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static DEFINE_STATIC_KEY_FALSE(trace_function_exports_enabled); |
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static DEFINE_STATIC_KEY_FALSE(trace_event_exports_enabled); |
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static DEFINE_STATIC_KEY_FALSE(trace_marker_exports_enabled); |
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static inline void ftrace_exports_enable(struct trace_export *export) |
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{ |
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if (export->flags & TRACE_EXPORT_FUNCTION) |
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static_branch_inc(&trace_function_exports_enabled); |
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if (export->flags & TRACE_EXPORT_EVENT) |
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static_branch_inc(&trace_event_exports_enabled); |
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if (export->flags & TRACE_EXPORT_MARKER) |
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static_branch_inc(&trace_marker_exports_enabled); |
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} |
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static inline void ftrace_exports_disable(struct trace_export *export) |
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{ |
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if (export->flags & TRACE_EXPORT_FUNCTION) |
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static_branch_dec(&trace_function_exports_enabled); |
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if (export->flags & TRACE_EXPORT_EVENT) |
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static_branch_dec(&trace_event_exports_enabled); |
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if (export->flags & TRACE_EXPORT_MARKER) |
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static_branch_dec(&trace_marker_exports_enabled); |
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} |
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static void ftrace_exports(struct ring_buffer_event *event, int flag) |
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{ |
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struct trace_export *export; |
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preempt_disable_notrace(); |
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export = rcu_dereference_raw_check(ftrace_exports_list); |
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while (export) { |
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trace_process_export(export, event, flag); |
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export = rcu_dereference_raw_check(export->next); |
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} |
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preempt_enable_notrace(); |
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} |
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static inline void |
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add_trace_export(struct trace_export **list, struct trace_export *export) |
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{ |
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rcu_assign_pointer(export->next, *list); |
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/* |
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* We are entering export into the list but another |
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* CPU might be walking that list. We need to make sure |
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* the export->next pointer is valid before another CPU sees |
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* the export pointer included into the list. |
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*/ |
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rcu_assign_pointer(*list, export); |
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} |
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static inline int |
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rm_trace_export(struct trace_export **list, struct trace_export *export) |
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{ |
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struct trace_export **p; |
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for (p = list; *p != NULL; p = &(*p)->next) |
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if (*p == export) |
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break; |
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if (*p != export) |
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return -1; |
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rcu_assign_pointer(*p, (*p)->next); |
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return 0; |
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} |
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static inline void |
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add_ftrace_export(struct trace_export **list, struct trace_export *export) |
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{ |
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ftrace_exports_enable(export); |
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add_trace_export(list, export); |
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} |
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static inline int |
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rm_ftrace_export(struct trace_export **list, struct trace_export *export) |
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{ |
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int ret; |
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ret = rm_trace_export(list, export); |
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ftrace_exports_disable(export); |
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return ret; |
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} |
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int register_ftrace_export(struct trace_export *export) |
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{ |
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if (WARN_ON_ONCE(!export->write)) |
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return -1; |
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mutex_lock(&ftrace_export_lock); |
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add_ftrace_export(&ftrace_exports_list, export); |
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mutex_unlock(&ftrace_export_lock); |
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return 0; |
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} |
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EXPORT_SYMBOL_GPL(register_ftrace_export); |
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int unregister_ftrace_export(struct trace_export *export) |
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{ |
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int ret; |
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mutex_lock(&ftrace_export_lock); |
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ret = rm_ftrace_export(&ftrace_exports_list, export); |
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mutex_unlock(&ftrace_export_lock); |
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return ret; |
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} |
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EXPORT_SYMBOL_GPL(unregister_ftrace_export); |
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/* trace_flags holds trace_options default values */ |
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#define TRACE_DEFAULT_FLAGS \ |
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(FUNCTION_DEFAULT_FLAGS | \ |
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TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK | \ |
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TRACE_ITER_ANNOTATE | TRACE_ITER_CONTEXT_INFO | \ |
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TRACE_ITER_RECORD_CMD | TRACE_ITER_OVERWRITE | \ |
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TRACE_ITER_IRQ_INFO | TRACE_ITER_MARKERS | \ |
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TRACE_ITER_HASH_PTR) |
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|
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/* trace_options that are only supported by global_trace */ |
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#define TOP_LEVEL_TRACE_FLAGS (TRACE_ITER_PRINTK | \ |
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TRACE_ITER_PRINTK_MSGONLY | TRACE_ITER_RECORD_CMD) |
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|
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/* trace_flags that are default zero for instances */ |
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#define ZEROED_TRACE_FLAGS \ |
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(TRACE_ITER_EVENT_FORK | TRACE_ITER_FUNC_FORK) |
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|
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/* |
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* The global_trace is the descriptor that holds the top-level tracing |
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* buffers for the live tracing. |
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*/ |
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static struct trace_array global_trace = { |
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.trace_flags = TRACE_DEFAULT_FLAGS, |
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}; |
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|
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LIST_HEAD(ftrace_trace_arrays); |
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|
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int trace_array_get(struct trace_array *this_tr) |
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{ |
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struct trace_array *tr; |
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int ret = -ENODEV; |
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mutex_lock(&trace_types_lock); |
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list_for_each_entry(tr, &ftrace_trace_arrays, list) { |
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if (tr == this_tr) { |
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tr->ref++; |
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ret = 0; |
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break; |
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} |
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} |
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mutex_unlock(&trace_types_lock); |
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|
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return ret; |
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} |
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static void __trace_array_put(struct trace_array *this_tr) |
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{ |
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WARN_ON(!this_tr->ref); |
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this_tr->ref--; |
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} |
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|
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/** |
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* trace_array_put - Decrement the reference counter for this trace array. |
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* @this_tr : pointer to the trace array |
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* |
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* NOTE: Use this when we no longer need the trace array returned by |
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* trace_array_get_by_name(). This ensures the trace array can be later |
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* destroyed. |
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* |
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*/ |
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void trace_array_put(struct trace_array *this_tr) |
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{ |
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if (!this_tr) |
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return; |
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|
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mutex_lock(&trace_types_lock); |
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__trace_array_put(this_tr); |
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mutex_unlock(&trace_types_lock); |
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} |
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EXPORT_SYMBOL_GPL(trace_array_put); |
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|
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int tracing_check_open_get_tr(struct trace_array *tr) |
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{ |
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int ret; |
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|
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ret = security_locked_down(LOCKDOWN_TRACEFS); |
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if (ret) |
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return ret; |
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|
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if (tracing_disabled) |
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return -ENODEV; |
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|
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if (tr && trace_array_get(tr) < 0) |
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return -ENODEV; |
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|
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return 0; |
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} |
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|
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int call_filter_check_discard(struct trace_event_call *call, void *rec, |
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struct trace_buffer *buffer, |
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struct ring_buffer_event *event) |
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{ |
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if (unlikely(call->flags & TRACE_EVENT_FL_FILTERED) && |
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!filter_match_preds(call->filter, rec)) { |
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__trace_event_discard_commit(buffer, event); |
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return 1; |
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} |
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|
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return 0; |
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} |
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|
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void trace_free_pid_list(struct trace_pid_list *pid_list) |
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{ |
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vfree(pid_list->pids); |
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kfree(pid_list); |
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} |
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|
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/** |
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* trace_find_filtered_pid - check if a pid exists in a filtered_pid list |
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* @filtered_pids: The list of pids to check |
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* @search_pid: The PID to find in @filtered_pids |
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* |
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* Returns true if @search_pid is fonud in @filtered_pids, and false otherwis. |
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*/ |
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bool |
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trace_find_filtered_pid(struct trace_pid_list *filtered_pids, pid_t search_pid) |
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{ |
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/* |
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* If pid_max changed after filtered_pids was created, we |
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* by default ignore all pids greater than the previous pid_max. |
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*/ |
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if (search_pid >= filtered_pids->pid_max) |
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return false; |
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|
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return test_bit(search_pid, filtered_pids->pids); |
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} |
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|
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/** |
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* trace_ignore_this_task - should a task be ignored for tracing |
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* @filtered_pids: The list of pids to check |
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* @filtered_no_pids: The list of pids not to be traced |
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* @task: The task that should be ignored if not filtered |
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* |
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* Checks if @task should be traced or not from @filtered_pids. |
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* Returns true if @task should *NOT* be traced. |
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* Returns false if @task should be traced. |
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*/ |
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bool |
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trace_ignore_this_task(struct trace_pid_list *filtered_pids, |
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struct trace_pid_list *filtered_no_pids, |
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struct task_struct *task) |
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{ |
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/* |
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* If filterd_no_pids is not empty, and the task's pid is listed |
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* in filtered_no_pids, then return true. |
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* Otherwise, if filtered_pids is empty, that means we can |
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* trace all tasks. If it has content, then only trace pids |
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* within filtered_pids. |
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*/ |
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|
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return (filtered_pids && |
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!trace_find_filtered_pid(filtered_pids, task->pid)) || |
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(filtered_no_pids && |
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trace_find_filtered_pid(filtered_no_pids, task->pid)); |
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} |
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|
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/** |
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* trace_filter_add_remove_task - Add or remove a task from a pid_list |
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* @pid_list: The list to modify |
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* @self: The current task for fork or NULL for exit |
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* @task: The task to add or remove |
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* |
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* If adding a task, if @self is defined, the task is only added if @self |
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* is also included in @pid_list. This happens on fork and tasks should |
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* only be added when the parent is listed. If @self is NULL, then the |
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* @task pid will be removed from the list, which would happen on exit |
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* of a task. |
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*/ |
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void trace_filter_add_remove_task(struct trace_pid_list *pid_list, |
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struct task_struct *self, |
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struct task_struct *task) |
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{ |
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if (!pid_list) |
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return; |
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|
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/* For forks, we only add if the forking task is listed */ |
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if (self) { |
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if (!trace_find_filtered_pid(pid_list, self->pid)) |
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return; |
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} |
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|
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/* Sorry, but we don't support pid_max changing after setting */ |
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if (task->pid >= pid_list->pid_max) |
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return; |
|
|
|
/* "self" is set for forks, and NULL for exits */ |
|
if (self) |
|
set_bit(task->pid, pid_list->pids); |
|
else |
|
clear_bit(task->pid, pid_list->pids); |
|
} |
|
|
|
/** |
|
* trace_pid_next - Used for seq_file to get to the next pid of a pid_list |
|
* @pid_list: The pid list to show |
|
* @v: The last pid that was shown (+1 the actual pid to let zero be displayed) |
|
* @pos: The position of the file |
|
* |
|
* This is used by the seq_file "next" operation to iterate the pids |
|
* listed in a trace_pid_list structure. |
|
* |
|
* Returns the pid+1 as we want to display pid of zero, but NULL would |
|
* stop the iteration. |
|
*/ |
|
void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos) |
|
{ |
|
unsigned long pid = (unsigned long)v; |
|
|
|
(*pos)++; |
|
|
|
/* pid already is +1 of the actual prevous bit */ |
|
pid = find_next_bit(pid_list->pids, pid_list->pid_max, pid); |
|
|
|
/* Return pid + 1 to allow zero to be represented */ |
|
if (pid < pid_list->pid_max) |
|
return (void *)(pid + 1); |
|
|
|
return NULL; |
|
} |
|
|
|
/** |
|
* trace_pid_start - Used for seq_file to start reading pid lists |
|
* @pid_list: The pid list to show |
|
* @pos: The position of the file |
|
* |
|
* This is used by seq_file "start" operation to start the iteration |
|
* of listing pids. |
|
* |
|
* Returns the pid+1 as we want to display pid of zero, but NULL would |
|
* stop the iteration. |
|
*/ |
|
void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos) |
|
{ |
|
unsigned long pid; |
|
loff_t l = 0; |
|
|
|
pid = find_first_bit(pid_list->pids, pid_list->pid_max); |
|
if (pid >= pid_list->pid_max) |
|
return NULL; |
|
|
|
/* Return pid + 1 so that zero can be the exit value */ |
|
for (pid++; pid && l < *pos; |
|
pid = (unsigned long)trace_pid_next(pid_list, (void *)pid, &l)) |
|
; |
|
return (void *)pid; |
|
} |
|
|
|
/** |
|
* trace_pid_show - show the current pid in seq_file processing |
|
* @m: The seq_file structure to write into |
|
* @v: A void pointer of the pid (+1) value to display |
|
* |
|
* Can be directly used by seq_file operations to display the current |
|
* pid value. |
|
*/ |
|
int trace_pid_show(struct seq_file *m, void *v) |
|
{ |
|
unsigned long pid = (unsigned long)v - 1; |
|
|
|
seq_printf(m, "%lu\n", pid); |
|
return 0; |
|
} |
|
|
|
/* 128 should be much more than enough */ |
|
#define PID_BUF_SIZE 127 |
|
|
|
int trace_pid_write(struct trace_pid_list *filtered_pids, |
|
struct trace_pid_list **new_pid_list, |
|
const char __user *ubuf, size_t cnt) |
|
{ |
|
struct trace_pid_list *pid_list; |
|
struct trace_parser parser; |
|
unsigned long val; |
|
int nr_pids = 0; |
|
ssize_t read = 0; |
|
ssize_t ret = 0; |
|
loff_t pos; |
|
pid_t pid; |
|
|
|
if (trace_parser_get_init(&parser, PID_BUF_SIZE + 1)) |
|
return -ENOMEM; |
|
|
|
/* |
|
* Always recreate a new array. The write is an all or nothing |
|
* operation. Always create a new array when adding new pids by |
|
* the user. If the operation fails, then the current list is |
|
* not modified. |
|
*/ |
|
pid_list = kmalloc(sizeof(*pid_list), GFP_KERNEL); |
|
if (!pid_list) { |
|
trace_parser_put(&parser); |
|
return -ENOMEM; |
|
} |
|
|
|
pid_list->pid_max = READ_ONCE(pid_max); |
|
|
|
/* Only truncating will shrink pid_max */ |
|
if (filtered_pids && filtered_pids->pid_max > pid_list->pid_max) |
|
pid_list->pid_max = filtered_pids->pid_max; |
|
|
|
pid_list->pids = vzalloc((pid_list->pid_max + 7) >> 3); |
|
if (!pid_list->pids) { |
|
trace_parser_put(&parser); |
|
kfree(pid_list); |
|
return -ENOMEM; |
|
} |
|
|
|
if (filtered_pids) { |
|
/* copy the current bits to the new max */ |
|
for_each_set_bit(pid, filtered_pids->pids, |
|
filtered_pids->pid_max) { |
|
set_bit(pid, pid_list->pids); |
|
nr_pids++; |
|
} |
|
} |
|
|
|
while (cnt > 0) { |
|
|
|
pos = 0; |
|
|
|
ret = trace_get_user(&parser, ubuf, cnt, &pos); |
|
if (ret < 0 || !trace_parser_loaded(&parser)) |
|
break; |
|
|
|
read += ret; |
|
ubuf += ret; |
|
cnt -= ret; |
|
|
|
ret = -EINVAL; |
|
if (kstrtoul(parser.buffer, 0, &val)) |
|
break; |
|
if (val >= pid_list->pid_max) |
|
break; |
|
|
|
pid = (pid_t)val; |
|
|
|
set_bit(pid, pid_list->pids); |
|
nr_pids++; |
|
|
|
trace_parser_clear(&parser); |
|
ret = 0; |
|
} |
|
trace_parser_put(&parser); |
|
|
|
if (ret < 0) { |
|
trace_free_pid_list(pid_list); |
|
return ret; |
|
} |
|
|
|
if (!nr_pids) { |
|
/* Cleared the list of pids */ |
|
trace_free_pid_list(pid_list); |
|
read = ret; |
|
pid_list = NULL; |
|
} |
|
|
|
*new_pid_list = pid_list; |
|
|
|
return read; |
|
} |
|
|
|
static u64 buffer_ftrace_now(struct array_buffer *buf, int cpu) |
|
{ |
|
u64 ts; |
|
|
|
/* Early boot up does not have a buffer yet */ |
|
if (!buf->buffer) |
|
return trace_clock_local(); |
|
|
|
ts = ring_buffer_time_stamp(buf->buffer, cpu); |
|
ring_buffer_normalize_time_stamp(buf->buffer, cpu, &ts); |
|
|
|
return ts; |
|
} |
|
|
|
u64 ftrace_now(int cpu) |
|
{ |
|
return buffer_ftrace_now(&global_trace.array_buffer, cpu); |
|
} |
|
|
|
/** |
|
* tracing_is_enabled - Show if global_trace has been enabled |
|
* |
|
* Shows if the global trace has been enabled or not. It uses the |
|
* mirror flag "buffer_disabled" to be used in fast paths such as for |
|
* the irqsoff tracer. But it may be inaccurate due to races. If you |
|
* need to know the accurate state, use tracing_is_on() which is a little |
|
* slower, but accurate. |
|
*/ |
|
int tracing_is_enabled(void) |
|
{ |
|
/* |
|
* For quick access (irqsoff uses this in fast path), just |
|
* return the mirror variable of the state of the ring buffer. |
|
* It's a little racy, but we don't really care. |
|
*/ |
|
smp_rmb(); |
|
return !global_trace.buffer_disabled; |
|
} |
|
|
|
/* |
|
* trace_buf_size is the size in bytes that is allocated |
|
* for a buffer. Note, the number of bytes is always rounded |
|
* to page size. |
|
* |
|
* This number is purposely set to a low number of 16384. |
|
* If the dump on oops happens, it will be much appreciated |
|
* to not have to wait for all that output. Anyway this can be |
|
* boot time and run time configurable. |
|
*/ |
|
#define TRACE_BUF_SIZE_DEFAULT 1441792UL /* 16384 * 88 (sizeof(entry)) */ |
|
|
|
static unsigned long trace_buf_size = TRACE_BUF_SIZE_DEFAULT; |
|
|
|
/* trace_types holds a link list of available tracers. */ |
|
static struct tracer *trace_types __read_mostly; |
|
|
|
/* |
|
* trace_types_lock is used to protect the trace_types list. |
|
*/ |
|
DEFINE_MUTEX(trace_types_lock); |
|
|
|
/* |
|
* serialize the access of the ring buffer |
|
* |
|
* ring buffer serializes readers, but it is low level protection. |
|
* The validity of the events (which returns by ring_buffer_peek() ..etc) |
|
* are not protected by ring buffer. |
|
* |
|
* The content of events may become garbage if we allow other process consumes |
|
* these events concurrently: |
|
* A) the page of the consumed events may become a normal page |
|
* (not reader page) in ring buffer, and this page will be rewrited |
|
* by events producer. |
|
* B) The page of the consumed events may become a page for splice_read, |
|
* and this page will be returned to system. |
|
* |
|
* These primitives allow multi process access to different cpu ring buffer |
|
* concurrently. |
|
* |
|
* These primitives don't distinguish read-only and read-consume access. |
|
* Multi read-only access are also serialized. |
|
*/ |
|
|
|
#ifdef CONFIG_SMP |
|
static DECLARE_RWSEM(all_cpu_access_lock); |
|
static DEFINE_PER_CPU(struct mutex, cpu_access_lock); |
|
|
|
static inline void trace_access_lock(int cpu) |
|
{ |
|
if (cpu == RING_BUFFER_ALL_CPUS) { |
|
/* gain it for accessing the whole ring buffer. */ |
|
down_write(&all_cpu_access_lock); |
|
} else { |
|
/* gain it for accessing a cpu ring buffer. */ |
|
|
|
/* Firstly block other trace_access_lock(RING_BUFFER_ALL_CPUS). */ |
|
down_read(&all_cpu_access_lock); |
|
|
|
/* Secondly block other access to this @cpu ring buffer. */ |
|
mutex_lock(&per_cpu(cpu_access_lock, cpu)); |
|
} |
|
} |
|
|
|
static inline void trace_access_unlock(int cpu) |
|
{ |
|
if (cpu == RING_BUFFER_ALL_CPUS) { |
|
up_write(&all_cpu_access_lock); |
|
} else { |
|
mutex_unlock(&per_cpu(cpu_access_lock, cpu)); |
|
up_read(&all_cpu_access_lock); |
|
} |
|
} |
|
|
|
static inline void trace_access_lock_init(void) |
|
{ |
|
int cpu; |
|
|
|
for_each_possible_cpu(cpu) |
|
mutex_init(&per_cpu(cpu_access_lock, cpu)); |
|
} |
|
|
|
#else |
|
|
|
static DEFINE_MUTEX(access_lock); |
|
|
|
static inline void trace_access_lock(int cpu) |
|
{ |
|
(void)cpu; |
|
mutex_lock(&access_lock); |
|
} |
|
|
|
static inline void trace_access_unlock(int cpu) |
|
{ |
|
(void)cpu; |
|
mutex_unlock(&access_lock); |
|
} |
|
|
|
static inline void trace_access_lock_init(void) |
|
{ |
|
} |
|
|
|
#endif |
|
|
|
#ifdef CONFIG_STACKTRACE |
|
static void __ftrace_trace_stack(struct trace_buffer *buffer, |
|
unsigned int trace_ctx, |
|
int skip, struct pt_regs *regs); |
|
static inline void ftrace_trace_stack(struct trace_array *tr, |
|
struct trace_buffer *buffer, |
|
unsigned int trace_ctx, |
|
int skip, struct pt_regs *regs); |
|
|
|
#else |
|
static inline void __ftrace_trace_stack(struct trace_buffer *buffer, |
|
unsigned int trace_ctx, |
|
int skip, struct pt_regs *regs) |
|
{ |
|
} |
|
static inline void ftrace_trace_stack(struct trace_array *tr, |
|
struct trace_buffer *buffer, |
|
unsigned long trace_ctx, |
|
int skip, struct pt_regs *regs) |
|
{ |
|
} |
|
|
|
#endif |
|
|
|
static __always_inline void |
|
trace_event_setup(struct ring_buffer_event *event, |
|
int type, unsigned int trace_ctx) |
|
{ |
|
struct trace_entry *ent = ring_buffer_event_data(event); |
|
|
|
tracing_generic_entry_update(ent, type, trace_ctx); |
|
} |
|
|
|
static __always_inline struct ring_buffer_event * |
|
__trace_buffer_lock_reserve(struct trace_buffer *buffer, |
|
int type, |
|
unsigned long len, |
|
unsigned int trace_ctx) |
|
{ |
|
struct ring_buffer_event *event; |
|
|
|
event = ring_buffer_lock_reserve(buffer, len); |
|
if (event != NULL) |
|
trace_event_setup(event, type, trace_ctx); |
|
|
|
return event; |
|
} |
|
|
|
void tracer_tracing_on(struct trace_array *tr) |
|
{ |
|
if (tr->array_buffer.buffer) |
|
ring_buffer_record_on(tr->array_buffer.buffer); |
|
/* |
|
* This flag is looked at when buffers haven't been allocated |
|
* yet, or by some tracers (like irqsoff), that just want to |
|
* know if the ring buffer has been disabled, but it can handle |
|
* races of where it gets disabled but we still do a record. |
|
* As the check is in the fast path of the tracers, it is more |
|
* important to be fast than accurate. |
|
*/ |
|
tr->buffer_disabled = 0; |
|
/* Make the flag seen by readers */ |
|
smp_wmb(); |
|
} |
|
|
|
/** |
|
* tracing_on - enable tracing buffers |
|
* |
|
* This function enables tracing buffers that may have been |
|
* disabled with tracing_off. |
|
*/ |
|
void tracing_on(void) |
|
{ |
|
tracer_tracing_on(&global_trace); |
|
} |
|
EXPORT_SYMBOL_GPL(tracing_on); |
|
|
|
|
|
static __always_inline void |
|
__buffer_unlock_commit(struct trace_buffer *buffer, struct ring_buffer_event *event) |
|
{ |
|
__this_cpu_write(trace_taskinfo_save, true); |
|
|
|
/* If this is the temp buffer, we need to commit fully */ |
|
if (this_cpu_read(trace_buffered_event) == event) { |
|
/* Length is in event->array[0] */ |
|
ring_buffer_write(buffer, event->array[0], &event->array[1]); |
|
/* Release the temp buffer */ |
|
this_cpu_dec(trace_buffered_event_cnt); |
|
} else |
|
ring_buffer_unlock_commit(buffer, event); |
|
} |
|
|
|
/** |
|
* __trace_puts - write a constant string into the trace buffer. |
|
* @ip: The address of the caller |
|
* @str: The constant string to write |
|
* @size: The size of the string. |
|
*/ |
|
int __trace_puts(unsigned long ip, const char *str, int size) |
|
{ |
|
struct ring_buffer_event *event; |
|
struct trace_buffer *buffer; |
|
struct print_entry *entry; |
|
unsigned int trace_ctx; |
|
int alloc; |
|
|
|
if (!(global_trace.trace_flags & TRACE_ITER_PRINTK)) |
|
return 0; |
|
|
|
if (unlikely(tracing_selftest_running || tracing_disabled)) |
|
return 0; |
|
|
|
alloc = sizeof(*entry) + size + 2; /* possible \n added */ |
|
|
|
trace_ctx = tracing_gen_ctx(); |
|
buffer = global_trace.array_buffer.buffer; |
|
ring_buffer_nest_start(buffer); |
|
event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc, |
|
trace_ctx); |
|
if (!event) { |
|
size = 0; |
|
goto out; |
|
} |
|
|
|
entry = ring_buffer_event_data(event); |
|
entry->ip = ip; |
|
|
|
memcpy(&entry->buf, str, size); |
|
|
|
/* Add a newline if necessary */ |
|
if (entry->buf[size - 1] != '\n') { |
|
entry->buf[size] = '\n'; |
|
entry->buf[size + 1] = '\0'; |
|
} else |
|
entry->buf[size] = '\0'; |
|
|
|
__buffer_unlock_commit(buffer, event); |
|
ftrace_trace_stack(&global_trace, buffer, trace_ctx, 4, NULL); |
|
out: |
|
ring_buffer_nest_end(buffer); |
|
return size; |
|
} |
|
EXPORT_SYMBOL_GPL(__trace_puts); |
|
|
|
/** |
|
* __trace_bputs - write the pointer to a constant string into trace buffer |
|
* @ip: The address of the caller |
|
* @str: The constant string to write to the buffer to |
|
*/ |
|
int __trace_bputs(unsigned long ip, const char *str) |
|
{ |
|
struct ring_buffer_event *event; |
|
struct trace_buffer *buffer; |
|
struct bputs_entry *entry; |
|
unsigned int trace_ctx; |
|
int size = sizeof(struct bputs_entry); |
|
int ret = 0; |
|
|
|
if (!(global_trace.trace_flags & TRACE_ITER_PRINTK)) |
|
return 0; |
|
|
|
if (unlikely(tracing_selftest_running || tracing_disabled)) |
|
return 0; |
|
|
|
trace_ctx = tracing_gen_ctx(); |
|
buffer = global_trace.array_buffer.buffer; |
|
|
|
ring_buffer_nest_start(buffer); |
|
event = __trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size, |
|
trace_ctx); |
|
if (!event) |
|
goto out; |
|
|
|
entry = ring_buffer_event_data(event); |
|
entry->ip = ip; |
|
entry->str = str; |
|
|
|
__buffer_unlock_commit(buffer, event); |
|
ftrace_trace_stack(&global_trace, buffer, trace_ctx, 4, NULL); |
|
|
|
ret = 1; |
|
out: |
|
ring_buffer_nest_end(buffer); |
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(__trace_bputs); |
|
|
|
#ifdef CONFIG_TRACER_SNAPSHOT |
|
static void tracing_snapshot_instance_cond(struct trace_array *tr, |
|
void *cond_data) |
|
{ |
|
struct tracer *tracer = tr->current_trace; |
|
unsigned long flags; |
|
|
|
if (in_nmi()) { |
|
internal_trace_puts("*** SNAPSHOT CALLED FROM NMI CONTEXT ***\n"); |
|
internal_trace_puts("*** snapshot is being ignored ***\n"); |
|
return; |
|
} |
|
|
|
if (!tr->allocated_snapshot) { |
|
internal_trace_puts("*** SNAPSHOT NOT ALLOCATED ***\n"); |
|
internal_trace_puts("*** stopping trace here! ***\n"); |
|
tracing_off(); |
|
return; |
|
} |
|
|
|
/* Note, snapshot can not be used when the tracer uses it */ |
|
if (tracer->use_max_tr) { |
|
internal_trace_puts("*** LATENCY TRACER ACTIVE ***\n"); |
|
internal_trace_puts("*** Can not use snapshot (sorry) ***\n"); |
|
return; |
|
} |
|
|
|
local_irq_save(flags); |
|
update_max_tr(tr, current, smp_processor_id(), cond_data); |
|
local_irq_restore(flags); |
|
} |
|
|
|
void tracing_snapshot_instance(struct trace_array *tr) |
|
{ |
|
tracing_snapshot_instance_cond(tr, NULL); |
|
} |
|
|
|
/** |
|
* tracing_snapshot - take a snapshot of the current buffer. |
|
* |
|
* This causes a swap between the snapshot buffer and the current live |
|
* tracing buffer. You can use this to take snapshots of the live |
|
* trace when some condition is triggered, but continue to trace. |
|
* |
|
* Note, make sure to allocate the snapshot with either |
|
* a tracing_snapshot_alloc(), or by doing it manually |
|
* with: echo 1 > /sys/kernel/debug/tracing/snapshot |
|
* |
|
* If the snapshot buffer is not allocated, it will stop tracing. |
|
* Basically making a permanent snapshot. |
|
*/ |
|
void tracing_snapshot(void) |
|
{ |
|
struct trace_array *tr = &global_trace; |
|
|
|
tracing_snapshot_instance(tr); |
|
} |
|
EXPORT_SYMBOL_GPL(tracing_snapshot); |
|
|
|
/** |
|
* tracing_snapshot_cond - conditionally take a snapshot of the current buffer. |
|
* @tr: The tracing instance to snapshot |
|
* @cond_data: The data to be tested conditionally, and possibly saved |
|
* |
|
* This is the same as tracing_snapshot() except that the snapshot is |
|
* conditional - the snapshot will only happen if the |
|
* cond_snapshot.update() implementation receiving the cond_data |
|
* returns true, which means that the trace array's cond_snapshot |
|
* update() operation used the cond_data to determine whether the |
|
* snapshot should be taken, and if it was, presumably saved it along |
|
* with the snapshot. |
|
*/ |
|
void tracing_snapshot_cond(struct trace_array *tr, void *cond_data) |
|
{ |
|
tracing_snapshot_instance_cond(tr, cond_data); |
|
} |
|
EXPORT_SYMBOL_GPL(tracing_snapshot_cond); |
|
|
|
/** |
|
* tracing_snapshot_cond_data - get the user data associated with a snapshot |
|
* @tr: The tracing instance |
|
* |
|
* When the user enables a conditional snapshot using |
|
* tracing_snapshot_cond_enable(), the user-defined cond_data is saved |
|
* with the snapshot. This accessor is used to retrieve it. |
|
* |
|
* Should not be called from cond_snapshot.update(), since it takes |
|
* the tr->max_lock lock, which the code calling |
|
* cond_snapshot.update() has already done. |
|
* |
|
* Returns the cond_data associated with the trace array's snapshot. |
|
*/ |
|
void *tracing_cond_snapshot_data(struct trace_array *tr) |
|
{ |
|
void *cond_data = NULL; |
|
|
|
arch_spin_lock(&tr->max_lock); |
|
|
|
if (tr->cond_snapshot) |
|
cond_data = tr->cond_snapshot->cond_data; |
|
|
|
arch_spin_unlock(&tr->max_lock); |
|
|
|
return cond_data; |
|
} |
|
EXPORT_SYMBOL_GPL(tracing_cond_snapshot_data); |
|
|
|
static int resize_buffer_duplicate_size(struct array_buffer *trace_buf, |
|
struct array_buffer *size_buf, int cpu_id); |
|
static void set_buffer_entries(struct array_buffer *buf, unsigned long val); |
|
|
|
int tracing_alloc_snapshot_instance(struct trace_array *tr) |
|
{ |
|
int ret; |
|
|
|
if (!tr->allocated_snapshot) { |
|
|
|
/* allocate spare buffer */ |
|
ret = resize_buffer_duplicate_size(&tr->max_buffer, |
|
&tr->array_buffer, RING_BUFFER_ALL_CPUS); |
|
if (ret < 0) |
|
return ret; |
|
|
|
tr->allocated_snapshot = true; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static void free_snapshot(struct trace_array *tr) |
|
{ |
|
/* |
|
* We don't free the ring buffer. instead, resize it because |
|
* The max_tr ring buffer has some state (e.g. ring->clock) and |
|
* we want preserve it. |
|
*/ |
|
ring_buffer_resize(tr->max_buffer.buffer, 1, RING_BUFFER_ALL_CPUS); |
|
set_buffer_entries(&tr->max_buffer, 1); |
|
tracing_reset_online_cpus(&tr->max_buffer); |
|
tr->allocated_snapshot = false; |
|
} |
|
|
|
/** |
|
* tracing_alloc_snapshot - allocate snapshot buffer. |
|
* |
|
* This only allocates the snapshot buffer if it isn't already |
|
* allocated - it doesn't also take a snapshot. |
|
* |
|
* This is meant to be used in cases where the snapshot buffer needs |
|
* to be set up for events that can't sleep but need to be able to |
|
* trigger a snapshot. |
|
*/ |
|
int tracing_alloc_snapshot(void) |
|
{ |
|
struct trace_array *tr = &global_trace; |
|
int ret; |
|
|
|
ret = tracing_alloc_snapshot_instance(tr); |
|
WARN_ON(ret < 0); |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(tracing_alloc_snapshot); |
|
|
|
/** |
|
* tracing_snapshot_alloc - allocate and take a snapshot of the current buffer. |
|
* |
|
* This is similar to tracing_snapshot(), but it will allocate the |
|
* snapshot buffer if it isn't already allocated. Use this only |
|
* where it is safe to sleep, as the allocation may sleep. |
|
* |
|
* This causes a swap between the snapshot buffer and the current live |
|
* tracing buffer. You can use this to take snapshots of the live |
|
* trace when some condition is triggered, but continue to trace. |
|
*/ |
|
void tracing_snapshot_alloc(void) |
|
{ |
|
int ret; |
|
|
|
ret = tracing_alloc_snapshot(); |
|
if (ret < 0) |
|
return; |
|
|
|
tracing_snapshot(); |
|
} |
|
EXPORT_SYMBOL_GPL(tracing_snapshot_alloc); |
|
|
|
/** |
|
* tracing_snapshot_cond_enable - enable conditional snapshot for an instance |
|
* @tr: The tracing instance |
|
* @cond_data: User data to associate with the snapshot |
|
* @update: Implementation of the cond_snapshot update function |
|
* |
|
* Check whether the conditional snapshot for the given instance has |
|
* already been enabled, or if the current tracer is already using a |
|
* snapshot; if so, return -EBUSY, else create a cond_snapshot and |
|
* save the cond_data and update function inside. |
|
* |
|
* Returns 0 if successful, error otherwise. |
|
*/ |
|
int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data, |
|
cond_update_fn_t update) |
|
{ |
|
struct cond_snapshot *cond_snapshot; |
|
int ret = 0; |
|
|
|
cond_snapshot = kzalloc(sizeof(*cond_snapshot), GFP_KERNEL); |
|
if (!cond_snapshot) |
|
return -ENOMEM; |
|
|
|
cond_snapshot->cond_data = cond_data; |
|
cond_snapshot->update = update; |
|
|
|
mutex_lock(&trace_types_lock); |
|
|
|
ret = tracing_alloc_snapshot_instance(tr); |
|
if (ret) |
|
goto fail_unlock; |
|
|
|
if (tr->current_trace->use_max_tr) { |
|
ret = -EBUSY; |
|
goto fail_unlock; |
|
} |
|
|
|
/* |
|
* The cond_snapshot can only change to NULL without the |
|
* trace_types_lock. We don't care if we race with it going |
|
* to NULL, but we want to make sure that it's not set to |
|
* something other than NULL when we get here, which we can |
|
* do safely with only holding the trace_types_lock and not |
|
* having to take the max_lock. |
|
*/ |
|
if (tr->cond_snapshot) { |
|
ret = -EBUSY; |
|
goto fail_unlock; |
|
} |
|
|
|
arch_spin_lock(&tr->max_lock); |
|
tr->cond_snapshot = cond_snapshot; |
|
arch_spin_unlock(&tr->max_lock); |
|
|
|
mutex_unlock(&trace_types_lock); |
|
|
|
return ret; |
|
|
|
fail_unlock: |
|
mutex_unlock(&trace_types_lock); |
|
kfree(cond_snapshot); |
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(tracing_snapshot_cond_enable); |
|
|
|
/** |
|
* tracing_snapshot_cond_disable - disable conditional snapshot for an instance |
|
* @tr: The tracing instance |
|
* |
|
* Check whether the conditional snapshot for the given instance is |
|
* enabled; if so, free the cond_snapshot associated with it, |
|
* otherwise return -EINVAL. |
|
* |
|
* Returns 0 if successful, error otherwise. |
|
*/ |
|
int tracing_snapshot_cond_disable(struct trace_array *tr) |
|
{ |
|
int ret = 0; |
|
|
|
arch_spin_lock(&tr->max_lock); |
|
|
|
if (!tr->cond_snapshot) |
|
ret = -EINVAL; |
|
else { |
|
kfree(tr->cond_snapshot); |
|
tr->cond_snapshot = NULL; |
|
} |
|
|
|
arch_spin_unlock(&tr->max_lock); |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(tracing_snapshot_cond_disable); |
|
#else |
|
void tracing_snapshot(void) |
|
{ |
|
WARN_ONCE(1, "Snapshot feature not enabled, but internal snapshot used"); |
|
} |
|
EXPORT_SYMBOL_GPL(tracing_snapshot); |
|
void tracing_snapshot_cond(struct trace_array *tr, void *cond_data) |
|
{ |
|
WARN_ONCE(1, "Snapshot feature not enabled, but internal conditional snapshot used"); |
|
} |
|
EXPORT_SYMBOL_GPL(tracing_snapshot_cond); |
|
int tracing_alloc_snapshot(void) |
|
{ |
|
WARN_ONCE(1, "Snapshot feature not enabled, but snapshot allocation used"); |
|
return -ENODEV; |
|
} |
|
EXPORT_SYMBOL_GPL(tracing_alloc_snapshot); |
|
void tracing_snapshot_alloc(void) |
|
{ |
|
/* Give warning */ |
|
tracing_snapshot(); |
|
} |
|
EXPORT_SYMBOL_GPL(tracing_snapshot_alloc); |
|
void *tracing_cond_snapshot_data(struct trace_array *tr) |
|
{ |
|
return NULL; |
|
} |
|
EXPORT_SYMBOL_GPL(tracing_cond_snapshot_data); |
|
int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data, cond_update_fn_t update) |
|
{ |
|
return -ENODEV; |
|
} |
|
EXPORT_SYMBOL_GPL(tracing_snapshot_cond_enable); |
|
int tracing_snapshot_cond_disable(struct trace_array *tr) |
|
{ |
|
return false; |
|
} |
|
EXPORT_SYMBOL_GPL(tracing_snapshot_cond_disable); |
|
#endif /* CONFIG_TRACER_SNAPSHOT */ |
|
|
|
void tracer_tracing_off(struct trace_array *tr) |
|
{ |
|
if (tr->array_buffer.buffer) |
|
ring_buffer_record_off(tr->array_buffer.buffer); |
|
/* |
|
* This flag is looked at when buffers haven't been allocated |
|
* yet, or by some tracers (like irqsoff), that just want to |
|
* know if the ring buffer has been disabled, but it can handle |
|
* races of where it gets disabled but we still do a record. |
|
* As the check is in the fast path of the tracers, it is more |
|
* important to be fast than accurate. |
|
*/ |
|
tr->buffer_disabled = 1; |
|
/* Make the flag seen by readers */ |
|
smp_wmb(); |
|
} |
|
|
|
/** |
|
* tracing_off - turn off tracing buffers |
|
* |
|
* This function stops the tracing buffers from recording data. |
|
* It does not disable any overhead the tracers themselves may |
|
* be causing. This function simply causes all recording to |
|
* the ring buffers to fail. |
|
*/ |
|
void tracing_off(void) |
|
{ |
|
tracer_tracing_off(&global_trace); |
|
} |
|
EXPORT_SYMBOL_GPL(tracing_off); |
|
|
|
void disable_trace_on_warning(void) |
|
{ |
|
if (__disable_trace_on_warning) { |
|
trace_array_printk_buf(global_trace.array_buffer.buffer, _THIS_IP_, |
|
"Disabling tracing due to warning\n"); |
|
tracing_off(); |
|
} |
|
} |
|
|
|
/** |
|
* tracer_tracing_is_on - show real state of ring buffer enabled |
|
* @tr : the trace array to know if ring buffer is enabled |
|
* |
|
* Shows real state of the ring buffer if it is enabled or not. |
|
*/ |
|
bool tracer_tracing_is_on(struct trace_array *tr) |
|
{ |
|
if (tr->array_buffer.buffer) |
|
return ring_buffer_record_is_on(tr->array_buffer.buffer); |
|
return !tr->buffer_disabled; |
|
} |
|
|
|
/** |
|
* tracing_is_on - show state of ring buffers enabled |
|
*/ |
|
int tracing_is_on(void) |
|
{ |
|
return tracer_tracing_is_on(&global_trace); |
|
} |
|
EXPORT_SYMBOL_GPL(tracing_is_on); |
|
|
|
static int __init set_buf_size(char *str) |
|
{ |
|
unsigned long buf_size; |
|
|
|
if (!str) |
|
return 0; |
|
buf_size = memparse(str, &str); |
|
/* nr_entries can not be zero */ |
|
if (buf_size == 0) |
|
return 0; |
|
trace_buf_size = buf_size; |
|
return 1; |
|
} |
|
__setup("trace_buf_size=", set_buf_size); |
|
|
|
static int __init set_tracing_thresh(char *str) |
|
{ |
|
unsigned long threshold; |
|
int ret; |
|
|
|
if (!str) |
|
return 0; |
|
ret = kstrtoul(str, 0, &threshold); |
|
if (ret < 0) |
|
return 0; |
|
tracing_thresh = threshold * 1000; |
|
return 1; |
|
} |
|
__setup("tracing_thresh=", set_tracing_thresh); |
|
|
|
unsigned long nsecs_to_usecs(unsigned long nsecs) |
|
{ |
|
return nsecs / 1000; |
|
} |
|
|
|
/* |
|
* TRACE_FLAGS is defined as a tuple matching bit masks with strings. |
|
* It uses C(a, b) where 'a' is the eval (enum) name and 'b' is the string that |
|
* matches it. By defining "C(a, b) b", TRACE_FLAGS becomes a list |
|
* of strings in the order that the evals (enum) were defined. |
|
*/ |
|
#undef C |
|
#define C(a, b) b |
|
|
|
/* These must match the bit postions in trace_iterator_flags */ |
|
static const char *trace_options[] = { |
|
TRACE_FLAGS |
|
NULL |
|
}; |
|
|
|
static struct { |
|
u64 (*func)(void); |
|
const char *name; |
|
int in_ns; /* is this clock in nanoseconds? */ |
|
} trace_clocks[] = { |
|
{ trace_clock_local, "local", 1 }, |
|
{ trace_clock_global, "global", 1 }, |
|
{ trace_clock_counter, "counter", 0 }, |
|
{ trace_clock_jiffies, "uptime", 0 }, |
|
{ trace_clock, "perf", 1 }, |
|
{ ktime_get_mono_fast_ns, "mono", 1 }, |
|
{ ktime_get_raw_fast_ns, "mono_raw", 1 }, |
|
{ ktime_get_boot_fast_ns, "boot", 1 }, |
|
ARCH_TRACE_CLOCKS |
|
}; |
|
|
|
bool trace_clock_in_ns(struct trace_array *tr) |
|
{ |
|
if (trace_clocks[tr->clock_id].in_ns) |
|
return true; |
|
|
|
return false; |
|
} |
|
|
|
/* |
|
* trace_parser_get_init - gets the buffer for trace parser |
|
*/ |
|
int trace_parser_get_init(struct trace_parser *parser, int size) |
|
{ |
|
memset(parser, 0, sizeof(*parser)); |
|
|
|
parser->buffer = kmalloc(size, GFP_KERNEL); |
|
if (!parser->buffer) |
|
return 1; |
|
|
|
parser->size = size; |
|
return 0; |
|
} |
|
|
|
/* |
|
* trace_parser_put - frees the buffer for trace parser |
|
*/ |
|
void trace_parser_put(struct trace_parser *parser) |
|
{ |
|
kfree(parser->buffer); |
|
parser->buffer = NULL; |
|
} |
|
|
|
/* |
|
* trace_get_user - reads the user input string separated by space |
|
* (matched by isspace(ch)) |
|
* |
|
* For each string found the 'struct trace_parser' is updated, |
|
* and the function returns. |
|
* |
|
* Returns number of bytes read. |
|
* |
|
* See kernel/trace/trace.h for 'struct trace_parser' details. |
|
*/ |
|
int trace_get_user(struct trace_parser *parser, const char __user *ubuf, |
|
size_t cnt, loff_t *ppos) |
|
{ |
|
char ch; |
|
size_t read = 0; |
|
ssize_t ret; |
|
|
|
if (!*ppos) |
|
trace_parser_clear(parser); |
|
|
|
ret = get_user(ch, ubuf++); |
|
if (ret) |
|
goto out; |
|
|
|
read++; |
|
cnt--; |
|
|
|
/* |
|
* The parser is not finished with the last write, |
|
* continue reading the user input without skipping spaces. |
|
*/ |
|
if (!parser->cont) { |
|
/* skip white space */ |
|
while (cnt && isspace(ch)) { |
|
ret = get_user(ch, ubuf++); |
|
if (ret) |
|
goto out; |
|
read++; |
|
cnt--; |
|
} |
|
|
|
parser->idx = 0; |
|
|
|
/* only spaces were written */ |
|
if (isspace(ch) || !ch) { |
|
*ppos += read; |
|
ret = read; |
|
goto out; |
|
} |
|
} |
|
|
|
/* read the non-space input */ |
|
while (cnt && !isspace(ch) && ch) { |
|
if (parser->idx < parser->size - 1) |
|
parser->buffer[parser->idx++] = ch; |
|
else { |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
ret = get_user(ch, ubuf++); |
|
if (ret) |
|
goto out; |
|
read++; |
|
cnt--; |
|
} |
|
|
|
/* We either got finished input or we have to wait for another call. */ |
|
if (isspace(ch) || !ch) { |
|
parser->buffer[parser->idx] = 0; |
|
parser->cont = false; |
|
} else if (parser->idx < parser->size - 1) { |
|
parser->cont = true; |
|
parser->buffer[parser->idx++] = ch; |
|
/* Make sure the parsed string always terminates with '\0'. */ |
|
parser->buffer[parser->idx] = 0; |
|
} else { |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
|
|
*ppos += read; |
|
ret = read; |
|
|
|
out: |
|
return ret; |
|
} |
|
|
|
/* TODO add a seq_buf_to_buffer() */ |
|
static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt) |
|
{ |
|
int len; |
|
|
|
if (trace_seq_used(s) <= s->seq.readpos) |
|
return -EBUSY; |
|
|
|
len = trace_seq_used(s) - s->seq.readpos; |
|
if (cnt > len) |
|
cnt = len; |
|
memcpy(buf, s->buffer + s->seq.readpos, cnt); |
|
|
|
s->seq.readpos += cnt; |
|
return cnt; |
|
} |
|
|
|
unsigned long __read_mostly tracing_thresh; |
|
static const struct file_operations tracing_max_lat_fops; |
|
|
|
#if (defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)) && \ |
|
defined(CONFIG_FSNOTIFY) |
|
|
|
static struct workqueue_struct *fsnotify_wq; |
|
|
|
static void latency_fsnotify_workfn(struct work_struct *work) |
|
{ |
|
struct trace_array *tr = container_of(work, struct trace_array, |
|
fsnotify_work); |
|
fsnotify_inode(tr->d_max_latency->d_inode, FS_MODIFY); |
|
} |
|
|
|
static void latency_fsnotify_workfn_irq(struct irq_work *iwork) |
|
{ |
|
struct trace_array *tr = container_of(iwork, struct trace_array, |
|
fsnotify_irqwork); |
|
queue_work(fsnotify_wq, &tr->fsnotify_work); |
|
} |
|
|
|
static void trace_create_maxlat_file(struct trace_array *tr, |
|
struct dentry *d_tracer) |
|
{ |
|
INIT_WORK(&tr->fsnotify_work, latency_fsnotify_workfn); |
|
init_irq_work(&tr->fsnotify_irqwork, latency_fsnotify_workfn_irq); |
|
tr->d_max_latency = trace_create_file("tracing_max_latency", 0644, |
|
d_tracer, &tr->max_latency, |
|
&tracing_max_lat_fops); |
|
} |
|
|
|
__init static int latency_fsnotify_init(void) |
|
{ |
|
fsnotify_wq = alloc_workqueue("tr_max_lat_wq", |
|
WQ_UNBOUND | WQ_HIGHPRI, 0); |
|
if (!fsnotify_wq) { |
|
pr_err("Unable to allocate tr_max_lat_wq\n"); |
|
return -ENOMEM; |
|
} |
|
return 0; |
|
} |
|
|
|
late_initcall_sync(latency_fsnotify_init); |
|
|
|
void latency_fsnotify(struct trace_array *tr) |
|
{ |
|
if (!fsnotify_wq) |
|
return; |
|
/* |
|
* We cannot call queue_work(&tr->fsnotify_work) from here because it's |
|
* possible that we are called from __schedule() or do_idle(), which |
|
* could cause a deadlock. |
|
*/ |
|
irq_work_queue(&tr->fsnotify_irqwork); |
|
} |
|
|
|
/* |
|
* (defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)) && \ |
|
* defined(CONFIG_FSNOTIFY) |
|
*/ |
|
#else |
|
|
|
#define trace_create_maxlat_file(tr, d_tracer) \ |
|
trace_create_file("tracing_max_latency", 0644, d_tracer, \ |
|
&tr->max_latency, &tracing_max_lat_fops) |
|
|
|
#endif |
|
|
|
#ifdef CONFIG_TRACER_MAX_TRACE |
|
/* |
|
* Copy the new maximum trace into the separate maximum-trace |
|
* structure. (this way the maximum trace is permanently saved, |
|
* for later retrieval via /sys/kernel/tracing/tracing_max_latency) |
|
*/ |
|
static void |
|
__update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) |
|
{ |
|
struct array_buffer *trace_buf = &tr->array_buffer; |
|
struct array_buffer *max_buf = &tr->max_buffer; |
|
struct trace_array_cpu *data = per_cpu_ptr(trace_buf->data, cpu); |
|
struct trace_array_cpu *max_data = per_cpu_ptr(max_buf->data, cpu); |
|
|
|
max_buf->cpu = cpu; |
|
max_buf->time_start = data->preempt_timestamp; |
|
|
|
max_data->saved_latency = tr->max_latency; |
|
max_data->critical_start = data->critical_start; |
|
max_data->critical_end = data->critical_end; |
|
|
|
strncpy(max_data->comm, tsk->comm, TASK_COMM_LEN); |
|
max_data->pid = tsk->pid; |
|
/* |
|
* If tsk == current, then use current_uid(), as that does not use |
|
* RCU. The irq tracer can be called out of RCU scope. |
|
*/ |
|
if (tsk == current) |
|
max_data->uid = current_uid(); |
|
else |
|
max_data->uid = task_uid(tsk); |
|
|
|
max_data->nice = tsk->static_prio - 20 - MAX_RT_PRIO; |
|
max_data->policy = tsk->policy; |
|
max_data->rt_priority = tsk->rt_priority; |
|
|
|
/* record this tasks comm */ |
|
tracing_record_cmdline(tsk); |
|
latency_fsnotify(tr); |
|
} |
|
|
|
/** |
|
* update_max_tr - snapshot all trace buffers from global_trace to max_tr |
|
* @tr: tracer |
|
* @tsk: the task with the latency |
|
* @cpu: The cpu that initiated the trace. |
|
* @cond_data: User data associated with a conditional snapshot |
|
* |
|
* Flip the buffers between the @tr and the max_tr and record information |
|
* about which task was the cause of this latency. |
|
*/ |
|
void |
|
update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu, |
|
void *cond_data) |
|
{ |
|
if (tr->stop_count) |
|
return; |
|
|
|
WARN_ON_ONCE(!irqs_disabled()); |
|
|
|
if (!tr->allocated_snapshot) { |
|
/* Only the nop tracer should hit this when disabling */ |
|
WARN_ON_ONCE(tr->current_trace != &nop_trace); |
|
return; |
|
} |
|
|
|
arch_spin_lock(&tr->max_lock); |
|
|
|
/* Inherit the recordable setting from array_buffer */ |
|
if (ring_buffer_record_is_set_on(tr->array_buffer.buffer)) |
|
ring_buffer_record_on(tr->max_buffer.buffer); |
|
else |
|
ring_buffer_record_off(tr->max_buffer.buffer); |
|
|
|
#ifdef CONFIG_TRACER_SNAPSHOT |
|
if (tr->cond_snapshot && !tr->cond_snapshot->update(tr, cond_data)) |
|
goto out_unlock; |
|
#endif |
|
swap(tr->array_buffer.buffer, tr->max_buffer.buffer); |
|
|
|
__update_max_tr(tr, tsk, cpu); |
|
|
|
out_unlock: |
|
arch_spin_unlock(&tr->max_lock); |
|
} |
|
|
|
/** |
|
* update_max_tr_single - only copy one trace over, and reset the rest |
|
* @tr: tracer |
|
* @tsk: task with the latency |
|
* @cpu: the cpu of the buffer to copy. |
|
* |
|
* Flip the trace of a single CPU buffer between the @tr and the max_tr. |
|
*/ |
|
void |
|
update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) |
|
{ |
|
int ret; |
|
|
|
if (tr->stop_count) |
|
return; |
|
|
|
WARN_ON_ONCE(!irqs_disabled()); |
|
if (!tr->allocated_snapshot) { |
|
/* Only the nop tracer should hit this when disabling */ |
|
WARN_ON_ONCE(tr->current_trace != &nop_trace); |
|
return; |
|
} |
|
|
|
arch_spin_lock(&tr->max_lock); |
|
|
|
ret = ring_buffer_swap_cpu(tr->max_buffer.buffer, tr->array_buffer.buffer, cpu); |
|
|
|
if (ret == -EBUSY) { |
|
/* |
|
* We failed to swap the buffer due to a commit taking |
|
* place on this CPU. We fail to record, but we reset |
|
* the max trace buffer (no one writes directly to it) |
|
* and flag that it failed. |
|
*/ |
|
trace_array_printk_buf(tr->max_buffer.buffer, _THIS_IP_, |
|
"Failed to swap buffers due to commit in progress\n"); |
|
} |
|
|
|
WARN_ON_ONCE(ret && ret != -EAGAIN && ret != -EBUSY); |
|
|
|
__update_max_tr(tr, tsk, cpu); |
|
arch_spin_unlock(&tr->max_lock); |
|
} |
|
#endif /* CONFIG_TRACER_MAX_TRACE */ |
|
|
|
static int wait_on_pipe(struct trace_iterator *iter, int full) |
|
{ |
|
/* Iterators are static, they should be filled or empty */ |
|
if (trace_buffer_iter(iter, iter->cpu_file)) |
|
return 0; |
|
|
|
return ring_buffer_wait(iter->array_buffer->buffer, iter->cpu_file, |
|
full); |
|
} |
|
|
|
#ifdef CONFIG_FTRACE_STARTUP_TEST |
|
static bool selftests_can_run; |
|
|
|
struct trace_selftests { |
|
struct list_head list; |
|
struct tracer *type; |
|
}; |
|
|
|
static LIST_HEAD(postponed_selftests); |
|
|
|
static int save_selftest(struct tracer *type) |
|
{ |
|
struct trace_selftests *selftest; |
|
|
|
selftest = kmalloc(sizeof(*selftest), GFP_KERNEL); |
|
if (!selftest) |
|
return -ENOMEM; |
|
|
|
selftest->type = type; |
|
list_add(&selftest->list, &postponed_selftests); |
|
return 0; |
|
} |
|
|
|
static int run_tracer_selftest(struct tracer *type) |
|
{ |
|
struct trace_array *tr = &global_trace; |
|
struct tracer *saved_tracer = tr->current_trace; |
|
int ret; |
|
|
|
if (!type->selftest || tracing_selftest_disabled) |
|
return 0; |
|
|
|
/* |
|
* If a tracer registers early in boot up (before scheduling is |
|
* initialized and such), then do not run its selftests yet. |
|
* Instead, run it a little later in the boot process. |
|
*/ |
|
if (!selftests_can_run) |
|
return save_selftest(type); |
|
|
|
if (!tracing_is_on()) { |
|
pr_warn("Selftest for tracer %s skipped due to tracing disabled\n", |
|
type->name); |
|
return 0; |
|
} |
|
|
|
/* |
|
* Run a selftest on this tracer. |
|
* Here we reset the trace buffer, and set the current |
|
* tracer to be this tracer. The tracer can then run some |
|
* internal tracing to verify that everything is in order. |
|
* If we fail, we do not register this tracer. |
|
*/ |
|
tracing_reset_online_cpus(&tr->array_buffer); |
|
|
|
tr->current_trace = type; |
|
|
|
#ifdef CONFIG_TRACER_MAX_TRACE |
|
if (type->use_max_tr) { |
|
/* If we expanded the buffers, make sure the max is expanded too */ |
|
if (ring_buffer_expanded) |
|
ring_buffer_resize(tr->max_buffer.buffer, trace_buf_size, |
|
RING_BUFFER_ALL_CPUS); |
|
tr->allocated_snapshot = true; |
|
} |
|
#endif |
|
|
|
/* the test is responsible for initializing and enabling */ |
|
pr_info("Testing tracer %s: ", type->name); |
|
ret = type->selftest(type, tr); |
|
/* the test is responsible for resetting too */ |
|
tr->current_trace = saved_tracer; |
|
if (ret) { |
|
printk(KERN_CONT "FAILED!\n"); |
|
/* Add the warning after printing 'FAILED' */ |
|
WARN_ON(1); |
|
return -1; |
|
} |
|
/* Only reset on passing, to avoid touching corrupted buffers */ |
|
tracing_reset_online_cpus(&tr->array_buffer); |
|
|
|
#ifdef CONFIG_TRACER_MAX_TRACE |
|
if (type->use_max_tr) { |
|
tr->allocated_snapshot = false; |
|
|
|
/* Shrink the max buffer again */ |
|
if (ring_buffer_expanded) |
|
ring_buffer_resize(tr->max_buffer.buffer, 1, |
|
RING_BUFFER_ALL_CPUS); |
|
} |
|
#endif |
|
|
|
printk(KERN_CONT "PASSED\n"); |
|
return 0; |
|
} |
|
|
|
static __init int init_trace_selftests(void) |
|
{ |
|
struct trace_selftests *p, *n; |
|
struct tracer *t, **last; |
|
int ret; |
|
|
|
selftests_can_run = true; |
|
|
|
mutex_lock(&trace_types_lock); |
|
|
|
if (list_empty(&postponed_selftests)) |
|
goto out; |
|
|
|
pr_info("Running postponed tracer tests:\n"); |
|
|
|
tracing_selftest_running = true; |
|
list_for_each_entry_safe(p, n, &postponed_selftests, list) { |
|
/* This loop can take minutes when sanitizers are enabled, so |
|
* lets make sure we allow RCU processing. |
|
*/ |
|
cond_resched(); |
|
ret = run_tracer_selftest(p->type); |
|
/* If the test fails, then warn and remove from available_tracers */ |
|
if (ret < 0) { |
|
WARN(1, "tracer: %s failed selftest, disabling\n", |
|
p->type->name); |
|
last = &trace_types; |
|
for (t = trace_types; t; t = t->next) { |
|
if (t == p->type) { |
|
*last = t->next; |
|
break; |
|
} |
|
last = &t->next; |
|
} |
|
} |
|
list_del(&p->list); |
|
kfree(p); |
|
} |
|
tracing_selftest_running = false; |
|
|
|
out: |
|
mutex_unlock(&trace_types_lock); |
|
|
|
return 0; |
|
} |
|
core_initcall(init_trace_selftests); |
|
#else |
|
static inline int run_tracer_selftest(struct tracer *type) |
|
{ |
|
return 0; |
|
} |
|
#endif /* CONFIG_FTRACE_STARTUP_TEST */ |
|
|
|
static void add_tracer_options(struct trace_array *tr, struct tracer *t); |
|
|
|
static void __init apply_trace_boot_options(void); |
|
|
|
/** |
|
* register_tracer - register a tracer with the ftrace system. |
|
* @type: the plugin for the tracer |
|
* |
|
* Register a new plugin tracer. |
|
*/ |
|
int __init register_tracer(struct tracer *type) |
|
{ |
|
struct tracer *t; |
|
int ret = 0; |
|
|
|
if (!type->name) { |
|
pr_info("Tracer must have a name\n"); |
|
return -1; |
|
} |
|
|
|
if (strlen(type->name) >= MAX_TRACER_SIZE) { |
|
pr_info("Tracer has a name longer than %d\n", MAX_TRACER_SIZE); |
|
return -1; |
|
} |
|
|
|
if (security_locked_down(LOCKDOWN_TRACEFS)) { |
|
pr_warn("Can not register tracer %s due to lockdown\n", |
|
type->name); |
|
return -EPERM; |
|
} |
|
|
|
mutex_lock(&trace_types_lock); |
|
|
|
tracing_selftest_running = true; |
|
|
|
for (t = trace_types; t; t = t->next) { |
|
if (strcmp(type->name, t->name) == 0) { |
|
/* already found */ |
|
pr_info("Tracer %s already registered\n", |
|
type->name); |
|
ret = -1; |
|
goto out; |
|
} |
|
} |
|
|
|
if (!type->set_flag) |
|
type->set_flag = &dummy_set_flag; |
|
if (!type->flags) { |
|
/*allocate a dummy tracer_flags*/ |
|
type->flags = kmalloc(sizeof(*type->flags), GFP_KERNEL); |
|
if (!type->flags) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
type->flags->val = 0; |
|
type->flags->opts = dummy_tracer_opt; |
|
} else |
|
if (!type->flags->opts) |
|
type->flags->opts = dummy_tracer_opt; |
|
|
|
/* store the tracer for __set_tracer_option */ |
|
type->flags->trace = type; |
|
|
|
ret = run_tracer_selftest(type); |
|
if (ret < 0) |
|
goto out; |
|
|
|
type->next = trace_types; |
|
trace_types = type; |
|
add_tracer_options(&global_trace, type); |
|
|
|
out: |
|
tracing_selftest_running = false; |
|
mutex_unlock(&trace_types_lock); |
|
|
|
if (ret || !default_bootup_tracer) |
|
goto out_unlock; |
|
|
|
if (strncmp(default_bootup_tracer, type->name, MAX_TRACER_SIZE)) |
|
goto out_unlock; |
|
|
|
printk(KERN_INFO "Starting tracer '%s'\n", type->name); |
|
/* Do we want this tracer to start on bootup? */ |
|
tracing_set_tracer(&global_trace, type->name); |
|
default_bootup_tracer = NULL; |
|
|
|
apply_trace_boot_options(); |
|
|
|
/* disable other selftests, since this will break it. */ |
|
disable_tracing_selftest("running a tracer"); |
|
|
|
out_unlock: |
|
return ret; |
|
} |
|
|
|
static void tracing_reset_cpu(struct array_buffer *buf, int cpu) |
|
{ |
|
struct trace_buffer *buffer = buf->buffer; |
|
|
|
if (!buffer) |
|
return; |
|
|
|
ring_buffer_record_disable(buffer); |
|
|
|
/* Make sure all commits have finished */ |
|
synchronize_rcu(); |
|
ring_buffer_reset_cpu(buffer, cpu); |
|
|
|
ring_buffer_record_enable(buffer); |
|
} |
|
|
|
void tracing_reset_online_cpus(struct array_buffer *buf) |
|
{ |
|
struct trace_buffer *buffer = buf->buffer; |
|
|
|
if (!buffer) |
|
return; |
|
|
|
ring_buffer_record_disable(buffer); |
|
|
|
/* Make sure all commits have finished */ |
|
synchronize_rcu(); |
|
|
|
buf->time_start = buffer_ftrace_now(buf, buf->cpu); |
|
|
|
ring_buffer_reset_online_cpus(buffer); |
|
|
|
ring_buffer_record_enable(buffer); |
|
} |
|
|
|
/* Must have trace_types_lock held */ |
|
void tracing_reset_all_online_cpus(void) |
|
{ |
|
struct trace_array *tr; |
|
|
|
list_for_each_entry(tr, &ftrace_trace_arrays, list) { |
|
if (!tr->clear_trace) |
|
continue; |
|
tr->clear_trace = false; |
|
tracing_reset_online_cpus(&tr->array_buffer); |
|
#ifdef CONFIG_TRACER_MAX_TRACE |
|
tracing_reset_online_cpus(&tr->max_buffer); |
|
#endif |
|
} |
|
} |
|
|
|
static int *tgid_map; |
|
|
|
#define SAVED_CMDLINES_DEFAULT 128 |
|
#define NO_CMDLINE_MAP UINT_MAX |
|
static arch_spinlock_t trace_cmdline_lock = __ARCH_SPIN_LOCK_UNLOCKED; |
|
struct saved_cmdlines_buffer { |
|
unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1]; |
|
unsigned *map_cmdline_to_pid; |
|
unsigned cmdline_num; |
|
int cmdline_idx; |
|
char *saved_cmdlines; |
|
}; |
|
static struct saved_cmdlines_buffer *savedcmd; |
|
|
|
/* temporary disable recording */ |
|
static atomic_t trace_record_taskinfo_disabled __read_mostly; |
|
|
|
static inline char *get_saved_cmdlines(int idx) |
|
{ |
|
return &savedcmd->saved_cmdlines[idx * TASK_COMM_LEN]; |
|
} |
|
|
|
static inline void set_cmdline(int idx, const char *cmdline) |
|
{ |
|
strncpy(get_saved_cmdlines(idx), cmdline, TASK_COMM_LEN); |
|
} |
|
|
|
static int allocate_cmdlines_buffer(unsigned int val, |
|
struct saved_cmdlines_buffer *s) |
|
{ |
|
s->map_cmdline_to_pid = kmalloc_array(val, |
|
sizeof(*s->map_cmdline_to_pid), |
|
GFP_KERNEL); |
|
if (!s->map_cmdline_to_pid) |
|
return -ENOMEM; |
|
|
|
s->saved_cmdlines = kmalloc_array(TASK_COMM_LEN, val, GFP_KERNEL); |
|
if (!s->saved_cmdlines) { |
|
kfree(s->map_cmdline_to_pid); |
|
return -ENOMEM; |
|
} |
|
|
|
s->cmdline_idx = 0; |
|
s->cmdline_num = val; |
|
memset(&s->map_pid_to_cmdline, NO_CMDLINE_MAP, |
|
sizeof(s->map_pid_to_cmdline)); |
|
memset(s->map_cmdline_to_pid, NO_CMDLINE_MAP, |
|
val * sizeof(*s->map_cmdline_to_pid)); |
|
|
|
return 0; |
|
} |
|
|
|
static int trace_create_savedcmd(void) |
|
{ |
|
int ret; |
|
|
|
savedcmd = kmalloc(sizeof(*savedcmd), GFP_KERNEL); |
|
if (!savedcmd) |
|
return -ENOMEM; |
|
|
|
ret = allocate_cmdlines_buffer(SAVED_CMDLINES_DEFAULT, savedcmd); |
|
if (ret < 0) { |
|
kfree(savedcmd); |
|
savedcmd = NULL; |
|
return -ENOMEM; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
int is_tracing_stopped(void) |
|
{ |
|
return global_trace.stop_count; |
|
} |
|
|
|
/** |
|
* tracing_start - quick start of the tracer |
|
* |
|
* If tracing is enabled but was stopped by tracing_stop, |
|
* this will start the tracer back up. |
|
*/ |
|
void tracing_start(void) |
|
{ |
|
struct trace_buffer *buffer; |
|
unsigned long flags; |
|
|
|
if (tracing_disabled) |
|
return; |
|
|
|
raw_spin_lock_irqsave(&global_trace.start_lock, flags); |
|
if (--global_trace.stop_count) { |
|
if (global_trace.stop_count < 0) { |
|
/* Someone screwed up their debugging */ |
|
WARN_ON_ONCE(1); |
|
global_trace.stop_count = 0; |
|
} |
|
goto out; |
|
} |
|
|
|
/* Prevent the buffers from switching */ |
|
arch_spin_lock(&global_trace.max_lock); |
|
|
|
buffer = global_trace.array_buffer.buffer; |
|
if (buffer) |
|
ring_buffer_record_enable(buffer); |
|
|
|
#ifdef CONFIG_TRACER_MAX_TRACE |
|
buffer = global_trace.max_buffer.buffer; |
|
if (buffer) |
|
ring_buffer_record_enable(buffer); |
|
#endif |
|
|
|
arch_spin_unlock(&global_trace.max_lock); |
|
|
|
out: |
|
raw_spin_unlock_irqrestore(&global_trace.start_lock, flags); |
|
} |
|
|
|
static void tracing_start_tr(struct trace_array *tr) |
|
{ |
|
struct trace_buffer *buffer; |
|
unsigned long flags; |
|
|
|
if (tracing_disabled) |
|
return; |
|
|
|
/* If global, we need to also start the max tracer */ |
|
if (tr->flags & TRACE_ARRAY_FL_GLOBAL) |
|
return tracing_start(); |
|
|
|
raw_spin_lock_irqsave(&tr->start_lock, flags); |
|
|
|
if (--tr->stop_count) { |
|
if (tr->stop_count < 0) { |
|
/* Someone screwed up their debugging */ |
|
WARN_ON_ONCE(1); |
|
tr->stop_count = 0; |
|
} |
|
goto out; |
|
} |
|
|
|
buffer = tr->array_buffer.buffer; |
|
if (buffer) |
|
ring_buffer_record_enable(buffer); |
|
|
|
out: |
|
raw_spin_unlock_irqrestore(&tr->start_lock, flags); |
|
} |
|
|
|
/** |
|
* tracing_stop - quick stop of the tracer |
|
* |
|
* Light weight way to stop tracing. Use in conjunction with |
|
* tracing_start. |
|
*/ |
|
void tracing_stop(void) |
|
{ |
|
struct trace_buffer *buffer; |
|
unsigned long flags; |
|
|
|
raw_spin_lock_irqsave(&global_trace.start_lock, flags); |
|
if (global_trace.stop_count++) |
|
goto out; |
|
|
|
/* Prevent the buffers from switching */ |
|
arch_spin_lock(&global_trace.max_lock); |
|
|
|
buffer = global_trace.array_buffer.buffer; |
|
if (buffer) |
|
ring_buffer_record_disable(buffer); |
|
|
|
#ifdef CONFIG_TRACER_MAX_TRACE |
|
buffer = global_trace.max_buffer.buffer; |
|
if (buffer) |
|
ring_buffer_record_disable(buffer); |
|
#endif |
|
|
|
arch_spin_unlock(&global_trace.max_lock); |
|
|
|
out: |
|
raw_spin_unlock_irqrestore(&global_trace.start_lock, flags); |
|
} |
|
|
|
static void tracing_stop_tr(struct trace_array *tr) |
|
{ |
|
struct trace_buffer *buffer; |
|
unsigned long flags; |
|
|
|
/* If global, we need to also stop the max tracer */ |
|
if (tr->flags & TRACE_ARRAY_FL_GLOBAL) |
|
return tracing_stop(); |
|
|
|
raw_spin_lock_irqsave(&tr->start_lock, flags); |
|
if (tr->stop_count++) |
|
goto out; |
|
|
|
buffer = tr->array_buffer.buffer; |
|
if (buffer) |
|
ring_buffer_record_disable(buffer); |
|
|
|
out: |
|
raw_spin_unlock_irqrestore(&tr->start_lock, flags); |
|
} |
|
|
|
static int trace_save_cmdline(struct task_struct *tsk) |
|
{ |
|
unsigned tpid, idx; |
|
|
|
/* treat recording of idle task as a success */ |
|
if (!tsk->pid) |
|
return 1; |
|
|
|
tpid = tsk->pid & (PID_MAX_DEFAULT - 1); |
|
|
|
/* |
|
* It's not the end of the world if we don't get |
|
* the lock, but we also don't want to spin |
|
* nor do we want to disable interrupts, |
|
* so if we miss here, then better luck next time. |
|
*/ |
|
if (!arch_spin_trylock(&trace_cmdline_lock)) |
|
return 0; |
|
|
|
idx = savedcmd->map_pid_to_cmdline[tpid]; |
|
if (idx == NO_CMDLINE_MAP) { |
|
idx = (savedcmd->cmdline_idx + 1) % savedcmd->cmdline_num; |
|
|
|
savedcmd->map_pid_to_cmdline[tpid] = idx; |
|
savedcmd->cmdline_idx = idx; |
|
} |
|
|
|
savedcmd->map_cmdline_to_pid[idx] = tsk->pid; |
|
set_cmdline(idx, tsk->comm); |
|
|
|
arch_spin_unlock(&trace_cmdline_lock); |
|
|
|
return 1; |
|
} |
|
|
|
static void __trace_find_cmdline(int pid, char comm[]) |
|
{ |
|
unsigned map; |
|
int tpid; |
|
|
|
if (!pid) { |
|
strcpy(comm, "<idle>"); |
|
return; |
|
} |
|
|
|
if (WARN_ON_ONCE(pid < 0)) { |
|
strcpy(comm, "<XXX>"); |
|
return; |
|
} |
|
|
|
tpid = pid & (PID_MAX_DEFAULT - 1); |
|
map = savedcmd->map_pid_to_cmdline[tpid]; |
|
if (map != NO_CMDLINE_MAP) { |
|
tpid = savedcmd->map_cmdline_to_pid[map]; |
|
if (tpid == pid) { |
|
strlcpy(comm, get_saved_cmdlines(map), TASK_COMM_LEN); |
|
return; |
|
} |
|
} |
|
strcpy(comm, "<...>"); |
|
} |
|
|
|
void trace_find_cmdline(int pid, char comm[]) |
|
{ |
|
preempt_disable(); |
|
arch_spin_lock(&trace_cmdline_lock); |
|
|
|
__trace_find_cmdline(pid, comm); |
|
|
|
arch_spin_unlock(&trace_cmdline_lock); |
|
preempt_enable(); |
|
} |
|
|
|
int trace_find_tgid(int pid) |
|
{ |
|
if (unlikely(!tgid_map || !pid || pid > PID_MAX_DEFAULT)) |
|
return 0; |
|
|
|
return tgid_map[pid]; |
|
} |
|
|
|
static int trace_save_tgid(struct task_struct *tsk) |
|
{ |
|
/* treat recording of idle task as a success */ |
|
if (!tsk->pid) |
|
return 1; |
|
|
|
if (unlikely(!tgid_map || tsk->pid > PID_MAX_DEFAULT)) |
|
return 0; |
|
|
|
tgid_map[tsk->pid] = tsk->tgid; |
|
return 1; |
|
} |
|
|
|
static bool tracing_record_taskinfo_skip(int flags) |
|
{ |
|
if (unlikely(!(flags & (TRACE_RECORD_CMDLINE | TRACE_RECORD_TGID)))) |
|
return true; |
|
if (atomic_read(&trace_record_taskinfo_disabled) || !tracing_is_on()) |
|
return true; |
|
if (!__this_cpu_read(trace_taskinfo_save)) |
|
return true; |
|
return false; |
|
} |
|
|
|
/** |
|
* tracing_record_taskinfo - record the task info of a task |
|
* |
|
* @task: task to record |
|
* @flags: TRACE_RECORD_CMDLINE for recording comm |
|
* TRACE_RECORD_TGID for recording tgid |
|
*/ |
|
void tracing_record_taskinfo(struct task_struct *task, int flags) |
|
{ |
|
bool done; |
|
|
|
if (tracing_record_taskinfo_skip(flags)) |
|
return; |
|
|
|
/* |
|
* Record as much task information as possible. If some fail, continue |
|
* to try to record the others. |
|
*/ |
|
done = !(flags & TRACE_RECORD_CMDLINE) || trace_save_cmdline(task); |
|
done &= !(flags & TRACE_RECORD_TGID) || trace_save_tgid(task); |
|
|
|
/* If recording any information failed, retry again soon. */ |
|
if (!done) |
|
return; |
|
|
|
__this_cpu_write(trace_taskinfo_save, false); |
|
} |
|
|
|
/** |
|
* tracing_record_taskinfo_sched_switch - record task info for sched_switch |
|
* |
|
* @prev: previous task during sched_switch |
|
* @next: next task during sched_switch |
|
* @flags: TRACE_RECORD_CMDLINE for recording comm |
|
* TRACE_RECORD_TGID for recording tgid |
|
*/ |
|
void tracing_record_taskinfo_sched_switch(struct task_struct *prev, |
|
struct task_struct *next, int flags) |
|
{ |
|
bool done; |
|
|
|
if (tracing_record_taskinfo_skip(flags)) |
|
return; |
|
|
|
/* |
|
* Record as much task information as possible. If some fail, continue |
|
* to try to record the others. |
|
*/ |
|
done = !(flags & TRACE_RECORD_CMDLINE) || trace_save_cmdline(prev); |
|
done &= !(flags & TRACE_RECORD_CMDLINE) || trace_save_cmdline(next); |
|
done &= !(flags & TRACE_RECORD_TGID) || trace_save_tgid(prev); |
|
done &= !(flags & TRACE_RECORD_TGID) || trace_save_tgid(next); |
|
|
|
/* If recording any information failed, retry again soon. */ |
|
if (!done) |
|
return; |
|
|
|
__this_cpu_write(trace_taskinfo_save, false); |
|
} |
|
|
|
/* Helpers to record a specific task information */ |
|
void tracing_record_cmdline(struct task_struct *task) |
|
{ |
|
tracing_record_taskinfo(task, TRACE_RECORD_CMDLINE); |
|
} |
|
|
|
void tracing_record_tgid(struct task_struct *task) |
|
{ |
|
tracing_record_taskinfo(task, TRACE_RECORD_TGID); |
|
} |
|
|
|
/* |
|
* Several functions return TRACE_TYPE_PARTIAL_LINE if the trace_seq |
|
* overflowed, and TRACE_TYPE_HANDLED otherwise. This helper function |
|
* simplifies those functions and keeps them in sync. |
|
*/ |
|
enum print_line_t trace_handle_return(struct trace_seq *s) |
|
{ |
|
return trace_seq_has_overflowed(s) ? |
|
TRACE_TYPE_PARTIAL_LINE : TRACE_TYPE_HANDLED; |
|
} |
|
EXPORT_SYMBOL_GPL(trace_handle_return); |
|
|
|
unsigned int tracing_gen_ctx_irq_test(unsigned int irqs_status) |
|
{ |
|
unsigned int trace_flags = irqs_status; |
|
unsigned int pc; |
|
|
|
pc = preempt_count(); |
|
|
|
if (pc & NMI_MASK) |
|
trace_flags |= TRACE_FLAG_NMI; |
|
if (pc & HARDIRQ_MASK) |
|
trace_flags |= TRACE_FLAG_HARDIRQ; |
|
if (in_serving_softirq()) |
|
trace_flags |= TRACE_FLAG_SOFTIRQ; |
|
|
|
if (tif_need_resched()) |
|
trace_flags |= TRACE_FLAG_NEED_RESCHED; |
|
if (test_preempt_need_resched()) |
|
trace_flags |= TRACE_FLAG_PREEMPT_RESCHED; |
|
return (trace_flags << 16) | (pc & 0xff); |
|
} |
|
|
|
struct ring_buffer_event * |
|
trace_buffer_lock_reserve(struct trace_buffer *buffer, |
|
int type, |
|
unsigned long len, |
|
unsigned int trace_ctx) |
|
{ |
|
return __trace_buffer_lock_reserve(buffer, type, len, trace_ctx); |
|
} |
|
|
|
DEFINE_PER_CPU(struct ring_buffer_event *, trace_buffered_event); |
|
DEFINE_PER_CPU(int, trace_buffered_event_cnt); |
|
static int trace_buffered_event_ref; |
|
|
|
/** |
|
* trace_buffered_event_enable - enable buffering events |
|
* |
|
* When events are being filtered, it is quicker to use a temporary |
|
* buffer to write the event data into if there's a likely chance |
|
* that it will not be committed. The discard of the ring buffer |
|
* is not as fast as committing, and is much slower than copying |
|
* a commit. |
|
* |
|
* When an event is to be filtered, allocate per cpu buffers to |
|
* write the event data into, and if the event is filtered and discarded |
|
* it is simply dropped, otherwise, the entire data is to be committed |
|
* in one shot. |
|
*/ |
|
void trace_buffered_event_enable(void) |
|
{ |
|
struct ring_buffer_event *event; |
|
struct page *page; |
|
int cpu; |
|
|
|
WARN_ON_ONCE(!mutex_is_locked(&event_mutex)); |
|
|
|
if (trace_buffered_event_ref++) |
|
return; |
|
|
|
for_each_tracing_cpu(cpu) { |
|
page = alloc_pages_node(cpu_to_node(cpu), |
|
GFP_KERNEL | __GFP_NORETRY, 0); |
|
if (!page) |
|
goto failed; |
|
|
|
event = page_address(page); |
|
memset(event, 0, sizeof(*event)); |
|
|
|
per_cpu(trace_buffered_event, cpu) = event; |
|
|
|
preempt_disable(); |
|
if (cpu == smp_processor_id() && |
|
__this_cpu_read(trace_buffered_event) != |
|
per_cpu(trace_buffered_event, cpu)) |
|
WARN_ON_ONCE(1); |
|
preempt_enable(); |
|
} |
|
|
|
return; |
|
failed: |
|
trace_buffered_event_disable(); |
|
} |
|
|
|
static void enable_trace_buffered_event(void *data) |
|
{ |
|
/* Probably not needed, but do it anyway */ |
|
smp_rmb(); |
|
this_cpu_dec(trace_buffered_event_cnt); |
|
} |
|
|
|
static void disable_trace_buffered_event(void *data) |
|
{ |
|
this_cpu_inc(trace_buffered_event_cnt); |
|
} |
|
|
|
/** |
|
* trace_buffered_event_disable - disable buffering events |
|
* |
|
* When a filter is removed, it is faster to not use the buffered |
|
* events, and to commit directly into the ring buffer. Free up |
|
* the temp buffers when there are no more users. This requires |
|
* special synchronization with current events. |
|
*/ |
|
void trace_buffered_event_disable(void) |
|
{ |
|
int cpu; |
|
|
|
WARN_ON_ONCE(!mutex_is_locked(&event_mutex)); |
|
|
|
if (WARN_ON_ONCE(!trace_buffered_event_ref)) |
|
return; |
|
|
|
if (--trace_buffered_event_ref) |
|
return; |
|
|
|
preempt_disable(); |
|
/* For each CPU, set the buffer as used. */ |
|
smp_call_function_many(tracing_buffer_mask, |
|
disable_trace_buffered_event, NULL, 1); |
|
preempt_enable(); |
|
|
|
/* Wait for all current users to finish */ |
|
synchronize_rcu(); |
|
|
|
for_each_tracing_cpu(cpu) { |
|
free_page((unsigned long)per_cpu(trace_buffered_event, cpu)); |
|
per_cpu(trace_buffered_event, cpu) = NULL; |
|
} |
|
/* |
|
* Make sure trace_buffered_event is NULL before clearing |
|
* trace_buffered_event_cnt. |
|
*/ |
|
smp_wmb(); |
|
|
|
preempt_disable(); |
|
/* Do the work on each cpu */ |
|
smp_call_function_many(tracing_buffer_mask, |
|
enable_trace_buffered_event, NULL, 1); |
|
preempt_enable(); |
|
} |
|
|
|
static struct trace_buffer *temp_buffer; |
|
|
|
struct ring_buffer_event * |
|
trace_event_buffer_lock_reserve(struct trace_buffer **current_rb, |
|
struct trace_event_file *trace_file, |
|
int type, unsigned long len, |
|
unsigned int trace_ctx) |
|
{ |
|
struct ring_buffer_event *entry; |
|
int val; |
|
|
|
*current_rb = trace_file->tr->array_buffer.buffer; |
|
|
|
if (!ring_buffer_time_stamp_abs(*current_rb) && (trace_file->flags & |
|
(EVENT_FILE_FL_SOFT_DISABLED | EVENT_FILE_FL_FILTERED)) && |
|
(entry = this_cpu_read(trace_buffered_event))) { |
|
/* Try to use the per cpu buffer first */ |
|
val = this_cpu_inc_return(trace_buffered_event_cnt); |
|
if ((len < (PAGE_SIZE - sizeof(*entry))) && val == 1) { |
|
trace_event_setup(entry, type, trace_ctx); |
|
entry->array[0] = len; |
|
return entry; |
|
} |
|
this_cpu_dec(trace_buffered_event_cnt); |
|
} |
|
|
|
entry = __trace_buffer_lock_reserve(*current_rb, type, len, |
|
trace_ctx); |
|
/* |
|
* If tracing is off, but we have triggers enabled |
|
* we still need to look at the event data. Use the temp_buffer |
|
* to store the trace event for the trigger to use. It's recursive |
|
* safe and will not be recorded anywhere. |
|
*/ |
|
if (!entry && trace_file->flags & EVENT_FILE_FL_TRIGGER_COND) { |
|
*current_rb = temp_buffer; |
|
entry = __trace_buffer_lock_reserve(*current_rb, type, len, |
|
trace_ctx); |
|
} |
|
return entry; |
|
} |
|
EXPORT_SYMBOL_GPL(trace_event_buffer_lock_reserve); |
|
|
|
static DEFINE_SPINLOCK(tracepoint_iter_lock); |
|
static DEFINE_MUTEX(tracepoint_printk_mutex); |
|
|
|
static void output_printk(struct trace_event_buffer *fbuffer) |
|
{ |
|
struct trace_event_call *event_call; |
|
struct trace_event_file *file; |
|
struct trace_event *event; |
|
unsigned long flags; |
|
struct trace_iterator *iter = tracepoint_print_iter; |
|
|
|
/* We should never get here if iter is NULL */ |
|
if (WARN_ON_ONCE(!iter)) |
|
return; |
|
|
|
event_call = fbuffer->trace_file->event_call; |
|
if (!event_call || !event_call->event.funcs || |
|
!event_call->event.funcs->trace) |
|
return; |
|
|
|
file = fbuffer->trace_file; |
|
if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags) || |
|
(unlikely(file->flags & EVENT_FILE_FL_FILTERED) && |
|
!filter_match_preds(file->filter, fbuffer->entry))) |
|
return; |
|
|
|
event = &fbuffer->trace_file->event_call->event; |
|
|
|
spin_lock_irqsave(&tracepoint_iter_lock, flags); |
|
trace_seq_init(&iter->seq); |
|
iter->ent = fbuffer->entry; |
|
event_call->event.funcs->trace(iter, 0, event); |
|
trace_seq_putc(&iter->seq, 0); |
|
printk("%s", iter->seq.buffer); |
|
|
|
spin_unlock_irqrestore(&tracepoint_iter_lock, flags); |
|
} |
|
|
|
int tracepoint_printk_sysctl(struct ctl_table *table, int write, |
|
void *buffer, size_t *lenp, |
|
loff_t *ppos) |
|
{ |
|
int save_tracepoint_printk; |
|
int ret; |
|
|
|
mutex_lock(&tracepoint_printk_mutex); |
|
save_tracepoint_printk = tracepoint_printk; |
|
|
|
ret = proc_dointvec(table, write, buffer, lenp, ppos); |
|
|
|
/* |
|
* This will force exiting early, as tracepoint_printk |
|
* is always zero when tracepoint_printk_iter is not allocated |
|
*/ |
|
if (!tracepoint_print_iter) |
|
tracepoint_printk = 0; |
|
|
|
if (save_tracepoint_printk == tracepoint_printk) |
|
goto out; |
|
|
|
if (tracepoint_printk) |
|
static_key_enable(&tracepoint_printk_key.key); |
|
else |
|
static_key_disable(&tracepoint_printk_key.key); |
|
|
|
out: |
|
mutex_unlock(&tracepoint_printk_mutex); |
|
|
|
return ret; |
|
} |
|
|
|
void trace_event_buffer_commit(struct trace_event_buffer *fbuffer) |
|
{ |
|
if (static_key_false(&tracepoint_printk_key.key)) |
|
output_printk(fbuffer); |
|
|
|
if (static_branch_unlikely(&trace_event_exports_enabled)) |
|
ftrace_exports(fbuffer->event, TRACE_EXPORT_EVENT); |
|
event_trigger_unlock_commit_regs(fbuffer->trace_file, fbuffer->buffer, |
|
fbuffer->event, fbuffer->entry, |
|
fbuffer->trace_ctx, fbuffer->regs); |
|
} |
|
EXPORT_SYMBOL_GPL(trace_event_buffer_commit); |
|
|
|
/* |
|
* Skip 3: |
|
* |
|
* trace_buffer_unlock_commit_regs() |
|
* trace_event_buffer_commit() |
|
* trace_event_raw_event_xxx() |
|
*/ |
|
# define STACK_SKIP 3 |
|
|
|
void trace_buffer_unlock_commit_regs(struct trace_array *tr, |
|
struct trace_buffer *buffer, |
|
struct ring_buffer_event *event, |
|
unsigned int trace_ctx, |
|
struct pt_regs *regs) |
|
{ |
|
__buffer_unlock_commit(buffer, event); |
|
|
|
/* |
|
* If regs is not set, then skip the necessary functions. |
|
* Note, we can still get here via blktrace, wakeup tracer |
|
* and mmiotrace, but that's ok if they lose a function or |
|
* two. They are not that meaningful. |
|
*/ |
|
ftrace_trace_stack(tr, buffer, trace_ctx, regs ? 0 : STACK_SKIP, regs); |
|
ftrace_trace_userstack(tr, buffer, trace_ctx); |
|
} |
|
|
|
/* |
|
* Similar to trace_buffer_unlock_commit_regs() but do not dump stack. |
|
*/ |
|
void |
|
trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer, |
|
struct ring_buffer_event *event) |
|
{ |
|
__buffer_unlock_commit(buffer, event); |
|
} |
|
|
|
void |
|
trace_function(struct trace_array *tr, unsigned long ip, unsigned long |
|
parent_ip, unsigned int trace_ctx) |
|
{ |
|
struct trace_event_call *call = &event_function; |
|
struct trace_buffer *buffer = tr->array_buffer.buffer; |
|
struct ring_buffer_event *event; |
|
struct ftrace_entry *entry; |
|
|
|
event = __trace_buffer_lock_reserve(buffer, TRACE_FN, sizeof(*entry), |
|
trace_ctx); |
|
if (!event) |
|
return; |
|
entry = ring_buffer_event_data(event); |
|
entry->ip = ip; |
|
entry->parent_ip = parent_ip; |
|
|
|
if (!call_filter_check_discard(call, entry, buffer, event)) { |
|
if (static_branch_unlikely(&trace_function_exports_enabled)) |
|
ftrace_exports(event, TRACE_EXPORT_FUNCTION); |
|
__buffer_unlock_commit(buffer, event); |
|
} |
|
} |
|
|
|
#ifdef CONFIG_STACKTRACE |
|
|
|
/* Allow 4 levels of nesting: normal, softirq, irq, NMI */ |
|
#define FTRACE_KSTACK_NESTING 4 |
|
|
|
#define FTRACE_KSTACK_ENTRIES (PAGE_SIZE / FTRACE_KSTACK_NESTING) |
|
|
|
struct ftrace_stack { |
|
unsigned long calls[FTRACE_KSTACK_ENTRIES]; |
|
}; |
|
|
|
|
|
struct ftrace_stacks { |
|
struct ftrace_stack stacks[FTRACE_KSTACK_NESTING]; |
|
}; |
|
|
|
static DEFINE_PER_CPU(struct ftrace_stacks, ftrace_stacks); |
|
static DEFINE_PER_CPU(int, ftrace_stack_reserve); |
|
|
|
static void __ftrace_trace_stack(struct trace_buffer *buffer, |
|
unsigned int trace_ctx, |
|
int skip, struct pt_regs *regs) |
|
{ |
|
struct trace_event_call *call = &event_kernel_stack; |
|
struct ring_buffer_event *event; |
|
unsigned int size, nr_entries; |
|
struct ftrace_stack *fstack; |
|
struct stack_entry *entry; |
|
int stackidx; |
|
|
|
/* |
|
* Add one, for this function and the call to save_stack_trace() |
|
* If regs is set, then these functions will not be in the way. |
|
*/ |
|
#ifndef CONFIG_UNWINDER_ORC |
|
if (!regs) |
|
skip++; |
|
#endif |
|
|
|
preempt_disable_notrace(); |
|
|
|
stackidx = __this_cpu_inc_return(ftrace_stack_reserve) - 1; |
|
|
|
/* This should never happen. If it does, yell once and skip */ |
|
if (WARN_ON_ONCE(stackidx >= FTRACE_KSTACK_NESTING)) |
|
goto out; |
|
|
|
/* |
|
* The above __this_cpu_inc_return() is 'atomic' cpu local. An |
|
* interrupt will either see the value pre increment or post |
|
* increment. If the interrupt happens pre increment it will have |
|
* restored the counter when it returns. We just need a barrier to |
|
* keep gcc from moving things around. |
|
*/ |
|
barrier(); |
|
|
|
fstack = this_cpu_ptr(ftrace_stacks.stacks) + stackidx; |
|
size = ARRAY_SIZE(fstack->calls); |
|
|
|
if (regs) { |
|
nr_entries = stack_trace_save_regs(regs, fstack->calls, |
|
size, skip); |
|
} else { |
|
nr_entries = stack_trace_save(fstack->calls, size, skip); |
|
} |
|
|
|
size = nr_entries * sizeof(unsigned long); |
|
event = __trace_buffer_lock_reserve(buffer, TRACE_STACK, |
|
(sizeof(*entry) - sizeof(entry->caller)) + size, |
|
trace_ctx); |
|
if (!event) |
|
goto out; |
|
entry = ring_buffer_event_data(event); |
|
|
|
memcpy(&entry->caller, fstack->calls, size); |
|
entry->size = nr_entries; |
|
|
|
if (!call_filter_check_discard(call, entry, buffer, event)) |
|
__buffer_unlock_commit(buffer, event); |
|
|
|
out: |
|
/* Again, don't let gcc optimize things here */ |
|
barrier(); |
|
__this_cpu_dec(ftrace_stack_reserve); |
|
preempt_enable_notrace(); |
|
|
|
} |
|
|
|
static inline void ftrace_trace_stack(struct trace_array *tr, |
|
struct trace_buffer *buffer, |
|
unsigned int trace_ctx, |
|
int skip, struct pt_regs *regs) |
|
{ |
|
if (!(tr->trace_flags & TRACE_ITER_STACKTRACE)) |
|
return; |
|
|
|
__ftrace_trace_stack(buffer, trace_ctx, skip, regs); |
|
} |
|
|
|
void __trace_stack(struct trace_array *tr, unsigned int trace_ctx, |
|
int skip) |
|
{ |
|
struct trace_buffer *buffer = tr->array_buffer.buffer; |
|
|
|
if (rcu_is_watching()) { |
|
__ftrace_trace_stack(buffer, trace_ctx, skip, NULL); |
|
return; |
|
} |
|
|
|
/* |
|
* When an NMI triggers, RCU is enabled via rcu_nmi_enter(), |
|
* but if the above rcu_is_watching() failed, then the NMI |
|
* triggered someplace critical, and rcu_irq_enter() should |
|
* not be called from NMI. |
|
*/ |
|
if (unlikely(in_nmi())) |
|
return; |
|
|
|
rcu_irq_enter_irqson(); |
|
__ftrace_trace_stack(buffer, trace_ctx, skip, NULL); |
|
rcu_irq_exit_irqson(); |
|
} |
|
|
|
/** |
|
* trace_dump_stack - record a stack back trace in the trace buffer |
|
* @skip: Number of functions to skip (helper handlers) |
|
*/ |
|
void trace_dump_stack(int skip) |
|
{ |
|
if (tracing_disabled || tracing_selftest_running) |
|
return; |
|
|
|
#ifndef CONFIG_UNWINDER_ORC |
|
/* Skip 1 to skip this function. */ |
|
skip++; |
|
#endif |
|
__ftrace_trace_stack(global_trace.array_buffer.buffer, |
|
tracing_gen_ctx(), skip, NULL); |
|
} |
|
EXPORT_SYMBOL_GPL(trace_dump_stack); |
|
|
|
#ifdef CONFIG_USER_STACKTRACE_SUPPORT |
|
static DEFINE_PER_CPU(int, user_stack_count); |
|
|
|
static void |
|
ftrace_trace_userstack(struct trace_array *tr, |
|
struct trace_buffer *buffer, unsigned int trace_ctx) |
|
{ |
|
struct trace_event_call *call = &event_user_stack; |
|
struct ring_buffer_event *event; |
|
struct userstack_entry *entry; |
|
|
|
if (!(tr->trace_flags & TRACE_ITER_USERSTACKTRACE)) |
|
return; |
|
|
|
/* |
|
* NMIs can not handle page faults, even with fix ups. |
|
* The save user stack can (and often does) fault. |
|
*/ |
|
if (unlikely(in_nmi())) |
|
return; |
|
|
|
/* |
|
* prevent recursion, since the user stack tracing may |
|
* trigger other kernel events. |
|
*/ |
|
preempt_disable(); |
|
if (__this_cpu_read(user_stack_count)) |
|
goto out; |
|
|
|
__this_cpu_inc(user_stack_count); |
|
|
|
event = __trace_buffer_lock_reserve(buffer, TRACE_USER_STACK, |
|
sizeof(*entry), trace_ctx); |
|
if (!event) |
|
goto out_drop_count; |
|
entry = ring_buffer_event_data(event); |
|
|
|
entry->tgid = current->tgid; |
|
memset(&entry->caller, 0, sizeof(entry->caller)); |
|
|
|
stack_trace_save_user(entry->caller, FTRACE_STACK_ENTRIES); |
|
if (!call_filter_check_discard(call, entry, buffer, event)) |
|
__buffer_unlock_commit(buffer, event); |
|
|
|
out_drop_count: |
|
__this_cpu_dec(user_stack_count); |
|
out: |
|
preempt_enable(); |
|
} |
|
#else /* CONFIG_USER_STACKTRACE_SUPPORT */ |
|
static void ftrace_trace_userstack(struct trace_array *tr, |
|
struct trace_buffer *buffer, |
|
unsigned int trace_ctx) |
|
{ |
|
} |
|
#endif /* !CONFIG_USER_STACKTRACE_SUPPORT */ |
|
|
|
#endif /* CONFIG_STACKTRACE */ |
|
|
|
/* created for use with alloc_percpu */ |
|
struct trace_buffer_struct { |
|
int nesting; |
|
char buffer[4][TRACE_BUF_SIZE]; |
|
}; |
|
|
|
static struct trace_buffer_struct *trace_percpu_buffer; |
|
|
|
/* |
|
* This allows for lockless recording. If we're nested too deeply, then |
|
* this returns NULL. |
|
*/ |
|
static char *get_trace_buf(void) |
|
{ |
|
struct trace_buffer_struct *buffer = this_cpu_ptr(trace_percpu_buffer); |
|
|
|
if (!buffer || buffer->nesting >= 4) |
|
return NULL; |
|
|
|
buffer->nesting++; |
|
|
|
/* Interrupts must see nesting incremented before we use the buffer */ |
|
barrier(); |
|
return &buffer->buffer[buffer->nesting - 1][0]; |
|
} |
|
|
|
static void put_trace_buf(void) |
|
{ |
|
/* Don't let the decrement of nesting leak before this */ |
|
barrier(); |
|
this_cpu_dec(trace_percpu_buffer->nesting); |
|
} |
|
|
|
static int alloc_percpu_trace_buffer(void) |
|
{ |
|
struct trace_buffer_struct *buffers; |
|
|
|
if (trace_percpu_buffer) |
|
return 0; |
|
|
|
buffers = alloc_percpu(struct trace_buffer_struct); |
|
if (MEM_FAIL(!buffers, "Could not allocate percpu trace_printk buffer")) |
|
return -ENOMEM; |
|
|
|
trace_percpu_buffer = buffers; |
|
return 0; |
|
} |
|
|
|
static int buffers_allocated; |
|
|
|
void trace_printk_init_buffers(void) |
|
{ |
|
if (buffers_allocated) |
|
return; |
|
|
|
if (alloc_percpu_trace_buffer()) |
|
return; |
|
|
|
/* trace_printk() is for debug use only. Don't use it in production. */ |
|
|
|
pr_warn("\n"); |
|
pr_warn("**********************************************************\n"); |
|
pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); |
|
pr_warn("** **\n"); |
|
pr_warn("** trace_printk() being used. Allocating extra memory. **\n"); |
|
pr_warn("** **\n"); |
|
pr_warn("** This means that this is a DEBUG kernel and it is **\n"); |
|
pr_warn("** unsafe for production use. **\n"); |
|
pr_warn("** **\n"); |
|
pr_warn("** If you see this message and you are not debugging **\n"); |
|
pr_warn("** the kernel, report this immediately to your vendor! **\n"); |
|
pr_warn("** **\n"); |
|
pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); |
|
pr_warn("**********************************************************\n"); |
|
|
|
/* Expand the buffers to set size */ |
|
tracing_update_buffers(); |
|
|
|
buffers_allocated = 1; |
|
|
|
/* |
|
* trace_printk_init_buffers() can be called by modules. |
|
* If that happens, then we need to start cmdline recording |
|
* directly here. If the global_trace.buffer is already |
|
* allocated here, then this was called by module code. |
|
*/ |
|
if (global_trace.array_buffer.buffer) |
|
tracing_start_cmdline_record(); |
|
} |
|
EXPORT_SYMBOL_GPL(trace_printk_init_buffers); |
|
|
|
void trace_printk_start_comm(void) |
|
{ |
|
/* Start tracing comms if trace printk is set */ |
|
if (!buffers_allocated) |
|
return; |
|
tracing_start_cmdline_record(); |
|
} |
|
|
|
static void trace_printk_start_stop_comm(int enabled) |
|
{ |
|
if (!buffers_allocated) |
|
return; |
|
|
|
if (enabled) |
|
tracing_start_cmdline_record(); |
|
else |
|
tracing_stop_cmdline_record(); |
|
} |
|
|
|
/** |
|
* trace_vbprintk - write binary msg to tracing buffer |
|
* @ip: The address of the caller |
|
* @fmt: The string format to write to the buffer |
|
* @args: Arguments for @fmt |
|
*/ |
|
int trace_vbprintk(unsigned long ip, const char *fmt, va_list args) |
|
{ |
|
struct trace_event_call *call = &event_bprint; |
|
struct ring_buffer_event *event; |
|
struct trace_buffer *buffer; |
|
struct trace_array *tr = &global_trace; |
|
struct bprint_entry *entry; |
|
unsigned int trace_ctx; |
|
char *tbuffer; |
|
int len = 0, size; |
|
|
|
if (unlikely(tracing_selftest_running || tracing_disabled)) |
|
return 0; |
|
|
|
/* Don't pollute graph traces with trace_vprintk internals */ |
|
pause_graph_tracing(); |
|
|
|
trace_ctx = tracing_gen_ctx(); |
|
preempt_disable_notrace(); |
|
|
|
tbuffer = get_trace_buf(); |
|
if (!tbuffer) { |
|
len = 0; |
|
goto out_nobuffer; |
|
} |
|
|
|
len = vbin_printf((u32 *)tbuffer, TRACE_BUF_SIZE/sizeof(int), fmt, args); |
|
|
|
if (len > TRACE_BUF_SIZE/sizeof(int) || len < 0) |
|
goto out_put; |
|
|
|
size = sizeof(*entry) + sizeof(u32) * len; |
|
buffer = tr->array_buffer.buffer; |
|
ring_buffer_nest_start(buffer); |
|
event = __trace_buffer_lock_reserve(buffer, TRACE_BPRINT, size, |
|
trace_ctx); |
|
if (!event) |
|
goto out; |
|
entry = ring_buffer_event_data(event); |
|
entry->ip = ip; |
|
entry->fmt = fmt; |
|
|
|
memcpy(entry->buf, tbuffer, sizeof(u32) * len); |
|
if (!call_filter_check_discard(call, entry, buffer, event)) { |
|
__buffer_unlock_commit(buffer, event); |
|
ftrace_trace_stack(tr, buffer, trace_ctx, 6, NULL); |
|
} |
|
|
|
out: |
|
ring_buffer_nest_end(buffer); |
|
out_put: |
|
put_trace_buf(); |
|
|
|
out_nobuffer: |
|
preempt_enable_notrace(); |
|
unpause_graph_tracing(); |
|
|
|
return len; |
|
} |
|
EXPORT_SYMBOL_GPL(trace_vbprintk); |
|
|
|
__printf(3, 0) |
|
static int |
|
__trace_array_vprintk(struct trace_buffer *buffer, |
|
unsigned long ip, const char *fmt, va_list args) |
|
{ |
|
struct trace_event_call *call = &event_print; |
|
struct ring_buffer_event *event; |
|
int len = 0, size; |
|
struct print_entry *entry; |
|
unsigned int trace_ctx; |
|
char *tbuffer; |
|
|
|
if (tracing_disabled || tracing_selftest_running) |
|
return 0; |
|
|
|
/* Don't pollute graph traces with trace_vprintk internals */ |
|
pause_graph_tracing(); |
|
|
|
trace_ctx = tracing_gen_ctx(); |
|
preempt_disable_notrace(); |
|
|
|
|
|
tbuffer = get_trace_buf(); |
|
if (!tbuffer) { |
|
len = 0; |
|
goto out_nobuffer; |
|
} |
|
|
|
len = vscnprintf(tbuffer, TRACE_BUF_SIZE, fmt, args); |
|
|
|
size = sizeof(*entry) + len + 1; |
|
ring_buffer_nest_start(buffer); |
|
event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, size, |
|
trace_ctx); |
|
if (!event) |
|
goto out; |
|
entry = ring_buffer_event_data(event); |
|
entry->ip = ip; |
|
|
|
memcpy(&entry->buf, tbuffer, len + 1); |
|
if (!call_filter_check_discard(call, entry, buffer, event)) { |
|
__buffer_unlock_commit(buffer, event); |
|
ftrace_trace_stack(&global_trace, buffer, trace_ctx, 6, NULL); |
|
} |
|
|
|
out: |
|
ring_buffer_nest_end(buffer); |
|
put_trace_buf(); |
|
|
|
out_nobuffer: |
|
preempt_enable_notrace(); |
|
unpause_graph_tracing(); |
|
|
|
return len; |
|
} |
|
|
|
__printf(3, 0) |
|
int trace_array_vprintk(struct trace_array *tr, |
|
unsigned long ip, const char *fmt, va_list args) |
|
{ |
|
return __trace_array_vprintk(tr->array_buffer.buffer, ip, fmt, args); |
|
} |
|
|
|
/** |
|
* trace_array_printk - Print a message to a specific instance |
|
* @tr: The instance trace_array descriptor |
|
* @ip: The instruction pointer that this is called from. |
|
* @fmt: The format to print (printf format) |
|
* |
|
* If a subsystem sets up its own instance, they have the right to |
|
* printk strings into their tracing instance buffer using this |
|
* function. Note, this function will not write into the top level |
|
* buffer (use trace_printk() for that), as writing into the top level |
|
* buffer should only have events that can be individually disabled. |
|
* trace_printk() is only used for debugging a kernel, and should not |
|
* be ever encorporated in normal use. |
|
* |
|
* trace_array_printk() can be used, as it will not add noise to the |
|
* top level tracing buffer. |
|
* |
|
* Note, trace_array_init_printk() must be called on @tr before this |
|
* can be used. |
|
*/ |
|
__printf(3, 0) |
|
int trace_array_printk(struct trace_array *tr, |
|
unsigned long ip, const char *fmt, ...) |
|
{ |
|
int ret; |
|
va_list ap; |
|
|
|
if (!tr) |
|
return -ENOENT; |
|
|
|
/* This is only allowed for created instances */ |
|
if (tr == &global_trace) |
|
return 0; |
|
|
|
if (!(tr->trace_flags & TRACE_ITER_PRINTK)) |
|
return 0; |
|
|
|
va_start(ap, fmt); |
|
ret = trace_array_vprintk(tr, ip, fmt, ap); |
|
va_end(ap); |
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(trace_array_printk); |
|
|
|
/** |
|
* trace_array_init_printk - Initialize buffers for trace_array_printk() |
|
* @tr: The trace array to initialize the buffers for |
|
* |
|
* As trace_array_printk() only writes into instances, they are OK to |
|
* have in the kernel (unlike trace_printk()). This needs to be called |
|
* before trace_array_printk() can be used on a trace_array. |
|
*/ |
|
int trace_array_init_printk(struct trace_array *tr) |
|
{ |
|
if (!tr) |
|
return -ENOENT; |
|
|
|
/* This is only allowed for created instances */ |
|
if (tr == &global_trace) |
|
return -EINVAL; |
|
|
|
return alloc_percpu_trace_buffer(); |
|
} |
|
EXPORT_SYMBOL_GPL(trace_array_init_printk); |
|
|
|
__printf(3, 4) |
|
int trace_array_printk_buf(struct trace_buffer *buffer, |
|
unsigned long ip, const char *fmt, ...) |
|
{ |
|
int ret; |
|
va_list ap; |
|
|
|
if (!(global_trace.trace_flags & TRACE_ITER_PRINTK)) |
|
return 0; |
|
|
|
va_start(ap, fmt); |
|
ret = __trace_array_vprintk(buffer, ip, fmt, ap); |
|
va_end(ap); |
|
return ret; |
|
} |
|
|
|
__printf(2, 0) |
|
int trace_vprintk(unsigned long ip, const char *fmt, va_list args) |
|
{ |
|
return trace_array_vprintk(&global_trace, ip, fmt, args); |
|
} |
|
EXPORT_SYMBOL_GPL(trace_vprintk); |
|
|
|
static void trace_iterator_increment(struct trace_iterator *iter) |
|
{ |
|
struct ring_buffer_iter *buf_iter = trace_buffer_iter(iter, iter->cpu); |
|
|
|
iter->idx++; |
|
if (buf_iter) |
|
ring_buffer_iter_advance(buf_iter); |
|
} |
|
|
|
static struct trace_entry * |
|
peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts, |
|
unsigned long *lost_events) |
|
{ |
|
struct ring_buffer_event *event; |
|
struct ring_buffer_iter *buf_iter = trace_buffer_iter(iter, cpu); |
|
|
|
if (buf_iter) { |
|
event = ring_buffer_iter_peek(buf_iter, ts); |
|
if (lost_events) |
|
*lost_events = ring_buffer_iter_dropped(buf_iter) ? |
|
(unsigned long)-1 : 0; |
|
} else { |
|
event = ring_buffer_peek(iter->array_buffer->buffer, cpu, ts, |
|
lost_events); |
|
} |
|
|
|
if (event) { |
|
iter->ent_size = ring_buffer_event_length(event); |
|
return ring_buffer_event_data(event); |
|
} |
|
iter->ent_size = 0; |
|
return NULL; |
|
} |
|
|
|
static struct trace_entry * |
|
__find_next_entry(struct trace_iterator *iter, int *ent_cpu, |
|
unsigned long *missing_events, u64 *ent_ts) |
|
{ |
|
struct trace_buffer *buffer = iter->array_buffer->buffer; |
|
struct trace_entry *ent, *next = NULL; |
|
unsigned long lost_events = 0, next_lost = 0; |
|
int cpu_file = iter->cpu_file; |
|
u64 next_ts = 0, ts; |
|
int next_cpu = -1; |
|
int next_size = 0; |
|
int cpu; |
|
|
|
/* |
|
* If we are in a per_cpu trace file, don't bother by iterating over |
|
* all cpu and peek directly. |
|
*/ |
|
if (cpu_file > RING_BUFFER_ALL_CPUS) { |
|
if (ring_buffer_empty_cpu(buffer, cpu_file)) |
|
return NULL; |
|
ent = peek_next_entry(iter, cpu_file, ent_ts, missing_events); |
|
if (ent_cpu) |
|
*ent_cpu = cpu_file; |
|
|
|
return ent; |
|
} |
|
|
|
for_each_tracing_cpu(cpu) { |
|
|
|
if (ring_buffer_empty_cpu(buffer, cpu)) |
|
continue; |
|
|
|
ent = peek_next_entry(iter, cpu, &ts, &lost_events); |
|
|
|
/* |
|
* Pick the entry with the smallest timestamp: |
|
*/ |
|
if (ent && (!next || ts < next_ts)) { |
|
next = ent; |
|
next_cpu = cpu; |
|
next_ts = ts; |
|
next_lost = lost_events; |
|
next_size = iter->ent_size; |
|
} |
|
} |
|
|
|
iter->ent_size = next_size; |
|
|
|
if (ent_cpu) |
|
*ent_cpu = next_cpu; |
|
|
|
if (ent_ts) |
|
*ent_ts = next_ts; |
|
|
|
if (missing_events) |
|
*missing_events = next_lost; |
|
|
|
return next; |
|
} |
|
|
|
#define STATIC_FMT_BUF_SIZE 128 |
|
static char static_fmt_buf[STATIC_FMT_BUF_SIZE]; |
|
|
|
static char *trace_iter_expand_format(struct trace_iterator *iter) |
|
{ |
|
char *tmp; |
|
|
|
/* |
|
* iter->tr is NULL when used with tp_printk, which makes |
|
* this get called where it is not safe to call krealloc(). |
|
*/ |
|
if (!iter->tr || iter->fmt == static_fmt_buf) |
|
return NULL; |
|
|
|
tmp = krealloc(iter->fmt, iter->fmt_size + STATIC_FMT_BUF_SIZE, |
|
GFP_KERNEL); |
|
if (tmp) { |
|
iter->fmt_size += STATIC_FMT_BUF_SIZE; |
|
iter->fmt = tmp; |
|
} |
|
|
|
return tmp; |
|
} |
|
|
|
const char *trace_event_format(struct trace_iterator *iter, const char *fmt) |
|
{ |
|
const char *p, *new_fmt; |
|
char *q; |
|
|
|
if (WARN_ON_ONCE(!fmt)) |
|
return fmt; |
|
|
|
if (!iter->tr || iter->tr->trace_flags & TRACE_ITER_HASH_PTR) |
|
return fmt; |
|
|
|
p = fmt; |
|
new_fmt = q = iter->fmt; |
|
while (*p) { |
|
if (unlikely(q - new_fmt + 3 > iter->fmt_size)) { |
|
if (!trace_iter_expand_format(iter)) |
|
return fmt; |
|
|
|
q += iter->fmt - new_fmt; |
|
new_fmt = iter->fmt; |
|
} |
|
|
|
*q++ = *p++; |
|
|
|
/* Replace %p with %px */ |
|
if (p[-1] == '%') { |
|
if (p[0] == '%') { |
|
*q++ = *p++; |
|
} else if (p[0] == 'p' && !isalnum(p[1])) { |
|
*q++ = *p++; |
|
*q++ = 'x'; |
|
} |
|
} |
|
} |
|
*q = '\0'; |
|
|
|
return new_fmt; |
|
} |
|
|
|
#define STATIC_TEMP_BUF_SIZE 128 |
|
static char static_temp_buf[STATIC_TEMP_BUF_SIZE] __aligned(4); |
|
|
|
/* Find the next real entry, without updating the iterator itself */ |
|
struct trace_entry *trace_find_next_entry(struct trace_iterator *iter, |
|
int *ent_cpu, u64 *ent_ts) |
|
{ |
|
/* __find_next_entry will reset ent_size */ |
|
int ent_size = iter->ent_size; |
|
struct trace_entry *entry; |
|
|
|
/* |
|
* If called from ftrace_dump(), then the iter->temp buffer |
|
* will be the static_temp_buf and not created from kmalloc. |
|
* If the entry size is greater than the buffer, we can |
|
* not save it. Just return NULL in that case. This is only |
|
* used to add markers when two consecutive events' time |
|
* stamps have a large delta. See trace_print_lat_context() |
|
*/ |
|
if (iter->temp == static_temp_buf && |
|
STATIC_TEMP_BUF_SIZE < ent_size) |
|
return NULL; |
|
|
|
/* |
|
* The __find_next_entry() may call peek_next_entry(), which may |
|
* call ring_buffer_peek() that may make the contents of iter->ent |
|
* undefined. Need to copy iter->ent now. |
|
*/ |
|
if (iter->ent && iter->ent != iter->temp) { |
|
if ((!iter->temp || iter->temp_size < iter->ent_size) && |
|
!WARN_ON_ONCE(iter->temp == static_temp_buf)) { |
|
void *temp; |
|
temp = kmalloc(iter->ent_size, GFP_KERNEL); |
|
if (!temp) |
|
return NULL; |
|
kfree(iter->temp); |
|
iter->temp = temp; |
|
iter->temp_size = iter->ent_size; |
|
} |
|
memcpy(iter->temp, iter->ent, iter->ent_size); |
|
iter->ent = iter->temp; |
|
} |
|
entry = __find_next_entry(iter, ent_cpu, NULL, ent_ts); |
|
/* Put back the original ent_size */ |
|
iter->ent_size = ent_size; |
|
|
|
return entry; |
|
} |
|
|
|
/* Find the next real entry, and increment the iterator to the next entry */ |
|
void *trace_find_next_entry_inc(struct trace_iterator *iter) |
|
{ |
|
iter->ent = __find_next_entry(iter, &iter->cpu, |
|
&iter->lost_events, &iter->ts); |
|
|
|
if (iter->ent) |
|
trace_iterator_increment(iter); |
|
|
|
return iter->ent ? iter : NULL; |
|
} |
|
|
|
static void trace_consume(struct trace_iterator *iter) |
|
{ |
|
ring_buffer_consume(iter->array_buffer->buffer, iter->cpu, &iter->ts, |
|
&iter->lost_events); |
|
} |
|
|
|
static void *s_next(struct seq_file *m, void *v, loff_t *pos) |
|
{ |
|
struct trace_iterator *iter = m->private; |
|
int i = (int)*pos; |
|
void *ent; |
|
|
|
WARN_ON_ONCE(iter->leftover); |
|
|
|
(*pos)++; |
|
|
|
/* can't go backwards */ |
|
if (iter->idx > i) |
|
return NULL; |
|
|
|
if (iter->idx < 0) |
|
ent = trace_find_next_entry_inc(iter); |
|
else |
|
ent = iter; |
|
|
|
while (ent && iter->idx < i) |
|
ent = trace_find_next_entry_inc(iter); |
|
|
|
iter->pos = *pos; |
|
|
|
return ent; |
|
} |
|
|
|
void tracing_iter_reset(struct trace_iterator *iter, int cpu) |
|
{ |
|
struct ring_buffer_iter *buf_iter; |
|
unsigned long entries = 0; |
|
u64 ts; |
|
|
|
per_cpu_ptr(iter->array_buffer->data, cpu)->skipped_entries = 0; |
|
|
|
buf_iter = trace_buffer_iter(iter, cpu); |
|
if (!buf_iter) |
|
return; |
|
|
|
ring_buffer_iter_reset(buf_iter); |
|
|
|
/* |
|
* We could have the case with the max latency tracers |
|
* that a reset never took place on a cpu. This is evident |
|
* by the timestamp being before the start of the buffer. |
|
*/ |
|
while (ring_buffer_iter_peek(buf_iter, &ts)) { |
|
if (ts >= iter->array_buffer->time_start) |
|
break; |
|
entries++; |
|
ring_buffer_iter_advance(buf_iter); |
|
} |
|
|
|
per_cpu_ptr(iter->array_buffer->data, cpu)->skipped_entries = entries; |
|
} |
|
|
|
/* |
|
* The current tracer is copied to avoid a global locking |
|
* all around. |
|
*/ |
|
static void *s_start(struct seq_file *m, loff_t *pos) |
|
{ |
|
struct trace_iterator *iter = m->private; |
|
struct trace_array *tr = iter->tr; |
|
int cpu_file = iter->cpu_file; |
|
void *p = NULL; |
|
loff_t l = 0; |
|
int cpu; |
|
|
|
/* |
|
* copy the tracer to avoid using a global lock all around. |
|
* iter->trace is a copy of current_trace, the pointer to the |
|
* name may be used instead of a strcmp(), as iter->trace->name |
|
* will point to the same string as current_trace->name. |
|
*/ |
|
mutex_lock(&trace_types_lock); |
|
if (unlikely(tr->current_trace && iter->trace->name != tr->current_trace->name)) |
|
*iter->trace = *tr->current_trace; |
|
mutex_unlock(&trace_types_lock); |
|
|
|
#ifdef CONFIG_TRACER_MAX_TRACE |
|
if (iter->snapshot && iter->trace->use_max_tr) |
|
return ERR_PTR(-EBUSY); |
|
#endif |
|
|
|
if (!iter->snapshot) |
|
atomic_inc(&trace_record_taskinfo_disabled); |
|
|
|
if (*pos != iter->pos) { |
|
iter->ent = NULL; |
|
iter->cpu = 0; |
|
iter->idx = -1; |
|
|
|
if (cpu_file == RING_BUFFER_ALL_CPUS) { |
|
for_each_tracing_cpu(cpu) |
|
tracing_iter_reset(iter, cpu); |
|
} else |
|
tracing_iter_reset(iter, cpu_file); |
|
|
|
iter->leftover = 0; |
|
for (p = iter; p && l < *pos; p = s_next(m, p, &l)) |
|
; |
|
|
|
} else { |
|
/* |
|
* If we overflowed the seq_file before, then we want |
|
* to just reuse the trace_seq buffer again. |
|
*/ |
|
if (iter->leftover) |
|
p = iter; |
|
else { |
|
l = *pos - 1; |
|
p = s_next(m, p, &l); |
|
} |
|
} |
|
|
|
trace_event_read_lock(); |
|
trace_access_lock(cpu_file); |
|
return p; |
|
} |
|
|
|
static void s_stop(struct seq_file *m, void *p) |
|
{ |
|
struct trace_iterator *iter = m->private; |
|
|
|
#ifdef CONFIG_TRACER_MAX_TRACE |
|
if (iter->snapshot && iter->trace->use_max_tr) |
|
return; |
|
#endif |
|
|
|
if (!iter->snapshot) |
|
atomic_dec(&trace_record_taskinfo_disabled); |
|
|
|
trace_access_unlock(iter->cpu_file); |
|
trace_event_read_unlock(); |
|
} |
|
|
|
static void |
|
get_total_entries_cpu(struct array_buffer *buf, unsigned long *total, |
|
unsigned long *entries, int cpu) |
|
{ |
|
unsigned long count; |
|
|
|
count = ring_buffer_entries_cpu(buf->buffer, cpu); |
|
/* |
|
* If this buffer has skipped entries, then we hold all |
|
* entries for the trace and we need to ignore the |
|
* ones before the time stamp. |
|
*/ |
|
if (per_cpu_ptr(buf->data, cpu)->skipped_entries) { |
|
count -= per_cpu_ptr(buf->data, cpu)->skipped_entries; |
|
/* total is the same as the entries */ |
|
*total = count; |
|
} else |
|
*total = count + |
|
ring_buffer_overrun_cpu(buf->buffer, cpu); |
|
*entries = count; |
|
} |
|
|
|
static void |
|
get_total_entries(struct array_buffer *buf, |
|
unsigned long *total, unsigned long *entries) |
|
{ |
|
unsigned long t, e; |
|
int cpu; |
|
|
|
*total = 0; |
|
*entries = 0; |
|
|
|
for_each_tracing_cpu(cpu) { |
|
get_total_entries_cpu(buf, &t, &e, cpu); |
|
*total += t; |
|
*entries += e; |
|
} |
|
} |
|
|
|
unsigned long trace_total_entries_cpu(struct trace_array *tr, int cpu) |
|
{ |
|
unsigned long total, entries; |
|
|
|
if (!tr) |
|
tr = &global_trace; |
|
|
|
get_total_entries_cpu(&tr->array_buffer, &total, &entries, cpu); |
|
|
|
return entries; |
|
} |
|
|
|
unsigned long trace_total_entries(struct trace_array *tr) |
|
{ |
|
unsigned long total, entries; |
|
|
|
if (!tr) |
|
tr = &global_trace; |
|
|
|
get_total_entries(&tr->array_buffer, &total, &entries); |
|
|
|
return entries; |
|
} |
|
|
|
static void print_lat_help_header(struct seq_file *m) |
|
{ |
|
seq_puts(m, "# _------=> CPU# \n" |
|
"# / _-----=> irqs-off \n" |
|
"# | / _----=> need-resched \n" |
|
"# || / _---=> hardirq/softirq \n" |
|
"# ||| / _--=> preempt-depth \n" |
|
"# |||| / delay \n" |
|
"# cmd pid ||||| time | caller \n" |
|
"# \\ / ||||| \\ | / \n"); |
|
} |
|
|
|
static void print_event_info(struct array_buffer *buf, struct seq_file *m) |
|
{ |
|
unsigned long total; |
|
unsigned long entries; |
|
|
|
get_total_entries(buf, &total, &entries); |
|
seq_printf(m, "# entries-in-buffer/entries-written: %lu/%lu #P:%d\n", |
|
entries, total, num_online_cpus()); |
|
seq_puts(m, "#\n"); |
|
} |
|
|
|
static void print_func_help_header(struct array_buffer *buf, struct seq_file *m, |
|
unsigned int flags) |
|
{ |
|
bool tgid = flags & TRACE_ITER_RECORD_TGID; |
|
|
|
print_event_info(buf, m); |
|
|
|
seq_printf(m, "# TASK-PID %s CPU# TIMESTAMP FUNCTION\n", tgid ? " TGID " : ""); |
|
seq_printf(m, "# | | %s | | |\n", tgid ? " | " : ""); |
|
} |
|
|
|
static void print_func_help_header_irq(struct array_buffer *buf, struct seq_file *m, |
|
unsigned int flags) |
|
{ |
|
bool tgid = flags & TRACE_ITER_RECORD_TGID; |
|
const char *space = " "; |
|
int prec = tgid ? 12 : 2; |
|
|
|
print_event_info(buf, m); |
|
|
|
seq_printf(m, "# %.*s _-----=> irqs-off\n", prec, space); |
|
seq_printf(m, "# %.*s / _----=> need-resched\n", prec, space); |
|
seq_printf(m, "# %.*s| / _---=> hardirq/softirq\n", prec, space); |
|
seq_printf(m, "# %.*s|| / _--=> preempt-depth\n", prec, space); |
|
seq_printf(m, "# %.*s||| / delay\n", prec, space); |
|
seq_printf(m, "# TASK-PID %.*s CPU# |||| TIMESTAMP FUNCTION\n", prec, " TGID "); |
|
seq_printf(m, "# | | %.*s | |||| | |\n", prec, " | "); |
|
} |
|
|
|
void |
|
print_trace_header(struct seq_file *m, struct trace_iterator *iter) |
|
{ |
|
unsigned long sym_flags = (global_trace.trace_flags & TRACE_ITER_SYM_MASK); |
|
struct array_buffer *buf = iter->array_buffer; |
|
struct trace_array_cpu *data = per_cpu_ptr(buf->data, buf->cpu); |
|
struct tracer *type = iter->trace; |
|
unsigned long entries; |
|
unsigned long total; |
|
const char *name = "preemption"; |
|
|
|
name = type->name; |
|
|
|
get_total_entries(buf, &total, &entries); |
|
|
|
seq_printf(m, "# %s latency trace v1.1.5 on %s\n", |
|
name, UTS_RELEASE); |
|
seq_puts(m, "# -----------------------------------" |
|
"---------------------------------\n"); |
|
seq_printf(m, "# latency: %lu us, #%lu/%lu, CPU#%d |" |
|
" (M:%s VP:%d, KP:%d, SP:%d HP:%d", |
|
nsecs_to_usecs(data->saved_latency), |
|
entries, |
|
total, |
|
buf->cpu, |
|
#if defined(CONFIG_PREEMPT_NONE) |
|
"server", |
|
#elif defined(CONFIG_PREEMPT_VOLUNTARY) |
|
"desktop", |
|
#elif defined(CONFIG_PREEMPT) |
|
"preempt", |
|
#elif defined(CONFIG_PREEMPT_RT) |
|
"preempt_rt", |
|
#else |
|
"unknown", |
|
#endif |
|
/* These are reserved for later use */ |
|
0, 0, 0, 0); |
|
#ifdef CONFIG_SMP |
|
seq_printf(m, " #P:%d)\n", num_online_cpus()); |
|
#else |
|
seq_puts(m, ")\n"); |
|
#endif |
|
seq_puts(m, "# -----------------\n"); |
|
seq_printf(m, "# | task: %.16s-%d " |
|
"(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n", |
|
data->comm, data->pid, |
|
from_kuid_munged(seq_user_ns(m), data->uid), data->nice, |
|
data->policy, data->rt_priority); |
|
seq_puts(m, "# -----------------\n"); |
|
|
|
if (data->critical_start) { |
|
seq_puts(m, "# => started at: "); |
|
seq_print_ip_sym(&iter->seq, data->critical_start, sym_flags); |
|
trace_print_seq(m, &iter->seq); |
|
seq_puts(m, "\n# => ended at: "); |
|
seq_print_ip_sym(&iter->seq, data->critical_end, sym_flags); |
|
trace_print_seq(m, &iter->seq); |
|
seq_puts(m, "\n#\n"); |
|
} |
|
|
|
seq_puts(m, "#\n"); |
|
} |
|
|
|
static void test_cpu_buff_start(struct trace_iterator *iter) |
|
{ |
|
struct trace_seq *s = &iter->seq; |
|
struct trace_array *tr = iter->tr; |
|
|
|
if (!(tr->trace_flags & TRACE_ITER_ANNOTATE)) |
|
return; |
|
|
|
if (!(iter->iter_flags & TRACE_FILE_ANNOTATE)) |
|
return; |
|
|
|
if (cpumask_available(iter->started) && |
|
cpumask_test_cpu(iter->cpu, iter->started)) |
|
return; |
|
|
|
if (per_cpu_ptr(iter->array_buffer->data, iter->cpu)->skipped_entries) |
|
return; |
|
|
|
if (cpumask_available(iter->started)) |
|
cpumask_set_cpu(iter->cpu, iter->started); |
|
|
|
/* Don't print started cpu buffer for the first entry of the trace */ |
|
if (iter->idx > 1) |
|
trace_seq_printf(s, "##### CPU %u buffer started ####\n", |
|
iter->cpu); |
|
} |
|
|
|
static enum print_line_t print_trace_fmt(struct trace_iterator *iter) |
|
{ |
|
struct trace_array *tr = iter->tr; |
|
struct trace_seq *s = &iter->seq; |
|
unsigned long sym_flags = (tr->trace_flags & TRACE_ITER_SYM_MASK); |
|
struct trace_entry *entry; |
|
struct trace_event *event; |
|
|
|
entry = iter->ent; |
|
|
|
test_cpu_buff_start(iter); |
|
|
|
event = ftrace_find_event(entry->type); |
|
|
|
if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) { |
|
if (iter->iter_flags & TRACE_FILE_LAT_FMT) |
|
trace_print_lat_context(iter); |
|
else |
|
trace_print_context(iter); |
|
} |
|
|
|
if (trace_seq_has_overflowed(s)) |
|
return TRACE_TYPE_PARTIAL_LINE; |
|
|
|
if (event) |
|
return event->funcs->trace(iter, sym_flags, event); |
|
|
|
trace_seq_printf(s, "Unknown type %d\n", entry->type); |
|
|
|
return trace_handle_return(s); |
|
} |
|
|
|
static enum print_line_t print_raw_fmt(struct trace_iterator *iter) |
|
{ |
|
struct trace_array *tr = iter->tr; |
|
struct trace_seq *s = &iter->seq; |
|
struct trace_entry *entry; |
|
struct trace_event *event; |
|
|
|
entry = iter->ent; |
|
|
|
if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) |
|
trace_seq_printf(s, "%d %d %llu ", |
|
entry->pid, iter->cpu, iter->ts); |
|
|
|
if (trace_seq_has_overflowed(s)) |
|
return TRACE_TYPE_PARTIAL_LINE; |
|
|
|
event = ftrace_find_event(entry->type); |
|
if (event) |
|
return event->funcs->raw(iter, 0, event); |
|
|
|
trace_seq_printf(s, "%d ?\n", entry->type); |
|
|
|
return trace_handle_return(s); |
|
} |
|
|
|
static enum print_line_t print_hex_fmt(struct trace_iterator *iter) |
|
{ |
|
struct trace_array *tr = iter->tr; |
|
struct trace_seq *s = &iter->seq; |
|
unsigned char newline = '\n'; |
|
struct trace_entry *entry; |
|
struct trace_event *event; |
|
|
|
entry = iter->ent; |
|
|
|
if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) { |
|
SEQ_PUT_HEX_FIELD(s, entry->pid); |
|
SEQ_PUT_HEX_FIELD(s, iter->cpu); |
|
SEQ_PUT_HEX_FIELD(s, iter->ts); |
|
if (trace_seq_has_overflowed(s)) |
|
return TRACE_TYPE_PARTIAL_LINE; |
|
} |
|
|
|
event = ftrace_find_event(entry->type); |
|
if (event) { |
|
enum print_line_t ret = event->funcs->hex(iter, 0, event); |
|
if (ret != TRACE_TYPE_HANDLED) |
|
return ret; |
|
} |
|
|
|
SEQ_PUT_FIELD(s, newline); |
|
|
|
return trace_handle_return(s); |
|
} |
|
|
|
static enum print_line_t print_bin_fmt(struct trace_iterator *iter) |
|
{ |
|
struct trace_array *tr = iter->tr; |
|
struct trace_seq *s = &iter->seq; |
|
struct trace_entry *entry; |
|
struct trace_event *event; |
|
|
|
entry = iter->ent; |
|
|
|
if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) { |
|
SEQ_PUT_FIELD(s, entry->pid); |
|
SEQ_PUT_FIELD(s, iter->cpu); |
|
SEQ_PUT_FIELD(s, iter->ts); |
|
if (trace_seq_has_overflowed(s)) |
|
return TRACE_TYPE_PARTIAL_LINE; |
|
} |
|
|
|
event = ftrace_find_event(entry->type); |
|
return event ? event->funcs->binary(iter, 0, event) : |
|
TRACE_TYPE_HANDLED; |
|
} |
|
|
|
int trace_empty(struct trace_iterator *iter) |
|
{ |
|
struct ring_buffer_iter *buf_iter; |
|
int cpu; |
|
|
|
/* If we are looking at one CPU buffer, only check that one */ |
|
if (iter->cpu_file != RING_BUFFER_ALL_CPUS) { |
|
cpu = iter->cpu_file; |
|
buf_iter = trace_buffer_iter(iter, cpu); |
|
if (buf_iter) { |
|
if (!ring_buffer_iter_empty(buf_iter)) |
|
return 0; |
|
} else { |
|
if (!ring_buffer_empty_cpu(iter->array_buffer->buffer, cpu)) |
|
return 0; |
|
} |
|
return 1; |
|
} |
|
|
|
for_each_tracing_cpu(cpu) { |
|
buf_iter = trace_buffer_iter(iter, cpu); |
|
if (buf_iter) { |
|
if (!ring_buffer_iter_empty(buf_iter)) |
|
return 0; |
|
} else { |
|
if (!ring_buffer_empty_cpu(iter->array_buffer->buffer, cpu)) |
|
return 0; |
|
} |
|
} |
|
|
|
return 1; |
|
} |
|
|
|
/* Called with trace_event_read_lock() held. */ |
|
enum print_line_t print_trace_line(struct trace_iterator *iter) |
|
{ |
|
struct trace_array *tr = iter->tr; |
|
unsigned long trace_flags = tr->trace_flags; |
|
enum print_line_t ret; |
|
|
|
if (iter->lost_events) { |
|
if (iter->lost_events == (unsigned long)-1) |
|
trace_seq_printf(&iter->seq, "CPU:%d [LOST EVENTS]\n", |
|
iter->cpu); |
|
else |
|
trace_seq_printf(&iter->seq, "CPU:%d [LOST %lu EVENTS]\n", |
|
iter->cpu, iter->lost_events); |
|
if (trace_seq_has_overflowed(&iter->seq)) |
|
return TRACE_TYPE_PARTIAL_LINE; |
|
} |
|
|
|
if (iter->trace && iter->trace->print_line) { |
|
ret = iter->trace->print_line(iter); |
|
if (ret != TRACE_TYPE_UNHANDLED) |
|
return ret; |
|
} |
|
|
|
if (iter->ent->type == TRACE_BPUTS && |
|
trace_flags & TRACE_ITER_PRINTK && |
|
trace_flags & TRACE_ITER_PRINTK_MSGONLY) |
|
return trace_print_bputs_msg_only(iter); |
|
|
|
if (iter->ent->type == TRACE_BPRINT && |
|
trace_flags & TRACE_ITER_PRINTK && |
|
trace_flags & TRACE_ITER_PRINTK_MSGONLY) |
|
return trace_print_bprintk_msg_only(iter); |
|
|
|
if (iter->ent->type == TRACE_PRINT && |
|
trace_flags & TRACE_ITER_PRINTK && |
|
trace_flags & TRACE_ITER_PRINTK_MSGONLY) |
|
return trace_print_printk_msg_only(iter); |
|
|
|
if (trace_flags & TRACE_ITER_BIN) |
|
return print_bin_fmt(iter); |
|
|
|
if (trace_flags & TRACE_ITER_HEX) |
|
return print_hex_fmt(iter); |
|
|
|
if (trace_flags & TRACE_ITER_RAW) |
|
return print_raw_fmt(iter); |
|
|
|
return print_trace_fmt(iter); |
|
} |
|
|
|
void trace_latency_header(struct seq_file *m) |
|
{ |
|
struct trace_iterator *iter = m->private; |
|
struct trace_array *tr = iter->tr; |
|
|
|
/* print nothing if the buffers are empty */ |
|
if (trace_empty(iter)) |
|
return; |
|
|
|
if (iter->iter_flags & TRACE_FILE_LAT_FMT) |
|
print_trace_header(m, iter); |
|
|
|
if (!(tr->trace_flags & TRACE_ITER_VERBOSE)) |
|
print_lat_help_header(m); |
|
} |
|
|
|
void trace_default_header(struct seq_file *m) |
|
{ |
|
struct trace_iterator *iter = m->private; |
|
struct trace_array *tr = iter->tr; |
|
unsigned long trace_flags = tr->trace_flags; |
|
|
|
if (!(trace_flags & TRACE_ITER_CONTEXT_INFO)) |
|
return; |
|
|
|
if (iter->iter_flags & TRACE_FILE_LAT_FMT) { |
|
/* print nothing if the buffers are empty */ |
|
if (trace_empty(iter)) |
|
return; |
|
print_trace_header(m, iter); |
|
if (!(trace_flags & TRACE_ITER_VERBOSE)) |
|
print_lat_help_header(m); |
|
} else { |
|
if (!(trace_flags & TRACE_ITER_VERBOSE)) { |
|
if (trace_flags & TRACE_ITER_IRQ_INFO) |
|
print_func_help_header_irq(iter->array_buffer, |
|
m, trace_flags); |
|
else |
|
print_func_help_header(iter->array_buffer, m, |
|
trace_flags); |
|
} |
|
} |
|
} |
|
|
|
static void test_ftrace_alive(struct seq_file *m) |
|
{ |
|
if (!ftrace_is_dead()) |
|
return; |
|
seq_puts(m, "# WARNING: FUNCTION TRACING IS CORRUPTED\n" |
|
"# MAY BE MISSING FUNCTION EVENTS\n"); |
|
} |
|
|
|
#ifdef CONFIG_TRACER_MAX_TRACE |
|
static void show_snapshot_main_help(struct seq_file *m) |
|
{ |
|
seq_puts(m, "# echo 0 > snapshot : Clears and frees snapshot buffer\n" |
|
"# echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.\n" |
|
"# Takes a snapshot of the main buffer.\n" |
|
"# echo 2 > snapshot : Clears snapshot buffer (but does not allocate or free)\n" |
|
"# (Doesn't have to be '2' works with any number that\n" |
|
"# is not a '0' or '1')\n"); |
|
} |
|
|
|
static void show_snapshot_percpu_help(struct seq_file *m) |
|
{ |
|
seq_puts(m, "# echo 0 > snapshot : Invalid for per_cpu snapshot file.\n"); |
|
#ifdef CONFIG_RING_BUFFER_ALLOW_SWAP |
|
seq_puts(m, "# echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.\n" |
|
"# Takes a snapshot of the main buffer for this cpu.\n"); |
|
#else |
|
seq_puts(m, "# echo 1 > snapshot : Not supported with this kernel.\n" |
|
"# Must use main snapshot file to allocate.\n"); |
|
#endif |
|
seq_puts(m, "# echo 2 > snapshot : Clears this cpu's snapshot buffer (but does not allocate)\n" |
|
"# (Doesn't have to be '2' works with any number that\n" |
|
"# is not a '0' or '1')\n"); |
|
} |
|
|
|
static void print_snapshot_help(struct seq_file *m, struct trace_iterator *iter) |
|
{ |
|
if (iter->tr->allocated_snapshot) |
|
seq_puts(m, "#\n# * Snapshot is allocated *\n#\n"); |
|
else |
|
seq_puts(m, "#\n# * Snapshot is freed *\n#\n"); |
|
|
|
seq_puts(m, "# Snapshot commands:\n"); |
|
if (iter->cpu_file == RING_BUFFER_ALL_CPUS) |
|
show_snapshot_main_help(m); |
|
else |
|
show_snapshot_percpu_help(m); |
|
} |
|
#else |
|
/* Should never be called */ |
|
static inline void print_snapshot_help(struct seq_file *m, struct trace_iterator *iter) { } |
|
#endif |
|
|
|
static int s_show(struct seq_file *m, void *v) |
|
{ |
|
struct trace_iterator *iter = v; |
|
int ret; |
|
|
|
if (iter->ent == NULL) { |
|
if (iter->tr) { |
|
seq_printf(m, "# tracer: %s\n", iter->trace->name); |
|
seq_puts(m, "#\n"); |
|
test_ftrace_alive(m); |
|
} |
|
if (iter->snapshot && trace_empty(iter)) |
|
print_snapshot_help(m, iter); |
|
else if (iter->trace && iter->trace->print_header) |
|
iter->trace->print_header(m); |
|
else |
|
trace_default_header(m); |
|
|
|
} else if (iter->leftover) { |
|
/* |
|
* If we filled the seq_file buffer earlier, we |
|
* want to just show it now. |
|
*/ |
|
ret = trace_print_seq(m, &iter->seq); |
|
|
|
/* ret should this time be zero, but you never know */ |
|
iter->leftover = ret; |
|
|
|
} else { |
|
print_trace_line(iter); |
|
ret = trace_print_seq(m, &iter->seq); |
|
/* |
|
* If we overflow the seq_file buffer, then it will |
|
* ask us for this data again at start up. |
|
* Use that instead. |
|
* ret is 0 if seq_file write succeeded. |
|
* -1 otherwise. |
|
*/ |
|
iter->leftover = ret; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* Should be used after trace_array_get(), trace_types_lock |
|
* ensures that i_cdev was already initialized. |
|
*/ |
|
static inline int tracing_get_cpu(struct inode *inode) |
|
{ |
|
if (inode->i_cdev) /* See trace_create_cpu_file() */ |
|
return (long)inode->i_cdev - 1; |
|
return RING_BUFFER_ALL_CPUS; |
|
} |
|
|
|
static const struct seq_operations tracer_seq_ops = { |
|
.start = s_start, |
|
.next = s_next, |
|
.stop = s_stop, |
|
.show = s_show, |
|
}; |
|
|
|
static struct trace_iterator * |
|
__tracing_open(struct inode *inode, struct file *file, bool snapshot) |
|
{ |
|
struct trace_array *tr = inode->i_private; |
|
struct trace_iterator *iter; |
|
int cpu; |
|
|
|
if (tracing_disabled) |
|
return ERR_PTR(-ENODEV); |
|
|
|
iter = __seq_open_private(file, &tracer_seq_ops, sizeof(*iter)); |
|
if (!iter) |
|
return ERR_PTR(-ENOMEM); |
|
|
|
iter->buffer_iter = kcalloc(nr_cpu_ids, sizeof(*iter->buffer_iter), |
|
GFP_KERNEL); |
|
if (!iter->buffer_iter) |
|
goto release; |
|
|
|
/* |
|
* trace_find_next_entry() may need to save off iter->ent. |
|
* It will place it into the iter->temp buffer. As most |
|
* events are less than 128, allocate a buffer of that size. |
|
* If one is greater, then trace_find_next_entry() will |
|
* allocate a new buffer to adjust for the bigger iter->ent. |
|
* It's not critical if it fails to get allocated here. |
|
*/ |
|
iter->temp = kmalloc(128, GFP_KERNEL); |
|
if (iter->temp) |
|
iter->temp_size = 128; |
|
|
|
/* |
|
* trace_event_printf() may need to modify given format |
|
* string to replace %p with %px so that it shows real address |
|
* instead of hash value. However, that is only for the event |
|
* tracing, other tracer may not need. Defer the allocation |
|
* until it is needed. |
|
*/ |
|
iter->fmt = NULL; |
|
iter->fmt_size = 0; |
|
|
|
/* |
|
* We make a copy of the current tracer to avoid concurrent |
|
* changes on it while we are reading. |
|
*/ |
|
mutex_lock(&trace_types_lock); |
|
iter->trace = kzalloc(sizeof(*iter->trace), GFP_KERNEL); |
|
if (!iter->trace) |
|
goto fail; |
|
|
|
*iter->trace = *tr->current_trace; |
|
|
|
if (!zalloc_cpumask_var(&iter->started, GFP_KERNEL)) |
|
goto fail; |
|
|
|
iter->tr = tr; |
|
|
|
#ifdef CONFIG_TRACER_MAX_TRACE |
|
/* Currently only the top directory has a snapshot */ |
|
if (tr->current_trace->print_max || snapshot) |
|
iter->array_buffer = &tr->max_buffer; |
|
else |
|
#endif |
|
iter->array_buffer = &tr->array_buffer; |
|
iter->snapshot = snapshot; |
|
iter->pos = -1; |
|
iter->cpu_file = tracing_get_cpu(inode); |
|
mutex_init(&iter->mutex); |
|
|
|
/* Notify the tracer early; before we stop tracing. */ |
|
if (iter->trace->open) |
|
iter->trace->open(iter); |
|
|
|
/* Annotate start of buffers if we had overruns */ |
|
if (ring_buffer_overruns(iter->array_buffer->buffer)) |
|
iter->iter_flags |= TRACE_FILE_ANNOTATE; |
|
|
|
/* Output in nanoseconds only if we are using a clock in nanoseconds. */ |
|
if (trace_clocks[tr->clock_id].in_ns) |
|
iter->iter_flags |= TRACE_FILE_TIME_IN_NS; |
|
|
|
/* |
|
* If pause-on-trace is enabled, then stop the trace while |
|
* dumping, unless this is the "snapshot" file |
|
*/ |
|
if (!iter->snapshot && (tr->trace_flags & TRACE_ITER_PAUSE_ON_TRACE)) |
|
tracing_stop_tr(tr); |
|
|
|
if (iter->cpu_file == RING_BUFFER_ALL_CPUS) { |
|
for_each_tracing_cpu(cpu) { |
|
iter->buffer_iter[cpu] = |
|
ring_buffer_read_prepare(iter->array_buffer->buffer, |
|
cpu, GFP_KERNEL); |
|
} |
|
ring_buffer_read_prepare_sync(); |
|
for_each_tracing_cpu(cpu) { |
|
ring_buffer_read_start(iter->buffer_iter[cpu]); |
|
tracing_iter_reset(iter, cpu); |
|
} |
|
} else { |
|
cpu = iter->cpu_file; |
|
iter->buffer_iter[cpu] = |
|
ring_buffer_read_prepare(iter->array_buffer->buffer, |
|
cpu, GFP_KERNEL); |
|
ring_buffer_read_prepare_sync(); |
|
ring_buffer_read_start(iter->buffer_iter[cpu]); |
|
tracing_iter_reset(iter, cpu); |
|
} |
|
|
|
mutex_unlock(&trace_types_lock); |
|
|
|
return iter; |
|
|
|
fail: |
|
mutex_unlock(&trace_types_lock); |
|
kfree(iter->trace); |
|
kfree(iter->temp); |
|
kfree(iter->buffer_iter); |
|
release: |
|
seq_release_private(inode, file); |
|
return ERR_PTR(-ENOMEM); |
|
} |
|
|
|
int tracing_open_generic(struct inode *inode, struct file *filp) |
|
{ |
|
int ret; |
|
|
|
ret = tracing_check_open_get_tr(NULL); |
|
if (ret) |
|
return ret; |
|
|
|
filp->private_data = inode->i_private; |
|
return 0; |
|
} |
|
|
|
bool tracing_is_disabled(void) |
|
{ |
|
return (tracing_disabled) ? true: false; |
|
} |
|
|
|
/* |
|
* Open and update trace_array ref count. |
|
* Must have the current trace_array passed to it. |
|
*/ |
|
int tracing_open_generic_tr(struct inode *inode, struct file *filp) |
|
{ |
|
struct trace_array *tr = inode->i_private; |
|
int ret; |
|
|
|
ret = tracing_check_open_get_tr(tr); |
|
if (ret) |
|
return ret; |
|
|
|
filp->private_data = inode->i_private; |
|
|
|
return 0; |
|
} |
|
|
|
static int tracing_release(struct inode *inode, struct file *file) |
|
{ |
|
struct trace_array *tr = inode->i_private; |
|
struct seq_file *m = file->private_data; |
|
struct trace_iterator *iter; |
|
int cpu; |
|
|
|
if (!(file->f_mode & FMODE_READ)) { |
|
trace_array_put(tr); |
|
return 0; |
|
} |
|
|
|
/* Writes do not use seq_file */ |
|
iter = m->private; |
|
mutex_lock(&trace_types_lock); |
|
|
|
for_each_tracing_cpu(cpu) { |
|
if (iter->buffer_iter[cpu]) |
|
ring_buffer_read_finish(iter->buffer_iter[cpu]); |
|
} |
|
|
|
if (iter->trace && iter->trace->close) |
|
iter->trace->close(iter); |
|
|
|
if (!iter->snapshot && tr->stop_count) |
|
/* reenable tracing if it was previously enabled */ |
|
tracing_start_tr(tr); |
|
|
|
__trace_array_put(tr); |
|
|
|
mutex_unlock(&trace_types_lock); |
|
|
|
mutex_destroy(&iter->mutex); |
|
free_cpumask_var(iter->started); |
|
kfree(iter->fmt); |
|
kfree(iter->temp); |
|
kfree(iter->trace); |
|
kfree(iter->buffer_iter); |
|
seq_release_private(inode, file); |
|
|
|
return 0; |
|
} |
|
|
|
static int tracing_release_generic_tr(struct inode *inode, struct file *file) |
|
{ |
|
struct trace_array *tr = inode->i_private; |
|
|
|
trace_array_put(tr); |
|
return 0; |
|
} |
|
|
|
static int tracing_single_release_tr(struct inode *inode, struct file *file) |
|
{ |
|
struct trace_array *tr = inode->i_private; |
|
|
|
trace_array_put(tr); |
|
|
|
return single_release(inode, file); |
|
} |
|
|
|
static int tracing_open(struct inode *inode, struct file *file) |
|
{ |
|
struct trace_array *tr = inode->i_private; |
|
struct trace_iterator *iter; |
|
int ret; |
|
|
|
ret = tracing_check_open_get_tr(tr); |
|
if (ret) |
|
return ret; |
|
|
|
/* If this file was open for write, then erase contents */ |
|
if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { |
|
int cpu = tracing_get_cpu(inode); |
|
struct array_buffer *trace_buf = &tr->array_buffer; |
|
|
|
#ifdef CONFIG_TRACER_MAX_TRACE |
|
if (tr->current_trace->print_max) |
|
trace_buf = &tr->max_buffer; |
|
#endif |
|
|
|
if (cpu == RING_BUFFER_ALL_CPUS) |
|
tracing_reset_online_cpus(trace_buf); |
|
else |
|
tracing_reset_cpu(trace_buf, cpu); |
|
} |
|
|
|
if (file->f_mode & FMODE_READ) { |
|
iter = __tracing_open(inode, file, false); |
|
if (IS_ERR(iter)) |
|
ret = PTR_ERR(iter); |
|
else if (tr->trace_flags & TRACE_ITER_LATENCY_FMT) |
|
iter->iter_flags |= TRACE_FILE_LAT_FMT; |
|
} |
|
|
|
if (ret < 0) |
|
trace_array_put(tr); |
|
|
|
return ret; |
|
} |
|
|
|
/* |
|
* Some tracers are not suitable for instance buffers. |
|
* A tracer is always available for the global array (toplevel) |
|
* or if it explicitly states that it is. |
|
*/ |
|
static bool |
|
trace_ok_for_array(struct tracer *t, struct trace_array *tr) |
|
{ |
|
return (tr->flags & TRACE_ARRAY_FL_GLOBAL) || t->allow_instances; |
|
} |
|
|
|
/* Find the next tracer that this trace array may use */ |
|
static struct tracer * |
|
get_tracer_for_array(struct trace_array *tr, struct tracer *t) |
|
{ |
|
while (t && !trace_ok_for_array(t, tr)) |
|
t = t->next; |
|
|
|
return t; |
|
} |
|
|
|
static void * |
|
t_next(struct seq_file *m, void *v, loff_t *pos) |
|
{ |
|
struct trace_array *tr = m->private; |
|
struct tracer *t = v; |
|
|
|
(*pos)++; |
|
|
|
if (t) |
|
t = get_tracer_for_array(tr, t->next); |
|
|
|
return t; |
|
} |
|
|
|
static void *t_start(struct seq_file *m, loff_t *pos) |
|
{ |
|
struct trace_array *tr = m->private; |
|
struct tracer *t; |
|
loff_t l = 0; |
|
|
|
mutex_lock(&trace_types_lock); |
|
|
|
t = get_tracer_for_array(tr, trace_types); |
|
for (; t && l < *pos; t = t_next(m, t, &l)) |
|
; |
|
|
|
return t; |
|
} |
|
|
|
static void t_stop(struct seq_file *m, void *p) |
|
{ |
|
mutex_unlock(&trace_types_lock); |
|
} |
|
|
|
static int t_show(struct seq_file *m, void *v) |
|
{ |
|
struct tracer *t = v; |
|
|
|
if (!t) |
|
return 0; |
|
|
|
seq_puts(m, t->name); |
|
if (t->next) |
|
seq_putc(m, ' '); |
|
else |
|
seq_putc(m, '\n'); |
|
|
|
return 0; |
|
} |
|
|
|
static const struct seq_operations show_traces_seq_ops = { |
|
.start = t_start, |
|
.next = t_next, |
|
.stop = t_stop, |
|
.show = t_show, |
|
}; |
|
|
|
static int show_traces_open(struct inode *inode, struct file *file) |
|
{ |
|
struct trace_array *tr = inode->i_private; |
|
struct seq_file *m; |
|
int ret; |
|
|
|
ret = tracing_check_open_get_tr(tr); |
|
if (ret) |
|
return ret; |
|
|
|
ret = seq_open(file, &show_traces_seq_ops); |
|
if (ret) { |
|
trace_array_put(tr); |
|
return ret; |
|
} |
|
|
|
m = file->private_data; |
|
m->private = tr; |
|
|
|
return 0; |
|
} |
|
|
|
static int show_traces_release(struct inode *inode, struct file *file) |
|
{ |
|
struct trace_array *tr = inode->i_private; |
|
|
|
trace_array_put(tr); |
|
return seq_release(inode, file); |
|
} |
|
|
|
static ssize_t |
|
tracing_write_stub(struct file *filp, const char __user *ubuf, |
|
size_t count, loff_t *ppos) |
|
{ |
|
return count; |
|
} |
|
|
|
loff_t tracing_lseek(struct file *file, loff_t offset, int whence) |
|
{ |
|
int ret; |
|
|
|
if (file->f_mode & FMODE_READ) |
|
ret = seq_lseek(file, offset, whence); |
|
else |
|
file->f_pos = ret = 0; |
|
|
|
return ret; |
|
} |
|
|
|
static const struct file_operations tracing_fops = { |
|
.open = tracing_open, |
|
.read = seq_read, |
|
.write = tracing_write_stub, |
|
.llseek = tracing_lseek, |
|
.release = tracing_release, |
|
}; |
|
|
|
static const struct file_operations show_traces_fops = { |
|
.open = show_traces_open, |
|
.read = seq_read, |
|
.llseek = seq_lseek, |
|
.release = show_traces_release, |
|
}; |
|
|
|
static ssize_t |
|
tracing_cpumask_read(struct file *filp, char __user *ubuf, |
|
size_t count, loff_t *ppos) |
|
{ |
|
struct trace_array *tr = file_inode(filp)->i_private; |
|
char *mask_str; |
|
int len; |
|
|
|
len = snprintf(NULL, 0, "%*pb\n", |
|
cpumask_pr_args(tr->tracing_cpumask)) + 1; |
|
mask_str = kmalloc(len, GFP_KERNEL); |
|
if (!mask_str) |
|
return -ENOMEM; |
|
|
|
len = snprintf(mask_str, len, "%*pb\n", |
|
cpumask_pr_args(tr->tracing_cpumask)); |
|
if (len >= count) { |
|
count = -EINVAL; |
|
goto out_err; |
|
} |
|
count = simple_read_from_buffer(ubuf, count, ppos, mask_str, len); |
|
|
|
out_err: |
|
kfree(mask_str); |
|
|
|
return count; |
|
} |
|
|
|
int tracing_set_cpumask(struct trace_array *tr, |
|
cpumask_var_t tracing_cpumask_new) |
|
{ |
|
int cpu; |
|
|
|
if (!tr) |
|
return -EINVAL; |
|
|
|
local_irq_disable(); |
|
arch_spin_lock(&tr->max_lock); |
|
for_each_tracing_cpu(cpu) { |
|
/* |
|
* Increase/decrease the disabled counter if we are |
|
* about to flip a bit in the cpumask: |
|
*/ |
|
if (cpumask_test_cpu(cpu, tr->tracing_cpumask) && |
|
!cpumask_test_cpu(cpu, tracing_cpumask_new)) { |
|
atomic_inc(&per_cpu_ptr(tr->array_buffer.data, cpu)->disabled); |
|
ring_buffer_record_disable_cpu(tr->array_buffer.buffer, cpu); |
|
} |
|
if (!cpumask_test_cpu(cpu, tr->tracing_cpumask) && |
|
cpumask_test_cpu(cpu, tracing_cpumask_new)) { |
|
atomic_dec(&per_cpu_ptr(tr->array_buffer.data, cpu)->disabled); |
|
ring_buffer_record_enable_cpu(tr->array_buffer.buffer, cpu); |
|
} |
|
} |
|
arch_spin_unlock(&tr->max_lock); |
|
local_irq_enable(); |
|
|
|
cpumask_copy(tr->tracing_cpumask, tracing_cpumask_new); |
|
|
|
return 0; |
|
} |
|
|
|
static ssize_t |
|
tracing_cpumask_write(struct file *filp, const char __user *ubuf, |
|
size_t count, loff_t *ppos) |
|
{ |
|
struct trace_array *tr = file_inode(filp)->i_private; |
|
cpumask_var_t tracing_cpumask_new; |
|
int err; |
|
|
|
if (!alloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL)) |
|
return -ENOMEM; |
|
|
|
err = cpumask_parse_user(ubuf, count, tracing_cpumask_new); |
|
if (err) |
|
goto err_free; |
|
|
|
err = tracing_set_cpumask(tr, tracing_cpumask_new); |
|
if (err) |
|
goto err_free; |
|
|
|
free_cpumask_var(tracing_cpumask_new); |
|
|
|
return count; |
|
|
|
err_free: |
|
free_cpumask_var(tracing_cpumask_new); |
|
|
|
return err; |
|
} |
|
|
|
static const struct file_operations tracing_cpumask_fops = { |
|
.open = tracing_open_generic_tr, |
|
.read = tracing_cpumask_read, |
|
.write = tracing_cpumask_write, |
|
.release = tracing_release_generic_tr, |
|
.llseek = generic_file_llseek, |
|
}; |
|
|
|
static int tracing_trace_options_show(struct seq_file *m, void *v) |
|
{ |
|
struct tracer_opt *trace_opts; |
|
struct trace_array *tr = m->private; |
|
u32 tracer_flags; |
|
int i; |
|
|
|
mutex_lock(&trace_types_lock); |
|
tracer_flags = tr->current_trace->flags->val; |
|
trace_opts = tr->current_trace->flags->opts; |
|
|
|
for (i = 0; trace_options[i]; i++) { |
|
if (tr->trace_flags & (1 << i)) |
|
seq_printf(m, "%s\n", trace_options[i]); |
|
else |
|
seq_printf(m, "no%s\n", trace_options[i]); |
|
} |
|
|
|
for (i = 0; trace_opts[i].name; i++) { |
|
if (tracer_flags & trace_opts[i].bit) |
|
seq_printf(m, "%s\n", trace_opts[i].name); |
|
else |
|
seq_printf(m, "no%s\n", trace_opts[i].name); |
|
} |
|
mutex_unlock(&trace_types_lock); |
|
|
|
return 0; |
|
} |
|
|
|
static int __set_tracer_option(struct trace_array *tr, |
|
struct tracer_flags *tracer_flags, |
|
struct tracer_opt *opts, int neg) |
|
{ |
|
struct tracer *trace = tracer_flags->trace; |
|
int ret; |
|
|
|
ret = trace->set_flag(tr, tracer_flags->val, opts->bit, !neg); |
|
if (ret) |
|
return ret; |
|
|
|
if (neg) |
|
tracer_flags->val &= ~opts->bit; |
|
else |
|
tracer_flags->val |= opts->bit; |
|
return 0; |
|
} |
|
|
|
/* Try to assign a tracer specific option */ |
|
static int set_tracer_option(struct trace_array *tr, char *cmp, int neg) |
|
{ |
|
struct tracer *trace = tr->current_trace; |
|
struct tracer_flags *tracer_flags = trace->flags; |
|
struct tracer_opt *opts = NULL; |
|
int i; |
|
|
|
for (i = 0; tracer_flags->opts[i].name; i++) { |
|
opts = &tracer_flags->opts[i]; |
|
|
|
if (strcmp(cmp, opts->name) == 0) |
|
return __set_tracer_option(tr, trace->flags, opts, neg); |
|
} |
|
|
|
return -EINVAL; |
|
} |
|
|
|
/* Some tracers require overwrite to stay enabled */ |
|
int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set) |
|
{ |
|
if (tracer->enabled && (mask & TRACE_ITER_OVERWRITE) && !set) |
|
return -1; |
|
|
|
return 0; |
|
} |
|
|
|
int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled) |
|
{ |
|
if ((mask == TRACE_ITER_RECORD_TGID) || |
|
(mask == TRACE_ITER_RECORD_CMD)) |
|
lockdep_assert_held(&event_mutex); |
|
|
|
/* do nothing if flag is already set */ |
|
if (!!(tr->trace_flags & mask) == !!enabled) |
|
return 0; |
|
|
|
/* Give the tracer a chance to approve the change */ |
|
if (tr->current_trace->flag_changed) |
|
if (tr->current_trace->flag_changed(tr, mask, !!enabled)) |
|
return -EINVAL; |
|
|
|
if (enabled) |
|
tr->trace_flags |= mask; |
|
else |
|
tr->trace_flags &= ~mask; |
|
|
|
if (mask == TRACE_ITER_RECORD_CMD) |
|
trace_event_enable_cmd_record(enabled); |
|
|
|
if (mask == TRACE_ITER_RECORD_TGID) { |
|
if (!tgid_map) |
|
tgid_map = kvcalloc(PID_MAX_DEFAULT + 1, |
|
sizeof(*tgid_map), |
|
GFP_KERNEL); |
|
if (!tgid_map) { |
|
tr->trace_flags &= ~TRACE_ITER_RECORD_TGID; |
|
return -ENOMEM; |
|
} |
|
|
|
trace_event_enable_tgid_record(enabled); |
|
} |
|
|
|
if (mask == TRACE_ITER_EVENT_FORK) |
|
trace_event_follow_fork(tr, enabled); |
|
|
|
if (mask == TRACE_ITER_FUNC_FORK) |
|
ftrace_pid_follow_fork(tr, enabled); |
|
|
|
if (mask == TRACE_ITER_OVERWRITE) { |
|
ring_buffer_change_overwrite(tr->array_buffer.buffer, enabled); |
|
#ifdef CONFIG_TRACER_MAX_TRACE |
|
ring_buffer_change_overwrite(tr->max_buffer.buffer, enabled); |
|
#endif |
|
} |
|
|
|
if (mask == TRACE_ITER_PRINTK) { |
|
trace_printk_start_stop_comm(enabled); |
|
trace_printk_control(enabled); |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
int trace_set_options(struct trace_array *tr, char *option) |
|
{ |
|
char *cmp; |
|
int neg = 0; |
|
int ret; |
|
size_t orig_len = strlen(option); |
|
int len; |
|
|
|
cmp = strstrip(option); |
|
|
|
len = str_has_prefix(cmp, "no"); |
|
if (len) |
|
neg = 1; |
|
|
|
cmp += len; |
|
|
|
mutex_lock(&event_mutex); |
|
mutex_lock(&trace_types_lock); |
|
|
|
ret = match_string(trace_options, -1, cmp); |
|
/* If no option could be set, test the specific tracer options */ |
|
if (ret < 0) |
|
ret = set_tracer_option(tr, cmp, neg); |
|
else |
|
ret = set_tracer_flag(tr, 1 << ret, !neg); |
|
|
|
mutex_unlock(&trace_types_lock); |
|
mutex_unlock(&event_mutex); |
|
|
|
/* |
|
* If the first trailing whitespace is replaced with '\0' by strstrip, |
|
* turn it back into a space. |
|
*/ |
|
if (orig_len > strlen(option)) |
|
option[strlen(option)] = ' '; |
|
|
|
return ret; |
|
} |
|
|
|
static void __init apply_trace_boot_options(void) |
|
{ |
|
char *buf = trace_boot_options_buf; |
|
char *option; |
|
|
|
while (true) { |
|
option = strsep(&buf, ","); |
|
|
|
if (!option) |
|
break; |
|
|
|
if (*option) |
|
trace_set_options(&global_trace, option); |
|
|
|
/* Put back the comma to allow this to be called again */ |
|
if (buf) |
|
*(buf - 1) = ','; |
|
} |
|
} |
|
|
|
static ssize_t |
|
tracing_trace_options_write(struct file *filp, const char __user *ubuf, |
|
size_t cnt, loff_t *ppos) |
|
{ |
|
struct seq_file *m = filp->private_data; |
|
struct trace_array *tr = m->private; |
|
char buf[64]; |
|
int ret; |
|
|
|
if (cnt >= sizeof(buf)) |
|
return -EINVAL; |
|
|
|
if (copy_from_user(buf, ubuf, cnt)) |
|
return -EFAULT; |
|
|
|
buf[cnt] = 0; |
|
|
|
ret = trace_set_options(tr, buf); |
|
if (ret < 0) |
|
return ret; |
|
|
|
*ppos += cnt; |
|
|
|
return cnt; |
|
} |
|
|
|
static int tracing_trace_options_open(struct inode *inode, struct file *file) |
|
{ |
|
struct trace_array *tr = inode->i_private; |
|
int ret; |
|
|
|
ret = tracing_check_open_get_tr(tr); |
|
if (ret) |
|
return ret; |
|
|
|
ret = single_open(file, tracing_trace_options_show, inode->i_private); |
|
if (ret < 0) |
|
trace_array_put(tr); |
|
|
|
return ret; |
|
} |
|
|
|
static const struct file_operations tracing_iter_fops = { |
|
.open = tracing_trace_options_open, |
|
.read = seq_read, |
|
.llseek = seq_lseek, |
|
.release = tracing_single_release_tr, |
|
.write = tracing_trace_options_write, |
|
}; |
|
|
|
static const char readme_msg[] = |
|
"tracing mini-HOWTO:\n\n" |
|
"# echo 0 > tracing_on : quick way to disable tracing\n" |
|
"# echo 1 > tracing_on : quick way to re-enable tracing\n\n" |
|
" Important files:\n" |
|
" trace\t\t\t- The static contents of the buffer\n" |
|
"\t\t\t To clear the buffer write into this file: echo > trace\n" |
|
" trace_pipe\t\t- A consuming read to see the contents of the buffer\n" |
|
" current_tracer\t- function and latency tracers\n" |
|
" available_tracers\t- list of configured tracers for current_tracer\n" |
|
" error_log\t- error log for failed commands (that support it)\n" |
|
" buffer_size_kb\t- view and modify size of per cpu buffer\n" |
|
" buffer_total_size_kb - view total size of all cpu buffers\n\n" |
|
" trace_clock\t\t-change the clock used to order events\n" |
|
" local: Per cpu clock but may not be synced across CPUs\n" |
|
" global: Synced across CPUs but slows tracing down.\n" |
|
" counter: Not a clock, but just an increment\n" |
|
" uptime: Jiffy counter from time of boot\n" |
|
" perf: Same clock that perf events use\n" |
|
#ifdef CONFIG_X86_64 |
|
" x86-tsc: TSC cycle counter\n" |
|
#endif |
|
"\n timestamp_mode\t-view the mode used to timestamp events\n" |
|
" delta: Delta difference against a buffer-wide timestamp\n" |
|
" absolute: Absolute (standalone) timestamp\n" |
|
"\n trace_marker\t\t- Writes into this file writes into the kernel buffer\n" |
|
"\n trace_marker_raw\t\t- Writes into this file writes binary data into the kernel buffer\n" |
|
" tracing_cpumask\t- Limit which CPUs to trace\n" |
|
" instances\t\t- Make sub-buffers with: mkdir instances/foo\n" |
|
"\t\t\t Remove sub-buffer with rmdir\n" |
|
" trace_options\t\t- Set format or modify how tracing happens\n" |
|
"\t\t\t Disable an option by prefixing 'no' to the\n" |
|
"\t\t\t option name\n" |
|
" saved_cmdlines_size\t- echo command number in here to store comm-pid list\n" |
|
#ifdef CONFIG_DYNAMIC_FTRACE |
|
"\n available_filter_functions - list of functions that can be filtered on\n" |
|
" set_ftrace_filter\t- echo function name in here to only trace these\n" |
|
"\t\t\t functions\n" |
|
"\t accepts: func_full_name or glob-matching-pattern\n" |
|
"\t modules: Can select a group via module\n" |
|
"\t Format: :mod:<module-name>\n" |
|
"\t example: echo :mod:ext3 > set_ftrace_filter\n" |
|
"\t triggers: a command to perform when function is hit\n" |
|
"\t Format: <function>:<trigger>[:count]\n" |
|
"\t trigger: traceon, traceoff\n" |
|
"\t\t enable_event:<system>:<event>\n" |
|
"\t\t disable_event:<system>:<event>\n" |
|
#ifdef CONFIG_STACKTRACE |
|
"\t\t stacktrace\n" |
|
#endif |
|
#ifdef CONFIG_TRACER_SNAPSHOT |
|
"\t\t snapshot\n" |
|
#endif |
|
"\t\t dump\n" |
|
"\t\t cpudump\n" |
|
"\t example: echo do_fault:traceoff > set_ftrace_filter\n" |
|
"\t echo do_trap:traceoff:3 > set_ftrace_filter\n" |
|
"\t The first one will disable tracing every time do_fault is hit\n" |
|
"\t The second will disable tracing at most 3 times when do_trap is hit\n" |
|
"\t The first time do trap is hit and it disables tracing, the\n" |
|
"\t counter will decrement to 2. If tracing is already disabled,\n" |
|
"\t the counter will not decrement. It only decrements when the\n" |
|
"\t trigger did work\n" |
|
"\t To remove trigger without count:\n" |
|
"\t echo '!<function>:<trigger> > set_ftrace_filter\n" |
|
"\t To remove trigger with a count:\n" |
|
"\t echo '!<function>:<trigger>:0 > set_ftrace_filter\n" |
|
" set_ftrace_notrace\t- echo function name in here to never trace.\n" |
|
"\t accepts: func_full_name, *func_end, func_begin*, *func_middle*\n" |
|
"\t modules: Can select a group via module command :mod:\n" |
|
"\t Does not accept triggers\n" |
|
#endif /* CONFIG_DYNAMIC_FTRACE */ |
|
#ifdef CONFIG_FUNCTION_TRACER |
|
" set_ftrace_pid\t- Write pid(s) to only function trace those pids\n" |
|
"\t\t (function)\n" |
|
" set_ftrace_notrace_pid\t- Write pid(s) to not function trace those pids\n" |
|
"\t\t (function)\n" |
|
#endif |
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER |
|
" set_graph_function\t- Trace the nested calls of a function (function_graph)\n" |
|
" set_graph_notrace\t- Do not trace the nested calls of a function (function_graph)\n" |
|
" max_graph_depth\t- Trace a limited depth of nested calls (0 is unlimited)\n" |
|
#endif |
|
#ifdef CONFIG_TRACER_SNAPSHOT |
|
"\n snapshot\t\t- Like 'trace' but shows the content of the static\n" |
|
"\t\t\t snapshot buffer. Read the contents for more\n" |
|
"\t\t\t information\n" |
|
#endif |
|
#ifdef CONFIG_STACK_TRACER |
|
" stack_trace\t\t- Shows the max stack trace when active\n" |
|
" stack_max_size\t- Shows current max stack size that was traced\n" |
|
"\t\t\t Write into this file to reset the max size (trigger a\n" |
|
"\t\t\t new trace)\n" |
|
#ifdef CONFIG_DYNAMIC_FTRACE |
|
" stack_trace_filter\t- Like set_ftrace_filter but limits what stack_trace\n" |
|
"\t\t\t traces\n" |
|
#endif |
|
#endif /* CONFIG_STACK_TRACER */ |
|
#ifdef CONFIG_DYNAMIC_EVENTS |
|
" dynamic_events\t\t- Create/append/remove/show the generic dynamic events\n" |
|
"\t\t\t Write into this file to define/undefine new trace events.\n" |
|
#endif |
|
#ifdef CONFIG_KPROBE_EVENTS |
|
" kprobe_events\t\t- Create/append/remove/show the kernel dynamic events\n" |
|
"\t\t\t Write into this file to define/undefine new trace events.\n" |
|
#endif |
|
#ifdef CONFIG_UPROBE_EVENTS |
|
" uprobe_events\t\t- Create/append/remove/show the userspace dynamic events\n" |
|
"\t\t\t Write into this file to define/undefine new trace events.\n" |
|
#endif |
|
#if defined(CONFIG_KPROBE_EVENTS) || defined(CONFIG_UPROBE_EVENTS) |
|
"\t accepts: event-definitions (one definition per line)\n" |
|
"\t Format: p[:[<group>/]<event>] <place> [<args>]\n" |
|
"\t r[maxactive][:[<group>/]<event>] <place> [<args>]\n" |
|
#ifdef CONFIG_HIST_TRIGGERS |
|
"\t s:[synthetic/]<event> <field> [<field>]\n" |
|
#endif |
|
"\t -:[<group>/]<event>\n" |
|
#ifdef CONFIG_KPROBE_EVENTS |
|
"\t place: [<module>:]<symbol>[+<offset>]|<memaddr>\n" |
|
"place (kretprobe): [<module>:]<symbol>[+<offset>]%return|<memaddr>\n" |
|
#endif |
|
#ifdef CONFIG_UPROBE_EVENTS |
|
" place (uprobe): <path>:<offset>[%return][(ref_ctr_offset)]\n" |
|
#endif |
|
"\t args: <name>=fetcharg[:type]\n" |
|
"\t fetcharg: %<register>, @<address>, @<symbol>[+|-<offset>],\n" |
|
#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API |
|
"\t $stack<index>, $stack, $retval, $comm, $arg<N>,\n" |
|
#else |
|
"\t $stack<index>, $stack, $retval, $comm,\n" |
|
#endif |
|
"\t +|-[u]<offset>(<fetcharg>), \\imm-value, \\\"imm-string\"\n" |
|
"\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, string, symbol,\n" |
|
"\t b<bit-width>@<bit-offset>/<container-size>, ustring,\n" |
|
"\t <type>\\[<array-size>\\]\n" |
|
#ifdef CONFIG_HIST_TRIGGERS |
|
"\t field: <stype> <name>;\n" |
|
"\t stype: u8/u16/u32/u64, s8/s16/s32/s64, pid_t,\n" |
|
"\t [unsigned] char/int/long\n" |
|
#endif |
|
#endif |
|
" events/\t\t- Directory containing all trace event subsystems:\n" |
|
" enable\t\t- Write 0/1 to enable/disable tracing of all events\n" |
|
" events/<system>/\t- Directory containing all trace events for <system>:\n" |
|
" enable\t\t- Write 0/1 to enable/disable tracing of all <system>\n" |
|
"\t\t\t events\n" |
|
" filter\t\t- If set, only events passing filter are traced\n" |
|
" events/<system>/<event>/\t- Directory containing control files for\n" |
|
"\t\t\t <event>:\n" |
|
" enable\t\t- Write 0/1 to enable/disable tracing of <event>\n" |
|
" filter\t\t- If set, only events passing filter are traced\n" |
|
" trigger\t\t- If set, a command to perform when event is hit\n" |
|
"\t Format: <trigger>[:count][if <filter>]\n" |
|
"\t trigger: traceon, traceoff\n" |
|
"\t enable_event:<system>:<event>\n" |
|
"\t disable_event:<system>:<event>\n" |
|
#ifdef CONFIG_HIST_TRIGGERS |
|
"\t enable_hist:<system>:<event>\n" |
|
"\t disable_hist:<system>:<event>\n" |
|
#endif |
|
#ifdef CONFIG_STACKTRACE |
|
"\t\t stacktrace\n" |
|
#endif |
|
#ifdef CONFIG_TRACER_SNAPSHOT |
|
"\t\t snapshot\n" |
|
#endif |
|
#ifdef CONFIG_HIST_TRIGGERS |
|
"\t\t hist (see below)\n" |
|
#endif |
|
"\t example: echo traceoff > events/block/block_unplug/trigger\n" |
|
"\t echo traceoff:3 > events/block/block_unplug/trigger\n" |
|
"\t echo 'enable_event:kmem:kmalloc:3 if nr_rq > 1' > \\\n" |
|
"\t events/block/block_unplug/trigger\n" |
|
"\t The first disables tracing every time block_unplug is hit.\n" |
|
"\t The second disables tracing the first 3 times block_unplug is hit.\n" |
|
"\t The third enables the kmalloc event the first 3 times block_unplug\n" |
|
"\t is hit and has value of greater than 1 for the 'nr_rq' event field.\n" |
|
"\t Like function triggers, the counter is only decremented if it\n" |
|
"\t enabled or disabled tracing.\n" |
|
"\t To remove a trigger without a count:\n" |
|
"\t echo '!<trigger> > <system>/<event>/trigger\n" |
|
"\t To remove a trigger with a count:\n" |
|
"\t echo '!<trigger>:0 > <system>/<event>/trigger\n" |
|
"\t Filters can be ignored when removing a trigger.\n" |
|
#ifdef CONFIG_HIST_TRIGGERS |
|
" hist trigger\t- If set, event hits are aggregated into a hash table\n" |
|
"\t Format: hist:keys=<field1[,field2,...]>\n" |
|
"\t [:values=<field1[,field2,...]>]\n" |
|
"\t [:sort=<field1[,field2,...]>]\n" |
|
"\t [:size=#entries]\n" |
|
"\t [:pause][:continue][:clear]\n" |
|
"\t [:name=histname1]\n" |
|
"\t [:<handler>.<action>]\n" |
|
"\t [if <filter>]\n\n" |
|
"\t When a matching event is hit, an entry is added to a hash\n" |
|
"\t table using the key(s) and value(s) named, and the value of a\n" |
|
"\t sum called 'hitcount' is incremented. Keys and values\n" |
|
"\t correspond to fields in the event's format description. Keys\n" |
|
"\t can be any field, or the special string 'stacktrace'.\n" |
|
"\t Compound keys consisting of up to two fields can be specified\n" |
|
"\t by the 'keys' keyword. Values must correspond to numeric\n" |
|
"\t fields. Sort keys consisting of up to two fields can be\n" |
|
"\t specified using the 'sort' keyword. The sort direction can\n" |
|
"\t be modified by appending '.descending' or '.ascending' to a\n" |
|
"\t sort field. The 'size' parameter can be used to specify more\n" |
|
"\t or fewer than the default 2048 entries for the hashtable size.\n" |
|
"\t If a hist trigger is given a name using the 'name' parameter,\n" |
|
"\t its histogram data will be shared with other triggers of the\n" |
|
"\t same name, and trigger hits will update this common data.\n\n" |
|
"\t Reading the 'hist' file for the event will dump the hash\n" |
|
"\t table in its entirety to stdout. If there are multiple hist\n" |
|
"\t triggers attached to an event, there will be a table for each\n" |
|
"\t trigger in the output. The table displayed for a named\n" |
|
"\t trigger will be the same as any other instance having the\n" |
|
"\t same name. The default format used to display a given field\n" |
|
"\t can be modified by appending any of the following modifiers\n" |
|
"\t to the field name, as applicable:\n\n" |
|
"\t .hex display a number as a hex value\n" |
|
"\t .sym display an address as a symbol\n" |
|
"\t .sym-offset display an address as a symbol and offset\n" |
|
"\t .execname display a common_pid as a program name\n" |
|
"\t .syscall display a syscall id as a syscall name\n" |
|
"\t .log2 display log2 value rather than raw number\n" |
|
"\t .usecs display a common_timestamp in microseconds\n\n" |
|
"\t The 'pause' parameter can be used to pause an existing hist\n" |
|
"\t trigger or to start a hist trigger but not log any events\n" |
|
"\t until told to do so. 'continue' can be used to start or\n" |
|
"\t restart a paused hist trigger.\n\n" |
|
"\t The 'clear' parameter will clear the contents of a running\n" |
|
"\t hist trigger and leave its current paused/active state\n" |
|
"\t unchanged.\n\n" |
|
"\t The enable_hist and disable_hist triggers can be used to\n" |
|
"\t have one event conditionally start and stop another event's\n" |
|
"\t already-attached hist trigger. The syntax is analogous to\n" |
|
"\t the enable_event and disable_event triggers.\n\n" |
|
"\t Hist trigger handlers and actions are executed whenever a\n" |
|
"\t a histogram entry is added or updated. They take the form:\n\n" |
|
"\t <handler>.<action>\n\n" |
|
"\t The available handlers are:\n\n" |
|
"\t onmatch(matching.event) - invoke on addition or update\n" |
|
"\t onmax(var) - invoke if var exceeds current max\n" |
|
"\t onchange(var) - invoke action if var changes\n\n" |
|
"\t The available actions are:\n\n" |
|
"\t trace(<synthetic_event>,param list) - generate synthetic event\n" |
|
"\t save(field,...) - save current event fields\n" |
|
#ifdef CONFIG_TRACER_SNAPSHOT |
|
"\t snapshot() - snapshot the trace buffer\n\n" |
|
#endif |
|
#ifdef CONFIG_SYNTH_EVENTS |
|
" events/synthetic_events\t- Create/append/remove/show synthetic events\n" |
|
"\t Write into this file to define/undefine new synthetic events.\n" |
|
"\t example: echo 'myevent u64 lat; char name[]' >> synthetic_events\n" |
|
#endif |
|
#endif |
|
; |
|
|
|
static ssize_t |
|
tracing_readme_read(struct file *filp, char __user *ubuf, |
|
size_t cnt, loff_t *ppos) |
|
{ |
|
return simple_read_from_buffer(ubuf, cnt, ppos, |
|
readme_msg, strlen(readme_msg)); |
|
} |
|
|
|
static const struct file_operations tracing_readme_fops = { |
|
.open = tracing_open_generic, |
|
.read = tracing_readme_read, |
|
.llseek = generic_file_llseek, |
|
}; |
|
|
|
static void *saved_tgids_next(struct seq_file *m, void *v, loff_t *pos) |
|
{ |
|
int *ptr = v; |
|
|
|
if (*pos || m->count) |
|
ptr++; |
|
|
|
(*pos)++; |
|
|
|
for (; ptr <= &tgid_map[PID_MAX_DEFAULT]; ptr++) { |
|
if (trace_find_tgid(*ptr)) |
|
return ptr; |
|
} |
|
|
|
return NULL; |
|
} |
|
|
|
static void *saved_tgids_start(struct seq_file *m, loff_t *pos) |
|
{ |
|
void *v; |
|
loff_t l = 0; |
|
|
|
if (!tgid_map) |
|
return NULL; |
|
|
|
v = &tgid_map[0]; |
|
while (l <= *pos) { |
|
v = saved_tgids_next(m, v, &l); |
|
if (!v) |
|
return NULL; |
|
} |
|
|
|
return v; |
|
} |
|
|
|
static void saved_tgids_stop(struct seq_file *m, void *v) |
|
{ |
|
} |
|
|
|
static int saved_tgids_show(struct seq_file *m, void *v) |
|
{ |
|
int pid = (int *)v - tgid_map; |
|
|
|
seq_printf(m, "%d %d\n", pid, trace_find_tgid(pid)); |
|
return 0; |
|
} |
|
|
|
static const struct seq_operations tracing_saved_tgids_seq_ops = { |
|
.start = saved_tgids_start, |
|
.stop = saved_tgids_stop, |
|
.next = saved_tgids_next, |
|
.show = saved_tgids_show, |
|
}; |
|
|
|
static int tracing_saved_tgids_open(struct inode *inode, struct file *filp) |
|
{ |
|
int ret; |
|
|
|
ret = tracing_check_open_get_tr(NULL); |
|
if (ret) |
|
return ret; |
|
|
|
return seq_open(filp, &tracing_saved_tgids_seq_ops); |
|
} |
|
|
|
|
|
static const struct file_operations tracing_saved_tgids_fops = { |
|
.open = tracing_saved_tgids_open, |
|
.read = seq_read, |
|
.llseek = seq_lseek, |
|
.release = seq_release, |
|
}; |
|
|
|
static void *saved_cmdlines_next(struct seq_file *m, void *v, loff_t *pos) |
|
{ |
|
unsigned int *ptr = v; |
|
|
|
if (*pos || m->count) |
|
ptr++; |
|
|
|
(*pos)++; |
|
|
|
for (; ptr < &savedcmd->map_cmdline_to_pid[savedcmd->cmdline_num]; |
|
ptr++) { |
|
if (*ptr == -1 || *ptr == NO_CMDLINE_MAP) |
|
continue; |
|
|
|
return ptr; |
|
} |
|
|
|
return NULL; |
|
} |
|
|
|
static void *saved_cmdlines_start(struct seq_file *m, loff_t *pos) |
|
{ |
|
void *v; |
|
loff_t l = 0; |
|
|
|
preempt_disable(); |
|
arch_spin_lock(&trace_cmdline_lock); |
|
|
|
v = &savedcmd->map_cmdline_to_pid[0]; |
|
while (l <= *pos) { |
|
v = saved_cmdlines_next(m, v, &l); |
|
if (!v) |
|
return NULL; |
|
} |
|
|
|
return v; |
|
} |
|
|
|
static void saved_cmdlines_stop(struct seq_file *m, void *v) |
|
{ |
|
arch_spin_unlock(&trace_cmdline_lock); |
|
preempt_enable(); |
|
} |
|
|
|
static int saved_cmdlines_show(struct seq_file *m, void *v) |
|
{ |
|
char buf[TASK_COMM_LEN]; |
|
unsigned int *pid = v; |
|
|
|
__trace_find_cmdline(*pid, buf); |
|
seq_printf(m, "%d %s\n", *pid, buf); |
|
return 0; |
|
} |
|
|
|
static const struct seq_operations tracing_saved_cmdlines_seq_ops = { |
|
.start = saved_cmdlines_start, |
|
.next = saved_cmdlines_next, |
|
.stop = saved_cmdlines_stop, |
|
.show = saved_cmdlines_show, |
|
}; |
|
|
|
static int tracing_saved_cmdlines_open(struct inode *inode, struct file *filp) |
|
{ |
|
int ret; |
|
|
|
ret = tracing_check_open_get_tr(NULL); |
|
if (ret) |
|
return ret; |
|
|
|
return seq_open(filp, &tracing_saved_cmdlines_seq_ops); |
|
} |
|
|
|
static const struct file_operations tracing_saved_cmdlines_fops = { |
|
.open = tracing_saved_cmdlines_open, |
|
.read = seq_read, |
|
.llseek = seq_lseek, |
|
.release = seq_release, |
|
}; |
|
|
|
static ssize_t |
|
tracing_saved_cmdlines_size_read(struct file *filp, char __user *ubuf, |
|
size_t cnt, loff_t *ppos) |
|
{ |
|
char buf[64]; |
|
int r; |
|
|
|
arch_spin_lock(&trace_cmdline_lock); |
|
r = scnprintf(buf, sizeof(buf), "%u\n", savedcmd->cmdline_num); |
|
arch_spin_unlock(&trace_cmdline_lock); |
|
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
|
} |
|
|
|
static void free_saved_cmdlines_buffer(struct saved_cmdlines_buffer *s) |
|
{ |
|
kfree(s->saved_cmdlines); |
|
kfree(s->map_cmdline_to_pid); |
|
kfree(s); |
|
} |
|
|
|
static int tracing_resize_saved_cmdlines(unsigned int val) |
|
{ |
|
struct saved_cmdlines_buffer *s, *savedcmd_temp; |
|
|
|
s = kmalloc(sizeof(*s), GFP_KERNEL); |
|
if (!s) |
|
return -ENOMEM; |
|
|
|
if (allocate_cmdlines_buffer(val, s) < 0) { |
|
kfree(s); |
|
return -ENOMEM; |
|
} |
|
|
|
arch_spin_lock(&trace_cmdline_lock); |
|
savedcmd_temp = savedcmd; |
|
savedcmd = s; |
|
arch_spin_unlock(&trace_cmdline_lock); |
|
free_saved_cmdlines_buffer(savedcmd_temp); |
|
|
|
return 0; |
|
} |
|
|
|
static ssize_t |
|
tracing_saved_cmdlines_size_write(struct file *filp, const char __user *ubuf, |
|
size_t cnt, loff_t *ppos) |
|
{ |
|
unsigned long val; |
|
int ret; |
|
|
|
ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
|
if (ret) |
|
return ret; |
|
|
|
/* must have at least 1 entry or less than PID_MAX_DEFAULT */ |
|
if (!val || val > PID_MAX_DEFAULT) |
|
return -EINVAL; |
|
|
|
ret = tracing_resize_saved_cmdlines((unsigned int)val); |
|
if (ret < 0) |
|
return ret; |
|
|
|
*ppos += cnt; |
|
|
|
return cnt; |
|
} |
|
|
|
static const struct file_operations tracing_saved_cmdlines_size_fops = { |
|
.open = tracing_open_generic, |
|
.read = tracing_saved_cmdlines_size_read, |
|
.write = tracing_saved_cmdlines_size_write, |
|
}; |
|
|
|
#ifdef CONFIG_TRACE_EVAL_MAP_FILE |
|
static union trace_eval_map_item * |
|
update_eval_map(union trace_eval_map_item *ptr) |
|
{ |
|
if (!ptr->map.eval_string) { |
|
if (ptr->tail.next) { |
|
ptr = ptr->tail.next; |
|
/* Set ptr to the next real item (skip head) */ |
|
ptr++; |
|
} else |
|
return NULL; |
|
} |
|
return ptr; |
|
} |
|
|
|
static void *eval_map_next(struct seq_file *m, void *v, loff_t *pos) |
|
{ |
|
union trace_eval_map_item *ptr = v; |
|
|
|
/* |
|
* Paranoid! If ptr points to end, we don't want to increment past it. |
|
* This really should never happen. |
|
*/ |
|
(*pos)++; |
|
ptr = update_eval_map(ptr); |
|
if (WARN_ON_ONCE(!ptr)) |
|
return NULL; |
|
|
|
ptr++; |
|
ptr = update_eval_map(ptr); |
|
|
|
return ptr; |
|
} |
|
|
|
static void *eval_map_start(struct seq_file *m, loff_t *pos) |
|
{ |
|
union trace_eval_map_item *v; |
|
loff_t l = 0; |
|
|
|
mutex_lock(&trace_eval_mutex); |
|
|
|
v = trace_eval_maps; |
|
if (v) |
|
v++; |
|
|
|
while (v && l < *pos) { |
|
v = eval_map_next(m, v, &l); |
|
} |
|
|
|
return v; |
|
} |
|
|
|
static void eval_map_stop(struct seq_file *m, void *v) |
|
{ |
|
mutex_unlock(&trace_eval_mutex); |
|
} |
|
|
|
static int eval_map_show(struct seq_file *m, void *v) |
|
{ |
|
union trace_eval_map_item *ptr = v; |
|
|
|
seq_printf(m, "%s %ld (%s)\n", |
|
ptr->map.eval_string, ptr->map.eval_value, |
|
ptr->map.system); |
|
|
|
return 0; |
|
} |
|
|
|
static const struct seq_operations tracing_eval_map_seq_ops = { |
|
.start = eval_map_start, |
|
.next = eval_map_next, |
|
.stop = eval_map_stop, |
|
.show = eval_map_show, |
|
}; |
|
|
|
static int tracing_eval_map_open(struct inode *inode, struct file *filp) |
|
{ |
|
int ret; |
|
|
|
ret = tracing_check_open_get_tr(NULL); |
|
if (ret) |
|
return ret; |
|
|
|
return seq_open(filp, &tracing_eval_map_seq_ops); |
|
} |
|
|
|
static const struct file_operations tracing_eval_map_fops = { |
|
.open = tracing_eval_map_open, |
|
.read = seq_read, |
|
.llseek = seq_lseek, |
|
.release = seq_release, |
|
}; |
|
|
|
static inline union trace_eval_map_item * |
|
trace_eval_jmp_to_tail(union trace_eval_map_item *ptr) |
|
{ |
|
/* Return tail of array given the head */ |
|
return ptr + ptr->head.length + 1; |
|
} |
|
|
|
static void |
|
trace_insert_eval_map_file(struct module *mod, struct trace_eval_map **start, |
|
int len) |
|
{ |
|
struct trace_eval_map **stop; |
|
struct trace_eval_map **map; |
|
union trace_eval_map_item *map_array; |
|
union trace_eval_map_item *ptr; |
|
|
|
stop = start + len; |
|
|
|
/* |
|
* The trace_eval_maps contains the map plus a head and tail item, |
|
* where the head holds the module and length of array, and the |
|
* tail holds a pointer to the next list. |
|
*/ |
|
map_array = kmalloc_array(len + 2, sizeof(*map_array), GFP_KERNEL); |
|
if (!map_array) { |
|
pr_warn("Unable to allocate trace eval mapping\n"); |
|
return; |
|
} |
|
|
|
mutex_lock(&trace_eval_mutex); |
|
|
|
if (!trace_eval_maps) |
|
trace_eval_maps = map_array; |
|
else { |
|
ptr = trace_eval_maps; |
|
for (;;) { |
|
ptr = trace_eval_jmp_to_tail(ptr); |
|
if (!ptr->tail.next) |
|
break; |
|
ptr = ptr->tail.next; |
|
|
|
} |
|
ptr->tail.next = map_array; |
|
} |
|
map_array->head.mod = mod; |
|
map_array->head.length = len; |
|
map_array++; |
|
|
|
for (map = start; (unsigned long)map < (unsigned long)stop; map++) { |
|
map_array->map = **map; |
|
map_array++; |
|
} |
|
memset(map_array, 0, sizeof(*map_array)); |
|
|
|
mutex_unlock(&trace_eval_mutex); |
|
} |
|
|
|
static void trace_create_eval_file(struct dentry *d_tracer) |
|
{ |
|
trace_create_file("eval_map", 0444, d_tracer, |
|
NULL, &tracing_eval_map_fops); |
|
} |
|
|
|
#else /* CONFIG_TRACE_EVAL_MAP_FILE */ |
|
static inline void trace_create_eval_file(struct dentry *d_tracer) { } |
|
static inline void trace_insert_eval_map_file(struct module *mod, |
|
struct trace_eval_map **start, int len) { } |
|
#endif /* !CONFIG_TRACE_EVAL_MAP_FILE */ |
|
|
|
static void trace_insert_eval_map(struct module *mod, |
|
struct trace_eval_map **start, int len) |
|
{ |
|
struct trace_eval_map **map; |
|
|
|
if (len <= 0) |
|
return; |
|
|
|
map = start; |
|
|
|
trace_event_eval_update(map, len); |
|
|
|
trace_insert_eval_map_file(mod, start, len); |
|
} |
|
|
|
static ssize_t |
|
tracing_set_trace_read(struct file *filp, char __user *ubuf, |
|
size_t cnt, loff_t *ppos) |
|
{ |
|
struct trace_array *tr = filp->private_data; |
|
char buf[MAX_TRACER_SIZE+2]; |
|
int r; |
|
|
|
mutex_lock(&trace_types_lock); |
|
r = sprintf(buf, "%s\n", tr->current_trace->name); |
|
mutex_unlock(&trace_types_lock); |
|
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
|
} |
|
|
|
int tracer_init(struct tracer *t, struct trace_array *tr) |
|
{ |
|
tracing_reset_online_cpus(&tr->array_buffer); |
|
return t->init(tr); |
|
} |
|
|
|
static void set_buffer_entries(struct array_buffer *buf, unsigned long val) |
|
{ |
|
int cpu; |
|
|
|
for_each_tracing_cpu(cpu) |
|
per_cpu_ptr(buf->data, cpu)->entries = val; |
|
} |
|
|
|
#ifdef CONFIG_TRACER_MAX_TRACE |
|
/* resize @tr's buffer to the size of @size_tr's entries */ |
|
static int resize_buffer_duplicate_size(struct array_buffer *trace_buf, |
|
struct array_buffer *size_buf, int cpu_id) |
|
{ |
|
int cpu, ret = 0; |
|
|
|
if (cpu_id == RING_BUFFER_ALL_CPUS) { |
|
for_each_tracing_cpu(cpu) { |
|
ret = ring_buffer_resize(trace_buf->buffer, |
|
per_cpu_ptr(size_buf->data, cpu)->entries, cpu); |
|
if (ret < 0) |
|
break; |
|
per_cpu_ptr(trace_buf->data, cpu)->entries = |
|
per_cpu_ptr(size_buf->data, cpu)->entries; |
|
} |
|
} else { |
|
ret = ring_buffer_resize(trace_buf->buffer, |
|
per_cpu_ptr(size_buf->data, cpu_id)->entries, cpu_id); |
|
if (ret == 0) |
|
per_cpu_ptr(trace_buf->data, cpu_id)->entries = |
|
per_cpu_ptr(size_buf->data, cpu_id)->entries; |
|
} |
|
|
|
return ret; |
|
} |
|
#endif /* CONFIG_TRACER_MAX_TRACE */ |
|
|
|
static int __tracing_resize_ring_buffer(struct trace_array *tr, |
|
unsigned long size, int cpu) |
|
{ |
|
int ret; |
|
|
|
/* |
|
* If kernel or user changes the size of the ring buffer |
|
* we use the size that was given, and we can forget about |
|
* expanding it later. |
|
*/ |
|
ring_buffer_expanded = true; |
|
|
|
/* May be called before buffers are initialized */ |
|
if (!tr->array_buffer.buffer) |
|
return 0; |
|
|
|
ret = ring_buffer_resize(tr->array_buffer.buffer, size, cpu); |
|
if (ret < 0) |
|
return ret; |
|
|
|
#ifdef CONFIG_TRACER_MAX_TRACE |
|
if (!(tr->flags & TRACE_ARRAY_FL_GLOBAL) || |
|
!tr->current_trace->use_max_tr) |
|
goto out; |
|
|
|
ret = ring_buffer_resize(tr->max_buffer.buffer, size, cpu); |
|
if (ret < 0) { |
|
int r = resize_buffer_duplicate_size(&tr->array_buffer, |
|
&tr->array_buffer, cpu); |
|
if (r < 0) { |
|
/* |
|
* AARGH! We are left with different |
|
* size max buffer!!!! |
|
* The max buffer is our "snapshot" buffer. |
|
* When a tracer needs a snapshot (one of the |
|
* latency tracers), it swaps the max buffer |
|
* with the saved snap shot. We succeeded to |
|
* update the size of the main buffer, but failed to |
|
* update the size of the max buffer. But when we tried |
|
* to reset the main buffer to the original size, we |
|
* failed there too. This is very unlikely to |
|
* happen, but if it does, warn and kill all |
|
* tracing. |
|
*/ |
|
WARN_ON(1); |
|
tracing_disabled = 1; |
|
} |
|
return ret; |
|
} |
|
|
|
if (cpu == RING_BUFFER_ALL_CPUS) |
|
set_buffer_entries(&tr->max_buffer, size); |
|
else |
|
per_cpu_ptr(tr->max_buffer.data, cpu)->entries = size; |
|
|
|
out: |
|
#endif /* CONFIG_TRACER_MAX_TRACE */ |
|
|
|
if (cpu == RING_BUFFER_ALL_CPUS) |
|
set_buffer_entries(&tr->array_buffer, size); |
|
else |
|
per_cpu_ptr(tr->array_buffer.data, cpu)->entries = size; |
|
|
|
return ret; |
|
} |
|
|
|
ssize_t tracing_resize_ring_buffer(struct trace_array *tr, |
|
unsigned long size, int cpu_id) |
|
{ |
|
int ret = size; |
|
|
|
mutex_lock(&trace_types_lock); |
|
|
|
if (cpu_id != RING_BUFFER_ALL_CPUS) { |
|
/* make sure, this cpu is enabled in the mask */ |
|
if (!cpumask_test_cpu(cpu_id, tracing_buffer_mask)) { |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
} |
|
|
|
ret = __tracing_resize_ring_buffer(tr, size, cpu_id); |
|
if (ret < 0) |
|
ret = -ENOMEM; |
|
|
|
out: |
|
mutex_unlock(&trace_types_lock); |
|
|
|
return ret; |
|
} |
|
|
|
|
|
/** |
|
* tracing_update_buffers - used by tracing facility to expand ring buffers |
|
* |
|
* To save on memory when the tracing is never used on a system with it |
|
* configured in. The ring buffers are set to a minimum size. But once |
|
* a user starts to use the tracing facility, then they need to grow |
|
* to their default size. |
|
* |
|
* This function is to be called when a tracer is about to be used. |
|
*/ |
|
int tracing_update_buffers(void) |
|
{ |
|
int ret = 0; |
|
|
|
mutex_lock(&trace_types_lock); |
|
if (!ring_buffer_expanded) |
|
ret = __tracing_resize_ring_buffer(&global_trace, trace_buf_size, |
|
RING_BUFFER_ALL_CPUS); |
|
mutex_unlock(&trace_types_lock); |
|
|
|
return ret; |
|
} |
|
|
|
struct trace_option_dentry; |
|
|
|
static void |
|
create_trace_option_files(struct trace_array *tr, struct tracer *tracer); |
|
|
|
/* |
|
* Used to clear out the tracer before deletion of an instance. |
|
* Must have trace_types_lock held. |
|
*/ |
|
static void tracing_set_nop(struct trace_array *tr) |
|
{ |
|
if (tr->current_trace == &nop_trace) |
|
return; |
|
|
|
tr->current_trace->enabled--; |
|
|
|
if (tr->current_trace->reset) |
|
tr->current_trace->reset(tr); |
|
|
|
tr->current_trace = &nop_trace; |
|
} |
|
|
|
static void add_tracer_options(struct trace_array *tr, struct tracer *t) |
|
{ |
|
/* Only enable if the directory has been created already. */ |
|
if (!tr->dir) |
|
return; |
|
|
|
create_trace_option_files(tr, t); |
|
} |
|
|
|
int tracing_set_tracer(struct trace_array *tr, const char *buf) |
|
{ |
|
struct tracer *t; |
|
#ifdef CONFIG_TRACER_MAX_TRACE |
|
bool had_max_tr; |
|
#endif |
|
int ret = 0; |
|
|
|
mutex_lock(&trace_types_lock); |
|
|
|
if (!ring_buffer_expanded) { |
|
ret = __tracing_resize_ring_buffer(tr, trace_buf_size, |
|
RING_BUFFER_ALL_CPUS); |
|
if (ret < 0) |
|
goto out; |
|
ret = 0; |
|
} |
|
|
|
for (t = trace_types; t; t = t->next) { |
|
if (strcmp(t->name, buf) == 0) |
|
break; |
|
} |
|
if (!t) { |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
if (t == tr->current_trace) |
|
goto out; |
|
|
|
#ifdef CONFIG_TRACER_SNAPSHOT |
|
if (t->use_max_tr) { |
|
arch_spin_lock(&tr->max_lock); |
|
if (tr->cond_snapshot) |
|
ret = -EBUSY; |
|
arch_spin_unlock(&tr->max_lock); |
|
if (ret) |
|
goto out; |
|
} |
|
#endif |
|
/* Some tracers won't work on kernel command line */ |
|
if (system_state < SYSTEM_RUNNING && t->noboot) { |
|
pr_warn("Tracer '%s' is not allowed on command line, ignored\n", |
|
t->name); |
|
goto out; |
|
} |
|
|
|
/* Some tracers are only allowed for the top level buffer */ |
|
if (!trace_ok_for_array(t, tr)) { |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
|
|
/* If trace pipe files are being read, we can't change the tracer */ |
|
if (tr->trace_ref) { |
|
ret = -EBUSY; |
|
goto out; |
|
} |
|
|
|
trace_branch_disable(); |
|
|
|
tr->current_trace->enabled--; |
|
|
|
if (tr->current_trace->reset) |
|
tr->current_trace->reset(tr); |
|
|
|
/* Current trace needs to be nop_trace before synchronize_rcu */ |
|
tr->current_trace = &nop_trace; |
|
|
|
#ifdef CONFIG_TRACER_MAX_TRACE |
|
had_max_tr = tr->allocated_snapshot; |
|
|
|
if (had_max_tr && !t->use_max_tr) { |
|
/* |
|
* We need to make sure that the update_max_tr sees that |
|
* current_trace changed to nop_trace to keep it from |
|
* swapping the buffers after we resize it. |
|
* The update_max_tr is called from interrupts disabled |
|
* so a synchronized_sched() is sufficient. |
|
*/ |
|
synchronize_rcu(); |
|
free_snapshot(tr); |
|
} |
|
#endif |
|
|
|
#ifdef CONFIG_TRACER_MAX_TRACE |
|
if (t->use_max_tr && !had_max_tr) { |
|
ret = tracing_alloc_snapshot_instance(tr); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
#endif |
|
|
|
if (t->init) { |
|
ret = tracer_init(t, tr); |
|
if (ret) |
|
goto out; |
|
} |
|
|
|
tr->current_trace = t; |
|
tr->current_trace->enabled++; |
|
trace_branch_enable(tr); |
|
out: |
|
mutex_unlock(&trace_types_lock); |
|
|
|
return ret; |
|
} |
|
|
|
static ssize_t |
|
tracing_set_trace_write(struct file *filp, const char __user *ubuf, |
|
size_t cnt, loff_t *ppos) |
|
{ |
|
struct trace_array *tr = filp->private_data; |
|
char buf[MAX_TRACER_SIZE+1]; |
|
int i; |
|
size_t ret; |
|
int err; |
|
|
|
ret = cnt; |
|
|
|
if (cnt > MAX_TRACER_SIZE) |
|
cnt = MAX_TRACER_SIZE; |
|
|
|
if (copy_from_user(buf, ubuf, cnt)) |
|
return -EFAULT; |
|
|
|
buf[cnt] = 0; |
|
|
|
/* strip ending whitespace. */ |
|
for (i = cnt - 1; i > 0 && isspace(buf[i]); i--) |
|
buf[i] = 0; |
|
|
|
err = tracing_set_tracer(tr, buf); |
|
if (err) |
|
return err; |
|
|
|
*ppos += ret; |
|
|
|
return ret; |
|
} |
|
|
|
static ssize_t |
|
tracing_nsecs_read(unsigned long *ptr, char __user *ubuf, |
|
size_t cnt, loff_t *ppos) |
|
{ |
|
char buf[64]; |
|
int r; |
|
|
|
r = snprintf(buf, sizeof(buf), "%ld\n", |
|
*ptr == (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr)); |
|
if (r > sizeof(buf)) |
|
r = sizeof(buf); |
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
|
} |
|
|
|
static ssize_t |
|
tracing_nsecs_write(unsigned long *ptr, const char __user *ubuf, |
|
size_t cnt, loff_t *ppos) |
|
{ |
|
unsigned long val; |
|
int ret; |
|
|
|
ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
|
if (ret) |
|
return ret; |
|
|
|
*ptr = val * 1000; |
|
|
|
return cnt; |
|
} |
|
|
|
static ssize_t |
|
tracing_thresh_read(struct file *filp, char __user *ubuf, |
|
size_t cnt, loff_t *ppos) |
|
{ |
|
return tracing_nsecs_read(&tracing_thresh, ubuf, cnt, ppos); |
|
} |
|
|
|
static ssize_t |
|
tracing_thresh_write(struct file *filp, const char __user *ubuf, |
|
size_t cnt, loff_t *ppos) |
|
{ |
|
struct trace_array *tr = filp->private_data; |
|
int ret; |
|
|
|
mutex_lock(&trace_types_lock); |
|
ret = tracing_nsecs_write(&tracing_thresh, ubuf, cnt, ppos); |
|
if (ret < 0) |
|
goto out; |
|
|
|
if (tr->current_trace->update_thresh) { |
|
ret = tr->current_trace->update_thresh(tr); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
|
|
ret = cnt; |
|
out: |
|
mutex_unlock(&trace_types_lock); |
|
|
|
return ret; |
|
} |
|
|
|
#if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER) |
|
|
|
static ssize_t |
|
tracing_max_lat_read(struct file *filp, char __user *ubuf, |
|
size_t cnt, loff_t *ppos) |
|
{ |
|
return tracing_nsecs_read(filp->private_data, ubuf, cnt, ppos); |
|
} |
|
|
|
static ssize_t |
|
tracing_max_lat_write(struct file *filp, const char __user *ubuf, |
|
size_t cnt, loff_t *ppos) |
|
{ |
|
return tracing_nsecs_write(filp->private_data, ubuf, cnt, ppos); |
|
} |
|
|
|
#endif |
|
|
|
static int tracing_open_pipe(struct inode *inode, struct file *filp) |
|
{ |
|
struct trace_array *tr = inode->i_private; |
|
struct trace_iterator *iter; |
|
int ret; |
|
|
|
ret = tracing_check_open_get_tr(tr); |
|
if (ret) |
|
return ret; |
|
|
|
mutex_lock(&trace_types_lock); |
|
|
|
/* create a buffer to store the information to pass to userspace */ |
|
iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
|
if (!iter) { |
|
ret = -ENOMEM; |
|
__trace_array_put(tr); |
|
goto out; |
|
} |
|
|
|
trace_seq_init(&iter->seq); |
|
iter->trace = tr->current_trace; |
|
|
|
if (!alloc_cpumask_var(&iter->started, GFP_KERNEL)) { |
|
ret = -ENOMEM; |
|
goto fail; |
|
} |
|
|
|
/* trace pipe does not show start of buffer */ |
|
cpumask_setall(iter->started); |
|
|
|
if (tr->trace_flags & TRACE_ITER_LATENCY_FMT) |
|
iter->iter_flags |= TRACE_FILE_LAT_FMT; |
|
|
|
/* Output in nanoseconds only if we are using a clock in nanoseconds. */ |
|
if (trace_clocks[tr->clock_id].in_ns) |
|
iter->iter_flags |= TRACE_FILE_TIME_IN_NS; |
|
|
|
iter->tr = tr; |
|
iter->array_buffer = &tr->array_buffer; |
|
iter->cpu_file = tracing_get_cpu(inode); |
|
mutex_init(&iter->mutex); |
|
filp->private_data = iter; |
|
|
|
if (iter->trace->pipe_open) |
|
iter->trace->pipe_open(iter); |
|
|
|
nonseekable_open(inode, filp); |
|
|
|
tr->trace_ref++; |
|
out: |
|
mutex_unlock(&trace_types_lock); |
|
return ret; |
|
|
|
fail: |
|
kfree(iter); |
|
__trace_array_put(tr); |
|
mutex_unlock(&trace_types_lock); |
|
return ret; |
|
} |
|
|
|
static int tracing_release_pipe(struct inode *inode, struct file *file) |
|
{ |
|
struct trace_iterator *iter = file->private_data; |
|
struct trace_array *tr = inode->i_private; |
|
|
|
mutex_lock(&trace_types_lock); |
|
|
|
tr->trace_ref--; |
|
|
|
if (iter->trace->pipe_close) |
|
iter->trace->pipe_close(iter); |
|
|
|
mutex_unlock(&trace_types_lock); |
|
|
|
free_cpumask_var(iter->started); |
|
mutex_destroy(&iter->mutex); |
|
kfree(iter); |
|
|
|
trace_array_put(tr); |
|
|
|
return 0; |
|
} |
|
|
|
static __poll_t |
|
trace_poll(struct trace_iterator *iter, struct file *filp, poll_table *poll_table) |
|
{ |
|
struct trace_array *tr = iter->tr; |
|
|
|
/* Iterators are static, they should be filled or empty */ |
|
if (trace_buffer_iter(iter, iter->cpu_file)) |
|
return EPOLLIN | EPOLLRDNORM; |
|
|
|
if (tr->trace_flags & TRACE_ITER_BLOCK) |
|
/* |
|
* Always select as readable when in blocking mode |
|
*/ |
|
return EPOLLIN | EPOLLRDNORM; |
|
else |
|
return ring_buffer_poll_wait(iter->array_buffer->buffer, iter->cpu_file, |
|
filp, poll_table); |
|
} |
|
|
|
static __poll_t |
|
tracing_poll_pipe(struct file *filp, poll_table *poll_table) |
|
{ |
|
struct trace_iterator *iter = filp->private_data; |
|
|
|
return trace_poll(iter, filp, poll_table); |
|
} |
|
|
|
/* Must be called with iter->mutex held. */ |
|
static int tracing_wait_pipe(struct file *filp) |
|
{ |
|
struct trace_iterator *iter = filp->private_data; |
|
int ret; |
|
|
|
while (trace_empty(iter)) { |
|
|
|
if ((filp->f_flags & O_NONBLOCK)) { |
|
return -EAGAIN; |
|
} |
|
|
|
/* |
|
* We block until we read something and tracing is disabled. |
|
* We still block if tracing is disabled, but we have never |
|
* read anything. This allows a user to cat this file, and |
|
* then enable tracing. But after we have read something, |
|
* we give an EOF when tracing is again disabled. |
|
* |
|
* iter->pos will be 0 if we haven't read anything. |
|
*/ |
|
if (!tracer_tracing_is_on(iter->tr) && iter->pos) |
|
break; |
|
|
|
mutex_unlock(&iter->mutex); |
|
|
|
ret = wait_on_pipe(iter, 0); |
|
|
|
mutex_lock(&iter->mutex); |
|
|
|
if (ret) |
|
return ret; |
|
} |
|
|
|
return 1; |
|
} |
|
|
|
/* |
|
* Consumer reader. |
|
*/ |
|
static ssize_t |
|
tracing_read_pipe(struct file *filp, char __user *ubuf, |
|
size_t cnt, loff_t *ppos) |
|
{ |
|
struct trace_iterator *iter = filp->private_data; |
|
ssize_t sret; |
|
|
|
/* |
|
* Avoid more than one consumer on a single file descriptor |
|
* This is just a matter of traces coherency, the ring buffer itself |
|
* is protected. |
|
*/ |
|
mutex_lock(&iter->mutex); |
|
|
|
/* return any leftover data */ |
|
sret = trace_seq_to_user(&iter->seq, ubuf, cnt); |
|
if (sret != -EBUSY) |
|
goto out; |
|
|
|
trace_seq_init(&iter->seq); |
|
|
|
if (iter->trace->read) { |
|
sret = iter->trace->read(iter, filp, ubuf, cnt, ppos); |
|
if (sret) |
|
goto out; |
|
} |
|
|
|
waitagain: |
|
sret = tracing_wait_pipe(filp); |
|
if (sret <= 0) |
|
goto out; |
|
|
|
/* stop when tracing is finished */ |
|
if (trace_empty(iter)) { |
|
sret = 0; |
|
goto out; |
|
} |
|
|
|
if (cnt >= PAGE_SIZE) |
|
cnt = PAGE_SIZE - 1; |
|
|
|
/* reset all but tr, trace, and overruns */ |
|
memset(&iter->seq, 0, |
|
sizeof(struct trace_iterator) - |
|
offsetof(struct trace_iterator, seq)); |
|
cpumask_clear(iter->started); |
|
trace_seq_init(&iter->seq); |
|
iter->pos = -1; |
|
|
|
trace_event_read_lock(); |
|
trace_access_lock(iter->cpu_file); |
|
while (trace_find_next_entry_inc(iter) != NULL) { |
|
enum print_line_t ret; |
|
int save_len = iter->seq.seq.len; |
|
|
|
ret = print_trace_line(iter); |
|
if (ret == TRACE_TYPE_PARTIAL_LINE) { |
|
/* don't print partial lines */ |
|
iter->seq.seq.len = save_len; |
|
break; |
|
} |
|
if (ret != TRACE_TYPE_NO_CONSUME) |
|
trace_consume(iter); |
|
|
|
if (trace_seq_used(&iter->seq) >= cnt) |
|
break; |
|
|
|
/* |
|
* Setting the full flag means we reached the trace_seq buffer |
|
* size and we should leave by partial output condition above. |
|
* One of the trace_seq_* functions is not used properly. |
|
*/ |
|
WARN_ONCE(iter->seq.full, "full flag set for trace type %d", |
|
iter->ent->type); |
|
} |
|
trace_access_unlock(iter->cpu_file); |
|
trace_event_read_unlock(); |
|
|
|
/* Now copy what we have to the user */ |
|
sret = trace_seq_to_user(&iter->seq, ubuf, cnt); |
|
if (iter->seq.seq.readpos >= trace_seq_used(&iter->seq)) |
|
trace_seq_init(&iter->seq); |
|
|
|
/* |
|
* If there was nothing to send to user, in spite of consuming trace |
|
* entries, go back to wait for more entries. |
|
*/ |
|
if (sret == -EBUSY) |
|
goto waitagain; |
|
|
|
out: |
|
mutex_unlock(&iter->mutex); |
|
|
|
return sret; |
|
} |
|
|
|
static void tracing_spd_release_pipe(struct splice_pipe_desc *spd, |
|
unsigned int idx) |
|
{ |
|
__free_page(spd->pages[idx]); |
|
} |
|
|
|
static size_t |
|
tracing_fill_pipe_page(size_t rem, struct trace_iterator *iter) |
|
{ |
|
size_t count; |
|
int save_len; |
|
int ret; |
|
|
|
/* Seq buffer is page-sized, exactly what we need. */ |
|
for (;;) { |
|
save_len = iter->seq.seq.len; |
|
ret = print_trace_line(iter); |
|
|
|
if (trace_seq_has_overflowed(&iter->seq)) { |
|
iter->seq.seq.len = save_len; |
|
break; |
|
} |
|
|
|
/* |
|
* This should not be hit, because it should only |
|
* be set if the iter->seq overflowed. But check it |
|
* anyway to be safe. |
|
*/ |
|
if (ret == TRACE_TYPE_PARTIAL_LINE) { |
|
iter->seq.seq.len = save_len; |
|
break; |
|
} |
|
|
|
count = trace_seq_used(&iter->seq) - save_len; |
|
if (rem < count) { |
|
rem = 0; |
|
iter->seq.seq.len = save_len; |
|
break; |
|
} |
|
|
|
if (ret != TRACE_TYPE_NO_CONSUME) |
|
trace_consume(iter); |
|
rem -= count; |
|
if (!trace_find_next_entry_inc(iter)) { |
|
rem = 0; |
|
iter->ent = NULL; |
|
break; |
|
} |
|
} |
|
|
|
return rem; |
|
} |
|
|
|
static ssize_t tracing_splice_read_pipe(struct file *filp, |
|
loff_t *ppos, |
|
struct pipe_inode_info *pipe, |
|
size_t len, |
|
unsigned int flags) |
|
{ |
|
struct page *pages_def[PIPE_DEF_BUFFERS]; |
|
struct partial_page partial_def[PIPE_DEF_BUFFERS]; |
|
struct trace_iterator *iter = filp->private_data; |
|
struct splice_pipe_desc spd = { |
|
.pages = pages_def, |
|
.partial = partial_def, |
|
.nr_pages = 0, /* This gets updated below. */ |
|
.nr_pages_max = PIPE_DEF_BUFFERS, |
|
.ops = &default_pipe_buf_ops, |
|
.spd_release = tracing_spd_release_pipe, |
|
}; |
|
ssize_t ret; |
|
size_t rem; |
|
unsigned int i; |
|
|
|
if (splice_grow_spd(pipe, &spd)) |
|
return -ENOMEM; |
|
|
|
mutex_lock(&iter->mutex); |
|
|
|
if (iter->trace->splice_read) { |
|
ret = iter->trace->splice_read(iter, filp, |
|
ppos, pipe, len, flags); |
|
if (ret) |
|
goto out_err; |
|
} |
|
|
|
ret = tracing_wait_pipe(filp); |
|
if (ret <= 0) |
|
goto out_err; |
|
|
|
if (!iter->ent && !trace_find_next_entry_inc(iter)) { |
|
ret = -EFAULT; |
|
goto out_err; |
|
} |
|
|
|
trace_event_read_lock(); |
|
trace_access_lock(iter->cpu_file); |
|
|
|
/* Fill as many pages as possible. */ |
|
for (i = 0, rem = len; i < spd.nr_pages_max && rem; i++) { |
|
spd.pages[i] = alloc_page(GFP_KERNEL); |
|
if (!spd.pages[i]) |
|
break; |
|
|
|
rem = tracing_fill_pipe_page(rem, iter); |
|
|
|
/* Copy the data into the page, so we can start over. */ |
|
ret = trace_seq_to_buffer(&iter->seq, |
|
page_address(spd.pages[i]), |
|
trace_seq_used(&iter->seq)); |
|
if (ret < 0) { |
|
__free_page(spd.pages[i]); |
|
break; |
|
} |
|
spd.partial[i].offset = 0; |
|
spd.partial[i].len = trace_seq_used(&iter->seq); |
|
|
|
trace_seq_init(&iter->seq); |
|
} |
|
|
|
trace_access_unlock(iter->cpu_file); |
|
trace_event_read_unlock(); |
|
mutex_unlock(&iter->mutex); |
|
|
|
spd.nr_pages = i; |
|
|
|
if (i) |
|
ret = splice_to_pipe(pipe, &spd); |
|
else |
|
ret = 0; |
|
out: |
|
splice_shrink_spd(&spd); |
|
return ret; |
|
|
|
out_err: |
|
mutex_unlock(&iter->mutex); |
|
goto out; |
|
} |
|
|
|
static ssize_t |
|
tracing_entries_read(struct file *filp, char __user *ubuf, |
|
size_t cnt, loff_t *ppos) |
|
{ |
|
struct inode *inode = file_inode(filp); |
|
struct trace_array *tr = inode->i_private; |
|
int cpu = tracing_get_cpu(inode); |
|
char buf[64]; |
|
int r = 0; |
|
ssize_t ret; |
|
|
|
mutex_lock(&trace_types_lock); |
|
|
|
if (cpu == RING_BUFFER_ALL_CPUS) { |
|
int cpu, buf_size_same; |
|
unsigned long size; |
|
|
|
size = 0; |
|
buf_size_same = 1; |
|
/* check if all cpu sizes are same */ |
|
for_each_tracing_cpu(cpu) { |
|
/* fill in the size from first enabled cpu */ |
|
if (size == 0) |
|
size = per_cpu_ptr(tr->array_buffer.data, cpu)->entries; |
|
if (size != per_cpu_ptr(tr->array_buffer.data, cpu)->entries) { |
|
buf_size_same = 0; |
|
break; |
|
} |
|
} |
|
|
|
if (buf_size_same) { |
|
if (!ring_buffer_expanded) |
|
r = sprintf(buf, "%lu (expanded: %lu)\n", |
|
size >> 10, |
|
trace_buf_size >> 10); |
|
else |
|
r = sprintf(buf, "%lu\n", size >> 10); |
|
} else |
|
r = sprintf(buf, "X\n"); |
|
} else |
|
r = sprintf(buf, "%lu\n", per_cpu_ptr(tr->array_buffer.data, cpu)->entries >> 10); |
|
|
|
mutex_unlock(&trace_types_lock); |
|
|
|
ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
|
return ret; |
|
} |
|
|
|
static ssize_t |
|
tracing_entries_write(struct file *filp, const char __user *ubuf, |
|
size_t cnt, loff_t *ppos) |
|
{ |
|
struct inode *inode = file_inode(filp); |
|
struct trace_array *tr = inode->i_private; |
|
unsigned long val; |
|
int ret; |
|
|
|
ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
|
if (ret) |
|
return ret; |
|
|
|
/* must have at least 1 entry */ |
|
if (!val) |
|
return -EINVAL; |
|
|
|
/* value is in KB */ |
|
val <<= 10; |
|
ret = tracing_resize_ring_buffer(tr, val, tracing_get_cpu(inode)); |
|
if (ret < 0) |
|
return ret; |
|
|
|
*ppos += cnt; |
|
|
|
return cnt; |
|
} |
|
|
|
static ssize_t |
|
tracing_total_entries_read(struct file *filp, char __user *ubuf, |
|
size_t cnt, loff_t *ppos) |
|
{ |
|
struct trace_array *tr = filp->private_data; |
|
char buf[64]; |
|
int r, cpu; |
|
unsigned long size = 0, expanded_size = 0; |
|
|
|
mutex_lock(&trace_types_lock); |
|
for_each_tracing_cpu(cpu) { |
|
size += per_cpu_ptr(tr->array_buffer.data, cpu)->entries >> 10; |
|
if (!ring_buffer_expanded) |
|
expanded_size += trace_buf_size >> 10; |
|
} |
|
if (ring_buffer_expanded) |
|
r = sprintf(buf, "%lu\n", size); |
|
else |
|
r = sprintf(buf, "%lu (expanded: %lu)\n", size, expanded_size); |
|
mutex_unlock(&trace_types_lock); |
|
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
|
} |
|
|
|
static ssize_t |
|
tracing_free_buffer_write(struct file *filp, const char __user *ubuf, |
|
size_t cnt, loff_t *ppos) |
|
{ |
|
/* |
|
* There is no need to read what the user has written, this function |
|
* is just to make sure that there is no error when "echo" is used |
|
*/ |
|
|
|
*ppos += cnt; |
|
|
|
return cnt; |
|
} |
|
|
|
static int |
|
tracing_free_buffer_release(struct inode *inode, struct file *filp) |
|
{ |
|
struct trace_array *tr = inode->i_private; |
|
|
|
/* disable tracing ? */ |
|
if (tr->trace_flags & TRACE_ITER_STOP_ON_FREE) |
|
tracer_tracing_off(tr); |
|
/* resize the ring buffer to 0 */ |
|
tracing_resize_ring_buffer(tr, 0, RING_BUFFER_ALL_CPUS); |
|
|
|
trace_array_put(tr); |
|
|
|
return 0; |
|
} |
|
|
|
static ssize_t |
|
tracing_mark_write(struct file *filp, const char __user *ubuf, |
|
size_t cnt, loff_t *fpos) |
|
{ |
|
struct trace_array *tr = filp->private_data; |
|
struct ring_buffer_event *event; |
|
enum event_trigger_type tt = ETT_NONE; |
|
struct trace_buffer *buffer; |
|
struct print_entry *entry; |
|
ssize_t written; |
|
int size; |
|
int len; |
|
|
|
/* Used in tracing_mark_raw_write() as well */ |
|
#define FAULTED_STR "<faulted>" |
|
#define FAULTED_SIZE (sizeof(FAULTED_STR) - 1) /* '\0' is already accounted for */ |
|
|
|
if (tracing_disabled) |
|
return -EINVAL; |
|
|
|
if (!(tr->trace_flags & TRACE_ITER_MARKERS)) |
|
return -EINVAL; |
|
|
|
if (cnt > TRACE_BUF_SIZE) |
|
cnt = TRACE_BUF_SIZE; |
|
|
|
BUILD_BUG_ON(TRACE_BUF_SIZE >= PAGE_SIZE); |
|
|
|
size = sizeof(*entry) + cnt + 2; /* add '\0' and possible '\n' */ |
|
|
|
/* If less than "<faulted>", then make sure we can still add that */ |
|
if (cnt < FAULTED_SIZE) |
|
size += FAULTED_SIZE - cnt; |
|
|
|
buffer = tr->array_buffer.buffer; |
|
event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, size, |
|
tracing_gen_ctx()); |
|
if (unlikely(!event)) |
|
/* Ring buffer disabled, return as if not open for write */ |
|
return -EBADF; |
|
|
|
entry = ring_buffer_event_data(event); |
|
entry->ip = _THIS_IP_; |
|
|
|
len = __copy_from_user_inatomic(&entry->buf, ubuf, cnt); |
|
if (len) { |
|
memcpy(&entry->buf, FAULTED_STR, FAULTED_SIZE); |
|
cnt = FAULTED_SIZE; |
|
written = -EFAULT; |
|
} else |
|
written = cnt; |
|
|
|
if (tr->trace_marker_file && !list_empty(&tr->trace_marker_file->triggers)) { |
|
/* do not add \n before testing triggers, but add \0 */ |
|
entry->buf[cnt] = '\0'; |
|
tt = event_triggers_call(tr->trace_marker_file, entry, event); |
|
} |
|
|
|
if (entry->buf[cnt - 1] != '\n') { |
|
entry->buf[cnt] = '\n'; |
|
entry->buf[cnt + 1] = '\0'; |
|
} else |
|
entry->buf[cnt] = '\0'; |
|
|
|
if (static_branch_unlikely(&trace_marker_exports_enabled)) |
|
ftrace_exports(event, TRACE_EXPORT_MARKER); |
|
__buffer_unlock_commit(buffer, event); |
|
|
|
if (tt) |
|
event_triggers_post_call(tr->trace_marker_file, tt); |
|
|
|
if (written > 0) |
|
*fpos += written; |
|
|
|
return written; |
|
} |
|
|
|
/* Limit it for now to 3K (including tag) */ |
|
#define RAW_DATA_MAX_SIZE (1024*3) |
|
|
|
static ssize_t |
|
tracing_mark_raw_write(struct file *filp, const char __user *ubuf, |
|
size_t cnt, loff_t *fpos) |
|
{ |
|
struct trace_array *tr = filp->private_data; |
|
struct ring_buffer_event *event; |
|
struct trace_buffer *buffer; |
|
struct raw_data_entry *entry; |
|
ssize_t written; |
|
int size; |
|
int len; |
|
|
|
#define FAULT_SIZE_ID (FAULTED_SIZE + sizeof(int)) |
|
|
|
if (tracing_disabled) |
|
return -EINVAL; |
|
|
|
if (!(tr->trace_flags & TRACE_ITER_MARKERS)) |
|
return -EINVAL; |
|
|
|
/* The marker must at least have a tag id */ |
|
if (cnt < sizeof(unsigned int) || cnt > RAW_DATA_MAX_SIZE) |
|
return -EINVAL; |
|
|
|
if (cnt > TRACE_BUF_SIZE) |
|
cnt = TRACE_BUF_SIZE; |
|
|
|
BUILD_BUG_ON(TRACE_BUF_SIZE >= PAGE_SIZE); |
|
|
|
size = sizeof(*entry) + cnt; |
|
if (cnt < FAULT_SIZE_ID) |
|
size += FAULT_SIZE_ID - cnt; |
|
|
|
buffer = tr->array_buffer.buffer; |
|
event = __trace_buffer_lock_reserve(buffer, TRACE_RAW_DATA, size, |
|
tracing_gen_ctx()); |
|
if (!event) |
|
/* Ring buffer disabled, return as if not open for write */ |
|
return -EBADF; |
|
|
|
entry = ring_buffer_event_data(event); |
|
|
|
len = __copy_from_user_inatomic(&entry->id, ubuf, cnt); |
|
if (len) { |
|
entry->id = -1; |
|
memcpy(&entry->buf, FAULTED_STR, FAULTED_SIZE); |
|
written = -EFAULT; |
|
} else |
|
written = cnt; |
|
|
|
__buffer_unlock_commit(buffer, event); |
|
|
|
if (written > 0) |
|
*fpos += written; |
|
|
|
return written; |
|
} |
|
|
|
static int tracing_clock_show(struct seq_file *m, void *v) |
|
{ |
|
struct trace_array *tr = m->private; |
|
int i; |
|
|
|
for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) |
|
seq_printf(m, |
|
"%s%s%s%s", i ? " " : "", |
|
i == tr->clock_id ? "[" : "", trace_clocks[i].name, |
|
i == tr->clock_id ? "]" : ""); |
|
seq_putc(m, '\n'); |
|
|
|
return 0; |
|
} |
|
|
|
int tracing_set_clock(struct trace_array *tr, const char *clockstr) |
|
{ |
|
int i; |
|
|
|
for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) { |
|
if (strcmp(trace_clocks[i].name, clockstr) == 0) |
|
break; |
|
} |
|
if (i == ARRAY_SIZE(trace_clocks)) |
|
return -EINVAL; |
|
|
|
mutex_lock(&trace_types_lock); |
|
|
|
tr->clock_id = i; |
|
|
|
ring_buffer_set_clock(tr->array_buffer.buffer, trace_clocks[i].func); |
|
|
|
/* |
|
* New clock may not be consistent with the previous clock. |
|
* Reset the buffer so that it doesn't have incomparable timestamps. |
|
*/ |
|
tracing_reset_online_cpus(&tr->array_buffer); |
|
|
|
#ifdef CONFIG_TRACER_MAX_TRACE |
|
if (tr->max_buffer.buffer) |
|
ring_buffer_set_clock(tr->max_buffer.buffer, trace_clocks[i].func); |
|
tracing_reset_online_cpus(&tr->max_buffer); |
|
#endif |
|
|
|
mutex_unlock(&trace_types_lock); |
|
|
|
return 0; |
|
} |
|
|
|
static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf, |
|
size_t cnt, loff_t *fpos) |
|
{ |
|
struct seq_file *m = filp->private_data; |
|
struct trace_array *tr = m->private; |
|
char buf[64]; |
|
const char *clockstr; |
|
int ret; |
|
|
|
if (cnt >= sizeof(buf)) |
|
return -EINVAL; |
|
|
|
if (copy_from_user(buf, ubuf, cnt)) |
|
return -EFAULT; |
|
|
|
buf[cnt] = 0; |
|
|
|
clockstr = strstrip(buf); |
|
|
|
ret = tracing_set_clock(tr, clockstr); |
|
if (ret) |
|
return ret; |
|
|
|
*fpos += cnt; |
|
|
|
return cnt; |
|
} |
|
|
|
static int tracing_clock_open(struct inode *inode, struct file *file) |
|
{ |
|
struct trace_array *tr = inode->i_private; |
|
int ret; |
|
|
|
ret = tracing_check_open_get_tr(tr); |
|
if (ret) |
|
return ret; |
|
|
|
ret = single_open(file, tracing_clock_show, inode->i_private); |
|
if (ret < 0) |
|
trace_array_put(tr); |
|
|
|
return ret; |
|
} |
|
|
|
static int tracing_time_stamp_mode_show(struct seq_file *m, void *v) |
|
{ |
|
struct trace_array *tr = m->private; |
|
|
|
mutex_lock(&trace_types_lock); |
|
|
|
if (ring_buffer_time_stamp_abs(tr->array_buffer.buffer)) |
|
seq_puts(m, "delta [absolute]\n"); |
|
else |
|
seq_puts(m, "[delta] absolute\n"); |
|
|
|
mutex_unlock(&trace_types_lock); |
|
|
|
return 0; |
|
} |
|
|
|
static int tracing_time_stamp_mode_open(struct inode *inode, struct file *file) |
|
{ |
|
struct trace_array *tr = inode->i_private; |
|
int ret; |
|
|
|
ret = tracing_check_open_get_tr(tr); |
|
if (ret) |
|
return ret; |
|
|
|
ret = single_open(file, tracing_time_stamp_mode_show, inode->i_private); |
|
if (ret < 0) |
|
trace_array_put(tr); |
|
|
|
return ret; |
|
} |
|
|
|
int tracing_set_time_stamp_abs(struct trace_array *tr, bool abs) |
|
{ |
|
int ret = 0; |
|
|
|
mutex_lock(&trace_types_lock); |
|
|
|
if (abs && tr->time_stamp_abs_ref++) |
|
goto out; |
|
|
|
if (!abs) { |
|
if (WARN_ON_ONCE(!tr->time_stamp_abs_ref)) { |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
|
|
if (--tr->time_stamp_abs_ref) |
|
goto out; |
|
} |
|
|
|
ring_buffer_set_time_stamp_abs(tr->array_buffer.buffer, abs); |
|
|
|
#ifdef CONFIG_TRACER_MAX_TRACE |
|
if (tr->max_buffer.buffer) |
|
ring_buffer_set_time_stamp_abs(tr->max_buffer.buffer, abs); |
|
#endif |
|
out: |
|
mutex_unlock(&trace_types_lock); |
|
|
|
return ret; |
|
} |
|
|
|
struct ftrace_buffer_info { |
|
struct trace_iterator iter; |
|
void *spare; |
|
unsigned int spare_cpu; |
|
unsigned int read; |
|
}; |
|
|
|
#ifdef CONFIG_TRACER_SNAPSHOT |
|
static int tracing_snapshot_open(struct inode *inode, struct file *file) |
|
{ |
|
struct trace_array *tr = inode->i_private; |
|
struct trace_iterator *iter; |
|
struct seq_file *m; |
|
int ret; |
|
|
|
ret = tracing_check_open_get_tr(tr); |
|
if (ret) |
|
return ret; |
|
|
|
if (file->f_mode & FMODE_READ) { |
|
iter = __tracing_open(inode, file, true); |
|
if (IS_ERR(iter)) |
|
ret = PTR_ERR(iter); |
|
} else { |
|
/* Writes still need the seq_file to hold the private data */ |
|
ret = -ENOMEM; |
|
m = kzalloc(sizeof(*m), GFP_KERNEL); |
|
if (!m) |
|
goto out; |
|
iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
|
if (!iter) { |
|
kfree(m); |
|
goto out; |
|
} |
|
ret = 0; |
|
|
|
iter->tr = tr; |
|
iter->array_buffer = &tr->max_buffer; |
|
iter->cpu_file = tracing_get_cpu(inode); |
|
m->private = iter; |
|
file->private_data = m; |
|
} |
|
out: |
|
if (ret < 0) |
|
trace_array_put(tr); |
|
|
|
return ret; |
|
} |
|
|
|
static ssize_t |
|
tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt, |
|
loff_t *ppos) |
|
{ |
|
struct seq_file *m = filp->private_data; |
|
struct trace_iterator *iter = m->private; |
|
struct trace_array *tr = iter->tr; |
|
unsigned long val; |
|
int ret; |
|
|
|
ret = tracing_update_buffers(); |
|
if (ret < 0) |
|
return ret; |
|
|
|
ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
|
if (ret) |
|
return ret; |
|
|
|
mutex_lock(&trace_types_lock); |
|
|
|
if (tr->current_trace->use_max_tr) { |
|
ret = -EBUSY; |
|
goto out; |
|
} |
|
|
|
arch_spin_lock(&tr->max_lock); |
|
if (tr->cond_snapshot) |
|
ret = -EBUSY; |
|
arch_spin_unlock(&tr->max_lock); |
|
if (ret) |
|
goto out; |
|
|
|
switch (val) { |
|
case 0: |
|
if (iter->cpu_file != RING_BUFFER_ALL_CPUS) { |
|
ret = -EINVAL; |
|
break; |
|
} |
|
if (tr->allocated_snapshot) |
|
free_snapshot(tr); |
|
break; |
|
case 1: |
|
/* Only allow per-cpu swap if the ring buffer supports it */ |
|
#ifndef CONFIG_RING_BUFFER_ALLOW_SWAP |
|
if (iter->cpu_file != RING_BUFFER_ALL_CPUS) { |
|
ret = -EINVAL; |
|
break; |
|
} |
|
#endif |
|
if (tr->allocated_snapshot) |
|
ret = resize_buffer_duplicate_size(&tr->max_buffer, |
|
&tr->array_buffer, iter->cpu_file); |
|
else |
|
ret = tracing_alloc_snapshot_instance(tr); |
|
if (ret < 0) |
|
break; |
|
local_irq_disable(); |
|
/* Now, we're going to swap */ |
|
if (iter->cpu_file == RING_BUFFER_ALL_CPUS) |
|
update_max_tr(tr, current, smp_processor_id(), NULL); |
|
else |
|
update_max_tr_single(tr, current, iter->cpu_file); |
|
local_irq_enable(); |
|
break; |
|
default: |
|
if (tr->allocated_snapshot) { |
|
if (iter->cpu_file == RING_BUFFER_ALL_CPUS) |
|
tracing_reset_online_cpus(&tr->max_buffer); |
|
else |
|
tracing_reset_cpu(&tr->max_buffer, iter->cpu_file); |
|
} |
|
break; |
|
} |
|
|
|
if (ret >= 0) { |
|
*ppos += cnt; |
|
ret = cnt; |
|
} |
|
out: |
|
mutex_unlock(&trace_types_lock); |
|
return ret; |
|
} |
|
|
|
static int tracing_snapshot_release(struct inode *inode, struct file *file) |
|
{ |
|
struct seq_file *m = file->private_data; |
|
int ret; |
|
|
|
ret = tracing_release(inode, file); |
|
|
|
if (file->f_mode & FMODE_READ) |
|
return ret; |
|
|
|
/* If write only, the seq_file is just a stub */ |
|
if (m) |
|
kfree(m->private); |
|
kfree(m); |
|
|
|
return 0; |
|
} |
|
|
|
static int tracing_buffers_open(struct inode *inode, struct file *filp); |
|
static ssize_t tracing_buffers_read(struct file *filp, char __user *ubuf, |
|
size_t count, loff_t *ppos); |
|
static int tracing_buffers_release(struct inode *inode, struct file *file); |
|
static ssize_t tracing_buffers_splice_read(struct file *file, loff_t *ppos, |
|
struct pipe_inode_info *pipe, size_t len, unsigned int flags); |
|
|
|
static int snapshot_raw_open(struct inode *inode, struct file *filp) |
|
{ |
|
struct ftrace_buffer_info *info; |
|
int ret; |
|
|
|
/* The following checks for tracefs lockdown */ |
|
ret = tracing_buffers_open(inode, filp); |
|
if (ret < 0) |
|
return ret; |
|
|
|
info = filp->private_data; |
|
|
|
if (info->iter.trace->use_max_tr) { |
|
tracing_buffers_release(inode, filp); |
|
return -EBUSY; |
|
} |
|
|
|
info->iter.snapshot = true; |
|
info->iter.array_buffer = &info->iter.tr->max_buffer; |
|
|
|
return ret; |
|
} |
|
|
|
#endif /* CONFIG_TRACER_SNAPSHOT */ |
|
|
|
|
|
static const struct file_operations tracing_thresh_fops = { |
|
.open = tracing_open_generic, |
|
.read = tracing_thresh_read, |
|
.write = tracing_thresh_write, |
|
.llseek = generic_file_llseek, |
|
}; |
|
|
|
#if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER) |
|
static const struct file_operations tracing_max_lat_fops = { |
|
.open = tracing_open_generic, |
|
.read = tracing_max_lat_read, |
|
.write = tracing_max_lat_write, |
|
.llseek = generic_file_llseek, |
|
}; |
|
#endif |
|
|
|
static const struct file_operations set_tracer_fops = { |
|
.open = tracing_open_generic, |
|
.read = tracing_set_trace_read, |
|
.write = tracing_set_trace_write, |
|
.llseek = generic_file_llseek, |
|
}; |
|
|
|
static const struct file_operations tracing_pipe_fops = { |
|
.open = tracing_open_pipe, |
|
.poll = tracing_poll_pipe, |
|
.read = tracing_read_pipe, |
|
.splice_read = tracing_splice_read_pipe, |
|
.release = tracing_release_pipe, |
|
.llseek = no_llseek, |
|
}; |
|
|
|
static const struct file_operations tracing_entries_fops = { |
|
.open = tracing_open_generic_tr, |
|
.read = tracing_entries_read, |
|
.write = tracing_entries_write, |
|
.llseek = generic_file_llseek, |
|
.release = tracing_release_generic_tr, |
|
}; |
|
|
|
static const struct file_operations tracing_total_entries_fops = { |
|
.open = tracing_open_generic_tr, |
|
.read = tracing_total_entries_read, |
|
.llseek = generic_file_llseek, |
|
.release = tracing_release_generic_tr, |
|
}; |
|
|
|
static const struct file_operations tracing_free_buffer_fops = { |
|
.open = tracing_open_generic_tr, |
|
.write = tracing_free_buffer_write, |
|
.release = tracing_free_buffer_release, |
|
}; |
|
|
|
static const struct file_operations tracing_mark_fops = { |
|
.open = tracing_open_generic_tr, |
|
.write = tracing_mark_write, |
|
.llseek = generic_file_llseek, |
|
.release = tracing_release_generic_tr, |
|
}; |
|
|
|
static const struct file_operations tracing_mark_raw_fops = { |
|
.open = tracing_open_generic_tr, |
|
.write = tracing_mark_raw_write, |
|
.llseek = generic_file_llseek, |
|
.release = tracing_release_generic_tr, |
|
}; |
|
|
|
static const struct file_operations trace_clock_fops = { |
|
.open = tracing_clock_open, |
|
.read = seq_read, |
|
.llseek = seq_lseek, |
|
.release = tracing_single_release_tr, |
|
.write = tracing_clock_write, |
|
}; |
|
|
|
static const struct file_operations trace_time_stamp_mode_fops = { |
|
.open = tracing_time_stamp_mode_open, |
|
.read = seq_read, |
|
.llseek = seq_lseek, |
|
.release = tracing_single_release_tr, |
|
}; |
|
|
|
#ifdef CONFIG_TRACER_SNAPSHOT |
|
static const struct file_operations snapshot_fops = { |
|
.open = tracing_snapshot_open, |
|
.read = seq_read, |
|
.write = tracing_snapshot_write, |
|
.llseek = tracing_lseek, |
|
.release = tracing_snapshot_release, |
|
}; |
|
|
|
static const struct file_operations snapshot_raw_fops = { |
|
.open = snapshot_raw_open, |
|
.read = tracing_buffers_read, |
|
.release = tracing_buffers_release, |
|
.splice_read = tracing_buffers_splice_read, |
|
.llseek = no_llseek, |
|
}; |
|
|
|
#endif /* CONFIG_TRACER_SNAPSHOT */ |
|
|
|
#define TRACING_LOG_ERRS_MAX 8 |
|
#define TRACING_LOG_LOC_MAX 128 |
|
|
|
#define CMD_PREFIX " Command: " |
|
|
|
struct err_info { |
|
const char **errs; /* ptr to loc-specific array of err strings */ |
|
u8 type; /* index into errs -> specific err string */ |
|
u8 pos; /* MAX_FILTER_STR_VAL = 256 */ |
|
u64 ts; |
|
}; |
|
|
|
struct tracing_log_err { |
|
struct list_head list; |
|
struct err_info info; |
|
char loc[TRACING_LOG_LOC_MAX]; /* err location */ |
|
char cmd[MAX_FILTER_STR_VAL]; /* what caused err */ |
|
}; |
|
|
|
static DEFINE_MUTEX(tracing_err_log_lock); |
|
|
|
static struct tracing_log_err *get_tracing_log_err(struct trace_array *tr) |
|
{ |
|
struct tracing_log_err *err; |
|
|
|
if (tr->n_err_log_entries < TRACING_LOG_ERRS_MAX) { |
|
err = kzalloc(sizeof(*err), GFP_KERNEL); |
|
if (!err) |
|
err = ERR_PTR(-ENOMEM); |
|
tr->n_err_log_entries++; |
|
|
|
return err; |
|
} |
|
|
|
err = list_first_entry(&tr->err_log, struct tracing_log_err, list); |
|
list_del(&err->list); |
|
|
|
return err; |
|
} |
|
|
|
/** |
|
* err_pos - find the position of a string within a command for error careting |
|
* @cmd: The tracing command that caused the error |
|
* @str: The string to position the caret at within @cmd |
|
* |
|
* Finds the position of the first occurence of @str within @cmd. The |
|
* return value can be passed to tracing_log_err() for caret placement |
|
* within @cmd. |
|
* |
|
* Returns the index within @cmd of the first occurence of @str or 0 |
|
* if @str was not found. |
|
*/ |
|
unsigned int err_pos(char *cmd, const char *str) |
|
{ |
|
char *found; |
|
|
|
if (WARN_ON(!strlen(cmd))) |
|
return 0; |
|
|
|
found = strstr(cmd, str); |
|
if (found) |
|
return found - cmd; |
|
|
|
return 0; |
|
} |
|
|
|
/** |
|
* tracing_log_err - write an error to the tracing error log |
|
* @tr: The associated trace array for the error (NULL for top level array) |
|
* @loc: A string describing where the error occurred |
|
* @cmd: The tracing command that caused the error |
|
* @errs: The array of loc-specific static error strings |
|
* @type: The index into errs[], which produces the specific static err string |
|
* @pos: The position the caret should be placed in the cmd |
|
* |
|
* Writes an error into tracing/error_log of the form: |
|
* |
|
* <loc>: error: <text> |
|
* Command: <cmd> |
|
* ^ |
|
* |
|
* tracing/error_log is a small log file containing the last |
|
* TRACING_LOG_ERRS_MAX errors (8). Memory for errors isn't allocated |
|
* unless there has been a tracing error, and the error log can be |
|
* cleared and have its memory freed by writing the empty string in |
|
* truncation mode to it i.e. echo > tracing/error_log. |
|
* |
|
* NOTE: the @errs array along with the @type param are used to |
|
* produce a static error string - this string is not copied and saved |
|
* when the error is logged - only a pointer to it is saved. See |
|
* existing callers for examples of how static strings are typically |
|
* defined for use with tracing_log_err(). |
|
*/ |
|
void tracing_log_err(struct trace_array *tr, |
|
const char *loc, const char *cmd, |
|
const char **errs, u8 type, u8 pos) |
|
{ |
|
struct tracing_log_err *err; |
|
|
|
if (!tr) |
|
tr = &global_trace; |
|
|
|
mutex_lock(&tracing_err_log_lock); |
|
err = get_tracing_log_err(tr); |
|
if (PTR_ERR(err) == -ENOMEM) { |
|
mutex_unlock(&tracing_err_log_lock); |
|
return; |
|
} |
|
|
|
snprintf(err->loc, TRACING_LOG_LOC_MAX, "%s: error: ", loc); |
|
snprintf(err->cmd, MAX_FILTER_STR_VAL,"\n" CMD_PREFIX "%s\n", cmd); |
|
|
|
err->info.errs = errs; |
|
err->info.type = type; |
|
err->info.pos = pos; |
|
err->info.ts = local_clock(); |
|
|
|
list_add_tail(&err->list, &tr->err_log); |
|
mutex_unlock(&tracing_err_log_lock); |
|
} |
|
|
|
static void clear_tracing_err_log(struct trace_array *tr) |
|
{ |
|
struct tracing_log_err *err, *next; |
|
|
|
mutex_lock(&tracing_err_log_lock); |
|
list_for_each_entry_safe(err, next, &tr->err_log, list) { |
|
list_del(&err->list); |
|
kfree(err); |
|
} |
|
|
|
tr->n_err_log_entries = 0; |
|
mutex_unlock(&tracing_err_log_lock); |
|
} |
|
|
|
static void *tracing_err_log_seq_start(struct seq_file *m, loff_t *pos) |
|
{ |
|
struct trace_array *tr = m->private; |
|
|
|
mutex_lock(&tracing_err_log_lock); |
|
|
|
return seq_list_start(&tr->err_log, *pos); |
|
} |
|
|
|
static void *tracing_err_log_seq_next(struct seq_file *m, void *v, loff_t *pos) |
|
{ |
|
struct trace_array *tr = m->private; |
|
|
|
return seq_list_next(v, &tr->err_log, pos); |
|
} |
|
|
|
static void tracing_err_log_seq_stop(struct seq_file *m, void *v) |
|
{ |
|
mutex_unlock(&tracing_err_log_lock); |
|
} |
|
|
|
static void tracing_err_log_show_pos(struct seq_file *m, u8 pos) |
|
{ |
|
u8 i; |
|
|
|
for (i = 0; i < sizeof(CMD_PREFIX) - 1; i++) |
|
seq_putc(m, ' '); |
|
for (i = 0; i < pos; i++) |
|
seq_putc(m, ' '); |
|
seq_puts(m, "^\n"); |
|
} |
|
|
|
static int tracing_err_log_seq_show(struct seq_file *m, void *v) |
|
{ |
|
struct tracing_log_err *err = v; |
|
|
|
if (err) { |
|
const char *err_text = err->info.errs[err->info.type]; |
|
u64 sec = err->info.ts; |
|
u32 nsec; |
|
|
|
nsec = do_div(sec, NSEC_PER_SEC); |
|
seq_printf(m, "[%5llu.%06u] %s%s", sec, nsec / 1000, |
|
err->loc, err_text); |
|
seq_printf(m, "%s", err->cmd); |
|
tracing_err_log_show_pos(m, err->info.pos); |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static const struct seq_operations tracing_err_log_seq_ops = { |
|
.start = tracing_err_log_seq_start, |
|
.next = tracing_err_log_seq_next, |
|
.stop = tracing_err_log_seq_stop, |
|
.show = tracing_err_log_seq_show |
|
}; |
|
|
|
static int tracing_err_log_open(struct inode *inode, struct file *file) |
|
{ |
|
struct trace_array *tr = inode->i_private; |
|
int ret = 0; |
|
|
|
ret = tracing_check_open_get_tr(tr); |
|
if (ret) |
|
return ret; |
|
|
|
/* If this file was opened for write, then erase contents */ |
|
if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) |
|
clear_tracing_err_log(tr); |
|
|
|
if (file->f_mode & FMODE_READ) { |
|
ret = seq_open(file, &tracing_err_log_seq_ops); |
|
if (!ret) { |
|
struct seq_file *m = file->private_data; |
|
m->private = tr; |
|
} else { |
|
trace_array_put(tr); |
|
} |
|
} |
|
return ret; |
|
} |
|
|
|
static ssize_t tracing_err_log_write(struct file *file, |
|
const char __user *buffer, |
|
size_t count, loff_t *ppos) |
|
{ |
|
return count; |
|
} |
|
|
|
static int tracing_err_log_release(struct inode *inode, struct file *file) |
|
{ |
|
struct trace_array *tr = inode->i_private; |
|
|
|
trace_array_put(tr); |
|
|
|
if (file->f_mode & FMODE_READ) |
|
seq_release(inode, file); |
|
|
|
return 0; |
|
} |
|
|
|
static const struct file_operations tracing_err_log_fops = { |
|
.open = tracing_err_log_open, |
|
.write = tracing_err_log_write, |
|
.read = seq_read, |
|
.llseek = seq_lseek, |
|
.release = tracing_err_log_release, |
|
}; |
|
|
|
static int tracing_buffers_open(struct inode *inode, struct file *filp) |
|
{ |
|
struct trace_array *tr = inode->i_private; |
|
struct ftrace_buffer_info *info; |
|
int ret; |
|
|
|
ret = tracing_check_open_get_tr(tr); |
|
if (ret) |
|
return ret; |
|
|
|
info = kvzalloc(sizeof(*info), GFP_KERNEL); |
|
if (!info) { |
|
trace_array_put(tr); |
|
return -ENOMEM; |
|
} |
|
|
|
mutex_lock(&trace_types_lock); |
|
|
|
info->iter.tr = tr; |
|
info->iter.cpu_file = tracing_get_cpu(inode); |
|
info->iter.trace = tr->current_trace; |
|
info->iter.array_buffer = &tr->array_buffer; |
|
info->spare = NULL; |
|
/* Force reading ring buffer for first read */ |
|
info->read = (unsigned int)-1; |
|
|
|
filp->private_data = info; |
|
|
|
tr->trace_ref++; |
|
|
|
mutex_unlock(&trace_types_lock); |
|
|
|
ret = nonseekable_open(inode, filp); |
|
if (ret < 0) |
|
trace_array_put(tr); |
|
|
|
return ret; |
|
} |
|
|
|
static __poll_t |
|
tracing_buffers_poll(struct file *filp, poll_table *poll_table) |
|
{ |
|
struct ftrace_buffer_info *info = filp->private_data; |
|
struct trace_iterator *iter = &info->iter; |
|
|
|
return trace_poll(iter, filp, poll_table); |
|
} |
|
|
|
static ssize_t |
|
tracing_buffers_read(struct file *filp, char __user *ubuf, |
|
size_t count, loff_t *ppos) |
|
{ |
|
struct ftrace_buffer_info *info = filp->private_data; |
|
struct trace_iterator *iter = &info->iter; |
|
ssize_t ret = 0; |
|
ssize_t size; |
|
|
|
if (!count) |
|
return 0; |
|
|
|
#ifdef CONFIG_TRACER_MAX_TRACE |
|
if (iter->snapshot && iter->tr->current_trace->use_max_tr) |
|
return -EBUSY; |
|
#endif |
|
|
|
if (!info->spare) { |
|
info->spare = ring_buffer_alloc_read_page(iter->array_buffer->buffer, |
|
iter->cpu_file); |
|
if (IS_ERR(info->spare)) { |
|
ret = PTR_ERR(info->spare); |
|
info->spare = NULL; |
|
} else { |
|
info->spare_cpu = iter->cpu_file; |
|
} |
|
} |
|
if (!info->spare) |
|
return ret; |
|
|
|
/* Do we have previous read data to read? */ |
|
if (info->read < PAGE_SIZE) |
|
goto read; |
|
|
|
again: |
|
trace_access_lock(iter->cpu_file); |
|
ret = ring_buffer_read_page(iter->array_buffer->buffer, |
|
&info->spare, |
|
count, |
|
iter->cpu_file, 0); |
|
trace_access_unlock(iter->cpu_file); |
|
|
|
if (ret < 0) { |
|
if (trace_empty(iter)) { |
|
if ((filp->f_flags & O_NONBLOCK)) |
|
return -EAGAIN; |
|
|
|
ret = wait_on_pipe(iter, 0); |
|
if (ret) |
|
return ret; |
|
|
|
goto again; |
|
} |
|
return 0; |
|
} |
|
|
|
info->read = 0; |
|
read: |
|
size = PAGE_SIZE - info->read; |
|
if (size > count) |
|
size = count; |
|
|
|
ret = copy_to_user(ubuf, info->spare + info->read, size); |
|
if (ret == size) |
|
return -EFAULT; |
|
|
|
size -= ret; |
|
|
|
*ppos += size; |
|
info->read += size; |
|
|
|
return size; |
|
} |
|
|
|
static int tracing_buffers_release(struct inode *inode, struct file *file) |
|
{ |
|
struct ftrace_buffer_info *info = file->private_data; |
|
struct trace_iterator *iter = &info->iter; |
|
|
|
mutex_lock(&trace_types_lock); |
|
|
|
iter->tr->trace_ref--; |
|
|
|
__trace_array_put(iter->tr); |
|
|
|
if (info->spare) |
|
ring_buffer_free_read_page(iter->array_buffer->buffer, |
|
info->spare_cpu, info->spare); |
|
kvfree(info); |
|
|
|
mutex_unlock(&trace_types_lock); |
|
|
|
return 0; |
|
} |
|
|
|
struct buffer_ref { |
|
struct trace_buffer *buffer; |
|
void *page; |
|
int cpu; |
|
refcount_t refcount; |
|
}; |
|
|
|
static void buffer_ref_release(struct buffer_ref *ref) |
|
{ |
|
if (!refcount_dec_and_test(&ref->refcount)) |
|
return; |
|
ring_buffer_free_read_page(ref->buffer, ref->cpu, ref->page); |
|
kfree(ref); |
|
} |
|
|
|
static void buffer_pipe_buf_release(struct pipe_inode_info *pipe, |
|
struct pipe_buffer *buf) |
|
{ |
|
struct buffer_ref *ref = (struct buffer_ref *)buf->private; |
|
|
|
buffer_ref_release(ref); |
|
buf->private = 0; |
|
} |
|
|
|
static bool buffer_pipe_buf_get(struct pipe_inode_info *pipe, |
|
struct pipe_buffer *buf) |
|
{ |
|
struct buffer_ref *ref = (struct buffer_ref *)buf->private; |
|
|
|
if (refcount_read(&ref->refcount) > INT_MAX/2) |
|
return false; |
|
|
|
refcount_inc(&ref->refcount); |
|
return true; |
|
} |
|
|
|
/* Pipe buffer operations for a buffer. */ |
|
static const struct pipe_buf_operations buffer_pipe_buf_ops = { |
|
.release = buffer_pipe_buf_release, |
|
.get = buffer_pipe_buf_get, |
|
}; |
|
|
|
/* |
|
* Callback from splice_to_pipe(), if we need to release some pages |
|
* at the end of the spd in case we error'ed out in filling the pipe. |
|
*/ |
|
static void buffer_spd_release(struct splice_pipe_desc *spd, unsigned int i) |
|
{ |
|
struct buffer_ref *ref = |
|
(struct buffer_ref *)spd->partial[i].private; |
|
|
|
buffer_ref_release(ref); |
|
spd->partial[i].private = 0; |
|
} |
|
|
|
static ssize_t |
|
tracing_buffers_splice_read(struct file *file, loff_t *ppos, |
|
struct pipe_inode_info *pipe, size_t len, |
|
unsigned int flags) |
|
{ |
|
struct ftrace_buffer_info *info = file->private_data; |
|
struct trace_iterator *iter = &info->iter; |
|
struct partial_page partial_def[PIPE_DEF_BUFFERS]; |
|
struct page *pages_def[PIPE_DEF_BUFFERS]; |
|
struct splice_pipe_desc spd = { |
|
.pages = pages_def, |
|
.partial = partial_def, |
|
.nr_pages_max = PIPE_DEF_BUFFERS, |
|
.ops = &buffer_pipe_buf_ops, |
|
.spd_release = buffer_spd_release, |
|
}; |
|
struct buffer_ref *ref; |
|
int entries, i; |
|
ssize_t ret = 0; |
|
|
|
#ifdef CONFIG_TRACER_MAX_TRACE |
|
if (iter->snapshot && iter->tr->current_trace->use_max_tr) |
|
return -EBUSY; |
|
#endif |
|
|
|
if (*ppos & (PAGE_SIZE - 1)) |
|
return -EINVAL; |
|
|
|
if (len & (PAGE_SIZE - 1)) { |
|
if (len < PAGE_SIZE) |
|
return -EINVAL; |
|
len &= PAGE_MASK; |
|
} |
|
|
|
if (splice_grow_spd(pipe, &spd)) |
|
return -ENOMEM; |
|
|
|
again: |
|
trace_access_lock(iter->cpu_file); |
|
entries = ring_buffer_entries_cpu(iter->array_buffer->buffer, iter->cpu_file); |
|
|
|
for (i = 0; i < spd.nr_pages_max && len && entries; i++, len -= PAGE_SIZE) { |
|
struct page *page; |
|
int r; |
|
|
|
ref = kzalloc(sizeof(*ref), GFP_KERNEL); |
|
if (!ref) { |
|
ret = -ENOMEM; |
|
break; |
|
} |
|
|
|
refcount_set(&ref->refcount, 1); |
|
ref->buffer = iter->array_buffer->buffer; |
|
ref->page = ring_buffer_alloc_read_page(ref->buffer, iter->cpu_file); |
|
if (IS_ERR(ref->page)) { |
|
ret = PTR_ERR(ref->page); |
|
ref->page = NULL; |
|
kfree(ref); |
|
break; |
|
} |
|
ref->cpu = iter->cpu_file; |
|
|
|
r = ring_buffer_read_page(ref->buffer, &ref->page, |
|
len, iter->cpu_file, 1); |
|
if (r < 0) { |
|
ring_buffer_free_read_page(ref->buffer, ref->cpu, |
|
ref->page); |
|
kfree(ref); |
|
break; |
|
} |
|
|
|
page = virt_to_page(ref->page); |
|
|
|
spd.pages[i] = page; |
|
spd.partial[i].len = PAGE_SIZE; |
|
spd.partial[i].offset = 0; |
|
spd.partial[i].private = (unsigned long)ref; |
|
spd.nr_pages++; |
|
*ppos += PAGE_SIZE; |
|
|
|
entries = ring_buffer_entries_cpu(iter->array_buffer->buffer, iter->cpu_file); |
|
} |
|
|
|
trace_access_unlock(iter->cpu_file); |
|
spd.nr_pages = i; |
|
|
|
/* did we read anything? */ |
|
if (!spd.nr_pages) { |
|
if (ret) |
|
goto out; |
|
|
|
ret = -EAGAIN; |
|
if ((file->f_flags & O_NONBLOCK) || (flags & SPLICE_F_NONBLOCK)) |
|
goto out; |
|
|
|
ret = wait_on_pipe(iter, iter->tr->buffer_percent); |
|
if (ret) |
|
goto out; |
|
|
|
goto again; |
|
} |
|
|
|
ret = splice_to_pipe(pipe, &spd); |
|
out: |
|
splice_shrink_spd(&spd); |
|
|
|
return ret; |
|
} |
|
|
|
static const struct file_operations tracing_buffers_fops = { |
|
.open = tracing_buffers_open, |
|
.read = tracing_buffers_read, |
|
.poll = tracing_buffers_poll, |
|
.release = tracing_buffers_release, |
|
.splice_read = tracing_buffers_splice_read, |
|
.llseek = no_llseek, |
|
}; |
|
|
|
static ssize_t |
|
tracing_stats_read(struct file *filp, char __user *ubuf, |
|
size_t count, loff_t *ppos) |
|
{ |
|
struct inode *inode = file_inode(filp); |
|
struct trace_array *tr = inode->i_private; |
|
struct array_buffer *trace_buf = &tr->array_buffer; |
|
int cpu = tracing_get_cpu(inode); |
|
struct trace_seq *s; |
|
unsigned long cnt; |
|
unsigned long long t; |
|
unsigned long usec_rem; |
|
|
|
s = kmalloc(sizeof(*s), GFP_KERNEL); |
|
if (!s) |
|
return -ENOMEM; |
|
|
|
trace_seq_init(s); |
|
|
|
cnt = ring_buffer_entries_cpu(trace_buf->buffer, cpu); |
|
trace_seq_printf(s, "entries: %ld\n", cnt); |
|
|
|
cnt = ring_buffer_overrun_cpu(trace_buf->buffer, cpu); |
|
trace_seq_printf(s, "overrun: %ld\n", cnt); |
|
|
|
cnt = ring_buffer_commit_overrun_cpu(trace_buf->buffer, cpu); |
|
trace_seq_printf(s, "commit overrun: %ld\n", cnt); |
|
|
|
cnt = ring_buffer_bytes_cpu(trace_buf->buffer, cpu); |
|
trace_seq_printf(s, "bytes: %ld\n", cnt); |
|
|
|
if (trace_clocks[tr->clock_id].in_ns) { |
|
/* local or global for trace_clock */ |
|
t = ns2usecs(ring_buffer_oldest_event_ts(trace_buf->buffer, cpu)); |
|
usec_rem = do_div(t, USEC_PER_SEC); |
|
trace_seq_printf(s, "oldest event ts: %5llu.%06lu\n", |
|
t, usec_rem); |
|
|
|
t = ns2usecs(ring_buffer_time_stamp(trace_buf->buffer, cpu)); |
|
usec_rem = do_div(t, USEC_PER_SEC); |
|
trace_seq_printf(s, "now ts: %5llu.%06lu\n", t, usec_rem); |
|
} else { |
|
/* counter or tsc mode for trace_clock */ |
|
trace_seq_printf(s, "oldest event ts: %llu\n", |
|
ring_buffer_oldest_event_ts(trace_buf->buffer, cpu)); |
|
|
|
trace_seq_printf(s, "now ts: %llu\n", |
|
ring_buffer_time_stamp(trace_buf->buffer, cpu)); |
|
} |
|
|
|
cnt = ring_buffer_dropped_events_cpu(trace_buf->buffer, cpu); |
|
trace_seq_printf(s, "dropped events: %ld\n", cnt); |
|
|
|
cnt = ring_buffer_read_events_cpu(trace_buf->buffer, cpu); |
|
trace_seq_printf(s, "read events: %ld\n", cnt); |
|
|
|
count = simple_read_from_buffer(ubuf, count, ppos, |
|
s->buffer, trace_seq_used(s)); |
|
|
|
kfree(s); |
|
|
|
return count; |
|
} |
|
|
|
static const struct file_operations tracing_stats_fops = { |
|
.open = tracing_open_generic_tr, |
|
.read = tracing_stats_read, |
|
.llseek = generic_file_llseek, |
|
.release = tracing_release_generic_tr, |
|
}; |
|
|
|
#ifdef CONFIG_DYNAMIC_FTRACE |
|
|
|
static ssize_t |
|
tracing_read_dyn_info(struct file *filp, char __user *ubuf, |
|
size_t cnt, loff_t *ppos) |
|
{ |
|
ssize_t ret; |
|
char *buf; |
|
int r; |
|
|
|
/* 256 should be plenty to hold the amount needed */ |
|
buf = kmalloc(256, GFP_KERNEL); |
|
if (!buf) |
|
return -ENOMEM; |
|
|
|
r = scnprintf(buf, 256, "%ld pages:%ld groups: %ld\n", |
|
ftrace_update_tot_cnt, |
|
ftrace_number_of_pages, |
|
ftrace_number_of_groups); |
|
|
|
ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
|
kfree(buf); |
|
return ret; |
|
} |
|
|
|
static const struct file_operations tracing_dyn_info_fops = { |
|
.open = tracing_open_generic, |
|
.read = tracing_read_dyn_info, |
|
.llseek = generic_file_llseek, |
|
}; |
|
#endif /* CONFIG_DYNAMIC_FTRACE */ |
|
|
|
#if defined(CONFIG_TRACER_SNAPSHOT) && defined(CONFIG_DYNAMIC_FTRACE) |
|
static void |
|
ftrace_snapshot(unsigned long ip, unsigned long parent_ip, |
|
struct trace_array *tr, struct ftrace_probe_ops *ops, |
|
void *data) |
|
{ |
|
tracing_snapshot_instance(tr); |
|
} |
|
|
|
static void |
|
ftrace_count_snapshot(unsigned long ip, unsigned long parent_ip, |
|
struct trace_array *tr, struct ftrace_probe_ops *ops, |
|
void *data) |
|
{ |
|
struct ftrace_func_mapper *mapper = data; |
|
long *count = NULL; |
|
|
|
if (mapper) |
|
count = (long *)ftrace_func_mapper_find_ip(mapper, ip); |
|
|
|
if (count) { |
|
|
|
if (*count <= 0) |
|
return; |
|
|
|
(*count)--; |
|
} |
|
|
|
tracing_snapshot_instance(tr); |
|
} |
|
|
|
static int |
|
ftrace_snapshot_print(struct seq_file *m, unsigned long ip, |
|
struct ftrace_probe_ops *ops, void *data) |
|
{ |
|
struct ftrace_func_mapper *mapper = data; |
|
long *count = NULL; |
|
|
|
seq_printf(m, "%ps:", (void *)ip); |
|
|
|
seq_puts(m, "snapshot"); |
|
|
|
if (mapper) |
|
count = (long *)ftrace_func_mapper_find_ip(mapper, ip); |
|
|
|
if (count) |
|
seq_printf(m, ":count=%ld\n", *count); |
|
else |
|
seq_puts(m, ":unlimited\n"); |
|
|
|
return 0; |
|
} |
|
|
|
static int |
|
ftrace_snapshot_init(struct ftrace_probe_ops *ops, struct trace_array *tr, |
|
unsigned long ip, void *init_data, void **data) |
|
{ |
|
struct ftrace_func_mapper *mapper = *data; |
|
|
|
if (!mapper) { |
|
mapper = allocate_ftrace_func_mapper(); |
|
if (!mapper) |
|
return -ENOMEM; |
|
*data = mapper; |
|
} |
|
|
|
return ftrace_func_mapper_add_ip(mapper, ip, init_data); |
|
} |
|
|
|
static void |
|
ftrace_snapshot_free(struct ftrace_probe_ops *ops, struct trace_array *tr, |
|
unsigned long ip, void *data) |
|
{ |
|
struct ftrace_func_mapper *mapper = data; |
|
|
|
if (!ip) { |
|
if (!mapper) |
|
return; |
|
free_ftrace_func_mapper(mapper, NULL); |
|
return; |
|
} |
|
|
|
ftrace_func_mapper_remove_ip(mapper, ip); |
|
} |
|
|
|
static struct ftrace_probe_ops snapshot_probe_ops = { |
|
.func = ftrace_snapshot, |
|
.print = ftrace_snapshot_print, |
|
}; |
|
|
|
static struct ftrace_probe_ops snapshot_count_probe_ops = { |
|
.func = ftrace_count_snapshot, |
|
.print = ftrace_snapshot_print, |
|
.init = ftrace_snapshot_init, |
|
.free = ftrace_snapshot_free, |
|
}; |
|
|
|
static int |
|
ftrace_trace_snapshot_callback(struct trace_array *tr, struct ftrace_hash *hash, |
|
char *glob, char *cmd, char *param, int enable) |
|
{ |
|
struct ftrace_probe_ops *ops; |
|
void *count = (void *)-1; |
|
char *number; |
|
int ret; |
|
|
|
if (!tr) |
|
return -ENODEV; |
|
|
|
/* hash funcs only work with set_ftrace_filter */ |
|
if (!enable) |
|
return -EINVAL; |
|
|
|
ops = param ? &snapshot_count_probe_ops : &snapshot_probe_ops; |
|
|
|
if (glob[0] == '!') |
|
return unregister_ftrace_function_probe_func(glob+1, tr, ops); |
|
|
|
if (!param) |
|
goto out_reg; |
|
|
|
number = strsep(¶m, ":"); |
|
|
|
if (!strlen(number)) |
|
goto out_reg; |
|
|
|
/* |
|
* We use the callback data field (which is a pointer) |
|
* as our counter. |
|
*/ |
|
ret = kstrtoul(number, 0, (unsigned long *)&count); |
|
if (ret) |
|
return ret; |
|
|
|
out_reg: |
|
ret = tracing_alloc_snapshot_instance(tr); |
|
if (ret < 0) |
|
goto out; |
|
|
|
ret = register_ftrace_function_probe(glob, tr, ops, count); |
|
|
|
out: |
|
return ret < 0 ? ret : 0; |
|
} |
|
|
|
static struct ftrace_func_command ftrace_snapshot_cmd = { |
|
.name = "snapshot", |
|
.func = ftrace_trace_snapshot_callback, |
|
}; |
|
|
|
static __init int register_snapshot_cmd(void) |
|
{ |
|
return register_ftrace_command(&ftrace_snapshot_cmd); |
|
} |
|
#else |
|
static inline __init int register_snapshot_cmd(void) { return 0; } |
|
#endif /* defined(CONFIG_TRACER_SNAPSHOT) && defined(CONFIG_DYNAMIC_FTRACE) */ |
|
|
|
static struct dentry *tracing_get_dentry(struct trace_array *tr) |
|
{ |
|
if (WARN_ON(!tr->dir)) |
|
return ERR_PTR(-ENODEV); |
|
|
|
/* Top directory uses NULL as the parent */ |
|
if (tr->flags & TRACE_ARRAY_FL_GLOBAL) |
|
return NULL; |
|
|
|
/* All sub buffers have a descriptor */ |
|
return tr->dir; |
|
} |
|
|
|
static struct dentry *tracing_dentry_percpu(struct trace_array *tr, int cpu) |
|
{ |
|
struct dentry *d_tracer; |
|
|
|
if (tr->percpu_dir) |
|
return tr->percpu_dir; |
|
|
|
d_tracer = tracing_get_dentry(tr); |
|
if (IS_ERR(d_tracer)) |
|
return NULL; |
|
|
|
tr->percpu_dir = tracefs_create_dir("per_cpu", d_tracer); |
|
|
|
MEM_FAIL(!tr->percpu_dir, |
|
"Could not create tracefs directory 'per_cpu/%d'\n", cpu); |
|
|
|
return tr->percpu_dir; |
|
} |
|
|
|
static struct dentry * |
|
trace_create_cpu_file(const char *name, umode_t mode, struct dentry *parent, |
|
void *data, long cpu, const struct file_operations *fops) |
|
{ |
|
struct dentry *ret = trace_create_file(name, mode, parent, data, fops); |
|
|
|
if (ret) /* See tracing_get_cpu() */ |
|
d_inode(ret)->i_cdev = (void *)(cpu + 1); |
|
return ret; |
|
} |
|
|
|
static void |
|
tracing_init_tracefs_percpu(struct trace_array *tr, long cpu) |
|
{ |
|
struct dentry *d_percpu = tracing_dentry_percpu(tr, cpu); |
|
struct dentry *d_cpu; |
|
char cpu_dir[30]; /* 30 characters should be more than enough */ |
|
|
|
if (!d_percpu) |
|
return; |
|
|
|
snprintf(cpu_dir, 30, "cpu%ld", cpu); |
|
d_cpu = tracefs_create_dir(cpu_dir, d_percpu); |
|
if (!d_cpu) { |
|
pr_warn("Could not create tracefs '%s' entry\n", cpu_dir); |
|
return; |
|
} |
|
|
|
/* per cpu trace_pipe */ |
|
trace_create_cpu_file("trace_pipe", 0444, d_cpu, |
|
tr, cpu, &tracing_pipe_fops); |
|
|
|
/* per cpu trace */ |
|
trace_create_cpu_file("trace", 0644, d_cpu, |
|
tr, cpu, &tracing_fops); |
|
|
|
trace_create_cpu_file("trace_pipe_raw", 0444, d_cpu, |
|
tr, cpu, &tracing_buffers_fops); |
|
|
|
trace_create_cpu_file("stats", 0444, d_cpu, |
|
tr, cpu, &tracing_stats_fops); |
|
|
|
trace_create_cpu_file("buffer_size_kb", 0444, d_cpu, |
|
tr, cpu, &tracing_entries_fops); |
|
|
|
#ifdef CONFIG_TRACER_SNAPSHOT |
|
trace_create_cpu_file("snapshot", 0644, d_cpu, |
|
tr, cpu, &snapshot_fops); |
|
|
|
trace_create_cpu_file("snapshot_raw", 0444, d_cpu, |
|
tr, cpu, &snapshot_raw_fops); |
|
#endif |
|
} |
|
|
|
#ifdef CONFIG_FTRACE_SELFTEST |
|
/* Let selftest have access to static functions in this file */ |
|
#include "trace_selftest.c" |
|
#endif |
|
|
|
static ssize_t |
|
trace_options_read(struct file *filp, char __user *ubuf, size_t cnt, |
|
loff_t *ppos) |
|
{ |
|
struct trace_option_dentry *topt = filp->private_data; |
|
char *buf; |
|
|
|
if (topt->flags->val & topt->opt->bit) |
|
buf = "1\n"; |
|
else |
|
buf = "0\n"; |
|
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); |
|
} |
|
|
|
static ssize_t |
|
trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt, |
|
loff_t *ppos) |
|
{ |
|
struct trace_option_dentry *topt = filp->private_data; |
|
unsigned long val; |
|
int ret; |
|
|
|
ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
|
if (ret) |
|
return ret; |
|
|
|
if (val != 0 && val != 1) |
|
return -EINVAL; |
|
|
|
if (!!(topt->flags->val & topt->opt->bit) != val) { |
|
mutex_lock(&trace_types_lock); |
|
ret = __set_tracer_option(topt->tr, topt->flags, |
|
topt->opt, !val); |
|
mutex_unlock(&trace_types_lock); |
|
if (ret) |
|
return ret; |
|
} |
|
|
|
*ppos += cnt; |
|
|
|
return cnt; |
|
} |
|
|
|
|
|
static const struct file_operations trace_options_fops = { |
|
.open = tracing_open_generic, |
|
.read = trace_options_read, |
|
.write = trace_options_write, |
|
.llseek = generic_file_llseek, |
|
}; |
|
|
|
/* |
|
* In order to pass in both the trace_array descriptor as well as the index |
|
* to the flag that the trace option file represents, the trace_array |
|
* has a character array of trace_flags_index[], which holds the index |
|
* of the bit for the flag it represents. index[0] == 0, index[1] == 1, etc. |
|
* The address of this character array is passed to the flag option file |
|
* read/write callbacks. |
|
* |
|
* In order to extract both the index and the trace_array descriptor, |
|
* get_tr_index() uses the following algorithm. |
|
* |
|
* idx = *ptr; |
|
* |
|
* As the pointer itself contains the address of the index (remember |
|
* index[1] == 1). |
|
* |
|
* Then to get the trace_array descriptor, by subtracting that index |
|
* from the ptr, we get to the start of the index itself. |
|
* |
|
* ptr - idx == &index[0] |
|
* |
|
* Then a simple container_of() from that pointer gets us to the |
|
* trace_array descriptor. |
|
*/ |
|
static void get_tr_index(void *data, struct trace_array **ptr, |
|
unsigned int *pindex) |
|
{ |
|
*pindex = *(unsigned char *)data; |
|
|
|
*ptr = container_of(data - *pindex, struct trace_array, |
|
trace_flags_index); |
|
} |
|
|
|
static ssize_t |
|
trace_options_core_read(struct file *filp, char __user *ubuf, size_t cnt, |
|
loff_t *ppos) |
|
{ |
|
void *tr_index = filp->private_data; |
|
struct trace_array *tr; |
|
unsigned int index; |
|
char *buf; |
|
|
|
get_tr_index(tr_index, &tr, &index); |
|
|
|
if (tr->trace_flags & (1 << index)) |
|
buf = "1\n"; |
|
else |
|
buf = "0\n"; |
|
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); |
|
} |
|
|
|
static ssize_t |
|
trace_options_core_write(struct file *filp, const char __user *ubuf, size_t cnt, |
|
loff_t *ppos) |
|
{ |
|
void *tr_index = filp->private_data; |
|
struct trace_array *tr; |
|
unsigned int index; |
|
unsigned long val; |
|
int ret; |
|
|
|
get_tr_index(tr_index, &tr, &index); |
|
|
|
ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
|
if (ret) |
|
return ret; |
|
|
|
if (val != 0 && val != 1) |
|
return -EINVAL; |
|
|
|
mutex_lock(&event_mutex); |
|
mutex_lock(&trace_types_lock); |
|
ret = set_tracer_flag(tr, 1 << index, val); |
|
mutex_unlock(&trace_types_lock); |
|
mutex_unlock(&event_mutex); |
|
|
|
if (ret < 0) |
|
return ret; |
|
|
|
*ppos += cnt; |
|
|
|
return cnt; |
|
} |
|
|
|
static const struct file_operations trace_options_core_fops = { |
|
.open = tracing_open_generic, |
|
.read = trace_options_core_read, |
|
.write = trace_options_core_write, |
|
.llseek = generic_file_llseek, |
|
}; |
|
|
|
struct dentry *trace_create_file(const char *name, |
|
umode_t mode, |
|
struct dentry *parent, |
|
void *data, |
|
const struct file_operations *fops) |
|
{ |
|
struct dentry *ret; |
|
|
|
ret = tracefs_create_file(name, mode, parent, data, fops); |
|
if (!ret) |
|
pr_warn("Could not create tracefs '%s' entry\n", name); |
|
|
|
return ret; |
|
} |
|
|
|
|
|
static struct dentry *trace_options_init_dentry(struct trace_array *tr) |
|
{ |
|
struct dentry *d_tracer; |
|
|
|
if (tr->options) |
|
return tr->options; |
|
|
|
d_tracer = tracing_get_dentry(tr); |
|
if (IS_ERR(d_tracer)) |
|
return NULL; |
|
|
|
tr->options = tracefs_create_dir("options", d_tracer); |
|
if (!tr->options) { |
|
pr_warn("Could not create tracefs directory 'options'\n"); |
|
return NULL; |
|
} |
|
|
|
return tr->options; |
|
} |
|
|
|
static void |
|
create_trace_option_file(struct trace_array *tr, |
|
struct trace_option_dentry *topt, |
|
struct tracer_flags *flags, |
|
struct tracer_opt *opt) |
|
{ |
|
struct dentry *t_options; |
|
|
|
t_options = trace_options_init_dentry(tr); |
|
if (!t_options) |
|
return; |
|
|
|
topt->flags = flags; |
|
topt->opt = opt; |
|
topt->tr = tr; |
|
|
|
topt->entry = trace_create_file(opt->name, 0644, t_options, topt, |
|
&trace_options_fops); |
|
|
|
} |
|
|
|
static void |
|
create_trace_option_files(struct trace_array *tr, struct tracer *tracer) |
|
{ |
|
struct trace_option_dentry *topts; |
|
struct trace_options *tr_topts; |
|
struct tracer_flags *flags; |
|
struct tracer_opt *opts; |
|
int cnt; |
|
int i; |
|
|
|
if (!tracer) |
|
return; |
|
|
|
flags = tracer->flags; |
|
|
|
if (!flags || !flags->opts) |
|
return; |
|
|
|
/* |
|
* If this is an instance, only create flags for tracers |
|
* the instance may have. |
|
*/ |
|
if (!trace_ok_for_array(tracer, tr)) |
|
return; |
|
|
|
for (i = 0; i < tr->nr_topts; i++) { |
|
/* Make sure there's no duplicate flags. */ |
|
if (WARN_ON_ONCE(tr->topts[i].tracer->flags == tracer->flags)) |
|
return; |
|
} |
|
|
|
opts = flags->opts; |
|
|
|
for (cnt = 0; opts[cnt].name; cnt++) |
|
; |
|
|
|
topts = kcalloc(cnt + 1, sizeof(*topts), GFP_KERNEL); |
|
if (!topts) |
|
return; |
|
|
|
tr_topts = krealloc(tr->topts, sizeof(*tr->topts) * (tr->nr_topts + 1), |
|
GFP_KERNEL); |
|
if (!tr_topts) { |
|
kfree(topts); |
|
return; |
|
} |
|
|
|
tr->topts = tr_topts; |
|
tr->topts[tr->nr_topts].tracer = tracer; |
|
tr->topts[tr->nr_topts].topts = topts; |
|
tr->nr_topts++; |
|
|
|
for (cnt = 0; opts[cnt].name; cnt++) { |
|
create_trace_option_file(tr, &topts[cnt], flags, |
|
&opts[cnt]); |
|
MEM_FAIL(topts[cnt].entry == NULL, |
|
"Failed to create trace option: %s", |
|
opts[cnt].name); |
|
} |
|
} |
|
|
|
static struct dentry * |
|
create_trace_option_core_file(struct trace_array *tr, |
|
const char *option, long index) |
|
{ |
|
struct dentry *t_options; |
|
|
|
t_options = trace_options_init_dentry(tr); |
|
if (!t_options) |
|
return NULL; |
|
|
|
return trace_create_file(option, 0644, t_options, |
|
(void *)&tr->trace_flags_index[index], |
|
&trace_options_core_fops); |
|
} |
|
|
|
static void create_trace_options_dir(struct trace_array *tr) |
|
{ |
|
struct dentry *t_options; |
|
bool top_level = tr == &global_trace; |
|
int i; |
|
|
|
t_options = trace_options_init_dentry(tr); |
|
if (!t_options) |
|
return; |
|
|
|
for (i = 0; trace_options[i]; i++) { |
|
if (top_level || |
|
!((1 << i) & TOP_LEVEL_TRACE_FLAGS)) |
|
create_trace_option_core_file(tr, trace_options[i], i); |
|
} |
|
} |
|
|
|
static ssize_t |
|
rb_simple_read(struct file *filp, char __user *ubuf, |
|
size_t cnt, loff_t *ppos) |
|
{ |
|
struct trace_array *tr = filp->private_data; |
|
char buf[64]; |
|
int r; |
|
|
|
r = tracer_tracing_is_on(tr); |
|
r = sprintf(buf, "%d\n", r); |
|
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
|
} |
|
|
|
static ssize_t |
|
rb_simple_write(struct file *filp, const char __user *ubuf, |
|
size_t cnt, loff_t *ppos) |
|
{ |
|
struct trace_array *tr = filp->private_data; |
|
struct trace_buffer *buffer = tr->array_buffer.buffer; |
|
unsigned long val; |
|
int ret; |
|
|
|
ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
|
if (ret) |
|
return ret; |
|
|
|
if (buffer) { |
|
mutex_lock(&trace_types_lock); |
|
if (!!val == tracer_tracing_is_on(tr)) { |
|
val = 0; /* do nothing */ |
|
} else if (val) { |
|
tracer_tracing_on(tr); |
|
if (tr->current_trace->start) |
|
tr->current_trace->start(tr); |
|
} else { |
|
tracer_tracing_off(tr); |
|
if (tr->current_trace->stop) |
|
tr->current_trace->stop(tr); |
|
} |
|
mutex_unlock(&trace_types_lock); |
|
} |
|
|
|
(*ppos)++; |
|
|
|
return cnt; |
|
} |
|
|
|
static const struct file_operations rb_simple_fops = { |
|
.open = tracing_open_generic_tr, |
|
.read = rb_simple_read, |
|
.write = rb_simple_write, |
|
.release = tracing_release_generic_tr, |
|
.llseek = default_llseek, |
|
}; |
|
|
|
static ssize_t |
|
buffer_percent_read(struct file *filp, char __user *ubuf, |
|
size_t cnt, loff_t *ppos) |
|
{ |
|
struct trace_array *tr = filp->private_data; |
|
char buf[64]; |
|
int r; |
|
|
|
r = tr->buffer_percent; |
|
r = sprintf(buf, "%d\n", r); |
|
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
|
} |
|
|
|
static ssize_t |
|
buffer_percent_write(struct file *filp, const char __user *ubuf, |
|
size_t cnt, loff_t *ppos) |
|
{ |
|
struct trace_array *tr = filp->private_data; |
|
unsigned long val; |
|
int ret; |
|
|
|
ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
|
if (ret) |
|
return ret; |
|
|
|
if (val > 100) |
|
return -EINVAL; |
|
|
|
if (!val) |
|
val = 1; |
|
|
|
tr->buffer_percent = val; |
|
|
|
(*ppos)++; |
|
|
|
return cnt; |
|
} |
|
|
|
static const struct file_operations buffer_percent_fops = { |
|
.open = tracing_open_generic_tr, |
|
.read = buffer_percent_read, |
|
.write = buffer_percent_write, |
|
.release = tracing_release_generic_tr, |
|
.llseek = default_llseek, |
|
}; |
|
|
|
static struct dentry *trace_instance_dir; |
|
|
|
static void |
|
init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer); |
|
|
|
static int |
|
allocate_trace_buffer(struct trace_array *tr, struct array_buffer *buf, int size) |
|
{ |
|
enum ring_buffer_flags rb_flags; |
|
|
|
rb_flags = tr->trace_flags & TRACE_ITER_OVERWRITE ? RB_FL_OVERWRITE : 0; |
|
|
|
buf->tr = tr; |
|
|
|
buf->buffer = ring_buffer_alloc(size, rb_flags); |
|
if (!buf->buffer) |
|
return -ENOMEM; |
|
|
|
buf->data = alloc_percpu(struct trace_array_cpu); |
|
if (!buf->data) { |
|
ring_buffer_free(buf->buffer); |
|
buf->buffer = NULL; |
|
return -ENOMEM; |
|
} |
|
|
|
/* Allocate the first page for all buffers */ |
|
set_buffer_entries(&tr->array_buffer, |
|
ring_buffer_size(tr->array_buffer.buffer, 0)); |
|
|
|
return 0; |
|
} |
|
|
|
static int allocate_trace_buffers(struct trace_array *tr, int size) |
|
{ |
|
int ret; |
|
|
|
ret = allocate_trace_buffer(tr, &tr->array_buffer, size); |
|
if (ret) |
|
return ret; |
|
|
|
#ifdef CONFIG_TRACER_MAX_TRACE |
|
ret = allocate_trace_buffer(tr, &tr->max_buffer, |
|
allocate_snapshot ? size : 1); |
|
if (MEM_FAIL(ret, "Failed to allocate trace buffer\n")) { |
|
ring_buffer_free(tr->array_buffer.buffer); |
|
tr->array_buffer.buffer = NULL; |
|
free_percpu(tr->array_buffer.data); |
|
tr->array_buffer.data = NULL; |
|
return -ENOMEM; |
|
} |
|
tr->allocated_snapshot = allocate_snapshot; |
|
|
|
/* |
|
* Only the top level trace array gets its snapshot allocated |
|
* from the kernel command line. |
|
*/ |
|
allocate_snapshot = false; |
|
#endif |
|
|
|
return 0; |
|
} |
|
|
|
static void free_trace_buffer(struct array_buffer *buf) |
|
{ |
|
if (buf->buffer) { |
|
ring_buffer_free(buf->buffer); |
|
buf->buffer = NULL; |
|
free_percpu(buf->data); |
|
buf->data = NULL; |
|
} |
|
} |
|
|
|
static void free_trace_buffers(struct trace_array *tr) |
|
{ |
|
if (!tr) |
|
return; |
|
|
|
free_trace_buffer(&tr->array_buffer); |
|
|
|
#ifdef CONFIG_TRACER_MAX_TRACE |
|
free_trace_buffer(&tr->max_buffer); |
|
#endif |
|
} |
|
|
|
static void init_trace_flags_index(struct trace_array *tr) |
|
{ |
|
int i; |
|
|
|
/* Used by the trace options files */ |
|
for (i = 0; i < TRACE_FLAGS_MAX_SIZE; i++) |
|
tr->trace_flags_index[i] = i; |
|
} |
|
|
|
static void __update_tracer_options(struct trace_array *tr) |
|
{ |
|
struct tracer *t; |
|
|
|
for (t = trace_types; t; t = t->next) |
|
add_tracer_options(tr, t); |
|
} |
|
|
|
static void update_tracer_options(struct trace_array *tr) |
|
{ |
|
mutex_lock(&trace_types_lock); |
|
__update_tracer_options(tr); |
|
mutex_unlock(&trace_types_lock); |
|
} |
|
|
|
/* Must have trace_types_lock held */ |
|
struct trace_array *trace_array_find(const char *instance) |
|
{ |
|
struct trace_array *tr, *found = NULL; |
|
|
|
list_for_each_entry(tr, &ftrace_trace_arrays, list) { |
|
if (tr->name && strcmp(tr->name, instance) == 0) { |
|
found = tr; |
|
break; |
|
} |
|
} |
|
|
|
return found; |
|
} |
|
|
|
struct trace_array *trace_array_find_get(const char *instance) |
|
{ |
|
struct trace_array *tr; |
|
|
|
mutex_lock(&trace_types_lock); |
|
tr = trace_array_find(instance); |
|
if (tr) |
|
tr->ref++; |
|
mutex_unlock(&trace_types_lock); |
|
|
|
return tr; |
|
} |
|
|
|
static int trace_array_create_dir(struct trace_array *tr) |
|
{ |
|
int ret; |
|
|
|
tr->dir = tracefs_create_dir(tr->name, trace_instance_dir); |
|
if (!tr->dir) |
|
return -EINVAL; |
|
|
|
ret = event_trace_add_tracer(tr->dir, tr); |
|
if (ret) |
|
tracefs_remove(tr->dir); |
|
|
|
init_tracer_tracefs(tr, tr->dir); |
|
__update_tracer_options(tr); |
|
|
|
return ret; |
|
} |
|
|
|
static struct trace_array *trace_array_create(const char *name) |
|
{ |
|
struct trace_array *tr; |
|
int ret; |
|
|
|
ret = -ENOMEM; |
|
tr = kzalloc(sizeof(*tr), GFP_KERNEL); |
|
if (!tr) |
|
return ERR_PTR(ret); |
|
|
|
tr->name = kstrdup(name, GFP_KERNEL); |
|
if (!tr->name) |
|
goto out_free_tr; |
|
|
|
if (!alloc_cpumask_var(&tr->tracing_cpumask, GFP_KERNEL)) |
|
goto out_free_tr; |
|
|
|
tr->trace_flags = global_trace.trace_flags & ~ZEROED_TRACE_FLAGS; |
|
|
|
cpumask_copy(tr->tracing_cpumask, cpu_all_mask); |
|
|
|
raw_spin_lock_init(&tr->start_lock); |
|
|
|
tr->max_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; |
|
|
|
tr->current_trace = &nop_trace; |
|
|
|
INIT_LIST_HEAD(&tr->systems); |
|
INIT_LIST_HEAD(&tr->events); |
|
INIT_LIST_HEAD(&tr->hist_vars); |
|
INIT_LIST_HEAD(&tr->err_log); |
|
|
|
if (allocate_trace_buffers(tr, trace_buf_size) < 0) |
|
goto out_free_tr; |
|
|
|
if (ftrace_allocate_ftrace_ops(tr) < 0) |
|
goto out_free_tr; |
|
|
|
ftrace_init_trace_array(tr); |
|
|
|
init_trace_flags_index(tr); |
|
|
|
if (trace_instance_dir) { |
|
ret = trace_array_create_dir(tr); |
|
if (ret) |
|
goto out_free_tr; |
|
} else |
|
__trace_early_add_events(tr); |
|
|
|
list_add(&tr->list, &ftrace_trace_arrays); |
|
|
|
tr->ref++; |
|
|
|
return tr; |
|
|
|
out_free_tr: |
|
ftrace_free_ftrace_ops(tr); |
|
free_trace_buffers(tr); |
|
free_cpumask_var(tr->tracing_cpumask); |
|
kfree(tr->name); |
|
kfree(tr); |
|
|
|
return ERR_PTR(ret); |
|
} |
|
|
|
static int instance_mkdir(const char *name) |
|
{ |
|
struct trace_array *tr; |
|
int ret; |
|
|
|
mutex_lock(&event_mutex); |
|
mutex_lock(&trace_types_lock); |
|
|
|
ret = -EEXIST; |
|
if (trace_array_find(name)) |
|
goto out_unlock; |
|
|
|
tr = trace_array_create(name); |
|
|
|
ret = PTR_ERR_OR_ZERO(tr); |
|
|
|
out_unlock: |
|
mutex_unlock(&trace_types_lock); |
|
mutex_unlock(&event_mutex); |
|
return ret; |
|
} |
|
|
|
/** |
|
* trace_array_get_by_name - Create/Lookup a trace array, given its name. |
|
* @name: The name of the trace array to be looked up/created. |
|
* |
|
* Returns pointer to trace array with given name. |
|
* NULL, if it cannot be created. |
|
* |
|
* NOTE: This function increments the reference counter associated with the |
|
* trace array returned. This makes sure it cannot be freed while in use. |
|
* Use trace_array_put() once the trace array is no longer needed. |
|
* If the trace_array is to be freed, trace_array_destroy() needs to |
|
* be called after the trace_array_put(), or simply let user space delete |
|
* it from the tracefs instances directory. But until the |
|
* trace_array_put() is called, user space can not delete it. |
|
* |
|
*/ |
|
struct trace_array *trace_array_get_by_name(const char *name) |
|
{ |
|
struct trace_array *tr; |
|
|
|
mutex_lock(&event_mutex); |
|
mutex_lock(&trace_types_lock); |
|
|
|
list_for_each_entry(tr, &ftrace_trace_arrays, list) { |
|
if (tr->name && strcmp(tr->name, name) == 0) |
|
goto out_unlock; |
|
} |
|
|
|
tr = trace_array_create(name); |
|
|
|
if (IS_ERR(tr)) |
|
tr = NULL; |
|
out_unlock: |
|
if (tr) |
|
tr->ref++; |
|
|
|
mutex_unlock(&trace_types_lock); |
|
mutex_unlock(&event_mutex); |
|
return tr; |
|
} |
|
EXPORT_SYMBOL_GPL(trace_array_get_by_name); |
|
|
|
static int __remove_instance(struct trace_array *tr) |
|
{ |
|
int i; |
|
|
|
/* Reference counter for a newly created trace array = 1. */ |
|
if (tr->ref > 1 || (tr->current_trace && tr->trace_ref)) |
|
return -EBUSY; |
|
|
|
list_del(&tr->list); |
|
|
|
/* Disable all the flags that were enabled coming in */ |
|
for (i = 0; i < TRACE_FLAGS_MAX_SIZE; i++) { |
|
if ((1 << i) & ZEROED_TRACE_FLAGS) |
|
set_tracer_flag(tr, 1 << i, 0); |
|
} |
|
|
|
tracing_set_nop(tr); |
|
clear_ftrace_function_probes(tr); |
|
event_trace_del_tracer(tr); |
|
ftrace_clear_pids(tr); |
|
ftrace_destroy_function_files(tr); |
|
tracefs_remove(tr->dir); |
|
free_trace_buffers(tr); |
|
|
|
for (i = 0; i < tr->nr_topts; i++) { |
|
kfree(tr->topts[i].topts); |
|
} |
|
kfree(tr->topts); |
|
|
|
free_cpumask_var(tr->tracing_cpumask); |
|
kfree(tr->name); |
|
kfree(tr); |
|
|
|
return 0; |
|
} |
|
|
|
int trace_array_destroy(struct trace_array *this_tr) |
|
{ |
|
struct trace_array *tr; |
|
int ret; |
|
|
|
if (!this_tr) |
|
return -EINVAL; |
|
|
|
mutex_lock(&event_mutex); |
|
mutex_lock(&trace_types_lock); |
|
|
|
ret = -ENODEV; |
|
|
|
/* Making sure trace array exists before destroying it. */ |
|
list_for_each_entry(tr, &ftrace_trace_arrays, list) { |
|
if (tr == this_tr) { |
|
ret = __remove_instance(tr); |
|
break; |
|
} |
|
} |
|
|
|
mutex_unlock(&trace_types_lock); |
|
mutex_unlock(&event_mutex); |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(trace_array_destroy); |
|
|
|
static int instance_rmdir(const char *name) |
|
{ |
|
struct trace_array *tr; |
|
int ret; |
|
|
|
mutex_lock(&event_mutex); |
|
mutex_lock(&trace_types_lock); |
|
|
|
ret = -ENODEV; |
|
tr = trace_array_find(name); |
|
if (tr) |
|
ret = __remove_instance(tr); |
|
|
|
mutex_unlock(&trace_types_lock); |
|
mutex_unlock(&event_mutex); |
|
|
|
return ret; |
|
} |
|
|
|
static __init void create_trace_instances(struct dentry *d_tracer) |
|
{ |
|
struct trace_array *tr; |
|
|
|
trace_instance_dir = tracefs_create_instance_dir("instances", d_tracer, |
|
instance_mkdir, |
|
instance_rmdir); |
|
if (MEM_FAIL(!trace_instance_dir, "Failed to create instances directory\n")) |
|
return; |
|
|
|
mutex_lock(&event_mutex); |
|
mutex_lock(&trace_types_lock); |
|
|
|
list_for_each_entry(tr, &ftrace_trace_arrays, list) { |
|
if (!tr->name) |
|
continue; |
|
if (MEM_FAIL(trace_array_create_dir(tr) < 0, |
|
"Failed to create instance directory\n")) |
|
break; |
|
} |
|
|
|
mutex_unlock(&trace_types_lock); |
|
mutex_unlock(&event_mutex); |
|
} |
|
|
|
static void |
|
init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer) |
|
{ |
|
struct trace_event_file *file; |
|
int cpu; |
|
|
|
trace_create_file("available_tracers", 0444, d_tracer, |
|
tr, &show_traces_fops); |
|
|
|
trace_create_file("current_tracer", 0644, d_tracer, |
|
tr, &set_tracer_fops); |
|
|
|
trace_create_file("tracing_cpumask", 0644, d_tracer, |
|
tr, &tracing_cpumask_fops); |
|
|
|
trace_create_file("trace_options", 0644, d_tracer, |
|
tr, &tracing_iter_fops); |
|
|
|
trace_create_file("trace", 0644, d_tracer, |
|
tr, &tracing_fops); |
|
|
|
trace_create_file("trace_pipe", 0444, d_tracer, |
|
tr, &tracing_pipe_fops); |
|
|
|
trace_create_file("buffer_size_kb", 0644, d_tracer, |
|
tr, &tracing_entries_fops); |
|
|
|
trace_create_file("buffer_total_size_kb", 0444, d_tracer, |
|
tr, &tracing_total_entries_fops); |
|
|
|
trace_create_file("free_buffer", 0200, d_tracer, |
|
tr, &tracing_free_buffer_fops); |
|
|
|
trace_create_file("trace_marker", 0220, d_tracer, |
|
tr, &tracing_mark_fops); |
|
|
|
file = __find_event_file(tr, "ftrace", "print"); |
|
if (file && file->dir) |
|
trace_create_file("trigger", 0644, file->dir, file, |
|
&event_trigger_fops); |
|
tr->trace_marker_file = file; |
|
|
|
trace_create_file("trace_marker_raw", 0220, d_tracer, |
|
tr, &tracing_mark_raw_fops); |
|
|
|
trace_create_file("trace_clock", 0644, d_tracer, tr, |
|
&trace_clock_fops); |
|
|
|
trace_create_file("tracing_on", 0644, d_tracer, |
|
tr, &rb_simple_fops); |
|
|
|
trace_create_file("timestamp_mode", 0444, d_tracer, tr, |
|
&trace_time_stamp_mode_fops); |
|
|
|
tr->buffer_percent = 50; |
|
|
|
trace_create_file("buffer_percent", 0444, d_tracer, |
|
tr, &buffer_percent_fops); |
|
|
|
create_trace_options_dir(tr); |
|
|
|
#if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER) |
|
trace_create_maxlat_file(tr, d_tracer); |
|
#endif |
|
|
|
if (ftrace_create_function_files(tr, d_tracer)) |
|
MEM_FAIL(1, "Could not allocate function filter files"); |
|
|
|
#ifdef CONFIG_TRACER_SNAPSHOT |
|
trace_create_file("snapshot", 0644, d_tracer, |
|
tr, &snapshot_fops); |
|
#endif |
|
|
|
trace_create_file("error_log", 0644, d_tracer, |
|
tr, &tracing_err_log_fops); |
|
|
|
for_each_tracing_cpu(cpu) |
|
tracing_init_tracefs_percpu(tr, cpu); |
|
|
|
ftrace_init_tracefs(tr, d_tracer); |
|
} |
|
|
|
static struct vfsmount *trace_automount(struct dentry *mntpt, void *ingore) |
|
{ |
|
struct vfsmount *mnt; |
|
struct file_system_type *type; |
|
|
|
/* |
|
* To maintain backward compatibility for tools that mount |
|
* debugfs to get to the tracing facility, tracefs is automatically |
|
* mounted to the debugfs/tracing directory. |
|
*/ |
|
type = get_fs_type("tracefs"); |
|
if (!type) |
|
return NULL; |
|
mnt = vfs_submount(mntpt, type, "tracefs", NULL); |
|
put_filesystem(type); |
|
if (IS_ERR(mnt)) |
|
return NULL; |
|
mntget(mnt); |
|
|
|
return mnt; |
|
} |
|
|
|
/** |
|
* tracing_init_dentry - initialize top level trace array |
|
* |
|
* This is called when creating files or directories in the tracing |
|
* directory. It is called via fs_initcall() by any of the boot up code |
|
* and expects to return the dentry of the top level tracing directory. |
|
*/ |
|
int tracing_init_dentry(void) |
|
{ |
|
struct trace_array *tr = &global_trace; |
|
|
|
if (security_locked_down(LOCKDOWN_TRACEFS)) { |
|
pr_warn("Tracing disabled due to lockdown\n"); |
|
return -EPERM; |
|
} |
|
|
|
/* The top level trace array uses NULL as parent */ |
|
if (tr->dir) |
|
return 0; |
|
|
|
if (WARN_ON(!tracefs_initialized())) |
|
return -ENODEV; |
|
|
|
/* |
|
* As there may still be users that expect the tracing |
|
* files to exist in debugfs/tracing, we must automount |
|
* the tracefs file system there, so older tools still |
|
* work with the newer kerenl. |
|
*/ |
|
tr->dir = debugfs_create_automount("tracing", NULL, |
|
trace_automount, NULL); |
|
|
|
return 0; |
|
} |
|
|
|
extern struct trace_eval_map *__start_ftrace_eval_maps[]; |
|
extern struct trace_eval_map *__stop_ftrace_eval_maps[]; |
|
|
|
static struct workqueue_struct *eval_map_wq __initdata; |
|
static struct work_struct eval_map_work __initdata; |
|
|
|
static void __init eval_map_work_func(struct work_struct *work) |
|
{ |
|
int len; |
|
|
|
len = __stop_ftrace_eval_maps - __start_ftrace_eval_maps; |
|
trace_insert_eval_map(NULL, __start_ftrace_eval_maps, len); |
|
} |
|
|
|
static int __init trace_eval_init(void) |
|
{ |
|
INIT_WORK(&eval_map_work, eval_map_work_func); |
|
|
|
eval_map_wq = alloc_workqueue("eval_map_wq", WQ_UNBOUND, 0); |
|
if (!eval_map_wq) { |
|
pr_err("Unable to allocate eval_map_wq\n"); |
|
/* Do work here */ |
|
eval_map_work_func(&eval_map_work); |
|
return -ENOMEM; |
|
} |
|
|
|
queue_work(eval_map_wq, &eval_map_work); |
|
return 0; |
|
} |
|
|
|
static int __init trace_eval_sync(void) |
|
{ |
|
/* Make sure the eval map updates are finished */ |
|
if (eval_map_wq) |
|
destroy_workqueue(eval_map_wq); |
|
return 0; |
|
} |
|
|
|
late_initcall_sync(trace_eval_sync); |
|
|
|
|
|
#ifdef CONFIG_MODULES |
|
static void trace_module_add_evals(struct module *mod) |
|
{ |
|
if (!mod->num_trace_evals) |
|
return; |
|
|
|
/* |
|
* Modules with bad taint do not have events created, do |
|
* not bother with enums either. |
|
*/ |
|
if (trace_module_has_bad_taint(mod)) |
|
return; |
|
|
|
trace_insert_eval_map(mod, mod->trace_evals, mod->num_trace_evals); |
|
} |
|
|
|
#ifdef CONFIG_TRACE_EVAL_MAP_FILE |
|
static void trace_module_remove_evals(struct module *mod) |
|
{ |
|
union trace_eval_map_item *map; |
|
union trace_eval_map_item **last = &trace_eval_maps; |
|
|
|
if (!mod->num_trace_evals) |
|
return; |
|
|
|
mutex_lock(&trace_eval_mutex); |
|
|
|
map = trace_eval_maps; |
|
|
|
while (map) { |
|
if (map->head.mod == mod) |
|
break; |
|
map = trace_eval_jmp_to_tail(map); |
|
last = &map->tail.next; |
|
map = map->tail.next; |
|
} |
|
if (!map) |
|
goto out; |
|
|
|
*last = trace_eval_jmp_to_tail(map)->tail.next; |
|
kfree(map); |
|
out: |
|
mutex_unlock(&trace_eval_mutex); |
|
} |
|
#else |
|
static inline void trace_module_remove_evals(struct module *mod) { } |
|
#endif /* CONFIG_TRACE_EVAL_MAP_FILE */ |
|
|
|
static int trace_module_notify(struct notifier_block *self, |
|
unsigned long val, void *data) |
|
{ |
|
struct module *mod = data; |
|
|
|
switch (val) { |
|
case MODULE_STATE_COMING: |
|
trace_module_add_evals(mod); |
|
break; |
|
case MODULE_STATE_GOING: |
|
trace_module_remove_evals(mod); |
|
break; |
|
} |
|
|
|
return NOTIFY_OK; |
|
} |
|
|
|
static struct notifier_block trace_module_nb = { |
|
.notifier_call = trace_module_notify, |
|
.priority = 0, |
|
}; |
|
#endif /* CONFIG_MODULES */ |
|
|
|
static __init int tracer_init_tracefs(void) |
|
{ |
|
int ret; |
|
|
|
trace_access_lock_init(); |
|
|
|
ret = tracing_init_dentry(); |
|
if (ret) |
|
return 0; |
|
|
|
event_trace_init(); |
|
|
|
init_tracer_tracefs(&global_trace, NULL); |
|
ftrace_init_tracefs_toplevel(&global_trace, NULL); |
|
|
|
trace_create_file("tracing_thresh", 0644, NULL, |
|
&global_trace, &tracing_thresh_fops); |
|
|
|
trace_create_file("README", 0444, NULL, |
|
NULL, &tracing_readme_fops); |
|
|
|
trace_create_file("saved_cmdlines", 0444, NULL, |
|
NULL, &tracing_saved_cmdlines_fops); |
|
|
|
trace_create_file("saved_cmdlines_size", 0644, NULL, |
|
NULL, &tracing_saved_cmdlines_size_fops); |
|
|
|
trace_create_file("saved_tgids", 0444, NULL, |
|
NULL, &tracing_saved_tgids_fops); |
|
|
|
trace_eval_init(); |
|
|
|
trace_create_eval_file(NULL); |
|
|
|
#ifdef CONFIG_MODULES |
|
register_module_notifier(&trace_module_nb); |
|
#endif |
|
|
|
#ifdef CONFIG_DYNAMIC_FTRACE |
|
trace_create_file("dyn_ftrace_total_info", 0444, NULL, |
|
NULL, &tracing_dyn_info_fops); |
|
#endif |
|
|
|
create_trace_instances(NULL); |
|
|
|
update_tracer_options(&global_trace); |
|
|
|
return 0; |
|
} |
|
|
|
static int trace_panic_handler(struct notifier_block *this, |
|
unsigned long event, void *unused) |
|
{ |
|
if (ftrace_dump_on_oops) |
|
ftrace_dump(ftrace_dump_on_oops); |
|
return NOTIFY_OK; |
|
} |
|
|
|
static struct notifier_block trace_panic_notifier = { |
|
.notifier_call = trace_panic_handler, |
|
.next = NULL, |
|
.priority = 150 /* priority: INT_MAX >= x >= 0 */ |
|
}; |
|
|
|
static int trace_die_handler(struct notifier_block *self, |
|
unsigned long val, |
|
void *data) |
|
{ |
|
switch (val) { |
|
case DIE_OOPS: |
|
if (ftrace_dump_on_oops) |
|
ftrace_dump(ftrace_dump_on_oops); |
|
break; |
|
default: |
|
break; |
|
} |
|
return NOTIFY_OK; |
|
} |
|
|
|
static struct notifier_block trace_die_notifier = { |
|
.notifier_call = trace_die_handler, |
|
.priority = 200 |
|
}; |
|
|
|
/* |
|
* printk is set to max of 1024, we really don't need it that big. |
|
* Nothing should be printing 1000 characters anyway. |
|
*/ |
|
#define TRACE_MAX_PRINT 1000 |
|
|
|
/* |
|
* Define here KERN_TRACE so that we have one place to modify |
|
* it if we decide to change what log level the ftrace dump |
|
* should be at. |
|
*/ |
|
#define KERN_TRACE KERN_EMERG |
|
|
|
void |
|
trace_printk_seq(struct trace_seq *s) |
|
{ |
|
/* Probably should print a warning here. */ |
|
if (s->seq.len >= TRACE_MAX_PRINT) |
|
s->seq.len = TRACE_MAX_PRINT; |
|
|
|
/* |
|
* More paranoid code. Although the buffer size is set to |
|
* PAGE_SIZE, and TRACE_MAX_PRINT is 1000, this is just |
|
* an extra layer of protection. |
|
*/ |
|
if (WARN_ON_ONCE(s->seq.len >= s->seq.size)) |
|
s->seq.len = s->seq.size - 1; |
|
|
|
/* should be zero ended, but we are paranoid. */ |
|
s->buffer[s->seq.len] = 0; |
|
|
|
printk(KERN_TRACE "%s", s->buffer); |
|
|
|
trace_seq_init(s); |
|
} |
|
|
|
void trace_init_global_iter(struct trace_iterator *iter) |
|
{ |
|
iter->tr = &global_trace; |
|
iter->trace = iter->tr->current_trace; |
|
iter->cpu_file = RING_BUFFER_ALL_CPUS; |
|
iter->array_buffer = &global_trace.array_buffer; |
|
|
|
if (iter->trace && iter->trace->open) |
|
iter->trace->open(iter); |
|
|
|
/* Annotate start of buffers if we had overruns */ |
|
if (ring_buffer_overruns(iter->array_buffer->buffer)) |
|
iter->iter_flags |= TRACE_FILE_ANNOTATE; |
|
|
|
/* Output in nanoseconds only if we are using a clock in nanoseconds. */ |
|
if (trace_clocks[iter->tr->clock_id].in_ns) |
|
iter->iter_flags |= TRACE_FILE_TIME_IN_NS; |
|
} |
|
|
|
void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) |
|
{ |
|
/* use static because iter can be a bit big for the stack */ |
|
static struct trace_iterator iter; |
|
static atomic_t dump_running; |
|
struct trace_array *tr = &global_trace; |
|
unsigned int old_userobj; |
|
unsigned long flags; |
|
int cnt = 0, cpu; |
|
|
|
/* Only allow one dump user at a time. */ |
|
if (atomic_inc_return(&dump_running) != 1) { |
|
atomic_dec(&dump_running); |
|
return; |
|
} |
|
|
|
/* |
|
* Always turn off tracing when we dump. |
|
* We don't need to show trace output of what happens |
|
* between multiple crashes. |
|
* |
|
* If the user does a sysrq-z, then they can re-enable |
|
* tracing with echo 1 > tracing_on. |
|
*/ |
|
tracing_off(); |
|
|
|
local_irq_save(flags); |
|
printk_nmi_direct_enter(); |
|
|
|
/* Simulate the iterator */ |
|
trace_init_global_iter(&iter); |
|
/* Can not use kmalloc for iter.temp and iter.fmt */ |
|
iter.temp = static_temp_buf; |
|
iter.temp_size = STATIC_TEMP_BUF_SIZE; |
|
iter.fmt = static_fmt_buf; |
|
iter.fmt_size = STATIC_FMT_BUF_SIZE; |
|
|
|
for_each_tracing_cpu(cpu) { |
|
atomic_inc(&per_cpu_ptr(iter.array_buffer->data, cpu)->disabled); |
|
} |
|
|
|
old_userobj = tr->trace_flags & TRACE_ITER_SYM_USEROBJ; |
|
|
|
/* don't look at user memory in panic mode */ |
|
tr->trace_flags &= ~TRACE_ITER_SYM_USEROBJ; |
|
|
|
switch (oops_dump_mode) { |
|
case DUMP_ALL: |
|
iter.cpu_file = RING_BUFFER_ALL_CPUS; |
|
break; |
|
case DUMP_ORIG: |
|
iter.cpu_file = raw_smp_processor_id(); |
|
break; |
|
case DUMP_NONE: |
|
goto out_enable; |
|
default: |
|
printk(KERN_TRACE "Bad dumping mode, switching to all CPUs dump\n"); |
|
iter.cpu_file = RING_BUFFER_ALL_CPUS; |
|
} |
|
|
|
printk(KERN_TRACE "Dumping ftrace buffer:\n"); |
|
|
|
/* Did function tracer already get disabled? */ |
|
if (ftrace_is_dead()) { |
|
printk("# WARNING: FUNCTION TRACING IS CORRUPTED\n"); |
|
printk("# MAY BE MISSING FUNCTION EVENTS\n"); |
|
} |
|
|
|
/* |
|
* We need to stop all tracing on all CPUS to read |
|
* the next buffer. This is a bit expensive, but is |
|
* not done often. We fill all what we can read, |
|
* and then release the locks again. |
|
*/ |
|
|
|
while (!trace_empty(&iter)) { |
|
|
|
if (!cnt) |
|
printk(KERN_TRACE "---------------------------------\n"); |
|
|
|
cnt++; |
|
|
|
trace_iterator_reset(&iter); |
|
iter.iter_flags |= TRACE_FILE_LAT_FMT; |
|
|
|
if (trace_find_next_entry_inc(&iter) != NULL) { |
|
int ret; |
|
|
|
ret = print_trace_line(&iter); |
|
if (ret != TRACE_TYPE_NO_CONSUME) |
|
trace_consume(&iter); |
|
} |
|
touch_nmi_watchdog(); |
|
|
|
trace_printk_seq(&iter.seq); |
|
} |
|
|
|
if (!cnt) |
|
printk(KERN_TRACE " (ftrace buffer empty)\n"); |
|
else |
|
printk(KERN_TRACE "---------------------------------\n"); |
|
|
|
out_enable: |
|
tr->trace_flags |= old_userobj; |
|
|
|
for_each_tracing_cpu(cpu) { |
|
atomic_dec(&per_cpu_ptr(iter.array_buffer->data, cpu)->disabled); |
|
} |
|
atomic_dec(&dump_running); |
|
printk_nmi_direct_exit(); |
|
local_irq_restore(flags); |
|
} |
|
EXPORT_SYMBOL_GPL(ftrace_dump); |
|
|
|
#define WRITE_BUFSIZE 4096 |
|
|
|
ssize_t trace_parse_run_command(struct file *file, const char __user *buffer, |
|
size_t count, loff_t *ppos, |
|
int (*createfn)(const char *)) |
|
{ |
|
char *kbuf, *buf, *tmp; |
|
int ret = 0; |
|
size_t done = 0; |
|
size_t size; |
|
|
|
kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL); |
|
if (!kbuf) |
|
return -ENOMEM; |
|
|
|
while (done < count) { |
|
size = count - done; |
|
|
|
if (size >= WRITE_BUFSIZE) |
|
size = WRITE_BUFSIZE - 1; |
|
|
|
if (copy_from_user(kbuf, buffer + done, size)) { |
|
ret = -EFAULT; |
|
goto out; |
|
} |
|
kbuf[size] = '\0'; |
|
buf = kbuf; |
|
do { |
|
tmp = strchr(buf, '\n'); |
|
if (tmp) { |
|
*tmp = '\0'; |
|
size = tmp - buf + 1; |
|
} else { |
|
size = strlen(buf); |
|
if (done + size < count) { |
|
if (buf != kbuf) |
|
break; |
|
/* This can accept WRITE_BUFSIZE - 2 ('\n' + '\0') */ |
|
pr_warn("Line length is too long: Should be less than %d\n", |
|
WRITE_BUFSIZE - 2); |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
} |
|
done += size; |
|
|
|
/* Remove comments */ |
|
tmp = strchr(buf, '#'); |
|
|
|
if (tmp) |
|
*tmp = '\0'; |
|
|
|
ret = createfn(buf); |
|
if (ret) |
|
goto out; |
|
buf += size; |
|
|
|
} while (done < count); |
|
} |
|
ret = done; |
|
|
|
out: |
|
kfree(kbuf); |
|
|
|
return ret; |
|
} |
|
|
|
__init static int tracer_alloc_buffers(void) |
|
{ |
|
int ring_buf_size; |
|
int ret = -ENOMEM; |
|
|
|
|
|
if (security_locked_down(LOCKDOWN_TRACEFS)) { |
|
pr_warn("Tracing disabled due to lockdown\n"); |
|
return -EPERM; |
|
} |
|
|
|
/* |
|
* Make sure we don't accidentally add more trace options |
|
* than we have bits for. |
|
*/ |
|
BUILD_BUG_ON(TRACE_ITER_LAST_BIT > TRACE_FLAGS_MAX_SIZE); |
|
|
|
if (!alloc_cpumask_var(&tracing_buffer_mask, GFP_KERNEL)) |
|
goto out; |
|
|
|
if (!alloc_cpumask_var(&global_trace.tracing_cpumask, GFP_KERNEL)) |
|
goto out_free_buffer_mask; |
|
|
|
/* Only allocate trace_printk buffers if a trace_printk exists */ |
|
if (&__stop___trace_bprintk_fmt != &__start___trace_bprintk_fmt) |
|
/* Must be called before global_trace.buffer is allocated */ |
|
trace_printk_init_buffers(); |
|
|
|
/* To save memory, keep the ring buffer size to its minimum */ |
|
if (ring_buffer_expanded) |
|
ring_buf_size = trace_buf_size; |
|
else |
|
ring_buf_size = 1; |
|
|
|
cpumask_copy(tracing_buffer_mask, cpu_possible_mask); |
|
cpumask_copy(global_trace.tracing_cpumask, cpu_all_mask); |
|
|
|
raw_spin_lock_init(&global_trace.start_lock); |
|
|
|
/* |
|
* The prepare callbacks allocates some memory for the ring buffer. We |
|
* don't free the buffer if the CPU goes down. If we were to free |
|
* the buffer, then the user would lose any trace that was in the |
|
* buffer. The memory will be removed once the "instance" is removed. |
|
*/ |
|
ret = cpuhp_setup_state_multi(CPUHP_TRACE_RB_PREPARE, |
|
"trace/RB:preapre", trace_rb_cpu_prepare, |
|
NULL); |
|
if (ret < 0) |
|
goto out_free_cpumask; |
|
/* Used for event triggers */ |
|
ret = -ENOMEM; |
|
temp_buffer = ring_buffer_alloc(PAGE_SIZE, RB_FL_OVERWRITE); |
|
if (!temp_buffer) |
|
goto out_rm_hp_state; |
|
|
|
if (trace_create_savedcmd() < 0) |
|
goto out_free_temp_buffer; |
|
|
|
/* TODO: make the number of buffers hot pluggable with CPUS */ |
|
if (allocate_trace_buffers(&global_trace, ring_buf_size) < 0) { |
|
MEM_FAIL(1, "tracer: failed to allocate ring buffer!\n"); |
|
goto out_free_savedcmd; |
|
} |
|
|
|
if (global_trace.buffer_disabled) |
|
tracing_off(); |
|
|
|
if (trace_boot_clock) { |
|
ret = tracing_set_clock(&global_trace, trace_boot_clock); |
|
if (ret < 0) |
|
pr_warn("Trace clock %s not defined, going back to default\n", |
|
trace_boot_clock); |
|
} |
|
|
|
/* |
|
* register_tracer() might reference current_trace, so it |
|
* needs to be set before we register anything. This is |
|
* just a bootstrap of current_trace anyway. |
|
*/ |
|
global_trace.current_trace = &nop_trace; |
|
|
|
global_trace.max_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; |
|
|
|
ftrace_init_global_array_ops(&global_trace); |
|
|
|
init_trace_flags_index(&global_trace); |
|
|
|
register_tracer(&nop_trace); |
|
|
|
/* Function tracing may start here (via kernel command line) */ |
|
init_function_trace(); |
|
|
|
/* All seems OK, enable tracing */ |
|
tracing_disabled = 0; |
|
|
|
atomic_notifier_chain_register(&panic_notifier_list, |
|
&trace_panic_notifier); |
|
|
|
register_die_notifier(&trace_die_notifier); |
|
|
|
global_trace.flags = TRACE_ARRAY_FL_GLOBAL; |
|
|
|
INIT_LIST_HEAD(&global_trace.systems); |
|
INIT_LIST_HEAD(&global_trace.events); |
|
INIT_LIST_HEAD(&global_trace.hist_vars); |
|
INIT_LIST_HEAD(&global_trace.err_log); |
|
list_add(&global_trace.list, &ftrace_trace_arrays); |
|
|
|
apply_trace_boot_options(); |
|
|
|
register_snapshot_cmd(); |
|
|
|
return 0; |
|
|
|
out_free_savedcmd: |
|
free_saved_cmdlines_buffer(savedcmd); |
|
out_free_temp_buffer: |
|
ring_buffer_free(temp_buffer); |
|
out_rm_hp_state: |
|
cpuhp_remove_multi_state(CPUHP_TRACE_RB_PREPARE); |
|
out_free_cpumask: |
|
free_cpumask_var(global_trace.tracing_cpumask); |
|
out_free_buffer_mask: |
|
free_cpumask_var(tracing_buffer_mask); |
|
out: |
|
return ret; |
|
} |
|
|
|
void __init early_trace_init(void) |
|
{ |
|
if (tracepoint_printk) { |
|
tracepoint_print_iter = |
|
kzalloc(sizeof(*tracepoint_print_iter), GFP_KERNEL); |
|
if (MEM_FAIL(!tracepoint_print_iter, |
|
"Failed to allocate trace iterator\n")) |
|
tracepoint_printk = 0; |
|
else |
|
static_key_enable(&tracepoint_printk_key.key); |
|
} |
|
tracer_alloc_buffers(); |
|
} |
|
|
|
void __init trace_init(void) |
|
{ |
|
trace_event_init(); |
|
} |
|
|
|
__init static int clear_boot_tracer(void) |
|
{ |
|
/* |
|
* The default tracer at boot buffer is an init section. |
|
* This function is called in lateinit. If we did not |
|
* find the boot tracer, then clear it out, to prevent |
|
* later registration from accessing the buffer that is |
|
* about to be freed. |
|
*/ |
|
if (!default_bootup_tracer) |
|
return 0; |
|
|
|
printk(KERN_INFO "ftrace bootup tracer '%s' not registered.\n", |
|
default_bootup_tracer); |
|
default_bootup_tracer = NULL; |
|
|
|
return 0; |
|
} |
|
|
|
fs_initcall(tracer_init_tracefs); |
|
late_initcall_sync(clear_boot_tracer); |
|
|
|
#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK |
|
__init static int tracing_set_default_clock(void) |
|
{ |
|
/* sched_clock_stable() is determined in late_initcall */ |
|
if (!trace_boot_clock && !sched_clock_stable()) { |
|
if (security_locked_down(LOCKDOWN_TRACEFS)) { |
|
pr_warn("Can not set tracing clock due to lockdown\n"); |
|
return -EPERM; |
|
} |
|
|
|
printk(KERN_WARNING |
|
"Unstable clock detected, switching default tracing clock to \"global\"\n" |
|
"If you want to keep using the local clock, then add:\n" |
|
" \"trace_clock=local\"\n" |
|
"on the kernel command line\n"); |
|
tracing_set_clock(&global_trace, "global"); |
|
} |
|
|
|
return 0; |
|
} |
|
late_initcall_sync(tracing_set_default_clock); |
|
#endif
|
|
|