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7890 lines
187 KiB
7890 lines
187 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Infrastructure for profiling code inserted by 'gcc -pg'. |
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* |
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* Copyright (C) 2007-2008 Steven Rostedt <[email protected]> |
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* Copyright (C) 2004-2008 Ingo Molnar <[email protected]> |
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* |
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* Originally ported from the -rt patch by: |
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* Copyright (C) 2007 Arnaldo Carvalho de Melo <[email protected]> |
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* |
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* Based on code in the latency_tracer, that is: |
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* |
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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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|
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#include <linux/stop_machine.h> |
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#include <linux/clocksource.h> |
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#include <linux/sched/task.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/tracefs.h> |
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#include <linux/hardirq.h> |
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#include <linux/kthread.h> |
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#include <linux/uaccess.h> |
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#include <linux/bsearch.h> |
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#include <linux/module.h> |
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#include <linux/ftrace.h> |
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#include <linux/sysctl.h> |
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#include <linux/slab.h> |
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#include <linux/ctype.h> |
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#include <linux/sort.h> |
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#include <linux/list.h> |
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#include <linux/hash.h> |
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#include <linux/rcupdate.h> |
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#include <linux/kprobes.h> |
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|
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#include <trace/events/sched.h> |
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|
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#include <asm/sections.h> |
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#include <asm/setup.h> |
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|
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#include "ftrace_internal.h" |
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#include "trace_output.h" |
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#include "trace_stat.h" |
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|
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#define FTRACE_WARN_ON(cond) \ |
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({ \ |
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int ___r = cond; \ |
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if (WARN_ON(___r)) \ |
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ftrace_kill(); \ |
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___r; \ |
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}) |
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|
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#define FTRACE_WARN_ON_ONCE(cond) \ |
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({ \ |
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int ___r = cond; \ |
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if (WARN_ON_ONCE(___r)) \ |
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ftrace_kill(); \ |
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___r; \ |
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}) |
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|
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/* hash bits for specific function selection */ |
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#define FTRACE_HASH_DEFAULT_BITS 10 |
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#define FTRACE_HASH_MAX_BITS 12 |
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|
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#ifdef CONFIG_DYNAMIC_FTRACE |
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#define INIT_OPS_HASH(opsname) \ |
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.func_hash = &opsname.local_hash, \ |
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.local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock), |
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#else |
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#define INIT_OPS_HASH(opsname) |
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#endif |
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|
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enum { |
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FTRACE_MODIFY_ENABLE_FL = (1 << 0), |
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FTRACE_MODIFY_MAY_SLEEP_FL = (1 << 1), |
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}; |
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|
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struct ftrace_ops ftrace_list_end __read_mostly = { |
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.func = ftrace_stub, |
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.flags = FTRACE_OPS_FL_STUB, |
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INIT_OPS_HASH(ftrace_list_end) |
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}; |
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|
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/* ftrace_enabled is a method to turn ftrace on or off */ |
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int ftrace_enabled __read_mostly; |
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static int last_ftrace_enabled; |
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|
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/* Current function tracing op */ |
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struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end; |
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/* What to set function_trace_op to */ |
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static struct ftrace_ops *set_function_trace_op; |
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|
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static bool ftrace_pids_enabled(struct ftrace_ops *ops) |
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{ |
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struct trace_array *tr; |
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|
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if (!(ops->flags & FTRACE_OPS_FL_PID) || !ops->private) |
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return false; |
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|
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tr = ops->private; |
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|
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return tr->function_pids != NULL || tr->function_no_pids != NULL; |
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} |
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|
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static void ftrace_update_trampoline(struct ftrace_ops *ops); |
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|
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/* |
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* ftrace_disabled is set when an anomaly is discovered. |
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* ftrace_disabled is much stronger than ftrace_enabled. |
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*/ |
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static int ftrace_disabled __read_mostly; |
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|
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DEFINE_MUTEX(ftrace_lock); |
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|
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struct ftrace_ops __rcu *ftrace_ops_list __read_mostly = &ftrace_list_end; |
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ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; |
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struct ftrace_ops global_ops; |
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|
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/* Defined by vmlinux.lds.h see the commment above arch_ftrace_ops_list_func for details */ |
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void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, |
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struct ftrace_ops *op, struct ftrace_regs *fregs); |
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|
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static inline void ftrace_ops_init(struct ftrace_ops *ops) |
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{ |
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#ifdef CONFIG_DYNAMIC_FTRACE |
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if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) { |
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mutex_init(&ops->local_hash.regex_lock); |
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ops->func_hash = &ops->local_hash; |
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ops->flags |= FTRACE_OPS_FL_INITIALIZED; |
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} |
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#endif |
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} |
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|
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static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip, |
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struct ftrace_ops *op, struct ftrace_regs *fregs) |
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{ |
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struct trace_array *tr = op->private; |
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int pid; |
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|
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if (tr) { |
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pid = this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid); |
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if (pid == FTRACE_PID_IGNORE) |
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return; |
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if (pid != FTRACE_PID_TRACE && |
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pid != current->pid) |
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return; |
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} |
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|
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op->saved_func(ip, parent_ip, op, fregs); |
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} |
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|
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static void ftrace_sync_ipi(void *data) |
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{ |
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/* Probably not needed, but do it anyway */ |
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smp_rmb(); |
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} |
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|
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static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops) |
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{ |
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/* |
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* If this is a dynamic, RCU, or per CPU ops, or we force list func, |
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* then it needs to call the list anyway. |
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*/ |
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if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_RCU) || |
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FTRACE_FORCE_LIST_FUNC) |
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return ftrace_ops_list_func; |
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|
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return ftrace_ops_get_func(ops); |
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} |
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|
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static void update_ftrace_function(void) |
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{ |
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ftrace_func_t func; |
|
|
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/* |
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* Prepare the ftrace_ops that the arch callback will use. |
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* If there's only one ftrace_ops registered, the ftrace_ops_list |
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* will point to the ops we want. |
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*/ |
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set_function_trace_op = rcu_dereference_protected(ftrace_ops_list, |
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lockdep_is_held(&ftrace_lock)); |
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|
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/* If there's no ftrace_ops registered, just call the stub function */ |
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if (set_function_trace_op == &ftrace_list_end) { |
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func = ftrace_stub; |
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|
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/* |
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* If we are at the end of the list and this ops is |
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* recursion safe and not dynamic and the arch supports passing ops, |
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* then have the mcount trampoline call the function directly. |
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*/ |
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} else if (rcu_dereference_protected(ftrace_ops_list->next, |
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lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { |
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func = ftrace_ops_get_list_func(ftrace_ops_list); |
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|
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} else { |
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/* Just use the default ftrace_ops */ |
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set_function_trace_op = &ftrace_list_end; |
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func = ftrace_ops_list_func; |
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} |
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|
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update_function_graph_func(); |
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|
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/* If there's no change, then do nothing more here */ |
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if (ftrace_trace_function == func) |
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return; |
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|
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/* |
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* If we are using the list function, it doesn't care |
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* about the function_trace_ops. |
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*/ |
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if (func == ftrace_ops_list_func) { |
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ftrace_trace_function = func; |
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/* |
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* Don't even bother setting function_trace_ops, |
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* it would be racy to do so anyway. |
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*/ |
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return; |
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} |
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|
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#ifndef CONFIG_DYNAMIC_FTRACE |
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/* |
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* For static tracing, we need to be a bit more careful. |
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* The function change takes affect immediately. Thus, |
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* we need to coordinate the setting of the function_trace_ops |
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* with the setting of the ftrace_trace_function. |
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* |
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* Set the function to the list ops, which will call the |
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* function we want, albeit indirectly, but it handles the |
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* ftrace_ops and doesn't depend on function_trace_op. |
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*/ |
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ftrace_trace_function = ftrace_ops_list_func; |
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/* |
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* Make sure all CPUs see this. Yes this is slow, but static |
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* tracing is slow and nasty to have enabled. |
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*/ |
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synchronize_rcu_tasks_rude(); |
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/* Now all cpus are using the list ops. */ |
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function_trace_op = set_function_trace_op; |
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/* Make sure the function_trace_op is visible on all CPUs */ |
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smp_wmb(); |
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/* Nasty way to force a rmb on all cpus */ |
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smp_call_function(ftrace_sync_ipi, NULL, 1); |
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/* OK, we are all set to update the ftrace_trace_function now! */ |
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#endif /* !CONFIG_DYNAMIC_FTRACE */ |
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|
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ftrace_trace_function = func; |
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} |
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|
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static void add_ftrace_ops(struct ftrace_ops __rcu **list, |
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struct ftrace_ops *ops) |
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{ |
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rcu_assign_pointer(ops->next, *list); |
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|
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/* |
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* We are entering ops 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 ops->next pointer is valid before another CPU sees |
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* the ops pointer included into the list. |
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*/ |
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rcu_assign_pointer(*list, ops); |
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} |
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static int remove_ftrace_ops(struct ftrace_ops __rcu **list, |
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struct ftrace_ops *ops) |
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{ |
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struct ftrace_ops **p; |
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|
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/* |
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* If we are removing the last function, then simply point |
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* to the ftrace_stub. |
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*/ |
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if (rcu_dereference_protected(*list, |
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lockdep_is_held(&ftrace_lock)) == ops && |
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rcu_dereference_protected(ops->next, |
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lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { |
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*list = &ftrace_list_end; |
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return 0; |
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} |
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|
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for (p = list; *p != &ftrace_list_end; p = &(*p)->next) |
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if (*p == ops) |
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break; |
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|
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if (*p != ops) |
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return -1; |
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*p = (*p)->next; |
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return 0; |
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} |
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static void ftrace_update_trampoline(struct ftrace_ops *ops); |
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int __register_ftrace_function(struct ftrace_ops *ops) |
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{ |
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if (ops->flags & FTRACE_OPS_FL_DELETED) |
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return -EINVAL; |
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|
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if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED)) |
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return -EBUSY; |
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|
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#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
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/* |
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* If the ftrace_ops specifies SAVE_REGS, then it only can be used |
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* if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set. |
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* Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant. |
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*/ |
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if (ops->flags & FTRACE_OPS_FL_SAVE_REGS && |
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!(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)) |
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return -EINVAL; |
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|
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if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED) |
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ops->flags |= FTRACE_OPS_FL_SAVE_REGS; |
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#endif |
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if (!ftrace_enabled && (ops->flags & FTRACE_OPS_FL_PERMANENT)) |
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return -EBUSY; |
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|
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if (!is_kernel_core_data((unsigned long)ops)) |
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ops->flags |= FTRACE_OPS_FL_DYNAMIC; |
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|
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add_ftrace_ops(&ftrace_ops_list, ops); |
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|
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/* Always save the function, and reset at unregistering */ |
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ops->saved_func = ops->func; |
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|
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if (ftrace_pids_enabled(ops)) |
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ops->func = ftrace_pid_func; |
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|
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ftrace_update_trampoline(ops); |
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|
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if (ftrace_enabled) |
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update_ftrace_function(); |
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|
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return 0; |
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} |
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|
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int __unregister_ftrace_function(struct ftrace_ops *ops) |
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{ |
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int ret; |
|
|
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if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED))) |
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return -EBUSY; |
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|
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ret = remove_ftrace_ops(&ftrace_ops_list, ops); |
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|
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if (ret < 0) |
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return ret; |
|
|
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if (ftrace_enabled) |
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update_ftrace_function(); |
|
|
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ops->func = ops->saved_func; |
|
|
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return 0; |
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} |
|
|
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static void ftrace_update_pid_func(void) |
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{ |
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struct ftrace_ops *op; |
|
|
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/* Only do something if we are tracing something */ |
|
if (ftrace_trace_function == ftrace_stub) |
|
return; |
|
|
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do_for_each_ftrace_op(op, ftrace_ops_list) { |
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if (op->flags & FTRACE_OPS_FL_PID) { |
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op->func = ftrace_pids_enabled(op) ? |
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ftrace_pid_func : op->saved_func; |
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ftrace_update_trampoline(op); |
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} |
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} while_for_each_ftrace_op(op); |
|
|
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update_ftrace_function(); |
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} |
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|
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#ifdef CONFIG_FUNCTION_PROFILER |
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struct ftrace_profile { |
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struct hlist_node node; |
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unsigned long ip; |
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unsigned long counter; |
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#ifdef CONFIG_FUNCTION_GRAPH_TRACER |
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unsigned long long time; |
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unsigned long long time_squared; |
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#endif |
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}; |
|
|
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struct ftrace_profile_page { |
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struct ftrace_profile_page *next; |
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unsigned long index; |
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struct ftrace_profile records[]; |
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}; |
|
|
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struct ftrace_profile_stat { |
|
atomic_t disabled; |
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struct hlist_head *hash; |
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struct ftrace_profile_page *pages; |
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struct ftrace_profile_page *start; |
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struct tracer_stat stat; |
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}; |
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|
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#define PROFILE_RECORDS_SIZE \ |
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(PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) |
|
|
|
#define PROFILES_PER_PAGE \ |
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(PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) |
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|
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static int ftrace_profile_enabled __read_mostly; |
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|
|
/* ftrace_profile_lock - synchronize the enable and disable of the profiler */ |
|
static DEFINE_MUTEX(ftrace_profile_lock); |
|
|
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static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
|
|
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#define FTRACE_PROFILE_HASH_BITS 10 |
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#define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS) |
|
|
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static void * |
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function_stat_next(void *v, int idx) |
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{ |
|
struct ftrace_profile *rec = v; |
|
struct ftrace_profile_page *pg; |
|
|
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pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
|
|
|
again: |
|
if (idx != 0) |
|
rec++; |
|
|
|
if ((void *)rec >= (void *)&pg->records[pg->index]) { |
|
pg = pg->next; |
|
if (!pg) |
|
return NULL; |
|
rec = &pg->records[0]; |
|
if (!rec->counter) |
|
goto again; |
|
} |
|
|
|
return rec; |
|
} |
|
|
|
static void *function_stat_start(struct tracer_stat *trace) |
|
{ |
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struct ftrace_profile_stat *stat = |
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container_of(trace, struct ftrace_profile_stat, stat); |
|
|
|
if (!stat || !stat->start) |
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return NULL; |
|
|
|
return function_stat_next(&stat->start->records[0], 0); |
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} |
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER |
|
/* function graph compares on total time */ |
|
static int function_stat_cmp(const void *p1, const void *p2) |
|
{ |
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const struct ftrace_profile *a = p1; |
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const struct ftrace_profile *b = p2; |
|
|
|
if (a->time < b->time) |
|
return -1; |
|
if (a->time > b->time) |
|
return 1; |
|
else |
|
return 0; |
|
} |
|
#else |
|
/* not function graph compares against hits */ |
|
static int function_stat_cmp(const void *p1, const void *p2) |
|
{ |
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const struct ftrace_profile *a = p1; |
|
const struct ftrace_profile *b = p2; |
|
|
|
if (a->counter < b->counter) |
|
return -1; |
|
if (a->counter > b->counter) |
|
return 1; |
|
else |
|
return 0; |
|
} |
|
#endif |
|
|
|
static int function_stat_headers(struct seq_file *m) |
|
{ |
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER |
|
seq_puts(m, " Function " |
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"Hit Time Avg s^2\n" |
|
" -------- " |
|
"--- ---- --- ---\n"); |
|
#else |
|
seq_puts(m, " Function Hit\n" |
|
" -------- ---\n"); |
|
#endif |
|
return 0; |
|
} |
|
|
|
static int function_stat_show(struct seq_file *m, void *v) |
|
{ |
|
struct ftrace_profile *rec = v; |
|
char str[KSYM_SYMBOL_LEN]; |
|
int ret = 0; |
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER |
|
static struct trace_seq s; |
|
unsigned long long avg; |
|
unsigned long long stddev; |
|
#endif |
|
mutex_lock(&ftrace_profile_lock); |
|
|
|
/* we raced with function_profile_reset() */ |
|
if (unlikely(rec->counter == 0)) { |
|
ret = -EBUSY; |
|
goto out; |
|
} |
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER |
|
avg = div64_ul(rec->time, rec->counter); |
|
if (tracing_thresh && (avg < tracing_thresh)) |
|
goto out; |
|
#endif |
|
|
|
kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
|
seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER |
|
seq_puts(m, " "); |
|
|
|
/* Sample standard deviation (s^2) */ |
|
if (rec->counter <= 1) |
|
stddev = 0; |
|
else { |
|
/* |
|
* Apply Welford's method: |
|
* s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2) |
|
*/ |
|
stddev = rec->counter * rec->time_squared - |
|
rec->time * rec->time; |
|
|
|
/* |
|
* Divide only 1000 for ns^2 -> us^2 conversion. |
|
* trace_print_graph_duration will divide 1000 again. |
|
*/ |
|
stddev = div64_ul(stddev, |
|
rec->counter * (rec->counter - 1) * 1000); |
|
} |
|
|
|
trace_seq_init(&s); |
|
trace_print_graph_duration(rec->time, &s); |
|
trace_seq_puts(&s, " "); |
|
trace_print_graph_duration(avg, &s); |
|
trace_seq_puts(&s, " "); |
|
trace_print_graph_duration(stddev, &s); |
|
trace_print_seq(m, &s); |
|
#endif |
|
seq_putc(m, '\n'); |
|
out: |
|
mutex_unlock(&ftrace_profile_lock); |
|
|
|
return ret; |
|
} |
|
|
|
static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
|
{ |
|
struct ftrace_profile_page *pg; |
|
|
|
pg = stat->pages = stat->start; |
|
|
|
while (pg) { |
|
memset(pg->records, 0, PROFILE_RECORDS_SIZE); |
|
pg->index = 0; |
|
pg = pg->next; |
|
} |
|
|
|
memset(stat->hash, 0, |
|
FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
|
} |
|
|
|
static int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
|
{ |
|
struct ftrace_profile_page *pg; |
|
int functions; |
|
int pages; |
|
int i; |
|
|
|
/* If we already allocated, do nothing */ |
|
if (stat->pages) |
|
return 0; |
|
|
|
stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
|
if (!stat->pages) |
|
return -ENOMEM; |
|
|
|
#ifdef CONFIG_DYNAMIC_FTRACE |
|
functions = ftrace_update_tot_cnt; |
|
#else |
|
/* |
|
* We do not know the number of functions that exist because |
|
* dynamic tracing is what counts them. With past experience |
|
* we have around 20K functions. That should be more than enough. |
|
* It is highly unlikely we will execute every function in |
|
* the kernel. |
|
*/ |
|
functions = 20000; |
|
#endif |
|
|
|
pg = stat->start = stat->pages; |
|
|
|
pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
|
|
|
for (i = 1; i < pages; i++) { |
|
pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
|
if (!pg->next) |
|
goto out_free; |
|
pg = pg->next; |
|
} |
|
|
|
return 0; |
|
|
|
out_free: |
|
pg = stat->start; |
|
while (pg) { |
|
unsigned long tmp = (unsigned long)pg; |
|
|
|
pg = pg->next; |
|
free_page(tmp); |
|
} |
|
|
|
stat->pages = NULL; |
|
stat->start = NULL; |
|
|
|
return -ENOMEM; |
|
} |
|
|
|
static int ftrace_profile_init_cpu(int cpu) |
|
{ |
|
struct ftrace_profile_stat *stat; |
|
int size; |
|
|
|
stat = &per_cpu(ftrace_profile_stats, cpu); |
|
|
|
if (stat->hash) { |
|
/* If the profile is already created, simply reset it */ |
|
ftrace_profile_reset(stat); |
|
return 0; |
|
} |
|
|
|
/* |
|
* We are profiling all functions, but usually only a few thousand |
|
* functions are hit. We'll make a hash of 1024 items. |
|
*/ |
|
size = FTRACE_PROFILE_HASH_SIZE; |
|
|
|
stat->hash = kcalloc(size, sizeof(struct hlist_head), GFP_KERNEL); |
|
|
|
if (!stat->hash) |
|
return -ENOMEM; |
|
|
|
/* Preallocate the function profiling pages */ |
|
if (ftrace_profile_pages_init(stat) < 0) { |
|
kfree(stat->hash); |
|
stat->hash = NULL; |
|
return -ENOMEM; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int ftrace_profile_init(void) |
|
{ |
|
int cpu; |
|
int ret = 0; |
|
|
|
for_each_possible_cpu(cpu) { |
|
ret = ftrace_profile_init_cpu(cpu); |
|
if (ret) |
|
break; |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
/* interrupts must be disabled */ |
|
static struct ftrace_profile * |
|
ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) |
|
{ |
|
struct ftrace_profile *rec; |
|
struct hlist_head *hhd; |
|
unsigned long key; |
|
|
|
key = hash_long(ip, FTRACE_PROFILE_HASH_BITS); |
|
hhd = &stat->hash[key]; |
|
|
|
if (hlist_empty(hhd)) |
|
return NULL; |
|
|
|
hlist_for_each_entry_rcu_notrace(rec, hhd, node) { |
|
if (rec->ip == ip) |
|
return rec; |
|
} |
|
|
|
return NULL; |
|
} |
|
|
|
static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
|
struct ftrace_profile *rec) |
|
{ |
|
unsigned long key; |
|
|
|
key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS); |
|
hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
|
} |
|
|
|
/* |
|
* The memory is already allocated, this simply finds a new record to use. |
|
*/ |
|
static struct ftrace_profile * |
|
ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
|
{ |
|
struct ftrace_profile *rec = NULL; |
|
|
|
/* prevent recursion (from NMIs) */ |
|
if (atomic_inc_return(&stat->disabled) != 1) |
|
goto out; |
|
|
|
/* |
|
* Try to find the function again since an NMI |
|
* could have added it |
|
*/ |
|
rec = ftrace_find_profiled_func(stat, ip); |
|
if (rec) |
|
goto out; |
|
|
|
if (stat->pages->index == PROFILES_PER_PAGE) { |
|
if (!stat->pages->next) |
|
goto out; |
|
stat->pages = stat->pages->next; |
|
} |
|
|
|
rec = &stat->pages->records[stat->pages->index++]; |
|
rec->ip = ip; |
|
ftrace_add_profile(stat, rec); |
|
|
|
out: |
|
atomic_dec(&stat->disabled); |
|
|
|
return rec; |
|
} |
|
|
|
static void |
|
function_profile_call(unsigned long ip, unsigned long parent_ip, |
|
struct ftrace_ops *ops, struct ftrace_regs *fregs) |
|
{ |
|
struct ftrace_profile_stat *stat; |
|
struct ftrace_profile *rec; |
|
unsigned long flags; |
|
|
|
if (!ftrace_profile_enabled) |
|
return; |
|
|
|
local_irq_save(flags); |
|
|
|
stat = this_cpu_ptr(&ftrace_profile_stats); |
|
if (!stat->hash || !ftrace_profile_enabled) |
|
goto out; |
|
|
|
rec = ftrace_find_profiled_func(stat, ip); |
|
if (!rec) { |
|
rec = ftrace_profile_alloc(stat, ip); |
|
if (!rec) |
|
goto out; |
|
} |
|
|
|
rec->counter++; |
|
out: |
|
local_irq_restore(flags); |
|
} |
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER |
|
static bool fgraph_graph_time = true; |
|
|
|
void ftrace_graph_graph_time_control(bool enable) |
|
{ |
|
fgraph_graph_time = enable; |
|
} |
|
|
|
static int profile_graph_entry(struct ftrace_graph_ent *trace) |
|
{ |
|
struct ftrace_ret_stack *ret_stack; |
|
|
|
function_profile_call(trace->func, 0, NULL, NULL); |
|
|
|
/* If function graph is shutting down, ret_stack can be NULL */ |
|
if (!current->ret_stack) |
|
return 0; |
|
|
|
ret_stack = ftrace_graph_get_ret_stack(current, 0); |
|
if (ret_stack) |
|
ret_stack->subtime = 0; |
|
|
|
return 1; |
|
} |
|
|
|
static void profile_graph_return(struct ftrace_graph_ret *trace) |
|
{ |
|
struct ftrace_ret_stack *ret_stack; |
|
struct ftrace_profile_stat *stat; |
|
unsigned long long calltime; |
|
struct ftrace_profile *rec; |
|
unsigned long flags; |
|
|
|
local_irq_save(flags); |
|
stat = this_cpu_ptr(&ftrace_profile_stats); |
|
if (!stat->hash || !ftrace_profile_enabled) |
|
goto out; |
|
|
|
/* If the calltime was zero'd ignore it */ |
|
if (!trace->calltime) |
|
goto out; |
|
|
|
calltime = trace->rettime - trace->calltime; |
|
|
|
if (!fgraph_graph_time) { |
|
|
|
/* Append this call time to the parent time to subtract */ |
|
ret_stack = ftrace_graph_get_ret_stack(current, 1); |
|
if (ret_stack) |
|
ret_stack->subtime += calltime; |
|
|
|
ret_stack = ftrace_graph_get_ret_stack(current, 0); |
|
if (ret_stack && ret_stack->subtime < calltime) |
|
calltime -= ret_stack->subtime; |
|
else |
|
calltime = 0; |
|
} |
|
|
|
rec = ftrace_find_profiled_func(stat, trace->func); |
|
if (rec) { |
|
rec->time += calltime; |
|
rec->time_squared += calltime * calltime; |
|
} |
|
|
|
out: |
|
local_irq_restore(flags); |
|
} |
|
|
|
static struct fgraph_ops fprofiler_ops = { |
|
.entryfunc = &profile_graph_entry, |
|
.retfunc = &profile_graph_return, |
|
}; |
|
|
|
static int register_ftrace_profiler(void) |
|
{ |
|
return register_ftrace_graph(&fprofiler_ops); |
|
} |
|
|
|
static void unregister_ftrace_profiler(void) |
|
{ |
|
unregister_ftrace_graph(&fprofiler_ops); |
|
} |
|
#else |
|
static struct ftrace_ops ftrace_profile_ops __read_mostly = { |
|
.func = function_profile_call, |
|
.flags = FTRACE_OPS_FL_INITIALIZED, |
|
INIT_OPS_HASH(ftrace_profile_ops) |
|
}; |
|
|
|
static int register_ftrace_profiler(void) |
|
{ |
|
return register_ftrace_function(&ftrace_profile_ops); |
|
} |
|
|
|
static void unregister_ftrace_profiler(void) |
|
{ |
|
unregister_ftrace_function(&ftrace_profile_ops); |
|
} |
|
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
|
|
|
static ssize_t |
|
ftrace_profile_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; |
|
|
|
val = !!val; |
|
|
|
mutex_lock(&ftrace_profile_lock); |
|
if (ftrace_profile_enabled ^ val) { |
|
if (val) { |
|
ret = ftrace_profile_init(); |
|
if (ret < 0) { |
|
cnt = ret; |
|
goto out; |
|
} |
|
|
|
ret = register_ftrace_profiler(); |
|
if (ret < 0) { |
|
cnt = ret; |
|
goto out; |
|
} |
|
ftrace_profile_enabled = 1; |
|
} else { |
|
ftrace_profile_enabled = 0; |
|
/* |
|
* unregister_ftrace_profiler calls stop_machine |
|
* so this acts like an synchronize_rcu. |
|
*/ |
|
unregister_ftrace_profiler(); |
|
} |
|
} |
|
out: |
|
mutex_unlock(&ftrace_profile_lock); |
|
|
|
*ppos += cnt; |
|
|
|
return cnt; |
|
} |
|
|
|
static ssize_t |
|
ftrace_profile_read(struct file *filp, char __user *ubuf, |
|
size_t cnt, loff_t *ppos) |
|
{ |
|
char buf[64]; /* big enough to hold a number */ |
|
int r; |
|
|
|
r = sprintf(buf, "%u\n", ftrace_profile_enabled); |
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
|
} |
|
|
|
static const struct file_operations ftrace_profile_fops = { |
|
.open = tracing_open_generic, |
|
.read = ftrace_profile_read, |
|
.write = ftrace_profile_write, |
|
.llseek = default_llseek, |
|
}; |
|
|
|
/* used to initialize the real stat files */ |
|
static struct tracer_stat function_stats __initdata = { |
|
.name = "functions", |
|
.stat_start = function_stat_start, |
|
.stat_next = function_stat_next, |
|
.stat_cmp = function_stat_cmp, |
|
.stat_headers = function_stat_headers, |
|
.stat_show = function_stat_show |
|
}; |
|
|
|
static __init void ftrace_profile_tracefs(struct dentry *d_tracer) |
|
{ |
|
struct ftrace_profile_stat *stat; |
|
struct dentry *entry; |
|
char *name; |
|
int ret; |
|
int cpu; |
|
|
|
for_each_possible_cpu(cpu) { |
|
stat = &per_cpu(ftrace_profile_stats, cpu); |
|
|
|
name = kasprintf(GFP_KERNEL, "function%d", cpu); |
|
if (!name) { |
|
/* |
|
* The files created are permanent, if something happens |
|
* we still do not free memory. |
|
*/ |
|
WARN(1, |
|
"Could not allocate stat file for cpu %d\n", |
|
cpu); |
|
return; |
|
} |
|
stat->stat = function_stats; |
|
stat->stat.name = name; |
|
ret = register_stat_tracer(&stat->stat); |
|
if (ret) { |
|
WARN(1, |
|
"Could not register function stat for cpu %d\n", |
|
cpu); |
|
kfree(name); |
|
return; |
|
} |
|
} |
|
|
|
entry = tracefs_create_file("function_profile_enabled", |
|
TRACE_MODE_WRITE, d_tracer, NULL, |
|
&ftrace_profile_fops); |
|
if (!entry) |
|
pr_warn("Could not create tracefs 'function_profile_enabled' entry\n"); |
|
} |
|
|
|
#else /* CONFIG_FUNCTION_PROFILER */ |
|
static __init void ftrace_profile_tracefs(struct dentry *d_tracer) |
|
{ |
|
} |
|
#endif /* CONFIG_FUNCTION_PROFILER */ |
|
|
|
#ifdef CONFIG_DYNAMIC_FTRACE |
|
|
|
static struct ftrace_ops *removed_ops; |
|
|
|
/* |
|
* Set when doing a global update, like enabling all recs or disabling them. |
|
* It is not set when just updating a single ftrace_ops. |
|
*/ |
|
static bool update_all_ops; |
|
|
|
#ifndef CONFIG_FTRACE_MCOUNT_RECORD |
|
# error Dynamic ftrace depends on MCOUNT_RECORD |
|
#endif |
|
|
|
struct ftrace_func_probe { |
|
struct ftrace_probe_ops *probe_ops; |
|
struct ftrace_ops ops; |
|
struct trace_array *tr; |
|
struct list_head list; |
|
void *data; |
|
int ref; |
|
}; |
|
|
|
/* |
|
* We make these constant because no one should touch them, |
|
* but they are used as the default "empty hash", to avoid allocating |
|
* it all the time. These are in a read only section such that if |
|
* anyone does try to modify it, it will cause an exception. |
|
*/ |
|
static const struct hlist_head empty_buckets[1]; |
|
static const struct ftrace_hash empty_hash = { |
|
.buckets = (struct hlist_head *)empty_buckets, |
|
}; |
|
#define EMPTY_HASH ((struct ftrace_hash *)&empty_hash) |
|
|
|
struct ftrace_ops global_ops = { |
|
.func = ftrace_stub, |
|
.local_hash.notrace_hash = EMPTY_HASH, |
|
.local_hash.filter_hash = EMPTY_HASH, |
|
INIT_OPS_HASH(global_ops) |
|
.flags = FTRACE_OPS_FL_INITIALIZED | |
|
FTRACE_OPS_FL_PID, |
|
}; |
|
|
|
/* |
|
* Used by the stack unwinder to know about dynamic ftrace trampolines. |
|
*/ |
|
struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr) |
|
{ |
|
struct ftrace_ops *op = NULL; |
|
|
|
/* |
|
* Some of the ops may be dynamically allocated, |
|
* they are freed after a synchronize_rcu(). |
|
*/ |
|
preempt_disable_notrace(); |
|
|
|
do_for_each_ftrace_op(op, ftrace_ops_list) { |
|
/* |
|
* This is to check for dynamically allocated trampolines. |
|
* Trampolines that are in kernel text will have |
|
* core_kernel_text() return true. |
|
*/ |
|
if (op->trampoline && op->trampoline_size) |
|
if (addr >= op->trampoline && |
|
addr < op->trampoline + op->trampoline_size) { |
|
preempt_enable_notrace(); |
|
return op; |
|
} |
|
} while_for_each_ftrace_op(op); |
|
preempt_enable_notrace(); |
|
|
|
return NULL; |
|
} |
|
|
|
/* |
|
* This is used by __kernel_text_address() to return true if the |
|
* address is on a dynamically allocated trampoline that would |
|
* not return true for either core_kernel_text() or |
|
* is_module_text_address(). |
|
*/ |
|
bool is_ftrace_trampoline(unsigned long addr) |
|
{ |
|
return ftrace_ops_trampoline(addr) != NULL; |
|
} |
|
|
|
struct ftrace_page { |
|
struct ftrace_page *next; |
|
struct dyn_ftrace *records; |
|
int index; |
|
int order; |
|
}; |
|
|
|
#define ENTRY_SIZE sizeof(struct dyn_ftrace) |
|
#define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE) |
|
|
|
static struct ftrace_page *ftrace_pages_start; |
|
static struct ftrace_page *ftrace_pages; |
|
|
|
static __always_inline unsigned long |
|
ftrace_hash_key(struct ftrace_hash *hash, unsigned long ip) |
|
{ |
|
if (hash->size_bits > 0) |
|
return hash_long(ip, hash->size_bits); |
|
|
|
return 0; |
|
} |
|
|
|
/* Only use this function if ftrace_hash_empty() has already been tested */ |
|
static __always_inline struct ftrace_func_entry * |
|
__ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) |
|
{ |
|
unsigned long key; |
|
struct ftrace_func_entry *entry; |
|
struct hlist_head *hhd; |
|
|
|
key = ftrace_hash_key(hash, ip); |
|
hhd = &hash->buckets[key]; |
|
|
|
hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) { |
|
if (entry->ip == ip) |
|
return entry; |
|
} |
|
return NULL; |
|
} |
|
|
|
/** |
|
* ftrace_lookup_ip - Test to see if an ip exists in an ftrace_hash |
|
* @hash: The hash to look at |
|
* @ip: The instruction pointer to test |
|
* |
|
* Search a given @hash to see if a given instruction pointer (@ip) |
|
* exists in it. |
|
* |
|
* Returns the entry that holds the @ip if found. NULL otherwise. |
|
*/ |
|
struct ftrace_func_entry * |
|
ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) |
|
{ |
|
if (ftrace_hash_empty(hash)) |
|
return NULL; |
|
|
|
return __ftrace_lookup_ip(hash, ip); |
|
} |
|
|
|
static void __add_hash_entry(struct ftrace_hash *hash, |
|
struct ftrace_func_entry *entry) |
|
{ |
|
struct hlist_head *hhd; |
|
unsigned long key; |
|
|
|
key = ftrace_hash_key(hash, entry->ip); |
|
hhd = &hash->buckets[key]; |
|
hlist_add_head(&entry->hlist, hhd); |
|
hash->count++; |
|
} |
|
|
|
static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip) |
|
{ |
|
struct ftrace_func_entry *entry; |
|
|
|
entry = kmalloc(sizeof(*entry), GFP_KERNEL); |
|
if (!entry) |
|
return -ENOMEM; |
|
|
|
entry->ip = ip; |
|
__add_hash_entry(hash, entry); |
|
|
|
return 0; |
|
} |
|
|
|
static void |
|
free_hash_entry(struct ftrace_hash *hash, |
|
struct ftrace_func_entry *entry) |
|
{ |
|
hlist_del(&entry->hlist); |
|
kfree(entry); |
|
hash->count--; |
|
} |
|
|
|
static void |
|
remove_hash_entry(struct ftrace_hash *hash, |
|
struct ftrace_func_entry *entry) |
|
{ |
|
hlist_del_rcu(&entry->hlist); |
|
hash->count--; |
|
} |
|
|
|
static void ftrace_hash_clear(struct ftrace_hash *hash) |
|
{ |
|
struct hlist_head *hhd; |
|
struct hlist_node *tn; |
|
struct ftrace_func_entry *entry; |
|
int size = 1 << hash->size_bits; |
|
int i; |
|
|
|
if (!hash->count) |
|
return; |
|
|
|
for (i = 0; i < size; i++) { |
|
hhd = &hash->buckets[i]; |
|
hlist_for_each_entry_safe(entry, tn, hhd, hlist) |
|
free_hash_entry(hash, entry); |
|
} |
|
FTRACE_WARN_ON(hash->count); |
|
} |
|
|
|
static void free_ftrace_mod(struct ftrace_mod_load *ftrace_mod) |
|
{ |
|
list_del(&ftrace_mod->list); |
|
kfree(ftrace_mod->module); |
|
kfree(ftrace_mod->func); |
|
kfree(ftrace_mod); |
|
} |
|
|
|
static void clear_ftrace_mod_list(struct list_head *head) |
|
{ |
|
struct ftrace_mod_load *p, *n; |
|
|
|
/* stack tracer isn't supported yet */ |
|
if (!head) |
|
return; |
|
|
|
mutex_lock(&ftrace_lock); |
|
list_for_each_entry_safe(p, n, head, list) |
|
free_ftrace_mod(p); |
|
mutex_unlock(&ftrace_lock); |
|
} |
|
|
|
static void free_ftrace_hash(struct ftrace_hash *hash) |
|
{ |
|
if (!hash || hash == EMPTY_HASH) |
|
return; |
|
ftrace_hash_clear(hash); |
|
kfree(hash->buckets); |
|
kfree(hash); |
|
} |
|
|
|
static void __free_ftrace_hash_rcu(struct rcu_head *rcu) |
|
{ |
|
struct ftrace_hash *hash; |
|
|
|
hash = container_of(rcu, struct ftrace_hash, rcu); |
|
free_ftrace_hash(hash); |
|
} |
|
|
|
static void free_ftrace_hash_rcu(struct ftrace_hash *hash) |
|
{ |
|
if (!hash || hash == EMPTY_HASH) |
|
return; |
|
call_rcu(&hash->rcu, __free_ftrace_hash_rcu); |
|
} |
|
|
|
void ftrace_free_filter(struct ftrace_ops *ops) |
|
{ |
|
ftrace_ops_init(ops); |
|
free_ftrace_hash(ops->func_hash->filter_hash); |
|
free_ftrace_hash(ops->func_hash->notrace_hash); |
|
} |
|
|
|
static struct ftrace_hash *alloc_ftrace_hash(int size_bits) |
|
{ |
|
struct ftrace_hash *hash; |
|
int size; |
|
|
|
hash = kzalloc(sizeof(*hash), GFP_KERNEL); |
|
if (!hash) |
|
return NULL; |
|
|
|
size = 1 << size_bits; |
|
hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL); |
|
|
|
if (!hash->buckets) { |
|
kfree(hash); |
|
return NULL; |
|
} |
|
|
|
hash->size_bits = size_bits; |
|
|
|
return hash; |
|
} |
|
|
|
|
|
static int ftrace_add_mod(struct trace_array *tr, |
|
const char *func, const char *module, |
|
int enable) |
|
{ |
|
struct ftrace_mod_load *ftrace_mod; |
|
struct list_head *mod_head = enable ? &tr->mod_trace : &tr->mod_notrace; |
|
|
|
ftrace_mod = kzalloc(sizeof(*ftrace_mod), GFP_KERNEL); |
|
if (!ftrace_mod) |
|
return -ENOMEM; |
|
|
|
ftrace_mod->func = kstrdup(func, GFP_KERNEL); |
|
ftrace_mod->module = kstrdup(module, GFP_KERNEL); |
|
ftrace_mod->enable = enable; |
|
|
|
if (!ftrace_mod->func || !ftrace_mod->module) |
|
goto out_free; |
|
|
|
list_add(&ftrace_mod->list, mod_head); |
|
|
|
return 0; |
|
|
|
out_free: |
|
free_ftrace_mod(ftrace_mod); |
|
|
|
return -ENOMEM; |
|
} |
|
|
|
static struct ftrace_hash * |
|
alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) |
|
{ |
|
struct ftrace_func_entry *entry; |
|
struct ftrace_hash *new_hash; |
|
int size; |
|
int ret; |
|
int i; |
|
|
|
new_hash = alloc_ftrace_hash(size_bits); |
|
if (!new_hash) |
|
return NULL; |
|
|
|
if (hash) |
|
new_hash->flags = hash->flags; |
|
|
|
/* Empty hash? */ |
|
if (ftrace_hash_empty(hash)) |
|
return new_hash; |
|
|
|
size = 1 << hash->size_bits; |
|
for (i = 0; i < size; i++) { |
|
hlist_for_each_entry(entry, &hash->buckets[i], hlist) { |
|
ret = add_hash_entry(new_hash, entry->ip); |
|
if (ret < 0) |
|
goto free_hash; |
|
} |
|
} |
|
|
|
FTRACE_WARN_ON(new_hash->count != hash->count); |
|
|
|
return new_hash; |
|
|
|
free_hash: |
|
free_ftrace_hash(new_hash); |
|
return NULL; |
|
} |
|
|
|
static void |
|
ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash); |
|
static void |
|
ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash); |
|
|
|
static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, |
|
struct ftrace_hash *new_hash); |
|
|
|
static struct ftrace_hash *dup_hash(struct ftrace_hash *src, int size) |
|
{ |
|
struct ftrace_func_entry *entry; |
|
struct ftrace_hash *new_hash; |
|
struct hlist_head *hhd; |
|
struct hlist_node *tn; |
|
int bits = 0; |
|
int i; |
|
|
|
/* |
|
* Use around half the size (max bit of it), but |
|
* a minimum of 2 is fine (as size of 0 or 1 both give 1 for bits). |
|
*/ |
|
bits = fls(size / 2); |
|
|
|
/* Don't allocate too much */ |
|
if (bits > FTRACE_HASH_MAX_BITS) |
|
bits = FTRACE_HASH_MAX_BITS; |
|
|
|
new_hash = alloc_ftrace_hash(bits); |
|
if (!new_hash) |
|
return NULL; |
|
|
|
new_hash->flags = src->flags; |
|
|
|
size = 1 << src->size_bits; |
|
for (i = 0; i < size; i++) { |
|
hhd = &src->buckets[i]; |
|
hlist_for_each_entry_safe(entry, tn, hhd, hlist) { |
|
remove_hash_entry(src, entry); |
|
__add_hash_entry(new_hash, entry); |
|
} |
|
} |
|
return new_hash; |
|
} |
|
|
|
static struct ftrace_hash * |
|
__ftrace_hash_move(struct ftrace_hash *src) |
|
{ |
|
int size = src->count; |
|
|
|
/* |
|
* If the new source is empty, just return the empty_hash. |
|
*/ |
|
if (ftrace_hash_empty(src)) |
|
return EMPTY_HASH; |
|
|
|
return dup_hash(src, size); |
|
} |
|
|
|
static int |
|
ftrace_hash_move(struct ftrace_ops *ops, int enable, |
|
struct ftrace_hash **dst, struct ftrace_hash *src) |
|
{ |
|
struct ftrace_hash *new_hash; |
|
int ret; |
|
|
|
/* Reject setting notrace hash on IPMODIFY ftrace_ops */ |
|
if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable) |
|
return -EINVAL; |
|
|
|
new_hash = __ftrace_hash_move(src); |
|
if (!new_hash) |
|
return -ENOMEM; |
|
|
|
/* Make sure this can be applied if it is IPMODIFY ftrace_ops */ |
|
if (enable) { |
|
/* IPMODIFY should be updated only when filter_hash updating */ |
|
ret = ftrace_hash_ipmodify_update(ops, new_hash); |
|
if (ret < 0) { |
|
free_ftrace_hash(new_hash); |
|
return ret; |
|
} |
|
} |
|
|
|
/* |
|
* Remove the current set, update the hash and add |
|
* them back. |
|
*/ |
|
ftrace_hash_rec_disable_modify(ops, enable); |
|
|
|
rcu_assign_pointer(*dst, new_hash); |
|
|
|
ftrace_hash_rec_enable_modify(ops, enable); |
|
|
|
return 0; |
|
} |
|
|
|
static bool hash_contains_ip(unsigned long ip, |
|
struct ftrace_ops_hash *hash) |
|
{ |
|
/* |
|
* The function record is a match if it exists in the filter |
|
* hash and not in the notrace hash. Note, an empty hash is |
|
* considered a match for the filter hash, but an empty |
|
* notrace hash is considered not in the notrace hash. |
|
*/ |
|
return (ftrace_hash_empty(hash->filter_hash) || |
|
__ftrace_lookup_ip(hash->filter_hash, ip)) && |
|
(ftrace_hash_empty(hash->notrace_hash) || |
|
!__ftrace_lookup_ip(hash->notrace_hash, ip)); |
|
} |
|
|
|
/* |
|
* Test the hashes for this ops to see if we want to call |
|
* the ops->func or not. |
|
* |
|
* It's a match if the ip is in the ops->filter_hash or |
|
* the filter_hash does not exist or is empty, |
|
* AND |
|
* the ip is not in the ops->notrace_hash. |
|
* |
|
* This needs to be called with preemption disabled as |
|
* the hashes are freed with call_rcu(). |
|
*/ |
|
int |
|
ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) |
|
{ |
|
struct ftrace_ops_hash hash; |
|
int ret; |
|
|
|
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
|
/* |
|
* There's a small race when adding ops that the ftrace handler |
|
* that wants regs, may be called without them. We can not |
|
* allow that handler to be called if regs is NULL. |
|
*/ |
|
if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS)) |
|
return 0; |
|
#endif |
|
|
|
rcu_assign_pointer(hash.filter_hash, ops->func_hash->filter_hash); |
|
rcu_assign_pointer(hash.notrace_hash, ops->func_hash->notrace_hash); |
|
|
|
if (hash_contains_ip(ip, &hash)) |
|
ret = 1; |
|
else |
|
ret = 0; |
|
|
|
return ret; |
|
} |
|
|
|
/* |
|
* This is a double for. Do not use 'break' to break out of the loop, |
|
* you must use a goto. |
|
*/ |
|
#define do_for_each_ftrace_rec(pg, rec) \ |
|
for (pg = ftrace_pages_start; pg; pg = pg->next) { \ |
|
int _____i; \ |
|
for (_____i = 0; _____i < pg->index; _____i++) { \ |
|
rec = &pg->records[_____i]; |
|
|
|
#define while_for_each_ftrace_rec() \ |
|
} \ |
|
} |
|
|
|
|
|
static int ftrace_cmp_recs(const void *a, const void *b) |
|
{ |
|
const struct dyn_ftrace *key = a; |
|
const struct dyn_ftrace *rec = b; |
|
|
|
if (key->flags < rec->ip) |
|
return -1; |
|
if (key->ip >= rec->ip + MCOUNT_INSN_SIZE) |
|
return 1; |
|
return 0; |
|
} |
|
|
|
static struct dyn_ftrace *lookup_rec(unsigned long start, unsigned long end) |
|
{ |
|
struct ftrace_page *pg; |
|
struct dyn_ftrace *rec = NULL; |
|
struct dyn_ftrace key; |
|
|
|
key.ip = start; |
|
key.flags = end; /* overload flags, as it is unsigned long */ |
|
|
|
for (pg = ftrace_pages_start; pg; pg = pg->next) { |
|
if (end < pg->records[0].ip || |
|
start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) |
|
continue; |
|
rec = bsearch(&key, pg->records, pg->index, |
|
sizeof(struct dyn_ftrace), |
|
ftrace_cmp_recs); |
|
if (rec) |
|
break; |
|
} |
|
return rec; |
|
} |
|
|
|
/** |
|
* ftrace_location_range - return the first address of a traced location |
|
* if it touches the given ip range |
|
* @start: start of range to search. |
|
* @end: end of range to search (inclusive). @end points to the last byte |
|
* to check. |
|
* |
|
* Returns rec->ip if the related ftrace location is a least partly within |
|
* the given address range. That is, the first address of the instruction |
|
* that is either a NOP or call to the function tracer. It checks the ftrace |
|
* internal tables to determine if the address belongs or not. |
|
*/ |
|
unsigned long ftrace_location_range(unsigned long start, unsigned long end) |
|
{ |
|
struct dyn_ftrace *rec; |
|
|
|
rec = lookup_rec(start, end); |
|
if (rec) |
|
return rec->ip; |
|
|
|
return 0; |
|
} |
|
|
|
/** |
|
* ftrace_location - return true if the ip giving is a traced location |
|
* @ip: the instruction pointer to check |
|
* |
|
* Returns rec->ip if @ip given is a pointer to a ftrace location. |
|
* That is, the instruction that is either a NOP or call to |
|
* the function tracer. It checks the ftrace internal tables to |
|
* determine if the address belongs or not. |
|
*/ |
|
unsigned long ftrace_location(unsigned long ip) |
|
{ |
|
return ftrace_location_range(ip, ip); |
|
} |
|
|
|
/** |
|
* ftrace_text_reserved - return true if range contains an ftrace location |
|
* @start: start of range to search |
|
* @end: end of range to search (inclusive). @end points to the last byte to check. |
|
* |
|
* Returns 1 if @start and @end contains a ftrace location. |
|
* That is, the instruction that is either a NOP or call to |
|
* the function tracer. It checks the ftrace internal tables to |
|
* determine if the address belongs or not. |
|
*/ |
|
int ftrace_text_reserved(const void *start, const void *end) |
|
{ |
|
unsigned long ret; |
|
|
|
ret = ftrace_location_range((unsigned long)start, |
|
(unsigned long)end); |
|
|
|
return (int)!!ret; |
|
} |
|
|
|
/* Test if ops registered to this rec needs regs */ |
|
static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec) |
|
{ |
|
struct ftrace_ops *ops; |
|
bool keep_regs = false; |
|
|
|
for (ops = ftrace_ops_list; |
|
ops != &ftrace_list_end; ops = ops->next) { |
|
/* pass rec in as regs to have non-NULL val */ |
|
if (ftrace_ops_test(ops, rec->ip, rec)) { |
|
if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) { |
|
keep_regs = true; |
|
break; |
|
} |
|
} |
|
} |
|
|
|
return keep_regs; |
|
} |
|
|
|
static struct ftrace_ops * |
|
ftrace_find_tramp_ops_any(struct dyn_ftrace *rec); |
|
static struct ftrace_ops * |
|
ftrace_find_tramp_ops_any_other(struct dyn_ftrace *rec, struct ftrace_ops *op_exclude); |
|
static struct ftrace_ops * |
|
ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops); |
|
|
|
static bool __ftrace_hash_rec_update(struct ftrace_ops *ops, |
|
int filter_hash, |
|
bool inc) |
|
{ |
|
struct ftrace_hash *hash; |
|
struct ftrace_hash *other_hash; |
|
struct ftrace_page *pg; |
|
struct dyn_ftrace *rec; |
|
bool update = false; |
|
int count = 0; |
|
int all = false; |
|
|
|
/* Only update if the ops has been registered */ |
|
if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) |
|
return false; |
|
|
|
/* |
|
* In the filter_hash case: |
|
* If the count is zero, we update all records. |
|
* Otherwise we just update the items in the hash. |
|
* |
|
* In the notrace_hash case: |
|
* We enable the update in the hash. |
|
* As disabling notrace means enabling the tracing, |
|
* and enabling notrace means disabling, the inc variable |
|
* gets inversed. |
|
*/ |
|
if (filter_hash) { |
|
hash = ops->func_hash->filter_hash; |
|
other_hash = ops->func_hash->notrace_hash; |
|
if (ftrace_hash_empty(hash)) |
|
all = true; |
|
} else { |
|
inc = !inc; |
|
hash = ops->func_hash->notrace_hash; |
|
other_hash = ops->func_hash->filter_hash; |
|
/* |
|
* If the notrace hash has no items, |
|
* then there's nothing to do. |
|
*/ |
|
if (ftrace_hash_empty(hash)) |
|
return false; |
|
} |
|
|
|
do_for_each_ftrace_rec(pg, rec) { |
|
int in_other_hash = 0; |
|
int in_hash = 0; |
|
int match = 0; |
|
|
|
if (rec->flags & FTRACE_FL_DISABLED) |
|
continue; |
|
|
|
if (all) { |
|
/* |
|
* Only the filter_hash affects all records. |
|
* Update if the record is not in the notrace hash. |
|
*/ |
|
if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip)) |
|
match = 1; |
|
} else { |
|
in_hash = !!ftrace_lookup_ip(hash, rec->ip); |
|
in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip); |
|
|
|
/* |
|
* If filter_hash is set, we want to match all functions |
|
* that are in the hash but not in the other hash. |
|
* |
|
* If filter_hash is not set, then we are decrementing. |
|
* That means we match anything that is in the hash |
|
* and also in the other_hash. That is, we need to turn |
|
* off functions in the other hash because they are disabled |
|
* by this hash. |
|
*/ |
|
if (filter_hash && in_hash && !in_other_hash) |
|
match = 1; |
|
else if (!filter_hash && in_hash && |
|
(in_other_hash || ftrace_hash_empty(other_hash))) |
|
match = 1; |
|
} |
|
if (!match) |
|
continue; |
|
|
|
if (inc) { |
|
rec->flags++; |
|
if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX)) |
|
return false; |
|
|
|
if (ops->flags & FTRACE_OPS_FL_DIRECT) |
|
rec->flags |= FTRACE_FL_DIRECT; |
|
|
|
/* |
|
* If there's only a single callback registered to a |
|
* function, and the ops has a trampoline registered |
|
* for it, then we can call it directly. |
|
*/ |
|
if (ftrace_rec_count(rec) == 1 && ops->trampoline) |
|
rec->flags |= FTRACE_FL_TRAMP; |
|
else |
|
/* |
|
* If we are adding another function callback |
|
* to this function, and the previous had a |
|
* custom trampoline in use, then we need to go |
|
* back to the default trampoline. |
|
*/ |
|
rec->flags &= ~FTRACE_FL_TRAMP; |
|
|
|
/* |
|
* If any ops wants regs saved for this function |
|
* then all ops will get saved regs. |
|
*/ |
|
if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) |
|
rec->flags |= FTRACE_FL_REGS; |
|
} else { |
|
if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0)) |
|
return false; |
|
rec->flags--; |
|
|
|
/* |
|
* Only the internal direct_ops should have the |
|
* DIRECT flag set. Thus, if it is removing a |
|
* function, then that function should no longer |
|
* be direct. |
|
*/ |
|
if (ops->flags & FTRACE_OPS_FL_DIRECT) |
|
rec->flags &= ~FTRACE_FL_DIRECT; |
|
|
|
/* |
|
* If the rec had REGS enabled and the ops that is |
|
* being removed had REGS set, then see if there is |
|
* still any ops for this record that wants regs. |
|
* If not, we can stop recording them. |
|
*/ |
|
if (ftrace_rec_count(rec) > 0 && |
|
rec->flags & FTRACE_FL_REGS && |
|
ops->flags & FTRACE_OPS_FL_SAVE_REGS) { |
|
if (!test_rec_ops_needs_regs(rec)) |
|
rec->flags &= ~FTRACE_FL_REGS; |
|
} |
|
|
|
/* |
|
* The TRAMP needs to be set only if rec count |
|
* is decremented to one, and the ops that is |
|
* left has a trampoline. As TRAMP can only be |
|
* enabled if there is only a single ops attached |
|
* to it. |
|
*/ |
|
if (ftrace_rec_count(rec) == 1 && |
|
ftrace_find_tramp_ops_any_other(rec, ops)) |
|
rec->flags |= FTRACE_FL_TRAMP; |
|
else |
|
rec->flags &= ~FTRACE_FL_TRAMP; |
|
|
|
/* |
|
* flags will be cleared in ftrace_check_record() |
|
* if rec count is zero. |
|
*/ |
|
} |
|
count++; |
|
|
|
/* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */ |
|
update |= ftrace_test_record(rec, true) != FTRACE_UPDATE_IGNORE; |
|
|
|
/* Shortcut, if we handled all records, we are done. */ |
|
if (!all && count == hash->count) |
|
return update; |
|
} while_for_each_ftrace_rec(); |
|
|
|
return update; |
|
} |
|
|
|
static bool ftrace_hash_rec_disable(struct ftrace_ops *ops, |
|
int filter_hash) |
|
{ |
|
return __ftrace_hash_rec_update(ops, filter_hash, 0); |
|
} |
|
|
|
static bool ftrace_hash_rec_enable(struct ftrace_ops *ops, |
|
int filter_hash) |
|
{ |
|
return __ftrace_hash_rec_update(ops, filter_hash, 1); |
|
} |
|
|
|
static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops, |
|
int filter_hash, int inc) |
|
{ |
|
struct ftrace_ops *op; |
|
|
|
__ftrace_hash_rec_update(ops, filter_hash, inc); |
|
|
|
if (ops->func_hash != &global_ops.local_hash) |
|
return; |
|
|
|
/* |
|
* If the ops shares the global_ops hash, then we need to update |
|
* all ops that are enabled and use this hash. |
|
*/ |
|
do_for_each_ftrace_op(op, ftrace_ops_list) { |
|
/* Already done */ |
|
if (op == ops) |
|
continue; |
|
if (op->func_hash == &global_ops.local_hash) |
|
__ftrace_hash_rec_update(op, filter_hash, inc); |
|
} while_for_each_ftrace_op(op); |
|
} |
|
|
|
static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, |
|
int filter_hash) |
|
{ |
|
ftrace_hash_rec_update_modify(ops, filter_hash, 0); |
|
} |
|
|
|
static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, |
|
int filter_hash) |
|
{ |
|
ftrace_hash_rec_update_modify(ops, filter_hash, 1); |
|
} |
|
|
|
/* |
|
* Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK |
|
* or no-needed to update, -EBUSY if it detects a conflict of the flag |
|
* on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs. |
|
* Note that old_hash and new_hash has below meanings |
|
* - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected) |
|
* - If the hash is EMPTY_HASH, it hits nothing |
|
* - Anything else hits the recs which match the hash entries. |
|
*/ |
|
static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops, |
|
struct ftrace_hash *old_hash, |
|
struct ftrace_hash *new_hash) |
|
{ |
|
struct ftrace_page *pg; |
|
struct dyn_ftrace *rec, *end = NULL; |
|
int in_old, in_new; |
|
|
|
/* Only update if the ops has been registered */ |
|
if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) |
|
return 0; |
|
|
|
if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY)) |
|
return 0; |
|
|
|
/* |
|
* Since the IPMODIFY is a very address sensitive action, we do not |
|
* allow ftrace_ops to set all functions to new hash. |
|
*/ |
|
if (!new_hash || !old_hash) |
|
return -EINVAL; |
|
|
|
/* Update rec->flags */ |
|
do_for_each_ftrace_rec(pg, rec) { |
|
|
|
if (rec->flags & FTRACE_FL_DISABLED) |
|
continue; |
|
|
|
/* We need to update only differences of filter_hash */ |
|
in_old = !!ftrace_lookup_ip(old_hash, rec->ip); |
|
in_new = !!ftrace_lookup_ip(new_hash, rec->ip); |
|
if (in_old == in_new) |
|
continue; |
|
|
|
if (in_new) { |
|
/* New entries must ensure no others are using it */ |
|
if (rec->flags & FTRACE_FL_IPMODIFY) |
|
goto rollback; |
|
rec->flags |= FTRACE_FL_IPMODIFY; |
|
} else /* Removed entry */ |
|
rec->flags &= ~FTRACE_FL_IPMODIFY; |
|
} while_for_each_ftrace_rec(); |
|
|
|
return 0; |
|
|
|
rollback: |
|
end = rec; |
|
|
|
/* Roll back what we did above */ |
|
do_for_each_ftrace_rec(pg, rec) { |
|
|
|
if (rec->flags & FTRACE_FL_DISABLED) |
|
continue; |
|
|
|
if (rec == end) |
|
goto err_out; |
|
|
|
in_old = !!ftrace_lookup_ip(old_hash, rec->ip); |
|
in_new = !!ftrace_lookup_ip(new_hash, rec->ip); |
|
if (in_old == in_new) |
|
continue; |
|
|
|
if (in_new) |
|
rec->flags &= ~FTRACE_FL_IPMODIFY; |
|
else |
|
rec->flags |= FTRACE_FL_IPMODIFY; |
|
} while_for_each_ftrace_rec(); |
|
|
|
err_out: |
|
return -EBUSY; |
|
} |
|
|
|
static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops) |
|
{ |
|
struct ftrace_hash *hash = ops->func_hash->filter_hash; |
|
|
|
if (ftrace_hash_empty(hash)) |
|
hash = NULL; |
|
|
|
return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash); |
|
} |
|
|
|
/* Disabling always succeeds */ |
|
static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops) |
|
{ |
|
struct ftrace_hash *hash = ops->func_hash->filter_hash; |
|
|
|
if (ftrace_hash_empty(hash)) |
|
hash = NULL; |
|
|
|
__ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH); |
|
} |
|
|
|
static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, |
|
struct ftrace_hash *new_hash) |
|
{ |
|
struct ftrace_hash *old_hash = ops->func_hash->filter_hash; |
|
|
|
if (ftrace_hash_empty(old_hash)) |
|
old_hash = NULL; |
|
|
|
if (ftrace_hash_empty(new_hash)) |
|
new_hash = NULL; |
|
|
|
return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash); |
|
} |
|
|
|
static void print_ip_ins(const char *fmt, const unsigned char *p) |
|
{ |
|
char ins[MCOUNT_INSN_SIZE]; |
|
int i; |
|
|
|
if (copy_from_kernel_nofault(ins, p, MCOUNT_INSN_SIZE)) { |
|
printk(KERN_CONT "%s[FAULT] %px\n", fmt, p); |
|
return; |
|
} |
|
|
|
printk(KERN_CONT "%s", fmt); |
|
|
|
for (i = 0; i < MCOUNT_INSN_SIZE; i++) |
|
printk(KERN_CONT "%s%02x", i ? ":" : "", ins[i]); |
|
} |
|
|
|
enum ftrace_bug_type ftrace_bug_type; |
|
const void *ftrace_expected; |
|
|
|
static void print_bug_type(void) |
|
{ |
|
switch (ftrace_bug_type) { |
|
case FTRACE_BUG_UNKNOWN: |
|
break; |
|
case FTRACE_BUG_INIT: |
|
pr_info("Initializing ftrace call sites\n"); |
|
break; |
|
case FTRACE_BUG_NOP: |
|
pr_info("Setting ftrace call site to NOP\n"); |
|
break; |
|
case FTRACE_BUG_CALL: |
|
pr_info("Setting ftrace call site to call ftrace function\n"); |
|
break; |
|
case FTRACE_BUG_UPDATE: |
|
pr_info("Updating ftrace call site to call a different ftrace function\n"); |
|
break; |
|
} |
|
} |
|
|
|
/** |
|
* ftrace_bug - report and shutdown function tracer |
|
* @failed: The failed type (EFAULT, EINVAL, EPERM) |
|
* @rec: The record that failed |
|
* |
|
* The arch code that enables or disables the function tracing |
|
* can call ftrace_bug() when it has detected a problem in |
|
* modifying the code. @failed should be one of either: |
|
* EFAULT - if the problem happens on reading the @ip address |
|
* EINVAL - if what is read at @ip is not what was expected |
|
* EPERM - if the problem happens on writing to the @ip address |
|
*/ |
|
void ftrace_bug(int failed, struct dyn_ftrace *rec) |
|
{ |
|
unsigned long ip = rec ? rec->ip : 0; |
|
|
|
pr_info("------------[ ftrace bug ]------------\n"); |
|
|
|
switch (failed) { |
|
case -EFAULT: |
|
pr_info("ftrace faulted on modifying "); |
|
print_ip_sym(KERN_INFO, ip); |
|
break; |
|
case -EINVAL: |
|
pr_info("ftrace failed to modify "); |
|
print_ip_sym(KERN_INFO, ip); |
|
print_ip_ins(" actual: ", (unsigned char *)ip); |
|
pr_cont("\n"); |
|
if (ftrace_expected) { |
|
print_ip_ins(" expected: ", ftrace_expected); |
|
pr_cont("\n"); |
|
} |
|
break; |
|
case -EPERM: |
|
pr_info("ftrace faulted on writing "); |
|
print_ip_sym(KERN_INFO, ip); |
|
break; |
|
default: |
|
pr_info("ftrace faulted on unknown error "); |
|
print_ip_sym(KERN_INFO, ip); |
|
} |
|
print_bug_type(); |
|
if (rec) { |
|
struct ftrace_ops *ops = NULL; |
|
|
|
pr_info("ftrace record flags: %lx\n", rec->flags); |
|
pr_cont(" (%ld)%s", ftrace_rec_count(rec), |
|
rec->flags & FTRACE_FL_REGS ? " R" : " "); |
|
if (rec->flags & FTRACE_FL_TRAMP_EN) { |
|
ops = ftrace_find_tramp_ops_any(rec); |
|
if (ops) { |
|
do { |
|
pr_cont("\ttramp: %pS (%pS)", |
|
(void *)ops->trampoline, |
|
(void *)ops->func); |
|
ops = ftrace_find_tramp_ops_next(rec, ops); |
|
} while (ops); |
|
} else |
|
pr_cont("\ttramp: ERROR!"); |
|
|
|
} |
|
ip = ftrace_get_addr_curr(rec); |
|
pr_cont("\n expected tramp: %lx\n", ip); |
|
} |
|
|
|
FTRACE_WARN_ON_ONCE(1); |
|
} |
|
|
|
static int ftrace_check_record(struct dyn_ftrace *rec, bool enable, bool update) |
|
{ |
|
unsigned long flag = 0UL; |
|
|
|
ftrace_bug_type = FTRACE_BUG_UNKNOWN; |
|
|
|
if (rec->flags & FTRACE_FL_DISABLED) |
|
return FTRACE_UPDATE_IGNORE; |
|
|
|
/* |
|
* If we are updating calls: |
|
* |
|
* If the record has a ref count, then we need to enable it |
|
* because someone is using it. |
|
* |
|
* Otherwise we make sure its disabled. |
|
* |
|
* If we are disabling calls, then disable all records that |
|
* are enabled. |
|
*/ |
|
if (enable && ftrace_rec_count(rec)) |
|
flag = FTRACE_FL_ENABLED; |
|
|
|
/* |
|
* If enabling and the REGS flag does not match the REGS_EN, or |
|
* the TRAMP flag doesn't match the TRAMP_EN, then do not ignore |
|
* this record. Set flags to fail the compare against ENABLED. |
|
* Same for direct calls. |
|
*/ |
|
if (flag) { |
|
if (!(rec->flags & FTRACE_FL_REGS) != |
|
!(rec->flags & FTRACE_FL_REGS_EN)) |
|
flag |= FTRACE_FL_REGS; |
|
|
|
if (!(rec->flags & FTRACE_FL_TRAMP) != |
|
!(rec->flags & FTRACE_FL_TRAMP_EN)) |
|
flag |= FTRACE_FL_TRAMP; |
|
|
|
/* |
|
* Direct calls are special, as count matters. |
|
* We must test the record for direct, if the |
|
* DIRECT and DIRECT_EN do not match, but only |
|
* if the count is 1. That's because, if the |
|
* count is something other than one, we do not |
|
* want the direct enabled (it will be done via the |
|
* direct helper). But if DIRECT_EN is set, and |
|
* the count is not one, we need to clear it. |
|
*/ |
|
if (ftrace_rec_count(rec) == 1) { |
|
if (!(rec->flags & FTRACE_FL_DIRECT) != |
|
!(rec->flags & FTRACE_FL_DIRECT_EN)) |
|
flag |= FTRACE_FL_DIRECT; |
|
} else if (rec->flags & FTRACE_FL_DIRECT_EN) { |
|
flag |= FTRACE_FL_DIRECT; |
|
} |
|
} |
|
|
|
/* If the state of this record hasn't changed, then do nothing */ |
|
if ((rec->flags & FTRACE_FL_ENABLED) == flag) |
|
return FTRACE_UPDATE_IGNORE; |
|
|
|
if (flag) { |
|
/* Save off if rec is being enabled (for return value) */ |
|
flag ^= rec->flags & FTRACE_FL_ENABLED; |
|
|
|
if (update) { |
|
rec->flags |= FTRACE_FL_ENABLED; |
|
if (flag & FTRACE_FL_REGS) { |
|
if (rec->flags & FTRACE_FL_REGS) |
|
rec->flags |= FTRACE_FL_REGS_EN; |
|
else |
|
rec->flags &= ~FTRACE_FL_REGS_EN; |
|
} |
|
if (flag & FTRACE_FL_TRAMP) { |
|
if (rec->flags & FTRACE_FL_TRAMP) |
|
rec->flags |= FTRACE_FL_TRAMP_EN; |
|
else |
|
rec->flags &= ~FTRACE_FL_TRAMP_EN; |
|
} |
|
|
|
if (flag & FTRACE_FL_DIRECT) { |
|
/* |
|
* If there's only one user (direct_ops helper) |
|
* then we can call the direct function |
|
* directly (no ftrace trampoline). |
|
*/ |
|
if (ftrace_rec_count(rec) == 1) { |
|
if (rec->flags & FTRACE_FL_DIRECT) |
|
rec->flags |= FTRACE_FL_DIRECT_EN; |
|
else |
|
rec->flags &= ~FTRACE_FL_DIRECT_EN; |
|
} else { |
|
/* |
|
* Can only call directly if there's |
|
* only one callback to the function. |
|
*/ |
|
rec->flags &= ~FTRACE_FL_DIRECT_EN; |
|
} |
|
} |
|
} |
|
|
|
/* |
|
* If this record is being updated from a nop, then |
|
* return UPDATE_MAKE_CALL. |
|
* Otherwise, |
|
* return UPDATE_MODIFY_CALL to tell the caller to convert |
|
* from the save regs, to a non-save regs function or |
|
* vice versa, or from a trampoline call. |
|
*/ |
|
if (flag & FTRACE_FL_ENABLED) { |
|
ftrace_bug_type = FTRACE_BUG_CALL; |
|
return FTRACE_UPDATE_MAKE_CALL; |
|
} |
|
|
|
ftrace_bug_type = FTRACE_BUG_UPDATE; |
|
return FTRACE_UPDATE_MODIFY_CALL; |
|
} |
|
|
|
if (update) { |
|
/* If there's no more users, clear all flags */ |
|
if (!ftrace_rec_count(rec)) |
|
rec->flags = 0; |
|
else |
|
/* |
|
* Just disable the record, but keep the ops TRAMP |
|
* and REGS states. The _EN flags must be disabled though. |
|
*/ |
|
rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN | |
|
FTRACE_FL_REGS_EN | FTRACE_FL_DIRECT_EN); |
|
} |
|
|
|
ftrace_bug_type = FTRACE_BUG_NOP; |
|
return FTRACE_UPDATE_MAKE_NOP; |
|
} |
|
|
|
/** |
|
* ftrace_update_record - set a record that now is tracing or not |
|
* @rec: the record to update |
|
* @enable: set to true if the record is tracing, false to force disable |
|
* |
|
* The records that represent all functions that can be traced need |
|
* to be updated when tracing has been enabled. |
|
*/ |
|
int ftrace_update_record(struct dyn_ftrace *rec, bool enable) |
|
{ |
|
return ftrace_check_record(rec, enable, true); |
|
} |
|
|
|
/** |
|
* ftrace_test_record - check if the record has been enabled or not |
|
* @rec: the record to test |
|
* @enable: set to true to check if enabled, false if it is disabled |
|
* |
|
* The arch code may need to test if a record is already set to |
|
* tracing to determine how to modify the function code that it |
|
* represents. |
|
*/ |
|
int ftrace_test_record(struct dyn_ftrace *rec, bool enable) |
|
{ |
|
return ftrace_check_record(rec, enable, false); |
|
} |
|
|
|
static struct ftrace_ops * |
|
ftrace_find_tramp_ops_any(struct dyn_ftrace *rec) |
|
{ |
|
struct ftrace_ops *op; |
|
unsigned long ip = rec->ip; |
|
|
|
do_for_each_ftrace_op(op, ftrace_ops_list) { |
|
|
|
if (!op->trampoline) |
|
continue; |
|
|
|
if (hash_contains_ip(ip, op->func_hash)) |
|
return op; |
|
} while_for_each_ftrace_op(op); |
|
|
|
return NULL; |
|
} |
|
|
|
static struct ftrace_ops * |
|
ftrace_find_tramp_ops_any_other(struct dyn_ftrace *rec, struct ftrace_ops *op_exclude) |
|
{ |
|
struct ftrace_ops *op; |
|
unsigned long ip = rec->ip; |
|
|
|
do_for_each_ftrace_op(op, ftrace_ops_list) { |
|
|
|
if (op == op_exclude || !op->trampoline) |
|
continue; |
|
|
|
if (hash_contains_ip(ip, op->func_hash)) |
|
return op; |
|
} while_for_each_ftrace_op(op); |
|
|
|
return NULL; |
|
} |
|
|
|
static struct ftrace_ops * |
|
ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, |
|
struct ftrace_ops *op) |
|
{ |
|
unsigned long ip = rec->ip; |
|
|
|
while_for_each_ftrace_op(op) { |
|
|
|
if (!op->trampoline) |
|
continue; |
|
|
|
if (hash_contains_ip(ip, op->func_hash)) |
|
return op; |
|
} |
|
|
|
return NULL; |
|
} |
|
|
|
static struct ftrace_ops * |
|
ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec) |
|
{ |
|
struct ftrace_ops *op; |
|
unsigned long ip = rec->ip; |
|
|
|
/* |
|
* Need to check removed ops first. |
|
* If they are being removed, and this rec has a tramp, |
|
* and this rec is in the ops list, then it would be the |
|
* one with the tramp. |
|
*/ |
|
if (removed_ops) { |
|
if (hash_contains_ip(ip, &removed_ops->old_hash)) |
|
return removed_ops; |
|
} |
|
|
|
/* |
|
* Need to find the current trampoline for a rec. |
|
* Now, a trampoline is only attached to a rec if there |
|
* was a single 'ops' attached to it. But this can be called |
|
* when we are adding another op to the rec or removing the |
|
* current one. Thus, if the op is being added, we can |
|
* ignore it because it hasn't attached itself to the rec |
|
* yet. |
|
* |
|
* If an ops is being modified (hooking to different functions) |
|
* then we don't care about the new functions that are being |
|
* added, just the old ones (that are probably being removed). |
|
* |
|
* If we are adding an ops to a function that already is using |
|
* a trampoline, it needs to be removed (trampolines are only |
|
* for single ops connected), then an ops that is not being |
|
* modified also needs to be checked. |
|
*/ |
|
do_for_each_ftrace_op(op, ftrace_ops_list) { |
|
|
|
if (!op->trampoline) |
|
continue; |
|
|
|
/* |
|
* If the ops is being added, it hasn't gotten to |
|
* the point to be removed from this tree yet. |
|
*/ |
|
if (op->flags & FTRACE_OPS_FL_ADDING) |
|
continue; |
|
|
|
|
|
/* |
|
* If the ops is being modified and is in the old |
|
* hash, then it is probably being removed from this |
|
* function. |
|
*/ |
|
if ((op->flags & FTRACE_OPS_FL_MODIFYING) && |
|
hash_contains_ip(ip, &op->old_hash)) |
|
return op; |
|
/* |
|
* If the ops is not being added or modified, and it's |
|
* in its normal filter hash, then this must be the one |
|
* we want! |
|
*/ |
|
if (!(op->flags & FTRACE_OPS_FL_MODIFYING) && |
|
hash_contains_ip(ip, op->func_hash)) |
|
return op; |
|
|
|
} while_for_each_ftrace_op(op); |
|
|
|
return NULL; |
|
} |
|
|
|
static struct ftrace_ops * |
|
ftrace_find_tramp_ops_new(struct dyn_ftrace *rec) |
|
{ |
|
struct ftrace_ops *op; |
|
unsigned long ip = rec->ip; |
|
|
|
do_for_each_ftrace_op(op, ftrace_ops_list) { |
|
/* pass rec in as regs to have non-NULL val */ |
|
if (hash_contains_ip(ip, op->func_hash)) |
|
return op; |
|
} while_for_each_ftrace_op(op); |
|
|
|
return NULL; |
|
} |
|
|
|
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS |
|
/* Protected by rcu_tasks for reading, and direct_mutex for writing */ |
|
static struct ftrace_hash *direct_functions = EMPTY_HASH; |
|
static DEFINE_MUTEX(direct_mutex); |
|
int ftrace_direct_func_count; |
|
|
|
/* |
|
* Search the direct_functions hash to see if the given instruction pointer |
|
* has a direct caller attached to it. |
|
*/ |
|
unsigned long ftrace_find_rec_direct(unsigned long ip) |
|
{ |
|
struct ftrace_func_entry *entry; |
|
|
|
entry = __ftrace_lookup_ip(direct_functions, ip); |
|
if (!entry) |
|
return 0; |
|
|
|
return entry->direct; |
|
} |
|
|
|
static struct ftrace_func_entry* |
|
ftrace_add_rec_direct(unsigned long ip, unsigned long addr, |
|
struct ftrace_hash **free_hash) |
|
{ |
|
struct ftrace_func_entry *entry; |
|
|
|
if (ftrace_hash_empty(direct_functions) || |
|
direct_functions->count > 2 * (1 << direct_functions->size_bits)) { |
|
struct ftrace_hash *new_hash; |
|
int size = ftrace_hash_empty(direct_functions) ? 0 : |
|
direct_functions->count + 1; |
|
|
|
if (size < 32) |
|
size = 32; |
|
|
|
new_hash = dup_hash(direct_functions, size); |
|
if (!new_hash) |
|
return NULL; |
|
|
|
*free_hash = direct_functions; |
|
direct_functions = new_hash; |
|
} |
|
|
|
entry = kmalloc(sizeof(*entry), GFP_KERNEL); |
|
if (!entry) |
|
return NULL; |
|
|
|
entry->ip = ip; |
|
entry->direct = addr; |
|
__add_hash_entry(direct_functions, entry); |
|
return entry; |
|
} |
|
|
|
static void call_direct_funcs(unsigned long ip, unsigned long pip, |
|
struct ftrace_ops *ops, struct ftrace_regs *fregs) |
|
{ |
|
struct pt_regs *regs = ftrace_get_regs(fregs); |
|
unsigned long addr; |
|
|
|
addr = ftrace_find_rec_direct(ip); |
|
if (!addr) |
|
return; |
|
|
|
arch_ftrace_set_direct_caller(regs, addr); |
|
} |
|
|
|
struct ftrace_ops direct_ops = { |
|
.func = call_direct_funcs, |
|
.flags = FTRACE_OPS_FL_IPMODIFY |
|
| FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_REGS |
|
| FTRACE_OPS_FL_PERMANENT, |
|
/* |
|
* By declaring the main trampoline as this trampoline |
|
* it will never have one allocated for it. Allocated |
|
* trampolines should not call direct functions. |
|
* The direct_ops should only be called by the builtin |
|
* ftrace_regs_caller trampoline. |
|
*/ |
|
.trampoline = FTRACE_REGS_ADDR, |
|
}; |
|
#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ |
|
|
|
/** |
|
* ftrace_get_addr_new - Get the call address to set to |
|
* @rec: The ftrace record descriptor |
|
* |
|
* If the record has the FTRACE_FL_REGS set, that means that it |
|
* wants to convert to a callback that saves all regs. If FTRACE_FL_REGS |
|
* is not set, then it wants to convert to the normal callback. |
|
* |
|
* Returns the address of the trampoline to set to |
|
*/ |
|
unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec) |
|
{ |
|
struct ftrace_ops *ops; |
|
unsigned long addr; |
|
|
|
if ((rec->flags & FTRACE_FL_DIRECT) && |
|
(ftrace_rec_count(rec) == 1)) { |
|
addr = ftrace_find_rec_direct(rec->ip); |
|
if (addr) |
|
return addr; |
|
WARN_ON_ONCE(1); |
|
} |
|
|
|
/* Trampolines take precedence over regs */ |
|
if (rec->flags & FTRACE_FL_TRAMP) { |
|
ops = ftrace_find_tramp_ops_new(rec); |
|
if (FTRACE_WARN_ON(!ops || !ops->trampoline)) { |
|
pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n", |
|
(void *)rec->ip, (void *)rec->ip, rec->flags); |
|
/* Ftrace is shutting down, return anything */ |
|
return (unsigned long)FTRACE_ADDR; |
|
} |
|
return ops->trampoline; |
|
} |
|
|
|
if (rec->flags & FTRACE_FL_REGS) |
|
return (unsigned long)FTRACE_REGS_ADDR; |
|
else |
|
return (unsigned long)FTRACE_ADDR; |
|
} |
|
|
|
/** |
|
* ftrace_get_addr_curr - Get the call address that is already there |
|
* @rec: The ftrace record descriptor |
|
* |
|
* The FTRACE_FL_REGS_EN is set when the record already points to |
|
* a function that saves all the regs. Basically the '_EN' version |
|
* represents the current state of the function. |
|
* |
|
* Returns the address of the trampoline that is currently being called |
|
*/ |
|
unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec) |
|
{ |
|
struct ftrace_ops *ops; |
|
unsigned long addr; |
|
|
|
/* Direct calls take precedence over trampolines */ |
|
if (rec->flags & FTRACE_FL_DIRECT_EN) { |
|
addr = ftrace_find_rec_direct(rec->ip); |
|
if (addr) |
|
return addr; |
|
WARN_ON_ONCE(1); |
|
} |
|
|
|
/* Trampolines take precedence over regs */ |
|
if (rec->flags & FTRACE_FL_TRAMP_EN) { |
|
ops = ftrace_find_tramp_ops_curr(rec); |
|
if (FTRACE_WARN_ON(!ops)) { |
|
pr_warn("Bad trampoline accounting at: %p (%pS)\n", |
|
(void *)rec->ip, (void *)rec->ip); |
|
/* Ftrace is shutting down, return anything */ |
|
return (unsigned long)FTRACE_ADDR; |
|
} |
|
return ops->trampoline; |
|
} |
|
|
|
if (rec->flags & FTRACE_FL_REGS_EN) |
|
return (unsigned long)FTRACE_REGS_ADDR; |
|
else |
|
return (unsigned long)FTRACE_ADDR; |
|
} |
|
|
|
static int |
|
__ftrace_replace_code(struct dyn_ftrace *rec, bool enable) |
|
{ |
|
unsigned long ftrace_old_addr; |
|
unsigned long ftrace_addr; |
|
int ret; |
|
|
|
ftrace_addr = ftrace_get_addr_new(rec); |
|
|
|
/* This needs to be done before we call ftrace_update_record */ |
|
ftrace_old_addr = ftrace_get_addr_curr(rec); |
|
|
|
ret = ftrace_update_record(rec, enable); |
|
|
|
ftrace_bug_type = FTRACE_BUG_UNKNOWN; |
|
|
|
switch (ret) { |
|
case FTRACE_UPDATE_IGNORE: |
|
return 0; |
|
|
|
case FTRACE_UPDATE_MAKE_CALL: |
|
ftrace_bug_type = FTRACE_BUG_CALL; |
|
return ftrace_make_call(rec, ftrace_addr); |
|
|
|
case FTRACE_UPDATE_MAKE_NOP: |
|
ftrace_bug_type = FTRACE_BUG_NOP; |
|
return ftrace_make_nop(NULL, rec, ftrace_old_addr); |
|
|
|
case FTRACE_UPDATE_MODIFY_CALL: |
|
ftrace_bug_type = FTRACE_BUG_UPDATE; |
|
return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr); |
|
} |
|
|
|
return -1; /* unknown ftrace bug */ |
|
} |
|
|
|
void __weak ftrace_replace_code(int mod_flags) |
|
{ |
|
struct dyn_ftrace *rec; |
|
struct ftrace_page *pg; |
|
bool enable = mod_flags & FTRACE_MODIFY_ENABLE_FL; |
|
int schedulable = mod_flags & FTRACE_MODIFY_MAY_SLEEP_FL; |
|
int failed; |
|
|
|
if (unlikely(ftrace_disabled)) |
|
return; |
|
|
|
do_for_each_ftrace_rec(pg, rec) { |
|
|
|
if (rec->flags & FTRACE_FL_DISABLED) |
|
continue; |
|
|
|
failed = __ftrace_replace_code(rec, enable); |
|
if (failed) { |
|
ftrace_bug(failed, rec); |
|
/* Stop processing */ |
|
return; |
|
} |
|
if (schedulable) |
|
cond_resched(); |
|
} while_for_each_ftrace_rec(); |
|
} |
|
|
|
struct ftrace_rec_iter { |
|
struct ftrace_page *pg; |
|
int index; |
|
}; |
|
|
|
/** |
|
* ftrace_rec_iter_start - start up iterating over traced functions |
|
* |
|
* Returns an iterator handle that is used to iterate over all |
|
* the records that represent address locations where functions |
|
* are traced. |
|
* |
|
* May return NULL if no records are available. |
|
*/ |
|
struct ftrace_rec_iter *ftrace_rec_iter_start(void) |
|
{ |
|
/* |
|
* We only use a single iterator. |
|
* Protected by the ftrace_lock mutex. |
|
*/ |
|
static struct ftrace_rec_iter ftrace_rec_iter; |
|
struct ftrace_rec_iter *iter = &ftrace_rec_iter; |
|
|
|
iter->pg = ftrace_pages_start; |
|
iter->index = 0; |
|
|
|
/* Could have empty pages */ |
|
while (iter->pg && !iter->pg->index) |
|
iter->pg = iter->pg->next; |
|
|
|
if (!iter->pg) |
|
return NULL; |
|
|
|
return iter; |
|
} |
|
|
|
/** |
|
* ftrace_rec_iter_next - get the next record to process. |
|
* @iter: The handle to the iterator. |
|
* |
|
* Returns the next iterator after the given iterator @iter. |
|
*/ |
|
struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter) |
|
{ |
|
iter->index++; |
|
|
|
if (iter->index >= iter->pg->index) { |
|
iter->pg = iter->pg->next; |
|
iter->index = 0; |
|
|
|
/* Could have empty pages */ |
|
while (iter->pg && !iter->pg->index) |
|
iter->pg = iter->pg->next; |
|
} |
|
|
|
if (!iter->pg) |
|
return NULL; |
|
|
|
return iter; |
|
} |
|
|
|
/** |
|
* ftrace_rec_iter_record - get the record at the iterator location |
|
* @iter: The current iterator location |
|
* |
|
* Returns the record that the current @iter is at. |
|
*/ |
|
struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter) |
|
{ |
|
return &iter->pg->records[iter->index]; |
|
} |
|
|
|
static int |
|
ftrace_nop_initialize(struct module *mod, struct dyn_ftrace *rec) |
|
{ |
|
int ret; |
|
|
|
if (unlikely(ftrace_disabled)) |
|
return 0; |
|
|
|
ret = ftrace_init_nop(mod, rec); |
|
if (ret) { |
|
ftrace_bug_type = FTRACE_BUG_INIT; |
|
ftrace_bug(ret, rec); |
|
return 0; |
|
} |
|
return 1; |
|
} |
|
|
|
/* |
|
* archs can override this function if they must do something |
|
* before the modifying code is performed. |
|
*/ |
|
int __weak ftrace_arch_code_modify_prepare(void) |
|
{ |
|
return 0; |
|
} |
|
|
|
/* |
|
* archs can override this function if they must do something |
|
* after the modifying code is performed. |
|
*/ |
|
int __weak ftrace_arch_code_modify_post_process(void) |
|
{ |
|
return 0; |
|
} |
|
|
|
void ftrace_modify_all_code(int command) |
|
{ |
|
int update = command & FTRACE_UPDATE_TRACE_FUNC; |
|
int mod_flags = 0; |
|
int err = 0; |
|
|
|
if (command & FTRACE_MAY_SLEEP) |
|
mod_flags = FTRACE_MODIFY_MAY_SLEEP_FL; |
|
|
|
/* |
|
* If the ftrace_caller calls a ftrace_ops func directly, |
|
* we need to make sure that it only traces functions it |
|
* expects to trace. When doing the switch of functions, |
|
* we need to update to the ftrace_ops_list_func first |
|
* before the transition between old and new calls are set, |
|
* as the ftrace_ops_list_func will check the ops hashes |
|
* to make sure the ops are having the right functions |
|
* traced. |
|
*/ |
|
if (update) { |
|
err = ftrace_update_ftrace_func(ftrace_ops_list_func); |
|
if (FTRACE_WARN_ON(err)) |
|
return; |
|
} |
|
|
|
if (command & FTRACE_UPDATE_CALLS) |
|
ftrace_replace_code(mod_flags | FTRACE_MODIFY_ENABLE_FL); |
|
else if (command & FTRACE_DISABLE_CALLS) |
|
ftrace_replace_code(mod_flags); |
|
|
|
if (update && ftrace_trace_function != ftrace_ops_list_func) { |
|
function_trace_op = set_function_trace_op; |
|
smp_wmb(); |
|
/* If irqs are disabled, we are in stop machine */ |
|
if (!irqs_disabled()) |
|
smp_call_function(ftrace_sync_ipi, NULL, 1); |
|
err = ftrace_update_ftrace_func(ftrace_trace_function); |
|
if (FTRACE_WARN_ON(err)) |
|
return; |
|
} |
|
|
|
if (command & FTRACE_START_FUNC_RET) |
|
err = ftrace_enable_ftrace_graph_caller(); |
|
else if (command & FTRACE_STOP_FUNC_RET) |
|
err = ftrace_disable_ftrace_graph_caller(); |
|
FTRACE_WARN_ON(err); |
|
} |
|
|
|
static int __ftrace_modify_code(void *data) |
|
{ |
|
int *command = data; |
|
|
|
ftrace_modify_all_code(*command); |
|
|
|
return 0; |
|
} |
|
|
|
/** |
|
* ftrace_run_stop_machine - go back to the stop machine method |
|
* @command: The command to tell ftrace what to do |
|
* |
|
* If an arch needs to fall back to the stop machine method, the |
|
* it can call this function. |
|
*/ |
|
void ftrace_run_stop_machine(int command) |
|
{ |
|
stop_machine(__ftrace_modify_code, &command, NULL); |
|
} |
|
|
|
/** |
|
* arch_ftrace_update_code - modify the code to trace or not trace |
|
* @command: The command that needs to be done |
|
* |
|
* Archs can override this function if it does not need to |
|
* run stop_machine() to modify code. |
|
*/ |
|
void __weak arch_ftrace_update_code(int command) |
|
{ |
|
ftrace_run_stop_machine(command); |
|
} |
|
|
|
static void ftrace_run_update_code(int command) |
|
{ |
|
int ret; |
|
|
|
ret = ftrace_arch_code_modify_prepare(); |
|
FTRACE_WARN_ON(ret); |
|
if (ret) |
|
return; |
|
|
|
/* |
|
* By default we use stop_machine() to modify the code. |
|
* But archs can do what ever they want as long as it |
|
* is safe. The stop_machine() is the safest, but also |
|
* produces the most overhead. |
|
*/ |
|
arch_ftrace_update_code(command); |
|
|
|
ret = ftrace_arch_code_modify_post_process(); |
|
FTRACE_WARN_ON(ret); |
|
} |
|
|
|
static void ftrace_run_modify_code(struct ftrace_ops *ops, int command, |
|
struct ftrace_ops_hash *old_hash) |
|
{ |
|
ops->flags |= FTRACE_OPS_FL_MODIFYING; |
|
ops->old_hash.filter_hash = old_hash->filter_hash; |
|
ops->old_hash.notrace_hash = old_hash->notrace_hash; |
|
ftrace_run_update_code(command); |
|
ops->old_hash.filter_hash = NULL; |
|
ops->old_hash.notrace_hash = NULL; |
|
ops->flags &= ~FTRACE_OPS_FL_MODIFYING; |
|
} |
|
|
|
static ftrace_func_t saved_ftrace_func; |
|
static int ftrace_start_up; |
|
|
|
void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops) |
|
{ |
|
} |
|
|
|
/* List of trace_ops that have allocated trampolines */ |
|
static LIST_HEAD(ftrace_ops_trampoline_list); |
|
|
|
static void ftrace_add_trampoline_to_kallsyms(struct ftrace_ops *ops) |
|
{ |
|
lockdep_assert_held(&ftrace_lock); |
|
list_add_rcu(&ops->list, &ftrace_ops_trampoline_list); |
|
} |
|
|
|
static void ftrace_remove_trampoline_from_kallsyms(struct ftrace_ops *ops) |
|
{ |
|
lockdep_assert_held(&ftrace_lock); |
|
list_del_rcu(&ops->list); |
|
synchronize_rcu(); |
|
} |
|
|
|
/* |
|
* "__builtin__ftrace" is used as a module name in /proc/kallsyms for symbols |
|
* for pages allocated for ftrace purposes, even though "__builtin__ftrace" is |
|
* not a module. |
|
*/ |
|
#define FTRACE_TRAMPOLINE_MOD "__builtin__ftrace" |
|
#define FTRACE_TRAMPOLINE_SYM "ftrace_trampoline" |
|
|
|
static void ftrace_trampoline_free(struct ftrace_ops *ops) |
|
{ |
|
if (ops && (ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP) && |
|
ops->trampoline) { |
|
/* |
|
* Record the text poke event before the ksymbol unregister |
|
* event. |
|
*/ |
|
perf_event_text_poke((void *)ops->trampoline, |
|
(void *)ops->trampoline, |
|
ops->trampoline_size, NULL, 0); |
|
perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL, |
|
ops->trampoline, ops->trampoline_size, |
|
true, FTRACE_TRAMPOLINE_SYM); |
|
/* Remove from kallsyms after the perf events */ |
|
ftrace_remove_trampoline_from_kallsyms(ops); |
|
} |
|
|
|
arch_ftrace_trampoline_free(ops); |
|
} |
|
|
|
static void ftrace_startup_enable(int command) |
|
{ |
|
if (saved_ftrace_func != ftrace_trace_function) { |
|
saved_ftrace_func = ftrace_trace_function; |
|
command |= FTRACE_UPDATE_TRACE_FUNC; |
|
} |
|
|
|
if (!command || !ftrace_enabled) |
|
return; |
|
|
|
ftrace_run_update_code(command); |
|
} |
|
|
|
static void ftrace_startup_all(int command) |
|
{ |
|
update_all_ops = true; |
|
ftrace_startup_enable(command); |
|
update_all_ops = false; |
|
} |
|
|
|
int ftrace_startup(struct ftrace_ops *ops, int command) |
|
{ |
|
int ret; |
|
|
|
if (unlikely(ftrace_disabled)) |
|
return -ENODEV; |
|
|
|
ret = __register_ftrace_function(ops); |
|
if (ret) |
|
return ret; |
|
|
|
ftrace_start_up++; |
|
|
|
/* |
|
* Note that ftrace probes uses this to start up |
|
* and modify functions it will probe. But we still |
|
* set the ADDING flag for modification, as probes |
|
* do not have trampolines. If they add them in the |
|
* future, then the probes will need to distinguish |
|
* between adding and updating probes. |
|
*/ |
|
ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING; |
|
|
|
ret = ftrace_hash_ipmodify_enable(ops); |
|
if (ret < 0) { |
|
/* Rollback registration process */ |
|
__unregister_ftrace_function(ops); |
|
ftrace_start_up--; |
|
ops->flags &= ~FTRACE_OPS_FL_ENABLED; |
|
if (ops->flags & FTRACE_OPS_FL_DYNAMIC) |
|
ftrace_trampoline_free(ops); |
|
return ret; |
|
} |
|
|
|
if (ftrace_hash_rec_enable(ops, 1)) |
|
command |= FTRACE_UPDATE_CALLS; |
|
|
|
ftrace_startup_enable(command); |
|
|
|
ops->flags &= ~FTRACE_OPS_FL_ADDING; |
|
|
|
return 0; |
|
} |
|
|
|
int ftrace_shutdown(struct ftrace_ops *ops, int command) |
|
{ |
|
int ret; |
|
|
|
if (unlikely(ftrace_disabled)) |
|
return -ENODEV; |
|
|
|
ret = __unregister_ftrace_function(ops); |
|
if (ret) |
|
return ret; |
|
|
|
ftrace_start_up--; |
|
/* |
|
* Just warn in case of unbalance, no need to kill ftrace, it's not |
|
* critical but the ftrace_call callers may be never nopped again after |
|
* further ftrace uses. |
|
*/ |
|
WARN_ON_ONCE(ftrace_start_up < 0); |
|
|
|
/* Disabling ipmodify never fails */ |
|
ftrace_hash_ipmodify_disable(ops); |
|
|
|
if (ftrace_hash_rec_disable(ops, 1)) |
|
command |= FTRACE_UPDATE_CALLS; |
|
|
|
ops->flags &= ~FTRACE_OPS_FL_ENABLED; |
|
|
|
if (saved_ftrace_func != ftrace_trace_function) { |
|
saved_ftrace_func = ftrace_trace_function; |
|
command |= FTRACE_UPDATE_TRACE_FUNC; |
|
} |
|
|
|
if (!command || !ftrace_enabled) { |
|
/* |
|
* If these are dynamic or per_cpu ops, they still |
|
* need their data freed. Since, function tracing is |
|
* not currently active, we can just free them |
|
* without synchronizing all CPUs. |
|
*/ |
|
if (ops->flags & FTRACE_OPS_FL_DYNAMIC) |
|
goto free_ops; |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* If the ops uses a trampoline, then it needs to be |
|
* tested first on update. |
|
*/ |
|
ops->flags |= FTRACE_OPS_FL_REMOVING; |
|
removed_ops = ops; |
|
|
|
/* The trampoline logic checks the old hashes */ |
|
ops->old_hash.filter_hash = ops->func_hash->filter_hash; |
|
ops->old_hash.notrace_hash = ops->func_hash->notrace_hash; |
|
|
|
ftrace_run_update_code(command); |
|
|
|
/* |
|
* If there's no more ops registered with ftrace, run a |
|
* sanity check to make sure all rec flags are cleared. |
|
*/ |
|
if (rcu_dereference_protected(ftrace_ops_list, |
|
lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { |
|
struct ftrace_page *pg; |
|
struct dyn_ftrace *rec; |
|
|
|
do_for_each_ftrace_rec(pg, rec) { |
|
if (FTRACE_WARN_ON_ONCE(rec->flags & ~FTRACE_FL_DISABLED)) |
|
pr_warn(" %pS flags:%lx\n", |
|
(void *)rec->ip, rec->flags); |
|
} while_for_each_ftrace_rec(); |
|
} |
|
|
|
ops->old_hash.filter_hash = NULL; |
|
ops->old_hash.notrace_hash = NULL; |
|
|
|
removed_ops = NULL; |
|
ops->flags &= ~FTRACE_OPS_FL_REMOVING; |
|
|
|
/* |
|
* Dynamic ops may be freed, we must make sure that all |
|
* callers are done before leaving this function. |
|
* The same goes for freeing the per_cpu data of the per_cpu |
|
* ops. |
|
*/ |
|
if (ops->flags & FTRACE_OPS_FL_DYNAMIC) { |
|
/* |
|
* We need to do a hard force of sched synchronization. |
|
* This is because we use preempt_disable() to do RCU, but |
|
* the function tracers can be called where RCU is not watching |
|
* (like before user_exit()). We can not rely on the RCU |
|
* infrastructure to do the synchronization, thus we must do it |
|
* ourselves. |
|
*/ |
|
synchronize_rcu_tasks_rude(); |
|
|
|
/* |
|
* When the kernel is preemptive, tasks can be preempted |
|
* while on a ftrace trampoline. Just scheduling a task on |
|
* a CPU is not good enough to flush them. Calling |
|
* synchronize_rcu_tasks() will wait for those tasks to |
|
* execute and either schedule voluntarily or enter user space. |
|
*/ |
|
if (IS_ENABLED(CONFIG_PREEMPTION)) |
|
synchronize_rcu_tasks(); |
|
|
|
free_ops: |
|
ftrace_trampoline_free(ops); |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static void ftrace_startup_sysctl(void) |
|
{ |
|
int command; |
|
|
|
if (unlikely(ftrace_disabled)) |
|
return; |
|
|
|
/* Force update next time */ |
|
saved_ftrace_func = NULL; |
|
/* ftrace_start_up is true if we want ftrace running */ |
|
if (ftrace_start_up) { |
|
command = FTRACE_UPDATE_CALLS; |
|
if (ftrace_graph_active) |
|
command |= FTRACE_START_FUNC_RET; |
|
ftrace_startup_enable(command); |
|
} |
|
} |
|
|
|
static void ftrace_shutdown_sysctl(void) |
|
{ |
|
int command; |
|
|
|
if (unlikely(ftrace_disabled)) |
|
return; |
|
|
|
/* ftrace_start_up is true if ftrace is running */ |
|
if (ftrace_start_up) { |
|
command = FTRACE_DISABLE_CALLS; |
|
if (ftrace_graph_active) |
|
command |= FTRACE_STOP_FUNC_RET; |
|
ftrace_run_update_code(command); |
|
} |
|
} |
|
|
|
static u64 ftrace_update_time; |
|
unsigned long ftrace_update_tot_cnt; |
|
unsigned long ftrace_number_of_pages; |
|
unsigned long ftrace_number_of_groups; |
|
|
|
static inline int ops_traces_mod(struct ftrace_ops *ops) |
|
{ |
|
/* |
|
* Filter_hash being empty will default to trace module. |
|
* But notrace hash requires a test of individual module functions. |
|
*/ |
|
return ftrace_hash_empty(ops->func_hash->filter_hash) && |
|
ftrace_hash_empty(ops->func_hash->notrace_hash); |
|
} |
|
|
|
/* |
|
* Check if the current ops references the record. |
|
* |
|
* If the ops traces all functions, then it was already accounted for. |
|
* If the ops does not trace the current record function, skip it. |
|
* If the ops ignores the function via notrace filter, skip it. |
|
*/ |
|
static inline bool |
|
ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec) |
|
{ |
|
/* If ops isn't enabled, ignore it */ |
|
if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) |
|
return false; |
|
|
|
/* If ops traces all then it includes this function */ |
|
if (ops_traces_mod(ops)) |
|
return true; |
|
|
|
/* The function must be in the filter */ |
|
if (!ftrace_hash_empty(ops->func_hash->filter_hash) && |
|
!__ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip)) |
|
return false; |
|
|
|
/* If in notrace hash, we ignore it too */ |
|
if (ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip)) |
|
return false; |
|
|
|
return true; |
|
} |
|
|
|
static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs) |
|
{ |
|
bool init_nop = ftrace_need_init_nop(); |
|
struct ftrace_page *pg; |
|
struct dyn_ftrace *p; |
|
u64 start, stop; |
|
unsigned long update_cnt = 0; |
|
unsigned long rec_flags = 0; |
|
int i; |
|
|
|
start = ftrace_now(raw_smp_processor_id()); |
|
|
|
/* |
|
* When a module is loaded, this function is called to convert |
|
* the calls to mcount in its text to nops, and also to create |
|
* an entry in the ftrace data. Now, if ftrace is activated |
|
* after this call, but before the module sets its text to |
|
* read-only, the modification of enabling ftrace can fail if |
|
* the read-only is done while ftrace is converting the calls. |
|
* To prevent this, the module's records are set as disabled |
|
* and will be enabled after the call to set the module's text |
|
* to read-only. |
|
*/ |
|
if (mod) |
|
rec_flags |= FTRACE_FL_DISABLED; |
|
|
|
for (pg = new_pgs; pg; pg = pg->next) { |
|
|
|
for (i = 0; i < pg->index; i++) { |
|
|
|
/* If something went wrong, bail without enabling anything */ |
|
if (unlikely(ftrace_disabled)) |
|
return -1; |
|
|
|
p = &pg->records[i]; |
|
p->flags = rec_flags; |
|
|
|
/* |
|
* Do the initial record conversion from mcount jump |
|
* to the NOP instructions. |
|
*/ |
|
if (init_nop && !ftrace_nop_initialize(mod, p)) |
|
break; |
|
|
|
update_cnt++; |
|
} |
|
} |
|
|
|
stop = ftrace_now(raw_smp_processor_id()); |
|
ftrace_update_time = stop - start; |
|
ftrace_update_tot_cnt += update_cnt; |
|
|
|
return 0; |
|
} |
|
|
|
static int ftrace_allocate_records(struct ftrace_page *pg, int count) |
|
{ |
|
int order; |
|
int pages; |
|
int cnt; |
|
|
|
if (WARN_ON(!count)) |
|
return -EINVAL; |
|
|
|
/* We want to fill as much as possible, with no empty pages */ |
|
pages = DIV_ROUND_UP(count, ENTRIES_PER_PAGE); |
|
order = fls(pages) - 1; |
|
|
|
again: |
|
pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order); |
|
|
|
if (!pg->records) { |
|
/* if we can't allocate this size, try something smaller */ |
|
if (!order) |
|
return -ENOMEM; |
|
order >>= 1; |
|
goto again; |
|
} |
|
|
|
ftrace_number_of_pages += 1 << order; |
|
ftrace_number_of_groups++; |
|
|
|
cnt = (PAGE_SIZE << order) / ENTRY_SIZE; |
|
pg->order = order; |
|
|
|
if (cnt > count) |
|
cnt = count; |
|
|
|
return cnt; |
|
} |
|
|
|
static struct ftrace_page * |
|
ftrace_allocate_pages(unsigned long num_to_init) |
|
{ |
|
struct ftrace_page *start_pg; |
|
struct ftrace_page *pg; |
|
int cnt; |
|
|
|
if (!num_to_init) |
|
return NULL; |
|
|
|
start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL); |
|
if (!pg) |
|
return NULL; |
|
|
|
/* |
|
* Try to allocate as much as possible in one continues |
|
* location that fills in all of the space. We want to |
|
* waste as little space as possible. |
|
*/ |
|
for (;;) { |
|
cnt = ftrace_allocate_records(pg, num_to_init); |
|
if (cnt < 0) |
|
goto free_pages; |
|
|
|
num_to_init -= cnt; |
|
if (!num_to_init) |
|
break; |
|
|
|
pg->next = kzalloc(sizeof(*pg), GFP_KERNEL); |
|
if (!pg->next) |
|
goto free_pages; |
|
|
|
pg = pg->next; |
|
} |
|
|
|
return start_pg; |
|
|
|
free_pages: |
|
pg = start_pg; |
|
while (pg) { |
|
if (pg->records) { |
|
free_pages((unsigned long)pg->records, pg->order); |
|
ftrace_number_of_pages -= 1 << pg->order; |
|
} |
|
start_pg = pg->next; |
|
kfree(pg); |
|
pg = start_pg; |
|
ftrace_number_of_groups--; |
|
} |
|
pr_info("ftrace: FAILED to allocate memory for functions\n"); |
|
return NULL; |
|
} |
|
|
|
#define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ |
|
|
|
struct ftrace_iterator { |
|
loff_t pos; |
|
loff_t func_pos; |
|
loff_t mod_pos; |
|
struct ftrace_page *pg; |
|
struct dyn_ftrace *func; |
|
struct ftrace_func_probe *probe; |
|
struct ftrace_func_entry *probe_entry; |
|
struct trace_parser parser; |
|
struct ftrace_hash *hash; |
|
struct ftrace_ops *ops; |
|
struct trace_array *tr; |
|
struct list_head *mod_list; |
|
int pidx; |
|
int idx; |
|
unsigned flags; |
|
}; |
|
|
|
static void * |
|
t_probe_next(struct seq_file *m, loff_t *pos) |
|
{ |
|
struct ftrace_iterator *iter = m->private; |
|
struct trace_array *tr = iter->ops->private; |
|
struct list_head *func_probes; |
|
struct ftrace_hash *hash; |
|
struct list_head *next; |
|
struct hlist_node *hnd = NULL; |
|
struct hlist_head *hhd; |
|
int size; |
|
|
|
(*pos)++; |
|
iter->pos = *pos; |
|
|
|
if (!tr) |
|
return NULL; |
|
|
|
func_probes = &tr->func_probes; |
|
if (list_empty(func_probes)) |
|
return NULL; |
|
|
|
if (!iter->probe) { |
|
next = func_probes->next; |
|
iter->probe = list_entry(next, struct ftrace_func_probe, list); |
|
} |
|
|
|
if (iter->probe_entry) |
|
hnd = &iter->probe_entry->hlist; |
|
|
|
hash = iter->probe->ops.func_hash->filter_hash; |
|
|
|
/* |
|
* A probe being registered may temporarily have an empty hash |
|
* and it's at the end of the func_probes list. |
|
*/ |
|
if (!hash || hash == EMPTY_HASH) |
|
return NULL; |
|
|
|
size = 1 << hash->size_bits; |
|
|
|
retry: |
|
if (iter->pidx >= size) { |
|
if (iter->probe->list.next == func_probes) |
|
return NULL; |
|
next = iter->probe->list.next; |
|
iter->probe = list_entry(next, struct ftrace_func_probe, list); |
|
hash = iter->probe->ops.func_hash->filter_hash; |
|
size = 1 << hash->size_bits; |
|
iter->pidx = 0; |
|
} |
|
|
|
hhd = &hash->buckets[iter->pidx]; |
|
|
|
if (hlist_empty(hhd)) { |
|
iter->pidx++; |
|
hnd = NULL; |
|
goto retry; |
|
} |
|
|
|
if (!hnd) |
|
hnd = hhd->first; |
|
else { |
|
hnd = hnd->next; |
|
if (!hnd) { |
|
iter->pidx++; |
|
goto retry; |
|
} |
|
} |
|
|
|
if (WARN_ON_ONCE(!hnd)) |
|
return NULL; |
|
|
|
iter->probe_entry = hlist_entry(hnd, struct ftrace_func_entry, hlist); |
|
|
|
return iter; |
|
} |
|
|
|
static void *t_probe_start(struct seq_file *m, loff_t *pos) |
|
{ |
|
struct ftrace_iterator *iter = m->private; |
|
void *p = NULL; |
|
loff_t l; |
|
|
|
if (!(iter->flags & FTRACE_ITER_DO_PROBES)) |
|
return NULL; |
|
|
|
if (iter->mod_pos > *pos) |
|
return NULL; |
|
|
|
iter->probe = NULL; |
|
iter->probe_entry = NULL; |
|
iter->pidx = 0; |
|
for (l = 0; l <= (*pos - iter->mod_pos); ) { |
|
p = t_probe_next(m, &l); |
|
if (!p) |
|
break; |
|
} |
|
if (!p) |
|
return NULL; |
|
|
|
/* Only set this if we have an item */ |
|
iter->flags |= FTRACE_ITER_PROBE; |
|
|
|
return iter; |
|
} |
|
|
|
static int |
|
t_probe_show(struct seq_file *m, struct ftrace_iterator *iter) |
|
{ |
|
struct ftrace_func_entry *probe_entry; |
|
struct ftrace_probe_ops *probe_ops; |
|
struct ftrace_func_probe *probe; |
|
|
|
probe = iter->probe; |
|
probe_entry = iter->probe_entry; |
|
|
|
if (WARN_ON_ONCE(!probe || !probe_entry)) |
|
return -EIO; |
|
|
|
probe_ops = probe->probe_ops; |
|
|
|
if (probe_ops->print) |
|
return probe_ops->print(m, probe_entry->ip, probe_ops, probe->data); |
|
|
|
seq_printf(m, "%ps:%ps\n", (void *)probe_entry->ip, |
|
(void *)probe_ops->func); |
|
|
|
return 0; |
|
} |
|
|
|
static void * |
|
t_mod_next(struct seq_file *m, loff_t *pos) |
|
{ |
|
struct ftrace_iterator *iter = m->private; |
|
struct trace_array *tr = iter->tr; |
|
|
|
(*pos)++; |
|
iter->pos = *pos; |
|
|
|
iter->mod_list = iter->mod_list->next; |
|
|
|
if (iter->mod_list == &tr->mod_trace || |
|
iter->mod_list == &tr->mod_notrace) { |
|
iter->flags &= ~FTRACE_ITER_MOD; |
|
return NULL; |
|
} |
|
|
|
iter->mod_pos = *pos; |
|
|
|
return iter; |
|
} |
|
|
|
static void *t_mod_start(struct seq_file *m, loff_t *pos) |
|
{ |
|
struct ftrace_iterator *iter = m->private; |
|
void *p = NULL; |
|
loff_t l; |
|
|
|
if (iter->func_pos > *pos) |
|
return NULL; |
|
|
|
iter->mod_pos = iter->func_pos; |
|
|
|
/* probes are only available if tr is set */ |
|
if (!iter->tr) |
|
return NULL; |
|
|
|
for (l = 0; l <= (*pos - iter->func_pos); ) { |
|
p = t_mod_next(m, &l); |
|
if (!p) |
|
break; |
|
} |
|
if (!p) { |
|
iter->flags &= ~FTRACE_ITER_MOD; |
|
return t_probe_start(m, pos); |
|
} |
|
|
|
/* Only set this if we have an item */ |
|
iter->flags |= FTRACE_ITER_MOD; |
|
|
|
return iter; |
|
} |
|
|
|
static int |
|
t_mod_show(struct seq_file *m, struct ftrace_iterator *iter) |
|
{ |
|
struct ftrace_mod_load *ftrace_mod; |
|
struct trace_array *tr = iter->tr; |
|
|
|
if (WARN_ON_ONCE(!iter->mod_list) || |
|
iter->mod_list == &tr->mod_trace || |
|
iter->mod_list == &tr->mod_notrace) |
|
return -EIO; |
|
|
|
ftrace_mod = list_entry(iter->mod_list, struct ftrace_mod_load, list); |
|
|
|
if (ftrace_mod->func) |
|
seq_printf(m, "%s", ftrace_mod->func); |
|
else |
|
seq_putc(m, '*'); |
|
|
|
seq_printf(m, ":mod:%s\n", ftrace_mod->module); |
|
|
|
return 0; |
|
} |
|
|
|
static void * |
|
t_func_next(struct seq_file *m, loff_t *pos) |
|
{ |
|
struct ftrace_iterator *iter = m->private; |
|
struct dyn_ftrace *rec = NULL; |
|
|
|
(*pos)++; |
|
|
|
retry: |
|
if (iter->idx >= iter->pg->index) { |
|
if (iter->pg->next) { |
|
iter->pg = iter->pg->next; |
|
iter->idx = 0; |
|
goto retry; |
|
} |
|
} else { |
|
rec = &iter->pg->records[iter->idx++]; |
|
if (((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) && |
|
!ftrace_lookup_ip(iter->hash, rec->ip)) || |
|
|
|
((iter->flags & FTRACE_ITER_ENABLED) && |
|
!(rec->flags & FTRACE_FL_ENABLED))) { |
|
|
|
rec = NULL; |
|
goto retry; |
|
} |
|
} |
|
|
|
if (!rec) |
|
return NULL; |
|
|
|
iter->pos = iter->func_pos = *pos; |
|
iter->func = rec; |
|
|
|
return iter; |
|
} |
|
|
|
static void * |
|
t_next(struct seq_file *m, void *v, loff_t *pos) |
|
{ |
|
struct ftrace_iterator *iter = m->private; |
|
loff_t l = *pos; /* t_probe_start() must use original pos */ |
|
void *ret; |
|
|
|
if (unlikely(ftrace_disabled)) |
|
return NULL; |
|
|
|
if (iter->flags & FTRACE_ITER_PROBE) |
|
return t_probe_next(m, pos); |
|
|
|
if (iter->flags & FTRACE_ITER_MOD) |
|
return t_mod_next(m, pos); |
|
|
|
if (iter->flags & FTRACE_ITER_PRINTALL) { |
|
/* next must increment pos, and t_probe_start does not */ |
|
(*pos)++; |
|
return t_mod_start(m, &l); |
|
} |
|
|
|
ret = t_func_next(m, pos); |
|
|
|
if (!ret) |
|
return t_mod_start(m, &l); |
|
|
|
return ret; |
|
} |
|
|
|
static void reset_iter_read(struct ftrace_iterator *iter) |
|
{ |
|
iter->pos = 0; |
|
iter->func_pos = 0; |
|
iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_PROBE | FTRACE_ITER_MOD); |
|
} |
|
|
|
static void *t_start(struct seq_file *m, loff_t *pos) |
|
{ |
|
struct ftrace_iterator *iter = m->private; |
|
void *p = NULL; |
|
loff_t l; |
|
|
|
mutex_lock(&ftrace_lock); |
|
|
|
if (unlikely(ftrace_disabled)) |
|
return NULL; |
|
|
|
/* |
|
* If an lseek was done, then reset and start from beginning. |
|
*/ |
|
if (*pos < iter->pos) |
|
reset_iter_read(iter); |
|
|
|
/* |
|
* For set_ftrace_filter reading, if we have the filter |
|
* off, we can short cut and just print out that all |
|
* functions are enabled. |
|
*/ |
|
if ((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) && |
|
ftrace_hash_empty(iter->hash)) { |
|
iter->func_pos = 1; /* Account for the message */ |
|
if (*pos > 0) |
|
return t_mod_start(m, pos); |
|
iter->flags |= FTRACE_ITER_PRINTALL; |
|
/* reset in case of seek/pread */ |
|
iter->flags &= ~FTRACE_ITER_PROBE; |
|
return iter; |
|
} |
|
|
|
if (iter->flags & FTRACE_ITER_MOD) |
|
return t_mod_start(m, pos); |
|
|
|
/* |
|
* Unfortunately, we need to restart at ftrace_pages_start |
|
* every time we let go of the ftrace_mutex. This is because |
|
* those pointers can change without the lock. |
|
*/ |
|
iter->pg = ftrace_pages_start; |
|
iter->idx = 0; |
|
for (l = 0; l <= *pos; ) { |
|
p = t_func_next(m, &l); |
|
if (!p) |
|
break; |
|
} |
|
|
|
if (!p) |
|
return t_mod_start(m, pos); |
|
|
|
return iter; |
|
} |
|
|
|
static void t_stop(struct seq_file *m, void *p) |
|
{ |
|
mutex_unlock(&ftrace_lock); |
|
} |
|
|
|
void * __weak |
|
arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec) |
|
{ |
|
return NULL; |
|
} |
|
|
|
static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops, |
|
struct dyn_ftrace *rec) |
|
{ |
|
void *ptr; |
|
|
|
ptr = arch_ftrace_trampoline_func(ops, rec); |
|
if (ptr) |
|
seq_printf(m, " ->%pS", ptr); |
|
} |
|
|
|
static int t_show(struct seq_file *m, void *v) |
|
{ |
|
struct ftrace_iterator *iter = m->private; |
|
struct dyn_ftrace *rec; |
|
|
|
if (iter->flags & FTRACE_ITER_PROBE) |
|
return t_probe_show(m, iter); |
|
|
|
if (iter->flags & FTRACE_ITER_MOD) |
|
return t_mod_show(m, iter); |
|
|
|
if (iter->flags & FTRACE_ITER_PRINTALL) { |
|
if (iter->flags & FTRACE_ITER_NOTRACE) |
|
seq_puts(m, "#### no functions disabled ####\n"); |
|
else |
|
seq_puts(m, "#### all functions enabled ####\n"); |
|
return 0; |
|
} |
|
|
|
rec = iter->func; |
|
|
|
if (!rec) |
|
return 0; |
|
|
|
seq_printf(m, "%ps", (void *)rec->ip); |
|
if (iter->flags & FTRACE_ITER_ENABLED) { |
|
struct ftrace_ops *ops; |
|
|
|
seq_printf(m, " (%ld)%s%s%s", |
|
ftrace_rec_count(rec), |
|
rec->flags & FTRACE_FL_REGS ? " R" : " ", |
|
rec->flags & FTRACE_FL_IPMODIFY ? " I" : " ", |
|
rec->flags & FTRACE_FL_DIRECT ? " D" : " "); |
|
if (rec->flags & FTRACE_FL_TRAMP_EN) { |
|
ops = ftrace_find_tramp_ops_any(rec); |
|
if (ops) { |
|
do { |
|
seq_printf(m, "\ttramp: %pS (%pS)", |
|
(void *)ops->trampoline, |
|
(void *)ops->func); |
|
add_trampoline_func(m, ops, rec); |
|
ops = ftrace_find_tramp_ops_next(rec, ops); |
|
} while (ops); |
|
} else |
|
seq_puts(m, "\ttramp: ERROR!"); |
|
} else { |
|
add_trampoline_func(m, NULL, rec); |
|
} |
|
if (rec->flags & FTRACE_FL_DIRECT) { |
|
unsigned long direct; |
|
|
|
direct = ftrace_find_rec_direct(rec->ip); |
|
if (direct) |
|
seq_printf(m, "\n\tdirect-->%pS", (void *)direct); |
|
} |
|
} |
|
|
|
seq_putc(m, '\n'); |
|
|
|
return 0; |
|
} |
|
|
|
static const struct seq_operations show_ftrace_seq_ops = { |
|
.start = t_start, |
|
.next = t_next, |
|
.stop = t_stop, |
|
.show = t_show, |
|
}; |
|
|
|
static int |
|
ftrace_avail_open(struct inode *inode, struct file *file) |
|
{ |
|
struct ftrace_iterator *iter; |
|
int ret; |
|
|
|
ret = security_locked_down(LOCKDOWN_TRACEFS); |
|
if (ret) |
|
return ret; |
|
|
|
if (unlikely(ftrace_disabled)) |
|
return -ENODEV; |
|
|
|
iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
|
if (!iter) |
|
return -ENOMEM; |
|
|
|
iter->pg = ftrace_pages_start; |
|
iter->ops = &global_ops; |
|
|
|
return 0; |
|
} |
|
|
|
static int |
|
ftrace_enabled_open(struct inode *inode, struct file *file) |
|
{ |
|
struct ftrace_iterator *iter; |
|
|
|
/* |
|
* This shows us what functions are currently being |
|
* traced and by what. Not sure if we want lockdown |
|
* to hide such critical information for an admin. |
|
* Although, perhaps it can show information we don't |
|
* want people to see, but if something is tracing |
|
* something, we probably want to know about it. |
|
*/ |
|
|
|
iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
|
if (!iter) |
|
return -ENOMEM; |
|
|
|
iter->pg = ftrace_pages_start; |
|
iter->flags = FTRACE_ITER_ENABLED; |
|
iter->ops = &global_ops; |
|
|
|
return 0; |
|
} |
|
|
|
/** |
|
* ftrace_regex_open - initialize function tracer filter files |
|
* @ops: The ftrace_ops that hold the hash filters |
|
* @flag: The type of filter to process |
|
* @inode: The inode, usually passed in to your open routine |
|
* @file: The file, usually passed in to your open routine |
|
* |
|
* ftrace_regex_open() initializes the filter files for the |
|
* @ops. Depending on @flag it may process the filter hash or |
|
* the notrace hash of @ops. With this called from the open |
|
* routine, you can use ftrace_filter_write() for the write |
|
* routine if @flag has FTRACE_ITER_FILTER set, or |
|
* ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set. |
|
* tracing_lseek() should be used as the lseek routine, and |
|
* release must call ftrace_regex_release(). |
|
*/ |
|
int |
|
ftrace_regex_open(struct ftrace_ops *ops, int flag, |
|
struct inode *inode, struct file *file) |
|
{ |
|
struct ftrace_iterator *iter; |
|
struct ftrace_hash *hash; |
|
struct list_head *mod_head; |
|
struct trace_array *tr = ops->private; |
|
int ret = -ENOMEM; |
|
|
|
ftrace_ops_init(ops); |
|
|
|
if (unlikely(ftrace_disabled)) |
|
return -ENODEV; |
|
|
|
if (tracing_check_open_get_tr(tr)) |
|
return -ENODEV; |
|
|
|
iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
|
if (!iter) |
|
goto out; |
|
|
|
if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) |
|
goto out; |
|
|
|
iter->ops = ops; |
|
iter->flags = flag; |
|
iter->tr = tr; |
|
|
|
mutex_lock(&ops->func_hash->regex_lock); |
|
|
|
if (flag & FTRACE_ITER_NOTRACE) { |
|
hash = ops->func_hash->notrace_hash; |
|
mod_head = tr ? &tr->mod_notrace : NULL; |
|
} else { |
|
hash = ops->func_hash->filter_hash; |
|
mod_head = tr ? &tr->mod_trace : NULL; |
|
} |
|
|
|
iter->mod_list = mod_head; |
|
|
|
if (file->f_mode & FMODE_WRITE) { |
|
const int size_bits = FTRACE_HASH_DEFAULT_BITS; |
|
|
|
if (file->f_flags & O_TRUNC) { |
|
iter->hash = alloc_ftrace_hash(size_bits); |
|
clear_ftrace_mod_list(mod_head); |
|
} else { |
|
iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash); |
|
} |
|
|
|
if (!iter->hash) { |
|
trace_parser_put(&iter->parser); |
|
goto out_unlock; |
|
} |
|
} else |
|
iter->hash = hash; |
|
|
|
ret = 0; |
|
|
|
if (file->f_mode & FMODE_READ) { |
|
iter->pg = ftrace_pages_start; |
|
|
|
ret = seq_open(file, &show_ftrace_seq_ops); |
|
if (!ret) { |
|
struct seq_file *m = file->private_data; |
|
m->private = iter; |
|
} else { |
|
/* Failed */ |
|
free_ftrace_hash(iter->hash); |
|
trace_parser_put(&iter->parser); |
|
} |
|
} else |
|
file->private_data = iter; |
|
|
|
out_unlock: |
|
mutex_unlock(&ops->func_hash->regex_lock); |
|
|
|
out: |
|
if (ret) { |
|
kfree(iter); |
|
if (tr) |
|
trace_array_put(tr); |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
static int |
|
ftrace_filter_open(struct inode *inode, struct file *file) |
|
{ |
|
struct ftrace_ops *ops = inode->i_private; |
|
|
|
/* Checks for tracefs lockdown */ |
|
return ftrace_regex_open(ops, |
|
FTRACE_ITER_FILTER | FTRACE_ITER_DO_PROBES, |
|
inode, file); |
|
} |
|
|
|
static int |
|
ftrace_notrace_open(struct inode *inode, struct file *file) |
|
{ |
|
struct ftrace_ops *ops = inode->i_private; |
|
|
|
/* Checks for tracefs lockdown */ |
|
return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE, |
|
inode, file); |
|
} |
|
|
|
/* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */ |
|
struct ftrace_glob { |
|
char *search; |
|
unsigned len; |
|
int type; |
|
}; |
|
|
|
/* |
|
* If symbols in an architecture don't correspond exactly to the user-visible |
|
* name of what they represent, it is possible to define this function to |
|
* perform the necessary adjustments. |
|
*/ |
|
char * __weak arch_ftrace_match_adjust(char *str, const char *search) |
|
{ |
|
return str; |
|
} |
|
|
|
static int ftrace_match(char *str, struct ftrace_glob *g) |
|
{ |
|
int matched = 0; |
|
int slen; |
|
|
|
str = arch_ftrace_match_adjust(str, g->search); |
|
|
|
switch (g->type) { |
|
case MATCH_FULL: |
|
if (strcmp(str, g->search) == 0) |
|
matched = 1; |
|
break; |
|
case MATCH_FRONT_ONLY: |
|
if (strncmp(str, g->search, g->len) == 0) |
|
matched = 1; |
|
break; |
|
case MATCH_MIDDLE_ONLY: |
|
if (strstr(str, g->search)) |
|
matched = 1; |
|
break; |
|
case MATCH_END_ONLY: |
|
slen = strlen(str); |
|
if (slen >= g->len && |
|
memcmp(str + slen - g->len, g->search, g->len) == 0) |
|
matched = 1; |
|
break; |
|
case MATCH_GLOB: |
|
if (glob_match(g->search, str)) |
|
matched = 1; |
|
break; |
|
} |
|
|
|
return matched; |
|
} |
|
|
|
static int |
|
enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter) |
|
{ |
|
struct ftrace_func_entry *entry; |
|
int ret = 0; |
|
|
|
entry = ftrace_lookup_ip(hash, rec->ip); |
|
if (clear_filter) { |
|
/* Do nothing if it doesn't exist */ |
|
if (!entry) |
|
return 0; |
|
|
|
free_hash_entry(hash, entry); |
|
} else { |
|
/* Do nothing if it exists */ |
|
if (entry) |
|
return 0; |
|
|
|
ret = add_hash_entry(hash, rec->ip); |
|
} |
|
return ret; |
|
} |
|
|
|
static int |
|
add_rec_by_index(struct ftrace_hash *hash, struct ftrace_glob *func_g, |
|
int clear_filter) |
|
{ |
|
long index = simple_strtoul(func_g->search, NULL, 0); |
|
struct ftrace_page *pg; |
|
struct dyn_ftrace *rec; |
|
|
|
/* The index starts at 1 */ |
|
if (--index < 0) |
|
return 0; |
|
|
|
do_for_each_ftrace_rec(pg, rec) { |
|
if (pg->index <= index) { |
|
index -= pg->index; |
|
/* this is a double loop, break goes to the next page */ |
|
break; |
|
} |
|
rec = &pg->records[index]; |
|
enter_record(hash, rec, clear_filter); |
|
return 1; |
|
} while_for_each_ftrace_rec(); |
|
return 0; |
|
} |
|
|
|
static int |
|
ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g, |
|
struct ftrace_glob *mod_g, int exclude_mod) |
|
{ |
|
char str[KSYM_SYMBOL_LEN]; |
|
char *modname; |
|
|
|
kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); |
|
|
|
if (mod_g) { |
|
int mod_matches = (modname) ? ftrace_match(modname, mod_g) : 0; |
|
|
|
/* blank module name to match all modules */ |
|
if (!mod_g->len) { |
|
/* blank module globbing: modname xor exclude_mod */ |
|
if (!exclude_mod != !modname) |
|
goto func_match; |
|
return 0; |
|
} |
|
|
|
/* |
|
* exclude_mod is set to trace everything but the given |
|
* module. If it is set and the module matches, then |
|
* return 0. If it is not set, and the module doesn't match |
|
* also return 0. Otherwise, check the function to see if |
|
* that matches. |
|
*/ |
|
if (!mod_matches == !exclude_mod) |
|
return 0; |
|
func_match: |
|
/* blank search means to match all funcs in the mod */ |
|
if (!func_g->len) |
|
return 1; |
|
} |
|
|
|
return ftrace_match(str, func_g); |
|
} |
|
|
|
static int |
|
match_records(struct ftrace_hash *hash, char *func, int len, char *mod) |
|
{ |
|
struct ftrace_page *pg; |
|
struct dyn_ftrace *rec; |
|
struct ftrace_glob func_g = { .type = MATCH_FULL }; |
|
struct ftrace_glob mod_g = { .type = MATCH_FULL }; |
|
struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL; |
|
int exclude_mod = 0; |
|
int found = 0; |
|
int ret; |
|
int clear_filter = 0; |
|
|
|
if (func) { |
|
func_g.type = filter_parse_regex(func, len, &func_g.search, |
|
&clear_filter); |
|
func_g.len = strlen(func_g.search); |
|
} |
|
|
|
if (mod) { |
|
mod_g.type = filter_parse_regex(mod, strlen(mod), |
|
&mod_g.search, &exclude_mod); |
|
mod_g.len = strlen(mod_g.search); |
|
} |
|
|
|
mutex_lock(&ftrace_lock); |
|
|
|
if (unlikely(ftrace_disabled)) |
|
goto out_unlock; |
|
|
|
if (func_g.type == MATCH_INDEX) { |
|
found = add_rec_by_index(hash, &func_g, clear_filter); |
|
goto out_unlock; |
|
} |
|
|
|
do_for_each_ftrace_rec(pg, rec) { |
|
|
|
if (rec->flags & FTRACE_FL_DISABLED) |
|
continue; |
|
|
|
if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) { |
|
ret = enter_record(hash, rec, clear_filter); |
|
if (ret < 0) { |
|
found = ret; |
|
goto out_unlock; |
|
} |
|
found = 1; |
|
} |
|
} while_for_each_ftrace_rec(); |
|
out_unlock: |
|
mutex_unlock(&ftrace_lock); |
|
|
|
return found; |
|
} |
|
|
|
static int |
|
ftrace_match_records(struct ftrace_hash *hash, char *buff, int len) |
|
{ |
|
return match_records(hash, buff, len, NULL); |
|
} |
|
|
|
static void ftrace_ops_update_code(struct ftrace_ops *ops, |
|
struct ftrace_ops_hash *old_hash) |
|
{ |
|
struct ftrace_ops *op; |
|
|
|
if (!ftrace_enabled) |
|
return; |
|
|
|
if (ops->flags & FTRACE_OPS_FL_ENABLED) { |
|
ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash); |
|
return; |
|
} |
|
|
|
/* |
|
* If this is the shared global_ops filter, then we need to |
|
* check if there is another ops that shares it, is enabled. |
|
* If so, we still need to run the modify code. |
|
*/ |
|
if (ops->func_hash != &global_ops.local_hash) |
|
return; |
|
|
|
do_for_each_ftrace_op(op, ftrace_ops_list) { |
|
if (op->func_hash == &global_ops.local_hash && |
|
op->flags & FTRACE_OPS_FL_ENABLED) { |
|
ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash); |
|
/* Only need to do this once */ |
|
return; |
|
} |
|
} while_for_each_ftrace_op(op); |
|
} |
|
|
|
static int ftrace_hash_move_and_update_ops(struct ftrace_ops *ops, |
|
struct ftrace_hash **orig_hash, |
|
struct ftrace_hash *hash, |
|
int enable) |
|
{ |
|
struct ftrace_ops_hash old_hash_ops; |
|
struct ftrace_hash *old_hash; |
|
int ret; |
|
|
|
old_hash = *orig_hash; |
|
old_hash_ops.filter_hash = ops->func_hash->filter_hash; |
|
old_hash_ops.notrace_hash = ops->func_hash->notrace_hash; |
|
ret = ftrace_hash_move(ops, enable, orig_hash, hash); |
|
if (!ret) { |
|
ftrace_ops_update_code(ops, &old_hash_ops); |
|
free_ftrace_hash_rcu(old_hash); |
|
} |
|
return ret; |
|
} |
|
|
|
static bool module_exists(const char *module) |
|
{ |
|
/* All modules have the symbol __this_module */ |
|
static const char this_mod[] = "__this_module"; |
|
char modname[MAX_PARAM_PREFIX_LEN + sizeof(this_mod) + 2]; |
|
unsigned long val; |
|
int n; |
|
|
|
n = snprintf(modname, sizeof(modname), "%s:%s", module, this_mod); |
|
|
|
if (n > sizeof(modname) - 1) |
|
return false; |
|
|
|
val = module_kallsyms_lookup_name(modname); |
|
return val != 0; |
|
} |
|
|
|
static int cache_mod(struct trace_array *tr, |
|
const char *func, char *module, int enable) |
|
{ |
|
struct ftrace_mod_load *ftrace_mod, *n; |
|
struct list_head *head = enable ? &tr->mod_trace : &tr->mod_notrace; |
|
int ret; |
|
|
|
mutex_lock(&ftrace_lock); |
|
|
|
/* We do not cache inverse filters */ |
|
if (func[0] == '!') { |
|
func++; |
|
ret = -EINVAL; |
|
|
|
/* Look to remove this hash */ |
|
list_for_each_entry_safe(ftrace_mod, n, head, list) { |
|
if (strcmp(ftrace_mod->module, module) != 0) |
|
continue; |
|
|
|
/* no func matches all */ |
|
if (strcmp(func, "*") == 0 || |
|
(ftrace_mod->func && |
|
strcmp(ftrace_mod->func, func) == 0)) { |
|
ret = 0; |
|
free_ftrace_mod(ftrace_mod); |
|
continue; |
|
} |
|
} |
|
goto out; |
|
} |
|
|
|
ret = -EINVAL; |
|
/* We only care about modules that have not been loaded yet */ |
|
if (module_exists(module)) |
|
goto out; |
|
|
|
/* Save this string off, and execute it when the module is loaded */ |
|
ret = ftrace_add_mod(tr, func, module, enable); |
|
out: |
|
mutex_unlock(&ftrace_lock); |
|
|
|
return ret; |
|
} |
|
|
|
static int |
|
ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, |
|
int reset, int enable); |
|
|
|
#ifdef CONFIG_MODULES |
|
static void process_mod_list(struct list_head *head, struct ftrace_ops *ops, |
|
char *mod, bool enable) |
|
{ |
|
struct ftrace_mod_load *ftrace_mod, *n; |
|
struct ftrace_hash **orig_hash, *new_hash; |
|
LIST_HEAD(process_mods); |
|
char *func; |
|
|
|
mutex_lock(&ops->func_hash->regex_lock); |
|
|
|
if (enable) |
|
orig_hash = &ops->func_hash->filter_hash; |
|
else |
|
orig_hash = &ops->func_hash->notrace_hash; |
|
|
|
new_hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, |
|
*orig_hash); |
|
if (!new_hash) |
|
goto out; /* warn? */ |
|
|
|
mutex_lock(&ftrace_lock); |
|
|
|
list_for_each_entry_safe(ftrace_mod, n, head, list) { |
|
|
|
if (strcmp(ftrace_mod->module, mod) != 0) |
|
continue; |
|
|
|
if (ftrace_mod->func) |
|
func = kstrdup(ftrace_mod->func, GFP_KERNEL); |
|
else |
|
func = kstrdup("*", GFP_KERNEL); |
|
|
|
if (!func) /* warn? */ |
|
continue; |
|
|
|
list_move(&ftrace_mod->list, &process_mods); |
|
|
|
/* Use the newly allocated func, as it may be "*" */ |
|
kfree(ftrace_mod->func); |
|
ftrace_mod->func = func; |
|
} |
|
|
|
mutex_unlock(&ftrace_lock); |
|
|
|
list_for_each_entry_safe(ftrace_mod, n, &process_mods, list) { |
|
|
|
func = ftrace_mod->func; |
|
|
|
/* Grabs ftrace_lock, which is why we have this extra step */ |
|
match_records(new_hash, func, strlen(func), mod); |
|
free_ftrace_mod(ftrace_mod); |
|
} |
|
|
|
if (enable && list_empty(head)) |
|
new_hash->flags &= ~FTRACE_HASH_FL_MOD; |
|
|
|
mutex_lock(&ftrace_lock); |
|
|
|
ftrace_hash_move_and_update_ops(ops, orig_hash, |
|
new_hash, enable); |
|
mutex_unlock(&ftrace_lock); |
|
|
|
out: |
|
mutex_unlock(&ops->func_hash->regex_lock); |
|
|
|
free_ftrace_hash(new_hash); |
|
} |
|
|
|
static void process_cached_mods(const char *mod_name) |
|
{ |
|
struct trace_array *tr; |
|
char *mod; |
|
|
|
mod = kstrdup(mod_name, GFP_KERNEL); |
|
if (!mod) |
|
return; |
|
|
|
mutex_lock(&trace_types_lock); |
|
list_for_each_entry(tr, &ftrace_trace_arrays, list) { |
|
if (!list_empty(&tr->mod_trace)) |
|
process_mod_list(&tr->mod_trace, tr->ops, mod, true); |
|
if (!list_empty(&tr->mod_notrace)) |
|
process_mod_list(&tr->mod_notrace, tr->ops, mod, false); |
|
} |
|
mutex_unlock(&trace_types_lock); |
|
|
|
kfree(mod); |
|
} |
|
#endif |
|
|
|
/* |
|
* We register the module command as a template to show others how |
|
* to register the a command as well. |
|
*/ |
|
|
|
static int |
|
ftrace_mod_callback(struct trace_array *tr, struct ftrace_hash *hash, |
|
char *func_orig, char *cmd, char *module, int enable) |
|
{ |
|
char *func; |
|
int ret; |
|
|
|
/* match_records() modifies func, and we need the original */ |
|
func = kstrdup(func_orig, GFP_KERNEL); |
|
if (!func) |
|
return -ENOMEM; |
|
|
|
/* |
|
* cmd == 'mod' because we only registered this func |
|
* for the 'mod' ftrace_func_command. |
|
* But if you register one func with multiple commands, |
|
* you can tell which command was used by the cmd |
|
* parameter. |
|
*/ |
|
ret = match_records(hash, func, strlen(func), module); |
|
kfree(func); |
|
|
|
if (!ret) |
|
return cache_mod(tr, func_orig, module, enable); |
|
if (ret < 0) |
|
return ret; |
|
return 0; |
|
} |
|
|
|
static struct ftrace_func_command ftrace_mod_cmd = { |
|
.name = "mod", |
|
.func = ftrace_mod_callback, |
|
}; |
|
|
|
static int __init ftrace_mod_cmd_init(void) |
|
{ |
|
return register_ftrace_command(&ftrace_mod_cmd); |
|
} |
|
core_initcall(ftrace_mod_cmd_init); |
|
|
|
static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, |
|
struct ftrace_ops *op, struct ftrace_regs *fregs) |
|
{ |
|
struct ftrace_probe_ops *probe_ops; |
|
struct ftrace_func_probe *probe; |
|
|
|
probe = container_of(op, struct ftrace_func_probe, ops); |
|
probe_ops = probe->probe_ops; |
|
|
|
/* |
|
* Disable preemption for these calls to prevent a RCU grace |
|
* period. This syncs the hash iteration and freeing of items |
|
* on the hash. rcu_read_lock is too dangerous here. |
|
*/ |
|
preempt_disable_notrace(); |
|
probe_ops->func(ip, parent_ip, probe->tr, probe_ops, probe->data); |
|
preempt_enable_notrace(); |
|
} |
|
|
|
struct ftrace_func_map { |
|
struct ftrace_func_entry entry; |
|
void *data; |
|
}; |
|
|
|
struct ftrace_func_mapper { |
|
struct ftrace_hash hash; |
|
}; |
|
|
|
/** |
|
* allocate_ftrace_func_mapper - allocate a new ftrace_func_mapper |
|
* |
|
* Returns a ftrace_func_mapper descriptor that can be used to map ips to data. |
|
*/ |
|
struct ftrace_func_mapper *allocate_ftrace_func_mapper(void) |
|
{ |
|
struct ftrace_hash *hash; |
|
|
|
/* |
|
* The mapper is simply a ftrace_hash, but since the entries |
|
* in the hash are not ftrace_func_entry type, we define it |
|
* as a separate structure. |
|
*/ |
|
hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); |
|
return (struct ftrace_func_mapper *)hash; |
|
} |
|
|
|
/** |
|
* ftrace_func_mapper_find_ip - Find some data mapped to an ip |
|
* @mapper: The mapper that has the ip maps |
|
* @ip: the instruction pointer to find the data for |
|
* |
|
* Returns the data mapped to @ip if found otherwise NULL. The return |
|
* is actually the address of the mapper data pointer. The address is |
|
* returned for use cases where the data is no bigger than a long, and |
|
* the user can use the data pointer as its data instead of having to |
|
* allocate more memory for the reference. |
|
*/ |
|
void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper, |
|
unsigned long ip) |
|
{ |
|
struct ftrace_func_entry *entry; |
|
struct ftrace_func_map *map; |
|
|
|
entry = ftrace_lookup_ip(&mapper->hash, ip); |
|
if (!entry) |
|
return NULL; |
|
|
|
map = (struct ftrace_func_map *)entry; |
|
return &map->data; |
|
} |
|
|
|
/** |
|
* ftrace_func_mapper_add_ip - Map some data to an ip |
|
* @mapper: The mapper that has the ip maps |
|
* @ip: The instruction pointer address to map @data to |
|
* @data: The data to map to @ip |
|
* |
|
* Returns 0 on success otherwise an error. |
|
*/ |
|
int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper, |
|
unsigned long ip, void *data) |
|
{ |
|
struct ftrace_func_entry *entry; |
|
struct ftrace_func_map *map; |
|
|
|
entry = ftrace_lookup_ip(&mapper->hash, ip); |
|
if (entry) |
|
return -EBUSY; |
|
|
|
map = kmalloc(sizeof(*map), GFP_KERNEL); |
|
if (!map) |
|
return -ENOMEM; |
|
|
|
map->entry.ip = ip; |
|
map->data = data; |
|
|
|
__add_hash_entry(&mapper->hash, &map->entry); |
|
|
|
return 0; |
|
} |
|
|
|
/** |
|
* ftrace_func_mapper_remove_ip - Remove an ip from the mapping |
|
* @mapper: The mapper that has the ip maps |
|
* @ip: The instruction pointer address to remove the data from |
|
* |
|
* Returns the data if it is found, otherwise NULL. |
|
* Note, if the data pointer is used as the data itself, (see |
|
* ftrace_func_mapper_find_ip(), then the return value may be meaningless, |
|
* if the data pointer was set to zero. |
|
*/ |
|
void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper, |
|
unsigned long ip) |
|
{ |
|
struct ftrace_func_entry *entry; |
|
struct ftrace_func_map *map; |
|
void *data; |
|
|
|
entry = ftrace_lookup_ip(&mapper->hash, ip); |
|
if (!entry) |
|
return NULL; |
|
|
|
map = (struct ftrace_func_map *)entry; |
|
data = map->data; |
|
|
|
remove_hash_entry(&mapper->hash, entry); |
|
kfree(entry); |
|
|
|
return data; |
|
} |
|
|
|
/** |
|
* free_ftrace_func_mapper - free a mapping of ips and data |
|
* @mapper: The mapper that has the ip maps |
|
* @free_func: A function to be called on each data item. |
|
* |
|
* This is used to free the function mapper. The @free_func is optional |
|
* and can be used if the data needs to be freed as well. |
|
*/ |
|
void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper, |
|
ftrace_mapper_func free_func) |
|
{ |
|
struct ftrace_func_entry *entry; |
|
struct ftrace_func_map *map; |
|
struct hlist_head *hhd; |
|
int size, i; |
|
|
|
if (!mapper) |
|
return; |
|
|
|
if (free_func && mapper->hash.count) { |
|
size = 1 << mapper->hash.size_bits; |
|
for (i = 0; i < size; i++) { |
|
hhd = &mapper->hash.buckets[i]; |
|
hlist_for_each_entry(entry, hhd, hlist) { |
|
map = (struct ftrace_func_map *)entry; |
|
free_func(map); |
|
} |
|
} |
|
} |
|
free_ftrace_hash(&mapper->hash); |
|
} |
|
|
|
static void release_probe(struct ftrace_func_probe *probe) |
|
{ |
|
struct ftrace_probe_ops *probe_ops; |
|
|
|
mutex_lock(&ftrace_lock); |
|
|
|
WARN_ON(probe->ref <= 0); |
|
|
|
/* Subtract the ref that was used to protect this instance */ |
|
probe->ref--; |
|
|
|
if (!probe->ref) { |
|
probe_ops = probe->probe_ops; |
|
/* |
|
* Sending zero as ip tells probe_ops to free |
|
* the probe->data itself |
|
*/ |
|
if (probe_ops->free) |
|
probe_ops->free(probe_ops, probe->tr, 0, probe->data); |
|
list_del(&probe->list); |
|
kfree(probe); |
|
} |
|
mutex_unlock(&ftrace_lock); |
|
} |
|
|
|
static void acquire_probe_locked(struct ftrace_func_probe *probe) |
|
{ |
|
/* |
|
* Add one ref to keep it from being freed when releasing the |
|
* ftrace_lock mutex. |
|
*/ |
|
probe->ref++; |
|
} |
|
|
|
int |
|
register_ftrace_function_probe(char *glob, struct trace_array *tr, |
|
struct ftrace_probe_ops *probe_ops, |
|
void *data) |
|
{ |
|
struct ftrace_func_entry *entry; |
|
struct ftrace_func_probe *probe; |
|
struct ftrace_hash **orig_hash; |
|
struct ftrace_hash *old_hash; |
|
struct ftrace_hash *hash; |
|
int count = 0; |
|
int size; |
|
int ret; |
|
int i; |
|
|
|
if (WARN_ON(!tr)) |
|
return -EINVAL; |
|
|
|
/* We do not support '!' for function probes */ |
|
if (WARN_ON(glob[0] == '!')) |
|
return -EINVAL; |
|
|
|
|
|
mutex_lock(&ftrace_lock); |
|
/* Check if the probe_ops is already registered */ |
|
list_for_each_entry(probe, &tr->func_probes, list) { |
|
if (probe->probe_ops == probe_ops) |
|
break; |
|
} |
|
if (&probe->list == &tr->func_probes) { |
|
probe = kzalloc(sizeof(*probe), GFP_KERNEL); |
|
if (!probe) { |
|
mutex_unlock(&ftrace_lock); |
|
return -ENOMEM; |
|
} |
|
probe->probe_ops = probe_ops; |
|
probe->ops.func = function_trace_probe_call; |
|
probe->tr = tr; |
|
ftrace_ops_init(&probe->ops); |
|
list_add(&probe->list, &tr->func_probes); |
|
} |
|
|
|
acquire_probe_locked(probe); |
|
|
|
mutex_unlock(&ftrace_lock); |
|
|
|
/* |
|
* Note, there's a small window here that the func_hash->filter_hash |
|
* may be NULL or empty. Need to be careful when reading the loop. |
|
*/ |
|
mutex_lock(&probe->ops.func_hash->regex_lock); |
|
|
|
orig_hash = &probe->ops.func_hash->filter_hash; |
|
old_hash = *orig_hash; |
|
hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); |
|
|
|
if (!hash) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
ret = ftrace_match_records(hash, glob, strlen(glob)); |
|
|
|
/* Nothing found? */ |
|
if (!ret) |
|
ret = -EINVAL; |
|
|
|
if (ret < 0) |
|
goto out; |
|
|
|
size = 1 << hash->size_bits; |
|
for (i = 0; i < size; i++) { |
|
hlist_for_each_entry(entry, &hash->buckets[i], hlist) { |
|
if (ftrace_lookup_ip(old_hash, entry->ip)) |
|
continue; |
|
/* |
|
* The caller might want to do something special |
|
* for each function we find. We call the callback |
|
* to give the caller an opportunity to do so. |
|
*/ |
|
if (probe_ops->init) { |
|
ret = probe_ops->init(probe_ops, tr, |
|
entry->ip, data, |
|
&probe->data); |
|
if (ret < 0) { |
|
if (probe_ops->free && count) |
|
probe_ops->free(probe_ops, tr, |
|
0, probe->data); |
|
probe->data = NULL; |
|
goto out; |
|
} |
|
} |
|
count++; |
|
} |
|
} |
|
|
|
mutex_lock(&ftrace_lock); |
|
|
|
if (!count) { |
|
/* Nothing was added? */ |
|
ret = -EINVAL; |
|
goto out_unlock; |
|
} |
|
|
|
ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash, |
|
hash, 1); |
|
if (ret < 0) |
|
goto err_unlock; |
|
|
|
/* One ref for each new function traced */ |
|
probe->ref += count; |
|
|
|
if (!(probe->ops.flags & FTRACE_OPS_FL_ENABLED)) |
|
ret = ftrace_startup(&probe->ops, 0); |
|
|
|
out_unlock: |
|
mutex_unlock(&ftrace_lock); |
|
|
|
if (!ret) |
|
ret = count; |
|
out: |
|
mutex_unlock(&probe->ops.func_hash->regex_lock); |
|
free_ftrace_hash(hash); |
|
|
|
release_probe(probe); |
|
|
|
return ret; |
|
|
|
err_unlock: |
|
if (!probe_ops->free || !count) |
|
goto out_unlock; |
|
|
|
/* Failed to do the move, need to call the free functions */ |
|
for (i = 0; i < size; i++) { |
|
hlist_for_each_entry(entry, &hash->buckets[i], hlist) { |
|
if (ftrace_lookup_ip(old_hash, entry->ip)) |
|
continue; |
|
probe_ops->free(probe_ops, tr, entry->ip, probe->data); |
|
} |
|
} |
|
goto out_unlock; |
|
} |
|
|
|
int |
|
unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr, |
|
struct ftrace_probe_ops *probe_ops) |
|
{ |
|
struct ftrace_ops_hash old_hash_ops; |
|
struct ftrace_func_entry *entry; |
|
struct ftrace_func_probe *probe; |
|
struct ftrace_glob func_g; |
|
struct ftrace_hash **orig_hash; |
|
struct ftrace_hash *old_hash; |
|
struct ftrace_hash *hash = NULL; |
|
struct hlist_node *tmp; |
|
struct hlist_head hhd; |
|
char str[KSYM_SYMBOL_LEN]; |
|
int count = 0; |
|
int i, ret = -ENODEV; |
|
int size; |
|
|
|
if (!glob || !strlen(glob) || !strcmp(glob, "*")) |
|
func_g.search = NULL; |
|
else { |
|
int not; |
|
|
|
func_g.type = filter_parse_regex(glob, strlen(glob), |
|
&func_g.search, ¬); |
|
func_g.len = strlen(func_g.search); |
|
|
|
/* we do not support '!' for function probes */ |
|
if (WARN_ON(not)) |
|
return -EINVAL; |
|
} |
|
|
|
mutex_lock(&ftrace_lock); |
|
/* Check if the probe_ops is already registered */ |
|
list_for_each_entry(probe, &tr->func_probes, list) { |
|
if (probe->probe_ops == probe_ops) |
|
break; |
|
} |
|
if (&probe->list == &tr->func_probes) |
|
goto err_unlock_ftrace; |
|
|
|
ret = -EINVAL; |
|
if (!(probe->ops.flags & FTRACE_OPS_FL_INITIALIZED)) |
|
goto err_unlock_ftrace; |
|
|
|
acquire_probe_locked(probe); |
|
|
|
mutex_unlock(&ftrace_lock); |
|
|
|
mutex_lock(&probe->ops.func_hash->regex_lock); |
|
|
|
orig_hash = &probe->ops.func_hash->filter_hash; |
|
old_hash = *orig_hash; |
|
|
|
if (ftrace_hash_empty(old_hash)) |
|
goto out_unlock; |
|
|
|
old_hash_ops.filter_hash = old_hash; |
|
/* Probes only have filters */ |
|
old_hash_ops.notrace_hash = NULL; |
|
|
|
ret = -ENOMEM; |
|
hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); |
|
if (!hash) |
|
goto out_unlock; |
|
|
|
INIT_HLIST_HEAD(&hhd); |
|
|
|
size = 1 << hash->size_bits; |
|
for (i = 0; i < size; i++) { |
|
hlist_for_each_entry_safe(entry, tmp, &hash->buckets[i], hlist) { |
|
|
|
if (func_g.search) { |
|
kallsyms_lookup(entry->ip, NULL, NULL, |
|
NULL, str); |
|
if (!ftrace_match(str, &func_g)) |
|
continue; |
|
} |
|
count++; |
|
remove_hash_entry(hash, entry); |
|
hlist_add_head(&entry->hlist, &hhd); |
|
} |
|
} |
|
|
|
/* Nothing found? */ |
|
if (!count) { |
|
ret = -EINVAL; |
|
goto out_unlock; |
|
} |
|
|
|
mutex_lock(&ftrace_lock); |
|
|
|
WARN_ON(probe->ref < count); |
|
|
|
probe->ref -= count; |
|
|
|
if (ftrace_hash_empty(hash)) |
|
ftrace_shutdown(&probe->ops, 0); |
|
|
|
ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash, |
|
hash, 1); |
|
|
|
/* still need to update the function call sites */ |
|
if (ftrace_enabled && !ftrace_hash_empty(hash)) |
|
ftrace_run_modify_code(&probe->ops, FTRACE_UPDATE_CALLS, |
|
&old_hash_ops); |
|
synchronize_rcu(); |
|
|
|
hlist_for_each_entry_safe(entry, tmp, &hhd, hlist) { |
|
hlist_del(&entry->hlist); |
|
if (probe_ops->free) |
|
probe_ops->free(probe_ops, tr, entry->ip, probe->data); |
|
kfree(entry); |
|
} |
|
mutex_unlock(&ftrace_lock); |
|
|
|
out_unlock: |
|
mutex_unlock(&probe->ops.func_hash->regex_lock); |
|
free_ftrace_hash(hash); |
|
|
|
release_probe(probe); |
|
|
|
return ret; |
|
|
|
err_unlock_ftrace: |
|
mutex_unlock(&ftrace_lock); |
|
return ret; |
|
} |
|
|
|
void clear_ftrace_function_probes(struct trace_array *tr) |
|
{ |
|
struct ftrace_func_probe *probe, *n; |
|
|
|
list_for_each_entry_safe(probe, n, &tr->func_probes, list) |
|
unregister_ftrace_function_probe_func(NULL, tr, probe->probe_ops); |
|
} |
|
|
|
static LIST_HEAD(ftrace_commands); |
|
static DEFINE_MUTEX(ftrace_cmd_mutex); |
|
|
|
/* |
|
* Currently we only register ftrace commands from __init, so mark this |
|
* __init too. |
|
*/ |
|
__init int register_ftrace_command(struct ftrace_func_command *cmd) |
|
{ |
|
struct ftrace_func_command *p; |
|
int ret = 0; |
|
|
|
mutex_lock(&ftrace_cmd_mutex); |
|
list_for_each_entry(p, &ftrace_commands, list) { |
|
if (strcmp(cmd->name, p->name) == 0) { |
|
ret = -EBUSY; |
|
goto out_unlock; |
|
} |
|
} |
|
list_add(&cmd->list, &ftrace_commands); |
|
out_unlock: |
|
mutex_unlock(&ftrace_cmd_mutex); |
|
|
|
return ret; |
|
} |
|
|
|
/* |
|
* Currently we only unregister ftrace commands from __init, so mark |
|
* this __init too. |
|
*/ |
|
__init int unregister_ftrace_command(struct ftrace_func_command *cmd) |
|
{ |
|
struct ftrace_func_command *p, *n; |
|
int ret = -ENODEV; |
|
|
|
mutex_lock(&ftrace_cmd_mutex); |
|
list_for_each_entry_safe(p, n, &ftrace_commands, list) { |
|
if (strcmp(cmd->name, p->name) == 0) { |
|
ret = 0; |
|
list_del_init(&p->list); |
|
goto out_unlock; |
|
} |
|
} |
|
out_unlock: |
|
mutex_unlock(&ftrace_cmd_mutex); |
|
|
|
return ret; |
|
} |
|
|
|
static int ftrace_process_regex(struct ftrace_iterator *iter, |
|
char *buff, int len, int enable) |
|
{ |
|
struct ftrace_hash *hash = iter->hash; |
|
struct trace_array *tr = iter->ops->private; |
|
char *func, *command, *next = buff; |
|
struct ftrace_func_command *p; |
|
int ret = -EINVAL; |
|
|
|
func = strsep(&next, ":"); |
|
|
|
if (!next) { |
|
ret = ftrace_match_records(hash, func, len); |
|
if (!ret) |
|
ret = -EINVAL; |
|
if (ret < 0) |
|
return ret; |
|
return 0; |
|
} |
|
|
|
/* command found */ |
|
|
|
command = strsep(&next, ":"); |
|
|
|
mutex_lock(&ftrace_cmd_mutex); |
|
list_for_each_entry(p, &ftrace_commands, list) { |
|
if (strcmp(p->name, command) == 0) { |
|
ret = p->func(tr, hash, func, command, next, enable); |
|
goto out_unlock; |
|
} |
|
} |
|
out_unlock: |
|
mutex_unlock(&ftrace_cmd_mutex); |
|
|
|
return ret; |
|
} |
|
|
|
static ssize_t |
|
ftrace_regex_write(struct file *file, const char __user *ubuf, |
|
size_t cnt, loff_t *ppos, int enable) |
|
{ |
|
struct ftrace_iterator *iter; |
|
struct trace_parser *parser; |
|
ssize_t ret, read; |
|
|
|
if (!cnt) |
|
return 0; |
|
|
|
if (file->f_mode & FMODE_READ) { |
|
struct seq_file *m = file->private_data; |
|
iter = m->private; |
|
} else |
|
iter = file->private_data; |
|
|
|
if (unlikely(ftrace_disabled)) |
|
return -ENODEV; |
|
|
|
/* iter->hash is a local copy, so we don't need regex_lock */ |
|
|
|
parser = &iter->parser; |
|
read = trace_get_user(parser, ubuf, cnt, ppos); |
|
|
|
if (read >= 0 && trace_parser_loaded(parser) && |
|
!trace_parser_cont(parser)) { |
|
ret = ftrace_process_regex(iter, parser->buffer, |
|
parser->idx, enable); |
|
trace_parser_clear(parser); |
|
if (ret < 0) |
|
goto out; |
|
} |
|
|
|
ret = read; |
|
out: |
|
return ret; |
|
} |
|
|
|
ssize_t |
|
ftrace_filter_write(struct file *file, const char __user *ubuf, |
|
size_t cnt, loff_t *ppos) |
|
{ |
|
return ftrace_regex_write(file, ubuf, cnt, ppos, 1); |
|
} |
|
|
|
ssize_t |
|
ftrace_notrace_write(struct file *file, const char __user *ubuf, |
|
size_t cnt, loff_t *ppos) |
|
{ |
|
return ftrace_regex_write(file, ubuf, cnt, ppos, 0); |
|
} |
|
|
|
static int |
|
ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) |
|
{ |
|
struct ftrace_func_entry *entry; |
|
|
|
if (!ftrace_location(ip)) |
|
return -EINVAL; |
|
|
|
if (remove) { |
|
entry = ftrace_lookup_ip(hash, ip); |
|
if (!entry) |
|
return -ENOENT; |
|
free_hash_entry(hash, entry); |
|
return 0; |
|
} |
|
|
|
return add_hash_entry(hash, ip); |
|
} |
|
|
|
static int |
|
ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, |
|
unsigned long ip, int remove, int reset, int enable) |
|
{ |
|
struct ftrace_hash **orig_hash; |
|
struct ftrace_hash *hash; |
|
int ret; |
|
|
|
if (unlikely(ftrace_disabled)) |
|
return -ENODEV; |
|
|
|
mutex_lock(&ops->func_hash->regex_lock); |
|
|
|
if (enable) |
|
orig_hash = &ops->func_hash->filter_hash; |
|
else |
|
orig_hash = &ops->func_hash->notrace_hash; |
|
|
|
if (reset) |
|
hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); |
|
else |
|
hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); |
|
|
|
if (!hash) { |
|
ret = -ENOMEM; |
|
goto out_regex_unlock; |
|
} |
|
|
|
if (buf && !ftrace_match_records(hash, buf, len)) { |
|
ret = -EINVAL; |
|
goto out_regex_unlock; |
|
} |
|
if (ip) { |
|
ret = ftrace_match_addr(hash, ip, remove); |
|
if (ret < 0) |
|
goto out_regex_unlock; |
|
} |
|
|
|
mutex_lock(&ftrace_lock); |
|
ret = ftrace_hash_move_and_update_ops(ops, orig_hash, hash, enable); |
|
mutex_unlock(&ftrace_lock); |
|
|
|
out_regex_unlock: |
|
mutex_unlock(&ops->func_hash->regex_lock); |
|
|
|
free_ftrace_hash(hash); |
|
return ret; |
|
} |
|
|
|
static int |
|
ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove, |
|
int reset, int enable) |
|
{ |
|
return ftrace_set_hash(ops, NULL, 0, ip, remove, reset, enable); |
|
} |
|
|
|
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS |
|
|
|
struct ftrace_direct_func { |
|
struct list_head next; |
|
unsigned long addr; |
|
int count; |
|
}; |
|
|
|
static LIST_HEAD(ftrace_direct_funcs); |
|
|
|
/** |
|
* ftrace_find_direct_func - test an address if it is a registered direct caller |
|
* @addr: The address of a registered direct caller |
|
* |
|
* This searches to see if a ftrace direct caller has been registered |
|
* at a specific address, and if so, it returns a descriptor for it. |
|
* |
|
* This can be used by architecture code to see if an address is |
|
* a direct caller (trampoline) attached to a fentry/mcount location. |
|
* This is useful for the function_graph tracer, as it may need to |
|
* do adjustments if it traced a location that also has a direct |
|
* trampoline attached to it. |
|
*/ |
|
struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr) |
|
{ |
|
struct ftrace_direct_func *entry; |
|
bool found = false; |
|
|
|
/* May be called by fgraph trampoline (protected by rcu tasks) */ |
|
list_for_each_entry_rcu(entry, &ftrace_direct_funcs, next) { |
|
if (entry->addr == addr) { |
|
found = true; |
|
break; |
|
} |
|
} |
|
if (found) |
|
return entry; |
|
|
|
return NULL; |
|
} |
|
|
|
static struct ftrace_direct_func *ftrace_alloc_direct_func(unsigned long addr) |
|
{ |
|
struct ftrace_direct_func *direct; |
|
|
|
direct = kmalloc(sizeof(*direct), GFP_KERNEL); |
|
if (!direct) |
|
return NULL; |
|
direct->addr = addr; |
|
direct->count = 0; |
|
list_add_rcu(&direct->next, &ftrace_direct_funcs); |
|
ftrace_direct_func_count++; |
|
return direct; |
|
} |
|
|
|
/** |
|
* register_ftrace_direct - Call a custom trampoline directly |
|
* @ip: The address of the nop at the beginning of a function |
|
* @addr: The address of the trampoline to call at @ip |
|
* |
|
* This is used to connect a direct call from the nop location (@ip) |
|
* at the start of ftrace traced functions. The location that it calls |
|
* (@addr) must be able to handle a direct call, and save the parameters |
|
* of the function being traced, and restore them (or inject new ones |
|
* if needed), before returning. |
|
* |
|
* Returns: |
|
* 0 on success |
|
* -EBUSY - Another direct function is already attached (there can be only one) |
|
* -ENODEV - @ip does not point to a ftrace nop location (or not supported) |
|
* -ENOMEM - There was an allocation failure. |
|
*/ |
|
int register_ftrace_direct(unsigned long ip, unsigned long addr) |
|
{ |
|
struct ftrace_direct_func *direct; |
|
struct ftrace_func_entry *entry; |
|
struct ftrace_hash *free_hash = NULL; |
|
struct dyn_ftrace *rec; |
|
int ret = -EBUSY; |
|
|
|
mutex_lock(&direct_mutex); |
|
|
|
/* See if there's a direct function at @ip already */ |
|
if (ftrace_find_rec_direct(ip)) |
|
goto out_unlock; |
|
|
|
ret = -ENODEV; |
|
rec = lookup_rec(ip, ip); |
|
if (!rec) |
|
goto out_unlock; |
|
|
|
/* |
|
* Check if the rec says it has a direct call but we didn't |
|
* find one earlier? |
|
*/ |
|
if (WARN_ON(rec->flags & FTRACE_FL_DIRECT)) |
|
goto out_unlock; |
|
|
|
/* Make sure the ip points to the exact record */ |
|
if (ip != rec->ip) { |
|
ip = rec->ip; |
|
/* Need to check this ip for a direct. */ |
|
if (ftrace_find_rec_direct(ip)) |
|
goto out_unlock; |
|
} |
|
|
|
ret = -ENOMEM; |
|
direct = ftrace_find_direct_func(addr); |
|
if (!direct) { |
|
direct = ftrace_alloc_direct_func(addr); |
|
if (!direct) |
|
goto out_unlock; |
|
} |
|
|
|
entry = ftrace_add_rec_direct(ip, addr, &free_hash); |
|
if (!entry) |
|
goto out_unlock; |
|
|
|
ret = ftrace_set_filter_ip(&direct_ops, ip, 0, 0); |
|
if (ret) |
|
remove_hash_entry(direct_functions, entry); |
|
|
|
if (!ret && !(direct_ops.flags & FTRACE_OPS_FL_ENABLED)) { |
|
ret = register_ftrace_function(&direct_ops); |
|
if (ret) |
|
ftrace_set_filter_ip(&direct_ops, ip, 1, 0); |
|
} |
|
|
|
if (ret) { |
|
kfree(entry); |
|
if (!direct->count) { |
|
list_del_rcu(&direct->next); |
|
synchronize_rcu_tasks(); |
|
kfree(direct); |
|
if (free_hash) |
|
free_ftrace_hash(free_hash); |
|
free_hash = NULL; |
|
ftrace_direct_func_count--; |
|
} |
|
} else { |
|
direct->count++; |
|
} |
|
out_unlock: |
|
mutex_unlock(&direct_mutex); |
|
|
|
if (free_hash) { |
|
synchronize_rcu_tasks(); |
|
free_ftrace_hash(free_hash); |
|
} |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(register_ftrace_direct); |
|
|
|
static struct ftrace_func_entry *find_direct_entry(unsigned long *ip, |
|
struct dyn_ftrace **recp) |
|
{ |
|
struct ftrace_func_entry *entry; |
|
struct dyn_ftrace *rec; |
|
|
|
rec = lookup_rec(*ip, *ip); |
|
if (!rec) |
|
return NULL; |
|
|
|
entry = __ftrace_lookup_ip(direct_functions, rec->ip); |
|
if (!entry) { |
|
WARN_ON(rec->flags & FTRACE_FL_DIRECT); |
|
return NULL; |
|
} |
|
|
|
WARN_ON(!(rec->flags & FTRACE_FL_DIRECT)); |
|
|
|
/* Passed in ip just needs to be on the call site */ |
|
*ip = rec->ip; |
|
|
|
if (recp) |
|
*recp = rec; |
|
|
|
return entry; |
|
} |
|
|
|
int unregister_ftrace_direct(unsigned long ip, unsigned long addr) |
|
{ |
|
struct ftrace_direct_func *direct; |
|
struct ftrace_func_entry *entry; |
|
struct ftrace_hash *hash; |
|
int ret = -ENODEV; |
|
|
|
mutex_lock(&direct_mutex); |
|
|
|
entry = find_direct_entry(&ip, NULL); |
|
if (!entry) |
|
goto out_unlock; |
|
|
|
hash = direct_ops.func_hash->filter_hash; |
|
if (hash->count == 1) |
|
unregister_ftrace_function(&direct_ops); |
|
|
|
ret = ftrace_set_filter_ip(&direct_ops, ip, 1, 0); |
|
|
|
WARN_ON(ret); |
|
|
|
remove_hash_entry(direct_functions, entry); |
|
|
|
direct = ftrace_find_direct_func(addr); |
|
if (!WARN_ON(!direct)) { |
|
/* This is the good path (see the ! before WARN) */ |
|
direct->count--; |
|
WARN_ON(direct->count < 0); |
|
if (!direct->count) { |
|
list_del_rcu(&direct->next); |
|
synchronize_rcu_tasks(); |
|
kfree(direct); |
|
kfree(entry); |
|
ftrace_direct_func_count--; |
|
} |
|
} |
|
out_unlock: |
|
mutex_unlock(&direct_mutex); |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(unregister_ftrace_direct); |
|
|
|
static struct ftrace_ops stub_ops = { |
|
.func = ftrace_stub, |
|
}; |
|
|
|
/** |
|
* ftrace_modify_direct_caller - modify ftrace nop directly |
|
* @entry: The ftrace hash entry of the direct helper for @rec |
|
* @rec: The record representing the function site to patch |
|
* @old_addr: The location that the site at @rec->ip currently calls |
|
* @new_addr: The location that the site at @rec->ip should call |
|
* |
|
* An architecture may overwrite this function to optimize the |
|
* changing of the direct callback on an ftrace nop location. |
|
* This is called with the ftrace_lock mutex held, and no other |
|
* ftrace callbacks are on the associated record (@rec). Thus, |
|
* it is safe to modify the ftrace record, where it should be |
|
* currently calling @old_addr directly, to call @new_addr. |
|
* |
|
* Safety checks should be made to make sure that the code at |
|
* @rec->ip is currently calling @old_addr. And this must |
|
* also update entry->direct to @new_addr. |
|
*/ |
|
int __weak ftrace_modify_direct_caller(struct ftrace_func_entry *entry, |
|
struct dyn_ftrace *rec, |
|
unsigned long old_addr, |
|
unsigned long new_addr) |
|
{ |
|
unsigned long ip = rec->ip; |
|
int ret; |
|
|
|
/* |
|
* The ftrace_lock was used to determine if the record |
|
* had more than one registered user to it. If it did, |
|
* we needed to prevent that from changing to do the quick |
|
* switch. But if it did not (only a direct caller was attached) |
|
* then this function is called. But this function can deal |
|
* with attached callers to the rec that we care about, and |
|
* since this function uses standard ftrace calls that take |
|
* the ftrace_lock mutex, we need to release it. |
|
*/ |
|
mutex_unlock(&ftrace_lock); |
|
|
|
/* |
|
* By setting a stub function at the same address, we force |
|
* the code to call the iterator and the direct_ops helper. |
|
* This means that @ip does not call the direct call, and |
|
* we can simply modify it. |
|
*/ |
|
ret = ftrace_set_filter_ip(&stub_ops, ip, 0, 0); |
|
if (ret) |
|
goto out_lock; |
|
|
|
ret = register_ftrace_function(&stub_ops); |
|
if (ret) { |
|
ftrace_set_filter_ip(&stub_ops, ip, 1, 0); |
|
goto out_lock; |
|
} |
|
|
|
entry->direct = new_addr; |
|
|
|
/* |
|
* By removing the stub, we put back the direct call, calling |
|
* the @new_addr. |
|
*/ |
|
unregister_ftrace_function(&stub_ops); |
|
ftrace_set_filter_ip(&stub_ops, ip, 1, 0); |
|
|
|
out_lock: |
|
mutex_lock(&ftrace_lock); |
|
|
|
return ret; |
|
} |
|
|
|
/** |
|
* modify_ftrace_direct - Modify an existing direct call to call something else |
|
* @ip: The instruction pointer to modify |
|
* @old_addr: The address that the current @ip calls directly |
|
* @new_addr: The address that the @ip should call |
|
* |
|
* This modifies a ftrace direct caller at an instruction pointer without |
|
* having to disable it first. The direct call will switch over to the |
|
* @new_addr without missing anything. |
|
* |
|
* Returns: zero on success. Non zero on error, which includes: |
|
* -ENODEV : the @ip given has no direct caller attached |
|
* -EINVAL : the @old_addr does not match the current direct caller |
|
*/ |
|
int modify_ftrace_direct(unsigned long ip, |
|
unsigned long old_addr, unsigned long new_addr) |
|
{ |
|
struct ftrace_direct_func *direct, *new_direct = NULL; |
|
struct ftrace_func_entry *entry; |
|
struct dyn_ftrace *rec; |
|
int ret = -ENODEV; |
|
|
|
mutex_lock(&direct_mutex); |
|
|
|
mutex_lock(&ftrace_lock); |
|
entry = find_direct_entry(&ip, &rec); |
|
if (!entry) |
|
goto out_unlock; |
|
|
|
ret = -EINVAL; |
|
if (entry->direct != old_addr) |
|
goto out_unlock; |
|
|
|
direct = ftrace_find_direct_func(old_addr); |
|
if (WARN_ON(!direct)) |
|
goto out_unlock; |
|
if (direct->count > 1) { |
|
ret = -ENOMEM; |
|
new_direct = ftrace_alloc_direct_func(new_addr); |
|
if (!new_direct) |
|
goto out_unlock; |
|
direct->count--; |
|
new_direct->count++; |
|
} else { |
|
direct->addr = new_addr; |
|
} |
|
|
|
/* |
|
* If there's no other ftrace callback on the rec->ip location, |
|
* then it can be changed directly by the architecture. |
|
* If there is another caller, then we just need to change the |
|
* direct caller helper to point to @new_addr. |
|
*/ |
|
if (ftrace_rec_count(rec) == 1) { |
|
ret = ftrace_modify_direct_caller(entry, rec, old_addr, new_addr); |
|
} else { |
|
entry->direct = new_addr; |
|
ret = 0; |
|
} |
|
|
|
if (unlikely(ret && new_direct)) { |
|
direct->count++; |
|
list_del_rcu(&new_direct->next); |
|
synchronize_rcu_tasks(); |
|
kfree(new_direct); |
|
ftrace_direct_func_count--; |
|
} |
|
|
|
out_unlock: |
|
mutex_unlock(&ftrace_lock); |
|
mutex_unlock(&direct_mutex); |
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(modify_ftrace_direct); |
|
|
|
#define MULTI_FLAGS (FTRACE_OPS_FL_IPMODIFY | FTRACE_OPS_FL_DIRECT | \ |
|
FTRACE_OPS_FL_SAVE_REGS) |
|
|
|
static int check_direct_multi(struct ftrace_ops *ops) |
|
{ |
|
if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) |
|
return -EINVAL; |
|
if ((ops->flags & MULTI_FLAGS) != MULTI_FLAGS) |
|
return -EINVAL; |
|
return 0; |
|
} |
|
|
|
static void remove_direct_functions_hash(struct ftrace_hash *hash, unsigned long addr) |
|
{ |
|
struct ftrace_func_entry *entry, *del; |
|
int size, i; |
|
|
|
size = 1 << hash->size_bits; |
|
for (i = 0; i < size; i++) { |
|
hlist_for_each_entry(entry, &hash->buckets[i], hlist) { |
|
del = __ftrace_lookup_ip(direct_functions, entry->ip); |
|
if (del && del->direct == addr) { |
|
remove_hash_entry(direct_functions, del); |
|
kfree(del); |
|
} |
|
} |
|
} |
|
} |
|
|
|
/** |
|
* register_ftrace_direct_multi - Call a custom trampoline directly |
|
* for multiple functions registered in @ops |
|
* @ops: The address of the struct ftrace_ops object |
|
* @addr: The address of the trampoline to call at @ops functions |
|
* |
|
* This is used to connect a direct calls to @addr from the nop locations |
|
* of the functions registered in @ops (with by ftrace_set_filter_ip |
|
* function). |
|
* |
|
* The location that it calls (@addr) must be able to handle a direct call, |
|
* and save the parameters of the function being traced, and restore them |
|
* (or inject new ones if needed), before returning. |
|
* |
|
* Returns: |
|
* 0 on success |
|
* -EINVAL - The @ops object was already registered with this call or |
|
* when there are no functions in @ops object. |
|
* -EBUSY - Another direct function is already attached (there can be only one) |
|
* -ENODEV - @ip does not point to a ftrace nop location (or not supported) |
|
* -ENOMEM - There was an allocation failure. |
|
*/ |
|
int register_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) |
|
{ |
|
struct ftrace_hash *hash, *free_hash = NULL; |
|
struct ftrace_func_entry *entry, *new; |
|
int err = -EBUSY, size, i; |
|
|
|
if (ops->func || ops->trampoline) |
|
return -EINVAL; |
|
if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) |
|
return -EINVAL; |
|
if (ops->flags & FTRACE_OPS_FL_ENABLED) |
|
return -EINVAL; |
|
|
|
hash = ops->func_hash->filter_hash; |
|
if (ftrace_hash_empty(hash)) |
|
return -EINVAL; |
|
|
|
mutex_lock(&direct_mutex); |
|
|
|
/* Make sure requested entries are not already registered.. */ |
|
size = 1 << hash->size_bits; |
|
for (i = 0; i < size; i++) { |
|
hlist_for_each_entry(entry, &hash->buckets[i], hlist) { |
|
if (ftrace_find_rec_direct(entry->ip)) |
|
goto out_unlock; |
|
} |
|
} |
|
|
|
/* ... and insert them to direct_functions hash. */ |
|
err = -ENOMEM; |
|
for (i = 0; i < size; i++) { |
|
hlist_for_each_entry(entry, &hash->buckets[i], hlist) { |
|
new = ftrace_add_rec_direct(entry->ip, addr, &free_hash); |
|
if (!new) |
|
goto out_remove; |
|
entry->direct = addr; |
|
} |
|
} |
|
|
|
ops->func = call_direct_funcs; |
|
ops->flags = MULTI_FLAGS; |
|
ops->trampoline = FTRACE_REGS_ADDR; |
|
|
|
err = register_ftrace_function(ops); |
|
|
|
out_remove: |
|
if (err) |
|
remove_direct_functions_hash(hash, addr); |
|
|
|
out_unlock: |
|
mutex_unlock(&direct_mutex); |
|
|
|
if (free_hash) { |
|
synchronize_rcu_tasks(); |
|
free_ftrace_hash(free_hash); |
|
} |
|
return err; |
|
} |
|
EXPORT_SYMBOL_GPL(register_ftrace_direct_multi); |
|
|
|
/** |
|
* unregister_ftrace_direct_multi - Remove calls to custom trampoline |
|
* previously registered by register_ftrace_direct_multi for @ops object. |
|
* @ops: The address of the struct ftrace_ops object |
|
* |
|
* This is used to remove a direct calls to @addr from the nop locations |
|
* of the functions registered in @ops (with by ftrace_set_filter_ip |
|
* function). |
|
* |
|
* Returns: |
|
* 0 on success |
|
* -EINVAL - The @ops object was not properly registered. |
|
*/ |
|
int unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) |
|
{ |
|
struct ftrace_hash *hash = ops->func_hash->filter_hash; |
|
int err; |
|
|
|
if (check_direct_multi(ops)) |
|
return -EINVAL; |
|
if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) |
|
return -EINVAL; |
|
|
|
mutex_lock(&direct_mutex); |
|
err = unregister_ftrace_function(ops); |
|
remove_direct_functions_hash(hash, addr); |
|
mutex_unlock(&direct_mutex); |
|
|
|
/* cleanup for possible another register call */ |
|
ops->func = NULL; |
|
ops->trampoline = 0; |
|
return err; |
|
} |
|
EXPORT_SYMBOL_GPL(unregister_ftrace_direct_multi); |
|
|
|
/** |
|
* modify_ftrace_direct_multi - Modify an existing direct 'multi' call |
|
* to call something else |
|
* @ops: The address of the struct ftrace_ops object |
|
* @addr: The address of the new trampoline to call at @ops functions |
|
* |
|
* This is used to unregister currently registered direct caller and |
|
* register new one @addr on functions registered in @ops object. |
|
* |
|
* Note there's window between ftrace_shutdown and ftrace_startup calls |
|
* where there will be no callbacks called. |
|
* |
|
* Returns: zero on success. Non zero on error, which includes: |
|
* -EINVAL - The @ops object was not properly registered. |
|
*/ |
|
int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) |
|
{ |
|
struct ftrace_hash *hash; |
|
struct ftrace_func_entry *entry, *iter; |
|
static struct ftrace_ops tmp_ops = { |
|
.func = ftrace_stub, |
|
.flags = FTRACE_OPS_FL_STUB, |
|
}; |
|
int i, size; |
|
int err; |
|
|
|
if (check_direct_multi(ops)) |
|
return -EINVAL; |
|
if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) |
|
return -EINVAL; |
|
|
|
mutex_lock(&direct_mutex); |
|
|
|
/* Enable the tmp_ops to have the same functions as the direct ops */ |
|
ftrace_ops_init(&tmp_ops); |
|
tmp_ops.func_hash = ops->func_hash; |
|
|
|
err = register_ftrace_function(&tmp_ops); |
|
if (err) |
|
goto out_direct; |
|
|
|
/* |
|
* Now the ftrace_ops_list_func() is called to do the direct callers. |
|
* We can safely change the direct functions attached to each entry. |
|
*/ |
|
mutex_lock(&ftrace_lock); |
|
|
|
hash = ops->func_hash->filter_hash; |
|
size = 1 << hash->size_bits; |
|
for (i = 0; i < size; i++) { |
|
hlist_for_each_entry(iter, &hash->buckets[i], hlist) { |
|
entry = __ftrace_lookup_ip(direct_functions, iter->ip); |
|
if (!entry) |
|
continue; |
|
entry->direct = addr; |
|
} |
|
} |
|
|
|
mutex_unlock(&ftrace_lock); |
|
|
|
/* Removing the tmp_ops will add the updated direct callers to the functions */ |
|
unregister_ftrace_function(&tmp_ops); |
|
|
|
out_direct: |
|
mutex_unlock(&direct_mutex); |
|
return err; |
|
} |
|
EXPORT_SYMBOL_GPL(modify_ftrace_direct_multi); |
|
#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ |
|
|
|
/** |
|
* ftrace_set_filter_ip - set a function to filter on in ftrace by address |
|
* @ops - the ops to set the filter with |
|
* @ip - the address to add to or remove from the filter. |
|
* @remove - non zero to remove the ip from the filter |
|
* @reset - non zero to reset all filters before applying this filter. |
|
* |
|
* Filters denote which functions should be enabled when tracing is enabled |
|
* If @ip is NULL, it fails to update filter. |
|
*/ |
|
int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, |
|
int remove, int reset) |
|
{ |
|
ftrace_ops_init(ops); |
|
return ftrace_set_addr(ops, ip, remove, reset, 1); |
|
} |
|
EXPORT_SYMBOL_GPL(ftrace_set_filter_ip); |
|
|
|
/** |
|
* ftrace_ops_set_global_filter - setup ops to use global filters |
|
* @ops - the ops which will use the global filters |
|
* |
|
* ftrace users who need global function trace filtering should call this. |
|
* It can set the global filter only if ops were not initialized before. |
|
*/ |
|
void ftrace_ops_set_global_filter(struct ftrace_ops *ops) |
|
{ |
|
if (ops->flags & FTRACE_OPS_FL_INITIALIZED) |
|
return; |
|
|
|
ftrace_ops_init(ops); |
|
ops->func_hash = &global_ops.local_hash; |
|
} |
|
EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter); |
|
|
|
static int |
|
ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, |
|
int reset, int enable) |
|
{ |
|
return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable); |
|
} |
|
|
|
/** |
|
* ftrace_set_filter - set a function to filter on in ftrace |
|
* @ops - the ops to set the filter with |
|
* @buf - the string that holds the function filter text. |
|
* @len - the length of the string. |
|
* @reset - non zero to reset all filters before applying this filter. |
|
* |
|
* Filters denote which functions should be enabled when tracing is enabled. |
|
* If @buf is NULL and reset is set, all functions will be enabled for tracing. |
|
*/ |
|
int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, |
|
int len, int reset) |
|
{ |
|
ftrace_ops_init(ops); |
|
return ftrace_set_regex(ops, buf, len, reset, 1); |
|
} |
|
EXPORT_SYMBOL_GPL(ftrace_set_filter); |
|
|
|
/** |
|
* ftrace_set_notrace - set a function to not trace in ftrace |
|
* @ops - the ops to set the notrace filter with |
|
* @buf - the string that holds the function notrace text. |
|
* @len - the length of the string. |
|
* @reset - non zero to reset all filters before applying this filter. |
|
* |
|
* Notrace Filters denote which functions should not be enabled when tracing |
|
* is enabled. If @buf is NULL and reset is set, all functions will be enabled |
|
* for tracing. |
|
*/ |
|
int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, |
|
int len, int reset) |
|
{ |
|
ftrace_ops_init(ops); |
|
return ftrace_set_regex(ops, buf, len, reset, 0); |
|
} |
|
EXPORT_SYMBOL_GPL(ftrace_set_notrace); |
|
/** |
|
* ftrace_set_global_filter - set a function to filter on with global tracers |
|
* @buf - the string that holds the function filter text. |
|
* @len - the length of the string. |
|
* @reset - non zero to reset all filters before applying this filter. |
|
* |
|
* Filters denote which functions should be enabled when tracing is enabled. |
|
* If @buf is NULL and reset is set, all functions will be enabled for tracing. |
|
*/ |
|
void ftrace_set_global_filter(unsigned char *buf, int len, int reset) |
|
{ |
|
ftrace_set_regex(&global_ops, buf, len, reset, 1); |
|
} |
|
EXPORT_SYMBOL_GPL(ftrace_set_global_filter); |
|
|
|
/** |
|
* ftrace_set_global_notrace - set a function to not trace with global tracers |
|
* @buf - the string that holds the function notrace text. |
|
* @len - the length of the string. |
|
* @reset - non zero to reset all filters before applying this filter. |
|
* |
|
* Notrace Filters denote which functions should not be enabled when tracing |
|
* is enabled. If @buf is NULL and reset is set, all functions will be enabled |
|
* for tracing. |
|
*/ |
|
void ftrace_set_global_notrace(unsigned char *buf, int len, int reset) |
|
{ |
|
ftrace_set_regex(&global_ops, buf, len, reset, 0); |
|
} |
|
EXPORT_SYMBOL_GPL(ftrace_set_global_notrace); |
|
|
|
/* |
|
* command line interface to allow users to set filters on boot up. |
|
*/ |
|
#define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE |
|
static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; |
|
static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; |
|
|
|
/* Used by function selftest to not test if filter is set */ |
|
bool ftrace_filter_param __initdata; |
|
|
|
static int __init set_ftrace_notrace(char *str) |
|
{ |
|
ftrace_filter_param = true; |
|
strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); |
|
return 1; |
|
} |
|
__setup("ftrace_notrace=", set_ftrace_notrace); |
|
|
|
static int __init set_ftrace_filter(char *str) |
|
{ |
|
ftrace_filter_param = true; |
|
strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); |
|
return 1; |
|
} |
|
__setup("ftrace_filter=", set_ftrace_filter); |
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER |
|
static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
|
static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata; |
|
static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer); |
|
|
|
static int __init set_graph_function(char *str) |
|
{ |
|
strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); |
|
return 1; |
|
} |
|
__setup("ftrace_graph_filter=", set_graph_function); |
|
|
|
static int __init set_graph_notrace_function(char *str) |
|
{ |
|
strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE); |
|
return 1; |
|
} |
|
__setup("ftrace_graph_notrace=", set_graph_notrace_function); |
|
|
|
static int __init set_graph_max_depth_function(char *str) |
|
{ |
|
if (!str) |
|
return 0; |
|
fgraph_max_depth = simple_strtoul(str, NULL, 0); |
|
return 1; |
|
} |
|
__setup("ftrace_graph_max_depth=", set_graph_max_depth_function); |
|
|
|
static void __init set_ftrace_early_graph(char *buf, int enable) |
|
{ |
|
int ret; |
|
char *func; |
|
struct ftrace_hash *hash; |
|
|
|
hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); |
|
if (MEM_FAIL(!hash, "Failed to allocate hash\n")) |
|
return; |
|
|
|
while (buf) { |
|
func = strsep(&buf, ","); |
|
/* we allow only one expression at a time */ |
|
ret = ftrace_graph_set_hash(hash, func); |
|
if (ret) |
|
printk(KERN_DEBUG "ftrace: function %s not " |
|
"traceable\n", func); |
|
} |
|
|
|
if (enable) |
|
ftrace_graph_hash = hash; |
|
else |
|
ftrace_graph_notrace_hash = hash; |
|
} |
|
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
|
|
|
void __init |
|
ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable) |
|
{ |
|
char *func; |
|
|
|
ftrace_ops_init(ops); |
|
|
|
while (buf) { |
|
func = strsep(&buf, ","); |
|
ftrace_set_regex(ops, func, strlen(func), 0, enable); |
|
} |
|
} |
|
|
|
static void __init set_ftrace_early_filters(void) |
|
{ |
|
if (ftrace_filter_buf[0]) |
|
ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1); |
|
if (ftrace_notrace_buf[0]) |
|
ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0); |
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER |
|
if (ftrace_graph_buf[0]) |
|
set_ftrace_early_graph(ftrace_graph_buf, 1); |
|
if (ftrace_graph_notrace_buf[0]) |
|
set_ftrace_early_graph(ftrace_graph_notrace_buf, 0); |
|
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
|
} |
|
|
|
int ftrace_regex_release(struct inode *inode, struct file *file) |
|
{ |
|
struct seq_file *m = (struct seq_file *)file->private_data; |
|
struct ftrace_iterator *iter; |
|
struct ftrace_hash **orig_hash; |
|
struct trace_parser *parser; |
|
int filter_hash; |
|
|
|
if (file->f_mode & FMODE_READ) { |
|
iter = m->private; |
|
seq_release(inode, file); |
|
} else |
|
iter = file->private_data; |
|
|
|
parser = &iter->parser; |
|
if (trace_parser_loaded(parser)) { |
|
int enable = !(iter->flags & FTRACE_ITER_NOTRACE); |
|
|
|
ftrace_process_regex(iter, parser->buffer, |
|
parser->idx, enable); |
|
} |
|
|
|
trace_parser_put(parser); |
|
|
|
mutex_lock(&iter->ops->func_hash->regex_lock); |
|
|
|
if (file->f_mode & FMODE_WRITE) { |
|
filter_hash = !!(iter->flags & FTRACE_ITER_FILTER); |
|
|
|
if (filter_hash) { |
|
orig_hash = &iter->ops->func_hash->filter_hash; |
|
if (iter->tr && !list_empty(&iter->tr->mod_trace)) |
|
iter->hash->flags |= FTRACE_HASH_FL_MOD; |
|
} else |
|
orig_hash = &iter->ops->func_hash->notrace_hash; |
|
|
|
mutex_lock(&ftrace_lock); |
|
ftrace_hash_move_and_update_ops(iter->ops, orig_hash, |
|
iter->hash, filter_hash); |
|
mutex_unlock(&ftrace_lock); |
|
} else { |
|
/* For read only, the hash is the ops hash */ |
|
iter->hash = NULL; |
|
} |
|
|
|
mutex_unlock(&iter->ops->func_hash->regex_lock); |
|
free_ftrace_hash(iter->hash); |
|
if (iter->tr) |
|
trace_array_put(iter->tr); |
|
kfree(iter); |
|
|
|
return 0; |
|
} |
|
|
|
static const struct file_operations ftrace_avail_fops = { |
|
.open = ftrace_avail_open, |
|
.read = seq_read, |
|
.llseek = seq_lseek, |
|
.release = seq_release_private, |
|
}; |
|
|
|
static const struct file_operations ftrace_enabled_fops = { |
|
.open = ftrace_enabled_open, |
|
.read = seq_read, |
|
.llseek = seq_lseek, |
|
.release = seq_release_private, |
|
}; |
|
|
|
static const struct file_operations ftrace_filter_fops = { |
|
.open = ftrace_filter_open, |
|
.read = seq_read, |
|
.write = ftrace_filter_write, |
|
.llseek = tracing_lseek, |
|
.release = ftrace_regex_release, |
|
}; |
|
|
|
static const struct file_operations ftrace_notrace_fops = { |
|
.open = ftrace_notrace_open, |
|
.read = seq_read, |
|
.write = ftrace_notrace_write, |
|
.llseek = tracing_lseek, |
|
.release = ftrace_regex_release, |
|
}; |
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER |
|
|
|
static DEFINE_MUTEX(graph_lock); |
|
|
|
struct ftrace_hash __rcu *ftrace_graph_hash = EMPTY_HASH; |
|
struct ftrace_hash __rcu *ftrace_graph_notrace_hash = EMPTY_HASH; |
|
|
|
enum graph_filter_type { |
|
GRAPH_FILTER_NOTRACE = 0, |
|
GRAPH_FILTER_FUNCTION, |
|
}; |
|
|
|
#define FTRACE_GRAPH_EMPTY ((void *)1) |
|
|
|
struct ftrace_graph_data { |
|
struct ftrace_hash *hash; |
|
struct ftrace_func_entry *entry; |
|
int idx; /* for hash table iteration */ |
|
enum graph_filter_type type; |
|
struct ftrace_hash *new_hash; |
|
const struct seq_operations *seq_ops; |
|
struct trace_parser parser; |
|
}; |
|
|
|
static void * |
|
__g_next(struct seq_file *m, loff_t *pos) |
|
{ |
|
struct ftrace_graph_data *fgd = m->private; |
|
struct ftrace_func_entry *entry = fgd->entry; |
|
struct hlist_head *head; |
|
int i, idx = fgd->idx; |
|
|
|
if (*pos >= fgd->hash->count) |
|
return NULL; |
|
|
|
if (entry) { |
|
hlist_for_each_entry_continue(entry, hlist) { |
|
fgd->entry = entry; |
|
return entry; |
|
} |
|
|
|
idx++; |
|
} |
|
|
|
for (i = idx; i < 1 << fgd->hash->size_bits; i++) { |
|
head = &fgd->hash->buckets[i]; |
|
hlist_for_each_entry(entry, head, hlist) { |
|
fgd->entry = entry; |
|
fgd->idx = i; |
|
return entry; |
|
} |
|
} |
|
return NULL; |
|
} |
|
|
|
static void * |
|
g_next(struct seq_file *m, void *v, loff_t *pos) |
|
{ |
|
(*pos)++; |
|
return __g_next(m, pos); |
|
} |
|
|
|
static void *g_start(struct seq_file *m, loff_t *pos) |
|
{ |
|
struct ftrace_graph_data *fgd = m->private; |
|
|
|
mutex_lock(&graph_lock); |
|
|
|
if (fgd->type == GRAPH_FILTER_FUNCTION) |
|
fgd->hash = rcu_dereference_protected(ftrace_graph_hash, |
|
lockdep_is_held(&graph_lock)); |
|
else |
|
fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash, |
|
lockdep_is_held(&graph_lock)); |
|
|
|
/* Nothing, tell g_show to print all functions are enabled */ |
|
if (ftrace_hash_empty(fgd->hash) && !*pos) |
|
return FTRACE_GRAPH_EMPTY; |
|
|
|
fgd->idx = 0; |
|
fgd->entry = NULL; |
|
return __g_next(m, pos); |
|
} |
|
|
|
static void g_stop(struct seq_file *m, void *p) |
|
{ |
|
mutex_unlock(&graph_lock); |
|
} |
|
|
|
static int g_show(struct seq_file *m, void *v) |
|
{ |
|
struct ftrace_func_entry *entry = v; |
|
|
|
if (!entry) |
|
return 0; |
|
|
|
if (entry == FTRACE_GRAPH_EMPTY) { |
|
struct ftrace_graph_data *fgd = m->private; |
|
|
|
if (fgd->type == GRAPH_FILTER_FUNCTION) |
|
seq_puts(m, "#### all functions enabled ####\n"); |
|
else |
|
seq_puts(m, "#### no functions disabled ####\n"); |
|
return 0; |
|
} |
|
|
|
seq_printf(m, "%ps\n", (void *)entry->ip); |
|
|
|
return 0; |
|
} |
|
|
|
static const struct seq_operations ftrace_graph_seq_ops = { |
|
.start = g_start, |
|
.next = g_next, |
|
.stop = g_stop, |
|
.show = g_show, |
|
}; |
|
|
|
static int |
|
__ftrace_graph_open(struct inode *inode, struct file *file, |
|
struct ftrace_graph_data *fgd) |
|
{ |
|
int ret; |
|
struct ftrace_hash *new_hash = NULL; |
|
|
|
ret = security_locked_down(LOCKDOWN_TRACEFS); |
|
if (ret) |
|
return ret; |
|
|
|
if (file->f_mode & FMODE_WRITE) { |
|
const int size_bits = FTRACE_HASH_DEFAULT_BITS; |
|
|
|
if (trace_parser_get_init(&fgd->parser, FTRACE_BUFF_MAX)) |
|
return -ENOMEM; |
|
|
|
if (file->f_flags & O_TRUNC) |
|
new_hash = alloc_ftrace_hash(size_bits); |
|
else |
|
new_hash = alloc_and_copy_ftrace_hash(size_bits, |
|
fgd->hash); |
|
if (!new_hash) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
} |
|
|
|
if (file->f_mode & FMODE_READ) { |
|
ret = seq_open(file, &ftrace_graph_seq_ops); |
|
if (!ret) { |
|
struct seq_file *m = file->private_data; |
|
m->private = fgd; |
|
} else { |
|
/* Failed */ |
|
free_ftrace_hash(new_hash); |
|
new_hash = NULL; |
|
} |
|
} else |
|
file->private_data = fgd; |
|
|
|
out: |
|
if (ret < 0 && file->f_mode & FMODE_WRITE) |
|
trace_parser_put(&fgd->parser); |
|
|
|
fgd->new_hash = new_hash; |
|
|
|
/* |
|
* All uses of fgd->hash must be taken with the graph_lock |
|
* held. The graph_lock is going to be released, so force |
|
* fgd->hash to be reinitialized when it is taken again. |
|
*/ |
|
fgd->hash = NULL; |
|
|
|
return ret; |
|
} |
|
|
|
static int |
|
ftrace_graph_open(struct inode *inode, struct file *file) |
|
{ |
|
struct ftrace_graph_data *fgd; |
|
int ret; |
|
|
|
if (unlikely(ftrace_disabled)) |
|
return -ENODEV; |
|
|
|
fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); |
|
if (fgd == NULL) |
|
return -ENOMEM; |
|
|
|
mutex_lock(&graph_lock); |
|
|
|
fgd->hash = rcu_dereference_protected(ftrace_graph_hash, |
|
lockdep_is_held(&graph_lock)); |
|
fgd->type = GRAPH_FILTER_FUNCTION; |
|
fgd->seq_ops = &ftrace_graph_seq_ops; |
|
|
|
ret = __ftrace_graph_open(inode, file, fgd); |
|
if (ret < 0) |
|
kfree(fgd); |
|
|
|
mutex_unlock(&graph_lock); |
|
return ret; |
|
} |
|
|
|
static int |
|
ftrace_graph_notrace_open(struct inode *inode, struct file *file) |
|
{ |
|
struct ftrace_graph_data *fgd; |
|
int ret; |
|
|
|
if (unlikely(ftrace_disabled)) |
|
return -ENODEV; |
|
|
|
fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); |
|
if (fgd == NULL) |
|
return -ENOMEM; |
|
|
|
mutex_lock(&graph_lock); |
|
|
|
fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash, |
|
lockdep_is_held(&graph_lock)); |
|
fgd->type = GRAPH_FILTER_NOTRACE; |
|
fgd->seq_ops = &ftrace_graph_seq_ops; |
|
|
|
ret = __ftrace_graph_open(inode, file, fgd); |
|
if (ret < 0) |
|
kfree(fgd); |
|
|
|
mutex_unlock(&graph_lock); |
|
return ret; |
|
} |
|
|
|
static int |
|
ftrace_graph_release(struct inode *inode, struct file *file) |
|
{ |
|
struct ftrace_graph_data *fgd; |
|
struct ftrace_hash *old_hash, *new_hash; |
|
struct trace_parser *parser; |
|
int ret = 0; |
|
|
|
if (file->f_mode & FMODE_READ) { |
|
struct seq_file *m = file->private_data; |
|
|
|
fgd = m->private; |
|
seq_release(inode, file); |
|
} else { |
|
fgd = file->private_data; |
|
} |
|
|
|
|
|
if (file->f_mode & FMODE_WRITE) { |
|
|
|
parser = &fgd->parser; |
|
|
|
if (trace_parser_loaded((parser))) { |
|
ret = ftrace_graph_set_hash(fgd->new_hash, |
|
parser->buffer); |
|
} |
|
|
|
trace_parser_put(parser); |
|
|
|
new_hash = __ftrace_hash_move(fgd->new_hash); |
|
if (!new_hash) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
mutex_lock(&graph_lock); |
|
|
|
if (fgd->type == GRAPH_FILTER_FUNCTION) { |
|
old_hash = rcu_dereference_protected(ftrace_graph_hash, |
|
lockdep_is_held(&graph_lock)); |
|
rcu_assign_pointer(ftrace_graph_hash, new_hash); |
|
} else { |
|
old_hash = rcu_dereference_protected(ftrace_graph_notrace_hash, |
|
lockdep_is_held(&graph_lock)); |
|
rcu_assign_pointer(ftrace_graph_notrace_hash, new_hash); |
|
} |
|
|
|
mutex_unlock(&graph_lock); |
|
|
|
/* |
|
* We need to do a hard force of sched synchronization. |
|
* This is because we use preempt_disable() to do RCU, but |
|
* the function tracers can be called where RCU is not watching |
|
* (like before user_exit()). We can not rely on the RCU |
|
* infrastructure to do the synchronization, thus we must do it |
|
* ourselves. |
|
*/ |
|
if (old_hash != EMPTY_HASH) |
|
synchronize_rcu_tasks_rude(); |
|
|
|
free_ftrace_hash(old_hash); |
|
} |
|
|
|
out: |
|
free_ftrace_hash(fgd->new_hash); |
|
kfree(fgd); |
|
|
|
return ret; |
|
} |
|
|
|
static int |
|
ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer) |
|
{ |
|
struct ftrace_glob func_g; |
|
struct dyn_ftrace *rec; |
|
struct ftrace_page *pg; |
|
struct ftrace_func_entry *entry; |
|
int fail = 1; |
|
int not; |
|
|
|
/* decode regex */ |
|
func_g.type = filter_parse_regex(buffer, strlen(buffer), |
|
&func_g.search, ¬); |
|
|
|
func_g.len = strlen(func_g.search); |
|
|
|
mutex_lock(&ftrace_lock); |
|
|
|
if (unlikely(ftrace_disabled)) { |
|
mutex_unlock(&ftrace_lock); |
|
return -ENODEV; |
|
} |
|
|
|
do_for_each_ftrace_rec(pg, rec) { |
|
|
|
if (rec->flags & FTRACE_FL_DISABLED) |
|
continue; |
|
|
|
if (ftrace_match_record(rec, &func_g, NULL, 0)) { |
|
entry = ftrace_lookup_ip(hash, rec->ip); |
|
|
|
if (!not) { |
|
fail = 0; |
|
|
|
if (entry) |
|
continue; |
|
if (add_hash_entry(hash, rec->ip) < 0) |
|
goto out; |
|
} else { |
|
if (entry) { |
|
free_hash_entry(hash, entry); |
|
fail = 0; |
|
} |
|
} |
|
} |
|
} while_for_each_ftrace_rec(); |
|
out: |
|
mutex_unlock(&ftrace_lock); |
|
|
|
if (fail) |
|
return -EINVAL; |
|
|
|
return 0; |
|
} |
|
|
|
static ssize_t |
|
ftrace_graph_write(struct file *file, const char __user *ubuf, |
|
size_t cnt, loff_t *ppos) |
|
{ |
|
ssize_t read, ret = 0; |
|
struct ftrace_graph_data *fgd = file->private_data; |
|
struct trace_parser *parser; |
|
|
|
if (!cnt) |
|
return 0; |
|
|
|
/* Read mode uses seq functions */ |
|
if (file->f_mode & FMODE_READ) { |
|
struct seq_file *m = file->private_data; |
|
fgd = m->private; |
|
} |
|
|
|
parser = &fgd->parser; |
|
|
|
read = trace_get_user(parser, ubuf, cnt, ppos); |
|
|
|
if (read >= 0 && trace_parser_loaded(parser) && |
|
!trace_parser_cont(parser)) { |
|
|
|
ret = ftrace_graph_set_hash(fgd->new_hash, |
|
parser->buffer); |
|
trace_parser_clear(parser); |
|
} |
|
|
|
if (!ret) |
|
ret = read; |
|
|
|
return ret; |
|
} |
|
|
|
static const struct file_operations ftrace_graph_fops = { |
|
.open = ftrace_graph_open, |
|
.read = seq_read, |
|
.write = ftrace_graph_write, |
|
.llseek = tracing_lseek, |
|
.release = ftrace_graph_release, |
|
}; |
|
|
|
static const struct file_operations ftrace_graph_notrace_fops = { |
|
.open = ftrace_graph_notrace_open, |
|
.read = seq_read, |
|
.write = ftrace_graph_write, |
|
.llseek = tracing_lseek, |
|
.release = ftrace_graph_release, |
|
}; |
|
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
|
|
|
void ftrace_create_filter_files(struct ftrace_ops *ops, |
|
struct dentry *parent) |
|
{ |
|
|
|
trace_create_file("set_ftrace_filter", TRACE_MODE_WRITE, parent, |
|
ops, &ftrace_filter_fops); |
|
|
|
trace_create_file("set_ftrace_notrace", TRACE_MODE_WRITE, parent, |
|
ops, &ftrace_notrace_fops); |
|
} |
|
|
|
/* |
|
* The name "destroy_filter_files" is really a misnomer. Although |
|
* in the future, it may actually delete the files, but this is |
|
* really intended to make sure the ops passed in are disabled |
|
* and that when this function returns, the caller is free to |
|
* free the ops. |
|
* |
|
* The "destroy" name is only to match the "create" name that this |
|
* should be paired with. |
|
*/ |
|
void ftrace_destroy_filter_files(struct ftrace_ops *ops) |
|
{ |
|
mutex_lock(&ftrace_lock); |
|
if (ops->flags & FTRACE_OPS_FL_ENABLED) |
|
ftrace_shutdown(ops, 0); |
|
ops->flags |= FTRACE_OPS_FL_DELETED; |
|
ftrace_free_filter(ops); |
|
mutex_unlock(&ftrace_lock); |
|
} |
|
|
|
static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer) |
|
{ |
|
|
|
trace_create_file("available_filter_functions", TRACE_MODE_READ, |
|
d_tracer, NULL, &ftrace_avail_fops); |
|
|
|
trace_create_file("enabled_functions", TRACE_MODE_READ, |
|
d_tracer, NULL, &ftrace_enabled_fops); |
|
|
|
ftrace_create_filter_files(&global_ops, d_tracer); |
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER |
|
trace_create_file("set_graph_function", TRACE_MODE_WRITE, d_tracer, |
|
NULL, |
|
&ftrace_graph_fops); |
|
trace_create_file("set_graph_notrace", TRACE_MODE_WRITE, d_tracer, |
|
NULL, |
|
&ftrace_graph_notrace_fops); |
|
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
|
|
|
return 0; |
|
} |
|
|
|
static int ftrace_cmp_ips(const void *a, const void *b) |
|
{ |
|
const unsigned long *ipa = a; |
|
const unsigned long *ipb = b; |
|
|
|
if (*ipa > *ipb) |
|
return 1; |
|
if (*ipa < *ipb) |
|
return -1; |
|
return 0; |
|
} |
|
|
|
#ifdef CONFIG_FTRACE_SORT_STARTUP_TEST |
|
static void test_is_sorted(unsigned long *start, unsigned long count) |
|
{ |
|
int i; |
|
|
|
for (i = 1; i < count; i++) { |
|
if (WARN(start[i - 1] > start[i], |
|
"[%d] %pS at %lx is not sorted with %pS at %lx\n", i, |
|
(void *)start[i - 1], start[i - 1], |
|
(void *)start[i], start[i])) |
|
break; |
|
} |
|
if (i == count) |
|
pr_info("ftrace section at %px sorted properly\n", start); |
|
} |
|
#else |
|
static void test_is_sorted(unsigned long *start, unsigned long count) |
|
{ |
|
} |
|
#endif |
|
|
|
static int ftrace_process_locs(struct module *mod, |
|
unsigned long *start, |
|
unsigned long *end) |
|
{ |
|
struct ftrace_page *start_pg; |
|
struct ftrace_page *pg; |
|
struct dyn_ftrace *rec; |
|
unsigned long count; |
|
unsigned long *p; |
|
unsigned long addr; |
|
unsigned long flags = 0; /* Shut up gcc */ |
|
int ret = -ENOMEM; |
|
|
|
count = end - start; |
|
|
|
if (!count) |
|
return 0; |
|
|
|
/* |
|
* Sorting mcount in vmlinux at build time depend on |
|
* CONFIG_BUILDTIME_MCOUNT_SORT, while mcount loc in |
|
* modules can not be sorted at build time. |
|
*/ |
|
if (!IS_ENABLED(CONFIG_BUILDTIME_MCOUNT_SORT) || mod) { |
|
sort(start, count, sizeof(*start), |
|
ftrace_cmp_ips, NULL); |
|
} else { |
|
test_is_sorted(start, count); |
|
} |
|
|
|
start_pg = ftrace_allocate_pages(count); |
|
if (!start_pg) |
|
return -ENOMEM; |
|
|
|
mutex_lock(&ftrace_lock); |
|
|
|
/* |
|
* Core and each module needs their own pages, as |
|
* modules will free them when they are removed. |
|
* Force a new page to be allocated for modules. |
|
*/ |
|
if (!mod) { |
|
WARN_ON(ftrace_pages || ftrace_pages_start); |
|
/* First initialization */ |
|
ftrace_pages = ftrace_pages_start = start_pg; |
|
} else { |
|
if (!ftrace_pages) |
|
goto out; |
|
|
|
if (WARN_ON(ftrace_pages->next)) { |
|
/* Hmm, we have free pages? */ |
|
while (ftrace_pages->next) |
|
ftrace_pages = ftrace_pages->next; |
|
} |
|
|
|
ftrace_pages->next = start_pg; |
|
} |
|
|
|
p = start; |
|
pg = start_pg; |
|
while (p < end) { |
|
unsigned long end_offset; |
|
addr = ftrace_call_adjust(*p++); |
|
/* |
|
* Some architecture linkers will pad between |
|
* the different mcount_loc sections of different |
|
* object files to satisfy alignments. |
|
* Skip any NULL pointers. |
|
*/ |
|
if (!addr) |
|
continue; |
|
|
|
end_offset = (pg->index+1) * sizeof(pg->records[0]); |
|
if (end_offset > PAGE_SIZE << pg->order) { |
|
/* We should have allocated enough */ |
|
if (WARN_ON(!pg->next)) |
|
break; |
|
pg = pg->next; |
|
} |
|
|
|
rec = &pg->records[pg->index++]; |
|
rec->ip = addr; |
|
} |
|
|
|
/* We should have used all pages */ |
|
WARN_ON(pg->next); |
|
|
|
/* Assign the last page to ftrace_pages */ |
|
ftrace_pages = pg; |
|
|
|
/* |
|
* We only need to disable interrupts on start up |
|
* because we are modifying code that an interrupt |
|
* may execute, and the modification is not atomic. |
|
* But for modules, nothing runs the code we modify |
|
* until we are finished with it, and there's no |
|
* reason to cause large interrupt latencies while we do it. |
|
*/ |
|
if (!mod) |
|
local_irq_save(flags); |
|
ftrace_update_code(mod, start_pg); |
|
if (!mod) |
|
local_irq_restore(flags); |
|
ret = 0; |
|
out: |
|
mutex_unlock(&ftrace_lock); |
|
|
|
return ret; |
|
} |
|
|
|
struct ftrace_mod_func { |
|
struct list_head list; |
|
char *name; |
|
unsigned long ip; |
|
unsigned int size; |
|
}; |
|
|
|
struct ftrace_mod_map { |
|
struct rcu_head rcu; |
|
struct list_head list; |
|
struct module *mod; |
|
unsigned long start_addr; |
|
unsigned long end_addr; |
|
struct list_head funcs; |
|
unsigned int num_funcs; |
|
}; |
|
|
|
static int ftrace_get_trampoline_kallsym(unsigned int symnum, |
|
unsigned long *value, char *type, |
|
char *name, char *module_name, |
|
int *exported) |
|
{ |
|
struct ftrace_ops *op; |
|
|
|
list_for_each_entry_rcu(op, &ftrace_ops_trampoline_list, list) { |
|
if (!op->trampoline || symnum--) |
|
continue; |
|
*value = op->trampoline; |
|
*type = 't'; |
|
strlcpy(name, FTRACE_TRAMPOLINE_SYM, KSYM_NAME_LEN); |
|
strlcpy(module_name, FTRACE_TRAMPOLINE_MOD, MODULE_NAME_LEN); |
|
*exported = 0; |
|
return 0; |
|
} |
|
|
|
return -ERANGE; |
|
} |
|
|
|
#ifdef CONFIG_MODULES |
|
|
|
#define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next) |
|
|
|
static LIST_HEAD(ftrace_mod_maps); |
|
|
|
static int referenced_filters(struct dyn_ftrace *rec) |
|
{ |
|
struct ftrace_ops *ops; |
|
int cnt = 0; |
|
|
|
for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) { |
|
if (ops_references_rec(ops, rec)) { |
|
if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_DIRECT)) |
|
continue; |
|
if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_IPMODIFY)) |
|
continue; |
|
cnt++; |
|
if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) |
|
rec->flags |= FTRACE_FL_REGS; |
|
if (cnt == 1 && ops->trampoline) |
|
rec->flags |= FTRACE_FL_TRAMP; |
|
else |
|
rec->flags &= ~FTRACE_FL_TRAMP; |
|
} |
|
} |
|
|
|
return cnt; |
|
} |
|
|
|
static void |
|
clear_mod_from_hash(struct ftrace_page *pg, struct ftrace_hash *hash) |
|
{ |
|
struct ftrace_func_entry *entry; |
|
struct dyn_ftrace *rec; |
|
int i; |
|
|
|
if (ftrace_hash_empty(hash)) |
|
return; |
|
|
|
for (i = 0; i < pg->index; i++) { |
|
rec = &pg->records[i]; |
|
entry = __ftrace_lookup_ip(hash, rec->ip); |
|
/* |
|
* Do not allow this rec to match again. |
|
* Yeah, it may waste some memory, but will be removed |
|
* if/when the hash is modified again. |
|
*/ |
|
if (entry) |
|
entry->ip = 0; |
|
} |
|
} |
|
|
|
/* Clear any records from hashes */ |
|
static void clear_mod_from_hashes(struct ftrace_page *pg) |
|
{ |
|
struct trace_array *tr; |
|
|
|
mutex_lock(&trace_types_lock); |
|
list_for_each_entry(tr, &ftrace_trace_arrays, list) { |
|
if (!tr->ops || !tr->ops->func_hash) |
|
continue; |
|
mutex_lock(&tr->ops->func_hash->regex_lock); |
|
clear_mod_from_hash(pg, tr->ops->func_hash->filter_hash); |
|
clear_mod_from_hash(pg, tr->ops->func_hash->notrace_hash); |
|
mutex_unlock(&tr->ops->func_hash->regex_lock); |
|
} |
|
mutex_unlock(&trace_types_lock); |
|
} |
|
|
|
static void ftrace_free_mod_map(struct rcu_head *rcu) |
|
{ |
|
struct ftrace_mod_map *mod_map = container_of(rcu, struct ftrace_mod_map, rcu); |
|
struct ftrace_mod_func *mod_func; |
|
struct ftrace_mod_func *n; |
|
|
|
/* All the contents of mod_map are now not visible to readers */ |
|
list_for_each_entry_safe(mod_func, n, &mod_map->funcs, list) { |
|
kfree(mod_func->name); |
|
list_del(&mod_func->list); |
|
kfree(mod_func); |
|
} |
|
|
|
kfree(mod_map); |
|
} |
|
|
|
void ftrace_release_mod(struct module *mod) |
|
{ |
|
struct ftrace_mod_map *mod_map; |
|
struct ftrace_mod_map *n; |
|
struct dyn_ftrace *rec; |
|
struct ftrace_page **last_pg; |
|
struct ftrace_page *tmp_page = NULL; |
|
struct ftrace_page *pg; |
|
|
|
mutex_lock(&ftrace_lock); |
|
|
|
if (ftrace_disabled) |
|
goto out_unlock; |
|
|
|
list_for_each_entry_safe(mod_map, n, &ftrace_mod_maps, list) { |
|
if (mod_map->mod == mod) { |
|
list_del_rcu(&mod_map->list); |
|
call_rcu(&mod_map->rcu, ftrace_free_mod_map); |
|
break; |
|
} |
|
} |
|
|
|
/* |
|
* Each module has its own ftrace_pages, remove |
|
* them from the list. |
|
*/ |
|
last_pg = &ftrace_pages_start; |
|
for (pg = ftrace_pages_start; pg; pg = *last_pg) { |
|
rec = &pg->records[0]; |
|
if (within_module_core(rec->ip, mod) || |
|
within_module_init(rec->ip, mod)) { |
|
/* |
|
* As core pages are first, the first |
|
* page should never be a module page. |
|
*/ |
|
if (WARN_ON(pg == ftrace_pages_start)) |
|
goto out_unlock; |
|
|
|
/* Check if we are deleting the last page */ |
|
if (pg == ftrace_pages) |
|
ftrace_pages = next_to_ftrace_page(last_pg); |
|
|
|
ftrace_update_tot_cnt -= pg->index; |
|
*last_pg = pg->next; |
|
|
|
pg->next = tmp_page; |
|
tmp_page = pg; |
|
} else |
|
last_pg = &pg->next; |
|
} |
|
out_unlock: |
|
mutex_unlock(&ftrace_lock); |
|
|
|
for (pg = tmp_page; pg; pg = tmp_page) { |
|
|
|
/* Needs to be called outside of ftrace_lock */ |
|
clear_mod_from_hashes(pg); |
|
|
|
if (pg->records) { |
|
free_pages((unsigned long)pg->records, pg->order); |
|
ftrace_number_of_pages -= 1 << pg->order; |
|
} |
|
tmp_page = pg->next; |
|
kfree(pg); |
|
ftrace_number_of_groups--; |
|
} |
|
} |
|
|
|
void ftrace_module_enable(struct module *mod) |
|
{ |
|
struct dyn_ftrace *rec; |
|
struct ftrace_page *pg; |
|
|
|
mutex_lock(&ftrace_lock); |
|
|
|
if (ftrace_disabled) |
|
goto out_unlock; |
|
|
|
/* |
|
* If the tracing is enabled, go ahead and enable the record. |
|
* |
|
* The reason not to enable the record immediately is the |
|
* inherent check of ftrace_make_nop/ftrace_make_call for |
|
* correct previous instructions. Making first the NOP |
|
* conversion puts the module to the correct state, thus |
|
* passing the ftrace_make_call check. |
|
* |
|
* We also delay this to after the module code already set the |
|
* text to read-only, as we now need to set it back to read-write |
|
* so that we can modify the text. |
|
*/ |
|
if (ftrace_start_up) |
|
ftrace_arch_code_modify_prepare(); |
|
|
|
do_for_each_ftrace_rec(pg, rec) { |
|
int cnt; |
|
/* |
|
* do_for_each_ftrace_rec() is a double loop. |
|
* module text shares the pg. If a record is |
|
* not part of this module, then skip this pg, |
|
* which the "break" will do. |
|
*/ |
|
if (!within_module_core(rec->ip, mod) && |
|
!within_module_init(rec->ip, mod)) |
|
break; |
|
|
|
cnt = 0; |
|
|
|
/* |
|
* When adding a module, we need to check if tracers are |
|
* currently enabled and if they are, and can trace this record, |
|
* we need to enable the module functions as well as update the |
|
* reference counts for those function records. |
|
*/ |
|
if (ftrace_start_up) |
|
cnt += referenced_filters(rec); |
|
|
|
rec->flags &= ~FTRACE_FL_DISABLED; |
|
rec->flags += cnt; |
|
|
|
if (ftrace_start_up && cnt) { |
|
int failed = __ftrace_replace_code(rec, 1); |
|
if (failed) { |
|
ftrace_bug(failed, rec); |
|
goto out_loop; |
|
} |
|
} |
|
|
|
} while_for_each_ftrace_rec(); |
|
|
|
out_loop: |
|
if (ftrace_start_up) |
|
ftrace_arch_code_modify_post_process(); |
|
|
|
out_unlock: |
|
mutex_unlock(&ftrace_lock); |
|
|
|
process_cached_mods(mod->name); |
|
} |
|
|
|
void ftrace_module_init(struct module *mod) |
|
{ |
|
if (ftrace_disabled || !mod->num_ftrace_callsites) |
|
return; |
|
|
|
ftrace_process_locs(mod, mod->ftrace_callsites, |
|
mod->ftrace_callsites + mod->num_ftrace_callsites); |
|
} |
|
|
|
static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map, |
|
struct dyn_ftrace *rec) |
|
{ |
|
struct ftrace_mod_func *mod_func; |
|
unsigned long symsize; |
|
unsigned long offset; |
|
char str[KSYM_SYMBOL_LEN]; |
|
char *modname; |
|
const char *ret; |
|
|
|
ret = kallsyms_lookup(rec->ip, &symsize, &offset, &modname, str); |
|
if (!ret) |
|
return; |
|
|
|
mod_func = kmalloc(sizeof(*mod_func), GFP_KERNEL); |
|
if (!mod_func) |
|
return; |
|
|
|
mod_func->name = kstrdup(str, GFP_KERNEL); |
|
if (!mod_func->name) { |
|
kfree(mod_func); |
|
return; |
|
} |
|
|
|
mod_func->ip = rec->ip - offset; |
|
mod_func->size = symsize; |
|
|
|
mod_map->num_funcs++; |
|
|
|
list_add_rcu(&mod_func->list, &mod_map->funcs); |
|
} |
|
|
|
static struct ftrace_mod_map * |
|
allocate_ftrace_mod_map(struct module *mod, |
|
unsigned long start, unsigned long end) |
|
{ |
|
struct ftrace_mod_map *mod_map; |
|
|
|
mod_map = kmalloc(sizeof(*mod_map), GFP_KERNEL); |
|
if (!mod_map) |
|
return NULL; |
|
|
|
mod_map->mod = mod; |
|
mod_map->start_addr = start; |
|
mod_map->end_addr = end; |
|
mod_map->num_funcs = 0; |
|
|
|
INIT_LIST_HEAD_RCU(&mod_map->funcs); |
|
|
|
list_add_rcu(&mod_map->list, &ftrace_mod_maps); |
|
|
|
return mod_map; |
|
} |
|
|
|
static const char * |
|
ftrace_func_address_lookup(struct ftrace_mod_map *mod_map, |
|
unsigned long addr, unsigned long *size, |
|
unsigned long *off, char *sym) |
|
{ |
|
struct ftrace_mod_func *found_func = NULL; |
|
struct ftrace_mod_func *mod_func; |
|
|
|
list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) { |
|
if (addr >= mod_func->ip && |
|
addr < mod_func->ip + mod_func->size) { |
|
found_func = mod_func; |
|
break; |
|
} |
|
} |
|
|
|
if (found_func) { |
|
if (size) |
|
*size = found_func->size; |
|
if (off) |
|
*off = addr - found_func->ip; |
|
if (sym) |
|
strlcpy(sym, found_func->name, KSYM_NAME_LEN); |
|
|
|
return found_func->name; |
|
} |
|
|
|
return NULL; |
|
} |
|
|
|
const char * |
|
ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, |
|
unsigned long *off, char **modname, char *sym) |
|
{ |
|
struct ftrace_mod_map *mod_map; |
|
const char *ret = NULL; |
|
|
|
/* mod_map is freed via call_rcu() */ |
|
preempt_disable(); |
|
list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) { |
|
ret = ftrace_func_address_lookup(mod_map, addr, size, off, sym); |
|
if (ret) { |
|
if (modname) |
|
*modname = mod_map->mod->name; |
|
break; |
|
} |
|
} |
|
preempt_enable(); |
|
|
|
return ret; |
|
} |
|
|
|
int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, |
|
char *type, char *name, |
|
char *module_name, int *exported) |
|
{ |
|
struct ftrace_mod_map *mod_map; |
|
struct ftrace_mod_func *mod_func; |
|
int ret; |
|
|
|
preempt_disable(); |
|
list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) { |
|
|
|
if (symnum >= mod_map->num_funcs) { |
|
symnum -= mod_map->num_funcs; |
|
continue; |
|
} |
|
|
|
list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) { |
|
if (symnum > 1) { |
|
symnum--; |
|
continue; |
|
} |
|
|
|
*value = mod_func->ip; |
|
*type = 'T'; |
|
strlcpy(name, mod_func->name, KSYM_NAME_LEN); |
|
strlcpy(module_name, mod_map->mod->name, MODULE_NAME_LEN); |
|
*exported = 1; |
|
preempt_enable(); |
|
return 0; |
|
} |
|
WARN_ON(1); |
|
break; |
|
} |
|
ret = ftrace_get_trampoline_kallsym(symnum, value, type, name, |
|
module_name, exported); |
|
preempt_enable(); |
|
return ret; |
|
} |
|
|
|
#else |
|
static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map, |
|
struct dyn_ftrace *rec) { } |
|
static inline struct ftrace_mod_map * |
|
allocate_ftrace_mod_map(struct module *mod, |
|
unsigned long start, unsigned long end) |
|
{ |
|
return NULL; |
|
} |
|
int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, |
|
char *type, char *name, char *module_name, |
|
int *exported) |
|
{ |
|
int ret; |
|
|
|
preempt_disable(); |
|
ret = ftrace_get_trampoline_kallsym(symnum, value, type, name, |
|
module_name, exported); |
|
preempt_enable(); |
|
return ret; |
|
} |
|
#endif /* CONFIG_MODULES */ |
|
|
|
struct ftrace_init_func { |
|
struct list_head list; |
|
unsigned long ip; |
|
}; |
|
|
|
/* Clear any init ips from hashes */ |
|
static void |
|
clear_func_from_hash(struct ftrace_init_func *func, struct ftrace_hash *hash) |
|
{ |
|
struct ftrace_func_entry *entry; |
|
|
|
entry = ftrace_lookup_ip(hash, func->ip); |
|
/* |
|
* Do not allow this rec to match again. |
|
* Yeah, it may waste some memory, but will be removed |
|
* if/when the hash is modified again. |
|
*/ |
|
if (entry) |
|
entry->ip = 0; |
|
} |
|
|
|
static void |
|
clear_func_from_hashes(struct ftrace_init_func *func) |
|
{ |
|
struct trace_array *tr; |
|
|
|
mutex_lock(&trace_types_lock); |
|
list_for_each_entry(tr, &ftrace_trace_arrays, list) { |
|
if (!tr->ops || !tr->ops->func_hash) |
|
continue; |
|
mutex_lock(&tr->ops->func_hash->regex_lock); |
|
clear_func_from_hash(func, tr->ops->func_hash->filter_hash); |
|
clear_func_from_hash(func, tr->ops->func_hash->notrace_hash); |
|
mutex_unlock(&tr->ops->func_hash->regex_lock); |
|
} |
|
mutex_unlock(&trace_types_lock); |
|
} |
|
|
|
static void add_to_clear_hash_list(struct list_head *clear_list, |
|
struct dyn_ftrace *rec) |
|
{ |
|
struct ftrace_init_func *func; |
|
|
|
func = kmalloc(sizeof(*func), GFP_KERNEL); |
|
if (!func) { |
|
MEM_FAIL(1, "alloc failure, ftrace filter could be stale\n"); |
|
return; |
|
} |
|
|
|
func->ip = rec->ip; |
|
list_add(&func->list, clear_list); |
|
} |
|
|
|
void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr) |
|
{ |
|
unsigned long start = (unsigned long)(start_ptr); |
|
unsigned long end = (unsigned long)(end_ptr); |
|
struct ftrace_page **last_pg = &ftrace_pages_start; |
|
struct ftrace_page *pg; |
|
struct dyn_ftrace *rec; |
|
struct dyn_ftrace key; |
|
struct ftrace_mod_map *mod_map = NULL; |
|
struct ftrace_init_func *func, *func_next; |
|
struct list_head clear_hash; |
|
|
|
INIT_LIST_HEAD(&clear_hash); |
|
|
|
key.ip = start; |
|
key.flags = end; /* overload flags, as it is unsigned long */ |
|
|
|
mutex_lock(&ftrace_lock); |
|
|
|
/* |
|
* If we are freeing module init memory, then check if |
|
* any tracer is active. If so, we need to save a mapping of |
|
* the module functions being freed with the address. |
|
*/ |
|
if (mod && ftrace_ops_list != &ftrace_list_end) |
|
mod_map = allocate_ftrace_mod_map(mod, start, end); |
|
|
|
for (pg = ftrace_pages_start; pg; last_pg = &pg->next, pg = *last_pg) { |
|
if (end < pg->records[0].ip || |
|
start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) |
|
continue; |
|
again: |
|
rec = bsearch(&key, pg->records, pg->index, |
|
sizeof(struct dyn_ftrace), |
|
ftrace_cmp_recs); |
|
if (!rec) |
|
continue; |
|
|
|
/* rec will be cleared from hashes after ftrace_lock unlock */ |
|
add_to_clear_hash_list(&clear_hash, rec); |
|
|
|
if (mod_map) |
|
save_ftrace_mod_rec(mod_map, rec); |
|
|
|
pg->index--; |
|
ftrace_update_tot_cnt--; |
|
if (!pg->index) { |
|
*last_pg = pg->next; |
|
if (pg->records) { |
|
free_pages((unsigned long)pg->records, pg->order); |
|
ftrace_number_of_pages -= 1 << pg->order; |
|
} |
|
ftrace_number_of_groups--; |
|
kfree(pg); |
|
pg = container_of(last_pg, struct ftrace_page, next); |
|
if (!(*last_pg)) |
|
ftrace_pages = pg; |
|
continue; |
|
} |
|
memmove(rec, rec + 1, |
|
(pg->index - (rec - pg->records)) * sizeof(*rec)); |
|
/* More than one function may be in this block */ |
|
goto again; |
|
} |
|
mutex_unlock(&ftrace_lock); |
|
|
|
list_for_each_entry_safe(func, func_next, &clear_hash, list) { |
|
clear_func_from_hashes(func); |
|
kfree(func); |
|
} |
|
} |
|
|
|
void __init ftrace_free_init_mem(void) |
|
{ |
|
void *start = (void *)(&__init_begin); |
|
void *end = (void *)(&__init_end); |
|
|
|
ftrace_free_mem(NULL, start, end); |
|
} |
|
|
|
int __init __weak ftrace_dyn_arch_init(void) |
|
{ |
|
return 0; |
|
} |
|
|
|
void __init ftrace_init(void) |
|
{ |
|
extern unsigned long __start_mcount_loc[]; |
|
extern unsigned long __stop_mcount_loc[]; |
|
unsigned long count, flags; |
|
int ret; |
|
|
|
local_irq_save(flags); |
|
ret = ftrace_dyn_arch_init(); |
|
local_irq_restore(flags); |
|
if (ret) |
|
goto failed; |
|
|
|
count = __stop_mcount_loc - __start_mcount_loc; |
|
if (!count) { |
|
pr_info("ftrace: No functions to be traced?\n"); |
|
goto failed; |
|
} |
|
|
|
pr_info("ftrace: allocating %ld entries in %ld pages\n", |
|
count, count / ENTRIES_PER_PAGE + 1); |
|
|
|
last_ftrace_enabled = ftrace_enabled = 1; |
|
|
|
ret = ftrace_process_locs(NULL, |
|
__start_mcount_loc, |
|
__stop_mcount_loc); |
|
|
|
pr_info("ftrace: allocated %ld pages with %ld groups\n", |
|
ftrace_number_of_pages, ftrace_number_of_groups); |
|
|
|
set_ftrace_early_filters(); |
|
|
|
return; |
|
failed: |
|
ftrace_disabled = 1; |
|
} |
|
|
|
/* Do nothing if arch does not support this */ |
|
void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops) |
|
{ |
|
} |
|
|
|
static void ftrace_update_trampoline(struct ftrace_ops *ops) |
|
{ |
|
unsigned long trampoline = ops->trampoline; |
|
|
|
arch_ftrace_update_trampoline(ops); |
|
if (ops->trampoline && ops->trampoline != trampoline && |
|
(ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP)) { |
|
/* Add to kallsyms before the perf events */ |
|
ftrace_add_trampoline_to_kallsyms(ops); |
|
perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL, |
|
ops->trampoline, ops->trampoline_size, false, |
|
FTRACE_TRAMPOLINE_SYM); |
|
/* |
|
* Record the perf text poke event after the ksymbol register |
|
* event. |
|
*/ |
|
perf_event_text_poke((void *)ops->trampoline, NULL, 0, |
|
(void *)ops->trampoline, |
|
ops->trampoline_size); |
|
} |
|
} |
|
|
|
void ftrace_init_trace_array(struct trace_array *tr) |
|
{ |
|
INIT_LIST_HEAD(&tr->func_probes); |
|
INIT_LIST_HEAD(&tr->mod_trace); |
|
INIT_LIST_HEAD(&tr->mod_notrace); |
|
} |
|
#else |
|
|
|
struct ftrace_ops global_ops = { |
|
.func = ftrace_stub, |
|
.flags = FTRACE_OPS_FL_INITIALIZED | |
|
FTRACE_OPS_FL_PID, |
|
}; |
|
|
|
static int __init ftrace_nodyn_init(void) |
|
{ |
|
ftrace_enabled = 1; |
|
return 0; |
|
} |
|
core_initcall(ftrace_nodyn_init); |
|
|
|
static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; } |
|
static inline void ftrace_startup_all(int command) { } |
|
|
|
# define ftrace_startup_sysctl() do { } while (0) |
|
# define ftrace_shutdown_sysctl() do { } while (0) |
|
|
|
static void ftrace_update_trampoline(struct ftrace_ops *ops) |
|
{ |
|
} |
|
|
|
#endif /* CONFIG_DYNAMIC_FTRACE */ |
|
|
|
__init void ftrace_init_global_array_ops(struct trace_array *tr) |
|
{ |
|
tr->ops = &global_ops; |
|
tr->ops->private = tr; |
|
ftrace_init_trace_array(tr); |
|
} |
|
|
|
void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func) |
|
{ |
|
/* If we filter on pids, update to use the pid function */ |
|
if (tr->flags & TRACE_ARRAY_FL_GLOBAL) { |
|
if (WARN_ON(tr->ops->func != ftrace_stub)) |
|
printk("ftrace ops had %pS for function\n", |
|
tr->ops->func); |
|
} |
|
tr->ops->func = func; |
|
tr->ops->private = tr; |
|
} |
|
|
|
void ftrace_reset_array_ops(struct trace_array *tr) |
|
{ |
|
tr->ops->func = ftrace_stub; |
|
} |
|
|
|
static nokprobe_inline void |
|
__ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, |
|
struct ftrace_ops *ignored, struct ftrace_regs *fregs) |
|
{ |
|
struct pt_regs *regs = ftrace_get_regs(fregs); |
|
struct ftrace_ops *op; |
|
int bit; |
|
|
|
/* |
|
* The ftrace_test_and_set_recursion() will disable preemption, |
|
* which is required since some of the ops may be dynamically |
|
* allocated, they must be freed after a synchronize_rcu(). |
|
*/ |
|
bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START); |
|
if (bit < 0) |
|
return; |
|
|
|
do_for_each_ftrace_op(op, ftrace_ops_list) { |
|
/* Stub functions don't need to be called nor tested */ |
|
if (op->flags & FTRACE_OPS_FL_STUB) |
|
continue; |
|
/* |
|
* Check the following for each ops before calling their func: |
|
* if RCU flag is set, then rcu_is_watching() must be true |
|
* if PER_CPU is set, then ftrace_function_local_disable() |
|
* must be false |
|
* Otherwise test if the ip matches the ops filter |
|
* |
|
* If any of the above fails then the op->func() is not executed. |
|
*/ |
|
if ((!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) && |
|
ftrace_ops_test(op, ip, regs)) { |
|
if (FTRACE_WARN_ON(!op->func)) { |
|
pr_warn("op=%p %pS\n", op, op); |
|
goto out; |
|
} |
|
op->func(ip, parent_ip, op, fregs); |
|
} |
|
} while_for_each_ftrace_op(op); |
|
out: |
|
trace_clear_recursion(bit); |
|
} |
|
|
|
/* |
|
* Some archs only support passing ip and parent_ip. Even though |
|
* the list function ignores the op parameter, we do not want any |
|
* C side effects, where a function is called without the caller |
|
* sending a third parameter. |
|
* Archs are to support both the regs and ftrace_ops at the same time. |
|
* If they support ftrace_ops, it is assumed they support regs. |
|
* If call backs want to use regs, they must either check for regs |
|
* being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS. |
|
* Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved. |
|
* An architecture can pass partial regs with ftrace_ops and still |
|
* set the ARCH_SUPPORTS_FTRACE_OPS. |
|
* |
|
* In vmlinux.lds.h, ftrace_ops_list_func() is defined to be |
|
* arch_ftrace_ops_list_func. |
|
*/ |
|
#if ARCH_SUPPORTS_FTRACE_OPS |
|
void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, |
|
struct ftrace_ops *op, struct ftrace_regs *fregs) |
|
{ |
|
__ftrace_ops_list_func(ip, parent_ip, NULL, fregs); |
|
} |
|
#else |
|
void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip) |
|
{ |
|
__ftrace_ops_list_func(ip, parent_ip, NULL, NULL); |
|
} |
|
#endif |
|
NOKPROBE_SYMBOL(arch_ftrace_ops_list_func); |
|
|
|
/* |
|
* If there's only one function registered but it does not support |
|
* recursion, needs RCU protection and/or requires per cpu handling, then |
|
* this function will be called by the mcount trampoline. |
|
*/ |
|
static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip, |
|
struct ftrace_ops *op, struct ftrace_regs *fregs) |
|
{ |
|
int bit; |
|
|
|
bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START); |
|
if (bit < 0) |
|
return; |
|
|
|
if (!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) |
|
op->func(ip, parent_ip, op, fregs); |
|
|
|
trace_clear_recursion(bit); |
|
} |
|
NOKPROBE_SYMBOL(ftrace_ops_assist_func); |
|
|
|
/** |
|
* ftrace_ops_get_func - get the function a trampoline should call |
|
* @ops: the ops to get the function for |
|
* |
|
* Normally the mcount trampoline will call the ops->func, but there |
|
* are times that it should not. For example, if the ops does not |
|
* have its own recursion protection, then it should call the |
|
* ftrace_ops_assist_func() instead. |
|
* |
|
* Returns the function that the trampoline should call for @ops. |
|
*/ |
|
ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops) |
|
{ |
|
/* |
|
* If the function does not handle recursion or needs to be RCU safe, |
|
* then we need to call the assist handler. |
|
*/ |
|
if (ops->flags & (FTRACE_OPS_FL_RECURSION | |
|
FTRACE_OPS_FL_RCU)) |
|
return ftrace_ops_assist_func; |
|
|
|
return ops->func; |
|
} |
|
|
|
static void |
|
ftrace_filter_pid_sched_switch_probe(void *data, bool preempt, |
|
struct task_struct *prev, struct task_struct *next) |
|
{ |
|
struct trace_array *tr = data; |
|
struct trace_pid_list *pid_list; |
|
struct trace_pid_list *no_pid_list; |
|
|
|
pid_list = rcu_dereference_sched(tr->function_pids); |
|
no_pid_list = rcu_dereference_sched(tr->function_no_pids); |
|
|
|
if (trace_ignore_this_task(pid_list, no_pid_list, next)) |
|
this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid, |
|
FTRACE_PID_IGNORE); |
|
else |
|
this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid, |
|
next->pid); |
|
} |
|
|
|
static void |
|
ftrace_pid_follow_sched_process_fork(void *data, |
|
struct task_struct *self, |
|
struct task_struct *task) |
|
{ |
|
struct trace_pid_list *pid_list; |
|
struct trace_array *tr = data; |
|
|
|
pid_list = rcu_dereference_sched(tr->function_pids); |
|
trace_filter_add_remove_task(pid_list, self, task); |
|
|
|
pid_list = rcu_dereference_sched(tr->function_no_pids); |
|
trace_filter_add_remove_task(pid_list, self, task); |
|
} |
|
|
|
static void |
|
ftrace_pid_follow_sched_process_exit(void *data, struct task_struct *task) |
|
{ |
|
struct trace_pid_list *pid_list; |
|
struct trace_array *tr = data; |
|
|
|
pid_list = rcu_dereference_sched(tr->function_pids); |
|
trace_filter_add_remove_task(pid_list, NULL, task); |
|
|
|
pid_list = rcu_dereference_sched(tr->function_no_pids); |
|
trace_filter_add_remove_task(pid_list, NULL, task); |
|
} |
|
|
|
void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) |
|
{ |
|
if (enable) { |
|
register_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork, |
|
tr); |
|
register_trace_sched_process_free(ftrace_pid_follow_sched_process_exit, |
|
tr); |
|
} else { |
|
unregister_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork, |
|
tr); |
|
unregister_trace_sched_process_free(ftrace_pid_follow_sched_process_exit, |
|
tr); |
|
} |
|
} |
|
|
|
static void clear_ftrace_pids(struct trace_array *tr, int type) |
|
{ |
|
struct trace_pid_list *pid_list; |
|
struct trace_pid_list *no_pid_list; |
|
int cpu; |
|
|
|
pid_list = rcu_dereference_protected(tr->function_pids, |
|
lockdep_is_held(&ftrace_lock)); |
|
no_pid_list = rcu_dereference_protected(tr->function_no_pids, |
|
lockdep_is_held(&ftrace_lock)); |
|
|
|
/* Make sure there's something to do */ |
|
if (!pid_type_enabled(type, pid_list, no_pid_list)) |
|
return; |
|
|
|
/* See if the pids still need to be checked after this */ |
|
if (!still_need_pid_events(type, pid_list, no_pid_list)) { |
|
unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr); |
|
for_each_possible_cpu(cpu) |
|
per_cpu_ptr(tr->array_buffer.data, cpu)->ftrace_ignore_pid = FTRACE_PID_TRACE; |
|
} |
|
|
|
if (type & TRACE_PIDS) |
|
rcu_assign_pointer(tr->function_pids, NULL); |
|
|
|
if (type & TRACE_NO_PIDS) |
|
rcu_assign_pointer(tr->function_no_pids, NULL); |
|
|
|
/* Wait till all users are no longer using pid filtering */ |
|
synchronize_rcu(); |
|
|
|
if ((type & TRACE_PIDS) && pid_list) |
|
trace_pid_list_free(pid_list); |
|
|
|
if ((type & TRACE_NO_PIDS) && no_pid_list) |
|
trace_pid_list_free(no_pid_list); |
|
} |
|
|
|
void ftrace_clear_pids(struct trace_array *tr) |
|
{ |
|
mutex_lock(&ftrace_lock); |
|
|
|
clear_ftrace_pids(tr, TRACE_PIDS | TRACE_NO_PIDS); |
|
|
|
mutex_unlock(&ftrace_lock); |
|
} |
|
|
|
static void ftrace_pid_reset(struct trace_array *tr, int type) |
|
{ |
|
mutex_lock(&ftrace_lock); |
|
clear_ftrace_pids(tr, type); |
|
|
|
ftrace_update_pid_func(); |
|
ftrace_startup_all(0); |
|
|
|
mutex_unlock(&ftrace_lock); |
|
} |
|
|
|
/* Greater than any max PID */ |
|
#define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1) |
|
|
|
static void *fpid_start(struct seq_file *m, loff_t *pos) |
|
__acquires(RCU) |
|
{ |
|
struct trace_pid_list *pid_list; |
|
struct trace_array *tr = m->private; |
|
|
|
mutex_lock(&ftrace_lock); |
|
rcu_read_lock_sched(); |
|
|
|
pid_list = rcu_dereference_sched(tr->function_pids); |
|
|
|
if (!pid_list) |
|
return !(*pos) ? FTRACE_NO_PIDS : NULL; |
|
|
|
return trace_pid_start(pid_list, pos); |
|
} |
|
|
|
static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) |
|
{ |
|
struct trace_array *tr = m->private; |
|
struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids); |
|
|
|
if (v == FTRACE_NO_PIDS) { |
|
(*pos)++; |
|
return NULL; |
|
} |
|
return trace_pid_next(pid_list, v, pos); |
|
} |
|
|
|
static void fpid_stop(struct seq_file *m, void *p) |
|
__releases(RCU) |
|
{ |
|
rcu_read_unlock_sched(); |
|
mutex_unlock(&ftrace_lock); |
|
} |
|
|
|
static int fpid_show(struct seq_file *m, void *v) |
|
{ |
|
if (v == FTRACE_NO_PIDS) { |
|
seq_puts(m, "no pid\n"); |
|
return 0; |
|
} |
|
|
|
return trace_pid_show(m, v); |
|
} |
|
|
|
static const struct seq_operations ftrace_pid_sops = { |
|
.start = fpid_start, |
|
.next = fpid_next, |
|
.stop = fpid_stop, |
|
.show = fpid_show, |
|
}; |
|
|
|
static void *fnpid_start(struct seq_file *m, loff_t *pos) |
|
__acquires(RCU) |
|
{ |
|
struct trace_pid_list *pid_list; |
|
struct trace_array *tr = m->private; |
|
|
|
mutex_lock(&ftrace_lock); |
|
rcu_read_lock_sched(); |
|
|
|
pid_list = rcu_dereference_sched(tr->function_no_pids); |
|
|
|
if (!pid_list) |
|
return !(*pos) ? FTRACE_NO_PIDS : NULL; |
|
|
|
return trace_pid_start(pid_list, pos); |
|
} |
|
|
|
static void *fnpid_next(struct seq_file *m, void *v, loff_t *pos) |
|
{ |
|
struct trace_array *tr = m->private; |
|
struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_no_pids); |
|
|
|
if (v == FTRACE_NO_PIDS) { |
|
(*pos)++; |
|
return NULL; |
|
} |
|
return trace_pid_next(pid_list, v, pos); |
|
} |
|
|
|
static const struct seq_operations ftrace_no_pid_sops = { |
|
.start = fnpid_start, |
|
.next = fnpid_next, |
|
.stop = fpid_stop, |
|
.show = fpid_show, |
|
}; |
|
|
|
static int pid_open(struct inode *inode, struct file *file, int type) |
|
{ |
|
const struct seq_operations *seq_ops; |
|
struct trace_array *tr = inode->i_private; |
|
struct seq_file *m; |
|
int ret = 0; |
|
|
|
ret = tracing_check_open_get_tr(tr); |
|
if (ret) |
|
return ret; |
|
|
|
if ((file->f_mode & FMODE_WRITE) && |
|
(file->f_flags & O_TRUNC)) |
|
ftrace_pid_reset(tr, type); |
|
|
|
switch (type) { |
|
case TRACE_PIDS: |
|
seq_ops = &ftrace_pid_sops; |
|
break; |
|
case TRACE_NO_PIDS: |
|
seq_ops = &ftrace_no_pid_sops; |
|
break; |
|
default: |
|
trace_array_put(tr); |
|
WARN_ON_ONCE(1); |
|
return -EINVAL; |
|
} |
|
|
|
ret = seq_open(file, seq_ops); |
|
if (ret < 0) { |
|
trace_array_put(tr); |
|
} else { |
|
m = file->private_data; |
|
/* copy tr over to seq ops */ |
|
m->private = tr; |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
static int |
|
ftrace_pid_open(struct inode *inode, struct file *file) |
|
{ |
|
return pid_open(inode, file, TRACE_PIDS); |
|
} |
|
|
|
static int |
|
ftrace_no_pid_open(struct inode *inode, struct file *file) |
|
{ |
|
return pid_open(inode, file, TRACE_NO_PIDS); |
|
} |
|
|
|
static void ignore_task_cpu(void *data) |
|
{ |
|
struct trace_array *tr = data; |
|
struct trace_pid_list *pid_list; |
|
struct trace_pid_list *no_pid_list; |
|
|
|
/* |
|
* This function is called by on_each_cpu() while the |
|
* event_mutex is held. |
|
*/ |
|
pid_list = rcu_dereference_protected(tr->function_pids, |
|
mutex_is_locked(&ftrace_lock)); |
|
no_pid_list = rcu_dereference_protected(tr->function_no_pids, |
|
mutex_is_locked(&ftrace_lock)); |
|
|
|
if (trace_ignore_this_task(pid_list, no_pid_list, current)) |
|
this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid, |
|
FTRACE_PID_IGNORE); |
|
else |
|
this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid, |
|
current->pid); |
|
} |
|
|
|
static ssize_t |
|
pid_write(struct file *filp, const char __user *ubuf, |
|
size_t cnt, loff_t *ppos, int type) |
|
{ |
|
struct seq_file *m = filp->private_data; |
|
struct trace_array *tr = m->private; |
|
struct trace_pid_list *filtered_pids; |
|
struct trace_pid_list *other_pids; |
|
struct trace_pid_list *pid_list; |
|
ssize_t ret; |
|
|
|
if (!cnt) |
|
return 0; |
|
|
|
mutex_lock(&ftrace_lock); |
|
|
|
switch (type) { |
|
case TRACE_PIDS: |
|
filtered_pids = rcu_dereference_protected(tr->function_pids, |
|
lockdep_is_held(&ftrace_lock)); |
|
other_pids = rcu_dereference_protected(tr->function_no_pids, |
|
lockdep_is_held(&ftrace_lock)); |
|
break; |
|
case TRACE_NO_PIDS: |
|
filtered_pids = rcu_dereference_protected(tr->function_no_pids, |
|
lockdep_is_held(&ftrace_lock)); |
|
other_pids = rcu_dereference_protected(tr->function_pids, |
|
lockdep_is_held(&ftrace_lock)); |
|
break; |
|
default: |
|
ret = -EINVAL; |
|
WARN_ON_ONCE(1); |
|
goto out; |
|
} |
|
|
|
ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt); |
|
if (ret < 0) |
|
goto out; |
|
|
|
switch (type) { |
|
case TRACE_PIDS: |
|
rcu_assign_pointer(tr->function_pids, pid_list); |
|
break; |
|
case TRACE_NO_PIDS: |
|
rcu_assign_pointer(tr->function_no_pids, pid_list); |
|
break; |
|
} |
|
|
|
|
|
if (filtered_pids) { |
|
synchronize_rcu(); |
|
trace_pid_list_free(filtered_pids); |
|
} else if (pid_list && !other_pids) { |
|
/* Register a probe to set whether to ignore the tracing of a task */ |
|
register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr); |
|
} |
|
|
|
/* |
|
* Ignoring of pids is done at task switch. But we have to |
|
* check for those tasks that are currently running. |
|
* Always do this in case a pid was appended or removed. |
|
*/ |
|
on_each_cpu(ignore_task_cpu, tr, 1); |
|
|
|
ftrace_update_pid_func(); |
|
ftrace_startup_all(0); |
|
out: |
|
mutex_unlock(&ftrace_lock); |
|
|
|
if (ret > 0) |
|
*ppos += ret; |
|
|
|
return ret; |
|
} |
|
|
|
static ssize_t |
|
ftrace_pid_write(struct file *filp, const char __user *ubuf, |
|
size_t cnt, loff_t *ppos) |
|
{ |
|
return pid_write(filp, ubuf, cnt, ppos, TRACE_PIDS); |
|
} |
|
|
|
static ssize_t |
|
ftrace_no_pid_write(struct file *filp, const char __user *ubuf, |
|
size_t cnt, loff_t *ppos) |
|
{ |
|
return pid_write(filp, ubuf, cnt, ppos, TRACE_NO_PIDS); |
|
} |
|
|
|
static int |
|
ftrace_pid_release(struct inode *inode, struct file *file) |
|
{ |
|
struct trace_array *tr = inode->i_private; |
|
|
|
trace_array_put(tr); |
|
|
|
return seq_release(inode, file); |
|
} |
|
|
|
static const struct file_operations ftrace_pid_fops = { |
|
.open = ftrace_pid_open, |
|
.write = ftrace_pid_write, |
|
.read = seq_read, |
|
.llseek = tracing_lseek, |
|
.release = ftrace_pid_release, |
|
}; |
|
|
|
static const struct file_operations ftrace_no_pid_fops = { |
|
.open = ftrace_no_pid_open, |
|
.write = ftrace_no_pid_write, |
|
.read = seq_read, |
|
.llseek = tracing_lseek, |
|
.release = ftrace_pid_release, |
|
}; |
|
|
|
void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer) |
|
{ |
|
trace_create_file("set_ftrace_pid", TRACE_MODE_WRITE, d_tracer, |
|
tr, &ftrace_pid_fops); |
|
trace_create_file("set_ftrace_notrace_pid", TRACE_MODE_WRITE, |
|
d_tracer, tr, &ftrace_no_pid_fops); |
|
} |
|
|
|
void __init ftrace_init_tracefs_toplevel(struct trace_array *tr, |
|
struct dentry *d_tracer) |
|
{ |
|
/* Only the top level directory has the dyn_tracefs and profile */ |
|
WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL)); |
|
|
|
ftrace_init_dyn_tracefs(d_tracer); |
|
ftrace_profile_tracefs(d_tracer); |
|
} |
|
|
|
/** |
|
* ftrace_kill - kill ftrace |
|
* |
|
* This function should be used by panic code. It stops ftrace |
|
* but in a not so nice way. If you need to simply kill ftrace |
|
* from a non-atomic section, use ftrace_kill. |
|
*/ |
|
void ftrace_kill(void) |
|
{ |
|
ftrace_disabled = 1; |
|
ftrace_enabled = 0; |
|
ftrace_trace_function = ftrace_stub; |
|
} |
|
|
|
/** |
|
* ftrace_is_dead - Test if ftrace is dead or not. |
|
* |
|
* Returns 1 if ftrace is "dead", zero otherwise. |
|
*/ |
|
int ftrace_is_dead(void) |
|
{ |
|
return ftrace_disabled; |
|
} |
|
|
|
/** |
|
* register_ftrace_function - register a function for profiling |
|
* @ops - ops structure that holds the function for profiling. |
|
* |
|
* Register a function to be called by all functions in the |
|
* kernel. |
|
* |
|
* Note: @ops->func and all the functions it calls must be labeled |
|
* with "notrace", otherwise it will go into a |
|
* recursive loop. |
|
*/ |
|
int register_ftrace_function(struct ftrace_ops *ops) |
|
{ |
|
int ret; |
|
|
|
ftrace_ops_init(ops); |
|
|
|
mutex_lock(&ftrace_lock); |
|
|
|
ret = ftrace_startup(ops, 0); |
|
|
|
mutex_unlock(&ftrace_lock); |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(register_ftrace_function); |
|
|
|
/** |
|
* unregister_ftrace_function - unregister a function for profiling. |
|
* @ops - ops structure that holds the function to unregister |
|
* |
|
* Unregister a function that was added to be called by ftrace profiling. |
|
*/ |
|
int unregister_ftrace_function(struct ftrace_ops *ops) |
|
{ |
|
int ret; |
|
|
|
mutex_lock(&ftrace_lock); |
|
ret = ftrace_shutdown(ops, 0); |
|
mutex_unlock(&ftrace_lock); |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(unregister_ftrace_function); |
|
|
|
static bool is_permanent_ops_registered(void) |
|
{ |
|
struct ftrace_ops *op; |
|
|
|
do_for_each_ftrace_op(op, ftrace_ops_list) { |
|
if (op->flags & FTRACE_OPS_FL_PERMANENT) |
|
return true; |
|
} while_for_each_ftrace_op(op); |
|
|
|
return false; |
|
} |
|
|
|
int |
|
ftrace_enable_sysctl(struct ctl_table *table, int write, |
|
void *buffer, size_t *lenp, loff_t *ppos) |
|
{ |
|
int ret = -ENODEV; |
|
|
|
mutex_lock(&ftrace_lock); |
|
|
|
if (unlikely(ftrace_disabled)) |
|
goto out; |
|
|
|
ret = proc_dointvec(table, write, buffer, lenp, ppos); |
|
|
|
if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
|
goto out; |
|
|
|
if (ftrace_enabled) { |
|
|
|
/* we are starting ftrace again */ |
|
if (rcu_dereference_protected(ftrace_ops_list, |
|
lockdep_is_held(&ftrace_lock)) != &ftrace_list_end) |
|
update_ftrace_function(); |
|
|
|
ftrace_startup_sysctl(); |
|
|
|
} else { |
|
if (is_permanent_ops_registered()) { |
|
ftrace_enabled = true; |
|
ret = -EBUSY; |
|
goto out; |
|
} |
|
|
|
/* stopping ftrace calls (just send to ftrace_stub) */ |
|
ftrace_trace_function = ftrace_stub; |
|
|
|
ftrace_shutdown_sysctl(); |
|
} |
|
|
|
last_ftrace_enabled = !!ftrace_enabled; |
|
out: |
|
mutex_unlock(&ftrace_lock); |
|
return ret; |
|
}
|
|
|