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2241 lines
53 KiB
2241 lines
53 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* trace_events_synth - synthetic trace events |
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* |
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* Copyright (C) 2015, 2020 Tom Zanussi <[email protected]> |
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*/ |
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|
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#include <linux/module.h> |
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#include <linux/kallsyms.h> |
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#include <linux/security.h> |
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#include <linux/mutex.h> |
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#include <linux/slab.h> |
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#include <linux/stacktrace.h> |
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#include <linux/rculist.h> |
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#include <linux/tracefs.h> |
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|
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/* for gfp flag names */ |
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#include <linux/trace_events.h> |
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#include <trace/events/mmflags.h> |
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|
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#include "trace_synth.h" |
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|
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#undef ERRORS |
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#define ERRORS \ |
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C(BAD_NAME, "Illegal name"), \ |
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C(INVALID_CMD, "Command must be of the form: <name> field[;field] ..."),\ |
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C(INVALID_DYN_CMD, "Command must be of the form: s or -:[synthetic/]<name> field[;field] ..."),\ |
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C(EVENT_EXISTS, "Event already exists"), \ |
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C(TOO_MANY_FIELDS, "Too many fields"), \ |
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C(INCOMPLETE_TYPE, "Incomplete type"), \ |
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C(INVALID_TYPE, "Invalid type"), \ |
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C(INVALID_FIELD, "Invalid field"), \ |
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C(INVALID_ARRAY_SPEC, "Invalid array specification"), |
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|
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#undef C |
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#define C(a, b) SYNTH_ERR_##a |
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|
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enum { ERRORS }; |
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|
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#undef C |
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#define C(a, b) b |
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|
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static const char *err_text[] = { ERRORS }; |
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|
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static char last_cmd[MAX_FILTER_STR_VAL]; |
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|
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static int errpos(const char *str) |
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{ |
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return err_pos(last_cmd, str); |
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} |
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|
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static void last_cmd_set(const char *str) |
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{ |
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if (!str) |
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return; |
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|
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strncpy(last_cmd, str, MAX_FILTER_STR_VAL - 1); |
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} |
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|
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static void synth_err(u8 err_type, u8 err_pos) |
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{ |
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tracing_log_err(NULL, "synthetic_events", last_cmd, err_text, |
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err_type, err_pos); |
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} |
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|
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static int create_synth_event(const char *raw_command); |
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static int synth_event_show(struct seq_file *m, struct dyn_event *ev); |
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static int synth_event_release(struct dyn_event *ev); |
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static bool synth_event_is_busy(struct dyn_event *ev); |
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static bool synth_event_match(const char *system, const char *event, |
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int argc, const char **argv, struct dyn_event *ev); |
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|
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static struct dyn_event_operations synth_event_ops = { |
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.create = create_synth_event, |
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.show = synth_event_show, |
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.is_busy = synth_event_is_busy, |
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.free = synth_event_release, |
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.match = synth_event_match, |
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}; |
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|
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static bool is_synth_event(struct dyn_event *ev) |
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{ |
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return ev->ops == &synth_event_ops; |
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} |
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|
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static struct synth_event *to_synth_event(struct dyn_event *ev) |
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{ |
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return container_of(ev, struct synth_event, devent); |
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} |
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|
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static bool synth_event_is_busy(struct dyn_event *ev) |
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{ |
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struct synth_event *event = to_synth_event(ev); |
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|
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return event->ref != 0; |
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} |
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|
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static bool synth_event_match(const char *system, const char *event, |
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int argc, const char **argv, struct dyn_event *ev) |
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{ |
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struct synth_event *sev = to_synth_event(ev); |
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|
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return strcmp(sev->name, event) == 0 && |
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(!system || strcmp(system, SYNTH_SYSTEM) == 0); |
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} |
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|
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struct synth_trace_event { |
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struct trace_entry ent; |
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u64 fields[]; |
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}; |
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|
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static int synth_event_define_fields(struct trace_event_call *call) |
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{ |
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struct synth_trace_event trace; |
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int offset = offsetof(typeof(trace), fields); |
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struct synth_event *event = call->data; |
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unsigned int i, size, n_u64; |
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char *name, *type; |
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bool is_signed; |
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int ret = 0; |
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|
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for (i = 0, n_u64 = 0; i < event->n_fields; i++) { |
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size = event->fields[i]->size; |
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is_signed = event->fields[i]->is_signed; |
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type = event->fields[i]->type; |
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name = event->fields[i]->name; |
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ret = trace_define_field(call, type, name, offset, size, |
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is_signed, FILTER_OTHER); |
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if (ret) |
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break; |
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event->fields[i]->offset = n_u64; |
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|
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if (event->fields[i]->is_string && !event->fields[i]->is_dynamic) { |
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offset += STR_VAR_LEN_MAX; |
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n_u64 += STR_VAR_LEN_MAX / sizeof(u64); |
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} else { |
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offset += sizeof(u64); |
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n_u64++; |
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} |
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} |
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|
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event->n_u64 = n_u64; |
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|
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return ret; |
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} |
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|
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static bool synth_field_signed(char *type) |
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{ |
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if (str_has_prefix(type, "u")) |
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return false; |
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if (strcmp(type, "gfp_t") == 0) |
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return false; |
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|
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return true; |
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} |
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|
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static int synth_field_is_string(char *type) |
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{ |
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if (strstr(type, "char[") != NULL) |
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return true; |
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|
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return false; |
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} |
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|
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static int synth_field_string_size(char *type) |
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{ |
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char buf[4], *end, *start; |
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unsigned int len; |
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int size, err; |
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|
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start = strstr(type, "char["); |
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if (start == NULL) |
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return -EINVAL; |
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start += sizeof("char[") - 1; |
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|
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end = strchr(type, ']'); |
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if (!end || end < start || type + strlen(type) > end + 1) |
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return -EINVAL; |
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|
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len = end - start; |
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if (len > 3) |
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return -EINVAL; |
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|
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if (len == 0) |
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return 0; /* variable-length string */ |
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|
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strncpy(buf, start, len); |
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buf[len] = '\0'; |
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|
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err = kstrtouint(buf, 0, &size); |
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if (err) |
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return err; |
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|
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if (size > STR_VAR_LEN_MAX) |
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return -EINVAL; |
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|
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return size; |
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} |
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static int synth_field_size(char *type) |
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{ |
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int size = 0; |
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|
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if (strcmp(type, "s64") == 0) |
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size = sizeof(s64); |
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else if (strcmp(type, "u64") == 0) |
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size = sizeof(u64); |
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else if (strcmp(type, "s32") == 0) |
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size = sizeof(s32); |
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else if (strcmp(type, "u32") == 0) |
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size = sizeof(u32); |
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else if (strcmp(type, "s16") == 0) |
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size = sizeof(s16); |
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else if (strcmp(type, "u16") == 0) |
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size = sizeof(u16); |
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else if (strcmp(type, "s8") == 0) |
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size = sizeof(s8); |
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else if (strcmp(type, "u8") == 0) |
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size = sizeof(u8); |
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else if (strcmp(type, "char") == 0) |
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size = sizeof(char); |
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else if (strcmp(type, "unsigned char") == 0) |
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size = sizeof(unsigned char); |
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else if (strcmp(type, "int") == 0) |
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size = sizeof(int); |
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else if (strcmp(type, "unsigned int") == 0) |
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size = sizeof(unsigned int); |
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else if (strcmp(type, "long") == 0) |
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size = sizeof(long); |
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else if (strcmp(type, "unsigned long") == 0) |
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size = sizeof(unsigned long); |
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else if (strcmp(type, "bool") == 0) |
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size = sizeof(bool); |
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else if (strcmp(type, "pid_t") == 0) |
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size = sizeof(pid_t); |
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else if (strcmp(type, "gfp_t") == 0) |
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size = sizeof(gfp_t); |
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else if (synth_field_is_string(type)) |
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size = synth_field_string_size(type); |
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|
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return size; |
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} |
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static const char *synth_field_fmt(char *type) |
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{ |
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const char *fmt = "%llu"; |
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|
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if (strcmp(type, "s64") == 0) |
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fmt = "%lld"; |
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else if (strcmp(type, "u64") == 0) |
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fmt = "%llu"; |
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else if (strcmp(type, "s32") == 0) |
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fmt = "%d"; |
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else if (strcmp(type, "u32") == 0) |
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fmt = "%u"; |
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else if (strcmp(type, "s16") == 0) |
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fmt = "%d"; |
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else if (strcmp(type, "u16") == 0) |
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fmt = "%u"; |
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else if (strcmp(type, "s8") == 0) |
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fmt = "%d"; |
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else if (strcmp(type, "u8") == 0) |
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fmt = "%u"; |
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else if (strcmp(type, "char") == 0) |
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fmt = "%d"; |
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else if (strcmp(type, "unsigned char") == 0) |
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fmt = "%u"; |
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else if (strcmp(type, "int") == 0) |
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fmt = "%d"; |
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else if (strcmp(type, "unsigned int") == 0) |
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fmt = "%u"; |
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else if (strcmp(type, "long") == 0) |
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fmt = "%ld"; |
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else if (strcmp(type, "unsigned long") == 0) |
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fmt = "%lu"; |
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else if (strcmp(type, "bool") == 0) |
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fmt = "%d"; |
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else if (strcmp(type, "pid_t") == 0) |
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fmt = "%d"; |
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else if (strcmp(type, "gfp_t") == 0) |
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fmt = "%x"; |
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else if (synth_field_is_string(type)) |
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fmt = "%.*s"; |
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|
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return fmt; |
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} |
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|
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static void print_synth_event_num_val(struct trace_seq *s, |
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char *print_fmt, char *name, |
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int size, u64 val, char *space) |
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{ |
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switch (size) { |
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case 1: |
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trace_seq_printf(s, print_fmt, name, (u8)val, space); |
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break; |
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|
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case 2: |
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trace_seq_printf(s, print_fmt, name, (u16)val, space); |
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break; |
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case 4: |
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trace_seq_printf(s, print_fmt, name, (u32)val, space); |
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break; |
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default: |
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trace_seq_printf(s, print_fmt, name, val, space); |
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break; |
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} |
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} |
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|
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static enum print_line_t print_synth_event(struct trace_iterator *iter, |
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int flags, |
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struct trace_event *event) |
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{ |
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struct trace_array *tr = iter->tr; |
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struct trace_seq *s = &iter->seq; |
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struct synth_trace_event *entry; |
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struct synth_event *se; |
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unsigned int i, n_u64; |
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char print_fmt[32]; |
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const char *fmt; |
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entry = (struct synth_trace_event *)iter->ent; |
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se = container_of(event, struct synth_event, call.event); |
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|
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trace_seq_printf(s, "%s: ", se->name); |
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|
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for (i = 0, n_u64 = 0; i < se->n_fields; i++) { |
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if (trace_seq_has_overflowed(s)) |
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goto end; |
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fmt = synth_field_fmt(se->fields[i]->type); |
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|
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/* parameter types */ |
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if (tr && tr->trace_flags & TRACE_ITER_VERBOSE) |
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trace_seq_printf(s, "%s ", fmt); |
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|
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snprintf(print_fmt, sizeof(print_fmt), "%%s=%s%%s", fmt); |
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|
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/* parameter values */ |
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if (se->fields[i]->is_string) { |
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if (se->fields[i]->is_dynamic) { |
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u32 offset, data_offset; |
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char *str_field; |
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offset = (u32)entry->fields[n_u64]; |
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data_offset = offset & 0xffff; |
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str_field = (char *)entry + data_offset; |
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|
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trace_seq_printf(s, print_fmt, se->fields[i]->name, |
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STR_VAR_LEN_MAX, |
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str_field, |
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i == se->n_fields - 1 ? "" : " "); |
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n_u64++; |
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} else { |
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trace_seq_printf(s, print_fmt, se->fields[i]->name, |
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STR_VAR_LEN_MAX, |
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(char *)&entry->fields[n_u64], |
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i == se->n_fields - 1 ? "" : " "); |
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n_u64 += STR_VAR_LEN_MAX / sizeof(u64); |
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} |
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} else { |
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struct trace_print_flags __flags[] = { |
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__def_gfpflag_names, {-1, NULL} }; |
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char *space = (i == se->n_fields - 1 ? "" : " "); |
|
|
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print_synth_event_num_val(s, print_fmt, |
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se->fields[i]->name, |
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se->fields[i]->size, |
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entry->fields[n_u64], |
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space); |
|
|
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if (strcmp(se->fields[i]->type, "gfp_t") == 0) { |
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trace_seq_puts(s, " ("); |
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trace_print_flags_seq(s, "|", |
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entry->fields[n_u64], |
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__flags); |
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trace_seq_putc(s, ')'); |
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} |
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n_u64++; |
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} |
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} |
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end: |
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trace_seq_putc(s, '\n'); |
|
|
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return trace_handle_return(s); |
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} |
|
|
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static struct trace_event_functions synth_event_funcs = { |
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.trace = print_synth_event |
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}; |
|
|
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static unsigned int trace_string(struct synth_trace_event *entry, |
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struct synth_event *event, |
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char *str_val, |
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bool is_dynamic, |
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unsigned int data_size, |
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unsigned int *n_u64) |
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{ |
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unsigned int len = 0; |
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char *str_field; |
|
|
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if (is_dynamic) { |
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u32 data_offset; |
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|
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data_offset = offsetof(typeof(*entry), fields); |
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data_offset += event->n_u64 * sizeof(u64); |
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data_offset += data_size; |
|
|
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str_field = (char *)entry + data_offset; |
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|
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len = strlen(str_val) + 1; |
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strscpy(str_field, str_val, len); |
|
|
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data_offset |= len << 16; |
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*(u32 *)&entry->fields[*n_u64] = data_offset; |
|
|
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(*n_u64)++; |
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} else { |
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str_field = (char *)&entry->fields[*n_u64]; |
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|
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strscpy(str_field, str_val, STR_VAR_LEN_MAX); |
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(*n_u64) += STR_VAR_LEN_MAX / sizeof(u64); |
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} |
|
|
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return len; |
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} |
|
|
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static notrace void trace_event_raw_event_synth(void *__data, |
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u64 *var_ref_vals, |
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unsigned int *var_ref_idx) |
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{ |
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unsigned int i, n_u64, val_idx, len, data_size = 0; |
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struct trace_event_file *trace_file = __data; |
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struct synth_trace_event *entry; |
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struct trace_event_buffer fbuffer; |
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struct trace_buffer *buffer; |
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struct synth_event *event; |
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int fields_size = 0; |
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|
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event = trace_file->event_call->data; |
|
|
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if (trace_trigger_soft_disabled(trace_file)) |
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return; |
|
|
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fields_size = event->n_u64 * sizeof(u64); |
|
|
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for (i = 0; i < event->n_dynamic_fields; i++) { |
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unsigned int field_pos = event->dynamic_fields[i]->field_pos; |
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char *str_val; |
|
|
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val_idx = var_ref_idx[field_pos]; |
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str_val = (char *)(long)var_ref_vals[val_idx]; |
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|
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len = strlen(str_val) + 1; |
|
|
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fields_size += len; |
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} |
|
|
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/* |
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* Avoid ring buffer recursion detection, as this event |
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* is being performed within another event. |
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*/ |
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buffer = trace_file->tr->array_buffer.buffer; |
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ring_buffer_nest_start(buffer); |
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|
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entry = trace_event_buffer_reserve(&fbuffer, trace_file, |
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sizeof(*entry) + fields_size); |
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if (!entry) |
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goto out; |
|
|
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for (i = 0, n_u64 = 0; i < event->n_fields; i++) { |
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val_idx = var_ref_idx[i]; |
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if (event->fields[i]->is_string) { |
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char *str_val = (char *)(long)var_ref_vals[val_idx]; |
|
|
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len = trace_string(entry, event, str_val, |
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event->fields[i]->is_dynamic, |
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data_size, &n_u64); |
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data_size += len; /* only dynamic string increments */ |
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} else { |
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struct synth_field *field = event->fields[i]; |
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u64 val = var_ref_vals[val_idx]; |
|
|
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switch (field->size) { |
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case 1: |
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*(u8 *)&entry->fields[n_u64] = (u8)val; |
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break; |
|
|
|
case 2: |
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*(u16 *)&entry->fields[n_u64] = (u16)val; |
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break; |
|
|
|
case 4: |
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*(u32 *)&entry->fields[n_u64] = (u32)val; |
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break; |
|
|
|
default: |
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entry->fields[n_u64] = val; |
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break; |
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} |
|
n_u64++; |
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} |
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} |
|
|
|
trace_event_buffer_commit(&fbuffer); |
|
out: |
|
ring_buffer_nest_end(buffer); |
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} |
|
|
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static void free_synth_event_print_fmt(struct trace_event_call *call) |
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{ |
|
if (call) { |
|
kfree(call->print_fmt); |
|
call->print_fmt = NULL; |
|
} |
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} |
|
|
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static int __set_synth_event_print_fmt(struct synth_event *event, |
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char *buf, int len) |
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{ |
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const char *fmt; |
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int pos = 0; |
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int i; |
|
|
|
/* When len=0, we just calculate the needed length */ |
|
#define LEN_OR_ZERO (len ? len - pos : 0) |
|
|
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pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); |
|
for (i = 0; i < event->n_fields; i++) { |
|
fmt = synth_field_fmt(event->fields[i]->type); |
|
pos += snprintf(buf + pos, LEN_OR_ZERO, "%s=%s%s", |
|
event->fields[i]->name, fmt, |
|
i == event->n_fields - 1 ? "" : ", "); |
|
} |
|
pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); |
|
|
|
for (i = 0; i < event->n_fields; i++) { |
|
if (event->fields[i]->is_string && |
|
event->fields[i]->is_dynamic) |
|
pos += snprintf(buf + pos, LEN_OR_ZERO, |
|
", __get_str(%s)", event->fields[i]->name); |
|
else |
|
pos += snprintf(buf + pos, LEN_OR_ZERO, |
|
", REC->%s", event->fields[i]->name); |
|
} |
|
|
|
#undef LEN_OR_ZERO |
|
|
|
/* return the length of print_fmt */ |
|
return pos; |
|
} |
|
|
|
static int set_synth_event_print_fmt(struct trace_event_call *call) |
|
{ |
|
struct synth_event *event = call->data; |
|
char *print_fmt; |
|
int len; |
|
|
|
/* First: called with 0 length to calculate the needed length */ |
|
len = __set_synth_event_print_fmt(event, NULL, 0); |
|
|
|
print_fmt = kmalloc(len + 1, GFP_KERNEL); |
|
if (!print_fmt) |
|
return -ENOMEM; |
|
|
|
/* Second: actually write the @print_fmt */ |
|
__set_synth_event_print_fmt(event, print_fmt, len + 1); |
|
call->print_fmt = print_fmt; |
|
|
|
return 0; |
|
} |
|
|
|
static void free_synth_field(struct synth_field *field) |
|
{ |
|
kfree(field->type); |
|
kfree(field->name); |
|
kfree(field); |
|
} |
|
|
|
static int check_field_version(const char *prefix, const char *field_type, |
|
const char *field_name) |
|
{ |
|
/* |
|
* For backward compatibility, the old synthetic event command |
|
* format did not require semicolons, and in order to not |
|
* break user space, that old format must still work. If a new |
|
* feature is added, then the format that uses the new feature |
|
* will be required to have semicolons, as nothing that uses |
|
* the old format would be using the new, yet to be created, |
|
* feature. When a new feature is added, this will detect it, |
|
* and return a number greater than 1, and require the format |
|
* to use semicolons. |
|
*/ |
|
return 1; |
|
} |
|
|
|
static struct synth_field *parse_synth_field(int argc, char **argv, |
|
int *consumed, int *field_version) |
|
{ |
|
const char *prefix = NULL, *field_type = argv[0], *field_name, *array; |
|
struct synth_field *field; |
|
int len, ret = -ENOMEM; |
|
struct seq_buf s; |
|
ssize_t size; |
|
|
|
if (!strcmp(field_type, "unsigned")) { |
|
if (argc < 3) { |
|
synth_err(SYNTH_ERR_INCOMPLETE_TYPE, errpos(field_type)); |
|
return ERR_PTR(-EINVAL); |
|
} |
|
prefix = "unsigned "; |
|
field_type = argv[1]; |
|
field_name = argv[2]; |
|
*consumed += 3; |
|
} else { |
|
field_name = argv[1]; |
|
*consumed += 2; |
|
} |
|
|
|
if (!field_name) { |
|
synth_err(SYNTH_ERR_INVALID_FIELD, errpos(field_type)); |
|
return ERR_PTR(-EINVAL); |
|
} |
|
|
|
*field_version = check_field_version(prefix, field_type, field_name); |
|
|
|
field = kzalloc(sizeof(*field), GFP_KERNEL); |
|
if (!field) |
|
return ERR_PTR(-ENOMEM); |
|
|
|
len = strlen(field_name); |
|
array = strchr(field_name, '['); |
|
if (array) |
|
len -= strlen(array); |
|
|
|
field->name = kmemdup_nul(field_name, len, GFP_KERNEL); |
|
if (!field->name) |
|
goto free; |
|
|
|
if (!is_good_name(field->name)) { |
|
synth_err(SYNTH_ERR_BAD_NAME, errpos(field_name)); |
|
ret = -EINVAL; |
|
goto free; |
|
} |
|
|
|
len = strlen(field_type) + 1; |
|
|
|
if (array) |
|
len += strlen(array); |
|
|
|
if (prefix) |
|
len += strlen(prefix); |
|
|
|
field->type = kzalloc(len, GFP_KERNEL); |
|
if (!field->type) |
|
goto free; |
|
|
|
seq_buf_init(&s, field->type, len); |
|
if (prefix) |
|
seq_buf_puts(&s, prefix); |
|
seq_buf_puts(&s, field_type); |
|
if (array) |
|
seq_buf_puts(&s, array); |
|
if (WARN_ON_ONCE(!seq_buf_buffer_left(&s))) |
|
goto free; |
|
|
|
s.buffer[s.len] = '\0'; |
|
|
|
size = synth_field_size(field->type); |
|
if (size < 0) { |
|
if (array) |
|
synth_err(SYNTH_ERR_INVALID_ARRAY_SPEC, errpos(field_name)); |
|
else |
|
synth_err(SYNTH_ERR_INVALID_TYPE, errpos(field_type)); |
|
ret = -EINVAL; |
|
goto free; |
|
} else if (size == 0) { |
|
if (synth_field_is_string(field->type)) { |
|
char *type; |
|
|
|
len = sizeof("__data_loc ") + strlen(field->type) + 1; |
|
type = kzalloc(len, GFP_KERNEL); |
|
if (!type) |
|
goto free; |
|
|
|
seq_buf_init(&s, type, len); |
|
seq_buf_puts(&s, "__data_loc "); |
|
seq_buf_puts(&s, field->type); |
|
|
|
if (WARN_ON_ONCE(!seq_buf_buffer_left(&s))) |
|
goto free; |
|
s.buffer[s.len] = '\0'; |
|
|
|
kfree(field->type); |
|
field->type = type; |
|
|
|
field->is_dynamic = true; |
|
size = sizeof(u64); |
|
} else { |
|
synth_err(SYNTH_ERR_INVALID_TYPE, errpos(field_type)); |
|
ret = -EINVAL; |
|
goto free; |
|
} |
|
} |
|
field->size = size; |
|
|
|
if (synth_field_is_string(field->type)) |
|
field->is_string = true; |
|
|
|
field->is_signed = synth_field_signed(field->type); |
|
out: |
|
return field; |
|
free: |
|
free_synth_field(field); |
|
field = ERR_PTR(ret); |
|
goto out; |
|
} |
|
|
|
static void free_synth_tracepoint(struct tracepoint *tp) |
|
{ |
|
if (!tp) |
|
return; |
|
|
|
kfree(tp->name); |
|
kfree(tp); |
|
} |
|
|
|
static struct tracepoint *alloc_synth_tracepoint(char *name) |
|
{ |
|
struct tracepoint *tp; |
|
|
|
tp = kzalloc(sizeof(*tp), GFP_KERNEL); |
|
if (!tp) |
|
return ERR_PTR(-ENOMEM); |
|
|
|
tp->name = kstrdup(name, GFP_KERNEL); |
|
if (!tp->name) { |
|
kfree(tp); |
|
return ERR_PTR(-ENOMEM); |
|
} |
|
|
|
return tp; |
|
} |
|
|
|
struct synth_event *find_synth_event(const char *name) |
|
{ |
|
struct dyn_event *pos; |
|
struct synth_event *event; |
|
|
|
for_each_dyn_event(pos) { |
|
if (!is_synth_event(pos)) |
|
continue; |
|
event = to_synth_event(pos); |
|
if (strcmp(event->name, name) == 0) |
|
return event; |
|
} |
|
|
|
return NULL; |
|
} |
|
|
|
static struct trace_event_fields synth_event_fields_array[] = { |
|
{ .type = TRACE_FUNCTION_TYPE, |
|
.define_fields = synth_event_define_fields }, |
|
{} |
|
}; |
|
|
|
static int register_synth_event(struct synth_event *event) |
|
{ |
|
struct trace_event_call *call = &event->call; |
|
int ret = 0; |
|
|
|
event->call.class = &event->class; |
|
event->class.system = kstrdup(SYNTH_SYSTEM, GFP_KERNEL); |
|
if (!event->class.system) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
event->tp = alloc_synth_tracepoint(event->name); |
|
if (IS_ERR(event->tp)) { |
|
ret = PTR_ERR(event->tp); |
|
event->tp = NULL; |
|
goto out; |
|
} |
|
|
|
INIT_LIST_HEAD(&call->class->fields); |
|
call->event.funcs = &synth_event_funcs; |
|
call->class->fields_array = synth_event_fields_array; |
|
|
|
ret = register_trace_event(&call->event); |
|
if (!ret) { |
|
ret = -ENODEV; |
|
goto out; |
|
} |
|
call->flags = TRACE_EVENT_FL_TRACEPOINT; |
|
call->class->reg = trace_event_reg; |
|
call->class->probe = trace_event_raw_event_synth; |
|
call->data = event; |
|
call->tp = event->tp; |
|
|
|
ret = trace_add_event_call(call); |
|
if (ret) { |
|
pr_warn("Failed to register synthetic event: %s\n", |
|
trace_event_name(call)); |
|
goto err; |
|
} |
|
|
|
ret = set_synth_event_print_fmt(call); |
|
if (ret < 0) { |
|
trace_remove_event_call(call); |
|
goto err; |
|
} |
|
out: |
|
return ret; |
|
err: |
|
unregister_trace_event(&call->event); |
|
goto out; |
|
} |
|
|
|
static int unregister_synth_event(struct synth_event *event) |
|
{ |
|
struct trace_event_call *call = &event->call; |
|
int ret; |
|
|
|
ret = trace_remove_event_call(call); |
|
|
|
return ret; |
|
} |
|
|
|
static void free_synth_event(struct synth_event *event) |
|
{ |
|
unsigned int i; |
|
|
|
if (!event) |
|
return; |
|
|
|
for (i = 0; i < event->n_fields; i++) |
|
free_synth_field(event->fields[i]); |
|
|
|
kfree(event->fields); |
|
kfree(event->dynamic_fields); |
|
kfree(event->name); |
|
kfree(event->class.system); |
|
free_synth_tracepoint(event->tp); |
|
free_synth_event_print_fmt(&event->call); |
|
kfree(event); |
|
} |
|
|
|
static struct synth_event *alloc_synth_event(const char *name, int n_fields, |
|
struct synth_field **fields) |
|
{ |
|
unsigned int i, j, n_dynamic_fields = 0; |
|
struct synth_event *event; |
|
|
|
event = kzalloc(sizeof(*event), GFP_KERNEL); |
|
if (!event) { |
|
event = ERR_PTR(-ENOMEM); |
|
goto out; |
|
} |
|
|
|
event->name = kstrdup(name, GFP_KERNEL); |
|
if (!event->name) { |
|
kfree(event); |
|
event = ERR_PTR(-ENOMEM); |
|
goto out; |
|
} |
|
|
|
event->fields = kcalloc(n_fields, sizeof(*event->fields), GFP_KERNEL); |
|
if (!event->fields) { |
|
free_synth_event(event); |
|
event = ERR_PTR(-ENOMEM); |
|
goto out; |
|
} |
|
|
|
for (i = 0; i < n_fields; i++) |
|
if (fields[i]->is_dynamic) |
|
n_dynamic_fields++; |
|
|
|
if (n_dynamic_fields) { |
|
event->dynamic_fields = kcalloc(n_dynamic_fields, |
|
sizeof(*event->dynamic_fields), |
|
GFP_KERNEL); |
|
if (!event->dynamic_fields) { |
|
free_synth_event(event); |
|
event = ERR_PTR(-ENOMEM); |
|
goto out; |
|
} |
|
} |
|
|
|
dyn_event_init(&event->devent, &synth_event_ops); |
|
|
|
for (i = 0, j = 0; i < n_fields; i++) { |
|
event->fields[i] = fields[i]; |
|
|
|
if (fields[i]->is_dynamic) { |
|
event->dynamic_fields[j] = fields[i]; |
|
event->dynamic_fields[j]->field_pos = i; |
|
event->dynamic_fields[j++] = fields[i]; |
|
event->n_dynamic_fields++; |
|
} |
|
} |
|
event->n_fields = n_fields; |
|
out: |
|
return event; |
|
} |
|
|
|
static int synth_event_check_arg_fn(void *data) |
|
{ |
|
struct dynevent_arg_pair *arg_pair = data; |
|
int size; |
|
|
|
size = synth_field_size((char *)arg_pair->lhs); |
|
if (size == 0) { |
|
if (strstr((char *)arg_pair->lhs, "[")) |
|
return 0; |
|
} |
|
|
|
return size ? 0 : -EINVAL; |
|
} |
|
|
|
/** |
|
* synth_event_add_field - Add a new field to a synthetic event cmd |
|
* @cmd: A pointer to the dynevent_cmd struct representing the new event |
|
* @type: The type of the new field to add |
|
* @name: The name of the new field to add |
|
* |
|
* Add a new field to a synthetic event cmd object. Field ordering is in |
|
* the same order the fields are added. |
|
* |
|
* See synth_field_size() for available types. If field_name contains |
|
* [n] the field is considered to be an array. |
|
* |
|
* Return: 0 if successful, error otherwise. |
|
*/ |
|
int synth_event_add_field(struct dynevent_cmd *cmd, const char *type, |
|
const char *name) |
|
{ |
|
struct dynevent_arg_pair arg_pair; |
|
int ret; |
|
|
|
if (cmd->type != DYNEVENT_TYPE_SYNTH) |
|
return -EINVAL; |
|
|
|
if (!type || !name) |
|
return -EINVAL; |
|
|
|
dynevent_arg_pair_init(&arg_pair, 0, ';'); |
|
|
|
arg_pair.lhs = type; |
|
arg_pair.rhs = name; |
|
|
|
ret = dynevent_arg_pair_add(cmd, &arg_pair, synth_event_check_arg_fn); |
|
if (ret) |
|
return ret; |
|
|
|
if (++cmd->n_fields > SYNTH_FIELDS_MAX) |
|
ret = -EINVAL; |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(synth_event_add_field); |
|
|
|
/** |
|
* synth_event_add_field_str - Add a new field to a synthetic event cmd |
|
* @cmd: A pointer to the dynevent_cmd struct representing the new event |
|
* @type_name: The type and name of the new field to add, as a single string |
|
* |
|
* Add a new field to a synthetic event cmd object, as a single |
|
* string. The @type_name string is expected to be of the form 'type |
|
* name', which will be appended by ';'. No sanity checking is done - |
|
* what's passed in is assumed to already be well-formed. Field |
|
* ordering is in the same order the fields are added. |
|
* |
|
* See synth_field_size() for available types. If field_name contains |
|
* [n] the field is considered to be an array. |
|
* |
|
* Return: 0 if successful, error otherwise. |
|
*/ |
|
int synth_event_add_field_str(struct dynevent_cmd *cmd, const char *type_name) |
|
{ |
|
struct dynevent_arg arg; |
|
int ret; |
|
|
|
if (cmd->type != DYNEVENT_TYPE_SYNTH) |
|
return -EINVAL; |
|
|
|
if (!type_name) |
|
return -EINVAL; |
|
|
|
dynevent_arg_init(&arg, ';'); |
|
|
|
arg.str = type_name; |
|
|
|
ret = dynevent_arg_add(cmd, &arg, NULL); |
|
if (ret) |
|
return ret; |
|
|
|
if (++cmd->n_fields > SYNTH_FIELDS_MAX) |
|
ret = -EINVAL; |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(synth_event_add_field_str); |
|
|
|
/** |
|
* synth_event_add_fields - Add multiple fields to a synthetic event cmd |
|
* @cmd: A pointer to the dynevent_cmd struct representing the new event |
|
* @fields: An array of type/name field descriptions |
|
* @n_fields: The number of field descriptions contained in the fields array |
|
* |
|
* Add a new set of fields to a synthetic event cmd object. The event |
|
* fields that will be defined for the event should be passed in as an |
|
* array of struct synth_field_desc, and the number of elements in the |
|
* array passed in as n_fields. Field ordering will retain the |
|
* ordering given in the fields array. |
|
* |
|
* See synth_field_size() for available types. If field_name contains |
|
* [n] the field is considered to be an array. |
|
* |
|
* Return: 0 if successful, error otherwise. |
|
*/ |
|
int synth_event_add_fields(struct dynevent_cmd *cmd, |
|
struct synth_field_desc *fields, |
|
unsigned int n_fields) |
|
{ |
|
unsigned int i; |
|
int ret = 0; |
|
|
|
for (i = 0; i < n_fields; i++) { |
|
if (fields[i].type == NULL || fields[i].name == NULL) { |
|
ret = -EINVAL; |
|
break; |
|
} |
|
|
|
ret = synth_event_add_field(cmd, fields[i].type, fields[i].name); |
|
if (ret) |
|
break; |
|
} |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(synth_event_add_fields); |
|
|
|
/** |
|
* __synth_event_gen_cmd_start - Start a synthetic event command from arg list |
|
* @cmd: A pointer to the dynevent_cmd struct representing the new event |
|
* @name: The name of the synthetic event |
|
* @mod: The module creating the event, NULL if not created from a module |
|
* @args: Variable number of arg (pairs), one pair for each field |
|
* |
|
* NOTE: Users normally won't want to call this function directly, but |
|
* rather use the synth_event_gen_cmd_start() wrapper, which |
|
* automatically adds a NULL to the end of the arg list. If this |
|
* function is used directly, make sure the last arg in the variable |
|
* arg list is NULL. |
|
* |
|
* Generate a synthetic event command to be executed by |
|
* synth_event_gen_cmd_end(). This function can be used to generate |
|
* the complete command or only the first part of it; in the latter |
|
* case, synth_event_add_field(), synth_event_add_field_str(), or |
|
* synth_event_add_fields() can be used to add more fields following |
|
* this. |
|
* |
|
* There should be an even number variable args, each pair consisting |
|
* of a type followed by a field name. |
|
* |
|
* See synth_field_size() for available types. If field_name contains |
|
* [n] the field is considered to be an array. |
|
* |
|
* Return: 0 if successful, error otherwise. |
|
*/ |
|
int __synth_event_gen_cmd_start(struct dynevent_cmd *cmd, const char *name, |
|
struct module *mod, ...) |
|
{ |
|
struct dynevent_arg arg; |
|
va_list args; |
|
int ret; |
|
|
|
cmd->event_name = name; |
|
cmd->private_data = mod; |
|
|
|
if (cmd->type != DYNEVENT_TYPE_SYNTH) |
|
return -EINVAL; |
|
|
|
dynevent_arg_init(&arg, 0); |
|
arg.str = name; |
|
ret = dynevent_arg_add(cmd, &arg, NULL); |
|
if (ret) |
|
return ret; |
|
|
|
va_start(args, mod); |
|
for (;;) { |
|
const char *type, *name; |
|
|
|
type = va_arg(args, const char *); |
|
if (!type) |
|
break; |
|
name = va_arg(args, const char *); |
|
if (!name) |
|
break; |
|
|
|
if (++cmd->n_fields > SYNTH_FIELDS_MAX) { |
|
ret = -EINVAL; |
|
break; |
|
} |
|
|
|
ret = synth_event_add_field(cmd, type, name); |
|
if (ret) |
|
break; |
|
} |
|
va_end(args); |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(__synth_event_gen_cmd_start); |
|
|
|
/** |
|
* synth_event_gen_cmd_array_start - Start synthetic event command from an array |
|
* @cmd: A pointer to the dynevent_cmd struct representing the new event |
|
* @name: The name of the synthetic event |
|
* @fields: An array of type/name field descriptions |
|
* @n_fields: The number of field descriptions contained in the fields array |
|
* |
|
* Generate a synthetic event command to be executed by |
|
* synth_event_gen_cmd_end(). This function can be used to generate |
|
* the complete command or only the first part of it; in the latter |
|
* case, synth_event_add_field(), synth_event_add_field_str(), or |
|
* synth_event_add_fields() can be used to add more fields following |
|
* this. |
|
* |
|
* The event fields that will be defined for the event should be |
|
* passed in as an array of struct synth_field_desc, and the number of |
|
* elements in the array passed in as n_fields. Field ordering will |
|
* retain the ordering given in the fields array. |
|
* |
|
* See synth_field_size() for available types. If field_name contains |
|
* [n] the field is considered to be an array. |
|
* |
|
* Return: 0 if successful, error otherwise. |
|
*/ |
|
int synth_event_gen_cmd_array_start(struct dynevent_cmd *cmd, const char *name, |
|
struct module *mod, |
|
struct synth_field_desc *fields, |
|
unsigned int n_fields) |
|
{ |
|
struct dynevent_arg arg; |
|
unsigned int i; |
|
int ret = 0; |
|
|
|
cmd->event_name = name; |
|
cmd->private_data = mod; |
|
|
|
if (cmd->type != DYNEVENT_TYPE_SYNTH) |
|
return -EINVAL; |
|
|
|
if (n_fields > SYNTH_FIELDS_MAX) |
|
return -EINVAL; |
|
|
|
dynevent_arg_init(&arg, 0); |
|
arg.str = name; |
|
ret = dynevent_arg_add(cmd, &arg, NULL); |
|
if (ret) |
|
return ret; |
|
|
|
for (i = 0; i < n_fields; i++) { |
|
if (fields[i].type == NULL || fields[i].name == NULL) |
|
return -EINVAL; |
|
|
|
ret = synth_event_add_field(cmd, fields[i].type, fields[i].name); |
|
if (ret) |
|
break; |
|
} |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(synth_event_gen_cmd_array_start); |
|
|
|
static int __create_synth_event(const char *name, const char *raw_fields) |
|
{ |
|
char **argv, *field_str, *tmp_fields, *saved_fields = NULL; |
|
struct synth_field *field, *fields[SYNTH_FIELDS_MAX]; |
|
int consumed, cmd_version = 1, n_fields_this_loop; |
|
int i, argc, n_fields = 0, ret = 0; |
|
struct synth_event *event = NULL; |
|
|
|
/* |
|
* Argument syntax: |
|
* - Add synthetic event: <event_name> field[;field] ... |
|
* - Remove synthetic event: !<event_name> field[;field] ... |
|
* where 'field' = type field_name |
|
*/ |
|
|
|
if (name[0] == '\0') { |
|
synth_err(SYNTH_ERR_INVALID_CMD, 0); |
|
return -EINVAL; |
|
} |
|
|
|
if (!is_good_name(name)) { |
|
synth_err(SYNTH_ERR_BAD_NAME, errpos(name)); |
|
return -EINVAL; |
|
} |
|
|
|
mutex_lock(&event_mutex); |
|
|
|
event = find_synth_event(name); |
|
if (event) { |
|
synth_err(SYNTH_ERR_EVENT_EXISTS, errpos(name)); |
|
ret = -EEXIST; |
|
goto err; |
|
} |
|
|
|
tmp_fields = saved_fields = kstrdup(raw_fields, GFP_KERNEL); |
|
if (!tmp_fields) { |
|
ret = -ENOMEM; |
|
goto err; |
|
} |
|
|
|
while ((field_str = strsep(&tmp_fields, ";")) != NULL) { |
|
argv = argv_split(GFP_KERNEL, field_str, &argc); |
|
if (!argv) { |
|
ret = -ENOMEM; |
|
goto err; |
|
} |
|
|
|
if (!argc) { |
|
argv_free(argv); |
|
continue; |
|
} |
|
|
|
n_fields_this_loop = 0; |
|
consumed = 0; |
|
while (argc > consumed) { |
|
int field_version; |
|
|
|
field = parse_synth_field(argc - consumed, |
|
argv + consumed, &consumed, |
|
&field_version); |
|
if (IS_ERR(field)) { |
|
argv_free(argv); |
|
ret = PTR_ERR(field); |
|
goto err; |
|
} |
|
|
|
/* |
|
* Track the highest version of any field we |
|
* found in the command. |
|
*/ |
|
if (field_version > cmd_version) |
|
cmd_version = field_version; |
|
|
|
/* |
|
* Now sort out what is and isn't valid for |
|
* each supported version. |
|
* |
|
* If we see more than 1 field per loop, it |
|
* means we have multiple fields between |
|
* semicolons, and that's something we no |
|
* longer support in a version 2 or greater |
|
* command. |
|
*/ |
|
if (cmd_version > 1 && n_fields_this_loop >= 1) { |
|
synth_err(SYNTH_ERR_INVALID_CMD, errpos(field_str)); |
|
ret = -EINVAL; |
|
goto err; |
|
} |
|
|
|
fields[n_fields++] = field; |
|
if (n_fields == SYNTH_FIELDS_MAX) { |
|
synth_err(SYNTH_ERR_TOO_MANY_FIELDS, 0); |
|
ret = -EINVAL; |
|
goto err; |
|
} |
|
|
|
n_fields_this_loop++; |
|
} |
|
|
|
if (consumed < argc) { |
|
synth_err(SYNTH_ERR_INVALID_CMD, 0); |
|
ret = -EINVAL; |
|
goto err; |
|
} |
|
|
|
argv_free(argv); |
|
} |
|
|
|
if (n_fields == 0) { |
|
synth_err(SYNTH_ERR_INVALID_CMD, 0); |
|
ret = -EINVAL; |
|
goto err; |
|
} |
|
|
|
event = alloc_synth_event(name, n_fields, fields); |
|
if (IS_ERR(event)) { |
|
ret = PTR_ERR(event); |
|
event = NULL; |
|
goto err; |
|
} |
|
ret = register_synth_event(event); |
|
if (!ret) |
|
dyn_event_add(&event->devent); |
|
else |
|
free_synth_event(event); |
|
out: |
|
mutex_unlock(&event_mutex); |
|
|
|
kfree(saved_fields); |
|
|
|
return ret; |
|
err: |
|
for (i = 0; i < n_fields; i++) |
|
free_synth_field(fields[i]); |
|
|
|
goto out; |
|
} |
|
|
|
/** |
|
* synth_event_create - Create a new synthetic event |
|
* @name: The name of the new synthetic event |
|
* @fields: An array of type/name field descriptions |
|
* @n_fields: The number of field descriptions contained in the fields array |
|
* @mod: The module creating the event, NULL if not created from a module |
|
* |
|
* Create a new synthetic event with the given name under the |
|
* trace/events/synthetic/ directory. The event fields that will be |
|
* defined for the event should be passed in as an array of struct |
|
* synth_field_desc, and the number elements in the array passed in as |
|
* n_fields. Field ordering will retain the ordering given in the |
|
* fields array. |
|
* |
|
* If the new synthetic event is being created from a module, the mod |
|
* param must be non-NULL. This will ensure that the trace buffer |
|
* won't contain unreadable events. |
|
* |
|
* The new synth event should be deleted using synth_event_delete() |
|
* function. The new synthetic event can be generated from modules or |
|
* other kernel code using trace_synth_event() and related functions. |
|
* |
|
* Return: 0 if successful, error otherwise. |
|
*/ |
|
int synth_event_create(const char *name, struct synth_field_desc *fields, |
|
unsigned int n_fields, struct module *mod) |
|
{ |
|
struct dynevent_cmd cmd; |
|
char *buf; |
|
int ret; |
|
|
|
buf = kzalloc(MAX_DYNEVENT_CMD_LEN, GFP_KERNEL); |
|
if (!buf) |
|
return -ENOMEM; |
|
|
|
synth_event_cmd_init(&cmd, buf, MAX_DYNEVENT_CMD_LEN); |
|
|
|
ret = synth_event_gen_cmd_array_start(&cmd, name, mod, |
|
fields, n_fields); |
|
if (ret) |
|
goto out; |
|
|
|
ret = synth_event_gen_cmd_end(&cmd); |
|
out: |
|
kfree(buf); |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(synth_event_create); |
|
|
|
static int destroy_synth_event(struct synth_event *se) |
|
{ |
|
int ret; |
|
|
|
if (se->ref) |
|
ret = -EBUSY; |
|
else { |
|
ret = unregister_synth_event(se); |
|
if (!ret) { |
|
dyn_event_remove(&se->devent); |
|
free_synth_event(se); |
|
} |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
/** |
|
* synth_event_delete - Delete a synthetic event |
|
* @event_name: The name of the new synthetic event |
|
* |
|
* Delete a synthetic event that was created with synth_event_create(). |
|
* |
|
* Return: 0 if successful, error otherwise. |
|
*/ |
|
int synth_event_delete(const char *event_name) |
|
{ |
|
struct synth_event *se = NULL; |
|
struct module *mod = NULL; |
|
int ret = -ENOENT; |
|
|
|
mutex_lock(&event_mutex); |
|
se = find_synth_event(event_name); |
|
if (se) { |
|
mod = se->mod; |
|
ret = destroy_synth_event(se); |
|
} |
|
mutex_unlock(&event_mutex); |
|
|
|
if (mod) { |
|
mutex_lock(&trace_types_lock); |
|
/* |
|
* It is safest to reset the ring buffer if the module |
|
* being unloaded registered any events that were |
|
* used. The only worry is if a new module gets |
|
* loaded, and takes on the same id as the events of |
|
* this module. When printing out the buffer, traced |
|
* events left over from this module may be passed to |
|
* the new module events and unexpected results may |
|
* occur. |
|
*/ |
|
tracing_reset_all_online_cpus(); |
|
mutex_unlock(&trace_types_lock); |
|
} |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(synth_event_delete); |
|
|
|
static int check_command(const char *raw_command) |
|
{ |
|
char **argv = NULL, *cmd, *saved_cmd, *name_and_field; |
|
int argc, ret = 0; |
|
|
|
cmd = saved_cmd = kstrdup(raw_command, GFP_KERNEL); |
|
if (!cmd) |
|
return -ENOMEM; |
|
|
|
name_and_field = strsep(&cmd, ";"); |
|
if (!name_and_field) { |
|
ret = -EINVAL; |
|
goto free; |
|
} |
|
|
|
if (name_and_field[0] == '!') |
|
goto free; |
|
|
|
argv = argv_split(GFP_KERNEL, name_and_field, &argc); |
|
if (!argv) { |
|
ret = -ENOMEM; |
|
goto free; |
|
} |
|
argv_free(argv); |
|
|
|
if (argc < 3) |
|
ret = -EINVAL; |
|
free: |
|
kfree(saved_cmd); |
|
|
|
return ret; |
|
} |
|
|
|
static int create_or_delete_synth_event(const char *raw_command) |
|
{ |
|
char *name = NULL, *fields, *p; |
|
int ret = 0; |
|
|
|
raw_command = skip_spaces(raw_command); |
|
if (raw_command[0] == '\0') |
|
return ret; |
|
|
|
last_cmd_set(raw_command); |
|
|
|
ret = check_command(raw_command); |
|
if (ret) { |
|
synth_err(SYNTH_ERR_INVALID_CMD, 0); |
|
return ret; |
|
} |
|
|
|
p = strpbrk(raw_command, " \t"); |
|
if (!p && raw_command[0] != '!') { |
|
synth_err(SYNTH_ERR_INVALID_CMD, 0); |
|
ret = -EINVAL; |
|
goto free; |
|
} |
|
|
|
name = kmemdup_nul(raw_command, p ? p - raw_command : strlen(raw_command), GFP_KERNEL); |
|
if (!name) |
|
return -ENOMEM; |
|
|
|
if (name[0] == '!') { |
|
ret = synth_event_delete(name + 1); |
|
goto free; |
|
} |
|
|
|
fields = skip_spaces(p); |
|
|
|
ret = __create_synth_event(name, fields); |
|
free: |
|
kfree(name); |
|
|
|
return ret; |
|
} |
|
|
|
static int synth_event_run_command(struct dynevent_cmd *cmd) |
|
{ |
|
struct synth_event *se; |
|
int ret; |
|
|
|
ret = create_or_delete_synth_event(cmd->seq.buffer); |
|
if (ret) |
|
return ret; |
|
|
|
se = find_synth_event(cmd->event_name); |
|
if (WARN_ON(!se)) |
|
return -ENOENT; |
|
|
|
se->mod = cmd->private_data; |
|
|
|
return ret; |
|
} |
|
|
|
/** |
|
* synth_event_cmd_init - Initialize a synthetic event command object |
|
* @cmd: A pointer to the dynevent_cmd struct representing the new event |
|
* @buf: A pointer to the buffer used to build the command |
|
* @maxlen: The length of the buffer passed in @buf |
|
* |
|
* Initialize a synthetic event command object. Use this before |
|
* calling any of the other dyenvent_cmd functions. |
|
*/ |
|
void synth_event_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen) |
|
{ |
|
dynevent_cmd_init(cmd, buf, maxlen, DYNEVENT_TYPE_SYNTH, |
|
synth_event_run_command); |
|
} |
|
EXPORT_SYMBOL_GPL(synth_event_cmd_init); |
|
|
|
static inline int |
|
__synth_event_trace_init(struct trace_event_file *file, |
|
struct synth_event_trace_state *trace_state) |
|
{ |
|
int ret = 0; |
|
|
|
memset(trace_state, '\0', sizeof(*trace_state)); |
|
|
|
/* |
|
* Normal event tracing doesn't get called at all unless the |
|
* ENABLED bit is set (which attaches the probe thus allowing |
|
* this code to be called, etc). Because this is called |
|
* directly by the user, we don't have that but we still need |
|
* to honor not logging when disabled. For the iterated |
|
* trace case, we save the enabled state upon start and just |
|
* ignore the following data calls. |
|
*/ |
|
if (!(file->flags & EVENT_FILE_FL_ENABLED) || |
|
trace_trigger_soft_disabled(file)) { |
|
trace_state->disabled = true; |
|
ret = -ENOENT; |
|
goto out; |
|
} |
|
|
|
trace_state->event = file->event_call->data; |
|
out: |
|
return ret; |
|
} |
|
|
|
static inline int |
|
__synth_event_trace_start(struct trace_event_file *file, |
|
struct synth_event_trace_state *trace_state, |
|
int dynamic_fields_size) |
|
{ |
|
int entry_size, fields_size = 0; |
|
int ret = 0; |
|
|
|
fields_size = trace_state->event->n_u64 * sizeof(u64); |
|
fields_size += dynamic_fields_size; |
|
|
|
/* |
|
* Avoid ring buffer recursion detection, as this event |
|
* is being performed within another event. |
|
*/ |
|
trace_state->buffer = file->tr->array_buffer.buffer; |
|
ring_buffer_nest_start(trace_state->buffer); |
|
|
|
entry_size = sizeof(*trace_state->entry) + fields_size; |
|
trace_state->entry = trace_event_buffer_reserve(&trace_state->fbuffer, |
|
file, |
|
entry_size); |
|
if (!trace_state->entry) { |
|
ring_buffer_nest_end(trace_state->buffer); |
|
ret = -EINVAL; |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
static inline void |
|
__synth_event_trace_end(struct synth_event_trace_state *trace_state) |
|
{ |
|
trace_event_buffer_commit(&trace_state->fbuffer); |
|
|
|
ring_buffer_nest_end(trace_state->buffer); |
|
} |
|
|
|
/** |
|
* synth_event_trace - Trace a synthetic event |
|
* @file: The trace_event_file representing the synthetic event |
|
* @n_vals: The number of values in vals |
|
* @args: Variable number of args containing the event values |
|
* |
|
* Trace a synthetic event using the values passed in the variable |
|
* argument list. |
|
* |
|
* The argument list should be a list 'n_vals' u64 values. The number |
|
* of vals must match the number of field in the synthetic event, and |
|
* must be in the same order as the synthetic event fields. |
|
* |
|
* All vals should be cast to u64, and string vals are just pointers |
|
* to strings, cast to u64. Strings will be copied into space |
|
* reserved in the event for the string, using these pointers. |
|
* |
|
* Return: 0 on success, err otherwise. |
|
*/ |
|
int synth_event_trace(struct trace_event_file *file, unsigned int n_vals, ...) |
|
{ |
|
unsigned int i, n_u64, len, data_size = 0; |
|
struct synth_event_trace_state state; |
|
va_list args; |
|
int ret; |
|
|
|
ret = __synth_event_trace_init(file, &state); |
|
if (ret) { |
|
if (ret == -ENOENT) |
|
ret = 0; /* just disabled, not really an error */ |
|
return ret; |
|
} |
|
|
|
if (state.event->n_dynamic_fields) { |
|
va_start(args, n_vals); |
|
|
|
for (i = 0; i < state.event->n_fields; i++) { |
|
u64 val = va_arg(args, u64); |
|
|
|
if (state.event->fields[i]->is_string && |
|
state.event->fields[i]->is_dynamic) { |
|
char *str_val = (char *)(long)val; |
|
|
|
data_size += strlen(str_val) + 1; |
|
} |
|
} |
|
|
|
va_end(args); |
|
} |
|
|
|
ret = __synth_event_trace_start(file, &state, data_size); |
|
if (ret) |
|
return ret; |
|
|
|
if (n_vals != state.event->n_fields) { |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
|
|
data_size = 0; |
|
|
|
va_start(args, n_vals); |
|
for (i = 0, n_u64 = 0; i < state.event->n_fields; i++) { |
|
u64 val; |
|
|
|
val = va_arg(args, u64); |
|
|
|
if (state.event->fields[i]->is_string) { |
|
char *str_val = (char *)(long)val; |
|
|
|
len = trace_string(state.entry, state.event, str_val, |
|
state.event->fields[i]->is_dynamic, |
|
data_size, &n_u64); |
|
data_size += len; /* only dynamic string increments */ |
|
} else { |
|
struct synth_field *field = state.event->fields[i]; |
|
|
|
switch (field->size) { |
|
case 1: |
|
*(u8 *)&state.entry->fields[n_u64] = (u8)val; |
|
break; |
|
|
|
case 2: |
|
*(u16 *)&state.entry->fields[n_u64] = (u16)val; |
|
break; |
|
|
|
case 4: |
|
*(u32 *)&state.entry->fields[n_u64] = (u32)val; |
|
break; |
|
|
|
default: |
|
state.entry->fields[n_u64] = val; |
|
break; |
|
} |
|
n_u64++; |
|
} |
|
} |
|
va_end(args); |
|
out: |
|
__synth_event_trace_end(&state); |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(synth_event_trace); |
|
|
|
/** |
|
* synth_event_trace_array - Trace a synthetic event from an array |
|
* @file: The trace_event_file representing the synthetic event |
|
* @vals: Array of values |
|
* @n_vals: The number of values in vals |
|
* |
|
* Trace a synthetic event using the values passed in as 'vals'. |
|
* |
|
* The 'vals' array is just an array of 'n_vals' u64. The number of |
|
* vals must match the number of field in the synthetic event, and |
|
* must be in the same order as the synthetic event fields. |
|
* |
|
* All vals should be cast to u64, and string vals are just pointers |
|
* to strings, cast to u64. Strings will be copied into space |
|
* reserved in the event for the string, using these pointers. |
|
* |
|
* Return: 0 on success, err otherwise. |
|
*/ |
|
int synth_event_trace_array(struct trace_event_file *file, u64 *vals, |
|
unsigned int n_vals) |
|
{ |
|
unsigned int i, n_u64, field_pos, len, data_size = 0; |
|
struct synth_event_trace_state state; |
|
char *str_val; |
|
int ret; |
|
|
|
ret = __synth_event_trace_init(file, &state); |
|
if (ret) { |
|
if (ret == -ENOENT) |
|
ret = 0; /* just disabled, not really an error */ |
|
return ret; |
|
} |
|
|
|
if (state.event->n_dynamic_fields) { |
|
for (i = 0; i < state.event->n_dynamic_fields; i++) { |
|
field_pos = state.event->dynamic_fields[i]->field_pos; |
|
str_val = (char *)(long)vals[field_pos]; |
|
len = strlen(str_val) + 1; |
|
data_size += len; |
|
} |
|
} |
|
|
|
ret = __synth_event_trace_start(file, &state, data_size); |
|
if (ret) |
|
return ret; |
|
|
|
if (n_vals != state.event->n_fields) { |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
|
|
data_size = 0; |
|
|
|
for (i = 0, n_u64 = 0; i < state.event->n_fields; i++) { |
|
if (state.event->fields[i]->is_string) { |
|
char *str_val = (char *)(long)vals[i]; |
|
|
|
len = trace_string(state.entry, state.event, str_val, |
|
state.event->fields[i]->is_dynamic, |
|
data_size, &n_u64); |
|
data_size += len; /* only dynamic string increments */ |
|
} else { |
|
struct synth_field *field = state.event->fields[i]; |
|
u64 val = vals[i]; |
|
|
|
switch (field->size) { |
|
case 1: |
|
*(u8 *)&state.entry->fields[n_u64] = (u8)val; |
|
break; |
|
|
|
case 2: |
|
*(u16 *)&state.entry->fields[n_u64] = (u16)val; |
|
break; |
|
|
|
case 4: |
|
*(u32 *)&state.entry->fields[n_u64] = (u32)val; |
|
break; |
|
|
|
default: |
|
state.entry->fields[n_u64] = val; |
|
break; |
|
} |
|
n_u64++; |
|
} |
|
} |
|
out: |
|
__synth_event_trace_end(&state); |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(synth_event_trace_array); |
|
|
|
/** |
|
* synth_event_trace_start - Start piecewise synthetic event trace |
|
* @file: The trace_event_file representing the synthetic event |
|
* @trace_state: A pointer to object tracking the piecewise trace state |
|
* |
|
* Start the trace of a synthetic event field-by-field rather than all |
|
* at once. |
|
* |
|
* This function 'opens' an event trace, which means space is reserved |
|
* for the event in the trace buffer, after which the event's |
|
* individual field values can be set through either |
|
* synth_event_add_next_val() or synth_event_add_val(). |
|
* |
|
* A pointer to a trace_state object is passed in, which will keep |
|
* track of the current event trace state until the event trace is |
|
* closed (and the event finally traced) using |
|
* synth_event_trace_end(). |
|
* |
|
* Note that synth_event_trace_end() must be called after all values |
|
* have been added for each event trace, regardless of whether adding |
|
* all field values succeeded or not. |
|
* |
|
* Note also that for a given event trace, all fields must be added |
|
* using either synth_event_add_next_val() or synth_event_add_val() |
|
* but not both together or interleaved. |
|
* |
|
* Return: 0 on success, err otherwise. |
|
*/ |
|
int synth_event_trace_start(struct trace_event_file *file, |
|
struct synth_event_trace_state *trace_state) |
|
{ |
|
int ret; |
|
|
|
if (!trace_state) |
|
return -EINVAL; |
|
|
|
ret = __synth_event_trace_init(file, trace_state); |
|
if (ret) { |
|
if (ret == -ENOENT) |
|
ret = 0; /* just disabled, not really an error */ |
|
return ret; |
|
} |
|
|
|
if (trace_state->event->n_dynamic_fields) |
|
return -ENOTSUPP; |
|
|
|
ret = __synth_event_trace_start(file, trace_state, 0); |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(synth_event_trace_start); |
|
|
|
static int __synth_event_add_val(const char *field_name, u64 val, |
|
struct synth_event_trace_state *trace_state) |
|
{ |
|
struct synth_field *field = NULL; |
|
struct synth_trace_event *entry; |
|
struct synth_event *event; |
|
int i, ret = 0; |
|
|
|
if (!trace_state) { |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
|
|
/* can't mix add_next_synth_val() with add_synth_val() */ |
|
if (field_name) { |
|
if (trace_state->add_next) { |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
trace_state->add_name = true; |
|
} else { |
|
if (trace_state->add_name) { |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
trace_state->add_next = true; |
|
} |
|
|
|
if (trace_state->disabled) |
|
goto out; |
|
|
|
event = trace_state->event; |
|
if (trace_state->add_name) { |
|
for (i = 0; i < event->n_fields; i++) { |
|
field = event->fields[i]; |
|
if (strcmp(field->name, field_name) == 0) |
|
break; |
|
} |
|
if (!field) { |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
} else { |
|
if (trace_state->cur_field >= event->n_fields) { |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
field = event->fields[trace_state->cur_field++]; |
|
} |
|
|
|
entry = trace_state->entry; |
|
if (field->is_string) { |
|
char *str_val = (char *)(long)val; |
|
char *str_field; |
|
|
|
if (field->is_dynamic) { /* add_val can't do dynamic strings */ |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
|
|
if (!str_val) { |
|
ret = -EINVAL; |
|
goto out; |
|
} |
|
|
|
str_field = (char *)&entry->fields[field->offset]; |
|
strscpy(str_field, str_val, STR_VAR_LEN_MAX); |
|
} else { |
|
switch (field->size) { |
|
case 1: |
|
*(u8 *)&trace_state->entry->fields[field->offset] = (u8)val; |
|
break; |
|
|
|
case 2: |
|
*(u16 *)&trace_state->entry->fields[field->offset] = (u16)val; |
|
break; |
|
|
|
case 4: |
|
*(u32 *)&trace_state->entry->fields[field->offset] = (u32)val; |
|
break; |
|
|
|
default: |
|
trace_state->entry->fields[field->offset] = val; |
|
break; |
|
} |
|
} |
|
out: |
|
return ret; |
|
} |
|
|
|
/** |
|
* synth_event_add_next_val - Add the next field's value to an open synth trace |
|
* @val: The value to set the next field to |
|
* @trace_state: A pointer to object tracking the piecewise trace state |
|
* |
|
* Set the value of the next field in an event that's been opened by |
|
* synth_event_trace_start(). |
|
* |
|
* The val param should be the value cast to u64. If the value points |
|
* to a string, the val param should be a char * cast to u64. |
|
* |
|
* This function assumes all the fields in an event are to be set one |
|
* after another - successive calls to this function are made, one for |
|
* each field, in the order of the fields in the event, until all |
|
* fields have been set. If you'd rather set each field individually |
|
* without regard to ordering, synth_event_add_val() can be used |
|
* instead. |
|
* |
|
* Note however that synth_event_add_next_val() and |
|
* synth_event_add_val() can't be intermixed for a given event trace - |
|
* one or the other but not both can be used at the same time. |
|
* |
|
* Note also that synth_event_trace_end() must be called after all |
|
* values have been added for each event trace, regardless of whether |
|
* adding all field values succeeded or not. |
|
* |
|
* Return: 0 on success, err otherwise. |
|
*/ |
|
int synth_event_add_next_val(u64 val, |
|
struct synth_event_trace_state *trace_state) |
|
{ |
|
return __synth_event_add_val(NULL, val, trace_state); |
|
} |
|
EXPORT_SYMBOL_GPL(synth_event_add_next_val); |
|
|
|
/** |
|
* synth_event_add_val - Add a named field's value to an open synth trace |
|
* @field_name: The name of the synthetic event field value to set |
|
* @val: The value to set the next field to |
|
* @trace_state: A pointer to object tracking the piecewise trace state |
|
* |
|
* Set the value of the named field in an event that's been opened by |
|
* synth_event_trace_start(). |
|
* |
|
* The val param should be the value cast to u64. If the value points |
|
* to a string, the val param should be a char * cast to u64. |
|
* |
|
* This function looks up the field name, and if found, sets the field |
|
* to the specified value. This lookup makes this function more |
|
* expensive than synth_event_add_next_val(), so use that or the |
|
* none-piecewise synth_event_trace() instead if efficiency is more |
|
* important. |
|
* |
|
* Note however that synth_event_add_next_val() and |
|
* synth_event_add_val() can't be intermixed for a given event trace - |
|
* one or the other but not both can be used at the same time. |
|
* |
|
* Note also that synth_event_trace_end() must be called after all |
|
* values have been added for each event trace, regardless of whether |
|
* adding all field values succeeded or not. |
|
* |
|
* Return: 0 on success, err otherwise. |
|
*/ |
|
int synth_event_add_val(const char *field_name, u64 val, |
|
struct synth_event_trace_state *trace_state) |
|
{ |
|
return __synth_event_add_val(field_name, val, trace_state); |
|
} |
|
EXPORT_SYMBOL_GPL(synth_event_add_val); |
|
|
|
/** |
|
* synth_event_trace_end - End piecewise synthetic event trace |
|
* @trace_state: A pointer to object tracking the piecewise trace state |
|
* |
|
* End the trace of a synthetic event opened by |
|
* synth_event_trace__start(). |
|
* |
|
* This function 'closes' an event trace, which basically means that |
|
* it commits the reserved event and cleans up other loose ends. |
|
* |
|
* A pointer to a trace_state object is passed in, which will keep |
|
* track of the current event trace state opened with |
|
* synth_event_trace_start(). |
|
* |
|
* Note that this function must be called after all values have been |
|
* added for each event trace, regardless of whether adding all field |
|
* values succeeded or not. |
|
* |
|
* Return: 0 on success, err otherwise. |
|
*/ |
|
int synth_event_trace_end(struct synth_event_trace_state *trace_state) |
|
{ |
|
if (!trace_state) |
|
return -EINVAL; |
|
|
|
__synth_event_trace_end(trace_state); |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(synth_event_trace_end); |
|
|
|
static int create_synth_event(const char *raw_command) |
|
{ |
|
char *fields, *p; |
|
const char *name; |
|
int len, ret = 0; |
|
|
|
raw_command = skip_spaces(raw_command); |
|
if (raw_command[0] == '\0') |
|
return ret; |
|
|
|
last_cmd_set(raw_command); |
|
|
|
p = strpbrk(raw_command, " \t"); |
|
if (!p) { |
|
synth_err(SYNTH_ERR_INVALID_CMD, 0); |
|
return -EINVAL; |
|
} |
|
|
|
fields = skip_spaces(p); |
|
|
|
name = raw_command; |
|
|
|
if (name[0] != 's' || name[1] != ':') |
|
return -ECANCELED; |
|
name += 2; |
|
|
|
/* This interface accepts group name prefix */ |
|
if (strchr(name, '/')) { |
|
len = str_has_prefix(name, SYNTH_SYSTEM "/"); |
|
if (len == 0) { |
|
synth_err(SYNTH_ERR_INVALID_DYN_CMD, 0); |
|
return -EINVAL; |
|
} |
|
name += len; |
|
} |
|
|
|
len = name - raw_command; |
|
|
|
ret = check_command(raw_command + len); |
|
if (ret) { |
|
synth_err(SYNTH_ERR_INVALID_CMD, 0); |
|
return ret; |
|
} |
|
|
|
name = kmemdup_nul(raw_command + len, p - raw_command - len, GFP_KERNEL); |
|
if (!name) |
|
return -ENOMEM; |
|
|
|
ret = __create_synth_event(name, fields); |
|
|
|
kfree(name); |
|
|
|
return ret; |
|
} |
|
|
|
static int synth_event_release(struct dyn_event *ev) |
|
{ |
|
struct synth_event *event = to_synth_event(ev); |
|
int ret; |
|
|
|
if (event->ref) |
|
return -EBUSY; |
|
|
|
ret = unregister_synth_event(event); |
|
if (ret) |
|
return ret; |
|
|
|
dyn_event_remove(ev); |
|
free_synth_event(event); |
|
return 0; |
|
} |
|
|
|
static int __synth_event_show(struct seq_file *m, struct synth_event *event) |
|
{ |
|
struct synth_field *field; |
|
unsigned int i; |
|
char *type, *t; |
|
|
|
seq_printf(m, "%s\t", event->name); |
|
|
|
for (i = 0; i < event->n_fields; i++) { |
|
field = event->fields[i]; |
|
|
|
type = field->type; |
|
t = strstr(type, "__data_loc"); |
|
if (t) { /* __data_loc belongs in format but not event desc */ |
|
t += sizeof("__data_loc"); |
|
type = t; |
|
} |
|
|
|
/* parameter values */ |
|
seq_printf(m, "%s %s%s", type, field->name, |
|
i == event->n_fields - 1 ? "" : "; "); |
|
} |
|
|
|
seq_putc(m, '\n'); |
|
|
|
return 0; |
|
} |
|
|
|
static int synth_event_show(struct seq_file *m, struct dyn_event *ev) |
|
{ |
|
struct synth_event *event = to_synth_event(ev); |
|
|
|
seq_printf(m, "s:%s/", event->class.system); |
|
|
|
return __synth_event_show(m, event); |
|
} |
|
|
|
static int synth_events_seq_show(struct seq_file *m, void *v) |
|
{ |
|
struct dyn_event *ev = v; |
|
|
|
if (!is_synth_event(ev)) |
|
return 0; |
|
|
|
return __synth_event_show(m, to_synth_event(ev)); |
|
} |
|
|
|
static const struct seq_operations synth_events_seq_op = { |
|
.start = dyn_event_seq_start, |
|
.next = dyn_event_seq_next, |
|
.stop = dyn_event_seq_stop, |
|
.show = synth_events_seq_show, |
|
}; |
|
|
|
static int synth_events_open(struct inode *inode, struct file *file) |
|
{ |
|
int ret; |
|
|
|
ret = security_locked_down(LOCKDOWN_TRACEFS); |
|
if (ret) |
|
return ret; |
|
|
|
if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { |
|
ret = dyn_events_release_all(&synth_event_ops); |
|
if (ret < 0) |
|
return ret; |
|
} |
|
|
|
return seq_open(file, &synth_events_seq_op); |
|
} |
|
|
|
static ssize_t synth_events_write(struct file *file, |
|
const char __user *buffer, |
|
size_t count, loff_t *ppos) |
|
{ |
|
return trace_parse_run_command(file, buffer, count, ppos, |
|
create_or_delete_synth_event); |
|
} |
|
|
|
static const struct file_operations synth_events_fops = { |
|
.open = synth_events_open, |
|
.write = synth_events_write, |
|
.read = seq_read, |
|
.llseek = seq_lseek, |
|
.release = seq_release, |
|
}; |
|
|
|
/* |
|
* Register dynevent at core_initcall. This allows kernel to setup kprobe |
|
* events in postcore_initcall without tracefs. |
|
*/ |
|
static __init int trace_events_synth_init_early(void) |
|
{ |
|
int err = 0; |
|
|
|
err = dyn_event_register(&synth_event_ops); |
|
if (err) |
|
pr_warn("Could not register synth_event_ops\n"); |
|
|
|
return err; |
|
} |
|
core_initcall(trace_events_synth_init_early); |
|
|
|
static __init int trace_events_synth_init(void) |
|
{ |
|
struct dentry *entry = NULL; |
|
int err = 0; |
|
err = tracing_init_dentry(); |
|
if (err) |
|
goto err; |
|
|
|
entry = tracefs_create_file("synthetic_events", 0644, NULL, |
|
NULL, &synth_events_fops); |
|
if (!entry) { |
|
err = -ENODEV; |
|
goto err; |
|
} |
|
|
|
return err; |
|
err: |
|
pr_warn("Could not create tracefs 'synthetic_events' entry\n"); |
|
|
|
return err; |
|
} |
|
|
|
fs_initcall(trace_events_synth_init);
|
|
|