Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0
2 : /*
3 : * event tracer
4 : *
5 : * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
6 : *
7 : * - Added format output of fields of the trace point.
8 : * This was based off of work by Tom Zanussi <tzanussi@gmail.com>.
9 : *
10 : */
11 :
12 : #define pr_fmt(fmt) fmt
13 :
14 : #include <linux/workqueue.h>
15 : #include <linux/security.h>
16 : #include <linux/spinlock.h>
17 : #include <linux/kthread.h>
18 : #include <linux/tracefs.h>
19 : #include <linux/uaccess.h>
20 : #include <linux/module.h>
21 : #include <linux/ctype.h>
22 : #include <linux/sort.h>
23 : #include <linux/slab.h>
24 : #include <linux/delay.h>
25 :
26 : #include <trace/events/sched.h>
27 : #include <trace/syscall.h>
28 :
29 : #include <asm/setup.h>
30 :
31 : #include "trace_output.h"
32 :
33 : #undef TRACE_SYSTEM
34 : #define TRACE_SYSTEM "TRACE_SYSTEM"
35 :
36 : DEFINE_MUTEX(event_mutex);
37 :
38 : LIST_HEAD(ftrace_events);
39 : static LIST_HEAD(ftrace_generic_fields);
40 : static LIST_HEAD(ftrace_common_fields);
41 : static bool eventdir_initialized;
42 :
43 : #define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
44 :
45 : static struct kmem_cache *field_cachep;
46 : static struct kmem_cache *file_cachep;
47 :
48 0 : static inline int system_refcount(struct event_subsystem *system)
49 : {
50 0 : return system->ref_count;
51 : }
52 :
53 0 : static int system_refcount_inc(struct event_subsystem *system)
54 : {
55 0 : return system->ref_count++;
56 : }
57 :
58 0 : static int system_refcount_dec(struct event_subsystem *system)
59 : {
60 0 : return --system->ref_count;
61 : }
62 :
63 : /* Double loops, do not use break, only goto's work */
64 : #define do_for_each_event_file(tr, file) \
65 : list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
66 : list_for_each_entry(file, &tr->events, list)
67 :
68 : #define do_for_each_event_file_safe(tr, file) \
69 : list_for_each_entry(tr, &ftrace_trace_arrays, list) { \
70 : struct trace_event_file *___n; \
71 : list_for_each_entry_safe(file, ___n, &tr->events, list)
72 :
73 : #define while_for_each_event_file() \
74 : }
75 :
76 : static struct ftrace_event_field *
77 0 : __find_event_field(struct list_head *head, char *name)
78 : {
79 0 : struct ftrace_event_field *field;
80 :
81 0 : list_for_each_entry(field, head, link) {
82 0 : if (!strcmp(field->name, name))
83 0 : return field;
84 : }
85 :
86 : return NULL;
87 : }
88 :
89 : struct ftrace_event_field *
90 0 : trace_find_event_field(struct trace_event_call *call, char *name)
91 : {
92 0 : struct ftrace_event_field *field;
93 0 : struct list_head *head;
94 :
95 0 : head = trace_get_fields(call);
96 0 : field = __find_event_field(head, name);
97 0 : if (field)
98 : return field;
99 :
100 0 : field = __find_event_field(&ftrace_generic_fields, name);
101 0 : if (field)
102 : return field;
103 :
104 0 : return __find_event_field(&ftrace_common_fields, name);
105 : }
106 :
107 1686 : static int __trace_define_field(struct list_head *head, const char *type,
108 : const char *name, int offset, int size,
109 : int is_signed, int filter_type)
110 : {
111 1686 : struct ftrace_event_field *field;
112 :
113 1686 : field = kmem_cache_alloc(field_cachep, GFP_TRACE);
114 1686 : if (!field)
115 : return -ENOMEM;
116 :
117 1686 : field->name = name;
118 1686 : field->type = type;
119 :
120 1686 : if (filter_type == FILTER_OTHER)
121 1680 : field->filter_type = filter_assign_type(type);
122 : else
123 6 : field->filter_type = filter_type;
124 :
125 1686 : field->offset = offset;
126 1686 : field->size = size;
127 1686 : field->is_signed = is_signed;
128 :
129 1686 : list_add(&field->link, head);
130 :
131 1686 : return 0;
132 : }
133 :
134 1678 : int trace_define_field(struct trace_event_call *call, const char *type,
135 : const char *name, int offset, int size, int is_signed,
136 : int filter_type)
137 : {
138 1678 : struct list_head *head;
139 :
140 1678 : if (WARN_ON(!call->class))
141 : return 0;
142 :
143 1678 : head = trace_get_fields(call);
144 1678 : return __trace_define_field(head, type, name, offset, size,
145 : is_signed, filter_type);
146 : }
147 : EXPORT_SYMBOL_GPL(trace_define_field);
148 :
149 : #define __generic_field(type, item, filter_type) \
150 : ret = __trace_define_field(&ftrace_generic_fields, #type, \
151 : #item, 0, 0, is_signed_type(type), \
152 : filter_type); \
153 : if (ret) \
154 : return ret;
155 :
156 : #define __common_field(type, item) \
157 : ret = __trace_define_field(&ftrace_common_fields, #type, \
158 : "common_" #item, \
159 : offsetof(typeof(ent), item), \
160 : sizeof(ent.item), \
161 : is_signed_type(type), FILTER_OTHER); \
162 : if (ret) \
163 : return ret;
164 :
165 1 : static int trace_define_generic_fields(void)
166 : {
167 1 : int ret;
168 :
169 1 : __generic_field(int, CPU, FILTER_CPU);
170 1 : __generic_field(int, cpu, FILTER_CPU);
171 1 : __generic_field(char *, COMM, FILTER_COMM);
172 1 : __generic_field(char *, comm, FILTER_COMM);
173 :
174 : return ret;
175 : }
176 :
177 1 : static int trace_define_common_fields(void)
178 : {
179 1 : int ret;
180 1 : struct trace_entry ent;
181 :
182 1 : __common_field(unsigned short, type);
183 1 : __common_field(unsigned char, flags);
184 1 : __common_field(unsigned char, preempt_count);
185 1 : __common_field(int, pid);
186 :
187 : return ret;
188 : }
189 :
190 0 : static void trace_destroy_fields(struct trace_event_call *call)
191 : {
192 0 : struct ftrace_event_field *field, *next;
193 0 : struct list_head *head;
194 :
195 0 : head = trace_get_fields(call);
196 0 : list_for_each_entry_safe(field, next, head, link) {
197 0 : list_del(&field->link);
198 0 : kmem_cache_free(field_cachep, field);
199 : }
200 0 : }
201 :
202 : /*
203 : * run-time version of trace_event_get_offsets_<call>() that returns the last
204 : * accessible offset of trace fields excluding __dynamic_array bytes
205 : */
206 0 : int trace_event_get_offsets(struct trace_event_call *call)
207 : {
208 0 : struct ftrace_event_field *tail;
209 0 : struct list_head *head;
210 :
211 0 : head = trace_get_fields(call);
212 : /*
213 : * head->next points to the last field with the largest offset,
214 : * since it was added last by trace_define_field()
215 : */
216 0 : tail = list_first_entry(head, struct ftrace_event_field, link);
217 0 : return tail->offset + tail->size;
218 : }
219 :
220 527 : int trace_event_raw_init(struct trace_event_call *call)
221 : {
222 527 : int id;
223 :
224 527 : id = register_trace_event(&call->event);
225 527 : if (!id)
226 0 : return -ENODEV;
227 :
228 : return 0;
229 : }
230 : EXPORT_SYMBOL_GPL(trace_event_raw_init);
231 :
232 0 : bool trace_event_ignore_this_pid(struct trace_event_file *trace_file)
233 : {
234 0 : struct trace_array *tr = trace_file->tr;
235 0 : struct trace_array_cpu *data;
236 0 : struct trace_pid_list *no_pid_list;
237 0 : struct trace_pid_list *pid_list;
238 :
239 0 : pid_list = rcu_dereference_raw(tr->filtered_pids);
240 0 : no_pid_list = rcu_dereference_raw(tr->filtered_no_pids);
241 :
242 0 : if (!pid_list && !no_pid_list)
243 : return false;
244 :
245 0 : data = this_cpu_ptr(tr->array_buffer.data);
246 :
247 0 : return data->ignore_pid;
248 : }
249 : EXPORT_SYMBOL_GPL(trace_event_ignore_this_pid);
250 :
251 0 : void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer,
252 : struct trace_event_file *trace_file,
253 : unsigned long len)
254 : {
255 0 : struct trace_event_call *event_call = trace_file->event_call;
256 :
257 0 : if ((trace_file->flags & EVENT_FILE_FL_PID_FILTER) &&
258 0 : trace_event_ignore_this_pid(trace_file))
259 : return NULL;
260 :
261 : /*
262 : * If CONFIG_PREEMPTION is enabled, then the tracepoint itself disables
263 : * preemption (adding one to the preempt_count). Since we are
264 : * interested in the preempt_count at the time the tracepoint was
265 : * hit, we need to subtract one to offset the increment.
266 : */
267 0 : fbuffer->trace_ctx = tracing_gen_ctx_dec();
268 0 : fbuffer->trace_file = trace_file;
269 :
270 0 : fbuffer->event =
271 0 : trace_event_buffer_lock_reserve(&fbuffer->buffer, trace_file,
272 : event_call->event.type, len,
273 : fbuffer->trace_ctx);
274 0 : if (!fbuffer->event)
275 : return NULL;
276 :
277 0 : fbuffer->regs = NULL;
278 0 : fbuffer->entry = ring_buffer_event_data(fbuffer->event);
279 0 : return fbuffer->entry;
280 : }
281 : EXPORT_SYMBOL_GPL(trace_event_buffer_reserve);
282 :
283 0 : int trace_event_reg(struct trace_event_call *call,
284 : enum trace_reg type, void *data)
285 : {
286 0 : struct trace_event_file *file = data;
287 :
288 0 : WARN_ON(!(call->flags & TRACE_EVENT_FL_TRACEPOINT));
289 0 : switch (type) {
290 0 : case TRACE_REG_REGISTER:
291 0 : return tracepoint_probe_register(call->tp,
292 0 : call->class->probe,
293 : file);
294 0 : case TRACE_REG_UNREGISTER:
295 0 : tracepoint_probe_unregister(call->tp,
296 0 : call->class->probe,
297 : file);
298 0 : return 0;
299 :
300 : #ifdef CONFIG_PERF_EVENTS
301 0 : case TRACE_REG_PERF_REGISTER:
302 0 : return tracepoint_probe_register(call->tp,
303 0 : call->class->perf_probe,
304 : call);
305 0 : case TRACE_REG_PERF_UNREGISTER:
306 0 : tracepoint_probe_unregister(call->tp,
307 0 : call->class->perf_probe,
308 : call);
309 0 : return 0;
310 : case TRACE_REG_PERF_OPEN:
311 : case TRACE_REG_PERF_CLOSE:
312 : case TRACE_REG_PERF_ADD:
313 : case TRACE_REG_PERF_DEL:
314 : return 0;
315 : #endif
316 : }
317 : return 0;
318 : }
319 : EXPORT_SYMBOL_GPL(trace_event_reg);
320 :
321 0 : void trace_event_enable_cmd_record(bool enable)
322 : {
323 0 : struct trace_event_file *file;
324 0 : struct trace_array *tr;
325 :
326 0 : lockdep_assert_held(&event_mutex);
327 :
328 0 : do_for_each_event_file(tr, file) {
329 :
330 0 : if (!(file->flags & EVENT_FILE_FL_ENABLED))
331 0 : continue;
332 :
333 0 : if (enable) {
334 0 : tracing_start_cmdline_record();
335 0 : set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
336 : } else {
337 0 : tracing_stop_cmdline_record();
338 0 : clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
339 : }
340 0 : } while_for_each_event_file();
341 0 : }
342 :
343 0 : void trace_event_enable_tgid_record(bool enable)
344 : {
345 0 : struct trace_event_file *file;
346 0 : struct trace_array *tr;
347 :
348 0 : lockdep_assert_held(&event_mutex);
349 :
350 0 : do_for_each_event_file(tr, file) {
351 0 : if (!(file->flags & EVENT_FILE_FL_ENABLED))
352 0 : continue;
353 :
354 0 : if (enable) {
355 0 : tracing_start_tgid_record();
356 0 : set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
357 : } else {
358 0 : tracing_stop_tgid_record();
359 0 : clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT,
360 0 : &file->flags);
361 : }
362 0 : } while_for_each_event_file();
363 0 : }
364 :
365 0 : static int __ftrace_event_enable_disable(struct trace_event_file *file,
366 : int enable, int soft_disable)
367 : {
368 0 : struct trace_event_call *call = file->event_call;
369 0 : struct trace_array *tr = file->tr;
370 0 : unsigned long file_flags = file->flags;
371 0 : int ret = 0;
372 0 : int disable;
373 :
374 0 : switch (enable) {
375 0 : case 0:
376 : /*
377 : * When soft_disable is set and enable is cleared, the sm_ref
378 : * reference counter is decremented. If it reaches 0, we want
379 : * to clear the SOFT_DISABLED flag but leave the event in the
380 : * state that it was. That is, if the event was enabled and
381 : * SOFT_DISABLED isn't set, then do nothing. But if SOFT_DISABLED
382 : * is set we do not want the event to be enabled before we
383 : * clear the bit.
384 : *
385 : * When soft_disable is not set but the SOFT_MODE flag is,
386 : * we do nothing. Do not disable the tracepoint, otherwise
387 : * "soft enable"s (clearing the SOFT_DISABLED bit) wont work.
388 : */
389 0 : if (soft_disable) {
390 0 : if (atomic_dec_return(&file->sm_ref) > 0)
391 : break;
392 0 : disable = file->flags & EVENT_FILE_FL_SOFT_DISABLED;
393 0 : clear_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
394 : } else
395 0 : disable = !(file->flags & EVENT_FILE_FL_SOFT_MODE);
396 :
397 0 : if (disable && (file->flags & EVENT_FILE_FL_ENABLED)) {
398 0 : clear_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
399 0 : if (file->flags & EVENT_FILE_FL_RECORDED_CMD) {
400 0 : tracing_stop_cmdline_record();
401 0 : clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
402 : }
403 :
404 0 : if (file->flags & EVENT_FILE_FL_RECORDED_TGID) {
405 0 : tracing_stop_tgid_record();
406 0 : clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
407 : }
408 :
409 0 : call->class->reg(call, TRACE_REG_UNREGISTER, file);
410 : }
411 : /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
412 0 : if (file->flags & EVENT_FILE_FL_SOFT_MODE)
413 0 : set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
414 : else
415 0 : clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
416 : break;
417 0 : case 1:
418 : /*
419 : * When soft_disable is set and enable is set, we want to
420 : * register the tracepoint for the event, but leave the event
421 : * as is. That means, if the event was already enabled, we do
422 : * nothing (but set SOFT_MODE). If the event is disabled, we
423 : * set SOFT_DISABLED before enabling the event tracepoint, so
424 : * it still seems to be disabled.
425 : */
426 0 : if (!soft_disable)
427 0 : clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
428 : else {
429 0 : if (atomic_inc_return(&file->sm_ref) > 1)
430 : break;
431 0 : set_bit(EVENT_FILE_FL_SOFT_MODE_BIT, &file->flags);
432 : }
433 :
434 0 : if (!(file->flags & EVENT_FILE_FL_ENABLED)) {
435 0 : bool cmd = false, tgid = false;
436 :
437 : /* Keep the event disabled, when going to SOFT_MODE. */
438 0 : if (soft_disable)
439 0 : set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
440 :
441 0 : if (tr->trace_flags & TRACE_ITER_RECORD_CMD) {
442 0 : cmd = true;
443 0 : tracing_start_cmdline_record();
444 0 : set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
445 : }
446 :
447 0 : if (tr->trace_flags & TRACE_ITER_RECORD_TGID) {
448 0 : tgid = true;
449 0 : tracing_start_tgid_record();
450 0 : set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
451 : }
452 :
453 0 : ret = call->class->reg(call, TRACE_REG_REGISTER, file);
454 0 : if (ret) {
455 0 : if (cmd)
456 0 : tracing_stop_cmdline_record();
457 0 : if (tgid)
458 0 : tracing_stop_tgid_record();
459 0 : pr_info("event trace: Could not enable event "
460 : "%s\n", trace_event_name(call));
461 0 : break;
462 : }
463 0 : set_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
464 :
465 : /* WAS_ENABLED gets set but never cleared. */
466 0 : set_bit(EVENT_FILE_FL_WAS_ENABLED_BIT, &file->flags);
467 : }
468 : break;
469 : }
470 :
471 : /* Enable or disable use of trace_buffered_event */
472 0 : if ((file_flags & EVENT_FILE_FL_SOFT_DISABLED) !=
473 0 : (file->flags & EVENT_FILE_FL_SOFT_DISABLED)) {
474 0 : if (file->flags & EVENT_FILE_FL_SOFT_DISABLED)
475 0 : trace_buffered_event_enable();
476 : else
477 0 : trace_buffered_event_disable();
478 : }
479 :
480 0 : return ret;
481 : }
482 :
483 0 : int trace_event_enable_disable(struct trace_event_file *file,
484 : int enable, int soft_disable)
485 : {
486 0 : return __ftrace_event_enable_disable(file, enable, soft_disable);
487 : }
488 :
489 0 : static int ftrace_event_enable_disable(struct trace_event_file *file,
490 : int enable)
491 : {
492 0 : return __ftrace_event_enable_disable(file, enable, 0);
493 : }
494 :
495 0 : static void ftrace_clear_events(struct trace_array *tr)
496 : {
497 0 : struct trace_event_file *file;
498 :
499 0 : mutex_lock(&event_mutex);
500 0 : list_for_each_entry(file, &tr->events, list) {
501 0 : ftrace_event_enable_disable(file, 0);
502 : }
503 0 : mutex_unlock(&event_mutex);
504 0 : }
505 :
506 : static void
507 0 : event_filter_pid_sched_process_exit(void *data, struct task_struct *task)
508 : {
509 0 : struct trace_pid_list *pid_list;
510 0 : struct trace_array *tr = data;
511 :
512 0 : pid_list = rcu_dereference_raw(tr->filtered_pids);
513 0 : trace_filter_add_remove_task(pid_list, NULL, task);
514 :
515 0 : pid_list = rcu_dereference_raw(tr->filtered_no_pids);
516 0 : trace_filter_add_remove_task(pid_list, NULL, task);
517 0 : }
518 :
519 : static void
520 0 : event_filter_pid_sched_process_fork(void *data,
521 : struct task_struct *self,
522 : struct task_struct *task)
523 : {
524 0 : struct trace_pid_list *pid_list;
525 0 : struct trace_array *tr = data;
526 :
527 0 : pid_list = rcu_dereference_sched(tr->filtered_pids);
528 0 : trace_filter_add_remove_task(pid_list, self, task);
529 :
530 0 : pid_list = rcu_dereference_sched(tr->filtered_no_pids);
531 0 : trace_filter_add_remove_task(pid_list, self, task);
532 0 : }
533 :
534 0 : void trace_event_follow_fork(struct trace_array *tr, bool enable)
535 : {
536 0 : if (enable) {
537 0 : register_trace_prio_sched_process_fork(event_filter_pid_sched_process_fork,
538 : tr, INT_MIN);
539 0 : register_trace_prio_sched_process_free(event_filter_pid_sched_process_exit,
540 : tr, INT_MAX);
541 : } else {
542 0 : unregister_trace_sched_process_fork(event_filter_pid_sched_process_fork,
543 : tr);
544 0 : unregister_trace_sched_process_free(event_filter_pid_sched_process_exit,
545 : tr);
546 : }
547 0 : }
548 :
549 : static void
550 0 : event_filter_pid_sched_switch_probe_pre(void *data, bool preempt,
551 : struct task_struct *prev, struct task_struct *next)
552 : {
553 0 : struct trace_array *tr = data;
554 0 : struct trace_pid_list *no_pid_list;
555 0 : struct trace_pid_list *pid_list;
556 0 : bool ret;
557 :
558 0 : pid_list = rcu_dereference_sched(tr->filtered_pids);
559 0 : no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
560 :
561 : /*
562 : * Sched switch is funny, as we only want to ignore it
563 : * in the notrace case if both prev and next should be ignored.
564 : */
565 0 : ret = trace_ignore_this_task(NULL, no_pid_list, prev) &&
566 0 : trace_ignore_this_task(NULL, no_pid_list, next);
567 :
568 0 : this_cpu_write(tr->array_buffer.data->ignore_pid, ret ||
569 : (trace_ignore_this_task(pid_list, NULL, prev) &&
570 : trace_ignore_this_task(pid_list, NULL, next)));
571 0 : }
572 :
573 : static void
574 0 : event_filter_pid_sched_switch_probe_post(void *data, bool preempt,
575 : struct task_struct *prev, struct task_struct *next)
576 : {
577 0 : struct trace_array *tr = data;
578 0 : struct trace_pid_list *no_pid_list;
579 0 : struct trace_pid_list *pid_list;
580 :
581 0 : pid_list = rcu_dereference_sched(tr->filtered_pids);
582 0 : no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
583 :
584 0 : this_cpu_write(tr->array_buffer.data->ignore_pid,
585 : trace_ignore_this_task(pid_list, no_pid_list, next));
586 0 : }
587 :
588 : static void
589 0 : event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task)
590 : {
591 0 : struct trace_array *tr = data;
592 0 : struct trace_pid_list *no_pid_list;
593 0 : struct trace_pid_list *pid_list;
594 :
595 : /* Nothing to do if we are already tracing */
596 0 : if (!this_cpu_read(tr->array_buffer.data->ignore_pid))
597 : return;
598 :
599 0 : pid_list = rcu_dereference_sched(tr->filtered_pids);
600 0 : no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
601 :
602 0 : this_cpu_write(tr->array_buffer.data->ignore_pid,
603 : trace_ignore_this_task(pid_list, no_pid_list, task));
604 : }
605 :
606 : static void
607 0 : event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task)
608 : {
609 0 : struct trace_array *tr = data;
610 0 : struct trace_pid_list *no_pid_list;
611 0 : struct trace_pid_list *pid_list;
612 :
613 : /* Nothing to do if we are not tracing */
614 0 : if (this_cpu_read(tr->array_buffer.data->ignore_pid))
615 : return;
616 :
617 0 : pid_list = rcu_dereference_sched(tr->filtered_pids);
618 0 : no_pid_list = rcu_dereference_sched(tr->filtered_no_pids);
619 :
620 : /* Set tracing if current is enabled */
621 0 : this_cpu_write(tr->array_buffer.data->ignore_pid,
622 : trace_ignore_this_task(pid_list, no_pid_list, current));
623 : }
624 :
625 0 : static void unregister_pid_events(struct trace_array *tr)
626 : {
627 0 : unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_pre, tr);
628 0 : unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_post, tr);
629 :
630 0 : unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre, tr);
631 0 : unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_post, tr);
632 :
633 0 : unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre, tr);
634 0 : unregister_trace_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post, tr);
635 :
636 0 : unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_pre, tr);
637 0 : unregister_trace_sched_waking(event_filter_pid_sched_wakeup_probe_post, tr);
638 0 : }
639 :
640 0 : static void __ftrace_clear_event_pids(struct trace_array *tr, int type)
641 : {
642 0 : struct trace_pid_list *pid_list;
643 0 : struct trace_pid_list *no_pid_list;
644 0 : struct trace_event_file *file;
645 0 : int cpu;
646 :
647 0 : pid_list = rcu_dereference_protected(tr->filtered_pids,
648 : lockdep_is_held(&event_mutex));
649 0 : no_pid_list = rcu_dereference_protected(tr->filtered_no_pids,
650 : lockdep_is_held(&event_mutex));
651 :
652 : /* Make sure there's something to do */
653 0 : if (!pid_type_enabled(type, pid_list, no_pid_list))
654 : return;
655 :
656 0 : if (!still_need_pid_events(type, pid_list, no_pid_list)) {
657 0 : unregister_pid_events(tr);
658 :
659 0 : list_for_each_entry(file, &tr->events, list) {
660 0 : clear_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
661 : }
662 :
663 0 : for_each_possible_cpu(cpu)
664 0 : per_cpu_ptr(tr->array_buffer.data, cpu)->ignore_pid = false;
665 : }
666 :
667 0 : if (type & TRACE_PIDS)
668 0 : rcu_assign_pointer(tr->filtered_pids, NULL);
669 :
670 0 : if (type & TRACE_NO_PIDS)
671 0 : rcu_assign_pointer(tr->filtered_no_pids, NULL);
672 :
673 : /* Wait till all users are no longer using pid filtering */
674 0 : tracepoint_synchronize_unregister();
675 :
676 0 : if ((type & TRACE_PIDS) && pid_list)
677 0 : trace_free_pid_list(pid_list);
678 :
679 0 : if ((type & TRACE_NO_PIDS) && no_pid_list)
680 0 : trace_free_pid_list(no_pid_list);
681 : }
682 :
683 0 : static void ftrace_clear_event_pids(struct trace_array *tr, int type)
684 : {
685 0 : mutex_lock(&event_mutex);
686 0 : __ftrace_clear_event_pids(tr, type);
687 0 : mutex_unlock(&event_mutex);
688 0 : }
689 :
690 0 : static void __put_system(struct event_subsystem *system)
691 : {
692 0 : struct event_filter *filter = system->filter;
693 :
694 0 : WARN_ON_ONCE(system_refcount(system) == 0);
695 0 : if (system_refcount_dec(system))
696 : return;
697 :
698 0 : list_del(&system->list);
699 :
700 0 : if (filter) {
701 0 : kfree(filter->filter_string);
702 0 : kfree(filter);
703 : }
704 0 : kfree_const(system->name);
705 0 : kfree(system);
706 : }
707 :
708 0 : static void __get_system(struct event_subsystem *system)
709 : {
710 0 : WARN_ON_ONCE(system_refcount(system) == 0);
711 0 : system_refcount_inc(system);
712 0 : }
713 :
714 0 : static void __get_system_dir(struct trace_subsystem_dir *dir)
715 : {
716 0 : WARN_ON_ONCE(dir->ref_count == 0);
717 0 : dir->ref_count++;
718 0 : __get_system(dir->subsystem);
719 0 : }
720 :
721 0 : static void __put_system_dir(struct trace_subsystem_dir *dir)
722 : {
723 0 : WARN_ON_ONCE(dir->ref_count == 0);
724 : /* If the subsystem is about to be freed, the dir must be too */
725 0 : WARN_ON_ONCE(system_refcount(dir->subsystem) == 1 && dir->ref_count != 1);
726 :
727 0 : __put_system(dir->subsystem);
728 0 : if (!--dir->ref_count)
729 0 : kfree(dir);
730 0 : }
731 :
732 0 : static void put_system(struct trace_subsystem_dir *dir)
733 : {
734 0 : mutex_lock(&event_mutex);
735 0 : __put_system_dir(dir);
736 0 : mutex_unlock(&event_mutex);
737 0 : }
738 :
739 0 : static void remove_subsystem(struct trace_subsystem_dir *dir)
740 : {
741 0 : if (!dir)
742 : return;
743 :
744 0 : if (!--dir->nr_events) {
745 0 : tracefs_remove(dir->entry);
746 0 : list_del(&dir->list);
747 0 : __put_system_dir(dir);
748 : }
749 : }
750 :
751 0 : static void remove_event_file_dir(struct trace_event_file *file)
752 : {
753 0 : struct dentry *dir = file->dir;
754 0 : struct dentry *child;
755 :
756 0 : if (dir) {
757 0 : spin_lock(&dir->d_lock); /* probably unneeded */
758 0 : list_for_each_entry(child, &dir->d_subdirs, d_child) {
759 0 : if (d_really_is_positive(child)) /* probably unneeded */
760 0 : d_inode(child)->i_private = NULL;
761 : }
762 0 : spin_unlock(&dir->d_lock);
763 :
764 0 : tracefs_remove(dir);
765 : }
766 :
767 0 : list_del(&file->list);
768 0 : remove_subsystem(file->system);
769 0 : free_event_filter(file->filter);
770 0 : kmem_cache_free(file_cachep, file);
771 0 : }
772 :
773 : /*
774 : * __ftrace_set_clr_event(NULL, NULL, NULL, set) will set/unset all events.
775 : */
776 : static int
777 0 : __ftrace_set_clr_event_nolock(struct trace_array *tr, const char *match,
778 : const char *sub, const char *event, int set)
779 : {
780 0 : struct trace_event_file *file;
781 0 : struct trace_event_call *call;
782 0 : const char *name;
783 0 : int ret = -EINVAL;
784 0 : int eret = 0;
785 :
786 0 : list_for_each_entry(file, &tr->events, list) {
787 :
788 0 : call = file->event_call;
789 0 : name = trace_event_name(call);
790 :
791 0 : if (!name || !call->class || !call->class->reg)
792 0 : continue;
793 :
794 0 : if (call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
795 0 : continue;
796 :
797 0 : if (match &&
798 0 : strcmp(match, name) != 0 &&
799 0 : strcmp(match, call->class->system) != 0)
800 0 : continue;
801 :
802 0 : if (sub && strcmp(sub, call->class->system) != 0)
803 0 : continue;
804 :
805 0 : if (event && strcmp(event, name) != 0)
806 0 : continue;
807 :
808 0 : ret = ftrace_event_enable_disable(file, set);
809 :
810 : /*
811 : * Save the first error and return that. Some events
812 : * may still have been enabled, but let the user
813 : * know that something went wrong.
814 : */
815 0 : if (ret && !eret)
816 0 : eret = ret;
817 :
818 : ret = eret;
819 : }
820 :
821 0 : return ret;
822 : }
823 :
824 0 : static int __ftrace_set_clr_event(struct trace_array *tr, const char *match,
825 : const char *sub, const char *event, int set)
826 : {
827 0 : int ret;
828 :
829 0 : mutex_lock(&event_mutex);
830 0 : ret = __ftrace_set_clr_event_nolock(tr, match, sub, event, set);
831 0 : mutex_unlock(&event_mutex);
832 :
833 0 : return ret;
834 : }
835 :
836 0 : int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set)
837 : {
838 0 : char *event = NULL, *sub = NULL, *match;
839 0 : int ret;
840 :
841 0 : if (!tr)
842 : return -ENOENT;
843 : /*
844 : * The buf format can be <subsystem>:<event-name>
845 : * *:<event-name> means any event by that name.
846 : * :<event-name> is the same.
847 : *
848 : * <subsystem>:* means all events in that subsystem
849 : * <subsystem>: means the same.
850 : *
851 : * <name> (no ':') means all events in a subsystem with
852 : * the name <name> or any event that matches <name>
853 : */
854 :
855 0 : match = strsep(&buf, ":");
856 0 : if (buf) {
857 0 : sub = match;
858 0 : event = buf;
859 0 : match = NULL;
860 :
861 0 : if (!strlen(sub) || strcmp(sub, "*") == 0)
862 0 : sub = NULL;
863 0 : if (!strlen(event) || strcmp(event, "*") == 0)
864 0 : event = NULL;
865 : }
866 :
867 0 : ret = __ftrace_set_clr_event(tr, match, sub, event, set);
868 :
869 : /* Put back the colon to allow this to be called again */
870 0 : if (buf)
871 0 : *(buf - 1) = ':';
872 :
873 : return ret;
874 : }
875 :
876 : /**
877 : * trace_set_clr_event - enable or disable an event
878 : * @system: system name to match (NULL for any system)
879 : * @event: event name to match (NULL for all events, within system)
880 : * @set: 1 to enable, 0 to disable
881 : *
882 : * This is a way for other parts of the kernel to enable or disable
883 : * event recording.
884 : *
885 : * Returns 0 on success, -EINVAL if the parameters do not match any
886 : * registered events.
887 : */
888 0 : int trace_set_clr_event(const char *system, const char *event, int set)
889 : {
890 0 : struct trace_array *tr = top_trace_array();
891 :
892 0 : if (!tr)
893 : return -ENODEV;
894 :
895 0 : return __ftrace_set_clr_event(tr, NULL, system, event, set);
896 : }
897 : EXPORT_SYMBOL_GPL(trace_set_clr_event);
898 :
899 : /**
900 : * trace_array_set_clr_event - enable or disable an event for a trace array.
901 : * @tr: concerned trace array.
902 : * @system: system name to match (NULL for any system)
903 : * @event: event name to match (NULL for all events, within system)
904 : * @enable: true to enable, false to disable
905 : *
906 : * This is a way for other parts of the kernel to enable or disable
907 : * event recording.
908 : *
909 : * Returns 0 on success, -EINVAL if the parameters do not match any
910 : * registered events.
911 : */
912 0 : int trace_array_set_clr_event(struct trace_array *tr, const char *system,
913 : const char *event, bool enable)
914 : {
915 0 : int set;
916 :
917 0 : if (!tr)
918 : return -ENOENT;
919 :
920 0 : set = (enable == true) ? 1 : 0;
921 0 : return __ftrace_set_clr_event(tr, NULL, system, event, set);
922 : }
923 : EXPORT_SYMBOL_GPL(trace_array_set_clr_event);
924 :
925 : /* 128 should be much more than enough */
926 : #define EVENT_BUF_SIZE 127
927 :
928 : static ssize_t
929 0 : ftrace_event_write(struct file *file, const char __user *ubuf,
930 : size_t cnt, loff_t *ppos)
931 : {
932 0 : struct trace_parser parser;
933 0 : struct seq_file *m = file->private_data;
934 0 : struct trace_array *tr = m->private;
935 0 : ssize_t read, ret;
936 :
937 0 : if (!cnt)
938 : return 0;
939 :
940 0 : ret = tracing_update_buffers();
941 0 : if (ret < 0)
942 : return ret;
943 :
944 0 : if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1))
945 : return -ENOMEM;
946 :
947 0 : read = trace_get_user(&parser, ubuf, cnt, ppos);
948 :
949 0 : if (read >= 0 && trace_parser_loaded((&parser))) {
950 0 : int set = 1;
951 :
952 0 : if (*parser.buffer == '!')
953 0 : set = 0;
954 :
955 0 : ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
956 0 : if (ret)
957 0 : goto out_put;
958 : }
959 :
960 : ret = read;
961 :
962 0 : out_put:
963 0 : trace_parser_put(&parser);
964 :
965 0 : return ret;
966 : }
967 :
968 : static void *
969 0 : t_next(struct seq_file *m, void *v, loff_t *pos)
970 : {
971 0 : struct trace_event_file *file = v;
972 0 : struct trace_event_call *call;
973 0 : struct trace_array *tr = m->private;
974 :
975 0 : (*pos)++;
976 :
977 0 : list_for_each_entry_continue(file, &tr->events, list) {
978 0 : call = file->event_call;
979 : /*
980 : * The ftrace subsystem is for showing formats only.
981 : * They can not be enabled or disabled via the event files.
982 : */
983 0 : if (call->class && call->class->reg &&
984 0 : !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
985 0 : return file;
986 : }
987 :
988 : return NULL;
989 : }
990 :
991 0 : static void *t_start(struct seq_file *m, loff_t *pos)
992 : {
993 0 : struct trace_event_file *file;
994 0 : struct trace_array *tr = m->private;
995 0 : loff_t l;
996 :
997 0 : mutex_lock(&event_mutex);
998 :
999 0 : file = list_entry(&tr->events, struct trace_event_file, list);
1000 0 : for (l = 0; l <= *pos; ) {
1001 0 : file = t_next(m, file, &l);
1002 0 : if (!file)
1003 : break;
1004 : }
1005 0 : return file;
1006 : }
1007 :
1008 : static void *
1009 0 : s_next(struct seq_file *m, void *v, loff_t *pos)
1010 : {
1011 0 : struct trace_event_file *file = v;
1012 0 : struct trace_array *tr = m->private;
1013 :
1014 0 : (*pos)++;
1015 :
1016 0 : list_for_each_entry_continue(file, &tr->events, list) {
1017 0 : if (file->flags & EVENT_FILE_FL_ENABLED)
1018 0 : return file;
1019 : }
1020 :
1021 : return NULL;
1022 : }
1023 :
1024 0 : static void *s_start(struct seq_file *m, loff_t *pos)
1025 : {
1026 0 : struct trace_event_file *file;
1027 0 : struct trace_array *tr = m->private;
1028 0 : loff_t l;
1029 :
1030 0 : mutex_lock(&event_mutex);
1031 :
1032 0 : file = list_entry(&tr->events, struct trace_event_file, list);
1033 0 : for (l = 0; l <= *pos; ) {
1034 0 : file = s_next(m, file, &l);
1035 0 : if (!file)
1036 : break;
1037 : }
1038 0 : return file;
1039 : }
1040 :
1041 0 : static int t_show(struct seq_file *m, void *v)
1042 : {
1043 0 : struct trace_event_file *file = v;
1044 0 : struct trace_event_call *call = file->event_call;
1045 :
1046 0 : if (strcmp(call->class->system, TRACE_SYSTEM) != 0)
1047 0 : seq_printf(m, "%s:", call->class->system);
1048 0 : seq_printf(m, "%s\n", trace_event_name(call));
1049 :
1050 0 : return 0;
1051 : }
1052 :
1053 0 : static void t_stop(struct seq_file *m, void *p)
1054 : {
1055 0 : mutex_unlock(&event_mutex);
1056 0 : }
1057 :
1058 : static void *
1059 0 : __next(struct seq_file *m, void *v, loff_t *pos, int type)
1060 : {
1061 0 : struct trace_array *tr = m->private;
1062 0 : struct trace_pid_list *pid_list;
1063 :
1064 0 : if (type == TRACE_PIDS)
1065 0 : pid_list = rcu_dereference_sched(tr->filtered_pids);
1066 : else
1067 0 : pid_list = rcu_dereference_sched(tr->filtered_no_pids);
1068 :
1069 0 : return trace_pid_next(pid_list, v, pos);
1070 : }
1071 :
1072 : static void *
1073 0 : p_next(struct seq_file *m, void *v, loff_t *pos)
1074 : {
1075 0 : return __next(m, v, pos, TRACE_PIDS);
1076 : }
1077 :
1078 : static void *
1079 0 : np_next(struct seq_file *m, void *v, loff_t *pos)
1080 : {
1081 0 : return __next(m, v, pos, TRACE_NO_PIDS);
1082 : }
1083 :
1084 0 : static void *__start(struct seq_file *m, loff_t *pos, int type)
1085 : __acquires(RCU)
1086 : {
1087 0 : struct trace_pid_list *pid_list;
1088 0 : struct trace_array *tr = m->private;
1089 :
1090 : /*
1091 : * Grab the mutex, to keep calls to p_next() having the same
1092 : * tr->filtered_pids as p_start() has.
1093 : * If we just passed the tr->filtered_pids around, then RCU would
1094 : * have been enough, but doing that makes things more complex.
1095 : */
1096 0 : mutex_lock(&event_mutex);
1097 0 : rcu_read_lock_sched();
1098 :
1099 0 : if (type == TRACE_PIDS)
1100 0 : pid_list = rcu_dereference_sched(tr->filtered_pids);
1101 : else
1102 0 : pid_list = rcu_dereference_sched(tr->filtered_no_pids);
1103 :
1104 0 : if (!pid_list)
1105 : return NULL;
1106 :
1107 0 : return trace_pid_start(pid_list, pos);
1108 : }
1109 :
1110 0 : static void *p_start(struct seq_file *m, loff_t *pos)
1111 : __acquires(RCU)
1112 : {
1113 0 : return __start(m, pos, TRACE_PIDS);
1114 : }
1115 :
1116 0 : static void *np_start(struct seq_file *m, loff_t *pos)
1117 : __acquires(RCU)
1118 : {
1119 0 : return __start(m, pos, TRACE_NO_PIDS);
1120 : }
1121 :
1122 0 : static void p_stop(struct seq_file *m, void *p)
1123 : __releases(RCU)
1124 : {
1125 0 : rcu_read_unlock_sched();
1126 0 : mutex_unlock(&event_mutex);
1127 0 : }
1128 :
1129 : static ssize_t
1130 0 : event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1131 : loff_t *ppos)
1132 : {
1133 0 : struct trace_event_file *file;
1134 0 : unsigned long flags;
1135 0 : char buf[4] = "0";
1136 :
1137 0 : mutex_lock(&event_mutex);
1138 0 : file = event_file_data(filp);
1139 0 : if (likely(file))
1140 0 : flags = file->flags;
1141 0 : mutex_unlock(&event_mutex);
1142 :
1143 0 : if (!file)
1144 : return -ENODEV;
1145 :
1146 0 : if (flags & EVENT_FILE_FL_ENABLED &&
1147 : !(flags & EVENT_FILE_FL_SOFT_DISABLED))
1148 0 : strcpy(buf, "1");
1149 :
1150 0 : if (flags & EVENT_FILE_FL_SOFT_DISABLED ||
1151 : flags & EVENT_FILE_FL_SOFT_MODE)
1152 0 : strcat(buf, "*");
1153 :
1154 0 : strcat(buf, "\n");
1155 :
1156 0 : return simple_read_from_buffer(ubuf, cnt, ppos, buf, strlen(buf));
1157 : }
1158 :
1159 : static ssize_t
1160 0 : event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1161 : loff_t *ppos)
1162 : {
1163 0 : struct trace_event_file *file;
1164 0 : unsigned long val;
1165 0 : int ret;
1166 :
1167 0 : ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1168 0 : if (ret)
1169 0 : return ret;
1170 :
1171 0 : ret = tracing_update_buffers();
1172 0 : if (ret < 0)
1173 0 : return ret;
1174 :
1175 0 : switch (val) {
1176 0 : case 0:
1177 : case 1:
1178 0 : ret = -ENODEV;
1179 0 : mutex_lock(&event_mutex);
1180 0 : file = event_file_data(filp);
1181 0 : if (likely(file))
1182 0 : ret = ftrace_event_enable_disable(file, val);
1183 0 : mutex_unlock(&event_mutex);
1184 0 : break;
1185 :
1186 : default:
1187 : return -EINVAL;
1188 : }
1189 :
1190 0 : *ppos += cnt;
1191 :
1192 0 : return ret ? ret : cnt;
1193 : }
1194 :
1195 : static ssize_t
1196 0 : system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
1197 : loff_t *ppos)
1198 : {
1199 0 : const char set_to_char[4] = { '?', '0', '1', 'X' };
1200 0 : struct trace_subsystem_dir *dir = filp->private_data;
1201 0 : struct event_subsystem *system = dir->subsystem;
1202 0 : struct trace_event_call *call;
1203 0 : struct trace_event_file *file;
1204 0 : struct trace_array *tr = dir->tr;
1205 0 : char buf[2];
1206 0 : int set = 0;
1207 0 : int ret;
1208 :
1209 0 : mutex_lock(&event_mutex);
1210 0 : list_for_each_entry(file, &tr->events, list) {
1211 0 : call = file->event_call;
1212 0 : if ((call->flags & TRACE_EVENT_FL_IGNORE_ENABLE) ||
1213 0 : !trace_event_name(call) || !call->class || !call->class->reg)
1214 0 : continue;
1215 :
1216 0 : if (system && strcmp(call->class->system, system->name) != 0)
1217 0 : continue;
1218 :
1219 : /*
1220 : * We need to find out if all the events are set
1221 : * or if all events or cleared, or if we have
1222 : * a mixture.
1223 : */
1224 0 : set |= (1 << !!(file->flags & EVENT_FILE_FL_ENABLED));
1225 :
1226 : /*
1227 : * If we have a mixture, no need to look further.
1228 : */
1229 0 : if (set == 3)
1230 : break;
1231 : }
1232 0 : mutex_unlock(&event_mutex);
1233 :
1234 0 : buf[0] = set_to_char[set];
1235 0 : buf[1] = '\n';
1236 :
1237 0 : ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
1238 :
1239 0 : return ret;
1240 : }
1241 :
1242 : static ssize_t
1243 0 : system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
1244 : loff_t *ppos)
1245 : {
1246 0 : struct trace_subsystem_dir *dir = filp->private_data;
1247 0 : struct event_subsystem *system = dir->subsystem;
1248 0 : const char *name = NULL;
1249 0 : unsigned long val;
1250 0 : ssize_t ret;
1251 :
1252 0 : ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
1253 0 : if (ret)
1254 : return ret;
1255 :
1256 0 : ret = tracing_update_buffers();
1257 0 : if (ret < 0)
1258 : return ret;
1259 :
1260 0 : if (val != 0 && val != 1)
1261 : return -EINVAL;
1262 :
1263 : /*
1264 : * Opening of "enable" adds a ref count to system,
1265 : * so the name is safe to use.
1266 : */
1267 0 : if (system)
1268 0 : name = system->name;
1269 :
1270 0 : ret = __ftrace_set_clr_event(dir->tr, NULL, name, NULL, val);
1271 0 : if (ret)
1272 0 : goto out;
1273 :
1274 0 : ret = cnt;
1275 :
1276 0 : out:
1277 0 : *ppos += cnt;
1278 :
1279 0 : return ret;
1280 : }
1281 :
1282 : enum {
1283 : FORMAT_HEADER = 1,
1284 : FORMAT_FIELD_SEPERATOR = 2,
1285 : FORMAT_PRINTFMT = 3,
1286 : };
1287 :
1288 0 : static void *f_next(struct seq_file *m, void *v, loff_t *pos)
1289 : {
1290 0 : struct trace_event_call *call = event_file_data(m->private);
1291 0 : struct list_head *common_head = &ftrace_common_fields;
1292 0 : struct list_head *head = trace_get_fields(call);
1293 0 : struct list_head *node = v;
1294 :
1295 0 : (*pos)++;
1296 :
1297 0 : switch ((unsigned long)v) {
1298 0 : case FORMAT_HEADER:
1299 0 : node = common_head;
1300 0 : break;
1301 :
1302 0 : case FORMAT_FIELD_SEPERATOR:
1303 0 : node = head;
1304 0 : break;
1305 :
1306 : case FORMAT_PRINTFMT:
1307 : /* all done */
1308 : return NULL;
1309 : }
1310 :
1311 0 : node = node->prev;
1312 0 : if (node == common_head)
1313 : return (void *)FORMAT_FIELD_SEPERATOR;
1314 0 : else if (node == head)
1315 : return (void *)FORMAT_PRINTFMT;
1316 : else
1317 0 : return node;
1318 : }
1319 :
1320 0 : static int f_show(struct seq_file *m, void *v)
1321 : {
1322 0 : struct trace_event_call *call = event_file_data(m->private);
1323 0 : struct ftrace_event_field *field;
1324 0 : const char *array_descriptor;
1325 :
1326 0 : switch ((unsigned long)v) {
1327 : case FORMAT_HEADER:
1328 0 : seq_printf(m, "name: %s\n", trace_event_name(call));
1329 0 : seq_printf(m, "ID: %d\n", call->event.type);
1330 0 : seq_puts(m, "format:\n");
1331 0 : return 0;
1332 :
1333 0 : case FORMAT_FIELD_SEPERATOR:
1334 0 : seq_putc(m, '\n');
1335 0 : return 0;
1336 :
1337 0 : case FORMAT_PRINTFMT:
1338 0 : seq_printf(m, "\nprint fmt: %s\n",
1339 : call->print_fmt);
1340 0 : return 0;
1341 : }
1342 :
1343 0 : field = list_entry(v, struct ftrace_event_field, link);
1344 : /*
1345 : * Smartly shows the array type(except dynamic array).
1346 : * Normal:
1347 : * field:TYPE VAR
1348 : * If TYPE := TYPE[LEN], it is shown:
1349 : * field:TYPE VAR[LEN]
1350 : */
1351 0 : array_descriptor = strchr(field->type, '[');
1352 :
1353 0 : if (str_has_prefix(field->type, "__data_loc"))
1354 : array_descriptor = NULL;
1355 :
1356 0 : if (!array_descriptor)
1357 0 : seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1358 : field->type, field->name, field->offset,
1359 0 : field->size, !!field->is_signed);
1360 : else
1361 0 : seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n",
1362 0 : (int)(array_descriptor - field->type),
1363 : field->type, field->name,
1364 : array_descriptor, field->offset,
1365 0 : field->size, !!field->is_signed);
1366 :
1367 : return 0;
1368 : }
1369 :
1370 0 : static void *f_start(struct seq_file *m, loff_t *pos)
1371 : {
1372 0 : void *p = (void *)FORMAT_HEADER;
1373 0 : loff_t l = 0;
1374 :
1375 : /* ->stop() is called even if ->start() fails */
1376 0 : mutex_lock(&event_mutex);
1377 0 : if (!event_file_data(m->private))
1378 0 : return ERR_PTR(-ENODEV);
1379 :
1380 0 : while (l < *pos && p)
1381 0 : p = f_next(m, p, &l);
1382 :
1383 : return p;
1384 : }
1385 :
1386 0 : static void f_stop(struct seq_file *m, void *p)
1387 : {
1388 0 : mutex_unlock(&event_mutex);
1389 0 : }
1390 :
1391 : static const struct seq_operations trace_format_seq_ops = {
1392 : .start = f_start,
1393 : .next = f_next,
1394 : .stop = f_stop,
1395 : .show = f_show,
1396 : };
1397 :
1398 0 : static int trace_format_open(struct inode *inode, struct file *file)
1399 : {
1400 0 : struct seq_file *m;
1401 0 : int ret;
1402 :
1403 : /* Do we want to hide event format files on tracefs lockdown? */
1404 :
1405 0 : ret = seq_open(file, &trace_format_seq_ops);
1406 0 : if (ret < 0)
1407 : return ret;
1408 :
1409 0 : m = file->private_data;
1410 0 : m->private = file;
1411 :
1412 0 : return 0;
1413 : }
1414 :
1415 : static ssize_t
1416 0 : event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1417 : {
1418 0 : int id = (long)event_file_data(filp);
1419 0 : char buf[32];
1420 0 : int len;
1421 :
1422 0 : if (unlikely(!id))
1423 : return -ENODEV;
1424 :
1425 0 : len = sprintf(buf, "%d\n", id);
1426 :
1427 0 : return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
1428 : }
1429 :
1430 : static ssize_t
1431 0 : event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1432 : loff_t *ppos)
1433 : {
1434 0 : struct trace_event_file *file;
1435 0 : struct trace_seq *s;
1436 0 : int r = -ENODEV;
1437 :
1438 0 : if (*ppos)
1439 : return 0;
1440 :
1441 0 : s = kmalloc(sizeof(*s), GFP_KERNEL);
1442 :
1443 0 : if (!s)
1444 : return -ENOMEM;
1445 :
1446 0 : trace_seq_init(s);
1447 :
1448 0 : mutex_lock(&event_mutex);
1449 0 : file = event_file_data(filp);
1450 0 : if (file)
1451 0 : print_event_filter(file, s);
1452 0 : mutex_unlock(&event_mutex);
1453 :
1454 0 : if (file)
1455 0 : r = simple_read_from_buffer(ubuf, cnt, ppos,
1456 0 : s->buffer, trace_seq_used(s));
1457 :
1458 0 : kfree(s);
1459 :
1460 0 : return r;
1461 : }
1462 :
1463 : static ssize_t
1464 0 : event_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1465 : loff_t *ppos)
1466 : {
1467 0 : struct trace_event_file *file;
1468 0 : char *buf;
1469 0 : int err = -ENODEV;
1470 :
1471 0 : if (cnt >= PAGE_SIZE)
1472 : return -EINVAL;
1473 :
1474 0 : buf = memdup_user_nul(ubuf, cnt);
1475 0 : if (IS_ERR(buf))
1476 0 : return PTR_ERR(buf);
1477 :
1478 0 : mutex_lock(&event_mutex);
1479 0 : file = event_file_data(filp);
1480 0 : if (file)
1481 0 : err = apply_event_filter(file, buf);
1482 0 : mutex_unlock(&event_mutex);
1483 :
1484 0 : kfree(buf);
1485 0 : if (err < 0)
1486 0 : return err;
1487 :
1488 0 : *ppos += cnt;
1489 :
1490 0 : return cnt;
1491 : }
1492 :
1493 : static LIST_HEAD(event_subsystems);
1494 :
1495 0 : static int subsystem_open(struct inode *inode, struct file *filp)
1496 : {
1497 0 : struct event_subsystem *system = NULL;
1498 0 : struct trace_subsystem_dir *dir = NULL; /* Initialize for gcc */
1499 0 : struct trace_array *tr;
1500 0 : int ret;
1501 :
1502 0 : if (tracing_is_disabled())
1503 : return -ENODEV;
1504 :
1505 : /* Make sure the system still exists */
1506 0 : mutex_lock(&event_mutex);
1507 0 : mutex_lock(&trace_types_lock);
1508 0 : list_for_each_entry(tr, &ftrace_trace_arrays, list) {
1509 0 : list_for_each_entry(dir, &tr->systems, list) {
1510 0 : if (dir == inode->i_private) {
1511 : /* Don't open systems with no events */
1512 0 : if (dir->nr_events) {
1513 0 : __get_system_dir(dir);
1514 0 : system = dir->subsystem;
1515 : }
1516 0 : goto exit_loop;
1517 : }
1518 : }
1519 : }
1520 0 : exit_loop:
1521 0 : mutex_unlock(&trace_types_lock);
1522 0 : mutex_unlock(&event_mutex);
1523 :
1524 0 : if (!system)
1525 : return -ENODEV;
1526 :
1527 : /* Some versions of gcc think dir can be uninitialized here */
1528 0 : WARN_ON(!dir);
1529 :
1530 : /* Still need to increment the ref count of the system */
1531 0 : if (trace_array_get(tr) < 0) {
1532 0 : put_system(dir);
1533 0 : return -ENODEV;
1534 : }
1535 :
1536 0 : ret = tracing_open_generic(inode, filp);
1537 0 : if (ret < 0) {
1538 0 : trace_array_put(tr);
1539 0 : put_system(dir);
1540 : }
1541 :
1542 : return ret;
1543 : }
1544 :
1545 0 : static int system_tr_open(struct inode *inode, struct file *filp)
1546 : {
1547 0 : struct trace_subsystem_dir *dir;
1548 0 : struct trace_array *tr = inode->i_private;
1549 0 : int ret;
1550 :
1551 : /* Make a temporary dir that has no system but points to tr */
1552 0 : dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1553 0 : if (!dir)
1554 : return -ENOMEM;
1555 :
1556 0 : ret = tracing_open_generic_tr(inode, filp);
1557 0 : if (ret < 0) {
1558 0 : kfree(dir);
1559 0 : return ret;
1560 : }
1561 0 : dir->tr = tr;
1562 0 : filp->private_data = dir;
1563 :
1564 0 : return 0;
1565 : }
1566 :
1567 0 : static int subsystem_release(struct inode *inode, struct file *file)
1568 : {
1569 0 : struct trace_subsystem_dir *dir = file->private_data;
1570 :
1571 0 : trace_array_put(dir->tr);
1572 :
1573 : /*
1574 : * If dir->subsystem is NULL, then this is a temporary
1575 : * descriptor that was made for a trace_array to enable
1576 : * all subsystems.
1577 : */
1578 0 : if (dir->subsystem)
1579 0 : put_system(dir);
1580 : else
1581 0 : kfree(dir);
1582 :
1583 0 : return 0;
1584 : }
1585 :
1586 : static ssize_t
1587 0 : subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
1588 : loff_t *ppos)
1589 : {
1590 0 : struct trace_subsystem_dir *dir = filp->private_data;
1591 0 : struct event_subsystem *system = dir->subsystem;
1592 0 : struct trace_seq *s;
1593 0 : int r;
1594 :
1595 0 : if (*ppos)
1596 : return 0;
1597 :
1598 0 : s = kmalloc(sizeof(*s), GFP_KERNEL);
1599 0 : if (!s)
1600 : return -ENOMEM;
1601 :
1602 0 : trace_seq_init(s);
1603 :
1604 0 : print_subsystem_event_filter(system, s);
1605 0 : r = simple_read_from_buffer(ubuf, cnt, ppos,
1606 0 : s->buffer, trace_seq_used(s));
1607 :
1608 0 : kfree(s);
1609 :
1610 0 : return r;
1611 : }
1612 :
1613 : static ssize_t
1614 0 : subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
1615 : loff_t *ppos)
1616 : {
1617 0 : struct trace_subsystem_dir *dir = filp->private_data;
1618 0 : char *buf;
1619 0 : int err;
1620 :
1621 0 : if (cnt >= PAGE_SIZE)
1622 : return -EINVAL;
1623 :
1624 0 : buf = memdup_user_nul(ubuf, cnt);
1625 0 : if (IS_ERR(buf))
1626 0 : return PTR_ERR(buf);
1627 :
1628 0 : err = apply_subsystem_event_filter(dir, buf);
1629 0 : kfree(buf);
1630 0 : if (err < 0)
1631 0 : return err;
1632 :
1633 0 : *ppos += cnt;
1634 :
1635 0 : return cnt;
1636 : }
1637 :
1638 : static ssize_t
1639 0 : show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
1640 : {
1641 0 : int (*func)(struct trace_seq *s) = filp->private_data;
1642 0 : struct trace_seq *s;
1643 0 : int r;
1644 :
1645 0 : if (*ppos)
1646 : return 0;
1647 :
1648 0 : s = kmalloc(sizeof(*s), GFP_KERNEL);
1649 0 : if (!s)
1650 : return -ENOMEM;
1651 :
1652 0 : trace_seq_init(s);
1653 :
1654 0 : func(s);
1655 0 : r = simple_read_from_buffer(ubuf, cnt, ppos,
1656 0 : s->buffer, trace_seq_used(s));
1657 :
1658 0 : kfree(s);
1659 :
1660 0 : return r;
1661 : }
1662 :
1663 0 : static void ignore_task_cpu(void *data)
1664 : {
1665 0 : struct trace_array *tr = data;
1666 0 : struct trace_pid_list *pid_list;
1667 0 : struct trace_pid_list *no_pid_list;
1668 :
1669 : /*
1670 : * This function is called by on_each_cpu() while the
1671 : * event_mutex is held.
1672 : */
1673 0 : pid_list = rcu_dereference_protected(tr->filtered_pids,
1674 : mutex_is_locked(&event_mutex));
1675 0 : no_pid_list = rcu_dereference_protected(tr->filtered_no_pids,
1676 : mutex_is_locked(&event_mutex));
1677 :
1678 0 : this_cpu_write(tr->array_buffer.data->ignore_pid,
1679 : trace_ignore_this_task(pid_list, no_pid_list, current));
1680 0 : }
1681 :
1682 0 : static void register_pid_events(struct trace_array *tr)
1683 : {
1684 : /*
1685 : * Register a probe that is called before all other probes
1686 : * to set ignore_pid if next or prev do not match.
1687 : * Register a probe this is called after all other probes
1688 : * to only keep ignore_pid set if next pid matches.
1689 : */
1690 0 : register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre,
1691 : tr, INT_MAX);
1692 0 : register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post,
1693 : tr, 0);
1694 :
1695 0 : register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre,
1696 : tr, INT_MAX);
1697 0 : register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post,
1698 : tr, 0);
1699 :
1700 0 : register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_pre,
1701 : tr, INT_MAX);
1702 0 : register_trace_prio_sched_wakeup_new(event_filter_pid_sched_wakeup_probe_post,
1703 : tr, 0);
1704 :
1705 0 : register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_pre,
1706 : tr, INT_MAX);
1707 0 : register_trace_prio_sched_waking(event_filter_pid_sched_wakeup_probe_post,
1708 : tr, 0);
1709 0 : }
1710 :
1711 : static ssize_t
1712 0 : event_pid_write(struct file *filp, const char __user *ubuf,
1713 : size_t cnt, loff_t *ppos, int type)
1714 : {
1715 0 : struct seq_file *m = filp->private_data;
1716 0 : struct trace_array *tr = m->private;
1717 0 : struct trace_pid_list *filtered_pids = NULL;
1718 0 : struct trace_pid_list *other_pids = NULL;
1719 0 : struct trace_pid_list *pid_list;
1720 0 : struct trace_event_file *file;
1721 0 : ssize_t ret;
1722 :
1723 0 : if (!cnt)
1724 : return 0;
1725 :
1726 0 : ret = tracing_update_buffers();
1727 0 : if (ret < 0)
1728 : return ret;
1729 :
1730 0 : mutex_lock(&event_mutex);
1731 :
1732 0 : if (type == TRACE_PIDS) {
1733 0 : filtered_pids = rcu_dereference_protected(tr->filtered_pids,
1734 : lockdep_is_held(&event_mutex));
1735 0 : other_pids = rcu_dereference_protected(tr->filtered_no_pids,
1736 : lockdep_is_held(&event_mutex));
1737 : } else {
1738 0 : filtered_pids = rcu_dereference_protected(tr->filtered_no_pids,
1739 : lockdep_is_held(&event_mutex));
1740 0 : other_pids = rcu_dereference_protected(tr->filtered_pids,
1741 : lockdep_is_held(&event_mutex));
1742 : }
1743 :
1744 0 : ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
1745 0 : if (ret < 0)
1746 0 : goto out;
1747 :
1748 0 : if (type == TRACE_PIDS)
1749 0 : rcu_assign_pointer(tr->filtered_pids, pid_list);
1750 : else
1751 0 : rcu_assign_pointer(tr->filtered_no_pids, pid_list);
1752 :
1753 0 : list_for_each_entry(file, &tr->events, list) {
1754 0 : set_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
1755 : }
1756 :
1757 0 : if (filtered_pids) {
1758 0 : tracepoint_synchronize_unregister();
1759 0 : trace_free_pid_list(filtered_pids);
1760 0 : } else if (pid_list && !other_pids) {
1761 0 : register_pid_events(tr);
1762 : }
1763 :
1764 : /*
1765 : * Ignoring of pids is done at task switch. But we have to
1766 : * check for those tasks that are currently running.
1767 : * Always do this in case a pid was appended or removed.
1768 : */
1769 0 : on_each_cpu(ignore_task_cpu, tr, 1);
1770 :
1771 0 : out:
1772 0 : mutex_unlock(&event_mutex);
1773 :
1774 0 : if (ret > 0)
1775 0 : *ppos += ret;
1776 :
1777 : return ret;
1778 : }
1779 :
1780 : static ssize_t
1781 0 : ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
1782 : size_t cnt, loff_t *ppos)
1783 : {
1784 0 : return event_pid_write(filp, ubuf, cnt, ppos, TRACE_PIDS);
1785 : }
1786 :
1787 : static ssize_t
1788 0 : ftrace_event_npid_write(struct file *filp, const char __user *ubuf,
1789 : size_t cnt, loff_t *ppos)
1790 : {
1791 0 : return event_pid_write(filp, ubuf, cnt, ppos, TRACE_NO_PIDS);
1792 : }
1793 :
1794 : static int ftrace_event_avail_open(struct inode *inode, struct file *file);
1795 : static int ftrace_event_set_open(struct inode *inode, struct file *file);
1796 : static int ftrace_event_set_pid_open(struct inode *inode, struct file *file);
1797 : static int ftrace_event_set_npid_open(struct inode *inode, struct file *file);
1798 : static int ftrace_event_release(struct inode *inode, struct file *file);
1799 :
1800 : static const struct seq_operations show_event_seq_ops = {
1801 : .start = t_start,
1802 : .next = t_next,
1803 : .show = t_show,
1804 : .stop = t_stop,
1805 : };
1806 :
1807 : static const struct seq_operations show_set_event_seq_ops = {
1808 : .start = s_start,
1809 : .next = s_next,
1810 : .show = t_show,
1811 : .stop = t_stop,
1812 : };
1813 :
1814 : static const struct seq_operations show_set_pid_seq_ops = {
1815 : .start = p_start,
1816 : .next = p_next,
1817 : .show = trace_pid_show,
1818 : .stop = p_stop,
1819 : };
1820 :
1821 : static const struct seq_operations show_set_no_pid_seq_ops = {
1822 : .start = np_start,
1823 : .next = np_next,
1824 : .show = trace_pid_show,
1825 : .stop = p_stop,
1826 : };
1827 :
1828 : static const struct file_operations ftrace_avail_fops = {
1829 : .open = ftrace_event_avail_open,
1830 : .read = seq_read,
1831 : .llseek = seq_lseek,
1832 : .release = seq_release,
1833 : };
1834 :
1835 : static const struct file_operations ftrace_set_event_fops = {
1836 : .open = ftrace_event_set_open,
1837 : .read = seq_read,
1838 : .write = ftrace_event_write,
1839 : .llseek = seq_lseek,
1840 : .release = ftrace_event_release,
1841 : };
1842 :
1843 : static const struct file_operations ftrace_set_event_pid_fops = {
1844 : .open = ftrace_event_set_pid_open,
1845 : .read = seq_read,
1846 : .write = ftrace_event_pid_write,
1847 : .llseek = seq_lseek,
1848 : .release = ftrace_event_release,
1849 : };
1850 :
1851 : static const struct file_operations ftrace_set_event_notrace_pid_fops = {
1852 : .open = ftrace_event_set_npid_open,
1853 : .read = seq_read,
1854 : .write = ftrace_event_npid_write,
1855 : .llseek = seq_lseek,
1856 : .release = ftrace_event_release,
1857 : };
1858 :
1859 : static const struct file_operations ftrace_enable_fops = {
1860 : .open = tracing_open_generic,
1861 : .read = event_enable_read,
1862 : .write = event_enable_write,
1863 : .llseek = default_llseek,
1864 : };
1865 :
1866 : static const struct file_operations ftrace_event_format_fops = {
1867 : .open = trace_format_open,
1868 : .read = seq_read,
1869 : .llseek = seq_lseek,
1870 : .release = seq_release,
1871 : };
1872 :
1873 : static const struct file_operations ftrace_event_id_fops = {
1874 : .read = event_id_read,
1875 : .llseek = default_llseek,
1876 : };
1877 :
1878 : static const struct file_operations ftrace_event_filter_fops = {
1879 : .open = tracing_open_generic,
1880 : .read = event_filter_read,
1881 : .write = event_filter_write,
1882 : .llseek = default_llseek,
1883 : };
1884 :
1885 : static const struct file_operations ftrace_subsystem_filter_fops = {
1886 : .open = subsystem_open,
1887 : .read = subsystem_filter_read,
1888 : .write = subsystem_filter_write,
1889 : .llseek = default_llseek,
1890 : .release = subsystem_release,
1891 : };
1892 :
1893 : static const struct file_operations ftrace_system_enable_fops = {
1894 : .open = subsystem_open,
1895 : .read = system_enable_read,
1896 : .write = system_enable_write,
1897 : .llseek = default_llseek,
1898 : .release = subsystem_release,
1899 : };
1900 :
1901 : static const struct file_operations ftrace_tr_enable_fops = {
1902 : .open = system_tr_open,
1903 : .read = system_enable_read,
1904 : .write = system_enable_write,
1905 : .llseek = default_llseek,
1906 : .release = subsystem_release,
1907 : };
1908 :
1909 : static const struct file_operations ftrace_show_header_fops = {
1910 : .open = tracing_open_generic,
1911 : .read = show_header,
1912 : .llseek = default_llseek,
1913 : };
1914 :
1915 : static int
1916 0 : ftrace_event_open(struct inode *inode, struct file *file,
1917 : const struct seq_operations *seq_ops)
1918 : {
1919 0 : struct seq_file *m;
1920 0 : int ret;
1921 :
1922 0 : ret = security_locked_down(LOCKDOWN_TRACEFS);
1923 0 : if (ret)
1924 : return ret;
1925 :
1926 0 : ret = seq_open(file, seq_ops);
1927 0 : if (ret < 0)
1928 : return ret;
1929 0 : m = file->private_data;
1930 : /* copy tr over to seq ops */
1931 0 : m->private = inode->i_private;
1932 :
1933 0 : return ret;
1934 : }
1935 :
1936 0 : static int ftrace_event_release(struct inode *inode, struct file *file)
1937 : {
1938 0 : struct trace_array *tr = inode->i_private;
1939 :
1940 0 : trace_array_put(tr);
1941 :
1942 0 : return seq_release(inode, file);
1943 : }
1944 :
1945 : static int
1946 0 : ftrace_event_avail_open(struct inode *inode, struct file *file)
1947 : {
1948 0 : const struct seq_operations *seq_ops = &show_event_seq_ops;
1949 :
1950 : /* Checks for tracefs lockdown */
1951 0 : return ftrace_event_open(inode, file, seq_ops);
1952 : }
1953 :
1954 : static int
1955 0 : ftrace_event_set_open(struct inode *inode, struct file *file)
1956 : {
1957 0 : const struct seq_operations *seq_ops = &show_set_event_seq_ops;
1958 0 : struct trace_array *tr = inode->i_private;
1959 0 : int ret;
1960 :
1961 0 : ret = tracing_check_open_get_tr(tr);
1962 0 : if (ret)
1963 : return ret;
1964 :
1965 0 : if ((file->f_mode & FMODE_WRITE) &&
1966 : (file->f_flags & O_TRUNC))
1967 0 : ftrace_clear_events(tr);
1968 :
1969 0 : ret = ftrace_event_open(inode, file, seq_ops);
1970 0 : if (ret < 0)
1971 0 : trace_array_put(tr);
1972 : return ret;
1973 : }
1974 :
1975 : static int
1976 0 : ftrace_event_set_pid_open(struct inode *inode, struct file *file)
1977 : {
1978 0 : const struct seq_operations *seq_ops = &show_set_pid_seq_ops;
1979 0 : struct trace_array *tr = inode->i_private;
1980 0 : int ret;
1981 :
1982 0 : ret = tracing_check_open_get_tr(tr);
1983 0 : if (ret)
1984 : return ret;
1985 :
1986 0 : if ((file->f_mode & FMODE_WRITE) &&
1987 : (file->f_flags & O_TRUNC))
1988 0 : ftrace_clear_event_pids(tr, TRACE_PIDS);
1989 :
1990 0 : ret = ftrace_event_open(inode, file, seq_ops);
1991 0 : if (ret < 0)
1992 0 : trace_array_put(tr);
1993 : return ret;
1994 : }
1995 :
1996 : static int
1997 0 : ftrace_event_set_npid_open(struct inode *inode, struct file *file)
1998 : {
1999 0 : const struct seq_operations *seq_ops = &show_set_no_pid_seq_ops;
2000 0 : struct trace_array *tr = inode->i_private;
2001 0 : int ret;
2002 :
2003 0 : ret = tracing_check_open_get_tr(tr);
2004 0 : if (ret)
2005 : return ret;
2006 :
2007 0 : if ((file->f_mode & FMODE_WRITE) &&
2008 : (file->f_flags & O_TRUNC))
2009 0 : ftrace_clear_event_pids(tr, TRACE_NO_PIDS);
2010 :
2011 0 : ret = ftrace_event_open(inode, file, seq_ops);
2012 0 : if (ret < 0)
2013 0 : trace_array_put(tr);
2014 : return ret;
2015 : }
2016 :
2017 : static struct event_subsystem *
2018 58 : create_new_subsystem(const char *name)
2019 : {
2020 58 : struct event_subsystem *system;
2021 :
2022 : /* need to create new entry */
2023 58 : system = kmalloc(sizeof(*system), GFP_KERNEL);
2024 58 : if (!system)
2025 : return NULL;
2026 :
2027 58 : system->ref_count = 1;
2028 :
2029 : /* Only allocate if dynamic (kprobes and modules) */
2030 58 : system->name = kstrdup_const(name, GFP_KERNEL);
2031 58 : if (!system->name)
2032 0 : goto out_free;
2033 :
2034 58 : system->filter = NULL;
2035 :
2036 58 : system->filter = kzalloc(sizeof(struct event_filter), GFP_KERNEL);
2037 58 : if (!system->filter)
2038 0 : goto out_free;
2039 :
2040 58 : list_add(&system->list, &event_subsystems);
2041 :
2042 58 : return system;
2043 :
2044 0 : out_free:
2045 0 : kfree_const(system->name);
2046 0 : kfree(system);
2047 0 : return NULL;
2048 : }
2049 :
2050 : static struct dentry *
2051 542 : event_subsystem_dir(struct trace_array *tr, const char *name,
2052 : struct trace_event_file *file, struct dentry *parent)
2053 : {
2054 542 : struct trace_subsystem_dir *dir;
2055 542 : struct event_subsystem *system;
2056 542 : struct dentry *entry;
2057 :
2058 : /* First see if we did not already create this dir */
2059 2195 : list_for_each_entry(dir, &tr->systems, list) {
2060 2137 : system = dir->subsystem;
2061 2137 : if (strcmp(system->name, name) == 0) {
2062 484 : dir->nr_events++;
2063 484 : file->system = dir;
2064 484 : return dir->entry;
2065 : }
2066 : }
2067 :
2068 : /* Now see if the system itself exists. */
2069 1711 : list_for_each_entry(system, &event_subsystems, list) {
2070 1653 : if (strcmp(system->name, name) == 0)
2071 : break;
2072 : }
2073 : /* Reset system variable when not found */
2074 58 : if (&system->list == &event_subsystems)
2075 58 : system = NULL;
2076 :
2077 58 : dir = kmalloc(sizeof(*dir), GFP_KERNEL);
2078 58 : if (!dir)
2079 0 : goto out_fail;
2080 :
2081 58 : if (!system) {
2082 58 : system = create_new_subsystem(name);
2083 58 : if (!system)
2084 0 : goto out_free;
2085 : } else
2086 0 : __get_system(system);
2087 :
2088 58 : dir->entry = tracefs_create_dir(name, parent);
2089 58 : if (!dir->entry) {
2090 0 : pr_warn("Failed to create system directory %s\n", name);
2091 0 : __put_system(system);
2092 0 : goto out_free;
2093 : }
2094 :
2095 58 : dir->tr = tr;
2096 58 : dir->ref_count = 1;
2097 58 : dir->nr_events = 1;
2098 58 : dir->subsystem = system;
2099 58 : file->system = dir;
2100 :
2101 : /* the ftrace system is special, do not create enable or filter files */
2102 58 : if (strcmp(name, "ftrace") != 0) {
2103 :
2104 57 : entry = tracefs_create_file("filter", 0644, dir->entry, dir,
2105 : &ftrace_subsystem_filter_fops);
2106 57 : if (!entry) {
2107 0 : kfree(system->filter);
2108 0 : system->filter = NULL;
2109 0 : pr_warn("Could not create tracefs '%s/filter' entry\n", name);
2110 : }
2111 :
2112 57 : trace_create_file("enable", 0644, dir->entry, dir,
2113 : &ftrace_system_enable_fops);
2114 : }
2115 :
2116 58 : list_add(&dir->list, &tr->systems);
2117 :
2118 58 : return dir->entry;
2119 :
2120 0 : out_free:
2121 0 : kfree(dir);
2122 0 : out_fail:
2123 : /* Only print this message if failed on memory allocation */
2124 0 : if (!dir || !system)
2125 0 : pr_warn("No memory to create event subsystem %s\n", name);
2126 : return NULL;
2127 : }
2128 :
2129 : static int
2130 1084 : event_define_fields(struct trace_event_call *call)
2131 : {
2132 1084 : struct list_head *head;
2133 1084 : int ret = 0;
2134 :
2135 : /*
2136 : * Other events may have the same class. Only update
2137 : * the fields if they are not already defined.
2138 : */
2139 1084 : head = trace_get_fields(call);
2140 1084 : if (list_empty(head)) {
2141 370 : struct trace_event_fields *field = call->class->fields_array;
2142 370 : unsigned int offset = sizeof(struct trace_entry);
2143 :
2144 2048 : for (; field->type; field++) {
2145 1678 : if (field->type == TRACE_FUNCTION_TYPE) {
2146 0 : field->define_fields(call);
2147 0 : break;
2148 : }
2149 :
2150 1678 : offset = ALIGN(offset, field->align);
2151 1678 : ret = trace_define_field(call, field->type, field->name,
2152 : offset, field->size,
2153 : field->is_signed, field->filter_type);
2154 1678 : if (WARN_ON_ONCE(ret)) {
2155 0 : pr_err("error code is %d\n", ret);
2156 0 : break;
2157 : }
2158 :
2159 1678 : offset += field->size;
2160 : }
2161 : }
2162 :
2163 1084 : return ret;
2164 : }
2165 :
2166 : static int
2167 542 : event_create_dir(struct dentry *parent, struct trace_event_file *file)
2168 : {
2169 542 : struct trace_event_call *call = file->event_call;
2170 542 : struct trace_array *tr = file->tr;
2171 542 : struct dentry *d_events;
2172 542 : const char *name;
2173 542 : int ret;
2174 :
2175 : /*
2176 : * If the trace point header did not define TRACE_SYSTEM
2177 : * then the system would be called "TRACE_SYSTEM".
2178 : */
2179 542 : if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
2180 542 : d_events = event_subsystem_dir(tr, call->class->system, file, parent);
2181 542 : if (!d_events)
2182 : return -ENOMEM;
2183 : } else
2184 : d_events = parent;
2185 :
2186 542 : name = trace_event_name(call);
2187 542 : file->dir = tracefs_create_dir(name, d_events);
2188 542 : if (!file->dir) {
2189 0 : pr_warn("Could not create tracefs '%s' directory\n", name);
2190 0 : return -1;
2191 : }
2192 :
2193 542 : if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
2194 527 : trace_create_file("enable", 0644, file->dir, file,
2195 : &ftrace_enable_fops);
2196 :
2197 : #ifdef CONFIG_PERF_EVENTS
2198 542 : if (call->event.type && call->class->reg)
2199 528 : trace_create_file("id", 0444, file->dir,
2200 528 : (void *)(long)call->event.type,
2201 : &ftrace_event_id_fops);
2202 : #endif
2203 :
2204 542 : ret = event_define_fields(call);
2205 542 : if (ret < 0) {
2206 0 : pr_warn("Could not initialize trace point events/%s\n", name);
2207 0 : return ret;
2208 : }
2209 :
2210 : /*
2211 : * Only event directories that can be enabled should have
2212 : * triggers or filters.
2213 : */
2214 542 : if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) {
2215 527 : trace_create_file("filter", 0644, file->dir, file,
2216 : &ftrace_event_filter_fops);
2217 :
2218 527 : trace_create_file("trigger", 0644, file->dir, file,
2219 : &event_trigger_fops);
2220 : }
2221 :
2222 : #ifdef CONFIG_HIST_TRIGGERS
2223 : trace_create_file("hist", 0444, file->dir, file,
2224 : &event_hist_fops);
2225 : #endif
2226 : #ifdef CONFIG_HIST_TRIGGERS_DEBUG
2227 : trace_create_file("hist_debug", 0444, file->dir, file,
2228 : &event_hist_debug_fops);
2229 : #endif
2230 542 : trace_create_file("format", 0444, file->dir, call,
2231 : &ftrace_event_format_fops);
2232 :
2233 : #ifdef CONFIG_TRACE_EVENT_INJECT
2234 : if (call->event.type && call->class->reg)
2235 : trace_create_file("inject", 0200, file->dir, file,
2236 : &event_inject_fops);
2237 : #endif
2238 :
2239 542 : return 0;
2240 : }
2241 :
2242 0 : static void remove_event_from_tracers(struct trace_event_call *call)
2243 : {
2244 0 : struct trace_event_file *file;
2245 0 : struct trace_array *tr;
2246 :
2247 0 : do_for_each_event_file_safe(tr, file) {
2248 0 : if (file->event_call != call)
2249 0 : continue;
2250 :
2251 0 : remove_event_file_dir(file);
2252 : /*
2253 : * The do_for_each_event_file_safe() is
2254 : * a double loop. After finding the call for this
2255 : * trace_array, we use break to jump to the next
2256 : * trace_array.
2257 : */
2258 0 : break;
2259 0 : } while_for_each_event_file();
2260 0 : }
2261 :
2262 0 : static void event_remove(struct trace_event_call *call)
2263 : {
2264 0 : struct trace_array *tr;
2265 0 : struct trace_event_file *file;
2266 :
2267 0 : do_for_each_event_file(tr, file) {
2268 0 : if (file->event_call != call)
2269 0 : continue;
2270 :
2271 0 : if (file->flags & EVENT_FILE_FL_WAS_ENABLED)
2272 0 : tr->clear_trace = true;
2273 :
2274 0 : ftrace_event_enable_disable(file, 0);
2275 : /*
2276 : * The do_for_each_event_file() is
2277 : * a double loop. After finding the call for this
2278 : * trace_array, we use break to jump to the next
2279 : * trace_array.
2280 : */
2281 : break;
2282 0 : } while_for_each_event_file();
2283 :
2284 0 : if (call->event.funcs)
2285 0 : __unregister_trace_event(&call->event);
2286 0 : remove_event_from_tracers(call);
2287 0 : list_del(&call->list);
2288 0 : }
2289 :
2290 542 : static int event_init(struct trace_event_call *call)
2291 : {
2292 542 : int ret = 0;
2293 542 : const char *name;
2294 :
2295 542 : name = trace_event_name(call);
2296 542 : if (WARN_ON(!name))
2297 : return -EINVAL;
2298 :
2299 542 : if (call->class->raw_init) {
2300 527 : ret = call->class->raw_init(call);
2301 527 : if (ret < 0 && ret != -ENOSYS)
2302 0 : pr_warn("Could not initialize trace events/%s\n", name);
2303 : }
2304 :
2305 : return ret;
2306 : }
2307 :
2308 : static int
2309 0 : __register_event(struct trace_event_call *call, struct module *mod)
2310 : {
2311 0 : int ret;
2312 :
2313 0 : ret = event_init(call);
2314 0 : if (ret < 0)
2315 : return ret;
2316 :
2317 0 : list_add(&call->list, &ftrace_events);
2318 0 : call->mod = mod;
2319 :
2320 0 : return 0;
2321 : }
2322 :
2323 479 : static char *eval_replace(char *ptr, struct trace_eval_map *map, int len)
2324 : {
2325 479 : int rlen;
2326 479 : int elen;
2327 :
2328 : /* Find the length of the eval value as a string */
2329 479 : elen = snprintf(ptr, 0, "%ld", map->eval_value);
2330 : /* Make sure there's enough room to replace the string with the value */
2331 479 : if (len < elen)
2332 : return NULL;
2333 :
2334 479 : snprintf(ptr, elen + 1, "%ld", map->eval_value);
2335 :
2336 : /* Get the rest of the string of ptr */
2337 479 : rlen = strlen(ptr + len);
2338 479 : memmove(ptr + elen, ptr + len, rlen);
2339 : /* Make sure we end the new string */
2340 479 : ptr[elen + rlen] = 0;
2341 :
2342 479 : return ptr + elen;
2343 : }
2344 :
2345 2949 : static void update_event_printk(struct trace_event_call *call,
2346 : struct trace_eval_map *map)
2347 : {
2348 2949 : char *ptr;
2349 2949 : int quote = 0;
2350 2949 : int len = strlen(map->eval_string);
2351 :
2352 1005338 : for (ptr = call->print_fmt; *ptr; ptr++) {
2353 1004624 : if (*ptr == '\\') {
2354 0 : ptr++;
2355 : /* paranoid */
2356 0 : if (!*ptr)
2357 : break;
2358 0 : continue;
2359 : }
2360 1004624 : if (*ptr == '"') {
2361 68172 : quote ^= 1;
2362 68172 : continue;
2363 : }
2364 936452 : if (quote)
2365 476472 : continue;
2366 459980 : if (isdigit(*ptr)) {
2367 : /* skip numbers */
2368 152110 : do {
2369 152110 : ptr++;
2370 : /* Check for alpha chars like ULL */
2371 152110 : } while (isalnum(*ptr));
2372 37013 : if (!*ptr)
2373 : break;
2374 : /*
2375 : * A number must have some kind of delimiter after
2376 : * it, and we can ignore that too.
2377 : */
2378 36905 : continue;
2379 : }
2380 422967 : if (isalpha(*ptr) || *ptr == '_') {
2381 65685 : if (strncmp(map->eval_string, ptr, len) == 0 &&
2382 498 : !isalnum(ptr[len]) && ptr[len] != '_') {
2383 479 : ptr = eval_replace(ptr, map, len);
2384 : /* enum/sizeof string smaller than value */
2385 479 : if (WARN_ON_ONCE(!ptr))
2386 : return;
2387 : /*
2388 : * No need to decrement here, as eval_replace()
2389 : * returns the pointer to the character passed
2390 : * the eval, and two evals can not be placed
2391 : * back to back without something in between.
2392 : * We can skip that something in between.
2393 : */
2394 479 : continue;
2395 : }
2396 65206 : skip_more:
2397 509543 : do {
2398 509543 : ptr++;
2399 509543 : } while (isalnum(*ptr) || *ptr == '_');
2400 80596 : if (!*ptr)
2401 : break;
2402 : /*
2403 : * If what comes after this variable is a '.' or
2404 : * '->' then we can continue to ignore that string.
2405 : */
2406 78469 : if (*ptr == '.' || (ptr[0] == '-' && ptr[1] == '>')) {
2407 15390 : ptr += *ptr == '.' ? 1 : 2;
2408 15390 : if (!*ptr)
2409 : break;
2410 15390 : goto skip_more;
2411 : }
2412 : /*
2413 : * Once again, we can skip the delimiter that came
2414 : * after the string.
2415 : */
2416 63079 : continue;
2417 : }
2418 : }
2419 : }
2420 :
2421 1 : void trace_event_eval_update(struct trace_eval_map **map, int len)
2422 : {
2423 1 : struct trace_event_call *call, *p;
2424 1 : const char *last_system = NULL;
2425 1 : bool first = false;
2426 1 : int last_i;
2427 1 : int i;
2428 :
2429 1 : down_write(&trace_event_sem);
2430 543 : list_for_each_entry_safe(call, p, &ftrace_events, list) {
2431 : /* events are usually grouped together with systems */
2432 542 : if (!last_system || call->class->system != last_system) {
2433 58 : first = true;
2434 58 : last_i = 0;
2435 58 : last_system = call->class->system;
2436 : }
2437 :
2438 : /*
2439 : * Since calls are grouped by systems, the likelyhood that the
2440 : * next call in the iteration belongs to the same system as the
2441 : * previous call is high. As an optimization, we skip searching
2442 : * for a map[] that matches the call's system if the last call
2443 : * was from the same system. That's what last_i is for. If the
2444 : * call has the same system as the previous call, then last_i
2445 : * will be the index of the first map[] that has a matching
2446 : * system.
2447 : */
2448 113700 : for (i = last_i; i < len; i++) {
2449 113158 : if (call->class->system == map[i]->system) {
2450 : /* Save the first system if need be */
2451 2949 : if (first) {
2452 16 : last_i = i;
2453 16 : first = false;
2454 : }
2455 2949 : update_event_printk(call, map[i]);
2456 : }
2457 : }
2458 : }
2459 1 : up_write(&trace_event_sem);
2460 1 : }
2461 :
2462 : static struct trace_event_file *
2463 542 : trace_create_new_event(struct trace_event_call *call,
2464 : struct trace_array *tr)
2465 : {
2466 542 : struct trace_event_file *file;
2467 :
2468 542 : file = kmem_cache_alloc(file_cachep, GFP_TRACE);
2469 542 : if (!file)
2470 : return NULL;
2471 :
2472 542 : file->event_call = call;
2473 542 : file->tr = tr;
2474 542 : atomic_set(&file->sm_ref, 0);
2475 542 : atomic_set(&file->tm_ref, 0);
2476 542 : INIT_LIST_HEAD(&file->triggers);
2477 542 : list_add(&file->list, &tr->events);
2478 :
2479 542 : return file;
2480 : }
2481 :
2482 : /* Add an event to a trace directory */
2483 : static int
2484 0 : __trace_add_new_event(struct trace_event_call *call, struct trace_array *tr)
2485 : {
2486 0 : struct trace_event_file *file;
2487 :
2488 0 : file = trace_create_new_event(call, tr);
2489 0 : if (!file)
2490 : return -ENOMEM;
2491 :
2492 0 : if (eventdir_initialized)
2493 0 : return event_create_dir(tr->event_dir, file);
2494 : else
2495 0 : return event_define_fields(call);
2496 : }
2497 :
2498 : /*
2499 : * Just create a decriptor for early init. A descriptor is required
2500 : * for enabling events at boot. We want to enable events before
2501 : * the filesystem is initialized.
2502 : */
2503 : static int
2504 542 : __trace_early_add_new_event(struct trace_event_call *call,
2505 : struct trace_array *tr)
2506 : {
2507 542 : struct trace_event_file *file;
2508 :
2509 542 : file = trace_create_new_event(call, tr);
2510 542 : if (!file)
2511 : return -ENOMEM;
2512 :
2513 542 : return event_define_fields(call);
2514 : }
2515 :
2516 : struct ftrace_module_file_ops;
2517 : static void __add_event_to_tracers(struct trace_event_call *call);
2518 :
2519 : /* Add an additional event_call dynamically */
2520 0 : int trace_add_event_call(struct trace_event_call *call)
2521 : {
2522 0 : int ret;
2523 0 : lockdep_assert_held(&event_mutex);
2524 :
2525 0 : mutex_lock(&trace_types_lock);
2526 :
2527 0 : ret = __register_event(call, NULL);
2528 0 : if (ret >= 0)
2529 0 : __add_event_to_tracers(call);
2530 :
2531 0 : mutex_unlock(&trace_types_lock);
2532 0 : return ret;
2533 : }
2534 :
2535 : /*
2536 : * Must be called under locking of trace_types_lock, event_mutex and
2537 : * trace_event_sem.
2538 : */
2539 0 : static void __trace_remove_event_call(struct trace_event_call *call)
2540 : {
2541 0 : event_remove(call);
2542 0 : trace_destroy_fields(call);
2543 0 : free_event_filter(call->filter);
2544 0 : call->filter = NULL;
2545 0 : }
2546 :
2547 0 : static int probe_remove_event_call(struct trace_event_call *call)
2548 : {
2549 0 : struct trace_array *tr;
2550 0 : struct trace_event_file *file;
2551 :
2552 : #ifdef CONFIG_PERF_EVENTS
2553 0 : if (call->perf_refcount)
2554 : return -EBUSY;
2555 : #endif
2556 0 : do_for_each_event_file(tr, file) {
2557 0 : if (file->event_call != call)
2558 0 : continue;
2559 : /*
2560 : * We can't rely on ftrace_event_enable_disable(enable => 0)
2561 : * we are going to do, EVENT_FILE_FL_SOFT_MODE can suppress
2562 : * TRACE_REG_UNREGISTER.
2563 : */
2564 0 : if (file->flags & EVENT_FILE_FL_ENABLED)
2565 : return -EBUSY;
2566 : /*
2567 : * The do_for_each_event_file_safe() is
2568 : * a double loop. After finding the call for this
2569 : * trace_array, we use break to jump to the next
2570 : * trace_array.
2571 : */
2572 : break;
2573 0 : } while_for_each_event_file();
2574 :
2575 0 : __trace_remove_event_call(call);
2576 :
2577 0 : return 0;
2578 : }
2579 :
2580 : /* Remove an event_call */
2581 0 : int trace_remove_event_call(struct trace_event_call *call)
2582 : {
2583 0 : int ret;
2584 :
2585 0 : lockdep_assert_held(&event_mutex);
2586 :
2587 0 : mutex_lock(&trace_types_lock);
2588 0 : down_write(&trace_event_sem);
2589 0 : ret = probe_remove_event_call(call);
2590 0 : up_write(&trace_event_sem);
2591 0 : mutex_unlock(&trace_types_lock);
2592 :
2593 0 : return ret;
2594 : }
2595 :
2596 : #define for_each_event(event, start, end) \
2597 : for (event = start; \
2598 : (unsigned long)event < (unsigned long)end; \
2599 : event++)
2600 :
2601 : #ifdef CONFIG_MODULES
2602 :
2603 : static void trace_module_add_events(struct module *mod)
2604 : {
2605 : struct trace_event_call **call, **start, **end;
2606 :
2607 : if (!mod->num_trace_events)
2608 : return;
2609 :
2610 : /* Don't add infrastructure for mods without tracepoints */
2611 : if (trace_module_has_bad_taint(mod)) {
2612 : pr_err("%s: module has bad taint, not creating trace events\n",
2613 : mod->name);
2614 : return;
2615 : }
2616 :
2617 : start = mod->trace_events;
2618 : end = mod->trace_events + mod->num_trace_events;
2619 :
2620 : for_each_event(call, start, end) {
2621 : __register_event(*call, mod);
2622 : __add_event_to_tracers(*call);
2623 : }
2624 : }
2625 :
2626 : static void trace_module_remove_events(struct module *mod)
2627 : {
2628 : struct trace_event_call *call, *p;
2629 :
2630 : down_write(&trace_event_sem);
2631 : list_for_each_entry_safe(call, p, &ftrace_events, list) {
2632 : if (call->mod == mod)
2633 : __trace_remove_event_call(call);
2634 : }
2635 : up_write(&trace_event_sem);
2636 :
2637 : /*
2638 : * It is safest to reset the ring buffer if the module being unloaded
2639 : * registered any events that were used. The only worry is if
2640 : * a new module gets loaded, and takes on the same id as the events
2641 : * of this module. When printing out the buffer, traced events left
2642 : * over from this module may be passed to the new module events and
2643 : * unexpected results may occur.
2644 : */
2645 : tracing_reset_all_online_cpus();
2646 : }
2647 :
2648 : static int trace_module_notify(struct notifier_block *self,
2649 : unsigned long val, void *data)
2650 : {
2651 : struct module *mod = data;
2652 :
2653 : mutex_lock(&event_mutex);
2654 : mutex_lock(&trace_types_lock);
2655 : switch (val) {
2656 : case MODULE_STATE_COMING:
2657 : trace_module_add_events(mod);
2658 : break;
2659 : case MODULE_STATE_GOING:
2660 : trace_module_remove_events(mod);
2661 : break;
2662 : }
2663 : mutex_unlock(&trace_types_lock);
2664 : mutex_unlock(&event_mutex);
2665 :
2666 : return NOTIFY_OK;
2667 : }
2668 :
2669 : static struct notifier_block trace_module_nb = {
2670 : .notifier_call = trace_module_notify,
2671 : .priority = 1, /* higher than trace.c module notify */
2672 : };
2673 : #endif /* CONFIG_MODULES */
2674 :
2675 : /* Create a new event directory structure for a trace directory. */
2676 : static void
2677 0 : __trace_add_event_dirs(struct trace_array *tr)
2678 : {
2679 0 : struct trace_event_call *call;
2680 0 : int ret;
2681 :
2682 0 : list_for_each_entry(call, &ftrace_events, list) {
2683 0 : ret = __trace_add_new_event(call, tr);
2684 0 : if (ret < 0)
2685 0 : pr_warn("Could not create directory for event %s\n",
2686 : trace_event_name(call));
2687 : }
2688 0 : }
2689 :
2690 : /* Returns any file that matches the system and event */
2691 : struct trace_event_file *
2692 1 : __find_event_file(struct trace_array *tr, const char *system, const char *event)
2693 : {
2694 1 : struct trace_event_file *file;
2695 1 : struct trace_event_call *call;
2696 1 : const char *name;
2697 :
2698 142 : list_for_each_entry(file, &tr->events, list) {
2699 :
2700 142 : call = file->event_call;
2701 142 : name = trace_event_name(call);
2702 :
2703 142 : if (!name || !call->class)
2704 0 : continue;
2705 :
2706 142 : if (strcmp(event, name) == 0 &&
2707 1 : strcmp(system, call->class->system) == 0)
2708 1 : return file;
2709 : }
2710 : return NULL;
2711 : }
2712 :
2713 : /* Returns valid trace event files that match system and event */
2714 : struct trace_event_file *
2715 0 : find_event_file(struct trace_array *tr, const char *system, const char *event)
2716 : {
2717 0 : struct trace_event_file *file;
2718 :
2719 0 : file = __find_event_file(tr, system, event);
2720 0 : if (!file || !file->event_call->class->reg ||
2721 0 : file->event_call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)
2722 0 : return NULL;
2723 :
2724 : return file;
2725 : }
2726 :
2727 : /**
2728 : * trace_get_event_file - Find and return a trace event file
2729 : * @instance: The name of the trace instance containing the event
2730 : * @system: The name of the system containing the event
2731 : * @event: The name of the event
2732 : *
2733 : * Return a trace event file given the trace instance name, trace
2734 : * system, and trace event name. If the instance name is NULL, it
2735 : * refers to the top-level trace array.
2736 : *
2737 : * This function will look it up and return it if found, after calling
2738 : * trace_array_get() to prevent the instance from going away, and
2739 : * increment the event's module refcount to prevent it from being
2740 : * removed.
2741 : *
2742 : * To release the file, call trace_put_event_file(), which will call
2743 : * trace_array_put() and decrement the event's module refcount.
2744 : *
2745 : * Return: The trace event on success, ERR_PTR otherwise.
2746 : */
2747 0 : struct trace_event_file *trace_get_event_file(const char *instance,
2748 : const char *system,
2749 : const char *event)
2750 : {
2751 0 : struct trace_array *tr = top_trace_array();
2752 0 : struct trace_event_file *file = NULL;
2753 0 : int ret = -EINVAL;
2754 :
2755 0 : if (instance) {
2756 0 : tr = trace_array_find_get(instance);
2757 0 : if (!tr)
2758 0 : return ERR_PTR(-ENOENT);
2759 : } else {
2760 0 : ret = trace_array_get(tr);
2761 0 : if (ret)
2762 0 : return ERR_PTR(ret);
2763 : }
2764 :
2765 0 : mutex_lock(&event_mutex);
2766 :
2767 0 : file = find_event_file(tr, system, event);
2768 0 : if (!file) {
2769 0 : trace_array_put(tr);
2770 0 : ret = -EINVAL;
2771 0 : goto out;
2772 : }
2773 :
2774 : /* Don't let event modules unload while in use */
2775 0 : ret = try_module_get(file->event_call->mod);
2776 : if (!ret) {
2777 : trace_array_put(tr);
2778 : ret = -EBUSY;
2779 : goto out;
2780 : }
2781 :
2782 0 : ret = 0;
2783 0 : out:
2784 0 : mutex_unlock(&event_mutex);
2785 :
2786 0 : if (ret)
2787 0 : file = ERR_PTR(ret);
2788 :
2789 : return file;
2790 : }
2791 : EXPORT_SYMBOL_GPL(trace_get_event_file);
2792 :
2793 : /**
2794 : * trace_put_event_file - Release a file from trace_get_event_file()
2795 : * @file: The trace event file
2796 : *
2797 : * If a file was retrieved using trace_get_event_file(), this should
2798 : * be called when it's no longer needed. It will cancel the previous
2799 : * trace_array_get() called by that function, and decrement the
2800 : * event's module refcount.
2801 : */
2802 0 : void trace_put_event_file(struct trace_event_file *file)
2803 : {
2804 0 : mutex_lock(&event_mutex);
2805 0 : module_put(file->event_call->mod);
2806 0 : mutex_unlock(&event_mutex);
2807 :
2808 0 : trace_array_put(file->tr);
2809 0 : }
2810 : EXPORT_SYMBOL_GPL(trace_put_event_file);
2811 :
2812 : #ifdef CONFIG_DYNAMIC_FTRACE
2813 :
2814 : /* Avoid typos */
2815 : #define ENABLE_EVENT_STR "enable_event"
2816 : #define DISABLE_EVENT_STR "disable_event"
2817 :
2818 : struct event_probe_data {
2819 : struct trace_event_file *file;
2820 : unsigned long count;
2821 : int ref;
2822 : bool enable;
2823 : };
2824 :
2825 : static void update_event_probe(struct event_probe_data *data)
2826 : {
2827 : if (data->enable)
2828 : clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
2829 : else
2830 : set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
2831 : }
2832 :
2833 : static void
2834 : event_enable_probe(unsigned long ip, unsigned long parent_ip,
2835 : struct trace_array *tr, struct ftrace_probe_ops *ops,
2836 : void *data)
2837 : {
2838 : struct ftrace_func_mapper *mapper = data;
2839 : struct event_probe_data *edata;
2840 : void **pdata;
2841 :
2842 : pdata = ftrace_func_mapper_find_ip(mapper, ip);
2843 : if (!pdata || !*pdata)
2844 : return;
2845 :
2846 : edata = *pdata;
2847 : update_event_probe(edata);
2848 : }
2849 :
2850 : static void
2851 : event_enable_count_probe(unsigned long ip, unsigned long parent_ip,
2852 : struct trace_array *tr, struct ftrace_probe_ops *ops,
2853 : void *data)
2854 : {
2855 : struct ftrace_func_mapper *mapper = data;
2856 : struct event_probe_data *edata;
2857 : void **pdata;
2858 :
2859 : pdata = ftrace_func_mapper_find_ip(mapper, ip);
2860 : if (!pdata || !*pdata)
2861 : return;
2862 :
2863 : edata = *pdata;
2864 :
2865 : if (!edata->count)
2866 : return;
2867 :
2868 : /* Skip if the event is in a state we want to switch to */
2869 : if (edata->enable == !(edata->file->flags & EVENT_FILE_FL_SOFT_DISABLED))
2870 : return;
2871 :
2872 : if (edata->count != -1)
2873 : (edata->count)--;
2874 :
2875 : update_event_probe(edata);
2876 : }
2877 :
2878 : static int
2879 : event_enable_print(struct seq_file *m, unsigned long ip,
2880 : struct ftrace_probe_ops *ops, void *data)
2881 : {
2882 : struct ftrace_func_mapper *mapper = data;
2883 : struct event_probe_data *edata;
2884 : void **pdata;
2885 :
2886 : pdata = ftrace_func_mapper_find_ip(mapper, ip);
2887 :
2888 : if (WARN_ON_ONCE(!pdata || !*pdata))
2889 : return 0;
2890 :
2891 : edata = *pdata;
2892 :
2893 : seq_printf(m, "%ps:", (void *)ip);
2894 :
2895 : seq_printf(m, "%s:%s:%s",
2896 : edata->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR,
2897 : edata->file->event_call->class->system,
2898 : trace_event_name(edata->file->event_call));
2899 :
2900 : if (edata->count == -1)
2901 : seq_puts(m, ":unlimited\n");
2902 : else
2903 : seq_printf(m, ":count=%ld\n", edata->count);
2904 :
2905 : return 0;
2906 : }
2907 :
2908 : static int
2909 : event_enable_init(struct ftrace_probe_ops *ops, struct trace_array *tr,
2910 : unsigned long ip, void *init_data, void **data)
2911 : {
2912 : struct ftrace_func_mapper *mapper = *data;
2913 : struct event_probe_data *edata = init_data;
2914 : int ret;
2915 :
2916 : if (!mapper) {
2917 : mapper = allocate_ftrace_func_mapper();
2918 : if (!mapper)
2919 : return -ENODEV;
2920 : *data = mapper;
2921 : }
2922 :
2923 : ret = ftrace_func_mapper_add_ip(mapper, ip, edata);
2924 : if (ret < 0)
2925 : return ret;
2926 :
2927 : edata->ref++;
2928 :
2929 : return 0;
2930 : }
2931 :
2932 : static int free_probe_data(void *data)
2933 : {
2934 : struct event_probe_data *edata = data;
2935 :
2936 : edata->ref--;
2937 : if (!edata->ref) {
2938 : /* Remove the SOFT_MODE flag */
2939 : __ftrace_event_enable_disable(edata->file, 0, 1);
2940 : module_put(edata->file->event_call->mod);
2941 : kfree(edata);
2942 : }
2943 : return 0;
2944 : }
2945 :
2946 : static void
2947 : event_enable_free(struct ftrace_probe_ops *ops, struct trace_array *tr,
2948 : unsigned long ip, void *data)
2949 : {
2950 : struct ftrace_func_mapper *mapper = data;
2951 : struct event_probe_data *edata;
2952 :
2953 : if (!ip) {
2954 : if (!mapper)
2955 : return;
2956 : free_ftrace_func_mapper(mapper, free_probe_data);
2957 : return;
2958 : }
2959 :
2960 : edata = ftrace_func_mapper_remove_ip(mapper, ip);
2961 :
2962 : if (WARN_ON_ONCE(!edata))
2963 : return;
2964 :
2965 : if (WARN_ON_ONCE(edata->ref <= 0))
2966 : return;
2967 :
2968 : free_probe_data(edata);
2969 : }
2970 :
2971 : static struct ftrace_probe_ops event_enable_probe_ops = {
2972 : .func = event_enable_probe,
2973 : .print = event_enable_print,
2974 : .init = event_enable_init,
2975 : .free = event_enable_free,
2976 : };
2977 :
2978 : static struct ftrace_probe_ops event_enable_count_probe_ops = {
2979 : .func = event_enable_count_probe,
2980 : .print = event_enable_print,
2981 : .init = event_enable_init,
2982 : .free = event_enable_free,
2983 : };
2984 :
2985 : static struct ftrace_probe_ops event_disable_probe_ops = {
2986 : .func = event_enable_probe,
2987 : .print = event_enable_print,
2988 : .init = event_enable_init,
2989 : .free = event_enable_free,
2990 : };
2991 :
2992 : static struct ftrace_probe_ops event_disable_count_probe_ops = {
2993 : .func = event_enable_count_probe,
2994 : .print = event_enable_print,
2995 : .init = event_enable_init,
2996 : .free = event_enable_free,
2997 : };
2998 :
2999 : static int
3000 : event_enable_func(struct trace_array *tr, struct ftrace_hash *hash,
3001 : char *glob, char *cmd, char *param, int enabled)
3002 : {
3003 : struct trace_event_file *file;
3004 : struct ftrace_probe_ops *ops;
3005 : struct event_probe_data *data;
3006 : const char *system;
3007 : const char *event;
3008 : char *number;
3009 : bool enable;
3010 : int ret;
3011 :
3012 : if (!tr)
3013 : return -ENODEV;
3014 :
3015 : /* hash funcs only work with set_ftrace_filter */
3016 : if (!enabled || !param)
3017 : return -EINVAL;
3018 :
3019 : system = strsep(¶m, ":");
3020 : if (!param)
3021 : return -EINVAL;
3022 :
3023 : event = strsep(¶m, ":");
3024 :
3025 : mutex_lock(&event_mutex);
3026 :
3027 : ret = -EINVAL;
3028 : file = find_event_file(tr, system, event);
3029 : if (!file)
3030 : goto out;
3031 :
3032 : enable = strcmp(cmd, ENABLE_EVENT_STR) == 0;
3033 :
3034 : if (enable)
3035 : ops = param ? &event_enable_count_probe_ops : &event_enable_probe_ops;
3036 : else
3037 : ops = param ? &event_disable_count_probe_ops : &event_disable_probe_ops;
3038 :
3039 : if (glob[0] == '!') {
3040 : ret = unregister_ftrace_function_probe_func(glob+1, tr, ops);
3041 : goto out;
3042 : }
3043 :
3044 : ret = -ENOMEM;
3045 :
3046 : data = kzalloc(sizeof(*data), GFP_KERNEL);
3047 : if (!data)
3048 : goto out;
3049 :
3050 : data->enable = enable;
3051 : data->count = -1;
3052 : data->file = file;
3053 :
3054 : if (!param)
3055 : goto out_reg;
3056 :
3057 : number = strsep(¶m, ":");
3058 :
3059 : ret = -EINVAL;
3060 : if (!strlen(number))
3061 : goto out_free;
3062 :
3063 : /*
3064 : * We use the callback data field (which is a pointer)
3065 : * as our counter.
3066 : */
3067 : ret = kstrtoul(number, 0, &data->count);
3068 : if (ret)
3069 : goto out_free;
3070 :
3071 : out_reg:
3072 : /* Don't let event modules unload while probe registered */
3073 : ret = try_module_get(file->event_call->mod);
3074 : if (!ret) {
3075 : ret = -EBUSY;
3076 : goto out_free;
3077 : }
3078 :
3079 : ret = __ftrace_event_enable_disable(file, 1, 1);
3080 : if (ret < 0)
3081 : goto out_put;
3082 :
3083 : ret = register_ftrace_function_probe(glob, tr, ops, data);
3084 : /*
3085 : * The above returns on success the # of functions enabled,
3086 : * but if it didn't find any functions it returns zero.
3087 : * Consider no functions a failure too.
3088 : */
3089 : if (!ret) {
3090 : ret = -ENOENT;
3091 : goto out_disable;
3092 : } else if (ret < 0)
3093 : goto out_disable;
3094 : /* Just return zero, not the number of enabled functions */
3095 : ret = 0;
3096 : out:
3097 : mutex_unlock(&event_mutex);
3098 : return ret;
3099 :
3100 : out_disable:
3101 : __ftrace_event_enable_disable(file, 0, 1);
3102 : out_put:
3103 : module_put(file->event_call->mod);
3104 : out_free:
3105 : kfree(data);
3106 : goto out;
3107 : }
3108 :
3109 : static struct ftrace_func_command event_enable_cmd = {
3110 : .name = ENABLE_EVENT_STR,
3111 : .func = event_enable_func,
3112 : };
3113 :
3114 : static struct ftrace_func_command event_disable_cmd = {
3115 : .name = DISABLE_EVENT_STR,
3116 : .func = event_enable_func,
3117 : };
3118 :
3119 : static __init int register_event_cmds(void)
3120 : {
3121 : int ret;
3122 :
3123 : ret = register_ftrace_command(&event_enable_cmd);
3124 : if (WARN_ON(ret < 0))
3125 : return ret;
3126 : ret = register_ftrace_command(&event_disable_cmd);
3127 : if (WARN_ON(ret < 0))
3128 : unregister_ftrace_command(&event_enable_cmd);
3129 : return ret;
3130 : }
3131 : #else
3132 1 : static inline int register_event_cmds(void) { return 0; }
3133 : #endif /* CONFIG_DYNAMIC_FTRACE */
3134 :
3135 : /*
3136 : * The top level array and trace arrays created by boot-time tracing
3137 : * have already had its trace_event_file descriptors created in order
3138 : * to allow for early events to be recorded.
3139 : * This function is called after the tracefs has been initialized,
3140 : * and we now have to create the files associated to the events.
3141 : */
3142 1 : static void __trace_early_add_event_dirs(struct trace_array *tr)
3143 : {
3144 1 : struct trace_event_file *file;
3145 1 : int ret;
3146 :
3147 :
3148 543 : list_for_each_entry(file, &tr->events, list) {
3149 542 : ret = event_create_dir(tr->event_dir, file);
3150 542 : if (ret < 0)
3151 0 : pr_warn("Could not create directory for event %s\n",
3152 : trace_event_name(file->event_call));
3153 : }
3154 1 : }
3155 :
3156 : /*
3157 : * For early boot up, the top trace array and the trace arrays created
3158 : * by boot-time tracing require to have a list of events that can be
3159 : * enabled. This must be done before the filesystem is set up in order
3160 : * to allow events to be traced early.
3161 : */
3162 1 : void __trace_early_add_events(struct trace_array *tr)
3163 : {
3164 1 : struct trace_event_call *call;
3165 1 : int ret;
3166 :
3167 543 : list_for_each_entry(call, &ftrace_events, list) {
3168 : /* Early boot up should not have any modules loaded */
3169 542 : if (WARN_ON_ONCE(call->mod))
3170 0 : continue;
3171 :
3172 542 : ret = __trace_early_add_new_event(call, tr);
3173 542 : if (ret < 0)
3174 0 : pr_warn("Could not create early event %s\n",
3175 : trace_event_name(call));
3176 : }
3177 1 : }
3178 :
3179 : /* Remove the event directory structure for a trace directory. */
3180 : static void
3181 0 : __trace_remove_event_dirs(struct trace_array *tr)
3182 : {
3183 0 : struct trace_event_file *file, *next;
3184 :
3185 0 : list_for_each_entry_safe(file, next, &tr->events, list)
3186 0 : remove_event_file_dir(file);
3187 0 : }
3188 :
3189 0 : static void __add_event_to_tracers(struct trace_event_call *call)
3190 : {
3191 0 : struct trace_array *tr;
3192 :
3193 0 : list_for_each_entry(tr, &ftrace_trace_arrays, list)
3194 0 : __trace_add_new_event(call, tr);
3195 0 : }
3196 :
3197 : extern struct trace_event_call *__start_ftrace_events[];
3198 : extern struct trace_event_call *__stop_ftrace_events[];
3199 :
3200 : static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
3201 :
3202 0 : static __init int setup_trace_event(char *str)
3203 : {
3204 0 : strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
3205 0 : ring_buffer_expanded = true;
3206 0 : disable_tracing_selftest("running event tracing");
3207 :
3208 0 : return 1;
3209 : }
3210 : __setup("trace_event=", setup_trace_event);
3211 :
3212 : /* Expects to have event_mutex held when called */
3213 : static int
3214 1 : create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
3215 : {
3216 1 : struct dentry *d_events;
3217 1 : struct dentry *entry;
3218 :
3219 1 : entry = tracefs_create_file("set_event", 0644, parent,
3220 : tr, &ftrace_set_event_fops);
3221 1 : if (!entry) {
3222 0 : pr_warn("Could not create tracefs 'set_event' entry\n");
3223 0 : return -ENOMEM;
3224 : }
3225 :
3226 1 : d_events = tracefs_create_dir("events", parent);
3227 1 : if (!d_events) {
3228 0 : pr_warn("Could not create tracefs 'events' directory\n");
3229 0 : return -ENOMEM;
3230 : }
3231 :
3232 1 : entry = trace_create_file("enable", 0644, d_events,
3233 : tr, &ftrace_tr_enable_fops);
3234 1 : if (!entry) {
3235 0 : pr_warn("Could not create tracefs 'enable' entry\n");
3236 0 : return -ENOMEM;
3237 : }
3238 :
3239 : /* There are not as crucial, just warn if they are not created */
3240 :
3241 1 : entry = tracefs_create_file("set_event_pid", 0644, parent,
3242 : tr, &ftrace_set_event_pid_fops);
3243 1 : if (!entry)
3244 0 : pr_warn("Could not create tracefs 'set_event_pid' entry\n");
3245 :
3246 1 : entry = tracefs_create_file("set_event_notrace_pid", 0644, parent,
3247 : tr, &ftrace_set_event_notrace_pid_fops);
3248 1 : if (!entry)
3249 0 : pr_warn("Could not create tracefs 'set_event_notrace_pid' entry\n");
3250 :
3251 : /* ring buffer internal formats */
3252 1 : entry = trace_create_file("header_page", 0444, d_events,
3253 : ring_buffer_print_page_header,
3254 : &ftrace_show_header_fops);
3255 1 : if (!entry)
3256 0 : pr_warn("Could not create tracefs 'header_page' entry\n");
3257 :
3258 1 : entry = trace_create_file("header_event", 0444, d_events,
3259 : ring_buffer_print_entry_header,
3260 : &ftrace_show_header_fops);
3261 1 : if (!entry)
3262 0 : pr_warn("Could not create tracefs 'header_event' entry\n");
3263 :
3264 1 : tr->event_dir = d_events;
3265 :
3266 1 : return 0;
3267 : }
3268 :
3269 : /**
3270 : * event_trace_add_tracer - add a instance of a trace_array to events
3271 : * @parent: The parent dentry to place the files/directories for events in
3272 : * @tr: The trace array associated with these events
3273 : *
3274 : * When a new instance is created, it needs to set up its events
3275 : * directory, as well as other files associated with events. It also
3276 : * creates the event hierarchy in the @parent/events directory.
3277 : *
3278 : * Returns 0 on success.
3279 : *
3280 : * Must be called with event_mutex held.
3281 : */
3282 0 : int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr)
3283 : {
3284 0 : int ret;
3285 :
3286 0 : lockdep_assert_held(&event_mutex);
3287 :
3288 0 : ret = create_event_toplevel_files(parent, tr);
3289 0 : if (ret)
3290 0 : goto out;
3291 :
3292 0 : down_write(&trace_event_sem);
3293 : /* If tr already has the event list, it is initialized in early boot. */
3294 0 : if (unlikely(!list_empty(&tr->events)))
3295 0 : __trace_early_add_event_dirs(tr);
3296 : else
3297 0 : __trace_add_event_dirs(tr);
3298 0 : up_write(&trace_event_sem);
3299 :
3300 0 : out:
3301 0 : return ret;
3302 : }
3303 :
3304 : /*
3305 : * The top trace array already had its file descriptors created.
3306 : * Now the files themselves need to be created.
3307 : */
3308 : static __init int
3309 1 : early_event_add_tracer(struct dentry *parent, struct trace_array *tr)
3310 : {
3311 1 : int ret;
3312 :
3313 1 : mutex_lock(&event_mutex);
3314 :
3315 1 : ret = create_event_toplevel_files(parent, tr);
3316 1 : if (ret)
3317 0 : goto out_unlock;
3318 :
3319 1 : down_write(&trace_event_sem);
3320 1 : __trace_early_add_event_dirs(tr);
3321 1 : up_write(&trace_event_sem);
3322 :
3323 1 : out_unlock:
3324 1 : mutex_unlock(&event_mutex);
3325 :
3326 1 : return ret;
3327 : }
3328 :
3329 : /* Must be called with event_mutex held */
3330 0 : int event_trace_del_tracer(struct trace_array *tr)
3331 : {
3332 0 : lockdep_assert_held(&event_mutex);
3333 :
3334 : /* Disable any event triggers and associated soft-disabled events */
3335 0 : clear_event_triggers(tr);
3336 :
3337 : /* Clear the pid list */
3338 0 : __ftrace_clear_event_pids(tr, TRACE_PIDS | TRACE_NO_PIDS);
3339 :
3340 : /* Disable any running events */
3341 0 : __ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
3342 :
3343 : /* Make sure no more events are being executed */
3344 0 : tracepoint_synchronize_unregister();
3345 :
3346 0 : down_write(&trace_event_sem);
3347 0 : __trace_remove_event_dirs(tr);
3348 0 : tracefs_remove(tr->event_dir);
3349 0 : up_write(&trace_event_sem);
3350 :
3351 0 : tr->event_dir = NULL;
3352 :
3353 0 : return 0;
3354 : }
3355 :
3356 1 : static __init int event_trace_memsetup(void)
3357 : {
3358 1 : field_cachep = KMEM_CACHE(ftrace_event_field, SLAB_PANIC);
3359 1 : file_cachep = KMEM_CACHE(trace_event_file, SLAB_PANIC);
3360 1 : return 0;
3361 : }
3362 :
3363 : static __init void
3364 2 : early_enable_events(struct trace_array *tr, bool disable_first)
3365 : {
3366 2 : char *buf = bootup_event_buf;
3367 4 : char *token;
3368 4 : int ret;
3369 :
3370 4 : while (true) {
3371 4 : token = strsep(&buf, ",");
3372 :
3373 4 : if (!token)
3374 : break;
3375 :
3376 2 : if (*token) {
3377 : /* Restarting syscalls requires that we stop them first */
3378 0 : if (disable_first)
3379 0 : ftrace_set_clr_event(tr, token, 0);
3380 :
3381 0 : ret = ftrace_set_clr_event(tr, token, 1);
3382 0 : if (ret)
3383 0 : pr_warn("Failed to enable trace event: %s\n", token);
3384 : }
3385 :
3386 : /* Put back the comma to allow this to be called again */
3387 2 : if (buf)
3388 0 : *(buf - 1) = ',';
3389 : }
3390 2 : }
3391 :
3392 1 : static __init int event_trace_enable(void)
3393 : {
3394 1 : struct trace_array *tr = top_trace_array();
3395 1 : struct trace_event_call **iter, *call;
3396 1 : int ret;
3397 :
3398 1 : if (!tr)
3399 : return -ENODEV;
3400 :
3401 543 : for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
3402 :
3403 542 : call = *iter;
3404 542 : ret = event_init(call);
3405 542 : if (!ret)
3406 542 : list_add(&call->list, &ftrace_events);
3407 : }
3408 :
3409 : /*
3410 : * We need the top trace array to have a working set of trace
3411 : * points at early init, before the debug files and directories
3412 : * are created. Create the file entries now, and attach them
3413 : * to the actual file dentries later.
3414 : */
3415 1 : __trace_early_add_events(tr);
3416 :
3417 1 : early_enable_events(tr, false);
3418 :
3419 1 : trace_printk_start_comm();
3420 :
3421 1 : register_event_cmds();
3422 :
3423 1 : register_trigger_cmds();
3424 :
3425 1 : return 0;
3426 : }
3427 :
3428 : /*
3429 : * event_trace_enable() is called from trace_event_init() first to
3430 : * initialize events and perhaps start any events that are on the
3431 : * command line. Unfortunately, there are some events that will not
3432 : * start this early, like the system call tracepoints that need
3433 : * to set the %SYSCALL_WORK_SYSCALL_TRACEPOINT flag of pid 1. But
3434 : * event_trace_enable() is called before pid 1 starts, and this flag
3435 : * is never set, making the syscall tracepoint never get reached, but
3436 : * the event is enabled regardless (and not doing anything).
3437 : */
3438 1 : static __init int event_trace_enable_again(void)
3439 : {
3440 1 : struct trace_array *tr;
3441 :
3442 1 : tr = top_trace_array();
3443 1 : if (!tr)
3444 : return -ENODEV;
3445 :
3446 1 : early_enable_events(tr, true);
3447 :
3448 1 : return 0;
3449 : }
3450 :
3451 : early_initcall(event_trace_enable_again);
3452 :
3453 : /* Init fields which doesn't related to the tracefs */
3454 1 : static __init int event_trace_init_fields(void)
3455 : {
3456 1 : if (trace_define_generic_fields())
3457 0 : pr_warn("tracing: Failed to allocated generic fields");
3458 :
3459 1 : if (trace_define_common_fields())
3460 0 : pr_warn("tracing: Failed to allocate common fields");
3461 :
3462 1 : return 0;
3463 : }
3464 :
3465 1 : __init int event_trace_init(void)
3466 : {
3467 1 : struct trace_array *tr;
3468 1 : struct dentry *entry;
3469 1 : int ret;
3470 :
3471 1 : tr = top_trace_array();
3472 1 : if (!tr)
3473 : return -ENODEV;
3474 :
3475 1 : entry = tracefs_create_file("available_events", 0444, NULL,
3476 : tr, &ftrace_avail_fops);
3477 1 : if (!entry)
3478 0 : pr_warn("Could not create tracefs 'available_events' entry\n");
3479 :
3480 1 : ret = early_event_add_tracer(NULL, tr);
3481 1 : if (ret)
3482 : return ret;
3483 :
3484 : #ifdef CONFIG_MODULES
3485 : ret = register_module_notifier(&trace_module_nb);
3486 : if (ret)
3487 : pr_warn("Failed to register trace events module notifier\n");
3488 : #endif
3489 :
3490 1 : eventdir_initialized = true;
3491 :
3492 1 : return 0;
3493 : }
3494 :
3495 1 : void __init trace_event_init(void)
3496 : {
3497 1 : event_trace_memsetup();
3498 1 : init_ftrace_syscalls();
3499 1 : event_trace_enable();
3500 1 : event_trace_init_fields();
3501 1 : }
3502 :
3503 : #ifdef CONFIG_EVENT_TRACE_STARTUP_TEST
3504 :
3505 : static DEFINE_SPINLOCK(test_spinlock);
3506 : static DEFINE_SPINLOCK(test_spinlock_irq);
3507 : static DEFINE_MUTEX(test_mutex);
3508 :
3509 : static __init void test_work(struct work_struct *dummy)
3510 : {
3511 : spin_lock(&test_spinlock);
3512 : spin_lock_irq(&test_spinlock_irq);
3513 : udelay(1);
3514 : spin_unlock_irq(&test_spinlock_irq);
3515 : spin_unlock(&test_spinlock);
3516 :
3517 : mutex_lock(&test_mutex);
3518 : msleep(1);
3519 : mutex_unlock(&test_mutex);
3520 : }
3521 :
3522 : static __init int event_test_thread(void *unused)
3523 : {
3524 : void *test_malloc;
3525 :
3526 : test_malloc = kmalloc(1234, GFP_KERNEL);
3527 : if (!test_malloc)
3528 : pr_info("failed to kmalloc\n");
3529 :
3530 : schedule_on_each_cpu(test_work);
3531 :
3532 : kfree(test_malloc);
3533 :
3534 : set_current_state(TASK_INTERRUPTIBLE);
3535 : while (!kthread_should_stop()) {
3536 : schedule();
3537 : set_current_state(TASK_INTERRUPTIBLE);
3538 : }
3539 : __set_current_state(TASK_RUNNING);
3540 :
3541 : return 0;
3542 : }
3543 :
3544 : /*
3545 : * Do various things that may trigger events.
3546 : */
3547 : static __init void event_test_stuff(void)
3548 : {
3549 : struct task_struct *test_thread;
3550 :
3551 : test_thread = kthread_run(event_test_thread, NULL, "test-events");
3552 : msleep(1);
3553 : kthread_stop(test_thread);
3554 : }
3555 :
3556 : /*
3557 : * For every trace event defined, we will test each trace point separately,
3558 : * and then by groups, and finally all trace points.
3559 : */
3560 : static __init void event_trace_self_tests(void)
3561 : {
3562 : struct trace_subsystem_dir *dir;
3563 : struct trace_event_file *file;
3564 : struct trace_event_call *call;
3565 : struct event_subsystem *system;
3566 : struct trace_array *tr;
3567 : int ret;
3568 :
3569 : tr = top_trace_array();
3570 : if (!tr)
3571 : return;
3572 :
3573 : pr_info("Running tests on trace events:\n");
3574 :
3575 : list_for_each_entry(file, &tr->events, list) {
3576 :
3577 : call = file->event_call;
3578 :
3579 : /* Only test those that have a probe */
3580 : if (!call->class || !call->class->probe)
3581 : continue;
3582 :
3583 : /*
3584 : * Testing syscall events here is pretty useless, but
3585 : * we still do it if configured. But this is time consuming.
3586 : * What we really need is a user thread to perform the
3587 : * syscalls as we test.
3588 : */
3589 : #ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS
3590 : if (call->class->system &&
3591 : strcmp(call->class->system, "syscalls") == 0)
3592 : continue;
3593 : #endif
3594 :
3595 : pr_info("Testing event %s: ", trace_event_name(call));
3596 :
3597 : /*
3598 : * If an event is already enabled, someone is using
3599 : * it and the self test should not be on.
3600 : */
3601 : if (file->flags & EVENT_FILE_FL_ENABLED) {
3602 : pr_warn("Enabled event during self test!\n");
3603 : WARN_ON_ONCE(1);
3604 : continue;
3605 : }
3606 :
3607 : ftrace_event_enable_disable(file, 1);
3608 : event_test_stuff();
3609 : ftrace_event_enable_disable(file, 0);
3610 :
3611 : pr_cont("OK\n");
3612 : }
3613 :
3614 : /* Now test at the sub system level */
3615 :
3616 : pr_info("Running tests on trace event systems:\n");
3617 :
3618 : list_for_each_entry(dir, &tr->systems, list) {
3619 :
3620 : system = dir->subsystem;
3621 :
3622 : /* the ftrace system is special, skip it */
3623 : if (strcmp(system->name, "ftrace") == 0)
3624 : continue;
3625 :
3626 : pr_info("Testing event system %s: ", system->name);
3627 :
3628 : ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 1);
3629 : if (WARN_ON_ONCE(ret)) {
3630 : pr_warn("error enabling system %s\n",
3631 : system->name);
3632 : continue;
3633 : }
3634 :
3635 : event_test_stuff();
3636 :
3637 : ret = __ftrace_set_clr_event(tr, NULL, system->name, NULL, 0);
3638 : if (WARN_ON_ONCE(ret)) {
3639 : pr_warn("error disabling system %s\n",
3640 : system->name);
3641 : continue;
3642 : }
3643 :
3644 : pr_cont("OK\n");
3645 : }
3646 :
3647 : /* Test with all events enabled */
3648 :
3649 : pr_info("Running tests on all trace events:\n");
3650 : pr_info("Testing all events: ");
3651 :
3652 : ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 1);
3653 : if (WARN_ON_ONCE(ret)) {
3654 : pr_warn("error enabling all events\n");
3655 : return;
3656 : }
3657 :
3658 : event_test_stuff();
3659 :
3660 : /* reset sysname */
3661 : ret = __ftrace_set_clr_event(tr, NULL, NULL, NULL, 0);
3662 : if (WARN_ON_ONCE(ret)) {
3663 : pr_warn("error disabling all events\n");
3664 : return;
3665 : }
3666 :
3667 : pr_cont("OK\n");
3668 : }
3669 :
3670 : #ifdef CONFIG_FUNCTION_TRACER
3671 :
3672 : static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable);
3673 :
3674 : static struct trace_event_file event_trace_file __initdata;
3675 :
3676 : static void __init
3677 : function_test_events_call(unsigned long ip, unsigned long parent_ip,
3678 : struct ftrace_ops *op, struct ftrace_regs *regs)
3679 : {
3680 : struct trace_buffer *buffer;
3681 : struct ring_buffer_event *event;
3682 : struct ftrace_entry *entry;
3683 : unsigned int trace_ctx;
3684 : long disabled;
3685 : int cpu;
3686 :
3687 : trace_ctx = tracing_gen_ctx();
3688 : preempt_disable_notrace();
3689 : cpu = raw_smp_processor_id();
3690 : disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu));
3691 :
3692 : if (disabled != 1)
3693 : goto out;
3694 :
3695 : event = trace_event_buffer_lock_reserve(&buffer, &event_trace_file,
3696 : TRACE_FN, sizeof(*entry),
3697 : trace_ctx);
3698 : if (!event)
3699 : goto out;
3700 : entry = ring_buffer_event_data(event);
3701 : entry->ip = ip;
3702 : entry->parent_ip = parent_ip;
3703 :
3704 : event_trigger_unlock_commit(&event_trace_file, buffer, event,
3705 : entry, trace_ctx);
3706 : out:
3707 : atomic_dec(&per_cpu(ftrace_test_event_disable, cpu));
3708 : preempt_enable_notrace();
3709 : }
3710 :
3711 : static struct ftrace_ops trace_ops __initdata =
3712 : {
3713 : .func = function_test_events_call,
3714 : };
3715 :
3716 : static __init void event_trace_self_test_with_function(void)
3717 : {
3718 : int ret;
3719 :
3720 : event_trace_file.tr = top_trace_array();
3721 : if (WARN_ON(!event_trace_file.tr))
3722 : return;
3723 :
3724 : ret = register_ftrace_function(&trace_ops);
3725 : if (WARN_ON(ret < 0)) {
3726 : pr_info("Failed to enable function tracer for event tests\n");
3727 : return;
3728 : }
3729 : pr_info("Running tests again, along with the function tracer\n");
3730 : event_trace_self_tests();
3731 : unregister_ftrace_function(&trace_ops);
3732 : }
3733 : #else
3734 : static __init void event_trace_self_test_with_function(void)
3735 : {
3736 : }
3737 : #endif
3738 :
3739 : static __init int event_trace_self_tests_init(void)
3740 : {
3741 : if (!tracing_selftest_disabled) {
3742 : event_trace_self_tests();
3743 : event_trace_self_test_with_function();
3744 : }
3745 :
3746 : return 0;
3747 : }
3748 :
3749 : late_initcall(event_trace_self_tests_init);
3750 :
3751 : #endif
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