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1 | /* | |
2 | * ring buffer based function tracer | |
3 | * | |
4 | * Copyright (C) 2007-2012 Steven Rostedt <srostedt@redhat.com> | |
5 | * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com> | |
6 | * | |
7 | * Originally taken from the RT patch by: | |
8 | * Arnaldo Carvalho de Melo <acme@redhat.com> | |
9 | * | |
10 | * Based on code from the latency_tracer, that is: | |
11 | * Copyright (C) 2004-2006 Ingo Molnar | |
12 | * Copyright (C) 2004 Nadia Yvette Chambers | |
13 | */ | |
14 | #include <linux/ring_buffer.h> | |
15 | #include <generated/utsrelease.h> | |
16 | #include <linux/stacktrace.h> | |
17 | #include <linux/writeback.h> | |
18 | #include <linux/kallsyms.h> | |
19 | #include <linux/seq_file.h> | |
20 | #include <linux/notifier.h> | |
21 | #include <linux/irqflags.h> | |
22 | #include <linux/debugfs.h> | |
23 | #include <linux/pagemap.h> | |
24 | #include <linux/hardirq.h> | |
25 | #include <linux/linkage.h> | |
26 | #include <linux/uaccess.h> | |
27 | #include <linux/kprobes.h> | |
28 | #include <linux/ftrace.h> | |
29 | #include <linux/module.h> | |
30 | #include <linux/percpu.h> | |
31 | #include <linux/splice.h> | |
32 | #include <linux/kdebug.h> | |
33 | #include <linux/string.h> | |
34 | #include <linux/rwsem.h> | |
35 | #include <linux/slab.h> | |
36 | #include <linux/ctype.h> | |
37 | #include <linux/init.h> | |
38 | #include <linux/poll.h> | |
39 | #include <linux/nmi.h> | |
40 | #include <linux/fs.h> | |
41 | #include <linux/sched/rt.h> | |
42 | ||
43 | #include "trace.h" | |
44 | #include "trace_output.h" | |
45 | ||
46 | /* | |
47 | * On boot up, the ring buffer is set to the minimum size, so that | |
48 | * we do not waste memory on systems that are not using tracing. | |
49 | */ | |
50 | bool ring_buffer_expanded; | |
51 | ||
52 | /* | |
53 | * We need to change this state when a selftest is running. | |
54 | * A selftest will lurk into the ring-buffer to count the | |
55 | * entries inserted during the selftest although some concurrent | |
56 | * insertions into the ring-buffer such as trace_printk could occurred | |
57 | * at the same time, giving false positive or negative results. | |
58 | */ | |
59 | static bool __read_mostly tracing_selftest_running; | |
60 | ||
61 | /* | |
62 | * If a tracer is running, we do not want to run SELFTEST. | |
63 | */ | |
64 | bool __read_mostly tracing_selftest_disabled; | |
65 | ||
66 | /* For tracers that don't implement custom flags */ | |
67 | static struct tracer_opt dummy_tracer_opt[] = { | |
68 | { } | |
69 | }; | |
70 | ||
71 | static struct tracer_flags dummy_tracer_flags = { | |
72 | .val = 0, | |
73 | .opts = dummy_tracer_opt | |
74 | }; | |
75 | ||
76 | static int dummy_set_flag(u32 old_flags, u32 bit, int set) | |
77 | { | |
78 | return 0; | |
79 | } | |
80 | ||
81 | /* | |
82 | * To prevent the comm cache from being overwritten when no | |
83 | * tracing is active, only save the comm when a trace event | |
84 | * occurred. | |
85 | */ | |
86 | static DEFINE_PER_CPU(bool, trace_cmdline_save); | |
87 | ||
88 | /* | |
89 | * Kill all tracing for good (never come back). | |
90 | * It is initialized to 1 but will turn to zero if the initialization | |
91 | * of the tracer is successful. But that is the only place that sets | |
92 | * this back to zero. | |
93 | */ | |
94 | static int tracing_disabled = 1; | |
95 | ||
96 | DEFINE_PER_CPU(int, ftrace_cpu_disabled); | |
97 | ||
98 | cpumask_var_t __read_mostly tracing_buffer_mask; | |
99 | ||
100 | /* | |
101 | * ftrace_dump_on_oops - variable to dump ftrace buffer on oops | |
102 | * | |
103 | * If there is an oops (or kernel panic) and the ftrace_dump_on_oops | |
104 | * is set, then ftrace_dump is called. This will output the contents | |
105 | * of the ftrace buffers to the console. This is very useful for | |
106 | * capturing traces that lead to crashes and outputing it to a | |
107 | * serial console. | |
108 | * | |
109 | * It is default off, but you can enable it with either specifying | |
110 | * "ftrace_dump_on_oops" in the kernel command line, or setting | |
111 | * /proc/sys/kernel/ftrace_dump_on_oops | |
112 | * Set 1 if you want to dump buffers of all CPUs | |
113 | * Set 2 if you want to dump the buffer of the CPU that triggered oops | |
114 | */ | |
115 | ||
116 | enum ftrace_dump_mode ftrace_dump_on_oops; | |
117 | ||
118 | /* When set, tracing will stop when a WARN*() is hit */ | |
119 | int __disable_trace_on_warning; | |
120 | ||
121 | static int tracing_set_tracer(const char *buf); | |
122 | ||
123 | #define MAX_TRACER_SIZE 100 | |
124 | static char bootup_tracer_buf[MAX_TRACER_SIZE] __initdata; | |
125 | static char *default_bootup_tracer; | |
126 | ||
127 | static bool allocate_snapshot; | |
128 | ||
129 | static int __init set_cmdline_ftrace(char *str) | |
130 | { | |
131 | strlcpy(bootup_tracer_buf, str, MAX_TRACER_SIZE); | |
132 | default_bootup_tracer = bootup_tracer_buf; | |
133 | /* We are using ftrace early, expand it */ | |
134 | ring_buffer_expanded = true; | |
135 | return 1; | |
136 | } | |
137 | __setup("ftrace=", set_cmdline_ftrace); | |
138 | ||
139 | static int __init set_ftrace_dump_on_oops(char *str) | |
140 | { | |
141 | if (*str++ != '=' || !*str) { | |
142 | ftrace_dump_on_oops = DUMP_ALL; | |
143 | return 1; | |
144 | } | |
145 | ||
146 | if (!strcmp("orig_cpu", str)) { | |
147 | ftrace_dump_on_oops = DUMP_ORIG; | |
148 | return 1; | |
149 | } | |
150 | ||
151 | return 0; | |
152 | } | |
153 | __setup("ftrace_dump_on_oops", set_ftrace_dump_on_oops); | |
154 | ||
155 | static int __init stop_trace_on_warning(char *str) | |
156 | { | |
157 | __disable_trace_on_warning = 1; | |
158 | return 1; | |
159 | } | |
160 | __setup("traceoff_on_warning=", stop_trace_on_warning); | |
161 | ||
162 | static int __init boot_alloc_snapshot(char *str) | |
163 | { | |
164 | allocate_snapshot = true; | |
165 | /* We also need the main ring buffer expanded */ | |
166 | ring_buffer_expanded = true; | |
167 | return 1; | |
168 | } | |
169 | __setup("alloc_snapshot", boot_alloc_snapshot); | |
170 | ||
171 | ||
172 | static char trace_boot_options_buf[MAX_TRACER_SIZE] __initdata; | |
173 | static char *trace_boot_options __initdata; | |
174 | ||
175 | static int __init set_trace_boot_options(char *str) | |
176 | { | |
177 | strlcpy(trace_boot_options_buf, str, MAX_TRACER_SIZE); | |
178 | trace_boot_options = trace_boot_options_buf; | |
179 | return 0; | |
180 | } | |
181 | __setup("trace_options=", set_trace_boot_options); | |
182 | ||
183 | ||
184 | unsigned long long ns2usecs(cycle_t nsec) | |
185 | { | |
186 | nsec += 500; | |
187 | do_div(nsec, 1000); | |
188 | return nsec; | |
189 | } | |
190 | ||
191 | /* | |
192 | * The global_trace is the descriptor that holds the tracing | |
193 | * buffers for the live tracing. For each CPU, it contains | |
194 | * a link list of pages that will store trace entries. The | |
195 | * page descriptor of the pages in the memory is used to hold | |
196 | * the link list by linking the lru item in the page descriptor | |
197 | * to each of the pages in the buffer per CPU. | |
198 | * | |
199 | * For each active CPU there is a data field that holds the | |
200 | * pages for the buffer for that CPU. Each CPU has the same number | |
201 | * of pages allocated for its buffer. | |
202 | */ | |
203 | static struct trace_array global_trace; | |
204 | ||
205 | LIST_HEAD(ftrace_trace_arrays); | |
206 | ||
207 | int trace_array_get(struct trace_array *this_tr) | |
208 | { | |
209 | struct trace_array *tr; | |
210 | int ret = -ENODEV; | |
211 | ||
212 | mutex_lock(&trace_types_lock); | |
213 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
214 | if (tr == this_tr) { | |
215 | tr->ref++; | |
216 | ret = 0; | |
217 | break; | |
218 | } | |
219 | } | |
220 | mutex_unlock(&trace_types_lock); | |
221 | ||
222 | return ret; | |
223 | } | |
224 | ||
225 | static void __trace_array_put(struct trace_array *this_tr) | |
226 | { | |
227 | WARN_ON(!this_tr->ref); | |
228 | this_tr->ref--; | |
229 | } | |
230 | ||
231 | void trace_array_put(struct trace_array *this_tr) | |
232 | { | |
233 | mutex_lock(&trace_types_lock); | |
234 | __trace_array_put(this_tr); | |
235 | mutex_unlock(&trace_types_lock); | |
236 | } | |
237 | ||
238 | int filter_current_check_discard(struct ring_buffer *buffer, | |
239 | struct ftrace_event_call *call, void *rec, | |
240 | struct ring_buffer_event *event) | |
241 | { | |
242 | return filter_check_discard(call, rec, buffer, event); | |
243 | } | |
244 | EXPORT_SYMBOL_GPL(filter_current_check_discard); | |
245 | ||
246 | cycle_t buffer_ftrace_now(struct trace_buffer *buf, int cpu) | |
247 | { | |
248 | u64 ts; | |
249 | ||
250 | /* Early boot up does not have a buffer yet */ | |
251 | if (!buf->buffer) | |
252 | return trace_clock_local(); | |
253 | ||
254 | ts = ring_buffer_time_stamp(buf->buffer, cpu); | |
255 | ring_buffer_normalize_time_stamp(buf->buffer, cpu, &ts); | |
256 | ||
257 | return ts; | |
258 | } | |
259 | ||
260 | cycle_t ftrace_now(int cpu) | |
261 | { | |
262 | return buffer_ftrace_now(&global_trace.trace_buffer, cpu); | |
263 | } | |
264 | ||
265 | /** | |
266 | * tracing_is_enabled - Show if global_trace has been disabled | |
267 | * | |
268 | * Shows if the global trace has been enabled or not. It uses the | |
269 | * mirror flag "buffer_disabled" to be used in fast paths such as for | |
270 | * the irqsoff tracer. But it may be inaccurate due to races. If you | |
271 | * need to know the accurate state, use tracing_is_on() which is a little | |
272 | * slower, but accurate. | |
273 | */ | |
274 | int tracing_is_enabled(void) | |
275 | { | |
276 | /* | |
277 | * For quick access (irqsoff uses this in fast path), just | |
278 | * return the mirror variable of the state of the ring buffer. | |
279 | * It's a little racy, but we don't really care. | |
280 | */ | |
281 | smp_rmb(); | |
282 | return !global_trace.buffer_disabled; | |
283 | } | |
284 | ||
285 | /* | |
286 | * trace_buf_size is the size in bytes that is allocated | |
287 | * for a buffer. Note, the number of bytes is always rounded | |
288 | * to page size. | |
289 | * | |
290 | * This number is purposely set to a low number of 16384. | |
291 | * If the dump on oops happens, it will be much appreciated | |
292 | * to not have to wait for all that output. Anyway this can be | |
293 | * boot time and run time configurable. | |
294 | */ | |
295 | #define TRACE_BUF_SIZE_DEFAULT 1441792UL /* 16384 * 88 (sizeof(entry)) */ | |
296 | ||
297 | static unsigned long trace_buf_size = TRACE_BUF_SIZE_DEFAULT; | |
298 | ||
299 | /* trace_types holds a link list of available tracers. */ | |
300 | static struct tracer *trace_types __read_mostly; | |
301 | ||
302 | /* | |
303 | * trace_types_lock is used to protect the trace_types list. | |
304 | */ | |
305 | DEFINE_MUTEX(trace_types_lock); | |
306 | ||
307 | /* | |
308 | * serialize the access of the ring buffer | |
309 | * | |
310 | * ring buffer serializes readers, but it is low level protection. | |
311 | * The validity of the events (which returns by ring_buffer_peek() ..etc) | |
312 | * are not protected by ring buffer. | |
313 | * | |
314 | * The content of events may become garbage if we allow other process consumes | |
315 | * these events concurrently: | |
316 | * A) the page of the consumed events may become a normal page | |
317 | * (not reader page) in ring buffer, and this page will be rewrited | |
318 | * by events producer. | |
319 | * B) The page of the consumed events may become a page for splice_read, | |
320 | * and this page will be returned to system. | |
321 | * | |
322 | * These primitives allow multi process access to different cpu ring buffer | |
323 | * concurrently. | |
324 | * | |
325 | * These primitives don't distinguish read-only and read-consume access. | |
326 | * Multi read-only access are also serialized. | |
327 | */ | |
328 | ||
329 | #ifdef CONFIG_SMP | |
330 | static DECLARE_RWSEM(all_cpu_access_lock); | |
331 | static DEFINE_PER_CPU(struct mutex, cpu_access_lock); | |
332 | ||
333 | static inline void trace_access_lock(int cpu) | |
334 | { | |
335 | if (cpu == RING_BUFFER_ALL_CPUS) { | |
336 | /* gain it for accessing the whole ring buffer. */ | |
337 | down_write(&all_cpu_access_lock); | |
338 | } else { | |
339 | /* gain it for accessing a cpu ring buffer. */ | |
340 | ||
341 | /* Firstly block other trace_access_lock(RING_BUFFER_ALL_CPUS). */ | |
342 | down_read(&all_cpu_access_lock); | |
343 | ||
344 | /* Secondly block other access to this @cpu ring buffer. */ | |
345 | mutex_lock(&per_cpu(cpu_access_lock, cpu)); | |
346 | } | |
347 | } | |
348 | ||
349 | static inline void trace_access_unlock(int cpu) | |
350 | { | |
351 | if (cpu == RING_BUFFER_ALL_CPUS) { | |
352 | up_write(&all_cpu_access_lock); | |
353 | } else { | |
354 | mutex_unlock(&per_cpu(cpu_access_lock, cpu)); | |
355 | up_read(&all_cpu_access_lock); | |
356 | } | |
357 | } | |
358 | ||
359 | static inline void trace_access_lock_init(void) | |
360 | { | |
361 | int cpu; | |
362 | ||
363 | for_each_possible_cpu(cpu) | |
364 | mutex_init(&per_cpu(cpu_access_lock, cpu)); | |
365 | } | |
366 | ||
367 | #else | |
368 | ||
369 | static DEFINE_MUTEX(access_lock); | |
370 | ||
371 | static inline void trace_access_lock(int cpu) | |
372 | { | |
373 | (void)cpu; | |
374 | mutex_lock(&access_lock); | |
375 | } | |
376 | ||
377 | static inline void trace_access_unlock(int cpu) | |
378 | { | |
379 | (void)cpu; | |
380 | mutex_unlock(&access_lock); | |
381 | } | |
382 | ||
383 | static inline void trace_access_lock_init(void) | |
384 | { | |
385 | } | |
386 | ||
387 | #endif | |
388 | ||
389 | /* trace_flags holds trace_options default values */ | |
390 | unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK | | |
391 | TRACE_ITER_ANNOTATE | TRACE_ITER_CONTEXT_INFO | TRACE_ITER_SLEEP_TIME | | |
392 | TRACE_ITER_GRAPH_TIME | TRACE_ITER_RECORD_CMD | TRACE_ITER_OVERWRITE | | |
393 | TRACE_ITER_IRQ_INFO | TRACE_ITER_MARKERS | TRACE_ITER_FUNCTION; | |
394 | ||
395 | static void tracer_tracing_on(struct trace_array *tr) | |
396 | { | |
397 | if (tr->trace_buffer.buffer) | |
398 | ring_buffer_record_on(tr->trace_buffer.buffer); | |
399 | /* | |
400 | * This flag is looked at when buffers haven't been allocated | |
401 | * yet, or by some tracers (like irqsoff), that just want to | |
402 | * know if the ring buffer has been disabled, but it can handle | |
403 | * races of where it gets disabled but we still do a record. | |
404 | * As the check is in the fast path of the tracers, it is more | |
405 | * important to be fast than accurate. | |
406 | */ | |
407 | tr->buffer_disabled = 0; | |
408 | /* Make the flag seen by readers */ | |
409 | smp_wmb(); | |
410 | } | |
411 | ||
412 | /** | |
413 | * tracing_on - enable tracing buffers | |
414 | * | |
415 | * This function enables tracing buffers that may have been | |
416 | * disabled with tracing_off. | |
417 | */ | |
418 | void tracing_on(void) | |
419 | { | |
420 | tracer_tracing_on(&global_trace); | |
421 | } | |
422 | EXPORT_SYMBOL_GPL(tracing_on); | |
423 | ||
424 | /** | |
425 | * __trace_puts - write a constant string into the trace buffer. | |
426 | * @ip: The address of the caller | |
427 | * @str: The constant string to write | |
428 | * @size: The size of the string. | |
429 | */ | |
430 | int __trace_puts(unsigned long ip, const char *str, int size) | |
431 | { | |
432 | struct ring_buffer_event *event; | |
433 | struct ring_buffer *buffer; | |
434 | struct print_entry *entry; | |
435 | unsigned long irq_flags; | |
436 | int alloc; | |
437 | ||
438 | alloc = sizeof(*entry) + size + 2; /* possible \n added */ | |
439 | ||
440 | local_save_flags(irq_flags); | |
441 | buffer = global_trace.trace_buffer.buffer; | |
442 | event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc, | |
443 | irq_flags, preempt_count()); | |
444 | if (!event) | |
445 | return 0; | |
446 | ||
447 | entry = ring_buffer_event_data(event); | |
448 | entry->ip = ip; | |
449 | ||
450 | memcpy(&entry->buf, str, size); | |
451 | ||
452 | /* Add a newline if necessary */ | |
453 | if (entry->buf[size - 1] != '\n') { | |
454 | entry->buf[size] = '\n'; | |
455 | entry->buf[size + 1] = '\0'; | |
456 | } else | |
457 | entry->buf[size] = '\0'; | |
458 | ||
459 | __buffer_unlock_commit(buffer, event); | |
460 | ||
461 | return size; | |
462 | } | |
463 | EXPORT_SYMBOL_GPL(__trace_puts); | |
464 | ||
465 | /** | |
466 | * __trace_bputs - write the pointer to a constant string into trace buffer | |
467 | * @ip: The address of the caller | |
468 | * @str: The constant string to write to the buffer to | |
469 | */ | |
470 | int __trace_bputs(unsigned long ip, const char *str) | |
471 | { | |
472 | struct ring_buffer_event *event; | |
473 | struct ring_buffer *buffer; | |
474 | struct bputs_entry *entry; | |
475 | unsigned long irq_flags; | |
476 | int size = sizeof(struct bputs_entry); | |
477 | ||
478 | local_save_flags(irq_flags); | |
479 | buffer = global_trace.trace_buffer.buffer; | |
480 | event = trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size, | |
481 | irq_flags, preempt_count()); | |
482 | if (!event) | |
483 | return 0; | |
484 | ||
485 | entry = ring_buffer_event_data(event); | |
486 | entry->ip = ip; | |
487 | entry->str = str; | |
488 | ||
489 | __buffer_unlock_commit(buffer, event); | |
490 | ||
491 | return 1; | |
492 | } | |
493 | EXPORT_SYMBOL_GPL(__trace_bputs); | |
494 | ||
495 | #ifdef CONFIG_TRACER_SNAPSHOT | |
496 | /** | |
497 | * trace_snapshot - take a snapshot of the current buffer. | |
498 | * | |
499 | * This causes a swap between the snapshot buffer and the current live | |
500 | * tracing buffer. You can use this to take snapshots of the live | |
501 | * trace when some condition is triggered, but continue to trace. | |
502 | * | |
503 | * Note, make sure to allocate the snapshot with either | |
504 | * a tracing_snapshot_alloc(), or by doing it manually | |
505 | * with: echo 1 > /sys/kernel/debug/tracing/snapshot | |
506 | * | |
507 | * If the snapshot buffer is not allocated, it will stop tracing. | |
508 | * Basically making a permanent snapshot. | |
509 | */ | |
510 | void tracing_snapshot(void) | |
511 | { | |
512 | struct trace_array *tr = &global_trace; | |
513 | struct tracer *tracer = tr->current_trace; | |
514 | unsigned long flags; | |
515 | ||
516 | if (in_nmi()) { | |
517 | internal_trace_puts("*** SNAPSHOT CALLED FROM NMI CONTEXT ***\n"); | |
518 | internal_trace_puts("*** snapshot is being ignored ***\n"); | |
519 | return; | |
520 | } | |
521 | ||
522 | if (!tr->allocated_snapshot) { | |
523 | internal_trace_puts("*** SNAPSHOT NOT ALLOCATED ***\n"); | |
524 | internal_trace_puts("*** stopping trace here! ***\n"); | |
525 | tracing_off(); | |
526 | return; | |
527 | } | |
528 | ||
529 | /* Note, snapshot can not be used when the tracer uses it */ | |
530 | if (tracer->use_max_tr) { | |
531 | internal_trace_puts("*** LATENCY TRACER ACTIVE ***\n"); | |
532 | internal_trace_puts("*** Can not use snapshot (sorry) ***\n"); | |
533 | return; | |
534 | } | |
535 | ||
536 | local_irq_save(flags); | |
537 | update_max_tr(tr, current, smp_processor_id()); | |
538 | local_irq_restore(flags); | |
539 | } | |
540 | EXPORT_SYMBOL_GPL(tracing_snapshot); | |
541 | ||
542 | static int resize_buffer_duplicate_size(struct trace_buffer *trace_buf, | |
543 | struct trace_buffer *size_buf, int cpu_id); | |
544 | static void set_buffer_entries(struct trace_buffer *buf, unsigned long val); | |
545 | ||
546 | static int alloc_snapshot(struct trace_array *tr) | |
547 | { | |
548 | int ret; | |
549 | ||
550 | if (!tr->allocated_snapshot) { | |
551 | ||
552 | /* allocate spare buffer */ | |
553 | ret = resize_buffer_duplicate_size(&tr->max_buffer, | |
554 | &tr->trace_buffer, RING_BUFFER_ALL_CPUS); | |
555 | if (ret < 0) | |
556 | return ret; | |
557 | ||
558 | tr->allocated_snapshot = true; | |
559 | } | |
560 | ||
561 | return 0; | |
562 | } | |
563 | ||
564 | void free_snapshot(struct trace_array *tr) | |
565 | { | |
566 | /* | |
567 | * We don't free the ring buffer. instead, resize it because | |
568 | * The max_tr ring buffer has some state (e.g. ring->clock) and | |
569 | * we want preserve it. | |
570 | */ | |
571 | ring_buffer_resize(tr->max_buffer.buffer, 1, RING_BUFFER_ALL_CPUS); | |
572 | set_buffer_entries(&tr->max_buffer, 1); | |
573 | tracing_reset_online_cpus(&tr->max_buffer); | |
574 | tr->allocated_snapshot = false; | |
575 | } | |
576 | ||
577 | /** | |
578 | * trace_snapshot_alloc - allocate and take a snapshot of the current buffer. | |
579 | * | |
580 | * This is similar to trace_snapshot(), but it will allocate the | |
581 | * snapshot buffer if it isn't already allocated. Use this only | |
582 | * where it is safe to sleep, as the allocation may sleep. | |
583 | * | |
584 | * This causes a swap between the snapshot buffer and the current live | |
585 | * tracing buffer. You can use this to take snapshots of the live | |
586 | * trace when some condition is triggered, but continue to trace. | |
587 | */ | |
588 | void tracing_snapshot_alloc(void) | |
589 | { | |
590 | struct trace_array *tr = &global_trace; | |
591 | int ret; | |
592 | ||
593 | ret = alloc_snapshot(tr); | |
594 | if (WARN_ON(ret < 0)) | |
595 | return; | |
596 | ||
597 | tracing_snapshot(); | |
598 | } | |
599 | EXPORT_SYMBOL_GPL(tracing_snapshot_alloc); | |
600 | #else | |
601 | void tracing_snapshot(void) | |
602 | { | |
603 | WARN_ONCE(1, "Snapshot feature not enabled, but internal snapshot used"); | |
604 | } | |
605 | EXPORT_SYMBOL_GPL(tracing_snapshot); | |
606 | void tracing_snapshot_alloc(void) | |
607 | { | |
608 | /* Give warning */ | |
609 | tracing_snapshot(); | |
610 | } | |
611 | EXPORT_SYMBOL_GPL(tracing_snapshot_alloc); | |
612 | #endif /* CONFIG_TRACER_SNAPSHOT */ | |
613 | ||
614 | static void tracer_tracing_off(struct trace_array *tr) | |
615 | { | |
616 | if (tr->trace_buffer.buffer) | |
617 | ring_buffer_record_off(tr->trace_buffer.buffer); | |
618 | /* | |
619 | * This flag is looked at when buffers haven't been allocated | |
620 | * yet, or by some tracers (like irqsoff), that just want to | |
621 | * know if the ring buffer has been disabled, but it can handle | |
622 | * races of where it gets disabled but we still do a record. | |
623 | * As the check is in the fast path of the tracers, it is more | |
624 | * important to be fast than accurate. | |
625 | */ | |
626 | tr->buffer_disabled = 1; | |
627 | /* Make the flag seen by readers */ | |
628 | smp_wmb(); | |
629 | } | |
630 | ||
631 | /** | |
632 | * tracing_off - turn off tracing buffers | |
633 | * | |
634 | * This function stops the tracing buffers from recording data. | |
635 | * It does not disable any overhead the tracers themselves may | |
636 | * be causing. This function simply causes all recording to | |
637 | * the ring buffers to fail. | |
638 | */ | |
639 | void tracing_off(void) | |
640 | { | |
641 | tracer_tracing_off(&global_trace); | |
642 | } | |
643 | EXPORT_SYMBOL_GPL(tracing_off); | |
644 | ||
645 | void disable_trace_on_warning(void) | |
646 | { | |
647 | if (__disable_trace_on_warning) | |
648 | tracing_off(); | |
649 | } | |
650 | ||
651 | /** | |
652 | * tracer_tracing_is_on - show real state of ring buffer enabled | |
653 | * @tr : the trace array to know if ring buffer is enabled | |
654 | * | |
655 | * Shows real state of the ring buffer if it is enabled or not. | |
656 | */ | |
657 | static int tracer_tracing_is_on(struct trace_array *tr) | |
658 | { | |
659 | if (tr->trace_buffer.buffer) | |
660 | return ring_buffer_record_is_on(tr->trace_buffer.buffer); | |
661 | return !tr->buffer_disabled; | |
662 | } | |
663 | ||
664 | /** | |
665 | * tracing_is_on - show state of ring buffers enabled | |
666 | */ | |
667 | int tracing_is_on(void) | |
668 | { | |
669 | return tracer_tracing_is_on(&global_trace); | |
670 | } | |
671 | EXPORT_SYMBOL_GPL(tracing_is_on); | |
672 | ||
673 | static int __init set_buf_size(char *str) | |
674 | { | |
675 | unsigned long buf_size; | |
676 | ||
677 | if (!str) | |
678 | return 0; | |
679 | buf_size = memparse(str, &str); | |
680 | /* nr_entries can not be zero */ | |
681 | if (buf_size == 0) | |
682 | return 0; | |
683 | trace_buf_size = buf_size; | |
684 | return 1; | |
685 | } | |
686 | __setup("trace_buf_size=", set_buf_size); | |
687 | ||
688 | static int __init set_tracing_thresh(char *str) | |
689 | { | |
690 | unsigned long threshold; | |
691 | int ret; | |
692 | ||
693 | if (!str) | |
694 | return 0; | |
695 | ret = kstrtoul(str, 0, &threshold); | |
696 | if (ret < 0) | |
697 | return 0; | |
698 | tracing_thresh = threshold * 1000; | |
699 | return 1; | |
700 | } | |
701 | __setup("tracing_thresh=", set_tracing_thresh); | |
702 | ||
703 | unsigned long nsecs_to_usecs(unsigned long nsecs) | |
704 | { | |
705 | return nsecs / 1000; | |
706 | } | |
707 | ||
708 | /* These must match the bit postions in trace_iterator_flags */ | |
709 | static const char *trace_options[] = { | |
710 | "print-parent", | |
711 | "sym-offset", | |
712 | "sym-addr", | |
713 | "verbose", | |
714 | "raw", | |
715 | "hex", | |
716 | "bin", | |
717 | "block", | |
718 | "stacktrace", | |
719 | "trace_printk", | |
720 | "ftrace_preempt", | |
721 | "branch", | |
722 | "annotate", | |
723 | "userstacktrace", | |
724 | "sym-userobj", | |
725 | "printk-msg-only", | |
726 | "context-info", | |
727 | "latency-format", | |
728 | "sleep-time", | |
729 | "graph-time", | |
730 | "record-cmd", | |
731 | "overwrite", | |
732 | "disable_on_free", | |
733 | "irq-info", | |
734 | "markers", | |
735 | "function-trace", | |
736 | NULL | |
737 | }; | |
738 | ||
739 | static struct { | |
740 | u64 (*func)(void); | |
741 | const char *name; | |
742 | int in_ns; /* is this clock in nanoseconds? */ | |
743 | } trace_clocks[] = { | |
744 | { trace_clock_local, "local", 1 }, | |
745 | { trace_clock_global, "global", 1 }, | |
746 | { trace_clock_counter, "counter", 0 }, | |
747 | { trace_clock_jiffies, "uptime", 1 }, | |
748 | { trace_clock, "perf", 1 }, | |
749 | ARCH_TRACE_CLOCKS | |
750 | }; | |
751 | ||
752 | /* | |
753 | * trace_parser_get_init - gets the buffer for trace parser | |
754 | */ | |
755 | int trace_parser_get_init(struct trace_parser *parser, int size) | |
756 | { | |
757 | memset(parser, 0, sizeof(*parser)); | |
758 | ||
759 | parser->buffer = kmalloc(size, GFP_KERNEL); | |
760 | if (!parser->buffer) | |
761 | return 1; | |
762 | ||
763 | parser->size = size; | |
764 | return 0; | |
765 | } | |
766 | ||
767 | /* | |
768 | * trace_parser_put - frees the buffer for trace parser | |
769 | */ | |
770 | void trace_parser_put(struct trace_parser *parser) | |
771 | { | |
772 | kfree(parser->buffer); | |
773 | } | |
774 | ||
775 | /* | |
776 | * trace_get_user - reads the user input string separated by space | |
777 | * (matched by isspace(ch)) | |
778 | * | |
779 | * For each string found the 'struct trace_parser' is updated, | |
780 | * and the function returns. | |
781 | * | |
782 | * Returns number of bytes read. | |
783 | * | |
784 | * See kernel/trace/trace.h for 'struct trace_parser' details. | |
785 | */ | |
786 | int trace_get_user(struct trace_parser *parser, const char __user *ubuf, | |
787 | size_t cnt, loff_t *ppos) | |
788 | { | |
789 | char ch; | |
790 | size_t read = 0; | |
791 | ssize_t ret; | |
792 | ||
793 | if (!*ppos) | |
794 | trace_parser_clear(parser); | |
795 | ||
796 | ret = get_user(ch, ubuf++); | |
797 | if (ret) | |
798 | goto out; | |
799 | ||
800 | read++; | |
801 | cnt--; | |
802 | ||
803 | /* | |
804 | * The parser is not finished with the last write, | |
805 | * continue reading the user input without skipping spaces. | |
806 | */ | |
807 | if (!parser->cont) { | |
808 | /* skip white space */ | |
809 | while (cnt && isspace(ch)) { | |
810 | ret = get_user(ch, ubuf++); | |
811 | if (ret) | |
812 | goto out; | |
813 | read++; | |
814 | cnt--; | |
815 | } | |
816 | ||
817 | /* only spaces were written */ | |
818 | if (isspace(ch)) { | |
819 | *ppos += read; | |
820 | ret = read; | |
821 | goto out; | |
822 | } | |
823 | ||
824 | parser->idx = 0; | |
825 | } | |
826 | ||
827 | /* read the non-space input */ | |
828 | while (cnt && !isspace(ch)) { | |
829 | if (parser->idx < parser->size - 1) | |
830 | parser->buffer[parser->idx++] = ch; | |
831 | else { | |
832 | ret = -EINVAL; | |
833 | goto out; | |
834 | } | |
835 | ret = get_user(ch, ubuf++); | |
836 | if (ret) | |
837 | goto out; | |
838 | read++; | |
839 | cnt--; | |
840 | } | |
841 | ||
842 | /* We either got finished input or we have to wait for another call. */ | |
843 | if (isspace(ch)) { | |
844 | parser->buffer[parser->idx] = 0; | |
845 | parser->cont = false; | |
846 | } else { | |
847 | parser->cont = true; | |
848 | parser->buffer[parser->idx++] = ch; | |
849 | } | |
850 | ||
851 | *ppos += read; | |
852 | ret = read; | |
853 | ||
854 | out: | |
855 | return ret; | |
856 | } | |
857 | ||
858 | ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt) | |
859 | { | |
860 | int len; | |
861 | int ret; | |
862 | ||
863 | if (!cnt) | |
864 | return 0; | |
865 | ||
866 | if (s->len <= s->readpos) | |
867 | return -EBUSY; | |
868 | ||
869 | len = s->len - s->readpos; | |
870 | if (cnt > len) | |
871 | cnt = len; | |
872 | ret = copy_to_user(ubuf, s->buffer + s->readpos, cnt); | |
873 | if (ret == cnt) | |
874 | return -EFAULT; | |
875 | ||
876 | cnt -= ret; | |
877 | ||
878 | s->readpos += cnt; | |
879 | return cnt; | |
880 | } | |
881 | ||
882 | static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt) | |
883 | { | |
884 | int len; | |
885 | ||
886 | if (s->len <= s->readpos) | |
887 | return -EBUSY; | |
888 | ||
889 | len = s->len - s->readpos; | |
890 | if (cnt > len) | |
891 | cnt = len; | |
892 | memcpy(buf, s->buffer + s->readpos, cnt); | |
893 | ||
894 | s->readpos += cnt; | |
895 | return cnt; | |
896 | } | |
897 | ||
898 | /* | |
899 | * ftrace_max_lock is used to protect the swapping of buffers | |
900 | * when taking a max snapshot. The buffers themselves are | |
901 | * protected by per_cpu spinlocks. But the action of the swap | |
902 | * needs its own lock. | |
903 | * | |
904 | * This is defined as a arch_spinlock_t in order to help | |
905 | * with performance when lockdep debugging is enabled. | |
906 | * | |
907 | * It is also used in other places outside the update_max_tr | |
908 | * so it needs to be defined outside of the | |
909 | * CONFIG_TRACER_MAX_TRACE. | |
910 | */ | |
911 | static arch_spinlock_t ftrace_max_lock = | |
912 | (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; | |
913 | ||
914 | unsigned long __read_mostly tracing_thresh; | |
915 | ||
916 | #ifdef CONFIG_TRACER_MAX_TRACE | |
917 | unsigned long __read_mostly tracing_max_latency; | |
918 | ||
919 | /* | |
920 | * Copy the new maximum trace into the separate maximum-trace | |
921 | * structure. (this way the maximum trace is permanently saved, | |
922 | * for later retrieval via /sys/kernel/debug/tracing/latency_trace) | |
923 | */ | |
924 | static void | |
925 | __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) | |
926 | { | |
927 | struct trace_buffer *trace_buf = &tr->trace_buffer; | |
928 | struct trace_buffer *max_buf = &tr->max_buffer; | |
929 | struct trace_array_cpu *data = per_cpu_ptr(trace_buf->data, cpu); | |
930 | struct trace_array_cpu *max_data = per_cpu_ptr(max_buf->data, cpu); | |
931 | ||
932 | max_buf->cpu = cpu; | |
933 | max_buf->time_start = data->preempt_timestamp; | |
934 | ||
935 | max_data->saved_latency = tracing_max_latency; | |
936 | max_data->critical_start = data->critical_start; | |
937 | max_data->critical_end = data->critical_end; | |
938 | ||
939 | memcpy(max_data->comm, tsk->comm, TASK_COMM_LEN); | |
940 | max_data->pid = tsk->pid; | |
941 | /* | |
942 | * If tsk == current, then use current_uid(), as that does not use | |
943 | * RCU. The irq tracer can be called out of RCU scope. | |
944 | */ | |
945 | if (tsk == current) | |
946 | max_data->uid = current_uid(); | |
947 | else | |
948 | max_data->uid = task_uid(tsk); | |
949 | ||
950 | max_data->nice = tsk->static_prio - 20 - MAX_RT_PRIO; | |
951 | max_data->policy = tsk->policy; | |
952 | max_data->rt_priority = tsk->rt_priority; | |
953 | ||
954 | /* record this tasks comm */ | |
955 | tracing_record_cmdline(tsk); | |
956 | } | |
957 | ||
958 | /** | |
959 | * update_max_tr - snapshot all trace buffers from global_trace to max_tr | |
960 | * @tr: tracer | |
961 | * @tsk: the task with the latency | |
962 | * @cpu: The cpu that initiated the trace. | |
963 | * | |
964 | * Flip the buffers between the @tr and the max_tr and record information | |
965 | * about which task was the cause of this latency. | |
966 | */ | |
967 | void | |
968 | update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) | |
969 | { | |
970 | struct ring_buffer *buf; | |
971 | ||
972 | if (tr->stop_count) | |
973 | return; | |
974 | ||
975 | WARN_ON_ONCE(!irqs_disabled()); | |
976 | ||
977 | if (!tr->allocated_snapshot) { | |
978 | /* Only the nop tracer should hit this when disabling */ | |
979 | WARN_ON_ONCE(tr->current_trace != &nop_trace); | |
980 | return; | |
981 | } | |
982 | ||
983 | arch_spin_lock(&ftrace_max_lock); | |
984 | ||
985 | buf = tr->trace_buffer.buffer; | |
986 | tr->trace_buffer.buffer = tr->max_buffer.buffer; | |
987 | tr->max_buffer.buffer = buf; | |
988 | ||
989 | __update_max_tr(tr, tsk, cpu); | |
990 | arch_spin_unlock(&ftrace_max_lock); | |
991 | } | |
992 | ||
993 | /** | |
994 | * update_max_tr_single - only copy one trace over, and reset the rest | |
995 | * @tr - tracer | |
996 | * @tsk - task with the latency | |
997 | * @cpu - the cpu of the buffer to copy. | |
998 | * | |
999 | * Flip the trace of a single CPU buffer between the @tr and the max_tr. | |
1000 | */ | |
1001 | void | |
1002 | update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) | |
1003 | { | |
1004 | int ret; | |
1005 | ||
1006 | if (tr->stop_count) | |
1007 | return; | |
1008 | ||
1009 | WARN_ON_ONCE(!irqs_disabled()); | |
1010 | if (!tr->allocated_snapshot) { | |
1011 | /* Only the nop tracer should hit this when disabling */ | |
1012 | WARN_ON_ONCE(tr->current_trace != &nop_trace); | |
1013 | return; | |
1014 | } | |
1015 | ||
1016 | arch_spin_lock(&ftrace_max_lock); | |
1017 | ||
1018 | ret = ring_buffer_swap_cpu(tr->max_buffer.buffer, tr->trace_buffer.buffer, cpu); | |
1019 | ||
1020 | if (ret == -EBUSY) { | |
1021 | /* | |
1022 | * We failed to swap the buffer due to a commit taking | |
1023 | * place on this CPU. We fail to record, but we reset | |
1024 | * the max trace buffer (no one writes directly to it) | |
1025 | * and flag that it failed. | |
1026 | */ | |
1027 | trace_array_printk_buf(tr->max_buffer.buffer, _THIS_IP_, | |
1028 | "Failed to swap buffers due to commit in progress\n"); | |
1029 | } | |
1030 | ||
1031 | WARN_ON_ONCE(ret && ret != -EAGAIN && ret != -EBUSY); | |
1032 | ||
1033 | __update_max_tr(tr, tsk, cpu); | |
1034 | arch_spin_unlock(&ftrace_max_lock); | |
1035 | } | |
1036 | #endif /* CONFIG_TRACER_MAX_TRACE */ | |
1037 | ||
1038 | static void default_wait_pipe(struct trace_iterator *iter) | |
1039 | { | |
1040 | /* Iterators are static, they should be filled or empty */ | |
1041 | if (trace_buffer_iter(iter, iter->cpu_file)) | |
1042 | return; | |
1043 | ||
1044 | ring_buffer_wait(iter->trace_buffer->buffer, iter->cpu_file); | |
1045 | } | |
1046 | ||
1047 | #ifdef CONFIG_FTRACE_STARTUP_TEST | |
1048 | static int run_tracer_selftest(struct tracer *type) | |
1049 | { | |
1050 | struct trace_array *tr = &global_trace; | |
1051 | struct tracer *saved_tracer = tr->current_trace; | |
1052 | int ret; | |
1053 | ||
1054 | if (!type->selftest || tracing_selftest_disabled) | |
1055 | return 0; | |
1056 | ||
1057 | /* | |
1058 | * Run a selftest on this tracer. | |
1059 | * Here we reset the trace buffer, and set the current | |
1060 | * tracer to be this tracer. The tracer can then run some | |
1061 | * internal tracing to verify that everything is in order. | |
1062 | * If we fail, we do not register this tracer. | |
1063 | */ | |
1064 | tracing_reset_online_cpus(&tr->trace_buffer); | |
1065 | ||
1066 | tr->current_trace = type; | |
1067 | ||
1068 | #ifdef CONFIG_TRACER_MAX_TRACE | |
1069 | if (type->use_max_tr) { | |
1070 | /* If we expanded the buffers, make sure the max is expanded too */ | |
1071 | if (ring_buffer_expanded) | |
1072 | ring_buffer_resize(tr->max_buffer.buffer, trace_buf_size, | |
1073 | RING_BUFFER_ALL_CPUS); | |
1074 | tr->allocated_snapshot = true; | |
1075 | } | |
1076 | #endif | |
1077 | ||
1078 | /* the test is responsible for initializing and enabling */ | |
1079 | pr_info("Testing tracer %s: ", type->name); | |
1080 | ret = type->selftest(type, tr); | |
1081 | /* the test is responsible for resetting too */ | |
1082 | tr->current_trace = saved_tracer; | |
1083 | if (ret) { | |
1084 | printk(KERN_CONT "FAILED!\n"); | |
1085 | /* Add the warning after printing 'FAILED' */ | |
1086 | WARN_ON(1); | |
1087 | return -1; | |
1088 | } | |
1089 | /* Only reset on passing, to avoid touching corrupted buffers */ | |
1090 | tracing_reset_online_cpus(&tr->trace_buffer); | |
1091 | ||
1092 | #ifdef CONFIG_TRACER_MAX_TRACE | |
1093 | if (type->use_max_tr) { | |
1094 | tr->allocated_snapshot = false; | |
1095 | ||
1096 | /* Shrink the max buffer again */ | |
1097 | if (ring_buffer_expanded) | |
1098 | ring_buffer_resize(tr->max_buffer.buffer, 1, | |
1099 | RING_BUFFER_ALL_CPUS); | |
1100 | } | |
1101 | #endif | |
1102 | ||
1103 | printk(KERN_CONT "PASSED\n"); | |
1104 | return 0; | |
1105 | } | |
1106 | #else | |
1107 | static inline int run_tracer_selftest(struct tracer *type) | |
1108 | { | |
1109 | return 0; | |
1110 | } | |
1111 | #endif /* CONFIG_FTRACE_STARTUP_TEST */ | |
1112 | ||
1113 | /** | |
1114 | * register_tracer - register a tracer with the ftrace system. | |
1115 | * @type - the plugin for the tracer | |
1116 | * | |
1117 | * Register a new plugin tracer. | |
1118 | */ | |
1119 | int register_tracer(struct tracer *type) | |
1120 | { | |
1121 | struct tracer *t; | |
1122 | int ret = 0; | |
1123 | ||
1124 | if (!type->name) { | |
1125 | pr_info("Tracer must have a name\n"); | |
1126 | return -1; | |
1127 | } | |
1128 | ||
1129 | if (strlen(type->name) >= MAX_TRACER_SIZE) { | |
1130 | pr_info("Tracer has a name longer than %d\n", MAX_TRACER_SIZE); | |
1131 | return -1; | |
1132 | } | |
1133 | ||
1134 | mutex_lock(&trace_types_lock); | |
1135 | ||
1136 | tracing_selftest_running = true; | |
1137 | ||
1138 | for (t = trace_types; t; t = t->next) { | |
1139 | if (strcmp(type->name, t->name) == 0) { | |
1140 | /* already found */ | |
1141 | pr_info("Tracer %s already registered\n", | |
1142 | type->name); | |
1143 | ret = -1; | |
1144 | goto out; | |
1145 | } | |
1146 | } | |
1147 | ||
1148 | if (!type->set_flag) | |
1149 | type->set_flag = &dummy_set_flag; | |
1150 | if (!type->flags) | |
1151 | type->flags = &dummy_tracer_flags; | |
1152 | else | |
1153 | if (!type->flags->opts) | |
1154 | type->flags->opts = dummy_tracer_opt; | |
1155 | if (!type->wait_pipe) | |
1156 | type->wait_pipe = default_wait_pipe; | |
1157 | ||
1158 | ret = run_tracer_selftest(type); | |
1159 | if (ret < 0) | |
1160 | goto out; | |
1161 | ||
1162 | type->next = trace_types; | |
1163 | trace_types = type; | |
1164 | ||
1165 | out: | |
1166 | tracing_selftest_running = false; | |
1167 | mutex_unlock(&trace_types_lock); | |
1168 | ||
1169 | if (ret || !default_bootup_tracer) | |
1170 | goto out_unlock; | |
1171 | ||
1172 | if (strncmp(default_bootup_tracer, type->name, MAX_TRACER_SIZE)) | |
1173 | goto out_unlock; | |
1174 | ||
1175 | printk(KERN_INFO "Starting tracer '%s'\n", type->name); | |
1176 | /* Do we want this tracer to start on bootup? */ | |
1177 | tracing_set_tracer(type->name); | |
1178 | default_bootup_tracer = NULL; | |
1179 | /* disable other selftests, since this will break it. */ | |
1180 | tracing_selftest_disabled = true; | |
1181 | #ifdef CONFIG_FTRACE_STARTUP_TEST | |
1182 | printk(KERN_INFO "Disabling FTRACE selftests due to running tracer '%s'\n", | |
1183 | type->name); | |
1184 | #endif | |
1185 | ||
1186 | out_unlock: | |
1187 | return ret; | |
1188 | } | |
1189 | ||
1190 | void tracing_reset(struct trace_buffer *buf, int cpu) | |
1191 | { | |
1192 | struct ring_buffer *buffer = buf->buffer; | |
1193 | ||
1194 | if (!buffer) | |
1195 | return; | |
1196 | ||
1197 | ring_buffer_record_disable(buffer); | |
1198 | ||
1199 | /* Make sure all commits have finished */ | |
1200 | synchronize_sched(); | |
1201 | ring_buffer_reset_cpu(buffer, cpu); | |
1202 | ||
1203 | ring_buffer_record_enable(buffer); | |
1204 | } | |
1205 | ||
1206 | void tracing_reset_online_cpus(struct trace_buffer *buf) | |
1207 | { | |
1208 | struct ring_buffer *buffer = buf->buffer; | |
1209 | int cpu; | |
1210 | ||
1211 | if (!buffer) | |
1212 | return; | |
1213 | ||
1214 | ring_buffer_record_disable(buffer); | |
1215 | ||
1216 | /* Make sure all commits have finished */ | |
1217 | synchronize_sched(); | |
1218 | ||
1219 | buf->time_start = buffer_ftrace_now(buf, buf->cpu); | |
1220 | ||
1221 | for_each_online_cpu(cpu) | |
1222 | ring_buffer_reset_cpu(buffer, cpu); | |
1223 | ||
1224 | ring_buffer_record_enable(buffer); | |
1225 | } | |
1226 | ||
1227 | /* Must have trace_types_lock held */ | |
1228 | void tracing_reset_all_online_cpus(void) | |
1229 | { | |
1230 | struct trace_array *tr; | |
1231 | ||
1232 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
1233 | tracing_reset_online_cpus(&tr->trace_buffer); | |
1234 | #ifdef CONFIG_TRACER_MAX_TRACE | |
1235 | tracing_reset_online_cpus(&tr->max_buffer); | |
1236 | #endif | |
1237 | } | |
1238 | } | |
1239 | ||
1240 | #define SAVED_CMDLINES 128 | |
1241 | #define NO_CMDLINE_MAP UINT_MAX | |
1242 | static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1]; | |
1243 | static unsigned map_cmdline_to_pid[SAVED_CMDLINES]; | |
1244 | static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN]; | |
1245 | static int cmdline_idx; | |
1246 | static arch_spinlock_t trace_cmdline_lock = __ARCH_SPIN_LOCK_UNLOCKED; | |
1247 | ||
1248 | /* temporary disable recording */ | |
1249 | static atomic_t trace_record_cmdline_disabled __read_mostly; | |
1250 | ||
1251 | static void trace_init_cmdlines(void) | |
1252 | { | |
1253 | memset(&map_pid_to_cmdline, NO_CMDLINE_MAP, sizeof(map_pid_to_cmdline)); | |
1254 | memset(&map_cmdline_to_pid, NO_CMDLINE_MAP, sizeof(map_cmdline_to_pid)); | |
1255 | cmdline_idx = 0; | |
1256 | } | |
1257 | ||
1258 | int is_tracing_stopped(void) | |
1259 | { | |
1260 | return global_trace.stop_count; | |
1261 | } | |
1262 | ||
1263 | /** | |
1264 | * ftrace_off_permanent - disable all ftrace code permanently | |
1265 | * | |
1266 | * This should only be called when a serious anomally has | |
1267 | * been detected. This will turn off the function tracing, | |
1268 | * ring buffers, and other tracing utilites. It takes no | |
1269 | * locks and can be called from any context. | |
1270 | */ | |
1271 | void ftrace_off_permanent(void) | |
1272 | { | |
1273 | tracing_disabled = 1; | |
1274 | ftrace_stop(); | |
1275 | tracing_off_permanent(); | |
1276 | } | |
1277 | ||
1278 | /** | |
1279 | * tracing_start - quick start of the tracer | |
1280 | * | |
1281 | * If tracing is enabled but was stopped by tracing_stop, | |
1282 | * this will start the tracer back up. | |
1283 | */ | |
1284 | void tracing_start(void) | |
1285 | { | |
1286 | struct ring_buffer *buffer; | |
1287 | unsigned long flags; | |
1288 | ||
1289 | if (tracing_disabled) | |
1290 | return; | |
1291 | ||
1292 | raw_spin_lock_irqsave(&global_trace.start_lock, flags); | |
1293 | if (--global_trace.stop_count) { | |
1294 | if (global_trace.stop_count < 0) { | |
1295 | /* Someone screwed up their debugging */ | |
1296 | WARN_ON_ONCE(1); | |
1297 | global_trace.stop_count = 0; | |
1298 | } | |
1299 | goto out; | |
1300 | } | |
1301 | ||
1302 | /* Prevent the buffers from switching */ | |
1303 | arch_spin_lock(&ftrace_max_lock); | |
1304 | ||
1305 | buffer = global_trace.trace_buffer.buffer; | |
1306 | if (buffer) | |
1307 | ring_buffer_record_enable(buffer); | |
1308 | ||
1309 | #ifdef CONFIG_TRACER_MAX_TRACE | |
1310 | buffer = global_trace.max_buffer.buffer; | |
1311 | if (buffer) | |
1312 | ring_buffer_record_enable(buffer); | |
1313 | #endif | |
1314 | ||
1315 | arch_spin_unlock(&ftrace_max_lock); | |
1316 | ||
1317 | ftrace_start(); | |
1318 | out: | |
1319 | raw_spin_unlock_irqrestore(&global_trace.start_lock, flags); | |
1320 | } | |
1321 | ||
1322 | static void tracing_start_tr(struct trace_array *tr) | |
1323 | { | |
1324 | struct ring_buffer *buffer; | |
1325 | unsigned long flags; | |
1326 | ||
1327 | if (tracing_disabled) | |
1328 | return; | |
1329 | ||
1330 | /* If global, we need to also start the max tracer */ | |
1331 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL) | |
1332 | return tracing_start(); | |
1333 | ||
1334 | raw_spin_lock_irqsave(&tr->start_lock, flags); | |
1335 | ||
1336 | if (--tr->stop_count) { | |
1337 | if (tr->stop_count < 0) { | |
1338 | /* Someone screwed up their debugging */ | |
1339 | WARN_ON_ONCE(1); | |
1340 | tr->stop_count = 0; | |
1341 | } | |
1342 | goto out; | |
1343 | } | |
1344 | ||
1345 | buffer = tr->trace_buffer.buffer; | |
1346 | if (buffer) | |
1347 | ring_buffer_record_enable(buffer); | |
1348 | ||
1349 | out: | |
1350 | raw_spin_unlock_irqrestore(&tr->start_lock, flags); | |
1351 | } | |
1352 | ||
1353 | /** | |
1354 | * tracing_stop - quick stop of the tracer | |
1355 | * | |
1356 | * Light weight way to stop tracing. Use in conjunction with | |
1357 | * tracing_start. | |
1358 | */ | |
1359 | void tracing_stop(void) | |
1360 | { | |
1361 | struct ring_buffer *buffer; | |
1362 | unsigned long flags; | |
1363 | ||
1364 | ftrace_stop(); | |
1365 | raw_spin_lock_irqsave(&global_trace.start_lock, flags); | |
1366 | if (global_trace.stop_count++) | |
1367 | goto out; | |
1368 | ||
1369 | /* Prevent the buffers from switching */ | |
1370 | arch_spin_lock(&ftrace_max_lock); | |
1371 | ||
1372 | buffer = global_trace.trace_buffer.buffer; | |
1373 | if (buffer) | |
1374 | ring_buffer_record_disable(buffer); | |
1375 | ||
1376 | #ifdef CONFIG_TRACER_MAX_TRACE | |
1377 | buffer = global_trace.max_buffer.buffer; | |
1378 | if (buffer) | |
1379 | ring_buffer_record_disable(buffer); | |
1380 | #endif | |
1381 | ||
1382 | arch_spin_unlock(&ftrace_max_lock); | |
1383 | ||
1384 | out: | |
1385 | raw_spin_unlock_irqrestore(&global_trace.start_lock, flags); | |
1386 | } | |
1387 | ||
1388 | static void tracing_stop_tr(struct trace_array *tr) | |
1389 | { | |
1390 | struct ring_buffer *buffer; | |
1391 | unsigned long flags; | |
1392 | ||
1393 | /* If global, we need to also stop the max tracer */ | |
1394 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL) | |
1395 | return tracing_stop(); | |
1396 | ||
1397 | raw_spin_lock_irqsave(&tr->start_lock, flags); | |
1398 | if (tr->stop_count++) | |
1399 | goto out; | |
1400 | ||
1401 | buffer = tr->trace_buffer.buffer; | |
1402 | if (buffer) | |
1403 | ring_buffer_record_disable(buffer); | |
1404 | ||
1405 | out: | |
1406 | raw_spin_unlock_irqrestore(&tr->start_lock, flags); | |
1407 | } | |
1408 | ||
1409 | void trace_stop_cmdline_recording(void); | |
1410 | ||
1411 | static void trace_save_cmdline(struct task_struct *tsk) | |
1412 | { | |
1413 | unsigned pid, idx; | |
1414 | ||
1415 | if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT)) | |
1416 | return; | |
1417 | ||
1418 | /* | |
1419 | * It's not the end of the world if we don't get | |
1420 | * the lock, but we also don't want to spin | |
1421 | * nor do we want to disable interrupts, | |
1422 | * so if we miss here, then better luck next time. | |
1423 | */ | |
1424 | if (!arch_spin_trylock(&trace_cmdline_lock)) | |
1425 | return; | |
1426 | ||
1427 | idx = map_pid_to_cmdline[tsk->pid]; | |
1428 | if (idx == NO_CMDLINE_MAP) { | |
1429 | idx = (cmdline_idx + 1) % SAVED_CMDLINES; | |
1430 | ||
1431 | /* | |
1432 | * Check whether the cmdline buffer at idx has a pid | |
1433 | * mapped. We are going to overwrite that entry so we | |
1434 | * need to clear the map_pid_to_cmdline. Otherwise we | |
1435 | * would read the new comm for the old pid. | |
1436 | */ | |
1437 | pid = map_cmdline_to_pid[idx]; | |
1438 | if (pid != NO_CMDLINE_MAP) | |
1439 | map_pid_to_cmdline[pid] = NO_CMDLINE_MAP; | |
1440 | ||
1441 | map_cmdline_to_pid[idx] = tsk->pid; | |
1442 | map_pid_to_cmdline[tsk->pid] = idx; | |
1443 | ||
1444 | cmdline_idx = idx; | |
1445 | } | |
1446 | ||
1447 | memcpy(&saved_cmdlines[idx], tsk->comm, TASK_COMM_LEN); | |
1448 | ||
1449 | arch_spin_unlock(&trace_cmdline_lock); | |
1450 | } | |
1451 | ||
1452 | void trace_find_cmdline(int pid, char comm[]) | |
1453 | { | |
1454 | unsigned map; | |
1455 | ||
1456 | if (!pid) { | |
1457 | strcpy(comm, "<idle>"); | |
1458 | return; | |
1459 | } | |
1460 | ||
1461 | if (WARN_ON_ONCE(pid < 0)) { | |
1462 | strcpy(comm, "<XXX>"); | |
1463 | return; | |
1464 | } | |
1465 | ||
1466 | if (pid > PID_MAX_DEFAULT) { | |
1467 | strcpy(comm, "<...>"); | |
1468 | return; | |
1469 | } | |
1470 | ||
1471 | preempt_disable(); | |
1472 | arch_spin_lock(&trace_cmdline_lock); | |
1473 | map = map_pid_to_cmdline[pid]; | |
1474 | if (map != NO_CMDLINE_MAP) | |
1475 | strcpy(comm, saved_cmdlines[map]); | |
1476 | else | |
1477 | strcpy(comm, "<...>"); | |
1478 | ||
1479 | arch_spin_unlock(&trace_cmdline_lock); | |
1480 | preempt_enable(); | |
1481 | } | |
1482 | ||
1483 | void tracing_record_cmdline(struct task_struct *tsk) | |
1484 | { | |
1485 | if (atomic_read(&trace_record_cmdline_disabled) || !tracing_is_on()) | |
1486 | return; | |
1487 | ||
1488 | if (!__this_cpu_read(trace_cmdline_save)) | |
1489 | return; | |
1490 | ||
1491 | __this_cpu_write(trace_cmdline_save, false); | |
1492 | ||
1493 | trace_save_cmdline(tsk); | |
1494 | } | |
1495 | ||
1496 | void | |
1497 | tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags, | |
1498 | int pc) | |
1499 | { | |
1500 | struct task_struct *tsk = current; | |
1501 | ||
1502 | entry->preempt_count = pc & 0xff; | |
1503 | entry->pid = (tsk) ? tsk->pid : 0; | |
1504 | entry->flags = | |
1505 | #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT | |
1506 | (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) | | |
1507 | #else | |
1508 | TRACE_FLAG_IRQS_NOSUPPORT | | |
1509 | #endif | |
1510 | ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) | | |
1511 | ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) | | |
1512 | (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0); | |
1513 | } | |
1514 | EXPORT_SYMBOL_GPL(tracing_generic_entry_update); | |
1515 | ||
1516 | struct ring_buffer_event * | |
1517 | trace_buffer_lock_reserve(struct ring_buffer *buffer, | |
1518 | int type, | |
1519 | unsigned long len, | |
1520 | unsigned long flags, int pc) | |
1521 | { | |
1522 | struct ring_buffer_event *event; | |
1523 | ||
1524 | event = ring_buffer_lock_reserve(buffer, len); | |
1525 | if (event != NULL) { | |
1526 | struct trace_entry *ent = ring_buffer_event_data(event); | |
1527 | ||
1528 | tracing_generic_entry_update(ent, flags, pc); | |
1529 | ent->type = type; | |
1530 | } | |
1531 | ||
1532 | return event; | |
1533 | } | |
1534 | ||
1535 | void | |
1536 | __buffer_unlock_commit(struct ring_buffer *buffer, struct ring_buffer_event *event) | |
1537 | { | |
1538 | __this_cpu_write(trace_cmdline_save, true); | |
1539 | ring_buffer_unlock_commit(buffer, event); | |
1540 | } | |
1541 | ||
1542 | static inline void | |
1543 | __trace_buffer_unlock_commit(struct ring_buffer *buffer, | |
1544 | struct ring_buffer_event *event, | |
1545 | unsigned long flags, int pc) | |
1546 | { | |
1547 | __buffer_unlock_commit(buffer, event); | |
1548 | ||
1549 | ftrace_trace_stack(buffer, flags, 6, pc); | |
1550 | ftrace_trace_userstack(buffer, flags, pc); | |
1551 | } | |
1552 | ||
1553 | void trace_buffer_unlock_commit(struct ring_buffer *buffer, | |
1554 | struct ring_buffer_event *event, | |
1555 | unsigned long flags, int pc) | |
1556 | { | |
1557 | __trace_buffer_unlock_commit(buffer, event, flags, pc); | |
1558 | } | |
1559 | EXPORT_SYMBOL_GPL(trace_buffer_unlock_commit); | |
1560 | ||
1561 | struct ring_buffer_event * | |
1562 | trace_event_buffer_lock_reserve(struct ring_buffer **current_rb, | |
1563 | struct ftrace_event_file *ftrace_file, | |
1564 | int type, unsigned long len, | |
1565 | unsigned long flags, int pc) | |
1566 | { | |
1567 | *current_rb = ftrace_file->tr->trace_buffer.buffer; | |
1568 | return trace_buffer_lock_reserve(*current_rb, | |
1569 | type, len, flags, pc); | |
1570 | } | |
1571 | EXPORT_SYMBOL_GPL(trace_event_buffer_lock_reserve); | |
1572 | ||
1573 | struct ring_buffer_event * | |
1574 | trace_current_buffer_lock_reserve(struct ring_buffer **current_rb, | |
1575 | int type, unsigned long len, | |
1576 | unsigned long flags, int pc) | |
1577 | { | |
1578 | *current_rb = global_trace.trace_buffer.buffer; | |
1579 | return trace_buffer_lock_reserve(*current_rb, | |
1580 | type, len, flags, pc); | |
1581 | } | |
1582 | EXPORT_SYMBOL_GPL(trace_current_buffer_lock_reserve); | |
1583 | ||
1584 | void trace_current_buffer_unlock_commit(struct ring_buffer *buffer, | |
1585 | struct ring_buffer_event *event, | |
1586 | unsigned long flags, int pc) | |
1587 | { | |
1588 | __trace_buffer_unlock_commit(buffer, event, flags, pc); | |
1589 | } | |
1590 | EXPORT_SYMBOL_GPL(trace_current_buffer_unlock_commit); | |
1591 | ||
1592 | void trace_buffer_unlock_commit_regs(struct ring_buffer *buffer, | |
1593 | struct ring_buffer_event *event, | |
1594 | unsigned long flags, int pc, | |
1595 | struct pt_regs *regs) | |
1596 | { | |
1597 | __buffer_unlock_commit(buffer, event); | |
1598 | ||
1599 | ftrace_trace_stack_regs(buffer, flags, 0, pc, regs); | |
1600 | ftrace_trace_userstack(buffer, flags, pc); | |
1601 | } | |
1602 | EXPORT_SYMBOL_GPL(trace_buffer_unlock_commit_regs); | |
1603 | ||
1604 | void trace_current_buffer_discard_commit(struct ring_buffer *buffer, | |
1605 | struct ring_buffer_event *event) | |
1606 | { | |
1607 | ring_buffer_discard_commit(buffer, event); | |
1608 | } | |
1609 | EXPORT_SYMBOL_GPL(trace_current_buffer_discard_commit); | |
1610 | ||
1611 | void | |
1612 | trace_function(struct trace_array *tr, | |
1613 | unsigned long ip, unsigned long parent_ip, unsigned long flags, | |
1614 | int pc) | |
1615 | { | |
1616 | struct ftrace_event_call *call = &event_function; | |
1617 | struct ring_buffer *buffer = tr->trace_buffer.buffer; | |
1618 | struct ring_buffer_event *event; | |
1619 | struct ftrace_entry *entry; | |
1620 | ||
1621 | /* If we are reading the ring buffer, don't trace */ | |
1622 | if (unlikely(__this_cpu_read(ftrace_cpu_disabled))) | |
1623 | return; | |
1624 | ||
1625 | event = trace_buffer_lock_reserve(buffer, TRACE_FN, sizeof(*entry), | |
1626 | flags, pc); | |
1627 | if (!event) | |
1628 | return; | |
1629 | entry = ring_buffer_event_data(event); | |
1630 | entry->ip = ip; | |
1631 | entry->parent_ip = parent_ip; | |
1632 | ||
1633 | if (!filter_check_discard(call, entry, buffer, event)) | |
1634 | __buffer_unlock_commit(buffer, event); | |
1635 | } | |
1636 | ||
1637 | #ifdef CONFIG_STACKTRACE | |
1638 | ||
1639 | #define FTRACE_STACK_MAX_ENTRIES (PAGE_SIZE / sizeof(unsigned long)) | |
1640 | struct ftrace_stack { | |
1641 | unsigned long calls[FTRACE_STACK_MAX_ENTRIES]; | |
1642 | }; | |
1643 | ||
1644 | static DEFINE_PER_CPU(struct ftrace_stack, ftrace_stack); | |
1645 | static DEFINE_PER_CPU(int, ftrace_stack_reserve); | |
1646 | ||
1647 | static void __ftrace_trace_stack(struct ring_buffer *buffer, | |
1648 | unsigned long flags, | |
1649 | int skip, int pc, struct pt_regs *regs) | |
1650 | { | |
1651 | struct ftrace_event_call *call = &event_kernel_stack; | |
1652 | struct ring_buffer_event *event; | |
1653 | struct stack_entry *entry; | |
1654 | struct stack_trace trace; | |
1655 | int use_stack; | |
1656 | int size = FTRACE_STACK_ENTRIES; | |
1657 | ||
1658 | trace.nr_entries = 0; | |
1659 | trace.skip = skip; | |
1660 | ||
1661 | /* | |
1662 | * Since events can happen in NMIs there's no safe way to | |
1663 | * use the per cpu ftrace_stacks. We reserve it and if an interrupt | |
1664 | * or NMI comes in, it will just have to use the default | |
1665 | * FTRACE_STACK_SIZE. | |
1666 | */ | |
1667 | preempt_disable_notrace(); | |
1668 | ||
1669 | use_stack = __this_cpu_inc_return(ftrace_stack_reserve); | |
1670 | /* | |
1671 | * We don't need any atomic variables, just a barrier. | |
1672 | * If an interrupt comes in, we don't care, because it would | |
1673 | * have exited and put the counter back to what we want. | |
1674 | * We just need a barrier to keep gcc from moving things | |
1675 | * around. | |
1676 | */ | |
1677 | barrier(); | |
1678 | if (use_stack == 1) { | |
1679 | trace.entries = &__get_cpu_var(ftrace_stack).calls[0]; | |
1680 | trace.max_entries = FTRACE_STACK_MAX_ENTRIES; | |
1681 | ||
1682 | if (regs) | |
1683 | save_stack_trace_regs(regs, &trace); | |
1684 | else | |
1685 | save_stack_trace(&trace); | |
1686 | ||
1687 | if (trace.nr_entries > size) | |
1688 | size = trace.nr_entries; | |
1689 | } else | |
1690 | /* From now on, use_stack is a boolean */ | |
1691 | use_stack = 0; | |
1692 | ||
1693 | size *= sizeof(unsigned long); | |
1694 | ||
1695 | event = trace_buffer_lock_reserve(buffer, TRACE_STACK, | |
1696 | sizeof(*entry) + size, flags, pc); | |
1697 | if (!event) | |
1698 | goto out; | |
1699 | entry = ring_buffer_event_data(event); | |
1700 | ||
1701 | memset(&entry->caller, 0, size); | |
1702 | ||
1703 | if (use_stack) | |
1704 | memcpy(&entry->caller, trace.entries, | |
1705 | trace.nr_entries * sizeof(unsigned long)); | |
1706 | else { | |
1707 | trace.max_entries = FTRACE_STACK_ENTRIES; | |
1708 | trace.entries = entry->caller; | |
1709 | if (regs) | |
1710 | save_stack_trace_regs(regs, &trace); | |
1711 | else | |
1712 | save_stack_trace(&trace); | |
1713 | } | |
1714 | ||
1715 | entry->size = trace.nr_entries; | |
1716 | ||
1717 | if (!filter_check_discard(call, entry, buffer, event)) | |
1718 | __buffer_unlock_commit(buffer, event); | |
1719 | ||
1720 | out: | |
1721 | /* Again, don't let gcc optimize things here */ | |
1722 | barrier(); | |
1723 | __this_cpu_dec(ftrace_stack_reserve); | |
1724 | preempt_enable_notrace(); | |
1725 | ||
1726 | } | |
1727 | ||
1728 | void ftrace_trace_stack_regs(struct ring_buffer *buffer, unsigned long flags, | |
1729 | int skip, int pc, struct pt_regs *regs) | |
1730 | { | |
1731 | if (!(trace_flags & TRACE_ITER_STACKTRACE)) | |
1732 | return; | |
1733 | ||
1734 | __ftrace_trace_stack(buffer, flags, skip, pc, regs); | |
1735 | } | |
1736 | ||
1737 | void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags, | |
1738 | int skip, int pc) | |
1739 | { | |
1740 | if (!(trace_flags & TRACE_ITER_STACKTRACE)) | |
1741 | return; | |
1742 | ||
1743 | __ftrace_trace_stack(buffer, flags, skip, pc, NULL); | |
1744 | } | |
1745 | ||
1746 | void __trace_stack(struct trace_array *tr, unsigned long flags, int skip, | |
1747 | int pc) | |
1748 | { | |
1749 | __ftrace_trace_stack(tr->trace_buffer.buffer, flags, skip, pc, NULL); | |
1750 | } | |
1751 | ||
1752 | /** | |
1753 | * trace_dump_stack - record a stack back trace in the trace buffer | |
1754 | * @skip: Number of functions to skip (helper handlers) | |
1755 | */ | |
1756 | void trace_dump_stack(int skip) | |
1757 | { | |
1758 | unsigned long flags; | |
1759 | ||
1760 | if (tracing_disabled || tracing_selftest_running) | |
1761 | return; | |
1762 | ||
1763 | local_save_flags(flags); | |
1764 | ||
1765 | /* | |
1766 | * Skip 3 more, seems to get us at the caller of | |
1767 | * this function. | |
1768 | */ | |
1769 | skip += 3; | |
1770 | __ftrace_trace_stack(global_trace.trace_buffer.buffer, | |
1771 | flags, skip, preempt_count(), NULL); | |
1772 | } | |
1773 | ||
1774 | static DEFINE_PER_CPU(int, user_stack_count); | |
1775 | ||
1776 | void | |
1777 | ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc) | |
1778 | { | |
1779 | struct ftrace_event_call *call = &event_user_stack; | |
1780 | struct ring_buffer_event *event; | |
1781 | struct userstack_entry *entry; | |
1782 | struct stack_trace trace; | |
1783 | ||
1784 | if (!(trace_flags & TRACE_ITER_USERSTACKTRACE)) | |
1785 | return; | |
1786 | ||
1787 | /* | |
1788 | * NMIs can not handle page faults, even with fix ups. | |
1789 | * The save user stack can (and often does) fault. | |
1790 | */ | |
1791 | if (unlikely(in_nmi())) | |
1792 | return; | |
1793 | ||
1794 | /* | |
1795 | * prevent recursion, since the user stack tracing may | |
1796 | * trigger other kernel events. | |
1797 | */ | |
1798 | preempt_disable(); | |
1799 | if (__this_cpu_read(user_stack_count)) | |
1800 | goto out; | |
1801 | ||
1802 | __this_cpu_inc(user_stack_count); | |
1803 | ||
1804 | event = trace_buffer_lock_reserve(buffer, TRACE_USER_STACK, | |
1805 | sizeof(*entry), flags, pc); | |
1806 | if (!event) | |
1807 | goto out_drop_count; | |
1808 | entry = ring_buffer_event_data(event); | |
1809 | ||
1810 | entry->tgid = current->tgid; | |
1811 | memset(&entry->caller, 0, sizeof(entry->caller)); | |
1812 | ||
1813 | trace.nr_entries = 0; | |
1814 | trace.max_entries = FTRACE_STACK_ENTRIES; | |
1815 | trace.skip = 0; | |
1816 | trace.entries = entry->caller; | |
1817 | ||
1818 | save_stack_trace_user(&trace); | |
1819 | if (!filter_check_discard(call, entry, buffer, event)) | |
1820 | __buffer_unlock_commit(buffer, event); | |
1821 | ||
1822 | out_drop_count: | |
1823 | __this_cpu_dec(user_stack_count); | |
1824 | out: | |
1825 | preempt_enable(); | |
1826 | } | |
1827 | ||
1828 | #ifdef UNUSED | |
1829 | static void __trace_userstack(struct trace_array *tr, unsigned long flags) | |
1830 | { | |
1831 | ftrace_trace_userstack(tr, flags, preempt_count()); | |
1832 | } | |
1833 | #endif /* UNUSED */ | |
1834 | ||
1835 | #endif /* CONFIG_STACKTRACE */ | |
1836 | ||
1837 | /* created for use with alloc_percpu */ | |
1838 | struct trace_buffer_struct { | |
1839 | char buffer[TRACE_BUF_SIZE]; | |
1840 | }; | |
1841 | ||
1842 | static struct trace_buffer_struct *trace_percpu_buffer; | |
1843 | static struct trace_buffer_struct *trace_percpu_sirq_buffer; | |
1844 | static struct trace_buffer_struct *trace_percpu_irq_buffer; | |
1845 | static struct trace_buffer_struct *trace_percpu_nmi_buffer; | |
1846 | ||
1847 | /* | |
1848 | * The buffer used is dependent on the context. There is a per cpu | |
1849 | * buffer for normal context, softirq contex, hard irq context and | |
1850 | * for NMI context. Thise allows for lockless recording. | |
1851 | * | |
1852 | * Note, if the buffers failed to be allocated, then this returns NULL | |
1853 | */ | |
1854 | static char *get_trace_buf(void) | |
1855 | { | |
1856 | struct trace_buffer_struct *percpu_buffer; | |
1857 | ||
1858 | /* | |
1859 | * If we have allocated per cpu buffers, then we do not | |
1860 | * need to do any locking. | |
1861 | */ | |
1862 | if (in_nmi()) | |
1863 | percpu_buffer = trace_percpu_nmi_buffer; | |
1864 | else if (in_irq()) | |
1865 | percpu_buffer = trace_percpu_irq_buffer; | |
1866 | else if (in_softirq()) | |
1867 | percpu_buffer = trace_percpu_sirq_buffer; | |
1868 | else | |
1869 | percpu_buffer = trace_percpu_buffer; | |
1870 | ||
1871 | if (!percpu_buffer) | |
1872 | return NULL; | |
1873 | ||
1874 | return this_cpu_ptr(&percpu_buffer->buffer[0]); | |
1875 | } | |
1876 | ||
1877 | static int alloc_percpu_trace_buffer(void) | |
1878 | { | |
1879 | struct trace_buffer_struct *buffers; | |
1880 | struct trace_buffer_struct *sirq_buffers; | |
1881 | struct trace_buffer_struct *irq_buffers; | |
1882 | struct trace_buffer_struct *nmi_buffers; | |
1883 | ||
1884 | buffers = alloc_percpu(struct trace_buffer_struct); | |
1885 | if (!buffers) | |
1886 | goto err_warn; | |
1887 | ||
1888 | sirq_buffers = alloc_percpu(struct trace_buffer_struct); | |
1889 | if (!sirq_buffers) | |
1890 | goto err_sirq; | |
1891 | ||
1892 | irq_buffers = alloc_percpu(struct trace_buffer_struct); | |
1893 | if (!irq_buffers) | |
1894 | goto err_irq; | |
1895 | ||
1896 | nmi_buffers = alloc_percpu(struct trace_buffer_struct); | |
1897 | if (!nmi_buffers) | |
1898 | goto err_nmi; | |
1899 | ||
1900 | trace_percpu_buffer = buffers; | |
1901 | trace_percpu_sirq_buffer = sirq_buffers; | |
1902 | trace_percpu_irq_buffer = irq_buffers; | |
1903 | trace_percpu_nmi_buffer = nmi_buffers; | |
1904 | ||
1905 | return 0; | |
1906 | ||
1907 | err_nmi: | |
1908 | free_percpu(irq_buffers); | |
1909 | err_irq: | |
1910 | free_percpu(sirq_buffers); | |
1911 | err_sirq: | |
1912 | free_percpu(buffers); | |
1913 | err_warn: | |
1914 | WARN(1, "Could not allocate percpu trace_printk buffer"); | |
1915 | return -ENOMEM; | |
1916 | } | |
1917 | ||
1918 | static int buffers_allocated; | |
1919 | ||
1920 | void trace_printk_init_buffers(void) | |
1921 | { | |
1922 | if (buffers_allocated) | |
1923 | return; | |
1924 | ||
1925 | if (alloc_percpu_trace_buffer()) | |
1926 | return; | |
1927 | ||
1928 | pr_info("ftrace: Allocated trace_printk buffers\n"); | |
1929 | ||
1930 | /* Expand the buffers to set size */ | |
1931 | tracing_update_buffers(); | |
1932 | ||
1933 | buffers_allocated = 1; | |
1934 | ||
1935 | /* | |
1936 | * trace_printk_init_buffers() can be called by modules. | |
1937 | * If that happens, then we need to start cmdline recording | |
1938 | * directly here. If the global_trace.buffer is already | |
1939 | * allocated here, then this was called by module code. | |
1940 | */ | |
1941 | if (global_trace.trace_buffer.buffer) | |
1942 | tracing_start_cmdline_record(); | |
1943 | } | |
1944 | ||
1945 | void trace_printk_start_comm(void) | |
1946 | { | |
1947 | /* Start tracing comms if trace printk is set */ | |
1948 | if (!buffers_allocated) | |
1949 | return; | |
1950 | tracing_start_cmdline_record(); | |
1951 | } | |
1952 | ||
1953 | static void trace_printk_start_stop_comm(int enabled) | |
1954 | { | |
1955 | if (!buffers_allocated) | |
1956 | return; | |
1957 | ||
1958 | if (enabled) | |
1959 | tracing_start_cmdline_record(); | |
1960 | else | |
1961 | tracing_stop_cmdline_record(); | |
1962 | } | |
1963 | ||
1964 | /** | |
1965 | * trace_vbprintk - write binary msg to tracing buffer | |
1966 | * | |
1967 | */ | |
1968 | int trace_vbprintk(unsigned long ip, const char *fmt, va_list args) | |
1969 | { | |
1970 | struct ftrace_event_call *call = &event_bprint; | |
1971 | struct ring_buffer_event *event; | |
1972 | struct ring_buffer *buffer; | |
1973 | struct trace_array *tr = &global_trace; | |
1974 | struct bprint_entry *entry; | |
1975 | unsigned long flags; | |
1976 | char *tbuffer; | |
1977 | int len = 0, size, pc; | |
1978 | ||
1979 | if (unlikely(tracing_selftest_running || tracing_disabled)) | |
1980 | return 0; | |
1981 | ||
1982 | /* Don't pollute graph traces with trace_vprintk internals */ | |
1983 | pause_graph_tracing(); | |
1984 | ||
1985 | pc = preempt_count(); | |
1986 | preempt_disable_notrace(); | |
1987 | ||
1988 | tbuffer = get_trace_buf(); | |
1989 | if (!tbuffer) { | |
1990 | len = 0; | |
1991 | goto out; | |
1992 | } | |
1993 | ||
1994 | len = vbin_printf((u32 *)tbuffer, TRACE_BUF_SIZE/sizeof(int), fmt, args); | |
1995 | ||
1996 | if (len > TRACE_BUF_SIZE/sizeof(int) || len < 0) | |
1997 | goto out; | |
1998 | ||
1999 | local_save_flags(flags); | |
2000 | size = sizeof(*entry) + sizeof(u32) * len; | |
2001 | buffer = tr->trace_buffer.buffer; | |
2002 | event = trace_buffer_lock_reserve(buffer, TRACE_BPRINT, size, | |
2003 | flags, pc); | |
2004 | if (!event) | |
2005 | goto out; | |
2006 | entry = ring_buffer_event_data(event); | |
2007 | entry->ip = ip; | |
2008 | entry->fmt = fmt; | |
2009 | ||
2010 | memcpy(entry->buf, tbuffer, sizeof(u32) * len); | |
2011 | if (!filter_check_discard(call, entry, buffer, event)) { | |
2012 | __buffer_unlock_commit(buffer, event); | |
2013 | ftrace_trace_stack(buffer, flags, 6, pc); | |
2014 | } | |
2015 | ||
2016 | out: | |
2017 | preempt_enable_notrace(); | |
2018 | unpause_graph_tracing(); | |
2019 | ||
2020 | return len; | |
2021 | } | |
2022 | EXPORT_SYMBOL_GPL(trace_vbprintk); | |
2023 | ||
2024 | static int | |
2025 | __trace_array_vprintk(struct ring_buffer *buffer, | |
2026 | unsigned long ip, const char *fmt, va_list args) | |
2027 | { | |
2028 | struct ftrace_event_call *call = &event_print; | |
2029 | struct ring_buffer_event *event; | |
2030 | int len = 0, size, pc; | |
2031 | struct print_entry *entry; | |
2032 | unsigned long flags; | |
2033 | char *tbuffer; | |
2034 | ||
2035 | if (tracing_disabled || tracing_selftest_running) | |
2036 | return 0; | |
2037 | ||
2038 | /* Don't pollute graph traces with trace_vprintk internals */ | |
2039 | pause_graph_tracing(); | |
2040 | ||
2041 | pc = preempt_count(); | |
2042 | preempt_disable_notrace(); | |
2043 | ||
2044 | ||
2045 | tbuffer = get_trace_buf(); | |
2046 | if (!tbuffer) { | |
2047 | len = 0; | |
2048 | goto out; | |
2049 | } | |
2050 | ||
2051 | len = vsnprintf(tbuffer, TRACE_BUF_SIZE, fmt, args); | |
2052 | if (len > TRACE_BUF_SIZE) | |
2053 | goto out; | |
2054 | ||
2055 | local_save_flags(flags); | |
2056 | size = sizeof(*entry) + len + 1; | |
2057 | event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size, | |
2058 | flags, pc); | |
2059 | if (!event) | |
2060 | goto out; | |
2061 | entry = ring_buffer_event_data(event); | |
2062 | entry->ip = ip; | |
2063 | ||
2064 | memcpy(&entry->buf, tbuffer, len); | |
2065 | entry->buf[len] = '\0'; | |
2066 | if (!filter_check_discard(call, entry, buffer, event)) { | |
2067 | __buffer_unlock_commit(buffer, event); | |
2068 | ftrace_trace_stack(buffer, flags, 6, pc); | |
2069 | } | |
2070 | out: | |
2071 | preempt_enable_notrace(); | |
2072 | unpause_graph_tracing(); | |
2073 | ||
2074 | return len; | |
2075 | } | |
2076 | ||
2077 | int trace_array_vprintk(struct trace_array *tr, | |
2078 | unsigned long ip, const char *fmt, va_list args) | |
2079 | { | |
2080 | return __trace_array_vprintk(tr->trace_buffer.buffer, ip, fmt, args); | |
2081 | } | |
2082 | ||
2083 | int trace_array_printk(struct trace_array *tr, | |
2084 | unsigned long ip, const char *fmt, ...) | |
2085 | { | |
2086 | int ret; | |
2087 | va_list ap; | |
2088 | ||
2089 | if (!(trace_flags & TRACE_ITER_PRINTK)) | |
2090 | return 0; | |
2091 | ||
2092 | va_start(ap, fmt); | |
2093 | ret = trace_array_vprintk(tr, ip, fmt, ap); | |
2094 | va_end(ap); | |
2095 | return ret; | |
2096 | } | |
2097 | ||
2098 | int trace_array_printk_buf(struct ring_buffer *buffer, | |
2099 | unsigned long ip, const char *fmt, ...) | |
2100 | { | |
2101 | int ret; | |
2102 | va_list ap; | |
2103 | ||
2104 | if (!(trace_flags & TRACE_ITER_PRINTK)) | |
2105 | return 0; | |
2106 | ||
2107 | va_start(ap, fmt); | |
2108 | ret = __trace_array_vprintk(buffer, ip, fmt, ap); | |
2109 | va_end(ap); | |
2110 | return ret; | |
2111 | } | |
2112 | ||
2113 | int trace_vprintk(unsigned long ip, const char *fmt, va_list args) | |
2114 | { | |
2115 | return trace_array_vprintk(&global_trace, ip, fmt, args); | |
2116 | } | |
2117 | EXPORT_SYMBOL_GPL(trace_vprintk); | |
2118 | ||
2119 | static void trace_iterator_increment(struct trace_iterator *iter) | |
2120 | { | |
2121 | struct ring_buffer_iter *buf_iter = trace_buffer_iter(iter, iter->cpu); | |
2122 | ||
2123 | iter->idx++; | |
2124 | if (buf_iter) | |
2125 | ring_buffer_read(buf_iter, NULL); | |
2126 | } | |
2127 | ||
2128 | static struct trace_entry * | |
2129 | peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts, | |
2130 | unsigned long *lost_events) | |
2131 | { | |
2132 | struct ring_buffer_event *event; | |
2133 | struct ring_buffer_iter *buf_iter = trace_buffer_iter(iter, cpu); | |
2134 | ||
2135 | if (buf_iter) | |
2136 | event = ring_buffer_iter_peek(buf_iter, ts); | |
2137 | else | |
2138 | event = ring_buffer_peek(iter->trace_buffer->buffer, cpu, ts, | |
2139 | lost_events); | |
2140 | ||
2141 | if (event) { | |
2142 | iter->ent_size = ring_buffer_event_length(event); | |
2143 | return ring_buffer_event_data(event); | |
2144 | } | |
2145 | iter->ent_size = 0; | |
2146 | return NULL; | |
2147 | } | |
2148 | ||
2149 | static struct trace_entry * | |
2150 | __find_next_entry(struct trace_iterator *iter, int *ent_cpu, | |
2151 | unsigned long *missing_events, u64 *ent_ts) | |
2152 | { | |
2153 | struct ring_buffer *buffer = iter->trace_buffer->buffer; | |
2154 | struct trace_entry *ent, *next = NULL; | |
2155 | unsigned long lost_events = 0, next_lost = 0; | |
2156 | int cpu_file = iter->cpu_file; | |
2157 | u64 next_ts = 0, ts; | |
2158 | int next_cpu = -1; | |
2159 | int next_size = 0; | |
2160 | int cpu; | |
2161 | ||
2162 | /* | |
2163 | * If we are in a per_cpu trace file, don't bother by iterating over | |
2164 | * all cpu and peek directly. | |
2165 | */ | |
2166 | if (cpu_file > RING_BUFFER_ALL_CPUS) { | |
2167 | if (ring_buffer_empty_cpu(buffer, cpu_file)) | |
2168 | return NULL; | |
2169 | ent = peek_next_entry(iter, cpu_file, ent_ts, missing_events); | |
2170 | if (ent_cpu) | |
2171 | *ent_cpu = cpu_file; | |
2172 | ||
2173 | return ent; | |
2174 | } | |
2175 | ||
2176 | for_each_tracing_cpu(cpu) { | |
2177 | ||
2178 | if (ring_buffer_empty_cpu(buffer, cpu)) | |
2179 | continue; | |
2180 | ||
2181 | ent = peek_next_entry(iter, cpu, &ts, &lost_events); | |
2182 | ||
2183 | /* | |
2184 | * Pick the entry with the smallest timestamp: | |
2185 | */ | |
2186 | if (ent && (!next || ts < next_ts)) { | |
2187 | next = ent; | |
2188 | next_cpu = cpu; | |
2189 | next_ts = ts; | |
2190 | next_lost = lost_events; | |
2191 | next_size = iter->ent_size; | |
2192 | } | |
2193 | } | |
2194 | ||
2195 | iter->ent_size = next_size; | |
2196 | ||
2197 | if (ent_cpu) | |
2198 | *ent_cpu = next_cpu; | |
2199 | ||
2200 | if (ent_ts) | |
2201 | *ent_ts = next_ts; | |
2202 | ||
2203 | if (missing_events) | |
2204 | *missing_events = next_lost; | |
2205 | ||
2206 | return next; | |
2207 | } | |
2208 | ||
2209 | /* Find the next real entry, without updating the iterator itself */ | |
2210 | struct trace_entry *trace_find_next_entry(struct trace_iterator *iter, | |
2211 | int *ent_cpu, u64 *ent_ts) | |
2212 | { | |
2213 | return __find_next_entry(iter, ent_cpu, NULL, ent_ts); | |
2214 | } | |
2215 | ||
2216 | /* Find the next real entry, and increment the iterator to the next entry */ | |
2217 | void *trace_find_next_entry_inc(struct trace_iterator *iter) | |
2218 | { | |
2219 | iter->ent = __find_next_entry(iter, &iter->cpu, | |
2220 | &iter->lost_events, &iter->ts); | |
2221 | ||
2222 | if (iter->ent) | |
2223 | trace_iterator_increment(iter); | |
2224 | ||
2225 | return iter->ent ? iter : NULL; | |
2226 | } | |
2227 | ||
2228 | static void trace_consume(struct trace_iterator *iter) | |
2229 | { | |
2230 | ring_buffer_consume(iter->trace_buffer->buffer, iter->cpu, &iter->ts, | |
2231 | &iter->lost_events); | |
2232 | } | |
2233 | ||
2234 | static void *s_next(struct seq_file *m, void *v, loff_t *pos) | |
2235 | { | |
2236 | struct trace_iterator *iter = m->private; | |
2237 | int i = (int)*pos; | |
2238 | void *ent; | |
2239 | ||
2240 | WARN_ON_ONCE(iter->leftover); | |
2241 | ||
2242 | (*pos)++; | |
2243 | ||
2244 | /* can't go backwards */ | |
2245 | if (iter->idx > i) | |
2246 | return NULL; | |
2247 | ||
2248 | if (iter->idx < 0) | |
2249 | ent = trace_find_next_entry_inc(iter); | |
2250 | else | |
2251 | ent = iter; | |
2252 | ||
2253 | while (ent && iter->idx < i) | |
2254 | ent = trace_find_next_entry_inc(iter); | |
2255 | ||
2256 | iter->pos = *pos; | |
2257 | ||
2258 | return ent; | |
2259 | } | |
2260 | ||
2261 | void tracing_iter_reset(struct trace_iterator *iter, int cpu) | |
2262 | { | |
2263 | struct ring_buffer_event *event; | |
2264 | struct ring_buffer_iter *buf_iter; | |
2265 | unsigned long entries = 0; | |
2266 | u64 ts; | |
2267 | ||
2268 | per_cpu_ptr(iter->trace_buffer->data, cpu)->skipped_entries = 0; | |
2269 | ||
2270 | buf_iter = trace_buffer_iter(iter, cpu); | |
2271 | if (!buf_iter) | |
2272 | return; | |
2273 | ||
2274 | ring_buffer_iter_reset(buf_iter); | |
2275 | ||
2276 | /* | |
2277 | * We could have the case with the max latency tracers | |
2278 | * that a reset never took place on a cpu. This is evident | |
2279 | * by the timestamp being before the start of the buffer. | |
2280 | */ | |
2281 | while ((event = ring_buffer_iter_peek(buf_iter, &ts))) { | |
2282 | if (ts >= iter->trace_buffer->time_start) | |
2283 | break; | |
2284 | entries++; | |
2285 | ring_buffer_read(buf_iter, NULL); | |
2286 | } | |
2287 | ||
2288 | per_cpu_ptr(iter->trace_buffer->data, cpu)->skipped_entries = entries; | |
2289 | } | |
2290 | ||
2291 | /* | |
2292 | * The current tracer is copied to avoid a global locking | |
2293 | * all around. | |
2294 | */ | |
2295 | static void *s_start(struct seq_file *m, loff_t *pos) | |
2296 | { | |
2297 | struct trace_iterator *iter = m->private; | |
2298 | struct trace_array *tr = iter->tr; | |
2299 | int cpu_file = iter->cpu_file; | |
2300 | void *p = NULL; | |
2301 | loff_t l = 0; | |
2302 | int cpu; | |
2303 | ||
2304 | /* | |
2305 | * copy the tracer to avoid using a global lock all around. | |
2306 | * iter->trace is a copy of current_trace, the pointer to the | |
2307 | * name may be used instead of a strcmp(), as iter->trace->name | |
2308 | * will point to the same string as current_trace->name. | |
2309 | */ | |
2310 | mutex_lock(&trace_types_lock); | |
2311 | if (unlikely(tr->current_trace && iter->trace->name != tr->current_trace->name)) | |
2312 | *iter->trace = *tr->current_trace; | |
2313 | mutex_unlock(&trace_types_lock); | |
2314 | ||
2315 | #ifdef CONFIG_TRACER_MAX_TRACE | |
2316 | if (iter->snapshot && iter->trace->use_max_tr) | |
2317 | return ERR_PTR(-EBUSY); | |
2318 | #endif | |
2319 | ||
2320 | if (!iter->snapshot) | |
2321 | atomic_inc(&trace_record_cmdline_disabled); | |
2322 | ||
2323 | if (*pos != iter->pos) { | |
2324 | iter->ent = NULL; | |
2325 | iter->cpu = 0; | |
2326 | iter->idx = -1; | |
2327 | ||
2328 | if (cpu_file == RING_BUFFER_ALL_CPUS) { | |
2329 | for_each_tracing_cpu(cpu) | |
2330 | tracing_iter_reset(iter, cpu); | |
2331 | } else | |
2332 | tracing_iter_reset(iter, cpu_file); | |
2333 | ||
2334 | iter->leftover = 0; | |
2335 | for (p = iter; p && l < *pos; p = s_next(m, p, &l)) | |
2336 | ; | |
2337 | ||
2338 | } else { | |
2339 | /* | |
2340 | * If we overflowed the seq_file before, then we want | |
2341 | * to just reuse the trace_seq buffer again. | |
2342 | */ | |
2343 | if (iter->leftover) | |
2344 | p = iter; | |
2345 | else { | |
2346 | l = *pos - 1; | |
2347 | p = s_next(m, p, &l); | |
2348 | } | |
2349 | } | |
2350 | ||
2351 | trace_event_read_lock(); | |
2352 | trace_access_lock(cpu_file); | |
2353 | return p; | |
2354 | } | |
2355 | ||
2356 | static void s_stop(struct seq_file *m, void *p) | |
2357 | { | |
2358 | struct trace_iterator *iter = m->private; | |
2359 | ||
2360 | #ifdef CONFIG_TRACER_MAX_TRACE | |
2361 | if (iter->snapshot && iter->trace->use_max_tr) | |
2362 | return; | |
2363 | #endif | |
2364 | ||
2365 | if (!iter->snapshot) | |
2366 | atomic_dec(&trace_record_cmdline_disabled); | |
2367 | ||
2368 | trace_access_unlock(iter->cpu_file); | |
2369 | trace_event_read_unlock(); | |
2370 | } | |
2371 | ||
2372 | static void | |
2373 | get_total_entries(struct trace_buffer *buf, | |
2374 | unsigned long *total, unsigned long *entries) | |
2375 | { | |
2376 | unsigned long count; | |
2377 | int cpu; | |
2378 | ||
2379 | *total = 0; | |
2380 | *entries = 0; | |
2381 | ||
2382 | for_each_tracing_cpu(cpu) { | |
2383 | count = ring_buffer_entries_cpu(buf->buffer, cpu); | |
2384 | /* | |
2385 | * If this buffer has skipped entries, then we hold all | |
2386 | * entries for the trace and we need to ignore the | |
2387 | * ones before the time stamp. | |
2388 | */ | |
2389 | if (per_cpu_ptr(buf->data, cpu)->skipped_entries) { | |
2390 | count -= per_cpu_ptr(buf->data, cpu)->skipped_entries; | |
2391 | /* total is the same as the entries */ | |
2392 | *total += count; | |
2393 | } else | |
2394 | *total += count + | |
2395 | ring_buffer_overrun_cpu(buf->buffer, cpu); | |
2396 | *entries += count; | |
2397 | } | |
2398 | } | |
2399 | ||
2400 | static void print_lat_help_header(struct seq_file *m) | |
2401 | { | |
2402 | seq_puts(m, "# _------=> CPU# \n"); | |
2403 | seq_puts(m, "# / _-----=> irqs-off \n"); | |
2404 | seq_puts(m, "# | / _----=> need-resched \n"); | |
2405 | seq_puts(m, "# || / _---=> hardirq/softirq \n"); | |
2406 | seq_puts(m, "# ||| / _--=> preempt-depth \n"); | |
2407 | seq_puts(m, "# |||| / delay \n"); | |
2408 | seq_puts(m, "# cmd pid ||||| time | caller \n"); | |
2409 | seq_puts(m, "# \\ / ||||| \\ | / \n"); | |
2410 | } | |
2411 | ||
2412 | static void print_event_info(struct trace_buffer *buf, struct seq_file *m) | |
2413 | { | |
2414 | unsigned long total; | |
2415 | unsigned long entries; | |
2416 | ||
2417 | get_total_entries(buf, &total, &entries); | |
2418 | seq_printf(m, "# entries-in-buffer/entries-written: %lu/%lu #P:%d\n", | |
2419 | entries, total, num_online_cpus()); | |
2420 | seq_puts(m, "#\n"); | |
2421 | } | |
2422 | ||
2423 | static void print_func_help_header(struct trace_buffer *buf, struct seq_file *m) | |
2424 | { | |
2425 | print_event_info(buf, m); | |
2426 | seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n"); | |
2427 | seq_puts(m, "# | | | | |\n"); | |
2428 | } | |
2429 | ||
2430 | static void print_func_help_header_irq(struct trace_buffer *buf, struct seq_file *m) | |
2431 | { | |
2432 | print_event_info(buf, m); | |
2433 | seq_puts(m, "# _-----=> irqs-off\n"); | |
2434 | seq_puts(m, "# / _----=> need-resched\n"); | |
2435 | seq_puts(m, "# | / _---=> hardirq/softirq\n"); | |
2436 | seq_puts(m, "# || / _--=> preempt-depth\n"); | |
2437 | seq_puts(m, "# ||| / delay\n"); | |
2438 | seq_puts(m, "# TASK-PID CPU# |||| TIMESTAMP FUNCTION\n"); | |
2439 | seq_puts(m, "# | | | |||| | |\n"); | |
2440 | } | |
2441 | ||
2442 | void | |
2443 | print_trace_header(struct seq_file *m, struct trace_iterator *iter) | |
2444 | { | |
2445 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); | |
2446 | struct trace_buffer *buf = iter->trace_buffer; | |
2447 | struct trace_array_cpu *data = per_cpu_ptr(buf->data, buf->cpu); | |
2448 | struct tracer *type = iter->trace; | |
2449 | unsigned long entries; | |
2450 | unsigned long total; | |
2451 | const char *name = "preemption"; | |
2452 | ||
2453 | name = type->name; | |
2454 | ||
2455 | get_total_entries(buf, &total, &entries); | |
2456 | ||
2457 | seq_printf(m, "# %s latency trace v1.1.5 on %s\n", | |
2458 | name, UTS_RELEASE); | |
2459 | seq_puts(m, "# -----------------------------------" | |
2460 | "---------------------------------\n"); | |
2461 | seq_printf(m, "# latency: %lu us, #%lu/%lu, CPU#%d |" | |
2462 | " (M:%s VP:%d, KP:%d, SP:%d HP:%d", | |
2463 | nsecs_to_usecs(data->saved_latency), | |
2464 | entries, | |
2465 | total, | |
2466 | buf->cpu, | |
2467 | #if defined(CONFIG_PREEMPT_NONE) | |
2468 | "server", | |
2469 | #elif defined(CONFIG_PREEMPT_VOLUNTARY) | |
2470 | "desktop", | |
2471 | #elif defined(CONFIG_PREEMPT) | |
2472 | "preempt", | |
2473 | #else | |
2474 | "unknown", | |
2475 | #endif | |
2476 | /* These are reserved for later use */ | |
2477 | 0, 0, 0, 0); | |
2478 | #ifdef CONFIG_SMP | |
2479 | seq_printf(m, " #P:%d)\n", num_online_cpus()); | |
2480 | #else | |
2481 | seq_puts(m, ")\n"); | |
2482 | #endif | |
2483 | seq_puts(m, "# -----------------\n"); | |
2484 | seq_printf(m, "# | task: %.16s-%d " | |
2485 | "(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n", | |
2486 | data->comm, data->pid, | |
2487 | from_kuid_munged(seq_user_ns(m), data->uid), data->nice, | |
2488 | data->policy, data->rt_priority); | |
2489 | seq_puts(m, "# -----------------\n"); | |
2490 | ||
2491 | if (data->critical_start) { | |
2492 | seq_puts(m, "# => started at: "); | |
2493 | seq_print_ip_sym(&iter->seq, data->critical_start, sym_flags); | |
2494 | trace_print_seq(m, &iter->seq); | |
2495 | seq_puts(m, "\n# => ended at: "); | |
2496 | seq_print_ip_sym(&iter->seq, data->critical_end, sym_flags); | |
2497 | trace_print_seq(m, &iter->seq); | |
2498 | seq_puts(m, "\n#\n"); | |
2499 | } | |
2500 | ||
2501 | seq_puts(m, "#\n"); | |
2502 | } | |
2503 | ||
2504 | static void test_cpu_buff_start(struct trace_iterator *iter) | |
2505 | { | |
2506 | struct trace_seq *s = &iter->seq; | |
2507 | ||
2508 | if (!(trace_flags & TRACE_ITER_ANNOTATE)) | |
2509 | return; | |
2510 | ||
2511 | if (!(iter->iter_flags & TRACE_FILE_ANNOTATE)) | |
2512 | return; | |
2513 | ||
2514 | if (cpumask_test_cpu(iter->cpu, iter->started)) | |
2515 | return; | |
2516 | ||
2517 | if (per_cpu_ptr(iter->trace_buffer->data, iter->cpu)->skipped_entries) | |
2518 | return; | |
2519 | ||
2520 | cpumask_set_cpu(iter->cpu, iter->started); | |
2521 | ||
2522 | /* Don't print started cpu buffer for the first entry of the trace */ | |
2523 | if (iter->idx > 1) | |
2524 | trace_seq_printf(s, "##### CPU %u buffer started ####\n", | |
2525 | iter->cpu); | |
2526 | } | |
2527 | ||
2528 | static enum print_line_t print_trace_fmt(struct trace_iterator *iter) | |
2529 | { | |
2530 | struct trace_seq *s = &iter->seq; | |
2531 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); | |
2532 | struct trace_entry *entry; | |
2533 | struct trace_event *event; | |
2534 | ||
2535 | entry = iter->ent; | |
2536 | ||
2537 | test_cpu_buff_start(iter); | |
2538 | ||
2539 | event = ftrace_find_event(entry->type); | |
2540 | ||
2541 | if (trace_flags & TRACE_ITER_CONTEXT_INFO) { | |
2542 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) { | |
2543 | if (!trace_print_lat_context(iter)) | |
2544 | goto partial; | |
2545 | } else { | |
2546 | if (!trace_print_context(iter)) | |
2547 | goto partial; | |
2548 | } | |
2549 | } | |
2550 | ||
2551 | if (event) | |
2552 | return event->funcs->trace(iter, sym_flags, event); | |
2553 | ||
2554 | if (!trace_seq_printf(s, "Unknown type %d\n", entry->type)) | |
2555 | goto partial; | |
2556 | ||
2557 | return TRACE_TYPE_HANDLED; | |
2558 | partial: | |
2559 | return TRACE_TYPE_PARTIAL_LINE; | |
2560 | } | |
2561 | ||
2562 | static enum print_line_t print_raw_fmt(struct trace_iterator *iter) | |
2563 | { | |
2564 | struct trace_seq *s = &iter->seq; | |
2565 | struct trace_entry *entry; | |
2566 | struct trace_event *event; | |
2567 | ||
2568 | entry = iter->ent; | |
2569 | ||
2570 | if (trace_flags & TRACE_ITER_CONTEXT_INFO) { | |
2571 | if (!trace_seq_printf(s, "%d %d %llu ", | |
2572 | entry->pid, iter->cpu, iter->ts)) | |
2573 | goto partial; | |
2574 | } | |
2575 | ||
2576 | event = ftrace_find_event(entry->type); | |
2577 | if (event) | |
2578 | return event->funcs->raw(iter, 0, event); | |
2579 | ||
2580 | if (!trace_seq_printf(s, "%d ?\n", entry->type)) | |
2581 | goto partial; | |
2582 | ||
2583 | return TRACE_TYPE_HANDLED; | |
2584 | partial: | |
2585 | return TRACE_TYPE_PARTIAL_LINE; | |
2586 | } | |
2587 | ||
2588 | static enum print_line_t print_hex_fmt(struct trace_iterator *iter) | |
2589 | { | |
2590 | struct trace_seq *s = &iter->seq; | |
2591 | unsigned char newline = '\n'; | |
2592 | struct trace_entry *entry; | |
2593 | struct trace_event *event; | |
2594 | ||
2595 | entry = iter->ent; | |
2596 | ||
2597 | if (trace_flags & TRACE_ITER_CONTEXT_INFO) { | |
2598 | SEQ_PUT_HEX_FIELD_RET(s, entry->pid); | |
2599 | SEQ_PUT_HEX_FIELD_RET(s, iter->cpu); | |
2600 | SEQ_PUT_HEX_FIELD_RET(s, iter->ts); | |
2601 | } | |
2602 | ||
2603 | event = ftrace_find_event(entry->type); | |
2604 | if (event) { | |
2605 | enum print_line_t ret = event->funcs->hex(iter, 0, event); | |
2606 | if (ret != TRACE_TYPE_HANDLED) | |
2607 | return ret; | |
2608 | } | |
2609 | ||
2610 | SEQ_PUT_FIELD_RET(s, newline); | |
2611 | ||
2612 | return TRACE_TYPE_HANDLED; | |
2613 | } | |
2614 | ||
2615 | static enum print_line_t print_bin_fmt(struct trace_iterator *iter) | |
2616 | { | |
2617 | struct trace_seq *s = &iter->seq; | |
2618 | struct trace_entry *entry; | |
2619 | struct trace_event *event; | |
2620 | ||
2621 | entry = iter->ent; | |
2622 | ||
2623 | if (trace_flags & TRACE_ITER_CONTEXT_INFO) { | |
2624 | SEQ_PUT_FIELD_RET(s, entry->pid); | |
2625 | SEQ_PUT_FIELD_RET(s, iter->cpu); | |
2626 | SEQ_PUT_FIELD_RET(s, iter->ts); | |
2627 | } | |
2628 | ||
2629 | event = ftrace_find_event(entry->type); | |
2630 | return event ? event->funcs->binary(iter, 0, event) : | |
2631 | TRACE_TYPE_HANDLED; | |
2632 | } | |
2633 | ||
2634 | int trace_empty(struct trace_iterator *iter) | |
2635 | { | |
2636 | struct ring_buffer_iter *buf_iter; | |
2637 | int cpu; | |
2638 | ||
2639 | /* If we are looking at one CPU buffer, only check that one */ | |
2640 | if (iter->cpu_file != RING_BUFFER_ALL_CPUS) { | |
2641 | cpu = iter->cpu_file; | |
2642 | buf_iter = trace_buffer_iter(iter, cpu); | |
2643 | if (buf_iter) { | |
2644 | if (!ring_buffer_iter_empty(buf_iter)) | |
2645 | return 0; | |
2646 | } else { | |
2647 | if (!ring_buffer_empty_cpu(iter->trace_buffer->buffer, cpu)) | |
2648 | return 0; | |
2649 | } | |
2650 | return 1; | |
2651 | } | |
2652 | ||
2653 | for_each_tracing_cpu(cpu) { | |
2654 | buf_iter = trace_buffer_iter(iter, cpu); | |
2655 | if (buf_iter) { | |
2656 | if (!ring_buffer_iter_empty(buf_iter)) | |
2657 | return 0; | |
2658 | } else { | |
2659 | if (!ring_buffer_empty_cpu(iter->trace_buffer->buffer, cpu)) | |
2660 | return 0; | |
2661 | } | |
2662 | } | |
2663 | ||
2664 | return 1; | |
2665 | } | |
2666 | ||
2667 | /* Called with trace_event_read_lock() held. */ | |
2668 | enum print_line_t print_trace_line(struct trace_iterator *iter) | |
2669 | { | |
2670 | enum print_line_t ret; | |
2671 | ||
2672 | if (iter->lost_events && | |
2673 | !trace_seq_printf(&iter->seq, "CPU:%d [LOST %lu EVENTS]\n", | |
2674 | iter->cpu, iter->lost_events)) | |
2675 | return TRACE_TYPE_PARTIAL_LINE; | |
2676 | ||
2677 | if (iter->trace && iter->trace->print_line) { | |
2678 | ret = iter->trace->print_line(iter); | |
2679 | if (ret != TRACE_TYPE_UNHANDLED) | |
2680 | return ret; | |
2681 | } | |
2682 | ||
2683 | if (iter->ent->type == TRACE_BPUTS && | |
2684 | trace_flags & TRACE_ITER_PRINTK && | |
2685 | trace_flags & TRACE_ITER_PRINTK_MSGONLY) | |
2686 | return trace_print_bputs_msg_only(iter); | |
2687 | ||
2688 | if (iter->ent->type == TRACE_BPRINT && | |
2689 | trace_flags & TRACE_ITER_PRINTK && | |
2690 | trace_flags & TRACE_ITER_PRINTK_MSGONLY) | |
2691 | return trace_print_bprintk_msg_only(iter); | |
2692 | ||
2693 | if (iter->ent->type == TRACE_PRINT && | |
2694 | trace_flags & TRACE_ITER_PRINTK && | |
2695 | trace_flags & TRACE_ITER_PRINTK_MSGONLY) | |
2696 | return trace_print_printk_msg_only(iter); | |
2697 | ||
2698 | if (trace_flags & TRACE_ITER_BIN) | |
2699 | return print_bin_fmt(iter); | |
2700 | ||
2701 | if (trace_flags & TRACE_ITER_HEX) | |
2702 | return print_hex_fmt(iter); | |
2703 | ||
2704 | if (trace_flags & TRACE_ITER_RAW) | |
2705 | return print_raw_fmt(iter); | |
2706 | ||
2707 | return print_trace_fmt(iter); | |
2708 | } | |
2709 | ||
2710 | void trace_latency_header(struct seq_file *m) | |
2711 | { | |
2712 | struct trace_iterator *iter = m->private; | |
2713 | ||
2714 | /* print nothing if the buffers are empty */ | |
2715 | if (trace_empty(iter)) | |
2716 | return; | |
2717 | ||
2718 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) | |
2719 | print_trace_header(m, iter); | |
2720 | ||
2721 | if (!(trace_flags & TRACE_ITER_VERBOSE)) | |
2722 | print_lat_help_header(m); | |
2723 | } | |
2724 | ||
2725 | void trace_default_header(struct seq_file *m) | |
2726 | { | |
2727 | struct trace_iterator *iter = m->private; | |
2728 | ||
2729 | if (!(trace_flags & TRACE_ITER_CONTEXT_INFO)) | |
2730 | return; | |
2731 | ||
2732 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) { | |
2733 | /* print nothing if the buffers are empty */ | |
2734 | if (trace_empty(iter)) | |
2735 | return; | |
2736 | print_trace_header(m, iter); | |
2737 | if (!(trace_flags & TRACE_ITER_VERBOSE)) | |
2738 | print_lat_help_header(m); | |
2739 | } else { | |
2740 | if (!(trace_flags & TRACE_ITER_VERBOSE)) { | |
2741 | if (trace_flags & TRACE_ITER_IRQ_INFO) | |
2742 | print_func_help_header_irq(iter->trace_buffer, m); | |
2743 | else | |
2744 | print_func_help_header(iter->trace_buffer, m); | |
2745 | } | |
2746 | } | |
2747 | } | |
2748 | ||
2749 | static void test_ftrace_alive(struct seq_file *m) | |
2750 | { | |
2751 | if (!ftrace_is_dead()) | |
2752 | return; | |
2753 | seq_printf(m, "# WARNING: FUNCTION TRACING IS CORRUPTED\n"); | |
2754 | seq_printf(m, "# MAY BE MISSING FUNCTION EVENTS\n"); | |
2755 | } | |
2756 | ||
2757 | #ifdef CONFIG_TRACER_MAX_TRACE | |
2758 | static void show_snapshot_main_help(struct seq_file *m) | |
2759 | { | |
2760 | seq_printf(m, "# echo 0 > snapshot : Clears and frees snapshot buffer\n"); | |
2761 | seq_printf(m, "# echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.\n"); | |
2762 | seq_printf(m, "# Takes a snapshot of the main buffer.\n"); | |
2763 | seq_printf(m, "# echo 2 > snapshot : Clears snapshot buffer (but does not allocate)\n"); | |
2764 | seq_printf(m, "# (Doesn't have to be '2' works with any number that\n"); | |
2765 | seq_printf(m, "# is not a '0' or '1')\n"); | |
2766 | } | |
2767 | ||
2768 | static void show_snapshot_percpu_help(struct seq_file *m) | |
2769 | { | |
2770 | seq_printf(m, "# echo 0 > snapshot : Invalid for per_cpu snapshot file.\n"); | |
2771 | #ifdef CONFIG_RING_BUFFER_ALLOW_SWAP | |
2772 | seq_printf(m, "# echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.\n"); | |
2773 | seq_printf(m, "# Takes a snapshot of the main buffer for this cpu.\n"); | |
2774 | #else | |
2775 | seq_printf(m, "# echo 1 > snapshot : Not supported with this kernel.\n"); | |
2776 | seq_printf(m, "# Must use main snapshot file to allocate.\n"); | |
2777 | #endif | |
2778 | seq_printf(m, "# echo 2 > snapshot : Clears this cpu's snapshot buffer (but does not allocate)\n"); | |
2779 | seq_printf(m, "# (Doesn't have to be '2' works with any number that\n"); | |
2780 | seq_printf(m, "# is not a '0' or '1')\n"); | |
2781 | } | |
2782 | ||
2783 | static void print_snapshot_help(struct seq_file *m, struct trace_iterator *iter) | |
2784 | { | |
2785 | if (iter->tr->allocated_snapshot) | |
2786 | seq_printf(m, "#\n# * Snapshot is allocated *\n#\n"); | |
2787 | else | |
2788 | seq_printf(m, "#\n# * Snapshot is freed *\n#\n"); | |
2789 | ||
2790 | seq_printf(m, "# Snapshot commands:\n"); | |
2791 | if (iter->cpu_file == RING_BUFFER_ALL_CPUS) | |
2792 | show_snapshot_main_help(m); | |
2793 | else | |
2794 | show_snapshot_percpu_help(m); | |
2795 | } | |
2796 | #else | |
2797 | /* Should never be called */ | |
2798 | static inline void print_snapshot_help(struct seq_file *m, struct trace_iterator *iter) { } | |
2799 | #endif | |
2800 | ||
2801 | static int s_show(struct seq_file *m, void *v) | |
2802 | { | |
2803 | struct trace_iterator *iter = v; | |
2804 | int ret; | |
2805 | ||
2806 | if (iter->ent == NULL) { | |
2807 | if (iter->tr) { | |
2808 | seq_printf(m, "# tracer: %s\n", iter->trace->name); | |
2809 | seq_puts(m, "#\n"); | |
2810 | test_ftrace_alive(m); | |
2811 | } | |
2812 | if (iter->snapshot && trace_empty(iter)) | |
2813 | print_snapshot_help(m, iter); | |
2814 | else if (iter->trace && iter->trace->print_header) | |
2815 | iter->trace->print_header(m); | |
2816 | else | |
2817 | trace_default_header(m); | |
2818 | ||
2819 | } else if (iter->leftover) { | |
2820 | /* | |
2821 | * If we filled the seq_file buffer earlier, we | |
2822 | * want to just show it now. | |
2823 | */ | |
2824 | ret = trace_print_seq(m, &iter->seq); | |
2825 | ||
2826 | /* ret should this time be zero, but you never know */ | |
2827 | iter->leftover = ret; | |
2828 | ||
2829 | } else { | |
2830 | print_trace_line(iter); | |
2831 | ret = trace_print_seq(m, &iter->seq); | |
2832 | /* | |
2833 | * If we overflow the seq_file buffer, then it will | |
2834 | * ask us for this data again at start up. | |
2835 | * Use that instead. | |
2836 | * ret is 0 if seq_file write succeeded. | |
2837 | * -1 otherwise. | |
2838 | */ | |
2839 | iter->leftover = ret; | |
2840 | } | |
2841 | ||
2842 | return 0; | |
2843 | } | |
2844 | ||
2845 | /* | |
2846 | * Should be used after trace_array_get(), trace_types_lock | |
2847 | * ensures that i_cdev was already initialized. | |
2848 | */ | |
2849 | static inline int tracing_get_cpu(struct inode *inode) | |
2850 | { | |
2851 | if (inode->i_cdev) /* See trace_create_cpu_file() */ | |
2852 | return (long)inode->i_cdev - 1; | |
2853 | return RING_BUFFER_ALL_CPUS; | |
2854 | } | |
2855 | ||
2856 | static const struct seq_operations tracer_seq_ops = { | |
2857 | .start = s_start, | |
2858 | .next = s_next, | |
2859 | .stop = s_stop, | |
2860 | .show = s_show, | |
2861 | }; | |
2862 | ||
2863 | static struct trace_iterator * | |
2864 | __tracing_open(struct inode *inode, struct file *file, bool snapshot) | |
2865 | { | |
2866 | struct trace_array *tr = inode->i_private; | |
2867 | struct trace_iterator *iter; | |
2868 | int cpu; | |
2869 | ||
2870 | if (tracing_disabled) | |
2871 | return ERR_PTR(-ENODEV); | |
2872 | ||
2873 | iter = __seq_open_private(file, &tracer_seq_ops, sizeof(*iter)); | |
2874 | if (!iter) | |
2875 | return ERR_PTR(-ENOMEM); | |
2876 | ||
2877 | iter->buffer_iter = kzalloc(sizeof(*iter->buffer_iter) * num_possible_cpus(), | |
2878 | GFP_KERNEL); | |
2879 | if (!iter->buffer_iter) | |
2880 | goto release; | |
2881 | ||
2882 | /* | |
2883 | * We make a copy of the current tracer to avoid concurrent | |
2884 | * changes on it while we are reading. | |
2885 | */ | |
2886 | mutex_lock(&trace_types_lock); | |
2887 | iter->trace = kzalloc(sizeof(*iter->trace), GFP_KERNEL); | |
2888 | if (!iter->trace) | |
2889 | goto fail; | |
2890 | ||
2891 | *iter->trace = *tr->current_trace; | |
2892 | ||
2893 | if (!zalloc_cpumask_var(&iter->started, GFP_KERNEL)) | |
2894 | goto fail; | |
2895 | ||
2896 | iter->tr = tr; | |
2897 | ||
2898 | #ifdef CONFIG_TRACER_MAX_TRACE | |
2899 | /* Currently only the top directory has a snapshot */ | |
2900 | if (tr->current_trace->print_max || snapshot) | |
2901 | iter->trace_buffer = &tr->max_buffer; | |
2902 | else | |
2903 | #endif | |
2904 | iter->trace_buffer = &tr->trace_buffer; | |
2905 | iter->snapshot = snapshot; | |
2906 | iter->pos = -1; | |
2907 | iter->cpu_file = tracing_get_cpu(inode); | |
2908 | mutex_init(&iter->mutex); | |
2909 | ||
2910 | /* Notify the tracer early; before we stop tracing. */ | |
2911 | if (iter->trace && iter->trace->open) | |
2912 | iter->trace->open(iter); | |
2913 | ||
2914 | /* Annotate start of buffers if we had overruns */ | |
2915 | if (ring_buffer_overruns(iter->trace_buffer->buffer)) | |
2916 | iter->iter_flags |= TRACE_FILE_ANNOTATE; | |
2917 | ||
2918 | /* Output in nanoseconds only if we are using a clock in nanoseconds. */ | |
2919 | if (trace_clocks[tr->clock_id].in_ns) | |
2920 | iter->iter_flags |= TRACE_FILE_TIME_IN_NS; | |
2921 | ||
2922 | /* stop the trace while dumping if we are not opening "snapshot" */ | |
2923 | if (!iter->snapshot) | |
2924 | tracing_stop_tr(tr); | |
2925 | ||
2926 | if (iter->cpu_file == RING_BUFFER_ALL_CPUS) { | |
2927 | for_each_tracing_cpu(cpu) { | |
2928 | iter->buffer_iter[cpu] = | |
2929 | ring_buffer_read_prepare(iter->trace_buffer->buffer, cpu); | |
2930 | } | |
2931 | ring_buffer_read_prepare_sync(); | |
2932 | for_each_tracing_cpu(cpu) { | |
2933 | ring_buffer_read_start(iter->buffer_iter[cpu]); | |
2934 | tracing_iter_reset(iter, cpu); | |
2935 | } | |
2936 | } else { | |
2937 | cpu = iter->cpu_file; | |
2938 | iter->buffer_iter[cpu] = | |
2939 | ring_buffer_read_prepare(iter->trace_buffer->buffer, cpu); | |
2940 | ring_buffer_read_prepare_sync(); | |
2941 | ring_buffer_read_start(iter->buffer_iter[cpu]); | |
2942 | tracing_iter_reset(iter, cpu); | |
2943 | } | |
2944 | ||
2945 | mutex_unlock(&trace_types_lock); | |
2946 | ||
2947 | return iter; | |
2948 | ||
2949 | fail: | |
2950 | mutex_unlock(&trace_types_lock); | |
2951 | kfree(iter->trace); | |
2952 | kfree(iter->buffer_iter); | |
2953 | release: | |
2954 | seq_release_private(inode, file); | |
2955 | return ERR_PTR(-ENOMEM); | |
2956 | } | |
2957 | ||
2958 | int tracing_open_generic(struct inode *inode, struct file *filp) | |
2959 | { | |
2960 | if (tracing_disabled) | |
2961 | return -ENODEV; | |
2962 | ||
2963 | filp->private_data = inode->i_private; | |
2964 | return 0; | |
2965 | } | |
2966 | ||
2967 | /* | |
2968 | * Open and update trace_array ref count. | |
2969 | * Must have the current trace_array passed to it. | |
2970 | */ | |
2971 | static int tracing_open_generic_tr(struct inode *inode, struct file *filp) | |
2972 | { | |
2973 | struct trace_array *tr = inode->i_private; | |
2974 | ||
2975 | if (tracing_disabled) | |
2976 | return -ENODEV; | |
2977 | ||
2978 | if (trace_array_get(tr) < 0) | |
2979 | return -ENODEV; | |
2980 | ||
2981 | filp->private_data = inode->i_private; | |
2982 | ||
2983 | return 0; | |
2984 | } | |
2985 | ||
2986 | static int tracing_release(struct inode *inode, struct file *file) | |
2987 | { | |
2988 | struct trace_array *tr = inode->i_private; | |
2989 | struct seq_file *m = file->private_data; | |
2990 | struct trace_iterator *iter; | |
2991 | int cpu; | |
2992 | ||
2993 | if (!(file->f_mode & FMODE_READ)) { | |
2994 | trace_array_put(tr); | |
2995 | return 0; | |
2996 | } | |
2997 | ||
2998 | /* Writes do not use seq_file */ | |
2999 | iter = m->private; | |
3000 | mutex_lock(&trace_types_lock); | |
3001 | ||
3002 | for_each_tracing_cpu(cpu) { | |
3003 | if (iter->buffer_iter[cpu]) | |
3004 | ring_buffer_read_finish(iter->buffer_iter[cpu]); | |
3005 | } | |
3006 | ||
3007 | if (iter->trace && iter->trace->close) | |
3008 | iter->trace->close(iter); | |
3009 | ||
3010 | if (!iter->snapshot) | |
3011 | /* reenable tracing if it was previously enabled */ | |
3012 | tracing_start_tr(tr); | |
3013 | ||
3014 | __trace_array_put(tr); | |
3015 | ||
3016 | mutex_unlock(&trace_types_lock); | |
3017 | ||
3018 | mutex_destroy(&iter->mutex); | |
3019 | free_cpumask_var(iter->started); | |
3020 | kfree(iter->trace); | |
3021 | kfree(iter->buffer_iter); | |
3022 | seq_release_private(inode, file); | |
3023 | ||
3024 | return 0; | |
3025 | } | |
3026 | ||
3027 | static int tracing_release_generic_tr(struct inode *inode, struct file *file) | |
3028 | { | |
3029 | struct trace_array *tr = inode->i_private; | |
3030 | ||
3031 | trace_array_put(tr); | |
3032 | return 0; | |
3033 | } | |
3034 | ||
3035 | static int tracing_single_release_tr(struct inode *inode, struct file *file) | |
3036 | { | |
3037 | struct trace_array *tr = inode->i_private; | |
3038 | ||
3039 | trace_array_put(tr); | |
3040 | ||
3041 | return single_release(inode, file); | |
3042 | } | |
3043 | ||
3044 | static int tracing_open(struct inode *inode, struct file *file) | |
3045 | { | |
3046 | struct trace_array *tr = inode->i_private; | |
3047 | struct trace_iterator *iter; | |
3048 | int ret = 0; | |
3049 | ||
3050 | if (trace_array_get(tr) < 0) | |
3051 | return -ENODEV; | |
3052 | ||
3053 | /* If this file was open for write, then erase contents */ | |
3054 | if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { | |
3055 | int cpu = tracing_get_cpu(inode); | |
3056 | ||
3057 | if (cpu == RING_BUFFER_ALL_CPUS) | |
3058 | tracing_reset_online_cpus(&tr->trace_buffer); | |
3059 | else | |
3060 | tracing_reset(&tr->trace_buffer, cpu); | |
3061 | } | |
3062 | ||
3063 | if (file->f_mode & FMODE_READ) { | |
3064 | iter = __tracing_open(inode, file, false); | |
3065 | if (IS_ERR(iter)) | |
3066 | ret = PTR_ERR(iter); | |
3067 | else if (trace_flags & TRACE_ITER_LATENCY_FMT) | |
3068 | iter->iter_flags |= TRACE_FILE_LAT_FMT; | |
3069 | } | |
3070 | ||
3071 | if (ret < 0) | |
3072 | trace_array_put(tr); | |
3073 | ||
3074 | return ret; | |
3075 | } | |
3076 | ||
3077 | static void * | |
3078 | t_next(struct seq_file *m, void *v, loff_t *pos) | |
3079 | { | |
3080 | struct tracer *t = v; | |
3081 | ||
3082 | (*pos)++; | |
3083 | ||
3084 | if (t) | |
3085 | t = t->next; | |
3086 | ||
3087 | return t; | |
3088 | } | |
3089 | ||
3090 | static void *t_start(struct seq_file *m, loff_t *pos) | |
3091 | { | |
3092 | struct tracer *t; | |
3093 | loff_t l = 0; | |
3094 | ||
3095 | mutex_lock(&trace_types_lock); | |
3096 | for (t = trace_types; t && l < *pos; t = t_next(m, t, &l)) | |
3097 | ; | |
3098 | ||
3099 | return t; | |
3100 | } | |
3101 | ||
3102 | static void t_stop(struct seq_file *m, void *p) | |
3103 | { | |
3104 | mutex_unlock(&trace_types_lock); | |
3105 | } | |
3106 | ||
3107 | static int t_show(struct seq_file *m, void *v) | |
3108 | { | |
3109 | struct tracer *t = v; | |
3110 | ||
3111 | if (!t) | |
3112 | return 0; | |
3113 | ||
3114 | seq_printf(m, "%s", t->name); | |
3115 | if (t->next) | |
3116 | seq_putc(m, ' '); | |
3117 | else | |
3118 | seq_putc(m, '\n'); | |
3119 | ||
3120 | return 0; | |
3121 | } | |
3122 | ||
3123 | static const struct seq_operations show_traces_seq_ops = { | |
3124 | .start = t_start, | |
3125 | .next = t_next, | |
3126 | .stop = t_stop, | |
3127 | .show = t_show, | |
3128 | }; | |
3129 | ||
3130 | static int show_traces_open(struct inode *inode, struct file *file) | |
3131 | { | |
3132 | if (tracing_disabled) | |
3133 | return -ENODEV; | |
3134 | ||
3135 | return seq_open(file, &show_traces_seq_ops); | |
3136 | } | |
3137 | ||
3138 | static ssize_t | |
3139 | tracing_write_stub(struct file *filp, const char __user *ubuf, | |
3140 | size_t count, loff_t *ppos) | |
3141 | { | |
3142 | return count; | |
3143 | } | |
3144 | ||
3145 | static loff_t tracing_seek(struct file *file, loff_t offset, int origin) | |
3146 | { | |
3147 | if (file->f_mode & FMODE_READ) | |
3148 | return seq_lseek(file, offset, origin); | |
3149 | else | |
3150 | return 0; | |
3151 | } | |
3152 | ||
3153 | static const struct file_operations tracing_fops = { | |
3154 | .open = tracing_open, | |
3155 | .read = seq_read, | |
3156 | .write = tracing_write_stub, | |
3157 | .llseek = tracing_seek, | |
3158 | .release = tracing_release, | |
3159 | }; | |
3160 | ||
3161 | static const struct file_operations show_traces_fops = { | |
3162 | .open = show_traces_open, | |
3163 | .read = seq_read, | |
3164 | .release = seq_release, | |
3165 | .llseek = seq_lseek, | |
3166 | }; | |
3167 | ||
3168 | /* | |
3169 | * The tracer itself will not take this lock, but still we want | |
3170 | * to provide a consistent cpumask to user-space: | |
3171 | */ | |
3172 | static DEFINE_MUTEX(tracing_cpumask_update_lock); | |
3173 | ||
3174 | /* | |
3175 | * Temporary storage for the character representation of the | |
3176 | * CPU bitmask (and one more byte for the newline): | |
3177 | */ | |
3178 | static char mask_str[NR_CPUS + 1]; | |
3179 | ||
3180 | static ssize_t | |
3181 | tracing_cpumask_read(struct file *filp, char __user *ubuf, | |
3182 | size_t count, loff_t *ppos) | |
3183 | { | |
3184 | struct trace_array *tr = file_inode(filp)->i_private; | |
3185 | int len; | |
3186 | ||
3187 | mutex_lock(&tracing_cpumask_update_lock); | |
3188 | ||
3189 | len = cpumask_scnprintf(mask_str, count, tr->tracing_cpumask); | |
3190 | if (count - len < 2) { | |
3191 | count = -EINVAL; | |
3192 | goto out_err; | |
3193 | } | |
3194 | len += sprintf(mask_str + len, "\n"); | |
3195 | count = simple_read_from_buffer(ubuf, count, ppos, mask_str, NR_CPUS+1); | |
3196 | ||
3197 | out_err: | |
3198 | mutex_unlock(&tracing_cpumask_update_lock); | |
3199 | ||
3200 | return count; | |
3201 | } | |
3202 | ||
3203 | static ssize_t | |
3204 | tracing_cpumask_write(struct file *filp, const char __user *ubuf, | |
3205 | size_t count, loff_t *ppos) | |
3206 | { | |
3207 | struct trace_array *tr = file_inode(filp)->i_private; | |
3208 | cpumask_var_t tracing_cpumask_new; | |
3209 | int err, cpu; | |
3210 | ||
3211 | if (!alloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL)) | |
3212 | return -ENOMEM; | |
3213 | ||
3214 | err = cpumask_parse_user(ubuf, count, tracing_cpumask_new); | |
3215 | if (err) | |
3216 | goto err_unlock; | |
3217 | ||
3218 | mutex_lock(&tracing_cpumask_update_lock); | |
3219 | ||
3220 | local_irq_disable(); | |
3221 | arch_spin_lock(&ftrace_max_lock); | |
3222 | for_each_tracing_cpu(cpu) { | |
3223 | /* | |
3224 | * Increase/decrease the disabled counter if we are | |
3225 | * about to flip a bit in the cpumask: | |
3226 | */ | |
3227 | if (cpumask_test_cpu(cpu, tr->tracing_cpumask) && | |
3228 | !cpumask_test_cpu(cpu, tracing_cpumask_new)) { | |
3229 | atomic_inc(&per_cpu_ptr(tr->trace_buffer.data, cpu)->disabled); | |
3230 | ring_buffer_record_disable_cpu(tr->trace_buffer.buffer, cpu); | |
3231 | } | |
3232 | if (!cpumask_test_cpu(cpu, tr->tracing_cpumask) && | |
3233 | cpumask_test_cpu(cpu, tracing_cpumask_new)) { | |
3234 | atomic_dec(&per_cpu_ptr(tr->trace_buffer.data, cpu)->disabled); | |
3235 | ring_buffer_record_enable_cpu(tr->trace_buffer.buffer, cpu); | |
3236 | } | |
3237 | } | |
3238 | arch_spin_unlock(&ftrace_max_lock); | |
3239 | local_irq_enable(); | |
3240 | ||
3241 | cpumask_copy(tr->tracing_cpumask, tracing_cpumask_new); | |
3242 | ||
3243 | mutex_unlock(&tracing_cpumask_update_lock); | |
3244 | free_cpumask_var(tracing_cpumask_new); | |
3245 | ||
3246 | return count; | |
3247 | ||
3248 | err_unlock: | |
3249 | free_cpumask_var(tracing_cpumask_new); | |
3250 | ||
3251 | return err; | |
3252 | } | |
3253 | ||
3254 | static const struct file_operations tracing_cpumask_fops = { | |
3255 | .open = tracing_open_generic_tr, | |
3256 | .read = tracing_cpumask_read, | |
3257 | .write = tracing_cpumask_write, | |
3258 | .release = tracing_release_generic_tr, | |
3259 | .llseek = generic_file_llseek, | |
3260 | }; | |
3261 | ||
3262 | static int tracing_trace_options_show(struct seq_file *m, void *v) | |
3263 | { | |
3264 | struct tracer_opt *trace_opts; | |
3265 | struct trace_array *tr = m->private; | |
3266 | u32 tracer_flags; | |
3267 | int i; | |
3268 | ||
3269 | mutex_lock(&trace_types_lock); | |
3270 | tracer_flags = tr->current_trace->flags->val; | |
3271 | trace_opts = tr->current_trace->flags->opts; | |
3272 | ||
3273 | for (i = 0; trace_options[i]; i++) { | |
3274 | if (trace_flags & (1 << i)) | |
3275 | seq_printf(m, "%s\n", trace_options[i]); | |
3276 | else | |
3277 | seq_printf(m, "no%s\n", trace_options[i]); | |
3278 | } | |
3279 | ||
3280 | for (i = 0; trace_opts[i].name; i++) { | |
3281 | if (tracer_flags & trace_opts[i].bit) | |
3282 | seq_printf(m, "%s\n", trace_opts[i].name); | |
3283 | else | |
3284 | seq_printf(m, "no%s\n", trace_opts[i].name); | |
3285 | } | |
3286 | mutex_unlock(&trace_types_lock); | |
3287 | ||
3288 | return 0; | |
3289 | } | |
3290 | ||
3291 | static int __set_tracer_option(struct tracer *trace, | |
3292 | struct tracer_flags *tracer_flags, | |
3293 | struct tracer_opt *opts, int neg) | |
3294 | { | |
3295 | int ret; | |
3296 | ||
3297 | ret = trace->set_flag(tracer_flags->val, opts->bit, !neg); | |
3298 | if (ret) | |
3299 | return ret; | |
3300 | ||
3301 | if (neg) | |
3302 | tracer_flags->val &= ~opts->bit; | |
3303 | else | |
3304 | tracer_flags->val |= opts->bit; | |
3305 | return 0; | |
3306 | } | |
3307 | ||
3308 | /* Try to assign a tracer specific option */ | |
3309 | static int set_tracer_option(struct tracer *trace, char *cmp, int neg) | |
3310 | { | |
3311 | struct tracer_flags *tracer_flags = trace->flags; | |
3312 | struct tracer_opt *opts = NULL; | |
3313 | int i; | |
3314 | ||
3315 | for (i = 0; tracer_flags->opts[i].name; i++) { | |
3316 | opts = &tracer_flags->opts[i]; | |
3317 | ||
3318 | if (strcmp(cmp, opts->name) == 0) | |
3319 | return __set_tracer_option(trace, trace->flags, | |
3320 | opts, neg); | |
3321 | } | |
3322 | ||
3323 | return -EINVAL; | |
3324 | } | |
3325 | ||
3326 | /* Some tracers require overwrite to stay enabled */ | |
3327 | int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set) | |
3328 | { | |
3329 | if (tracer->enabled && (mask & TRACE_ITER_OVERWRITE) && !set) | |
3330 | return -1; | |
3331 | ||
3332 | return 0; | |
3333 | } | |
3334 | ||
3335 | int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled) | |
3336 | { | |
3337 | /* do nothing if flag is already set */ | |
3338 | if (!!(trace_flags & mask) == !!enabled) | |
3339 | return 0; | |
3340 | ||
3341 | /* Give the tracer a chance to approve the change */ | |
3342 | if (tr->current_trace->flag_changed) | |
3343 | if (tr->current_trace->flag_changed(tr->current_trace, mask, !!enabled)) | |
3344 | return -EINVAL; | |
3345 | ||
3346 | if (enabled) | |
3347 | trace_flags |= mask; | |
3348 | else | |
3349 | trace_flags &= ~mask; | |
3350 | ||
3351 | if (mask == TRACE_ITER_RECORD_CMD) | |
3352 | trace_event_enable_cmd_record(enabled); | |
3353 | ||
3354 | if (mask == TRACE_ITER_OVERWRITE) { | |
3355 | ring_buffer_change_overwrite(tr->trace_buffer.buffer, enabled); | |
3356 | #ifdef CONFIG_TRACER_MAX_TRACE | |
3357 | ring_buffer_change_overwrite(tr->max_buffer.buffer, enabled); | |
3358 | #endif | |
3359 | } | |
3360 | ||
3361 | if (mask == TRACE_ITER_PRINTK) | |
3362 | trace_printk_start_stop_comm(enabled); | |
3363 | ||
3364 | return 0; | |
3365 | } | |
3366 | ||
3367 | static int trace_set_options(struct trace_array *tr, char *option) | |
3368 | { | |
3369 | char *cmp; | |
3370 | int neg = 0; | |
3371 | int ret = -ENODEV; | |
3372 | int i; | |
3373 | ||
3374 | cmp = strstrip(option); | |
3375 | ||
3376 | if (strncmp(cmp, "no", 2) == 0) { | |
3377 | neg = 1; | |
3378 | cmp += 2; | |
3379 | } | |
3380 | ||
3381 | mutex_lock(&trace_types_lock); | |
3382 | ||
3383 | for (i = 0; trace_options[i]; i++) { | |
3384 | if (strcmp(cmp, trace_options[i]) == 0) { | |
3385 | ret = set_tracer_flag(tr, 1 << i, !neg); | |
3386 | break; | |
3387 | } | |
3388 | } | |
3389 | ||
3390 | /* If no option could be set, test the specific tracer options */ | |
3391 | if (!trace_options[i]) | |
3392 | ret = set_tracer_option(tr->current_trace, cmp, neg); | |
3393 | ||
3394 | mutex_unlock(&trace_types_lock); | |
3395 | ||
3396 | return ret; | |
3397 | } | |
3398 | ||
3399 | static ssize_t | |
3400 | tracing_trace_options_write(struct file *filp, const char __user *ubuf, | |
3401 | size_t cnt, loff_t *ppos) | |
3402 | { | |
3403 | struct seq_file *m = filp->private_data; | |
3404 | struct trace_array *tr = m->private; | |
3405 | char buf[64]; | |
3406 | int ret; | |
3407 | ||
3408 | if (cnt >= sizeof(buf)) | |
3409 | return -EINVAL; | |
3410 | ||
3411 | if (copy_from_user(&buf, ubuf, cnt)) | |
3412 | return -EFAULT; | |
3413 | ||
3414 | buf[cnt] = 0; | |
3415 | ||
3416 | ret = trace_set_options(tr, buf); | |
3417 | if (ret < 0) | |
3418 | return ret; | |
3419 | ||
3420 | *ppos += cnt; | |
3421 | ||
3422 | return cnt; | |
3423 | } | |
3424 | ||
3425 | static int tracing_trace_options_open(struct inode *inode, struct file *file) | |
3426 | { | |
3427 | struct trace_array *tr = inode->i_private; | |
3428 | int ret; | |
3429 | ||
3430 | if (tracing_disabled) | |
3431 | return -ENODEV; | |
3432 | ||
3433 | if (trace_array_get(tr) < 0) | |
3434 | return -ENODEV; | |
3435 | ||
3436 | ret = single_open(file, tracing_trace_options_show, inode->i_private); | |
3437 | if (ret < 0) | |
3438 | trace_array_put(tr); | |
3439 | ||
3440 | return ret; | |
3441 | } | |
3442 | ||
3443 | static const struct file_operations tracing_iter_fops = { | |
3444 | .open = tracing_trace_options_open, | |
3445 | .read = seq_read, | |
3446 | .llseek = seq_lseek, | |
3447 | .release = tracing_single_release_tr, | |
3448 | .write = tracing_trace_options_write, | |
3449 | }; | |
3450 | ||
3451 | static const char readme_msg[] = | |
3452 | "tracing mini-HOWTO:\n\n" | |
3453 | "# echo 0 > tracing_on : quick way to disable tracing\n" | |
3454 | "# echo 1 > tracing_on : quick way to re-enable tracing\n\n" | |
3455 | " Important files:\n" | |
3456 | " trace\t\t\t- The static contents of the buffer\n" | |
3457 | "\t\t\t To clear the buffer write into this file: echo > trace\n" | |
3458 | " trace_pipe\t\t- A consuming read to see the contents of the buffer\n" | |
3459 | " current_tracer\t- function and latency tracers\n" | |
3460 | " available_tracers\t- list of configured tracers for current_tracer\n" | |
3461 | " buffer_size_kb\t- view and modify size of per cpu buffer\n" | |
3462 | " buffer_total_size_kb - view total size of all cpu buffers\n\n" | |
3463 | " trace_clock\t\t-change the clock used to order events\n" | |
3464 | " local: Per cpu clock but may not be synced across CPUs\n" | |
3465 | " global: Synced across CPUs but slows tracing down.\n" | |
3466 | " counter: Not a clock, but just an increment\n" | |
3467 | " uptime: Jiffy counter from time of boot\n" | |
3468 | " perf: Same clock that perf events use\n" | |
3469 | #ifdef CONFIG_X86_64 | |
3470 | " x86-tsc: TSC cycle counter\n" | |
3471 | #endif | |
3472 | "\n trace_marker\t\t- Writes into this file writes into the kernel buffer\n" | |
3473 | " tracing_cpumask\t- Limit which CPUs to trace\n" | |
3474 | " instances\t\t- Make sub-buffers with: mkdir instances/foo\n" | |
3475 | "\t\t\t Remove sub-buffer with rmdir\n" | |
3476 | " trace_options\t\t- Set format or modify how tracing happens\n" | |
3477 | "\t\t\t Disable an option by adding a suffix 'no' to the option name\n" | |
3478 | #ifdef CONFIG_DYNAMIC_FTRACE | |
3479 | "\n available_filter_functions - list of functions that can be filtered on\n" | |
3480 | " set_ftrace_filter\t- echo function name in here to only trace these functions\n" | |
3481 | " accepts: func_full_name, *func_end, func_begin*, *func_middle*\n" | |
3482 | " modules: Can select a group via module\n" | |
3483 | " Format: :mod:<module-name>\n" | |
3484 | " example: echo :mod:ext3 > set_ftrace_filter\n" | |
3485 | " triggers: a command to perform when function is hit\n" | |
3486 | " Format: <function>:<trigger>[:count]\n" | |
3487 | " trigger: traceon, traceoff\n" | |
3488 | " enable_event:<system>:<event>\n" | |
3489 | " disable_event:<system>:<event>\n" | |
3490 | #ifdef CONFIG_STACKTRACE | |
3491 | " stacktrace\n" | |
3492 | #endif | |
3493 | #ifdef CONFIG_TRACER_SNAPSHOT | |
3494 | " snapshot\n" | |
3495 | #endif | |
3496 | " example: echo do_fault:traceoff > set_ftrace_filter\n" | |
3497 | " echo do_trap:traceoff:3 > set_ftrace_filter\n" | |
3498 | " The first one will disable tracing every time do_fault is hit\n" | |
3499 | " The second will disable tracing at most 3 times when do_trap is hit\n" | |
3500 | " The first time do trap is hit and it disables tracing, the counter\n" | |
3501 | " will decrement to 2. If tracing is already disabled, the counter\n" | |
3502 | " will not decrement. It only decrements when the trigger did work\n" | |
3503 | " To remove trigger without count:\n" | |
3504 | " echo '!<function>:<trigger> > set_ftrace_filter\n" | |
3505 | " To remove trigger with a count:\n" | |
3506 | " echo '!<function>:<trigger>:0 > set_ftrace_filter\n" | |
3507 | " set_ftrace_notrace\t- echo function name in here to never trace.\n" | |
3508 | " accepts: func_full_name, *func_end, func_begin*, *func_middle*\n" | |
3509 | " modules: Can select a group via module command :mod:\n" | |
3510 | " Does not accept triggers\n" | |
3511 | #endif /* CONFIG_DYNAMIC_FTRACE */ | |
3512 | #ifdef CONFIG_FUNCTION_TRACER | |
3513 | " set_ftrace_pid\t- Write pid(s) to only function trace those pids (function)\n" | |
3514 | #endif | |
3515 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
3516 | " set_graph_function\t- Trace the nested calls of a function (function_graph)\n" | |
3517 | " max_graph_depth\t- Trace a limited depth of nested calls (0 is unlimited)\n" | |
3518 | #endif | |
3519 | #ifdef CONFIG_TRACER_SNAPSHOT | |
3520 | "\n snapshot\t\t- Like 'trace' but shows the content of the static snapshot buffer\n" | |
3521 | "\t\t\t Read the contents for more information\n" | |
3522 | #endif | |
3523 | #ifdef CONFIG_STACK_TRACER | |
3524 | " stack_trace\t\t- Shows the max stack trace when active\n" | |
3525 | " stack_max_size\t- Shows current max stack size that was traced\n" | |
3526 | "\t\t\t Write into this file to reset the max size (trigger a new trace)\n" | |
3527 | #ifdef CONFIG_DYNAMIC_FTRACE | |
3528 | " stack_trace_filter\t- Like set_ftrace_filter but limits what stack_trace traces\n" | |
3529 | #endif | |
3530 | #endif /* CONFIG_STACK_TRACER */ | |
3531 | ; | |
3532 | ||
3533 | static ssize_t | |
3534 | tracing_readme_read(struct file *filp, char __user *ubuf, | |
3535 | size_t cnt, loff_t *ppos) | |
3536 | { | |
3537 | return simple_read_from_buffer(ubuf, cnt, ppos, | |
3538 | readme_msg, strlen(readme_msg)); | |
3539 | } | |
3540 | ||
3541 | static const struct file_operations tracing_readme_fops = { | |
3542 | .open = tracing_open_generic, | |
3543 | .read = tracing_readme_read, | |
3544 | .llseek = generic_file_llseek, | |
3545 | }; | |
3546 | ||
3547 | static ssize_t | |
3548 | tracing_saved_cmdlines_read(struct file *file, char __user *ubuf, | |
3549 | size_t cnt, loff_t *ppos) | |
3550 | { | |
3551 | char *buf_comm; | |
3552 | char *file_buf; | |
3553 | char *buf; | |
3554 | int len = 0; | |
3555 | int pid; | |
3556 | int i; | |
3557 | ||
3558 | file_buf = kmalloc(SAVED_CMDLINES*(16+TASK_COMM_LEN), GFP_KERNEL); | |
3559 | if (!file_buf) | |
3560 | return -ENOMEM; | |
3561 | ||
3562 | buf_comm = kmalloc(TASK_COMM_LEN, GFP_KERNEL); | |
3563 | if (!buf_comm) { | |
3564 | kfree(file_buf); | |
3565 | return -ENOMEM; | |
3566 | } | |
3567 | ||
3568 | buf = file_buf; | |
3569 | ||
3570 | for (i = 0; i < SAVED_CMDLINES; i++) { | |
3571 | int r; | |
3572 | ||
3573 | pid = map_cmdline_to_pid[i]; | |
3574 | if (pid == -1 || pid == NO_CMDLINE_MAP) | |
3575 | continue; | |
3576 | ||
3577 | trace_find_cmdline(pid, buf_comm); | |
3578 | r = sprintf(buf, "%d %s\n", pid, buf_comm); | |
3579 | buf += r; | |
3580 | len += r; | |
3581 | } | |
3582 | ||
3583 | len = simple_read_from_buffer(ubuf, cnt, ppos, | |
3584 | file_buf, len); | |
3585 | ||
3586 | kfree(file_buf); | |
3587 | kfree(buf_comm); | |
3588 | ||
3589 | return len; | |
3590 | } | |
3591 | ||
3592 | static const struct file_operations tracing_saved_cmdlines_fops = { | |
3593 | .open = tracing_open_generic, | |
3594 | .read = tracing_saved_cmdlines_read, | |
3595 | .llseek = generic_file_llseek, | |
3596 | }; | |
3597 | ||
3598 | static ssize_t | |
3599 | tracing_set_trace_read(struct file *filp, char __user *ubuf, | |
3600 | size_t cnt, loff_t *ppos) | |
3601 | { | |
3602 | struct trace_array *tr = filp->private_data; | |
3603 | char buf[MAX_TRACER_SIZE+2]; | |
3604 | int r; | |
3605 | ||
3606 | mutex_lock(&trace_types_lock); | |
3607 | r = sprintf(buf, "%s\n", tr->current_trace->name); | |
3608 | mutex_unlock(&trace_types_lock); | |
3609 | ||
3610 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
3611 | } | |
3612 | ||
3613 | int tracer_init(struct tracer *t, struct trace_array *tr) | |
3614 | { | |
3615 | tracing_reset_online_cpus(&tr->trace_buffer); | |
3616 | return t->init(tr); | |
3617 | } | |
3618 | ||
3619 | static void set_buffer_entries(struct trace_buffer *buf, unsigned long val) | |
3620 | { | |
3621 | int cpu; | |
3622 | ||
3623 | for_each_tracing_cpu(cpu) | |
3624 | per_cpu_ptr(buf->data, cpu)->entries = val; | |
3625 | } | |
3626 | ||
3627 | #ifdef CONFIG_TRACER_MAX_TRACE | |
3628 | /* resize @tr's buffer to the size of @size_tr's entries */ | |
3629 | static int resize_buffer_duplicate_size(struct trace_buffer *trace_buf, | |
3630 | struct trace_buffer *size_buf, int cpu_id) | |
3631 | { | |
3632 | int cpu, ret = 0; | |
3633 | ||
3634 | if (cpu_id == RING_BUFFER_ALL_CPUS) { | |
3635 | for_each_tracing_cpu(cpu) { | |
3636 | ret = ring_buffer_resize(trace_buf->buffer, | |
3637 | per_cpu_ptr(size_buf->data, cpu)->entries, cpu); | |
3638 | if (ret < 0) | |
3639 | break; | |
3640 | per_cpu_ptr(trace_buf->data, cpu)->entries = | |
3641 | per_cpu_ptr(size_buf->data, cpu)->entries; | |
3642 | } | |
3643 | } else { | |
3644 | ret = ring_buffer_resize(trace_buf->buffer, | |
3645 | per_cpu_ptr(size_buf->data, cpu_id)->entries, cpu_id); | |
3646 | if (ret == 0) | |
3647 | per_cpu_ptr(trace_buf->data, cpu_id)->entries = | |
3648 | per_cpu_ptr(size_buf->data, cpu_id)->entries; | |
3649 | } | |
3650 | ||
3651 | return ret; | |
3652 | } | |
3653 | #endif /* CONFIG_TRACER_MAX_TRACE */ | |
3654 | ||
3655 | static int __tracing_resize_ring_buffer(struct trace_array *tr, | |
3656 | unsigned long size, int cpu) | |
3657 | { | |
3658 | int ret; | |
3659 | ||
3660 | /* | |
3661 | * If kernel or user changes the size of the ring buffer | |
3662 | * we use the size that was given, and we can forget about | |
3663 | * expanding it later. | |
3664 | */ | |
3665 | ring_buffer_expanded = true; | |
3666 | ||
3667 | /* May be called before buffers are initialized */ | |
3668 | if (!tr->trace_buffer.buffer) | |
3669 | return 0; | |
3670 | ||
3671 | ret = ring_buffer_resize(tr->trace_buffer.buffer, size, cpu); | |
3672 | if (ret < 0) | |
3673 | return ret; | |
3674 | ||
3675 | #ifdef CONFIG_TRACER_MAX_TRACE | |
3676 | if (!(tr->flags & TRACE_ARRAY_FL_GLOBAL) || | |
3677 | !tr->current_trace->use_max_tr) | |
3678 | goto out; | |
3679 | ||
3680 | ret = ring_buffer_resize(tr->max_buffer.buffer, size, cpu); | |
3681 | if (ret < 0) { | |
3682 | int r = resize_buffer_duplicate_size(&tr->trace_buffer, | |
3683 | &tr->trace_buffer, cpu); | |
3684 | if (r < 0) { | |
3685 | /* | |
3686 | * AARGH! We are left with different | |
3687 | * size max buffer!!!! | |
3688 | * The max buffer is our "snapshot" buffer. | |
3689 | * When a tracer needs a snapshot (one of the | |
3690 | * latency tracers), it swaps the max buffer | |
3691 | * with the saved snap shot. We succeeded to | |
3692 | * update the size of the main buffer, but failed to | |
3693 | * update the size of the max buffer. But when we tried | |
3694 | * to reset the main buffer to the original size, we | |
3695 | * failed there too. This is very unlikely to | |
3696 | * happen, but if it does, warn and kill all | |
3697 | * tracing. | |
3698 | */ | |
3699 | WARN_ON(1); | |
3700 | tracing_disabled = 1; | |
3701 | } | |
3702 | return ret; | |
3703 | } | |
3704 | ||
3705 | if (cpu == RING_BUFFER_ALL_CPUS) | |
3706 | set_buffer_entries(&tr->max_buffer, size); | |
3707 | else | |
3708 | per_cpu_ptr(tr->max_buffer.data, cpu)->entries = size; | |
3709 | ||
3710 | out: | |
3711 | #endif /* CONFIG_TRACER_MAX_TRACE */ | |
3712 | ||
3713 | if (cpu == RING_BUFFER_ALL_CPUS) | |
3714 | set_buffer_entries(&tr->trace_buffer, size); | |
3715 | else | |
3716 | per_cpu_ptr(tr->trace_buffer.data, cpu)->entries = size; | |
3717 | ||
3718 | return ret; | |
3719 | } | |
3720 | ||
3721 | static ssize_t tracing_resize_ring_buffer(struct trace_array *tr, | |
3722 | unsigned long size, int cpu_id) | |
3723 | { | |
3724 | int ret = size; | |
3725 | ||
3726 | mutex_lock(&trace_types_lock); | |
3727 | ||
3728 | if (cpu_id != RING_BUFFER_ALL_CPUS) { | |
3729 | /* make sure, this cpu is enabled in the mask */ | |
3730 | if (!cpumask_test_cpu(cpu_id, tracing_buffer_mask)) { | |
3731 | ret = -EINVAL; | |
3732 | goto out; | |
3733 | } | |
3734 | } | |
3735 | ||
3736 | ret = __tracing_resize_ring_buffer(tr, size, cpu_id); | |
3737 | if (ret < 0) | |
3738 | ret = -ENOMEM; | |
3739 | ||
3740 | out: | |
3741 | mutex_unlock(&trace_types_lock); | |
3742 | ||
3743 | return ret; | |
3744 | } | |
3745 | ||
3746 | ||
3747 | /** | |
3748 | * tracing_update_buffers - used by tracing facility to expand ring buffers | |
3749 | * | |
3750 | * To save on memory when the tracing is never used on a system with it | |
3751 | * configured in. The ring buffers are set to a minimum size. But once | |
3752 | * a user starts to use the tracing facility, then they need to grow | |
3753 | * to their default size. | |
3754 | * | |
3755 | * This function is to be called when a tracer is about to be used. | |
3756 | */ | |
3757 | int tracing_update_buffers(void) | |
3758 | { | |
3759 | int ret = 0; | |
3760 | ||
3761 | mutex_lock(&trace_types_lock); | |
3762 | if (!ring_buffer_expanded) | |
3763 | ret = __tracing_resize_ring_buffer(&global_trace, trace_buf_size, | |
3764 | RING_BUFFER_ALL_CPUS); | |
3765 | mutex_unlock(&trace_types_lock); | |
3766 | ||
3767 | return ret; | |
3768 | } | |
3769 | ||
3770 | struct trace_option_dentry; | |
3771 | ||
3772 | static struct trace_option_dentry * | |
3773 | create_trace_option_files(struct trace_array *tr, struct tracer *tracer); | |
3774 | ||
3775 | static void | |
3776 | destroy_trace_option_files(struct trace_option_dentry *topts); | |
3777 | ||
3778 | static int tracing_set_tracer(const char *buf) | |
3779 | { | |
3780 | static struct trace_option_dentry *topts; | |
3781 | struct trace_array *tr = &global_trace; | |
3782 | struct tracer *t; | |
3783 | #ifdef CONFIG_TRACER_MAX_TRACE | |
3784 | bool had_max_tr; | |
3785 | #endif | |
3786 | int ret = 0; | |
3787 | ||
3788 | mutex_lock(&trace_types_lock); | |
3789 | ||
3790 | if (!ring_buffer_expanded) { | |
3791 | ret = __tracing_resize_ring_buffer(tr, trace_buf_size, | |
3792 | RING_BUFFER_ALL_CPUS); | |
3793 | if (ret < 0) | |
3794 | goto out; | |
3795 | ret = 0; | |
3796 | } | |
3797 | ||
3798 | for (t = trace_types; t; t = t->next) { | |
3799 | if (strcmp(t->name, buf) == 0) | |
3800 | break; | |
3801 | } | |
3802 | if (!t) { | |
3803 | ret = -EINVAL; | |
3804 | goto out; | |
3805 | } | |
3806 | if (t == tr->current_trace) | |
3807 | goto out; | |
3808 | ||
3809 | trace_branch_disable(); | |
3810 | ||
3811 | tr->current_trace->enabled = false; | |
3812 | ||
3813 | if (tr->current_trace->reset) | |
3814 | tr->current_trace->reset(tr); | |
3815 | ||
3816 | /* Current trace needs to be nop_trace before synchronize_sched */ | |
3817 | tr->current_trace = &nop_trace; | |
3818 | ||
3819 | #ifdef CONFIG_TRACER_MAX_TRACE | |
3820 | had_max_tr = tr->allocated_snapshot; | |
3821 | ||
3822 | if (had_max_tr && !t->use_max_tr) { | |
3823 | /* | |
3824 | * We need to make sure that the update_max_tr sees that | |
3825 | * current_trace changed to nop_trace to keep it from | |
3826 | * swapping the buffers after we resize it. | |
3827 | * The update_max_tr is called from interrupts disabled | |
3828 | * so a synchronized_sched() is sufficient. | |
3829 | */ | |
3830 | synchronize_sched(); | |
3831 | free_snapshot(tr); | |
3832 | } | |
3833 | #endif | |
3834 | destroy_trace_option_files(topts); | |
3835 | ||
3836 | topts = create_trace_option_files(tr, t); | |
3837 | ||
3838 | #ifdef CONFIG_TRACER_MAX_TRACE | |
3839 | if (t->use_max_tr && !had_max_tr) { | |
3840 | ret = alloc_snapshot(tr); | |
3841 | if (ret < 0) | |
3842 | goto out; | |
3843 | } | |
3844 | #endif | |
3845 | ||
3846 | if (t->init) { | |
3847 | ret = tracer_init(t, tr); | |
3848 | if (ret) | |
3849 | goto out; | |
3850 | } | |
3851 | ||
3852 | tr->current_trace = t; | |
3853 | tr->current_trace->enabled = true; | |
3854 | trace_branch_enable(tr); | |
3855 | out: | |
3856 | mutex_unlock(&trace_types_lock); | |
3857 | ||
3858 | return ret; | |
3859 | } | |
3860 | ||
3861 | static ssize_t | |
3862 | tracing_set_trace_write(struct file *filp, const char __user *ubuf, | |
3863 | size_t cnt, loff_t *ppos) | |
3864 | { | |
3865 | char buf[MAX_TRACER_SIZE+1]; | |
3866 | int i; | |
3867 | size_t ret; | |
3868 | int err; | |
3869 | ||
3870 | ret = cnt; | |
3871 | ||
3872 | if (cnt > MAX_TRACER_SIZE) | |
3873 | cnt = MAX_TRACER_SIZE; | |
3874 | ||
3875 | if (copy_from_user(&buf, ubuf, cnt)) | |
3876 | return -EFAULT; | |
3877 | ||
3878 | buf[cnt] = 0; | |
3879 | ||
3880 | /* strip ending whitespace. */ | |
3881 | for (i = cnt - 1; i > 0 && isspace(buf[i]); i--) | |
3882 | buf[i] = 0; | |
3883 | ||
3884 | err = tracing_set_tracer(buf); | |
3885 | if (err) | |
3886 | return err; | |
3887 | ||
3888 | *ppos += ret; | |
3889 | ||
3890 | return ret; | |
3891 | } | |
3892 | ||
3893 | static ssize_t | |
3894 | tracing_max_lat_read(struct file *filp, char __user *ubuf, | |
3895 | size_t cnt, loff_t *ppos) | |
3896 | { | |
3897 | unsigned long *ptr = filp->private_data; | |
3898 | char buf[64]; | |
3899 | int r; | |
3900 | ||
3901 | r = snprintf(buf, sizeof(buf), "%ld\n", | |
3902 | *ptr == (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr)); | |
3903 | if (r > sizeof(buf)) | |
3904 | r = sizeof(buf); | |
3905 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
3906 | } | |
3907 | ||
3908 | static ssize_t | |
3909 | tracing_max_lat_write(struct file *filp, const char __user *ubuf, | |
3910 | size_t cnt, loff_t *ppos) | |
3911 | { | |
3912 | unsigned long *ptr = filp->private_data; | |
3913 | unsigned long val; | |
3914 | int ret; | |
3915 | ||
3916 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); | |
3917 | if (ret) | |
3918 | return ret; | |
3919 | ||
3920 | *ptr = val * 1000; | |
3921 | ||
3922 | return cnt; | |
3923 | } | |
3924 | ||
3925 | static int tracing_open_pipe(struct inode *inode, struct file *filp) | |
3926 | { | |
3927 | struct trace_array *tr = inode->i_private; | |
3928 | struct trace_iterator *iter; | |
3929 | int ret = 0; | |
3930 | ||
3931 | if (tracing_disabled) | |
3932 | return -ENODEV; | |
3933 | ||
3934 | if (trace_array_get(tr) < 0) | |
3935 | return -ENODEV; | |
3936 | ||
3937 | mutex_lock(&trace_types_lock); | |
3938 | ||
3939 | /* create a buffer to store the information to pass to userspace */ | |
3940 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); | |
3941 | if (!iter) { | |
3942 | ret = -ENOMEM; | |
3943 | __trace_array_put(tr); | |
3944 | goto out; | |
3945 | } | |
3946 | ||
3947 | /* | |
3948 | * We make a copy of the current tracer to avoid concurrent | |
3949 | * changes on it while we are reading. | |
3950 | */ | |
3951 | iter->trace = kmalloc(sizeof(*iter->trace), GFP_KERNEL); | |
3952 | if (!iter->trace) { | |
3953 | ret = -ENOMEM; | |
3954 | goto fail; | |
3955 | } | |
3956 | *iter->trace = *tr->current_trace; | |
3957 | ||
3958 | if (!alloc_cpumask_var(&iter->started, GFP_KERNEL)) { | |
3959 | ret = -ENOMEM; | |
3960 | goto fail; | |
3961 | } | |
3962 | ||
3963 | /* trace pipe does not show start of buffer */ | |
3964 | cpumask_setall(iter->started); | |
3965 | ||
3966 | if (trace_flags & TRACE_ITER_LATENCY_FMT) | |
3967 | iter->iter_flags |= TRACE_FILE_LAT_FMT; | |
3968 | ||
3969 | /* Output in nanoseconds only if we are using a clock in nanoseconds. */ | |
3970 | if (trace_clocks[tr->clock_id].in_ns) | |
3971 | iter->iter_flags |= TRACE_FILE_TIME_IN_NS; | |
3972 | ||
3973 | iter->tr = tr; | |
3974 | iter->trace_buffer = &tr->trace_buffer; | |
3975 | iter->cpu_file = tracing_get_cpu(inode); | |
3976 | mutex_init(&iter->mutex); | |
3977 | filp->private_data = iter; | |
3978 | ||
3979 | if (iter->trace->pipe_open) | |
3980 | iter->trace->pipe_open(iter); | |
3981 | ||
3982 | nonseekable_open(inode, filp); | |
3983 | out: | |
3984 | mutex_unlock(&trace_types_lock); | |
3985 | return ret; | |
3986 | ||
3987 | fail: | |
3988 | kfree(iter->trace); | |
3989 | kfree(iter); | |
3990 | __trace_array_put(tr); | |
3991 | mutex_unlock(&trace_types_lock); | |
3992 | return ret; | |
3993 | } | |
3994 | ||
3995 | static int tracing_release_pipe(struct inode *inode, struct file *file) | |
3996 | { | |
3997 | struct trace_iterator *iter = file->private_data; | |
3998 | struct trace_array *tr = inode->i_private; | |
3999 | ||
4000 | mutex_lock(&trace_types_lock); | |
4001 | ||
4002 | if (iter->trace->pipe_close) | |
4003 | iter->trace->pipe_close(iter); | |
4004 | ||
4005 | mutex_unlock(&trace_types_lock); | |
4006 | ||
4007 | free_cpumask_var(iter->started); | |
4008 | mutex_destroy(&iter->mutex); | |
4009 | kfree(iter->trace); | |
4010 | kfree(iter); | |
4011 | ||
4012 | trace_array_put(tr); | |
4013 | ||
4014 | return 0; | |
4015 | } | |
4016 | ||
4017 | static unsigned int | |
4018 | trace_poll(struct trace_iterator *iter, struct file *filp, poll_table *poll_table) | |
4019 | { | |
4020 | /* Iterators are static, they should be filled or empty */ | |
4021 | if (trace_buffer_iter(iter, iter->cpu_file)) | |
4022 | return POLLIN | POLLRDNORM; | |
4023 | ||
4024 | if (trace_flags & TRACE_ITER_BLOCK) | |
4025 | /* | |
4026 | * Always select as readable when in blocking mode | |
4027 | */ | |
4028 | return POLLIN | POLLRDNORM; | |
4029 | else | |
4030 | return ring_buffer_poll_wait(iter->trace_buffer->buffer, iter->cpu_file, | |
4031 | filp, poll_table); | |
4032 | } | |
4033 | ||
4034 | static unsigned int | |
4035 | tracing_poll_pipe(struct file *filp, poll_table *poll_table) | |
4036 | { | |
4037 | struct trace_iterator *iter = filp->private_data; | |
4038 | ||
4039 | return trace_poll(iter, filp, poll_table); | |
4040 | } | |
4041 | ||
4042 | /* | |
4043 | * This is a make-shift waitqueue. | |
4044 | * A tracer might use this callback on some rare cases: | |
4045 | * | |
4046 | * 1) the current tracer might hold the runqueue lock when it wakes up | |
4047 | * a reader, hence a deadlock (sched, function, and function graph tracers) | |
4048 | * 2) the function tracers, trace all functions, we don't want | |
4049 | * the overhead of calling wake_up and friends | |
4050 | * (and tracing them too) | |
4051 | * | |
4052 | * Anyway, this is really very primitive wakeup. | |
4053 | */ | |
4054 | void poll_wait_pipe(struct trace_iterator *iter) | |
4055 | { | |
4056 | set_current_state(TASK_INTERRUPTIBLE); | |
4057 | /* sleep for 100 msecs, and try again. */ | |
4058 | schedule_timeout(HZ / 10); | |
4059 | } | |
4060 | ||
4061 | /* Must be called with trace_types_lock mutex held. */ | |
4062 | static int tracing_wait_pipe(struct file *filp) | |
4063 | { | |
4064 | struct trace_iterator *iter = filp->private_data; | |
4065 | ||
4066 | while (trace_empty(iter)) { | |
4067 | ||
4068 | if ((filp->f_flags & O_NONBLOCK)) { | |
4069 | return -EAGAIN; | |
4070 | } | |
4071 | ||
4072 | mutex_unlock(&iter->mutex); | |
4073 | ||
4074 | iter->trace->wait_pipe(iter); | |
4075 | ||
4076 | mutex_lock(&iter->mutex); | |
4077 | ||
4078 | if (signal_pending(current)) | |
4079 | return -EINTR; | |
4080 | ||
4081 | /* | |
4082 | * We block until we read something and tracing is disabled. | |
4083 | * We still block if tracing is disabled, but we have never | |
4084 | * read anything. This allows a user to cat this file, and | |
4085 | * then enable tracing. But after we have read something, | |
4086 | * we give an EOF when tracing is again disabled. | |
4087 | * | |
4088 | * iter->pos will be 0 if we haven't read anything. | |
4089 | */ | |
4090 | if (!tracing_is_on() && iter->pos) | |
4091 | break; | |
4092 | } | |
4093 | ||
4094 | return 1; | |
4095 | } | |
4096 | ||
4097 | /* | |
4098 | * Consumer reader. | |
4099 | */ | |
4100 | static ssize_t | |
4101 | tracing_read_pipe(struct file *filp, char __user *ubuf, | |
4102 | size_t cnt, loff_t *ppos) | |
4103 | { | |
4104 | struct trace_iterator *iter = filp->private_data; | |
4105 | struct trace_array *tr = iter->tr; | |
4106 | ssize_t sret; | |
4107 | ||
4108 | /* return any leftover data */ | |
4109 | sret = trace_seq_to_user(&iter->seq, ubuf, cnt); | |
4110 | if (sret != -EBUSY) | |
4111 | return sret; | |
4112 | ||
4113 | trace_seq_init(&iter->seq); | |
4114 | ||
4115 | /* copy the tracer to avoid using a global lock all around */ | |
4116 | mutex_lock(&trace_types_lock); | |
4117 | if (unlikely(iter->trace->name != tr->current_trace->name)) | |
4118 | *iter->trace = *tr->current_trace; | |
4119 | mutex_unlock(&trace_types_lock); | |
4120 | ||
4121 | /* | |
4122 | * Avoid more than one consumer on a single file descriptor | |
4123 | * This is just a matter of traces coherency, the ring buffer itself | |
4124 | * is protected. | |
4125 | */ | |
4126 | mutex_lock(&iter->mutex); | |
4127 | if (iter->trace->read) { | |
4128 | sret = iter->trace->read(iter, filp, ubuf, cnt, ppos); | |
4129 | if (sret) | |
4130 | goto out; | |
4131 | } | |
4132 | ||
4133 | waitagain: | |
4134 | sret = tracing_wait_pipe(filp); | |
4135 | if (sret <= 0) | |
4136 | goto out; | |
4137 | ||
4138 | /* stop when tracing is finished */ | |
4139 | if (trace_empty(iter)) { | |
4140 | sret = 0; | |
4141 | goto out; | |
4142 | } | |
4143 | ||
4144 | if (cnt >= PAGE_SIZE) | |
4145 | cnt = PAGE_SIZE - 1; | |
4146 | ||
4147 | /* reset all but tr, trace, and overruns */ | |
4148 | memset(&iter->seq, 0, | |
4149 | sizeof(struct trace_iterator) - | |
4150 | offsetof(struct trace_iterator, seq)); | |
4151 | cpumask_clear(iter->started); | |
4152 | iter->pos = -1; | |
4153 | ||
4154 | trace_event_read_lock(); | |
4155 | trace_access_lock(iter->cpu_file); | |
4156 | while (trace_find_next_entry_inc(iter) != NULL) { | |
4157 | enum print_line_t ret; | |
4158 | int len = iter->seq.len; | |
4159 | ||
4160 | ret = print_trace_line(iter); | |
4161 | if (ret == TRACE_TYPE_PARTIAL_LINE) { | |
4162 | /* don't print partial lines */ | |
4163 | iter->seq.len = len; | |
4164 | break; | |
4165 | } | |
4166 | if (ret != TRACE_TYPE_NO_CONSUME) | |
4167 | trace_consume(iter); | |
4168 | ||
4169 | if (iter->seq.len >= cnt) | |
4170 | break; | |
4171 | ||
4172 | /* | |
4173 | * Setting the full flag means we reached the trace_seq buffer | |
4174 | * size and we should leave by partial output condition above. | |
4175 | * One of the trace_seq_* functions is not used properly. | |
4176 | */ | |
4177 | WARN_ONCE(iter->seq.full, "full flag set for trace type %d", | |
4178 | iter->ent->type); | |
4179 | } | |
4180 | trace_access_unlock(iter->cpu_file); | |
4181 | trace_event_read_unlock(); | |
4182 | ||
4183 | /* Now copy what we have to the user */ | |
4184 | sret = trace_seq_to_user(&iter->seq, ubuf, cnt); | |
4185 | if (iter->seq.readpos >= iter->seq.len) | |
4186 | trace_seq_init(&iter->seq); | |
4187 | ||
4188 | /* | |
4189 | * If there was nothing to send to user, in spite of consuming trace | |
4190 | * entries, go back to wait for more entries. | |
4191 | */ | |
4192 | if (sret == -EBUSY) | |
4193 | goto waitagain; | |
4194 | ||
4195 | out: | |
4196 | mutex_unlock(&iter->mutex); | |
4197 | ||
4198 | return sret; | |
4199 | } | |
4200 | ||
4201 | static void tracing_pipe_buf_release(struct pipe_inode_info *pipe, | |
4202 | struct pipe_buffer *buf) | |
4203 | { | |
4204 | __free_page(buf->page); | |
4205 | } | |
4206 | ||
4207 | static void tracing_spd_release_pipe(struct splice_pipe_desc *spd, | |
4208 | unsigned int idx) | |
4209 | { | |
4210 | __free_page(spd->pages[idx]); | |
4211 | } | |
4212 | ||
4213 | static const struct pipe_buf_operations tracing_pipe_buf_ops = { | |
4214 | .can_merge = 0, | |
4215 | .map = generic_pipe_buf_map, | |
4216 | .unmap = generic_pipe_buf_unmap, | |
4217 | .confirm = generic_pipe_buf_confirm, | |
4218 | .release = tracing_pipe_buf_release, | |
4219 | .steal = generic_pipe_buf_steal, | |
4220 | .get = generic_pipe_buf_get, | |
4221 | }; | |
4222 | ||
4223 | static size_t | |
4224 | tracing_fill_pipe_page(size_t rem, struct trace_iterator *iter) | |
4225 | { | |
4226 | size_t count; | |
4227 | int ret; | |
4228 | ||
4229 | /* Seq buffer is page-sized, exactly what we need. */ | |
4230 | for (;;) { | |
4231 | count = iter->seq.len; | |
4232 | ret = print_trace_line(iter); | |
4233 | count = iter->seq.len - count; | |
4234 | if (rem < count) { | |
4235 | rem = 0; | |
4236 | iter->seq.len -= count; | |
4237 | break; | |
4238 | } | |
4239 | if (ret == TRACE_TYPE_PARTIAL_LINE) { | |
4240 | iter->seq.len -= count; | |
4241 | break; | |
4242 | } | |
4243 | ||
4244 | if (ret != TRACE_TYPE_NO_CONSUME) | |
4245 | trace_consume(iter); | |
4246 | rem -= count; | |
4247 | if (!trace_find_next_entry_inc(iter)) { | |
4248 | rem = 0; | |
4249 | iter->ent = NULL; | |
4250 | break; | |
4251 | } | |
4252 | } | |
4253 | ||
4254 | return rem; | |
4255 | } | |
4256 | ||
4257 | static ssize_t tracing_splice_read_pipe(struct file *filp, | |
4258 | loff_t *ppos, | |
4259 | struct pipe_inode_info *pipe, | |
4260 | size_t len, | |
4261 | unsigned int flags) | |
4262 | { | |
4263 | struct page *pages_def[PIPE_DEF_BUFFERS]; | |
4264 | struct partial_page partial_def[PIPE_DEF_BUFFERS]; | |
4265 | struct trace_iterator *iter = filp->private_data; | |
4266 | struct splice_pipe_desc spd = { | |
4267 | .pages = pages_def, | |
4268 | .partial = partial_def, | |
4269 | .nr_pages = 0, /* This gets updated below. */ | |
4270 | .nr_pages_max = PIPE_DEF_BUFFERS, | |
4271 | .flags = flags, | |
4272 | .ops = &tracing_pipe_buf_ops, | |
4273 | .spd_release = tracing_spd_release_pipe, | |
4274 | }; | |
4275 | struct trace_array *tr = iter->tr; | |
4276 | ssize_t ret; | |
4277 | size_t rem; | |
4278 | unsigned int i; | |
4279 | ||
4280 | if (splice_grow_spd(pipe, &spd)) | |
4281 | return -ENOMEM; | |
4282 | ||
4283 | /* copy the tracer to avoid using a global lock all around */ | |
4284 | mutex_lock(&trace_types_lock); | |
4285 | if (unlikely(iter->trace->name != tr->current_trace->name)) | |
4286 | *iter->trace = *tr->current_trace; | |
4287 | mutex_unlock(&trace_types_lock); | |
4288 | ||
4289 | mutex_lock(&iter->mutex); | |
4290 | ||
4291 | if (iter->trace->splice_read) { | |
4292 | ret = iter->trace->splice_read(iter, filp, | |
4293 | ppos, pipe, len, flags); | |
4294 | if (ret) | |
4295 | goto out_err; | |
4296 | } | |
4297 | ||
4298 | ret = tracing_wait_pipe(filp); | |
4299 | if (ret <= 0) | |
4300 | goto out_err; | |
4301 | ||
4302 | if (!iter->ent && !trace_find_next_entry_inc(iter)) { | |
4303 | ret = -EFAULT; | |
4304 | goto out_err; | |
4305 | } | |
4306 | ||
4307 | trace_event_read_lock(); | |
4308 | trace_access_lock(iter->cpu_file); | |
4309 | ||
4310 | /* Fill as many pages as possible. */ | |
4311 | for (i = 0, rem = len; i < pipe->buffers && rem; i++) { | |
4312 | spd.pages[i] = alloc_page(GFP_KERNEL); | |
4313 | if (!spd.pages[i]) | |
4314 | break; | |
4315 | ||
4316 | rem = tracing_fill_pipe_page(rem, iter); | |
4317 | ||
4318 | /* Copy the data into the page, so we can start over. */ | |
4319 | ret = trace_seq_to_buffer(&iter->seq, | |
4320 | page_address(spd.pages[i]), | |
4321 | iter->seq.len); | |
4322 | if (ret < 0) { | |
4323 | __free_page(spd.pages[i]); | |
4324 | break; | |
4325 | } | |
4326 | spd.partial[i].offset = 0; | |
4327 | spd.partial[i].len = iter->seq.len; | |
4328 | ||
4329 | trace_seq_init(&iter->seq); | |
4330 | } | |
4331 | ||
4332 | trace_access_unlock(iter->cpu_file); | |
4333 | trace_event_read_unlock(); | |
4334 | mutex_unlock(&iter->mutex); | |
4335 | ||
4336 | spd.nr_pages = i; | |
4337 | ||
4338 | ret = splice_to_pipe(pipe, &spd); | |
4339 | out: | |
4340 | splice_shrink_spd(&spd); | |
4341 | return ret; | |
4342 | ||
4343 | out_err: | |
4344 | mutex_unlock(&iter->mutex); | |
4345 | goto out; | |
4346 | } | |
4347 | ||
4348 | static ssize_t | |
4349 | tracing_entries_read(struct file *filp, char __user *ubuf, | |
4350 | size_t cnt, loff_t *ppos) | |
4351 | { | |
4352 | struct inode *inode = file_inode(filp); | |
4353 | struct trace_array *tr = inode->i_private; | |
4354 | int cpu = tracing_get_cpu(inode); | |
4355 | char buf[64]; | |
4356 | int r = 0; | |
4357 | ssize_t ret; | |
4358 | ||
4359 | mutex_lock(&trace_types_lock); | |
4360 | ||
4361 | if (cpu == RING_BUFFER_ALL_CPUS) { | |
4362 | int cpu, buf_size_same; | |
4363 | unsigned long size; | |
4364 | ||
4365 | size = 0; | |
4366 | buf_size_same = 1; | |
4367 | /* check if all cpu sizes are same */ | |
4368 | for_each_tracing_cpu(cpu) { | |
4369 | /* fill in the size from first enabled cpu */ | |
4370 | if (size == 0) | |
4371 | size = per_cpu_ptr(tr->trace_buffer.data, cpu)->entries; | |
4372 | if (size != per_cpu_ptr(tr->trace_buffer.data, cpu)->entries) { | |
4373 | buf_size_same = 0; | |
4374 | break; | |
4375 | } | |
4376 | } | |
4377 | ||
4378 | if (buf_size_same) { | |
4379 | if (!ring_buffer_expanded) | |
4380 | r = sprintf(buf, "%lu (expanded: %lu)\n", | |
4381 | size >> 10, | |
4382 | trace_buf_size >> 10); | |
4383 | else | |
4384 | r = sprintf(buf, "%lu\n", size >> 10); | |
4385 | } else | |
4386 | r = sprintf(buf, "X\n"); | |
4387 | } else | |
4388 | r = sprintf(buf, "%lu\n", per_cpu_ptr(tr->trace_buffer.data, cpu)->entries >> 10); | |
4389 | ||
4390 | mutex_unlock(&trace_types_lock); | |
4391 | ||
4392 | ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
4393 | return ret; | |
4394 | } | |
4395 | ||
4396 | static ssize_t | |
4397 | tracing_entries_write(struct file *filp, const char __user *ubuf, | |
4398 | size_t cnt, loff_t *ppos) | |
4399 | { | |
4400 | struct inode *inode = file_inode(filp); | |
4401 | struct trace_array *tr = inode->i_private; | |
4402 | unsigned long val; | |
4403 | int ret; | |
4404 | ||
4405 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); | |
4406 | if (ret) | |
4407 | return ret; | |
4408 | ||
4409 | /* must have at least 1 entry */ | |
4410 | if (!val) | |
4411 | return -EINVAL; | |
4412 | ||
4413 | /* value is in KB */ | |
4414 | val <<= 10; | |
4415 | ret = tracing_resize_ring_buffer(tr, val, tracing_get_cpu(inode)); | |
4416 | if (ret < 0) | |
4417 | return ret; | |
4418 | ||
4419 | *ppos += cnt; | |
4420 | ||
4421 | return cnt; | |
4422 | } | |
4423 | ||
4424 | static ssize_t | |
4425 | tracing_total_entries_read(struct file *filp, char __user *ubuf, | |
4426 | size_t cnt, loff_t *ppos) | |
4427 | { | |
4428 | struct trace_array *tr = filp->private_data; | |
4429 | char buf[64]; | |
4430 | int r, cpu; | |
4431 | unsigned long size = 0, expanded_size = 0; | |
4432 | ||
4433 | mutex_lock(&trace_types_lock); | |
4434 | for_each_tracing_cpu(cpu) { | |
4435 | size += per_cpu_ptr(tr->trace_buffer.data, cpu)->entries >> 10; | |
4436 | if (!ring_buffer_expanded) | |
4437 | expanded_size += trace_buf_size >> 10; | |
4438 | } | |
4439 | if (ring_buffer_expanded) | |
4440 | r = sprintf(buf, "%lu\n", size); | |
4441 | else | |
4442 | r = sprintf(buf, "%lu (expanded: %lu)\n", size, expanded_size); | |
4443 | mutex_unlock(&trace_types_lock); | |
4444 | ||
4445 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
4446 | } | |
4447 | ||
4448 | static ssize_t | |
4449 | tracing_free_buffer_write(struct file *filp, const char __user *ubuf, | |
4450 | size_t cnt, loff_t *ppos) | |
4451 | { | |
4452 | /* | |
4453 | * There is no need to read what the user has written, this function | |
4454 | * is just to make sure that there is no error when "echo" is used | |
4455 | */ | |
4456 | ||
4457 | *ppos += cnt; | |
4458 | ||
4459 | return cnt; | |
4460 | } | |
4461 | ||
4462 | static int | |
4463 | tracing_free_buffer_release(struct inode *inode, struct file *filp) | |
4464 | { | |
4465 | struct trace_array *tr = inode->i_private; | |
4466 | ||
4467 | /* disable tracing ? */ | |
4468 | if (trace_flags & TRACE_ITER_STOP_ON_FREE) | |
4469 | tracer_tracing_off(tr); | |
4470 | /* resize the ring buffer to 0 */ | |
4471 | tracing_resize_ring_buffer(tr, 0, RING_BUFFER_ALL_CPUS); | |
4472 | ||
4473 | trace_array_put(tr); | |
4474 | ||
4475 | return 0; | |
4476 | } | |
4477 | ||
4478 | static ssize_t | |
4479 | tracing_mark_write(struct file *filp, const char __user *ubuf, | |
4480 | size_t cnt, loff_t *fpos) | |
4481 | { | |
4482 | unsigned long addr = (unsigned long)ubuf; | |
4483 | struct trace_array *tr = filp->private_data; | |
4484 | struct ring_buffer_event *event; | |
4485 | struct ring_buffer *buffer; | |
4486 | struct print_entry *entry; | |
4487 | unsigned long irq_flags; | |
4488 | struct page *pages[2]; | |
4489 | void *map_page[2]; | |
4490 | int nr_pages = 1; | |
4491 | ssize_t written; | |
4492 | int offset; | |
4493 | int size; | |
4494 | int len; | |
4495 | int ret; | |
4496 | int i; | |
4497 | ||
4498 | if (tracing_disabled) | |
4499 | return -EINVAL; | |
4500 | ||
4501 | if (!(trace_flags & TRACE_ITER_MARKERS)) | |
4502 | return -EINVAL; | |
4503 | ||
4504 | if (cnt > TRACE_BUF_SIZE) | |
4505 | cnt = TRACE_BUF_SIZE; | |
4506 | ||
4507 | /* | |
4508 | * Userspace is injecting traces into the kernel trace buffer. | |
4509 | * We want to be as non intrusive as possible. | |
4510 | * To do so, we do not want to allocate any special buffers | |
4511 | * or take any locks, but instead write the userspace data | |
4512 | * straight into the ring buffer. | |
4513 | * | |
4514 | * First we need to pin the userspace buffer into memory, | |
4515 | * which, most likely it is, because it just referenced it. | |
4516 | * But there's no guarantee that it is. By using get_user_pages_fast() | |
4517 | * and kmap_atomic/kunmap_atomic() we can get access to the | |
4518 | * pages directly. We then write the data directly into the | |
4519 | * ring buffer. | |
4520 | */ | |
4521 | BUILD_BUG_ON(TRACE_BUF_SIZE >= PAGE_SIZE); | |
4522 | ||
4523 | /* check if we cross pages */ | |
4524 | if ((addr & PAGE_MASK) != ((addr + cnt) & PAGE_MASK)) | |
4525 | nr_pages = 2; | |
4526 | ||
4527 | offset = addr & (PAGE_SIZE - 1); | |
4528 | addr &= PAGE_MASK; | |
4529 | ||
4530 | ret = get_user_pages_fast(addr, nr_pages, 0, pages); | |
4531 | if (ret < nr_pages) { | |
4532 | while (--ret >= 0) | |
4533 | put_page(pages[ret]); | |
4534 | written = -EFAULT; | |
4535 | goto out; | |
4536 | } | |
4537 | ||
4538 | for (i = 0; i < nr_pages; i++) | |
4539 | map_page[i] = kmap_atomic(pages[i]); | |
4540 | ||
4541 | local_save_flags(irq_flags); | |
4542 | size = sizeof(*entry) + cnt + 2; /* possible \n added */ | |
4543 | buffer = tr->trace_buffer.buffer; | |
4544 | event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size, | |
4545 | irq_flags, preempt_count()); | |
4546 | if (!event) { | |
4547 | /* Ring buffer disabled, return as if not open for write */ | |
4548 | written = -EBADF; | |
4549 | goto out_unlock; | |
4550 | } | |
4551 | ||
4552 | entry = ring_buffer_event_data(event); | |
4553 | entry->ip = _THIS_IP_; | |
4554 | ||
4555 | if (nr_pages == 2) { | |
4556 | len = PAGE_SIZE - offset; | |
4557 | memcpy(&entry->buf, map_page[0] + offset, len); | |
4558 | memcpy(&entry->buf[len], map_page[1], cnt - len); | |
4559 | } else | |
4560 | memcpy(&entry->buf, map_page[0] + offset, cnt); | |
4561 | ||
4562 | if (entry->buf[cnt - 1] != '\n') { | |
4563 | entry->buf[cnt] = '\n'; | |
4564 | entry->buf[cnt + 1] = '\0'; | |
4565 | } else | |
4566 | entry->buf[cnt] = '\0'; | |
4567 | ||
4568 | __buffer_unlock_commit(buffer, event); | |
4569 | ||
4570 | written = cnt; | |
4571 | ||
4572 | *fpos += written; | |
4573 | ||
4574 | out_unlock: | |
4575 | for (i = 0; i < nr_pages; i++){ | |
4576 | kunmap_atomic(map_page[i]); | |
4577 | put_page(pages[i]); | |
4578 | } | |
4579 | out: | |
4580 | return written; | |
4581 | } | |
4582 | ||
4583 | static int tracing_clock_show(struct seq_file *m, void *v) | |
4584 | { | |
4585 | struct trace_array *tr = m->private; | |
4586 | int i; | |
4587 | ||
4588 | for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) | |
4589 | seq_printf(m, | |
4590 | "%s%s%s%s", i ? " " : "", | |
4591 | i == tr->clock_id ? "[" : "", trace_clocks[i].name, | |
4592 | i == tr->clock_id ? "]" : ""); | |
4593 | seq_putc(m, '\n'); | |
4594 | ||
4595 | return 0; | |
4596 | } | |
4597 | ||
4598 | static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf, | |
4599 | size_t cnt, loff_t *fpos) | |
4600 | { | |
4601 | struct seq_file *m = filp->private_data; | |
4602 | struct trace_array *tr = m->private; | |
4603 | char buf[64]; | |
4604 | const char *clockstr; | |
4605 | int i; | |
4606 | ||
4607 | if (cnt >= sizeof(buf)) | |
4608 | return -EINVAL; | |
4609 | ||
4610 | if (copy_from_user(&buf, ubuf, cnt)) | |
4611 | return -EFAULT; | |
4612 | ||
4613 | buf[cnt] = 0; | |
4614 | ||
4615 | clockstr = strstrip(buf); | |
4616 | ||
4617 | for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) { | |
4618 | if (strcmp(trace_clocks[i].name, clockstr) == 0) | |
4619 | break; | |
4620 | } | |
4621 | if (i == ARRAY_SIZE(trace_clocks)) | |
4622 | return -EINVAL; | |
4623 | ||
4624 | mutex_lock(&trace_types_lock); | |
4625 | ||
4626 | tr->clock_id = i; | |
4627 | ||
4628 | ring_buffer_set_clock(tr->trace_buffer.buffer, trace_clocks[i].func); | |
4629 | ||
4630 | /* | |
4631 | * New clock may not be consistent with the previous clock. | |
4632 | * Reset the buffer so that it doesn't have incomparable timestamps. | |
4633 | */ | |
4634 | tracing_reset_online_cpus(&tr->trace_buffer); | |
4635 | ||
4636 | #ifdef CONFIG_TRACER_MAX_TRACE | |
4637 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL && tr->max_buffer.buffer) | |
4638 | ring_buffer_set_clock(tr->max_buffer.buffer, trace_clocks[i].func); | |
4639 | tracing_reset_online_cpus(&tr->max_buffer); | |
4640 | #endif | |
4641 | ||
4642 | mutex_unlock(&trace_types_lock); | |
4643 | ||
4644 | *fpos += cnt; | |
4645 | ||
4646 | return cnt; | |
4647 | } | |
4648 | ||
4649 | static int tracing_clock_open(struct inode *inode, struct file *file) | |
4650 | { | |
4651 | struct trace_array *tr = inode->i_private; | |
4652 | int ret; | |
4653 | ||
4654 | if (tracing_disabled) | |
4655 | return -ENODEV; | |
4656 | ||
4657 | if (trace_array_get(tr)) | |
4658 | return -ENODEV; | |
4659 | ||
4660 | ret = single_open(file, tracing_clock_show, inode->i_private); | |
4661 | if (ret < 0) | |
4662 | trace_array_put(tr); | |
4663 | ||
4664 | return ret; | |
4665 | } | |
4666 | ||
4667 | struct ftrace_buffer_info { | |
4668 | struct trace_iterator iter; | |
4669 | void *spare; | |
4670 | unsigned int read; | |
4671 | }; | |
4672 | ||
4673 | #ifdef CONFIG_TRACER_SNAPSHOT | |
4674 | static int tracing_snapshot_open(struct inode *inode, struct file *file) | |
4675 | { | |
4676 | struct trace_array *tr = inode->i_private; | |
4677 | struct trace_iterator *iter; | |
4678 | struct seq_file *m; | |
4679 | int ret = 0; | |
4680 | ||
4681 | if (trace_array_get(tr) < 0) | |
4682 | return -ENODEV; | |
4683 | ||
4684 | if (file->f_mode & FMODE_READ) { | |
4685 | iter = __tracing_open(inode, file, true); | |
4686 | if (IS_ERR(iter)) | |
4687 | ret = PTR_ERR(iter); | |
4688 | } else { | |
4689 | /* Writes still need the seq_file to hold the private data */ | |
4690 | ret = -ENOMEM; | |
4691 | m = kzalloc(sizeof(*m), GFP_KERNEL); | |
4692 | if (!m) | |
4693 | goto out; | |
4694 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); | |
4695 | if (!iter) { | |
4696 | kfree(m); | |
4697 | goto out; | |
4698 | } | |
4699 | ret = 0; | |
4700 | ||
4701 | iter->tr = tr; | |
4702 | iter->trace_buffer = &tr->max_buffer; | |
4703 | iter->cpu_file = tracing_get_cpu(inode); | |
4704 | m->private = iter; | |
4705 | file->private_data = m; | |
4706 | } | |
4707 | out: | |
4708 | if (ret < 0) | |
4709 | trace_array_put(tr); | |
4710 | ||
4711 | return ret; | |
4712 | } | |
4713 | ||
4714 | static ssize_t | |
4715 | tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt, | |
4716 | loff_t *ppos) | |
4717 | { | |
4718 | struct seq_file *m = filp->private_data; | |
4719 | struct trace_iterator *iter = m->private; | |
4720 | struct trace_array *tr = iter->tr; | |
4721 | unsigned long val; | |
4722 | int ret; | |
4723 | ||
4724 | ret = tracing_update_buffers(); | |
4725 | if (ret < 0) | |
4726 | return ret; | |
4727 | ||
4728 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); | |
4729 | if (ret) | |
4730 | return ret; | |
4731 | ||
4732 | mutex_lock(&trace_types_lock); | |
4733 | ||
4734 | if (tr->current_trace->use_max_tr) { | |
4735 | ret = -EBUSY; | |
4736 | goto out; | |
4737 | } | |
4738 | ||
4739 | switch (val) { | |
4740 | case 0: | |
4741 | if (iter->cpu_file != RING_BUFFER_ALL_CPUS) { | |
4742 | ret = -EINVAL; | |
4743 | break; | |
4744 | } | |
4745 | if (tr->allocated_snapshot) | |
4746 | free_snapshot(tr); | |
4747 | break; | |
4748 | case 1: | |
4749 | /* Only allow per-cpu swap if the ring buffer supports it */ | |
4750 | #ifndef CONFIG_RING_BUFFER_ALLOW_SWAP | |
4751 | if (iter->cpu_file != RING_BUFFER_ALL_CPUS) { | |
4752 | ret = -EINVAL; | |
4753 | break; | |
4754 | } | |
4755 | #endif | |
4756 | if (!tr->allocated_snapshot) { | |
4757 | ret = alloc_snapshot(tr); | |
4758 | if (ret < 0) | |
4759 | break; | |
4760 | } | |
4761 | local_irq_disable(); | |
4762 | /* Now, we're going to swap */ | |
4763 | if (iter->cpu_file == RING_BUFFER_ALL_CPUS) | |
4764 | update_max_tr(tr, current, smp_processor_id()); | |
4765 | else | |
4766 | update_max_tr_single(tr, current, iter->cpu_file); | |
4767 | local_irq_enable(); | |
4768 | break; | |
4769 | default: | |
4770 | if (tr->allocated_snapshot) { | |
4771 | if (iter->cpu_file == RING_BUFFER_ALL_CPUS) | |
4772 | tracing_reset_online_cpus(&tr->max_buffer); | |
4773 | else | |
4774 | tracing_reset(&tr->max_buffer, iter->cpu_file); | |
4775 | } | |
4776 | break; | |
4777 | } | |
4778 | ||
4779 | if (ret >= 0) { | |
4780 | *ppos += cnt; | |
4781 | ret = cnt; | |
4782 | } | |
4783 | out: | |
4784 | mutex_unlock(&trace_types_lock); | |
4785 | return ret; | |
4786 | } | |
4787 | ||
4788 | static int tracing_snapshot_release(struct inode *inode, struct file *file) | |
4789 | { | |
4790 | struct seq_file *m = file->private_data; | |
4791 | int ret; | |
4792 | ||
4793 | ret = tracing_release(inode, file); | |
4794 | ||
4795 | if (file->f_mode & FMODE_READ) | |
4796 | return ret; | |
4797 | ||
4798 | /* If write only, the seq_file is just a stub */ | |
4799 | if (m) | |
4800 | kfree(m->private); | |
4801 | kfree(m); | |
4802 | ||
4803 | return 0; | |
4804 | } | |
4805 | ||
4806 | static int tracing_buffers_open(struct inode *inode, struct file *filp); | |
4807 | static ssize_t tracing_buffers_read(struct file *filp, char __user *ubuf, | |
4808 | size_t count, loff_t *ppos); | |
4809 | static int tracing_buffers_release(struct inode *inode, struct file *file); | |
4810 | static ssize_t tracing_buffers_splice_read(struct file *file, loff_t *ppos, | |
4811 | struct pipe_inode_info *pipe, size_t len, unsigned int flags); | |
4812 | ||
4813 | static int snapshot_raw_open(struct inode *inode, struct file *filp) | |
4814 | { | |
4815 | struct ftrace_buffer_info *info; | |
4816 | int ret; | |
4817 | ||
4818 | ret = tracing_buffers_open(inode, filp); | |
4819 | if (ret < 0) | |
4820 | return ret; | |
4821 | ||
4822 | info = filp->private_data; | |
4823 | ||
4824 | if (info->iter.trace->use_max_tr) { | |
4825 | tracing_buffers_release(inode, filp); | |
4826 | return -EBUSY; | |
4827 | } | |
4828 | ||
4829 | info->iter.snapshot = true; | |
4830 | info->iter.trace_buffer = &info->iter.tr->max_buffer; | |
4831 | ||
4832 | return ret; | |
4833 | } | |
4834 | ||
4835 | #endif /* CONFIG_TRACER_SNAPSHOT */ | |
4836 | ||
4837 | ||
4838 | static const struct file_operations tracing_max_lat_fops = { | |
4839 | .open = tracing_open_generic, | |
4840 | .read = tracing_max_lat_read, | |
4841 | .write = tracing_max_lat_write, | |
4842 | .llseek = generic_file_llseek, | |
4843 | }; | |
4844 | ||
4845 | static const struct file_operations set_tracer_fops = { | |
4846 | .open = tracing_open_generic, | |
4847 | .read = tracing_set_trace_read, | |
4848 | .write = tracing_set_trace_write, | |
4849 | .llseek = generic_file_llseek, | |
4850 | }; | |
4851 | ||
4852 | static const struct file_operations tracing_pipe_fops = { | |
4853 | .open = tracing_open_pipe, | |
4854 | .poll = tracing_poll_pipe, | |
4855 | .read = tracing_read_pipe, | |
4856 | .splice_read = tracing_splice_read_pipe, | |
4857 | .release = tracing_release_pipe, | |
4858 | .llseek = no_llseek, | |
4859 | }; | |
4860 | ||
4861 | static const struct file_operations tracing_entries_fops = { | |
4862 | .open = tracing_open_generic_tr, | |
4863 | .read = tracing_entries_read, | |
4864 | .write = tracing_entries_write, | |
4865 | .llseek = generic_file_llseek, | |
4866 | .release = tracing_release_generic_tr, | |
4867 | }; | |
4868 | ||
4869 | static const struct file_operations tracing_total_entries_fops = { | |
4870 | .open = tracing_open_generic_tr, | |
4871 | .read = tracing_total_entries_read, | |
4872 | .llseek = generic_file_llseek, | |
4873 | .release = tracing_release_generic_tr, | |
4874 | }; | |
4875 | ||
4876 | static const struct file_operations tracing_free_buffer_fops = { | |
4877 | .open = tracing_open_generic_tr, | |
4878 | .write = tracing_free_buffer_write, | |
4879 | .release = tracing_free_buffer_release, | |
4880 | }; | |
4881 | ||
4882 | static const struct file_operations tracing_mark_fops = { | |
4883 | .open = tracing_open_generic_tr, | |
4884 | .write = tracing_mark_write, | |
4885 | .llseek = generic_file_llseek, | |
4886 | .release = tracing_release_generic_tr, | |
4887 | }; | |
4888 | ||
4889 | static const struct file_operations trace_clock_fops = { | |
4890 | .open = tracing_clock_open, | |
4891 | .read = seq_read, | |
4892 | .llseek = seq_lseek, | |
4893 | .release = tracing_single_release_tr, | |
4894 | .write = tracing_clock_write, | |
4895 | }; | |
4896 | ||
4897 | #ifdef CONFIG_TRACER_SNAPSHOT | |
4898 | static const struct file_operations snapshot_fops = { | |
4899 | .open = tracing_snapshot_open, | |
4900 | .read = seq_read, | |
4901 | .write = tracing_snapshot_write, | |
4902 | .llseek = tracing_seek, | |
4903 | .release = tracing_snapshot_release, | |
4904 | }; | |
4905 | ||
4906 | static const struct file_operations snapshot_raw_fops = { | |
4907 | .open = snapshot_raw_open, | |
4908 | .read = tracing_buffers_read, | |
4909 | .release = tracing_buffers_release, | |
4910 | .splice_read = tracing_buffers_splice_read, | |
4911 | .llseek = no_llseek, | |
4912 | }; | |
4913 | ||
4914 | #endif /* CONFIG_TRACER_SNAPSHOT */ | |
4915 | ||
4916 | static int tracing_buffers_open(struct inode *inode, struct file *filp) | |
4917 | { | |
4918 | struct trace_array *tr = inode->i_private; | |
4919 | struct ftrace_buffer_info *info; | |
4920 | int ret; | |
4921 | ||
4922 | if (tracing_disabled) | |
4923 | return -ENODEV; | |
4924 | ||
4925 | if (trace_array_get(tr) < 0) | |
4926 | return -ENODEV; | |
4927 | ||
4928 | info = kzalloc(sizeof(*info), GFP_KERNEL); | |
4929 | if (!info) { | |
4930 | trace_array_put(tr); | |
4931 | return -ENOMEM; | |
4932 | } | |
4933 | ||
4934 | mutex_lock(&trace_types_lock); | |
4935 | ||
4936 | info->iter.tr = tr; | |
4937 | info->iter.cpu_file = tracing_get_cpu(inode); | |
4938 | info->iter.trace = tr->current_trace; | |
4939 | info->iter.trace_buffer = &tr->trace_buffer; | |
4940 | info->spare = NULL; | |
4941 | /* Force reading ring buffer for first read */ | |
4942 | info->read = (unsigned int)-1; | |
4943 | ||
4944 | filp->private_data = info; | |
4945 | ||
4946 | mutex_unlock(&trace_types_lock); | |
4947 | ||
4948 | ret = nonseekable_open(inode, filp); | |
4949 | if (ret < 0) | |
4950 | trace_array_put(tr); | |
4951 | ||
4952 | return ret; | |
4953 | } | |
4954 | ||
4955 | static unsigned int | |
4956 | tracing_buffers_poll(struct file *filp, poll_table *poll_table) | |
4957 | { | |
4958 | struct ftrace_buffer_info *info = filp->private_data; | |
4959 | struct trace_iterator *iter = &info->iter; | |
4960 | ||
4961 | return trace_poll(iter, filp, poll_table); | |
4962 | } | |
4963 | ||
4964 | static ssize_t | |
4965 | tracing_buffers_read(struct file *filp, char __user *ubuf, | |
4966 | size_t count, loff_t *ppos) | |
4967 | { | |
4968 | struct ftrace_buffer_info *info = filp->private_data; | |
4969 | struct trace_iterator *iter = &info->iter; | |
4970 | ssize_t ret; | |
4971 | ssize_t size; | |
4972 | ||
4973 | if (!count) | |
4974 | return 0; | |
4975 | ||
4976 | mutex_lock(&trace_types_lock); | |
4977 | ||
4978 | #ifdef CONFIG_TRACER_MAX_TRACE | |
4979 | if (iter->snapshot && iter->tr->current_trace->use_max_tr) { | |
4980 | size = -EBUSY; | |
4981 | goto out_unlock; | |
4982 | } | |
4983 | #endif | |
4984 | ||
4985 | if (!info->spare) | |
4986 | info->spare = ring_buffer_alloc_read_page(iter->trace_buffer->buffer, | |
4987 | iter->cpu_file); | |
4988 | size = -ENOMEM; | |
4989 | if (!info->spare) | |
4990 | goto out_unlock; | |
4991 | ||
4992 | /* Do we have previous read data to read? */ | |
4993 | if (info->read < PAGE_SIZE) | |
4994 | goto read; | |
4995 | ||
4996 | again: | |
4997 | trace_access_lock(iter->cpu_file); | |
4998 | ret = ring_buffer_read_page(iter->trace_buffer->buffer, | |
4999 | &info->spare, | |
5000 | count, | |
5001 | iter->cpu_file, 0); | |
5002 | trace_access_unlock(iter->cpu_file); | |
5003 | ||
5004 | if (ret < 0) { | |
5005 | if (trace_empty(iter)) { | |
5006 | if ((filp->f_flags & O_NONBLOCK)) { | |
5007 | size = -EAGAIN; | |
5008 | goto out_unlock; | |
5009 | } | |
5010 | mutex_unlock(&trace_types_lock); | |
5011 | iter->trace->wait_pipe(iter); | |
5012 | mutex_lock(&trace_types_lock); | |
5013 | if (signal_pending(current)) { | |
5014 | size = -EINTR; | |
5015 | goto out_unlock; | |
5016 | } | |
5017 | goto again; | |
5018 | } | |
5019 | size = 0; | |
5020 | goto out_unlock; | |
5021 | } | |
5022 | ||
5023 | info->read = 0; | |
5024 | read: | |
5025 | size = PAGE_SIZE - info->read; | |
5026 | if (size > count) | |
5027 | size = count; | |
5028 | ||
5029 | ret = copy_to_user(ubuf, info->spare + info->read, size); | |
5030 | if (ret == size) { | |
5031 | size = -EFAULT; | |
5032 | goto out_unlock; | |
5033 | } | |
5034 | size -= ret; | |
5035 | ||
5036 | *ppos += size; | |
5037 | info->read += size; | |
5038 | ||
5039 | out_unlock: | |
5040 | mutex_unlock(&trace_types_lock); | |
5041 | ||
5042 | return size; | |
5043 | } | |
5044 | ||
5045 | static int tracing_buffers_release(struct inode *inode, struct file *file) | |
5046 | { | |
5047 | struct ftrace_buffer_info *info = file->private_data; | |
5048 | struct trace_iterator *iter = &info->iter; | |
5049 | ||
5050 | mutex_lock(&trace_types_lock); | |
5051 | ||
5052 | __trace_array_put(iter->tr); | |
5053 | ||
5054 | if (info->spare) | |
5055 | ring_buffer_free_read_page(iter->trace_buffer->buffer, info->spare); | |
5056 | kfree(info); | |
5057 | ||
5058 | mutex_unlock(&trace_types_lock); | |
5059 | ||
5060 | return 0; | |
5061 | } | |
5062 | ||
5063 | struct buffer_ref { | |
5064 | struct ring_buffer *buffer; | |
5065 | void *page; | |
5066 | int ref; | |
5067 | }; | |
5068 | ||
5069 | static void buffer_pipe_buf_release(struct pipe_inode_info *pipe, | |
5070 | struct pipe_buffer *buf) | |
5071 | { | |
5072 | struct buffer_ref *ref = (struct buffer_ref *)buf->private; | |
5073 | ||
5074 | if (--ref->ref) | |
5075 | return; | |
5076 | ||
5077 | ring_buffer_free_read_page(ref->buffer, ref->page); | |
5078 | kfree(ref); | |
5079 | buf->private = 0; | |
5080 | } | |
5081 | ||
5082 | static void buffer_pipe_buf_get(struct pipe_inode_info *pipe, | |
5083 | struct pipe_buffer *buf) | |
5084 | { | |
5085 | struct buffer_ref *ref = (struct buffer_ref *)buf->private; | |
5086 | ||
5087 | ref->ref++; | |
5088 | } | |
5089 | ||
5090 | /* Pipe buffer operations for a buffer. */ | |
5091 | static const struct pipe_buf_operations buffer_pipe_buf_ops = { | |
5092 | .can_merge = 0, | |
5093 | .map = generic_pipe_buf_map, | |
5094 | .unmap = generic_pipe_buf_unmap, | |
5095 | .confirm = generic_pipe_buf_confirm, | |
5096 | .release = buffer_pipe_buf_release, | |
5097 | .steal = generic_pipe_buf_steal, | |
5098 | .get = buffer_pipe_buf_get, | |
5099 | }; | |
5100 | ||
5101 | /* | |
5102 | * Callback from splice_to_pipe(), if we need to release some pages | |
5103 | * at the end of the spd in case we error'ed out in filling the pipe. | |
5104 | */ | |
5105 | static void buffer_spd_release(struct splice_pipe_desc *spd, unsigned int i) | |
5106 | { | |
5107 | struct buffer_ref *ref = | |
5108 | (struct buffer_ref *)spd->partial[i].private; | |
5109 | ||
5110 | if (--ref->ref) | |
5111 | return; | |
5112 | ||
5113 | ring_buffer_free_read_page(ref->buffer, ref->page); | |
5114 | kfree(ref); | |
5115 | spd->partial[i].private = 0; | |
5116 | } | |
5117 | ||
5118 | static ssize_t | |
5119 | tracing_buffers_splice_read(struct file *file, loff_t *ppos, | |
5120 | struct pipe_inode_info *pipe, size_t len, | |
5121 | unsigned int flags) | |
5122 | { | |
5123 | struct ftrace_buffer_info *info = file->private_data; | |
5124 | struct trace_iterator *iter = &info->iter; | |
5125 | struct partial_page partial_def[PIPE_DEF_BUFFERS]; | |
5126 | struct page *pages_def[PIPE_DEF_BUFFERS]; | |
5127 | struct splice_pipe_desc spd = { | |
5128 | .pages = pages_def, | |
5129 | .partial = partial_def, | |
5130 | .nr_pages_max = PIPE_DEF_BUFFERS, | |
5131 | .flags = flags, | |
5132 | .ops = &buffer_pipe_buf_ops, | |
5133 | .spd_release = buffer_spd_release, | |
5134 | }; | |
5135 | struct buffer_ref *ref; | |
5136 | int entries, size, i; | |
5137 | ssize_t ret; | |
5138 | ||
5139 | mutex_lock(&trace_types_lock); | |
5140 | ||
5141 | #ifdef CONFIG_TRACER_MAX_TRACE | |
5142 | if (iter->snapshot && iter->tr->current_trace->use_max_tr) { | |
5143 | ret = -EBUSY; | |
5144 | goto out; | |
5145 | } | |
5146 | #endif | |
5147 | ||
5148 | if (splice_grow_spd(pipe, &spd)) { | |
5149 | ret = -ENOMEM; | |
5150 | goto out; | |
5151 | } | |
5152 | ||
5153 | if (*ppos & (PAGE_SIZE - 1)) { | |
5154 | ret = -EINVAL; | |
5155 | goto out; | |
5156 | } | |
5157 | ||
5158 | if (len & (PAGE_SIZE - 1)) { | |
5159 | if (len < PAGE_SIZE) { | |
5160 | ret = -EINVAL; | |
5161 | goto out; | |
5162 | } | |
5163 | len &= PAGE_MASK; | |
5164 | } | |
5165 | ||
5166 | again: | |
5167 | trace_access_lock(iter->cpu_file); | |
5168 | entries = ring_buffer_entries_cpu(iter->trace_buffer->buffer, iter->cpu_file); | |
5169 | ||
5170 | for (i = 0; i < pipe->buffers && len && entries; i++, len -= PAGE_SIZE) { | |
5171 | struct page *page; | |
5172 | int r; | |
5173 | ||
5174 | ref = kzalloc(sizeof(*ref), GFP_KERNEL); | |
5175 | if (!ref) | |
5176 | break; | |
5177 | ||
5178 | ref->ref = 1; | |
5179 | ref->buffer = iter->trace_buffer->buffer; | |
5180 | ref->page = ring_buffer_alloc_read_page(ref->buffer, iter->cpu_file); | |
5181 | if (!ref->page) { | |
5182 | kfree(ref); | |
5183 | break; | |
5184 | } | |
5185 | ||
5186 | r = ring_buffer_read_page(ref->buffer, &ref->page, | |
5187 | len, iter->cpu_file, 1); | |
5188 | if (r < 0) { | |
5189 | ring_buffer_free_read_page(ref->buffer, ref->page); | |
5190 | kfree(ref); | |
5191 | break; | |
5192 | } | |
5193 | ||
5194 | /* | |
5195 | * zero out any left over data, this is going to | |
5196 | * user land. | |
5197 | */ | |
5198 | size = ring_buffer_page_len(ref->page); | |
5199 | if (size < PAGE_SIZE) | |
5200 | memset(ref->page + size, 0, PAGE_SIZE - size); | |
5201 | ||
5202 | page = virt_to_page(ref->page); | |
5203 | ||
5204 | spd.pages[i] = page; | |
5205 | spd.partial[i].len = PAGE_SIZE; | |
5206 | spd.partial[i].offset = 0; | |
5207 | spd.partial[i].private = (unsigned long)ref; | |
5208 | spd.nr_pages++; | |
5209 | *ppos += PAGE_SIZE; | |
5210 | ||
5211 | entries = ring_buffer_entries_cpu(iter->trace_buffer->buffer, iter->cpu_file); | |
5212 | } | |
5213 | ||
5214 | trace_access_unlock(iter->cpu_file); | |
5215 | spd.nr_pages = i; | |
5216 | ||
5217 | /* did we read anything? */ | |
5218 | if (!spd.nr_pages) { | |
5219 | if ((file->f_flags & O_NONBLOCK) || (flags & SPLICE_F_NONBLOCK)) { | |
5220 | ret = -EAGAIN; | |
5221 | goto out; | |
5222 | } | |
5223 | mutex_unlock(&trace_types_lock); | |
5224 | iter->trace->wait_pipe(iter); | |
5225 | mutex_lock(&trace_types_lock); | |
5226 | if (signal_pending(current)) { | |
5227 | ret = -EINTR; | |
5228 | goto out; | |
5229 | } | |
5230 | goto again; | |
5231 | } | |
5232 | ||
5233 | ret = splice_to_pipe(pipe, &spd); | |
5234 | splice_shrink_spd(&spd); | |
5235 | out: | |
5236 | mutex_unlock(&trace_types_lock); | |
5237 | ||
5238 | return ret; | |
5239 | } | |
5240 | ||
5241 | static const struct file_operations tracing_buffers_fops = { | |
5242 | .open = tracing_buffers_open, | |
5243 | .read = tracing_buffers_read, | |
5244 | .poll = tracing_buffers_poll, | |
5245 | .release = tracing_buffers_release, | |
5246 | .splice_read = tracing_buffers_splice_read, | |
5247 | .llseek = no_llseek, | |
5248 | }; | |
5249 | ||
5250 | static ssize_t | |
5251 | tracing_stats_read(struct file *filp, char __user *ubuf, | |
5252 | size_t count, loff_t *ppos) | |
5253 | { | |
5254 | struct inode *inode = file_inode(filp); | |
5255 | struct trace_array *tr = inode->i_private; | |
5256 | struct trace_buffer *trace_buf = &tr->trace_buffer; | |
5257 | int cpu = tracing_get_cpu(inode); | |
5258 | struct trace_seq *s; | |
5259 | unsigned long cnt; | |
5260 | unsigned long long t; | |
5261 | unsigned long usec_rem; | |
5262 | ||
5263 | s = kmalloc(sizeof(*s), GFP_KERNEL); | |
5264 | if (!s) | |
5265 | return -ENOMEM; | |
5266 | ||
5267 | trace_seq_init(s); | |
5268 | ||
5269 | cnt = ring_buffer_entries_cpu(trace_buf->buffer, cpu); | |
5270 | trace_seq_printf(s, "entries: %ld\n", cnt); | |
5271 | ||
5272 | cnt = ring_buffer_overrun_cpu(trace_buf->buffer, cpu); | |
5273 | trace_seq_printf(s, "overrun: %ld\n", cnt); | |
5274 | ||
5275 | cnt = ring_buffer_commit_overrun_cpu(trace_buf->buffer, cpu); | |
5276 | trace_seq_printf(s, "commit overrun: %ld\n", cnt); | |
5277 | ||
5278 | cnt = ring_buffer_bytes_cpu(trace_buf->buffer, cpu); | |
5279 | trace_seq_printf(s, "bytes: %ld\n", cnt); | |
5280 | ||
5281 | if (trace_clocks[tr->clock_id].in_ns) { | |
5282 | /* local or global for trace_clock */ | |
5283 | t = ns2usecs(ring_buffer_oldest_event_ts(trace_buf->buffer, cpu)); | |
5284 | usec_rem = do_div(t, USEC_PER_SEC); | |
5285 | trace_seq_printf(s, "oldest event ts: %5llu.%06lu\n", | |
5286 | t, usec_rem); | |
5287 | ||
5288 | t = ns2usecs(ring_buffer_time_stamp(trace_buf->buffer, cpu)); | |
5289 | usec_rem = do_div(t, USEC_PER_SEC); | |
5290 | trace_seq_printf(s, "now ts: %5llu.%06lu\n", t, usec_rem); | |
5291 | } else { | |
5292 | /* counter or tsc mode for trace_clock */ | |
5293 | trace_seq_printf(s, "oldest event ts: %llu\n", | |
5294 | ring_buffer_oldest_event_ts(trace_buf->buffer, cpu)); | |
5295 | ||
5296 | trace_seq_printf(s, "now ts: %llu\n", | |
5297 | ring_buffer_time_stamp(trace_buf->buffer, cpu)); | |
5298 | } | |
5299 | ||
5300 | cnt = ring_buffer_dropped_events_cpu(trace_buf->buffer, cpu); | |
5301 | trace_seq_printf(s, "dropped events: %ld\n", cnt); | |
5302 | ||
5303 | cnt = ring_buffer_read_events_cpu(trace_buf->buffer, cpu); | |
5304 | trace_seq_printf(s, "read events: %ld\n", cnt); | |
5305 | ||
5306 | count = simple_read_from_buffer(ubuf, count, ppos, s->buffer, s->len); | |
5307 | ||
5308 | kfree(s); | |
5309 | ||
5310 | return count; | |
5311 | } | |
5312 | ||
5313 | static const struct file_operations tracing_stats_fops = { | |
5314 | .open = tracing_open_generic_tr, | |
5315 | .read = tracing_stats_read, | |
5316 | .llseek = generic_file_llseek, | |
5317 | .release = tracing_release_generic_tr, | |
5318 | }; | |
5319 | ||
5320 | #ifdef CONFIG_DYNAMIC_FTRACE | |
5321 | ||
5322 | int __weak ftrace_arch_read_dyn_info(char *buf, int size) | |
5323 | { | |
5324 | return 0; | |
5325 | } | |
5326 | ||
5327 | static ssize_t | |
5328 | tracing_read_dyn_info(struct file *filp, char __user *ubuf, | |
5329 | size_t cnt, loff_t *ppos) | |
5330 | { | |
5331 | static char ftrace_dyn_info_buffer[1024]; | |
5332 | static DEFINE_MUTEX(dyn_info_mutex); | |
5333 | unsigned long *p = filp->private_data; | |
5334 | char *buf = ftrace_dyn_info_buffer; | |
5335 | int size = ARRAY_SIZE(ftrace_dyn_info_buffer); | |
5336 | int r; | |
5337 | ||
5338 | mutex_lock(&dyn_info_mutex); | |
5339 | r = sprintf(buf, "%ld ", *p); | |
5340 | ||
5341 | r += ftrace_arch_read_dyn_info(buf+r, (size-1)-r); | |
5342 | buf[r++] = '\n'; | |
5343 | ||
5344 | r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
5345 | ||
5346 | mutex_unlock(&dyn_info_mutex); | |
5347 | ||
5348 | return r; | |
5349 | } | |
5350 | ||
5351 | static const struct file_operations tracing_dyn_info_fops = { | |
5352 | .open = tracing_open_generic, | |
5353 | .read = tracing_read_dyn_info, | |
5354 | .llseek = generic_file_llseek, | |
5355 | }; | |
5356 | #endif /* CONFIG_DYNAMIC_FTRACE */ | |
5357 | ||
5358 | #if defined(CONFIG_TRACER_SNAPSHOT) && defined(CONFIG_DYNAMIC_FTRACE) | |
5359 | static void | |
5360 | ftrace_snapshot(unsigned long ip, unsigned long parent_ip, void **data) | |
5361 | { | |
5362 | tracing_snapshot(); | |
5363 | } | |
5364 | ||
5365 | static void | |
5366 | ftrace_count_snapshot(unsigned long ip, unsigned long parent_ip, void **data) | |
5367 | { | |
5368 | unsigned long *count = (long *)data; | |
5369 | ||
5370 | if (!*count) | |
5371 | return; | |
5372 | ||
5373 | if (*count != -1) | |
5374 | (*count)--; | |
5375 | ||
5376 | tracing_snapshot(); | |
5377 | } | |
5378 | ||
5379 | static int | |
5380 | ftrace_snapshot_print(struct seq_file *m, unsigned long ip, | |
5381 | struct ftrace_probe_ops *ops, void *data) | |
5382 | { | |
5383 | long count = (long)data; | |
5384 | ||
5385 | seq_printf(m, "%ps:", (void *)ip); | |
5386 | ||
5387 | seq_printf(m, "snapshot"); | |
5388 | ||
5389 | if (count == -1) | |
5390 | seq_printf(m, ":unlimited\n"); | |
5391 | else | |
5392 | seq_printf(m, ":count=%ld\n", count); | |
5393 | ||
5394 | return 0; | |
5395 | } | |
5396 | ||
5397 | static struct ftrace_probe_ops snapshot_probe_ops = { | |
5398 | .func = ftrace_snapshot, | |
5399 | .print = ftrace_snapshot_print, | |
5400 | }; | |
5401 | ||
5402 | static struct ftrace_probe_ops snapshot_count_probe_ops = { | |
5403 | .func = ftrace_count_snapshot, | |
5404 | .print = ftrace_snapshot_print, | |
5405 | }; | |
5406 | ||
5407 | static int | |
5408 | ftrace_trace_snapshot_callback(struct ftrace_hash *hash, | |
5409 | char *glob, char *cmd, char *param, int enable) | |
5410 | { | |
5411 | struct ftrace_probe_ops *ops; | |
5412 | void *count = (void *)-1; | |
5413 | char *number; | |
5414 | int ret; | |
5415 | ||
5416 | /* hash funcs only work with set_ftrace_filter */ | |
5417 | if (!enable) | |
5418 | return -EINVAL; | |
5419 | ||
5420 | ops = param ? &snapshot_count_probe_ops : &snapshot_probe_ops; | |
5421 | ||
5422 | if (glob[0] == '!') { | |
5423 | unregister_ftrace_function_probe_func(glob+1, ops); | |
5424 | return 0; | |
5425 | } | |
5426 | ||
5427 | if (!param) | |
5428 | goto out_reg; | |
5429 | ||
5430 | number = strsep(¶m, ":"); | |
5431 | ||
5432 | if (!strlen(number)) | |
5433 | goto out_reg; | |
5434 | ||
5435 | /* | |
5436 | * We use the callback data field (which is a pointer) | |
5437 | * as our counter. | |
5438 | */ | |
5439 | ret = kstrtoul(number, 0, (unsigned long *)&count); | |
5440 | if (ret) | |
5441 | return ret; | |
5442 | ||
5443 | out_reg: | |
5444 | ret = register_ftrace_function_probe(glob, ops, count); | |
5445 | ||
5446 | if (ret >= 0) | |
5447 | alloc_snapshot(&global_trace); | |
5448 | ||
5449 | return ret < 0 ? ret : 0; | |
5450 | } | |
5451 | ||
5452 | static struct ftrace_func_command ftrace_snapshot_cmd = { | |
5453 | .name = "snapshot", | |
5454 | .func = ftrace_trace_snapshot_callback, | |
5455 | }; | |
5456 | ||
5457 | static int register_snapshot_cmd(void) | |
5458 | { | |
5459 | return register_ftrace_command(&ftrace_snapshot_cmd); | |
5460 | } | |
5461 | #else | |
5462 | static inline int register_snapshot_cmd(void) { return 0; } | |
5463 | #endif /* defined(CONFIG_TRACER_SNAPSHOT) && defined(CONFIG_DYNAMIC_FTRACE) */ | |
5464 | ||
5465 | struct dentry *tracing_init_dentry_tr(struct trace_array *tr) | |
5466 | { | |
5467 | if (tr->dir) | |
5468 | return tr->dir; | |
5469 | ||
5470 | if (!debugfs_initialized()) | |
5471 | return NULL; | |
5472 | ||
5473 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL) | |
5474 | tr->dir = debugfs_create_dir("tracing", NULL); | |
5475 | ||
5476 | if (!tr->dir) | |
5477 | pr_warn_once("Could not create debugfs directory 'tracing'\n"); | |
5478 | ||
5479 | return tr->dir; | |
5480 | } | |
5481 | ||
5482 | struct dentry *tracing_init_dentry(void) | |
5483 | { | |
5484 | return tracing_init_dentry_tr(&global_trace); | |
5485 | } | |
5486 | ||
5487 | static struct dentry *tracing_dentry_percpu(struct trace_array *tr, int cpu) | |
5488 | { | |
5489 | struct dentry *d_tracer; | |
5490 | ||
5491 | if (tr->percpu_dir) | |
5492 | return tr->percpu_dir; | |
5493 | ||
5494 | d_tracer = tracing_init_dentry_tr(tr); | |
5495 | if (!d_tracer) | |
5496 | return NULL; | |
5497 | ||
5498 | tr->percpu_dir = debugfs_create_dir("per_cpu", d_tracer); | |
5499 | ||
5500 | WARN_ONCE(!tr->percpu_dir, | |
5501 | "Could not create debugfs directory 'per_cpu/%d'\n", cpu); | |
5502 | ||
5503 | return tr->percpu_dir; | |
5504 | } | |
5505 | ||
5506 | static struct dentry * | |
5507 | trace_create_cpu_file(const char *name, umode_t mode, struct dentry *parent, | |
5508 | void *data, long cpu, const struct file_operations *fops) | |
5509 | { | |
5510 | struct dentry *ret = trace_create_file(name, mode, parent, data, fops); | |
5511 | ||
5512 | if (ret) /* See tracing_get_cpu() */ | |
5513 | ret->d_inode->i_cdev = (void *)(cpu + 1); | |
5514 | return ret; | |
5515 | } | |
5516 | ||
5517 | static void | |
5518 | tracing_init_debugfs_percpu(struct trace_array *tr, long cpu) | |
5519 | { | |
5520 | struct dentry *d_percpu = tracing_dentry_percpu(tr, cpu); | |
5521 | struct dentry *d_cpu; | |
5522 | char cpu_dir[30]; /* 30 characters should be more than enough */ | |
5523 | ||
5524 | if (!d_percpu) | |
5525 | return; | |
5526 | ||
5527 | snprintf(cpu_dir, 30, "cpu%ld", cpu); | |
5528 | d_cpu = debugfs_create_dir(cpu_dir, d_percpu); | |
5529 | if (!d_cpu) { | |
5530 | pr_warning("Could not create debugfs '%s' entry\n", cpu_dir); | |
5531 | return; | |
5532 | } | |
5533 | ||
5534 | /* per cpu trace_pipe */ | |
5535 | trace_create_cpu_file("trace_pipe", 0444, d_cpu, | |
5536 | tr, cpu, &tracing_pipe_fops); | |
5537 | ||
5538 | /* per cpu trace */ | |
5539 | trace_create_cpu_file("trace", 0644, d_cpu, | |
5540 | tr, cpu, &tracing_fops); | |
5541 | ||
5542 | trace_create_cpu_file("trace_pipe_raw", 0444, d_cpu, | |
5543 | tr, cpu, &tracing_buffers_fops); | |
5544 | ||
5545 | trace_create_cpu_file("stats", 0444, d_cpu, | |
5546 | tr, cpu, &tracing_stats_fops); | |
5547 | ||
5548 | trace_create_cpu_file("buffer_size_kb", 0444, d_cpu, | |
5549 | tr, cpu, &tracing_entries_fops); | |
5550 | ||
5551 | #ifdef CONFIG_TRACER_SNAPSHOT | |
5552 | trace_create_cpu_file("snapshot", 0644, d_cpu, | |
5553 | tr, cpu, &snapshot_fops); | |
5554 | ||
5555 | trace_create_cpu_file("snapshot_raw", 0444, d_cpu, | |
5556 | tr, cpu, &snapshot_raw_fops); | |
5557 | #endif | |
5558 | } | |
5559 | ||
5560 | #ifdef CONFIG_FTRACE_SELFTEST | |
5561 | /* Let selftest have access to static functions in this file */ | |
5562 | #include "trace_selftest.c" | |
5563 | #endif | |
5564 | ||
5565 | struct trace_option_dentry { | |
5566 | struct tracer_opt *opt; | |
5567 | struct tracer_flags *flags; | |
5568 | struct trace_array *tr; | |
5569 | struct dentry *entry; | |
5570 | }; | |
5571 | ||
5572 | static ssize_t | |
5573 | trace_options_read(struct file *filp, char __user *ubuf, size_t cnt, | |
5574 | loff_t *ppos) | |
5575 | { | |
5576 | struct trace_option_dentry *topt = filp->private_data; | |
5577 | char *buf; | |
5578 | ||
5579 | if (topt->flags->val & topt->opt->bit) | |
5580 | buf = "1\n"; | |
5581 | else | |
5582 | buf = "0\n"; | |
5583 | ||
5584 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); | |
5585 | } | |
5586 | ||
5587 | static ssize_t | |
5588 | trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt, | |
5589 | loff_t *ppos) | |
5590 | { | |
5591 | struct trace_option_dentry *topt = filp->private_data; | |
5592 | unsigned long val; | |
5593 | int ret; | |
5594 | ||
5595 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); | |
5596 | if (ret) | |
5597 | return ret; | |
5598 | ||
5599 | if (val != 0 && val != 1) | |
5600 | return -EINVAL; | |
5601 | ||
5602 | if (!!(topt->flags->val & topt->opt->bit) != val) { | |
5603 | mutex_lock(&trace_types_lock); | |
5604 | ret = __set_tracer_option(topt->tr->current_trace, topt->flags, | |
5605 | topt->opt, !val); | |
5606 | mutex_unlock(&trace_types_lock); | |
5607 | if (ret) | |
5608 | return ret; | |
5609 | } | |
5610 | ||
5611 | *ppos += cnt; | |
5612 | ||
5613 | return cnt; | |
5614 | } | |
5615 | ||
5616 | ||
5617 | static const struct file_operations trace_options_fops = { | |
5618 | .open = tracing_open_generic, | |
5619 | .read = trace_options_read, | |
5620 | .write = trace_options_write, | |
5621 | .llseek = generic_file_llseek, | |
5622 | }; | |
5623 | ||
5624 | static ssize_t | |
5625 | trace_options_core_read(struct file *filp, char __user *ubuf, size_t cnt, | |
5626 | loff_t *ppos) | |
5627 | { | |
5628 | long index = (long)filp->private_data; | |
5629 | char *buf; | |
5630 | ||
5631 | if (trace_flags & (1 << index)) | |
5632 | buf = "1\n"; | |
5633 | else | |
5634 | buf = "0\n"; | |
5635 | ||
5636 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); | |
5637 | } | |
5638 | ||
5639 | static ssize_t | |
5640 | trace_options_core_write(struct file *filp, const char __user *ubuf, size_t cnt, | |
5641 | loff_t *ppos) | |
5642 | { | |
5643 | struct trace_array *tr = &global_trace; | |
5644 | long index = (long)filp->private_data; | |
5645 | unsigned long val; | |
5646 | int ret; | |
5647 | ||
5648 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); | |
5649 | if (ret) | |
5650 | return ret; | |
5651 | ||
5652 | if (val != 0 && val != 1) | |
5653 | return -EINVAL; | |
5654 | ||
5655 | mutex_lock(&trace_types_lock); | |
5656 | ret = set_tracer_flag(tr, 1 << index, val); | |
5657 | mutex_unlock(&trace_types_lock); | |
5658 | ||
5659 | if (ret < 0) | |
5660 | return ret; | |
5661 | ||
5662 | *ppos += cnt; | |
5663 | ||
5664 | return cnt; | |
5665 | } | |
5666 | ||
5667 | static const struct file_operations trace_options_core_fops = { | |
5668 | .open = tracing_open_generic, | |
5669 | .read = trace_options_core_read, | |
5670 | .write = trace_options_core_write, | |
5671 | .llseek = generic_file_llseek, | |
5672 | }; | |
5673 | ||
5674 | struct dentry *trace_create_file(const char *name, | |
5675 | umode_t mode, | |
5676 | struct dentry *parent, | |
5677 | void *data, | |
5678 | const struct file_operations *fops) | |
5679 | { | |
5680 | struct dentry *ret; | |
5681 | ||
5682 | ret = debugfs_create_file(name, mode, parent, data, fops); | |
5683 | if (!ret) | |
5684 | pr_warning("Could not create debugfs '%s' entry\n", name); | |
5685 | ||
5686 | return ret; | |
5687 | } | |
5688 | ||
5689 | ||
5690 | static struct dentry *trace_options_init_dentry(struct trace_array *tr) | |
5691 | { | |
5692 | struct dentry *d_tracer; | |
5693 | ||
5694 | if (tr->options) | |
5695 | return tr->options; | |
5696 | ||
5697 | d_tracer = tracing_init_dentry_tr(tr); | |
5698 | if (!d_tracer) | |
5699 | return NULL; | |
5700 | ||
5701 | tr->options = debugfs_create_dir("options", d_tracer); | |
5702 | if (!tr->options) { | |
5703 | pr_warning("Could not create debugfs directory 'options'\n"); | |
5704 | return NULL; | |
5705 | } | |
5706 | ||
5707 | return tr->options; | |
5708 | } | |
5709 | ||
5710 | static void | |
5711 | create_trace_option_file(struct trace_array *tr, | |
5712 | struct trace_option_dentry *topt, | |
5713 | struct tracer_flags *flags, | |
5714 | struct tracer_opt *opt) | |
5715 | { | |
5716 | struct dentry *t_options; | |
5717 | ||
5718 | t_options = trace_options_init_dentry(tr); | |
5719 | if (!t_options) | |
5720 | return; | |
5721 | ||
5722 | topt->flags = flags; | |
5723 | topt->opt = opt; | |
5724 | topt->tr = tr; | |
5725 | ||
5726 | topt->entry = trace_create_file(opt->name, 0644, t_options, topt, | |
5727 | &trace_options_fops); | |
5728 | ||
5729 | } | |
5730 | ||
5731 | static struct trace_option_dentry * | |
5732 | create_trace_option_files(struct trace_array *tr, struct tracer *tracer) | |
5733 | { | |
5734 | struct trace_option_dentry *topts; | |
5735 | struct tracer_flags *flags; | |
5736 | struct tracer_opt *opts; | |
5737 | int cnt; | |
5738 | ||
5739 | if (!tracer) | |
5740 | return NULL; | |
5741 | ||
5742 | flags = tracer->flags; | |
5743 | ||
5744 | if (!flags || !flags->opts) | |
5745 | return NULL; | |
5746 | ||
5747 | opts = flags->opts; | |
5748 | ||
5749 | for (cnt = 0; opts[cnt].name; cnt++) | |
5750 | ; | |
5751 | ||
5752 | topts = kcalloc(cnt + 1, sizeof(*topts), GFP_KERNEL); | |
5753 | if (!topts) | |
5754 | return NULL; | |
5755 | ||
5756 | for (cnt = 0; opts[cnt].name; cnt++) | |
5757 | create_trace_option_file(tr, &topts[cnt], flags, | |
5758 | &opts[cnt]); | |
5759 | ||
5760 | return topts; | |
5761 | } | |
5762 | ||
5763 | static void | |
5764 | destroy_trace_option_files(struct trace_option_dentry *topts) | |
5765 | { | |
5766 | int cnt; | |
5767 | ||
5768 | if (!topts) | |
5769 | return; | |
5770 | ||
5771 | for (cnt = 0; topts[cnt].opt; cnt++) { | |
5772 | if (topts[cnt].entry) | |
5773 | debugfs_remove(topts[cnt].entry); | |
5774 | } | |
5775 | ||
5776 | kfree(topts); | |
5777 | } | |
5778 | ||
5779 | static struct dentry * | |
5780 | create_trace_option_core_file(struct trace_array *tr, | |
5781 | const char *option, long index) | |
5782 | { | |
5783 | struct dentry *t_options; | |
5784 | ||
5785 | t_options = trace_options_init_dentry(tr); | |
5786 | if (!t_options) | |
5787 | return NULL; | |
5788 | ||
5789 | return trace_create_file(option, 0644, t_options, (void *)index, | |
5790 | &trace_options_core_fops); | |
5791 | } | |
5792 | ||
5793 | static __init void create_trace_options_dir(struct trace_array *tr) | |
5794 | { | |
5795 | struct dentry *t_options; | |
5796 | int i; | |
5797 | ||
5798 | t_options = trace_options_init_dentry(tr); | |
5799 | if (!t_options) | |
5800 | return; | |
5801 | ||
5802 | for (i = 0; trace_options[i]; i++) | |
5803 | create_trace_option_core_file(tr, trace_options[i], i); | |
5804 | } | |
5805 | ||
5806 | static ssize_t | |
5807 | rb_simple_read(struct file *filp, char __user *ubuf, | |
5808 | size_t cnt, loff_t *ppos) | |
5809 | { | |
5810 | struct trace_array *tr = filp->private_data; | |
5811 | char buf[64]; | |
5812 | int r; | |
5813 | ||
5814 | r = tracer_tracing_is_on(tr); | |
5815 | r = sprintf(buf, "%d\n", r); | |
5816 | ||
5817 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
5818 | } | |
5819 | ||
5820 | static ssize_t | |
5821 | rb_simple_write(struct file *filp, const char __user *ubuf, | |
5822 | size_t cnt, loff_t *ppos) | |
5823 | { | |
5824 | struct trace_array *tr = filp->private_data; | |
5825 | struct ring_buffer *buffer = tr->trace_buffer.buffer; | |
5826 | unsigned long val; | |
5827 | int ret; | |
5828 | ||
5829 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); | |
5830 | if (ret) | |
5831 | return ret; | |
5832 | ||
5833 | if (buffer) { | |
5834 | mutex_lock(&trace_types_lock); | |
5835 | if (val) { | |
5836 | tracer_tracing_on(tr); | |
5837 | if (tr->current_trace->start) | |
5838 | tr->current_trace->start(tr); | |
5839 | } else { | |
5840 | tracer_tracing_off(tr); | |
5841 | if (tr->current_trace->stop) | |
5842 | tr->current_trace->stop(tr); | |
5843 | } | |
5844 | mutex_unlock(&trace_types_lock); | |
5845 | } | |
5846 | ||
5847 | (*ppos)++; | |
5848 | ||
5849 | return cnt; | |
5850 | } | |
5851 | ||
5852 | static const struct file_operations rb_simple_fops = { | |
5853 | .open = tracing_open_generic_tr, | |
5854 | .read = rb_simple_read, | |
5855 | .write = rb_simple_write, | |
5856 | .release = tracing_release_generic_tr, | |
5857 | .llseek = default_llseek, | |
5858 | }; | |
5859 | ||
5860 | struct dentry *trace_instance_dir; | |
5861 | ||
5862 | static void | |
5863 | init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer); | |
5864 | ||
5865 | static int | |
5866 | allocate_trace_buffer(struct trace_array *tr, struct trace_buffer *buf, int size) | |
5867 | { | |
5868 | enum ring_buffer_flags rb_flags; | |
5869 | ||
5870 | rb_flags = trace_flags & TRACE_ITER_OVERWRITE ? RB_FL_OVERWRITE : 0; | |
5871 | ||
5872 | buf->buffer = ring_buffer_alloc(size, rb_flags); | |
5873 | if (!buf->buffer) | |
5874 | return -ENOMEM; | |
5875 | ||
5876 | buf->data = alloc_percpu(struct trace_array_cpu); | |
5877 | if (!buf->data) { | |
5878 | ring_buffer_free(buf->buffer); | |
5879 | return -ENOMEM; | |
5880 | } | |
5881 | ||
5882 | /* Allocate the first page for all buffers */ | |
5883 | set_buffer_entries(&tr->trace_buffer, | |
5884 | ring_buffer_size(tr->trace_buffer.buffer, 0)); | |
5885 | ||
5886 | return 0; | |
5887 | } | |
5888 | ||
5889 | static int allocate_trace_buffers(struct trace_array *tr, int size) | |
5890 | { | |
5891 | int ret; | |
5892 | ||
5893 | ret = allocate_trace_buffer(tr, &tr->trace_buffer, size); | |
5894 | if (ret) | |
5895 | return ret; | |
5896 | ||
5897 | #ifdef CONFIG_TRACER_MAX_TRACE | |
5898 | ret = allocate_trace_buffer(tr, &tr->max_buffer, | |
5899 | allocate_snapshot ? size : 1); | |
5900 | if (WARN_ON(ret)) { | |
5901 | ring_buffer_free(tr->trace_buffer.buffer); | |
5902 | free_percpu(tr->trace_buffer.data); | |
5903 | return -ENOMEM; | |
5904 | } | |
5905 | tr->allocated_snapshot = allocate_snapshot; | |
5906 | ||
5907 | /* | |
5908 | * Only the top level trace array gets its snapshot allocated | |
5909 | * from the kernel command line. | |
5910 | */ | |
5911 | allocate_snapshot = false; | |
5912 | #endif | |
5913 | return 0; | |
5914 | } | |
5915 | ||
5916 | static int new_instance_create(const char *name) | |
5917 | { | |
5918 | struct trace_array *tr; | |
5919 | int ret; | |
5920 | ||
5921 | mutex_lock(&trace_types_lock); | |
5922 | ||
5923 | ret = -EEXIST; | |
5924 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
5925 | if (tr->name && strcmp(tr->name, name) == 0) | |
5926 | goto out_unlock; | |
5927 | } | |
5928 | ||
5929 | ret = -ENOMEM; | |
5930 | tr = kzalloc(sizeof(*tr), GFP_KERNEL); | |
5931 | if (!tr) | |
5932 | goto out_unlock; | |
5933 | ||
5934 | tr->name = kstrdup(name, GFP_KERNEL); | |
5935 | if (!tr->name) | |
5936 | goto out_free_tr; | |
5937 | ||
5938 | if (!alloc_cpumask_var(&tr->tracing_cpumask, GFP_KERNEL)) | |
5939 | goto out_free_tr; | |
5940 | ||
5941 | cpumask_copy(tr->tracing_cpumask, cpu_all_mask); | |
5942 | ||
5943 | raw_spin_lock_init(&tr->start_lock); | |
5944 | ||
5945 | tr->current_trace = &nop_trace; | |
5946 | ||
5947 | INIT_LIST_HEAD(&tr->systems); | |
5948 | INIT_LIST_HEAD(&tr->events); | |
5949 | ||
5950 | if (allocate_trace_buffers(tr, trace_buf_size) < 0) | |
5951 | goto out_free_tr; | |
5952 | ||
5953 | tr->dir = debugfs_create_dir(name, trace_instance_dir); | |
5954 | if (!tr->dir) | |
5955 | goto out_free_tr; | |
5956 | ||
5957 | ret = event_trace_add_tracer(tr->dir, tr); | |
5958 | if (ret) { | |
5959 | debugfs_remove_recursive(tr->dir); | |
5960 | goto out_free_tr; | |
5961 | } | |
5962 | ||
5963 | init_tracer_debugfs(tr, tr->dir); | |
5964 | ||
5965 | list_add(&tr->list, &ftrace_trace_arrays); | |
5966 | ||
5967 | mutex_unlock(&trace_types_lock); | |
5968 | ||
5969 | return 0; | |
5970 | ||
5971 | out_free_tr: | |
5972 | if (tr->trace_buffer.buffer) | |
5973 | ring_buffer_free(tr->trace_buffer.buffer); | |
5974 | free_cpumask_var(tr->tracing_cpumask); | |
5975 | kfree(tr->name); | |
5976 | kfree(tr); | |
5977 | ||
5978 | out_unlock: | |
5979 | mutex_unlock(&trace_types_lock); | |
5980 | ||
5981 | return ret; | |
5982 | ||
5983 | } | |
5984 | ||
5985 | static int instance_delete(const char *name) | |
5986 | { | |
5987 | struct trace_array *tr; | |
5988 | int found = 0; | |
5989 | int ret; | |
5990 | ||
5991 | mutex_lock(&trace_types_lock); | |
5992 | ||
5993 | ret = -ENODEV; | |
5994 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
5995 | if (tr->name && strcmp(tr->name, name) == 0) { | |
5996 | found = 1; | |
5997 | break; | |
5998 | } | |
5999 | } | |
6000 | if (!found) | |
6001 | goto out_unlock; | |
6002 | ||
6003 | ret = -EBUSY; | |
6004 | if (tr->ref) | |
6005 | goto out_unlock; | |
6006 | ||
6007 | list_del(&tr->list); | |
6008 | ||
6009 | event_trace_del_tracer(tr); | |
6010 | debugfs_remove_recursive(tr->dir); | |
6011 | free_percpu(tr->trace_buffer.data); | |
6012 | ring_buffer_free(tr->trace_buffer.buffer); | |
6013 | ||
6014 | kfree(tr->name); | |
6015 | kfree(tr); | |
6016 | ||
6017 | ret = 0; | |
6018 | ||
6019 | out_unlock: | |
6020 | mutex_unlock(&trace_types_lock); | |
6021 | ||
6022 | return ret; | |
6023 | } | |
6024 | ||
6025 | static int instance_mkdir (struct inode *inode, struct dentry *dentry, umode_t mode) | |
6026 | { | |
6027 | struct dentry *parent; | |
6028 | int ret; | |
6029 | ||
6030 | /* Paranoid: Make sure the parent is the "instances" directory */ | |
6031 | parent = hlist_entry(inode->i_dentry.first, struct dentry, d_alias); | |
6032 | if (WARN_ON_ONCE(parent != trace_instance_dir)) | |
6033 | return -ENOENT; | |
6034 | ||
6035 | /* | |
6036 | * The inode mutex is locked, but debugfs_create_dir() will also | |
6037 | * take the mutex. As the instances directory can not be destroyed | |
6038 | * or changed in any other way, it is safe to unlock it, and | |
6039 | * let the dentry try. If two users try to make the same dir at | |
6040 | * the same time, then the new_instance_create() will determine the | |
6041 | * winner. | |
6042 | */ | |
6043 | mutex_unlock(&inode->i_mutex); | |
6044 | ||
6045 | ret = new_instance_create(dentry->d_iname); | |
6046 | ||
6047 | mutex_lock(&inode->i_mutex); | |
6048 | ||
6049 | return ret; | |
6050 | } | |
6051 | ||
6052 | static int instance_rmdir(struct inode *inode, struct dentry *dentry) | |
6053 | { | |
6054 | struct dentry *parent; | |
6055 | int ret; | |
6056 | ||
6057 | /* Paranoid: Make sure the parent is the "instances" directory */ | |
6058 | parent = hlist_entry(inode->i_dentry.first, struct dentry, d_alias); | |
6059 | if (WARN_ON_ONCE(parent != trace_instance_dir)) | |
6060 | return -ENOENT; | |
6061 | ||
6062 | /* The caller did a dget() on dentry */ | |
6063 | mutex_unlock(&dentry->d_inode->i_mutex); | |
6064 | ||
6065 | /* | |
6066 | * The inode mutex is locked, but debugfs_create_dir() will also | |
6067 | * take the mutex. As the instances directory can not be destroyed | |
6068 | * or changed in any other way, it is safe to unlock it, and | |
6069 | * let the dentry try. If two users try to make the same dir at | |
6070 | * the same time, then the instance_delete() will determine the | |
6071 | * winner. | |
6072 | */ | |
6073 | mutex_unlock(&inode->i_mutex); | |
6074 | ||
6075 | ret = instance_delete(dentry->d_iname); | |
6076 | ||
6077 | mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT); | |
6078 | mutex_lock(&dentry->d_inode->i_mutex); | |
6079 | ||
6080 | return ret; | |
6081 | } | |
6082 | ||
6083 | static const struct inode_operations instance_dir_inode_operations = { | |
6084 | .lookup = simple_lookup, | |
6085 | .mkdir = instance_mkdir, | |
6086 | .rmdir = instance_rmdir, | |
6087 | }; | |
6088 | ||
6089 | static __init void create_trace_instances(struct dentry *d_tracer) | |
6090 | { | |
6091 | trace_instance_dir = debugfs_create_dir("instances", d_tracer); | |
6092 | if (WARN_ON(!trace_instance_dir)) | |
6093 | return; | |
6094 | ||
6095 | /* Hijack the dir inode operations, to allow mkdir */ | |
6096 | trace_instance_dir->d_inode->i_op = &instance_dir_inode_operations; | |
6097 | } | |
6098 | ||
6099 | static void | |
6100 | init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer) | |
6101 | { | |
6102 | int cpu; | |
6103 | ||
6104 | trace_create_file("tracing_cpumask", 0644, d_tracer, | |
6105 | tr, &tracing_cpumask_fops); | |
6106 | ||
6107 | trace_create_file("trace_options", 0644, d_tracer, | |
6108 | tr, &tracing_iter_fops); | |
6109 | ||
6110 | trace_create_file("trace", 0644, d_tracer, | |
6111 | tr, &tracing_fops); | |
6112 | ||
6113 | trace_create_file("trace_pipe", 0444, d_tracer, | |
6114 | tr, &tracing_pipe_fops); | |
6115 | ||
6116 | trace_create_file("buffer_size_kb", 0644, d_tracer, | |
6117 | tr, &tracing_entries_fops); | |
6118 | ||
6119 | trace_create_file("buffer_total_size_kb", 0444, d_tracer, | |
6120 | tr, &tracing_total_entries_fops); | |
6121 | ||
6122 | trace_create_file("free_buffer", 0200, d_tracer, | |
6123 | tr, &tracing_free_buffer_fops); | |
6124 | ||
6125 | trace_create_file("trace_marker", 0220, d_tracer, | |
6126 | tr, &tracing_mark_fops); | |
6127 | ||
6128 | trace_create_file("trace_clock", 0644, d_tracer, tr, | |
6129 | &trace_clock_fops); | |
6130 | ||
6131 | trace_create_file("tracing_on", 0644, d_tracer, | |
6132 | tr, &rb_simple_fops); | |
6133 | ||
6134 | #ifdef CONFIG_TRACER_SNAPSHOT | |
6135 | trace_create_file("snapshot", 0644, d_tracer, | |
6136 | tr, &snapshot_fops); | |
6137 | #endif | |
6138 | ||
6139 | for_each_tracing_cpu(cpu) | |
6140 | tracing_init_debugfs_percpu(tr, cpu); | |
6141 | ||
6142 | } | |
6143 | ||
6144 | static __init int tracer_init_debugfs(void) | |
6145 | { | |
6146 | struct dentry *d_tracer; | |
6147 | ||
6148 | trace_access_lock_init(); | |
6149 | ||
6150 | d_tracer = tracing_init_dentry(); | |
6151 | if (!d_tracer) | |
6152 | return 0; | |
6153 | ||
6154 | init_tracer_debugfs(&global_trace, d_tracer); | |
6155 | ||
6156 | trace_create_file("available_tracers", 0444, d_tracer, | |
6157 | &global_trace, &show_traces_fops); | |
6158 | ||
6159 | trace_create_file("current_tracer", 0644, d_tracer, | |
6160 | &global_trace, &set_tracer_fops); | |
6161 | ||
6162 | #ifdef CONFIG_TRACER_MAX_TRACE | |
6163 | trace_create_file("tracing_max_latency", 0644, d_tracer, | |
6164 | &tracing_max_latency, &tracing_max_lat_fops); | |
6165 | #endif | |
6166 | ||
6167 | trace_create_file("tracing_thresh", 0644, d_tracer, | |
6168 | &tracing_thresh, &tracing_max_lat_fops); | |
6169 | ||
6170 | trace_create_file("README", 0444, d_tracer, | |
6171 | NULL, &tracing_readme_fops); | |
6172 | ||
6173 | trace_create_file("saved_cmdlines", 0444, d_tracer, | |
6174 | NULL, &tracing_saved_cmdlines_fops); | |
6175 | ||
6176 | #ifdef CONFIG_DYNAMIC_FTRACE | |
6177 | trace_create_file("dyn_ftrace_total_info", 0444, d_tracer, | |
6178 | &ftrace_update_tot_cnt, &tracing_dyn_info_fops); | |
6179 | #endif | |
6180 | ||
6181 | create_trace_instances(d_tracer); | |
6182 | ||
6183 | create_trace_options_dir(&global_trace); | |
6184 | ||
6185 | return 0; | |
6186 | } | |
6187 | ||
6188 | static int trace_panic_handler(struct notifier_block *this, | |
6189 | unsigned long event, void *unused) | |
6190 | { | |
6191 | if (ftrace_dump_on_oops) | |
6192 | ftrace_dump(ftrace_dump_on_oops); | |
6193 | return NOTIFY_OK; | |
6194 | } | |
6195 | ||
6196 | static struct notifier_block trace_panic_notifier = { | |
6197 | .notifier_call = trace_panic_handler, | |
6198 | .next = NULL, | |
6199 | .priority = 150 /* priority: INT_MAX >= x >= 0 */ | |
6200 | }; | |
6201 | ||
6202 | static int trace_die_handler(struct notifier_block *self, | |
6203 | unsigned long val, | |
6204 | void *data) | |
6205 | { | |
6206 | switch (val) { | |
6207 | case DIE_OOPS: | |
6208 | if (ftrace_dump_on_oops) | |
6209 | ftrace_dump(ftrace_dump_on_oops); | |
6210 | break; | |
6211 | default: | |
6212 | break; | |
6213 | } | |
6214 | return NOTIFY_OK; | |
6215 | } | |
6216 | ||
6217 | static struct notifier_block trace_die_notifier = { | |
6218 | .notifier_call = trace_die_handler, | |
6219 | .priority = 200 | |
6220 | }; | |
6221 | ||
6222 | /* | |
6223 | * printk is set to max of 1024, we really don't need it that big. | |
6224 | * Nothing should be printing 1000 characters anyway. | |
6225 | */ | |
6226 | #define TRACE_MAX_PRINT 1000 | |
6227 | ||
6228 | /* | |
6229 | * Define here KERN_TRACE so that we have one place to modify | |
6230 | * it if we decide to change what log level the ftrace dump | |
6231 | * should be at. | |
6232 | */ | |
6233 | #define KERN_TRACE KERN_EMERG | |
6234 | ||
6235 | void | |
6236 | trace_printk_seq(struct trace_seq *s) | |
6237 | { | |
6238 | /* Probably should print a warning here. */ | |
6239 | if (s->len >= TRACE_MAX_PRINT) | |
6240 | s->len = TRACE_MAX_PRINT; | |
6241 | ||
6242 | /* should be zero ended, but we are paranoid. */ | |
6243 | s->buffer[s->len] = 0; | |
6244 | ||
6245 | printk(KERN_TRACE "%s", s->buffer); | |
6246 | ||
6247 | trace_seq_init(s); | |
6248 | } | |
6249 | ||
6250 | void trace_init_global_iter(struct trace_iterator *iter) | |
6251 | { | |
6252 | iter->tr = &global_trace; | |
6253 | iter->trace = iter->tr->current_trace; | |
6254 | iter->cpu_file = RING_BUFFER_ALL_CPUS; | |
6255 | iter->trace_buffer = &global_trace.trace_buffer; | |
6256 | } | |
6257 | ||
6258 | void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) | |
6259 | { | |
6260 | /* use static because iter can be a bit big for the stack */ | |
6261 | static struct trace_iterator iter; | |
6262 | static atomic_t dump_running; | |
6263 | unsigned int old_userobj; | |
6264 | unsigned long flags; | |
6265 | int cnt = 0, cpu; | |
6266 | ||
6267 | /* Only allow one dump user at a time. */ | |
6268 | if (atomic_inc_return(&dump_running) != 1) { | |
6269 | atomic_dec(&dump_running); | |
6270 | return; | |
6271 | } | |
6272 | ||
6273 | /* | |
6274 | * Always turn off tracing when we dump. | |
6275 | * We don't need to show trace output of what happens | |
6276 | * between multiple crashes. | |
6277 | * | |
6278 | * If the user does a sysrq-z, then they can re-enable | |
6279 | * tracing with echo 1 > tracing_on. | |
6280 | */ | |
6281 | tracing_off(); | |
6282 | ||
6283 | local_irq_save(flags); | |
6284 | ||
6285 | /* Simulate the iterator */ | |
6286 | trace_init_global_iter(&iter); | |
6287 | ||
6288 | for_each_tracing_cpu(cpu) { | |
6289 | atomic_inc(&per_cpu_ptr(iter.tr->trace_buffer.data, cpu)->disabled); | |
6290 | } | |
6291 | ||
6292 | old_userobj = trace_flags & TRACE_ITER_SYM_USEROBJ; | |
6293 | ||
6294 | /* don't look at user memory in panic mode */ | |
6295 | trace_flags &= ~TRACE_ITER_SYM_USEROBJ; | |
6296 | ||
6297 | switch (oops_dump_mode) { | |
6298 | case DUMP_ALL: | |
6299 | iter.cpu_file = RING_BUFFER_ALL_CPUS; | |
6300 | break; | |
6301 | case DUMP_ORIG: | |
6302 | iter.cpu_file = raw_smp_processor_id(); | |
6303 | break; | |
6304 | case DUMP_NONE: | |
6305 | goto out_enable; | |
6306 | default: | |
6307 | printk(KERN_TRACE "Bad dumping mode, switching to all CPUs dump\n"); | |
6308 | iter.cpu_file = RING_BUFFER_ALL_CPUS; | |
6309 | } | |
6310 | ||
6311 | printk(KERN_TRACE "Dumping ftrace buffer:\n"); | |
6312 | ||
6313 | /* Did function tracer already get disabled? */ | |
6314 | if (ftrace_is_dead()) { | |
6315 | printk("# WARNING: FUNCTION TRACING IS CORRUPTED\n"); | |
6316 | printk("# MAY BE MISSING FUNCTION EVENTS\n"); | |
6317 | } | |
6318 | ||
6319 | /* | |
6320 | * We need to stop all tracing on all CPUS to read the | |
6321 | * the next buffer. This is a bit expensive, but is | |
6322 | * not done often. We fill all what we can read, | |
6323 | * and then release the locks again. | |
6324 | */ | |
6325 | ||
6326 | while (!trace_empty(&iter)) { | |
6327 | ||
6328 | if (!cnt) | |
6329 | printk(KERN_TRACE "---------------------------------\n"); | |
6330 | ||
6331 | cnt++; | |
6332 | ||
6333 | /* reset all but tr, trace, and overruns */ | |
6334 | memset(&iter.seq, 0, | |
6335 | sizeof(struct trace_iterator) - | |
6336 | offsetof(struct trace_iterator, seq)); | |
6337 | iter.iter_flags |= TRACE_FILE_LAT_FMT; | |
6338 | iter.pos = -1; | |
6339 | ||
6340 | if (trace_find_next_entry_inc(&iter) != NULL) { | |
6341 | int ret; | |
6342 | ||
6343 | ret = print_trace_line(&iter); | |
6344 | if (ret != TRACE_TYPE_NO_CONSUME) | |
6345 | trace_consume(&iter); | |
6346 | } | |
6347 | touch_nmi_watchdog(); | |
6348 | ||
6349 | trace_printk_seq(&iter.seq); | |
6350 | } | |
6351 | ||
6352 | if (!cnt) | |
6353 | printk(KERN_TRACE " (ftrace buffer empty)\n"); | |
6354 | else | |
6355 | printk(KERN_TRACE "---------------------------------\n"); | |
6356 | ||
6357 | out_enable: | |
6358 | trace_flags |= old_userobj; | |
6359 | ||
6360 | for_each_tracing_cpu(cpu) { | |
6361 | atomic_dec(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled); | |
6362 | } | |
6363 | atomic_dec(&dump_running); | |
6364 | local_irq_restore(flags); | |
6365 | } | |
6366 | EXPORT_SYMBOL_GPL(ftrace_dump); | |
6367 | ||
6368 | __init static int tracer_alloc_buffers(void) | |
6369 | { | |
6370 | int ring_buf_size; | |
6371 | int ret = -ENOMEM; | |
6372 | ||
6373 | ||
6374 | if (!alloc_cpumask_var(&tracing_buffer_mask, GFP_KERNEL)) | |
6375 | goto out; | |
6376 | ||
6377 | if (!alloc_cpumask_var(&global_trace.tracing_cpumask, GFP_KERNEL)) | |
6378 | goto out_free_buffer_mask; | |
6379 | ||
6380 | /* Only allocate trace_printk buffers if a trace_printk exists */ | |
6381 | if (__stop___trace_bprintk_fmt != __start___trace_bprintk_fmt) | |
6382 | /* Must be called before global_trace.buffer is allocated */ | |
6383 | trace_printk_init_buffers(); | |
6384 | ||
6385 | /* To save memory, keep the ring buffer size to its minimum */ | |
6386 | if (ring_buffer_expanded) | |
6387 | ring_buf_size = trace_buf_size; | |
6388 | else | |
6389 | ring_buf_size = 1; | |
6390 | ||
6391 | cpumask_copy(tracing_buffer_mask, cpu_possible_mask); | |
6392 | cpumask_copy(global_trace.tracing_cpumask, cpu_all_mask); | |
6393 | ||
6394 | raw_spin_lock_init(&global_trace.start_lock); | |
6395 | ||
6396 | /* TODO: make the number of buffers hot pluggable with CPUS */ | |
6397 | if (allocate_trace_buffers(&global_trace, ring_buf_size) < 0) { | |
6398 | printk(KERN_ERR "tracer: failed to allocate ring buffer!\n"); | |
6399 | WARN_ON(1); | |
6400 | goto out_free_cpumask; | |
6401 | } | |
6402 | ||
6403 | if (global_trace.buffer_disabled) | |
6404 | tracing_off(); | |
6405 | ||
6406 | trace_init_cmdlines(); | |
6407 | ||
6408 | /* | |
6409 | * register_tracer() might reference current_trace, so it | |
6410 | * needs to be set before we register anything. This is | |
6411 | * just a bootstrap of current_trace anyway. | |
6412 | */ | |
6413 | global_trace.current_trace = &nop_trace; | |
6414 | ||
6415 | register_tracer(&nop_trace); | |
6416 | ||
6417 | /* All seems OK, enable tracing */ | |
6418 | tracing_disabled = 0; | |
6419 | ||
6420 | atomic_notifier_chain_register(&panic_notifier_list, | |
6421 | &trace_panic_notifier); | |
6422 | ||
6423 | register_die_notifier(&trace_die_notifier); | |
6424 | ||
6425 | global_trace.flags = TRACE_ARRAY_FL_GLOBAL; | |
6426 | ||
6427 | INIT_LIST_HEAD(&global_trace.systems); | |
6428 | INIT_LIST_HEAD(&global_trace.events); | |
6429 | list_add(&global_trace.list, &ftrace_trace_arrays); | |
6430 | ||
6431 | while (trace_boot_options) { | |
6432 | char *option; | |
6433 | ||
6434 | option = strsep(&trace_boot_options, ","); | |
6435 | trace_set_options(&global_trace, option); | |
6436 | } | |
6437 | ||
6438 | register_snapshot_cmd(); | |
6439 | ||
6440 | return 0; | |
6441 | ||
6442 | out_free_cpumask: | |
6443 | free_percpu(global_trace.trace_buffer.data); | |
6444 | #ifdef CONFIG_TRACER_MAX_TRACE | |
6445 | free_percpu(global_trace.max_buffer.data); | |
6446 | #endif | |
6447 | free_cpumask_var(global_trace.tracing_cpumask); | |
6448 | out_free_buffer_mask: | |
6449 | free_cpumask_var(tracing_buffer_mask); | |
6450 | out: | |
6451 | return ret; | |
6452 | } | |
6453 | ||
6454 | __init static int clear_boot_tracer(void) | |
6455 | { | |
6456 | /* | |
6457 | * The default tracer at boot buffer is an init section. | |
6458 | * This function is called in lateinit. If we did not | |
6459 | * find the boot tracer, then clear it out, to prevent | |
6460 | * later registration from accessing the buffer that is | |
6461 | * about to be freed. | |
6462 | */ | |
6463 | if (!default_bootup_tracer) | |
6464 | return 0; | |
6465 | ||
6466 | printk(KERN_INFO "ftrace bootup tracer '%s' not registered.\n", | |
6467 | default_bootup_tracer); | |
6468 | default_bootup_tracer = NULL; | |
6469 | ||
6470 | return 0; | |
6471 | } | |
6472 | ||
6473 | early_initcall(tracer_alloc_buffers); | |
6474 | fs_initcall(tracer_init_debugfs); | |
6475 | late_initcall(clear_boot_tracer); |