]>
Commit | Line | Data |
---|---|---|
1 | /* | |
2 | * ring buffer based function tracer | |
3 | * | |
4 | * Copyright (C) 2007-2008 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 William Lee Irwin III | |
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/fs.h> | |
40 | ||
41 | #include "trace.h" | |
42 | #include "trace_output.h" | |
43 | ||
44 | /* | |
45 | * On boot up, the ring buffer is set to the minimum size, so that | |
46 | * we do not waste memory on systems that are not using tracing. | |
47 | */ | |
48 | int ring_buffer_expanded; | |
49 | ||
50 | /* | |
51 | * We need to change this state when a selftest is running. | |
52 | * A selftest will lurk into the ring-buffer to count the | |
53 | * entries inserted during the selftest although some concurrent | |
54 | * insertions into the ring-buffer such as trace_printk could occurred | |
55 | * at the same time, giving false positive or negative results. | |
56 | */ | |
57 | static bool __read_mostly tracing_selftest_running; | |
58 | ||
59 | /* | |
60 | * If a tracer is running, we do not want to run SELFTEST. | |
61 | */ | |
62 | bool __read_mostly tracing_selftest_disabled; | |
63 | ||
64 | /* For tracers that don't implement custom flags */ | |
65 | static struct tracer_opt dummy_tracer_opt[] = { | |
66 | { } | |
67 | }; | |
68 | ||
69 | static struct tracer_flags dummy_tracer_flags = { | |
70 | .val = 0, | |
71 | .opts = dummy_tracer_opt | |
72 | }; | |
73 | ||
74 | static int dummy_set_flag(u32 old_flags, u32 bit, int set) | |
75 | { | |
76 | return 0; | |
77 | } | |
78 | ||
79 | /* | |
80 | * Kill all tracing for good (never come back). | |
81 | * It is initialized to 1 but will turn to zero if the initialization | |
82 | * of the tracer is successful. But that is the only place that sets | |
83 | * this back to zero. | |
84 | */ | |
85 | static int tracing_disabled = 1; | |
86 | ||
87 | DEFINE_PER_CPU(int, ftrace_cpu_disabled); | |
88 | ||
89 | static inline void ftrace_disable_cpu(void) | |
90 | { | |
91 | preempt_disable(); | |
92 | __this_cpu_inc(ftrace_cpu_disabled); | |
93 | } | |
94 | ||
95 | static inline void ftrace_enable_cpu(void) | |
96 | { | |
97 | __this_cpu_dec(ftrace_cpu_disabled); | |
98 | preempt_enable(); | |
99 | } | |
100 | ||
101 | cpumask_var_t __read_mostly tracing_buffer_mask; | |
102 | ||
103 | /* | |
104 | * ftrace_dump_on_oops - variable to dump ftrace buffer on oops | |
105 | * | |
106 | * If there is an oops (or kernel panic) and the ftrace_dump_on_oops | |
107 | * is set, then ftrace_dump is called. This will output the contents | |
108 | * of the ftrace buffers to the console. This is very useful for | |
109 | * capturing traces that lead to crashes and outputing it to a | |
110 | * serial console. | |
111 | * | |
112 | * It is default off, but you can enable it with either specifying | |
113 | * "ftrace_dump_on_oops" in the kernel command line, or setting | |
114 | * /proc/sys/kernel/ftrace_dump_on_oops | |
115 | * Set 1 if you want to dump buffers of all CPUs | |
116 | * Set 2 if you want to dump the buffer of the CPU that triggered oops | |
117 | */ | |
118 | ||
119 | enum ftrace_dump_mode ftrace_dump_on_oops; | |
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 int __init set_cmdline_ftrace(char *str) | |
128 | { | |
129 | strncpy(bootup_tracer_buf, str, MAX_TRACER_SIZE); | |
130 | default_bootup_tracer = bootup_tracer_buf; | |
131 | /* We are using ftrace early, expand it */ | |
132 | ring_buffer_expanded = 1; | |
133 | return 1; | |
134 | } | |
135 | __setup("ftrace=", set_cmdline_ftrace); | |
136 | ||
137 | static int __init set_ftrace_dump_on_oops(char *str) | |
138 | { | |
139 | if (*str++ != '=' || !*str) { | |
140 | ftrace_dump_on_oops = DUMP_ALL; | |
141 | return 1; | |
142 | } | |
143 | ||
144 | if (!strcmp("orig_cpu", str)) { | |
145 | ftrace_dump_on_oops = DUMP_ORIG; | |
146 | return 1; | |
147 | } | |
148 | ||
149 | return 0; | |
150 | } | |
151 | __setup("ftrace_dump_on_oops", set_ftrace_dump_on_oops); | |
152 | ||
153 | unsigned long long ns2usecs(cycle_t nsec) | |
154 | { | |
155 | nsec += 500; | |
156 | do_div(nsec, 1000); | |
157 | return nsec; | |
158 | } | |
159 | ||
160 | /* | |
161 | * The global_trace is the descriptor that holds the tracing | |
162 | * buffers for the live tracing. For each CPU, it contains | |
163 | * a link list of pages that will store trace entries. The | |
164 | * page descriptor of the pages in the memory is used to hold | |
165 | * the link list by linking the lru item in the page descriptor | |
166 | * to each of the pages in the buffer per CPU. | |
167 | * | |
168 | * For each active CPU there is a data field that holds the | |
169 | * pages for the buffer for that CPU. Each CPU has the same number | |
170 | * of pages allocated for its buffer. | |
171 | */ | |
172 | static struct trace_array global_trace; | |
173 | ||
174 | static DEFINE_PER_CPU(struct trace_array_cpu, global_trace_cpu); | |
175 | ||
176 | int filter_current_check_discard(struct ring_buffer *buffer, | |
177 | struct ftrace_event_call *call, void *rec, | |
178 | struct ring_buffer_event *event) | |
179 | { | |
180 | return filter_check_discard(call, rec, buffer, event); | |
181 | } | |
182 | EXPORT_SYMBOL_GPL(filter_current_check_discard); | |
183 | ||
184 | cycle_t ftrace_now(int cpu) | |
185 | { | |
186 | u64 ts; | |
187 | ||
188 | /* Early boot up does not have a buffer yet */ | |
189 | if (!global_trace.buffer) | |
190 | return trace_clock_local(); | |
191 | ||
192 | ts = ring_buffer_time_stamp(global_trace.buffer, cpu); | |
193 | ring_buffer_normalize_time_stamp(global_trace.buffer, cpu, &ts); | |
194 | ||
195 | return ts; | |
196 | } | |
197 | ||
198 | /* | |
199 | * The max_tr is used to snapshot the global_trace when a maximum | |
200 | * latency is reached. Some tracers will use this to store a maximum | |
201 | * trace while it continues examining live traces. | |
202 | * | |
203 | * The buffers for the max_tr are set up the same as the global_trace. | |
204 | * When a snapshot is taken, the link list of the max_tr is swapped | |
205 | * with the link list of the global_trace and the buffers are reset for | |
206 | * the global_trace so the tracing can continue. | |
207 | */ | |
208 | static struct trace_array max_tr; | |
209 | ||
210 | static DEFINE_PER_CPU(struct trace_array_cpu, max_tr_data); | |
211 | ||
212 | /* tracer_enabled is used to toggle activation of a tracer */ | |
213 | static int tracer_enabled = 1; | |
214 | ||
215 | /** | |
216 | * tracing_is_enabled - return tracer_enabled status | |
217 | * | |
218 | * This function is used by other tracers to know the status | |
219 | * of the tracer_enabled flag. Tracers may use this function | |
220 | * to know if it should enable their features when starting | |
221 | * up. See irqsoff tracer for an example (start_irqsoff_tracer). | |
222 | */ | |
223 | int tracing_is_enabled(void) | |
224 | { | |
225 | return tracer_enabled; | |
226 | } | |
227 | ||
228 | /* | |
229 | * trace_buf_size is the size in bytes that is allocated | |
230 | * for a buffer. Note, the number of bytes is always rounded | |
231 | * to page size. | |
232 | * | |
233 | * This number is purposely set to a low number of 16384. | |
234 | * If the dump on oops happens, it will be much appreciated | |
235 | * to not have to wait for all that output. Anyway this can be | |
236 | * boot time and run time configurable. | |
237 | */ | |
238 | #define TRACE_BUF_SIZE_DEFAULT 1441792UL /* 16384 * 88 (sizeof(entry)) */ | |
239 | ||
240 | static unsigned long trace_buf_size = TRACE_BUF_SIZE_DEFAULT; | |
241 | ||
242 | /* trace_types holds a link list of available tracers. */ | |
243 | static struct tracer *trace_types __read_mostly; | |
244 | ||
245 | /* current_trace points to the tracer that is currently active */ | |
246 | static struct tracer *current_trace __read_mostly; | |
247 | ||
248 | /* | |
249 | * trace_types_lock is used to protect the trace_types list. | |
250 | */ | |
251 | static DEFINE_MUTEX(trace_types_lock); | |
252 | ||
253 | /* | |
254 | * serialize the access of the ring buffer | |
255 | * | |
256 | * ring buffer serializes readers, but it is low level protection. | |
257 | * The validity of the events (which returns by ring_buffer_peek() ..etc) | |
258 | * are not protected by ring buffer. | |
259 | * | |
260 | * The content of events may become garbage if we allow other process consumes | |
261 | * these events concurrently: | |
262 | * A) the page of the consumed events may become a normal page | |
263 | * (not reader page) in ring buffer, and this page will be rewrited | |
264 | * by events producer. | |
265 | * B) The page of the consumed events may become a page for splice_read, | |
266 | * and this page will be returned to system. | |
267 | * | |
268 | * These primitives allow multi process access to different cpu ring buffer | |
269 | * concurrently. | |
270 | * | |
271 | * These primitives don't distinguish read-only and read-consume access. | |
272 | * Multi read-only access are also serialized. | |
273 | */ | |
274 | ||
275 | #ifdef CONFIG_SMP | |
276 | static DECLARE_RWSEM(all_cpu_access_lock); | |
277 | static DEFINE_PER_CPU(struct mutex, cpu_access_lock); | |
278 | ||
279 | static inline void trace_access_lock(int cpu) | |
280 | { | |
281 | if (cpu == TRACE_PIPE_ALL_CPU) { | |
282 | /* gain it for accessing the whole ring buffer. */ | |
283 | down_write(&all_cpu_access_lock); | |
284 | } else { | |
285 | /* gain it for accessing a cpu ring buffer. */ | |
286 | ||
287 | /* Firstly block other trace_access_lock(TRACE_PIPE_ALL_CPU). */ | |
288 | down_read(&all_cpu_access_lock); | |
289 | ||
290 | /* Secondly block other access to this @cpu ring buffer. */ | |
291 | mutex_lock(&per_cpu(cpu_access_lock, cpu)); | |
292 | } | |
293 | } | |
294 | ||
295 | static inline void trace_access_unlock(int cpu) | |
296 | { | |
297 | if (cpu == TRACE_PIPE_ALL_CPU) { | |
298 | up_write(&all_cpu_access_lock); | |
299 | } else { | |
300 | mutex_unlock(&per_cpu(cpu_access_lock, cpu)); | |
301 | up_read(&all_cpu_access_lock); | |
302 | } | |
303 | } | |
304 | ||
305 | static inline void trace_access_lock_init(void) | |
306 | { | |
307 | int cpu; | |
308 | ||
309 | for_each_possible_cpu(cpu) | |
310 | mutex_init(&per_cpu(cpu_access_lock, cpu)); | |
311 | } | |
312 | ||
313 | #else | |
314 | ||
315 | static DEFINE_MUTEX(access_lock); | |
316 | ||
317 | static inline void trace_access_lock(int cpu) | |
318 | { | |
319 | (void)cpu; | |
320 | mutex_lock(&access_lock); | |
321 | } | |
322 | ||
323 | static inline void trace_access_unlock(int cpu) | |
324 | { | |
325 | (void)cpu; | |
326 | mutex_unlock(&access_lock); | |
327 | } | |
328 | ||
329 | static inline void trace_access_lock_init(void) | |
330 | { | |
331 | } | |
332 | ||
333 | #endif | |
334 | ||
335 | /* trace_wait is a waitqueue for tasks blocked on trace_poll */ | |
336 | static DECLARE_WAIT_QUEUE_HEAD(trace_wait); | |
337 | ||
338 | /* trace_flags holds trace_options default values */ | |
339 | unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK | | |
340 | TRACE_ITER_ANNOTATE | TRACE_ITER_CONTEXT_INFO | TRACE_ITER_SLEEP_TIME | | |
341 | TRACE_ITER_GRAPH_TIME | TRACE_ITER_RECORD_CMD | TRACE_ITER_OVERWRITE; | |
342 | ||
343 | static int trace_stop_count; | |
344 | static DEFINE_SPINLOCK(tracing_start_lock); | |
345 | ||
346 | /** | |
347 | * trace_wake_up - wake up tasks waiting for trace input | |
348 | * | |
349 | * Simply wakes up any task that is blocked on the trace_wait | |
350 | * queue. These is used with trace_poll for tasks polling the trace. | |
351 | */ | |
352 | void trace_wake_up(void) | |
353 | { | |
354 | int cpu; | |
355 | ||
356 | if (trace_flags & TRACE_ITER_BLOCK) | |
357 | return; | |
358 | /* | |
359 | * The runqueue_is_locked() can fail, but this is the best we | |
360 | * have for now: | |
361 | */ | |
362 | cpu = get_cpu(); | |
363 | if (!runqueue_is_locked(cpu)) | |
364 | wake_up(&trace_wait); | |
365 | put_cpu(); | |
366 | } | |
367 | ||
368 | static int __init set_buf_size(char *str) | |
369 | { | |
370 | unsigned long buf_size; | |
371 | ||
372 | if (!str) | |
373 | return 0; | |
374 | buf_size = memparse(str, &str); | |
375 | /* nr_entries can not be zero */ | |
376 | if (buf_size == 0) | |
377 | return 0; | |
378 | trace_buf_size = buf_size; | |
379 | return 1; | |
380 | } | |
381 | __setup("trace_buf_size=", set_buf_size); | |
382 | ||
383 | static int __init set_tracing_thresh(char *str) | |
384 | { | |
385 | unsigned long threshhold; | |
386 | int ret; | |
387 | ||
388 | if (!str) | |
389 | return 0; | |
390 | ret = strict_strtoul(str, 0, &threshhold); | |
391 | if (ret < 0) | |
392 | return 0; | |
393 | tracing_thresh = threshhold * 1000; | |
394 | return 1; | |
395 | } | |
396 | __setup("tracing_thresh=", set_tracing_thresh); | |
397 | ||
398 | unsigned long nsecs_to_usecs(unsigned long nsecs) | |
399 | { | |
400 | return nsecs / 1000; | |
401 | } | |
402 | ||
403 | /* These must match the bit postions in trace_iterator_flags */ | |
404 | static const char *trace_options[] = { | |
405 | "print-parent", | |
406 | "sym-offset", | |
407 | "sym-addr", | |
408 | "verbose", | |
409 | "raw", | |
410 | "hex", | |
411 | "bin", | |
412 | "block", | |
413 | "stacktrace", | |
414 | "trace_printk", | |
415 | "ftrace_preempt", | |
416 | "branch", | |
417 | "annotate", | |
418 | "userstacktrace", | |
419 | "sym-userobj", | |
420 | "printk-msg-only", | |
421 | "context-info", | |
422 | "latency-format", | |
423 | "sleep-time", | |
424 | "graph-time", | |
425 | "record-cmd", | |
426 | "overwrite", | |
427 | NULL | |
428 | }; | |
429 | ||
430 | static struct { | |
431 | u64 (*func)(void); | |
432 | const char *name; | |
433 | } trace_clocks[] = { | |
434 | { trace_clock_local, "local" }, | |
435 | { trace_clock_global, "global" }, | |
436 | }; | |
437 | ||
438 | int trace_clock_id; | |
439 | ||
440 | /* | |
441 | * trace_parser_get_init - gets the buffer for trace parser | |
442 | */ | |
443 | int trace_parser_get_init(struct trace_parser *parser, int size) | |
444 | { | |
445 | memset(parser, 0, sizeof(*parser)); | |
446 | ||
447 | parser->buffer = kmalloc(size, GFP_KERNEL); | |
448 | if (!parser->buffer) | |
449 | return 1; | |
450 | ||
451 | parser->size = size; | |
452 | return 0; | |
453 | } | |
454 | ||
455 | /* | |
456 | * trace_parser_put - frees the buffer for trace parser | |
457 | */ | |
458 | void trace_parser_put(struct trace_parser *parser) | |
459 | { | |
460 | kfree(parser->buffer); | |
461 | } | |
462 | ||
463 | /* | |
464 | * trace_get_user - reads the user input string separated by space | |
465 | * (matched by isspace(ch)) | |
466 | * | |
467 | * For each string found the 'struct trace_parser' is updated, | |
468 | * and the function returns. | |
469 | * | |
470 | * Returns number of bytes read. | |
471 | * | |
472 | * See kernel/trace/trace.h for 'struct trace_parser' details. | |
473 | */ | |
474 | int trace_get_user(struct trace_parser *parser, const char __user *ubuf, | |
475 | size_t cnt, loff_t *ppos) | |
476 | { | |
477 | char ch; | |
478 | size_t read = 0; | |
479 | ssize_t ret; | |
480 | ||
481 | if (!*ppos) | |
482 | trace_parser_clear(parser); | |
483 | ||
484 | ret = get_user(ch, ubuf++); | |
485 | if (ret) | |
486 | goto out; | |
487 | ||
488 | read++; | |
489 | cnt--; | |
490 | ||
491 | /* | |
492 | * The parser is not finished with the last write, | |
493 | * continue reading the user input without skipping spaces. | |
494 | */ | |
495 | if (!parser->cont) { | |
496 | /* skip white space */ | |
497 | while (cnt && isspace(ch)) { | |
498 | ret = get_user(ch, ubuf++); | |
499 | if (ret) | |
500 | goto out; | |
501 | read++; | |
502 | cnt--; | |
503 | } | |
504 | ||
505 | /* only spaces were written */ | |
506 | if (isspace(ch)) { | |
507 | *ppos += read; | |
508 | ret = read; | |
509 | goto out; | |
510 | } | |
511 | ||
512 | parser->idx = 0; | |
513 | } | |
514 | ||
515 | /* read the non-space input */ | |
516 | while (cnt && !isspace(ch)) { | |
517 | if (parser->idx < parser->size - 1) | |
518 | parser->buffer[parser->idx++] = ch; | |
519 | else { | |
520 | ret = -EINVAL; | |
521 | goto out; | |
522 | } | |
523 | ret = get_user(ch, ubuf++); | |
524 | if (ret) | |
525 | goto out; | |
526 | read++; | |
527 | cnt--; | |
528 | } | |
529 | ||
530 | /* We either got finished input or we have to wait for another call. */ | |
531 | if (isspace(ch)) { | |
532 | parser->buffer[parser->idx] = 0; | |
533 | parser->cont = false; | |
534 | } else { | |
535 | parser->cont = true; | |
536 | parser->buffer[parser->idx++] = ch; | |
537 | } | |
538 | ||
539 | *ppos += read; | |
540 | ret = read; | |
541 | ||
542 | out: | |
543 | return ret; | |
544 | } | |
545 | ||
546 | ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt) | |
547 | { | |
548 | int len; | |
549 | int ret; | |
550 | ||
551 | if (!cnt) | |
552 | return 0; | |
553 | ||
554 | if (s->len <= s->readpos) | |
555 | return -EBUSY; | |
556 | ||
557 | len = s->len - s->readpos; | |
558 | if (cnt > len) | |
559 | cnt = len; | |
560 | ret = copy_to_user(ubuf, s->buffer + s->readpos, cnt); | |
561 | if (ret == cnt) | |
562 | return -EFAULT; | |
563 | ||
564 | cnt -= ret; | |
565 | ||
566 | s->readpos += cnt; | |
567 | return cnt; | |
568 | } | |
569 | ||
570 | static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt) | |
571 | { | |
572 | int len; | |
573 | void *ret; | |
574 | ||
575 | if (s->len <= s->readpos) | |
576 | return -EBUSY; | |
577 | ||
578 | len = s->len - s->readpos; | |
579 | if (cnt > len) | |
580 | cnt = len; | |
581 | ret = memcpy(buf, s->buffer + s->readpos, cnt); | |
582 | if (!ret) | |
583 | return -EFAULT; | |
584 | ||
585 | s->readpos += cnt; | |
586 | return cnt; | |
587 | } | |
588 | ||
589 | /* | |
590 | * ftrace_max_lock is used to protect the swapping of buffers | |
591 | * when taking a max snapshot. The buffers themselves are | |
592 | * protected by per_cpu spinlocks. But the action of the swap | |
593 | * needs its own lock. | |
594 | * | |
595 | * This is defined as a arch_spinlock_t in order to help | |
596 | * with performance when lockdep debugging is enabled. | |
597 | * | |
598 | * It is also used in other places outside the update_max_tr | |
599 | * so it needs to be defined outside of the | |
600 | * CONFIG_TRACER_MAX_TRACE. | |
601 | */ | |
602 | static arch_spinlock_t ftrace_max_lock = | |
603 | (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; | |
604 | ||
605 | unsigned long __read_mostly tracing_thresh; | |
606 | ||
607 | #ifdef CONFIG_TRACER_MAX_TRACE | |
608 | unsigned long __read_mostly tracing_max_latency; | |
609 | ||
610 | /* | |
611 | * Copy the new maximum trace into the separate maximum-trace | |
612 | * structure. (this way the maximum trace is permanently saved, | |
613 | * for later retrieval via /sys/kernel/debug/tracing/latency_trace) | |
614 | */ | |
615 | static void | |
616 | __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) | |
617 | { | |
618 | struct trace_array_cpu *data = tr->data[cpu]; | |
619 | struct trace_array_cpu *max_data; | |
620 | ||
621 | max_tr.cpu = cpu; | |
622 | max_tr.time_start = data->preempt_timestamp; | |
623 | ||
624 | max_data = max_tr.data[cpu]; | |
625 | max_data->saved_latency = tracing_max_latency; | |
626 | max_data->critical_start = data->critical_start; | |
627 | max_data->critical_end = data->critical_end; | |
628 | ||
629 | memcpy(max_data->comm, tsk->comm, TASK_COMM_LEN); | |
630 | max_data->pid = tsk->pid; | |
631 | max_data->uid = task_uid(tsk); | |
632 | max_data->nice = tsk->static_prio - 20 - MAX_RT_PRIO; | |
633 | max_data->policy = tsk->policy; | |
634 | max_data->rt_priority = tsk->rt_priority; | |
635 | ||
636 | /* record this tasks comm */ | |
637 | tracing_record_cmdline(tsk); | |
638 | } | |
639 | ||
640 | /** | |
641 | * update_max_tr - snapshot all trace buffers from global_trace to max_tr | |
642 | * @tr: tracer | |
643 | * @tsk: the task with the latency | |
644 | * @cpu: The cpu that initiated the trace. | |
645 | * | |
646 | * Flip the buffers between the @tr and the max_tr and record information | |
647 | * about which task was the cause of this latency. | |
648 | */ | |
649 | void | |
650 | update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) | |
651 | { | |
652 | struct ring_buffer *buf = tr->buffer; | |
653 | ||
654 | if (trace_stop_count) | |
655 | return; | |
656 | ||
657 | WARN_ON_ONCE(!irqs_disabled()); | |
658 | if (!current_trace->use_max_tr) { | |
659 | WARN_ON_ONCE(1); | |
660 | return; | |
661 | } | |
662 | arch_spin_lock(&ftrace_max_lock); | |
663 | ||
664 | tr->buffer = max_tr.buffer; | |
665 | max_tr.buffer = buf; | |
666 | ||
667 | __update_max_tr(tr, tsk, cpu); | |
668 | arch_spin_unlock(&ftrace_max_lock); | |
669 | } | |
670 | ||
671 | /** | |
672 | * update_max_tr_single - only copy one trace over, and reset the rest | |
673 | * @tr - tracer | |
674 | * @tsk - task with the latency | |
675 | * @cpu - the cpu of the buffer to copy. | |
676 | * | |
677 | * Flip the trace of a single CPU buffer between the @tr and the max_tr. | |
678 | */ | |
679 | void | |
680 | update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) | |
681 | { | |
682 | int ret; | |
683 | ||
684 | if (trace_stop_count) | |
685 | return; | |
686 | ||
687 | WARN_ON_ONCE(!irqs_disabled()); | |
688 | if (!current_trace->use_max_tr) { | |
689 | WARN_ON_ONCE(1); | |
690 | return; | |
691 | } | |
692 | ||
693 | arch_spin_lock(&ftrace_max_lock); | |
694 | ||
695 | ftrace_disable_cpu(); | |
696 | ||
697 | ret = ring_buffer_swap_cpu(max_tr.buffer, tr->buffer, cpu); | |
698 | ||
699 | if (ret == -EBUSY) { | |
700 | /* | |
701 | * We failed to swap the buffer due to a commit taking | |
702 | * place on this CPU. We fail to record, but we reset | |
703 | * the max trace buffer (no one writes directly to it) | |
704 | * and flag that it failed. | |
705 | */ | |
706 | trace_array_printk(&max_tr, _THIS_IP_, | |
707 | "Failed to swap buffers due to commit in progress\n"); | |
708 | } | |
709 | ||
710 | ftrace_enable_cpu(); | |
711 | ||
712 | WARN_ON_ONCE(ret && ret != -EAGAIN && ret != -EBUSY); | |
713 | ||
714 | __update_max_tr(tr, tsk, cpu); | |
715 | arch_spin_unlock(&ftrace_max_lock); | |
716 | } | |
717 | #endif /* CONFIG_TRACER_MAX_TRACE */ | |
718 | ||
719 | /** | |
720 | * register_tracer - register a tracer with the ftrace system. | |
721 | * @type - the plugin for the tracer | |
722 | * | |
723 | * Register a new plugin tracer. | |
724 | */ | |
725 | int register_tracer(struct tracer *type) | |
726 | __releases(kernel_lock) | |
727 | __acquires(kernel_lock) | |
728 | { | |
729 | struct tracer *t; | |
730 | int ret = 0; | |
731 | ||
732 | if (!type->name) { | |
733 | pr_info("Tracer must have a name\n"); | |
734 | return -1; | |
735 | } | |
736 | ||
737 | if (strlen(type->name) >= MAX_TRACER_SIZE) { | |
738 | pr_info("Tracer has a name longer than %d\n", MAX_TRACER_SIZE); | |
739 | return -1; | |
740 | } | |
741 | ||
742 | mutex_lock(&trace_types_lock); | |
743 | ||
744 | tracing_selftest_running = true; | |
745 | ||
746 | for (t = trace_types; t; t = t->next) { | |
747 | if (strcmp(type->name, t->name) == 0) { | |
748 | /* already found */ | |
749 | pr_info("Tracer %s already registered\n", | |
750 | type->name); | |
751 | ret = -1; | |
752 | goto out; | |
753 | } | |
754 | } | |
755 | ||
756 | if (!type->set_flag) | |
757 | type->set_flag = &dummy_set_flag; | |
758 | if (!type->flags) | |
759 | type->flags = &dummy_tracer_flags; | |
760 | else | |
761 | if (!type->flags->opts) | |
762 | type->flags->opts = dummy_tracer_opt; | |
763 | if (!type->wait_pipe) | |
764 | type->wait_pipe = default_wait_pipe; | |
765 | ||
766 | ||
767 | #ifdef CONFIG_FTRACE_STARTUP_TEST | |
768 | if (type->selftest && !tracing_selftest_disabled) { | |
769 | struct tracer *saved_tracer = current_trace; | |
770 | struct trace_array *tr = &global_trace; | |
771 | ||
772 | /* | |
773 | * Run a selftest on this tracer. | |
774 | * Here we reset the trace buffer, and set the current | |
775 | * tracer to be this tracer. The tracer can then run some | |
776 | * internal tracing to verify that everything is in order. | |
777 | * If we fail, we do not register this tracer. | |
778 | */ | |
779 | tracing_reset_online_cpus(tr); | |
780 | ||
781 | current_trace = type; | |
782 | ||
783 | /* If we expanded the buffers, make sure the max is expanded too */ | |
784 | if (ring_buffer_expanded && type->use_max_tr) | |
785 | ring_buffer_resize(max_tr.buffer, trace_buf_size); | |
786 | ||
787 | /* the test is responsible for initializing and enabling */ | |
788 | pr_info("Testing tracer %s: ", type->name); | |
789 | ret = type->selftest(type, tr); | |
790 | /* the test is responsible for resetting too */ | |
791 | current_trace = saved_tracer; | |
792 | if (ret) { | |
793 | printk(KERN_CONT "FAILED!\n"); | |
794 | goto out; | |
795 | } | |
796 | /* Only reset on passing, to avoid touching corrupted buffers */ | |
797 | tracing_reset_online_cpus(tr); | |
798 | ||
799 | /* Shrink the max buffer again */ | |
800 | if (ring_buffer_expanded && type->use_max_tr) | |
801 | ring_buffer_resize(max_tr.buffer, 1); | |
802 | ||
803 | printk(KERN_CONT "PASSED\n"); | |
804 | } | |
805 | #endif | |
806 | ||
807 | type->next = trace_types; | |
808 | trace_types = type; | |
809 | ||
810 | out: | |
811 | tracing_selftest_running = false; | |
812 | mutex_unlock(&trace_types_lock); | |
813 | ||
814 | if (ret || !default_bootup_tracer) | |
815 | goto out_unlock; | |
816 | ||
817 | if (strncmp(default_bootup_tracer, type->name, MAX_TRACER_SIZE)) | |
818 | goto out_unlock; | |
819 | ||
820 | printk(KERN_INFO "Starting tracer '%s'\n", type->name); | |
821 | /* Do we want this tracer to start on bootup? */ | |
822 | tracing_set_tracer(type->name); | |
823 | default_bootup_tracer = NULL; | |
824 | /* disable other selftests, since this will break it. */ | |
825 | tracing_selftest_disabled = 1; | |
826 | #ifdef CONFIG_FTRACE_STARTUP_TEST | |
827 | printk(KERN_INFO "Disabling FTRACE selftests due to running tracer '%s'\n", | |
828 | type->name); | |
829 | #endif | |
830 | ||
831 | out_unlock: | |
832 | return ret; | |
833 | } | |
834 | ||
835 | void unregister_tracer(struct tracer *type) | |
836 | { | |
837 | struct tracer **t; | |
838 | ||
839 | mutex_lock(&trace_types_lock); | |
840 | for (t = &trace_types; *t; t = &(*t)->next) { | |
841 | if (*t == type) | |
842 | goto found; | |
843 | } | |
844 | pr_info("Tracer %s not registered\n", type->name); | |
845 | goto out; | |
846 | ||
847 | found: | |
848 | *t = (*t)->next; | |
849 | ||
850 | if (type == current_trace && tracer_enabled) { | |
851 | tracer_enabled = 0; | |
852 | tracing_stop(); | |
853 | if (current_trace->stop) | |
854 | current_trace->stop(&global_trace); | |
855 | current_trace = &nop_trace; | |
856 | } | |
857 | out: | |
858 | mutex_unlock(&trace_types_lock); | |
859 | } | |
860 | ||
861 | static void __tracing_reset(struct ring_buffer *buffer, int cpu) | |
862 | { | |
863 | ftrace_disable_cpu(); | |
864 | ring_buffer_reset_cpu(buffer, cpu); | |
865 | ftrace_enable_cpu(); | |
866 | } | |
867 | ||
868 | void tracing_reset(struct trace_array *tr, int cpu) | |
869 | { | |
870 | struct ring_buffer *buffer = tr->buffer; | |
871 | ||
872 | ring_buffer_record_disable(buffer); | |
873 | ||
874 | /* Make sure all commits have finished */ | |
875 | synchronize_sched(); | |
876 | __tracing_reset(buffer, cpu); | |
877 | ||
878 | ring_buffer_record_enable(buffer); | |
879 | } | |
880 | ||
881 | void tracing_reset_online_cpus(struct trace_array *tr) | |
882 | { | |
883 | struct ring_buffer *buffer = tr->buffer; | |
884 | int cpu; | |
885 | ||
886 | ring_buffer_record_disable(buffer); | |
887 | ||
888 | /* Make sure all commits have finished */ | |
889 | synchronize_sched(); | |
890 | ||
891 | tr->time_start = ftrace_now(tr->cpu); | |
892 | ||
893 | for_each_online_cpu(cpu) | |
894 | __tracing_reset(buffer, cpu); | |
895 | ||
896 | ring_buffer_record_enable(buffer); | |
897 | } | |
898 | ||
899 | void tracing_reset_current(int cpu) | |
900 | { | |
901 | tracing_reset(&global_trace, cpu); | |
902 | } | |
903 | ||
904 | void tracing_reset_current_online_cpus(void) | |
905 | { | |
906 | tracing_reset_online_cpus(&global_trace); | |
907 | } | |
908 | ||
909 | #define SAVED_CMDLINES 128 | |
910 | #define NO_CMDLINE_MAP UINT_MAX | |
911 | static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1]; | |
912 | static unsigned map_cmdline_to_pid[SAVED_CMDLINES]; | |
913 | static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN]; | |
914 | static int cmdline_idx; | |
915 | static arch_spinlock_t trace_cmdline_lock = __ARCH_SPIN_LOCK_UNLOCKED; | |
916 | ||
917 | /* temporary disable recording */ | |
918 | static atomic_t trace_record_cmdline_disabled __read_mostly; | |
919 | ||
920 | static void trace_init_cmdlines(void) | |
921 | { | |
922 | memset(&map_pid_to_cmdline, NO_CMDLINE_MAP, sizeof(map_pid_to_cmdline)); | |
923 | memset(&map_cmdline_to_pid, NO_CMDLINE_MAP, sizeof(map_cmdline_to_pid)); | |
924 | cmdline_idx = 0; | |
925 | } | |
926 | ||
927 | int is_tracing_stopped(void) | |
928 | { | |
929 | return trace_stop_count; | |
930 | } | |
931 | ||
932 | /** | |
933 | * ftrace_off_permanent - disable all ftrace code permanently | |
934 | * | |
935 | * This should only be called when a serious anomally has | |
936 | * been detected. This will turn off the function tracing, | |
937 | * ring buffers, and other tracing utilites. It takes no | |
938 | * locks and can be called from any context. | |
939 | */ | |
940 | void ftrace_off_permanent(void) | |
941 | { | |
942 | tracing_disabled = 1; | |
943 | ftrace_stop(); | |
944 | tracing_off_permanent(); | |
945 | } | |
946 | ||
947 | /** | |
948 | * tracing_start - quick start of the tracer | |
949 | * | |
950 | * If tracing is enabled but was stopped by tracing_stop, | |
951 | * this will start the tracer back up. | |
952 | */ | |
953 | void tracing_start(void) | |
954 | { | |
955 | struct ring_buffer *buffer; | |
956 | unsigned long flags; | |
957 | ||
958 | if (tracing_disabled) | |
959 | return; | |
960 | ||
961 | spin_lock_irqsave(&tracing_start_lock, flags); | |
962 | if (--trace_stop_count) { | |
963 | if (trace_stop_count < 0) { | |
964 | /* Someone screwed up their debugging */ | |
965 | WARN_ON_ONCE(1); | |
966 | trace_stop_count = 0; | |
967 | } | |
968 | goto out; | |
969 | } | |
970 | ||
971 | /* Prevent the buffers from switching */ | |
972 | arch_spin_lock(&ftrace_max_lock); | |
973 | ||
974 | buffer = global_trace.buffer; | |
975 | if (buffer) | |
976 | ring_buffer_record_enable(buffer); | |
977 | ||
978 | buffer = max_tr.buffer; | |
979 | if (buffer) | |
980 | ring_buffer_record_enable(buffer); | |
981 | ||
982 | arch_spin_unlock(&ftrace_max_lock); | |
983 | ||
984 | ftrace_start(); | |
985 | out: | |
986 | spin_unlock_irqrestore(&tracing_start_lock, flags); | |
987 | } | |
988 | ||
989 | /** | |
990 | * tracing_stop - quick stop of the tracer | |
991 | * | |
992 | * Light weight way to stop tracing. Use in conjunction with | |
993 | * tracing_start. | |
994 | */ | |
995 | void tracing_stop(void) | |
996 | { | |
997 | struct ring_buffer *buffer; | |
998 | unsigned long flags; | |
999 | ||
1000 | ftrace_stop(); | |
1001 | spin_lock_irqsave(&tracing_start_lock, flags); | |
1002 | if (trace_stop_count++) | |
1003 | goto out; | |
1004 | ||
1005 | /* Prevent the buffers from switching */ | |
1006 | arch_spin_lock(&ftrace_max_lock); | |
1007 | ||
1008 | buffer = global_trace.buffer; | |
1009 | if (buffer) | |
1010 | ring_buffer_record_disable(buffer); | |
1011 | ||
1012 | buffer = max_tr.buffer; | |
1013 | if (buffer) | |
1014 | ring_buffer_record_disable(buffer); | |
1015 | ||
1016 | arch_spin_unlock(&ftrace_max_lock); | |
1017 | ||
1018 | out: | |
1019 | spin_unlock_irqrestore(&tracing_start_lock, flags); | |
1020 | } | |
1021 | ||
1022 | void trace_stop_cmdline_recording(void); | |
1023 | ||
1024 | static void trace_save_cmdline(struct task_struct *tsk) | |
1025 | { | |
1026 | unsigned pid, idx; | |
1027 | ||
1028 | if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT)) | |
1029 | return; | |
1030 | ||
1031 | /* | |
1032 | * It's not the end of the world if we don't get | |
1033 | * the lock, but we also don't want to spin | |
1034 | * nor do we want to disable interrupts, | |
1035 | * so if we miss here, then better luck next time. | |
1036 | */ | |
1037 | if (!arch_spin_trylock(&trace_cmdline_lock)) | |
1038 | return; | |
1039 | ||
1040 | idx = map_pid_to_cmdline[tsk->pid]; | |
1041 | if (idx == NO_CMDLINE_MAP) { | |
1042 | idx = (cmdline_idx + 1) % SAVED_CMDLINES; | |
1043 | ||
1044 | /* | |
1045 | * Check whether the cmdline buffer at idx has a pid | |
1046 | * mapped. We are going to overwrite that entry so we | |
1047 | * need to clear the map_pid_to_cmdline. Otherwise we | |
1048 | * would read the new comm for the old pid. | |
1049 | */ | |
1050 | pid = map_cmdline_to_pid[idx]; | |
1051 | if (pid != NO_CMDLINE_MAP) | |
1052 | map_pid_to_cmdline[pid] = NO_CMDLINE_MAP; | |
1053 | ||
1054 | map_cmdline_to_pid[idx] = tsk->pid; | |
1055 | map_pid_to_cmdline[tsk->pid] = idx; | |
1056 | ||
1057 | cmdline_idx = idx; | |
1058 | } | |
1059 | ||
1060 | memcpy(&saved_cmdlines[idx], tsk->comm, TASK_COMM_LEN); | |
1061 | ||
1062 | arch_spin_unlock(&trace_cmdline_lock); | |
1063 | } | |
1064 | ||
1065 | void trace_find_cmdline(int pid, char comm[]) | |
1066 | { | |
1067 | unsigned map; | |
1068 | ||
1069 | if (!pid) { | |
1070 | strcpy(comm, "<idle>"); | |
1071 | return; | |
1072 | } | |
1073 | ||
1074 | if (WARN_ON_ONCE(pid < 0)) { | |
1075 | strcpy(comm, "<XXX>"); | |
1076 | return; | |
1077 | } | |
1078 | ||
1079 | if (pid > PID_MAX_DEFAULT) { | |
1080 | strcpy(comm, "<...>"); | |
1081 | return; | |
1082 | } | |
1083 | ||
1084 | preempt_disable(); | |
1085 | arch_spin_lock(&trace_cmdline_lock); | |
1086 | map = map_pid_to_cmdline[pid]; | |
1087 | if (map != NO_CMDLINE_MAP) | |
1088 | strcpy(comm, saved_cmdlines[map]); | |
1089 | else | |
1090 | strcpy(comm, "<...>"); | |
1091 | ||
1092 | arch_spin_unlock(&trace_cmdline_lock); | |
1093 | preempt_enable(); | |
1094 | } | |
1095 | ||
1096 | void tracing_record_cmdline(struct task_struct *tsk) | |
1097 | { | |
1098 | if (atomic_read(&trace_record_cmdline_disabled) || !tracer_enabled || | |
1099 | !tracing_is_on()) | |
1100 | return; | |
1101 | ||
1102 | trace_save_cmdline(tsk); | |
1103 | } | |
1104 | ||
1105 | void | |
1106 | tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags, | |
1107 | int pc) | |
1108 | { | |
1109 | struct task_struct *tsk = current; | |
1110 | ||
1111 | entry->preempt_count = pc & 0xff; | |
1112 | entry->pid = (tsk) ? tsk->pid : 0; | |
1113 | entry->padding = 0; | |
1114 | entry->flags = | |
1115 | #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT | |
1116 | (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) | | |
1117 | #else | |
1118 | TRACE_FLAG_IRQS_NOSUPPORT | | |
1119 | #endif | |
1120 | ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) | | |
1121 | ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) | | |
1122 | (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0); | |
1123 | } | |
1124 | EXPORT_SYMBOL_GPL(tracing_generic_entry_update); | |
1125 | ||
1126 | struct ring_buffer_event * | |
1127 | trace_buffer_lock_reserve(struct ring_buffer *buffer, | |
1128 | int type, | |
1129 | unsigned long len, | |
1130 | unsigned long flags, int pc) | |
1131 | { | |
1132 | struct ring_buffer_event *event; | |
1133 | ||
1134 | event = ring_buffer_lock_reserve(buffer, len); | |
1135 | if (event != NULL) { | |
1136 | struct trace_entry *ent = ring_buffer_event_data(event); | |
1137 | ||
1138 | tracing_generic_entry_update(ent, flags, pc); | |
1139 | ent->type = type; | |
1140 | } | |
1141 | ||
1142 | return event; | |
1143 | } | |
1144 | ||
1145 | static inline void | |
1146 | __trace_buffer_unlock_commit(struct ring_buffer *buffer, | |
1147 | struct ring_buffer_event *event, | |
1148 | unsigned long flags, int pc, | |
1149 | int wake) | |
1150 | { | |
1151 | ring_buffer_unlock_commit(buffer, event); | |
1152 | ||
1153 | ftrace_trace_stack(buffer, flags, 6, pc); | |
1154 | ftrace_trace_userstack(buffer, flags, pc); | |
1155 | ||
1156 | if (wake) | |
1157 | trace_wake_up(); | |
1158 | } | |
1159 | ||
1160 | void trace_buffer_unlock_commit(struct ring_buffer *buffer, | |
1161 | struct ring_buffer_event *event, | |
1162 | unsigned long flags, int pc) | |
1163 | { | |
1164 | __trace_buffer_unlock_commit(buffer, event, flags, pc, 1); | |
1165 | } | |
1166 | ||
1167 | struct ring_buffer_event * | |
1168 | trace_current_buffer_lock_reserve(struct ring_buffer **current_rb, | |
1169 | int type, unsigned long len, | |
1170 | unsigned long flags, int pc) | |
1171 | { | |
1172 | *current_rb = global_trace.buffer; | |
1173 | return trace_buffer_lock_reserve(*current_rb, | |
1174 | type, len, flags, pc); | |
1175 | } | |
1176 | EXPORT_SYMBOL_GPL(trace_current_buffer_lock_reserve); | |
1177 | ||
1178 | void trace_current_buffer_unlock_commit(struct ring_buffer *buffer, | |
1179 | struct ring_buffer_event *event, | |
1180 | unsigned long flags, int pc) | |
1181 | { | |
1182 | __trace_buffer_unlock_commit(buffer, event, flags, pc, 1); | |
1183 | } | |
1184 | EXPORT_SYMBOL_GPL(trace_current_buffer_unlock_commit); | |
1185 | ||
1186 | void trace_nowake_buffer_unlock_commit(struct ring_buffer *buffer, | |
1187 | struct ring_buffer_event *event, | |
1188 | unsigned long flags, int pc) | |
1189 | { | |
1190 | __trace_buffer_unlock_commit(buffer, event, flags, pc, 0); | |
1191 | } | |
1192 | EXPORT_SYMBOL_GPL(trace_nowake_buffer_unlock_commit); | |
1193 | ||
1194 | void trace_current_buffer_discard_commit(struct ring_buffer *buffer, | |
1195 | struct ring_buffer_event *event) | |
1196 | { | |
1197 | ring_buffer_discard_commit(buffer, event); | |
1198 | } | |
1199 | EXPORT_SYMBOL_GPL(trace_current_buffer_discard_commit); | |
1200 | ||
1201 | void | |
1202 | trace_function(struct trace_array *tr, | |
1203 | unsigned long ip, unsigned long parent_ip, unsigned long flags, | |
1204 | int pc) | |
1205 | { | |
1206 | struct ftrace_event_call *call = &event_function; | |
1207 | struct ring_buffer *buffer = tr->buffer; | |
1208 | struct ring_buffer_event *event; | |
1209 | struct ftrace_entry *entry; | |
1210 | ||
1211 | /* If we are reading the ring buffer, don't trace */ | |
1212 | if (unlikely(__this_cpu_read(ftrace_cpu_disabled))) | |
1213 | return; | |
1214 | ||
1215 | event = trace_buffer_lock_reserve(buffer, TRACE_FN, sizeof(*entry), | |
1216 | flags, pc); | |
1217 | if (!event) | |
1218 | return; | |
1219 | entry = ring_buffer_event_data(event); | |
1220 | entry->ip = ip; | |
1221 | entry->parent_ip = parent_ip; | |
1222 | ||
1223 | if (!filter_check_discard(call, entry, buffer, event)) | |
1224 | ring_buffer_unlock_commit(buffer, event); | |
1225 | } | |
1226 | ||
1227 | void | |
1228 | ftrace(struct trace_array *tr, struct trace_array_cpu *data, | |
1229 | unsigned long ip, unsigned long parent_ip, unsigned long flags, | |
1230 | int pc) | |
1231 | { | |
1232 | if (likely(!atomic_read(&data->disabled))) | |
1233 | trace_function(tr, ip, parent_ip, flags, pc); | |
1234 | } | |
1235 | ||
1236 | #ifdef CONFIG_STACKTRACE | |
1237 | static void __ftrace_trace_stack(struct ring_buffer *buffer, | |
1238 | unsigned long flags, | |
1239 | int skip, int pc) | |
1240 | { | |
1241 | struct ftrace_event_call *call = &event_kernel_stack; | |
1242 | struct ring_buffer_event *event; | |
1243 | struct stack_entry *entry; | |
1244 | struct stack_trace trace; | |
1245 | ||
1246 | event = trace_buffer_lock_reserve(buffer, TRACE_STACK, | |
1247 | sizeof(*entry), flags, pc); | |
1248 | if (!event) | |
1249 | return; | |
1250 | entry = ring_buffer_event_data(event); | |
1251 | memset(&entry->caller, 0, sizeof(entry->caller)); | |
1252 | ||
1253 | trace.nr_entries = 0; | |
1254 | trace.max_entries = FTRACE_STACK_ENTRIES; | |
1255 | trace.skip = skip; | |
1256 | trace.entries = entry->caller; | |
1257 | ||
1258 | save_stack_trace(&trace); | |
1259 | if (!filter_check_discard(call, entry, buffer, event)) | |
1260 | ring_buffer_unlock_commit(buffer, event); | |
1261 | } | |
1262 | ||
1263 | void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags, | |
1264 | int skip, int pc) | |
1265 | { | |
1266 | if (!(trace_flags & TRACE_ITER_STACKTRACE)) | |
1267 | return; | |
1268 | ||
1269 | __ftrace_trace_stack(buffer, flags, skip, pc); | |
1270 | } | |
1271 | ||
1272 | void __trace_stack(struct trace_array *tr, unsigned long flags, int skip, | |
1273 | int pc) | |
1274 | { | |
1275 | __ftrace_trace_stack(tr->buffer, flags, skip, pc); | |
1276 | } | |
1277 | ||
1278 | /** | |
1279 | * trace_dump_stack - record a stack back trace in the trace buffer | |
1280 | */ | |
1281 | void trace_dump_stack(void) | |
1282 | { | |
1283 | unsigned long flags; | |
1284 | ||
1285 | if (tracing_disabled || tracing_selftest_running) | |
1286 | return; | |
1287 | ||
1288 | local_save_flags(flags); | |
1289 | ||
1290 | /* skipping 3 traces, seems to get us at the caller of this function */ | |
1291 | __ftrace_trace_stack(global_trace.buffer, flags, 3, preempt_count()); | |
1292 | } | |
1293 | ||
1294 | static DEFINE_PER_CPU(int, user_stack_count); | |
1295 | ||
1296 | void | |
1297 | ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc) | |
1298 | { | |
1299 | struct ftrace_event_call *call = &event_user_stack; | |
1300 | struct ring_buffer_event *event; | |
1301 | struct userstack_entry *entry; | |
1302 | struct stack_trace trace; | |
1303 | ||
1304 | if (!(trace_flags & TRACE_ITER_USERSTACKTRACE)) | |
1305 | return; | |
1306 | ||
1307 | /* | |
1308 | * NMIs can not handle page faults, even with fix ups. | |
1309 | * The save user stack can (and often does) fault. | |
1310 | */ | |
1311 | if (unlikely(in_nmi())) | |
1312 | return; | |
1313 | ||
1314 | /* | |
1315 | * prevent recursion, since the user stack tracing may | |
1316 | * trigger other kernel events. | |
1317 | */ | |
1318 | preempt_disable(); | |
1319 | if (__this_cpu_read(user_stack_count)) | |
1320 | goto out; | |
1321 | ||
1322 | __this_cpu_inc(user_stack_count); | |
1323 | ||
1324 | event = trace_buffer_lock_reserve(buffer, TRACE_USER_STACK, | |
1325 | sizeof(*entry), flags, pc); | |
1326 | if (!event) | |
1327 | goto out_drop_count; | |
1328 | entry = ring_buffer_event_data(event); | |
1329 | ||
1330 | entry->tgid = current->tgid; | |
1331 | memset(&entry->caller, 0, sizeof(entry->caller)); | |
1332 | ||
1333 | trace.nr_entries = 0; | |
1334 | trace.max_entries = FTRACE_STACK_ENTRIES; | |
1335 | trace.skip = 0; | |
1336 | trace.entries = entry->caller; | |
1337 | ||
1338 | save_stack_trace_user(&trace); | |
1339 | if (!filter_check_discard(call, entry, buffer, event)) | |
1340 | ring_buffer_unlock_commit(buffer, event); | |
1341 | ||
1342 | out_drop_count: | |
1343 | __this_cpu_dec(user_stack_count); | |
1344 | out: | |
1345 | preempt_enable(); | |
1346 | } | |
1347 | ||
1348 | #ifdef UNUSED | |
1349 | static void __trace_userstack(struct trace_array *tr, unsigned long flags) | |
1350 | { | |
1351 | ftrace_trace_userstack(tr, flags, preempt_count()); | |
1352 | } | |
1353 | #endif /* UNUSED */ | |
1354 | ||
1355 | #endif /* CONFIG_STACKTRACE */ | |
1356 | ||
1357 | /** | |
1358 | * trace_vbprintk - write binary msg to tracing buffer | |
1359 | * | |
1360 | */ | |
1361 | int trace_vbprintk(unsigned long ip, const char *fmt, va_list args) | |
1362 | { | |
1363 | static arch_spinlock_t trace_buf_lock = | |
1364 | (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; | |
1365 | static u32 trace_buf[TRACE_BUF_SIZE]; | |
1366 | ||
1367 | struct ftrace_event_call *call = &event_bprint; | |
1368 | struct ring_buffer_event *event; | |
1369 | struct ring_buffer *buffer; | |
1370 | struct trace_array *tr = &global_trace; | |
1371 | struct trace_array_cpu *data; | |
1372 | struct bprint_entry *entry; | |
1373 | unsigned long flags; | |
1374 | int disable; | |
1375 | int cpu, len = 0, size, pc; | |
1376 | ||
1377 | if (unlikely(tracing_selftest_running || tracing_disabled)) | |
1378 | return 0; | |
1379 | ||
1380 | /* Don't pollute graph traces with trace_vprintk internals */ | |
1381 | pause_graph_tracing(); | |
1382 | ||
1383 | pc = preempt_count(); | |
1384 | preempt_disable_notrace(); | |
1385 | cpu = raw_smp_processor_id(); | |
1386 | data = tr->data[cpu]; | |
1387 | ||
1388 | disable = atomic_inc_return(&data->disabled); | |
1389 | if (unlikely(disable != 1)) | |
1390 | goto out; | |
1391 | ||
1392 | /* Lockdep uses trace_printk for lock tracing */ | |
1393 | local_irq_save(flags); | |
1394 | arch_spin_lock(&trace_buf_lock); | |
1395 | len = vbin_printf(trace_buf, TRACE_BUF_SIZE, fmt, args); | |
1396 | ||
1397 | if (len > TRACE_BUF_SIZE || len < 0) | |
1398 | goto out_unlock; | |
1399 | ||
1400 | size = sizeof(*entry) + sizeof(u32) * len; | |
1401 | buffer = tr->buffer; | |
1402 | event = trace_buffer_lock_reserve(buffer, TRACE_BPRINT, size, | |
1403 | flags, pc); | |
1404 | if (!event) | |
1405 | goto out_unlock; | |
1406 | entry = ring_buffer_event_data(event); | |
1407 | entry->ip = ip; | |
1408 | entry->fmt = fmt; | |
1409 | ||
1410 | memcpy(entry->buf, trace_buf, sizeof(u32) * len); | |
1411 | if (!filter_check_discard(call, entry, buffer, event)) { | |
1412 | ring_buffer_unlock_commit(buffer, event); | |
1413 | ftrace_trace_stack(buffer, flags, 6, pc); | |
1414 | } | |
1415 | ||
1416 | out_unlock: | |
1417 | arch_spin_unlock(&trace_buf_lock); | |
1418 | local_irq_restore(flags); | |
1419 | ||
1420 | out: | |
1421 | atomic_dec_return(&data->disabled); | |
1422 | preempt_enable_notrace(); | |
1423 | unpause_graph_tracing(); | |
1424 | ||
1425 | return len; | |
1426 | } | |
1427 | EXPORT_SYMBOL_GPL(trace_vbprintk); | |
1428 | ||
1429 | int trace_array_printk(struct trace_array *tr, | |
1430 | unsigned long ip, const char *fmt, ...) | |
1431 | { | |
1432 | int ret; | |
1433 | va_list ap; | |
1434 | ||
1435 | if (!(trace_flags & TRACE_ITER_PRINTK)) | |
1436 | return 0; | |
1437 | ||
1438 | va_start(ap, fmt); | |
1439 | ret = trace_array_vprintk(tr, ip, fmt, ap); | |
1440 | va_end(ap); | |
1441 | return ret; | |
1442 | } | |
1443 | ||
1444 | int trace_array_vprintk(struct trace_array *tr, | |
1445 | unsigned long ip, const char *fmt, va_list args) | |
1446 | { | |
1447 | static arch_spinlock_t trace_buf_lock = __ARCH_SPIN_LOCK_UNLOCKED; | |
1448 | static char trace_buf[TRACE_BUF_SIZE]; | |
1449 | ||
1450 | struct ftrace_event_call *call = &event_print; | |
1451 | struct ring_buffer_event *event; | |
1452 | struct ring_buffer *buffer; | |
1453 | struct trace_array_cpu *data; | |
1454 | int cpu, len = 0, size, pc; | |
1455 | struct print_entry *entry; | |
1456 | unsigned long irq_flags; | |
1457 | int disable; | |
1458 | ||
1459 | if (tracing_disabled || tracing_selftest_running) | |
1460 | return 0; | |
1461 | ||
1462 | pc = preempt_count(); | |
1463 | preempt_disable_notrace(); | |
1464 | cpu = raw_smp_processor_id(); | |
1465 | data = tr->data[cpu]; | |
1466 | ||
1467 | disable = atomic_inc_return(&data->disabled); | |
1468 | if (unlikely(disable != 1)) | |
1469 | goto out; | |
1470 | ||
1471 | pause_graph_tracing(); | |
1472 | raw_local_irq_save(irq_flags); | |
1473 | arch_spin_lock(&trace_buf_lock); | |
1474 | len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args); | |
1475 | ||
1476 | size = sizeof(*entry) + len + 1; | |
1477 | buffer = tr->buffer; | |
1478 | event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size, | |
1479 | irq_flags, pc); | |
1480 | if (!event) | |
1481 | goto out_unlock; | |
1482 | entry = ring_buffer_event_data(event); | |
1483 | entry->ip = ip; | |
1484 | ||
1485 | memcpy(&entry->buf, trace_buf, len); | |
1486 | entry->buf[len] = '\0'; | |
1487 | if (!filter_check_discard(call, entry, buffer, event)) { | |
1488 | ring_buffer_unlock_commit(buffer, event); | |
1489 | ftrace_trace_stack(buffer, irq_flags, 6, pc); | |
1490 | } | |
1491 | ||
1492 | out_unlock: | |
1493 | arch_spin_unlock(&trace_buf_lock); | |
1494 | raw_local_irq_restore(irq_flags); | |
1495 | unpause_graph_tracing(); | |
1496 | out: | |
1497 | atomic_dec_return(&data->disabled); | |
1498 | preempt_enable_notrace(); | |
1499 | ||
1500 | return len; | |
1501 | } | |
1502 | ||
1503 | int trace_vprintk(unsigned long ip, const char *fmt, va_list args) | |
1504 | { | |
1505 | return trace_array_vprintk(&global_trace, ip, fmt, args); | |
1506 | } | |
1507 | EXPORT_SYMBOL_GPL(trace_vprintk); | |
1508 | ||
1509 | static void trace_iterator_increment(struct trace_iterator *iter) | |
1510 | { | |
1511 | /* Don't allow ftrace to trace into the ring buffers */ | |
1512 | ftrace_disable_cpu(); | |
1513 | ||
1514 | iter->idx++; | |
1515 | if (iter->buffer_iter[iter->cpu]) | |
1516 | ring_buffer_read(iter->buffer_iter[iter->cpu], NULL); | |
1517 | ||
1518 | ftrace_enable_cpu(); | |
1519 | } | |
1520 | ||
1521 | static struct trace_entry * | |
1522 | peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts, | |
1523 | unsigned long *lost_events) | |
1524 | { | |
1525 | struct ring_buffer_event *event; | |
1526 | struct ring_buffer_iter *buf_iter = iter->buffer_iter[cpu]; | |
1527 | ||
1528 | /* Don't allow ftrace to trace into the ring buffers */ | |
1529 | ftrace_disable_cpu(); | |
1530 | ||
1531 | if (buf_iter) | |
1532 | event = ring_buffer_iter_peek(buf_iter, ts); | |
1533 | else | |
1534 | event = ring_buffer_peek(iter->tr->buffer, cpu, ts, | |
1535 | lost_events); | |
1536 | ||
1537 | ftrace_enable_cpu(); | |
1538 | ||
1539 | return event ? ring_buffer_event_data(event) : NULL; | |
1540 | } | |
1541 | ||
1542 | static struct trace_entry * | |
1543 | __find_next_entry(struct trace_iterator *iter, int *ent_cpu, | |
1544 | unsigned long *missing_events, u64 *ent_ts) | |
1545 | { | |
1546 | struct ring_buffer *buffer = iter->tr->buffer; | |
1547 | struct trace_entry *ent, *next = NULL; | |
1548 | unsigned long lost_events = 0, next_lost = 0; | |
1549 | int cpu_file = iter->cpu_file; | |
1550 | u64 next_ts = 0, ts; | |
1551 | int next_cpu = -1; | |
1552 | int cpu; | |
1553 | ||
1554 | /* | |
1555 | * If we are in a per_cpu trace file, don't bother by iterating over | |
1556 | * all cpu and peek directly. | |
1557 | */ | |
1558 | if (cpu_file > TRACE_PIPE_ALL_CPU) { | |
1559 | if (ring_buffer_empty_cpu(buffer, cpu_file)) | |
1560 | return NULL; | |
1561 | ent = peek_next_entry(iter, cpu_file, ent_ts, missing_events); | |
1562 | if (ent_cpu) | |
1563 | *ent_cpu = cpu_file; | |
1564 | ||
1565 | return ent; | |
1566 | } | |
1567 | ||
1568 | for_each_tracing_cpu(cpu) { | |
1569 | ||
1570 | if (ring_buffer_empty_cpu(buffer, cpu)) | |
1571 | continue; | |
1572 | ||
1573 | ent = peek_next_entry(iter, cpu, &ts, &lost_events); | |
1574 | ||
1575 | /* | |
1576 | * Pick the entry with the smallest timestamp: | |
1577 | */ | |
1578 | if (ent && (!next || ts < next_ts)) { | |
1579 | next = ent; | |
1580 | next_cpu = cpu; | |
1581 | next_ts = ts; | |
1582 | next_lost = lost_events; | |
1583 | } | |
1584 | } | |
1585 | ||
1586 | if (ent_cpu) | |
1587 | *ent_cpu = next_cpu; | |
1588 | ||
1589 | if (ent_ts) | |
1590 | *ent_ts = next_ts; | |
1591 | ||
1592 | if (missing_events) | |
1593 | *missing_events = next_lost; | |
1594 | ||
1595 | return next; | |
1596 | } | |
1597 | ||
1598 | /* Find the next real entry, without updating the iterator itself */ | |
1599 | struct trace_entry *trace_find_next_entry(struct trace_iterator *iter, | |
1600 | int *ent_cpu, u64 *ent_ts) | |
1601 | { | |
1602 | return __find_next_entry(iter, ent_cpu, NULL, ent_ts); | |
1603 | } | |
1604 | ||
1605 | /* Find the next real entry, and increment the iterator to the next entry */ | |
1606 | void *trace_find_next_entry_inc(struct trace_iterator *iter) | |
1607 | { | |
1608 | iter->ent = __find_next_entry(iter, &iter->cpu, | |
1609 | &iter->lost_events, &iter->ts); | |
1610 | ||
1611 | if (iter->ent) | |
1612 | trace_iterator_increment(iter); | |
1613 | ||
1614 | return iter->ent ? iter : NULL; | |
1615 | } | |
1616 | ||
1617 | static void trace_consume(struct trace_iterator *iter) | |
1618 | { | |
1619 | /* Don't allow ftrace to trace into the ring buffers */ | |
1620 | ftrace_disable_cpu(); | |
1621 | ring_buffer_consume(iter->tr->buffer, iter->cpu, &iter->ts, | |
1622 | &iter->lost_events); | |
1623 | ftrace_enable_cpu(); | |
1624 | } | |
1625 | ||
1626 | static void *s_next(struct seq_file *m, void *v, loff_t *pos) | |
1627 | { | |
1628 | struct trace_iterator *iter = m->private; | |
1629 | int i = (int)*pos; | |
1630 | void *ent; | |
1631 | ||
1632 | WARN_ON_ONCE(iter->leftover); | |
1633 | ||
1634 | (*pos)++; | |
1635 | ||
1636 | /* can't go backwards */ | |
1637 | if (iter->idx > i) | |
1638 | return NULL; | |
1639 | ||
1640 | if (iter->idx < 0) | |
1641 | ent = trace_find_next_entry_inc(iter); | |
1642 | else | |
1643 | ent = iter; | |
1644 | ||
1645 | while (ent && iter->idx < i) | |
1646 | ent = trace_find_next_entry_inc(iter); | |
1647 | ||
1648 | iter->pos = *pos; | |
1649 | ||
1650 | return ent; | |
1651 | } | |
1652 | ||
1653 | void tracing_iter_reset(struct trace_iterator *iter, int cpu) | |
1654 | { | |
1655 | struct trace_array *tr = iter->tr; | |
1656 | struct ring_buffer_event *event; | |
1657 | struct ring_buffer_iter *buf_iter; | |
1658 | unsigned long entries = 0; | |
1659 | u64 ts; | |
1660 | ||
1661 | tr->data[cpu]->skipped_entries = 0; | |
1662 | ||
1663 | if (!iter->buffer_iter[cpu]) | |
1664 | return; | |
1665 | ||
1666 | buf_iter = iter->buffer_iter[cpu]; | |
1667 | ring_buffer_iter_reset(buf_iter); | |
1668 | ||
1669 | /* | |
1670 | * We could have the case with the max latency tracers | |
1671 | * that a reset never took place on a cpu. This is evident | |
1672 | * by the timestamp being before the start of the buffer. | |
1673 | */ | |
1674 | while ((event = ring_buffer_iter_peek(buf_iter, &ts))) { | |
1675 | if (ts >= iter->tr->time_start) | |
1676 | break; | |
1677 | entries++; | |
1678 | ring_buffer_read(buf_iter, NULL); | |
1679 | } | |
1680 | ||
1681 | tr->data[cpu]->skipped_entries = entries; | |
1682 | } | |
1683 | ||
1684 | /* | |
1685 | * The current tracer is copied to avoid a global locking | |
1686 | * all around. | |
1687 | */ | |
1688 | static void *s_start(struct seq_file *m, loff_t *pos) | |
1689 | { | |
1690 | struct trace_iterator *iter = m->private; | |
1691 | static struct tracer *old_tracer; | |
1692 | int cpu_file = iter->cpu_file; | |
1693 | void *p = NULL; | |
1694 | loff_t l = 0; | |
1695 | int cpu; | |
1696 | ||
1697 | /* copy the tracer to avoid using a global lock all around */ | |
1698 | mutex_lock(&trace_types_lock); | |
1699 | if (unlikely(old_tracer != current_trace && current_trace)) { | |
1700 | old_tracer = current_trace; | |
1701 | *iter->trace = *current_trace; | |
1702 | } | |
1703 | mutex_unlock(&trace_types_lock); | |
1704 | ||
1705 | atomic_inc(&trace_record_cmdline_disabled); | |
1706 | ||
1707 | if (*pos != iter->pos) { | |
1708 | iter->ent = NULL; | |
1709 | iter->cpu = 0; | |
1710 | iter->idx = -1; | |
1711 | ||
1712 | ftrace_disable_cpu(); | |
1713 | ||
1714 | if (cpu_file == TRACE_PIPE_ALL_CPU) { | |
1715 | for_each_tracing_cpu(cpu) | |
1716 | tracing_iter_reset(iter, cpu); | |
1717 | } else | |
1718 | tracing_iter_reset(iter, cpu_file); | |
1719 | ||
1720 | ftrace_enable_cpu(); | |
1721 | ||
1722 | iter->leftover = 0; | |
1723 | for (p = iter; p && l < *pos; p = s_next(m, p, &l)) | |
1724 | ; | |
1725 | ||
1726 | } else { | |
1727 | /* | |
1728 | * If we overflowed the seq_file before, then we want | |
1729 | * to just reuse the trace_seq buffer again. | |
1730 | */ | |
1731 | if (iter->leftover) | |
1732 | p = iter; | |
1733 | else { | |
1734 | l = *pos - 1; | |
1735 | p = s_next(m, p, &l); | |
1736 | } | |
1737 | } | |
1738 | ||
1739 | trace_event_read_lock(); | |
1740 | trace_access_lock(cpu_file); | |
1741 | return p; | |
1742 | } | |
1743 | ||
1744 | static void s_stop(struct seq_file *m, void *p) | |
1745 | { | |
1746 | struct trace_iterator *iter = m->private; | |
1747 | ||
1748 | atomic_dec(&trace_record_cmdline_disabled); | |
1749 | trace_access_unlock(iter->cpu_file); | |
1750 | trace_event_read_unlock(); | |
1751 | } | |
1752 | ||
1753 | static void print_lat_help_header(struct seq_file *m) | |
1754 | { | |
1755 | seq_puts(m, "# _------=> CPU# \n"); | |
1756 | seq_puts(m, "# / _-----=> irqs-off \n"); | |
1757 | seq_puts(m, "# | / _----=> need-resched \n"); | |
1758 | seq_puts(m, "# || / _---=> hardirq/softirq \n"); | |
1759 | seq_puts(m, "# ||| / _--=> preempt-depth \n"); | |
1760 | seq_puts(m, "# |||| / delay \n"); | |
1761 | seq_puts(m, "# cmd pid ||||| time | caller \n"); | |
1762 | seq_puts(m, "# \\ / ||||| \\ | / \n"); | |
1763 | } | |
1764 | ||
1765 | static void print_func_help_header(struct seq_file *m) | |
1766 | { | |
1767 | seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n"); | |
1768 | seq_puts(m, "# | | | | |\n"); | |
1769 | } | |
1770 | ||
1771 | ||
1772 | void | |
1773 | print_trace_header(struct seq_file *m, struct trace_iterator *iter) | |
1774 | { | |
1775 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); | |
1776 | struct trace_array *tr = iter->tr; | |
1777 | struct trace_array_cpu *data = tr->data[tr->cpu]; | |
1778 | struct tracer *type = current_trace; | |
1779 | unsigned long entries = 0; | |
1780 | unsigned long total = 0; | |
1781 | unsigned long count; | |
1782 | const char *name = "preemption"; | |
1783 | int cpu; | |
1784 | ||
1785 | if (type) | |
1786 | name = type->name; | |
1787 | ||
1788 | ||
1789 | for_each_tracing_cpu(cpu) { | |
1790 | count = ring_buffer_entries_cpu(tr->buffer, cpu); | |
1791 | /* | |
1792 | * If this buffer has skipped entries, then we hold all | |
1793 | * entries for the trace and we need to ignore the | |
1794 | * ones before the time stamp. | |
1795 | */ | |
1796 | if (tr->data[cpu]->skipped_entries) { | |
1797 | count -= tr->data[cpu]->skipped_entries; | |
1798 | /* total is the same as the entries */ | |
1799 | total += count; | |
1800 | } else | |
1801 | total += count + | |
1802 | ring_buffer_overrun_cpu(tr->buffer, cpu); | |
1803 | entries += count; | |
1804 | } | |
1805 | ||
1806 | seq_printf(m, "# %s latency trace v1.1.5 on %s\n", | |
1807 | name, UTS_RELEASE); | |
1808 | seq_puts(m, "# -----------------------------------" | |
1809 | "---------------------------------\n"); | |
1810 | seq_printf(m, "# latency: %lu us, #%lu/%lu, CPU#%d |" | |
1811 | " (M:%s VP:%d, KP:%d, SP:%d HP:%d", | |
1812 | nsecs_to_usecs(data->saved_latency), | |
1813 | entries, | |
1814 | total, | |
1815 | tr->cpu, | |
1816 | #if defined(CONFIG_PREEMPT_NONE) | |
1817 | "server", | |
1818 | #elif defined(CONFIG_PREEMPT_VOLUNTARY) | |
1819 | "desktop", | |
1820 | #elif defined(CONFIG_PREEMPT) | |
1821 | "preempt", | |
1822 | #else | |
1823 | "unknown", | |
1824 | #endif | |
1825 | /* These are reserved for later use */ | |
1826 | 0, 0, 0, 0); | |
1827 | #ifdef CONFIG_SMP | |
1828 | seq_printf(m, " #P:%d)\n", num_online_cpus()); | |
1829 | #else | |
1830 | seq_puts(m, ")\n"); | |
1831 | #endif | |
1832 | seq_puts(m, "# -----------------\n"); | |
1833 | seq_printf(m, "# | task: %.16s-%d " | |
1834 | "(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n", | |
1835 | data->comm, data->pid, data->uid, data->nice, | |
1836 | data->policy, data->rt_priority); | |
1837 | seq_puts(m, "# -----------------\n"); | |
1838 | ||
1839 | if (data->critical_start) { | |
1840 | seq_puts(m, "# => started at: "); | |
1841 | seq_print_ip_sym(&iter->seq, data->critical_start, sym_flags); | |
1842 | trace_print_seq(m, &iter->seq); | |
1843 | seq_puts(m, "\n# => ended at: "); | |
1844 | seq_print_ip_sym(&iter->seq, data->critical_end, sym_flags); | |
1845 | trace_print_seq(m, &iter->seq); | |
1846 | seq_puts(m, "\n#\n"); | |
1847 | } | |
1848 | ||
1849 | seq_puts(m, "#\n"); | |
1850 | } | |
1851 | ||
1852 | static void test_cpu_buff_start(struct trace_iterator *iter) | |
1853 | { | |
1854 | struct trace_seq *s = &iter->seq; | |
1855 | ||
1856 | if (!(trace_flags & TRACE_ITER_ANNOTATE)) | |
1857 | return; | |
1858 | ||
1859 | if (!(iter->iter_flags & TRACE_FILE_ANNOTATE)) | |
1860 | return; | |
1861 | ||
1862 | if (cpumask_test_cpu(iter->cpu, iter->started)) | |
1863 | return; | |
1864 | ||
1865 | if (iter->tr->data[iter->cpu]->skipped_entries) | |
1866 | return; | |
1867 | ||
1868 | cpumask_set_cpu(iter->cpu, iter->started); | |
1869 | ||
1870 | /* Don't print started cpu buffer for the first entry of the trace */ | |
1871 | if (iter->idx > 1) | |
1872 | trace_seq_printf(s, "##### CPU %u buffer started ####\n", | |
1873 | iter->cpu); | |
1874 | } | |
1875 | ||
1876 | static enum print_line_t print_trace_fmt(struct trace_iterator *iter) | |
1877 | { | |
1878 | struct trace_seq *s = &iter->seq; | |
1879 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); | |
1880 | struct trace_entry *entry; | |
1881 | struct trace_event *event; | |
1882 | ||
1883 | entry = iter->ent; | |
1884 | ||
1885 | test_cpu_buff_start(iter); | |
1886 | ||
1887 | event = ftrace_find_event(entry->type); | |
1888 | ||
1889 | if (trace_flags & TRACE_ITER_CONTEXT_INFO) { | |
1890 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) { | |
1891 | if (!trace_print_lat_context(iter)) | |
1892 | goto partial; | |
1893 | } else { | |
1894 | if (!trace_print_context(iter)) | |
1895 | goto partial; | |
1896 | } | |
1897 | } | |
1898 | ||
1899 | if (event) | |
1900 | return event->funcs->trace(iter, sym_flags, event); | |
1901 | ||
1902 | if (!trace_seq_printf(s, "Unknown type %d\n", entry->type)) | |
1903 | goto partial; | |
1904 | ||
1905 | return TRACE_TYPE_HANDLED; | |
1906 | partial: | |
1907 | return TRACE_TYPE_PARTIAL_LINE; | |
1908 | } | |
1909 | ||
1910 | static enum print_line_t print_raw_fmt(struct trace_iterator *iter) | |
1911 | { | |
1912 | struct trace_seq *s = &iter->seq; | |
1913 | struct trace_entry *entry; | |
1914 | struct trace_event *event; | |
1915 | ||
1916 | entry = iter->ent; | |
1917 | ||
1918 | if (trace_flags & TRACE_ITER_CONTEXT_INFO) { | |
1919 | if (!trace_seq_printf(s, "%d %d %llu ", | |
1920 | entry->pid, iter->cpu, iter->ts)) | |
1921 | goto partial; | |
1922 | } | |
1923 | ||
1924 | event = ftrace_find_event(entry->type); | |
1925 | if (event) | |
1926 | return event->funcs->raw(iter, 0, event); | |
1927 | ||
1928 | if (!trace_seq_printf(s, "%d ?\n", entry->type)) | |
1929 | goto partial; | |
1930 | ||
1931 | return TRACE_TYPE_HANDLED; | |
1932 | partial: | |
1933 | return TRACE_TYPE_PARTIAL_LINE; | |
1934 | } | |
1935 | ||
1936 | static enum print_line_t print_hex_fmt(struct trace_iterator *iter) | |
1937 | { | |
1938 | struct trace_seq *s = &iter->seq; | |
1939 | unsigned char newline = '\n'; | |
1940 | struct trace_entry *entry; | |
1941 | struct trace_event *event; | |
1942 | ||
1943 | entry = iter->ent; | |
1944 | ||
1945 | if (trace_flags & TRACE_ITER_CONTEXT_INFO) { | |
1946 | SEQ_PUT_HEX_FIELD_RET(s, entry->pid); | |
1947 | SEQ_PUT_HEX_FIELD_RET(s, iter->cpu); | |
1948 | SEQ_PUT_HEX_FIELD_RET(s, iter->ts); | |
1949 | } | |
1950 | ||
1951 | event = ftrace_find_event(entry->type); | |
1952 | if (event) { | |
1953 | enum print_line_t ret = event->funcs->hex(iter, 0, event); | |
1954 | if (ret != TRACE_TYPE_HANDLED) | |
1955 | return ret; | |
1956 | } | |
1957 | ||
1958 | SEQ_PUT_FIELD_RET(s, newline); | |
1959 | ||
1960 | return TRACE_TYPE_HANDLED; | |
1961 | } | |
1962 | ||
1963 | static enum print_line_t print_bin_fmt(struct trace_iterator *iter) | |
1964 | { | |
1965 | struct trace_seq *s = &iter->seq; | |
1966 | struct trace_entry *entry; | |
1967 | struct trace_event *event; | |
1968 | ||
1969 | entry = iter->ent; | |
1970 | ||
1971 | if (trace_flags & TRACE_ITER_CONTEXT_INFO) { | |
1972 | SEQ_PUT_FIELD_RET(s, entry->pid); | |
1973 | SEQ_PUT_FIELD_RET(s, iter->cpu); | |
1974 | SEQ_PUT_FIELD_RET(s, iter->ts); | |
1975 | } | |
1976 | ||
1977 | event = ftrace_find_event(entry->type); | |
1978 | return event ? event->funcs->binary(iter, 0, event) : | |
1979 | TRACE_TYPE_HANDLED; | |
1980 | } | |
1981 | ||
1982 | int trace_empty(struct trace_iterator *iter) | |
1983 | { | |
1984 | int cpu; | |
1985 | ||
1986 | /* If we are looking at one CPU buffer, only check that one */ | |
1987 | if (iter->cpu_file != TRACE_PIPE_ALL_CPU) { | |
1988 | cpu = iter->cpu_file; | |
1989 | if (iter->buffer_iter[cpu]) { | |
1990 | if (!ring_buffer_iter_empty(iter->buffer_iter[cpu])) | |
1991 | return 0; | |
1992 | } else { | |
1993 | if (!ring_buffer_empty_cpu(iter->tr->buffer, cpu)) | |
1994 | return 0; | |
1995 | } | |
1996 | return 1; | |
1997 | } | |
1998 | ||
1999 | for_each_tracing_cpu(cpu) { | |
2000 | if (iter->buffer_iter[cpu]) { | |
2001 | if (!ring_buffer_iter_empty(iter->buffer_iter[cpu])) | |
2002 | return 0; | |
2003 | } else { | |
2004 | if (!ring_buffer_empty_cpu(iter->tr->buffer, cpu)) | |
2005 | return 0; | |
2006 | } | |
2007 | } | |
2008 | ||
2009 | return 1; | |
2010 | } | |
2011 | ||
2012 | /* Called with trace_event_read_lock() held. */ | |
2013 | enum print_line_t print_trace_line(struct trace_iterator *iter) | |
2014 | { | |
2015 | enum print_line_t ret; | |
2016 | ||
2017 | if (iter->lost_events && | |
2018 | !trace_seq_printf(&iter->seq, "CPU:%d [LOST %lu EVENTS]\n", | |
2019 | iter->cpu, iter->lost_events)) | |
2020 | return TRACE_TYPE_PARTIAL_LINE; | |
2021 | ||
2022 | if (iter->trace && iter->trace->print_line) { | |
2023 | ret = iter->trace->print_line(iter); | |
2024 | if (ret != TRACE_TYPE_UNHANDLED) | |
2025 | return ret; | |
2026 | } | |
2027 | ||
2028 | if (iter->ent->type == TRACE_BPRINT && | |
2029 | trace_flags & TRACE_ITER_PRINTK && | |
2030 | trace_flags & TRACE_ITER_PRINTK_MSGONLY) | |
2031 | return trace_print_bprintk_msg_only(iter); | |
2032 | ||
2033 | if (iter->ent->type == TRACE_PRINT && | |
2034 | trace_flags & TRACE_ITER_PRINTK && | |
2035 | trace_flags & TRACE_ITER_PRINTK_MSGONLY) | |
2036 | return trace_print_printk_msg_only(iter); | |
2037 | ||
2038 | if (trace_flags & TRACE_ITER_BIN) | |
2039 | return print_bin_fmt(iter); | |
2040 | ||
2041 | if (trace_flags & TRACE_ITER_HEX) | |
2042 | return print_hex_fmt(iter); | |
2043 | ||
2044 | if (trace_flags & TRACE_ITER_RAW) | |
2045 | return print_raw_fmt(iter); | |
2046 | ||
2047 | return print_trace_fmt(iter); | |
2048 | } | |
2049 | ||
2050 | void trace_default_header(struct seq_file *m) | |
2051 | { | |
2052 | struct trace_iterator *iter = m->private; | |
2053 | ||
2054 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) { | |
2055 | /* print nothing if the buffers are empty */ | |
2056 | if (trace_empty(iter)) | |
2057 | return; | |
2058 | print_trace_header(m, iter); | |
2059 | if (!(trace_flags & TRACE_ITER_VERBOSE)) | |
2060 | print_lat_help_header(m); | |
2061 | } else { | |
2062 | if (!(trace_flags & TRACE_ITER_VERBOSE)) | |
2063 | print_func_help_header(m); | |
2064 | } | |
2065 | } | |
2066 | ||
2067 | static int s_show(struct seq_file *m, void *v) | |
2068 | { | |
2069 | struct trace_iterator *iter = v; | |
2070 | int ret; | |
2071 | ||
2072 | if (iter->ent == NULL) { | |
2073 | if (iter->tr) { | |
2074 | seq_printf(m, "# tracer: %s\n", iter->trace->name); | |
2075 | seq_puts(m, "#\n"); | |
2076 | } | |
2077 | if (iter->trace && iter->trace->print_header) | |
2078 | iter->trace->print_header(m); | |
2079 | else | |
2080 | trace_default_header(m); | |
2081 | ||
2082 | } else if (iter->leftover) { | |
2083 | /* | |
2084 | * If we filled the seq_file buffer earlier, we | |
2085 | * want to just show it now. | |
2086 | */ | |
2087 | ret = trace_print_seq(m, &iter->seq); | |
2088 | ||
2089 | /* ret should this time be zero, but you never know */ | |
2090 | iter->leftover = ret; | |
2091 | ||
2092 | } else { | |
2093 | print_trace_line(iter); | |
2094 | ret = trace_print_seq(m, &iter->seq); | |
2095 | /* | |
2096 | * If we overflow the seq_file buffer, then it will | |
2097 | * ask us for this data again at start up. | |
2098 | * Use that instead. | |
2099 | * ret is 0 if seq_file write succeeded. | |
2100 | * -1 otherwise. | |
2101 | */ | |
2102 | iter->leftover = ret; | |
2103 | } | |
2104 | ||
2105 | return 0; | |
2106 | } | |
2107 | ||
2108 | static const struct seq_operations tracer_seq_ops = { | |
2109 | .start = s_start, | |
2110 | .next = s_next, | |
2111 | .stop = s_stop, | |
2112 | .show = s_show, | |
2113 | }; | |
2114 | ||
2115 | static struct trace_iterator * | |
2116 | __tracing_open(struct inode *inode, struct file *file) | |
2117 | { | |
2118 | long cpu_file = (long) inode->i_private; | |
2119 | void *fail_ret = ERR_PTR(-ENOMEM); | |
2120 | struct trace_iterator *iter; | |
2121 | struct seq_file *m; | |
2122 | int cpu, ret; | |
2123 | ||
2124 | if (tracing_disabled) | |
2125 | return ERR_PTR(-ENODEV); | |
2126 | ||
2127 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); | |
2128 | if (!iter) | |
2129 | return ERR_PTR(-ENOMEM); | |
2130 | ||
2131 | /* | |
2132 | * We make a copy of the current tracer to avoid concurrent | |
2133 | * changes on it while we are reading. | |
2134 | */ | |
2135 | mutex_lock(&trace_types_lock); | |
2136 | iter->trace = kzalloc(sizeof(*iter->trace), GFP_KERNEL); | |
2137 | if (!iter->trace) | |
2138 | goto fail; | |
2139 | ||
2140 | if (current_trace) | |
2141 | *iter->trace = *current_trace; | |
2142 | ||
2143 | if (!zalloc_cpumask_var(&iter->started, GFP_KERNEL)) | |
2144 | goto fail; | |
2145 | ||
2146 | if (current_trace && current_trace->print_max) | |
2147 | iter->tr = &max_tr; | |
2148 | else | |
2149 | iter->tr = &global_trace; | |
2150 | iter->pos = -1; | |
2151 | mutex_init(&iter->mutex); | |
2152 | iter->cpu_file = cpu_file; | |
2153 | ||
2154 | /* Notify the tracer early; before we stop tracing. */ | |
2155 | if (iter->trace && iter->trace->open) | |
2156 | iter->trace->open(iter); | |
2157 | ||
2158 | /* Annotate start of buffers if we had overruns */ | |
2159 | if (ring_buffer_overruns(iter->tr->buffer)) | |
2160 | iter->iter_flags |= TRACE_FILE_ANNOTATE; | |
2161 | ||
2162 | /* stop the trace while dumping */ | |
2163 | tracing_stop(); | |
2164 | ||
2165 | if (iter->cpu_file == TRACE_PIPE_ALL_CPU) { | |
2166 | for_each_tracing_cpu(cpu) { | |
2167 | iter->buffer_iter[cpu] = | |
2168 | ring_buffer_read_prepare(iter->tr->buffer, cpu); | |
2169 | } | |
2170 | ring_buffer_read_prepare_sync(); | |
2171 | for_each_tracing_cpu(cpu) { | |
2172 | ring_buffer_read_start(iter->buffer_iter[cpu]); | |
2173 | tracing_iter_reset(iter, cpu); | |
2174 | } | |
2175 | } else { | |
2176 | cpu = iter->cpu_file; | |
2177 | iter->buffer_iter[cpu] = | |
2178 | ring_buffer_read_prepare(iter->tr->buffer, cpu); | |
2179 | ring_buffer_read_prepare_sync(); | |
2180 | ring_buffer_read_start(iter->buffer_iter[cpu]); | |
2181 | tracing_iter_reset(iter, cpu); | |
2182 | } | |
2183 | ||
2184 | ret = seq_open(file, &tracer_seq_ops); | |
2185 | if (ret < 0) { | |
2186 | fail_ret = ERR_PTR(ret); | |
2187 | goto fail_buffer; | |
2188 | } | |
2189 | ||
2190 | m = file->private_data; | |
2191 | m->private = iter; | |
2192 | ||
2193 | mutex_unlock(&trace_types_lock); | |
2194 | ||
2195 | return iter; | |
2196 | ||
2197 | fail_buffer: | |
2198 | for_each_tracing_cpu(cpu) { | |
2199 | if (iter->buffer_iter[cpu]) | |
2200 | ring_buffer_read_finish(iter->buffer_iter[cpu]); | |
2201 | } | |
2202 | free_cpumask_var(iter->started); | |
2203 | tracing_start(); | |
2204 | fail: | |
2205 | mutex_unlock(&trace_types_lock); | |
2206 | kfree(iter->trace); | |
2207 | kfree(iter); | |
2208 | ||
2209 | return fail_ret; | |
2210 | } | |
2211 | ||
2212 | int tracing_open_generic(struct inode *inode, struct file *filp) | |
2213 | { | |
2214 | if (tracing_disabled) | |
2215 | return -ENODEV; | |
2216 | ||
2217 | filp->private_data = inode->i_private; | |
2218 | return 0; | |
2219 | } | |
2220 | ||
2221 | static int tracing_release(struct inode *inode, struct file *file) | |
2222 | { | |
2223 | struct seq_file *m = file->private_data; | |
2224 | struct trace_iterator *iter; | |
2225 | int cpu; | |
2226 | ||
2227 | if (!(file->f_mode & FMODE_READ)) | |
2228 | return 0; | |
2229 | ||
2230 | iter = m->private; | |
2231 | ||
2232 | mutex_lock(&trace_types_lock); | |
2233 | for_each_tracing_cpu(cpu) { | |
2234 | if (iter->buffer_iter[cpu]) | |
2235 | ring_buffer_read_finish(iter->buffer_iter[cpu]); | |
2236 | } | |
2237 | ||
2238 | if (iter->trace && iter->trace->close) | |
2239 | iter->trace->close(iter); | |
2240 | ||
2241 | /* reenable tracing if it was previously enabled */ | |
2242 | tracing_start(); | |
2243 | mutex_unlock(&trace_types_lock); | |
2244 | ||
2245 | seq_release(inode, file); | |
2246 | mutex_destroy(&iter->mutex); | |
2247 | free_cpumask_var(iter->started); | |
2248 | kfree(iter->trace); | |
2249 | kfree(iter); | |
2250 | return 0; | |
2251 | } | |
2252 | ||
2253 | static int tracing_open(struct inode *inode, struct file *file) | |
2254 | { | |
2255 | struct trace_iterator *iter; | |
2256 | int ret = 0; | |
2257 | ||
2258 | /* If this file was open for write, then erase contents */ | |
2259 | if ((file->f_mode & FMODE_WRITE) && | |
2260 | (file->f_flags & O_TRUNC)) { | |
2261 | long cpu = (long) inode->i_private; | |
2262 | ||
2263 | if (cpu == TRACE_PIPE_ALL_CPU) | |
2264 | tracing_reset_online_cpus(&global_trace); | |
2265 | else | |
2266 | tracing_reset(&global_trace, cpu); | |
2267 | } | |
2268 | ||
2269 | if (file->f_mode & FMODE_READ) { | |
2270 | iter = __tracing_open(inode, file); | |
2271 | if (IS_ERR(iter)) | |
2272 | ret = PTR_ERR(iter); | |
2273 | else if (trace_flags & TRACE_ITER_LATENCY_FMT) | |
2274 | iter->iter_flags |= TRACE_FILE_LAT_FMT; | |
2275 | } | |
2276 | return ret; | |
2277 | } | |
2278 | ||
2279 | static void * | |
2280 | t_next(struct seq_file *m, void *v, loff_t *pos) | |
2281 | { | |
2282 | struct tracer *t = v; | |
2283 | ||
2284 | (*pos)++; | |
2285 | ||
2286 | if (t) | |
2287 | t = t->next; | |
2288 | ||
2289 | return t; | |
2290 | } | |
2291 | ||
2292 | static void *t_start(struct seq_file *m, loff_t *pos) | |
2293 | { | |
2294 | struct tracer *t; | |
2295 | loff_t l = 0; | |
2296 | ||
2297 | mutex_lock(&trace_types_lock); | |
2298 | for (t = trace_types; t && l < *pos; t = t_next(m, t, &l)) | |
2299 | ; | |
2300 | ||
2301 | return t; | |
2302 | } | |
2303 | ||
2304 | static void t_stop(struct seq_file *m, void *p) | |
2305 | { | |
2306 | mutex_unlock(&trace_types_lock); | |
2307 | } | |
2308 | ||
2309 | static int t_show(struct seq_file *m, void *v) | |
2310 | { | |
2311 | struct tracer *t = v; | |
2312 | ||
2313 | if (!t) | |
2314 | return 0; | |
2315 | ||
2316 | seq_printf(m, "%s", t->name); | |
2317 | if (t->next) | |
2318 | seq_putc(m, ' '); | |
2319 | else | |
2320 | seq_putc(m, '\n'); | |
2321 | ||
2322 | return 0; | |
2323 | } | |
2324 | ||
2325 | static const struct seq_operations show_traces_seq_ops = { | |
2326 | .start = t_start, | |
2327 | .next = t_next, | |
2328 | .stop = t_stop, | |
2329 | .show = t_show, | |
2330 | }; | |
2331 | ||
2332 | static int show_traces_open(struct inode *inode, struct file *file) | |
2333 | { | |
2334 | if (tracing_disabled) | |
2335 | return -ENODEV; | |
2336 | ||
2337 | return seq_open(file, &show_traces_seq_ops); | |
2338 | } | |
2339 | ||
2340 | static ssize_t | |
2341 | tracing_write_stub(struct file *filp, const char __user *ubuf, | |
2342 | size_t count, loff_t *ppos) | |
2343 | { | |
2344 | return count; | |
2345 | } | |
2346 | ||
2347 | static loff_t tracing_seek(struct file *file, loff_t offset, int origin) | |
2348 | { | |
2349 | if (file->f_mode & FMODE_READ) | |
2350 | return seq_lseek(file, offset, origin); | |
2351 | else | |
2352 | return 0; | |
2353 | } | |
2354 | ||
2355 | static const struct file_operations tracing_fops = { | |
2356 | .open = tracing_open, | |
2357 | .read = seq_read, | |
2358 | .write = tracing_write_stub, | |
2359 | .llseek = tracing_seek, | |
2360 | .release = tracing_release, | |
2361 | }; | |
2362 | ||
2363 | static const struct file_operations show_traces_fops = { | |
2364 | .open = show_traces_open, | |
2365 | .read = seq_read, | |
2366 | .release = seq_release, | |
2367 | .llseek = seq_lseek, | |
2368 | }; | |
2369 | ||
2370 | /* | |
2371 | * Only trace on a CPU if the bitmask is set: | |
2372 | */ | |
2373 | static cpumask_var_t tracing_cpumask; | |
2374 | ||
2375 | /* | |
2376 | * The tracer itself will not take this lock, but still we want | |
2377 | * to provide a consistent cpumask to user-space: | |
2378 | */ | |
2379 | static DEFINE_MUTEX(tracing_cpumask_update_lock); | |
2380 | ||
2381 | /* | |
2382 | * Temporary storage for the character representation of the | |
2383 | * CPU bitmask (and one more byte for the newline): | |
2384 | */ | |
2385 | static char mask_str[NR_CPUS + 1]; | |
2386 | ||
2387 | static ssize_t | |
2388 | tracing_cpumask_read(struct file *filp, char __user *ubuf, | |
2389 | size_t count, loff_t *ppos) | |
2390 | { | |
2391 | int len; | |
2392 | ||
2393 | mutex_lock(&tracing_cpumask_update_lock); | |
2394 | ||
2395 | len = cpumask_scnprintf(mask_str, count, tracing_cpumask); | |
2396 | if (count - len < 2) { | |
2397 | count = -EINVAL; | |
2398 | goto out_err; | |
2399 | } | |
2400 | len += sprintf(mask_str + len, "\n"); | |
2401 | count = simple_read_from_buffer(ubuf, count, ppos, mask_str, NR_CPUS+1); | |
2402 | ||
2403 | out_err: | |
2404 | mutex_unlock(&tracing_cpumask_update_lock); | |
2405 | ||
2406 | return count; | |
2407 | } | |
2408 | ||
2409 | static ssize_t | |
2410 | tracing_cpumask_write(struct file *filp, const char __user *ubuf, | |
2411 | size_t count, loff_t *ppos) | |
2412 | { | |
2413 | int err, cpu; | |
2414 | cpumask_var_t tracing_cpumask_new; | |
2415 | ||
2416 | if (!alloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL)) | |
2417 | return -ENOMEM; | |
2418 | ||
2419 | err = cpumask_parse_user(ubuf, count, tracing_cpumask_new); | |
2420 | if (err) | |
2421 | goto err_unlock; | |
2422 | ||
2423 | mutex_lock(&tracing_cpumask_update_lock); | |
2424 | ||
2425 | local_irq_disable(); | |
2426 | arch_spin_lock(&ftrace_max_lock); | |
2427 | for_each_tracing_cpu(cpu) { | |
2428 | /* | |
2429 | * Increase/decrease the disabled counter if we are | |
2430 | * about to flip a bit in the cpumask: | |
2431 | */ | |
2432 | if (cpumask_test_cpu(cpu, tracing_cpumask) && | |
2433 | !cpumask_test_cpu(cpu, tracing_cpumask_new)) { | |
2434 | atomic_inc(&global_trace.data[cpu]->disabled); | |
2435 | } | |
2436 | if (!cpumask_test_cpu(cpu, tracing_cpumask) && | |
2437 | cpumask_test_cpu(cpu, tracing_cpumask_new)) { | |
2438 | atomic_dec(&global_trace.data[cpu]->disabled); | |
2439 | } | |
2440 | } | |
2441 | arch_spin_unlock(&ftrace_max_lock); | |
2442 | local_irq_enable(); | |
2443 | ||
2444 | cpumask_copy(tracing_cpumask, tracing_cpumask_new); | |
2445 | ||
2446 | mutex_unlock(&tracing_cpumask_update_lock); | |
2447 | free_cpumask_var(tracing_cpumask_new); | |
2448 | ||
2449 | return count; | |
2450 | ||
2451 | err_unlock: | |
2452 | free_cpumask_var(tracing_cpumask_new); | |
2453 | ||
2454 | return err; | |
2455 | } | |
2456 | ||
2457 | static const struct file_operations tracing_cpumask_fops = { | |
2458 | .open = tracing_open_generic, | |
2459 | .read = tracing_cpumask_read, | |
2460 | .write = tracing_cpumask_write, | |
2461 | .llseek = generic_file_llseek, | |
2462 | }; | |
2463 | ||
2464 | static int tracing_trace_options_show(struct seq_file *m, void *v) | |
2465 | { | |
2466 | struct tracer_opt *trace_opts; | |
2467 | u32 tracer_flags; | |
2468 | int i; | |
2469 | ||
2470 | mutex_lock(&trace_types_lock); | |
2471 | tracer_flags = current_trace->flags->val; | |
2472 | trace_opts = current_trace->flags->opts; | |
2473 | ||
2474 | for (i = 0; trace_options[i]; i++) { | |
2475 | if (trace_flags & (1 << i)) | |
2476 | seq_printf(m, "%s\n", trace_options[i]); | |
2477 | else | |
2478 | seq_printf(m, "no%s\n", trace_options[i]); | |
2479 | } | |
2480 | ||
2481 | for (i = 0; trace_opts[i].name; i++) { | |
2482 | if (tracer_flags & trace_opts[i].bit) | |
2483 | seq_printf(m, "%s\n", trace_opts[i].name); | |
2484 | else | |
2485 | seq_printf(m, "no%s\n", trace_opts[i].name); | |
2486 | } | |
2487 | mutex_unlock(&trace_types_lock); | |
2488 | ||
2489 | return 0; | |
2490 | } | |
2491 | ||
2492 | static int __set_tracer_option(struct tracer *trace, | |
2493 | struct tracer_flags *tracer_flags, | |
2494 | struct tracer_opt *opts, int neg) | |
2495 | { | |
2496 | int ret; | |
2497 | ||
2498 | ret = trace->set_flag(tracer_flags->val, opts->bit, !neg); | |
2499 | if (ret) | |
2500 | return ret; | |
2501 | ||
2502 | if (neg) | |
2503 | tracer_flags->val &= ~opts->bit; | |
2504 | else | |
2505 | tracer_flags->val |= opts->bit; | |
2506 | return 0; | |
2507 | } | |
2508 | ||
2509 | /* Try to assign a tracer specific option */ | |
2510 | static int set_tracer_option(struct tracer *trace, char *cmp, int neg) | |
2511 | { | |
2512 | struct tracer_flags *tracer_flags = trace->flags; | |
2513 | struct tracer_opt *opts = NULL; | |
2514 | int i; | |
2515 | ||
2516 | for (i = 0; tracer_flags->opts[i].name; i++) { | |
2517 | opts = &tracer_flags->opts[i]; | |
2518 | ||
2519 | if (strcmp(cmp, opts->name) == 0) | |
2520 | return __set_tracer_option(trace, trace->flags, | |
2521 | opts, neg); | |
2522 | } | |
2523 | ||
2524 | return -EINVAL; | |
2525 | } | |
2526 | ||
2527 | static void set_tracer_flags(unsigned int mask, int enabled) | |
2528 | { | |
2529 | /* do nothing if flag is already set */ | |
2530 | if (!!(trace_flags & mask) == !!enabled) | |
2531 | return; | |
2532 | ||
2533 | if (enabled) | |
2534 | trace_flags |= mask; | |
2535 | else | |
2536 | trace_flags &= ~mask; | |
2537 | ||
2538 | if (mask == TRACE_ITER_RECORD_CMD) | |
2539 | trace_event_enable_cmd_record(enabled); | |
2540 | ||
2541 | if (mask == TRACE_ITER_OVERWRITE) | |
2542 | ring_buffer_change_overwrite(global_trace.buffer, enabled); | |
2543 | } | |
2544 | ||
2545 | static ssize_t | |
2546 | tracing_trace_options_write(struct file *filp, const char __user *ubuf, | |
2547 | size_t cnt, loff_t *ppos) | |
2548 | { | |
2549 | char buf[64]; | |
2550 | char *cmp; | |
2551 | int neg = 0; | |
2552 | int ret; | |
2553 | int i; | |
2554 | ||
2555 | if (cnt >= sizeof(buf)) | |
2556 | return -EINVAL; | |
2557 | ||
2558 | if (copy_from_user(&buf, ubuf, cnt)) | |
2559 | return -EFAULT; | |
2560 | ||
2561 | buf[cnt] = 0; | |
2562 | cmp = strstrip(buf); | |
2563 | ||
2564 | if (strncmp(cmp, "no", 2) == 0) { | |
2565 | neg = 1; | |
2566 | cmp += 2; | |
2567 | } | |
2568 | ||
2569 | for (i = 0; trace_options[i]; i++) { | |
2570 | if (strcmp(cmp, trace_options[i]) == 0) { | |
2571 | set_tracer_flags(1 << i, !neg); | |
2572 | break; | |
2573 | } | |
2574 | } | |
2575 | ||
2576 | /* If no option could be set, test the specific tracer options */ | |
2577 | if (!trace_options[i]) { | |
2578 | mutex_lock(&trace_types_lock); | |
2579 | ret = set_tracer_option(current_trace, cmp, neg); | |
2580 | mutex_unlock(&trace_types_lock); | |
2581 | if (ret) | |
2582 | return ret; | |
2583 | } | |
2584 | ||
2585 | *ppos += cnt; | |
2586 | ||
2587 | return cnt; | |
2588 | } | |
2589 | ||
2590 | static int tracing_trace_options_open(struct inode *inode, struct file *file) | |
2591 | { | |
2592 | if (tracing_disabled) | |
2593 | return -ENODEV; | |
2594 | return single_open(file, tracing_trace_options_show, NULL); | |
2595 | } | |
2596 | ||
2597 | static const struct file_operations tracing_iter_fops = { | |
2598 | .open = tracing_trace_options_open, | |
2599 | .read = seq_read, | |
2600 | .llseek = seq_lseek, | |
2601 | .release = single_release, | |
2602 | .write = tracing_trace_options_write, | |
2603 | }; | |
2604 | ||
2605 | static const char readme_msg[] = | |
2606 | "tracing mini-HOWTO:\n\n" | |
2607 | "# mount -t debugfs nodev /sys/kernel/debug\n\n" | |
2608 | "# cat /sys/kernel/debug/tracing/available_tracers\n" | |
2609 | "wakeup preemptirqsoff preemptoff irqsoff function sched_switch nop\n\n" | |
2610 | "# cat /sys/kernel/debug/tracing/current_tracer\n" | |
2611 | "nop\n" | |
2612 | "# echo sched_switch > /sys/kernel/debug/tracing/current_tracer\n" | |
2613 | "# cat /sys/kernel/debug/tracing/current_tracer\n" | |
2614 | "sched_switch\n" | |
2615 | "# cat /sys/kernel/debug/tracing/trace_options\n" | |
2616 | "noprint-parent nosym-offset nosym-addr noverbose\n" | |
2617 | "# echo print-parent > /sys/kernel/debug/tracing/trace_options\n" | |
2618 | "# echo 1 > /sys/kernel/debug/tracing/tracing_enabled\n" | |
2619 | "# cat /sys/kernel/debug/tracing/trace > /tmp/trace.txt\n" | |
2620 | "# echo 0 > /sys/kernel/debug/tracing/tracing_enabled\n" | |
2621 | ; | |
2622 | ||
2623 | static ssize_t | |
2624 | tracing_readme_read(struct file *filp, char __user *ubuf, | |
2625 | size_t cnt, loff_t *ppos) | |
2626 | { | |
2627 | return simple_read_from_buffer(ubuf, cnt, ppos, | |
2628 | readme_msg, strlen(readme_msg)); | |
2629 | } | |
2630 | ||
2631 | static const struct file_operations tracing_readme_fops = { | |
2632 | .open = tracing_open_generic, | |
2633 | .read = tracing_readme_read, | |
2634 | .llseek = generic_file_llseek, | |
2635 | }; | |
2636 | ||
2637 | static ssize_t | |
2638 | tracing_saved_cmdlines_read(struct file *file, char __user *ubuf, | |
2639 | size_t cnt, loff_t *ppos) | |
2640 | { | |
2641 | char *buf_comm; | |
2642 | char *file_buf; | |
2643 | char *buf; | |
2644 | int len = 0; | |
2645 | int pid; | |
2646 | int i; | |
2647 | ||
2648 | file_buf = kmalloc(SAVED_CMDLINES*(16+TASK_COMM_LEN), GFP_KERNEL); | |
2649 | if (!file_buf) | |
2650 | return -ENOMEM; | |
2651 | ||
2652 | buf_comm = kmalloc(TASK_COMM_LEN, GFP_KERNEL); | |
2653 | if (!buf_comm) { | |
2654 | kfree(file_buf); | |
2655 | return -ENOMEM; | |
2656 | } | |
2657 | ||
2658 | buf = file_buf; | |
2659 | ||
2660 | for (i = 0; i < SAVED_CMDLINES; i++) { | |
2661 | int r; | |
2662 | ||
2663 | pid = map_cmdline_to_pid[i]; | |
2664 | if (pid == -1 || pid == NO_CMDLINE_MAP) | |
2665 | continue; | |
2666 | ||
2667 | trace_find_cmdline(pid, buf_comm); | |
2668 | r = sprintf(buf, "%d %s\n", pid, buf_comm); | |
2669 | buf += r; | |
2670 | len += r; | |
2671 | } | |
2672 | ||
2673 | len = simple_read_from_buffer(ubuf, cnt, ppos, | |
2674 | file_buf, len); | |
2675 | ||
2676 | kfree(file_buf); | |
2677 | kfree(buf_comm); | |
2678 | ||
2679 | return len; | |
2680 | } | |
2681 | ||
2682 | static const struct file_operations tracing_saved_cmdlines_fops = { | |
2683 | .open = tracing_open_generic, | |
2684 | .read = tracing_saved_cmdlines_read, | |
2685 | .llseek = generic_file_llseek, | |
2686 | }; | |
2687 | ||
2688 | static ssize_t | |
2689 | tracing_ctrl_read(struct file *filp, char __user *ubuf, | |
2690 | size_t cnt, loff_t *ppos) | |
2691 | { | |
2692 | char buf[64]; | |
2693 | int r; | |
2694 | ||
2695 | r = sprintf(buf, "%u\n", tracer_enabled); | |
2696 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
2697 | } | |
2698 | ||
2699 | static ssize_t | |
2700 | tracing_ctrl_write(struct file *filp, const char __user *ubuf, | |
2701 | size_t cnt, loff_t *ppos) | |
2702 | { | |
2703 | struct trace_array *tr = filp->private_data; | |
2704 | char buf[64]; | |
2705 | unsigned long val; | |
2706 | int ret; | |
2707 | ||
2708 | if (cnt >= sizeof(buf)) | |
2709 | return -EINVAL; | |
2710 | ||
2711 | if (copy_from_user(&buf, ubuf, cnt)) | |
2712 | return -EFAULT; | |
2713 | ||
2714 | buf[cnt] = 0; | |
2715 | ||
2716 | ret = strict_strtoul(buf, 10, &val); | |
2717 | if (ret < 0) | |
2718 | return ret; | |
2719 | ||
2720 | val = !!val; | |
2721 | ||
2722 | mutex_lock(&trace_types_lock); | |
2723 | if (tracer_enabled ^ val) { | |
2724 | ||
2725 | /* Only need to warn if this is used to change the state */ | |
2726 | WARN_ONCE(1, "tracing_enabled is deprecated. Use tracing_on"); | |
2727 | ||
2728 | if (val) { | |
2729 | tracer_enabled = 1; | |
2730 | if (current_trace->start) | |
2731 | current_trace->start(tr); | |
2732 | tracing_start(); | |
2733 | } else { | |
2734 | tracer_enabled = 0; | |
2735 | tracing_stop(); | |
2736 | if (current_trace->stop) | |
2737 | current_trace->stop(tr); | |
2738 | } | |
2739 | } | |
2740 | mutex_unlock(&trace_types_lock); | |
2741 | ||
2742 | *ppos += cnt; | |
2743 | ||
2744 | return cnt; | |
2745 | } | |
2746 | ||
2747 | static ssize_t | |
2748 | tracing_set_trace_read(struct file *filp, char __user *ubuf, | |
2749 | size_t cnt, loff_t *ppos) | |
2750 | { | |
2751 | char buf[MAX_TRACER_SIZE+2]; | |
2752 | int r; | |
2753 | ||
2754 | mutex_lock(&trace_types_lock); | |
2755 | if (current_trace) | |
2756 | r = sprintf(buf, "%s\n", current_trace->name); | |
2757 | else | |
2758 | r = sprintf(buf, "\n"); | |
2759 | mutex_unlock(&trace_types_lock); | |
2760 | ||
2761 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
2762 | } | |
2763 | ||
2764 | int tracer_init(struct tracer *t, struct trace_array *tr) | |
2765 | { | |
2766 | tracing_reset_online_cpus(tr); | |
2767 | return t->init(tr); | |
2768 | } | |
2769 | ||
2770 | static int tracing_resize_ring_buffer(unsigned long size) | |
2771 | { | |
2772 | int ret; | |
2773 | ||
2774 | /* | |
2775 | * If kernel or user changes the size of the ring buffer | |
2776 | * we use the size that was given, and we can forget about | |
2777 | * expanding it later. | |
2778 | */ | |
2779 | ring_buffer_expanded = 1; | |
2780 | ||
2781 | ret = ring_buffer_resize(global_trace.buffer, size); | |
2782 | if (ret < 0) | |
2783 | return ret; | |
2784 | ||
2785 | if (!current_trace->use_max_tr) | |
2786 | goto out; | |
2787 | ||
2788 | ret = ring_buffer_resize(max_tr.buffer, size); | |
2789 | if (ret < 0) { | |
2790 | int r; | |
2791 | ||
2792 | r = ring_buffer_resize(global_trace.buffer, | |
2793 | global_trace.entries); | |
2794 | if (r < 0) { | |
2795 | /* | |
2796 | * AARGH! We are left with different | |
2797 | * size max buffer!!!! | |
2798 | * The max buffer is our "snapshot" buffer. | |
2799 | * When a tracer needs a snapshot (one of the | |
2800 | * latency tracers), it swaps the max buffer | |
2801 | * with the saved snap shot. We succeeded to | |
2802 | * update the size of the main buffer, but failed to | |
2803 | * update the size of the max buffer. But when we tried | |
2804 | * to reset the main buffer to the original size, we | |
2805 | * failed there too. This is very unlikely to | |
2806 | * happen, but if it does, warn and kill all | |
2807 | * tracing. | |
2808 | */ | |
2809 | WARN_ON(1); | |
2810 | tracing_disabled = 1; | |
2811 | } | |
2812 | return ret; | |
2813 | } | |
2814 | ||
2815 | max_tr.entries = size; | |
2816 | out: | |
2817 | global_trace.entries = size; | |
2818 | ||
2819 | return ret; | |
2820 | } | |
2821 | ||
2822 | ||
2823 | /** | |
2824 | * tracing_update_buffers - used by tracing facility to expand ring buffers | |
2825 | * | |
2826 | * To save on memory when the tracing is never used on a system with it | |
2827 | * configured in. The ring buffers are set to a minimum size. But once | |
2828 | * a user starts to use the tracing facility, then they need to grow | |
2829 | * to their default size. | |
2830 | * | |
2831 | * This function is to be called when a tracer is about to be used. | |
2832 | */ | |
2833 | int tracing_update_buffers(void) | |
2834 | { | |
2835 | int ret = 0; | |
2836 | ||
2837 | mutex_lock(&trace_types_lock); | |
2838 | if (!ring_buffer_expanded) | |
2839 | ret = tracing_resize_ring_buffer(trace_buf_size); | |
2840 | mutex_unlock(&trace_types_lock); | |
2841 | ||
2842 | return ret; | |
2843 | } | |
2844 | ||
2845 | struct trace_option_dentry; | |
2846 | ||
2847 | static struct trace_option_dentry * | |
2848 | create_trace_option_files(struct tracer *tracer); | |
2849 | ||
2850 | static void | |
2851 | destroy_trace_option_files(struct trace_option_dentry *topts); | |
2852 | ||
2853 | static int tracing_set_tracer(const char *buf) | |
2854 | { | |
2855 | static struct trace_option_dentry *topts; | |
2856 | struct trace_array *tr = &global_trace; | |
2857 | struct tracer *t; | |
2858 | int ret = 0; | |
2859 | ||
2860 | mutex_lock(&trace_types_lock); | |
2861 | ||
2862 | if (!ring_buffer_expanded) { | |
2863 | ret = tracing_resize_ring_buffer(trace_buf_size); | |
2864 | if (ret < 0) | |
2865 | goto out; | |
2866 | ret = 0; | |
2867 | } | |
2868 | ||
2869 | for (t = trace_types; t; t = t->next) { | |
2870 | if (strcmp(t->name, buf) == 0) | |
2871 | break; | |
2872 | } | |
2873 | if (!t) { | |
2874 | ret = -EINVAL; | |
2875 | goto out; | |
2876 | } | |
2877 | if (t == current_trace) | |
2878 | goto out; | |
2879 | ||
2880 | trace_branch_disable(); | |
2881 | if (current_trace && current_trace->reset) | |
2882 | current_trace->reset(tr); | |
2883 | if (current_trace && current_trace->use_max_tr) { | |
2884 | /* | |
2885 | * We don't free the ring buffer. instead, resize it because | |
2886 | * The max_tr ring buffer has some state (e.g. ring->clock) and | |
2887 | * we want preserve it. | |
2888 | */ | |
2889 | ring_buffer_resize(max_tr.buffer, 1); | |
2890 | max_tr.entries = 1; | |
2891 | } | |
2892 | destroy_trace_option_files(topts); | |
2893 | ||
2894 | current_trace = t; | |
2895 | ||
2896 | topts = create_trace_option_files(current_trace); | |
2897 | if (current_trace->use_max_tr) { | |
2898 | ret = ring_buffer_resize(max_tr.buffer, global_trace.entries); | |
2899 | if (ret < 0) | |
2900 | goto out; | |
2901 | max_tr.entries = global_trace.entries; | |
2902 | } | |
2903 | ||
2904 | if (t->init) { | |
2905 | ret = tracer_init(t, tr); | |
2906 | if (ret) | |
2907 | goto out; | |
2908 | } | |
2909 | ||
2910 | trace_branch_enable(tr); | |
2911 | out: | |
2912 | mutex_unlock(&trace_types_lock); | |
2913 | ||
2914 | return ret; | |
2915 | } | |
2916 | ||
2917 | static ssize_t | |
2918 | tracing_set_trace_write(struct file *filp, const char __user *ubuf, | |
2919 | size_t cnt, loff_t *ppos) | |
2920 | { | |
2921 | char buf[MAX_TRACER_SIZE+1]; | |
2922 | int i; | |
2923 | size_t ret; | |
2924 | int err; | |
2925 | ||
2926 | ret = cnt; | |
2927 | ||
2928 | if (cnt > MAX_TRACER_SIZE) | |
2929 | cnt = MAX_TRACER_SIZE; | |
2930 | ||
2931 | if (copy_from_user(&buf, ubuf, cnt)) | |
2932 | return -EFAULT; | |
2933 | ||
2934 | buf[cnt] = 0; | |
2935 | ||
2936 | /* strip ending whitespace. */ | |
2937 | for (i = cnt - 1; i > 0 && isspace(buf[i]); i--) | |
2938 | buf[i] = 0; | |
2939 | ||
2940 | err = tracing_set_tracer(buf); | |
2941 | if (err) | |
2942 | return err; | |
2943 | ||
2944 | *ppos += ret; | |
2945 | ||
2946 | return ret; | |
2947 | } | |
2948 | ||
2949 | static ssize_t | |
2950 | tracing_max_lat_read(struct file *filp, char __user *ubuf, | |
2951 | size_t cnt, loff_t *ppos) | |
2952 | { | |
2953 | unsigned long *ptr = filp->private_data; | |
2954 | char buf[64]; | |
2955 | int r; | |
2956 | ||
2957 | r = snprintf(buf, sizeof(buf), "%ld\n", | |
2958 | *ptr == (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr)); | |
2959 | if (r > sizeof(buf)) | |
2960 | r = sizeof(buf); | |
2961 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
2962 | } | |
2963 | ||
2964 | static ssize_t | |
2965 | tracing_max_lat_write(struct file *filp, const char __user *ubuf, | |
2966 | size_t cnt, loff_t *ppos) | |
2967 | { | |
2968 | unsigned long *ptr = filp->private_data; | |
2969 | char buf[64]; | |
2970 | unsigned long val; | |
2971 | int ret; | |
2972 | ||
2973 | if (cnt >= sizeof(buf)) | |
2974 | return -EINVAL; | |
2975 | ||
2976 | if (copy_from_user(&buf, ubuf, cnt)) | |
2977 | return -EFAULT; | |
2978 | ||
2979 | buf[cnt] = 0; | |
2980 | ||
2981 | ret = strict_strtoul(buf, 10, &val); | |
2982 | if (ret < 0) | |
2983 | return ret; | |
2984 | ||
2985 | *ptr = val * 1000; | |
2986 | ||
2987 | return cnt; | |
2988 | } | |
2989 | ||
2990 | static int tracing_open_pipe(struct inode *inode, struct file *filp) | |
2991 | { | |
2992 | long cpu_file = (long) inode->i_private; | |
2993 | struct trace_iterator *iter; | |
2994 | int ret = 0; | |
2995 | ||
2996 | if (tracing_disabled) | |
2997 | return -ENODEV; | |
2998 | ||
2999 | mutex_lock(&trace_types_lock); | |
3000 | ||
3001 | /* create a buffer to store the information to pass to userspace */ | |
3002 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); | |
3003 | if (!iter) { | |
3004 | ret = -ENOMEM; | |
3005 | goto out; | |
3006 | } | |
3007 | ||
3008 | /* | |
3009 | * We make a copy of the current tracer to avoid concurrent | |
3010 | * changes on it while we are reading. | |
3011 | */ | |
3012 | iter->trace = kmalloc(sizeof(*iter->trace), GFP_KERNEL); | |
3013 | if (!iter->trace) { | |
3014 | ret = -ENOMEM; | |
3015 | goto fail; | |
3016 | } | |
3017 | if (current_trace) | |
3018 | *iter->trace = *current_trace; | |
3019 | ||
3020 | if (!alloc_cpumask_var(&iter->started, GFP_KERNEL)) { | |
3021 | ret = -ENOMEM; | |
3022 | goto fail; | |
3023 | } | |
3024 | ||
3025 | /* trace pipe does not show start of buffer */ | |
3026 | cpumask_setall(iter->started); | |
3027 | ||
3028 | if (trace_flags & TRACE_ITER_LATENCY_FMT) | |
3029 | iter->iter_flags |= TRACE_FILE_LAT_FMT; | |
3030 | ||
3031 | iter->cpu_file = cpu_file; | |
3032 | iter->tr = &global_trace; | |
3033 | mutex_init(&iter->mutex); | |
3034 | filp->private_data = iter; | |
3035 | ||
3036 | if (iter->trace->pipe_open) | |
3037 | iter->trace->pipe_open(iter); | |
3038 | ||
3039 | nonseekable_open(inode, filp); | |
3040 | out: | |
3041 | mutex_unlock(&trace_types_lock); | |
3042 | return ret; | |
3043 | ||
3044 | fail: | |
3045 | kfree(iter->trace); | |
3046 | kfree(iter); | |
3047 | mutex_unlock(&trace_types_lock); | |
3048 | return ret; | |
3049 | } | |
3050 | ||
3051 | static int tracing_release_pipe(struct inode *inode, struct file *file) | |
3052 | { | |
3053 | struct trace_iterator *iter = file->private_data; | |
3054 | ||
3055 | mutex_lock(&trace_types_lock); | |
3056 | ||
3057 | if (iter->trace->pipe_close) | |
3058 | iter->trace->pipe_close(iter); | |
3059 | ||
3060 | mutex_unlock(&trace_types_lock); | |
3061 | ||
3062 | free_cpumask_var(iter->started); | |
3063 | mutex_destroy(&iter->mutex); | |
3064 | kfree(iter->trace); | |
3065 | kfree(iter); | |
3066 | ||
3067 | return 0; | |
3068 | } | |
3069 | ||
3070 | static unsigned int | |
3071 | tracing_poll_pipe(struct file *filp, poll_table *poll_table) | |
3072 | { | |
3073 | struct trace_iterator *iter = filp->private_data; | |
3074 | ||
3075 | if (trace_flags & TRACE_ITER_BLOCK) { | |
3076 | /* | |
3077 | * Always select as readable when in blocking mode | |
3078 | */ | |
3079 | return POLLIN | POLLRDNORM; | |
3080 | } else { | |
3081 | if (!trace_empty(iter)) | |
3082 | return POLLIN | POLLRDNORM; | |
3083 | poll_wait(filp, &trace_wait, poll_table); | |
3084 | if (!trace_empty(iter)) | |
3085 | return POLLIN | POLLRDNORM; | |
3086 | ||
3087 | return 0; | |
3088 | } | |
3089 | } | |
3090 | ||
3091 | ||
3092 | void default_wait_pipe(struct trace_iterator *iter) | |
3093 | { | |
3094 | DEFINE_WAIT(wait); | |
3095 | ||
3096 | prepare_to_wait(&trace_wait, &wait, TASK_INTERRUPTIBLE); | |
3097 | ||
3098 | if (trace_empty(iter)) | |
3099 | schedule(); | |
3100 | ||
3101 | finish_wait(&trace_wait, &wait); | |
3102 | } | |
3103 | ||
3104 | /* | |
3105 | * This is a make-shift waitqueue. | |
3106 | * A tracer might use this callback on some rare cases: | |
3107 | * | |
3108 | * 1) the current tracer might hold the runqueue lock when it wakes up | |
3109 | * a reader, hence a deadlock (sched, function, and function graph tracers) | |
3110 | * 2) the function tracers, trace all functions, we don't want | |
3111 | * the overhead of calling wake_up and friends | |
3112 | * (and tracing them too) | |
3113 | * | |
3114 | * Anyway, this is really very primitive wakeup. | |
3115 | */ | |
3116 | void poll_wait_pipe(struct trace_iterator *iter) | |
3117 | { | |
3118 | set_current_state(TASK_INTERRUPTIBLE); | |
3119 | /* sleep for 100 msecs, and try again. */ | |
3120 | schedule_timeout(HZ / 10); | |
3121 | } | |
3122 | ||
3123 | /* Must be called with trace_types_lock mutex held. */ | |
3124 | static int tracing_wait_pipe(struct file *filp) | |
3125 | { | |
3126 | struct trace_iterator *iter = filp->private_data; | |
3127 | ||
3128 | while (trace_empty(iter)) { | |
3129 | ||
3130 | if ((filp->f_flags & O_NONBLOCK)) { | |
3131 | return -EAGAIN; | |
3132 | } | |
3133 | ||
3134 | mutex_unlock(&iter->mutex); | |
3135 | ||
3136 | iter->trace->wait_pipe(iter); | |
3137 | ||
3138 | mutex_lock(&iter->mutex); | |
3139 | ||
3140 | if (signal_pending(current)) | |
3141 | return -EINTR; | |
3142 | ||
3143 | /* | |
3144 | * We block until we read something and tracing is disabled. | |
3145 | * We still block if tracing is disabled, but we have never | |
3146 | * read anything. This allows a user to cat this file, and | |
3147 | * then enable tracing. But after we have read something, | |
3148 | * we give an EOF when tracing is again disabled. | |
3149 | * | |
3150 | * iter->pos will be 0 if we haven't read anything. | |
3151 | */ | |
3152 | if (!tracer_enabled && iter->pos) | |
3153 | break; | |
3154 | } | |
3155 | ||
3156 | return 1; | |
3157 | } | |
3158 | ||
3159 | /* | |
3160 | * Consumer reader. | |
3161 | */ | |
3162 | static ssize_t | |
3163 | tracing_read_pipe(struct file *filp, char __user *ubuf, | |
3164 | size_t cnt, loff_t *ppos) | |
3165 | { | |
3166 | struct trace_iterator *iter = filp->private_data; | |
3167 | static struct tracer *old_tracer; | |
3168 | ssize_t sret; | |
3169 | ||
3170 | /* return any leftover data */ | |
3171 | sret = trace_seq_to_user(&iter->seq, ubuf, cnt); | |
3172 | if (sret != -EBUSY) | |
3173 | return sret; | |
3174 | ||
3175 | trace_seq_init(&iter->seq); | |
3176 | ||
3177 | /* copy the tracer to avoid using a global lock all around */ | |
3178 | mutex_lock(&trace_types_lock); | |
3179 | if (unlikely(old_tracer != current_trace && current_trace)) { | |
3180 | old_tracer = current_trace; | |
3181 | *iter->trace = *current_trace; | |
3182 | } | |
3183 | mutex_unlock(&trace_types_lock); | |
3184 | ||
3185 | /* | |
3186 | * Avoid more than one consumer on a single file descriptor | |
3187 | * This is just a matter of traces coherency, the ring buffer itself | |
3188 | * is protected. | |
3189 | */ | |
3190 | mutex_lock(&iter->mutex); | |
3191 | if (iter->trace->read) { | |
3192 | sret = iter->trace->read(iter, filp, ubuf, cnt, ppos); | |
3193 | if (sret) | |
3194 | goto out; | |
3195 | } | |
3196 | ||
3197 | waitagain: | |
3198 | sret = tracing_wait_pipe(filp); | |
3199 | if (sret <= 0) | |
3200 | goto out; | |
3201 | ||
3202 | /* stop when tracing is finished */ | |
3203 | if (trace_empty(iter)) { | |
3204 | sret = 0; | |
3205 | goto out; | |
3206 | } | |
3207 | ||
3208 | if (cnt >= PAGE_SIZE) | |
3209 | cnt = PAGE_SIZE - 1; | |
3210 | ||
3211 | /* reset all but tr, trace, and overruns */ | |
3212 | memset(&iter->seq, 0, | |
3213 | sizeof(struct trace_iterator) - | |
3214 | offsetof(struct trace_iterator, seq)); | |
3215 | iter->pos = -1; | |
3216 | ||
3217 | trace_event_read_lock(); | |
3218 | trace_access_lock(iter->cpu_file); | |
3219 | while (trace_find_next_entry_inc(iter) != NULL) { | |
3220 | enum print_line_t ret; | |
3221 | int len = iter->seq.len; | |
3222 | ||
3223 | ret = print_trace_line(iter); | |
3224 | if (ret == TRACE_TYPE_PARTIAL_LINE) { | |
3225 | /* don't print partial lines */ | |
3226 | iter->seq.len = len; | |
3227 | break; | |
3228 | } | |
3229 | if (ret != TRACE_TYPE_NO_CONSUME) | |
3230 | trace_consume(iter); | |
3231 | ||
3232 | if (iter->seq.len >= cnt) | |
3233 | break; | |
3234 | ||
3235 | /* | |
3236 | * Setting the full flag means we reached the trace_seq buffer | |
3237 | * size and we should leave by partial output condition above. | |
3238 | * One of the trace_seq_* functions is not used properly. | |
3239 | */ | |
3240 | WARN_ONCE(iter->seq.full, "full flag set for trace type %d", | |
3241 | iter->ent->type); | |
3242 | } | |
3243 | trace_access_unlock(iter->cpu_file); | |
3244 | trace_event_read_unlock(); | |
3245 | ||
3246 | /* Now copy what we have to the user */ | |
3247 | sret = trace_seq_to_user(&iter->seq, ubuf, cnt); | |
3248 | if (iter->seq.readpos >= iter->seq.len) | |
3249 | trace_seq_init(&iter->seq); | |
3250 | ||
3251 | /* | |
3252 | * If there was nothing to send to user, in spite of consuming trace | |
3253 | * entries, go back to wait for more entries. | |
3254 | */ | |
3255 | if (sret == -EBUSY) | |
3256 | goto waitagain; | |
3257 | ||
3258 | out: | |
3259 | mutex_unlock(&iter->mutex); | |
3260 | ||
3261 | return sret; | |
3262 | } | |
3263 | ||
3264 | static void tracing_pipe_buf_release(struct pipe_inode_info *pipe, | |
3265 | struct pipe_buffer *buf) | |
3266 | { | |
3267 | __free_page(buf->page); | |
3268 | } | |
3269 | ||
3270 | static void tracing_spd_release_pipe(struct splice_pipe_desc *spd, | |
3271 | unsigned int idx) | |
3272 | { | |
3273 | __free_page(spd->pages[idx]); | |
3274 | } | |
3275 | ||
3276 | static const struct pipe_buf_operations tracing_pipe_buf_ops = { | |
3277 | .can_merge = 0, | |
3278 | .map = generic_pipe_buf_map, | |
3279 | .unmap = generic_pipe_buf_unmap, | |
3280 | .confirm = generic_pipe_buf_confirm, | |
3281 | .release = tracing_pipe_buf_release, | |
3282 | .steal = generic_pipe_buf_steal, | |
3283 | .get = generic_pipe_buf_get, | |
3284 | }; | |
3285 | ||
3286 | static size_t | |
3287 | tracing_fill_pipe_page(size_t rem, struct trace_iterator *iter) | |
3288 | { | |
3289 | size_t count; | |
3290 | int ret; | |
3291 | ||
3292 | /* Seq buffer is page-sized, exactly what we need. */ | |
3293 | for (;;) { | |
3294 | count = iter->seq.len; | |
3295 | ret = print_trace_line(iter); | |
3296 | count = iter->seq.len - count; | |
3297 | if (rem < count) { | |
3298 | rem = 0; | |
3299 | iter->seq.len -= count; | |
3300 | break; | |
3301 | } | |
3302 | if (ret == TRACE_TYPE_PARTIAL_LINE) { | |
3303 | iter->seq.len -= count; | |
3304 | break; | |
3305 | } | |
3306 | ||
3307 | if (ret != TRACE_TYPE_NO_CONSUME) | |
3308 | trace_consume(iter); | |
3309 | rem -= count; | |
3310 | if (!trace_find_next_entry_inc(iter)) { | |
3311 | rem = 0; | |
3312 | iter->ent = NULL; | |
3313 | break; | |
3314 | } | |
3315 | } | |
3316 | ||
3317 | return rem; | |
3318 | } | |
3319 | ||
3320 | static ssize_t tracing_splice_read_pipe(struct file *filp, | |
3321 | loff_t *ppos, | |
3322 | struct pipe_inode_info *pipe, | |
3323 | size_t len, | |
3324 | unsigned int flags) | |
3325 | { | |
3326 | struct page *pages_def[PIPE_DEF_BUFFERS]; | |
3327 | struct partial_page partial_def[PIPE_DEF_BUFFERS]; | |
3328 | struct trace_iterator *iter = filp->private_data; | |
3329 | struct splice_pipe_desc spd = { | |
3330 | .pages = pages_def, | |
3331 | .partial = partial_def, | |
3332 | .nr_pages = 0, /* This gets updated below. */ | |
3333 | .flags = flags, | |
3334 | .ops = &tracing_pipe_buf_ops, | |
3335 | .spd_release = tracing_spd_release_pipe, | |
3336 | }; | |
3337 | static struct tracer *old_tracer; | |
3338 | ssize_t ret; | |
3339 | size_t rem; | |
3340 | unsigned int i; | |
3341 | ||
3342 | if (splice_grow_spd(pipe, &spd)) | |
3343 | return -ENOMEM; | |
3344 | ||
3345 | /* copy the tracer to avoid using a global lock all around */ | |
3346 | mutex_lock(&trace_types_lock); | |
3347 | if (unlikely(old_tracer != current_trace && current_trace)) { | |
3348 | old_tracer = current_trace; | |
3349 | *iter->trace = *current_trace; | |
3350 | } | |
3351 | mutex_unlock(&trace_types_lock); | |
3352 | ||
3353 | mutex_lock(&iter->mutex); | |
3354 | ||
3355 | if (iter->trace->splice_read) { | |
3356 | ret = iter->trace->splice_read(iter, filp, | |
3357 | ppos, pipe, len, flags); | |
3358 | if (ret) | |
3359 | goto out_err; | |
3360 | } | |
3361 | ||
3362 | ret = tracing_wait_pipe(filp); | |
3363 | if (ret <= 0) | |
3364 | goto out_err; | |
3365 | ||
3366 | if (!iter->ent && !trace_find_next_entry_inc(iter)) { | |
3367 | ret = -EFAULT; | |
3368 | goto out_err; | |
3369 | } | |
3370 | ||
3371 | trace_event_read_lock(); | |
3372 | trace_access_lock(iter->cpu_file); | |
3373 | ||
3374 | /* Fill as many pages as possible. */ | |
3375 | for (i = 0, rem = len; i < pipe->buffers && rem; i++) { | |
3376 | spd.pages[i] = alloc_page(GFP_KERNEL); | |
3377 | if (!spd.pages[i]) | |
3378 | break; | |
3379 | ||
3380 | rem = tracing_fill_pipe_page(rem, iter); | |
3381 | ||
3382 | /* Copy the data into the page, so we can start over. */ | |
3383 | ret = trace_seq_to_buffer(&iter->seq, | |
3384 | page_address(spd.pages[i]), | |
3385 | iter->seq.len); | |
3386 | if (ret < 0) { | |
3387 | __free_page(spd.pages[i]); | |
3388 | break; | |
3389 | } | |
3390 | spd.partial[i].offset = 0; | |
3391 | spd.partial[i].len = iter->seq.len; | |
3392 | ||
3393 | trace_seq_init(&iter->seq); | |
3394 | } | |
3395 | ||
3396 | trace_access_unlock(iter->cpu_file); | |
3397 | trace_event_read_unlock(); | |
3398 | mutex_unlock(&iter->mutex); | |
3399 | ||
3400 | spd.nr_pages = i; | |
3401 | ||
3402 | ret = splice_to_pipe(pipe, &spd); | |
3403 | out: | |
3404 | splice_shrink_spd(pipe, &spd); | |
3405 | return ret; | |
3406 | ||
3407 | out_err: | |
3408 | mutex_unlock(&iter->mutex); | |
3409 | goto out; | |
3410 | } | |
3411 | ||
3412 | static ssize_t | |
3413 | tracing_entries_read(struct file *filp, char __user *ubuf, | |
3414 | size_t cnt, loff_t *ppos) | |
3415 | { | |
3416 | struct trace_array *tr = filp->private_data; | |
3417 | char buf[96]; | |
3418 | int r; | |
3419 | ||
3420 | mutex_lock(&trace_types_lock); | |
3421 | if (!ring_buffer_expanded) | |
3422 | r = sprintf(buf, "%lu (expanded: %lu)\n", | |
3423 | tr->entries >> 10, | |
3424 | trace_buf_size >> 10); | |
3425 | else | |
3426 | r = sprintf(buf, "%lu\n", tr->entries >> 10); | |
3427 | mutex_unlock(&trace_types_lock); | |
3428 | ||
3429 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
3430 | } | |
3431 | ||
3432 | static ssize_t | |
3433 | tracing_entries_write(struct file *filp, const char __user *ubuf, | |
3434 | size_t cnt, loff_t *ppos) | |
3435 | { | |
3436 | unsigned long val; | |
3437 | char buf[64]; | |
3438 | int ret, cpu; | |
3439 | ||
3440 | if (cnt >= sizeof(buf)) | |
3441 | return -EINVAL; | |
3442 | ||
3443 | if (copy_from_user(&buf, ubuf, cnt)) | |
3444 | return -EFAULT; | |
3445 | ||
3446 | buf[cnt] = 0; | |
3447 | ||
3448 | ret = strict_strtoul(buf, 10, &val); | |
3449 | if (ret < 0) | |
3450 | return ret; | |
3451 | ||
3452 | /* must have at least 1 entry */ | |
3453 | if (!val) | |
3454 | return -EINVAL; | |
3455 | ||
3456 | mutex_lock(&trace_types_lock); | |
3457 | ||
3458 | tracing_stop(); | |
3459 | ||
3460 | /* disable all cpu buffers */ | |
3461 | for_each_tracing_cpu(cpu) { | |
3462 | if (global_trace.data[cpu]) | |
3463 | atomic_inc(&global_trace.data[cpu]->disabled); | |
3464 | if (max_tr.data[cpu]) | |
3465 | atomic_inc(&max_tr.data[cpu]->disabled); | |
3466 | } | |
3467 | ||
3468 | /* value is in KB */ | |
3469 | val <<= 10; | |
3470 | ||
3471 | if (val != global_trace.entries) { | |
3472 | ret = tracing_resize_ring_buffer(val); | |
3473 | if (ret < 0) { | |
3474 | cnt = ret; | |
3475 | goto out; | |
3476 | } | |
3477 | } | |
3478 | ||
3479 | *ppos += cnt; | |
3480 | ||
3481 | /* If check pages failed, return ENOMEM */ | |
3482 | if (tracing_disabled) | |
3483 | cnt = -ENOMEM; | |
3484 | out: | |
3485 | for_each_tracing_cpu(cpu) { | |
3486 | if (global_trace.data[cpu]) | |
3487 | atomic_dec(&global_trace.data[cpu]->disabled); | |
3488 | if (max_tr.data[cpu]) | |
3489 | atomic_dec(&max_tr.data[cpu]->disabled); | |
3490 | } | |
3491 | ||
3492 | tracing_start(); | |
3493 | mutex_unlock(&trace_types_lock); | |
3494 | ||
3495 | return cnt; | |
3496 | } | |
3497 | ||
3498 | static int mark_printk(const char *fmt, ...) | |
3499 | { | |
3500 | int ret; | |
3501 | va_list args; | |
3502 | va_start(args, fmt); | |
3503 | ret = trace_vprintk(0, fmt, args); | |
3504 | va_end(args); | |
3505 | return ret; | |
3506 | } | |
3507 | ||
3508 | static ssize_t | |
3509 | tracing_mark_write(struct file *filp, const char __user *ubuf, | |
3510 | size_t cnt, loff_t *fpos) | |
3511 | { | |
3512 | char *buf; | |
3513 | size_t written; | |
3514 | ||
3515 | if (tracing_disabled) | |
3516 | return -EINVAL; | |
3517 | ||
3518 | if (cnt > TRACE_BUF_SIZE) | |
3519 | cnt = TRACE_BUF_SIZE; | |
3520 | ||
3521 | buf = kmalloc(cnt + 2, GFP_KERNEL); | |
3522 | if (buf == NULL) | |
3523 | return -ENOMEM; | |
3524 | ||
3525 | if (copy_from_user(buf, ubuf, cnt)) { | |
3526 | kfree(buf); | |
3527 | return -EFAULT; | |
3528 | } | |
3529 | if (buf[cnt-1] != '\n') { | |
3530 | buf[cnt] = '\n'; | |
3531 | buf[cnt+1] = '\0'; | |
3532 | } else | |
3533 | buf[cnt] = '\0'; | |
3534 | ||
3535 | written = mark_printk("%s", buf); | |
3536 | kfree(buf); | |
3537 | *fpos += written; | |
3538 | ||
3539 | /* don't tell userspace we wrote more - it might confuse them */ | |
3540 | if (written > cnt) | |
3541 | written = cnt; | |
3542 | ||
3543 | return written; | |
3544 | } | |
3545 | ||
3546 | static int tracing_clock_show(struct seq_file *m, void *v) | |
3547 | { | |
3548 | int i; | |
3549 | ||
3550 | for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) | |
3551 | seq_printf(m, | |
3552 | "%s%s%s%s", i ? " " : "", | |
3553 | i == trace_clock_id ? "[" : "", trace_clocks[i].name, | |
3554 | i == trace_clock_id ? "]" : ""); | |
3555 | seq_putc(m, '\n'); | |
3556 | ||
3557 | return 0; | |
3558 | } | |
3559 | ||
3560 | static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf, | |
3561 | size_t cnt, loff_t *fpos) | |
3562 | { | |
3563 | char buf[64]; | |
3564 | const char *clockstr; | |
3565 | int i; | |
3566 | ||
3567 | if (cnt >= sizeof(buf)) | |
3568 | return -EINVAL; | |
3569 | ||
3570 | if (copy_from_user(&buf, ubuf, cnt)) | |
3571 | return -EFAULT; | |
3572 | ||
3573 | buf[cnt] = 0; | |
3574 | ||
3575 | clockstr = strstrip(buf); | |
3576 | ||
3577 | for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) { | |
3578 | if (strcmp(trace_clocks[i].name, clockstr) == 0) | |
3579 | break; | |
3580 | } | |
3581 | if (i == ARRAY_SIZE(trace_clocks)) | |
3582 | return -EINVAL; | |
3583 | ||
3584 | trace_clock_id = i; | |
3585 | ||
3586 | mutex_lock(&trace_types_lock); | |
3587 | ||
3588 | ring_buffer_set_clock(global_trace.buffer, trace_clocks[i].func); | |
3589 | if (max_tr.buffer) | |
3590 | ring_buffer_set_clock(max_tr.buffer, trace_clocks[i].func); | |
3591 | ||
3592 | mutex_unlock(&trace_types_lock); | |
3593 | ||
3594 | *fpos += cnt; | |
3595 | ||
3596 | return cnt; | |
3597 | } | |
3598 | ||
3599 | static int tracing_clock_open(struct inode *inode, struct file *file) | |
3600 | { | |
3601 | if (tracing_disabled) | |
3602 | return -ENODEV; | |
3603 | return single_open(file, tracing_clock_show, NULL); | |
3604 | } | |
3605 | ||
3606 | static const struct file_operations tracing_max_lat_fops = { | |
3607 | .open = tracing_open_generic, | |
3608 | .read = tracing_max_lat_read, | |
3609 | .write = tracing_max_lat_write, | |
3610 | .llseek = generic_file_llseek, | |
3611 | }; | |
3612 | ||
3613 | static const struct file_operations tracing_ctrl_fops = { | |
3614 | .open = tracing_open_generic, | |
3615 | .read = tracing_ctrl_read, | |
3616 | .write = tracing_ctrl_write, | |
3617 | .llseek = generic_file_llseek, | |
3618 | }; | |
3619 | ||
3620 | static const struct file_operations set_tracer_fops = { | |
3621 | .open = tracing_open_generic, | |
3622 | .read = tracing_set_trace_read, | |
3623 | .write = tracing_set_trace_write, | |
3624 | .llseek = generic_file_llseek, | |
3625 | }; | |
3626 | ||
3627 | static const struct file_operations tracing_pipe_fops = { | |
3628 | .open = tracing_open_pipe, | |
3629 | .poll = tracing_poll_pipe, | |
3630 | .read = tracing_read_pipe, | |
3631 | .splice_read = tracing_splice_read_pipe, | |
3632 | .release = tracing_release_pipe, | |
3633 | .llseek = no_llseek, | |
3634 | }; | |
3635 | ||
3636 | static const struct file_operations tracing_entries_fops = { | |
3637 | .open = tracing_open_generic, | |
3638 | .read = tracing_entries_read, | |
3639 | .write = tracing_entries_write, | |
3640 | .llseek = generic_file_llseek, | |
3641 | }; | |
3642 | ||
3643 | static const struct file_operations tracing_mark_fops = { | |
3644 | .open = tracing_open_generic, | |
3645 | .write = tracing_mark_write, | |
3646 | .llseek = generic_file_llseek, | |
3647 | }; | |
3648 | ||
3649 | static const struct file_operations trace_clock_fops = { | |
3650 | .open = tracing_clock_open, | |
3651 | .read = seq_read, | |
3652 | .llseek = seq_lseek, | |
3653 | .release = single_release, | |
3654 | .write = tracing_clock_write, | |
3655 | }; | |
3656 | ||
3657 | struct ftrace_buffer_info { | |
3658 | struct trace_array *tr; | |
3659 | void *spare; | |
3660 | int cpu; | |
3661 | unsigned int read; | |
3662 | }; | |
3663 | ||
3664 | static int tracing_buffers_open(struct inode *inode, struct file *filp) | |
3665 | { | |
3666 | int cpu = (int)(long)inode->i_private; | |
3667 | struct ftrace_buffer_info *info; | |
3668 | ||
3669 | if (tracing_disabled) | |
3670 | return -ENODEV; | |
3671 | ||
3672 | info = kzalloc(sizeof(*info), GFP_KERNEL); | |
3673 | if (!info) | |
3674 | return -ENOMEM; | |
3675 | ||
3676 | info->tr = &global_trace; | |
3677 | info->cpu = cpu; | |
3678 | info->spare = NULL; | |
3679 | /* Force reading ring buffer for first read */ | |
3680 | info->read = (unsigned int)-1; | |
3681 | ||
3682 | filp->private_data = info; | |
3683 | ||
3684 | return nonseekable_open(inode, filp); | |
3685 | } | |
3686 | ||
3687 | static ssize_t | |
3688 | tracing_buffers_read(struct file *filp, char __user *ubuf, | |
3689 | size_t count, loff_t *ppos) | |
3690 | { | |
3691 | struct ftrace_buffer_info *info = filp->private_data; | |
3692 | ssize_t ret; | |
3693 | size_t size; | |
3694 | ||
3695 | if (!count) | |
3696 | return 0; | |
3697 | ||
3698 | if (!info->spare) | |
3699 | info->spare = ring_buffer_alloc_read_page(info->tr->buffer); | |
3700 | if (!info->spare) | |
3701 | return -ENOMEM; | |
3702 | ||
3703 | /* Do we have previous read data to read? */ | |
3704 | if (info->read < PAGE_SIZE) | |
3705 | goto read; | |
3706 | ||
3707 | info->read = 0; | |
3708 | ||
3709 | trace_access_lock(info->cpu); | |
3710 | ret = ring_buffer_read_page(info->tr->buffer, | |
3711 | &info->spare, | |
3712 | count, | |
3713 | info->cpu, 0); | |
3714 | trace_access_unlock(info->cpu); | |
3715 | if (ret < 0) | |
3716 | return 0; | |
3717 | ||
3718 | read: | |
3719 | size = PAGE_SIZE - info->read; | |
3720 | if (size > count) | |
3721 | size = count; | |
3722 | ||
3723 | ret = copy_to_user(ubuf, info->spare + info->read, size); | |
3724 | if (ret == size) | |
3725 | return -EFAULT; | |
3726 | size -= ret; | |
3727 | ||
3728 | *ppos += size; | |
3729 | info->read += size; | |
3730 | ||
3731 | return size; | |
3732 | } | |
3733 | ||
3734 | static int tracing_buffers_release(struct inode *inode, struct file *file) | |
3735 | { | |
3736 | struct ftrace_buffer_info *info = file->private_data; | |
3737 | ||
3738 | if (info->spare) | |
3739 | ring_buffer_free_read_page(info->tr->buffer, info->spare); | |
3740 | kfree(info); | |
3741 | ||
3742 | return 0; | |
3743 | } | |
3744 | ||
3745 | struct buffer_ref { | |
3746 | struct ring_buffer *buffer; | |
3747 | void *page; | |
3748 | int ref; | |
3749 | }; | |
3750 | ||
3751 | static void buffer_pipe_buf_release(struct pipe_inode_info *pipe, | |
3752 | struct pipe_buffer *buf) | |
3753 | { | |
3754 | struct buffer_ref *ref = (struct buffer_ref *)buf->private; | |
3755 | ||
3756 | if (--ref->ref) | |
3757 | return; | |
3758 | ||
3759 | ring_buffer_free_read_page(ref->buffer, ref->page); | |
3760 | kfree(ref); | |
3761 | buf->private = 0; | |
3762 | } | |
3763 | ||
3764 | static int buffer_pipe_buf_steal(struct pipe_inode_info *pipe, | |
3765 | struct pipe_buffer *buf) | |
3766 | { | |
3767 | return 1; | |
3768 | } | |
3769 | ||
3770 | static void buffer_pipe_buf_get(struct pipe_inode_info *pipe, | |
3771 | struct pipe_buffer *buf) | |
3772 | { | |
3773 | struct buffer_ref *ref = (struct buffer_ref *)buf->private; | |
3774 | ||
3775 | ref->ref++; | |
3776 | } | |
3777 | ||
3778 | /* Pipe buffer operations for a buffer. */ | |
3779 | static const struct pipe_buf_operations buffer_pipe_buf_ops = { | |
3780 | .can_merge = 0, | |
3781 | .map = generic_pipe_buf_map, | |
3782 | .unmap = generic_pipe_buf_unmap, | |
3783 | .confirm = generic_pipe_buf_confirm, | |
3784 | .release = buffer_pipe_buf_release, | |
3785 | .steal = buffer_pipe_buf_steal, | |
3786 | .get = buffer_pipe_buf_get, | |
3787 | }; | |
3788 | ||
3789 | /* | |
3790 | * Callback from splice_to_pipe(), if we need to release some pages | |
3791 | * at the end of the spd in case we error'ed out in filling the pipe. | |
3792 | */ | |
3793 | static void buffer_spd_release(struct splice_pipe_desc *spd, unsigned int i) | |
3794 | { | |
3795 | struct buffer_ref *ref = | |
3796 | (struct buffer_ref *)spd->partial[i].private; | |
3797 | ||
3798 | if (--ref->ref) | |
3799 | return; | |
3800 | ||
3801 | ring_buffer_free_read_page(ref->buffer, ref->page); | |
3802 | kfree(ref); | |
3803 | spd->partial[i].private = 0; | |
3804 | } | |
3805 | ||
3806 | static ssize_t | |
3807 | tracing_buffers_splice_read(struct file *file, loff_t *ppos, | |
3808 | struct pipe_inode_info *pipe, size_t len, | |
3809 | unsigned int flags) | |
3810 | { | |
3811 | struct ftrace_buffer_info *info = file->private_data; | |
3812 | struct partial_page partial_def[PIPE_DEF_BUFFERS]; | |
3813 | struct page *pages_def[PIPE_DEF_BUFFERS]; | |
3814 | struct splice_pipe_desc spd = { | |
3815 | .pages = pages_def, | |
3816 | .partial = partial_def, | |
3817 | .flags = flags, | |
3818 | .ops = &buffer_pipe_buf_ops, | |
3819 | .spd_release = buffer_spd_release, | |
3820 | }; | |
3821 | struct buffer_ref *ref; | |
3822 | int entries, size, i; | |
3823 | size_t ret; | |
3824 | ||
3825 | if (splice_grow_spd(pipe, &spd)) | |
3826 | return -ENOMEM; | |
3827 | ||
3828 | if (*ppos & (PAGE_SIZE - 1)) { | |
3829 | WARN_ONCE(1, "Ftrace: previous read must page-align\n"); | |
3830 | ret = -EINVAL; | |
3831 | goto out; | |
3832 | } | |
3833 | ||
3834 | if (len & (PAGE_SIZE - 1)) { | |
3835 | WARN_ONCE(1, "Ftrace: splice_read should page-align\n"); | |
3836 | if (len < PAGE_SIZE) { | |
3837 | ret = -EINVAL; | |
3838 | goto out; | |
3839 | } | |
3840 | len &= PAGE_MASK; | |
3841 | } | |
3842 | ||
3843 | trace_access_lock(info->cpu); | |
3844 | entries = ring_buffer_entries_cpu(info->tr->buffer, info->cpu); | |
3845 | ||
3846 | for (i = 0; i < pipe->buffers && len && entries; i++, len -= PAGE_SIZE) { | |
3847 | struct page *page; | |
3848 | int r; | |
3849 | ||
3850 | ref = kzalloc(sizeof(*ref), GFP_KERNEL); | |
3851 | if (!ref) | |
3852 | break; | |
3853 | ||
3854 | ref->ref = 1; | |
3855 | ref->buffer = info->tr->buffer; | |
3856 | ref->page = ring_buffer_alloc_read_page(ref->buffer); | |
3857 | if (!ref->page) { | |
3858 | kfree(ref); | |
3859 | break; | |
3860 | } | |
3861 | ||
3862 | r = ring_buffer_read_page(ref->buffer, &ref->page, | |
3863 | len, info->cpu, 1); | |
3864 | if (r < 0) { | |
3865 | ring_buffer_free_read_page(ref->buffer, | |
3866 | ref->page); | |
3867 | kfree(ref); | |
3868 | break; | |
3869 | } | |
3870 | ||
3871 | /* | |
3872 | * zero out any left over data, this is going to | |
3873 | * user land. | |
3874 | */ | |
3875 | size = ring_buffer_page_len(ref->page); | |
3876 | if (size < PAGE_SIZE) | |
3877 | memset(ref->page + size, 0, PAGE_SIZE - size); | |
3878 | ||
3879 | page = virt_to_page(ref->page); | |
3880 | ||
3881 | spd.pages[i] = page; | |
3882 | spd.partial[i].len = PAGE_SIZE; | |
3883 | spd.partial[i].offset = 0; | |
3884 | spd.partial[i].private = (unsigned long)ref; | |
3885 | spd.nr_pages++; | |
3886 | *ppos += PAGE_SIZE; | |
3887 | ||
3888 | entries = ring_buffer_entries_cpu(info->tr->buffer, info->cpu); | |
3889 | } | |
3890 | ||
3891 | trace_access_unlock(info->cpu); | |
3892 | spd.nr_pages = i; | |
3893 | ||
3894 | /* did we read anything? */ | |
3895 | if (!spd.nr_pages) { | |
3896 | if (flags & SPLICE_F_NONBLOCK) | |
3897 | ret = -EAGAIN; | |
3898 | else | |
3899 | ret = 0; | |
3900 | /* TODO: block */ | |
3901 | goto out; | |
3902 | } | |
3903 | ||
3904 | ret = splice_to_pipe(pipe, &spd); | |
3905 | splice_shrink_spd(pipe, &spd); | |
3906 | out: | |
3907 | return ret; | |
3908 | } | |
3909 | ||
3910 | static const struct file_operations tracing_buffers_fops = { | |
3911 | .open = tracing_buffers_open, | |
3912 | .read = tracing_buffers_read, | |
3913 | .release = tracing_buffers_release, | |
3914 | .splice_read = tracing_buffers_splice_read, | |
3915 | .llseek = no_llseek, | |
3916 | }; | |
3917 | ||
3918 | static ssize_t | |
3919 | tracing_stats_read(struct file *filp, char __user *ubuf, | |
3920 | size_t count, loff_t *ppos) | |
3921 | { | |
3922 | unsigned long cpu = (unsigned long)filp->private_data; | |
3923 | struct trace_array *tr = &global_trace; | |
3924 | struct trace_seq *s; | |
3925 | unsigned long cnt; | |
3926 | ||
3927 | s = kmalloc(sizeof(*s), GFP_KERNEL); | |
3928 | if (!s) | |
3929 | return -ENOMEM; | |
3930 | ||
3931 | trace_seq_init(s); | |
3932 | ||
3933 | cnt = ring_buffer_entries_cpu(tr->buffer, cpu); | |
3934 | trace_seq_printf(s, "entries: %ld\n", cnt); | |
3935 | ||
3936 | cnt = ring_buffer_overrun_cpu(tr->buffer, cpu); | |
3937 | trace_seq_printf(s, "overrun: %ld\n", cnt); | |
3938 | ||
3939 | cnt = ring_buffer_commit_overrun_cpu(tr->buffer, cpu); | |
3940 | trace_seq_printf(s, "commit overrun: %ld\n", cnt); | |
3941 | ||
3942 | count = simple_read_from_buffer(ubuf, count, ppos, s->buffer, s->len); | |
3943 | ||
3944 | kfree(s); | |
3945 | ||
3946 | return count; | |
3947 | } | |
3948 | ||
3949 | static const struct file_operations tracing_stats_fops = { | |
3950 | .open = tracing_open_generic, | |
3951 | .read = tracing_stats_read, | |
3952 | .llseek = generic_file_llseek, | |
3953 | }; | |
3954 | ||
3955 | #ifdef CONFIG_DYNAMIC_FTRACE | |
3956 | ||
3957 | int __weak ftrace_arch_read_dyn_info(char *buf, int size) | |
3958 | { | |
3959 | return 0; | |
3960 | } | |
3961 | ||
3962 | static ssize_t | |
3963 | tracing_read_dyn_info(struct file *filp, char __user *ubuf, | |
3964 | size_t cnt, loff_t *ppos) | |
3965 | { | |
3966 | static char ftrace_dyn_info_buffer[1024]; | |
3967 | static DEFINE_MUTEX(dyn_info_mutex); | |
3968 | unsigned long *p = filp->private_data; | |
3969 | char *buf = ftrace_dyn_info_buffer; | |
3970 | int size = ARRAY_SIZE(ftrace_dyn_info_buffer); | |
3971 | int r; | |
3972 | ||
3973 | mutex_lock(&dyn_info_mutex); | |
3974 | r = sprintf(buf, "%ld ", *p); | |
3975 | ||
3976 | r += ftrace_arch_read_dyn_info(buf+r, (size-1)-r); | |
3977 | buf[r++] = '\n'; | |
3978 | ||
3979 | r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
3980 | ||
3981 | mutex_unlock(&dyn_info_mutex); | |
3982 | ||
3983 | return r; | |
3984 | } | |
3985 | ||
3986 | static const struct file_operations tracing_dyn_info_fops = { | |
3987 | .open = tracing_open_generic, | |
3988 | .read = tracing_read_dyn_info, | |
3989 | .llseek = generic_file_llseek, | |
3990 | }; | |
3991 | #endif | |
3992 | ||
3993 | static struct dentry *d_tracer; | |
3994 | ||
3995 | struct dentry *tracing_init_dentry(void) | |
3996 | { | |
3997 | static int once; | |
3998 | ||
3999 | if (d_tracer) | |
4000 | return d_tracer; | |
4001 | ||
4002 | if (!debugfs_initialized()) | |
4003 | return NULL; | |
4004 | ||
4005 | d_tracer = debugfs_create_dir("tracing", NULL); | |
4006 | ||
4007 | if (!d_tracer && !once) { | |
4008 | once = 1; | |
4009 | pr_warning("Could not create debugfs directory 'tracing'\n"); | |
4010 | return NULL; | |
4011 | } | |
4012 | ||
4013 | return d_tracer; | |
4014 | } | |
4015 | ||
4016 | static struct dentry *d_percpu; | |
4017 | ||
4018 | struct dentry *tracing_dentry_percpu(void) | |
4019 | { | |
4020 | static int once; | |
4021 | struct dentry *d_tracer; | |
4022 | ||
4023 | if (d_percpu) | |
4024 | return d_percpu; | |
4025 | ||
4026 | d_tracer = tracing_init_dentry(); | |
4027 | ||
4028 | if (!d_tracer) | |
4029 | return NULL; | |
4030 | ||
4031 | d_percpu = debugfs_create_dir("per_cpu", d_tracer); | |
4032 | ||
4033 | if (!d_percpu && !once) { | |
4034 | once = 1; | |
4035 | pr_warning("Could not create debugfs directory 'per_cpu'\n"); | |
4036 | return NULL; | |
4037 | } | |
4038 | ||
4039 | return d_percpu; | |
4040 | } | |
4041 | ||
4042 | static void tracing_init_debugfs_percpu(long cpu) | |
4043 | { | |
4044 | struct dentry *d_percpu = tracing_dentry_percpu(); | |
4045 | struct dentry *d_cpu; | |
4046 | char cpu_dir[30]; /* 30 characters should be more than enough */ | |
4047 | ||
4048 | snprintf(cpu_dir, 30, "cpu%ld", cpu); | |
4049 | d_cpu = debugfs_create_dir(cpu_dir, d_percpu); | |
4050 | if (!d_cpu) { | |
4051 | pr_warning("Could not create debugfs '%s' entry\n", cpu_dir); | |
4052 | return; | |
4053 | } | |
4054 | ||
4055 | /* per cpu trace_pipe */ | |
4056 | trace_create_file("trace_pipe", 0444, d_cpu, | |
4057 | (void *) cpu, &tracing_pipe_fops); | |
4058 | ||
4059 | /* per cpu trace */ | |
4060 | trace_create_file("trace", 0644, d_cpu, | |
4061 | (void *) cpu, &tracing_fops); | |
4062 | ||
4063 | trace_create_file("trace_pipe_raw", 0444, d_cpu, | |
4064 | (void *) cpu, &tracing_buffers_fops); | |
4065 | ||
4066 | trace_create_file("stats", 0444, d_cpu, | |
4067 | (void *) cpu, &tracing_stats_fops); | |
4068 | } | |
4069 | ||
4070 | #ifdef CONFIG_FTRACE_SELFTEST | |
4071 | /* Let selftest have access to static functions in this file */ | |
4072 | #include "trace_selftest.c" | |
4073 | #endif | |
4074 | ||
4075 | struct trace_option_dentry { | |
4076 | struct tracer_opt *opt; | |
4077 | struct tracer_flags *flags; | |
4078 | struct dentry *entry; | |
4079 | }; | |
4080 | ||
4081 | static ssize_t | |
4082 | trace_options_read(struct file *filp, char __user *ubuf, size_t cnt, | |
4083 | loff_t *ppos) | |
4084 | { | |
4085 | struct trace_option_dentry *topt = filp->private_data; | |
4086 | char *buf; | |
4087 | ||
4088 | if (topt->flags->val & topt->opt->bit) | |
4089 | buf = "1\n"; | |
4090 | else | |
4091 | buf = "0\n"; | |
4092 | ||
4093 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); | |
4094 | } | |
4095 | ||
4096 | static ssize_t | |
4097 | trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt, | |
4098 | loff_t *ppos) | |
4099 | { | |
4100 | struct trace_option_dentry *topt = filp->private_data; | |
4101 | unsigned long val; | |
4102 | char buf[64]; | |
4103 | int ret; | |
4104 | ||
4105 | if (cnt >= sizeof(buf)) | |
4106 | return -EINVAL; | |
4107 | ||
4108 | if (copy_from_user(&buf, ubuf, cnt)) | |
4109 | return -EFAULT; | |
4110 | ||
4111 | buf[cnt] = 0; | |
4112 | ||
4113 | ret = strict_strtoul(buf, 10, &val); | |
4114 | if (ret < 0) | |
4115 | return ret; | |
4116 | ||
4117 | if (val != 0 && val != 1) | |
4118 | return -EINVAL; | |
4119 | ||
4120 | if (!!(topt->flags->val & topt->opt->bit) != val) { | |
4121 | mutex_lock(&trace_types_lock); | |
4122 | ret = __set_tracer_option(current_trace, topt->flags, | |
4123 | topt->opt, !val); | |
4124 | mutex_unlock(&trace_types_lock); | |
4125 | if (ret) | |
4126 | return ret; | |
4127 | } | |
4128 | ||
4129 | *ppos += cnt; | |
4130 | ||
4131 | return cnt; | |
4132 | } | |
4133 | ||
4134 | ||
4135 | static const struct file_operations trace_options_fops = { | |
4136 | .open = tracing_open_generic, | |
4137 | .read = trace_options_read, | |
4138 | .write = trace_options_write, | |
4139 | .llseek = generic_file_llseek, | |
4140 | }; | |
4141 | ||
4142 | static ssize_t | |
4143 | trace_options_core_read(struct file *filp, char __user *ubuf, size_t cnt, | |
4144 | loff_t *ppos) | |
4145 | { | |
4146 | long index = (long)filp->private_data; | |
4147 | char *buf; | |
4148 | ||
4149 | if (trace_flags & (1 << index)) | |
4150 | buf = "1\n"; | |
4151 | else | |
4152 | buf = "0\n"; | |
4153 | ||
4154 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2); | |
4155 | } | |
4156 | ||
4157 | static ssize_t | |
4158 | trace_options_core_write(struct file *filp, const char __user *ubuf, size_t cnt, | |
4159 | loff_t *ppos) | |
4160 | { | |
4161 | long index = (long)filp->private_data; | |
4162 | char buf[64]; | |
4163 | unsigned long val; | |
4164 | int ret; | |
4165 | ||
4166 | if (cnt >= sizeof(buf)) | |
4167 | return -EINVAL; | |
4168 | ||
4169 | if (copy_from_user(&buf, ubuf, cnt)) | |
4170 | return -EFAULT; | |
4171 | ||
4172 | buf[cnt] = 0; | |
4173 | ||
4174 | ret = strict_strtoul(buf, 10, &val); | |
4175 | if (ret < 0) | |
4176 | return ret; | |
4177 | ||
4178 | if (val != 0 && val != 1) | |
4179 | return -EINVAL; | |
4180 | set_tracer_flags(1 << index, val); | |
4181 | ||
4182 | *ppos += cnt; | |
4183 | ||
4184 | return cnt; | |
4185 | } | |
4186 | ||
4187 | static const struct file_operations trace_options_core_fops = { | |
4188 | .open = tracing_open_generic, | |
4189 | .read = trace_options_core_read, | |
4190 | .write = trace_options_core_write, | |
4191 | .llseek = generic_file_llseek, | |
4192 | }; | |
4193 | ||
4194 | struct dentry *trace_create_file(const char *name, | |
4195 | mode_t mode, | |
4196 | struct dentry *parent, | |
4197 | void *data, | |
4198 | const struct file_operations *fops) | |
4199 | { | |
4200 | struct dentry *ret; | |
4201 | ||
4202 | ret = debugfs_create_file(name, mode, parent, data, fops); | |
4203 | if (!ret) | |
4204 | pr_warning("Could not create debugfs '%s' entry\n", name); | |
4205 | ||
4206 | return ret; | |
4207 | } | |
4208 | ||
4209 | ||
4210 | static struct dentry *trace_options_init_dentry(void) | |
4211 | { | |
4212 | struct dentry *d_tracer; | |
4213 | static struct dentry *t_options; | |
4214 | ||
4215 | if (t_options) | |
4216 | return t_options; | |
4217 | ||
4218 | d_tracer = tracing_init_dentry(); | |
4219 | if (!d_tracer) | |
4220 | return NULL; | |
4221 | ||
4222 | t_options = debugfs_create_dir("options", d_tracer); | |
4223 | if (!t_options) { | |
4224 | pr_warning("Could not create debugfs directory 'options'\n"); | |
4225 | return NULL; | |
4226 | } | |
4227 | ||
4228 | return t_options; | |
4229 | } | |
4230 | ||
4231 | static void | |
4232 | create_trace_option_file(struct trace_option_dentry *topt, | |
4233 | struct tracer_flags *flags, | |
4234 | struct tracer_opt *opt) | |
4235 | { | |
4236 | struct dentry *t_options; | |
4237 | ||
4238 | t_options = trace_options_init_dentry(); | |
4239 | if (!t_options) | |
4240 | return; | |
4241 | ||
4242 | topt->flags = flags; | |
4243 | topt->opt = opt; | |
4244 | ||
4245 | topt->entry = trace_create_file(opt->name, 0644, t_options, topt, | |
4246 | &trace_options_fops); | |
4247 | ||
4248 | } | |
4249 | ||
4250 | static struct trace_option_dentry * | |
4251 | create_trace_option_files(struct tracer *tracer) | |
4252 | { | |
4253 | struct trace_option_dentry *topts; | |
4254 | struct tracer_flags *flags; | |
4255 | struct tracer_opt *opts; | |
4256 | int cnt; | |
4257 | ||
4258 | if (!tracer) | |
4259 | return NULL; | |
4260 | ||
4261 | flags = tracer->flags; | |
4262 | ||
4263 | if (!flags || !flags->opts) | |
4264 | return NULL; | |
4265 | ||
4266 | opts = flags->opts; | |
4267 | ||
4268 | for (cnt = 0; opts[cnt].name; cnt++) | |
4269 | ; | |
4270 | ||
4271 | topts = kcalloc(cnt + 1, sizeof(*topts), GFP_KERNEL); | |
4272 | if (!topts) | |
4273 | return NULL; | |
4274 | ||
4275 | for (cnt = 0; opts[cnt].name; cnt++) | |
4276 | create_trace_option_file(&topts[cnt], flags, | |
4277 | &opts[cnt]); | |
4278 | ||
4279 | return topts; | |
4280 | } | |
4281 | ||
4282 | static void | |
4283 | destroy_trace_option_files(struct trace_option_dentry *topts) | |
4284 | { | |
4285 | int cnt; | |
4286 | ||
4287 | if (!topts) | |
4288 | return; | |
4289 | ||
4290 | for (cnt = 0; topts[cnt].opt; cnt++) { | |
4291 | if (topts[cnt].entry) | |
4292 | debugfs_remove(topts[cnt].entry); | |
4293 | } | |
4294 | ||
4295 | kfree(topts); | |
4296 | } | |
4297 | ||
4298 | static struct dentry * | |
4299 | create_trace_option_core_file(const char *option, long index) | |
4300 | { | |
4301 | struct dentry *t_options; | |
4302 | ||
4303 | t_options = trace_options_init_dentry(); | |
4304 | if (!t_options) | |
4305 | return NULL; | |
4306 | ||
4307 | return trace_create_file(option, 0644, t_options, (void *)index, | |
4308 | &trace_options_core_fops); | |
4309 | } | |
4310 | ||
4311 | static __init void create_trace_options_dir(void) | |
4312 | { | |
4313 | struct dentry *t_options; | |
4314 | int i; | |
4315 | ||
4316 | t_options = trace_options_init_dentry(); | |
4317 | if (!t_options) | |
4318 | return; | |
4319 | ||
4320 | for (i = 0; trace_options[i]; i++) | |
4321 | create_trace_option_core_file(trace_options[i], i); | |
4322 | } | |
4323 | ||
4324 | static __init int tracer_init_debugfs(void) | |
4325 | { | |
4326 | struct dentry *d_tracer; | |
4327 | int cpu; | |
4328 | ||
4329 | trace_access_lock_init(); | |
4330 | ||
4331 | d_tracer = tracing_init_dentry(); | |
4332 | ||
4333 | trace_create_file("tracing_enabled", 0644, d_tracer, | |
4334 | &global_trace, &tracing_ctrl_fops); | |
4335 | ||
4336 | trace_create_file("trace_options", 0644, d_tracer, | |
4337 | NULL, &tracing_iter_fops); | |
4338 | ||
4339 | trace_create_file("tracing_cpumask", 0644, d_tracer, | |
4340 | NULL, &tracing_cpumask_fops); | |
4341 | ||
4342 | trace_create_file("trace", 0644, d_tracer, | |
4343 | (void *) TRACE_PIPE_ALL_CPU, &tracing_fops); | |
4344 | ||
4345 | trace_create_file("available_tracers", 0444, d_tracer, | |
4346 | &global_trace, &show_traces_fops); | |
4347 | ||
4348 | trace_create_file("current_tracer", 0644, d_tracer, | |
4349 | &global_trace, &set_tracer_fops); | |
4350 | ||
4351 | #ifdef CONFIG_TRACER_MAX_TRACE | |
4352 | trace_create_file("tracing_max_latency", 0644, d_tracer, | |
4353 | &tracing_max_latency, &tracing_max_lat_fops); | |
4354 | #endif | |
4355 | ||
4356 | trace_create_file("tracing_thresh", 0644, d_tracer, | |
4357 | &tracing_thresh, &tracing_max_lat_fops); | |
4358 | ||
4359 | trace_create_file("README", 0444, d_tracer, | |
4360 | NULL, &tracing_readme_fops); | |
4361 | ||
4362 | trace_create_file("trace_pipe", 0444, d_tracer, | |
4363 | (void *) TRACE_PIPE_ALL_CPU, &tracing_pipe_fops); | |
4364 | ||
4365 | trace_create_file("buffer_size_kb", 0644, d_tracer, | |
4366 | &global_trace, &tracing_entries_fops); | |
4367 | ||
4368 | trace_create_file("trace_marker", 0220, d_tracer, | |
4369 | NULL, &tracing_mark_fops); | |
4370 | ||
4371 | trace_create_file("saved_cmdlines", 0444, d_tracer, | |
4372 | NULL, &tracing_saved_cmdlines_fops); | |
4373 | ||
4374 | trace_create_file("trace_clock", 0644, d_tracer, NULL, | |
4375 | &trace_clock_fops); | |
4376 | ||
4377 | #ifdef CONFIG_DYNAMIC_FTRACE | |
4378 | trace_create_file("dyn_ftrace_total_info", 0444, d_tracer, | |
4379 | &ftrace_update_tot_cnt, &tracing_dyn_info_fops); | |
4380 | #endif | |
4381 | ||
4382 | create_trace_options_dir(); | |
4383 | ||
4384 | for_each_tracing_cpu(cpu) | |
4385 | tracing_init_debugfs_percpu(cpu); | |
4386 | ||
4387 | return 0; | |
4388 | } | |
4389 | ||
4390 | static int trace_panic_handler(struct notifier_block *this, | |
4391 | unsigned long event, void *unused) | |
4392 | { | |
4393 | if (ftrace_dump_on_oops) | |
4394 | ftrace_dump(ftrace_dump_on_oops); | |
4395 | return NOTIFY_OK; | |
4396 | } | |
4397 | ||
4398 | static struct notifier_block trace_panic_notifier = { | |
4399 | .notifier_call = trace_panic_handler, | |
4400 | .next = NULL, | |
4401 | .priority = 150 /* priority: INT_MAX >= x >= 0 */ | |
4402 | }; | |
4403 | ||
4404 | static int trace_die_handler(struct notifier_block *self, | |
4405 | unsigned long val, | |
4406 | void *data) | |
4407 | { | |
4408 | switch (val) { | |
4409 | case DIE_OOPS: | |
4410 | if (ftrace_dump_on_oops) | |
4411 | ftrace_dump(ftrace_dump_on_oops); | |
4412 | break; | |
4413 | default: | |
4414 | break; | |
4415 | } | |
4416 | return NOTIFY_OK; | |
4417 | } | |
4418 | ||
4419 | static struct notifier_block trace_die_notifier = { | |
4420 | .notifier_call = trace_die_handler, | |
4421 | .priority = 200 | |
4422 | }; | |
4423 | ||
4424 | /* | |
4425 | * printk is set to max of 1024, we really don't need it that big. | |
4426 | * Nothing should be printing 1000 characters anyway. | |
4427 | */ | |
4428 | #define TRACE_MAX_PRINT 1000 | |
4429 | ||
4430 | /* | |
4431 | * Define here KERN_TRACE so that we have one place to modify | |
4432 | * it if we decide to change what log level the ftrace dump | |
4433 | * should be at. | |
4434 | */ | |
4435 | #define KERN_TRACE KERN_EMERG | |
4436 | ||
4437 | void | |
4438 | trace_printk_seq(struct trace_seq *s) | |
4439 | { | |
4440 | /* Probably should print a warning here. */ | |
4441 | if (s->len >= 1000) | |
4442 | s->len = 1000; | |
4443 | ||
4444 | /* should be zero ended, but we are paranoid. */ | |
4445 | s->buffer[s->len] = 0; | |
4446 | ||
4447 | printk(KERN_TRACE "%s", s->buffer); | |
4448 | ||
4449 | trace_seq_init(s); | |
4450 | } | |
4451 | ||
4452 | void trace_init_global_iter(struct trace_iterator *iter) | |
4453 | { | |
4454 | iter->tr = &global_trace; | |
4455 | iter->trace = current_trace; | |
4456 | iter->cpu_file = TRACE_PIPE_ALL_CPU; | |
4457 | } | |
4458 | ||
4459 | static void | |
4460 | __ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode) | |
4461 | { | |
4462 | static arch_spinlock_t ftrace_dump_lock = | |
4463 | (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; | |
4464 | /* use static because iter can be a bit big for the stack */ | |
4465 | static struct trace_iterator iter; | |
4466 | unsigned int old_userobj; | |
4467 | static int dump_ran; | |
4468 | unsigned long flags; | |
4469 | int cnt = 0, cpu; | |
4470 | ||
4471 | /* only one dump */ | |
4472 | local_irq_save(flags); | |
4473 | arch_spin_lock(&ftrace_dump_lock); | |
4474 | if (dump_ran) | |
4475 | goto out; | |
4476 | ||
4477 | dump_ran = 1; | |
4478 | ||
4479 | tracing_off(); | |
4480 | ||
4481 | if (disable_tracing) | |
4482 | ftrace_kill(); | |
4483 | ||
4484 | trace_init_global_iter(&iter); | |
4485 | ||
4486 | for_each_tracing_cpu(cpu) { | |
4487 | atomic_inc(&iter.tr->data[cpu]->disabled); | |
4488 | } | |
4489 | ||
4490 | old_userobj = trace_flags & TRACE_ITER_SYM_USEROBJ; | |
4491 | ||
4492 | /* don't look at user memory in panic mode */ | |
4493 | trace_flags &= ~TRACE_ITER_SYM_USEROBJ; | |
4494 | ||
4495 | /* Simulate the iterator */ | |
4496 | iter.tr = &global_trace; | |
4497 | iter.trace = current_trace; | |
4498 | ||
4499 | switch (oops_dump_mode) { | |
4500 | case DUMP_ALL: | |
4501 | iter.cpu_file = TRACE_PIPE_ALL_CPU; | |
4502 | break; | |
4503 | case DUMP_ORIG: | |
4504 | iter.cpu_file = raw_smp_processor_id(); | |
4505 | break; | |
4506 | case DUMP_NONE: | |
4507 | goto out_enable; | |
4508 | default: | |
4509 | printk(KERN_TRACE "Bad dumping mode, switching to all CPUs dump\n"); | |
4510 | iter.cpu_file = TRACE_PIPE_ALL_CPU; | |
4511 | } | |
4512 | ||
4513 | printk(KERN_TRACE "Dumping ftrace buffer:\n"); | |
4514 | ||
4515 | /* | |
4516 | * We need to stop all tracing on all CPUS to read the | |
4517 | * the next buffer. This is a bit expensive, but is | |
4518 | * not done often. We fill all what we can read, | |
4519 | * and then release the locks again. | |
4520 | */ | |
4521 | ||
4522 | while (!trace_empty(&iter)) { | |
4523 | ||
4524 | if (!cnt) | |
4525 | printk(KERN_TRACE "---------------------------------\n"); | |
4526 | ||
4527 | cnt++; | |
4528 | ||
4529 | /* reset all but tr, trace, and overruns */ | |
4530 | memset(&iter.seq, 0, | |
4531 | sizeof(struct trace_iterator) - | |
4532 | offsetof(struct trace_iterator, seq)); | |
4533 | iter.iter_flags |= TRACE_FILE_LAT_FMT; | |
4534 | iter.pos = -1; | |
4535 | ||
4536 | if (trace_find_next_entry_inc(&iter) != NULL) { | |
4537 | int ret; | |
4538 | ||
4539 | ret = print_trace_line(&iter); | |
4540 | if (ret != TRACE_TYPE_NO_CONSUME) | |
4541 | trace_consume(&iter); | |
4542 | } | |
4543 | ||
4544 | trace_printk_seq(&iter.seq); | |
4545 | } | |
4546 | ||
4547 | if (!cnt) | |
4548 | printk(KERN_TRACE " (ftrace buffer empty)\n"); | |
4549 | else | |
4550 | printk(KERN_TRACE "---------------------------------\n"); | |
4551 | ||
4552 | out_enable: | |
4553 | /* Re-enable tracing if requested */ | |
4554 | if (!disable_tracing) { | |
4555 | trace_flags |= old_userobj; | |
4556 | ||
4557 | for_each_tracing_cpu(cpu) { | |
4558 | atomic_dec(&iter.tr->data[cpu]->disabled); | |
4559 | } | |
4560 | tracing_on(); | |
4561 | } | |
4562 | ||
4563 | out: | |
4564 | arch_spin_unlock(&ftrace_dump_lock); | |
4565 | local_irq_restore(flags); | |
4566 | } | |
4567 | ||
4568 | /* By default: disable tracing after the dump */ | |
4569 | void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) | |
4570 | { | |
4571 | __ftrace_dump(true, oops_dump_mode); | |
4572 | } | |
4573 | ||
4574 | __init static int tracer_alloc_buffers(void) | |
4575 | { | |
4576 | int ring_buf_size; | |
4577 | enum ring_buffer_flags rb_flags; | |
4578 | int i; | |
4579 | int ret = -ENOMEM; | |
4580 | ||
4581 | ||
4582 | if (!alloc_cpumask_var(&tracing_buffer_mask, GFP_KERNEL)) | |
4583 | goto out; | |
4584 | ||
4585 | if (!alloc_cpumask_var(&tracing_cpumask, GFP_KERNEL)) | |
4586 | goto out_free_buffer_mask; | |
4587 | ||
4588 | /* To save memory, keep the ring buffer size to its minimum */ | |
4589 | if (ring_buffer_expanded) | |
4590 | ring_buf_size = trace_buf_size; | |
4591 | else | |
4592 | ring_buf_size = 1; | |
4593 | ||
4594 | rb_flags = trace_flags & TRACE_ITER_OVERWRITE ? RB_FL_OVERWRITE : 0; | |
4595 | ||
4596 | cpumask_copy(tracing_buffer_mask, cpu_possible_mask); | |
4597 | cpumask_copy(tracing_cpumask, cpu_all_mask); | |
4598 | ||
4599 | /* TODO: make the number of buffers hot pluggable with CPUS */ | |
4600 | global_trace.buffer = ring_buffer_alloc(ring_buf_size, rb_flags); | |
4601 | if (!global_trace.buffer) { | |
4602 | printk(KERN_ERR "tracer: failed to allocate ring buffer!\n"); | |
4603 | WARN_ON(1); | |
4604 | goto out_free_cpumask; | |
4605 | } | |
4606 | global_trace.entries = ring_buffer_size(global_trace.buffer); | |
4607 | ||
4608 | ||
4609 | #ifdef CONFIG_TRACER_MAX_TRACE | |
4610 | max_tr.buffer = ring_buffer_alloc(1, rb_flags); | |
4611 | if (!max_tr.buffer) { | |
4612 | printk(KERN_ERR "tracer: failed to allocate max ring buffer!\n"); | |
4613 | WARN_ON(1); | |
4614 | ring_buffer_free(global_trace.buffer); | |
4615 | goto out_free_cpumask; | |
4616 | } | |
4617 | max_tr.entries = 1; | |
4618 | #endif | |
4619 | ||
4620 | /* Allocate the first page for all buffers */ | |
4621 | for_each_tracing_cpu(i) { | |
4622 | global_trace.data[i] = &per_cpu(global_trace_cpu, i); | |
4623 | max_tr.data[i] = &per_cpu(max_tr_data, i); | |
4624 | } | |
4625 | ||
4626 | trace_init_cmdlines(); | |
4627 | ||
4628 | register_tracer(&nop_trace); | |
4629 | current_trace = &nop_trace; | |
4630 | /* All seems OK, enable tracing */ | |
4631 | tracing_disabled = 0; | |
4632 | ||
4633 | atomic_notifier_chain_register(&panic_notifier_list, | |
4634 | &trace_panic_notifier); | |
4635 | ||
4636 | register_die_notifier(&trace_die_notifier); | |
4637 | ||
4638 | return 0; | |
4639 | ||
4640 | out_free_cpumask: | |
4641 | free_cpumask_var(tracing_cpumask); | |
4642 | out_free_buffer_mask: | |
4643 | free_cpumask_var(tracing_buffer_mask); | |
4644 | out: | |
4645 | return ret; | |
4646 | } | |
4647 | ||
4648 | __init static int clear_boot_tracer(void) | |
4649 | { | |
4650 | /* | |
4651 | * The default tracer at boot buffer is an init section. | |
4652 | * This function is called in lateinit. If we did not | |
4653 | * find the boot tracer, then clear it out, to prevent | |
4654 | * later registration from accessing the buffer that is | |
4655 | * about to be freed. | |
4656 | */ | |
4657 | if (!default_bootup_tracer) | |
4658 | return 0; | |
4659 | ||
4660 | printk(KERN_INFO "ftrace bootup tracer '%s' not registered.\n", | |
4661 | default_bootup_tracer); | |
4662 | default_bootup_tracer = NULL; | |
4663 | ||
4664 | return 0; | |
4665 | } | |
4666 | ||
4667 | early_initcall(tracer_alloc_buffers); | |
4668 | fs_initcall(tracer_init_debugfs); | |
4669 | late_initcall(clear_boot_tracer); |