Commit | Line | Data |
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bc0c38d1 SR |
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/utsrelease.h> | |
15 | #include <linux/kallsyms.h> | |
16 | #include <linux/seq_file.h> | |
17 | #include <linux/debugfs.h> | |
4c11d7ae | 18 | #include <linux/pagemap.h> |
bc0c38d1 SR |
19 | #include <linux/hardirq.h> |
20 | #include <linux/linkage.h> | |
21 | #include <linux/uaccess.h> | |
22 | #include <linux/ftrace.h> | |
23 | #include <linux/module.h> | |
24 | #include <linux/percpu.h> | |
25 | #include <linux/ctype.h> | |
26 | #include <linux/init.h> | |
27 | #include <linux/gfp.h> | |
28 | #include <linux/fs.h> | |
29 | ||
30 | #include "trace.h" | |
31 | ||
32 | unsigned long __read_mostly tracing_max_latency = (cycle_t)ULONG_MAX; | |
33 | unsigned long __read_mostly tracing_thresh; | |
34 | ||
60a11774 SR |
35 | static int tracing_disabled = 1; |
36 | ||
bc0c38d1 SR |
37 | static long notrace |
38 | ns2usecs(cycle_t nsec) | |
39 | { | |
40 | nsec += 500; | |
41 | do_div(nsec, 1000); | |
42 | return nsec; | |
43 | } | |
44 | ||
45 | static atomic_t tracer_counter; | |
46 | static struct trace_array global_trace; | |
47 | ||
48 | static DEFINE_PER_CPU(struct trace_array_cpu, global_trace_cpu); | |
49 | ||
50 | static struct trace_array max_tr; | |
51 | ||
52 | static DEFINE_PER_CPU(struct trace_array_cpu, max_data); | |
53 | ||
54 | static int tracer_enabled; | |
4c11d7ae | 55 | static unsigned long trace_nr_entries = 16384UL; |
bc0c38d1 SR |
56 | |
57 | static struct tracer *trace_types __read_mostly; | |
58 | static struct tracer *current_trace __read_mostly; | |
59 | static int max_tracer_type_len; | |
60 | ||
61 | static DEFINE_MUTEX(trace_types_lock); | |
62 | ||
4c11d7ae SR |
63 | #define ENTRIES_PER_PAGE (PAGE_SIZE / sizeof(struct trace_entry)) |
64 | ||
bc0c38d1 SR |
65 | static int __init set_nr_entries(char *str) |
66 | { | |
67 | if (!str) | |
68 | return 0; | |
69 | trace_nr_entries = simple_strtoul(str, &str, 0); | |
70 | return 1; | |
71 | } | |
72 | __setup("trace_entries=", set_nr_entries); | |
73 | ||
57f50be1 SR |
74 | unsigned long nsecs_to_usecs(unsigned long nsecs) |
75 | { | |
76 | return nsecs / 1000; | |
77 | } | |
78 | ||
bc0c38d1 SR |
79 | enum trace_type { |
80 | __TRACE_FIRST_TYPE = 0, | |
81 | ||
82 | TRACE_FN, | |
83 | TRACE_CTX, | |
84 | ||
85 | __TRACE_LAST_TYPE | |
86 | }; | |
87 | ||
88 | enum trace_flag_type { | |
89 | TRACE_FLAG_IRQS_OFF = 0x01, | |
90 | TRACE_FLAG_NEED_RESCHED = 0x02, | |
91 | TRACE_FLAG_HARDIRQ = 0x04, | |
92 | TRACE_FLAG_SOFTIRQ = 0x08, | |
93 | }; | |
94 | ||
95 | enum trace_iterator_flags { | |
96 | TRACE_ITER_PRINT_PARENT = 0x01, | |
97 | TRACE_ITER_SYM_OFFSET = 0x02, | |
98 | TRACE_ITER_SYM_ADDR = 0x04, | |
99 | TRACE_ITER_VERBOSE = 0x08, | |
100 | }; | |
101 | ||
102 | #define TRACE_ITER_SYM_MASK \ | |
103 | (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR) | |
104 | ||
105 | /* These must match the bit postions above */ | |
106 | static const char *trace_options[] = { | |
107 | "print-parent", | |
108 | "sym-offset", | |
109 | "sym-addr", | |
110 | "verbose", | |
111 | NULL | |
112 | }; | |
113 | ||
114 | static unsigned trace_flags; | |
115 | ||
4c11d7ae | 116 | static DEFINE_SPINLOCK(ftrace_max_lock); |
bc0c38d1 SR |
117 | |
118 | /* | |
119 | * Copy the new maximum trace into the separate maximum-trace | |
120 | * structure. (this way the maximum trace is permanently saved, | |
121 | * for later retrieval via /debugfs/tracing/latency_trace) | |
122 | */ | |
4e3c3333 | 123 | static notrace void |
bc0c38d1 SR |
124 | __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) |
125 | { | |
126 | struct trace_array_cpu *data = tr->data[cpu]; | |
127 | ||
128 | max_tr.cpu = cpu; | |
129 | max_tr.time_start = data->preempt_timestamp; | |
130 | ||
131 | data = max_tr.data[cpu]; | |
132 | data->saved_latency = tracing_max_latency; | |
133 | ||
134 | memcpy(data->comm, tsk->comm, TASK_COMM_LEN); | |
135 | data->pid = tsk->pid; | |
136 | data->uid = tsk->uid; | |
137 | data->nice = tsk->static_prio - 20 - MAX_RT_PRIO; | |
138 | data->policy = tsk->policy; | |
139 | data->rt_priority = tsk->rt_priority; | |
140 | ||
141 | /* record this tasks comm */ | |
142 | tracing_record_cmdline(current); | |
143 | } | |
144 | ||
c7aafc54 IM |
145 | void check_pages(struct trace_array_cpu *data) |
146 | { | |
147 | struct page *page, *tmp; | |
148 | ||
149 | BUG_ON(data->trace_pages.next->prev != &data->trace_pages); | |
150 | BUG_ON(data->trace_pages.prev->next != &data->trace_pages); | |
151 | ||
152 | list_for_each_entry_safe(page, tmp, &data->trace_pages, lru) { | |
153 | BUG_ON(page->lru.next->prev != &page->lru); | |
154 | BUG_ON(page->lru.prev->next != &page->lru); | |
155 | } | |
156 | } | |
157 | ||
158 | void *head_page(struct trace_array_cpu *data) | |
159 | { | |
160 | struct page *page; | |
161 | ||
162 | check_pages(data); | |
163 | if (list_empty(&data->trace_pages)) | |
164 | return NULL; | |
165 | ||
166 | page = list_entry(data->trace_pages.next, struct page, lru); | |
167 | BUG_ON(&page->lru == &data->trace_pages); | |
168 | ||
169 | return page_address(page); | |
170 | } | |
171 | ||
214023c3 SR |
172 | static notrace int |
173 | trace_seq_printf(struct trace_seq *s, const char *fmt, ...) | |
174 | { | |
175 | int len = (PAGE_SIZE - 1) - s->len; | |
176 | va_list ap; | |
b3806b43 | 177 | int ret; |
214023c3 SR |
178 | |
179 | if (!len) | |
180 | return 0; | |
181 | ||
182 | va_start(ap, fmt); | |
b3806b43 | 183 | ret = vsnprintf(s->buffer + s->len, len, fmt, ap); |
214023c3 SR |
184 | va_end(ap); |
185 | ||
b3806b43 SR |
186 | /* If we can't write it all, don't bother writing anything */ |
187 | if (ret > len) | |
188 | return 0; | |
189 | ||
190 | s->len += ret; | |
214023c3 SR |
191 | |
192 | return len; | |
193 | } | |
194 | ||
195 | static notrace int | |
196 | trace_seq_puts(struct trace_seq *s, const char *str) | |
197 | { | |
198 | int len = strlen(str); | |
199 | ||
200 | if (len > ((PAGE_SIZE - 1) - s->len)) | |
b3806b43 | 201 | return 0; |
214023c3 SR |
202 | |
203 | memcpy(s->buffer + s->len, str, len); | |
204 | s->len += len; | |
205 | ||
206 | return len; | |
207 | } | |
208 | ||
209 | static notrace int | |
210 | trace_seq_putc(struct trace_seq *s, unsigned char c) | |
211 | { | |
212 | if (s->len >= (PAGE_SIZE - 1)) | |
213 | return 0; | |
214 | ||
215 | s->buffer[s->len++] = c; | |
216 | ||
217 | return 1; | |
218 | } | |
219 | ||
220 | static notrace void | |
221 | trace_seq_reset(struct trace_seq *s) | |
222 | { | |
223 | s->len = 0; | |
224 | } | |
225 | ||
226 | static notrace void | |
227 | trace_print_seq(struct seq_file *m, struct trace_seq *s) | |
228 | { | |
229 | int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len; | |
230 | ||
231 | s->buffer[len] = 0; | |
232 | seq_puts(m, s->buffer); | |
233 | ||
234 | trace_seq_reset(s); | |
235 | } | |
236 | ||
c7aafc54 IM |
237 | notrace static void |
238 | flip_trace(struct trace_array_cpu *tr1, struct trace_array_cpu *tr2) | |
239 | { | |
240 | struct list_head flip_pages; | |
241 | ||
242 | INIT_LIST_HEAD(&flip_pages); | |
243 | ||
93a588f4 | 244 | memcpy(&tr1->trace_head_idx, &tr2->trace_head_idx, |
c7aafc54 | 245 | sizeof(struct trace_array_cpu) - |
93a588f4 | 246 | offsetof(struct trace_array_cpu, trace_head_idx)); |
c7aafc54 IM |
247 | |
248 | check_pages(tr1); | |
249 | check_pages(tr2); | |
250 | list_splice_init(&tr1->trace_pages, &flip_pages); | |
251 | list_splice_init(&tr2->trace_pages, &tr1->trace_pages); | |
252 | list_splice_init(&flip_pages, &tr2->trace_pages); | |
253 | BUG_ON(!list_empty(&flip_pages)); | |
254 | check_pages(tr1); | |
255 | check_pages(tr2); | |
256 | } | |
257 | ||
bc0c38d1 SR |
258 | notrace void |
259 | update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) | |
260 | { | |
261 | struct trace_array_cpu *data; | |
bc0c38d1 SR |
262 | int i; |
263 | ||
4c11d7ae SR |
264 | WARN_ON_ONCE(!irqs_disabled()); |
265 | spin_lock(&ftrace_max_lock); | |
bc0c38d1 SR |
266 | /* clear out all the previous traces */ |
267 | for_each_possible_cpu(i) { | |
268 | data = tr->data[i]; | |
c7aafc54 | 269 | flip_trace(max_tr.data[i], data); |
89b2f978 | 270 | tracing_reset(data); |
bc0c38d1 SR |
271 | } |
272 | ||
273 | __update_max_tr(tr, tsk, cpu); | |
4c11d7ae | 274 | spin_unlock(&ftrace_max_lock); |
bc0c38d1 SR |
275 | } |
276 | ||
277 | /** | |
278 | * update_max_tr_single - only copy one trace over, and reset the rest | |
279 | * @tr - tracer | |
280 | * @tsk - task with the latency | |
281 | * @cpu - the cpu of the buffer to copy. | |
282 | */ | |
283 | notrace void | |
284 | update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) | |
285 | { | |
286 | struct trace_array_cpu *data = tr->data[cpu]; | |
bc0c38d1 SR |
287 | int i; |
288 | ||
4c11d7ae SR |
289 | WARN_ON_ONCE(!irqs_disabled()); |
290 | spin_lock(&ftrace_max_lock); | |
bc0c38d1 SR |
291 | for_each_possible_cpu(i) |
292 | tracing_reset(max_tr.data[i]); | |
293 | ||
c7aafc54 | 294 | flip_trace(max_tr.data[cpu], data); |
89b2f978 | 295 | tracing_reset(data); |
bc0c38d1 SR |
296 | |
297 | __update_max_tr(tr, tsk, cpu); | |
4c11d7ae | 298 | spin_unlock(&ftrace_max_lock); |
bc0c38d1 SR |
299 | } |
300 | ||
301 | int register_tracer(struct tracer *type) | |
302 | { | |
303 | struct tracer *t; | |
304 | int len; | |
305 | int ret = 0; | |
306 | ||
307 | if (!type->name) { | |
308 | pr_info("Tracer must have a name\n"); | |
309 | return -1; | |
310 | } | |
311 | ||
312 | mutex_lock(&trace_types_lock); | |
313 | for (t = trace_types; t; t = t->next) { | |
314 | if (strcmp(type->name, t->name) == 0) { | |
315 | /* already found */ | |
316 | pr_info("Trace %s already registered\n", | |
317 | type->name); | |
318 | ret = -1; | |
319 | goto out; | |
320 | } | |
321 | } | |
322 | ||
60a11774 SR |
323 | #ifdef CONFIG_FTRACE_STARTUP_TEST |
324 | if (type->selftest) { | |
325 | struct tracer *saved_tracer = current_trace; | |
326 | struct trace_array_cpu *data; | |
327 | struct trace_array *tr = &global_trace; | |
328 | int saved_ctrl = tr->ctrl; | |
329 | int i; | |
330 | /* | |
331 | * Run a selftest on this tracer. | |
332 | * Here we reset the trace buffer, and set the current | |
333 | * tracer to be this tracer. The tracer can then run some | |
334 | * internal tracing to verify that everything is in order. | |
335 | * If we fail, we do not register this tracer. | |
336 | */ | |
337 | for_each_possible_cpu(i) { | |
60a11774 | 338 | data = tr->data[i]; |
c7aafc54 IM |
339 | if (!head_page(data)) |
340 | continue; | |
60a11774 SR |
341 | tracing_reset(data); |
342 | } | |
343 | current_trace = type; | |
344 | tr->ctrl = 0; | |
345 | /* the test is responsible for initializing and enabling */ | |
346 | pr_info("Testing tracer %s: ", type->name); | |
347 | ret = type->selftest(type, tr); | |
348 | /* the test is responsible for resetting too */ | |
349 | current_trace = saved_tracer; | |
350 | tr->ctrl = saved_ctrl; | |
351 | if (ret) { | |
352 | printk(KERN_CONT "FAILED!\n"); | |
353 | goto out; | |
354 | } | |
1d4db00a SR |
355 | /* Only reset on passing, to avoid touching corrupted buffers */ |
356 | for_each_possible_cpu(i) { | |
357 | data = tr->data[i]; | |
358 | if (!head_page(data)) | |
359 | continue; | |
360 | tracing_reset(data); | |
361 | } | |
60a11774 SR |
362 | printk(KERN_CONT "PASSED\n"); |
363 | } | |
364 | #endif | |
365 | ||
bc0c38d1 SR |
366 | type->next = trace_types; |
367 | trace_types = type; | |
368 | len = strlen(type->name); | |
369 | if (len > max_tracer_type_len) | |
370 | max_tracer_type_len = len; | |
60a11774 | 371 | |
bc0c38d1 SR |
372 | out: |
373 | mutex_unlock(&trace_types_lock); | |
374 | ||
375 | return ret; | |
376 | } | |
377 | ||
378 | void unregister_tracer(struct tracer *type) | |
379 | { | |
380 | struct tracer **t; | |
381 | int len; | |
382 | ||
383 | mutex_lock(&trace_types_lock); | |
384 | for (t = &trace_types; *t; t = &(*t)->next) { | |
385 | if (*t == type) | |
386 | goto found; | |
387 | } | |
388 | pr_info("Trace %s not registered\n", type->name); | |
389 | goto out; | |
390 | ||
391 | found: | |
392 | *t = (*t)->next; | |
393 | if (strlen(type->name) != max_tracer_type_len) | |
394 | goto out; | |
395 | ||
396 | max_tracer_type_len = 0; | |
397 | for (t = &trace_types; *t; t = &(*t)->next) { | |
398 | len = strlen((*t)->name); | |
399 | if (len > max_tracer_type_len) | |
400 | max_tracer_type_len = len; | |
401 | } | |
402 | out: | |
403 | mutex_unlock(&trace_types_lock); | |
404 | } | |
405 | ||
4e3c3333 | 406 | notrace void tracing_reset(struct trace_array_cpu *data) |
bc0c38d1 SR |
407 | { |
408 | data->trace_idx = 0; | |
93a588f4 SR |
409 | data->trace_head = data->trace_tail = head_page(data); |
410 | data->trace_head_idx = 0; | |
411 | data->trace_tail_idx = 0; | |
bc0c38d1 SR |
412 | } |
413 | ||
414 | #ifdef CONFIG_FTRACE | |
4e3c3333 | 415 | static notrace void |
bc0c38d1 SR |
416 | function_trace_call(unsigned long ip, unsigned long parent_ip) |
417 | { | |
418 | struct trace_array *tr = &global_trace; | |
419 | struct trace_array_cpu *data; | |
420 | unsigned long flags; | |
421 | long disabled; | |
422 | int cpu; | |
423 | ||
424 | if (unlikely(!tracer_enabled)) | |
425 | return; | |
426 | ||
18cef379 | 427 | local_irq_save(flags); |
bc0c38d1 SR |
428 | cpu = raw_smp_processor_id(); |
429 | data = tr->data[cpu]; | |
430 | disabled = atomic_inc_return(&data->disabled); | |
431 | ||
432 | if (likely(disabled == 1)) | |
433 | ftrace(tr, data, ip, parent_ip, flags); | |
434 | ||
435 | atomic_dec(&data->disabled); | |
18cef379 | 436 | local_irq_restore(flags); |
bc0c38d1 SR |
437 | } |
438 | ||
439 | static struct ftrace_ops trace_ops __read_mostly = | |
440 | { | |
441 | .func = function_trace_call, | |
442 | }; | |
443 | #endif | |
444 | ||
445 | notrace void tracing_start_function_trace(void) | |
446 | { | |
447 | register_ftrace_function(&trace_ops); | |
448 | } | |
449 | ||
450 | notrace void tracing_stop_function_trace(void) | |
451 | { | |
452 | unregister_ftrace_function(&trace_ops); | |
453 | } | |
454 | ||
455 | #define SAVED_CMDLINES 128 | |
456 | static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1]; | |
457 | static unsigned map_cmdline_to_pid[SAVED_CMDLINES]; | |
458 | static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN]; | |
459 | static int cmdline_idx; | |
460 | static DEFINE_SPINLOCK(trace_cmdline_lock); | |
461 | atomic_t trace_record_cmdline_disabled; | |
462 | ||
463 | static void trace_init_cmdlines(void) | |
464 | { | |
465 | memset(&map_pid_to_cmdline, -1, sizeof(map_pid_to_cmdline)); | |
466 | memset(&map_cmdline_to_pid, -1, sizeof(map_cmdline_to_pid)); | |
467 | cmdline_idx = 0; | |
468 | } | |
469 | ||
470 | notrace void trace_stop_cmdline_recording(void); | |
471 | ||
4e3c3333 | 472 | static notrace void trace_save_cmdline(struct task_struct *tsk) |
bc0c38d1 SR |
473 | { |
474 | unsigned map; | |
475 | unsigned idx; | |
476 | ||
477 | if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT)) | |
478 | return; | |
479 | ||
480 | /* | |
481 | * It's not the end of the world if we don't get | |
482 | * the lock, but we also don't want to spin | |
483 | * nor do we want to disable interrupts, | |
484 | * so if we miss here, then better luck next time. | |
485 | */ | |
486 | if (!spin_trylock(&trace_cmdline_lock)) | |
487 | return; | |
488 | ||
489 | idx = map_pid_to_cmdline[tsk->pid]; | |
490 | if (idx >= SAVED_CMDLINES) { | |
491 | idx = (cmdline_idx + 1) % SAVED_CMDLINES; | |
492 | ||
493 | map = map_cmdline_to_pid[idx]; | |
494 | if (map <= PID_MAX_DEFAULT) | |
495 | map_pid_to_cmdline[map] = (unsigned)-1; | |
496 | ||
497 | map_pid_to_cmdline[tsk->pid] = idx; | |
498 | ||
499 | cmdline_idx = idx; | |
500 | } | |
501 | ||
502 | memcpy(&saved_cmdlines[idx], tsk->comm, TASK_COMM_LEN); | |
503 | ||
504 | spin_unlock(&trace_cmdline_lock); | |
505 | } | |
506 | ||
507 | static notrace char *trace_find_cmdline(int pid) | |
508 | { | |
509 | char *cmdline = "<...>"; | |
510 | unsigned map; | |
511 | ||
512 | if (!pid) | |
513 | return "<idle>"; | |
514 | ||
515 | if (pid > PID_MAX_DEFAULT) | |
516 | goto out; | |
517 | ||
518 | map = map_pid_to_cmdline[pid]; | |
519 | if (map >= SAVED_CMDLINES) | |
520 | goto out; | |
521 | ||
522 | cmdline = saved_cmdlines[map]; | |
523 | ||
524 | out: | |
525 | return cmdline; | |
526 | } | |
527 | ||
528 | notrace void tracing_record_cmdline(struct task_struct *tsk) | |
529 | { | |
530 | if (atomic_read(&trace_record_cmdline_disabled)) | |
531 | return; | |
532 | ||
533 | trace_save_cmdline(tsk); | |
534 | } | |
535 | ||
93a588f4 SR |
536 | static inline notrace struct list_head * |
537 | trace_next_list(struct trace_array_cpu *data, struct list_head *next) | |
538 | { | |
539 | /* | |
540 | * Roundrobin - but skip the head (which is not a real page): | |
541 | */ | |
542 | next = next->next; | |
543 | if (unlikely(next == &data->trace_pages)) | |
544 | next = next->next; | |
545 | BUG_ON(next == &data->trace_pages); | |
546 | ||
547 | return next; | |
548 | } | |
549 | ||
550 | static inline notrace void * | |
551 | trace_next_page(struct trace_array_cpu *data, void *addr) | |
552 | { | |
553 | struct list_head *next; | |
554 | struct page *page; | |
555 | ||
556 | page = virt_to_page(addr); | |
557 | ||
558 | next = trace_next_list(data, &page->lru); | |
559 | page = list_entry(next, struct page, lru); | |
560 | ||
561 | return page_address(page); | |
562 | } | |
563 | ||
bc0c38d1 | 564 | static inline notrace struct trace_entry * |
c7aafc54 | 565 | tracing_get_trace_entry(struct trace_array *tr, struct trace_array_cpu *data) |
bc0c38d1 SR |
566 | { |
567 | unsigned long idx, idx_next; | |
568 | struct trace_entry *entry; | |
569 | ||
4c11d7ae | 570 | data->trace_idx++; |
93a588f4 | 571 | idx = data->trace_head_idx; |
bc0c38d1 SR |
572 | idx_next = idx + 1; |
573 | ||
c7aafc54 IM |
574 | BUG_ON(idx * TRACE_ENTRY_SIZE >= PAGE_SIZE); |
575 | ||
93a588f4 | 576 | entry = data->trace_head + idx * TRACE_ENTRY_SIZE; |
4c11d7ae SR |
577 | |
578 | if (unlikely(idx_next >= ENTRIES_PER_PAGE)) { | |
93a588f4 | 579 | data->trace_head = trace_next_page(data, data->trace_head); |
bc0c38d1 SR |
580 | idx_next = 0; |
581 | } | |
582 | ||
93a588f4 SR |
583 | if (data->trace_head == data->trace_tail && |
584 | idx_next == data->trace_tail_idx) { | |
585 | /* overrun */ | |
586 | data->trace_tail_idx++; | |
587 | if (data->trace_tail_idx >= ENTRIES_PER_PAGE) { | |
588 | data->trace_tail = | |
589 | trace_next_page(data, data->trace_tail); | |
590 | data->trace_tail_idx = 0; | |
591 | } | |
592 | } | |
593 | ||
594 | data->trace_head_idx = idx_next; | |
bc0c38d1 SR |
595 | |
596 | return entry; | |
597 | } | |
598 | ||
599 | static inline notrace void | |
c7aafc54 | 600 | tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags) |
bc0c38d1 SR |
601 | { |
602 | struct task_struct *tsk = current; | |
603 | unsigned long pc; | |
604 | ||
605 | pc = preempt_count(); | |
606 | ||
c7aafc54 IM |
607 | entry->idx = atomic_inc_return(&tracer_counter); |
608 | entry->preempt_count = pc & 0xff; | |
609 | entry->pid = tsk->pid; | |
610 | entry->t = now(raw_smp_processor_id()); | |
bc0c38d1 SR |
611 | entry->flags = (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) | |
612 | ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) | | |
613 | ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) | | |
614 | (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0); | |
615 | } | |
616 | ||
617 | notrace void | |
618 | ftrace(struct trace_array *tr, struct trace_array_cpu *data, | |
c7aafc54 | 619 | unsigned long ip, unsigned long parent_ip, unsigned long flags) |
bc0c38d1 SR |
620 | { |
621 | struct trace_entry *entry; | |
622 | ||
b3806b43 | 623 | spin_lock(&data->lock); |
c7aafc54 | 624 | entry = tracing_get_trace_entry(tr, data); |
bc0c38d1 | 625 | tracing_generic_entry_update(entry, flags); |
c7aafc54 IM |
626 | entry->type = TRACE_FN; |
627 | entry->fn.ip = ip; | |
628 | entry->fn.parent_ip = parent_ip; | |
b3806b43 | 629 | spin_unlock(&data->lock); |
bc0c38d1 SR |
630 | } |
631 | ||
632 | notrace void | |
633 | tracing_sched_switch_trace(struct trace_array *tr, | |
634 | struct trace_array_cpu *data, | |
635 | struct task_struct *prev, struct task_struct *next, | |
636 | unsigned long flags) | |
637 | { | |
638 | struct trace_entry *entry; | |
639 | ||
b3806b43 | 640 | spin_lock(&data->lock); |
c7aafc54 | 641 | entry = tracing_get_trace_entry(tr, data); |
bc0c38d1 SR |
642 | tracing_generic_entry_update(entry, flags); |
643 | entry->type = TRACE_CTX; | |
644 | entry->ctx.prev_pid = prev->pid; | |
645 | entry->ctx.prev_prio = prev->prio; | |
646 | entry->ctx.prev_state = prev->state; | |
647 | entry->ctx.next_pid = next->pid; | |
648 | entry->ctx.next_prio = next->prio; | |
b3806b43 | 649 | spin_unlock(&data->lock); |
bc0c38d1 SR |
650 | } |
651 | ||
652 | enum trace_file_type { | |
653 | TRACE_FILE_LAT_FMT = 1, | |
654 | }; | |
655 | ||
656 | static struct trace_entry * | |
4c11d7ae SR |
657 | trace_entry_idx(struct trace_array *tr, struct trace_array_cpu *data, |
658 | struct trace_iterator *iter, int cpu) | |
bc0c38d1 | 659 | { |
4c11d7ae SR |
660 | struct page *page; |
661 | struct trace_entry *array; | |
bc0c38d1 | 662 | |
4c11d7ae | 663 | if (iter->next_idx[cpu] >= tr->entries || |
b3806b43 SR |
664 | iter->next_idx[cpu] >= data->trace_idx || |
665 | (data->trace_head == data->trace_tail && | |
666 | data->trace_head_idx == data->trace_tail_idx)) | |
bc0c38d1 SR |
667 | return NULL; |
668 | ||
4c11d7ae | 669 | if (!iter->next_page[cpu]) { |
93a588f4 SR |
670 | /* Initialize the iterator for this cpu trace buffer */ |
671 | WARN_ON(!data->trace_tail); | |
672 | page = virt_to_page(data->trace_tail); | |
673 | iter->next_page[cpu] = &page->lru; | |
674 | iter->next_page_idx[cpu] = data->trace_tail_idx; | |
4c11d7ae | 675 | } |
bc0c38d1 | 676 | |
4c11d7ae | 677 | page = list_entry(iter->next_page[cpu], struct page, lru); |
c7aafc54 IM |
678 | BUG_ON(&data->trace_pages == &page->lru); |
679 | ||
4c11d7ae SR |
680 | array = page_address(page); |
681 | ||
93a588f4 SR |
682 | /* Still possible to catch up to the tail */ |
683 | if (iter->next_idx[cpu] && array == data->trace_tail && | |
684 | iter->next_page_idx[cpu] == data->trace_tail_idx) | |
685 | return NULL; | |
686 | ||
687 | WARN_ON(iter->next_page_idx[cpu] >= ENTRIES_PER_PAGE); | |
4c11d7ae | 688 | return &array[iter->next_page_idx[cpu]]; |
bc0c38d1 SR |
689 | } |
690 | ||
691 | static struct notrace trace_entry * | |
692 | find_next_entry(struct trace_iterator *iter, int *ent_cpu) | |
693 | { | |
694 | struct trace_array *tr = iter->tr; | |
695 | struct trace_entry *ent, *next = NULL; | |
696 | int next_cpu = -1; | |
697 | int cpu; | |
698 | ||
699 | for_each_possible_cpu(cpu) { | |
c7aafc54 | 700 | if (!head_page(tr->data[cpu])) |
bc0c38d1 | 701 | continue; |
4c11d7ae | 702 | ent = trace_entry_idx(tr, tr->data[cpu], iter, cpu); |
bc0c38d1 SR |
703 | if (ent && |
704 | (!next || (long)(next->idx - ent->idx) > 0)) { | |
705 | next = ent; | |
706 | next_cpu = cpu; | |
707 | } | |
708 | } | |
709 | ||
710 | if (ent_cpu) | |
711 | *ent_cpu = next_cpu; | |
712 | ||
713 | return next; | |
714 | } | |
715 | ||
b3806b43 SR |
716 | static notrace void |
717 | trace_iterator_increment(struct trace_iterator *iter) | |
bc0c38d1 | 718 | { |
b3806b43 SR |
719 | iter->idx++; |
720 | iter->next_idx[iter->cpu]++; | |
721 | iter->next_page_idx[iter->cpu]++; | |
722 | if (iter->next_page_idx[iter->cpu] >= ENTRIES_PER_PAGE) { | |
723 | struct trace_array_cpu *data = iter->tr->data[iter->cpu]; | |
bc0c38d1 | 724 | |
b3806b43 SR |
725 | iter->next_page_idx[iter->cpu] = 0; |
726 | iter->next_page[iter->cpu] = | |
727 | trace_next_list(data, iter->next_page[iter->cpu]); | |
728 | } | |
729 | } | |
bc0c38d1 | 730 | |
b3806b43 SR |
731 | static notrace void |
732 | trace_consume(struct trace_iterator *iter) | |
733 | { | |
734 | struct trace_array_cpu *data = iter->tr->data[iter->cpu]; | |
735 | ||
736 | data->trace_tail_idx++; | |
737 | if (data->trace_tail_idx >= ENTRIES_PER_PAGE) { | |
738 | data->trace_tail = trace_next_page(data, data->trace_tail); | |
739 | data->trace_tail_idx = 0; | |
740 | } | |
4e3c3333 | 741 | |
b3806b43 SR |
742 | /* Check if we empty it, then reset the index */ |
743 | if (data->trace_head == data->trace_tail && | |
744 | data->trace_head_idx == data->trace_tail_idx) | |
745 | data->trace_idx = 0; | |
4c11d7ae | 746 | |
b3806b43 SR |
747 | trace_iterator_increment(iter); |
748 | } | |
749 | ||
750 | static notrace void * | |
751 | find_next_entry_inc(struct trace_iterator *iter) | |
752 | { | |
753 | struct trace_entry *next; | |
754 | int next_cpu = -1; | |
755 | ||
756 | next = find_next_entry(iter, &next_cpu); | |
93a588f4 | 757 | |
4e3c3333 IM |
758 | iter->prev_ent = iter->ent; |
759 | iter->prev_cpu = iter->cpu; | |
760 | ||
bc0c38d1 SR |
761 | iter->ent = next; |
762 | iter->cpu = next_cpu; | |
763 | ||
b3806b43 SR |
764 | if (next) |
765 | trace_iterator_increment(iter); | |
766 | ||
bc0c38d1 SR |
767 | return next ? iter : NULL; |
768 | } | |
769 | ||
4e3c3333 | 770 | static notrace void *s_next(struct seq_file *m, void *v, loff_t *pos) |
bc0c38d1 SR |
771 | { |
772 | struct trace_iterator *iter = m->private; | |
bc0c38d1 SR |
773 | void *last_ent = iter->ent; |
774 | int i = (int)*pos; | |
4e3c3333 | 775 | void *ent; |
bc0c38d1 SR |
776 | |
777 | (*pos)++; | |
778 | ||
779 | /* can't go backwards */ | |
780 | if (iter->idx > i) | |
781 | return NULL; | |
782 | ||
783 | if (iter->idx < 0) | |
784 | ent = find_next_entry_inc(iter); | |
785 | else | |
786 | ent = iter; | |
787 | ||
788 | while (ent && iter->idx < i) | |
789 | ent = find_next_entry_inc(iter); | |
790 | ||
791 | iter->pos = *pos; | |
792 | ||
793 | if (last_ent && !ent) | |
794 | seq_puts(m, "\n\nvim:ft=help\n"); | |
795 | ||
796 | return ent; | |
797 | } | |
798 | ||
799 | static void *s_start(struct seq_file *m, loff_t *pos) | |
800 | { | |
801 | struct trace_iterator *iter = m->private; | |
802 | void *p = NULL; | |
803 | loff_t l = 0; | |
804 | int i; | |
805 | ||
806 | mutex_lock(&trace_types_lock); | |
807 | ||
808 | if (!current_trace || current_trace != iter->trace) | |
809 | return NULL; | |
810 | ||
811 | atomic_inc(&trace_record_cmdline_disabled); | |
812 | ||
813 | /* let the tracer grab locks here if needed */ | |
814 | if (current_trace->start) | |
815 | current_trace->start(iter); | |
816 | ||
817 | if (*pos != iter->pos) { | |
818 | iter->ent = NULL; | |
819 | iter->cpu = 0; | |
820 | iter->idx = -1; | |
4e3c3333 IM |
821 | iter->prev_ent = NULL; |
822 | iter->prev_cpu = -1; | |
bc0c38d1 | 823 | |
4c11d7ae | 824 | for_each_possible_cpu(i) { |
bc0c38d1 | 825 | iter->next_idx[i] = 0; |
4c11d7ae SR |
826 | iter->next_page[i] = NULL; |
827 | } | |
bc0c38d1 SR |
828 | |
829 | for (p = iter; p && l < *pos; p = s_next(m, p, &l)) | |
830 | ; | |
831 | ||
832 | } else { | |
4c11d7ae | 833 | l = *pos - 1; |
bc0c38d1 SR |
834 | p = s_next(m, p, &l); |
835 | } | |
836 | ||
837 | return p; | |
838 | } | |
839 | ||
840 | static void s_stop(struct seq_file *m, void *p) | |
841 | { | |
842 | struct trace_iterator *iter = m->private; | |
843 | ||
844 | atomic_dec(&trace_record_cmdline_disabled); | |
845 | ||
846 | /* let the tracer release locks here if needed */ | |
847 | if (current_trace && current_trace == iter->trace && iter->trace->stop) | |
848 | iter->trace->stop(iter); | |
849 | ||
850 | mutex_unlock(&trace_types_lock); | |
851 | } | |
852 | ||
b3806b43 | 853 | static int |
214023c3 | 854 | seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address) |
bc0c38d1 SR |
855 | { |
856 | #ifdef CONFIG_KALLSYMS | |
857 | char str[KSYM_SYMBOL_LEN]; | |
858 | ||
859 | kallsyms_lookup(address, NULL, NULL, NULL, str); | |
860 | ||
b3806b43 | 861 | return trace_seq_printf(s, fmt, str); |
bc0c38d1 | 862 | #endif |
b3806b43 | 863 | return 1; |
bc0c38d1 SR |
864 | } |
865 | ||
b3806b43 | 866 | static int |
214023c3 SR |
867 | seq_print_sym_offset(struct trace_seq *s, const char *fmt, |
868 | unsigned long address) | |
bc0c38d1 SR |
869 | { |
870 | #ifdef CONFIG_KALLSYMS | |
871 | char str[KSYM_SYMBOL_LEN]; | |
872 | ||
873 | sprint_symbol(str, address); | |
b3806b43 | 874 | return trace_seq_printf(s, fmt, str); |
bc0c38d1 | 875 | #endif |
b3806b43 | 876 | return 1; |
bc0c38d1 SR |
877 | } |
878 | ||
879 | #ifndef CONFIG_64BIT | |
880 | # define IP_FMT "%08lx" | |
881 | #else | |
882 | # define IP_FMT "%016lx" | |
883 | #endif | |
884 | ||
b3806b43 | 885 | static notrace int |
214023c3 | 886 | seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags) |
bc0c38d1 | 887 | { |
b3806b43 SR |
888 | int ret; |
889 | ||
890 | if (!ip) | |
891 | return trace_seq_printf(s, "0"); | |
bc0c38d1 SR |
892 | |
893 | if (sym_flags & TRACE_ITER_SYM_OFFSET) | |
b3806b43 | 894 | ret = seq_print_sym_offset(s, "%s", ip); |
bc0c38d1 | 895 | else |
b3806b43 SR |
896 | ret = seq_print_sym_short(s, "%s", ip); |
897 | ||
898 | if (!ret) | |
899 | return 0; | |
bc0c38d1 SR |
900 | |
901 | if (sym_flags & TRACE_ITER_SYM_ADDR) | |
b3806b43 SR |
902 | ret = trace_seq_printf(s, " <" IP_FMT ">", ip); |
903 | return ret; | |
bc0c38d1 SR |
904 | } |
905 | ||
4e3c3333 | 906 | static notrace void print_lat_help_header(struct seq_file *m) |
bc0c38d1 SR |
907 | { |
908 | seq_puts(m, "# _------=> CPU# \n"); | |
909 | seq_puts(m, "# / _-----=> irqs-off \n"); | |
910 | seq_puts(m, "# | / _----=> need-resched \n"); | |
911 | seq_puts(m, "# || / _---=> hardirq/softirq \n"); | |
912 | seq_puts(m, "# ||| / _--=> preempt-depth \n"); | |
913 | seq_puts(m, "# |||| / \n"); | |
914 | seq_puts(m, "# ||||| delay \n"); | |
915 | seq_puts(m, "# cmd pid ||||| time | caller \n"); | |
916 | seq_puts(m, "# \\ / ||||| \\ | / \n"); | |
917 | } | |
918 | ||
4e3c3333 | 919 | static notrace void print_func_help_header(struct seq_file *m) |
bc0c38d1 SR |
920 | { |
921 | seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n"); | |
922 | seq_puts(m, "# | | | | |\n"); | |
923 | } | |
924 | ||
925 | ||
4e3c3333 | 926 | static notrace void |
bc0c38d1 SR |
927 | print_trace_header(struct seq_file *m, struct trace_iterator *iter) |
928 | { | |
929 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); | |
930 | struct trace_array *tr = iter->tr; | |
931 | struct trace_array_cpu *data = tr->data[tr->cpu]; | |
932 | struct tracer *type = current_trace; | |
4c11d7ae SR |
933 | unsigned long total = 0; |
934 | unsigned long entries = 0; | |
bc0c38d1 SR |
935 | int cpu; |
936 | const char *name = "preemption"; | |
937 | ||
938 | if (type) | |
939 | name = type->name; | |
940 | ||
941 | for_each_possible_cpu(cpu) { | |
c7aafc54 | 942 | if (head_page(tr->data[cpu])) { |
4c11d7ae SR |
943 | total += tr->data[cpu]->trace_idx; |
944 | if (tr->data[cpu]->trace_idx > tr->entries) | |
bc0c38d1 | 945 | entries += tr->entries; |
4c11d7ae | 946 | else |
bc0c38d1 SR |
947 | entries += tr->data[cpu]->trace_idx; |
948 | } | |
949 | } | |
950 | ||
951 | seq_printf(m, "%s latency trace v1.1.5 on %s\n", | |
952 | name, UTS_RELEASE); | |
953 | seq_puts(m, "-----------------------------------" | |
954 | "---------------------------------\n"); | |
955 | seq_printf(m, " latency: %lu us, #%lu/%lu, CPU#%d |" | |
956 | " (M:%s VP:%d, KP:%d, SP:%d HP:%d", | |
57f50be1 | 957 | nsecs_to_usecs(data->saved_latency), |
bc0c38d1 | 958 | entries, |
4c11d7ae | 959 | total, |
bc0c38d1 SR |
960 | tr->cpu, |
961 | #if defined(CONFIG_PREEMPT_NONE) | |
962 | "server", | |
963 | #elif defined(CONFIG_PREEMPT_VOLUNTARY) | |
964 | "desktop", | |
965 | #elif defined(CONFIG_PREEMPT_DESKTOP) | |
966 | "preempt", | |
967 | #else | |
968 | "unknown", | |
969 | #endif | |
970 | /* These are reserved for later use */ | |
971 | 0, 0, 0, 0); | |
972 | #ifdef CONFIG_SMP | |
973 | seq_printf(m, " #P:%d)\n", num_online_cpus()); | |
974 | #else | |
975 | seq_puts(m, ")\n"); | |
976 | #endif | |
977 | seq_puts(m, " -----------------\n"); | |
978 | seq_printf(m, " | task: %.16s-%d " | |
979 | "(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n", | |
980 | data->comm, data->pid, data->uid, data->nice, | |
981 | data->policy, data->rt_priority); | |
982 | seq_puts(m, " -----------------\n"); | |
983 | ||
984 | if (data->critical_start) { | |
985 | seq_puts(m, " => started at: "); | |
214023c3 SR |
986 | seq_print_ip_sym(&iter->seq, data->critical_start, sym_flags); |
987 | trace_print_seq(m, &iter->seq); | |
bc0c38d1 | 988 | seq_puts(m, "\n => ended at: "); |
214023c3 SR |
989 | seq_print_ip_sym(&iter->seq, data->critical_end, sym_flags); |
990 | trace_print_seq(m, &iter->seq); | |
bc0c38d1 SR |
991 | seq_puts(m, "\n"); |
992 | } | |
993 | ||
994 | seq_puts(m, "\n"); | |
995 | } | |
996 | ||
4e3c3333 | 997 | static notrace void |
214023c3 | 998 | lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu) |
bc0c38d1 SR |
999 | { |
1000 | int hardirq, softirq; | |
1001 | char *comm; | |
1002 | ||
1003 | comm = trace_find_cmdline(entry->pid); | |
1004 | ||
214023c3 SR |
1005 | trace_seq_printf(s, "%8.8s-%-5d ", comm, entry->pid); |
1006 | trace_seq_printf(s, "%d", cpu); | |
1007 | trace_seq_printf(s, "%c%c", | |
1008 | (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : '.', | |
1009 | ((entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.')); | |
bc0c38d1 SR |
1010 | |
1011 | hardirq = entry->flags & TRACE_FLAG_HARDIRQ; | |
1012 | softirq = entry->flags & TRACE_FLAG_SOFTIRQ; | |
1013 | if (hardirq && softirq) | |
214023c3 | 1014 | trace_seq_putc(s, 'H'); |
bc0c38d1 SR |
1015 | else { |
1016 | if (hardirq) | |
214023c3 | 1017 | trace_seq_putc(s, 'h'); |
bc0c38d1 SR |
1018 | else { |
1019 | if (softirq) | |
214023c3 | 1020 | trace_seq_putc(s, 's'); |
bc0c38d1 | 1021 | else |
214023c3 | 1022 | trace_seq_putc(s, '.'); |
bc0c38d1 SR |
1023 | } |
1024 | } | |
1025 | ||
1026 | if (entry->preempt_count) | |
214023c3 | 1027 | trace_seq_printf(s, "%x", entry->preempt_count); |
bc0c38d1 | 1028 | else |
214023c3 | 1029 | trace_seq_puts(s, "."); |
bc0c38d1 SR |
1030 | } |
1031 | ||
1032 | unsigned long preempt_mark_thresh = 100; | |
1033 | ||
4e3c3333 | 1034 | static notrace void |
214023c3 | 1035 | lat_print_timestamp(struct trace_seq *s, unsigned long long abs_usecs, |
bc0c38d1 SR |
1036 | unsigned long rel_usecs) |
1037 | { | |
214023c3 | 1038 | trace_seq_printf(s, " %4lldus", abs_usecs); |
bc0c38d1 | 1039 | if (rel_usecs > preempt_mark_thresh) |
214023c3 | 1040 | trace_seq_puts(s, "!: "); |
bc0c38d1 | 1041 | else if (rel_usecs > 1) |
214023c3 | 1042 | trace_seq_puts(s, "+: "); |
bc0c38d1 | 1043 | else |
214023c3 | 1044 | trace_seq_puts(s, " : "); |
bc0c38d1 SR |
1045 | } |
1046 | ||
1047 | static const char state_to_char[] = TASK_STATE_TO_CHAR_STR; | |
1048 | ||
4e3c3333 | 1049 | static notrace void |
214023c3 | 1050 | print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) |
bc0c38d1 | 1051 | { |
214023c3 | 1052 | struct trace_seq *s = &iter->seq; |
bc0c38d1 SR |
1053 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); |
1054 | struct trace_entry *next_entry = find_next_entry(iter, NULL); | |
1055 | unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE); | |
1056 | struct trace_entry *entry = iter->ent; | |
1057 | unsigned long abs_usecs; | |
1058 | unsigned long rel_usecs; | |
1059 | char *comm; | |
1060 | int S; | |
1061 | ||
1062 | if (!next_entry) | |
1063 | next_entry = entry; | |
1064 | rel_usecs = ns2usecs(next_entry->t - entry->t); | |
1065 | abs_usecs = ns2usecs(entry->t - iter->tr->time_start); | |
1066 | ||
1067 | if (verbose) { | |
1068 | comm = trace_find_cmdline(entry->pid); | |
214023c3 SR |
1069 | trace_seq_printf(s, "%16s %5d %d %d %08x %08x [%08lx]" |
1070 | " %ld.%03ldms (+%ld.%03ldms): ", | |
1071 | comm, | |
1072 | entry->pid, cpu, entry->flags, | |
1073 | entry->preempt_count, trace_idx, | |
1074 | ns2usecs(entry->t), | |
1075 | abs_usecs/1000, | |
1076 | abs_usecs % 1000, rel_usecs/1000, | |
1077 | rel_usecs % 1000); | |
bc0c38d1 | 1078 | } else { |
214023c3 SR |
1079 | lat_print_generic(s, entry, cpu); |
1080 | lat_print_timestamp(s, abs_usecs, rel_usecs); | |
bc0c38d1 SR |
1081 | } |
1082 | switch (entry->type) { | |
1083 | case TRACE_FN: | |
214023c3 SR |
1084 | seq_print_ip_sym(s, entry->fn.ip, sym_flags); |
1085 | trace_seq_puts(s, " ("); | |
1086 | seq_print_ip_sym(s, entry->fn.parent_ip, sym_flags); | |
1087 | trace_seq_puts(s, ")\n"); | |
bc0c38d1 SR |
1088 | break; |
1089 | case TRACE_CTX: | |
1090 | S = entry->ctx.prev_state < sizeof(state_to_char) ? | |
1091 | state_to_char[entry->ctx.prev_state] : 'X'; | |
1092 | comm = trace_find_cmdline(entry->ctx.next_pid); | |
214023c3 SR |
1093 | trace_seq_printf(s, " %d:%d:%c --> %d:%d %s\n", |
1094 | entry->ctx.prev_pid, | |
1095 | entry->ctx.prev_prio, | |
1096 | S, | |
1097 | entry->ctx.next_pid, | |
1098 | entry->ctx.next_prio, | |
1099 | comm); | |
bc0c38d1 | 1100 | break; |
89b2f978 | 1101 | default: |
214023c3 | 1102 | trace_seq_printf(s, "Unknown type %d\n", entry->type); |
bc0c38d1 SR |
1103 | } |
1104 | } | |
1105 | ||
4e3c3333 IM |
1106 | static notrace void sync_time_offset(struct trace_iterator *iter) |
1107 | { | |
1108 | struct trace_array_cpu *prev_array, *array; | |
1109 | struct trace_entry *prev_entry, *entry; | |
1110 | cycle_t prev_t, t; | |
1111 | ||
1112 | entry = iter->ent; | |
1113 | prev_entry = iter->prev_ent; | |
1114 | if (!prev_entry) | |
1115 | return; | |
1116 | ||
1117 | prev_array = iter->tr->data[iter->prev_cpu]; | |
1118 | array = iter->tr->data[iter->cpu]; | |
1119 | ||
1120 | prev_t = prev_entry->t + prev_array->time_offset; | |
1121 | t = entry->t + array->time_offset; | |
1122 | ||
1123 | /* | |
1124 | * If time goes backwards we increase the offset of | |
1125 | * the current array, to not have observable time warps. | |
1126 | * This will quickly synchronize the time offsets of | |
1127 | * multiple CPUs: | |
1128 | */ | |
1129 | if (t < prev_t) | |
1130 | array->time_offset += prev_t - t; | |
1131 | } | |
1132 | ||
b3806b43 | 1133 | static notrace int |
214023c3 | 1134 | print_trace_fmt(struct trace_iterator *iter) |
bc0c38d1 | 1135 | { |
214023c3 | 1136 | struct trace_seq *s = &iter->seq; |
bc0c38d1 | 1137 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); |
4e3c3333 | 1138 | struct trace_entry *entry; |
bc0c38d1 SR |
1139 | unsigned long usec_rem; |
1140 | unsigned long long t; | |
1141 | unsigned long secs; | |
1142 | char *comm; | |
1143 | int S; | |
b3806b43 | 1144 | int ret; |
bc0c38d1 | 1145 | |
4e3c3333 IM |
1146 | sync_time_offset(iter); |
1147 | entry = iter->ent; | |
1148 | ||
bc0c38d1 SR |
1149 | comm = trace_find_cmdline(iter->ent->pid); |
1150 | ||
4e3c3333 | 1151 | t = ns2usecs(entry->t + iter->tr->data[iter->cpu]->time_offset); |
bc0c38d1 SR |
1152 | usec_rem = do_div(t, 1000000ULL); |
1153 | secs = (unsigned long)t; | |
1154 | ||
b3806b43 SR |
1155 | ret = trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid); |
1156 | if (!ret) | |
1157 | return 0; | |
1158 | ret = trace_seq_printf(s, "[%02d] ", iter->cpu); | |
1159 | if (!ret) | |
1160 | return 0; | |
1161 | ret = trace_seq_printf(s, "%5lu.%06lu: ", secs, usec_rem); | |
1162 | if (!ret) | |
1163 | return 0; | |
bc0c38d1 SR |
1164 | |
1165 | switch (entry->type) { | |
1166 | case TRACE_FN: | |
b3806b43 SR |
1167 | ret = seq_print_ip_sym(s, entry->fn.ip, sym_flags); |
1168 | if (!ret) | |
1169 | return 0; | |
bc0c38d1 SR |
1170 | if ((sym_flags & TRACE_ITER_PRINT_PARENT) && |
1171 | entry->fn.parent_ip) { | |
b3806b43 SR |
1172 | ret = trace_seq_printf(s, " <-"); |
1173 | if (!ret) | |
1174 | return 0; | |
1175 | ret = seq_print_ip_sym(s, entry->fn.parent_ip, | |
1176 | sym_flags); | |
1177 | if (!ret) | |
1178 | return 0; | |
bc0c38d1 | 1179 | } |
b3806b43 SR |
1180 | ret = trace_seq_printf(s, "\n"); |
1181 | if (!ret) | |
1182 | return 0; | |
bc0c38d1 SR |
1183 | break; |
1184 | case TRACE_CTX: | |
1185 | S = entry->ctx.prev_state < sizeof(state_to_char) ? | |
1186 | state_to_char[entry->ctx.prev_state] : 'X'; | |
b3806b43 SR |
1187 | ret = trace_seq_printf(s, " %d:%d:%c ==> %d:%d\n", |
1188 | entry->ctx.prev_pid, | |
1189 | entry->ctx.prev_prio, | |
1190 | S, | |
1191 | entry->ctx.next_pid, | |
1192 | entry->ctx.next_prio); | |
1193 | if (!ret) | |
1194 | return 0; | |
bc0c38d1 SR |
1195 | break; |
1196 | } | |
b3806b43 | 1197 | return 1; |
bc0c38d1 SR |
1198 | } |
1199 | ||
1200 | static int trace_empty(struct trace_iterator *iter) | |
1201 | { | |
1202 | struct trace_array_cpu *data; | |
1203 | int cpu; | |
1204 | ||
1205 | for_each_possible_cpu(cpu) { | |
1206 | data = iter->tr->data[cpu]; | |
1207 | ||
b3806b43 SR |
1208 | if (head_page(data) && data->trace_idx && |
1209 | (data->trace_tail != data->trace_head || | |
1210 | data->trace_tail_idx != data->trace_head_idx)) | |
bc0c38d1 SR |
1211 | return 0; |
1212 | } | |
1213 | return 1; | |
1214 | } | |
1215 | ||
1216 | static int s_show(struct seq_file *m, void *v) | |
1217 | { | |
1218 | struct trace_iterator *iter = v; | |
1219 | ||
1220 | if (iter->ent == NULL) { | |
1221 | if (iter->tr) { | |
1222 | seq_printf(m, "# tracer: %s\n", iter->trace->name); | |
1223 | seq_puts(m, "#\n"); | |
1224 | } | |
1225 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) { | |
1226 | /* print nothing if the buffers are empty */ | |
1227 | if (trace_empty(iter)) | |
1228 | return 0; | |
1229 | print_trace_header(m, iter); | |
1230 | if (!(trace_flags & TRACE_ITER_VERBOSE)) | |
1231 | print_lat_help_header(m); | |
1232 | } else { | |
1233 | if (!(trace_flags & TRACE_ITER_VERBOSE)) | |
1234 | print_func_help_header(m); | |
1235 | } | |
1236 | } else { | |
1237 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) | |
214023c3 | 1238 | print_lat_fmt(iter, iter->idx, iter->cpu); |
bc0c38d1 | 1239 | else |
214023c3 SR |
1240 | print_trace_fmt(iter); |
1241 | trace_print_seq(m, &iter->seq); | |
bc0c38d1 SR |
1242 | } |
1243 | ||
1244 | return 0; | |
1245 | } | |
1246 | ||
1247 | static struct seq_operations tracer_seq_ops = { | |
4bf39a94 IM |
1248 | .start = s_start, |
1249 | .next = s_next, | |
1250 | .stop = s_stop, | |
1251 | .show = s_show, | |
bc0c38d1 SR |
1252 | }; |
1253 | ||
1254 | static struct trace_iterator notrace * | |
1255 | __tracing_open(struct inode *inode, struct file *file, int *ret) | |
1256 | { | |
1257 | struct trace_iterator *iter; | |
1258 | ||
60a11774 SR |
1259 | if (tracing_disabled) { |
1260 | *ret = -ENODEV; | |
1261 | return NULL; | |
1262 | } | |
1263 | ||
bc0c38d1 SR |
1264 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1265 | if (!iter) { | |
1266 | *ret = -ENOMEM; | |
1267 | goto out; | |
1268 | } | |
1269 | ||
1270 | mutex_lock(&trace_types_lock); | |
1271 | if (current_trace && current_trace->print_max) | |
1272 | iter->tr = &max_tr; | |
1273 | else | |
1274 | iter->tr = inode->i_private; | |
1275 | iter->trace = current_trace; | |
1276 | iter->pos = -1; | |
1277 | ||
1278 | /* TODO stop tracer */ | |
1279 | *ret = seq_open(file, &tracer_seq_ops); | |
1280 | if (!*ret) { | |
1281 | struct seq_file *m = file->private_data; | |
1282 | m->private = iter; | |
1283 | ||
1284 | /* stop the trace while dumping */ | |
1285 | if (iter->tr->ctrl) | |
1286 | tracer_enabled = 0; | |
1287 | ||
1288 | if (iter->trace && iter->trace->open) | |
1289 | iter->trace->open(iter); | |
1290 | } else { | |
1291 | kfree(iter); | |
1292 | iter = NULL; | |
1293 | } | |
1294 | mutex_unlock(&trace_types_lock); | |
1295 | ||
1296 | out: | |
1297 | return iter; | |
1298 | } | |
1299 | ||
1300 | int tracing_open_generic(struct inode *inode, struct file *filp) | |
1301 | { | |
60a11774 SR |
1302 | if (tracing_disabled) |
1303 | return -ENODEV; | |
1304 | ||
bc0c38d1 SR |
1305 | filp->private_data = inode->i_private; |
1306 | return 0; | |
1307 | } | |
1308 | ||
1309 | int tracing_release(struct inode *inode, struct file *file) | |
1310 | { | |
1311 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1312 | struct trace_iterator *iter = m->private; | |
1313 | ||
1314 | mutex_lock(&trace_types_lock); | |
1315 | if (iter->trace && iter->trace->close) | |
1316 | iter->trace->close(iter); | |
1317 | ||
1318 | /* reenable tracing if it was previously enabled */ | |
1319 | if (iter->tr->ctrl) | |
1320 | tracer_enabled = 1; | |
1321 | mutex_unlock(&trace_types_lock); | |
1322 | ||
1323 | seq_release(inode, file); | |
1324 | kfree(iter); | |
1325 | return 0; | |
1326 | } | |
1327 | ||
1328 | static int tracing_open(struct inode *inode, struct file *file) | |
1329 | { | |
1330 | int ret; | |
1331 | ||
1332 | __tracing_open(inode, file, &ret); | |
1333 | ||
1334 | return ret; | |
1335 | } | |
1336 | ||
1337 | static int tracing_lt_open(struct inode *inode, struct file *file) | |
1338 | { | |
1339 | struct trace_iterator *iter; | |
1340 | int ret; | |
1341 | ||
1342 | iter = __tracing_open(inode, file, &ret); | |
1343 | ||
1344 | if (!ret) | |
1345 | iter->iter_flags |= TRACE_FILE_LAT_FMT; | |
1346 | ||
1347 | return ret; | |
1348 | } | |
1349 | ||
1350 | ||
4e3c3333 | 1351 | static notrace void * |
bc0c38d1 SR |
1352 | t_next(struct seq_file *m, void *v, loff_t *pos) |
1353 | { | |
1354 | struct tracer *t = m->private; | |
1355 | ||
1356 | (*pos)++; | |
1357 | ||
1358 | if (t) | |
1359 | t = t->next; | |
1360 | ||
1361 | m->private = t; | |
1362 | ||
1363 | return t; | |
1364 | } | |
1365 | ||
1366 | static void *t_start(struct seq_file *m, loff_t *pos) | |
1367 | { | |
1368 | struct tracer *t = m->private; | |
1369 | loff_t l = 0; | |
1370 | ||
1371 | mutex_lock(&trace_types_lock); | |
1372 | for (; t && l < *pos; t = t_next(m, t, &l)) | |
1373 | ; | |
1374 | ||
1375 | return t; | |
1376 | } | |
1377 | ||
1378 | static void t_stop(struct seq_file *m, void *p) | |
1379 | { | |
1380 | mutex_unlock(&trace_types_lock); | |
1381 | } | |
1382 | ||
1383 | static int t_show(struct seq_file *m, void *v) | |
1384 | { | |
1385 | struct tracer *t = v; | |
1386 | ||
1387 | if (!t) | |
1388 | return 0; | |
1389 | ||
1390 | seq_printf(m, "%s", t->name); | |
1391 | if (t->next) | |
1392 | seq_putc(m, ' '); | |
1393 | else | |
1394 | seq_putc(m, '\n'); | |
1395 | ||
1396 | return 0; | |
1397 | } | |
1398 | ||
1399 | static struct seq_operations show_traces_seq_ops = { | |
4bf39a94 IM |
1400 | .start = t_start, |
1401 | .next = t_next, | |
1402 | .stop = t_stop, | |
1403 | .show = t_show, | |
bc0c38d1 SR |
1404 | }; |
1405 | ||
1406 | static int show_traces_open(struct inode *inode, struct file *file) | |
1407 | { | |
1408 | int ret; | |
1409 | ||
60a11774 SR |
1410 | if (tracing_disabled) |
1411 | return -ENODEV; | |
1412 | ||
bc0c38d1 SR |
1413 | ret = seq_open(file, &show_traces_seq_ops); |
1414 | if (!ret) { | |
1415 | struct seq_file *m = file->private_data; | |
1416 | m->private = trace_types; | |
1417 | } | |
1418 | ||
1419 | return ret; | |
1420 | } | |
1421 | ||
1422 | static struct file_operations tracing_fops = { | |
4bf39a94 IM |
1423 | .open = tracing_open, |
1424 | .read = seq_read, | |
1425 | .llseek = seq_lseek, | |
1426 | .release = tracing_release, | |
bc0c38d1 SR |
1427 | }; |
1428 | ||
1429 | static struct file_operations tracing_lt_fops = { | |
4bf39a94 IM |
1430 | .open = tracing_lt_open, |
1431 | .read = seq_read, | |
1432 | .llseek = seq_lseek, | |
1433 | .release = tracing_release, | |
bc0c38d1 SR |
1434 | }; |
1435 | ||
1436 | static struct file_operations show_traces_fops = { | |
1437 | .open = show_traces_open, | |
1438 | .read = seq_read, | |
1439 | .release = seq_release, | |
1440 | }; | |
1441 | ||
1442 | static ssize_t | |
1443 | tracing_iter_ctrl_read(struct file *filp, char __user *ubuf, | |
1444 | size_t cnt, loff_t *ppos) | |
1445 | { | |
1446 | char *buf; | |
1447 | int r = 0; | |
1448 | int len = 0; | |
1449 | int i; | |
1450 | ||
1451 | /* calulate max size */ | |
1452 | for (i = 0; trace_options[i]; i++) { | |
1453 | len += strlen(trace_options[i]); | |
1454 | len += 3; /* "no" and space */ | |
1455 | } | |
1456 | ||
1457 | /* +2 for \n and \0 */ | |
1458 | buf = kmalloc(len + 2, GFP_KERNEL); | |
1459 | if (!buf) | |
1460 | return -ENOMEM; | |
1461 | ||
1462 | for (i = 0; trace_options[i]; i++) { | |
1463 | if (trace_flags & (1 << i)) | |
1464 | r += sprintf(buf + r, "%s ", trace_options[i]); | |
1465 | else | |
1466 | r += sprintf(buf + r, "no%s ", trace_options[i]); | |
1467 | } | |
1468 | ||
1469 | r += sprintf(buf + r, "\n"); | |
1470 | WARN_ON(r >= len + 2); | |
1471 | ||
1472 | r = simple_read_from_buffer(ubuf, cnt, ppos, | |
1473 | buf, r); | |
1474 | ||
1475 | kfree(buf); | |
1476 | ||
1477 | return r; | |
1478 | } | |
1479 | ||
1480 | static ssize_t | |
1481 | tracing_iter_ctrl_write(struct file *filp, const char __user *ubuf, | |
1482 | size_t cnt, loff_t *ppos) | |
1483 | { | |
1484 | char buf[64]; | |
1485 | char *cmp = buf; | |
1486 | int neg = 0; | |
1487 | int i; | |
1488 | ||
1489 | if (cnt > 63) | |
1490 | cnt = 63; | |
1491 | ||
1492 | if (copy_from_user(&buf, ubuf, cnt)) | |
1493 | return -EFAULT; | |
1494 | ||
1495 | buf[cnt] = 0; | |
1496 | ||
1497 | if (strncmp(buf, "no", 2) == 0) { | |
1498 | neg = 1; | |
1499 | cmp += 2; | |
1500 | } | |
1501 | ||
1502 | for (i = 0; trace_options[i]; i++) { | |
1503 | int len = strlen(trace_options[i]); | |
1504 | ||
1505 | if (strncmp(cmp, trace_options[i], len) == 0) { | |
1506 | if (neg) | |
1507 | trace_flags &= ~(1 << i); | |
1508 | else | |
1509 | trace_flags |= (1 << i); | |
1510 | break; | |
1511 | } | |
1512 | } | |
1513 | ||
1514 | filp->f_pos += cnt; | |
1515 | ||
1516 | return cnt; | |
1517 | } | |
1518 | ||
1519 | static struct file_operations tracing_iter_fops = { | |
1520 | .open = tracing_open_generic, | |
1521 | .read = tracing_iter_ctrl_read, | |
1522 | .write = tracing_iter_ctrl_write, | |
1523 | }; | |
1524 | ||
7bd2f24c IM |
1525 | static const char readme_msg[] = |
1526 | "tracing mini-HOWTO:\n\n" | |
1527 | "# mkdir /debug\n" | |
1528 | "# mount -t debugfs nodev /debug\n\n" | |
1529 | "# cat /debug/tracing/available_tracers\n" | |
1530 | "wakeup preemptirqsoff preemptoff irqsoff ftrace sched_switch none\n\n" | |
1531 | "# cat /debug/tracing/current_tracer\n" | |
1532 | "none\n" | |
1533 | "# echo sched_switch > /debug/tracing/current_tracer\n" | |
1534 | "# cat /debug/tracing/current_tracer\n" | |
1535 | "sched_switch\n" | |
1536 | "# cat /debug/tracing/iter_ctrl\n" | |
1537 | "noprint-parent nosym-offset nosym-addr noverbose\n" | |
1538 | "# echo print-parent > /debug/tracing/iter_ctrl\n" | |
1539 | "# echo 1 > /debug/tracing/tracing_enabled\n" | |
1540 | "# cat /debug/tracing/trace > /tmp/trace.txt\n" | |
1541 | "echo 0 > /debug/tracing/tracing_enabled\n" | |
1542 | ; | |
1543 | ||
1544 | static ssize_t | |
1545 | tracing_readme_read(struct file *filp, char __user *ubuf, | |
1546 | size_t cnt, loff_t *ppos) | |
1547 | { | |
1548 | return simple_read_from_buffer(ubuf, cnt, ppos, | |
1549 | readme_msg, strlen(readme_msg)); | |
1550 | } | |
1551 | ||
1552 | static struct file_operations tracing_readme_fops = { | |
1553 | .open = tracing_open_generic, | |
1554 | .read = tracing_readme_read, | |
1555 | }; | |
1556 | ||
1557 | ||
bc0c38d1 SR |
1558 | static ssize_t |
1559 | tracing_ctrl_read(struct file *filp, char __user *ubuf, | |
1560 | size_t cnt, loff_t *ppos) | |
1561 | { | |
1562 | struct trace_array *tr = filp->private_data; | |
1563 | char buf[64]; | |
1564 | int r; | |
1565 | ||
1566 | r = sprintf(buf, "%ld\n", tr->ctrl); | |
4e3c3333 | 1567 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
bc0c38d1 SR |
1568 | } |
1569 | ||
1570 | static ssize_t | |
1571 | tracing_ctrl_write(struct file *filp, const char __user *ubuf, | |
1572 | size_t cnt, loff_t *ppos) | |
1573 | { | |
1574 | struct trace_array *tr = filp->private_data; | |
1575 | long val; | |
1576 | char buf[64]; | |
1577 | ||
1578 | if (cnt > 63) | |
1579 | cnt = 63; | |
1580 | ||
1581 | if (copy_from_user(&buf, ubuf, cnt)) | |
1582 | return -EFAULT; | |
1583 | ||
1584 | buf[cnt] = 0; | |
1585 | ||
1586 | val = simple_strtoul(buf, NULL, 10); | |
1587 | ||
1588 | val = !!val; | |
1589 | ||
1590 | mutex_lock(&trace_types_lock); | |
1591 | if (tr->ctrl ^ val) { | |
1592 | if (val) | |
1593 | tracer_enabled = 1; | |
1594 | else | |
1595 | tracer_enabled = 0; | |
1596 | ||
1597 | tr->ctrl = val; | |
1598 | ||
1599 | if (current_trace && current_trace->ctrl_update) | |
1600 | current_trace->ctrl_update(tr); | |
1601 | } | |
1602 | mutex_unlock(&trace_types_lock); | |
1603 | ||
1604 | filp->f_pos += cnt; | |
1605 | ||
1606 | return cnt; | |
1607 | } | |
1608 | ||
1609 | static ssize_t | |
1610 | tracing_set_trace_read(struct file *filp, char __user *ubuf, | |
1611 | size_t cnt, loff_t *ppos) | |
1612 | { | |
1613 | char buf[max_tracer_type_len+2]; | |
1614 | int r; | |
1615 | ||
1616 | mutex_lock(&trace_types_lock); | |
1617 | if (current_trace) | |
1618 | r = sprintf(buf, "%s\n", current_trace->name); | |
1619 | else | |
1620 | r = sprintf(buf, "\n"); | |
1621 | mutex_unlock(&trace_types_lock); | |
1622 | ||
4bf39a94 | 1623 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
bc0c38d1 SR |
1624 | } |
1625 | ||
1626 | static ssize_t | |
1627 | tracing_set_trace_write(struct file *filp, const char __user *ubuf, | |
1628 | size_t cnt, loff_t *ppos) | |
1629 | { | |
1630 | struct trace_array *tr = &global_trace; | |
1631 | struct tracer *t; | |
1632 | char buf[max_tracer_type_len+1]; | |
1633 | int i; | |
1634 | ||
1635 | if (cnt > max_tracer_type_len) | |
1636 | cnt = max_tracer_type_len; | |
1637 | ||
1638 | if (copy_from_user(&buf, ubuf, cnt)) | |
1639 | return -EFAULT; | |
1640 | ||
1641 | buf[cnt] = 0; | |
1642 | ||
1643 | /* strip ending whitespace. */ | |
1644 | for (i = cnt - 1; i > 0 && isspace(buf[i]); i--) | |
1645 | buf[i] = 0; | |
1646 | ||
1647 | mutex_lock(&trace_types_lock); | |
1648 | for (t = trace_types; t; t = t->next) { | |
1649 | if (strcmp(t->name, buf) == 0) | |
1650 | break; | |
1651 | } | |
1652 | if (!t || t == current_trace) | |
1653 | goto out; | |
1654 | ||
1655 | if (current_trace && current_trace->reset) | |
1656 | current_trace->reset(tr); | |
1657 | ||
1658 | current_trace = t; | |
1659 | if (t->init) | |
1660 | t->init(tr); | |
1661 | ||
1662 | out: | |
1663 | mutex_unlock(&trace_types_lock); | |
1664 | ||
1665 | filp->f_pos += cnt; | |
1666 | ||
1667 | return cnt; | |
1668 | } | |
1669 | ||
1670 | static ssize_t | |
1671 | tracing_max_lat_read(struct file *filp, char __user *ubuf, | |
1672 | size_t cnt, loff_t *ppos) | |
1673 | { | |
1674 | unsigned long *ptr = filp->private_data; | |
1675 | char buf[64]; | |
1676 | int r; | |
1677 | ||
1678 | r = snprintf(buf, 64, "%ld\n", | |
1679 | *ptr == (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr)); | |
1680 | if (r > 64) | |
1681 | r = 64; | |
4bf39a94 | 1682 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
bc0c38d1 SR |
1683 | } |
1684 | ||
1685 | static ssize_t | |
1686 | tracing_max_lat_write(struct file *filp, const char __user *ubuf, | |
1687 | size_t cnt, loff_t *ppos) | |
1688 | { | |
1689 | long *ptr = filp->private_data; | |
1690 | long val; | |
1691 | char buf[64]; | |
1692 | ||
1693 | if (cnt > 63) | |
1694 | cnt = 63; | |
1695 | ||
1696 | if (copy_from_user(&buf, ubuf, cnt)) | |
1697 | return -EFAULT; | |
1698 | ||
1699 | buf[cnt] = 0; | |
1700 | ||
1701 | val = simple_strtoul(buf, NULL, 10); | |
1702 | ||
1703 | *ptr = val * 1000; | |
1704 | ||
1705 | return cnt; | |
1706 | } | |
1707 | ||
b3806b43 SR |
1708 | static atomic_t tracing_reader; |
1709 | ||
1710 | static int tracing_open_pipe(struct inode *inode, struct file *filp) | |
1711 | { | |
1712 | struct trace_iterator *iter; | |
1713 | ||
1714 | if (tracing_disabled) | |
1715 | return -ENODEV; | |
1716 | ||
1717 | /* We only allow for reader of the pipe */ | |
1718 | if (atomic_inc_return(&tracing_reader) != 1) { | |
1719 | atomic_dec(&tracing_reader); | |
1720 | return -EBUSY; | |
1721 | } | |
1722 | ||
1723 | /* create a buffer to store the information to pass to userspace */ | |
1724 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); | |
1725 | if (!iter) | |
1726 | return -ENOMEM; | |
1727 | ||
1728 | iter->tr = &global_trace; | |
1729 | ||
1730 | filp->private_data = iter; | |
1731 | ||
1732 | return 0; | |
1733 | } | |
1734 | ||
1735 | static int tracing_release_pipe(struct inode *inode, struct file *file) | |
1736 | { | |
1737 | struct trace_iterator *iter = file->private_data; | |
1738 | ||
1739 | kfree(iter); | |
1740 | atomic_dec(&tracing_reader); | |
1741 | ||
1742 | return 0; | |
1743 | } | |
1744 | ||
1745 | /* | |
1746 | * Consumer reader. | |
1747 | */ | |
1748 | static ssize_t | |
1749 | tracing_read_pipe(struct file *filp, char __user *ubuf, | |
1750 | size_t cnt, loff_t *ppos) | |
1751 | { | |
1752 | struct trace_iterator *iter = filp->private_data; | |
1753 | struct trace_array_cpu *data; | |
1754 | static cpumask_t mask; | |
1755 | struct trace_entry *entry; | |
1756 | static int start; | |
1757 | unsigned long flags; | |
1758 | int read = 0; | |
1759 | int cpu; | |
1760 | int len; | |
1761 | int ret; | |
1762 | ||
1763 | /* return any leftover data */ | |
1764 | if (iter->seq.len > start) { | |
1765 | len = iter->seq.len - start; | |
1766 | if (cnt > len) | |
1767 | cnt = len; | |
1768 | ret = copy_to_user(ubuf, iter->seq.buffer + start, cnt); | |
1769 | if (ret) | |
1770 | cnt = -EFAULT; | |
1771 | ||
1772 | start += len; | |
1773 | ||
1774 | return cnt; | |
1775 | } | |
1776 | ||
1777 | trace_seq_reset(&iter->seq); | |
1778 | start = 0; | |
1779 | ||
1780 | while (trace_empty(iter)) { | |
1781 | /* | |
1782 | * This is a make-shift waitqueue. The reason we don't use | |
1783 | * an actual wait queue is because: | |
1784 | * 1) we only ever have one waiter | |
1785 | * 2) the tracing, traces all functions, we don't want | |
1786 | * the overhead of calling wake_up and friends | |
1787 | * (and tracing them too) | |
1788 | * Anyway, this is really very primitive wakeup. | |
1789 | */ | |
1790 | set_current_state(TASK_INTERRUPTIBLE); | |
1791 | iter->tr->waiter = current; | |
1792 | ||
1793 | /* sleep for one second, and try again. */ | |
1794 | schedule_timeout(HZ); | |
1795 | ||
1796 | iter->tr->waiter = NULL; | |
1797 | ||
1798 | if (signal_pending(current)) | |
1799 | return -EINTR; | |
1800 | ||
1801 | /* | |
1802 | * We block until we read something and tracing is disabled. | |
1803 | * We still block if tracing is disabled, but we have never | |
1804 | * read anything. This allows a user to cat this file, and | |
1805 | * then enable tracing. But after we have read something, | |
1806 | * we give an EOF when tracing is again disabled. | |
1807 | * | |
1808 | * iter->pos will be 0 if we haven't read anything. | |
1809 | */ | |
1810 | if (!tracer_enabled && iter->pos) | |
1811 | break; | |
1812 | ||
1813 | continue; | |
1814 | } | |
1815 | ||
1816 | /* stop when tracing is finished */ | |
1817 | if (trace_empty(iter)) | |
1818 | return 0; | |
1819 | ||
1820 | if (cnt >= PAGE_SIZE) | |
1821 | cnt = PAGE_SIZE - 1; | |
1822 | ||
1823 | memset(iter, 0, sizeof(*iter)); | |
1824 | iter->tr = &global_trace; | |
1825 | iter->pos = -1; | |
1826 | ||
1827 | /* | |
1828 | * We need to stop all tracing on all CPUS to read the | |
1829 | * the next buffer. This is a bit expensive, but is | |
1830 | * not done often. We fill all what we can read, | |
1831 | * and then release the locks again. | |
1832 | */ | |
1833 | ||
1834 | cpus_clear(mask); | |
1835 | local_irq_save(flags); | |
1836 | for_each_possible_cpu(cpu) { | |
1837 | data = iter->tr->data[cpu]; | |
1838 | ||
1839 | if (!head_page(data) || !data->trace_idx) | |
1840 | continue; | |
1841 | ||
1842 | atomic_inc(&data->disabled); | |
1843 | spin_lock(&data->lock); | |
1844 | cpu_set(cpu, mask); | |
1845 | } | |
1846 | ||
1847 | while ((entry = find_next_entry(iter, &cpu))) { | |
1848 | ||
1849 | if (!entry) | |
1850 | break; | |
1851 | ||
1852 | iter->ent = entry; | |
1853 | iter->cpu = cpu; | |
1854 | ||
1855 | ret = print_trace_fmt(iter); | |
1856 | if (!ret) | |
1857 | break; | |
1858 | ||
1859 | trace_consume(iter); | |
1860 | ||
1861 | if (iter->seq.len >= cnt) | |
1862 | break; | |
1863 | ||
1864 | } | |
1865 | ||
d4c5a2f5 | 1866 | for_each_cpu_mask(cpu, mask) { |
b3806b43 | 1867 | data = iter->tr->data[cpu]; |
b3806b43 SR |
1868 | spin_unlock(&data->lock); |
1869 | atomic_dec(&data->disabled); | |
1870 | } | |
1871 | local_irq_restore(flags); | |
1872 | ||
1873 | /* Now copy what we have to the user */ | |
1874 | read = iter->seq.len; | |
1875 | if (read > cnt) | |
1876 | read = cnt; | |
1877 | ||
1878 | ret = copy_to_user(ubuf, iter->seq.buffer, read); | |
1879 | ||
1880 | if (read < iter->seq.len) | |
1881 | start = read; | |
1882 | else | |
1883 | trace_seq_reset(&iter->seq); | |
1884 | ||
1885 | if (ret) | |
1886 | read = -EFAULT; | |
1887 | ||
1888 | return read; | |
1889 | } | |
1890 | ||
bc0c38d1 | 1891 | static struct file_operations tracing_max_lat_fops = { |
4bf39a94 IM |
1892 | .open = tracing_open_generic, |
1893 | .read = tracing_max_lat_read, | |
1894 | .write = tracing_max_lat_write, | |
bc0c38d1 SR |
1895 | }; |
1896 | ||
1897 | static struct file_operations tracing_ctrl_fops = { | |
4bf39a94 IM |
1898 | .open = tracing_open_generic, |
1899 | .read = tracing_ctrl_read, | |
1900 | .write = tracing_ctrl_write, | |
bc0c38d1 SR |
1901 | }; |
1902 | ||
1903 | static struct file_operations set_tracer_fops = { | |
4bf39a94 IM |
1904 | .open = tracing_open_generic, |
1905 | .read = tracing_set_trace_read, | |
1906 | .write = tracing_set_trace_write, | |
bc0c38d1 SR |
1907 | }; |
1908 | ||
b3806b43 | 1909 | static struct file_operations tracing_pipe_fops = { |
4bf39a94 IM |
1910 | .open = tracing_open_pipe, |
1911 | .read = tracing_read_pipe, | |
1912 | .release = tracing_release_pipe, | |
b3806b43 SR |
1913 | }; |
1914 | ||
bc0c38d1 SR |
1915 | #ifdef CONFIG_DYNAMIC_FTRACE |
1916 | ||
1917 | static ssize_t | |
1918 | tracing_read_long(struct file *filp, char __user *ubuf, | |
1919 | size_t cnt, loff_t *ppos) | |
1920 | { | |
1921 | unsigned long *p = filp->private_data; | |
1922 | char buf[64]; | |
1923 | int r; | |
1924 | ||
1925 | r = sprintf(buf, "%ld\n", *p); | |
4bf39a94 IM |
1926 | |
1927 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
bc0c38d1 SR |
1928 | } |
1929 | ||
1930 | static struct file_operations tracing_read_long_fops = { | |
4bf39a94 IM |
1931 | .open = tracing_open_generic, |
1932 | .read = tracing_read_long, | |
bc0c38d1 SR |
1933 | }; |
1934 | #endif | |
1935 | ||
1936 | static struct dentry *d_tracer; | |
1937 | ||
1938 | struct dentry *tracing_init_dentry(void) | |
1939 | { | |
1940 | static int once; | |
1941 | ||
1942 | if (d_tracer) | |
1943 | return d_tracer; | |
1944 | ||
1945 | d_tracer = debugfs_create_dir("tracing", NULL); | |
1946 | ||
1947 | if (!d_tracer && !once) { | |
1948 | once = 1; | |
1949 | pr_warning("Could not create debugfs directory 'tracing'\n"); | |
1950 | return NULL; | |
1951 | } | |
1952 | ||
1953 | return d_tracer; | |
1954 | } | |
1955 | ||
60a11774 SR |
1956 | #ifdef CONFIG_FTRACE_SELFTEST |
1957 | /* Let selftest have access to static functions in this file */ | |
1958 | #include "trace_selftest.c" | |
1959 | #endif | |
1960 | ||
bc0c38d1 SR |
1961 | static __init void tracer_init_debugfs(void) |
1962 | { | |
1963 | struct dentry *d_tracer; | |
1964 | struct dentry *entry; | |
1965 | ||
1966 | d_tracer = tracing_init_dentry(); | |
1967 | ||
1968 | entry = debugfs_create_file("tracing_enabled", 0644, d_tracer, | |
1969 | &global_trace, &tracing_ctrl_fops); | |
1970 | if (!entry) | |
1971 | pr_warning("Could not create debugfs 'tracing_enabled' entry\n"); | |
1972 | ||
1973 | entry = debugfs_create_file("iter_ctrl", 0644, d_tracer, | |
1974 | NULL, &tracing_iter_fops); | |
1975 | if (!entry) | |
1976 | pr_warning("Could not create debugfs 'iter_ctrl' entry\n"); | |
1977 | ||
1978 | entry = debugfs_create_file("latency_trace", 0444, d_tracer, | |
1979 | &global_trace, &tracing_lt_fops); | |
1980 | if (!entry) | |
1981 | pr_warning("Could not create debugfs 'latency_trace' entry\n"); | |
1982 | ||
1983 | entry = debugfs_create_file("trace", 0444, d_tracer, | |
1984 | &global_trace, &tracing_fops); | |
1985 | if (!entry) | |
1986 | pr_warning("Could not create debugfs 'trace' entry\n"); | |
1987 | ||
1988 | entry = debugfs_create_file("available_tracers", 0444, d_tracer, | |
1989 | &global_trace, &show_traces_fops); | |
1990 | if (!entry) | |
1991 | pr_warning("Could not create debugfs 'trace' entry\n"); | |
1992 | ||
1993 | entry = debugfs_create_file("current_tracer", 0444, d_tracer, | |
1994 | &global_trace, &set_tracer_fops); | |
1995 | if (!entry) | |
1996 | pr_warning("Could not create debugfs 'trace' entry\n"); | |
1997 | ||
1998 | entry = debugfs_create_file("tracing_max_latency", 0644, d_tracer, | |
1999 | &tracing_max_latency, | |
2000 | &tracing_max_lat_fops); | |
2001 | if (!entry) | |
2002 | pr_warning("Could not create debugfs " | |
2003 | "'tracing_max_latency' entry\n"); | |
2004 | ||
2005 | entry = debugfs_create_file("tracing_thresh", 0644, d_tracer, | |
2006 | &tracing_thresh, &tracing_max_lat_fops); | |
2007 | if (!entry) | |
2008 | pr_warning("Could not create debugfs " | |
2009 | "'tracing_threash' entry\n"); | |
7bd2f24c IM |
2010 | entry = debugfs_create_file("README", 0644, d_tracer, |
2011 | NULL, &tracing_readme_fops); | |
2012 | if (!entry) | |
2013 | pr_warning("Could not create debugfs 'README' entry\n"); | |
2014 | ||
b3806b43 SR |
2015 | entry = debugfs_create_file("trace_pipe", 0644, d_tracer, |
2016 | NULL, &tracing_pipe_fops); | |
2017 | if (!entry) | |
2018 | pr_warning("Could not create debugfs " | |
2019 | "'tracing_threash' entry\n"); | |
bc0c38d1 SR |
2020 | |
2021 | #ifdef CONFIG_DYNAMIC_FTRACE | |
2022 | entry = debugfs_create_file("dyn_ftrace_total_info", 0444, d_tracer, | |
2023 | &ftrace_update_tot_cnt, | |
2024 | &tracing_read_long_fops); | |
2025 | if (!entry) | |
2026 | pr_warning("Could not create debugfs " | |
2027 | "'dyn_ftrace_total_info' entry\n"); | |
2028 | #endif | |
2029 | } | |
2030 | ||
2031 | /* dummy trace to disable tracing */ | |
2032 | static struct tracer no_tracer __read_mostly = | |
2033 | { | |
4bf39a94 | 2034 | .name = "none", |
bc0c38d1 SR |
2035 | }; |
2036 | ||
4c11d7ae | 2037 | static int trace_alloc_page(void) |
bc0c38d1 | 2038 | { |
4c11d7ae | 2039 | struct trace_array_cpu *data; |
4c11d7ae SR |
2040 | struct page *page, *tmp; |
2041 | LIST_HEAD(pages); | |
c7aafc54 | 2042 | void *array; |
4c11d7ae SR |
2043 | int i; |
2044 | ||
2045 | /* first allocate a page for each CPU */ | |
2046 | for_each_possible_cpu(i) { | |
2047 | array = (void *)__get_free_page(GFP_KERNEL); | |
2048 | if (array == NULL) { | |
2049 | printk(KERN_ERR "tracer: failed to allocate page" | |
2050 | "for trace buffer!\n"); | |
2051 | goto free_pages; | |
2052 | } | |
2053 | ||
2054 | page = virt_to_page(array); | |
2055 | list_add(&page->lru, &pages); | |
2056 | ||
2057 | /* Only allocate if we are actually using the max trace */ | |
2058 | #ifdef CONFIG_TRACER_MAX_TRACE | |
2059 | array = (void *)__get_free_page(GFP_KERNEL); | |
2060 | if (array == NULL) { | |
2061 | printk(KERN_ERR "tracer: failed to allocate page" | |
2062 | "for trace buffer!\n"); | |
2063 | goto free_pages; | |
2064 | } | |
2065 | page = virt_to_page(array); | |
2066 | list_add(&page->lru, &pages); | |
2067 | #endif | |
2068 | } | |
2069 | ||
2070 | /* Now that we successfully allocate a page per CPU, add them */ | |
2071 | for_each_possible_cpu(i) { | |
2072 | data = global_trace.data[i]; | |
b3806b43 | 2073 | spin_lock_init(&data->lock); |
d4c5a2f5 | 2074 | lockdep_set_class(&data->lock, &data->lock_key); |
4c11d7ae | 2075 | page = list_entry(pages.next, struct page, lru); |
c7aafc54 | 2076 | list_del_init(&page->lru); |
4c11d7ae SR |
2077 | list_add_tail(&page->lru, &data->trace_pages); |
2078 | ClearPageLRU(page); | |
2079 | ||
2080 | #ifdef CONFIG_TRACER_MAX_TRACE | |
2081 | data = max_tr.data[i]; | |
b3806b43 | 2082 | spin_lock_init(&data->lock); |
d4c5a2f5 | 2083 | lockdep_set_class(&data->lock, &data->lock_key); |
4c11d7ae | 2084 | page = list_entry(pages.next, struct page, lru); |
c7aafc54 | 2085 | list_del_init(&page->lru); |
4c11d7ae SR |
2086 | list_add_tail(&page->lru, &data->trace_pages); |
2087 | SetPageLRU(page); | |
2088 | #endif | |
2089 | } | |
2090 | global_trace.entries += ENTRIES_PER_PAGE; | |
2091 | ||
2092 | return 0; | |
2093 | ||
2094 | free_pages: | |
2095 | list_for_each_entry_safe(page, tmp, &pages, lru) { | |
c7aafc54 | 2096 | list_del_init(&page->lru); |
4c11d7ae SR |
2097 | __free_page(page); |
2098 | } | |
2099 | return -ENOMEM; | |
bc0c38d1 SR |
2100 | } |
2101 | ||
2102 | __init static int tracer_alloc_buffers(void) | |
2103 | { | |
4c11d7ae SR |
2104 | struct trace_array_cpu *data; |
2105 | void *array; | |
2106 | struct page *page; | |
2107 | int pages = 0; | |
60a11774 | 2108 | int ret = -ENOMEM; |
bc0c38d1 SR |
2109 | int i; |
2110 | ||
4c11d7ae | 2111 | /* Allocate the first page for all buffers */ |
bc0c38d1 | 2112 | for_each_possible_cpu(i) { |
4c11d7ae | 2113 | data = global_trace.data[i] = &per_cpu(global_trace_cpu, i); |
bc0c38d1 SR |
2114 | max_tr.data[i] = &per_cpu(max_data, i); |
2115 | ||
4c11d7ae | 2116 | array = (void *)__get_free_page(GFP_KERNEL); |
bc0c38d1 | 2117 | if (array == NULL) { |
4c11d7ae SR |
2118 | printk(KERN_ERR "tracer: failed to allocate page" |
2119 | "for trace buffer!\n"); | |
bc0c38d1 SR |
2120 | goto free_buffers; |
2121 | } | |
4c11d7ae SR |
2122 | |
2123 | /* set the array to the list */ | |
2124 | INIT_LIST_HEAD(&data->trace_pages); | |
2125 | page = virt_to_page(array); | |
2126 | list_add(&page->lru, &data->trace_pages); | |
2127 | /* use the LRU flag to differentiate the two buffers */ | |
2128 | ClearPageLRU(page); | |
bc0c38d1 SR |
2129 | |
2130 | /* Only allocate if we are actually using the max trace */ | |
2131 | #ifdef CONFIG_TRACER_MAX_TRACE | |
4c11d7ae | 2132 | array = (void *)__get_free_page(GFP_KERNEL); |
bc0c38d1 | 2133 | if (array == NULL) { |
4c11d7ae SR |
2134 | printk(KERN_ERR "tracer: failed to allocate page" |
2135 | "for trace buffer!\n"); | |
bc0c38d1 SR |
2136 | goto free_buffers; |
2137 | } | |
4c11d7ae SR |
2138 | |
2139 | INIT_LIST_HEAD(&max_tr.data[i]->trace_pages); | |
2140 | page = virt_to_page(array); | |
2141 | list_add(&page->lru, &max_tr.data[i]->trace_pages); | |
2142 | SetPageLRU(page); | |
bc0c38d1 SR |
2143 | #endif |
2144 | } | |
2145 | ||
2146 | /* | |
2147 | * Since we allocate by orders of pages, we may be able to | |
2148 | * round up a bit. | |
2149 | */ | |
4c11d7ae | 2150 | global_trace.entries = ENTRIES_PER_PAGE; |
4c11d7ae SR |
2151 | pages++; |
2152 | ||
2153 | while (global_trace.entries < trace_nr_entries) { | |
2154 | if (trace_alloc_page()) | |
2155 | break; | |
2156 | pages++; | |
2157 | } | |
89b2f978 | 2158 | max_tr.entries = global_trace.entries; |
bc0c38d1 | 2159 | |
4c11d7ae SR |
2160 | pr_info("tracer: %d pages allocated for %ld", |
2161 | pages, trace_nr_entries); | |
bc0c38d1 SR |
2162 | pr_info(" entries of %ld bytes\n", (long)TRACE_ENTRY_SIZE); |
2163 | pr_info(" actual entries %ld\n", global_trace.entries); | |
2164 | ||
2165 | tracer_init_debugfs(); | |
2166 | ||
2167 | trace_init_cmdlines(); | |
2168 | ||
2169 | register_tracer(&no_tracer); | |
2170 | current_trace = &no_tracer; | |
2171 | ||
60a11774 SR |
2172 | /* All seems OK, enable tracing */ |
2173 | tracing_disabled = 0; | |
2174 | ||
bc0c38d1 SR |
2175 | return 0; |
2176 | ||
2177 | free_buffers: | |
2178 | for (i-- ; i >= 0; i--) { | |
4c11d7ae | 2179 | struct page *page, *tmp; |
bc0c38d1 SR |
2180 | struct trace_array_cpu *data = global_trace.data[i]; |
2181 | ||
c7aafc54 | 2182 | if (data) { |
4c11d7ae SR |
2183 | list_for_each_entry_safe(page, tmp, |
2184 | &data->trace_pages, lru) { | |
c7aafc54 | 2185 | list_del_init(&page->lru); |
4c11d7ae SR |
2186 | __free_page(page); |
2187 | } | |
bc0c38d1 SR |
2188 | } |
2189 | ||
2190 | #ifdef CONFIG_TRACER_MAX_TRACE | |
2191 | data = max_tr.data[i]; | |
c7aafc54 | 2192 | if (data) { |
4c11d7ae SR |
2193 | list_for_each_entry_safe(page, tmp, |
2194 | &data->trace_pages, lru) { | |
c7aafc54 | 2195 | list_del_init(&page->lru); |
4c11d7ae SR |
2196 | __free_page(page); |
2197 | } | |
bc0c38d1 SR |
2198 | } |
2199 | #endif | |
2200 | } | |
60a11774 | 2201 | return ret; |
bc0c38d1 | 2202 | } |
60a11774 | 2203 | fs_initcall(tracer_alloc_buffers); |