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 | ||
750ed1a4 IM |
45 | notrace cycle_t ftrace_now(int cpu) |
46 | { | |
47 | return cpu_clock(cpu); | |
48 | } | |
49 | ||
bc0c38d1 SR |
50 | static atomic_t tracer_counter; |
51 | static struct trace_array global_trace; | |
52 | ||
53 | static DEFINE_PER_CPU(struct trace_array_cpu, global_trace_cpu); | |
54 | ||
55 | static struct trace_array max_tr; | |
56 | ||
57 | static DEFINE_PER_CPU(struct trace_array_cpu, max_data); | |
58 | ||
59 | static int tracer_enabled; | |
4c11d7ae | 60 | static unsigned long trace_nr_entries = 16384UL; |
bc0c38d1 SR |
61 | |
62 | static struct tracer *trace_types __read_mostly; | |
63 | static struct tracer *current_trace __read_mostly; | |
64 | static int max_tracer_type_len; | |
65 | ||
66 | static DEFINE_MUTEX(trace_types_lock); | |
67 | ||
4c11d7ae SR |
68 | #define ENTRIES_PER_PAGE (PAGE_SIZE / sizeof(struct trace_entry)) |
69 | ||
bc0c38d1 SR |
70 | static int __init set_nr_entries(char *str) |
71 | { | |
72 | if (!str) | |
73 | return 0; | |
74 | trace_nr_entries = simple_strtoul(str, &str, 0); | |
75 | return 1; | |
76 | } | |
77 | __setup("trace_entries=", set_nr_entries); | |
78 | ||
57f50be1 SR |
79 | unsigned long nsecs_to_usecs(unsigned long nsecs) |
80 | { | |
81 | return nsecs / 1000; | |
82 | } | |
83 | ||
bc0c38d1 SR |
84 | enum trace_type { |
85 | __TRACE_FIRST_TYPE = 0, | |
86 | ||
87 | TRACE_FN, | |
88 | TRACE_CTX, | |
89 | ||
90 | __TRACE_LAST_TYPE | |
91 | }; | |
92 | ||
93 | enum trace_flag_type { | |
94 | TRACE_FLAG_IRQS_OFF = 0x01, | |
95 | TRACE_FLAG_NEED_RESCHED = 0x02, | |
96 | TRACE_FLAG_HARDIRQ = 0x04, | |
97 | TRACE_FLAG_SOFTIRQ = 0x08, | |
98 | }; | |
99 | ||
100 | enum trace_iterator_flags { | |
101 | TRACE_ITER_PRINT_PARENT = 0x01, | |
102 | TRACE_ITER_SYM_OFFSET = 0x02, | |
103 | TRACE_ITER_SYM_ADDR = 0x04, | |
104 | TRACE_ITER_VERBOSE = 0x08, | |
105 | }; | |
106 | ||
107 | #define TRACE_ITER_SYM_MASK \ | |
108 | (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR) | |
109 | ||
110 | /* These must match the bit postions above */ | |
111 | static const char *trace_options[] = { | |
112 | "print-parent", | |
113 | "sym-offset", | |
114 | "sym-addr", | |
115 | "verbose", | |
116 | NULL | |
117 | }; | |
118 | ||
119 | static unsigned trace_flags; | |
120 | ||
4c11d7ae | 121 | static DEFINE_SPINLOCK(ftrace_max_lock); |
bc0c38d1 SR |
122 | |
123 | /* | |
124 | * Copy the new maximum trace into the separate maximum-trace | |
125 | * structure. (this way the maximum trace is permanently saved, | |
126 | * for later retrieval via /debugfs/tracing/latency_trace) | |
127 | */ | |
4e3c3333 | 128 | static notrace void |
bc0c38d1 SR |
129 | __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) |
130 | { | |
131 | struct trace_array_cpu *data = tr->data[cpu]; | |
132 | ||
133 | max_tr.cpu = cpu; | |
134 | max_tr.time_start = data->preempt_timestamp; | |
135 | ||
136 | data = max_tr.data[cpu]; | |
137 | data->saved_latency = tracing_max_latency; | |
138 | ||
139 | memcpy(data->comm, tsk->comm, TASK_COMM_LEN); | |
140 | data->pid = tsk->pid; | |
141 | data->uid = tsk->uid; | |
142 | data->nice = tsk->static_prio - 20 - MAX_RT_PRIO; | |
143 | data->policy = tsk->policy; | |
144 | data->rt_priority = tsk->rt_priority; | |
145 | ||
146 | /* record this tasks comm */ | |
147 | tracing_record_cmdline(current); | |
148 | } | |
149 | ||
c7aafc54 IM |
150 | void check_pages(struct trace_array_cpu *data) |
151 | { | |
152 | struct page *page, *tmp; | |
153 | ||
154 | BUG_ON(data->trace_pages.next->prev != &data->trace_pages); | |
155 | BUG_ON(data->trace_pages.prev->next != &data->trace_pages); | |
156 | ||
157 | list_for_each_entry_safe(page, tmp, &data->trace_pages, lru) { | |
158 | BUG_ON(page->lru.next->prev != &page->lru); | |
159 | BUG_ON(page->lru.prev->next != &page->lru); | |
160 | } | |
161 | } | |
162 | ||
163 | void *head_page(struct trace_array_cpu *data) | |
164 | { | |
165 | struct page *page; | |
166 | ||
167 | check_pages(data); | |
168 | if (list_empty(&data->trace_pages)) | |
169 | return NULL; | |
170 | ||
171 | page = list_entry(data->trace_pages.next, struct page, lru); | |
172 | BUG_ON(&page->lru == &data->trace_pages); | |
173 | ||
174 | return page_address(page); | |
175 | } | |
176 | ||
214023c3 SR |
177 | static notrace int |
178 | trace_seq_printf(struct trace_seq *s, const char *fmt, ...) | |
179 | { | |
180 | int len = (PAGE_SIZE - 1) - s->len; | |
181 | va_list ap; | |
b3806b43 | 182 | int ret; |
214023c3 SR |
183 | |
184 | if (!len) | |
185 | return 0; | |
186 | ||
187 | va_start(ap, fmt); | |
b3806b43 | 188 | ret = vsnprintf(s->buffer + s->len, len, fmt, ap); |
214023c3 SR |
189 | va_end(ap); |
190 | ||
b3806b43 SR |
191 | /* If we can't write it all, don't bother writing anything */ |
192 | if (ret > len) | |
193 | return 0; | |
194 | ||
195 | s->len += ret; | |
214023c3 SR |
196 | |
197 | return len; | |
198 | } | |
199 | ||
200 | static notrace int | |
201 | trace_seq_puts(struct trace_seq *s, const char *str) | |
202 | { | |
203 | int len = strlen(str); | |
204 | ||
205 | if (len > ((PAGE_SIZE - 1) - s->len)) | |
b3806b43 | 206 | return 0; |
214023c3 SR |
207 | |
208 | memcpy(s->buffer + s->len, str, len); | |
209 | s->len += len; | |
210 | ||
211 | return len; | |
212 | } | |
213 | ||
214 | static notrace int | |
215 | trace_seq_putc(struct trace_seq *s, unsigned char c) | |
216 | { | |
217 | if (s->len >= (PAGE_SIZE - 1)) | |
218 | return 0; | |
219 | ||
220 | s->buffer[s->len++] = c; | |
221 | ||
222 | return 1; | |
223 | } | |
224 | ||
225 | static notrace void | |
226 | trace_seq_reset(struct trace_seq *s) | |
227 | { | |
228 | s->len = 0; | |
229 | } | |
230 | ||
231 | static notrace void | |
232 | trace_print_seq(struct seq_file *m, struct trace_seq *s) | |
233 | { | |
234 | int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len; | |
235 | ||
236 | s->buffer[len] = 0; | |
237 | seq_puts(m, s->buffer); | |
238 | ||
239 | trace_seq_reset(s); | |
240 | } | |
241 | ||
c7aafc54 IM |
242 | notrace static void |
243 | flip_trace(struct trace_array_cpu *tr1, struct trace_array_cpu *tr2) | |
244 | { | |
245 | struct list_head flip_pages; | |
246 | ||
247 | INIT_LIST_HEAD(&flip_pages); | |
248 | ||
93a588f4 | 249 | memcpy(&tr1->trace_head_idx, &tr2->trace_head_idx, |
c7aafc54 | 250 | sizeof(struct trace_array_cpu) - |
93a588f4 | 251 | offsetof(struct trace_array_cpu, trace_head_idx)); |
c7aafc54 IM |
252 | |
253 | check_pages(tr1); | |
254 | check_pages(tr2); | |
255 | list_splice_init(&tr1->trace_pages, &flip_pages); | |
256 | list_splice_init(&tr2->trace_pages, &tr1->trace_pages); | |
257 | list_splice_init(&flip_pages, &tr2->trace_pages); | |
258 | BUG_ON(!list_empty(&flip_pages)); | |
259 | check_pages(tr1); | |
260 | check_pages(tr2); | |
261 | } | |
262 | ||
bc0c38d1 SR |
263 | notrace void |
264 | update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) | |
265 | { | |
266 | struct trace_array_cpu *data; | |
bc0c38d1 SR |
267 | int i; |
268 | ||
4c11d7ae SR |
269 | WARN_ON_ONCE(!irqs_disabled()); |
270 | spin_lock(&ftrace_max_lock); | |
bc0c38d1 SR |
271 | /* clear out all the previous traces */ |
272 | for_each_possible_cpu(i) { | |
273 | data = tr->data[i]; | |
c7aafc54 | 274 | flip_trace(max_tr.data[i], data); |
89b2f978 | 275 | tracing_reset(data); |
bc0c38d1 SR |
276 | } |
277 | ||
278 | __update_max_tr(tr, tsk, cpu); | |
4c11d7ae | 279 | spin_unlock(&ftrace_max_lock); |
bc0c38d1 SR |
280 | } |
281 | ||
282 | /** | |
283 | * update_max_tr_single - only copy one trace over, and reset the rest | |
284 | * @tr - tracer | |
285 | * @tsk - task with the latency | |
286 | * @cpu - the cpu of the buffer to copy. | |
287 | */ | |
288 | notrace void | |
289 | update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) | |
290 | { | |
291 | struct trace_array_cpu *data = tr->data[cpu]; | |
bc0c38d1 SR |
292 | int i; |
293 | ||
4c11d7ae SR |
294 | WARN_ON_ONCE(!irqs_disabled()); |
295 | spin_lock(&ftrace_max_lock); | |
bc0c38d1 SR |
296 | for_each_possible_cpu(i) |
297 | tracing_reset(max_tr.data[i]); | |
298 | ||
c7aafc54 | 299 | flip_trace(max_tr.data[cpu], data); |
89b2f978 | 300 | tracing_reset(data); |
bc0c38d1 SR |
301 | |
302 | __update_max_tr(tr, tsk, cpu); | |
4c11d7ae | 303 | spin_unlock(&ftrace_max_lock); |
bc0c38d1 SR |
304 | } |
305 | ||
306 | int register_tracer(struct tracer *type) | |
307 | { | |
308 | struct tracer *t; | |
309 | int len; | |
310 | int ret = 0; | |
311 | ||
312 | if (!type->name) { | |
313 | pr_info("Tracer must have a name\n"); | |
314 | return -1; | |
315 | } | |
316 | ||
317 | mutex_lock(&trace_types_lock); | |
318 | for (t = trace_types; t; t = t->next) { | |
319 | if (strcmp(type->name, t->name) == 0) { | |
320 | /* already found */ | |
321 | pr_info("Trace %s already registered\n", | |
322 | type->name); | |
323 | ret = -1; | |
324 | goto out; | |
325 | } | |
326 | } | |
327 | ||
60a11774 SR |
328 | #ifdef CONFIG_FTRACE_STARTUP_TEST |
329 | if (type->selftest) { | |
330 | struct tracer *saved_tracer = current_trace; | |
331 | struct trace_array_cpu *data; | |
332 | struct trace_array *tr = &global_trace; | |
333 | int saved_ctrl = tr->ctrl; | |
334 | int i; | |
335 | /* | |
336 | * Run a selftest on this tracer. | |
337 | * Here we reset the trace buffer, and set the current | |
338 | * tracer to be this tracer. The tracer can then run some | |
339 | * internal tracing to verify that everything is in order. | |
340 | * If we fail, we do not register this tracer. | |
341 | */ | |
342 | for_each_possible_cpu(i) { | |
60a11774 | 343 | data = tr->data[i]; |
c7aafc54 IM |
344 | if (!head_page(data)) |
345 | continue; | |
60a11774 SR |
346 | tracing_reset(data); |
347 | } | |
348 | current_trace = type; | |
349 | tr->ctrl = 0; | |
350 | /* the test is responsible for initializing and enabling */ | |
351 | pr_info("Testing tracer %s: ", type->name); | |
352 | ret = type->selftest(type, tr); | |
353 | /* the test is responsible for resetting too */ | |
354 | current_trace = saved_tracer; | |
355 | tr->ctrl = saved_ctrl; | |
356 | if (ret) { | |
357 | printk(KERN_CONT "FAILED!\n"); | |
358 | goto out; | |
359 | } | |
1d4db00a SR |
360 | /* Only reset on passing, to avoid touching corrupted buffers */ |
361 | for_each_possible_cpu(i) { | |
362 | data = tr->data[i]; | |
363 | if (!head_page(data)) | |
364 | continue; | |
365 | tracing_reset(data); | |
366 | } | |
60a11774 SR |
367 | printk(KERN_CONT "PASSED\n"); |
368 | } | |
369 | #endif | |
370 | ||
bc0c38d1 SR |
371 | type->next = trace_types; |
372 | trace_types = type; | |
373 | len = strlen(type->name); | |
374 | if (len > max_tracer_type_len) | |
375 | max_tracer_type_len = len; | |
60a11774 | 376 | |
bc0c38d1 SR |
377 | out: |
378 | mutex_unlock(&trace_types_lock); | |
379 | ||
380 | return ret; | |
381 | } | |
382 | ||
383 | void unregister_tracer(struct tracer *type) | |
384 | { | |
385 | struct tracer **t; | |
386 | int len; | |
387 | ||
388 | mutex_lock(&trace_types_lock); | |
389 | for (t = &trace_types; *t; t = &(*t)->next) { | |
390 | if (*t == type) | |
391 | goto found; | |
392 | } | |
393 | pr_info("Trace %s not registered\n", type->name); | |
394 | goto out; | |
395 | ||
396 | found: | |
397 | *t = (*t)->next; | |
398 | if (strlen(type->name) != max_tracer_type_len) | |
399 | goto out; | |
400 | ||
401 | max_tracer_type_len = 0; | |
402 | for (t = &trace_types; *t; t = &(*t)->next) { | |
403 | len = strlen((*t)->name); | |
404 | if (len > max_tracer_type_len) | |
405 | max_tracer_type_len = len; | |
406 | } | |
407 | out: | |
408 | mutex_unlock(&trace_types_lock); | |
409 | } | |
410 | ||
4e3c3333 | 411 | notrace void tracing_reset(struct trace_array_cpu *data) |
bc0c38d1 SR |
412 | { |
413 | data->trace_idx = 0; | |
93a588f4 SR |
414 | data->trace_head = data->trace_tail = head_page(data); |
415 | data->trace_head_idx = 0; | |
416 | data->trace_tail_idx = 0; | |
bc0c38d1 SR |
417 | } |
418 | ||
419 | #ifdef CONFIG_FTRACE | |
4e3c3333 | 420 | static notrace void |
bc0c38d1 SR |
421 | function_trace_call(unsigned long ip, unsigned long parent_ip) |
422 | { | |
423 | struct trace_array *tr = &global_trace; | |
424 | struct trace_array_cpu *data; | |
425 | unsigned long flags; | |
426 | long disabled; | |
427 | int cpu; | |
428 | ||
429 | if (unlikely(!tracer_enabled)) | |
430 | return; | |
431 | ||
18cef379 | 432 | local_irq_save(flags); |
bc0c38d1 SR |
433 | cpu = raw_smp_processor_id(); |
434 | data = tr->data[cpu]; | |
435 | disabled = atomic_inc_return(&data->disabled); | |
436 | ||
437 | if (likely(disabled == 1)) | |
438 | ftrace(tr, data, ip, parent_ip, flags); | |
439 | ||
440 | atomic_dec(&data->disabled); | |
18cef379 | 441 | local_irq_restore(flags); |
bc0c38d1 SR |
442 | } |
443 | ||
444 | static struct ftrace_ops trace_ops __read_mostly = | |
445 | { | |
446 | .func = function_trace_call, | |
447 | }; | |
448 | #endif | |
449 | ||
450 | notrace void tracing_start_function_trace(void) | |
451 | { | |
452 | register_ftrace_function(&trace_ops); | |
453 | } | |
454 | ||
455 | notrace void tracing_stop_function_trace(void) | |
456 | { | |
457 | unregister_ftrace_function(&trace_ops); | |
458 | } | |
459 | ||
460 | #define SAVED_CMDLINES 128 | |
461 | static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1]; | |
462 | static unsigned map_cmdline_to_pid[SAVED_CMDLINES]; | |
463 | static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN]; | |
464 | static int cmdline_idx; | |
465 | static DEFINE_SPINLOCK(trace_cmdline_lock); | |
466 | atomic_t trace_record_cmdline_disabled; | |
467 | ||
468 | static void trace_init_cmdlines(void) | |
469 | { | |
470 | memset(&map_pid_to_cmdline, -1, sizeof(map_pid_to_cmdline)); | |
471 | memset(&map_cmdline_to_pid, -1, sizeof(map_cmdline_to_pid)); | |
472 | cmdline_idx = 0; | |
473 | } | |
474 | ||
475 | notrace void trace_stop_cmdline_recording(void); | |
476 | ||
4e3c3333 | 477 | static notrace void trace_save_cmdline(struct task_struct *tsk) |
bc0c38d1 SR |
478 | { |
479 | unsigned map; | |
480 | unsigned idx; | |
481 | ||
482 | if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT)) | |
483 | return; | |
484 | ||
485 | /* | |
486 | * It's not the end of the world if we don't get | |
487 | * the lock, but we also don't want to spin | |
488 | * nor do we want to disable interrupts, | |
489 | * so if we miss here, then better luck next time. | |
490 | */ | |
491 | if (!spin_trylock(&trace_cmdline_lock)) | |
492 | return; | |
493 | ||
494 | idx = map_pid_to_cmdline[tsk->pid]; | |
495 | if (idx >= SAVED_CMDLINES) { | |
496 | idx = (cmdline_idx + 1) % SAVED_CMDLINES; | |
497 | ||
498 | map = map_cmdline_to_pid[idx]; | |
499 | if (map <= PID_MAX_DEFAULT) | |
500 | map_pid_to_cmdline[map] = (unsigned)-1; | |
501 | ||
502 | map_pid_to_cmdline[tsk->pid] = idx; | |
503 | ||
504 | cmdline_idx = idx; | |
505 | } | |
506 | ||
507 | memcpy(&saved_cmdlines[idx], tsk->comm, TASK_COMM_LEN); | |
508 | ||
509 | spin_unlock(&trace_cmdline_lock); | |
510 | } | |
511 | ||
512 | static notrace char *trace_find_cmdline(int pid) | |
513 | { | |
514 | char *cmdline = "<...>"; | |
515 | unsigned map; | |
516 | ||
517 | if (!pid) | |
518 | return "<idle>"; | |
519 | ||
520 | if (pid > PID_MAX_DEFAULT) | |
521 | goto out; | |
522 | ||
523 | map = map_pid_to_cmdline[pid]; | |
524 | if (map >= SAVED_CMDLINES) | |
525 | goto out; | |
526 | ||
527 | cmdline = saved_cmdlines[map]; | |
528 | ||
529 | out: | |
530 | return cmdline; | |
531 | } | |
532 | ||
533 | notrace void tracing_record_cmdline(struct task_struct *tsk) | |
534 | { | |
535 | if (atomic_read(&trace_record_cmdline_disabled)) | |
536 | return; | |
537 | ||
538 | trace_save_cmdline(tsk); | |
539 | } | |
540 | ||
93a588f4 SR |
541 | static inline notrace struct list_head * |
542 | trace_next_list(struct trace_array_cpu *data, struct list_head *next) | |
543 | { | |
544 | /* | |
545 | * Roundrobin - but skip the head (which is not a real page): | |
546 | */ | |
547 | next = next->next; | |
548 | if (unlikely(next == &data->trace_pages)) | |
549 | next = next->next; | |
550 | BUG_ON(next == &data->trace_pages); | |
551 | ||
552 | return next; | |
553 | } | |
554 | ||
555 | static inline notrace void * | |
556 | trace_next_page(struct trace_array_cpu *data, void *addr) | |
557 | { | |
558 | struct list_head *next; | |
559 | struct page *page; | |
560 | ||
561 | page = virt_to_page(addr); | |
562 | ||
563 | next = trace_next_list(data, &page->lru); | |
564 | page = list_entry(next, struct page, lru); | |
565 | ||
566 | return page_address(page); | |
567 | } | |
568 | ||
bc0c38d1 | 569 | static inline notrace struct trace_entry * |
c7aafc54 | 570 | tracing_get_trace_entry(struct trace_array *tr, struct trace_array_cpu *data) |
bc0c38d1 SR |
571 | { |
572 | unsigned long idx, idx_next; | |
573 | struct trace_entry *entry; | |
574 | ||
4c11d7ae | 575 | data->trace_idx++; |
93a588f4 | 576 | idx = data->trace_head_idx; |
bc0c38d1 SR |
577 | idx_next = idx + 1; |
578 | ||
c7aafc54 IM |
579 | BUG_ON(idx * TRACE_ENTRY_SIZE >= PAGE_SIZE); |
580 | ||
93a588f4 | 581 | entry = data->trace_head + idx * TRACE_ENTRY_SIZE; |
4c11d7ae SR |
582 | |
583 | if (unlikely(idx_next >= ENTRIES_PER_PAGE)) { | |
93a588f4 | 584 | data->trace_head = trace_next_page(data, data->trace_head); |
bc0c38d1 SR |
585 | idx_next = 0; |
586 | } | |
587 | ||
93a588f4 SR |
588 | if (data->trace_head == data->trace_tail && |
589 | idx_next == data->trace_tail_idx) { | |
590 | /* overrun */ | |
591 | data->trace_tail_idx++; | |
592 | if (data->trace_tail_idx >= ENTRIES_PER_PAGE) { | |
593 | data->trace_tail = | |
594 | trace_next_page(data, data->trace_tail); | |
595 | data->trace_tail_idx = 0; | |
596 | } | |
597 | } | |
598 | ||
599 | data->trace_head_idx = idx_next; | |
bc0c38d1 SR |
600 | |
601 | return entry; | |
602 | } | |
603 | ||
604 | static inline notrace void | |
c7aafc54 | 605 | tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags) |
bc0c38d1 SR |
606 | { |
607 | struct task_struct *tsk = current; | |
608 | unsigned long pc; | |
609 | ||
610 | pc = preempt_count(); | |
611 | ||
c7aafc54 IM |
612 | entry->idx = atomic_inc_return(&tracer_counter); |
613 | entry->preempt_count = pc & 0xff; | |
614 | entry->pid = tsk->pid; | |
750ed1a4 | 615 | entry->t = ftrace_now(raw_smp_processor_id()); |
bc0c38d1 SR |
616 | entry->flags = (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) | |
617 | ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) | | |
618 | ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) | | |
619 | (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0); | |
620 | } | |
621 | ||
622 | notrace void | |
623 | ftrace(struct trace_array *tr, struct trace_array_cpu *data, | |
c7aafc54 | 624 | unsigned long ip, unsigned long parent_ip, unsigned long flags) |
bc0c38d1 SR |
625 | { |
626 | struct trace_entry *entry; | |
627 | ||
b3806b43 | 628 | spin_lock(&data->lock); |
c7aafc54 | 629 | entry = tracing_get_trace_entry(tr, data); |
bc0c38d1 | 630 | tracing_generic_entry_update(entry, flags); |
c7aafc54 IM |
631 | entry->type = TRACE_FN; |
632 | entry->fn.ip = ip; | |
633 | entry->fn.parent_ip = parent_ip; | |
b3806b43 | 634 | spin_unlock(&data->lock); |
bc0c38d1 SR |
635 | } |
636 | ||
637 | notrace void | |
638 | tracing_sched_switch_trace(struct trace_array *tr, | |
639 | struct trace_array_cpu *data, | |
640 | struct task_struct *prev, struct task_struct *next, | |
641 | unsigned long flags) | |
642 | { | |
643 | struct trace_entry *entry; | |
644 | ||
b3806b43 | 645 | spin_lock(&data->lock); |
c7aafc54 | 646 | entry = tracing_get_trace_entry(tr, data); |
bc0c38d1 SR |
647 | tracing_generic_entry_update(entry, flags); |
648 | entry->type = TRACE_CTX; | |
649 | entry->ctx.prev_pid = prev->pid; | |
650 | entry->ctx.prev_prio = prev->prio; | |
651 | entry->ctx.prev_state = prev->state; | |
652 | entry->ctx.next_pid = next->pid; | |
653 | entry->ctx.next_prio = next->prio; | |
b3806b43 | 654 | spin_unlock(&data->lock); |
bc0c38d1 SR |
655 | } |
656 | ||
657 | enum trace_file_type { | |
658 | TRACE_FILE_LAT_FMT = 1, | |
659 | }; | |
660 | ||
661 | static struct trace_entry * | |
4c11d7ae SR |
662 | trace_entry_idx(struct trace_array *tr, struct trace_array_cpu *data, |
663 | struct trace_iterator *iter, int cpu) | |
bc0c38d1 | 664 | { |
4c11d7ae SR |
665 | struct page *page; |
666 | struct trace_entry *array; | |
bc0c38d1 | 667 | |
4c11d7ae | 668 | if (iter->next_idx[cpu] >= tr->entries || |
b3806b43 SR |
669 | iter->next_idx[cpu] >= data->trace_idx || |
670 | (data->trace_head == data->trace_tail && | |
671 | data->trace_head_idx == data->trace_tail_idx)) | |
bc0c38d1 SR |
672 | return NULL; |
673 | ||
4c11d7ae | 674 | if (!iter->next_page[cpu]) { |
93a588f4 SR |
675 | /* Initialize the iterator for this cpu trace buffer */ |
676 | WARN_ON(!data->trace_tail); | |
677 | page = virt_to_page(data->trace_tail); | |
678 | iter->next_page[cpu] = &page->lru; | |
679 | iter->next_page_idx[cpu] = data->trace_tail_idx; | |
4c11d7ae | 680 | } |
bc0c38d1 | 681 | |
4c11d7ae | 682 | page = list_entry(iter->next_page[cpu], struct page, lru); |
c7aafc54 IM |
683 | BUG_ON(&data->trace_pages == &page->lru); |
684 | ||
4c11d7ae SR |
685 | array = page_address(page); |
686 | ||
93a588f4 SR |
687 | /* Still possible to catch up to the tail */ |
688 | if (iter->next_idx[cpu] && array == data->trace_tail && | |
689 | iter->next_page_idx[cpu] == data->trace_tail_idx) | |
690 | return NULL; | |
691 | ||
692 | WARN_ON(iter->next_page_idx[cpu] >= ENTRIES_PER_PAGE); | |
4c11d7ae | 693 | return &array[iter->next_page_idx[cpu]]; |
bc0c38d1 SR |
694 | } |
695 | ||
696 | static struct notrace trace_entry * | |
697 | find_next_entry(struct trace_iterator *iter, int *ent_cpu) | |
698 | { | |
699 | struct trace_array *tr = iter->tr; | |
700 | struct trace_entry *ent, *next = NULL; | |
701 | int next_cpu = -1; | |
702 | int cpu; | |
703 | ||
704 | for_each_possible_cpu(cpu) { | |
c7aafc54 | 705 | if (!head_page(tr->data[cpu])) |
bc0c38d1 | 706 | continue; |
4c11d7ae | 707 | ent = trace_entry_idx(tr, tr->data[cpu], iter, cpu); |
bc0c38d1 SR |
708 | if (ent && |
709 | (!next || (long)(next->idx - ent->idx) > 0)) { | |
710 | next = ent; | |
711 | next_cpu = cpu; | |
712 | } | |
713 | } | |
714 | ||
715 | if (ent_cpu) | |
716 | *ent_cpu = next_cpu; | |
717 | ||
718 | return next; | |
719 | } | |
720 | ||
b3806b43 SR |
721 | static notrace void |
722 | trace_iterator_increment(struct trace_iterator *iter) | |
bc0c38d1 | 723 | { |
b3806b43 SR |
724 | iter->idx++; |
725 | iter->next_idx[iter->cpu]++; | |
726 | iter->next_page_idx[iter->cpu]++; | |
727 | if (iter->next_page_idx[iter->cpu] >= ENTRIES_PER_PAGE) { | |
728 | struct trace_array_cpu *data = iter->tr->data[iter->cpu]; | |
bc0c38d1 | 729 | |
b3806b43 SR |
730 | iter->next_page_idx[iter->cpu] = 0; |
731 | iter->next_page[iter->cpu] = | |
732 | trace_next_list(data, iter->next_page[iter->cpu]); | |
733 | } | |
734 | } | |
bc0c38d1 | 735 | |
b3806b43 SR |
736 | static notrace void |
737 | trace_consume(struct trace_iterator *iter) | |
738 | { | |
739 | struct trace_array_cpu *data = iter->tr->data[iter->cpu]; | |
740 | ||
741 | data->trace_tail_idx++; | |
742 | if (data->trace_tail_idx >= ENTRIES_PER_PAGE) { | |
743 | data->trace_tail = trace_next_page(data, data->trace_tail); | |
744 | data->trace_tail_idx = 0; | |
745 | } | |
4e3c3333 | 746 | |
b3806b43 SR |
747 | /* Check if we empty it, then reset the index */ |
748 | if (data->trace_head == data->trace_tail && | |
749 | data->trace_head_idx == data->trace_tail_idx) | |
750 | data->trace_idx = 0; | |
4c11d7ae | 751 | |
b3806b43 SR |
752 | trace_iterator_increment(iter); |
753 | } | |
754 | ||
755 | static notrace void * | |
756 | find_next_entry_inc(struct trace_iterator *iter) | |
757 | { | |
758 | struct trace_entry *next; | |
759 | int next_cpu = -1; | |
760 | ||
761 | next = find_next_entry(iter, &next_cpu); | |
93a588f4 | 762 | |
4e3c3333 IM |
763 | iter->prev_ent = iter->ent; |
764 | iter->prev_cpu = iter->cpu; | |
765 | ||
bc0c38d1 SR |
766 | iter->ent = next; |
767 | iter->cpu = next_cpu; | |
768 | ||
b3806b43 SR |
769 | if (next) |
770 | trace_iterator_increment(iter); | |
771 | ||
bc0c38d1 SR |
772 | return next ? iter : NULL; |
773 | } | |
774 | ||
4e3c3333 | 775 | static notrace void *s_next(struct seq_file *m, void *v, loff_t *pos) |
bc0c38d1 SR |
776 | { |
777 | struct trace_iterator *iter = m->private; | |
bc0c38d1 SR |
778 | void *last_ent = iter->ent; |
779 | int i = (int)*pos; | |
4e3c3333 | 780 | void *ent; |
bc0c38d1 SR |
781 | |
782 | (*pos)++; | |
783 | ||
784 | /* can't go backwards */ | |
785 | if (iter->idx > i) | |
786 | return NULL; | |
787 | ||
788 | if (iter->idx < 0) | |
789 | ent = find_next_entry_inc(iter); | |
790 | else | |
791 | ent = iter; | |
792 | ||
793 | while (ent && iter->idx < i) | |
794 | ent = find_next_entry_inc(iter); | |
795 | ||
796 | iter->pos = *pos; | |
797 | ||
798 | if (last_ent && !ent) | |
799 | seq_puts(m, "\n\nvim:ft=help\n"); | |
800 | ||
801 | return ent; | |
802 | } | |
803 | ||
804 | static void *s_start(struct seq_file *m, loff_t *pos) | |
805 | { | |
806 | struct trace_iterator *iter = m->private; | |
807 | void *p = NULL; | |
808 | loff_t l = 0; | |
809 | int i; | |
810 | ||
811 | mutex_lock(&trace_types_lock); | |
812 | ||
813 | if (!current_trace || current_trace != iter->trace) | |
814 | return NULL; | |
815 | ||
816 | atomic_inc(&trace_record_cmdline_disabled); | |
817 | ||
818 | /* let the tracer grab locks here if needed */ | |
819 | if (current_trace->start) | |
820 | current_trace->start(iter); | |
821 | ||
822 | if (*pos != iter->pos) { | |
823 | iter->ent = NULL; | |
824 | iter->cpu = 0; | |
825 | iter->idx = -1; | |
4e3c3333 IM |
826 | iter->prev_ent = NULL; |
827 | iter->prev_cpu = -1; | |
bc0c38d1 | 828 | |
4c11d7ae | 829 | for_each_possible_cpu(i) { |
bc0c38d1 | 830 | iter->next_idx[i] = 0; |
4c11d7ae SR |
831 | iter->next_page[i] = NULL; |
832 | } | |
bc0c38d1 SR |
833 | |
834 | for (p = iter; p && l < *pos; p = s_next(m, p, &l)) | |
835 | ; | |
836 | ||
837 | } else { | |
4c11d7ae | 838 | l = *pos - 1; |
bc0c38d1 SR |
839 | p = s_next(m, p, &l); |
840 | } | |
841 | ||
842 | return p; | |
843 | } | |
844 | ||
845 | static void s_stop(struct seq_file *m, void *p) | |
846 | { | |
847 | struct trace_iterator *iter = m->private; | |
848 | ||
849 | atomic_dec(&trace_record_cmdline_disabled); | |
850 | ||
851 | /* let the tracer release locks here if needed */ | |
852 | if (current_trace && current_trace == iter->trace && iter->trace->stop) | |
853 | iter->trace->stop(iter); | |
854 | ||
855 | mutex_unlock(&trace_types_lock); | |
856 | } | |
857 | ||
b3806b43 | 858 | static int |
214023c3 | 859 | seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address) |
bc0c38d1 SR |
860 | { |
861 | #ifdef CONFIG_KALLSYMS | |
862 | char str[KSYM_SYMBOL_LEN]; | |
863 | ||
864 | kallsyms_lookup(address, NULL, NULL, NULL, str); | |
865 | ||
b3806b43 | 866 | return trace_seq_printf(s, fmt, str); |
bc0c38d1 | 867 | #endif |
b3806b43 | 868 | return 1; |
bc0c38d1 SR |
869 | } |
870 | ||
b3806b43 | 871 | static int |
214023c3 SR |
872 | seq_print_sym_offset(struct trace_seq *s, const char *fmt, |
873 | unsigned long address) | |
bc0c38d1 SR |
874 | { |
875 | #ifdef CONFIG_KALLSYMS | |
876 | char str[KSYM_SYMBOL_LEN]; | |
877 | ||
878 | sprint_symbol(str, address); | |
b3806b43 | 879 | return trace_seq_printf(s, fmt, str); |
bc0c38d1 | 880 | #endif |
b3806b43 | 881 | return 1; |
bc0c38d1 SR |
882 | } |
883 | ||
884 | #ifndef CONFIG_64BIT | |
885 | # define IP_FMT "%08lx" | |
886 | #else | |
887 | # define IP_FMT "%016lx" | |
888 | #endif | |
889 | ||
b3806b43 | 890 | static notrace int |
214023c3 | 891 | seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags) |
bc0c38d1 | 892 | { |
b3806b43 SR |
893 | int ret; |
894 | ||
895 | if (!ip) | |
896 | return trace_seq_printf(s, "0"); | |
bc0c38d1 SR |
897 | |
898 | if (sym_flags & TRACE_ITER_SYM_OFFSET) | |
b3806b43 | 899 | ret = seq_print_sym_offset(s, "%s", ip); |
bc0c38d1 | 900 | else |
b3806b43 SR |
901 | ret = seq_print_sym_short(s, "%s", ip); |
902 | ||
903 | if (!ret) | |
904 | return 0; | |
bc0c38d1 SR |
905 | |
906 | if (sym_flags & TRACE_ITER_SYM_ADDR) | |
b3806b43 SR |
907 | ret = trace_seq_printf(s, " <" IP_FMT ">", ip); |
908 | return ret; | |
bc0c38d1 SR |
909 | } |
910 | ||
4e3c3333 | 911 | static notrace void print_lat_help_header(struct seq_file *m) |
bc0c38d1 SR |
912 | { |
913 | seq_puts(m, "# _------=> CPU# \n"); | |
914 | seq_puts(m, "# / _-----=> irqs-off \n"); | |
915 | seq_puts(m, "# | / _----=> need-resched \n"); | |
916 | seq_puts(m, "# || / _---=> hardirq/softirq \n"); | |
917 | seq_puts(m, "# ||| / _--=> preempt-depth \n"); | |
918 | seq_puts(m, "# |||| / \n"); | |
919 | seq_puts(m, "# ||||| delay \n"); | |
920 | seq_puts(m, "# cmd pid ||||| time | caller \n"); | |
921 | seq_puts(m, "# \\ / ||||| \\ | / \n"); | |
922 | } | |
923 | ||
4e3c3333 | 924 | static notrace void print_func_help_header(struct seq_file *m) |
bc0c38d1 SR |
925 | { |
926 | seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n"); | |
927 | seq_puts(m, "# | | | | |\n"); | |
928 | } | |
929 | ||
930 | ||
4e3c3333 | 931 | static notrace void |
bc0c38d1 SR |
932 | print_trace_header(struct seq_file *m, struct trace_iterator *iter) |
933 | { | |
934 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); | |
935 | struct trace_array *tr = iter->tr; | |
936 | struct trace_array_cpu *data = tr->data[tr->cpu]; | |
937 | struct tracer *type = current_trace; | |
4c11d7ae SR |
938 | unsigned long total = 0; |
939 | unsigned long entries = 0; | |
bc0c38d1 SR |
940 | int cpu; |
941 | const char *name = "preemption"; | |
942 | ||
943 | if (type) | |
944 | name = type->name; | |
945 | ||
946 | for_each_possible_cpu(cpu) { | |
c7aafc54 | 947 | if (head_page(tr->data[cpu])) { |
4c11d7ae SR |
948 | total += tr->data[cpu]->trace_idx; |
949 | if (tr->data[cpu]->trace_idx > tr->entries) | |
bc0c38d1 | 950 | entries += tr->entries; |
4c11d7ae | 951 | else |
bc0c38d1 SR |
952 | entries += tr->data[cpu]->trace_idx; |
953 | } | |
954 | } | |
955 | ||
956 | seq_printf(m, "%s latency trace v1.1.5 on %s\n", | |
957 | name, UTS_RELEASE); | |
958 | seq_puts(m, "-----------------------------------" | |
959 | "---------------------------------\n"); | |
960 | seq_printf(m, " latency: %lu us, #%lu/%lu, CPU#%d |" | |
961 | " (M:%s VP:%d, KP:%d, SP:%d HP:%d", | |
57f50be1 | 962 | nsecs_to_usecs(data->saved_latency), |
bc0c38d1 | 963 | entries, |
4c11d7ae | 964 | total, |
bc0c38d1 SR |
965 | tr->cpu, |
966 | #if defined(CONFIG_PREEMPT_NONE) | |
967 | "server", | |
968 | #elif defined(CONFIG_PREEMPT_VOLUNTARY) | |
969 | "desktop", | |
970 | #elif defined(CONFIG_PREEMPT_DESKTOP) | |
971 | "preempt", | |
972 | #else | |
973 | "unknown", | |
974 | #endif | |
975 | /* These are reserved for later use */ | |
976 | 0, 0, 0, 0); | |
977 | #ifdef CONFIG_SMP | |
978 | seq_printf(m, " #P:%d)\n", num_online_cpus()); | |
979 | #else | |
980 | seq_puts(m, ")\n"); | |
981 | #endif | |
982 | seq_puts(m, " -----------------\n"); | |
983 | seq_printf(m, " | task: %.16s-%d " | |
984 | "(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n", | |
985 | data->comm, data->pid, data->uid, data->nice, | |
986 | data->policy, data->rt_priority); | |
987 | seq_puts(m, " -----------------\n"); | |
988 | ||
989 | if (data->critical_start) { | |
990 | seq_puts(m, " => started at: "); | |
214023c3 SR |
991 | seq_print_ip_sym(&iter->seq, data->critical_start, sym_flags); |
992 | trace_print_seq(m, &iter->seq); | |
bc0c38d1 | 993 | seq_puts(m, "\n => ended at: "); |
214023c3 SR |
994 | seq_print_ip_sym(&iter->seq, data->critical_end, sym_flags); |
995 | trace_print_seq(m, &iter->seq); | |
bc0c38d1 SR |
996 | seq_puts(m, "\n"); |
997 | } | |
998 | ||
999 | seq_puts(m, "\n"); | |
1000 | } | |
1001 | ||
4e3c3333 | 1002 | static notrace void |
214023c3 | 1003 | lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu) |
bc0c38d1 SR |
1004 | { |
1005 | int hardirq, softirq; | |
1006 | char *comm; | |
1007 | ||
1008 | comm = trace_find_cmdline(entry->pid); | |
1009 | ||
214023c3 SR |
1010 | trace_seq_printf(s, "%8.8s-%-5d ", comm, entry->pid); |
1011 | trace_seq_printf(s, "%d", cpu); | |
1012 | trace_seq_printf(s, "%c%c", | |
1013 | (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : '.', | |
1014 | ((entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.')); | |
bc0c38d1 SR |
1015 | |
1016 | hardirq = entry->flags & TRACE_FLAG_HARDIRQ; | |
1017 | softirq = entry->flags & TRACE_FLAG_SOFTIRQ; | |
1018 | if (hardirq && softirq) | |
214023c3 | 1019 | trace_seq_putc(s, 'H'); |
bc0c38d1 SR |
1020 | else { |
1021 | if (hardirq) | |
214023c3 | 1022 | trace_seq_putc(s, 'h'); |
bc0c38d1 SR |
1023 | else { |
1024 | if (softirq) | |
214023c3 | 1025 | trace_seq_putc(s, 's'); |
bc0c38d1 | 1026 | else |
214023c3 | 1027 | trace_seq_putc(s, '.'); |
bc0c38d1 SR |
1028 | } |
1029 | } | |
1030 | ||
1031 | if (entry->preempt_count) | |
214023c3 | 1032 | trace_seq_printf(s, "%x", entry->preempt_count); |
bc0c38d1 | 1033 | else |
214023c3 | 1034 | trace_seq_puts(s, "."); |
bc0c38d1 SR |
1035 | } |
1036 | ||
1037 | unsigned long preempt_mark_thresh = 100; | |
1038 | ||
4e3c3333 | 1039 | static notrace void |
214023c3 | 1040 | lat_print_timestamp(struct trace_seq *s, unsigned long long abs_usecs, |
bc0c38d1 SR |
1041 | unsigned long rel_usecs) |
1042 | { | |
214023c3 | 1043 | trace_seq_printf(s, " %4lldus", abs_usecs); |
bc0c38d1 | 1044 | if (rel_usecs > preempt_mark_thresh) |
214023c3 | 1045 | trace_seq_puts(s, "!: "); |
bc0c38d1 | 1046 | else if (rel_usecs > 1) |
214023c3 | 1047 | trace_seq_puts(s, "+: "); |
bc0c38d1 | 1048 | else |
214023c3 | 1049 | trace_seq_puts(s, " : "); |
bc0c38d1 SR |
1050 | } |
1051 | ||
1052 | static const char state_to_char[] = TASK_STATE_TO_CHAR_STR; | |
1053 | ||
4e3c3333 | 1054 | static notrace void |
214023c3 | 1055 | print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) |
bc0c38d1 | 1056 | { |
214023c3 | 1057 | struct trace_seq *s = &iter->seq; |
bc0c38d1 SR |
1058 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); |
1059 | struct trace_entry *next_entry = find_next_entry(iter, NULL); | |
1060 | unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE); | |
1061 | struct trace_entry *entry = iter->ent; | |
1062 | unsigned long abs_usecs; | |
1063 | unsigned long rel_usecs; | |
1064 | char *comm; | |
1065 | int S; | |
1066 | ||
1067 | if (!next_entry) | |
1068 | next_entry = entry; | |
1069 | rel_usecs = ns2usecs(next_entry->t - entry->t); | |
1070 | abs_usecs = ns2usecs(entry->t - iter->tr->time_start); | |
1071 | ||
1072 | if (verbose) { | |
1073 | comm = trace_find_cmdline(entry->pid); | |
214023c3 SR |
1074 | trace_seq_printf(s, "%16s %5d %d %d %08x %08x [%08lx]" |
1075 | " %ld.%03ldms (+%ld.%03ldms): ", | |
1076 | comm, | |
1077 | entry->pid, cpu, entry->flags, | |
1078 | entry->preempt_count, trace_idx, | |
1079 | ns2usecs(entry->t), | |
1080 | abs_usecs/1000, | |
1081 | abs_usecs % 1000, rel_usecs/1000, | |
1082 | rel_usecs % 1000); | |
bc0c38d1 | 1083 | } else { |
214023c3 SR |
1084 | lat_print_generic(s, entry, cpu); |
1085 | lat_print_timestamp(s, abs_usecs, rel_usecs); | |
bc0c38d1 SR |
1086 | } |
1087 | switch (entry->type) { | |
1088 | case TRACE_FN: | |
214023c3 SR |
1089 | seq_print_ip_sym(s, entry->fn.ip, sym_flags); |
1090 | trace_seq_puts(s, " ("); | |
1091 | seq_print_ip_sym(s, entry->fn.parent_ip, sym_flags); | |
1092 | trace_seq_puts(s, ")\n"); | |
bc0c38d1 SR |
1093 | break; |
1094 | case TRACE_CTX: | |
1095 | S = entry->ctx.prev_state < sizeof(state_to_char) ? | |
1096 | state_to_char[entry->ctx.prev_state] : 'X'; | |
1097 | comm = trace_find_cmdline(entry->ctx.next_pid); | |
214023c3 SR |
1098 | trace_seq_printf(s, " %d:%d:%c --> %d:%d %s\n", |
1099 | entry->ctx.prev_pid, | |
1100 | entry->ctx.prev_prio, | |
1101 | S, | |
1102 | entry->ctx.next_pid, | |
1103 | entry->ctx.next_prio, | |
1104 | comm); | |
bc0c38d1 | 1105 | break; |
89b2f978 | 1106 | default: |
214023c3 | 1107 | trace_seq_printf(s, "Unknown type %d\n", entry->type); |
bc0c38d1 SR |
1108 | } |
1109 | } | |
1110 | ||
4e3c3333 IM |
1111 | static notrace void sync_time_offset(struct trace_iterator *iter) |
1112 | { | |
1113 | struct trace_array_cpu *prev_array, *array; | |
1114 | struct trace_entry *prev_entry, *entry; | |
1115 | cycle_t prev_t, t; | |
1116 | ||
1117 | entry = iter->ent; | |
1118 | prev_entry = iter->prev_ent; | |
1119 | if (!prev_entry) | |
1120 | return; | |
1121 | ||
1122 | prev_array = iter->tr->data[iter->prev_cpu]; | |
1123 | array = iter->tr->data[iter->cpu]; | |
1124 | ||
1125 | prev_t = prev_entry->t + prev_array->time_offset; | |
1126 | t = entry->t + array->time_offset; | |
1127 | ||
1128 | /* | |
1129 | * If time goes backwards we increase the offset of | |
1130 | * the current array, to not have observable time warps. | |
1131 | * This will quickly synchronize the time offsets of | |
1132 | * multiple CPUs: | |
1133 | */ | |
1134 | if (t < prev_t) | |
1135 | array->time_offset += prev_t - t; | |
1136 | } | |
1137 | ||
b3806b43 | 1138 | static notrace int |
214023c3 | 1139 | print_trace_fmt(struct trace_iterator *iter) |
bc0c38d1 | 1140 | { |
214023c3 | 1141 | struct trace_seq *s = &iter->seq; |
bc0c38d1 | 1142 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); |
4e3c3333 | 1143 | struct trace_entry *entry; |
bc0c38d1 SR |
1144 | unsigned long usec_rem; |
1145 | unsigned long long t; | |
1146 | unsigned long secs; | |
1147 | char *comm; | |
1148 | int S; | |
b3806b43 | 1149 | int ret; |
bc0c38d1 | 1150 | |
4e3c3333 IM |
1151 | sync_time_offset(iter); |
1152 | entry = iter->ent; | |
1153 | ||
bc0c38d1 SR |
1154 | comm = trace_find_cmdline(iter->ent->pid); |
1155 | ||
4e3c3333 | 1156 | t = ns2usecs(entry->t + iter->tr->data[iter->cpu]->time_offset); |
bc0c38d1 SR |
1157 | usec_rem = do_div(t, 1000000ULL); |
1158 | secs = (unsigned long)t; | |
1159 | ||
b3806b43 SR |
1160 | ret = trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid); |
1161 | if (!ret) | |
1162 | return 0; | |
1163 | ret = trace_seq_printf(s, "[%02d] ", iter->cpu); | |
1164 | if (!ret) | |
1165 | return 0; | |
1166 | ret = trace_seq_printf(s, "%5lu.%06lu: ", secs, usec_rem); | |
1167 | if (!ret) | |
1168 | return 0; | |
bc0c38d1 SR |
1169 | |
1170 | switch (entry->type) { | |
1171 | case TRACE_FN: | |
b3806b43 SR |
1172 | ret = seq_print_ip_sym(s, entry->fn.ip, sym_flags); |
1173 | if (!ret) | |
1174 | return 0; | |
bc0c38d1 SR |
1175 | if ((sym_flags & TRACE_ITER_PRINT_PARENT) && |
1176 | entry->fn.parent_ip) { | |
b3806b43 SR |
1177 | ret = trace_seq_printf(s, " <-"); |
1178 | if (!ret) | |
1179 | return 0; | |
1180 | ret = seq_print_ip_sym(s, entry->fn.parent_ip, | |
1181 | sym_flags); | |
1182 | if (!ret) | |
1183 | return 0; | |
bc0c38d1 | 1184 | } |
b3806b43 SR |
1185 | ret = trace_seq_printf(s, "\n"); |
1186 | if (!ret) | |
1187 | return 0; | |
bc0c38d1 SR |
1188 | break; |
1189 | case TRACE_CTX: | |
1190 | S = entry->ctx.prev_state < sizeof(state_to_char) ? | |
1191 | state_to_char[entry->ctx.prev_state] : 'X'; | |
b3806b43 SR |
1192 | ret = trace_seq_printf(s, " %d:%d:%c ==> %d:%d\n", |
1193 | entry->ctx.prev_pid, | |
1194 | entry->ctx.prev_prio, | |
1195 | S, | |
1196 | entry->ctx.next_pid, | |
1197 | entry->ctx.next_prio); | |
1198 | if (!ret) | |
1199 | return 0; | |
bc0c38d1 SR |
1200 | break; |
1201 | } | |
b3806b43 | 1202 | return 1; |
bc0c38d1 SR |
1203 | } |
1204 | ||
1205 | static int trace_empty(struct trace_iterator *iter) | |
1206 | { | |
1207 | struct trace_array_cpu *data; | |
1208 | int cpu; | |
1209 | ||
1210 | for_each_possible_cpu(cpu) { | |
1211 | data = iter->tr->data[cpu]; | |
1212 | ||
b3806b43 SR |
1213 | if (head_page(data) && data->trace_idx && |
1214 | (data->trace_tail != data->trace_head || | |
1215 | data->trace_tail_idx != data->trace_head_idx)) | |
bc0c38d1 SR |
1216 | return 0; |
1217 | } | |
1218 | return 1; | |
1219 | } | |
1220 | ||
1221 | static int s_show(struct seq_file *m, void *v) | |
1222 | { | |
1223 | struct trace_iterator *iter = v; | |
1224 | ||
1225 | if (iter->ent == NULL) { | |
1226 | if (iter->tr) { | |
1227 | seq_printf(m, "# tracer: %s\n", iter->trace->name); | |
1228 | seq_puts(m, "#\n"); | |
1229 | } | |
1230 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) { | |
1231 | /* print nothing if the buffers are empty */ | |
1232 | if (trace_empty(iter)) | |
1233 | return 0; | |
1234 | print_trace_header(m, iter); | |
1235 | if (!(trace_flags & TRACE_ITER_VERBOSE)) | |
1236 | print_lat_help_header(m); | |
1237 | } else { | |
1238 | if (!(trace_flags & TRACE_ITER_VERBOSE)) | |
1239 | print_func_help_header(m); | |
1240 | } | |
1241 | } else { | |
1242 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) | |
214023c3 | 1243 | print_lat_fmt(iter, iter->idx, iter->cpu); |
bc0c38d1 | 1244 | else |
214023c3 SR |
1245 | print_trace_fmt(iter); |
1246 | trace_print_seq(m, &iter->seq); | |
bc0c38d1 SR |
1247 | } |
1248 | ||
1249 | return 0; | |
1250 | } | |
1251 | ||
1252 | static struct seq_operations tracer_seq_ops = { | |
4bf39a94 IM |
1253 | .start = s_start, |
1254 | .next = s_next, | |
1255 | .stop = s_stop, | |
1256 | .show = s_show, | |
bc0c38d1 SR |
1257 | }; |
1258 | ||
1259 | static struct trace_iterator notrace * | |
1260 | __tracing_open(struct inode *inode, struct file *file, int *ret) | |
1261 | { | |
1262 | struct trace_iterator *iter; | |
1263 | ||
60a11774 SR |
1264 | if (tracing_disabled) { |
1265 | *ret = -ENODEV; | |
1266 | return NULL; | |
1267 | } | |
1268 | ||
bc0c38d1 SR |
1269 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1270 | if (!iter) { | |
1271 | *ret = -ENOMEM; | |
1272 | goto out; | |
1273 | } | |
1274 | ||
1275 | mutex_lock(&trace_types_lock); | |
1276 | if (current_trace && current_trace->print_max) | |
1277 | iter->tr = &max_tr; | |
1278 | else | |
1279 | iter->tr = inode->i_private; | |
1280 | iter->trace = current_trace; | |
1281 | iter->pos = -1; | |
1282 | ||
1283 | /* TODO stop tracer */ | |
1284 | *ret = seq_open(file, &tracer_seq_ops); | |
1285 | if (!*ret) { | |
1286 | struct seq_file *m = file->private_data; | |
1287 | m->private = iter; | |
1288 | ||
1289 | /* stop the trace while dumping */ | |
1290 | if (iter->tr->ctrl) | |
1291 | tracer_enabled = 0; | |
1292 | ||
1293 | if (iter->trace && iter->trace->open) | |
1294 | iter->trace->open(iter); | |
1295 | } else { | |
1296 | kfree(iter); | |
1297 | iter = NULL; | |
1298 | } | |
1299 | mutex_unlock(&trace_types_lock); | |
1300 | ||
1301 | out: | |
1302 | return iter; | |
1303 | } | |
1304 | ||
1305 | int tracing_open_generic(struct inode *inode, struct file *filp) | |
1306 | { | |
60a11774 SR |
1307 | if (tracing_disabled) |
1308 | return -ENODEV; | |
1309 | ||
bc0c38d1 SR |
1310 | filp->private_data = inode->i_private; |
1311 | return 0; | |
1312 | } | |
1313 | ||
1314 | int tracing_release(struct inode *inode, struct file *file) | |
1315 | { | |
1316 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1317 | struct trace_iterator *iter = m->private; | |
1318 | ||
1319 | mutex_lock(&trace_types_lock); | |
1320 | if (iter->trace && iter->trace->close) | |
1321 | iter->trace->close(iter); | |
1322 | ||
1323 | /* reenable tracing if it was previously enabled */ | |
1324 | if (iter->tr->ctrl) | |
1325 | tracer_enabled = 1; | |
1326 | mutex_unlock(&trace_types_lock); | |
1327 | ||
1328 | seq_release(inode, file); | |
1329 | kfree(iter); | |
1330 | return 0; | |
1331 | } | |
1332 | ||
1333 | static int tracing_open(struct inode *inode, struct file *file) | |
1334 | { | |
1335 | int ret; | |
1336 | ||
1337 | __tracing_open(inode, file, &ret); | |
1338 | ||
1339 | return ret; | |
1340 | } | |
1341 | ||
1342 | static int tracing_lt_open(struct inode *inode, struct file *file) | |
1343 | { | |
1344 | struct trace_iterator *iter; | |
1345 | int ret; | |
1346 | ||
1347 | iter = __tracing_open(inode, file, &ret); | |
1348 | ||
1349 | if (!ret) | |
1350 | iter->iter_flags |= TRACE_FILE_LAT_FMT; | |
1351 | ||
1352 | return ret; | |
1353 | } | |
1354 | ||
1355 | ||
4e3c3333 | 1356 | static notrace void * |
bc0c38d1 SR |
1357 | t_next(struct seq_file *m, void *v, loff_t *pos) |
1358 | { | |
1359 | struct tracer *t = m->private; | |
1360 | ||
1361 | (*pos)++; | |
1362 | ||
1363 | if (t) | |
1364 | t = t->next; | |
1365 | ||
1366 | m->private = t; | |
1367 | ||
1368 | return t; | |
1369 | } | |
1370 | ||
1371 | static void *t_start(struct seq_file *m, loff_t *pos) | |
1372 | { | |
1373 | struct tracer *t = m->private; | |
1374 | loff_t l = 0; | |
1375 | ||
1376 | mutex_lock(&trace_types_lock); | |
1377 | for (; t && l < *pos; t = t_next(m, t, &l)) | |
1378 | ; | |
1379 | ||
1380 | return t; | |
1381 | } | |
1382 | ||
1383 | static void t_stop(struct seq_file *m, void *p) | |
1384 | { | |
1385 | mutex_unlock(&trace_types_lock); | |
1386 | } | |
1387 | ||
1388 | static int t_show(struct seq_file *m, void *v) | |
1389 | { | |
1390 | struct tracer *t = v; | |
1391 | ||
1392 | if (!t) | |
1393 | return 0; | |
1394 | ||
1395 | seq_printf(m, "%s", t->name); | |
1396 | if (t->next) | |
1397 | seq_putc(m, ' '); | |
1398 | else | |
1399 | seq_putc(m, '\n'); | |
1400 | ||
1401 | return 0; | |
1402 | } | |
1403 | ||
1404 | static struct seq_operations show_traces_seq_ops = { | |
4bf39a94 IM |
1405 | .start = t_start, |
1406 | .next = t_next, | |
1407 | .stop = t_stop, | |
1408 | .show = t_show, | |
bc0c38d1 SR |
1409 | }; |
1410 | ||
1411 | static int show_traces_open(struct inode *inode, struct file *file) | |
1412 | { | |
1413 | int ret; | |
1414 | ||
60a11774 SR |
1415 | if (tracing_disabled) |
1416 | return -ENODEV; | |
1417 | ||
bc0c38d1 SR |
1418 | ret = seq_open(file, &show_traces_seq_ops); |
1419 | if (!ret) { | |
1420 | struct seq_file *m = file->private_data; | |
1421 | m->private = trace_types; | |
1422 | } | |
1423 | ||
1424 | return ret; | |
1425 | } | |
1426 | ||
1427 | static struct file_operations tracing_fops = { | |
4bf39a94 IM |
1428 | .open = tracing_open, |
1429 | .read = seq_read, | |
1430 | .llseek = seq_lseek, | |
1431 | .release = tracing_release, | |
bc0c38d1 SR |
1432 | }; |
1433 | ||
1434 | static struct file_operations tracing_lt_fops = { | |
4bf39a94 IM |
1435 | .open = tracing_lt_open, |
1436 | .read = seq_read, | |
1437 | .llseek = seq_lseek, | |
1438 | .release = tracing_release, | |
bc0c38d1 SR |
1439 | }; |
1440 | ||
1441 | static struct file_operations show_traces_fops = { | |
1442 | .open = show_traces_open, | |
1443 | .read = seq_read, | |
1444 | .release = seq_release, | |
1445 | }; | |
1446 | ||
1447 | static ssize_t | |
1448 | tracing_iter_ctrl_read(struct file *filp, char __user *ubuf, | |
1449 | size_t cnt, loff_t *ppos) | |
1450 | { | |
1451 | char *buf; | |
1452 | int r = 0; | |
1453 | int len = 0; | |
1454 | int i; | |
1455 | ||
1456 | /* calulate max size */ | |
1457 | for (i = 0; trace_options[i]; i++) { | |
1458 | len += strlen(trace_options[i]); | |
1459 | len += 3; /* "no" and space */ | |
1460 | } | |
1461 | ||
1462 | /* +2 for \n and \0 */ | |
1463 | buf = kmalloc(len + 2, GFP_KERNEL); | |
1464 | if (!buf) | |
1465 | return -ENOMEM; | |
1466 | ||
1467 | for (i = 0; trace_options[i]; i++) { | |
1468 | if (trace_flags & (1 << i)) | |
1469 | r += sprintf(buf + r, "%s ", trace_options[i]); | |
1470 | else | |
1471 | r += sprintf(buf + r, "no%s ", trace_options[i]); | |
1472 | } | |
1473 | ||
1474 | r += sprintf(buf + r, "\n"); | |
1475 | WARN_ON(r >= len + 2); | |
1476 | ||
1477 | r = simple_read_from_buffer(ubuf, cnt, ppos, | |
1478 | buf, r); | |
1479 | ||
1480 | kfree(buf); | |
1481 | ||
1482 | return r; | |
1483 | } | |
1484 | ||
1485 | static ssize_t | |
1486 | tracing_iter_ctrl_write(struct file *filp, const char __user *ubuf, | |
1487 | size_t cnt, loff_t *ppos) | |
1488 | { | |
1489 | char buf[64]; | |
1490 | char *cmp = buf; | |
1491 | int neg = 0; | |
1492 | int i; | |
1493 | ||
1494 | if (cnt > 63) | |
1495 | cnt = 63; | |
1496 | ||
1497 | if (copy_from_user(&buf, ubuf, cnt)) | |
1498 | return -EFAULT; | |
1499 | ||
1500 | buf[cnt] = 0; | |
1501 | ||
1502 | if (strncmp(buf, "no", 2) == 0) { | |
1503 | neg = 1; | |
1504 | cmp += 2; | |
1505 | } | |
1506 | ||
1507 | for (i = 0; trace_options[i]; i++) { | |
1508 | int len = strlen(trace_options[i]); | |
1509 | ||
1510 | if (strncmp(cmp, trace_options[i], len) == 0) { | |
1511 | if (neg) | |
1512 | trace_flags &= ~(1 << i); | |
1513 | else | |
1514 | trace_flags |= (1 << i); | |
1515 | break; | |
1516 | } | |
1517 | } | |
1518 | ||
1519 | filp->f_pos += cnt; | |
1520 | ||
1521 | return cnt; | |
1522 | } | |
1523 | ||
1524 | static struct file_operations tracing_iter_fops = { | |
1525 | .open = tracing_open_generic, | |
1526 | .read = tracing_iter_ctrl_read, | |
1527 | .write = tracing_iter_ctrl_write, | |
1528 | }; | |
1529 | ||
7bd2f24c IM |
1530 | static const char readme_msg[] = |
1531 | "tracing mini-HOWTO:\n\n" | |
1532 | "# mkdir /debug\n" | |
1533 | "# mount -t debugfs nodev /debug\n\n" | |
1534 | "# cat /debug/tracing/available_tracers\n" | |
1535 | "wakeup preemptirqsoff preemptoff irqsoff ftrace sched_switch none\n\n" | |
1536 | "# cat /debug/tracing/current_tracer\n" | |
1537 | "none\n" | |
1538 | "# echo sched_switch > /debug/tracing/current_tracer\n" | |
1539 | "# cat /debug/tracing/current_tracer\n" | |
1540 | "sched_switch\n" | |
1541 | "# cat /debug/tracing/iter_ctrl\n" | |
1542 | "noprint-parent nosym-offset nosym-addr noverbose\n" | |
1543 | "# echo print-parent > /debug/tracing/iter_ctrl\n" | |
1544 | "# echo 1 > /debug/tracing/tracing_enabled\n" | |
1545 | "# cat /debug/tracing/trace > /tmp/trace.txt\n" | |
1546 | "echo 0 > /debug/tracing/tracing_enabled\n" | |
1547 | ; | |
1548 | ||
1549 | static ssize_t | |
1550 | tracing_readme_read(struct file *filp, char __user *ubuf, | |
1551 | size_t cnt, loff_t *ppos) | |
1552 | { | |
1553 | return simple_read_from_buffer(ubuf, cnt, ppos, | |
1554 | readme_msg, strlen(readme_msg)); | |
1555 | } | |
1556 | ||
1557 | static struct file_operations tracing_readme_fops = { | |
1558 | .open = tracing_open_generic, | |
1559 | .read = tracing_readme_read, | |
1560 | }; | |
1561 | ||
1562 | ||
bc0c38d1 SR |
1563 | static ssize_t |
1564 | tracing_ctrl_read(struct file *filp, char __user *ubuf, | |
1565 | size_t cnt, loff_t *ppos) | |
1566 | { | |
1567 | struct trace_array *tr = filp->private_data; | |
1568 | char buf[64]; | |
1569 | int r; | |
1570 | ||
1571 | r = sprintf(buf, "%ld\n", tr->ctrl); | |
4e3c3333 | 1572 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
bc0c38d1 SR |
1573 | } |
1574 | ||
1575 | static ssize_t | |
1576 | tracing_ctrl_write(struct file *filp, const char __user *ubuf, | |
1577 | size_t cnt, loff_t *ppos) | |
1578 | { | |
1579 | struct trace_array *tr = filp->private_data; | |
1580 | long val; | |
1581 | char buf[64]; | |
1582 | ||
1583 | if (cnt > 63) | |
1584 | cnt = 63; | |
1585 | ||
1586 | if (copy_from_user(&buf, ubuf, cnt)) | |
1587 | return -EFAULT; | |
1588 | ||
1589 | buf[cnt] = 0; | |
1590 | ||
1591 | val = simple_strtoul(buf, NULL, 10); | |
1592 | ||
1593 | val = !!val; | |
1594 | ||
1595 | mutex_lock(&trace_types_lock); | |
1596 | if (tr->ctrl ^ val) { | |
1597 | if (val) | |
1598 | tracer_enabled = 1; | |
1599 | else | |
1600 | tracer_enabled = 0; | |
1601 | ||
1602 | tr->ctrl = val; | |
1603 | ||
1604 | if (current_trace && current_trace->ctrl_update) | |
1605 | current_trace->ctrl_update(tr); | |
1606 | } | |
1607 | mutex_unlock(&trace_types_lock); | |
1608 | ||
1609 | filp->f_pos += cnt; | |
1610 | ||
1611 | return cnt; | |
1612 | } | |
1613 | ||
1614 | static ssize_t | |
1615 | tracing_set_trace_read(struct file *filp, char __user *ubuf, | |
1616 | size_t cnt, loff_t *ppos) | |
1617 | { | |
1618 | char buf[max_tracer_type_len+2]; | |
1619 | int r; | |
1620 | ||
1621 | mutex_lock(&trace_types_lock); | |
1622 | if (current_trace) | |
1623 | r = sprintf(buf, "%s\n", current_trace->name); | |
1624 | else | |
1625 | r = sprintf(buf, "\n"); | |
1626 | mutex_unlock(&trace_types_lock); | |
1627 | ||
4bf39a94 | 1628 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
bc0c38d1 SR |
1629 | } |
1630 | ||
1631 | static ssize_t | |
1632 | tracing_set_trace_write(struct file *filp, const char __user *ubuf, | |
1633 | size_t cnt, loff_t *ppos) | |
1634 | { | |
1635 | struct trace_array *tr = &global_trace; | |
1636 | struct tracer *t; | |
1637 | char buf[max_tracer_type_len+1]; | |
1638 | int i; | |
1639 | ||
1640 | if (cnt > max_tracer_type_len) | |
1641 | cnt = max_tracer_type_len; | |
1642 | ||
1643 | if (copy_from_user(&buf, ubuf, cnt)) | |
1644 | return -EFAULT; | |
1645 | ||
1646 | buf[cnt] = 0; | |
1647 | ||
1648 | /* strip ending whitespace. */ | |
1649 | for (i = cnt - 1; i > 0 && isspace(buf[i]); i--) | |
1650 | buf[i] = 0; | |
1651 | ||
1652 | mutex_lock(&trace_types_lock); | |
1653 | for (t = trace_types; t; t = t->next) { | |
1654 | if (strcmp(t->name, buf) == 0) | |
1655 | break; | |
1656 | } | |
1657 | if (!t || t == current_trace) | |
1658 | goto out; | |
1659 | ||
1660 | if (current_trace && current_trace->reset) | |
1661 | current_trace->reset(tr); | |
1662 | ||
1663 | current_trace = t; | |
1664 | if (t->init) | |
1665 | t->init(tr); | |
1666 | ||
1667 | out: | |
1668 | mutex_unlock(&trace_types_lock); | |
1669 | ||
1670 | filp->f_pos += cnt; | |
1671 | ||
1672 | return cnt; | |
1673 | } | |
1674 | ||
1675 | static ssize_t | |
1676 | tracing_max_lat_read(struct file *filp, char __user *ubuf, | |
1677 | size_t cnt, loff_t *ppos) | |
1678 | { | |
1679 | unsigned long *ptr = filp->private_data; | |
1680 | char buf[64]; | |
1681 | int r; | |
1682 | ||
1683 | r = snprintf(buf, 64, "%ld\n", | |
1684 | *ptr == (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr)); | |
1685 | if (r > 64) | |
1686 | r = 64; | |
4bf39a94 | 1687 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
bc0c38d1 SR |
1688 | } |
1689 | ||
1690 | static ssize_t | |
1691 | tracing_max_lat_write(struct file *filp, const char __user *ubuf, | |
1692 | size_t cnt, loff_t *ppos) | |
1693 | { | |
1694 | long *ptr = filp->private_data; | |
1695 | long val; | |
1696 | char buf[64]; | |
1697 | ||
1698 | if (cnt > 63) | |
1699 | cnt = 63; | |
1700 | ||
1701 | if (copy_from_user(&buf, ubuf, cnt)) | |
1702 | return -EFAULT; | |
1703 | ||
1704 | buf[cnt] = 0; | |
1705 | ||
1706 | val = simple_strtoul(buf, NULL, 10); | |
1707 | ||
1708 | *ptr = val * 1000; | |
1709 | ||
1710 | return cnt; | |
1711 | } | |
1712 | ||
b3806b43 SR |
1713 | static atomic_t tracing_reader; |
1714 | ||
1715 | static int tracing_open_pipe(struct inode *inode, struct file *filp) | |
1716 | { | |
1717 | struct trace_iterator *iter; | |
1718 | ||
1719 | if (tracing_disabled) | |
1720 | return -ENODEV; | |
1721 | ||
1722 | /* We only allow for reader of the pipe */ | |
1723 | if (atomic_inc_return(&tracing_reader) != 1) { | |
1724 | atomic_dec(&tracing_reader); | |
1725 | return -EBUSY; | |
1726 | } | |
1727 | ||
1728 | /* create a buffer to store the information to pass to userspace */ | |
1729 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); | |
1730 | if (!iter) | |
1731 | return -ENOMEM; | |
1732 | ||
1733 | iter->tr = &global_trace; | |
1734 | ||
1735 | filp->private_data = iter; | |
1736 | ||
1737 | return 0; | |
1738 | } | |
1739 | ||
1740 | static int tracing_release_pipe(struct inode *inode, struct file *file) | |
1741 | { | |
1742 | struct trace_iterator *iter = file->private_data; | |
1743 | ||
1744 | kfree(iter); | |
1745 | atomic_dec(&tracing_reader); | |
1746 | ||
1747 | return 0; | |
1748 | } | |
1749 | ||
1750 | /* | |
1751 | * Consumer reader. | |
1752 | */ | |
1753 | static ssize_t | |
1754 | tracing_read_pipe(struct file *filp, char __user *ubuf, | |
1755 | size_t cnt, loff_t *ppos) | |
1756 | { | |
1757 | struct trace_iterator *iter = filp->private_data; | |
1758 | struct trace_array_cpu *data; | |
1759 | static cpumask_t mask; | |
1760 | struct trace_entry *entry; | |
1761 | static int start; | |
1762 | unsigned long flags; | |
1763 | int read = 0; | |
1764 | int cpu; | |
1765 | int len; | |
1766 | int ret; | |
1767 | ||
1768 | /* return any leftover data */ | |
1769 | if (iter->seq.len > start) { | |
1770 | len = iter->seq.len - start; | |
1771 | if (cnt > len) | |
1772 | cnt = len; | |
1773 | ret = copy_to_user(ubuf, iter->seq.buffer + start, cnt); | |
1774 | if (ret) | |
1775 | cnt = -EFAULT; | |
1776 | ||
1777 | start += len; | |
1778 | ||
1779 | return cnt; | |
1780 | } | |
1781 | ||
1782 | trace_seq_reset(&iter->seq); | |
1783 | start = 0; | |
1784 | ||
1785 | while (trace_empty(iter)) { | |
1786 | /* | |
1787 | * This is a make-shift waitqueue. The reason we don't use | |
1788 | * an actual wait queue is because: | |
1789 | * 1) we only ever have one waiter | |
1790 | * 2) the tracing, traces all functions, we don't want | |
1791 | * the overhead of calling wake_up and friends | |
1792 | * (and tracing them too) | |
1793 | * Anyway, this is really very primitive wakeup. | |
1794 | */ | |
1795 | set_current_state(TASK_INTERRUPTIBLE); | |
1796 | iter->tr->waiter = current; | |
1797 | ||
1798 | /* sleep for one second, and try again. */ | |
1799 | schedule_timeout(HZ); | |
1800 | ||
1801 | iter->tr->waiter = NULL; | |
1802 | ||
1803 | if (signal_pending(current)) | |
1804 | return -EINTR; | |
1805 | ||
1806 | /* | |
1807 | * We block until we read something and tracing is disabled. | |
1808 | * We still block if tracing is disabled, but we have never | |
1809 | * read anything. This allows a user to cat this file, and | |
1810 | * then enable tracing. But after we have read something, | |
1811 | * we give an EOF when tracing is again disabled. | |
1812 | * | |
1813 | * iter->pos will be 0 if we haven't read anything. | |
1814 | */ | |
1815 | if (!tracer_enabled && iter->pos) | |
1816 | break; | |
1817 | ||
1818 | continue; | |
1819 | } | |
1820 | ||
1821 | /* stop when tracing is finished */ | |
1822 | if (trace_empty(iter)) | |
1823 | return 0; | |
1824 | ||
1825 | if (cnt >= PAGE_SIZE) | |
1826 | cnt = PAGE_SIZE - 1; | |
1827 | ||
1828 | memset(iter, 0, sizeof(*iter)); | |
1829 | iter->tr = &global_trace; | |
1830 | iter->pos = -1; | |
1831 | ||
1832 | /* | |
1833 | * We need to stop all tracing on all CPUS to read the | |
1834 | * the next buffer. This is a bit expensive, but is | |
1835 | * not done often. We fill all what we can read, | |
1836 | * and then release the locks again. | |
1837 | */ | |
1838 | ||
1839 | cpus_clear(mask); | |
1840 | local_irq_save(flags); | |
1841 | for_each_possible_cpu(cpu) { | |
1842 | data = iter->tr->data[cpu]; | |
1843 | ||
1844 | if (!head_page(data) || !data->trace_idx) | |
1845 | continue; | |
1846 | ||
1847 | atomic_inc(&data->disabled); | |
1848 | spin_lock(&data->lock); | |
1849 | cpu_set(cpu, mask); | |
1850 | } | |
1851 | ||
1852 | while ((entry = find_next_entry(iter, &cpu))) { | |
1853 | ||
1854 | if (!entry) | |
1855 | break; | |
1856 | ||
1857 | iter->ent = entry; | |
1858 | iter->cpu = cpu; | |
1859 | ||
1860 | ret = print_trace_fmt(iter); | |
1861 | if (!ret) | |
1862 | break; | |
1863 | ||
1864 | trace_consume(iter); | |
1865 | ||
1866 | if (iter->seq.len >= cnt) | |
1867 | break; | |
1868 | ||
1869 | } | |
1870 | ||
d4c5a2f5 | 1871 | for_each_cpu_mask(cpu, mask) { |
b3806b43 | 1872 | data = iter->tr->data[cpu]; |
b3806b43 SR |
1873 | spin_unlock(&data->lock); |
1874 | atomic_dec(&data->disabled); | |
1875 | } | |
1876 | local_irq_restore(flags); | |
1877 | ||
1878 | /* Now copy what we have to the user */ | |
1879 | read = iter->seq.len; | |
1880 | if (read > cnt) | |
1881 | read = cnt; | |
1882 | ||
1883 | ret = copy_to_user(ubuf, iter->seq.buffer, read); | |
1884 | ||
1885 | if (read < iter->seq.len) | |
1886 | start = read; | |
1887 | else | |
1888 | trace_seq_reset(&iter->seq); | |
1889 | ||
1890 | if (ret) | |
1891 | read = -EFAULT; | |
1892 | ||
1893 | return read; | |
1894 | } | |
1895 | ||
bc0c38d1 | 1896 | static struct file_operations tracing_max_lat_fops = { |
4bf39a94 IM |
1897 | .open = tracing_open_generic, |
1898 | .read = tracing_max_lat_read, | |
1899 | .write = tracing_max_lat_write, | |
bc0c38d1 SR |
1900 | }; |
1901 | ||
1902 | static struct file_operations tracing_ctrl_fops = { | |
4bf39a94 IM |
1903 | .open = tracing_open_generic, |
1904 | .read = tracing_ctrl_read, | |
1905 | .write = tracing_ctrl_write, | |
bc0c38d1 SR |
1906 | }; |
1907 | ||
1908 | static struct file_operations set_tracer_fops = { | |
4bf39a94 IM |
1909 | .open = tracing_open_generic, |
1910 | .read = tracing_set_trace_read, | |
1911 | .write = tracing_set_trace_write, | |
bc0c38d1 SR |
1912 | }; |
1913 | ||
b3806b43 | 1914 | static struct file_operations tracing_pipe_fops = { |
4bf39a94 IM |
1915 | .open = tracing_open_pipe, |
1916 | .read = tracing_read_pipe, | |
1917 | .release = tracing_release_pipe, | |
b3806b43 SR |
1918 | }; |
1919 | ||
bc0c38d1 SR |
1920 | #ifdef CONFIG_DYNAMIC_FTRACE |
1921 | ||
1922 | static ssize_t | |
1923 | tracing_read_long(struct file *filp, char __user *ubuf, | |
1924 | size_t cnt, loff_t *ppos) | |
1925 | { | |
1926 | unsigned long *p = filp->private_data; | |
1927 | char buf[64]; | |
1928 | int r; | |
1929 | ||
1930 | r = sprintf(buf, "%ld\n", *p); | |
4bf39a94 IM |
1931 | |
1932 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
bc0c38d1 SR |
1933 | } |
1934 | ||
1935 | static struct file_operations tracing_read_long_fops = { | |
4bf39a94 IM |
1936 | .open = tracing_open_generic, |
1937 | .read = tracing_read_long, | |
bc0c38d1 SR |
1938 | }; |
1939 | #endif | |
1940 | ||
1941 | static struct dentry *d_tracer; | |
1942 | ||
1943 | struct dentry *tracing_init_dentry(void) | |
1944 | { | |
1945 | static int once; | |
1946 | ||
1947 | if (d_tracer) | |
1948 | return d_tracer; | |
1949 | ||
1950 | d_tracer = debugfs_create_dir("tracing", NULL); | |
1951 | ||
1952 | if (!d_tracer && !once) { | |
1953 | once = 1; | |
1954 | pr_warning("Could not create debugfs directory 'tracing'\n"); | |
1955 | return NULL; | |
1956 | } | |
1957 | ||
1958 | return d_tracer; | |
1959 | } | |
1960 | ||
60a11774 SR |
1961 | #ifdef CONFIG_FTRACE_SELFTEST |
1962 | /* Let selftest have access to static functions in this file */ | |
1963 | #include "trace_selftest.c" | |
1964 | #endif | |
1965 | ||
bc0c38d1 SR |
1966 | static __init void tracer_init_debugfs(void) |
1967 | { | |
1968 | struct dentry *d_tracer; | |
1969 | struct dentry *entry; | |
1970 | ||
1971 | d_tracer = tracing_init_dentry(); | |
1972 | ||
1973 | entry = debugfs_create_file("tracing_enabled", 0644, d_tracer, | |
1974 | &global_trace, &tracing_ctrl_fops); | |
1975 | if (!entry) | |
1976 | pr_warning("Could not create debugfs 'tracing_enabled' entry\n"); | |
1977 | ||
1978 | entry = debugfs_create_file("iter_ctrl", 0644, d_tracer, | |
1979 | NULL, &tracing_iter_fops); | |
1980 | if (!entry) | |
1981 | pr_warning("Could not create debugfs 'iter_ctrl' entry\n"); | |
1982 | ||
1983 | entry = debugfs_create_file("latency_trace", 0444, d_tracer, | |
1984 | &global_trace, &tracing_lt_fops); | |
1985 | if (!entry) | |
1986 | pr_warning("Could not create debugfs 'latency_trace' entry\n"); | |
1987 | ||
1988 | entry = debugfs_create_file("trace", 0444, d_tracer, | |
1989 | &global_trace, &tracing_fops); | |
1990 | if (!entry) | |
1991 | pr_warning("Could not create debugfs 'trace' entry\n"); | |
1992 | ||
1993 | entry = debugfs_create_file("available_tracers", 0444, d_tracer, | |
1994 | &global_trace, &show_traces_fops); | |
1995 | if (!entry) | |
1996 | pr_warning("Could not create debugfs 'trace' entry\n"); | |
1997 | ||
1998 | entry = debugfs_create_file("current_tracer", 0444, d_tracer, | |
1999 | &global_trace, &set_tracer_fops); | |
2000 | if (!entry) | |
2001 | pr_warning("Could not create debugfs 'trace' entry\n"); | |
2002 | ||
2003 | entry = debugfs_create_file("tracing_max_latency", 0644, d_tracer, | |
2004 | &tracing_max_latency, | |
2005 | &tracing_max_lat_fops); | |
2006 | if (!entry) | |
2007 | pr_warning("Could not create debugfs " | |
2008 | "'tracing_max_latency' entry\n"); | |
2009 | ||
2010 | entry = debugfs_create_file("tracing_thresh", 0644, d_tracer, | |
2011 | &tracing_thresh, &tracing_max_lat_fops); | |
2012 | if (!entry) | |
2013 | pr_warning("Could not create debugfs " | |
2014 | "'tracing_threash' entry\n"); | |
7bd2f24c IM |
2015 | entry = debugfs_create_file("README", 0644, d_tracer, |
2016 | NULL, &tracing_readme_fops); | |
2017 | if (!entry) | |
2018 | pr_warning("Could not create debugfs 'README' entry\n"); | |
2019 | ||
b3806b43 SR |
2020 | entry = debugfs_create_file("trace_pipe", 0644, d_tracer, |
2021 | NULL, &tracing_pipe_fops); | |
2022 | if (!entry) | |
2023 | pr_warning("Could not create debugfs " | |
2024 | "'tracing_threash' entry\n"); | |
bc0c38d1 SR |
2025 | |
2026 | #ifdef CONFIG_DYNAMIC_FTRACE | |
2027 | entry = debugfs_create_file("dyn_ftrace_total_info", 0444, d_tracer, | |
2028 | &ftrace_update_tot_cnt, | |
2029 | &tracing_read_long_fops); | |
2030 | if (!entry) | |
2031 | pr_warning("Could not create debugfs " | |
2032 | "'dyn_ftrace_total_info' entry\n"); | |
2033 | #endif | |
2034 | } | |
2035 | ||
2036 | /* dummy trace to disable tracing */ | |
2037 | static struct tracer no_tracer __read_mostly = | |
2038 | { | |
4bf39a94 | 2039 | .name = "none", |
bc0c38d1 SR |
2040 | }; |
2041 | ||
4c11d7ae | 2042 | static int trace_alloc_page(void) |
bc0c38d1 | 2043 | { |
4c11d7ae | 2044 | struct trace_array_cpu *data; |
4c11d7ae SR |
2045 | struct page *page, *tmp; |
2046 | LIST_HEAD(pages); | |
c7aafc54 | 2047 | void *array; |
4c11d7ae SR |
2048 | int i; |
2049 | ||
2050 | /* first allocate a page for each CPU */ | |
2051 | for_each_possible_cpu(i) { | |
2052 | array = (void *)__get_free_page(GFP_KERNEL); | |
2053 | if (array == NULL) { | |
2054 | printk(KERN_ERR "tracer: failed to allocate page" | |
2055 | "for trace buffer!\n"); | |
2056 | goto free_pages; | |
2057 | } | |
2058 | ||
2059 | page = virt_to_page(array); | |
2060 | list_add(&page->lru, &pages); | |
2061 | ||
2062 | /* Only allocate if we are actually using the max trace */ | |
2063 | #ifdef CONFIG_TRACER_MAX_TRACE | |
2064 | array = (void *)__get_free_page(GFP_KERNEL); | |
2065 | if (array == NULL) { | |
2066 | printk(KERN_ERR "tracer: failed to allocate page" | |
2067 | "for trace buffer!\n"); | |
2068 | goto free_pages; | |
2069 | } | |
2070 | page = virt_to_page(array); | |
2071 | list_add(&page->lru, &pages); | |
2072 | #endif | |
2073 | } | |
2074 | ||
2075 | /* Now that we successfully allocate a page per CPU, add them */ | |
2076 | for_each_possible_cpu(i) { | |
2077 | data = global_trace.data[i]; | |
b3806b43 | 2078 | spin_lock_init(&data->lock); |
d4c5a2f5 | 2079 | lockdep_set_class(&data->lock, &data->lock_key); |
4c11d7ae | 2080 | page = list_entry(pages.next, struct page, lru); |
c7aafc54 | 2081 | list_del_init(&page->lru); |
4c11d7ae SR |
2082 | list_add_tail(&page->lru, &data->trace_pages); |
2083 | ClearPageLRU(page); | |
2084 | ||
2085 | #ifdef CONFIG_TRACER_MAX_TRACE | |
2086 | data = max_tr.data[i]; | |
b3806b43 | 2087 | spin_lock_init(&data->lock); |
d4c5a2f5 | 2088 | lockdep_set_class(&data->lock, &data->lock_key); |
4c11d7ae | 2089 | page = list_entry(pages.next, struct page, lru); |
c7aafc54 | 2090 | list_del_init(&page->lru); |
4c11d7ae SR |
2091 | list_add_tail(&page->lru, &data->trace_pages); |
2092 | SetPageLRU(page); | |
2093 | #endif | |
2094 | } | |
2095 | global_trace.entries += ENTRIES_PER_PAGE; | |
2096 | ||
2097 | return 0; | |
2098 | ||
2099 | free_pages: | |
2100 | list_for_each_entry_safe(page, tmp, &pages, lru) { | |
c7aafc54 | 2101 | list_del_init(&page->lru); |
4c11d7ae SR |
2102 | __free_page(page); |
2103 | } | |
2104 | return -ENOMEM; | |
bc0c38d1 SR |
2105 | } |
2106 | ||
2107 | __init static int tracer_alloc_buffers(void) | |
2108 | { | |
4c11d7ae SR |
2109 | struct trace_array_cpu *data; |
2110 | void *array; | |
2111 | struct page *page; | |
2112 | int pages = 0; | |
60a11774 | 2113 | int ret = -ENOMEM; |
bc0c38d1 SR |
2114 | int i; |
2115 | ||
4c11d7ae | 2116 | /* Allocate the first page for all buffers */ |
bc0c38d1 | 2117 | for_each_possible_cpu(i) { |
4c11d7ae | 2118 | data = global_trace.data[i] = &per_cpu(global_trace_cpu, i); |
bc0c38d1 SR |
2119 | max_tr.data[i] = &per_cpu(max_data, i); |
2120 | ||
4c11d7ae | 2121 | array = (void *)__get_free_page(GFP_KERNEL); |
bc0c38d1 | 2122 | if (array == NULL) { |
4c11d7ae SR |
2123 | printk(KERN_ERR "tracer: failed to allocate page" |
2124 | "for trace buffer!\n"); | |
bc0c38d1 SR |
2125 | goto free_buffers; |
2126 | } | |
4c11d7ae SR |
2127 | |
2128 | /* set the array to the list */ | |
2129 | INIT_LIST_HEAD(&data->trace_pages); | |
2130 | page = virt_to_page(array); | |
2131 | list_add(&page->lru, &data->trace_pages); | |
2132 | /* use the LRU flag to differentiate the two buffers */ | |
2133 | ClearPageLRU(page); | |
bc0c38d1 SR |
2134 | |
2135 | /* Only allocate if we are actually using the max trace */ | |
2136 | #ifdef CONFIG_TRACER_MAX_TRACE | |
4c11d7ae | 2137 | array = (void *)__get_free_page(GFP_KERNEL); |
bc0c38d1 | 2138 | if (array == NULL) { |
4c11d7ae SR |
2139 | printk(KERN_ERR "tracer: failed to allocate page" |
2140 | "for trace buffer!\n"); | |
bc0c38d1 SR |
2141 | goto free_buffers; |
2142 | } | |
4c11d7ae SR |
2143 | |
2144 | INIT_LIST_HEAD(&max_tr.data[i]->trace_pages); | |
2145 | page = virt_to_page(array); | |
2146 | list_add(&page->lru, &max_tr.data[i]->trace_pages); | |
2147 | SetPageLRU(page); | |
bc0c38d1 SR |
2148 | #endif |
2149 | } | |
2150 | ||
2151 | /* | |
2152 | * Since we allocate by orders of pages, we may be able to | |
2153 | * round up a bit. | |
2154 | */ | |
4c11d7ae | 2155 | global_trace.entries = ENTRIES_PER_PAGE; |
4c11d7ae SR |
2156 | pages++; |
2157 | ||
2158 | while (global_trace.entries < trace_nr_entries) { | |
2159 | if (trace_alloc_page()) | |
2160 | break; | |
2161 | pages++; | |
2162 | } | |
89b2f978 | 2163 | max_tr.entries = global_trace.entries; |
bc0c38d1 | 2164 | |
4c11d7ae SR |
2165 | pr_info("tracer: %d pages allocated for %ld", |
2166 | pages, trace_nr_entries); | |
bc0c38d1 SR |
2167 | pr_info(" entries of %ld bytes\n", (long)TRACE_ENTRY_SIZE); |
2168 | pr_info(" actual entries %ld\n", global_trace.entries); | |
2169 | ||
2170 | tracer_init_debugfs(); | |
2171 | ||
2172 | trace_init_cmdlines(); | |
2173 | ||
2174 | register_tracer(&no_tracer); | |
2175 | current_trace = &no_tracer; | |
2176 | ||
60a11774 SR |
2177 | /* All seems OK, enable tracing */ |
2178 | tracing_disabled = 0; | |
2179 | ||
bc0c38d1 SR |
2180 | return 0; |
2181 | ||
2182 | free_buffers: | |
2183 | for (i-- ; i >= 0; i--) { | |
4c11d7ae | 2184 | struct page *page, *tmp; |
bc0c38d1 SR |
2185 | struct trace_array_cpu *data = global_trace.data[i]; |
2186 | ||
c7aafc54 | 2187 | if (data) { |
4c11d7ae SR |
2188 | list_for_each_entry_safe(page, tmp, |
2189 | &data->trace_pages, lru) { | |
c7aafc54 | 2190 | list_del_init(&page->lru); |
4c11d7ae SR |
2191 | __free_page(page); |
2192 | } | |
bc0c38d1 SR |
2193 | } |
2194 | ||
2195 | #ifdef CONFIG_TRACER_MAX_TRACE | |
2196 | data = max_tr.data[i]; | |
c7aafc54 | 2197 | if (data) { |
4c11d7ae SR |
2198 | list_for_each_entry_safe(page, tmp, |
2199 | &data->trace_pages, lru) { | |
c7aafc54 | 2200 | list_del_init(&page->lru); |
4c11d7ae SR |
2201 | __free_page(page); |
2202 | } | |
bc0c38d1 SR |
2203 | } |
2204 | #endif | |
2205 | } | |
60a11774 | 2206 | return ret; |
bc0c38d1 | 2207 | } |
60a11774 | 2208 | fs_initcall(tracer_alloc_buffers); |