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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 | ||
35 | static long notrace | |
36 | ns2usecs(cycle_t nsec) | |
37 | { | |
38 | nsec += 500; | |
39 | do_div(nsec, 1000); | |
40 | return nsec; | |
41 | } | |
42 | ||
43 | static atomic_t tracer_counter; | |
44 | static struct trace_array global_trace; | |
45 | ||
46 | static DEFINE_PER_CPU(struct trace_array_cpu, global_trace_cpu); | |
47 | ||
48 | static struct trace_array max_tr; | |
49 | ||
50 | static DEFINE_PER_CPU(struct trace_array_cpu, max_data); | |
51 | ||
52 | static int tracer_enabled; | |
4c11d7ae | 53 | static unsigned long trace_nr_entries = 16384UL; |
bc0c38d1 SR |
54 | |
55 | static struct tracer *trace_types __read_mostly; | |
56 | static struct tracer *current_trace __read_mostly; | |
57 | static int max_tracer_type_len; | |
58 | ||
59 | static DEFINE_MUTEX(trace_types_lock); | |
60 | ||
4c11d7ae SR |
61 | #define ENTRIES_PER_PAGE (PAGE_SIZE / sizeof(struct trace_entry)) |
62 | ||
bc0c38d1 SR |
63 | static int __init set_nr_entries(char *str) |
64 | { | |
65 | if (!str) | |
66 | return 0; | |
67 | trace_nr_entries = simple_strtoul(str, &str, 0); | |
68 | return 1; | |
69 | } | |
70 | __setup("trace_entries=", set_nr_entries); | |
71 | ||
57f50be1 SR |
72 | unsigned long nsecs_to_usecs(unsigned long nsecs) |
73 | { | |
74 | return nsecs / 1000; | |
75 | } | |
76 | ||
bc0c38d1 SR |
77 | enum trace_type { |
78 | __TRACE_FIRST_TYPE = 0, | |
79 | ||
80 | TRACE_FN, | |
81 | TRACE_CTX, | |
82 | ||
83 | __TRACE_LAST_TYPE | |
84 | }; | |
85 | ||
86 | enum trace_flag_type { | |
87 | TRACE_FLAG_IRQS_OFF = 0x01, | |
88 | TRACE_FLAG_NEED_RESCHED = 0x02, | |
89 | TRACE_FLAG_HARDIRQ = 0x04, | |
90 | TRACE_FLAG_SOFTIRQ = 0x08, | |
91 | }; | |
92 | ||
93 | enum trace_iterator_flags { | |
94 | TRACE_ITER_PRINT_PARENT = 0x01, | |
95 | TRACE_ITER_SYM_OFFSET = 0x02, | |
96 | TRACE_ITER_SYM_ADDR = 0x04, | |
97 | TRACE_ITER_VERBOSE = 0x08, | |
98 | }; | |
99 | ||
100 | #define TRACE_ITER_SYM_MASK \ | |
101 | (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR) | |
102 | ||
103 | /* These must match the bit postions above */ | |
104 | static const char *trace_options[] = { | |
105 | "print-parent", | |
106 | "sym-offset", | |
107 | "sym-addr", | |
108 | "verbose", | |
109 | NULL | |
110 | }; | |
111 | ||
112 | static unsigned trace_flags; | |
113 | ||
4c11d7ae | 114 | static DEFINE_SPINLOCK(ftrace_max_lock); |
bc0c38d1 SR |
115 | |
116 | /* | |
117 | * Copy the new maximum trace into the separate maximum-trace | |
118 | * structure. (this way the maximum trace is permanently saved, | |
119 | * for later retrieval via /debugfs/tracing/latency_trace) | |
120 | */ | |
121 | static void notrace | |
122 | __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) | |
123 | { | |
124 | struct trace_array_cpu *data = tr->data[cpu]; | |
125 | ||
126 | max_tr.cpu = cpu; | |
127 | max_tr.time_start = data->preempt_timestamp; | |
128 | ||
129 | data = max_tr.data[cpu]; | |
130 | data->saved_latency = tracing_max_latency; | |
131 | ||
132 | memcpy(data->comm, tsk->comm, TASK_COMM_LEN); | |
133 | data->pid = tsk->pid; | |
134 | data->uid = tsk->uid; | |
135 | data->nice = tsk->static_prio - 20 - MAX_RT_PRIO; | |
136 | data->policy = tsk->policy; | |
137 | data->rt_priority = tsk->rt_priority; | |
138 | ||
139 | /* record this tasks comm */ | |
140 | tracing_record_cmdline(current); | |
141 | } | |
142 | ||
143 | notrace void | |
144 | update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) | |
145 | { | |
146 | struct trace_array_cpu *data; | |
147 | void *save_trace; | |
4c11d7ae | 148 | struct list_head save_pages; |
bc0c38d1 SR |
149 | int i; |
150 | ||
4c11d7ae SR |
151 | WARN_ON_ONCE(!irqs_disabled()); |
152 | spin_lock(&ftrace_max_lock); | |
bc0c38d1 SR |
153 | /* clear out all the previous traces */ |
154 | for_each_possible_cpu(i) { | |
155 | data = tr->data[i]; | |
156 | save_trace = max_tr.data[i]->trace; | |
4c11d7ae | 157 | save_pages = max_tr.data[i]->trace_pages; |
bc0c38d1 SR |
158 | memcpy(max_tr.data[i], data, sizeof(*data)); |
159 | data->trace = save_trace; | |
4c11d7ae | 160 | data->trace_pages = save_pages; |
89b2f978 | 161 | tracing_reset(data); |
bc0c38d1 SR |
162 | } |
163 | ||
164 | __update_max_tr(tr, tsk, cpu); | |
4c11d7ae | 165 | spin_unlock(&ftrace_max_lock); |
bc0c38d1 SR |
166 | } |
167 | ||
168 | /** | |
169 | * update_max_tr_single - only copy one trace over, and reset the rest | |
170 | * @tr - tracer | |
171 | * @tsk - task with the latency | |
172 | * @cpu - the cpu of the buffer to copy. | |
173 | */ | |
174 | notrace void | |
175 | update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) | |
176 | { | |
177 | struct trace_array_cpu *data = tr->data[cpu]; | |
178 | void *save_trace; | |
4c11d7ae | 179 | struct list_head save_pages; |
bc0c38d1 SR |
180 | int i; |
181 | ||
4c11d7ae SR |
182 | WARN_ON_ONCE(!irqs_disabled()); |
183 | spin_lock(&ftrace_max_lock); | |
bc0c38d1 SR |
184 | for_each_possible_cpu(i) |
185 | tracing_reset(max_tr.data[i]); | |
186 | ||
187 | save_trace = max_tr.data[cpu]->trace; | |
4c11d7ae | 188 | save_pages = max_tr.data[cpu]->trace_pages; |
bc0c38d1 SR |
189 | memcpy(max_tr.data[cpu], data, sizeof(*data)); |
190 | data->trace = save_trace; | |
4c11d7ae | 191 | data->trace_pages = save_pages; |
89b2f978 | 192 | tracing_reset(data); |
bc0c38d1 SR |
193 | |
194 | __update_max_tr(tr, tsk, cpu); | |
4c11d7ae | 195 | spin_unlock(&ftrace_max_lock); |
bc0c38d1 SR |
196 | } |
197 | ||
198 | int register_tracer(struct tracer *type) | |
199 | { | |
200 | struct tracer *t; | |
201 | int len; | |
202 | int ret = 0; | |
203 | ||
204 | if (!type->name) { | |
205 | pr_info("Tracer must have a name\n"); | |
206 | return -1; | |
207 | } | |
208 | ||
209 | mutex_lock(&trace_types_lock); | |
210 | for (t = trace_types; t; t = t->next) { | |
211 | if (strcmp(type->name, t->name) == 0) { | |
212 | /* already found */ | |
213 | pr_info("Trace %s already registered\n", | |
214 | type->name); | |
215 | ret = -1; | |
216 | goto out; | |
217 | } | |
218 | } | |
219 | ||
220 | type->next = trace_types; | |
221 | trace_types = type; | |
222 | len = strlen(type->name); | |
223 | if (len > max_tracer_type_len) | |
224 | max_tracer_type_len = len; | |
225 | out: | |
226 | mutex_unlock(&trace_types_lock); | |
227 | ||
228 | return ret; | |
229 | } | |
230 | ||
231 | void unregister_tracer(struct tracer *type) | |
232 | { | |
233 | struct tracer **t; | |
234 | int len; | |
235 | ||
236 | mutex_lock(&trace_types_lock); | |
237 | for (t = &trace_types; *t; t = &(*t)->next) { | |
238 | if (*t == type) | |
239 | goto found; | |
240 | } | |
241 | pr_info("Trace %s not registered\n", type->name); | |
242 | goto out; | |
243 | ||
244 | found: | |
245 | *t = (*t)->next; | |
246 | if (strlen(type->name) != max_tracer_type_len) | |
247 | goto out; | |
248 | ||
249 | max_tracer_type_len = 0; | |
250 | for (t = &trace_types; *t; t = &(*t)->next) { | |
251 | len = strlen((*t)->name); | |
252 | if (len > max_tracer_type_len) | |
253 | max_tracer_type_len = len; | |
254 | } | |
255 | out: | |
256 | mutex_unlock(&trace_types_lock); | |
257 | } | |
258 | ||
259 | void notrace tracing_reset(struct trace_array_cpu *data) | |
260 | { | |
261 | data->trace_idx = 0; | |
4c11d7ae SR |
262 | data->trace_current = data->trace; |
263 | data->trace_current_idx = 0; | |
bc0c38d1 SR |
264 | } |
265 | ||
266 | #ifdef CONFIG_FTRACE | |
267 | static void notrace | |
268 | function_trace_call(unsigned long ip, unsigned long parent_ip) | |
269 | { | |
270 | struct trace_array *tr = &global_trace; | |
271 | struct trace_array_cpu *data; | |
272 | unsigned long flags; | |
273 | long disabled; | |
274 | int cpu; | |
275 | ||
276 | if (unlikely(!tracer_enabled)) | |
277 | return; | |
278 | ||
18cef379 | 279 | local_irq_save(flags); |
bc0c38d1 SR |
280 | cpu = raw_smp_processor_id(); |
281 | data = tr->data[cpu]; | |
282 | disabled = atomic_inc_return(&data->disabled); | |
283 | ||
284 | if (likely(disabled == 1)) | |
285 | ftrace(tr, data, ip, parent_ip, flags); | |
286 | ||
287 | atomic_dec(&data->disabled); | |
18cef379 | 288 | local_irq_restore(flags); |
bc0c38d1 SR |
289 | } |
290 | ||
291 | static struct ftrace_ops trace_ops __read_mostly = | |
292 | { | |
293 | .func = function_trace_call, | |
294 | }; | |
295 | #endif | |
296 | ||
297 | notrace void tracing_start_function_trace(void) | |
298 | { | |
299 | register_ftrace_function(&trace_ops); | |
300 | } | |
301 | ||
302 | notrace void tracing_stop_function_trace(void) | |
303 | { | |
304 | unregister_ftrace_function(&trace_ops); | |
305 | } | |
306 | ||
307 | #define SAVED_CMDLINES 128 | |
308 | static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1]; | |
309 | static unsigned map_cmdline_to_pid[SAVED_CMDLINES]; | |
310 | static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN]; | |
311 | static int cmdline_idx; | |
312 | static DEFINE_SPINLOCK(trace_cmdline_lock); | |
313 | atomic_t trace_record_cmdline_disabled; | |
314 | ||
315 | static void trace_init_cmdlines(void) | |
316 | { | |
317 | memset(&map_pid_to_cmdline, -1, sizeof(map_pid_to_cmdline)); | |
318 | memset(&map_cmdline_to_pid, -1, sizeof(map_cmdline_to_pid)); | |
319 | cmdline_idx = 0; | |
320 | } | |
321 | ||
322 | notrace void trace_stop_cmdline_recording(void); | |
323 | ||
324 | static void notrace trace_save_cmdline(struct task_struct *tsk) | |
325 | { | |
326 | unsigned map; | |
327 | unsigned idx; | |
328 | ||
329 | if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT)) | |
330 | return; | |
331 | ||
332 | /* | |
333 | * It's not the end of the world if we don't get | |
334 | * the lock, but we also don't want to spin | |
335 | * nor do we want to disable interrupts, | |
336 | * so if we miss here, then better luck next time. | |
337 | */ | |
338 | if (!spin_trylock(&trace_cmdline_lock)) | |
339 | return; | |
340 | ||
341 | idx = map_pid_to_cmdline[tsk->pid]; | |
342 | if (idx >= SAVED_CMDLINES) { | |
343 | idx = (cmdline_idx + 1) % SAVED_CMDLINES; | |
344 | ||
345 | map = map_cmdline_to_pid[idx]; | |
346 | if (map <= PID_MAX_DEFAULT) | |
347 | map_pid_to_cmdline[map] = (unsigned)-1; | |
348 | ||
349 | map_pid_to_cmdline[tsk->pid] = idx; | |
350 | ||
351 | cmdline_idx = idx; | |
352 | } | |
353 | ||
354 | memcpy(&saved_cmdlines[idx], tsk->comm, TASK_COMM_LEN); | |
355 | ||
356 | spin_unlock(&trace_cmdline_lock); | |
357 | } | |
358 | ||
359 | static notrace char *trace_find_cmdline(int pid) | |
360 | { | |
361 | char *cmdline = "<...>"; | |
362 | unsigned map; | |
363 | ||
364 | if (!pid) | |
365 | return "<idle>"; | |
366 | ||
367 | if (pid > PID_MAX_DEFAULT) | |
368 | goto out; | |
369 | ||
370 | map = map_pid_to_cmdline[pid]; | |
371 | if (map >= SAVED_CMDLINES) | |
372 | goto out; | |
373 | ||
374 | cmdline = saved_cmdlines[map]; | |
375 | ||
376 | out: | |
377 | return cmdline; | |
378 | } | |
379 | ||
380 | notrace void tracing_record_cmdline(struct task_struct *tsk) | |
381 | { | |
382 | if (atomic_read(&trace_record_cmdline_disabled)) | |
383 | return; | |
384 | ||
385 | trace_save_cmdline(tsk); | |
386 | } | |
387 | ||
388 | static inline notrace struct trace_entry * | |
389 | tracing_get_trace_entry(struct trace_array *tr, | |
390 | struct trace_array_cpu *data) | |
391 | { | |
392 | unsigned long idx, idx_next; | |
393 | struct trace_entry *entry; | |
4c11d7ae SR |
394 | struct page *page; |
395 | struct list_head *next; | |
bc0c38d1 | 396 | |
4c11d7ae SR |
397 | data->trace_idx++; |
398 | idx = data->trace_current_idx; | |
bc0c38d1 SR |
399 | idx_next = idx + 1; |
400 | ||
4c11d7ae SR |
401 | entry = data->trace_current + idx * TRACE_ENTRY_SIZE; |
402 | ||
403 | if (unlikely(idx_next >= ENTRIES_PER_PAGE)) { | |
404 | page = virt_to_page(data->trace_current); | |
405 | if (unlikely(&page->lru == data->trace_pages.prev)) | |
406 | next = data->trace_pages.next; | |
407 | else | |
408 | next = page->lru.next; | |
409 | page = list_entry(next, struct page, lru); | |
410 | data->trace_current = page_address(page); | |
bc0c38d1 SR |
411 | idx_next = 0; |
412 | } | |
413 | ||
4c11d7ae | 414 | data->trace_current_idx = idx_next; |
bc0c38d1 SR |
415 | |
416 | return entry; | |
417 | } | |
418 | ||
419 | static inline notrace void | |
420 | tracing_generic_entry_update(struct trace_entry *entry, | |
421 | unsigned long flags) | |
422 | { | |
423 | struct task_struct *tsk = current; | |
424 | unsigned long pc; | |
425 | ||
426 | pc = preempt_count(); | |
427 | ||
428 | entry->idx = atomic_inc_return(&tracer_counter); | |
429 | entry->preempt_count = pc & 0xff; | |
430 | entry->pid = tsk->pid; | |
431 | entry->t = now(raw_smp_processor_id()); | |
432 | entry->flags = (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) | | |
433 | ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) | | |
434 | ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) | | |
435 | (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0); | |
436 | } | |
437 | ||
438 | notrace void | |
439 | ftrace(struct trace_array *tr, struct trace_array_cpu *data, | |
440 | unsigned long ip, unsigned long parent_ip, | |
441 | unsigned long flags) | |
442 | { | |
443 | struct trace_entry *entry; | |
444 | ||
445 | entry = tracing_get_trace_entry(tr, data); | |
446 | tracing_generic_entry_update(entry, flags); | |
447 | entry->type = TRACE_FN; | |
448 | entry->fn.ip = ip; | |
449 | entry->fn.parent_ip = parent_ip; | |
450 | } | |
451 | ||
452 | notrace void | |
453 | tracing_sched_switch_trace(struct trace_array *tr, | |
454 | struct trace_array_cpu *data, | |
455 | struct task_struct *prev, struct task_struct *next, | |
456 | unsigned long flags) | |
457 | { | |
458 | struct trace_entry *entry; | |
459 | ||
460 | entry = tracing_get_trace_entry(tr, data); | |
461 | tracing_generic_entry_update(entry, flags); | |
462 | entry->type = TRACE_CTX; | |
463 | entry->ctx.prev_pid = prev->pid; | |
464 | entry->ctx.prev_prio = prev->prio; | |
465 | entry->ctx.prev_state = prev->state; | |
466 | entry->ctx.next_pid = next->pid; | |
467 | entry->ctx.next_prio = next->prio; | |
468 | } | |
469 | ||
470 | enum trace_file_type { | |
471 | TRACE_FILE_LAT_FMT = 1, | |
472 | }; | |
473 | ||
474 | static struct trace_entry * | |
4c11d7ae SR |
475 | trace_entry_idx(struct trace_array *tr, struct trace_array_cpu *data, |
476 | struct trace_iterator *iter, int cpu) | |
bc0c38d1 | 477 | { |
4c11d7ae SR |
478 | struct page *page; |
479 | struct trace_entry *array; | |
bc0c38d1 | 480 | |
4c11d7ae SR |
481 | if (iter->next_idx[cpu] >= tr->entries || |
482 | iter->next_idx[cpu] >= data->trace_idx) | |
bc0c38d1 SR |
483 | return NULL; |
484 | ||
4c11d7ae SR |
485 | if (!iter->next_page[cpu]) { |
486 | /* | |
487 | * Initialize. If the count of elements in | |
488 | * this buffer is greater than the max entries | |
489 | * we had an underrun. Which means we looped around. | |
490 | * We can simply use the current pointer as our | |
491 | * starting point. | |
492 | */ | |
493 | if (data->trace_idx >= tr->entries) { | |
494 | page = virt_to_page(data->trace_current); | |
495 | iter->next_page[cpu] = &page->lru; | |
496 | iter->next_page_idx[cpu] = data->trace_current_idx; | |
497 | } else { | |
498 | iter->next_page[cpu] = data->trace_pages.next; | |
499 | iter->next_page_idx[cpu] = 0; | |
500 | } | |
501 | } | |
bc0c38d1 | 502 | |
4c11d7ae SR |
503 | page = list_entry(iter->next_page[cpu], struct page, lru); |
504 | array = page_address(page); | |
505 | ||
506 | return &array[iter->next_page_idx[cpu]]; | |
bc0c38d1 SR |
507 | } |
508 | ||
509 | static struct notrace trace_entry * | |
510 | find_next_entry(struct trace_iterator *iter, int *ent_cpu) | |
511 | { | |
512 | struct trace_array *tr = iter->tr; | |
513 | struct trace_entry *ent, *next = NULL; | |
514 | int next_cpu = -1; | |
515 | int cpu; | |
516 | ||
517 | for_each_possible_cpu(cpu) { | |
518 | if (!tr->data[cpu]->trace) | |
519 | continue; | |
4c11d7ae | 520 | ent = trace_entry_idx(tr, tr->data[cpu], iter, cpu); |
bc0c38d1 SR |
521 | if (ent && |
522 | (!next || (long)(next->idx - ent->idx) > 0)) { | |
523 | next = ent; | |
524 | next_cpu = cpu; | |
525 | } | |
526 | } | |
527 | ||
528 | if (ent_cpu) | |
529 | *ent_cpu = next_cpu; | |
530 | ||
531 | return next; | |
532 | } | |
533 | ||
534 | static void *find_next_entry_inc(struct trace_iterator *iter) | |
535 | { | |
536 | struct trace_entry *next; | |
537 | int next_cpu = -1; | |
538 | ||
539 | next = find_next_entry(iter, &next_cpu); | |
540 | ||
541 | if (next) { | |
bc0c38d1 | 542 | iter->idx++; |
4c11d7ae SR |
543 | iter->next_idx[next_cpu]++; |
544 | iter->next_page_idx[next_cpu]++; | |
545 | if (iter->next_page_idx[next_cpu] >= ENTRIES_PER_PAGE) { | |
546 | struct trace_array_cpu *data = iter->tr->data[next_cpu]; | |
547 | ||
548 | iter->next_page_idx[next_cpu] = 0; | |
549 | iter->next_page[next_cpu] = | |
550 | iter->next_page[next_cpu]->next; | |
551 | if (iter->next_page[next_cpu] == &data->trace_pages) | |
552 | iter->next_page[next_cpu] = | |
553 | data->trace_pages.next; | |
554 | } | |
bc0c38d1 SR |
555 | } |
556 | iter->ent = next; | |
557 | iter->cpu = next_cpu; | |
558 | ||
559 | return next ? iter : NULL; | |
560 | } | |
561 | ||
562 | static void notrace * | |
563 | s_next(struct seq_file *m, void *v, loff_t *pos) | |
564 | { | |
565 | struct trace_iterator *iter = m->private; | |
566 | void *ent; | |
567 | void *last_ent = iter->ent; | |
568 | int i = (int)*pos; | |
569 | ||
570 | (*pos)++; | |
571 | ||
572 | /* can't go backwards */ | |
573 | if (iter->idx > i) | |
574 | return NULL; | |
575 | ||
576 | if (iter->idx < 0) | |
577 | ent = find_next_entry_inc(iter); | |
578 | else | |
579 | ent = iter; | |
580 | ||
581 | while (ent && iter->idx < i) | |
582 | ent = find_next_entry_inc(iter); | |
583 | ||
584 | iter->pos = *pos; | |
585 | ||
586 | if (last_ent && !ent) | |
587 | seq_puts(m, "\n\nvim:ft=help\n"); | |
588 | ||
589 | return ent; | |
590 | } | |
591 | ||
592 | static void *s_start(struct seq_file *m, loff_t *pos) | |
593 | { | |
594 | struct trace_iterator *iter = m->private; | |
595 | void *p = NULL; | |
596 | loff_t l = 0; | |
597 | int i; | |
598 | ||
599 | mutex_lock(&trace_types_lock); | |
600 | ||
601 | if (!current_trace || current_trace != iter->trace) | |
602 | return NULL; | |
603 | ||
604 | atomic_inc(&trace_record_cmdline_disabled); | |
605 | ||
606 | /* let the tracer grab locks here if needed */ | |
607 | if (current_trace->start) | |
608 | current_trace->start(iter); | |
609 | ||
610 | if (*pos != iter->pos) { | |
611 | iter->ent = NULL; | |
612 | iter->cpu = 0; | |
613 | iter->idx = -1; | |
614 | ||
4c11d7ae | 615 | for_each_possible_cpu(i) { |
bc0c38d1 | 616 | iter->next_idx[i] = 0; |
4c11d7ae SR |
617 | iter->next_page[i] = NULL; |
618 | } | |
bc0c38d1 SR |
619 | |
620 | for (p = iter; p && l < *pos; p = s_next(m, p, &l)) | |
621 | ; | |
622 | ||
623 | } else { | |
4c11d7ae | 624 | l = *pos - 1; |
bc0c38d1 SR |
625 | p = s_next(m, p, &l); |
626 | } | |
627 | ||
628 | return p; | |
629 | } | |
630 | ||
631 | static void s_stop(struct seq_file *m, void *p) | |
632 | { | |
633 | struct trace_iterator *iter = m->private; | |
634 | ||
635 | atomic_dec(&trace_record_cmdline_disabled); | |
636 | ||
637 | /* let the tracer release locks here if needed */ | |
638 | if (current_trace && current_trace == iter->trace && iter->trace->stop) | |
639 | iter->trace->stop(iter); | |
640 | ||
641 | mutex_unlock(&trace_types_lock); | |
642 | } | |
643 | ||
644 | static void | |
645 | seq_print_sym_short(struct seq_file *m, const char *fmt, unsigned long address) | |
646 | { | |
647 | #ifdef CONFIG_KALLSYMS | |
648 | char str[KSYM_SYMBOL_LEN]; | |
649 | ||
650 | kallsyms_lookup(address, NULL, NULL, NULL, str); | |
651 | ||
652 | seq_printf(m, fmt, str); | |
653 | #endif | |
654 | } | |
655 | ||
656 | static void | |
657 | seq_print_sym_offset(struct seq_file *m, const char *fmt, unsigned long address) | |
658 | { | |
659 | #ifdef CONFIG_KALLSYMS | |
660 | char str[KSYM_SYMBOL_LEN]; | |
661 | ||
662 | sprint_symbol(str, address); | |
663 | seq_printf(m, fmt, str); | |
664 | #endif | |
665 | } | |
666 | ||
667 | #ifndef CONFIG_64BIT | |
668 | # define IP_FMT "%08lx" | |
669 | #else | |
670 | # define IP_FMT "%016lx" | |
671 | #endif | |
672 | ||
673 | static void notrace | |
674 | seq_print_ip_sym(struct seq_file *m, unsigned long ip, unsigned long sym_flags) | |
675 | { | |
676 | if (!ip) { | |
677 | seq_printf(m, "0"); | |
678 | return; | |
679 | } | |
680 | ||
681 | if (sym_flags & TRACE_ITER_SYM_OFFSET) | |
682 | seq_print_sym_offset(m, "%s", ip); | |
683 | else | |
684 | seq_print_sym_short(m, "%s", ip); | |
685 | ||
686 | if (sym_flags & TRACE_ITER_SYM_ADDR) | |
687 | seq_printf(m, " <" IP_FMT ">", ip); | |
688 | } | |
689 | ||
690 | static void notrace print_lat_help_header(struct seq_file *m) | |
691 | { | |
692 | seq_puts(m, "# _------=> CPU# \n"); | |
693 | seq_puts(m, "# / _-----=> irqs-off \n"); | |
694 | seq_puts(m, "# | / _----=> need-resched \n"); | |
695 | seq_puts(m, "# || / _---=> hardirq/softirq \n"); | |
696 | seq_puts(m, "# ||| / _--=> preempt-depth \n"); | |
697 | seq_puts(m, "# |||| / \n"); | |
698 | seq_puts(m, "# ||||| delay \n"); | |
699 | seq_puts(m, "# cmd pid ||||| time | caller \n"); | |
700 | seq_puts(m, "# \\ / ||||| \\ | / \n"); | |
701 | } | |
702 | ||
703 | static void notrace print_func_help_header(struct seq_file *m) | |
704 | { | |
705 | seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n"); | |
706 | seq_puts(m, "# | | | | |\n"); | |
707 | } | |
708 | ||
709 | ||
710 | static void notrace | |
711 | print_trace_header(struct seq_file *m, struct trace_iterator *iter) | |
712 | { | |
713 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); | |
714 | struct trace_array *tr = iter->tr; | |
715 | struct trace_array_cpu *data = tr->data[tr->cpu]; | |
716 | struct tracer *type = current_trace; | |
4c11d7ae SR |
717 | unsigned long total = 0; |
718 | unsigned long entries = 0; | |
bc0c38d1 SR |
719 | int cpu; |
720 | const char *name = "preemption"; | |
721 | ||
722 | if (type) | |
723 | name = type->name; | |
724 | ||
725 | for_each_possible_cpu(cpu) { | |
726 | if (tr->data[cpu]->trace) { | |
4c11d7ae SR |
727 | total += tr->data[cpu]->trace_idx; |
728 | if (tr->data[cpu]->trace_idx > tr->entries) | |
bc0c38d1 | 729 | entries += tr->entries; |
4c11d7ae | 730 | else |
bc0c38d1 SR |
731 | entries += tr->data[cpu]->trace_idx; |
732 | } | |
733 | } | |
734 | ||
735 | seq_printf(m, "%s latency trace v1.1.5 on %s\n", | |
736 | name, UTS_RELEASE); | |
737 | seq_puts(m, "-----------------------------------" | |
738 | "---------------------------------\n"); | |
739 | seq_printf(m, " latency: %lu us, #%lu/%lu, CPU#%d |" | |
740 | " (M:%s VP:%d, KP:%d, SP:%d HP:%d", | |
57f50be1 | 741 | nsecs_to_usecs(data->saved_latency), |
bc0c38d1 | 742 | entries, |
4c11d7ae | 743 | total, |
bc0c38d1 SR |
744 | tr->cpu, |
745 | #if defined(CONFIG_PREEMPT_NONE) | |
746 | "server", | |
747 | #elif defined(CONFIG_PREEMPT_VOLUNTARY) | |
748 | "desktop", | |
749 | #elif defined(CONFIG_PREEMPT_DESKTOP) | |
750 | "preempt", | |
751 | #else | |
752 | "unknown", | |
753 | #endif | |
754 | /* These are reserved for later use */ | |
755 | 0, 0, 0, 0); | |
756 | #ifdef CONFIG_SMP | |
757 | seq_printf(m, " #P:%d)\n", num_online_cpus()); | |
758 | #else | |
759 | seq_puts(m, ")\n"); | |
760 | #endif | |
761 | seq_puts(m, " -----------------\n"); | |
762 | seq_printf(m, " | task: %.16s-%d " | |
763 | "(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n", | |
764 | data->comm, data->pid, data->uid, data->nice, | |
765 | data->policy, data->rt_priority); | |
766 | seq_puts(m, " -----------------\n"); | |
767 | ||
768 | if (data->critical_start) { | |
769 | seq_puts(m, " => started at: "); | |
770 | seq_print_ip_sym(m, data->critical_start, sym_flags); | |
771 | seq_puts(m, "\n => ended at: "); | |
772 | seq_print_ip_sym(m, data->critical_end, sym_flags); | |
773 | seq_puts(m, "\n"); | |
774 | } | |
775 | ||
776 | seq_puts(m, "\n"); | |
777 | } | |
778 | ||
bc0c38d1 SR |
779 | static void notrace |
780 | lat_print_generic(struct seq_file *m, struct trace_entry *entry, int cpu) | |
781 | { | |
782 | int hardirq, softirq; | |
783 | char *comm; | |
784 | ||
785 | comm = trace_find_cmdline(entry->pid); | |
786 | ||
787 | seq_printf(m, "%8.8s-%-5d ", comm, entry->pid); | |
788 | seq_printf(m, "%d", cpu); | |
789 | seq_printf(m, "%c%c", | |
790 | (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : '.', | |
791 | ((entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.')); | |
792 | ||
793 | hardirq = entry->flags & TRACE_FLAG_HARDIRQ; | |
794 | softirq = entry->flags & TRACE_FLAG_SOFTIRQ; | |
795 | if (hardirq && softirq) | |
796 | seq_putc(m, 'H'); | |
797 | else { | |
798 | if (hardirq) | |
799 | seq_putc(m, 'h'); | |
800 | else { | |
801 | if (softirq) | |
802 | seq_putc(m, 's'); | |
803 | else | |
804 | seq_putc(m, '.'); | |
805 | } | |
806 | } | |
807 | ||
808 | if (entry->preempt_count) | |
809 | seq_printf(m, "%x", entry->preempt_count); | |
810 | else | |
811 | seq_puts(m, "."); | |
812 | } | |
813 | ||
814 | unsigned long preempt_mark_thresh = 100; | |
815 | ||
816 | static void notrace | |
817 | lat_print_timestamp(struct seq_file *m, unsigned long long abs_usecs, | |
818 | unsigned long rel_usecs) | |
819 | { | |
820 | seq_printf(m, " %4lldus", abs_usecs); | |
821 | if (rel_usecs > preempt_mark_thresh) | |
822 | seq_puts(m, "!: "); | |
823 | else if (rel_usecs > 1) | |
824 | seq_puts(m, "+: "); | |
825 | else | |
826 | seq_puts(m, " : "); | |
827 | } | |
828 | ||
829 | static const char state_to_char[] = TASK_STATE_TO_CHAR_STR; | |
830 | ||
831 | static void notrace | |
832 | print_lat_fmt(struct seq_file *m, struct trace_iterator *iter, | |
833 | unsigned int trace_idx, int cpu) | |
834 | { | |
835 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); | |
836 | struct trace_entry *next_entry = find_next_entry(iter, NULL); | |
837 | unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE); | |
838 | struct trace_entry *entry = iter->ent; | |
839 | unsigned long abs_usecs; | |
840 | unsigned long rel_usecs; | |
841 | char *comm; | |
842 | int S; | |
843 | ||
844 | if (!next_entry) | |
845 | next_entry = entry; | |
846 | rel_usecs = ns2usecs(next_entry->t - entry->t); | |
847 | abs_usecs = ns2usecs(entry->t - iter->tr->time_start); | |
848 | ||
849 | if (verbose) { | |
850 | comm = trace_find_cmdline(entry->pid); | |
851 | seq_printf(m, "%16s %5d %d %d %08x %08x [%08lx]" | |
852 | " %ld.%03ldms (+%ld.%03ldms): ", | |
853 | comm, | |
854 | entry->pid, cpu, entry->flags, | |
855 | entry->preempt_count, trace_idx, | |
856 | ns2usecs(entry->t), | |
857 | abs_usecs/1000, | |
858 | abs_usecs % 1000, rel_usecs/1000, rel_usecs % 1000); | |
859 | } else { | |
860 | lat_print_generic(m, entry, cpu); | |
861 | lat_print_timestamp(m, abs_usecs, rel_usecs); | |
862 | } | |
863 | switch (entry->type) { | |
864 | case TRACE_FN: | |
865 | seq_print_ip_sym(m, entry->fn.ip, sym_flags); | |
866 | seq_puts(m, " ("); | |
867 | seq_print_ip_sym(m, entry->fn.parent_ip, sym_flags); | |
868 | seq_puts(m, ")\n"); | |
869 | break; | |
870 | case TRACE_CTX: | |
871 | S = entry->ctx.prev_state < sizeof(state_to_char) ? | |
872 | state_to_char[entry->ctx.prev_state] : 'X'; | |
873 | comm = trace_find_cmdline(entry->ctx.next_pid); | |
874 | seq_printf(m, " %d:%d:%c --> %d:%d %s\n", | |
875 | entry->ctx.prev_pid, | |
876 | entry->ctx.prev_prio, | |
877 | S, | |
878 | entry->ctx.next_pid, | |
879 | entry->ctx.next_prio, | |
880 | comm); | |
881 | break; | |
89b2f978 SR |
882 | default: |
883 | seq_printf(m, "Unknown type %d\n", entry->type); | |
bc0c38d1 SR |
884 | } |
885 | } | |
886 | ||
887 | static void notrace | |
888 | print_trace_fmt(struct seq_file *m, struct trace_iterator *iter) | |
889 | { | |
890 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); | |
891 | struct trace_entry *entry = iter->ent; | |
892 | unsigned long usec_rem; | |
893 | unsigned long long t; | |
894 | unsigned long secs; | |
895 | char *comm; | |
896 | int S; | |
897 | ||
898 | comm = trace_find_cmdline(iter->ent->pid); | |
899 | ||
900 | t = ns2usecs(entry->t); | |
901 | usec_rem = do_div(t, 1000000ULL); | |
902 | secs = (unsigned long)t; | |
903 | ||
904 | seq_printf(m, "%16s-%-5d ", comm, entry->pid); | |
905 | seq_printf(m, "[%02d] ", iter->cpu); | |
906 | seq_printf(m, "%5lu.%06lu: ", secs, usec_rem); | |
907 | ||
908 | switch (entry->type) { | |
909 | case TRACE_FN: | |
910 | seq_print_ip_sym(m, entry->fn.ip, sym_flags); | |
911 | if ((sym_flags & TRACE_ITER_PRINT_PARENT) && | |
912 | entry->fn.parent_ip) { | |
913 | seq_printf(m, " <-"); | |
914 | seq_print_ip_sym(m, entry->fn.parent_ip, sym_flags); | |
915 | } | |
916 | break; | |
917 | case TRACE_CTX: | |
918 | S = entry->ctx.prev_state < sizeof(state_to_char) ? | |
919 | state_to_char[entry->ctx.prev_state] : 'X'; | |
920 | seq_printf(m, " %d:%d:%c ==> %d:%d\n", | |
921 | entry->ctx.prev_pid, | |
922 | entry->ctx.prev_prio, | |
923 | S, | |
924 | entry->ctx.next_pid, | |
925 | entry->ctx.next_prio); | |
926 | break; | |
927 | } | |
928 | seq_printf(m, "\n"); | |
929 | } | |
930 | ||
931 | static int trace_empty(struct trace_iterator *iter) | |
932 | { | |
933 | struct trace_array_cpu *data; | |
934 | int cpu; | |
935 | ||
936 | for_each_possible_cpu(cpu) { | |
937 | data = iter->tr->data[cpu]; | |
938 | ||
939 | if (data->trace && | |
4c11d7ae | 940 | data->trace_idx) |
bc0c38d1 SR |
941 | return 0; |
942 | } | |
943 | return 1; | |
944 | } | |
945 | ||
946 | static int s_show(struct seq_file *m, void *v) | |
947 | { | |
948 | struct trace_iterator *iter = v; | |
949 | ||
950 | if (iter->ent == NULL) { | |
951 | if (iter->tr) { | |
952 | seq_printf(m, "# tracer: %s\n", iter->trace->name); | |
953 | seq_puts(m, "#\n"); | |
954 | } | |
955 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) { | |
956 | /* print nothing if the buffers are empty */ | |
957 | if (trace_empty(iter)) | |
958 | return 0; | |
959 | print_trace_header(m, iter); | |
960 | if (!(trace_flags & TRACE_ITER_VERBOSE)) | |
961 | print_lat_help_header(m); | |
962 | } else { | |
963 | if (!(trace_flags & TRACE_ITER_VERBOSE)) | |
964 | print_func_help_header(m); | |
965 | } | |
966 | } else { | |
967 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) | |
968 | print_lat_fmt(m, iter, iter->idx, iter->cpu); | |
969 | else | |
970 | print_trace_fmt(m, iter); | |
971 | } | |
972 | ||
973 | return 0; | |
974 | } | |
975 | ||
976 | static struct seq_operations tracer_seq_ops = { | |
977 | .start = s_start, | |
978 | .next = s_next, | |
979 | .stop = s_stop, | |
980 | .show = s_show, | |
981 | }; | |
982 | ||
983 | static struct trace_iterator notrace * | |
984 | __tracing_open(struct inode *inode, struct file *file, int *ret) | |
985 | { | |
986 | struct trace_iterator *iter; | |
987 | ||
988 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); | |
989 | if (!iter) { | |
990 | *ret = -ENOMEM; | |
991 | goto out; | |
992 | } | |
993 | ||
994 | mutex_lock(&trace_types_lock); | |
995 | if (current_trace && current_trace->print_max) | |
996 | iter->tr = &max_tr; | |
997 | else | |
998 | iter->tr = inode->i_private; | |
999 | iter->trace = current_trace; | |
1000 | iter->pos = -1; | |
1001 | ||
1002 | /* TODO stop tracer */ | |
1003 | *ret = seq_open(file, &tracer_seq_ops); | |
1004 | if (!*ret) { | |
1005 | struct seq_file *m = file->private_data; | |
1006 | m->private = iter; | |
1007 | ||
1008 | /* stop the trace while dumping */ | |
1009 | if (iter->tr->ctrl) | |
1010 | tracer_enabled = 0; | |
1011 | ||
1012 | if (iter->trace && iter->trace->open) | |
1013 | iter->trace->open(iter); | |
1014 | } else { | |
1015 | kfree(iter); | |
1016 | iter = NULL; | |
1017 | } | |
1018 | mutex_unlock(&trace_types_lock); | |
1019 | ||
1020 | out: | |
1021 | return iter; | |
1022 | } | |
1023 | ||
1024 | int tracing_open_generic(struct inode *inode, struct file *filp) | |
1025 | { | |
1026 | filp->private_data = inode->i_private; | |
1027 | return 0; | |
1028 | } | |
1029 | ||
1030 | int tracing_release(struct inode *inode, struct file *file) | |
1031 | { | |
1032 | struct seq_file *m = (struct seq_file *)file->private_data; | |
1033 | struct trace_iterator *iter = m->private; | |
1034 | ||
1035 | mutex_lock(&trace_types_lock); | |
1036 | if (iter->trace && iter->trace->close) | |
1037 | iter->trace->close(iter); | |
1038 | ||
1039 | /* reenable tracing if it was previously enabled */ | |
1040 | if (iter->tr->ctrl) | |
1041 | tracer_enabled = 1; | |
1042 | mutex_unlock(&trace_types_lock); | |
1043 | ||
1044 | seq_release(inode, file); | |
1045 | kfree(iter); | |
1046 | return 0; | |
1047 | } | |
1048 | ||
1049 | static int tracing_open(struct inode *inode, struct file *file) | |
1050 | { | |
1051 | int ret; | |
1052 | ||
1053 | __tracing_open(inode, file, &ret); | |
1054 | ||
1055 | return ret; | |
1056 | } | |
1057 | ||
1058 | static int tracing_lt_open(struct inode *inode, struct file *file) | |
1059 | { | |
1060 | struct trace_iterator *iter; | |
1061 | int ret; | |
1062 | ||
1063 | iter = __tracing_open(inode, file, &ret); | |
1064 | ||
1065 | if (!ret) | |
1066 | iter->iter_flags |= TRACE_FILE_LAT_FMT; | |
1067 | ||
1068 | return ret; | |
1069 | } | |
1070 | ||
1071 | ||
1072 | static void notrace * | |
1073 | t_next(struct seq_file *m, void *v, loff_t *pos) | |
1074 | { | |
1075 | struct tracer *t = m->private; | |
1076 | ||
1077 | (*pos)++; | |
1078 | ||
1079 | if (t) | |
1080 | t = t->next; | |
1081 | ||
1082 | m->private = t; | |
1083 | ||
1084 | return t; | |
1085 | } | |
1086 | ||
1087 | static void *t_start(struct seq_file *m, loff_t *pos) | |
1088 | { | |
1089 | struct tracer *t = m->private; | |
1090 | loff_t l = 0; | |
1091 | ||
1092 | mutex_lock(&trace_types_lock); | |
1093 | for (; t && l < *pos; t = t_next(m, t, &l)) | |
1094 | ; | |
1095 | ||
1096 | return t; | |
1097 | } | |
1098 | ||
1099 | static void t_stop(struct seq_file *m, void *p) | |
1100 | { | |
1101 | mutex_unlock(&trace_types_lock); | |
1102 | } | |
1103 | ||
1104 | static int t_show(struct seq_file *m, void *v) | |
1105 | { | |
1106 | struct tracer *t = v; | |
1107 | ||
1108 | if (!t) | |
1109 | return 0; | |
1110 | ||
1111 | seq_printf(m, "%s", t->name); | |
1112 | if (t->next) | |
1113 | seq_putc(m, ' '); | |
1114 | else | |
1115 | seq_putc(m, '\n'); | |
1116 | ||
1117 | return 0; | |
1118 | } | |
1119 | ||
1120 | static struct seq_operations show_traces_seq_ops = { | |
1121 | .start = t_start, | |
1122 | .next = t_next, | |
1123 | .stop = t_stop, | |
1124 | .show = t_show, | |
1125 | }; | |
1126 | ||
1127 | static int show_traces_open(struct inode *inode, struct file *file) | |
1128 | { | |
1129 | int ret; | |
1130 | ||
1131 | ret = seq_open(file, &show_traces_seq_ops); | |
1132 | if (!ret) { | |
1133 | struct seq_file *m = file->private_data; | |
1134 | m->private = trace_types; | |
1135 | } | |
1136 | ||
1137 | return ret; | |
1138 | } | |
1139 | ||
1140 | static struct file_operations tracing_fops = { | |
1141 | .open = tracing_open, | |
1142 | .read = seq_read, | |
1143 | .llseek = seq_lseek, | |
1144 | .release = tracing_release, | |
1145 | }; | |
1146 | ||
1147 | static struct file_operations tracing_lt_fops = { | |
1148 | .open = tracing_lt_open, | |
1149 | .read = seq_read, | |
1150 | .llseek = seq_lseek, | |
1151 | .release = tracing_release, | |
1152 | }; | |
1153 | ||
1154 | static struct file_operations show_traces_fops = { | |
1155 | .open = show_traces_open, | |
1156 | .read = seq_read, | |
1157 | .release = seq_release, | |
1158 | }; | |
1159 | ||
1160 | static ssize_t | |
1161 | tracing_iter_ctrl_read(struct file *filp, char __user *ubuf, | |
1162 | size_t cnt, loff_t *ppos) | |
1163 | { | |
1164 | char *buf; | |
1165 | int r = 0; | |
1166 | int len = 0; | |
1167 | int i; | |
1168 | ||
1169 | /* calulate max size */ | |
1170 | for (i = 0; trace_options[i]; i++) { | |
1171 | len += strlen(trace_options[i]); | |
1172 | len += 3; /* "no" and space */ | |
1173 | } | |
1174 | ||
1175 | /* +2 for \n and \0 */ | |
1176 | buf = kmalloc(len + 2, GFP_KERNEL); | |
1177 | if (!buf) | |
1178 | return -ENOMEM; | |
1179 | ||
1180 | for (i = 0; trace_options[i]; i++) { | |
1181 | if (trace_flags & (1 << i)) | |
1182 | r += sprintf(buf + r, "%s ", trace_options[i]); | |
1183 | else | |
1184 | r += sprintf(buf + r, "no%s ", trace_options[i]); | |
1185 | } | |
1186 | ||
1187 | r += sprintf(buf + r, "\n"); | |
1188 | WARN_ON(r >= len + 2); | |
1189 | ||
1190 | r = simple_read_from_buffer(ubuf, cnt, ppos, | |
1191 | buf, r); | |
1192 | ||
1193 | kfree(buf); | |
1194 | ||
1195 | return r; | |
1196 | } | |
1197 | ||
1198 | static ssize_t | |
1199 | tracing_iter_ctrl_write(struct file *filp, const char __user *ubuf, | |
1200 | size_t cnt, loff_t *ppos) | |
1201 | { | |
1202 | char buf[64]; | |
1203 | char *cmp = buf; | |
1204 | int neg = 0; | |
1205 | int i; | |
1206 | ||
1207 | if (cnt > 63) | |
1208 | cnt = 63; | |
1209 | ||
1210 | if (copy_from_user(&buf, ubuf, cnt)) | |
1211 | return -EFAULT; | |
1212 | ||
1213 | buf[cnt] = 0; | |
1214 | ||
1215 | if (strncmp(buf, "no", 2) == 0) { | |
1216 | neg = 1; | |
1217 | cmp += 2; | |
1218 | } | |
1219 | ||
1220 | for (i = 0; trace_options[i]; i++) { | |
1221 | int len = strlen(trace_options[i]); | |
1222 | ||
1223 | if (strncmp(cmp, trace_options[i], len) == 0) { | |
1224 | if (neg) | |
1225 | trace_flags &= ~(1 << i); | |
1226 | else | |
1227 | trace_flags |= (1 << i); | |
1228 | break; | |
1229 | } | |
1230 | } | |
1231 | ||
1232 | filp->f_pos += cnt; | |
1233 | ||
1234 | return cnt; | |
1235 | } | |
1236 | ||
1237 | static struct file_operations tracing_iter_fops = { | |
1238 | .open = tracing_open_generic, | |
1239 | .read = tracing_iter_ctrl_read, | |
1240 | .write = tracing_iter_ctrl_write, | |
1241 | }; | |
1242 | ||
1243 | static ssize_t | |
1244 | tracing_ctrl_read(struct file *filp, char __user *ubuf, | |
1245 | size_t cnt, loff_t *ppos) | |
1246 | { | |
1247 | struct trace_array *tr = filp->private_data; | |
1248 | char buf[64]; | |
1249 | int r; | |
1250 | ||
1251 | r = sprintf(buf, "%ld\n", tr->ctrl); | |
1252 | return simple_read_from_buffer(ubuf, cnt, ppos, | |
1253 | buf, r); | |
1254 | } | |
1255 | ||
1256 | static ssize_t | |
1257 | tracing_ctrl_write(struct file *filp, const char __user *ubuf, | |
1258 | size_t cnt, loff_t *ppos) | |
1259 | { | |
1260 | struct trace_array *tr = filp->private_data; | |
1261 | long val; | |
1262 | char buf[64]; | |
1263 | ||
1264 | if (cnt > 63) | |
1265 | cnt = 63; | |
1266 | ||
1267 | if (copy_from_user(&buf, ubuf, cnt)) | |
1268 | return -EFAULT; | |
1269 | ||
1270 | buf[cnt] = 0; | |
1271 | ||
1272 | val = simple_strtoul(buf, NULL, 10); | |
1273 | ||
1274 | val = !!val; | |
1275 | ||
1276 | mutex_lock(&trace_types_lock); | |
1277 | if (tr->ctrl ^ val) { | |
1278 | if (val) | |
1279 | tracer_enabled = 1; | |
1280 | else | |
1281 | tracer_enabled = 0; | |
1282 | ||
1283 | tr->ctrl = val; | |
1284 | ||
1285 | if (current_trace && current_trace->ctrl_update) | |
1286 | current_trace->ctrl_update(tr); | |
1287 | } | |
1288 | mutex_unlock(&trace_types_lock); | |
1289 | ||
1290 | filp->f_pos += cnt; | |
1291 | ||
1292 | return cnt; | |
1293 | } | |
1294 | ||
1295 | static ssize_t | |
1296 | tracing_set_trace_read(struct file *filp, char __user *ubuf, | |
1297 | size_t cnt, loff_t *ppos) | |
1298 | { | |
1299 | char buf[max_tracer_type_len+2]; | |
1300 | int r; | |
1301 | ||
1302 | mutex_lock(&trace_types_lock); | |
1303 | if (current_trace) | |
1304 | r = sprintf(buf, "%s\n", current_trace->name); | |
1305 | else | |
1306 | r = sprintf(buf, "\n"); | |
1307 | mutex_unlock(&trace_types_lock); | |
1308 | ||
1309 | return simple_read_from_buffer(ubuf, cnt, ppos, | |
1310 | buf, r); | |
1311 | } | |
1312 | ||
1313 | static ssize_t | |
1314 | tracing_set_trace_write(struct file *filp, const char __user *ubuf, | |
1315 | size_t cnt, loff_t *ppos) | |
1316 | { | |
1317 | struct trace_array *tr = &global_trace; | |
1318 | struct tracer *t; | |
1319 | char buf[max_tracer_type_len+1]; | |
1320 | int i; | |
1321 | ||
1322 | if (cnt > max_tracer_type_len) | |
1323 | cnt = max_tracer_type_len; | |
1324 | ||
1325 | if (copy_from_user(&buf, ubuf, cnt)) | |
1326 | return -EFAULT; | |
1327 | ||
1328 | buf[cnt] = 0; | |
1329 | ||
1330 | /* strip ending whitespace. */ | |
1331 | for (i = cnt - 1; i > 0 && isspace(buf[i]); i--) | |
1332 | buf[i] = 0; | |
1333 | ||
1334 | mutex_lock(&trace_types_lock); | |
1335 | for (t = trace_types; t; t = t->next) { | |
1336 | if (strcmp(t->name, buf) == 0) | |
1337 | break; | |
1338 | } | |
1339 | if (!t || t == current_trace) | |
1340 | goto out; | |
1341 | ||
1342 | if (current_trace && current_trace->reset) | |
1343 | current_trace->reset(tr); | |
1344 | ||
1345 | current_trace = t; | |
1346 | if (t->init) | |
1347 | t->init(tr); | |
1348 | ||
1349 | out: | |
1350 | mutex_unlock(&trace_types_lock); | |
1351 | ||
1352 | filp->f_pos += cnt; | |
1353 | ||
1354 | return cnt; | |
1355 | } | |
1356 | ||
1357 | static ssize_t | |
1358 | tracing_max_lat_read(struct file *filp, char __user *ubuf, | |
1359 | size_t cnt, loff_t *ppos) | |
1360 | { | |
1361 | unsigned long *ptr = filp->private_data; | |
1362 | char buf[64]; | |
1363 | int r; | |
1364 | ||
1365 | r = snprintf(buf, 64, "%ld\n", | |
1366 | *ptr == (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr)); | |
1367 | if (r > 64) | |
1368 | r = 64; | |
1369 | return simple_read_from_buffer(ubuf, cnt, ppos, | |
1370 | buf, r); | |
1371 | } | |
1372 | ||
1373 | static ssize_t | |
1374 | tracing_max_lat_write(struct file *filp, const char __user *ubuf, | |
1375 | size_t cnt, loff_t *ppos) | |
1376 | { | |
1377 | long *ptr = filp->private_data; | |
1378 | long val; | |
1379 | char buf[64]; | |
1380 | ||
1381 | if (cnt > 63) | |
1382 | cnt = 63; | |
1383 | ||
1384 | if (copy_from_user(&buf, ubuf, cnt)) | |
1385 | return -EFAULT; | |
1386 | ||
1387 | buf[cnt] = 0; | |
1388 | ||
1389 | val = simple_strtoul(buf, NULL, 10); | |
1390 | ||
1391 | *ptr = val * 1000; | |
1392 | ||
1393 | return cnt; | |
1394 | } | |
1395 | ||
1396 | static struct file_operations tracing_max_lat_fops = { | |
1397 | .open = tracing_open_generic, | |
1398 | .read = tracing_max_lat_read, | |
1399 | .write = tracing_max_lat_write, | |
1400 | }; | |
1401 | ||
1402 | static struct file_operations tracing_ctrl_fops = { | |
1403 | .open = tracing_open_generic, | |
1404 | .read = tracing_ctrl_read, | |
1405 | .write = tracing_ctrl_write, | |
1406 | }; | |
1407 | ||
1408 | static struct file_operations set_tracer_fops = { | |
1409 | .open = tracing_open_generic, | |
1410 | .read = tracing_set_trace_read, | |
1411 | .write = tracing_set_trace_write, | |
1412 | }; | |
1413 | ||
1414 | #ifdef CONFIG_DYNAMIC_FTRACE | |
1415 | ||
1416 | static ssize_t | |
1417 | tracing_read_long(struct file *filp, char __user *ubuf, | |
1418 | size_t cnt, loff_t *ppos) | |
1419 | { | |
1420 | unsigned long *p = filp->private_data; | |
1421 | char buf[64]; | |
1422 | int r; | |
1423 | ||
1424 | r = sprintf(buf, "%ld\n", *p); | |
1425 | return simple_read_from_buffer(ubuf, cnt, ppos, | |
1426 | buf, r); | |
1427 | } | |
1428 | ||
1429 | static struct file_operations tracing_read_long_fops = { | |
1430 | .open = tracing_open_generic, | |
1431 | .read = tracing_read_long, | |
1432 | }; | |
1433 | #endif | |
1434 | ||
1435 | static struct dentry *d_tracer; | |
1436 | ||
1437 | struct dentry *tracing_init_dentry(void) | |
1438 | { | |
1439 | static int once; | |
1440 | ||
1441 | if (d_tracer) | |
1442 | return d_tracer; | |
1443 | ||
1444 | d_tracer = debugfs_create_dir("tracing", NULL); | |
1445 | ||
1446 | if (!d_tracer && !once) { | |
1447 | once = 1; | |
1448 | pr_warning("Could not create debugfs directory 'tracing'\n"); | |
1449 | return NULL; | |
1450 | } | |
1451 | ||
1452 | return d_tracer; | |
1453 | } | |
1454 | ||
1455 | static __init void tracer_init_debugfs(void) | |
1456 | { | |
1457 | struct dentry *d_tracer; | |
1458 | struct dentry *entry; | |
1459 | ||
1460 | d_tracer = tracing_init_dentry(); | |
1461 | ||
1462 | entry = debugfs_create_file("tracing_enabled", 0644, d_tracer, | |
1463 | &global_trace, &tracing_ctrl_fops); | |
1464 | if (!entry) | |
1465 | pr_warning("Could not create debugfs 'tracing_enabled' entry\n"); | |
1466 | ||
1467 | entry = debugfs_create_file("iter_ctrl", 0644, d_tracer, | |
1468 | NULL, &tracing_iter_fops); | |
1469 | if (!entry) | |
1470 | pr_warning("Could not create debugfs 'iter_ctrl' entry\n"); | |
1471 | ||
1472 | entry = debugfs_create_file("latency_trace", 0444, d_tracer, | |
1473 | &global_trace, &tracing_lt_fops); | |
1474 | if (!entry) | |
1475 | pr_warning("Could not create debugfs 'latency_trace' entry\n"); | |
1476 | ||
1477 | entry = debugfs_create_file("trace", 0444, d_tracer, | |
1478 | &global_trace, &tracing_fops); | |
1479 | if (!entry) | |
1480 | pr_warning("Could not create debugfs 'trace' entry\n"); | |
1481 | ||
1482 | entry = debugfs_create_file("available_tracers", 0444, d_tracer, | |
1483 | &global_trace, &show_traces_fops); | |
1484 | if (!entry) | |
1485 | pr_warning("Could not create debugfs 'trace' entry\n"); | |
1486 | ||
1487 | entry = debugfs_create_file("current_tracer", 0444, d_tracer, | |
1488 | &global_trace, &set_tracer_fops); | |
1489 | if (!entry) | |
1490 | pr_warning("Could not create debugfs 'trace' entry\n"); | |
1491 | ||
1492 | entry = debugfs_create_file("tracing_max_latency", 0644, d_tracer, | |
1493 | &tracing_max_latency, | |
1494 | &tracing_max_lat_fops); | |
1495 | if (!entry) | |
1496 | pr_warning("Could not create debugfs " | |
1497 | "'tracing_max_latency' entry\n"); | |
1498 | ||
1499 | entry = debugfs_create_file("tracing_thresh", 0644, d_tracer, | |
1500 | &tracing_thresh, &tracing_max_lat_fops); | |
1501 | if (!entry) | |
1502 | pr_warning("Could not create debugfs " | |
1503 | "'tracing_threash' entry\n"); | |
1504 | ||
1505 | #ifdef CONFIG_DYNAMIC_FTRACE | |
1506 | entry = debugfs_create_file("dyn_ftrace_total_info", 0444, d_tracer, | |
1507 | &ftrace_update_tot_cnt, | |
1508 | &tracing_read_long_fops); | |
1509 | if (!entry) | |
1510 | pr_warning("Could not create debugfs " | |
1511 | "'dyn_ftrace_total_info' entry\n"); | |
1512 | #endif | |
1513 | } | |
1514 | ||
1515 | /* dummy trace to disable tracing */ | |
1516 | static struct tracer no_tracer __read_mostly = | |
1517 | { | |
1518 | .name = "none", | |
1519 | }; | |
1520 | ||
4c11d7ae | 1521 | static int trace_alloc_page(void) |
bc0c38d1 | 1522 | { |
4c11d7ae SR |
1523 | struct trace_array_cpu *data; |
1524 | void *array; | |
1525 | struct page *page, *tmp; | |
1526 | LIST_HEAD(pages); | |
1527 | int i; | |
1528 | ||
1529 | /* first allocate a page for each CPU */ | |
1530 | for_each_possible_cpu(i) { | |
1531 | array = (void *)__get_free_page(GFP_KERNEL); | |
1532 | if (array == NULL) { | |
1533 | printk(KERN_ERR "tracer: failed to allocate page" | |
1534 | "for trace buffer!\n"); | |
1535 | goto free_pages; | |
1536 | } | |
1537 | ||
1538 | page = virt_to_page(array); | |
1539 | list_add(&page->lru, &pages); | |
1540 | ||
1541 | /* Only allocate if we are actually using the max trace */ | |
1542 | #ifdef CONFIG_TRACER_MAX_TRACE | |
1543 | array = (void *)__get_free_page(GFP_KERNEL); | |
1544 | if (array == NULL) { | |
1545 | printk(KERN_ERR "tracer: failed to allocate page" | |
1546 | "for trace buffer!\n"); | |
1547 | goto free_pages; | |
1548 | } | |
1549 | page = virt_to_page(array); | |
1550 | list_add(&page->lru, &pages); | |
1551 | #endif | |
1552 | } | |
1553 | ||
1554 | /* Now that we successfully allocate a page per CPU, add them */ | |
1555 | for_each_possible_cpu(i) { | |
1556 | data = global_trace.data[i]; | |
1557 | page = list_entry(pages.next, struct page, lru); | |
1558 | list_del(&page->lru); | |
1559 | list_add_tail(&page->lru, &data->trace_pages); | |
1560 | ClearPageLRU(page); | |
1561 | ||
1562 | #ifdef CONFIG_TRACER_MAX_TRACE | |
1563 | data = max_tr.data[i]; | |
1564 | page = list_entry(pages.next, struct page, lru); | |
1565 | list_del(&page->lru); | |
1566 | list_add_tail(&page->lru, &data->trace_pages); | |
1567 | SetPageLRU(page); | |
1568 | #endif | |
1569 | } | |
1570 | global_trace.entries += ENTRIES_PER_PAGE; | |
1571 | ||
1572 | return 0; | |
1573 | ||
1574 | free_pages: | |
1575 | list_for_each_entry_safe(page, tmp, &pages, lru) { | |
1576 | list_del(&page->lru); | |
1577 | __free_page(page); | |
1578 | } | |
1579 | return -ENOMEM; | |
bc0c38d1 SR |
1580 | } |
1581 | ||
1582 | __init static int tracer_alloc_buffers(void) | |
1583 | { | |
4c11d7ae SR |
1584 | struct trace_array_cpu *data; |
1585 | void *array; | |
1586 | struct page *page; | |
1587 | int pages = 0; | |
bc0c38d1 SR |
1588 | int i; |
1589 | ||
4c11d7ae | 1590 | /* Allocate the first page for all buffers */ |
bc0c38d1 | 1591 | for_each_possible_cpu(i) { |
4c11d7ae | 1592 | data = global_trace.data[i] = &per_cpu(global_trace_cpu, i); |
bc0c38d1 SR |
1593 | max_tr.data[i] = &per_cpu(max_data, i); |
1594 | ||
4c11d7ae | 1595 | array = (void *)__get_free_page(GFP_KERNEL); |
bc0c38d1 | 1596 | if (array == NULL) { |
4c11d7ae SR |
1597 | printk(KERN_ERR "tracer: failed to allocate page" |
1598 | "for trace buffer!\n"); | |
bc0c38d1 SR |
1599 | goto free_buffers; |
1600 | } | |
4c11d7ae SR |
1601 | data->trace = array; |
1602 | ||
1603 | /* set the array to the list */ | |
1604 | INIT_LIST_HEAD(&data->trace_pages); | |
1605 | page = virt_to_page(array); | |
1606 | list_add(&page->lru, &data->trace_pages); | |
1607 | /* use the LRU flag to differentiate the two buffers */ | |
1608 | ClearPageLRU(page); | |
bc0c38d1 SR |
1609 | |
1610 | /* Only allocate if we are actually using the max trace */ | |
1611 | #ifdef CONFIG_TRACER_MAX_TRACE | |
4c11d7ae | 1612 | array = (void *)__get_free_page(GFP_KERNEL); |
bc0c38d1 | 1613 | if (array == NULL) { |
4c11d7ae SR |
1614 | printk(KERN_ERR "tracer: failed to allocate page" |
1615 | "for trace buffer!\n"); | |
bc0c38d1 SR |
1616 | goto free_buffers; |
1617 | } | |
1618 | max_tr.data[i]->trace = array; | |
4c11d7ae SR |
1619 | |
1620 | INIT_LIST_HEAD(&max_tr.data[i]->trace_pages); | |
1621 | page = virt_to_page(array); | |
1622 | list_add(&page->lru, &max_tr.data[i]->trace_pages); | |
1623 | SetPageLRU(page); | |
bc0c38d1 SR |
1624 | #endif |
1625 | } | |
1626 | ||
1627 | /* | |
1628 | * Since we allocate by orders of pages, we may be able to | |
1629 | * round up a bit. | |
1630 | */ | |
4c11d7ae | 1631 | global_trace.entries = ENTRIES_PER_PAGE; |
4c11d7ae SR |
1632 | pages++; |
1633 | ||
1634 | while (global_trace.entries < trace_nr_entries) { | |
1635 | if (trace_alloc_page()) | |
1636 | break; | |
1637 | pages++; | |
1638 | } | |
89b2f978 | 1639 | max_tr.entries = global_trace.entries; |
bc0c38d1 | 1640 | |
4c11d7ae SR |
1641 | pr_info("tracer: %d pages allocated for %ld", |
1642 | pages, trace_nr_entries); | |
bc0c38d1 SR |
1643 | pr_info(" entries of %ld bytes\n", (long)TRACE_ENTRY_SIZE); |
1644 | pr_info(" actual entries %ld\n", global_trace.entries); | |
1645 | ||
1646 | tracer_init_debugfs(); | |
1647 | ||
1648 | trace_init_cmdlines(); | |
1649 | ||
1650 | register_tracer(&no_tracer); | |
1651 | current_trace = &no_tracer; | |
1652 | ||
1653 | return 0; | |
1654 | ||
1655 | free_buffers: | |
1656 | for (i-- ; i >= 0; i--) { | |
4c11d7ae | 1657 | struct page *page, *tmp; |
bc0c38d1 SR |
1658 | struct trace_array_cpu *data = global_trace.data[i]; |
1659 | ||
1660 | if (data && data->trace) { | |
4c11d7ae SR |
1661 | list_for_each_entry_safe(page, tmp, |
1662 | &data->trace_pages, lru) { | |
1663 | list_del(&page->lru); | |
1664 | __free_page(page); | |
1665 | } | |
bc0c38d1 SR |
1666 | data->trace = NULL; |
1667 | } | |
1668 | ||
1669 | #ifdef CONFIG_TRACER_MAX_TRACE | |
1670 | data = max_tr.data[i]; | |
1671 | if (data && data->trace) { | |
4c11d7ae SR |
1672 | list_for_each_entry_safe(page, tmp, |
1673 | &data->trace_pages, lru) { | |
1674 | list_del(&page->lru); | |
1675 | __free_page(page); | |
1676 | } | |
bc0c38d1 SR |
1677 | data->trace = NULL; |
1678 | } | |
1679 | #endif | |
1680 | } | |
1681 | return -ENOMEM; | |
1682 | } | |
1683 | ||
1684 | device_initcall(tracer_alloc_buffers); |