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