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1 | /* | |
2 | * | |
3 | * Function graph tracer. | |
4 | * Copyright (c) 2008-2009 Frederic Weisbecker <fweisbec@gmail.com> | |
5 | * Mostly borrowed from function tracer which | |
6 | * is Copyright (c) Steven Rostedt <srostedt@redhat.com> | |
7 | * | |
8 | */ | |
9 | #include <linux/debugfs.h> | |
10 | #include <linux/uaccess.h> | |
11 | #include <linux/ftrace.h> | |
12 | #include <linux/slab.h> | |
13 | #include <linux/fs.h> | |
14 | ||
15 | #include "trace.h" | |
16 | #include "trace_output.h" | |
17 | ||
18 | static bool kill_ftrace_graph; | |
19 | ||
20 | /** | |
21 | * ftrace_graph_is_dead - returns true if ftrace_graph_stop() was called | |
22 | * | |
23 | * ftrace_graph_stop() is called when a severe error is detected in | |
24 | * the function graph tracing. This function is called by the critical | |
25 | * paths of function graph to keep those paths from doing any more harm. | |
26 | */ | |
27 | bool ftrace_graph_is_dead(void) | |
28 | { | |
29 | return kill_ftrace_graph; | |
30 | } | |
31 | ||
32 | /** | |
33 | * ftrace_graph_stop - set to permanently disable function graph tracincg | |
34 | * | |
35 | * In case of an error int function graph tracing, this is called | |
36 | * to try to keep function graph tracing from causing any more harm. | |
37 | * Usually this is pretty severe and this is called to try to at least | |
38 | * get a warning out to the user. | |
39 | */ | |
40 | void ftrace_graph_stop(void) | |
41 | { | |
42 | kill_ftrace_graph = true; | |
43 | } | |
44 | ||
45 | /* When set, irq functions will be ignored */ | |
46 | static int ftrace_graph_skip_irqs; | |
47 | ||
48 | struct fgraph_cpu_data { | |
49 | pid_t last_pid; | |
50 | int depth; | |
51 | int depth_irq; | |
52 | int ignore; | |
53 | unsigned long enter_funcs[FTRACE_RETFUNC_DEPTH]; | |
54 | }; | |
55 | ||
56 | struct fgraph_data { | |
57 | struct fgraph_cpu_data __percpu *cpu_data; | |
58 | ||
59 | /* Place to preserve last processed entry. */ | |
60 | struct ftrace_graph_ent_entry ent; | |
61 | struct ftrace_graph_ret_entry ret; | |
62 | int failed; | |
63 | int cpu; | |
64 | }; | |
65 | ||
66 | #define TRACE_GRAPH_INDENT 2 | |
67 | ||
68 | static unsigned int max_depth; | |
69 | ||
70 | static struct tracer_opt trace_opts[] = { | |
71 | /* Display overruns? (for self-debug purpose) */ | |
72 | { TRACER_OPT(funcgraph-overrun, TRACE_GRAPH_PRINT_OVERRUN) }, | |
73 | /* Display CPU ? */ | |
74 | { TRACER_OPT(funcgraph-cpu, TRACE_GRAPH_PRINT_CPU) }, | |
75 | /* Display Overhead ? */ | |
76 | { TRACER_OPT(funcgraph-overhead, TRACE_GRAPH_PRINT_OVERHEAD) }, | |
77 | /* Display proc name/pid */ | |
78 | { TRACER_OPT(funcgraph-proc, TRACE_GRAPH_PRINT_PROC) }, | |
79 | /* Display duration of execution */ | |
80 | { TRACER_OPT(funcgraph-duration, TRACE_GRAPH_PRINT_DURATION) }, | |
81 | /* Display absolute time of an entry */ | |
82 | { TRACER_OPT(funcgraph-abstime, TRACE_GRAPH_PRINT_ABS_TIME) }, | |
83 | /* Display interrupts */ | |
84 | { TRACER_OPT(funcgraph-irqs, TRACE_GRAPH_PRINT_IRQS) }, | |
85 | /* Display function name after trailing } */ | |
86 | { TRACER_OPT(funcgraph-tail, TRACE_GRAPH_PRINT_TAIL) }, | |
87 | { } /* Empty entry */ | |
88 | }; | |
89 | ||
90 | static struct tracer_flags tracer_flags = { | |
91 | /* Don't display overruns, proc, or tail by default */ | |
92 | .val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD | | |
93 | TRACE_GRAPH_PRINT_DURATION | TRACE_GRAPH_PRINT_IRQS, | |
94 | .opts = trace_opts | |
95 | }; | |
96 | ||
97 | static struct trace_array *graph_array; | |
98 | ||
99 | /* | |
100 | * DURATION column is being also used to display IRQ signs, | |
101 | * following values are used by print_graph_irq and others | |
102 | * to fill in space into DURATION column. | |
103 | */ | |
104 | enum { | |
105 | FLAGS_FILL_FULL = 1 << TRACE_GRAPH_PRINT_FILL_SHIFT, | |
106 | FLAGS_FILL_START = 2 << TRACE_GRAPH_PRINT_FILL_SHIFT, | |
107 | FLAGS_FILL_END = 3 << TRACE_GRAPH_PRINT_FILL_SHIFT, | |
108 | }; | |
109 | ||
110 | static void | |
111 | print_graph_duration(unsigned long long duration, struct trace_seq *s, | |
112 | u32 flags); | |
113 | ||
114 | /* Add a function return address to the trace stack on thread info.*/ | |
115 | int | |
116 | ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth, | |
117 | unsigned long frame_pointer) | |
118 | { | |
119 | unsigned long long calltime; | |
120 | int index; | |
121 | ||
122 | if (unlikely(ftrace_graph_is_dead())) | |
123 | return -EBUSY; | |
124 | ||
125 | if (!current->ret_stack) | |
126 | return -EBUSY; | |
127 | ||
128 | /* | |
129 | * We must make sure the ret_stack is tested before we read | |
130 | * anything else. | |
131 | */ | |
132 | smp_rmb(); | |
133 | ||
134 | /* The return trace stack is full */ | |
135 | if (current->curr_ret_stack == FTRACE_RETFUNC_DEPTH - 1) { | |
136 | atomic_inc(¤t->trace_overrun); | |
137 | return -EBUSY; | |
138 | } | |
139 | ||
140 | /* | |
141 | * The curr_ret_stack is an index to ftrace return stack of | |
142 | * current task. Its value should be in [0, FTRACE_RETFUNC_ | |
143 | * DEPTH) when the function graph tracer is used. To support | |
144 | * filtering out specific functions, it makes the index | |
145 | * negative by subtracting huge value (FTRACE_NOTRACE_DEPTH) | |
146 | * so when it sees a negative index the ftrace will ignore | |
147 | * the record. And the index gets recovered when returning | |
148 | * from the filtered function by adding the FTRACE_NOTRACE_ | |
149 | * DEPTH and then it'll continue to record functions normally. | |
150 | * | |
151 | * The curr_ret_stack is initialized to -1 and get increased | |
152 | * in this function. So it can be less than -1 only if it was | |
153 | * filtered out via ftrace_graph_notrace_addr() which can be | |
154 | * set from set_graph_notrace file in debugfs by user. | |
155 | */ | |
156 | if (current->curr_ret_stack < -1) | |
157 | return -EBUSY; | |
158 | ||
159 | calltime = trace_clock_local(); | |
160 | ||
161 | index = ++current->curr_ret_stack; | |
162 | if (ftrace_graph_notrace_addr(func)) | |
163 | current->curr_ret_stack -= FTRACE_NOTRACE_DEPTH; | |
164 | barrier(); | |
165 | current->ret_stack[index].ret = ret; | |
166 | current->ret_stack[index].func = func; | |
167 | current->ret_stack[index].calltime = calltime; | |
168 | current->ret_stack[index].subtime = 0; | |
169 | current->ret_stack[index].fp = frame_pointer; | |
170 | *depth = current->curr_ret_stack; | |
171 | ||
172 | return 0; | |
173 | } | |
174 | ||
175 | /* Retrieve a function return address to the trace stack on thread info.*/ | |
176 | static void | |
177 | ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret, | |
178 | unsigned long frame_pointer) | |
179 | { | |
180 | int index; | |
181 | ||
182 | index = current->curr_ret_stack; | |
183 | ||
184 | /* | |
185 | * A negative index here means that it's just returned from a | |
186 | * notrace'd function. Recover index to get an original | |
187 | * return address. See ftrace_push_return_trace(). | |
188 | * | |
189 | * TODO: Need to check whether the stack gets corrupted. | |
190 | */ | |
191 | if (index < 0) | |
192 | index += FTRACE_NOTRACE_DEPTH; | |
193 | ||
194 | if (unlikely(index < 0 || index >= FTRACE_RETFUNC_DEPTH)) { | |
195 | ftrace_graph_stop(); | |
196 | WARN_ON(1); | |
197 | /* Might as well panic, otherwise we have no where to go */ | |
198 | *ret = (unsigned long)panic; | |
199 | return; | |
200 | } | |
201 | ||
202 | #if defined(CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST) && !defined(CC_USING_FENTRY) | |
203 | /* | |
204 | * The arch may choose to record the frame pointer used | |
205 | * and check it here to make sure that it is what we expect it | |
206 | * to be. If gcc does not set the place holder of the return | |
207 | * address in the frame pointer, and does a copy instead, then | |
208 | * the function graph trace will fail. This test detects this | |
209 | * case. | |
210 | * | |
211 | * Currently, x86_32 with optimize for size (-Os) makes the latest | |
212 | * gcc do the above. | |
213 | * | |
214 | * Note, -mfentry does not use frame pointers, and this test | |
215 | * is not needed if CC_USING_FENTRY is set. | |
216 | */ | |
217 | if (unlikely(current->ret_stack[index].fp != frame_pointer)) { | |
218 | ftrace_graph_stop(); | |
219 | WARN(1, "Bad frame pointer: expected %lx, received %lx\n" | |
220 | " from func %ps return to %lx\n", | |
221 | current->ret_stack[index].fp, | |
222 | frame_pointer, | |
223 | (void *)current->ret_stack[index].func, | |
224 | current->ret_stack[index].ret); | |
225 | *ret = (unsigned long)panic; | |
226 | return; | |
227 | } | |
228 | #endif | |
229 | ||
230 | *ret = current->ret_stack[index].ret; | |
231 | trace->func = current->ret_stack[index].func; | |
232 | trace->calltime = current->ret_stack[index].calltime; | |
233 | trace->overrun = atomic_read(¤t->trace_overrun); | |
234 | trace->depth = index; | |
235 | } | |
236 | ||
237 | /* | |
238 | * Send the trace to the ring-buffer. | |
239 | * @return the original return address. | |
240 | */ | |
241 | unsigned long ftrace_return_to_handler(unsigned long frame_pointer) | |
242 | { | |
243 | struct ftrace_graph_ret trace; | |
244 | unsigned long ret; | |
245 | ||
246 | ftrace_pop_return_trace(&trace, &ret, frame_pointer); | |
247 | trace.rettime = trace_clock_local(); | |
248 | barrier(); | |
249 | current->curr_ret_stack--; | |
250 | /* | |
251 | * The curr_ret_stack can be less than -1 only if it was | |
252 | * filtered out and it's about to return from the function. | |
253 | * Recover the index and continue to trace normal functions. | |
254 | */ | |
255 | if (current->curr_ret_stack < -1) { | |
256 | current->curr_ret_stack += FTRACE_NOTRACE_DEPTH; | |
257 | return ret; | |
258 | } | |
259 | ||
260 | /* | |
261 | * The trace should run after decrementing the ret counter | |
262 | * in case an interrupt were to come in. We don't want to | |
263 | * lose the interrupt if max_depth is set. | |
264 | */ | |
265 | ftrace_graph_return(&trace); | |
266 | ||
267 | if (unlikely(!ret)) { | |
268 | ftrace_graph_stop(); | |
269 | WARN_ON(1); | |
270 | /* Might as well panic. What else to do? */ | |
271 | ret = (unsigned long)panic; | |
272 | } | |
273 | ||
274 | return ret; | |
275 | } | |
276 | ||
277 | int __trace_graph_entry(struct trace_array *tr, | |
278 | struct ftrace_graph_ent *trace, | |
279 | unsigned long flags, | |
280 | int pc) | |
281 | { | |
282 | struct ftrace_event_call *call = &event_funcgraph_entry; | |
283 | struct ring_buffer_event *event; | |
284 | struct ring_buffer *buffer = tr->trace_buffer.buffer; | |
285 | struct ftrace_graph_ent_entry *entry; | |
286 | ||
287 | if (unlikely(__this_cpu_read(ftrace_cpu_disabled))) | |
288 | return 0; | |
289 | ||
290 | event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_ENT, | |
291 | sizeof(*entry), flags, pc); | |
292 | if (!event) | |
293 | return 0; | |
294 | entry = ring_buffer_event_data(event); | |
295 | entry->graph_ent = *trace; | |
296 | if (!call_filter_check_discard(call, entry, buffer, event)) | |
297 | __buffer_unlock_commit(buffer, event); | |
298 | ||
299 | return 1; | |
300 | } | |
301 | ||
302 | static inline int ftrace_graph_ignore_irqs(void) | |
303 | { | |
304 | if (!ftrace_graph_skip_irqs || trace_recursion_test(TRACE_IRQ_BIT)) | |
305 | return 0; | |
306 | ||
307 | return in_irq(); | |
308 | } | |
309 | ||
310 | int trace_graph_entry(struct ftrace_graph_ent *trace) | |
311 | { | |
312 | struct trace_array *tr = graph_array; | |
313 | struct trace_array_cpu *data; | |
314 | unsigned long flags; | |
315 | long disabled; | |
316 | int ret; | |
317 | int cpu; | |
318 | int pc; | |
319 | ||
320 | if (!ftrace_trace_task(current)) | |
321 | return 0; | |
322 | ||
323 | /* trace it when it is-nested-in or is a function enabled. */ | |
324 | if ((!(trace->depth || ftrace_graph_addr(trace->func)) || | |
325 | ftrace_graph_ignore_irqs()) || (trace->depth < 0) || | |
326 | (max_depth && trace->depth >= max_depth)) | |
327 | return 0; | |
328 | ||
329 | /* | |
330 | * Do not trace a function if it's filtered by set_graph_notrace. | |
331 | * Make the index of ret stack negative to indicate that it should | |
332 | * ignore further functions. But it needs its own ret stack entry | |
333 | * to recover the original index in order to continue tracing after | |
334 | * returning from the function. | |
335 | */ | |
336 | if (ftrace_graph_notrace_addr(trace->func)) | |
337 | return 1; | |
338 | ||
339 | local_irq_save(flags); | |
340 | cpu = raw_smp_processor_id(); | |
341 | data = per_cpu_ptr(tr->trace_buffer.data, cpu); | |
342 | disabled = atomic_inc_return(&data->disabled); | |
343 | if (likely(disabled == 1)) { | |
344 | pc = preempt_count(); | |
345 | ret = __trace_graph_entry(tr, trace, flags, pc); | |
346 | } else { | |
347 | ret = 0; | |
348 | } | |
349 | ||
350 | atomic_dec(&data->disabled); | |
351 | local_irq_restore(flags); | |
352 | ||
353 | return ret; | |
354 | } | |
355 | ||
356 | static int trace_graph_thresh_entry(struct ftrace_graph_ent *trace) | |
357 | { | |
358 | if (tracing_thresh) | |
359 | return 1; | |
360 | else | |
361 | return trace_graph_entry(trace); | |
362 | } | |
363 | ||
364 | static void | |
365 | __trace_graph_function(struct trace_array *tr, | |
366 | unsigned long ip, unsigned long flags, int pc) | |
367 | { | |
368 | u64 time = trace_clock_local(); | |
369 | struct ftrace_graph_ent ent = { | |
370 | .func = ip, | |
371 | .depth = 0, | |
372 | }; | |
373 | struct ftrace_graph_ret ret = { | |
374 | .func = ip, | |
375 | .depth = 0, | |
376 | .calltime = time, | |
377 | .rettime = time, | |
378 | }; | |
379 | ||
380 | __trace_graph_entry(tr, &ent, flags, pc); | |
381 | __trace_graph_return(tr, &ret, flags, pc); | |
382 | } | |
383 | ||
384 | void | |
385 | trace_graph_function(struct trace_array *tr, | |
386 | unsigned long ip, unsigned long parent_ip, | |
387 | unsigned long flags, int pc) | |
388 | { | |
389 | __trace_graph_function(tr, ip, flags, pc); | |
390 | } | |
391 | ||
392 | void __trace_graph_return(struct trace_array *tr, | |
393 | struct ftrace_graph_ret *trace, | |
394 | unsigned long flags, | |
395 | int pc) | |
396 | { | |
397 | struct ftrace_event_call *call = &event_funcgraph_exit; | |
398 | struct ring_buffer_event *event; | |
399 | struct ring_buffer *buffer = tr->trace_buffer.buffer; | |
400 | struct ftrace_graph_ret_entry *entry; | |
401 | ||
402 | if (unlikely(__this_cpu_read(ftrace_cpu_disabled))) | |
403 | return; | |
404 | ||
405 | event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RET, | |
406 | sizeof(*entry), flags, pc); | |
407 | if (!event) | |
408 | return; | |
409 | entry = ring_buffer_event_data(event); | |
410 | entry->ret = *trace; | |
411 | if (!call_filter_check_discard(call, entry, buffer, event)) | |
412 | __buffer_unlock_commit(buffer, event); | |
413 | } | |
414 | ||
415 | void trace_graph_return(struct ftrace_graph_ret *trace) | |
416 | { | |
417 | struct trace_array *tr = graph_array; | |
418 | struct trace_array_cpu *data; | |
419 | unsigned long flags; | |
420 | long disabled; | |
421 | int cpu; | |
422 | int pc; | |
423 | ||
424 | local_irq_save(flags); | |
425 | cpu = raw_smp_processor_id(); | |
426 | data = per_cpu_ptr(tr->trace_buffer.data, cpu); | |
427 | disabled = atomic_inc_return(&data->disabled); | |
428 | if (likely(disabled == 1)) { | |
429 | pc = preempt_count(); | |
430 | __trace_graph_return(tr, trace, flags, pc); | |
431 | } | |
432 | atomic_dec(&data->disabled); | |
433 | local_irq_restore(flags); | |
434 | } | |
435 | ||
436 | void set_graph_array(struct trace_array *tr) | |
437 | { | |
438 | graph_array = tr; | |
439 | ||
440 | /* Make graph_array visible before we start tracing */ | |
441 | ||
442 | smp_mb(); | |
443 | } | |
444 | ||
445 | static void trace_graph_thresh_return(struct ftrace_graph_ret *trace) | |
446 | { | |
447 | if (tracing_thresh && | |
448 | (trace->rettime - trace->calltime < tracing_thresh)) | |
449 | return; | |
450 | else | |
451 | trace_graph_return(trace); | |
452 | } | |
453 | ||
454 | static int graph_trace_init(struct trace_array *tr) | |
455 | { | |
456 | int ret; | |
457 | ||
458 | set_graph_array(tr); | |
459 | if (tracing_thresh) | |
460 | ret = register_ftrace_graph(&trace_graph_thresh_return, | |
461 | &trace_graph_thresh_entry); | |
462 | else | |
463 | ret = register_ftrace_graph(&trace_graph_return, | |
464 | &trace_graph_entry); | |
465 | if (ret) | |
466 | return ret; | |
467 | tracing_start_cmdline_record(); | |
468 | ||
469 | return 0; | |
470 | } | |
471 | ||
472 | static void graph_trace_reset(struct trace_array *tr) | |
473 | { | |
474 | tracing_stop_cmdline_record(); | |
475 | unregister_ftrace_graph(); | |
476 | } | |
477 | ||
478 | static int graph_trace_update_thresh(struct trace_array *tr) | |
479 | { | |
480 | graph_trace_reset(tr); | |
481 | return graph_trace_init(tr); | |
482 | } | |
483 | ||
484 | static int max_bytes_for_cpu; | |
485 | ||
486 | static void print_graph_cpu(struct trace_seq *s, int cpu) | |
487 | { | |
488 | /* | |
489 | * Start with a space character - to make it stand out | |
490 | * to the right a bit when trace output is pasted into | |
491 | * email: | |
492 | */ | |
493 | trace_seq_printf(s, " %*d) ", max_bytes_for_cpu, cpu); | |
494 | } | |
495 | ||
496 | #define TRACE_GRAPH_PROCINFO_LENGTH 14 | |
497 | ||
498 | static void print_graph_proc(struct trace_seq *s, pid_t pid) | |
499 | { | |
500 | char comm[TASK_COMM_LEN]; | |
501 | /* sign + log10(MAX_INT) + '\0' */ | |
502 | char pid_str[11]; | |
503 | int spaces = 0; | |
504 | int len; | |
505 | int i; | |
506 | ||
507 | trace_find_cmdline(pid, comm); | |
508 | comm[7] = '\0'; | |
509 | sprintf(pid_str, "%d", pid); | |
510 | ||
511 | /* 1 stands for the "-" character */ | |
512 | len = strlen(comm) + strlen(pid_str) + 1; | |
513 | ||
514 | if (len < TRACE_GRAPH_PROCINFO_LENGTH) | |
515 | spaces = TRACE_GRAPH_PROCINFO_LENGTH - len; | |
516 | ||
517 | /* First spaces to align center */ | |
518 | for (i = 0; i < spaces / 2; i++) | |
519 | trace_seq_putc(s, ' '); | |
520 | ||
521 | trace_seq_printf(s, "%s-%s", comm, pid_str); | |
522 | ||
523 | /* Last spaces to align center */ | |
524 | for (i = 0; i < spaces - (spaces / 2); i++) | |
525 | trace_seq_putc(s, ' '); | |
526 | } | |
527 | ||
528 | ||
529 | static void print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry) | |
530 | { | |
531 | trace_seq_putc(s, ' '); | |
532 | trace_print_lat_fmt(s, entry); | |
533 | } | |
534 | ||
535 | /* If the pid changed since the last trace, output this event */ | |
536 | static void | |
537 | verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data) | |
538 | { | |
539 | pid_t prev_pid; | |
540 | pid_t *last_pid; | |
541 | ||
542 | if (!data) | |
543 | return; | |
544 | ||
545 | last_pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid); | |
546 | ||
547 | if (*last_pid == pid) | |
548 | return; | |
549 | ||
550 | prev_pid = *last_pid; | |
551 | *last_pid = pid; | |
552 | ||
553 | if (prev_pid == -1) | |
554 | return; | |
555 | /* | |
556 | * Context-switch trace line: | |
557 | ||
558 | ------------------------------------------ | |
559 | | 1) migration/0--1 => sshd-1755 | |
560 | ------------------------------------------ | |
561 | ||
562 | */ | |
563 | trace_seq_puts(s, " ------------------------------------------\n"); | |
564 | print_graph_cpu(s, cpu); | |
565 | print_graph_proc(s, prev_pid); | |
566 | trace_seq_puts(s, " => "); | |
567 | print_graph_proc(s, pid); | |
568 | trace_seq_puts(s, "\n ------------------------------------------\n\n"); | |
569 | } | |
570 | ||
571 | static struct ftrace_graph_ret_entry * | |
572 | get_return_for_leaf(struct trace_iterator *iter, | |
573 | struct ftrace_graph_ent_entry *curr) | |
574 | { | |
575 | struct fgraph_data *data = iter->private; | |
576 | struct ring_buffer_iter *ring_iter = NULL; | |
577 | struct ring_buffer_event *event; | |
578 | struct ftrace_graph_ret_entry *next; | |
579 | ||
580 | /* | |
581 | * If the previous output failed to write to the seq buffer, | |
582 | * then we just reuse the data from before. | |
583 | */ | |
584 | if (data && data->failed) { | |
585 | curr = &data->ent; | |
586 | next = &data->ret; | |
587 | } else { | |
588 | ||
589 | ring_iter = trace_buffer_iter(iter, iter->cpu); | |
590 | ||
591 | /* First peek to compare current entry and the next one */ | |
592 | if (ring_iter) | |
593 | event = ring_buffer_iter_peek(ring_iter, NULL); | |
594 | else { | |
595 | /* | |
596 | * We need to consume the current entry to see | |
597 | * the next one. | |
598 | */ | |
599 | ring_buffer_consume(iter->trace_buffer->buffer, iter->cpu, | |
600 | NULL, NULL); | |
601 | event = ring_buffer_peek(iter->trace_buffer->buffer, iter->cpu, | |
602 | NULL, NULL); | |
603 | } | |
604 | ||
605 | if (!event) | |
606 | return NULL; | |
607 | ||
608 | next = ring_buffer_event_data(event); | |
609 | ||
610 | if (data) { | |
611 | /* | |
612 | * Save current and next entries for later reference | |
613 | * if the output fails. | |
614 | */ | |
615 | data->ent = *curr; | |
616 | /* | |
617 | * If the next event is not a return type, then | |
618 | * we only care about what type it is. Otherwise we can | |
619 | * safely copy the entire event. | |
620 | */ | |
621 | if (next->ent.type == TRACE_GRAPH_RET) | |
622 | data->ret = *next; | |
623 | else | |
624 | data->ret.ent.type = next->ent.type; | |
625 | } | |
626 | } | |
627 | ||
628 | if (next->ent.type != TRACE_GRAPH_RET) | |
629 | return NULL; | |
630 | ||
631 | if (curr->ent.pid != next->ent.pid || | |
632 | curr->graph_ent.func != next->ret.func) | |
633 | return NULL; | |
634 | ||
635 | /* this is a leaf, now advance the iterator */ | |
636 | if (ring_iter) | |
637 | ring_buffer_read(ring_iter, NULL); | |
638 | ||
639 | return next; | |
640 | } | |
641 | ||
642 | static void print_graph_abs_time(u64 t, struct trace_seq *s) | |
643 | { | |
644 | unsigned long usecs_rem; | |
645 | ||
646 | usecs_rem = do_div(t, NSEC_PER_SEC); | |
647 | usecs_rem /= 1000; | |
648 | ||
649 | trace_seq_printf(s, "%5lu.%06lu | ", | |
650 | (unsigned long)t, usecs_rem); | |
651 | } | |
652 | ||
653 | static void | |
654 | print_graph_irq(struct trace_iterator *iter, unsigned long addr, | |
655 | enum trace_type type, int cpu, pid_t pid, u32 flags) | |
656 | { | |
657 | struct trace_seq *s = &iter->seq; | |
658 | struct trace_entry *ent = iter->ent; | |
659 | ||
660 | if (addr < (unsigned long)__irqentry_text_start || | |
661 | addr >= (unsigned long)__irqentry_text_end) | |
662 | return; | |
663 | ||
664 | if (trace_flags & TRACE_ITER_CONTEXT_INFO) { | |
665 | /* Absolute time */ | |
666 | if (flags & TRACE_GRAPH_PRINT_ABS_TIME) | |
667 | print_graph_abs_time(iter->ts, s); | |
668 | ||
669 | /* Cpu */ | |
670 | if (flags & TRACE_GRAPH_PRINT_CPU) | |
671 | print_graph_cpu(s, cpu); | |
672 | ||
673 | /* Proc */ | |
674 | if (flags & TRACE_GRAPH_PRINT_PROC) { | |
675 | print_graph_proc(s, pid); | |
676 | trace_seq_puts(s, " | "); | |
677 | } | |
678 | ||
679 | /* Latency format */ | |
680 | if (trace_flags & TRACE_ITER_LATENCY_FMT) | |
681 | print_graph_lat_fmt(s, ent); | |
682 | } | |
683 | ||
684 | /* No overhead */ | |
685 | print_graph_duration(0, s, flags | FLAGS_FILL_START); | |
686 | ||
687 | if (type == TRACE_GRAPH_ENT) | |
688 | trace_seq_puts(s, "==========>"); | |
689 | else | |
690 | trace_seq_puts(s, "<=========="); | |
691 | ||
692 | print_graph_duration(0, s, flags | FLAGS_FILL_END); | |
693 | trace_seq_putc(s, '\n'); | |
694 | } | |
695 | ||
696 | void | |
697 | trace_print_graph_duration(unsigned long long duration, struct trace_seq *s) | |
698 | { | |
699 | unsigned long nsecs_rem = do_div(duration, 1000); | |
700 | /* log10(ULONG_MAX) + '\0' */ | |
701 | char usecs_str[21]; | |
702 | char nsecs_str[5]; | |
703 | int len; | |
704 | int i; | |
705 | ||
706 | sprintf(usecs_str, "%lu", (unsigned long) duration); | |
707 | ||
708 | /* Print msecs */ | |
709 | trace_seq_printf(s, "%s", usecs_str); | |
710 | ||
711 | len = strlen(usecs_str); | |
712 | ||
713 | /* Print nsecs (we don't want to exceed 7 numbers) */ | |
714 | if (len < 7) { | |
715 | size_t slen = min_t(size_t, sizeof(nsecs_str), 8UL - len); | |
716 | ||
717 | snprintf(nsecs_str, slen, "%03lu", nsecs_rem); | |
718 | trace_seq_printf(s, ".%s", nsecs_str); | |
719 | len += strlen(nsecs_str); | |
720 | } | |
721 | ||
722 | trace_seq_puts(s, " us "); | |
723 | ||
724 | /* Print remaining spaces to fit the row's width */ | |
725 | for (i = len; i < 7; i++) | |
726 | trace_seq_putc(s, ' '); | |
727 | } | |
728 | ||
729 | static void | |
730 | print_graph_duration(unsigned long long duration, struct trace_seq *s, | |
731 | u32 flags) | |
732 | { | |
733 | if (!(flags & TRACE_GRAPH_PRINT_DURATION) || | |
734 | !(trace_flags & TRACE_ITER_CONTEXT_INFO)) | |
735 | return; | |
736 | ||
737 | /* No real adata, just filling the column with spaces */ | |
738 | switch (flags & TRACE_GRAPH_PRINT_FILL_MASK) { | |
739 | case FLAGS_FILL_FULL: | |
740 | trace_seq_puts(s, " | "); | |
741 | return; | |
742 | case FLAGS_FILL_START: | |
743 | trace_seq_puts(s, " "); | |
744 | return; | |
745 | case FLAGS_FILL_END: | |
746 | trace_seq_puts(s, " |"); | |
747 | return; | |
748 | } | |
749 | ||
750 | /* Signal a overhead of time execution to the output */ | |
751 | if (flags & TRACE_GRAPH_PRINT_OVERHEAD) | |
752 | trace_seq_printf(s, "%c ", trace_find_mark(duration)); | |
753 | else | |
754 | trace_seq_puts(s, " "); | |
755 | ||
756 | trace_print_graph_duration(duration, s); | |
757 | trace_seq_puts(s, "| "); | |
758 | } | |
759 | ||
760 | /* Case of a leaf function on its call entry */ | |
761 | static enum print_line_t | |
762 | print_graph_entry_leaf(struct trace_iterator *iter, | |
763 | struct ftrace_graph_ent_entry *entry, | |
764 | struct ftrace_graph_ret_entry *ret_entry, | |
765 | struct trace_seq *s, u32 flags) | |
766 | { | |
767 | struct fgraph_data *data = iter->private; | |
768 | struct ftrace_graph_ret *graph_ret; | |
769 | struct ftrace_graph_ent *call; | |
770 | unsigned long long duration; | |
771 | int i; | |
772 | ||
773 | graph_ret = &ret_entry->ret; | |
774 | call = &entry->graph_ent; | |
775 | duration = graph_ret->rettime - graph_ret->calltime; | |
776 | ||
777 | if (data) { | |
778 | struct fgraph_cpu_data *cpu_data; | |
779 | int cpu = iter->cpu; | |
780 | ||
781 | cpu_data = per_cpu_ptr(data->cpu_data, cpu); | |
782 | ||
783 | /* | |
784 | * Comments display at + 1 to depth. Since | |
785 | * this is a leaf function, keep the comments | |
786 | * equal to this depth. | |
787 | */ | |
788 | cpu_data->depth = call->depth - 1; | |
789 | ||
790 | /* No need to keep this function around for this depth */ | |
791 | if (call->depth < FTRACE_RETFUNC_DEPTH) | |
792 | cpu_data->enter_funcs[call->depth] = 0; | |
793 | } | |
794 | ||
795 | /* Overhead and duration */ | |
796 | print_graph_duration(duration, s, flags); | |
797 | ||
798 | /* Function */ | |
799 | for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) | |
800 | trace_seq_putc(s, ' '); | |
801 | ||
802 | trace_seq_printf(s, "%ps();\n", (void *)call->func); | |
803 | ||
804 | return trace_handle_return(s); | |
805 | } | |
806 | ||
807 | static enum print_line_t | |
808 | print_graph_entry_nested(struct trace_iterator *iter, | |
809 | struct ftrace_graph_ent_entry *entry, | |
810 | struct trace_seq *s, int cpu, u32 flags) | |
811 | { | |
812 | struct ftrace_graph_ent *call = &entry->graph_ent; | |
813 | struct fgraph_data *data = iter->private; | |
814 | int i; | |
815 | ||
816 | if (data) { | |
817 | struct fgraph_cpu_data *cpu_data; | |
818 | int cpu = iter->cpu; | |
819 | ||
820 | cpu_data = per_cpu_ptr(data->cpu_data, cpu); | |
821 | cpu_data->depth = call->depth; | |
822 | ||
823 | /* Save this function pointer to see if the exit matches */ | |
824 | if (call->depth < FTRACE_RETFUNC_DEPTH) | |
825 | cpu_data->enter_funcs[call->depth] = call->func; | |
826 | } | |
827 | ||
828 | /* No time */ | |
829 | print_graph_duration(0, s, flags | FLAGS_FILL_FULL); | |
830 | ||
831 | /* Function */ | |
832 | for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) | |
833 | trace_seq_putc(s, ' '); | |
834 | ||
835 | trace_seq_printf(s, "%ps() {\n", (void *)call->func); | |
836 | ||
837 | if (trace_seq_has_overflowed(s)) | |
838 | return TRACE_TYPE_PARTIAL_LINE; | |
839 | ||
840 | /* | |
841 | * we already consumed the current entry to check the next one | |
842 | * and see if this is a leaf. | |
843 | */ | |
844 | return TRACE_TYPE_NO_CONSUME; | |
845 | } | |
846 | ||
847 | static void | |
848 | print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s, | |
849 | int type, unsigned long addr, u32 flags) | |
850 | { | |
851 | struct fgraph_data *data = iter->private; | |
852 | struct trace_entry *ent = iter->ent; | |
853 | int cpu = iter->cpu; | |
854 | ||
855 | /* Pid */ | |
856 | verif_pid(s, ent->pid, cpu, data); | |
857 | ||
858 | if (type) | |
859 | /* Interrupt */ | |
860 | print_graph_irq(iter, addr, type, cpu, ent->pid, flags); | |
861 | ||
862 | if (!(trace_flags & TRACE_ITER_CONTEXT_INFO)) | |
863 | return; | |
864 | ||
865 | /* Absolute time */ | |
866 | if (flags & TRACE_GRAPH_PRINT_ABS_TIME) | |
867 | print_graph_abs_time(iter->ts, s); | |
868 | ||
869 | /* Cpu */ | |
870 | if (flags & TRACE_GRAPH_PRINT_CPU) | |
871 | print_graph_cpu(s, cpu); | |
872 | ||
873 | /* Proc */ | |
874 | if (flags & TRACE_GRAPH_PRINT_PROC) { | |
875 | print_graph_proc(s, ent->pid); | |
876 | trace_seq_puts(s, " | "); | |
877 | } | |
878 | ||
879 | /* Latency format */ | |
880 | if (trace_flags & TRACE_ITER_LATENCY_FMT) | |
881 | print_graph_lat_fmt(s, ent); | |
882 | ||
883 | return; | |
884 | } | |
885 | ||
886 | /* | |
887 | * Entry check for irq code | |
888 | * | |
889 | * returns 1 if | |
890 | * - we are inside irq code | |
891 | * - we just entered irq code | |
892 | * | |
893 | * retunns 0 if | |
894 | * - funcgraph-interrupts option is set | |
895 | * - we are not inside irq code | |
896 | */ | |
897 | static int | |
898 | check_irq_entry(struct trace_iterator *iter, u32 flags, | |
899 | unsigned long addr, int depth) | |
900 | { | |
901 | int cpu = iter->cpu; | |
902 | int *depth_irq; | |
903 | struct fgraph_data *data = iter->private; | |
904 | ||
905 | /* | |
906 | * If we are either displaying irqs, or we got called as | |
907 | * a graph event and private data does not exist, | |
908 | * then we bypass the irq check. | |
909 | */ | |
910 | if ((flags & TRACE_GRAPH_PRINT_IRQS) || | |
911 | (!data)) | |
912 | return 0; | |
913 | ||
914 | depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq); | |
915 | ||
916 | /* | |
917 | * We are inside the irq code | |
918 | */ | |
919 | if (*depth_irq >= 0) | |
920 | return 1; | |
921 | ||
922 | if ((addr < (unsigned long)__irqentry_text_start) || | |
923 | (addr >= (unsigned long)__irqentry_text_end)) | |
924 | return 0; | |
925 | ||
926 | /* | |
927 | * We are entering irq code. | |
928 | */ | |
929 | *depth_irq = depth; | |
930 | return 1; | |
931 | } | |
932 | ||
933 | /* | |
934 | * Return check for irq code | |
935 | * | |
936 | * returns 1 if | |
937 | * - we are inside irq code | |
938 | * - we just left irq code | |
939 | * | |
940 | * returns 0 if | |
941 | * - funcgraph-interrupts option is set | |
942 | * - we are not inside irq code | |
943 | */ | |
944 | static int | |
945 | check_irq_return(struct trace_iterator *iter, u32 flags, int depth) | |
946 | { | |
947 | int cpu = iter->cpu; | |
948 | int *depth_irq; | |
949 | struct fgraph_data *data = iter->private; | |
950 | ||
951 | /* | |
952 | * If we are either displaying irqs, or we got called as | |
953 | * a graph event and private data does not exist, | |
954 | * then we bypass the irq check. | |
955 | */ | |
956 | if ((flags & TRACE_GRAPH_PRINT_IRQS) || | |
957 | (!data)) | |
958 | return 0; | |
959 | ||
960 | depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq); | |
961 | ||
962 | /* | |
963 | * We are not inside the irq code. | |
964 | */ | |
965 | if (*depth_irq == -1) | |
966 | return 0; | |
967 | ||
968 | /* | |
969 | * We are inside the irq code, and this is returning entry. | |
970 | * Let's not trace it and clear the entry depth, since | |
971 | * we are out of irq code. | |
972 | * | |
973 | * This condition ensures that we 'leave the irq code' once | |
974 | * we are out of the entry depth. Thus protecting us from | |
975 | * the RETURN entry loss. | |
976 | */ | |
977 | if (*depth_irq >= depth) { | |
978 | *depth_irq = -1; | |
979 | return 1; | |
980 | } | |
981 | ||
982 | /* | |
983 | * We are inside the irq code, and this is not the entry. | |
984 | */ | |
985 | return 1; | |
986 | } | |
987 | ||
988 | static enum print_line_t | |
989 | print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s, | |
990 | struct trace_iterator *iter, u32 flags) | |
991 | { | |
992 | struct fgraph_data *data = iter->private; | |
993 | struct ftrace_graph_ent *call = &field->graph_ent; | |
994 | struct ftrace_graph_ret_entry *leaf_ret; | |
995 | static enum print_line_t ret; | |
996 | int cpu = iter->cpu; | |
997 | ||
998 | if (check_irq_entry(iter, flags, call->func, call->depth)) | |
999 | return TRACE_TYPE_HANDLED; | |
1000 | ||
1001 | print_graph_prologue(iter, s, TRACE_GRAPH_ENT, call->func, flags); | |
1002 | ||
1003 | leaf_ret = get_return_for_leaf(iter, field); | |
1004 | if (leaf_ret) | |
1005 | ret = print_graph_entry_leaf(iter, field, leaf_ret, s, flags); | |
1006 | else | |
1007 | ret = print_graph_entry_nested(iter, field, s, cpu, flags); | |
1008 | ||
1009 | if (data) { | |
1010 | /* | |
1011 | * If we failed to write our output, then we need to make | |
1012 | * note of it. Because we already consumed our entry. | |
1013 | */ | |
1014 | if (s->full) { | |
1015 | data->failed = 1; | |
1016 | data->cpu = cpu; | |
1017 | } else | |
1018 | data->failed = 0; | |
1019 | } | |
1020 | ||
1021 | return ret; | |
1022 | } | |
1023 | ||
1024 | static enum print_line_t | |
1025 | print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s, | |
1026 | struct trace_entry *ent, struct trace_iterator *iter, | |
1027 | u32 flags) | |
1028 | { | |
1029 | unsigned long long duration = trace->rettime - trace->calltime; | |
1030 | struct fgraph_data *data = iter->private; | |
1031 | pid_t pid = ent->pid; | |
1032 | int cpu = iter->cpu; | |
1033 | int func_match = 1; | |
1034 | int i; | |
1035 | ||
1036 | if (check_irq_return(iter, flags, trace->depth)) | |
1037 | return TRACE_TYPE_HANDLED; | |
1038 | ||
1039 | if (data) { | |
1040 | struct fgraph_cpu_data *cpu_data; | |
1041 | int cpu = iter->cpu; | |
1042 | ||
1043 | cpu_data = per_cpu_ptr(data->cpu_data, cpu); | |
1044 | ||
1045 | /* | |
1046 | * Comments display at + 1 to depth. This is the | |
1047 | * return from a function, we now want the comments | |
1048 | * to display at the same level of the bracket. | |
1049 | */ | |
1050 | cpu_data->depth = trace->depth - 1; | |
1051 | ||
1052 | if (trace->depth < FTRACE_RETFUNC_DEPTH) { | |
1053 | if (cpu_data->enter_funcs[trace->depth] != trace->func) | |
1054 | func_match = 0; | |
1055 | cpu_data->enter_funcs[trace->depth] = 0; | |
1056 | } | |
1057 | } | |
1058 | ||
1059 | print_graph_prologue(iter, s, 0, 0, flags); | |
1060 | ||
1061 | /* Overhead and duration */ | |
1062 | print_graph_duration(duration, s, flags); | |
1063 | ||
1064 | /* Closing brace */ | |
1065 | for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) | |
1066 | trace_seq_putc(s, ' '); | |
1067 | ||
1068 | /* | |
1069 | * If the return function does not have a matching entry, | |
1070 | * then the entry was lost. Instead of just printing | |
1071 | * the '}' and letting the user guess what function this | |
1072 | * belongs to, write out the function name. Always do | |
1073 | * that if the funcgraph-tail option is enabled. | |
1074 | */ | |
1075 | if (func_match && !(flags & TRACE_GRAPH_PRINT_TAIL)) | |
1076 | trace_seq_puts(s, "}\n"); | |
1077 | else | |
1078 | trace_seq_printf(s, "} /* %ps */\n", (void *)trace->func); | |
1079 | ||
1080 | /* Overrun */ | |
1081 | if (flags & TRACE_GRAPH_PRINT_OVERRUN) | |
1082 | trace_seq_printf(s, " (Overruns: %lu)\n", | |
1083 | trace->overrun); | |
1084 | ||
1085 | print_graph_irq(iter, trace->func, TRACE_GRAPH_RET, | |
1086 | cpu, pid, flags); | |
1087 | ||
1088 | return trace_handle_return(s); | |
1089 | } | |
1090 | ||
1091 | static enum print_line_t | |
1092 | print_graph_comment(struct trace_seq *s, struct trace_entry *ent, | |
1093 | struct trace_iterator *iter, u32 flags) | |
1094 | { | |
1095 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); | |
1096 | struct fgraph_data *data = iter->private; | |
1097 | struct trace_event *event; | |
1098 | int depth = 0; | |
1099 | int ret; | |
1100 | int i; | |
1101 | ||
1102 | if (data) | |
1103 | depth = per_cpu_ptr(data->cpu_data, iter->cpu)->depth; | |
1104 | ||
1105 | print_graph_prologue(iter, s, 0, 0, flags); | |
1106 | ||
1107 | /* No time */ | |
1108 | print_graph_duration(0, s, flags | FLAGS_FILL_FULL); | |
1109 | ||
1110 | /* Indentation */ | |
1111 | if (depth > 0) | |
1112 | for (i = 0; i < (depth + 1) * TRACE_GRAPH_INDENT; i++) | |
1113 | trace_seq_putc(s, ' '); | |
1114 | ||
1115 | /* The comment */ | |
1116 | trace_seq_puts(s, "/* "); | |
1117 | ||
1118 | switch (iter->ent->type) { | |
1119 | case TRACE_BPRINT: | |
1120 | ret = trace_print_bprintk_msg_only(iter); | |
1121 | if (ret != TRACE_TYPE_HANDLED) | |
1122 | return ret; | |
1123 | break; | |
1124 | case TRACE_PRINT: | |
1125 | ret = trace_print_printk_msg_only(iter); | |
1126 | if (ret != TRACE_TYPE_HANDLED) | |
1127 | return ret; | |
1128 | break; | |
1129 | default: | |
1130 | event = ftrace_find_event(ent->type); | |
1131 | if (!event) | |
1132 | return TRACE_TYPE_UNHANDLED; | |
1133 | ||
1134 | ret = event->funcs->trace(iter, sym_flags, event); | |
1135 | if (ret != TRACE_TYPE_HANDLED) | |
1136 | return ret; | |
1137 | } | |
1138 | ||
1139 | if (trace_seq_has_overflowed(s)) | |
1140 | goto out; | |
1141 | ||
1142 | /* Strip ending newline */ | |
1143 | if (s->buffer[s->seq.len - 1] == '\n') { | |
1144 | s->buffer[s->seq.len - 1] = '\0'; | |
1145 | s->seq.len--; | |
1146 | } | |
1147 | ||
1148 | trace_seq_puts(s, " */\n"); | |
1149 | out: | |
1150 | return trace_handle_return(s); | |
1151 | } | |
1152 | ||
1153 | ||
1154 | enum print_line_t | |
1155 | print_graph_function_flags(struct trace_iterator *iter, u32 flags) | |
1156 | { | |
1157 | struct ftrace_graph_ent_entry *field; | |
1158 | struct fgraph_data *data = iter->private; | |
1159 | struct trace_entry *entry = iter->ent; | |
1160 | struct trace_seq *s = &iter->seq; | |
1161 | int cpu = iter->cpu; | |
1162 | int ret; | |
1163 | ||
1164 | if (data && per_cpu_ptr(data->cpu_data, cpu)->ignore) { | |
1165 | per_cpu_ptr(data->cpu_data, cpu)->ignore = 0; | |
1166 | return TRACE_TYPE_HANDLED; | |
1167 | } | |
1168 | ||
1169 | /* | |
1170 | * If the last output failed, there's a possibility we need | |
1171 | * to print out the missing entry which would never go out. | |
1172 | */ | |
1173 | if (data && data->failed) { | |
1174 | field = &data->ent; | |
1175 | iter->cpu = data->cpu; | |
1176 | ret = print_graph_entry(field, s, iter, flags); | |
1177 | if (ret == TRACE_TYPE_HANDLED && iter->cpu != cpu) { | |
1178 | per_cpu_ptr(data->cpu_data, iter->cpu)->ignore = 1; | |
1179 | ret = TRACE_TYPE_NO_CONSUME; | |
1180 | } | |
1181 | iter->cpu = cpu; | |
1182 | return ret; | |
1183 | } | |
1184 | ||
1185 | switch (entry->type) { | |
1186 | case TRACE_GRAPH_ENT: { | |
1187 | /* | |
1188 | * print_graph_entry() may consume the current event, | |
1189 | * thus @field may become invalid, so we need to save it. | |
1190 | * sizeof(struct ftrace_graph_ent_entry) is very small, | |
1191 | * it can be safely saved at the stack. | |
1192 | */ | |
1193 | struct ftrace_graph_ent_entry saved; | |
1194 | trace_assign_type(field, entry); | |
1195 | saved = *field; | |
1196 | return print_graph_entry(&saved, s, iter, flags); | |
1197 | } | |
1198 | case TRACE_GRAPH_RET: { | |
1199 | struct ftrace_graph_ret_entry *field; | |
1200 | trace_assign_type(field, entry); | |
1201 | return print_graph_return(&field->ret, s, entry, iter, flags); | |
1202 | } | |
1203 | case TRACE_STACK: | |
1204 | case TRACE_FN: | |
1205 | /* dont trace stack and functions as comments */ | |
1206 | return TRACE_TYPE_UNHANDLED; | |
1207 | ||
1208 | default: | |
1209 | return print_graph_comment(s, entry, iter, flags); | |
1210 | } | |
1211 | ||
1212 | return TRACE_TYPE_HANDLED; | |
1213 | } | |
1214 | ||
1215 | static enum print_line_t | |
1216 | print_graph_function(struct trace_iterator *iter) | |
1217 | { | |
1218 | return print_graph_function_flags(iter, tracer_flags.val); | |
1219 | } | |
1220 | ||
1221 | static enum print_line_t | |
1222 | print_graph_function_event(struct trace_iterator *iter, int flags, | |
1223 | struct trace_event *event) | |
1224 | { | |
1225 | return print_graph_function(iter); | |
1226 | } | |
1227 | ||
1228 | static void print_lat_header(struct seq_file *s, u32 flags) | |
1229 | { | |
1230 | static const char spaces[] = " " /* 16 spaces */ | |
1231 | " " /* 4 spaces */ | |
1232 | " "; /* 17 spaces */ | |
1233 | int size = 0; | |
1234 | ||
1235 | if (flags & TRACE_GRAPH_PRINT_ABS_TIME) | |
1236 | size += 16; | |
1237 | if (flags & TRACE_GRAPH_PRINT_CPU) | |
1238 | size += 4; | |
1239 | if (flags & TRACE_GRAPH_PRINT_PROC) | |
1240 | size += 17; | |
1241 | ||
1242 | seq_printf(s, "#%.*s _-----=> irqs-off \n", size, spaces); | |
1243 | seq_printf(s, "#%.*s / _----=> need-resched \n", size, spaces); | |
1244 | seq_printf(s, "#%.*s| / _---=> hardirq/softirq \n", size, spaces); | |
1245 | seq_printf(s, "#%.*s|| / _--=> preempt-depth \n", size, spaces); | |
1246 | seq_printf(s, "#%.*s||| / \n", size, spaces); | |
1247 | } | |
1248 | ||
1249 | static void __print_graph_headers_flags(struct seq_file *s, u32 flags) | |
1250 | { | |
1251 | int lat = trace_flags & TRACE_ITER_LATENCY_FMT; | |
1252 | ||
1253 | if (lat) | |
1254 | print_lat_header(s, flags); | |
1255 | ||
1256 | /* 1st line */ | |
1257 | seq_putc(s, '#'); | |
1258 | if (flags & TRACE_GRAPH_PRINT_ABS_TIME) | |
1259 | seq_puts(s, " TIME "); | |
1260 | if (flags & TRACE_GRAPH_PRINT_CPU) | |
1261 | seq_puts(s, " CPU"); | |
1262 | if (flags & TRACE_GRAPH_PRINT_PROC) | |
1263 | seq_puts(s, " TASK/PID "); | |
1264 | if (lat) | |
1265 | seq_puts(s, "||||"); | |
1266 | if (flags & TRACE_GRAPH_PRINT_DURATION) | |
1267 | seq_puts(s, " DURATION "); | |
1268 | seq_puts(s, " FUNCTION CALLS\n"); | |
1269 | ||
1270 | /* 2nd line */ | |
1271 | seq_putc(s, '#'); | |
1272 | if (flags & TRACE_GRAPH_PRINT_ABS_TIME) | |
1273 | seq_puts(s, " | "); | |
1274 | if (flags & TRACE_GRAPH_PRINT_CPU) | |
1275 | seq_puts(s, " | "); | |
1276 | if (flags & TRACE_GRAPH_PRINT_PROC) | |
1277 | seq_puts(s, " | | "); | |
1278 | if (lat) | |
1279 | seq_puts(s, "||||"); | |
1280 | if (flags & TRACE_GRAPH_PRINT_DURATION) | |
1281 | seq_puts(s, " | | "); | |
1282 | seq_puts(s, " | | | |\n"); | |
1283 | } | |
1284 | ||
1285 | static void print_graph_headers(struct seq_file *s) | |
1286 | { | |
1287 | print_graph_headers_flags(s, tracer_flags.val); | |
1288 | } | |
1289 | ||
1290 | void print_graph_headers_flags(struct seq_file *s, u32 flags) | |
1291 | { | |
1292 | struct trace_iterator *iter = s->private; | |
1293 | ||
1294 | if (!(trace_flags & TRACE_ITER_CONTEXT_INFO)) | |
1295 | return; | |
1296 | ||
1297 | if (trace_flags & TRACE_ITER_LATENCY_FMT) { | |
1298 | /* print nothing if the buffers are empty */ | |
1299 | if (trace_empty(iter)) | |
1300 | return; | |
1301 | ||
1302 | print_trace_header(s, iter); | |
1303 | } | |
1304 | ||
1305 | __print_graph_headers_flags(s, flags); | |
1306 | } | |
1307 | ||
1308 | void graph_trace_open(struct trace_iterator *iter) | |
1309 | { | |
1310 | /* pid and depth on the last trace processed */ | |
1311 | struct fgraph_data *data; | |
1312 | int cpu; | |
1313 | ||
1314 | iter->private = NULL; | |
1315 | ||
1316 | data = kzalloc(sizeof(*data), GFP_KERNEL); | |
1317 | if (!data) | |
1318 | goto out_err; | |
1319 | ||
1320 | data->cpu_data = alloc_percpu(struct fgraph_cpu_data); | |
1321 | if (!data->cpu_data) | |
1322 | goto out_err_free; | |
1323 | ||
1324 | for_each_possible_cpu(cpu) { | |
1325 | pid_t *pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid); | |
1326 | int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth); | |
1327 | int *ignore = &(per_cpu_ptr(data->cpu_data, cpu)->ignore); | |
1328 | int *depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq); | |
1329 | ||
1330 | *pid = -1; | |
1331 | *depth = 0; | |
1332 | *ignore = 0; | |
1333 | *depth_irq = -1; | |
1334 | } | |
1335 | ||
1336 | iter->private = data; | |
1337 | ||
1338 | return; | |
1339 | ||
1340 | out_err_free: | |
1341 | kfree(data); | |
1342 | out_err: | |
1343 | pr_warning("function graph tracer: not enough memory\n"); | |
1344 | } | |
1345 | ||
1346 | void graph_trace_close(struct trace_iterator *iter) | |
1347 | { | |
1348 | struct fgraph_data *data = iter->private; | |
1349 | ||
1350 | if (data) { | |
1351 | free_percpu(data->cpu_data); | |
1352 | kfree(data); | |
1353 | } | |
1354 | } | |
1355 | ||
1356 | static int | |
1357 | func_graph_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set) | |
1358 | { | |
1359 | if (bit == TRACE_GRAPH_PRINT_IRQS) | |
1360 | ftrace_graph_skip_irqs = !set; | |
1361 | ||
1362 | return 0; | |
1363 | } | |
1364 | ||
1365 | static struct trace_event_functions graph_functions = { | |
1366 | .trace = print_graph_function_event, | |
1367 | }; | |
1368 | ||
1369 | static struct trace_event graph_trace_entry_event = { | |
1370 | .type = TRACE_GRAPH_ENT, | |
1371 | .funcs = &graph_functions, | |
1372 | }; | |
1373 | ||
1374 | static struct trace_event graph_trace_ret_event = { | |
1375 | .type = TRACE_GRAPH_RET, | |
1376 | .funcs = &graph_functions | |
1377 | }; | |
1378 | ||
1379 | static struct tracer graph_trace __tracer_data = { | |
1380 | .name = "function_graph", | |
1381 | .update_thresh = graph_trace_update_thresh, | |
1382 | .open = graph_trace_open, | |
1383 | .pipe_open = graph_trace_open, | |
1384 | .close = graph_trace_close, | |
1385 | .pipe_close = graph_trace_close, | |
1386 | .init = graph_trace_init, | |
1387 | .reset = graph_trace_reset, | |
1388 | .print_line = print_graph_function, | |
1389 | .print_header = print_graph_headers, | |
1390 | .flags = &tracer_flags, | |
1391 | .set_flag = func_graph_set_flag, | |
1392 | #ifdef CONFIG_FTRACE_SELFTEST | |
1393 | .selftest = trace_selftest_startup_function_graph, | |
1394 | #endif | |
1395 | }; | |
1396 | ||
1397 | ||
1398 | static ssize_t | |
1399 | graph_depth_write(struct file *filp, const char __user *ubuf, size_t cnt, | |
1400 | loff_t *ppos) | |
1401 | { | |
1402 | unsigned long val; | |
1403 | int ret; | |
1404 | ||
1405 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); | |
1406 | if (ret) | |
1407 | return ret; | |
1408 | ||
1409 | max_depth = val; | |
1410 | ||
1411 | *ppos += cnt; | |
1412 | ||
1413 | return cnt; | |
1414 | } | |
1415 | ||
1416 | static ssize_t | |
1417 | graph_depth_read(struct file *filp, char __user *ubuf, size_t cnt, | |
1418 | loff_t *ppos) | |
1419 | { | |
1420 | char buf[15]; /* More than enough to hold UINT_MAX + "\n"*/ | |
1421 | int n; | |
1422 | ||
1423 | n = sprintf(buf, "%d\n", max_depth); | |
1424 | ||
1425 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, n); | |
1426 | } | |
1427 | ||
1428 | static const struct file_operations graph_depth_fops = { | |
1429 | .open = tracing_open_generic, | |
1430 | .write = graph_depth_write, | |
1431 | .read = graph_depth_read, | |
1432 | .llseek = generic_file_llseek, | |
1433 | }; | |
1434 | ||
1435 | static __init int init_graph_debugfs(void) | |
1436 | { | |
1437 | struct dentry *d_tracer; | |
1438 | ||
1439 | d_tracer = tracing_init_dentry(); | |
1440 | if (IS_ERR(d_tracer)) | |
1441 | return 0; | |
1442 | ||
1443 | trace_create_file("max_graph_depth", 0644, d_tracer, | |
1444 | NULL, &graph_depth_fops); | |
1445 | ||
1446 | return 0; | |
1447 | } | |
1448 | fs_initcall(init_graph_debugfs); | |
1449 | ||
1450 | static __init int init_graph_trace(void) | |
1451 | { | |
1452 | max_bytes_for_cpu = snprintf(NULL, 0, "%d", nr_cpu_ids - 1); | |
1453 | ||
1454 | if (!register_ftrace_event(&graph_trace_entry_event)) { | |
1455 | pr_warning("Warning: could not register graph trace events\n"); | |
1456 | return 1; | |
1457 | } | |
1458 | ||
1459 | if (!register_ftrace_event(&graph_trace_ret_event)) { | |
1460 | pr_warning("Warning: could not register graph trace events\n"); | |
1461 | return 1; | |
1462 | } | |
1463 | ||
1464 | return register_tracer(&graph_trace); | |
1465 | } | |
1466 | ||
1467 | core_initcall(init_graph_trace); |