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00447ccd AH |
1 | /* |
2 | * thread-stack.c: Synthesize a thread's stack using call / return events | |
3 | * Copyright (c) 2014, Intel Corporation. | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify it | |
6 | * under the terms and conditions of the GNU General Public License, | |
7 | * version 2, as published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope it will be useful, but WITHOUT | |
10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
12 | * more details. | |
13 | * | |
14 | */ | |
15 | ||
92a9e4f7 AH |
16 | #include <linux/rbtree.h> |
17 | #include <linux/list.h> | |
00447ccd AH |
18 | #include "thread.h" |
19 | #include "event.h" | |
92a9e4f7 | 20 | #include "machine.h" |
00447ccd AH |
21 | #include "util.h" |
22 | #include "debug.h" | |
92a9e4f7 AH |
23 | #include "symbol.h" |
24 | #include "comm.h" | |
00447ccd AH |
25 | #include "thread-stack.h" |
26 | ||
92a9e4f7 AH |
27 | #define CALL_PATH_BLOCK_SHIFT 8 |
28 | #define CALL_PATH_BLOCK_SIZE (1 << CALL_PATH_BLOCK_SHIFT) | |
29 | #define CALL_PATH_BLOCK_MASK (CALL_PATH_BLOCK_SIZE - 1) | |
00447ccd | 30 | |
92a9e4f7 AH |
31 | struct call_path_block { |
32 | struct call_path cp[CALL_PATH_BLOCK_SIZE]; | |
33 | struct list_head node; | |
34 | }; | |
35 | ||
36 | /** | |
37 | * struct call_path_root - root of all call paths. | |
38 | * @call_path: root call path | |
39 | * @blocks: list of blocks to store call paths | |
40 | * @next: next free space | |
41 | * @sz: number of spaces | |
42 | */ | |
43 | struct call_path_root { | |
44 | struct call_path call_path; | |
45 | struct list_head blocks; | |
46 | size_t next; | |
47 | size_t sz; | |
48 | }; | |
49 | ||
50 | /** | |
51 | * struct call_return_processor - provides a call-back to consume call-return | |
52 | * information. | |
53 | * @cpr: call path root | |
54 | * @process: call-back that accepts call/return information | |
55 | * @data: anonymous data for call-back | |
56 | */ | |
57 | struct call_return_processor { | |
58 | struct call_path_root *cpr; | |
59 | int (*process)(struct call_return *cr, void *data); | |
60 | void *data; | |
61 | }; | |
62 | ||
63 | #define STACK_GROWTH 2048 | |
64 | ||
65 | /** | |
66 | * struct thread_stack_entry - thread stack entry. | |
67 | * @ret_addr: return address | |
68 | * @timestamp: timestamp (if known) | |
69 | * @ref: external reference (e.g. db_id of sample) | |
70 | * @branch_count: the branch count when the entry was created | |
71 | * @cp: call path | |
72 | * @no_call: a 'call' was not seen | |
73 | */ | |
00447ccd AH |
74 | struct thread_stack_entry { |
75 | u64 ret_addr; | |
92a9e4f7 AH |
76 | u64 timestamp; |
77 | u64 ref; | |
78 | u64 branch_count; | |
79 | struct call_path *cp; | |
80 | bool no_call; | |
00447ccd AH |
81 | }; |
82 | ||
92a9e4f7 AH |
83 | /** |
84 | * struct thread_stack - thread stack constructed from 'call' and 'return' | |
85 | * branch samples. | |
86 | * @stack: array that holds the stack | |
87 | * @cnt: number of entries in the stack | |
88 | * @sz: current maximum stack size | |
89 | * @trace_nr: current trace number | |
90 | * @branch_count: running branch count | |
91 | * @kernel_start: kernel start address | |
92 | * @last_time: last timestamp | |
93 | * @crp: call/return processor | |
94 | * @comm: current comm | |
95 | */ | |
00447ccd AH |
96 | struct thread_stack { |
97 | struct thread_stack_entry *stack; | |
98 | size_t cnt; | |
99 | size_t sz; | |
100 | u64 trace_nr; | |
92a9e4f7 AH |
101 | u64 branch_count; |
102 | u64 kernel_start; | |
103 | u64 last_time; | |
104 | struct call_return_processor *crp; | |
105 | struct comm *comm; | |
00447ccd AH |
106 | }; |
107 | ||
108 | static int thread_stack__grow(struct thread_stack *ts) | |
109 | { | |
110 | struct thread_stack_entry *new_stack; | |
111 | size_t sz, new_sz; | |
112 | ||
113 | new_sz = ts->sz + STACK_GROWTH; | |
114 | sz = new_sz * sizeof(struct thread_stack_entry); | |
115 | ||
116 | new_stack = realloc(ts->stack, sz); | |
117 | if (!new_stack) | |
118 | return -ENOMEM; | |
119 | ||
120 | ts->stack = new_stack; | |
121 | ts->sz = new_sz; | |
122 | ||
123 | return 0; | |
124 | } | |
125 | ||
92a9e4f7 AH |
126 | static struct thread_stack *thread_stack__new(struct thread *thread, |
127 | struct call_return_processor *crp) | |
00447ccd AH |
128 | { |
129 | struct thread_stack *ts; | |
130 | ||
131 | ts = zalloc(sizeof(struct thread_stack)); | |
132 | if (!ts) | |
133 | return NULL; | |
134 | ||
135 | if (thread_stack__grow(ts)) { | |
136 | free(ts); | |
137 | return NULL; | |
138 | } | |
139 | ||
92a9e4f7 AH |
140 | if (thread->mg && thread->mg->machine) |
141 | ts->kernel_start = machine__kernel_start(thread->mg->machine); | |
142 | else | |
143 | ts->kernel_start = 1ULL << 63; | |
144 | ts->crp = crp; | |
145 | ||
00447ccd AH |
146 | return ts; |
147 | } | |
148 | ||
149 | static int thread_stack__push(struct thread_stack *ts, u64 ret_addr) | |
150 | { | |
151 | int err = 0; | |
152 | ||
153 | if (ts->cnt == ts->sz) { | |
154 | err = thread_stack__grow(ts); | |
155 | if (err) { | |
156 | pr_warning("Out of memory: discarding thread stack\n"); | |
157 | ts->cnt = 0; | |
158 | } | |
159 | } | |
160 | ||
161 | ts->stack[ts->cnt++].ret_addr = ret_addr; | |
162 | ||
163 | return err; | |
164 | } | |
165 | ||
166 | static void thread_stack__pop(struct thread_stack *ts, u64 ret_addr) | |
167 | { | |
168 | size_t i; | |
169 | ||
170 | /* | |
171 | * In some cases there may be functions which are not seen to return. | |
172 | * For example when setjmp / longjmp has been used. Or the perf context | |
173 | * switch in the kernel which doesn't stop and start tracing in exactly | |
174 | * the same code path. When that happens the return address will be | |
175 | * further down the stack. If the return address is not found at all, | |
176 | * we assume the opposite (i.e. this is a return for a call that wasn't | |
177 | * seen for some reason) and leave the stack alone. | |
178 | */ | |
179 | for (i = ts->cnt; i; ) { | |
180 | if (ts->stack[--i].ret_addr == ret_addr) { | |
181 | ts->cnt = i; | |
182 | return; | |
183 | } | |
184 | } | |
185 | } | |
186 | ||
92a9e4f7 AH |
187 | static bool thread_stack__in_kernel(struct thread_stack *ts) |
188 | { | |
189 | if (!ts->cnt) | |
190 | return false; | |
191 | ||
192 | return ts->stack[ts->cnt - 1].cp->in_kernel; | |
193 | } | |
194 | ||
195 | static int thread_stack__call_return(struct thread *thread, | |
196 | struct thread_stack *ts, size_t idx, | |
197 | u64 timestamp, u64 ref, bool no_return) | |
198 | { | |
199 | struct call_return_processor *crp = ts->crp; | |
200 | struct thread_stack_entry *tse; | |
201 | struct call_return cr = { | |
202 | .thread = thread, | |
203 | .comm = ts->comm, | |
204 | .db_id = 0, | |
205 | }; | |
206 | ||
207 | tse = &ts->stack[idx]; | |
208 | cr.cp = tse->cp; | |
209 | cr.call_time = tse->timestamp; | |
210 | cr.return_time = timestamp; | |
211 | cr.branch_count = ts->branch_count - tse->branch_count; | |
212 | cr.call_ref = tse->ref; | |
213 | cr.return_ref = ref; | |
214 | if (tse->no_call) | |
215 | cr.flags |= CALL_RETURN_NO_CALL; | |
216 | if (no_return) | |
217 | cr.flags |= CALL_RETURN_NO_RETURN; | |
218 | ||
219 | return crp->process(&cr, crp->data); | |
220 | } | |
221 | ||
a5499b37 | 222 | static int __thread_stack__flush(struct thread *thread, struct thread_stack *ts) |
92a9e4f7 AH |
223 | { |
224 | struct call_return_processor *crp = ts->crp; | |
225 | int err; | |
226 | ||
227 | if (!crp) { | |
228 | ts->cnt = 0; | |
229 | return 0; | |
230 | } | |
231 | ||
232 | while (ts->cnt) { | |
233 | err = thread_stack__call_return(thread, ts, --ts->cnt, | |
234 | ts->last_time, 0, true); | |
235 | if (err) { | |
236 | pr_err("Error flushing thread stack!\n"); | |
237 | ts->cnt = 0; | |
238 | return err; | |
239 | } | |
240 | } | |
241 | ||
242 | return 0; | |
243 | } | |
244 | ||
a5499b37 AH |
245 | int thread_stack__flush(struct thread *thread) |
246 | { | |
247 | if (thread->ts) | |
248 | return __thread_stack__flush(thread, thread->ts); | |
249 | ||
250 | return 0; | |
251 | } | |
252 | ||
00447ccd AH |
253 | int thread_stack__event(struct thread *thread, u32 flags, u64 from_ip, |
254 | u64 to_ip, u16 insn_len, u64 trace_nr) | |
255 | { | |
256 | if (!thread) | |
257 | return -EINVAL; | |
258 | ||
259 | if (!thread->ts) { | |
92a9e4f7 | 260 | thread->ts = thread_stack__new(thread, NULL); |
00447ccd AH |
261 | if (!thread->ts) { |
262 | pr_warning("Out of memory: no thread stack\n"); | |
263 | return -ENOMEM; | |
264 | } | |
265 | thread->ts->trace_nr = trace_nr; | |
266 | } | |
267 | ||
268 | /* | |
269 | * When the trace is discontinuous, the trace_nr changes. In that case | |
270 | * the stack might be completely invalid. Better to report nothing than | |
92a9e4f7 | 271 | * to report something misleading, so flush the stack. |
00447ccd AH |
272 | */ |
273 | if (trace_nr != thread->ts->trace_nr) { | |
92a9e4f7 | 274 | if (thread->ts->trace_nr) |
a5499b37 | 275 | __thread_stack__flush(thread, thread->ts); |
00447ccd | 276 | thread->ts->trace_nr = trace_nr; |
00447ccd AH |
277 | } |
278 | ||
92a9e4f7 AH |
279 | /* Stop here if thread_stack__process() is in use */ |
280 | if (thread->ts->crp) | |
281 | return 0; | |
282 | ||
00447ccd AH |
283 | if (flags & PERF_IP_FLAG_CALL) { |
284 | u64 ret_addr; | |
285 | ||
286 | if (!to_ip) | |
287 | return 0; | |
288 | ret_addr = from_ip + insn_len; | |
289 | if (ret_addr == to_ip) | |
290 | return 0; /* Zero-length calls are excluded */ | |
291 | return thread_stack__push(thread->ts, ret_addr); | |
292 | } else if (flags & PERF_IP_FLAG_RETURN) { | |
293 | if (!from_ip) | |
294 | return 0; | |
295 | thread_stack__pop(thread->ts, to_ip); | |
296 | } | |
297 | ||
298 | return 0; | |
299 | } | |
300 | ||
92a9e4f7 AH |
301 | void thread_stack__set_trace_nr(struct thread *thread, u64 trace_nr) |
302 | { | |
303 | if (!thread || !thread->ts) | |
304 | return; | |
305 | ||
306 | if (trace_nr != thread->ts->trace_nr) { | |
307 | if (thread->ts->trace_nr) | |
a5499b37 | 308 | __thread_stack__flush(thread, thread->ts); |
92a9e4f7 AH |
309 | thread->ts->trace_nr = trace_nr; |
310 | } | |
311 | } | |
312 | ||
00447ccd AH |
313 | void thread_stack__free(struct thread *thread) |
314 | { | |
315 | if (thread->ts) { | |
a5499b37 | 316 | __thread_stack__flush(thread, thread->ts); |
00447ccd AH |
317 | zfree(&thread->ts->stack); |
318 | zfree(&thread->ts); | |
319 | } | |
320 | } | |
321 | ||
322 | void thread_stack__sample(struct thread *thread, struct ip_callchain *chain, | |
323 | size_t sz, u64 ip) | |
324 | { | |
325 | size_t i; | |
326 | ||
327 | if (!thread || !thread->ts) | |
328 | chain->nr = 1; | |
329 | else | |
330 | chain->nr = min(sz, thread->ts->cnt + 1); | |
331 | ||
332 | chain->ips[0] = ip; | |
333 | ||
334 | for (i = 1; i < chain->nr; i++) | |
335 | chain->ips[i] = thread->ts->stack[thread->ts->cnt - i].ret_addr; | |
336 | } | |
92a9e4f7 AH |
337 | |
338 | static void call_path__init(struct call_path *cp, struct call_path *parent, | |
339 | struct symbol *sym, u64 ip, bool in_kernel) | |
340 | { | |
341 | cp->parent = parent; | |
342 | cp->sym = sym; | |
343 | cp->ip = sym ? 0 : ip; | |
344 | cp->db_id = 0; | |
345 | cp->in_kernel = in_kernel; | |
346 | RB_CLEAR_NODE(&cp->rb_node); | |
347 | cp->children = RB_ROOT; | |
348 | } | |
349 | ||
350 | static struct call_path_root *call_path_root__new(void) | |
351 | { | |
352 | struct call_path_root *cpr; | |
353 | ||
354 | cpr = zalloc(sizeof(struct call_path_root)); | |
355 | if (!cpr) | |
356 | return NULL; | |
357 | call_path__init(&cpr->call_path, NULL, NULL, 0, false); | |
358 | INIT_LIST_HEAD(&cpr->blocks); | |
359 | return cpr; | |
360 | } | |
361 | ||
362 | static void call_path_root__free(struct call_path_root *cpr) | |
363 | { | |
364 | struct call_path_block *pos, *n; | |
365 | ||
366 | list_for_each_entry_safe(pos, n, &cpr->blocks, node) { | |
367 | list_del(&pos->node); | |
368 | free(pos); | |
369 | } | |
370 | free(cpr); | |
371 | } | |
372 | ||
373 | static struct call_path *call_path__new(struct call_path_root *cpr, | |
374 | struct call_path *parent, | |
375 | struct symbol *sym, u64 ip, | |
376 | bool in_kernel) | |
377 | { | |
378 | struct call_path_block *cpb; | |
379 | struct call_path *cp; | |
380 | size_t n; | |
381 | ||
382 | if (cpr->next < cpr->sz) { | |
383 | cpb = list_last_entry(&cpr->blocks, struct call_path_block, | |
384 | node); | |
385 | } else { | |
386 | cpb = zalloc(sizeof(struct call_path_block)); | |
387 | if (!cpb) | |
388 | return NULL; | |
389 | list_add_tail(&cpb->node, &cpr->blocks); | |
390 | cpr->sz += CALL_PATH_BLOCK_SIZE; | |
391 | } | |
392 | ||
393 | n = cpr->next++ & CALL_PATH_BLOCK_MASK; | |
394 | cp = &cpb->cp[n]; | |
395 | ||
396 | call_path__init(cp, parent, sym, ip, in_kernel); | |
397 | ||
398 | return cp; | |
399 | } | |
400 | ||
401 | static struct call_path *call_path__findnew(struct call_path_root *cpr, | |
402 | struct call_path *parent, | |
403 | struct symbol *sym, u64 ip, u64 ks) | |
404 | { | |
405 | struct rb_node **p; | |
406 | struct rb_node *node_parent = NULL; | |
407 | struct call_path *cp; | |
408 | bool in_kernel = ip >= ks; | |
409 | ||
410 | if (sym) | |
411 | ip = 0; | |
412 | ||
413 | if (!parent) | |
414 | return call_path__new(cpr, parent, sym, ip, in_kernel); | |
415 | ||
416 | p = &parent->children.rb_node; | |
417 | while (*p != NULL) { | |
418 | node_parent = *p; | |
419 | cp = rb_entry(node_parent, struct call_path, rb_node); | |
420 | ||
421 | if (cp->sym == sym && cp->ip == ip) | |
422 | return cp; | |
423 | ||
424 | if (sym < cp->sym || (sym == cp->sym && ip < cp->ip)) | |
425 | p = &(*p)->rb_left; | |
426 | else | |
427 | p = &(*p)->rb_right; | |
428 | } | |
429 | ||
430 | cp = call_path__new(cpr, parent, sym, ip, in_kernel); | |
431 | if (!cp) | |
432 | return NULL; | |
433 | ||
434 | rb_link_node(&cp->rb_node, node_parent, p); | |
435 | rb_insert_color(&cp->rb_node, &parent->children); | |
436 | ||
437 | return cp; | |
438 | } | |
439 | ||
440 | struct call_return_processor * | |
441 | call_return_processor__new(int (*process)(struct call_return *cr, void *data), | |
442 | void *data) | |
443 | { | |
444 | struct call_return_processor *crp; | |
445 | ||
446 | crp = zalloc(sizeof(struct call_return_processor)); | |
447 | if (!crp) | |
448 | return NULL; | |
449 | crp->cpr = call_path_root__new(); | |
450 | if (!crp->cpr) | |
451 | goto out_free; | |
452 | crp->process = process; | |
453 | crp->data = data; | |
454 | return crp; | |
455 | ||
456 | out_free: | |
457 | free(crp); | |
458 | return NULL; | |
459 | } | |
460 | ||
461 | void call_return_processor__free(struct call_return_processor *crp) | |
462 | { | |
463 | if (crp) { | |
464 | call_path_root__free(crp->cpr); | |
465 | free(crp); | |
466 | } | |
467 | } | |
468 | ||
469 | static int thread_stack__push_cp(struct thread_stack *ts, u64 ret_addr, | |
470 | u64 timestamp, u64 ref, struct call_path *cp, | |
471 | bool no_call) | |
472 | { | |
473 | struct thread_stack_entry *tse; | |
474 | int err; | |
475 | ||
476 | if (ts->cnt == ts->sz) { | |
477 | err = thread_stack__grow(ts); | |
478 | if (err) | |
479 | return err; | |
480 | } | |
481 | ||
482 | tse = &ts->stack[ts->cnt++]; | |
483 | tse->ret_addr = ret_addr; | |
484 | tse->timestamp = timestamp; | |
485 | tse->ref = ref; | |
486 | tse->branch_count = ts->branch_count; | |
487 | tse->cp = cp; | |
488 | tse->no_call = no_call; | |
489 | ||
490 | return 0; | |
491 | } | |
492 | ||
493 | static int thread_stack__pop_cp(struct thread *thread, struct thread_stack *ts, | |
494 | u64 ret_addr, u64 timestamp, u64 ref, | |
495 | struct symbol *sym) | |
496 | { | |
497 | int err; | |
498 | ||
499 | if (!ts->cnt) | |
500 | return 1; | |
501 | ||
502 | if (ts->cnt == 1) { | |
503 | struct thread_stack_entry *tse = &ts->stack[0]; | |
504 | ||
505 | if (tse->cp->sym == sym) | |
506 | return thread_stack__call_return(thread, ts, --ts->cnt, | |
507 | timestamp, ref, false); | |
508 | } | |
509 | ||
510 | if (ts->stack[ts->cnt - 1].ret_addr == ret_addr) { | |
511 | return thread_stack__call_return(thread, ts, --ts->cnt, | |
512 | timestamp, ref, false); | |
513 | } else { | |
514 | size_t i = ts->cnt - 1; | |
515 | ||
516 | while (i--) { | |
517 | if (ts->stack[i].ret_addr != ret_addr) | |
518 | continue; | |
519 | i += 1; | |
520 | while (ts->cnt > i) { | |
521 | err = thread_stack__call_return(thread, ts, | |
522 | --ts->cnt, | |
523 | timestamp, ref, | |
524 | true); | |
525 | if (err) | |
526 | return err; | |
527 | } | |
528 | return thread_stack__call_return(thread, ts, --ts->cnt, | |
529 | timestamp, ref, false); | |
530 | } | |
531 | } | |
532 | ||
533 | return 1; | |
534 | } | |
535 | ||
536 | static int thread_stack__bottom(struct thread *thread, struct thread_stack *ts, | |
537 | struct perf_sample *sample, | |
538 | struct addr_location *from_al, | |
539 | struct addr_location *to_al, u64 ref) | |
540 | { | |
541 | struct call_path_root *cpr = ts->crp->cpr; | |
542 | struct call_path *cp; | |
543 | struct symbol *sym; | |
544 | u64 ip; | |
545 | ||
546 | if (sample->ip) { | |
547 | ip = sample->ip; | |
548 | sym = from_al->sym; | |
549 | } else if (sample->addr) { | |
550 | ip = sample->addr; | |
551 | sym = to_al->sym; | |
552 | } else { | |
553 | return 0; | |
554 | } | |
555 | ||
556 | cp = call_path__findnew(cpr, &cpr->call_path, sym, ip, | |
557 | ts->kernel_start); | |
558 | if (!cp) | |
559 | return -ENOMEM; | |
560 | ||
561 | return thread_stack__push_cp(thread->ts, ip, sample->time, ref, cp, | |
562 | true); | |
563 | } | |
564 | ||
565 | static int thread_stack__no_call_return(struct thread *thread, | |
566 | struct thread_stack *ts, | |
567 | struct perf_sample *sample, | |
568 | struct addr_location *from_al, | |
569 | struct addr_location *to_al, u64 ref) | |
570 | { | |
571 | struct call_path_root *cpr = ts->crp->cpr; | |
572 | struct call_path *cp, *parent; | |
573 | u64 ks = ts->kernel_start; | |
574 | int err; | |
575 | ||
576 | if (sample->ip >= ks && sample->addr < ks) { | |
577 | /* Return to userspace, so pop all kernel addresses */ | |
578 | while (thread_stack__in_kernel(ts)) { | |
579 | err = thread_stack__call_return(thread, ts, --ts->cnt, | |
580 | sample->time, ref, | |
581 | true); | |
582 | if (err) | |
583 | return err; | |
584 | } | |
585 | ||
586 | /* If the stack is empty, push the userspace address */ | |
587 | if (!ts->cnt) { | |
588 | cp = call_path__findnew(cpr, &cpr->call_path, | |
589 | to_al->sym, sample->addr, | |
590 | ts->kernel_start); | |
591 | if (!cp) | |
592 | return -ENOMEM; | |
593 | return thread_stack__push_cp(ts, 0, sample->time, ref, | |
594 | cp, true); | |
595 | } | |
596 | } else if (thread_stack__in_kernel(ts) && sample->ip < ks) { | |
597 | /* Return to userspace, so pop all kernel addresses */ | |
598 | while (thread_stack__in_kernel(ts)) { | |
599 | err = thread_stack__call_return(thread, ts, --ts->cnt, | |
600 | sample->time, ref, | |
601 | true); | |
602 | if (err) | |
603 | return err; | |
604 | } | |
605 | } | |
606 | ||
607 | if (ts->cnt) | |
608 | parent = ts->stack[ts->cnt - 1].cp; | |
609 | else | |
610 | parent = &cpr->call_path; | |
611 | ||
612 | /* This 'return' had no 'call', so push and pop top of stack */ | |
613 | cp = call_path__findnew(cpr, parent, from_al->sym, sample->ip, | |
614 | ts->kernel_start); | |
615 | if (!cp) | |
616 | return -ENOMEM; | |
617 | ||
618 | err = thread_stack__push_cp(ts, sample->addr, sample->time, ref, cp, | |
619 | true); | |
620 | if (err) | |
621 | return err; | |
622 | ||
623 | return thread_stack__pop_cp(thread, ts, sample->addr, sample->time, ref, | |
624 | to_al->sym); | |
625 | } | |
626 | ||
627 | static int thread_stack__trace_begin(struct thread *thread, | |
628 | struct thread_stack *ts, u64 timestamp, | |
629 | u64 ref) | |
630 | { | |
631 | struct thread_stack_entry *tse; | |
632 | int err; | |
633 | ||
634 | if (!ts->cnt) | |
635 | return 0; | |
636 | ||
637 | /* Pop trace end */ | |
638 | tse = &ts->stack[ts->cnt - 1]; | |
639 | if (tse->cp->sym == NULL && tse->cp->ip == 0) { | |
640 | err = thread_stack__call_return(thread, ts, --ts->cnt, | |
641 | timestamp, ref, false); | |
642 | if (err) | |
643 | return err; | |
644 | } | |
645 | ||
646 | return 0; | |
647 | } | |
648 | ||
649 | static int thread_stack__trace_end(struct thread_stack *ts, | |
650 | struct perf_sample *sample, u64 ref) | |
651 | { | |
652 | struct call_path_root *cpr = ts->crp->cpr; | |
653 | struct call_path *cp; | |
654 | u64 ret_addr; | |
655 | ||
656 | /* No point having 'trace end' on the bottom of the stack */ | |
657 | if (!ts->cnt || (ts->cnt == 1 && ts->stack[0].ref == ref)) | |
658 | return 0; | |
659 | ||
660 | cp = call_path__findnew(cpr, ts->stack[ts->cnt - 1].cp, NULL, 0, | |
661 | ts->kernel_start); | |
662 | if (!cp) | |
663 | return -ENOMEM; | |
664 | ||
665 | ret_addr = sample->ip + sample->insn_len; | |
666 | ||
667 | return thread_stack__push_cp(ts, ret_addr, sample->time, ref, cp, | |
668 | false); | |
669 | } | |
670 | ||
671 | int thread_stack__process(struct thread *thread, struct comm *comm, | |
672 | struct perf_sample *sample, | |
673 | struct addr_location *from_al, | |
674 | struct addr_location *to_al, u64 ref, | |
675 | struct call_return_processor *crp) | |
676 | { | |
677 | struct thread_stack *ts = thread->ts; | |
678 | int err = 0; | |
679 | ||
680 | if (ts) { | |
681 | if (!ts->crp) { | |
682 | /* Supersede thread_stack__event() */ | |
683 | thread_stack__free(thread); | |
684 | thread->ts = thread_stack__new(thread, crp); | |
685 | if (!thread->ts) | |
686 | return -ENOMEM; | |
687 | ts = thread->ts; | |
688 | ts->comm = comm; | |
689 | } | |
690 | } else { | |
691 | thread->ts = thread_stack__new(thread, crp); | |
692 | if (!thread->ts) | |
693 | return -ENOMEM; | |
694 | ts = thread->ts; | |
695 | ts->comm = comm; | |
696 | } | |
697 | ||
698 | /* Flush stack on exec */ | |
699 | if (ts->comm != comm && thread->pid_ == thread->tid) { | |
a5499b37 | 700 | err = __thread_stack__flush(thread, ts); |
92a9e4f7 AH |
701 | if (err) |
702 | return err; | |
703 | ts->comm = comm; | |
704 | } | |
705 | ||
706 | /* If the stack is empty, put the current symbol on the stack */ | |
707 | if (!ts->cnt) { | |
708 | err = thread_stack__bottom(thread, ts, sample, from_al, to_al, | |
709 | ref); | |
710 | if (err) | |
711 | return err; | |
712 | } | |
713 | ||
714 | ts->branch_count += 1; | |
715 | ts->last_time = sample->time; | |
716 | ||
717 | if (sample->flags & PERF_IP_FLAG_CALL) { | |
718 | struct call_path_root *cpr = ts->crp->cpr; | |
719 | struct call_path *cp; | |
720 | u64 ret_addr; | |
721 | ||
722 | if (!sample->ip || !sample->addr) | |
723 | return 0; | |
724 | ||
725 | ret_addr = sample->ip + sample->insn_len; | |
726 | if (ret_addr == sample->addr) | |
727 | return 0; /* Zero-length calls are excluded */ | |
728 | ||
729 | cp = call_path__findnew(cpr, ts->stack[ts->cnt - 1].cp, | |
730 | to_al->sym, sample->addr, | |
731 | ts->kernel_start); | |
732 | if (!cp) | |
733 | return -ENOMEM; | |
734 | err = thread_stack__push_cp(ts, ret_addr, sample->time, ref, | |
735 | cp, false); | |
736 | } else if (sample->flags & PERF_IP_FLAG_RETURN) { | |
737 | if (!sample->ip || !sample->addr) | |
738 | return 0; | |
739 | ||
740 | err = thread_stack__pop_cp(thread, ts, sample->addr, | |
741 | sample->time, ref, from_al->sym); | |
742 | if (err) { | |
743 | if (err < 0) | |
744 | return err; | |
745 | err = thread_stack__no_call_return(thread, ts, sample, | |
746 | from_al, to_al, ref); | |
747 | } | |
748 | } else if (sample->flags & PERF_IP_FLAG_TRACE_BEGIN) { | |
749 | err = thread_stack__trace_begin(thread, ts, sample->time, ref); | |
750 | } else if (sample->flags & PERF_IP_FLAG_TRACE_END) { | |
751 | err = thread_stack__trace_end(ts, sample, ref); | |
752 | } | |
753 | ||
754 | return err; | |
755 | } |