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1#include "../perf.h"
2#include <stdlib.h>
3#include <stdio.h>
4#include <string.h>
5#include "session.h"
6#include "thread.h"
7#include "thread-stack.h"
8#include "util.h"
9#include "debug.h"
10#include "comm.h"
11#include "unwind.h"
12
13int thread__init_map_groups(struct thread *thread, struct machine *machine)
14{
15 struct thread *leader;
16 pid_t pid = thread->pid_;
17
18 if (pid == thread->tid || pid == -1) {
19 thread->mg = map_groups__new(machine);
20 } else {
21 leader = __machine__findnew_thread(machine, pid, pid);
22 if (leader) {
23 thread->mg = map_groups__get(leader->mg);
24 thread__put(leader);
25 }
26 }
27
28 return thread->mg ? 0 : -1;
29}
30
31struct thread *thread__new(pid_t pid, pid_t tid)
32{
33 char *comm_str;
34 struct comm *comm;
35 struct thread *thread = zalloc(sizeof(*thread));
36
37 if (thread != NULL) {
38 thread->pid_ = pid;
39 thread->tid = tid;
40 thread->ppid = -1;
41 thread->cpu = -1;
42 INIT_LIST_HEAD(&thread->comm_list);
43
44 if (unwind__prepare_access(thread) < 0)
45 goto err_thread;
46
47 comm_str = malloc(32);
48 if (!comm_str)
49 goto err_thread;
50
51 snprintf(comm_str, 32, ":%d", tid);
52 comm = comm__new(comm_str, 0, false);
53 free(comm_str);
54 if (!comm)
55 goto err_thread;
56
57 list_add(&comm->list, &thread->comm_list);
58 atomic_set(&thread->refcnt, 1);
59 RB_CLEAR_NODE(&thread->rb_node);
60 }
61
62 return thread;
63
64err_thread:
65 free(thread);
66 return NULL;
67}
68
69void thread__delete(struct thread *thread)
70{
71 struct comm *comm, *tmp;
72
73 BUG_ON(!RB_EMPTY_NODE(&thread->rb_node));
74
75 thread_stack__free(thread);
76
77 if (thread->mg) {
78 map_groups__put(thread->mg);
79 thread->mg = NULL;
80 }
81 list_for_each_entry_safe(comm, tmp, &thread->comm_list, list) {
82 list_del(&comm->list);
83 comm__free(comm);
84 }
85 unwind__finish_access(thread);
86
87 free(thread);
88}
89
90struct thread *thread__get(struct thread *thread)
91{
92 if (thread)
93 atomic_inc(&thread->refcnt);
94 return thread;
95}
96
97void thread__put(struct thread *thread)
98{
99 if (thread && atomic_dec_and_test(&thread->refcnt)) {
100 /*
101 * Remove it from the dead_threads list, as last reference
102 * is gone.
103 */
104 list_del_init(&thread->node);
105 thread__delete(thread);
106 }
107}
108
109struct comm *thread__comm(const struct thread *thread)
110{
111 if (list_empty(&thread->comm_list))
112 return NULL;
113
114 return list_first_entry(&thread->comm_list, struct comm, list);
115}
116
117struct comm *thread__exec_comm(const struct thread *thread)
118{
119 struct comm *comm, *last = NULL;
120
121 list_for_each_entry(comm, &thread->comm_list, list) {
122 if (comm->exec)
123 return comm;
124 last = comm;
125 }
126
127 return last;
128}
129
130int __thread__set_comm(struct thread *thread, const char *str, u64 timestamp,
131 bool exec)
132{
133 struct comm *new, *curr = thread__comm(thread);
134 int err;
135
136 /* Override the default :tid entry */
137 if (!thread->comm_set) {
138 err = comm__override(curr, str, timestamp, exec);
139 if (err)
140 return err;
141 } else {
142 new = comm__new(str, timestamp, exec);
143 if (!new)
144 return -ENOMEM;
145 list_add(&new->list, &thread->comm_list);
146
147 if (exec)
148 unwind__flush_access(thread);
149 }
150
151 thread->comm_set = true;
152
153 return 0;
154}
155
156const char *thread__comm_str(const struct thread *thread)
157{
158 const struct comm *comm = thread__comm(thread);
159
160 if (!comm)
161 return NULL;
162
163 return comm__str(comm);
164}
165
166/* CHECKME: it should probably better return the max comm len from its comm list */
167int thread__comm_len(struct thread *thread)
168{
169 if (!thread->comm_len) {
170 const char *comm = thread__comm_str(thread);
171 if (!comm)
172 return 0;
173 thread->comm_len = strlen(comm);
174 }
175
176 return thread->comm_len;
177}
178
179size_t thread__fprintf(struct thread *thread, FILE *fp)
180{
181 return fprintf(fp, "Thread %d %s\n", thread->tid, thread__comm_str(thread)) +
182 map_groups__fprintf(thread->mg, fp);
183}
184
185void thread__insert_map(struct thread *thread, struct map *map)
186{
187 map_groups__fixup_overlappings(thread->mg, map, stderr);
188 map_groups__insert(thread->mg, map);
189}
190
191static int thread__clone_map_groups(struct thread *thread,
192 struct thread *parent)
193{
194 int i;
195
196 /* This is new thread, we share map groups for process. */
197 if (thread->pid_ == parent->pid_)
198 return 0;
199
200 if (thread->mg == parent->mg) {
201 pr_debug("broken map groups on thread %d/%d parent %d/%d\n",
202 thread->pid_, thread->tid, parent->pid_, parent->tid);
203 return 0;
204 }
205
206 /* But this one is new process, copy maps. */
207 for (i = 0; i < MAP__NR_TYPES; ++i)
208 if (map_groups__clone(thread->mg, parent->mg, i) < 0)
209 return -ENOMEM;
210
211 return 0;
212}
213
214int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp)
215{
216 int err;
217
218 if (parent->comm_set) {
219 const char *comm = thread__comm_str(parent);
220 if (!comm)
221 return -ENOMEM;
222 err = thread__set_comm(thread, comm, timestamp);
223 if (err)
224 return err;
225 }
226
227 thread->ppid = parent->tid;
228 return thread__clone_map_groups(thread, parent);
229}
230
231void thread__find_cpumode_addr_location(struct thread *thread,
232 enum map_type type, u64 addr,
233 struct addr_location *al)
234{
235 size_t i;
236 const u8 const cpumodes[] = {
237 PERF_RECORD_MISC_USER,
238 PERF_RECORD_MISC_KERNEL,
239 PERF_RECORD_MISC_GUEST_USER,
240 PERF_RECORD_MISC_GUEST_KERNEL
241 };
242
243 for (i = 0; i < ARRAY_SIZE(cpumodes); i++) {
244 thread__find_addr_location(thread, cpumodes[i], type, addr, al);
245 if (al->map)
246 break;
247 }
248}
1// SPDX-License-Identifier: GPL-2.0
2#include <errno.h>
3#include <stdlib.h>
4#include <stdio.h>
5#include <string.h>
6#include <linux/kernel.h>
7#include <linux/zalloc.h>
8#include "dso.h"
9#include "session.h"
10#include "thread.h"
11#include "thread-stack.h"
12#include "debug.h"
13#include "namespaces.h"
14#include "comm.h"
15#include "map.h"
16#include "symbol.h"
17#include "unwind.h"
18#include "callchain.h"
19
20#include <api/fs/fs.h>
21
22int thread__init_maps(struct thread *thread, struct machine *machine)
23{
24 pid_t pid = thread->pid_;
25
26 if (pid == thread->tid || pid == -1) {
27 thread->maps = maps__new(machine);
28 } else {
29 struct thread *leader = __machine__findnew_thread(machine, pid, pid);
30 if (leader) {
31 thread->maps = maps__get(leader->maps);
32 thread__put(leader);
33 }
34 }
35
36 return thread->maps ? 0 : -1;
37}
38
39struct thread *thread__new(pid_t pid, pid_t tid)
40{
41 char *comm_str;
42 struct comm *comm;
43 struct thread *thread = zalloc(sizeof(*thread));
44
45 if (thread != NULL) {
46 thread->pid_ = pid;
47 thread->tid = tid;
48 thread->ppid = -1;
49 thread->cpu = -1;
50 thread->guest_cpu = -1;
51 thread->lbr_stitch_enable = false;
52 INIT_LIST_HEAD(&thread->namespaces_list);
53 INIT_LIST_HEAD(&thread->comm_list);
54 init_rwsem(&thread->namespaces_lock);
55 init_rwsem(&thread->comm_lock);
56
57 comm_str = malloc(32);
58 if (!comm_str)
59 goto err_thread;
60
61 snprintf(comm_str, 32, ":%d", tid);
62 comm = comm__new(comm_str, 0, false);
63 free(comm_str);
64 if (!comm)
65 goto err_thread;
66
67 list_add(&comm->list, &thread->comm_list);
68 refcount_set(&thread->refcnt, 1);
69 RB_CLEAR_NODE(&thread->rb_node);
70 /* Thread holds first ref to nsdata. */
71 thread->nsinfo = nsinfo__new(pid);
72 srccode_state_init(&thread->srccode_state);
73 }
74
75 return thread;
76
77err_thread:
78 free(thread);
79 return NULL;
80}
81
82void thread__delete(struct thread *thread)
83{
84 struct namespaces *namespaces, *tmp_namespaces;
85 struct comm *comm, *tmp_comm;
86
87 BUG_ON(!RB_EMPTY_NODE(&thread->rb_node));
88
89 thread_stack__free(thread);
90
91 if (thread->maps) {
92 maps__put(thread->maps);
93 thread->maps = NULL;
94 }
95 down_write(&thread->namespaces_lock);
96 list_for_each_entry_safe(namespaces, tmp_namespaces,
97 &thread->namespaces_list, list) {
98 list_del_init(&namespaces->list);
99 namespaces__free(namespaces);
100 }
101 up_write(&thread->namespaces_lock);
102
103 down_write(&thread->comm_lock);
104 list_for_each_entry_safe(comm, tmp_comm, &thread->comm_list, list) {
105 list_del_init(&comm->list);
106 comm__free(comm);
107 }
108 up_write(&thread->comm_lock);
109
110 nsinfo__zput(thread->nsinfo);
111 srccode_state_free(&thread->srccode_state);
112
113 exit_rwsem(&thread->namespaces_lock);
114 exit_rwsem(&thread->comm_lock);
115 thread__free_stitch_list(thread);
116 free(thread);
117}
118
119struct thread *thread__get(struct thread *thread)
120{
121 if (thread)
122 refcount_inc(&thread->refcnt);
123 return thread;
124}
125
126void thread__put(struct thread *thread)
127{
128 if (thread && refcount_dec_and_test(&thread->refcnt)) {
129 /*
130 * Remove it from the dead threads list, as last reference is
131 * gone, if it is in a dead threads list.
132 *
133 * We may not be there anymore if say, the machine where it was
134 * stored was already deleted, so we already removed it from
135 * the dead threads and some other piece of code still keeps a
136 * reference.
137 *
138 * This is what 'perf sched' does and finally drops it in
139 * perf_sched__lat(), where it calls perf_sched__read_events(),
140 * that processes the events by creating a session and deleting
141 * it, which ends up destroying the list heads for the dead
142 * threads, but before it does that it removes all threads from
143 * it using list_del_init().
144 *
145 * So we need to check here if it is in a dead threads list and
146 * if so, remove it before finally deleting the thread, to avoid
147 * an use after free situation.
148 */
149 if (!list_empty(&thread->node))
150 list_del_init(&thread->node);
151 thread__delete(thread);
152 }
153}
154
155static struct namespaces *__thread__namespaces(const struct thread *thread)
156{
157 if (list_empty(&thread->namespaces_list))
158 return NULL;
159
160 return list_first_entry(&thread->namespaces_list, struct namespaces, list);
161}
162
163struct namespaces *thread__namespaces(struct thread *thread)
164{
165 struct namespaces *ns;
166
167 down_read(&thread->namespaces_lock);
168 ns = __thread__namespaces(thread);
169 up_read(&thread->namespaces_lock);
170
171 return ns;
172}
173
174static int __thread__set_namespaces(struct thread *thread, u64 timestamp,
175 struct perf_record_namespaces *event)
176{
177 struct namespaces *new, *curr = __thread__namespaces(thread);
178
179 new = namespaces__new(event);
180 if (!new)
181 return -ENOMEM;
182
183 list_add(&new->list, &thread->namespaces_list);
184
185 if (timestamp && curr) {
186 /*
187 * setns syscall must have changed few or all the namespaces
188 * of this thread. Update end time for the namespaces
189 * previously used.
190 */
191 curr = list_next_entry(new, list);
192 curr->end_time = timestamp;
193 }
194
195 return 0;
196}
197
198int thread__set_namespaces(struct thread *thread, u64 timestamp,
199 struct perf_record_namespaces *event)
200{
201 int ret;
202
203 down_write(&thread->namespaces_lock);
204 ret = __thread__set_namespaces(thread, timestamp, event);
205 up_write(&thread->namespaces_lock);
206 return ret;
207}
208
209struct comm *thread__comm(const struct thread *thread)
210{
211 if (list_empty(&thread->comm_list))
212 return NULL;
213
214 return list_first_entry(&thread->comm_list, struct comm, list);
215}
216
217struct comm *thread__exec_comm(const struct thread *thread)
218{
219 struct comm *comm, *last = NULL, *second_last = NULL;
220
221 list_for_each_entry(comm, &thread->comm_list, list) {
222 if (comm->exec)
223 return comm;
224 second_last = last;
225 last = comm;
226 }
227
228 /*
229 * 'last' with no start time might be the parent's comm of a synthesized
230 * thread (created by processing a synthesized fork event). For a main
231 * thread, that is very probably wrong. Prefer a later comm to avoid
232 * that case.
233 */
234 if (second_last && !last->start && thread->pid_ == thread->tid)
235 return second_last;
236
237 return last;
238}
239
240static int ____thread__set_comm(struct thread *thread, const char *str,
241 u64 timestamp, bool exec)
242{
243 struct comm *new, *curr = thread__comm(thread);
244
245 /* Override the default :tid entry */
246 if (!thread->comm_set) {
247 int err = comm__override(curr, str, timestamp, exec);
248 if (err)
249 return err;
250 } else {
251 new = comm__new(str, timestamp, exec);
252 if (!new)
253 return -ENOMEM;
254 list_add(&new->list, &thread->comm_list);
255
256 if (exec)
257 unwind__flush_access(thread->maps);
258 }
259
260 thread->comm_set = true;
261
262 return 0;
263}
264
265int __thread__set_comm(struct thread *thread, const char *str, u64 timestamp,
266 bool exec)
267{
268 int ret;
269
270 down_write(&thread->comm_lock);
271 ret = ____thread__set_comm(thread, str, timestamp, exec);
272 up_write(&thread->comm_lock);
273 return ret;
274}
275
276int thread__set_comm_from_proc(struct thread *thread)
277{
278 char path[64];
279 char *comm = NULL;
280 size_t sz;
281 int err = -1;
282
283 if (!(snprintf(path, sizeof(path), "%d/task/%d/comm",
284 thread->pid_, thread->tid) >= (int)sizeof(path)) &&
285 procfs__read_str(path, &comm, &sz) == 0) {
286 comm[sz - 1] = '\0';
287 err = thread__set_comm(thread, comm, 0);
288 }
289
290 return err;
291}
292
293static const char *__thread__comm_str(const struct thread *thread)
294{
295 const struct comm *comm = thread__comm(thread);
296
297 if (!comm)
298 return NULL;
299
300 return comm__str(comm);
301}
302
303const char *thread__comm_str(struct thread *thread)
304{
305 const char *str;
306
307 down_read(&thread->comm_lock);
308 str = __thread__comm_str(thread);
309 up_read(&thread->comm_lock);
310
311 return str;
312}
313
314/* CHECKME: it should probably better return the max comm len from its comm list */
315int thread__comm_len(struct thread *thread)
316{
317 if (!thread->comm_len) {
318 const char *comm = thread__comm_str(thread);
319 if (!comm)
320 return 0;
321 thread->comm_len = strlen(comm);
322 }
323
324 return thread->comm_len;
325}
326
327size_t thread__fprintf(struct thread *thread, FILE *fp)
328{
329 return fprintf(fp, "Thread %d %s\n", thread->tid, thread__comm_str(thread)) +
330 maps__fprintf(thread->maps, fp);
331}
332
333int thread__insert_map(struct thread *thread, struct map *map)
334{
335 int ret;
336
337 ret = unwind__prepare_access(thread->maps, map, NULL);
338 if (ret)
339 return ret;
340
341 maps__fixup_overlappings(thread->maps, map, stderr);
342 maps__insert(thread->maps, map);
343
344 return 0;
345}
346
347static int __thread__prepare_access(struct thread *thread)
348{
349 bool initialized = false;
350 int err = 0;
351 struct maps *maps = thread->maps;
352 struct map *map;
353
354 down_read(&maps->lock);
355
356 maps__for_each_entry(maps, map) {
357 err = unwind__prepare_access(thread->maps, map, &initialized);
358 if (err || initialized)
359 break;
360 }
361
362 up_read(&maps->lock);
363
364 return err;
365}
366
367static int thread__prepare_access(struct thread *thread)
368{
369 int err = 0;
370
371 if (dwarf_callchain_users)
372 err = __thread__prepare_access(thread);
373
374 return err;
375}
376
377static int thread__clone_maps(struct thread *thread, struct thread *parent, bool do_maps_clone)
378{
379 /* This is new thread, we share map groups for process. */
380 if (thread->pid_ == parent->pid_)
381 return thread__prepare_access(thread);
382
383 if (thread->maps == parent->maps) {
384 pr_debug("broken map groups on thread %d/%d parent %d/%d\n",
385 thread->pid_, thread->tid, parent->pid_, parent->tid);
386 return 0;
387 }
388 /* But this one is new process, copy maps. */
389 return do_maps_clone ? maps__clone(thread, parent->maps) : 0;
390}
391
392int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp, bool do_maps_clone)
393{
394 if (parent->comm_set) {
395 const char *comm = thread__comm_str(parent);
396 int err;
397 if (!comm)
398 return -ENOMEM;
399 err = thread__set_comm(thread, comm, timestamp);
400 if (err)
401 return err;
402 }
403
404 thread->ppid = parent->tid;
405 return thread__clone_maps(thread, parent, do_maps_clone);
406}
407
408void thread__find_cpumode_addr_location(struct thread *thread, u64 addr,
409 struct addr_location *al)
410{
411 size_t i;
412 const u8 cpumodes[] = {
413 PERF_RECORD_MISC_USER,
414 PERF_RECORD_MISC_KERNEL,
415 PERF_RECORD_MISC_GUEST_USER,
416 PERF_RECORD_MISC_GUEST_KERNEL
417 };
418
419 for (i = 0; i < ARRAY_SIZE(cpumodes); i++) {
420 thread__find_symbol(thread, cpumodes[i], addr, al);
421 if (al->map)
422 break;
423 }
424}
425
426struct thread *thread__main_thread(struct machine *machine, struct thread *thread)
427{
428 if (thread->pid_ == thread->tid)
429 return thread__get(thread);
430
431 if (thread->pid_ == -1)
432 return NULL;
433
434 return machine__find_thread(machine, thread->pid_, thread->pid_);
435}
436
437int thread__memcpy(struct thread *thread, struct machine *machine,
438 void *buf, u64 ip, int len, bool *is64bit)
439{
440 u8 cpumode = PERF_RECORD_MISC_USER;
441 struct addr_location al;
442 long offset;
443
444 if (machine__kernel_ip(machine, ip))
445 cpumode = PERF_RECORD_MISC_KERNEL;
446
447 if (!thread__find_map(thread, cpumode, ip, &al) || !al.map->dso ||
448 al.map->dso->data.status == DSO_DATA_STATUS_ERROR ||
449 map__load(al.map) < 0)
450 return -1;
451
452 offset = al.map->map_ip(al.map, ip);
453 if (is64bit)
454 *is64bit = al.map->dso->is_64_bit;
455
456 return dso__data_read_offset(al.map->dso, machine, offset, buf, len);
457}
458
459void thread__free_stitch_list(struct thread *thread)
460{
461 struct lbr_stitch *lbr_stitch = thread->lbr_stitch;
462 struct stitch_list *pos, *tmp;
463
464 if (!lbr_stitch)
465 return;
466
467 list_for_each_entry_safe(pos, tmp, &lbr_stitch->lists, node) {
468 list_del_init(&pos->node);
469 free(pos);
470 }
471
472 list_for_each_entry_safe(pos, tmp, &lbr_stitch->free_lists, node) {
473 list_del_init(&pos->node);
474 free(pos);
475 }
476
477 zfree(&lbr_stitch->prev_lbr_cursor);
478 zfree(&thread->lbr_stitch);
479}