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