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
22 int thread__init_maps(struct thread *thread, struct machine *machine)
23 {
24 pid_t pid = thread__pid(thread);
25
26 if (pid == thread__tid(thread) || pid == -1) {
27 thread__set_maps(thread, maps__new(machine));
28 } else {
29 struct thread *leader = machine__findnew_thread(machine, pid, pid);
30
31 if (leader) {
32 thread__set_maps(thread, maps__get(thread__maps(leader)));
33 thread__put(leader);
34 }
35 }
36
37 return thread__maps(thread) ? 0 : -1;
38 }
39
40 struct thread *thread__new(pid_t pid, pid_t tid)
41 {
42 RC_STRUCT(thread) *_thread = zalloc(sizeof(*_thread));
43 struct thread *thread;
44
45 if (ADD_RC_CHK(thread, _thread) != NULL) {
46 struct comm *comm;
47 char comm_str[32];
48
49 thread__set_pid(thread, pid);
50 thread__set_tid(thread, tid);
51 thread__set_ppid(thread, -1);
52 thread__set_cpu(thread, -1);
53 thread__set_guest_cpu(thread, -1);
54 thread__set_lbr_stitch_enable(thread, false);
55 INIT_LIST_HEAD(thread__namespaces_list(thread));
56 INIT_LIST_HEAD(thread__comm_list(thread));
57 init_rwsem(thread__namespaces_lock(thread));
58 init_rwsem(thread__comm_lock(thread));
59
60 snprintf(comm_str, sizeof(comm_str), ":%d", tid);
61 comm = comm__new(comm_str, 0, false);
62 if (!comm)
63 goto err_thread;
64
65 list_add(&comm->list, thread__comm_list(thread));
66 refcount_set(thread__refcnt(thread), 1);
67 /* Thread holds first ref to nsdata. */
68 RC_CHK_ACCESS(thread)->nsinfo = nsinfo__new(pid);
69 srccode_state_init(thread__srccode_state(thread));
70 }
71
72 return thread;
73
74 err_thread:
75 thread__delete(thread);
76 return NULL;
77 }
78
79 static void (*thread__priv_destructor)(void *priv);
80
81 void thread__set_priv_destructor(void (*destructor)(void *priv))
82 {
83 assert(thread__priv_destructor == NULL);
84
85 thread__priv_destructor = destructor;
86 }
87
88 void thread__delete(struct thread *thread)
89 {
90 struct namespaces *namespaces, *tmp_namespaces;
91 struct comm *comm, *tmp_comm;
92
93 thread_stack__free(thread);
94
95 if (thread__maps(thread)) {
96 maps__put(thread__maps(thread));
97 thread__set_maps(thread, NULL);
98 }
99 down_write(thread__namespaces_lock(thread));
100 list_for_each_entry_safe(namespaces, tmp_namespaces,
101 thread__namespaces_list(thread), list) {
102 list_del_init(&namespaces->list);
103 namespaces__free(namespaces);
104 }
105 up_write(thread__namespaces_lock(thread));
106
107 down_write(thread__comm_lock(thread));
108 list_for_each_entry_safe(comm, tmp_comm, thread__comm_list(thread), list) {
109 list_del_init(&comm->list);
110 comm__free(comm);
111 }
112 up_write(thread__comm_lock(thread));
113
114 nsinfo__zput(RC_CHK_ACCESS(thread)->nsinfo);
115 srccode_state_free(thread__srccode_state(thread));
116
117 exit_rwsem(thread__namespaces_lock(thread));
118 exit_rwsem(thread__comm_lock(thread));
119 thread__free_stitch_list(thread);
120
121 if (thread__priv_destructor)
122 thread__priv_destructor(thread__priv(thread));
123
124 RC_CHK_FREE(thread);
125 }
126
127 struct thread *thread__get(struct thread *thread)
128 {
129 struct thread *result;
130
131 if (RC_CHK_GET(result, thread))
132 refcount_inc(thread__refcnt(thread));
133
134 return result;
135 }
136
137 void thread__put(struct thread *thread)
138 {
139 if (thread && refcount_dec_and_test(thread__refcnt(thread)))
140 thread__delete(thread);
141 else
142 RC_CHK_PUT(thread);
143 }
144
145 static struct namespaces *__thread__namespaces(struct thread *thread)
146 {
147 if (list_empty(thread__namespaces_list(thread)))
148 return NULL;
149
150 return list_first_entry(thread__namespaces_list(thread), struct namespaces, list);
151 }
152
153 struct namespaces *thread__namespaces(struct thread *thread)
154 {
155 struct namespaces *ns;
156
157 down_read(thread__namespaces_lock(thread));
158 ns = __thread__namespaces(thread);
159 up_read(thread__namespaces_lock(thread));
160
161 return ns;
162 }
163
164 static int __thread__set_namespaces(struct thread *thread, u64 timestamp,
165 struct perf_record_namespaces *event)
166 {
167 struct namespaces *new, *curr = __thread__namespaces(thread);
168
169 new = namespaces__new(event);
170 if (!new)
171 return -ENOMEM;
172
173 list_add(&new->list, thread__namespaces_list(thread));
174
175 if (timestamp && curr) {
176 /*
177 * setns syscall must have changed few or all the namespaces
178 * of this thread. Update end time for the namespaces
179 * previously used.
180 */
181 curr = list_next_entry(new, list);
182 curr->end_time = timestamp;
183 }
184
185 return 0;
186 }
187
188 int thread__set_namespaces(struct thread *thread, u64 timestamp,
189 struct perf_record_namespaces *event)
190 {
191 int ret;
192
193 down_write(thread__namespaces_lock(thread));
194 ret = __thread__set_namespaces(thread, timestamp, event);
195 up_write(thread__namespaces_lock(thread));
196 return ret;
197 }
198
199 struct comm *thread__comm(struct thread *thread)
200 {
201 if (list_empty(thread__comm_list(thread)))
202 return NULL;
203
204 return list_first_entry(thread__comm_list(thread), struct comm, list);
205 }
206
207 struct comm *thread__exec_comm(struct thread *thread)
208 {
209 struct comm *comm, *last = NULL, *second_last = NULL;
210
211 list_for_each_entry(comm, thread__comm_list(thread), list) {
212 if (comm->exec)
213 return comm;
214 second_last = last;
215 last = comm;
216 }
217
218 /*
219 * 'last' with no start time might be the parent's comm of a synthesized
220 * thread (created by processing a synthesized fork event). For a main
221 * thread, that is very probably wrong. Prefer a later comm to avoid
222 * that case.
223 */
224 if (second_last && !last->start && thread__pid(thread) == thread__tid(thread))
225 return second_last;
226
227 return last;
228 }
229
230 static int ____thread__set_comm(struct thread *thread, const char *str,
231 u64 timestamp, bool exec)
232 {
233 struct comm *new, *curr = thread__comm(thread);
234
235 /* Override the default :tid entry */
236 if (!thread__comm_set(thread)) {
237 int err = comm__override(curr, str, timestamp, exec);
238 if (err)
239 return err;
240 } else {
241 new = comm__new(str, timestamp, exec);
242 if (!new)
243 return -ENOMEM;
244 list_add(&new->list, thread__comm_list(thread));
245
246 if (exec)
247 unwind__flush_access(thread__maps(thread));
248 }
249
250 thread__set_comm_set(thread, true);
251
252 return 0;
253 }
254
255 int __thread__set_comm(struct thread *thread, const char *str, u64 timestamp,
256 bool exec)
257 {
258 int ret;
259
260 down_write(thread__comm_lock(thread));
261 ret = ____thread__set_comm(thread, str, timestamp, exec);
262 up_write(thread__comm_lock(thread));
263 return ret;
264 }
265
266 int thread__set_comm_from_proc(struct thread *thread)
267 {
268 char path[64];
269 char *comm = NULL;
270 size_t sz;
271 int err = -1;
272
273 if (!(snprintf(path, sizeof(path), "%d/task/%d/comm",
274 thread__pid(thread), thread__tid(thread)) >= (int)sizeof(path)) &&
275 procfs__read_str(path, &comm, &sz) == 0) {
276 comm[sz - 1] = '\0';
277 err = thread__set_comm(thread, comm, 0);
278 }
279
280 return err;
281 }
282
283 static const char *__thread__comm_str(struct thread *thread)
284 {
285 const struct comm *comm = thread__comm(thread);
286
287 if (!comm)
288 return NULL;
289
290 return comm__str(comm);
291 }
292
293 const char *thread__comm_str(struct thread *thread)
294 {
295 const char *str;
296
297 down_read(thread__comm_lock(thread));
298 str = __thread__comm_str(thread);
299 up_read(thread__comm_lock(thread));
300
301 return str;
302 }
303
304 static int __thread__comm_len(struct thread *thread, const char *comm)
305 {
306 if (!comm)
307 return 0;
308 thread__set_comm_len(thread, strlen(comm));
309
310 return thread__var_comm_len(thread);
311 }
312
313 /* CHECKME: it should probably better return the max comm len from its comm list */
314 int thread__comm_len(struct thread *thread)
315 {
316 int comm_len = thread__var_comm_len(thread);
317
318 if (!comm_len) {
319 const char *comm;
320
321 down_read(thread__comm_lock(thread));
322 comm = __thread__comm_str(thread);
323 comm_len = __thread__comm_len(thread, comm);
324 up_read(thread__comm_lock(thread));
325 }
326
327 return comm_len;
328 }
329
330 size_t thread__fprintf(struct thread *thread, FILE *fp)
331 {
332 return fprintf(fp, "Thread %d %s\n", thread__tid(thread), thread__comm_str(thread)) +
333 maps__fprintf(thread__maps(thread), fp);
334 }
335
336 int thread__insert_map(struct thread *thread, struct map *map)
337 {
338 int ret;
339
340 ret = unwind__prepare_access(thread__maps(thread), map, NULL);
341 if (ret)
342 return ret;
343
344 return maps__fixup_overlap_and_insert(thread__maps(thread), map);
345 }
346
347 struct thread__prepare_access_maps_cb_args {
348 int err;
349 struct maps *maps;
350 };
351
352 static int thread__prepare_access_maps_cb(struct map *map, void *data)
353 {
354 bool initialized = false;
355 struct thread__prepare_access_maps_cb_args *args = data;
356
357 args->err = unwind__prepare_access(args->maps, map, &initialized);
358
359 return (args->err || initialized) ? 1 : 0;
360 }
361
362 static int thread__prepare_access(struct thread *thread)
363 {
364 struct thread__prepare_access_maps_cb_args args = {
365 .err = 0,
366 };
367
368 if (dwarf_callchain_users) {
369 args.maps = thread__maps(thread);
370 maps__for_each_map(thread__maps(thread), thread__prepare_access_maps_cb, &args);
371 }
372
373 return args.err;
374 }
375
376 static 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(thread) == thread__pid(parent))
380 return thread__prepare_access(thread);
381
382 if (maps__equal(thread__maps(thread), thread__maps(parent))) {
383 pr_debug("broken map groups on thread %d/%d parent %d/%d\n",
384 thread__pid(thread), thread__tid(thread),
385 thread__pid(parent), thread__tid(parent));
386 return 0;
387 }
388 /* But this one is new process, copy maps. */
389 return do_maps_clone ? maps__copy_from(thread__maps(thread), thread__maps(parent)) : 0;
390 }
391
392 int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp, bool do_maps_clone)
393 {
394 if (thread__comm_set(parent)) {
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__set_ppid(thread, thread__tid(parent));
405 return thread__clone_maps(thread, parent, do_maps_clone);
406 }
407
408 void 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
426 struct thread *thread__main_thread(struct machine *machine, struct thread *thread)
427 {
428 if (thread__pid(thread) == thread__tid(thread))
429 return thread__get(thread);
430
431 if (thread__pid(thread) == -1)
432 return NULL;
433
434 return machine__find_thread(machine, thread__pid(thread), thread__pid(thread));
435 }
436
437 int 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 struct dso *dso;
443 long offset;
444
445 if (machine__kernel_ip(machine, ip))
446 cpumode = PERF_RECORD_MISC_KERNEL;
447
448 addr_location__init(&al);
449 if (!thread__find_map(thread, cpumode, ip, &al)) {
450 addr_location__exit(&al);
451 return -1;
452 }
453
454 dso = map__dso(al.map);
455
456 if (!dso || dso__data(dso)->status == DSO_DATA_STATUS_ERROR || map__load(al.map) < 0) {
457 addr_location__exit(&al);
458 return -1;
459 }
460
461 offset = map__map_ip(al.map, ip);
462 if (is64bit)
463 *is64bit = dso__is_64_bit(dso);
464
465 addr_location__exit(&al);
466
467 return dso__data_read_offset(dso, machine, offset, buf, len);
468 }
469
470 void thread__free_stitch_list(struct thread *thread)
471 {
472 struct lbr_stitch *lbr_stitch = thread__lbr_stitch(thread);
473 struct stitch_list *pos, *tmp;
474
475 if (!lbr_stitch)
476 return;
477
478 list_for_each_entry_safe(pos, tmp, &lbr_stitch->lists, node) {
479 map_symbol__exit(&pos->cursor.ms);
480 list_del_init(&pos->node);
481 free(pos);
482 }
483
484 list_for_each_entry_safe(pos, tmp, &lbr_stitch->free_lists, node) {
485 list_del_init(&pos->node);
486 free(pos);
487 }
488
489 for (unsigned int i = 0 ; i < lbr_stitch->prev_lbr_cursor_size; i++)
490 map_symbol__exit(&lbr_stitch->prev_lbr_cursor[i].ms);
491
492 zfree(&lbr_stitch->prev_lbr_cursor);
493 free(thread__lbr_stitch(thread));
494 thread__set_lbr_stitch(thread, NULL);
495 }
496
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