1 // SPDX-License-Identifier: GPL-2.0
7 #include <linux/kernel.h>
10 #include "thread-stack.h"
13 #include "namespaces.h"
17 #include <api/fs/fs.h>
19 int thread__init_map_groups(struct thread *thread, struct machine *machine)
21 pid_t pid = thread->pid_;
23 if (pid == thread->tid || pid == -1) {
24 thread->mg = map_groups__new(machine);
26 struct thread *leader = __machine__findnew_thread(machine, pid, pid);
28 thread->mg = map_groups__get(leader->mg);
33 return thread->mg ? 0 : -1;
36 struct thread *thread__new(pid_t pid, pid_t tid)
40 struct thread *thread = zalloc(sizeof(*thread));
47 INIT_LIST_HEAD(&thread->namespaces_list);
48 INIT_LIST_HEAD(&thread->comm_list);
49 init_rwsem(&thread->namespaces_lock);
50 init_rwsem(&thread->comm_lock);
52 comm_str = malloc(32);
56 snprintf(comm_str, 32, ":%d", tid);
57 comm = comm__new(comm_str, 0, false);
62 list_add(&comm->list, &thread->comm_list);
63 refcount_set(&thread->refcnt, 1);
64 RB_CLEAR_NODE(&thread->rb_node);
65 /* Thread holds first ref to nsdata. */
66 thread->nsinfo = nsinfo__new(pid);
67 srccode_state_init(&thread->srccode_state);
77 void thread__delete(struct thread *thread)
79 struct namespaces *namespaces, *tmp_namespaces;
80 struct comm *comm, *tmp_comm;
82 BUG_ON(!RB_EMPTY_NODE(&thread->rb_node));
84 thread_stack__free(thread);
87 map_groups__put(thread->mg);
90 down_write(&thread->namespaces_lock);
91 list_for_each_entry_safe(namespaces, tmp_namespaces,
92 &thread->namespaces_list, list) {
93 list_del(&namespaces->list);
94 namespaces__free(namespaces);
96 up_write(&thread->namespaces_lock);
98 down_write(&thread->comm_lock);
99 list_for_each_entry_safe(comm, tmp_comm, &thread->comm_list, list) {
100 list_del(&comm->list);
103 up_write(&thread->comm_lock);
105 unwind__finish_access(thread);
106 nsinfo__zput(thread->nsinfo);
107 srccode_state_free(&thread->srccode_state);
109 exit_rwsem(&thread->namespaces_lock);
110 exit_rwsem(&thread->comm_lock);
114 struct thread *thread__get(struct thread *thread)
117 refcount_inc(&thread->refcnt);
121 void thread__put(struct thread *thread)
123 if (thread && refcount_dec_and_test(&thread->refcnt)) {
125 * Remove it from the dead_threads list, as last reference
128 list_del_init(&thread->node);
129 thread__delete(thread);
133 struct namespaces *thread__namespaces(const struct thread *thread)
135 if (list_empty(&thread->namespaces_list))
138 return list_first_entry(&thread->namespaces_list, struct namespaces, list);
141 static int __thread__set_namespaces(struct thread *thread, u64 timestamp,
142 struct namespaces_event *event)
144 struct namespaces *new, *curr = thread__namespaces(thread);
146 new = namespaces__new(event);
150 list_add(&new->list, &thread->namespaces_list);
152 if (timestamp && curr) {
154 * setns syscall must have changed few or all the namespaces
155 * of this thread. Update end time for the namespaces
158 curr = list_next_entry(new, list);
159 curr->end_time = timestamp;
165 int thread__set_namespaces(struct thread *thread, u64 timestamp,
166 struct namespaces_event *event)
170 down_write(&thread->namespaces_lock);
171 ret = __thread__set_namespaces(thread, timestamp, event);
172 up_write(&thread->namespaces_lock);
176 struct comm *thread__comm(const struct thread *thread)
178 if (list_empty(&thread->comm_list))
181 return list_first_entry(&thread->comm_list, struct comm, list);
184 struct comm *thread__exec_comm(const struct thread *thread)
186 struct comm *comm, *last = NULL;
188 list_for_each_entry(comm, &thread->comm_list, list) {
197 static int ____thread__set_comm(struct thread *thread, const char *str,
198 u64 timestamp, bool exec)
200 struct comm *new, *curr = thread__comm(thread);
202 /* Override the default :tid entry */
203 if (!thread->comm_set) {
204 int err = comm__override(curr, str, timestamp, exec);
208 new = comm__new(str, timestamp, exec);
211 list_add(&new->list, &thread->comm_list);
214 unwind__flush_access(thread);
217 thread->comm_set = true;
222 int __thread__set_comm(struct thread *thread, const char *str, u64 timestamp,
227 down_write(&thread->comm_lock);
228 ret = ____thread__set_comm(thread, str, timestamp, exec);
229 up_write(&thread->comm_lock);
233 int thread__set_comm_from_proc(struct thread *thread)
240 if (!(snprintf(path, sizeof(path), "%d/task/%d/comm",
241 thread->pid_, thread->tid) >= (int)sizeof(path)) &&
242 procfs__read_str(path, &comm, &sz) == 0) {
244 err = thread__set_comm(thread, comm, 0);
250 static const char *__thread__comm_str(const struct thread *thread)
252 const struct comm *comm = thread__comm(thread);
257 return comm__str(comm);
260 const char *thread__comm_str(const struct thread *thread)
264 down_read((struct rw_semaphore *)&thread->comm_lock);
265 str = __thread__comm_str(thread);
266 up_read((struct rw_semaphore *)&thread->comm_lock);
271 /* CHECKME: it should probably better return the max comm len from its comm list */
272 int thread__comm_len(struct thread *thread)
274 if (!thread->comm_len) {
275 const char *comm = thread__comm_str(thread);
278 thread->comm_len = strlen(comm);
281 return thread->comm_len;
284 size_t thread__fprintf(struct thread *thread, FILE *fp)
286 return fprintf(fp, "Thread %d %s\n", thread->tid, thread__comm_str(thread)) +
287 map_groups__fprintf(thread->mg, fp);
290 int thread__insert_map(struct thread *thread, struct map *map)
294 ret = unwind__prepare_access(thread, map, NULL);
298 map_groups__fixup_overlappings(thread->mg, map, stderr);
299 map_groups__insert(thread->mg, map);
304 static int __thread__prepare_access(struct thread *thread)
306 bool initialized = false;
308 struct maps *maps = &thread->mg->maps;
311 down_read(&maps->lock);
313 for (map = maps__first(maps); map; map = map__next(map)) {
314 err = unwind__prepare_access(thread, map, &initialized);
315 if (err || initialized)
319 up_read(&maps->lock);
324 static int thread__prepare_access(struct thread *thread)
328 if (symbol_conf.use_callchain)
329 err = __thread__prepare_access(thread);
334 static int thread__clone_map_groups(struct thread *thread,
335 struct thread *parent,
338 /* This is new thread, we share map groups for process. */
339 if (thread->pid_ == parent->pid_)
340 return thread__prepare_access(thread);
342 if (thread->mg == parent->mg) {
343 pr_debug("broken map groups on thread %d/%d parent %d/%d\n",
344 thread->pid_, thread->tid, parent->pid_, parent->tid);
347 /* But this one is new process, copy maps. */
348 return do_maps_clone ? map_groups__clone(thread, parent->mg) : 0;
351 int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp, bool do_maps_clone)
353 if (parent->comm_set) {
354 const char *comm = thread__comm_str(parent);
358 err = thread__set_comm(thread, comm, timestamp);
363 thread->ppid = parent->tid;
364 return thread__clone_map_groups(thread, parent, do_maps_clone);
367 void thread__find_cpumode_addr_location(struct thread *thread, u64 addr,
368 struct addr_location *al)
371 const u8 cpumodes[] = {
372 PERF_RECORD_MISC_USER,
373 PERF_RECORD_MISC_KERNEL,
374 PERF_RECORD_MISC_GUEST_USER,
375 PERF_RECORD_MISC_GUEST_KERNEL
378 for (i = 0; i < ARRAY_SIZE(cpumodes); i++) {
379 thread__find_symbol(thread, cpumodes[i], addr, al);
385 struct thread *thread__main_thread(struct machine *machine, struct thread *thread)
387 if (thread->pid_ == thread->tid)
388 return thread__get(thread);
390 if (thread->pid_ == -1)
393 return machine__find_thread(machine, thread->pid_, thread->pid_);