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);
76 void thread__delete(struct thread *thread)
78 struct namespaces *namespaces, *tmp_namespaces;
79 struct comm *comm, *tmp_comm;
81 BUG_ON(!RB_EMPTY_NODE(&thread->rb_node));
83 thread_stack__free(thread);
86 map_groups__put(thread->mg);
89 down_write(&thread->namespaces_lock);
90 list_for_each_entry_safe(namespaces, tmp_namespaces,
91 &thread->namespaces_list, list) {
92 list_del(&namespaces->list);
93 namespaces__free(namespaces);
95 up_write(&thread->namespaces_lock);
97 down_write(&thread->comm_lock);
98 list_for_each_entry_safe(comm, tmp_comm, &thread->comm_list, list) {
99 list_del(&comm->list);
102 up_write(&thread->comm_lock);
104 unwind__finish_access(thread);
105 nsinfo__zput(thread->nsinfo);
107 exit_rwsem(&thread->namespaces_lock);
108 exit_rwsem(&thread->comm_lock);
112 struct thread *thread__get(struct thread *thread)
115 refcount_inc(&thread->refcnt);
119 void thread__put(struct thread *thread)
121 if (thread && refcount_dec_and_test(&thread->refcnt)) {
123 * Remove it from the dead_threads list, as last reference
126 list_del_init(&thread->node);
127 thread__delete(thread);
131 struct namespaces *thread__namespaces(const struct thread *thread)
133 if (list_empty(&thread->namespaces_list))
136 return list_first_entry(&thread->namespaces_list, struct namespaces, list);
139 static int __thread__set_namespaces(struct thread *thread, u64 timestamp,
140 struct namespaces_event *event)
142 struct namespaces *new, *curr = thread__namespaces(thread);
144 new = namespaces__new(event);
148 list_add(&new->list, &thread->namespaces_list);
150 if (timestamp && curr) {
152 * setns syscall must have changed few or all the namespaces
153 * of this thread. Update end time for the namespaces
156 curr = list_next_entry(new, list);
157 curr->end_time = timestamp;
163 int thread__set_namespaces(struct thread *thread, u64 timestamp,
164 struct namespaces_event *event)
168 down_write(&thread->namespaces_lock);
169 ret = __thread__set_namespaces(thread, timestamp, event);
170 up_write(&thread->namespaces_lock);
174 struct comm *thread__comm(const struct thread *thread)
176 if (list_empty(&thread->comm_list))
179 return list_first_entry(&thread->comm_list, struct comm, list);
182 struct comm *thread__exec_comm(const struct thread *thread)
184 struct comm *comm, *last = NULL;
186 list_for_each_entry(comm, &thread->comm_list, list) {
195 static int ____thread__set_comm(struct thread *thread, const char *str,
196 u64 timestamp, bool exec)
198 struct comm *new, *curr = thread__comm(thread);
200 /* Override the default :tid entry */
201 if (!thread->comm_set) {
202 int err = comm__override(curr, str, timestamp, exec);
206 new = comm__new(str, timestamp, exec);
209 list_add(&new->list, &thread->comm_list);
212 unwind__flush_access(thread);
215 thread->comm_set = true;
220 int __thread__set_comm(struct thread *thread, const char *str, u64 timestamp,
225 down_write(&thread->comm_lock);
226 ret = ____thread__set_comm(thread, str, timestamp, exec);
227 up_write(&thread->comm_lock);
231 int thread__set_comm_from_proc(struct thread *thread)
238 if (!(snprintf(path, sizeof(path), "%d/task/%d/comm",
239 thread->pid_, thread->tid) >= (int)sizeof(path)) &&
240 procfs__read_str(path, &comm, &sz) == 0) {
242 err = thread__set_comm(thread, comm, 0);
248 static const char *__thread__comm_str(const struct thread *thread)
250 const struct comm *comm = thread__comm(thread);
255 return comm__str(comm);
258 const char *thread__comm_str(const struct thread *thread)
262 down_read((struct rw_semaphore *)&thread->comm_lock);
263 str = __thread__comm_str(thread);
264 up_read((struct rw_semaphore *)&thread->comm_lock);
269 /* CHECKME: it should probably better return the max comm len from its comm list */
270 int thread__comm_len(struct thread *thread)
272 if (!thread->comm_len) {
273 const char *comm = thread__comm_str(thread);
276 thread->comm_len = strlen(comm);
279 return thread->comm_len;
282 size_t thread__fprintf(struct thread *thread, FILE *fp)
284 return fprintf(fp, "Thread %d %s\n", thread->tid, thread__comm_str(thread)) +
285 map_groups__fprintf(thread->mg, fp);
288 int thread__insert_map(struct thread *thread, struct map *map)
292 ret = unwind__prepare_access(thread, map, NULL);
296 map_groups__fixup_overlappings(thread->mg, map, stderr);
297 map_groups__insert(thread->mg, map);
302 static int __thread__prepare_access(struct thread *thread)
304 bool initialized = false;
307 for (i = 0; i < MAP__NR_TYPES; ++i) {
308 struct maps *maps = &thread->mg->maps[i];
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);
325 static int thread__prepare_access(struct thread *thread)
329 if (symbol_conf.use_callchain)
330 err = __thread__prepare_access(thread);
335 static int thread__clone_map_groups(struct thread *thread,
336 struct thread *parent)
340 /* This is new thread, we share map groups for process. */
341 if (thread->pid_ == parent->pid_)
342 return thread__prepare_access(thread);
344 if (thread->mg == parent->mg) {
345 pr_debug("broken map groups on thread %d/%d parent %d/%d\n",
346 thread->pid_, thread->tid, parent->pid_, parent->tid);
350 /* But this one is new process, copy maps. */
351 for (i = 0; i < MAP__NR_TYPES; ++i)
352 if (map_groups__clone(thread, parent->mg, i) < 0)
358 int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp)
360 if (parent->comm_set) {
361 const char *comm = thread__comm_str(parent);
365 err = thread__set_comm(thread, comm, timestamp);
370 thread->ppid = parent->tid;
371 return thread__clone_map_groups(thread, parent);
374 void thread__find_cpumode_addr_location(struct thread *thread,
375 enum map_type type, u64 addr,
376 struct addr_location *al)
379 const u8 cpumodes[] = {
380 PERF_RECORD_MISC_USER,
381 PERF_RECORD_MISC_KERNEL,
382 PERF_RECORD_MISC_GUEST_USER,
383 PERF_RECORD_MISC_GUEST_KERNEL
386 for (i = 0; i < ARRAY_SIZE(cpumodes); i++) {
387 thread__find_addr_location(thread, cpumodes[i], type, addr, al);
393 struct thread *thread__main_thread(struct machine *machine, struct thread *thread)
395 if (thread->pid_ == thread->tid)
396 return thread__get(thread);
398 if (thread->pid_ == -1)
401 return machine__find_thread(machine, thread->pid_, thread->pid_);