xref: /linux/tools/perf/util/thread.c (revision f3a8b6645dc2e60d11f20c1c23afd964ff4e55ae)
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 
13 #include <api/fs/fs.h>
14 
15 int thread__init_map_groups(struct thread *thread, struct machine *machine)
16 {
17 	pid_t pid = thread->pid_;
18 
19 	if (pid == thread->tid || pid == -1) {
20 		thread->mg = map_groups__new(machine);
21 	} else {
22 		struct thread *leader = __machine__findnew_thread(machine, pid, pid);
23 		if (leader) {
24 			thread->mg = map_groups__get(leader->mg);
25 			thread__put(leader);
26 		}
27 	}
28 
29 	return thread->mg ? 0 : -1;
30 }
31 
32 struct thread *thread__new(pid_t pid, pid_t tid)
33 {
34 	char *comm_str;
35 	struct comm *comm;
36 	struct thread *thread = zalloc(sizeof(*thread));
37 
38 	if (thread != NULL) {
39 		thread->pid_ = pid;
40 		thread->tid = tid;
41 		thread->ppid = -1;
42 		thread->cpu = -1;
43 		INIT_LIST_HEAD(&thread->comm_list);
44 
45 		comm_str = malloc(32);
46 		if (!comm_str)
47 			goto err_thread;
48 
49 		snprintf(comm_str, 32, ":%d", tid);
50 		comm = comm__new(comm_str, 0, false);
51 		free(comm_str);
52 		if (!comm)
53 			goto err_thread;
54 
55 		list_add(&comm->list, &thread->comm_list);
56 		atomic_set(&thread->refcnt, 1);
57 		RB_CLEAR_NODE(&thread->rb_node);
58 	}
59 
60 	return thread;
61 
62 err_thread:
63 	free(thread);
64 	return NULL;
65 }
66 
67 void thread__delete(struct thread *thread)
68 {
69 	struct comm *comm, *tmp;
70 
71 	BUG_ON(!RB_EMPTY_NODE(&thread->rb_node));
72 
73 	thread_stack__free(thread);
74 
75 	if (thread->mg) {
76 		map_groups__put(thread->mg);
77 		thread->mg = NULL;
78 	}
79 	list_for_each_entry_safe(comm, tmp, &thread->comm_list, list) {
80 		list_del(&comm->list);
81 		comm__free(comm);
82 	}
83 	unwind__finish_access(thread);
84 
85 	free(thread);
86 }
87 
88 struct thread *thread__get(struct thread *thread)
89 {
90 	if (thread)
91 		atomic_inc(&thread->refcnt);
92 	return thread;
93 }
94 
95 void thread__put(struct thread *thread)
96 {
97 	if (thread && atomic_dec_and_test(&thread->refcnt)) {
98 		/*
99 		 * Remove it from the dead_threads list, as last reference
100 		 * is gone.
101 		 */
102 		list_del_init(&thread->node);
103 		thread__delete(thread);
104 	}
105 }
106 
107 struct comm *thread__comm(const struct thread *thread)
108 {
109 	if (list_empty(&thread->comm_list))
110 		return NULL;
111 
112 	return list_first_entry(&thread->comm_list, struct comm, list);
113 }
114 
115 struct comm *thread__exec_comm(const struct thread *thread)
116 {
117 	struct comm *comm, *last = NULL;
118 
119 	list_for_each_entry(comm, &thread->comm_list, list) {
120 		if (comm->exec)
121 			return comm;
122 		last = comm;
123 	}
124 
125 	return last;
126 }
127 
128 int __thread__set_comm(struct thread *thread, const char *str, u64 timestamp,
129 		       bool exec)
130 {
131 	struct comm *new, *curr = thread__comm(thread);
132 
133 	/* Override the default :tid entry */
134 	if (!thread->comm_set) {
135 		int err = comm__override(curr, str, timestamp, exec);
136 		if (err)
137 			return err;
138 	} else {
139 		new = comm__new(str, timestamp, exec);
140 		if (!new)
141 			return -ENOMEM;
142 		list_add(&new->list, &thread->comm_list);
143 
144 		if (exec)
145 			unwind__flush_access(thread);
146 	}
147 
148 	thread->comm_set = true;
149 
150 	return 0;
151 }
152 
153 int thread__set_comm_from_proc(struct thread *thread)
154 {
155 	char path[64];
156 	char *comm = NULL;
157 	size_t sz;
158 	int err = -1;
159 
160 	if (!(snprintf(path, sizeof(path), "%d/task/%d/comm",
161 		       thread->pid_, thread->tid) >= (int)sizeof(path)) &&
162 	    procfs__read_str(path, &comm, &sz) == 0) {
163 		comm[sz - 1] = '\0';
164 		err = thread__set_comm(thread, comm, 0);
165 	}
166 
167 	return err;
168 }
169 
170 const char *thread__comm_str(const struct thread *thread)
171 {
172 	const struct comm *comm = thread__comm(thread);
173 
174 	if (!comm)
175 		return NULL;
176 
177 	return comm__str(comm);
178 }
179 
180 /* CHECKME: it should probably better return the max comm len from its comm list */
181 int thread__comm_len(struct thread *thread)
182 {
183 	if (!thread->comm_len) {
184 		const char *comm = thread__comm_str(thread);
185 		if (!comm)
186 			return 0;
187 		thread->comm_len = strlen(comm);
188 	}
189 
190 	return thread->comm_len;
191 }
192 
193 size_t thread__fprintf(struct thread *thread, FILE *fp)
194 {
195 	return fprintf(fp, "Thread %d %s\n", thread->tid, thread__comm_str(thread)) +
196 	       map_groups__fprintf(thread->mg, fp);
197 }
198 
199 int thread__insert_map(struct thread *thread, struct map *map)
200 {
201 	int ret;
202 
203 	ret = unwind__prepare_access(thread, map, NULL);
204 	if (ret)
205 		return ret;
206 
207 	map_groups__fixup_overlappings(thread->mg, map, stderr);
208 	map_groups__insert(thread->mg, map);
209 
210 	return 0;
211 }
212 
213 static int __thread__prepare_access(struct thread *thread)
214 {
215 	bool initialized = false;
216 	int i, err = 0;
217 
218 	for (i = 0; i < MAP__NR_TYPES; ++i) {
219 		struct maps *maps = &thread->mg->maps[i];
220 		struct map *map;
221 
222 		pthread_rwlock_rdlock(&maps->lock);
223 
224 		for (map = maps__first(maps); map; map = map__next(map)) {
225 			err = unwind__prepare_access(thread, map, &initialized);
226 			if (err || initialized)
227 				break;
228 		}
229 
230 		pthread_rwlock_unlock(&maps->lock);
231 	}
232 
233 	return err;
234 }
235 
236 static int thread__prepare_access(struct thread *thread)
237 {
238 	int err = 0;
239 
240 	if (symbol_conf.use_callchain)
241 		err = __thread__prepare_access(thread);
242 
243 	return err;
244 }
245 
246 static int thread__clone_map_groups(struct thread *thread,
247 				    struct thread *parent)
248 {
249 	int i;
250 
251 	/* This is new thread, we share map groups for process. */
252 	if (thread->pid_ == parent->pid_)
253 		return thread__prepare_access(thread);
254 
255 	if (thread->mg == parent->mg) {
256 		pr_debug("broken map groups on thread %d/%d parent %d/%d\n",
257 			 thread->pid_, thread->tid, parent->pid_, parent->tid);
258 		return 0;
259 	}
260 
261 	/* But this one is new process, copy maps. */
262 	for (i = 0; i < MAP__NR_TYPES; ++i)
263 		if (map_groups__clone(thread, parent->mg, i) < 0)
264 			return -ENOMEM;
265 
266 	return 0;
267 }
268 
269 int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp)
270 {
271 	if (parent->comm_set) {
272 		const char *comm = thread__comm_str(parent);
273 		int err;
274 		if (!comm)
275 			return -ENOMEM;
276 		err = thread__set_comm(thread, comm, timestamp);
277 		if (err)
278 			return err;
279 	}
280 
281 	thread->ppid = parent->tid;
282 	return thread__clone_map_groups(thread, parent);
283 }
284 
285 void thread__find_cpumode_addr_location(struct thread *thread,
286 					enum map_type type, u64 addr,
287 					struct addr_location *al)
288 {
289 	size_t i;
290 	const u8 cpumodes[] = {
291 		PERF_RECORD_MISC_USER,
292 		PERF_RECORD_MISC_KERNEL,
293 		PERF_RECORD_MISC_GUEST_USER,
294 		PERF_RECORD_MISC_GUEST_KERNEL
295 	};
296 
297 	for (i = 0; i < ARRAY_SIZE(cpumodes); i++) {
298 		thread__find_addr_location(thread, cpumodes[i], type, addr, al);
299 		if (al->map)
300 			break;
301 	}
302 }
303 
304 struct thread *thread__main_thread(struct machine *machine, struct thread *thread)
305 {
306 	if (thread->pid_ == thread->tid)
307 		return thread__get(thread);
308 
309 	if (thread->pid_ == -1)
310 		return NULL;
311 
312 	return machine__find_thread(machine, thread->pid_, thread->pid_);
313 }
314