xref: /openbmc/linux/tools/perf/util/thread.c (revision 293d5b43)
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 	struct thread *leader;
18 	pid_t pid = thread->pid_;
19 
20 	if (pid == thread->tid || pid == -1) {
21 		thread->mg = map_groups__new(machine);
22 	} else {
23 		leader = __machine__findnew_thread(machine, pid, pid);
24 		if (leader) {
25 			thread->mg = map_groups__get(leader->mg);
26 			thread__put(leader);
27 		}
28 	}
29 
30 	return thread->mg ? 0 : -1;
31 }
32 
33 struct thread *thread__new(pid_t pid, pid_t tid)
34 {
35 	char *comm_str;
36 	struct comm *comm;
37 	struct thread *thread = zalloc(sizeof(*thread));
38 
39 	if (thread != NULL) {
40 		thread->pid_ = pid;
41 		thread->tid = tid;
42 		thread->ppid = -1;
43 		thread->cpu = -1;
44 		INIT_LIST_HEAD(&thread->comm_list);
45 
46 		comm_str = malloc(32);
47 		if (!comm_str)
48 			goto err_thread;
49 
50 		snprintf(comm_str, 32, ":%d", tid);
51 		comm = comm__new(comm_str, 0, false);
52 		free(comm_str);
53 		if (!comm)
54 			goto err_thread;
55 
56 		list_add(&comm->list, &thread->comm_list);
57 		atomic_set(&thread->refcnt, 1);
58 		RB_CLEAR_NODE(&thread->rb_node);
59 	}
60 
61 	return thread;
62 
63 err_thread:
64 	free(thread);
65 	return NULL;
66 }
67 
68 void thread__delete(struct thread *thread)
69 {
70 	struct comm *comm, *tmp;
71 
72 	BUG_ON(!RB_EMPTY_NODE(&thread->rb_node));
73 
74 	thread_stack__free(thread);
75 
76 	if (thread->mg) {
77 		map_groups__put(thread->mg);
78 		thread->mg = NULL;
79 	}
80 	list_for_each_entry_safe(comm, tmp, &thread->comm_list, list) {
81 		list_del(&comm->list);
82 		comm__free(comm);
83 	}
84 	unwind__finish_access(thread);
85 
86 	free(thread);
87 }
88 
89 struct thread *thread__get(struct thread *thread)
90 {
91 	if (thread)
92 		atomic_inc(&thread->refcnt);
93 	return thread;
94 }
95 
96 void thread__put(struct thread *thread)
97 {
98 	if (thread && atomic_dec_and_test(&thread->refcnt)) {
99 		/*
100 		 * Remove it from the dead_threads list, as last reference
101 		 * is gone.
102 		 */
103 		list_del_init(&thread->node);
104 		thread__delete(thread);
105 	}
106 }
107 
108 struct comm *thread__comm(const struct thread *thread)
109 {
110 	if (list_empty(&thread->comm_list))
111 		return NULL;
112 
113 	return list_first_entry(&thread->comm_list, struct comm, list);
114 }
115 
116 struct comm *thread__exec_comm(const struct thread *thread)
117 {
118 	struct comm *comm, *last = NULL;
119 
120 	list_for_each_entry(comm, &thread->comm_list, list) {
121 		if (comm->exec)
122 			return comm;
123 		last = comm;
124 	}
125 
126 	return last;
127 }
128 
129 int __thread__set_comm(struct thread *thread, const char *str, u64 timestamp,
130 		       bool exec)
131 {
132 	struct comm *new, *curr = thread__comm(thread);
133 	int err;
134 
135 	/* Override the default :tid entry */
136 	if (!thread->comm_set) {
137 		err = comm__override(curr, str, timestamp, exec);
138 		if (err)
139 			return err;
140 	} else {
141 		new = comm__new(str, timestamp, exec);
142 		if (!new)
143 			return -ENOMEM;
144 		list_add(&new->list, &thread->comm_list);
145 
146 		if (exec)
147 			unwind__flush_access(thread);
148 	}
149 
150 	thread->comm_set = true;
151 
152 	return 0;
153 }
154 
155 int thread__set_comm_from_proc(struct thread *thread)
156 {
157 	char path[64];
158 	char *comm = NULL;
159 	size_t sz;
160 	int err = -1;
161 
162 	if (!(snprintf(path, sizeof(path), "%d/task/%d/comm",
163 		       thread->pid_, thread->tid) >= (int)sizeof(path)) &&
164 	    procfs__read_str(path, &comm, &sz) == 0) {
165 		comm[sz - 1] = '\0';
166 		err = thread__set_comm(thread, comm, 0);
167 	}
168 
169 	return err;
170 }
171 
172 const char *thread__comm_str(const struct thread *thread)
173 {
174 	const struct comm *comm = thread__comm(thread);
175 
176 	if (!comm)
177 		return NULL;
178 
179 	return comm__str(comm);
180 }
181 
182 /* CHECKME: it should probably better return the max comm len from its comm list */
183 int thread__comm_len(struct thread *thread)
184 {
185 	if (!thread->comm_len) {
186 		const char *comm = thread__comm_str(thread);
187 		if (!comm)
188 			return 0;
189 		thread->comm_len = strlen(comm);
190 	}
191 
192 	return thread->comm_len;
193 }
194 
195 size_t thread__fprintf(struct thread *thread, FILE *fp)
196 {
197 	return fprintf(fp, "Thread %d %s\n", thread->tid, thread__comm_str(thread)) +
198 	       map_groups__fprintf(thread->mg, fp);
199 }
200 
201 int thread__insert_map(struct thread *thread, struct map *map)
202 {
203 	int ret;
204 
205 	ret = unwind__prepare_access(thread, map, NULL);
206 	if (ret)
207 		return ret;
208 
209 	map_groups__fixup_overlappings(thread->mg, map, stderr);
210 	map_groups__insert(thread->mg, map);
211 
212 	return 0;
213 }
214 
215 static int __thread__prepare_access(struct thread *thread)
216 {
217 	bool initialized = false;
218 	int i, err = 0;
219 
220 	for (i = 0; i < MAP__NR_TYPES; ++i) {
221 		struct maps *maps = &thread->mg->maps[i];
222 		struct map *map;
223 
224 		pthread_rwlock_rdlock(&maps->lock);
225 
226 		for (map = maps__first(maps); map; map = map__next(map)) {
227 			err = unwind__prepare_access(thread, map, &initialized);
228 			if (err || initialized)
229 				break;
230 		}
231 
232 		pthread_rwlock_unlock(&maps->lock);
233 	}
234 
235 	return err;
236 }
237 
238 static int thread__prepare_access(struct thread *thread)
239 {
240 	int err = 0;
241 
242 	if (symbol_conf.use_callchain)
243 		err = __thread__prepare_access(thread);
244 
245 	return err;
246 }
247 
248 static int thread__clone_map_groups(struct thread *thread,
249 				    struct thread *parent)
250 {
251 	int i;
252 
253 	/* This is new thread, we share map groups for process. */
254 	if (thread->pid_ == parent->pid_)
255 		return thread__prepare_access(thread);
256 
257 	if (thread->mg == parent->mg) {
258 		pr_debug("broken map groups on thread %d/%d parent %d/%d\n",
259 			 thread->pid_, thread->tid, parent->pid_, parent->tid);
260 		return 0;
261 	}
262 
263 	/* But this one is new process, copy maps. */
264 	for (i = 0; i < MAP__NR_TYPES; ++i)
265 		if (map_groups__clone(thread, parent->mg, i) < 0)
266 			return -ENOMEM;
267 
268 	return 0;
269 }
270 
271 int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp)
272 {
273 	int err;
274 
275 	if (parent->comm_set) {
276 		const char *comm = thread__comm_str(parent);
277 		if (!comm)
278 			return -ENOMEM;
279 		err = thread__set_comm(thread, comm, timestamp);
280 		if (err)
281 			return err;
282 	}
283 
284 	thread->ppid = parent->tid;
285 	return thread__clone_map_groups(thread, parent);
286 }
287 
288 void thread__find_cpumode_addr_location(struct thread *thread,
289 					enum map_type type, u64 addr,
290 					struct addr_location *al)
291 {
292 	size_t i;
293 	const u8 cpumodes[] = {
294 		PERF_RECORD_MISC_USER,
295 		PERF_RECORD_MISC_KERNEL,
296 		PERF_RECORD_MISC_GUEST_USER,
297 		PERF_RECORD_MISC_GUEST_KERNEL
298 	};
299 
300 	for (i = 0; i < ARRAY_SIZE(cpumodes); i++) {
301 		thread__find_addr_location(thread, cpumodes[i], type, addr, al);
302 		if (al->map)
303 			break;
304 	}
305 }
306 
307 struct thread *thread__main_thread(struct machine *machine, struct thread *thread)
308 {
309 	if (thread->pid_ == thread->tid)
310 		return thread__get(thread);
311 
312 	if (thread->pid_ == -1)
313 		return NULL;
314 
315 	return machine__find_thread(machine, thread->pid_, thread->pid_);
316 }
317