xref: /openbmc/linux/tools/perf/util/thread_map.c (revision 9470114d)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <dirent.h>
3 #include <errno.h>
4 #include <limits.h>
5 #include <stdbool.h>
6 #include <stdlib.h>
7 #include <stdio.h>
8 #include <sys/types.h>
9 #include <sys/stat.h>
10 #include <unistd.h>
11 #include "string2.h"
12 #include "strlist.h"
13 #include <string.h>
14 #include <api/fs/fs.h>
15 #include <linux/string.h>
16 #include <linux/zalloc.h>
17 #include "asm/bug.h"
18 #include "thread_map.h"
19 #include "debug.h"
20 #include "event.h"
21 #include <internal/threadmap.h>
22 
23 /* Skip "." and ".." directories */
24 static int filter(const struct dirent *dir)
25 {
26 	if (dir->d_name[0] == '.')
27 		return 0;
28 	else
29 		return 1;
30 }
31 
32 #define thread_map__alloc(__nr) perf_thread_map__realloc(NULL, __nr)
33 
34 struct perf_thread_map *thread_map__new_by_pid(pid_t pid)
35 {
36 	struct perf_thread_map *threads;
37 	char name[256];
38 	int items;
39 	struct dirent **namelist = NULL;
40 	int i;
41 
42 	sprintf(name, "/proc/%d/task", pid);
43 	items = scandir(name, &namelist, filter, NULL);
44 	if (items <= 0)
45 		return NULL;
46 
47 	threads = thread_map__alloc(items);
48 	if (threads != NULL) {
49 		for (i = 0; i < items; i++)
50 			perf_thread_map__set_pid(threads, i, atoi(namelist[i]->d_name));
51 		threads->nr = items;
52 		refcount_set(&threads->refcnt, 1);
53 	}
54 
55 	for (i=0; i<items; i++)
56 		zfree(&namelist[i]);
57 	free(namelist);
58 
59 	return threads;
60 }
61 
62 struct perf_thread_map *thread_map__new_by_tid(pid_t tid)
63 {
64 	struct perf_thread_map *threads = thread_map__alloc(1);
65 
66 	if (threads != NULL) {
67 		perf_thread_map__set_pid(threads, 0, tid);
68 		threads->nr = 1;
69 		refcount_set(&threads->refcnt, 1);
70 	}
71 
72 	return threads;
73 }
74 
75 static struct perf_thread_map *__thread_map__new_all_cpus(uid_t uid)
76 {
77 	DIR *proc;
78 	int max_threads = 32, items, i;
79 	char path[NAME_MAX + 1 + 6];
80 	struct dirent *dirent, **namelist = NULL;
81 	struct perf_thread_map *threads = thread_map__alloc(max_threads);
82 
83 	if (threads == NULL)
84 		goto out;
85 
86 	proc = opendir("/proc");
87 	if (proc == NULL)
88 		goto out_free_threads;
89 
90 	threads->nr = 0;
91 	refcount_set(&threads->refcnt, 1);
92 
93 	while ((dirent = readdir(proc)) != NULL) {
94 		char *end;
95 		bool grow = false;
96 		pid_t pid = strtol(dirent->d_name, &end, 10);
97 
98 		if (*end) /* only interested in proper numerical dirents */
99 			continue;
100 
101 		snprintf(path, sizeof(path), "/proc/%s", dirent->d_name);
102 
103 		if (uid != UINT_MAX) {
104 			struct stat st;
105 
106 			if (stat(path, &st) != 0 || st.st_uid != uid)
107 				continue;
108 		}
109 
110 		snprintf(path, sizeof(path), "/proc/%d/task", pid);
111 		items = scandir(path, &namelist, filter, NULL);
112 		if (items <= 0)
113 			goto out_free_closedir;
114 
115 		while (threads->nr + items >= max_threads) {
116 			max_threads *= 2;
117 			grow = true;
118 		}
119 
120 		if (grow) {
121 			struct perf_thread_map *tmp;
122 
123 			tmp = perf_thread_map__realloc(threads, max_threads);
124 			if (tmp == NULL)
125 				goto out_free_namelist;
126 
127 			threads = tmp;
128 		}
129 
130 		for (i = 0; i < items; i++) {
131 			perf_thread_map__set_pid(threads, threads->nr + i,
132 						    atoi(namelist[i]->d_name));
133 		}
134 
135 		for (i = 0; i < items; i++)
136 			zfree(&namelist[i]);
137 		free(namelist);
138 
139 		threads->nr += items;
140 	}
141 
142 out_closedir:
143 	closedir(proc);
144 out:
145 	return threads;
146 
147 out_free_threads:
148 	free(threads);
149 	return NULL;
150 
151 out_free_namelist:
152 	for (i = 0; i < items; i++)
153 		zfree(&namelist[i]);
154 	free(namelist);
155 
156 out_free_closedir:
157 	zfree(&threads);
158 	goto out_closedir;
159 }
160 
161 struct perf_thread_map *thread_map__new_all_cpus(void)
162 {
163 	return __thread_map__new_all_cpus(UINT_MAX);
164 }
165 
166 struct perf_thread_map *thread_map__new_by_uid(uid_t uid)
167 {
168 	return __thread_map__new_all_cpus(uid);
169 }
170 
171 struct perf_thread_map *thread_map__new(pid_t pid, pid_t tid, uid_t uid)
172 {
173 	if (pid != -1)
174 		return thread_map__new_by_pid(pid);
175 
176 	if (tid == -1 && uid != UINT_MAX)
177 		return thread_map__new_by_uid(uid);
178 
179 	return thread_map__new_by_tid(tid);
180 }
181 
182 static struct perf_thread_map *thread_map__new_by_pid_str(const char *pid_str)
183 {
184 	struct perf_thread_map *threads = NULL, *nt;
185 	char name[256];
186 	int items, total_tasks = 0;
187 	struct dirent **namelist = NULL;
188 	int i, j = 0;
189 	pid_t pid, prev_pid = INT_MAX;
190 	char *end_ptr;
191 	struct str_node *pos;
192 	struct strlist_config slist_config = { .dont_dupstr = true, };
193 	struct strlist *slist = strlist__new(pid_str, &slist_config);
194 
195 	if (!slist)
196 		return NULL;
197 
198 	strlist__for_each_entry(pos, slist) {
199 		pid = strtol(pos->s, &end_ptr, 10);
200 
201 		if (pid == INT_MIN || pid == INT_MAX ||
202 		    (*end_ptr != '\0' && *end_ptr != ','))
203 			goto out_free_threads;
204 
205 		if (pid == prev_pid)
206 			continue;
207 
208 		sprintf(name, "/proc/%d/task", pid);
209 		items = scandir(name, &namelist, filter, NULL);
210 		if (items <= 0)
211 			goto out_free_threads;
212 
213 		total_tasks += items;
214 		nt = perf_thread_map__realloc(threads, total_tasks);
215 		if (nt == NULL)
216 			goto out_free_namelist;
217 
218 		threads = nt;
219 
220 		for (i = 0; i < items; i++) {
221 			perf_thread_map__set_pid(threads, j++, atoi(namelist[i]->d_name));
222 			zfree(&namelist[i]);
223 		}
224 		threads->nr = total_tasks;
225 		free(namelist);
226 	}
227 
228 out:
229 	strlist__delete(slist);
230 	if (threads)
231 		refcount_set(&threads->refcnt, 1);
232 	return threads;
233 
234 out_free_namelist:
235 	for (i = 0; i < items; i++)
236 		zfree(&namelist[i]);
237 	free(namelist);
238 
239 out_free_threads:
240 	zfree(&threads);
241 	goto out;
242 }
243 
244 struct perf_thread_map *thread_map__new_by_tid_str(const char *tid_str)
245 {
246 	struct perf_thread_map *threads = NULL, *nt;
247 	int ntasks = 0;
248 	pid_t tid, prev_tid = INT_MAX;
249 	char *end_ptr;
250 	struct str_node *pos;
251 	struct strlist_config slist_config = { .dont_dupstr = true, };
252 	struct strlist *slist;
253 
254 	/* perf-stat expects threads to be generated even if tid not given */
255 	if (!tid_str)
256 		return perf_thread_map__new_dummy();
257 
258 	slist = strlist__new(tid_str, &slist_config);
259 	if (!slist)
260 		return NULL;
261 
262 	strlist__for_each_entry(pos, slist) {
263 		tid = strtol(pos->s, &end_ptr, 10);
264 
265 		if (tid == INT_MIN || tid == INT_MAX ||
266 		    (*end_ptr != '\0' && *end_ptr != ','))
267 			goto out_free_threads;
268 
269 		if (tid == prev_tid)
270 			continue;
271 
272 		ntasks++;
273 		nt = perf_thread_map__realloc(threads, ntasks);
274 
275 		if (nt == NULL)
276 			goto out_free_threads;
277 
278 		threads = nt;
279 		perf_thread_map__set_pid(threads, ntasks - 1, tid);
280 		threads->nr = ntasks;
281 	}
282 out:
283 	strlist__delete(slist);
284 	if (threads)
285 		refcount_set(&threads->refcnt, 1);
286 	return threads;
287 
288 out_free_threads:
289 	zfree(&threads);
290 	goto out;
291 }
292 
293 struct perf_thread_map *thread_map__new_str(const char *pid, const char *tid,
294 				       uid_t uid, bool all_threads)
295 {
296 	if (pid)
297 		return thread_map__new_by_pid_str(pid);
298 
299 	if (!tid && uid != UINT_MAX)
300 		return thread_map__new_by_uid(uid);
301 
302 	if (all_threads)
303 		return thread_map__new_all_cpus();
304 
305 	return thread_map__new_by_tid_str(tid);
306 }
307 
308 size_t thread_map__fprintf(struct perf_thread_map *threads, FILE *fp)
309 {
310 	int i;
311 	size_t printed = fprintf(fp, "%d thread%s: ",
312 				 threads->nr, threads->nr > 1 ? "s" : "");
313 	for (i = 0; i < threads->nr; ++i)
314 		printed += fprintf(fp, "%s%d", i ? ", " : "", perf_thread_map__pid(threads, i));
315 
316 	return printed + fprintf(fp, "\n");
317 }
318 
319 static int get_comm(char **comm, pid_t pid)
320 {
321 	char *path;
322 	size_t size;
323 	int err;
324 
325 	if (asprintf(&path, "%s/%d/comm", procfs__mountpoint(), pid) == -1)
326 		return -ENOMEM;
327 
328 	err = filename__read_str(path, comm, &size);
329 	if (!err) {
330 		/*
331 		 * We're reading 16 bytes, while filename__read_str
332 		 * allocates data per BUFSIZ bytes, so we can safely
333 		 * mark the end of the string.
334 		 */
335 		(*comm)[size] = 0;
336 		strim(*comm);
337 	}
338 
339 	free(path);
340 	return err;
341 }
342 
343 static void comm_init(struct perf_thread_map *map, int i)
344 {
345 	pid_t pid = perf_thread_map__pid(map, i);
346 	char *comm = NULL;
347 
348 	/* dummy pid comm initialization */
349 	if (pid == -1) {
350 		map->map[i].comm = strdup("dummy");
351 		return;
352 	}
353 
354 	/*
355 	 * The comm name is like extra bonus ;-),
356 	 * so just warn if we fail for any reason.
357 	 */
358 	if (get_comm(&comm, pid))
359 		pr_warning("Couldn't resolve comm name for pid %d\n", pid);
360 
361 	map->map[i].comm = comm;
362 }
363 
364 void thread_map__read_comms(struct perf_thread_map *threads)
365 {
366 	int i;
367 
368 	for (i = 0; i < threads->nr; ++i)
369 		comm_init(threads, i);
370 }
371 
372 static void thread_map__copy_event(struct perf_thread_map *threads,
373 				   struct perf_record_thread_map *event)
374 {
375 	unsigned i;
376 
377 	threads->nr = (int) event->nr;
378 
379 	for (i = 0; i < event->nr; i++) {
380 		perf_thread_map__set_pid(threads, i, (pid_t) event->entries[i].pid);
381 		threads->map[i].comm = strndup(event->entries[i].comm, 16);
382 	}
383 
384 	refcount_set(&threads->refcnt, 1);
385 }
386 
387 struct perf_thread_map *thread_map__new_event(struct perf_record_thread_map *event)
388 {
389 	struct perf_thread_map *threads;
390 
391 	threads = thread_map__alloc(event->nr);
392 	if (threads)
393 		thread_map__copy_event(threads, event);
394 
395 	return threads;
396 }
397 
398 bool thread_map__has(struct perf_thread_map *threads, pid_t pid)
399 {
400 	int i;
401 
402 	for (i = 0; i < threads->nr; ++i) {
403 		if (threads->map[i].pid == pid)
404 			return true;
405 	}
406 
407 	return false;
408 }
409 
410 int thread_map__remove(struct perf_thread_map *threads, int idx)
411 {
412 	int i;
413 
414 	if (threads->nr < 1)
415 		return -EINVAL;
416 
417 	if (idx >= threads->nr)
418 		return -EINVAL;
419 
420 	/*
421 	 * Free the 'idx' item and shift the rest up.
422 	 */
423 	zfree(&threads->map[idx].comm);
424 
425 	for (i = idx; i < threads->nr - 1; i++)
426 		threads->map[i] = threads->map[i + 1];
427 
428 	threads->nr--;
429 	return 0;
430 }
431