xref: /openbmc/linux/tools/perf/util/thread_map.c (revision 275876e2)
1 #include <dirent.h>
2 #include <limits.h>
3 #include <stdbool.h>
4 #include <stdlib.h>
5 #include <stdio.h>
6 #include <sys/types.h>
7 #include <sys/stat.h>
8 #include <unistd.h>
9 #include "strlist.h"
10 #include <string.h>
11 #include "thread_map.h"
12 #include "util.h"
13 
14 /* Skip "." and ".." directories */
15 static int filter(const struct dirent *dir)
16 {
17 	if (dir->d_name[0] == '.')
18 		return 0;
19 	else
20 		return 1;
21 }
22 
23 struct thread_map *thread_map__new_by_pid(pid_t pid)
24 {
25 	struct thread_map *threads;
26 	char name[256];
27 	int items;
28 	struct dirent **namelist = NULL;
29 	int i;
30 
31 	sprintf(name, "/proc/%d/task", pid);
32 	items = scandir(name, &namelist, filter, NULL);
33 	if (items <= 0)
34 		return NULL;
35 
36 	threads = malloc(sizeof(*threads) + sizeof(pid_t) * items);
37 	if (threads != NULL) {
38 		for (i = 0; i < items; i++)
39 			threads->map[i] = atoi(namelist[i]->d_name);
40 		threads->nr = items;
41 	}
42 
43 	for (i=0; i<items; i++)
44 		zfree(&namelist[i]);
45 	free(namelist);
46 
47 	return threads;
48 }
49 
50 struct thread_map *thread_map__new_by_tid(pid_t tid)
51 {
52 	struct thread_map *threads = malloc(sizeof(*threads) + sizeof(pid_t));
53 
54 	if (threads != NULL) {
55 		threads->map[0] = tid;
56 		threads->nr	= 1;
57 	}
58 
59 	return threads;
60 }
61 
62 struct thread_map *thread_map__new_by_uid(uid_t uid)
63 {
64 	DIR *proc;
65 	int max_threads = 32, items, i;
66 	char path[256];
67 	struct dirent dirent, *next, **namelist = NULL;
68 	struct thread_map *threads = malloc(sizeof(*threads) +
69 					    max_threads * sizeof(pid_t));
70 	if (threads == NULL)
71 		goto out;
72 
73 	proc = opendir("/proc");
74 	if (proc == NULL)
75 		goto out_free_threads;
76 
77 	threads->nr = 0;
78 
79 	while (!readdir_r(proc, &dirent, &next) && next) {
80 		char *end;
81 		bool grow = false;
82 		struct stat st;
83 		pid_t pid = strtol(dirent.d_name, &end, 10);
84 
85 		if (*end) /* only interested in proper numerical dirents */
86 			continue;
87 
88 		snprintf(path, sizeof(path), "/proc/%s", dirent.d_name);
89 
90 		if (stat(path, &st) != 0)
91 			continue;
92 
93 		if (st.st_uid != uid)
94 			continue;
95 
96 		snprintf(path, sizeof(path), "/proc/%d/task", pid);
97 		items = scandir(path, &namelist, filter, NULL);
98 		if (items <= 0)
99 			goto out_free_closedir;
100 
101 		while (threads->nr + items >= max_threads) {
102 			max_threads *= 2;
103 			grow = true;
104 		}
105 
106 		if (grow) {
107 			struct thread_map *tmp;
108 
109 			tmp = realloc(threads, (sizeof(*threads) +
110 						max_threads * sizeof(pid_t)));
111 			if (tmp == NULL)
112 				goto out_free_namelist;
113 
114 			threads = tmp;
115 		}
116 
117 		for (i = 0; i < items; i++)
118 			threads->map[threads->nr + i] = atoi(namelist[i]->d_name);
119 
120 		for (i = 0; i < items; i++)
121 			zfree(&namelist[i]);
122 		free(namelist);
123 
124 		threads->nr += items;
125 	}
126 
127 out_closedir:
128 	closedir(proc);
129 out:
130 	return threads;
131 
132 out_free_threads:
133 	free(threads);
134 	return NULL;
135 
136 out_free_namelist:
137 	for (i = 0; i < items; i++)
138 		zfree(&namelist[i]);
139 	free(namelist);
140 
141 out_free_closedir:
142 	zfree(&threads);
143 	goto out_closedir;
144 }
145 
146 struct thread_map *thread_map__new(pid_t pid, pid_t tid, uid_t uid)
147 {
148 	if (pid != -1)
149 		return thread_map__new_by_pid(pid);
150 
151 	if (tid == -1 && uid != UINT_MAX)
152 		return thread_map__new_by_uid(uid);
153 
154 	return thread_map__new_by_tid(tid);
155 }
156 
157 static struct thread_map *thread_map__new_by_pid_str(const char *pid_str)
158 {
159 	struct thread_map *threads = NULL, *nt;
160 	char name[256];
161 	int items, total_tasks = 0;
162 	struct dirent **namelist = NULL;
163 	int i, j = 0;
164 	pid_t pid, prev_pid = INT_MAX;
165 	char *end_ptr;
166 	struct str_node *pos;
167 	struct strlist *slist = strlist__new(false, pid_str);
168 
169 	if (!slist)
170 		return NULL;
171 
172 	strlist__for_each(pos, slist) {
173 		pid = strtol(pos->s, &end_ptr, 10);
174 
175 		if (pid == INT_MIN || pid == INT_MAX ||
176 		    (*end_ptr != '\0' && *end_ptr != ','))
177 			goto out_free_threads;
178 
179 		if (pid == prev_pid)
180 			continue;
181 
182 		sprintf(name, "/proc/%d/task", pid);
183 		items = scandir(name, &namelist, filter, NULL);
184 		if (items <= 0)
185 			goto out_free_threads;
186 
187 		total_tasks += items;
188 		nt = realloc(threads, (sizeof(*threads) +
189 				       sizeof(pid_t) * total_tasks));
190 		if (nt == NULL)
191 			goto out_free_namelist;
192 
193 		threads = nt;
194 
195 		for (i = 0; i < items; i++) {
196 			threads->map[j++] = atoi(namelist[i]->d_name);
197 			zfree(&namelist[i]);
198 		}
199 		threads->nr = total_tasks;
200 		free(namelist);
201 	}
202 
203 out:
204 	strlist__delete(slist);
205 	return threads;
206 
207 out_free_namelist:
208 	for (i = 0; i < items; i++)
209 		zfree(&namelist[i]);
210 	free(namelist);
211 
212 out_free_threads:
213 	zfree(&threads);
214 	goto out;
215 }
216 
217 static struct thread_map *thread_map__new_by_tid_str(const char *tid_str)
218 {
219 	struct thread_map *threads = NULL, *nt;
220 	int ntasks = 0;
221 	pid_t tid, prev_tid = INT_MAX;
222 	char *end_ptr;
223 	struct str_node *pos;
224 	struct strlist *slist;
225 
226 	/* perf-stat expects threads to be generated even if tid not given */
227 	if (!tid_str) {
228 		threads = malloc(sizeof(*threads) + sizeof(pid_t));
229 		if (threads != NULL) {
230 			threads->map[0] = -1;
231 			threads->nr	= 1;
232 		}
233 		return threads;
234 	}
235 
236 	slist = strlist__new(false, tid_str);
237 	if (!slist)
238 		return NULL;
239 
240 	strlist__for_each(pos, slist) {
241 		tid = strtol(pos->s, &end_ptr, 10);
242 
243 		if (tid == INT_MIN || tid == INT_MAX ||
244 		    (*end_ptr != '\0' && *end_ptr != ','))
245 			goto out_free_threads;
246 
247 		if (tid == prev_tid)
248 			continue;
249 
250 		ntasks++;
251 		nt = realloc(threads, sizeof(*threads) + sizeof(pid_t) * ntasks);
252 
253 		if (nt == NULL)
254 			goto out_free_threads;
255 
256 		threads = nt;
257 		threads->map[ntasks - 1] = tid;
258 		threads->nr		 = ntasks;
259 	}
260 out:
261 	return threads;
262 
263 out_free_threads:
264 	zfree(&threads);
265 	goto out;
266 }
267 
268 struct thread_map *thread_map__new_str(const char *pid, const char *tid,
269 				       uid_t uid)
270 {
271 	if (pid)
272 		return thread_map__new_by_pid_str(pid);
273 
274 	if (!tid && uid != UINT_MAX)
275 		return thread_map__new_by_uid(uid);
276 
277 	return thread_map__new_by_tid_str(tid);
278 }
279 
280 void thread_map__delete(struct thread_map *threads)
281 {
282 	free(threads);
283 }
284 
285 size_t thread_map__fprintf(struct thread_map *threads, FILE *fp)
286 {
287 	int i;
288 	size_t printed = fprintf(fp, "%d thread%s: ",
289 				 threads->nr, threads->nr > 1 ? "s" : "");
290 	for (i = 0; i < threads->nr; ++i)
291 		printed += fprintf(fp, "%s%d", i ? ", " : "", threads->map[i]);
292 
293 	return printed + fprintf(fp, "\n");
294 }
295