kernel/tools/perf/util/thread_map.c

   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 struct thread_map *thread_map__new_dummy(void)
 218 {
 219         struct thread_map *threads = malloc(sizeof(*threads) + sizeof(pid_t));
 220
 221         if (threads != NULL) {
 222                 threads->map[0] = -1;
 223                 threads->nr     = 1;
 224         }
 225         return threads;
 226 }
 227
 228 static struct thread_map *thread_map__new_by_tid_str(const char *tid_str)
 229 {
 230         struct thread_map *threads = NULL, *nt;
 231         int ntasks = 0;
 232         pid_t tid, prev_tid = INT_MAX;
 233         char *end_ptr;
 234         struct str_node *pos;
 235         struct strlist *slist;
 236
 237         /* perf-stat expects threads to be generated even if tid not given */
 238         if (!tid_str)
 239                 return thread_map__new_dummy();
 240
 241         slist = strlist__new(false, tid_str);
 242         if (!slist)
 243                 return NULL;
 244
 245         strlist__for_each(pos, slist) {
 246                 tid = strtol(pos->s, &end_ptr, 10);
 247
 248                 if (tid == INT_MIN || tid == INT_MAX ||
 249                     (*end_ptr != '\0' && *end_ptr != ','))
 250                         goto out_free_threads;
 251
 252                 if (tid == prev_tid)
 253                         continue;
 254
 255                 ntasks++;
 256                 nt = realloc(threads, sizeof(*threads) + sizeof(pid_t) * ntasks);
 257
 258                 if (nt == NULL)
 259                         goto out_free_threads;
 260
 261                 threads = nt;
 262                 threads->map[ntasks - 1] = tid;
 263                 threads->nr              = ntasks;
 264         }
 265 out:
 266         return threads;
 267
 268 out_free_threads:
 269         zfree(&threads);
 270         goto out;
 271 }
 272
 273 struct thread_map *thread_map__new_str(const char *pid, const char *tid,
 274                                        uid_t uid)
 275 {
 276         if (pid)
 277                 return thread_map__new_by_pid_str(pid);
 278
 279         if (!tid && uid != UINT_MAX)
 280                 return thread_map__new_by_uid(uid);
 281
 282         return thread_map__new_by_tid_str(tid);
 283 }
 284
 285 void thread_map__delete(struct thread_map *threads)
 286 {
 287         free(threads);
 288 }
 289
 290 size_t thread_map__fprintf(struct thread_map *threads, FILE *fp)
 291 {
 292         int i;
 293         size_t printed = fprintf(fp, "%d thread%s: ",
 294                                  threads->nr, threads->nr > 1 ? "s" : "");
 295         for (i = 0; i < threads->nr; ++i)
 296                 printed += fprintf(fp, "%s%d", i ? ", " : "", threads->map[i]);
 297
 298         return printed + fprintf(fp, "\n");
 299 }