tools/perf/util/thread.c

   1 #include "../perf.h"
   2 #include <stdlib.h>
   3 #include <stdio.h>
   4 #include <string.h>
   5 #include <linux/kernel.h>
   6 #include "session.h"
   7 #include "thread.h"
   8 #include "thread-stack.h"
   9 #include "util.h"
  10 #include "debug.h"
  11 #include "namespaces.h"
  12 #include "comm.h"
  13 #include "unwind.h"
  14
  15 #include <api/fs/fs.h>
  16
  17 int thread__init_map_groups(struct thread *thread, struct machine *machine)
  18 {
  19         pid_t pid = thread->pid_;
  20
  21         if (pid == thread->tid || pid == -1) {
  22                 thread->mg = map_groups__new(machine);
  23         } else {
  24                 struct thread *leader = __machine__findnew_thread(machine, pid, pid);
  25                 if (leader) {
  26                         thread->mg = map_groups__get(leader->mg);
  27                         thread__put(leader);
  28                 }
  29         }
  30
  31         return thread->mg ? 0 : -1;
  32 }
  33
  34 struct thread *thread__new(pid_t pid, pid_t tid)
  35 {
  36         char *comm_str;
  37         struct comm *comm;
  38         struct thread *thread = zalloc(sizeof(*thread));
  39
  40         if (thread != NULL) {
  41                 thread->pid_ = pid;
  42                 thread->tid = tid;
  43                 thread->ppid = -1;
  44                 thread->cpu = -1;
  45                 INIT_LIST_HEAD(&thread->namespaces_list);
  46                 INIT_LIST_HEAD(&thread->comm_list);
  47
  48                 comm_str = malloc(32);
  49                 if (!comm_str)
  50                         goto err_thread;
  51
  52                 snprintf(comm_str, 32, ":%d", tid);
  53                 comm = comm__new(comm_str, 0, false);
  54                 free(comm_str);
  55                 if (!comm)
  56                         goto err_thread;
  57
  58                 list_add(&comm->list, &thread->comm_list);
  59                 refcount_set(&thread->refcnt, 1);
  60                 RB_CLEAR_NODE(&thread->rb_node);
  61         }
  62
  63         return thread;
  64
  65 err_thread:
  66         free(thread);
  67         return NULL;
  68 }
  69
  70 void thread__delete(struct thread *thread)
  71 {
  72         struct namespaces *namespaces, *tmp_namespaces;
  73         struct comm *comm, *tmp_comm;
  74
  75         BUG_ON(!RB_EMPTY_NODE(&thread->rb_node));
  76
  77         thread_stack__free(thread);
  78
  79         if (thread->mg) {
  80                 map_groups__put(thread->mg);
  81                 thread->mg = NULL;
  82         }
  83         list_for_each_entry_safe(namespaces, tmp_namespaces,
  84                                  &thread->namespaces_list, list) {
  85                 list_del(&namespaces->list);
  86                 namespaces__free(namespaces);
  87         }
  88         list_for_each_entry_safe(comm, tmp_comm, &thread->comm_list, list) {
  89                 list_del(&comm->list);
  90                 comm__free(comm);
  91         }
  92         unwind__finish_access(thread);
  93
  94         free(thread);
  95 }
  96
  97 struct thread *thread__get(struct thread *thread)
  98 {
  99         if (thread)
 100                 refcount_inc(&thread->refcnt);
 101         return thread;
 102 }
 103
 104 void thread__put(struct thread *thread)
 105 {
 106         if (thread && refcount_dec_and_test(&thread->refcnt)) {
 107                 /*
 108                  * Remove it from the dead_threads list, as last reference
 109                  * is gone.
 110                  */
 111                 list_del_init(&thread->node);
 112                 thread__delete(thread);
 113         }
 114 }
 115
 116 struct namespaces *thread__namespaces(const struct thread *thread)
 117 {
 118         if (list_empty(&thread->namespaces_list))
 119                 return NULL;
 120
 121         return list_first_entry(&thread->namespaces_list, struct namespaces, list);
 122 }
 123
 124 int thread__set_namespaces(struct thread *thread, u64 timestamp,
 125                            struct namespaces_event *event)
 126 {
 127         struct namespaces *new, *curr = thread__namespaces(thread);
 128
 129         new = namespaces__new(event);
 130         if (!new)
 131                 return -ENOMEM;
 132
 133         list_add(&new->list, &thread->namespaces_list);
 134
 135         if (timestamp && curr) {
 136                 /*
 137                  * setns syscall must have changed few or all the namespaces
 138                  * of this thread. Update end time for the namespaces
 139                  * previously used.
 140                  */
 141                 curr = list_next_entry(new, list);
 142                 curr->end_time = timestamp;
 143         }
 144
 145         return 0;
 146 }
 147
 148 struct comm *thread__comm(const struct thread *thread)
 149 {
 150         if (list_empty(&thread->comm_list))
 151                 return NULL;
 152
 153         return list_first_entry(&thread->comm_list, struct comm, list);
 154 }
 155
 156 struct comm *thread__exec_comm(const struct thread *thread)
 157 {
 158         struct comm *comm, *last = NULL;
 159
 160         list_for_each_entry(comm, &thread->comm_list, list) {
 161                 if (comm->exec)
 162                         return comm;
 163                 last = comm;
 164         }
 165
 166         return last;
 167 }
 168
 169 int __thread__set_comm(struct thread *thread, const char *str, u64 timestamp,
 170                        bool exec)
 171 {
 172         struct comm *new, *curr = thread__comm(thread);
 173
 174         /* Override the default :tid entry */
 175         if (!thread->comm_set) {
 176                 int err = comm__override(curr, str, timestamp, exec);
 177                 if (err)
 178                         return err;
 179         } else {
 180                 new = comm__new(str, timestamp, exec);
 181                 if (!new)
 182                         return -ENOMEM;
 183                 list_add(&new->list, &thread->comm_list);
 184
 185                 if (exec)
 186                         unwind__flush_access(thread);
 187         }
 188
 189         thread->comm_set = true;
 190
 191         return 0;
 192 }
 193
 194 int thread__set_comm_from_proc(struct thread *thread)
 195 {
 196         char path[64];
 197         char *comm = NULL;
 198         size_t sz;
 199         int err = -1;
 200
 201         if (!(snprintf(path, sizeof(path), "%d/task/%d/comm",
 202                        thread->pid_, thread->tid) >= (int)sizeof(path)) &&
 203             procfs__read_str(path, &comm, &sz) == 0) {
 204                 comm[sz - 1] = '\0';
 205                 err = thread__set_comm(thread, comm, 0);
 206         }
 207
 208         return err;
 209 }
 210
 211 const char *thread__comm_str(const struct thread *thread)
 212 {
 213         const struct comm *comm = thread__comm(thread);
 214
 215         if (!comm)
 216                 return NULL;
 217
 218         return comm__str(comm);
 219 }
 220
 221 /* CHECKME: it should probably better return the max comm len from its comm list */
 222 int thread__comm_len(struct thread *thread)
 223 {
 224         if (!thread->comm_len) {
 225                 const char *comm = thread__comm_str(thread);
 226                 if (!comm)
 227                         return 0;
 228                 thread->comm_len = strlen(comm);
 229         }
 230
 231         return thread->comm_len;
 232 }
 233
 234 size_t thread__fprintf(struct thread *thread, FILE *fp)
 235 {
 236         return fprintf(fp, "Thread %d %s\n", thread->tid, thread__comm_str(thread)) +
 237                map_groups__fprintf(thread->mg, fp);
 238 }
 239
 240 int thread__insert_map(struct thread *thread, struct map *map)
 241 {
 242         int ret;
 243
 244         ret = unwind__prepare_access(thread, map, NULL);
 245         if (ret)
 246                 return ret;
 247
 248         map_groups__fixup_overlappings(thread->mg, map, stderr);
 249         map_groups__insert(thread->mg, map);
 250
 251         return 0;
 252 }
 253
 254 static int __thread__prepare_access(struct thread *thread)
 255 {
 256         bool initialized = false;
 257         int i, err = 0;
 258
 259         for (i = 0; i < MAP__NR_TYPES; ++i) {
 260                 struct maps *maps = &thread->mg->maps[i];
 261                 struct map *map;
 262
 263                 pthread_rwlock_rdlock(&maps->lock);
 264
 265                 for (map = maps__first(maps); map; map = map__next(map)) {
 266                         err = unwind__prepare_access(thread, map, &initialized);
 267                         if (err || initialized)
 268                                 break;
 269                 }
 270
 271                 pthread_rwlock_unlock(&maps->lock);
 272         }
 273
 274         return err;
 275 }
 276
 277 static int thread__prepare_access(struct thread *thread)
 278 {
 279         int err = 0;
 280
 281         if (symbol_conf.use_callchain)
 282                 err = __thread__prepare_access(thread);
 283
 284         return err;
 285 }
 286
 287 static int thread__clone_map_groups(struct thread *thread,
 288                                     struct thread *parent)
 289 {
 290         int i;
 291
 292         /* This is new thread, we share map groups for process. */
 293         if (thread->pid_ == parent->pid_)
 294                 return thread__prepare_access(thread);
 295
 296         if (thread->mg == parent->mg) {
 297                 pr_debug("broken map groups on thread %d/%d parent %d/%d\n",
 298                          thread->pid_, thread->tid, parent->pid_, parent->tid);
 299                 return 0;
 300         }
 301
 302         /* But this one is new process, copy maps. */
 303         for (i = 0; i < MAP__NR_TYPES; ++i)
 304                 if (map_groups__clone(thread, parent->mg, i) < 0)
 305                         return -ENOMEM;
 306
 307         return 0;
 308 }
 309
 310 int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp)
 311 {
 312         if (parent->comm_set) {
 313                 const char *comm = thread__comm_str(parent);
 314                 int err;
 315                 if (!comm)
 316                         return -ENOMEM;
 317                 err = thread__set_comm(thread, comm, timestamp);
 318                 if (err)
 319                         return err;
 320         }
 321
 322         thread->ppid = parent->tid;
 323         return thread__clone_map_groups(thread, parent);
 324 }
 325
 326 void thread__find_cpumode_addr_location(struct thread *thread,
 327                                         enum map_type type, u64 addr,
 328                                         struct addr_location *al)
 329 {
 330         size_t i;
 331         const u8 cpumodes[] = {
 332                 PERF_RECORD_MISC_USER,
 333                 PERF_RECORD_MISC_KERNEL,
 334                 PERF_RECORD_MISC_GUEST_USER,
 335                 PERF_RECORD_MISC_GUEST_KERNEL
 336         };
 337
 338         for (i = 0; i < ARRAY_SIZE(cpumodes); i++) {
 339                 thread__find_addr_location(thread, cpumodes[i], type, addr, al);
 340                 if (al->map)
 341                         break;
 342         }
 343 }
 344
 345 struct thread *thread__main_thread(struct machine *machine, struct thread *thread)
 346 {
 347         if (thread->pid_ == thread->tid)
 348                 return thread__get(thread);
 349
 350         if (thread->pid_ == -1)
 351                 return NULL;
 352
 353         return machine__find_thread(machine, thread->pid_, thread->pid_);
 354 }