tools/perf/util/thread.c

   1 #include "../perf.h"
   2 #include <errno.h>
   3 #include <stdlib.h>
   4 #include <stdio.h>
   5 #include <string.h>
   6 #include <linux/kernel.h>
   7 #include "session.h"
   8 #include "thread.h"
   9 #include "thread-stack.h"
  10 #include "util.h"
  11 #include "debug.h"
  12 #include "namespaces.h"
  13 #include "comm.h"
  14 #include "unwind.h"
  15
  16 #include <api/fs/fs.h>
  17
  18 int thread__init_map_groups(struct thread *thread, struct machine *machine)
  19 {
  20         pid_t pid = thread->pid_;
  21
  22         if (pid == thread->tid || pid == -1) {
  23                 thread->mg = map_groups__new(machine);
  24         } else {
  25                 struct thread *leader = __machine__findnew_thread(machine, pid, pid);
  26                 if (leader) {
  27                         thread->mg = map_groups__get(leader->mg);
  28                         thread__put(leader);
  29                 }
  30         }
  31
  32         return thread->mg ? 0 : -1;
  33 }
  34
  35 struct thread *thread__new(pid_t pid, pid_t tid)
  36 {
  37         char *comm_str;
  38         struct comm *comm;
  39         struct thread *thread = zalloc(sizeof(*thread));
  40
  41         if (thread != NULL) {
  42                 thread->pid_ = pid;
  43                 thread->tid = tid;
  44                 thread->ppid = -1;
  45                 thread->cpu = -1;
  46                 INIT_LIST_HEAD(&thread->namespaces_list);
  47                 INIT_LIST_HEAD(&thread->comm_list);
  48                 init_rwsem(&thread->namespaces_lock);
  49                 init_rwsem(&thread->comm_lock);
  50
  51                 comm_str = malloc(32);
  52                 if (!comm_str)
  53                         goto err_thread;
  54
  55                 snprintf(comm_str, 32, ":%d", tid);
  56                 comm = comm__new(comm_str, 0, false);
  57                 free(comm_str);
  58                 if (!comm)
  59                         goto err_thread;
  60
  61                 list_add(&comm->list, &thread->comm_list);
  62                 refcount_set(&thread->refcnt, 1);
  63                 RB_CLEAR_NODE(&thread->rb_node);
  64                 /* Thread holds first ref to nsdata. */
  65                 thread->nsinfo = nsinfo__new(pid);
  66         }
  67
  68         return thread;
  69
  70 err_thread:
  71         free(thread);
  72         return NULL;
  73 }
  74
  75 void thread__delete(struct thread *thread)
  76 {
  77         struct namespaces *namespaces, *tmp_namespaces;
  78         struct comm *comm, *tmp_comm;
  79
  80         BUG_ON(!RB_EMPTY_NODE(&thread->rb_node));
  81
  82         thread_stack__free(thread);
  83
  84         if (thread->mg) {
  85                 map_groups__put(thread->mg);
  86                 thread->mg = NULL;
  87         }
  88         down_write(&thread->namespaces_lock);
  89         list_for_each_entry_safe(namespaces, tmp_namespaces,
  90                                  &thread->namespaces_list, list) {
  91                 list_del(&namespaces->list);
  92                 namespaces__free(namespaces);
  93         }
  94         up_write(&thread->namespaces_lock);
  95
  96         down_write(&thread->comm_lock);
  97         list_for_each_entry_safe(comm, tmp_comm, &thread->comm_list, list) {
  98                 list_del(&comm->list);
  99                 comm__free(comm);
 100         }
 101         up_write(&thread->comm_lock);
 102
 103         unwind__finish_access(thread);
 104         nsinfo__zput(thread->nsinfo);
 105
 106         exit_rwsem(&thread->namespaces_lock);
 107         exit_rwsem(&thread->comm_lock);
 108         free(thread);
 109 }
 110
 111 struct thread *thread__get(struct thread *thread)
 112 {
 113         if (thread)
 114                 refcount_inc(&thread->refcnt);
 115         return thread;
 116 }
 117
 118 void thread__put(struct thread *thread)
 119 {
 120         if (thread && refcount_dec_and_test(&thread->refcnt)) {
 121                 /*
 122                  * Remove it from the dead_threads list, as last reference
 123                  * is gone.
 124                  */
 125                 list_del_init(&thread->node);
 126                 thread__delete(thread);
 127         }
 128 }
 129
 130 struct namespaces *thread__namespaces(const struct thread *thread)
 131 {
 132         if (list_empty(&thread->namespaces_list))
 133                 return NULL;
 134
 135         return list_first_entry(&thread->namespaces_list, struct namespaces, list);
 136 }
 137
 138 static int __thread__set_namespaces(struct thread *thread, u64 timestamp,
 139                                     struct namespaces_event *event)
 140 {
 141         struct namespaces *new, *curr = thread__namespaces(thread);
 142
 143         new = namespaces__new(event);
 144         if (!new)
 145                 return -ENOMEM;
 146
 147         list_add(&new->list, &thread->namespaces_list);
 148
 149         if (timestamp && curr) {
 150                 /*
 151                  * setns syscall must have changed few or all the namespaces
 152                  * of this thread. Update end time for the namespaces
 153                  * previously used.
 154                  */
 155                 curr = list_next_entry(new, list);
 156                 curr->end_time = timestamp;
 157         }
 158
 159         return 0;
 160 }
 161
 162 int thread__set_namespaces(struct thread *thread, u64 timestamp,
 163                            struct namespaces_event *event)
 164 {
 165         int ret;
 166
 167         down_write(&thread->namespaces_lock);
 168         ret = __thread__set_namespaces(thread, timestamp, event);
 169         up_write(&thread->namespaces_lock);
 170         return ret;
 171 }
 172
 173 struct comm *thread__comm(const struct thread *thread)
 174 {
 175         if (list_empty(&thread->comm_list))
 176                 return NULL;
 177
 178         return list_first_entry(&thread->comm_list, struct comm, list);
 179 }
 180
 181 struct comm *thread__exec_comm(const struct thread *thread)
 182 {
 183         struct comm *comm, *last = NULL;
 184
 185         list_for_each_entry(comm, &thread->comm_list, list) {
 186                 if (comm->exec)
 187                         return comm;
 188                 last = comm;
 189         }
 190
 191         return last;
 192 }
 193
 194 static int ____thread__set_comm(struct thread *thread, const char *str,
 195                                 u64 timestamp, bool exec)
 196 {
 197         struct comm *new, *curr = thread__comm(thread);
 198
 199         /* Override the default :tid entry */
 200         if (!thread->comm_set) {
 201                 int err = comm__override(curr, str, timestamp, exec);
 202                 if (err)
 203                         return err;
 204         } else {
 205                 new = comm__new(str, timestamp, exec);
 206                 if (!new)
 207                         return -ENOMEM;
 208                 list_add(&new->list, &thread->comm_list);
 209
 210                 if (exec)
 211                         unwind__flush_access(thread);
 212         }
 213
 214         thread->comm_set = true;
 215
 216         return 0;
 217 }
 218
 219 int __thread__set_comm(struct thread *thread, const char *str, u64 timestamp,
 220                        bool exec)
 221 {
 222         int ret;
 223
 224         down_write(&thread->comm_lock);
 225         ret = ____thread__set_comm(thread, str, timestamp, exec);
 226         up_write(&thread->comm_lock);
 227         return ret;
 228 }
 229
 230 int thread__set_comm_from_proc(struct thread *thread)
 231 {
 232         char path[64];
 233         char *comm = NULL;
 234         size_t sz;
 235         int err = -1;
 236
 237         if (!(snprintf(path, sizeof(path), "%d/task/%d/comm",
 238                        thread->pid_, thread->tid) >= (int)sizeof(path)) &&
 239             procfs__read_str(path, &comm, &sz) == 0) {
 240                 comm[sz - 1] = '\0';
 241                 err = thread__set_comm(thread, comm, 0);
 242         }
 243
 244         return err;
 245 }
 246
 247 static const char *__thread__comm_str(const struct thread *thread)
 248 {
 249         const struct comm *comm = thread__comm(thread);
 250
 251         if (!comm)
 252                 return NULL;
 253
 254         return comm__str(comm);
 255 }
 256
 257 const char *thread__comm_str(const struct thread *thread)
 258 {
 259         const char *str;
 260
 261         down_read((struct rw_semaphore *)&thread->comm_lock);
 262         str = __thread__comm_str(thread);
 263         up_read((struct rw_semaphore *)&thread->comm_lock);
 264
 265         return str;
 266 }
 267
 268 /* CHECKME: it should probably better return the max comm len from its comm list */
 269 int thread__comm_len(struct thread *thread)
 270 {
 271         if (!thread->comm_len) {
 272                 const char *comm = thread__comm_str(thread);
 273                 if (!comm)
 274                         return 0;
 275                 thread->comm_len = strlen(comm);
 276         }
 277
 278         return thread->comm_len;
 279 }
 280
 281 size_t thread__fprintf(struct thread *thread, FILE *fp)
 282 {
 283         return fprintf(fp, "Thread %d %s\n", thread->tid, thread__comm_str(thread)) +
 284                map_groups__fprintf(thread->mg, fp);
 285 }
 286
 287 int thread__insert_map(struct thread *thread, struct map *map)
 288 {
 289         int ret;
 290
 291         ret = unwind__prepare_access(thread, map, NULL);
 292         if (ret)
 293                 return ret;
 294
 295         map_groups__fixup_overlappings(thread->mg, map, stderr);
 296         map_groups__insert(thread->mg, map);
 297
 298         return 0;
 299 }
 300
 301 static int __thread__prepare_access(struct thread *thread)
 302 {
 303         bool initialized = false;
 304         int i, err = 0;
 305
 306         for (i = 0; i < MAP__NR_TYPES; ++i) {
 307                 struct maps *maps = &thread->mg->maps[i];
 308                 struct map *map;
 309
 310                 down_read(&maps->lock);
 311
 312                 for (map = maps__first(maps); map; map = map__next(map)) {
 313                         err = unwind__prepare_access(thread, map, &initialized);
 314                         if (err || initialized)
 315                                 break;
 316                 }
 317
 318                 up_read(&maps->lock);
 319         }
 320
 321         return err;
 322 }
 323
 324 static int thread__prepare_access(struct thread *thread)
 325 {
 326         int err = 0;
 327
 328         if (symbol_conf.use_callchain)
 329                 err = __thread__prepare_access(thread);
 330
 331         return err;
 332 }
 333
 334 static int thread__clone_map_groups(struct thread *thread,
 335                                     struct thread *parent)
 336 {
 337         int i;
 338
 339         /* This is new thread, we share map groups for process. */
 340         if (thread->pid_ == parent->pid_)
 341                 return thread__prepare_access(thread);
 342
 343         if (thread->mg == parent->mg) {
 344                 pr_debug("broken map groups on thread %d/%d parent %d/%d\n",
 345                          thread->pid_, thread->tid, parent->pid_, parent->tid);
 346                 return 0;
 347         }
 348
 349         /* But this one is new process, copy maps. */
 350         for (i = 0; i < MAP__NR_TYPES; ++i)
 351                 if (map_groups__clone(thread, parent->mg, i) < 0)
 352                         return -ENOMEM;
 353
 354         return 0;
 355 }
 356
 357 int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp)
 358 {
 359         if (parent->comm_set) {
 360                 const char *comm = thread__comm_str(parent);
 361                 int err;
 362                 if (!comm)
 363                         return -ENOMEM;
 364                 err = thread__set_comm(thread, comm, timestamp);
 365                 if (err)
 366                         return err;
 367         }
 368
 369         thread->ppid = parent->tid;
 370         return thread__clone_map_groups(thread, parent);
 371 }
 372
 373 void thread__find_cpumode_addr_location(struct thread *thread,
 374                                         enum map_type type, u64 addr,
 375                                         struct addr_location *al)
 376 {
 377         size_t i;
 378         const u8 cpumodes[] = {
 379                 PERF_RECORD_MISC_USER,
 380                 PERF_RECORD_MISC_KERNEL,
 381                 PERF_RECORD_MISC_GUEST_USER,
 382                 PERF_RECORD_MISC_GUEST_KERNEL
 383         };
 384
 385         for (i = 0; i < ARRAY_SIZE(cpumodes); i++) {
 386                 thread__find_addr_location(thread, cpumodes[i], type, addr, al);
 387                 if (al->map)
 388                         break;
 389         }
 390 }
 391
 392 struct thread *thread__main_thread(struct machine *machine, struct thread *thread)
 393 {
 394         if (thread->pid_ == thread->tid)
 395                 return thread__get(thread);
 396
 397         if (thread->pid_ == -1)
 398                 return NULL;
 399
 400         return machine__find_thread(machine, thread->pid_, thread->pid_);
 401 }