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
  49                 comm_str = malloc(32);
  50                 if (!comm_str)
  51                         goto err_thread;
  52
  53                 snprintf(comm_str, 32, ":%d", tid);
  54                 comm = comm__new(comm_str, 0, false);
  55                 free(comm_str);
  56                 if (!comm)
  57                         goto err_thread;
  58
  59                 list_add(&comm->list, &thread->comm_list);
  60                 refcount_set(&thread->refcnt, 1);
  61                 RB_CLEAR_NODE(&thread->rb_node);
  62         }
  63
  64         return thread;
  65
  66 err_thread:
  67         free(thread);
  68         return NULL;
  69 }
  70
  71 void thread__delete(struct thread *thread)
  72 {
  73         struct namespaces *namespaces, *tmp_namespaces;
  74         struct comm *comm, *tmp_comm;
  75
  76         BUG_ON(!RB_EMPTY_NODE(&thread->rb_node));
  77
  78         thread_stack__free(thread);
  79
  80         if (thread->mg) {
  81                 map_groups__put(thread->mg);
  82                 thread->mg = NULL;
  83         }
  84         list_for_each_entry_safe(namespaces, tmp_namespaces,
  85                                  &thread->namespaces_list, list) {
  86                 list_del(&namespaces->list);
  87                 namespaces__free(namespaces);
  88         }
  89         list_for_each_entry_safe(comm, tmp_comm, &thread->comm_list, list) {
  90                 list_del(&comm->list);
  91                 comm__free(comm);
  92         }
  93         unwind__finish_access(thread);
  94
  95         free(thread);
  96 }
  97
  98 struct thread *thread__get(struct thread *thread)
  99 {
 100         if (thread)
 101                 refcount_inc(&thread->refcnt);
 102         return thread;
 103 }
 104
 105 void thread__put(struct thread *thread)
 106 {
 107         if (thread && refcount_dec_and_test(&thread->refcnt)) {
 108                 /*
 109                  * Remove it from the dead_threads list, as last reference
 110                  * is gone.
 111                  */
 112                 list_del_init(&thread->node);
 113                 thread__delete(thread);
 114         }
 115 }
 116
 117 struct namespaces *thread__namespaces(const struct thread *thread)
 118 {
 119         if (list_empty(&thread->namespaces_list))
 120                 return NULL;
 121
 122         return list_first_entry(&thread->namespaces_list, struct namespaces, list);
 123 }
 124
 125 int thread__set_namespaces(struct thread *thread, u64 timestamp,
 126                            struct namespaces_event *event)
 127 {
 128         struct namespaces *new, *curr = thread__namespaces(thread);
 129
 130         new = namespaces__new(event);
 131         if (!new)
 132                 return -ENOMEM;
 133
 134         list_add(&new->list, &thread->namespaces_list);
 135
 136         if (timestamp && curr) {
 137                 /*
 138                  * setns syscall must have changed few or all the namespaces
 139                  * of this thread. Update end time for the namespaces
 140                  * previously used.
 141                  */
 142                 curr = list_next_entry(new, list);
 143                 curr->end_time = timestamp;
 144         }
 145
 146         return 0;
 147 }
 148
 149 struct comm *thread__comm(const struct thread *thread)
 150 {
 151         if (list_empty(&thread->comm_list))
 152                 return NULL;
 153
 154         return list_first_entry(&thread->comm_list, struct comm, list);
 155 }
 156
 157 struct comm *thread__exec_comm(const struct thread *thread)
 158 {
 159         struct comm *comm, *last = NULL;
 160
 161         list_for_each_entry(comm, &thread->comm_list, list) {
 162                 if (comm->exec)
 163                         return comm;
 164                 last = comm;
 165         }
 166
 167         return last;
 168 }
 169
 170 int __thread__set_comm(struct thread *thread, const char *str, u64 timestamp,
 171                        bool exec)
 172 {
 173         struct comm *new, *curr = thread__comm(thread);
 174
 175         /* Override the default :tid entry */
 176         if (!thread->comm_set) {
 177                 int err = comm__override(curr, str, timestamp, exec);
 178                 if (err)
 179                         return err;
 180         } else {
 181                 new = comm__new(str, timestamp, exec);
 182                 if (!new)
 183                         return -ENOMEM;
 184                 list_add(&new->list, &thread->comm_list);
 185
 186                 if (exec)
 187                         unwind__flush_access(thread);
 188         }
 189
 190         thread->comm_set = true;
 191
 192         return 0;
 193 }
 194
 195 int thread__set_comm_from_proc(struct thread *thread)
 196 {
 197         char path[64];
 198         char *comm = NULL;
 199         size_t sz;
 200         int err = -1;
 201
 202         if (!(snprintf(path, sizeof(path), "%d/task/%d/comm",
 203                        thread->pid_, thread->tid) >= (int)sizeof(path)) &&
 204             procfs__read_str(path, &comm, &sz) == 0) {
 205                 comm[sz - 1] = '\0';
 206                 err = thread__set_comm(thread, comm, 0);
 207         }
 208
 209         return err;
 210 }
 211
 212 const char *thread__comm_str(const struct thread *thread)
 213 {
 214         const struct comm *comm = thread__comm(thread);
 215
 216         if (!comm)
 217                 return NULL;
 218
 219         return comm__str(comm);
 220 }
 221
 222 /* CHECKME: it should probably better return the max comm len from its comm list */
 223 int thread__comm_len(struct thread *thread)
 224 {
 225         if (!thread->comm_len) {
 226                 const char *comm = thread__comm_str(thread);
 227                 if (!comm)
 228                         return 0;
 229                 thread->comm_len = strlen(comm);
 230         }
 231
 232         return thread->comm_len;
 233 }
 234
 235 size_t thread__fprintf(struct thread *thread, FILE *fp)
 236 {
 237         return fprintf(fp, "Thread %d %s\n", thread->tid, thread__comm_str(thread)) +
 238                map_groups__fprintf(thread->mg, fp);
 239 }
 240
 241 int thread__insert_map(struct thread *thread, struct map *map)
 242 {
 243         int ret;
 244
 245         ret = unwind__prepare_access(thread, map, NULL);
 246         if (ret)
 247                 return ret;
 248
 249         map_groups__fixup_overlappings(thread->mg, map, stderr);
 250         map_groups__insert(thread->mg, map);
 251
 252         return 0;
 253 }
 254
 255 static int __thread__prepare_access(struct thread *thread)
 256 {
 257         bool initialized = false;
 258         int i, err = 0;
 259
 260         for (i = 0; i < MAP__NR_TYPES; ++i) {
 261                 struct maps *maps = &thread->mg->maps[i];
 262                 struct map *map;
 263
 264                 pthread_rwlock_rdlock(&maps->lock);
 265
 266                 for (map = maps__first(maps); map; map = map__next(map)) {
 267                         err = unwind__prepare_access(thread, map, &initialized);
 268                         if (err || initialized)
 269                                 break;
 270                 }
 271
 272                 pthread_rwlock_unlock(&maps->lock);
 273         }
 274
 275         return err;
 276 }
 277
 278 static int thread__prepare_access(struct thread *thread)
 279 {
 280         int err = 0;
 281
 282         if (symbol_conf.use_callchain)
 283                 err = __thread__prepare_access(thread);
 284
 285         return err;
 286 }
 287
 288 static int thread__clone_map_groups(struct thread *thread,
 289                                     struct thread *parent)
 290 {
 291         int i;
 292
 293         /* This is new thread, we share map groups for process. */
 294         if (thread->pid_ == parent->pid_)
 295                 return thread__prepare_access(thread);
 296
 297         if (thread->mg == parent->mg) {
 298                 pr_debug("broken map groups on thread %d/%d parent %d/%d\n",
 299                          thread->pid_, thread->tid, parent->pid_, parent->tid);
 300                 return 0;
 301         }
 302
 303         /* But this one is new process, copy maps. */
 304         for (i = 0; i < MAP__NR_TYPES; ++i)
 305                 if (map_groups__clone(thread, parent->mg, i) < 0)
 306                         return -ENOMEM;
 307
 308         return 0;
 309 }
 310
 311 int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp)
 312 {
 313         if (parent->comm_set) {
 314                 const char *comm = thread__comm_str(parent);
 315                 int err;
 316                 if (!comm)
 317                         return -ENOMEM;
 318                 err = thread__set_comm(thread, comm, timestamp);
 319                 if (err)
 320                         return err;
 321         }
 322
 323         thread->ppid = parent->tid;
 324         return thread__clone_map_groups(thread, parent);
 325 }
 326
 327 void thread__find_cpumode_addr_location(struct thread *thread,
 328                                         enum map_type type, u64 addr,
 329                                         struct addr_location *al)
 330 {
 331         size_t i;
 332         const u8 cpumodes[] = {
 333                 PERF_RECORD_MISC_USER,
 334                 PERF_RECORD_MISC_KERNEL,
 335                 PERF_RECORD_MISC_GUEST_USER,
 336                 PERF_RECORD_MISC_GUEST_KERNEL
 337         };
 338
 339         for (i = 0; i < ARRAY_SIZE(cpumodes); i++) {
 340                 thread__find_addr_location(thread, cpumodes[i], type, addr, al);
 341                 if (al->map)
 342                         break;
 343         }
 344 }
 345
 346 struct thread *thread__main_thread(struct machine *machine, struct thread *thread)
 347 {
 348         if (thread->pid_ == thread->tid)
 349                 return thread__get(thread);
 350
 351         if (thread->pid_ == -1)
 352                 return NULL;
 353
 354         return machine__find_thread(machine, thread->pid_, thread->pid_);
 355 }