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                 /* Thread holds first ref to nsdata. */
  63                 thread->nsinfo = nsinfo__new(pid);
  64         }
  65
  66         return thread;
  67
  68 err_thread:
  69         free(thread);
  70         return NULL;
  71 }
  72
  73 void thread__delete(struct thread *thread)
  74 {
  75         struct namespaces *namespaces, *tmp_namespaces;
  76         struct comm *comm, *tmp_comm;
  77
  78         BUG_ON(!RB_EMPTY_NODE(&thread->rb_node));
  79
  80         thread_stack__free(thread);
  81
  82         if (thread->mg) {
  83                 map_groups__put(thread->mg);
  84                 thread->mg = NULL;
  85         }
  86         list_for_each_entry_safe(namespaces, tmp_namespaces,
  87                                  &thread->namespaces_list, list) {
  88                 list_del(&namespaces->list);
  89                 namespaces__free(namespaces);
  90         }
  91         list_for_each_entry_safe(comm, tmp_comm, &thread->comm_list, list) {
  92                 list_del(&comm->list);
  93                 comm__free(comm);
  94         }
  95         unwind__finish_access(thread);
  96         nsinfo__zput(thread->nsinfo);
  97
  98         free(thread);
  99 }
 100
 101 struct thread *thread__get(struct thread *thread)
 102 {
 103         if (thread)
 104                 refcount_inc(&thread->refcnt);
 105         return thread;
 106 }
 107
 108 void thread__put(struct thread *thread)
 109 {
 110         if (thread && refcount_dec_and_test(&thread->refcnt)) {
 111                 /*
 112                  * Remove it from the dead_threads list, as last reference
 113                  * is gone.
 114                  */
 115                 list_del_init(&thread->node);
 116                 thread__delete(thread);
 117         }
 118 }
 119
 120 struct namespaces *thread__namespaces(const struct thread *thread)
 121 {
 122         if (list_empty(&thread->namespaces_list))
 123                 return NULL;
 124
 125         return list_first_entry(&thread->namespaces_list, struct namespaces, list);
 126 }
 127
 128 int thread__set_namespaces(struct thread *thread, u64 timestamp,
 129                            struct namespaces_event *event)
 130 {
 131         struct namespaces *new, *curr = thread__namespaces(thread);
 132
 133         new = namespaces__new(event);
 134         if (!new)
 135                 return -ENOMEM;
 136
 137         list_add(&new->list, &thread->namespaces_list);
 138
 139         if (timestamp && curr) {
 140                 /*
 141                  * setns syscall must have changed few or all the namespaces
 142                  * of this thread. Update end time for the namespaces
 143                  * previously used.
 144                  */
 145                 curr = list_next_entry(new, list);
 146                 curr->end_time = timestamp;
 147         }
 148
 149         return 0;
 150 }
 151
 152 struct comm *thread__comm(const struct thread *thread)
 153 {
 154         if (list_empty(&thread->comm_list))
 155                 return NULL;
 156
 157         return list_first_entry(&thread->comm_list, struct comm, list);
 158 }
 159
 160 struct comm *thread__exec_comm(const struct thread *thread)
 161 {
 162         struct comm *comm, *last = NULL;
 163
 164         list_for_each_entry(comm, &thread->comm_list, list) {
 165                 if (comm->exec)
 166                         return comm;
 167                 last = comm;
 168         }
 169
 170         return last;
 171 }
 172
 173 int __thread__set_comm(struct thread *thread, const char *str, u64 timestamp,
 174                        bool exec)
 175 {
 176         struct comm *new, *curr = thread__comm(thread);
 177
 178         /* Override the default :tid entry */
 179         if (!thread->comm_set) {
 180                 int err = comm__override(curr, str, timestamp, exec);
 181                 if (err)
 182                         return err;
 183         } else {
 184                 new = comm__new(str, timestamp, exec);
 185                 if (!new)
 186                         return -ENOMEM;
 187                 list_add(&new->list, &thread->comm_list);
 188
 189                 if (exec)
 190                         unwind__flush_access(thread);
 191         }
 192
 193         thread->comm_set = true;
 194
 195         return 0;
 196 }
 197
 198 int thread__set_comm_from_proc(struct thread *thread)
 199 {
 200         char path[64];
 201         char *comm = NULL;
 202         size_t sz;
 203         int err = -1;
 204
 205         if (!(snprintf(path, sizeof(path), "%d/task/%d/comm",
 206                        thread->pid_, thread->tid) >= (int)sizeof(path)) &&
 207             procfs__read_str(path, &comm, &sz) == 0) {
 208                 comm[sz - 1] = '\0';
 209                 err = thread__set_comm(thread, comm, 0);
 210         }
 211
 212         return err;
 213 }
 214
 215 const char *thread__comm_str(const struct thread *thread)
 216 {
 217         const struct comm *comm = thread__comm(thread);
 218
 219         if (!comm)
 220                 return NULL;
 221
 222         return comm__str(comm);
 223 }
 224
 225 /* CHECKME: it should probably better return the max comm len from its comm list */
 226 int thread__comm_len(struct thread *thread)
 227 {
 228         if (!thread->comm_len) {
 229                 const char *comm = thread__comm_str(thread);
 230                 if (!comm)
 231                         return 0;
 232                 thread->comm_len = strlen(comm);
 233         }
 234
 235         return thread->comm_len;
 236 }
 237
 238 size_t thread__fprintf(struct thread *thread, FILE *fp)
 239 {
 240         return fprintf(fp, "Thread %d %s\n", thread->tid, thread__comm_str(thread)) +
 241                map_groups__fprintf(thread->mg, fp);
 242 }
 243
 244 int thread__insert_map(struct thread *thread, struct map *map)
 245 {
 246         int ret;
 247
 248         ret = unwind__prepare_access(thread, map, NULL);
 249         if (ret)
 250                 return ret;
 251
 252         map_groups__fixup_overlappings(thread->mg, map, stderr);
 253         map_groups__insert(thread->mg, map);
 254
 255         return 0;
 256 }
 257
 258 static int __thread__prepare_access(struct thread *thread)
 259 {
 260         bool initialized = false;
 261         int i, err = 0;
 262
 263         for (i = 0; i < MAP__NR_TYPES; ++i) {
 264                 struct maps *maps = &thread->mg->maps[i];
 265                 struct map *map;
 266
 267                 pthread_rwlock_rdlock(&maps->lock);
 268
 269                 for (map = maps__first(maps); map; map = map__next(map)) {
 270                         err = unwind__prepare_access(thread, map, &initialized);
 271                         if (err || initialized)
 272                                 break;
 273                 }
 274
 275                 pthread_rwlock_unlock(&maps->lock);
 276         }
 277
 278         return err;
 279 }
 280
 281 static int thread__prepare_access(struct thread *thread)
 282 {
 283         int err = 0;
 284
 285         if (symbol_conf.use_callchain)
 286                 err = __thread__prepare_access(thread);
 287
 288         return err;
 289 }
 290
 291 static int thread__clone_map_groups(struct thread *thread,
 292                                     struct thread *parent)
 293 {
 294         int i;
 295
 296         /* This is new thread, we share map groups for process. */
 297         if (thread->pid_ == parent->pid_)
 298                 return thread__prepare_access(thread);
 299
 300         if (thread->mg == parent->mg) {
 301                 pr_debug("broken map groups on thread %d/%d parent %d/%d\n",
 302                          thread->pid_, thread->tid, parent->pid_, parent->tid);
 303                 return 0;
 304         }
 305
 306         /* But this one is new process, copy maps. */
 307         for (i = 0; i < MAP__NR_TYPES; ++i)
 308                 if (map_groups__clone(thread, parent->mg, i) < 0)
 309                         return -ENOMEM;
 310
 311         return 0;
 312 }
 313
 314 int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp)
 315 {
 316         if (parent->comm_set) {
 317                 const char *comm = thread__comm_str(parent);
 318                 int err;
 319                 if (!comm)
 320                         return -ENOMEM;
 321                 err = thread__set_comm(thread, comm, timestamp);
 322                 if (err)
 323                         return err;
 324         }
 325
 326         thread->ppid = parent->tid;
 327         return thread__clone_map_groups(thread, parent);
 328 }
 329
 330 void thread__find_cpumode_addr_location(struct thread *thread,
 331                                         enum map_type type, u64 addr,
 332                                         struct addr_location *al)
 333 {
 334         size_t i;
 335         const u8 cpumodes[] = {
 336                 PERF_RECORD_MISC_USER,
 337                 PERF_RECORD_MISC_KERNEL,
 338                 PERF_RECORD_MISC_GUEST_USER,
 339                 PERF_RECORD_MISC_GUEST_KERNEL
 340         };
 341
 342         for (i = 0; i < ARRAY_SIZE(cpumodes); i++) {
 343                 thread__find_addr_location(thread, cpumodes[i], type, addr, al);
 344                 if (al->map)
 345                         break;
 346         }
 347 }
 348
 349 struct thread *thread__main_thread(struct machine *machine, struct thread *thread)
 350 {
 351         if (thread->pid_ == thread->tid)
 352                 return thread__get(thread);
 353
 354         if (thread->pid_ == -1)
 355                 return NULL;
 356
 357         return machine__find_thread(machine, thread->pid_, thread->pid_);
 358 }