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 } 402