1 // SPDX-License-Identifier: GPL-2.0 2 #include "../perf.h" 3 #include <errno.h> 4 #include <stdlib.h> 5 #include <stdio.h> 6 #include <string.h> 7 #include <linux/kernel.h> 8 #include "session.h" 9 #include "thread.h" 10 #include "thread-stack.h" 11 #include "util.h" 12 #include "debug.h" 13 #include "namespaces.h" 14 #include "comm.h" 15 #include "map.h" 16 #include "symbol.h" 17 #include "unwind.h" 18 #include "callchain.h" 19 20 #include <api/fs/fs.h> 21 22 int thread__init_map_groups(struct thread *thread, struct machine *machine) 23 { 24 pid_t pid = thread->pid_; 25 26 if (pid == thread->tid || pid == -1) { 27 thread->mg = map_groups__new(machine); 28 } else { 29 struct thread *leader = __machine__findnew_thread(machine, pid, pid); 30 if (leader) { 31 thread->mg = map_groups__get(leader->mg); 32 thread__put(leader); 33 } 34 } 35 36 return thread->mg ? 0 : -1; 37 } 38 39 struct thread *thread__new(pid_t pid, pid_t tid) 40 { 41 char *comm_str; 42 struct comm *comm; 43 struct thread *thread = zalloc(sizeof(*thread)); 44 45 if (thread != NULL) { 46 thread->pid_ = pid; 47 thread->tid = tid; 48 thread->ppid = -1; 49 thread->cpu = -1; 50 INIT_LIST_HEAD(&thread->namespaces_list); 51 INIT_LIST_HEAD(&thread->comm_list); 52 init_rwsem(&thread->namespaces_lock); 53 init_rwsem(&thread->comm_lock); 54 55 comm_str = malloc(32); 56 if (!comm_str) 57 goto err_thread; 58 59 snprintf(comm_str, 32, ":%d", tid); 60 comm = comm__new(comm_str, 0, false); 61 free(comm_str); 62 if (!comm) 63 goto err_thread; 64 65 list_add(&comm->list, &thread->comm_list); 66 refcount_set(&thread->refcnt, 1); 67 RB_CLEAR_NODE(&thread->rb_node); 68 /* Thread holds first ref to nsdata. */ 69 thread->nsinfo = nsinfo__new(pid); 70 srccode_state_init(&thread->srccode_state); 71 } 72 73 return thread; 74 75 err_thread: 76 free(thread); 77 return NULL; 78 } 79 80 void thread__delete(struct thread *thread) 81 { 82 struct namespaces *namespaces, *tmp_namespaces; 83 struct comm *comm, *tmp_comm; 84 85 BUG_ON(!RB_EMPTY_NODE(&thread->rb_node)); 86 87 thread_stack__free(thread); 88 89 if (thread->mg) { 90 map_groups__put(thread->mg); 91 thread->mg = NULL; 92 } 93 down_write(&thread->namespaces_lock); 94 list_for_each_entry_safe(namespaces, tmp_namespaces, 95 &thread->namespaces_list, list) { 96 list_del(&namespaces->list); 97 namespaces__free(namespaces); 98 } 99 up_write(&thread->namespaces_lock); 100 101 down_write(&thread->comm_lock); 102 list_for_each_entry_safe(comm, tmp_comm, &thread->comm_list, list) { 103 list_del(&comm->list); 104 comm__free(comm); 105 } 106 up_write(&thread->comm_lock); 107 108 unwind__finish_access(thread); 109 nsinfo__zput(thread->nsinfo); 110 srccode_state_free(&thread->srccode_state); 111 112 exit_rwsem(&thread->namespaces_lock); 113 exit_rwsem(&thread->comm_lock); 114 free(thread); 115 } 116 117 struct thread *thread__get(struct thread *thread) 118 { 119 if (thread) 120 refcount_inc(&thread->refcnt); 121 return thread; 122 } 123 124 void thread__put(struct thread *thread) 125 { 126 if (thread && refcount_dec_and_test(&thread->refcnt)) { 127 /* 128 * Remove it from the dead_threads list, as last reference 129 * is gone. 130 */ 131 list_del_init(&thread->node); 132 thread__delete(thread); 133 } 134 } 135 136 static struct namespaces *__thread__namespaces(const struct thread *thread) 137 { 138 if (list_empty(&thread->namespaces_list)) 139 return NULL; 140 141 return list_first_entry(&thread->namespaces_list, struct namespaces, list); 142 } 143 144 struct namespaces *thread__namespaces(const struct thread *thread) 145 { 146 struct namespaces *ns; 147 148 down_read((struct rw_semaphore *)&thread->namespaces_lock); 149 ns = __thread__namespaces(thread); 150 up_read((struct rw_semaphore *)&thread->namespaces_lock); 151 152 return ns; 153 } 154 155 static int __thread__set_namespaces(struct thread *thread, u64 timestamp, 156 struct namespaces_event *event) 157 { 158 struct namespaces *new, *curr = __thread__namespaces(thread); 159 160 new = namespaces__new(event); 161 if (!new) 162 return -ENOMEM; 163 164 list_add(&new->list, &thread->namespaces_list); 165 166 if (timestamp && curr) { 167 /* 168 * setns syscall must have changed few or all the namespaces 169 * of this thread. Update end time for the namespaces 170 * previously used. 171 */ 172 curr = list_next_entry(new, list); 173 curr->end_time = timestamp; 174 } 175 176 return 0; 177 } 178 179 int thread__set_namespaces(struct thread *thread, u64 timestamp, 180 struct namespaces_event *event) 181 { 182 int ret; 183 184 down_write(&thread->namespaces_lock); 185 ret = __thread__set_namespaces(thread, timestamp, event); 186 up_write(&thread->namespaces_lock); 187 return ret; 188 } 189 190 struct comm *thread__comm(const struct thread *thread) 191 { 192 if (list_empty(&thread->comm_list)) 193 return NULL; 194 195 return list_first_entry(&thread->comm_list, struct comm, list); 196 } 197 198 struct comm *thread__exec_comm(const struct thread *thread) 199 { 200 struct comm *comm, *last = NULL; 201 202 list_for_each_entry(comm, &thread->comm_list, list) { 203 if (comm->exec) 204 return comm; 205 last = comm; 206 } 207 208 return last; 209 } 210 211 static int ____thread__set_comm(struct thread *thread, const char *str, 212 u64 timestamp, bool exec) 213 { 214 struct comm *new, *curr = thread__comm(thread); 215 216 /* Override the default :tid entry */ 217 if (!thread->comm_set) { 218 int err = comm__override(curr, str, timestamp, exec); 219 if (err) 220 return err; 221 } else { 222 new = comm__new(str, timestamp, exec); 223 if (!new) 224 return -ENOMEM; 225 list_add(&new->list, &thread->comm_list); 226 227 if (exec) 228 unwind__flush_access(thread); 229 } 230 231 thread->comm_set = true; 232 233 return 0; 234 } 235 236 int __thread__set_comm(struct thread *thread, const char *str, u64 timestamp, 237 bool exec) 238 { 239 int ret; 240 241 down_write(&thread->comm_lock); 242 ret = ____thread__set_comm(thread, str, timestamp, exec); 243 up_write(&thread->comm_lock); 244 return ret; 245 } 246 247 int thread__set_comm_from_proc(struct thread *thread) 248 { 249 char path[64]; 250 char *comm = NULL; 251 size_t sz; 252 int err = -1; 253 254 if (!(snprintf(path, sizeof(path), "%d/task/%d/comm", 255 thread->pid_, thread->tid) >= (int)sizeof(path)) && 256 procfs__read_str(path, &comm, &sz) == 0) { 257 comm[sz - 1] = '\0'; 258 err = thread__set_comm(thread, comm, 0); 259 } 260 261 return err; 262 } 263 264 static const char *__thread__comm_str(const struct thread *thread) 265 { 266 const struct comm *comm = thread__comm(thread); 267 268 if (!comm) 269 return NULL; 270 271 return comm__str(comm); 272 } 273 274 const char *thread__comm_str(const struct thread *thread) 275 { 276 const char *str; 277 278 down_read((struct rw_semaphore *)&thread->comm_lock); 279 str = __thread__comm_str(thread); 280 up_read((struct rw_semaphore *)&thread->comm_lock); 281 282 return str; 283 } 284 285 /* CHECKME: it should probably better return the max comm len from its comm list */ 286 int thread__comm_len(struct thread *thread) 287 { 288 if (!thread->comm_len) { 289 const char *comm = thread__comm_str(thread); 290 if (!comm) 291 return 0; 292 thread->comm_len = strlen(comm); 293 } 294 295 return thread->comm_len; 296 } 297 298 size_t thread__fprintf(struct thread *thread, FILE *fp) 299 { 300 return fprintf(fp, "Thread %d %s\n", thread->tid, thread__comm_str(thread)) + 301 map_groups__fprintf(thread->mg, fp); 302 } 303 304 int thread__insert_map(struct thread *thread, struct map *map) 305 { 306 int ret; 307 308 ret = unwind__prepare_access(thread, map, NULL); 309 if (ret) 310 return ret; 311 312 map_groups__fixup_overlappings(thread->mg, map, stderr); 313 map_groups__insert(thread->mg, map); 314 315 return 0; 316 } 317 318 static int __thread__prepare_access(struct thread *thread) 319 { 320 bool initialized = false; 321 int err = 0; 322 struct maps *maps = &thread->mg->maps; 323 struct map *map; 324 325 down_read(&maps->lock); 326 327 for (map = maps__first(maps); map; map = map__next(map)) { 328 err = unwind__prepare_access(thread, map, &initialized); 329 if (err || initialized) 330 break; 331 } 332 333 up_read(&maps->lock); 334 335 return err; 336 } 337 338 static int thread__prepare_access(struct thread *thread) 339 { 340 int err = 0; 341 342 if (dwarf_callchain_users) 343 err = __thread__prepare_access(thread); 344 345 return err; 346 } 347 348 static int thread__clone_map_groups(struct thread *thread, 349 struct thread *parent, 350 bool do_maps_clone) 351 { 352 /* This is new thread, we share map groups for process. */ 353 if (thread->pid_ == parent->pid_) 354 return thread__prepare_access(thread); 355 356 if (thread->mg == parent->mg) { 357 pr_debug("broken map groups on thread %d/%d parent %d/%d\n", 358 thread->pid_, thread->tid, parent->pid_, parent->tid); 359 return 0; 360 } 361 /* But this one is new process, copy maps. */ 362 return do_maps_clone ? map_groups__clone(thread, parent->mg) : 0; 363 } 364 365 int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp, bool do_maps_clone) 366 { 367 if (parent->comm_set) { 368 const char *comm = thread__comm_str(parent); 369 int err; 370 if (!comm) 371 return -ENOMEM; 372 err = thread__set_comm(thread, comm, timestamp); 373 if (err) 374 return err; 375 } 376 377 thread->ppid = parent->tid; 378 return thread__clone_map_groups(thread, parent, do_maps_clone); 379 } 380 381 void thread__find_cpumode_addr_location(struct thread *thread, u64 addr, 382 struct addr_location *al) 383 { 384 size_t i; 385 const u8 cpumodes[] = { 386 PERF_RECORD_MISC_USER, 387 PERF_RECORD_MISC_KERNEL, 388 PERF_RECORD_MISC_GUEST_USER, 389 PERF_RECORD_MISC_GUEST_KERNEL 390 }; 391 392 for (i = 0; i < ARRAY_SIZE(cpumodes); i++) { 393 thread__find_symbol(thread, cpumodes[i], addr, al); 394 if (al->map) 395 break; 396 } 397 } 398 399 struct thread *thread__main_thread(struct machine *machine, struct thread *thread) 400 { 401 if (thread->pid_ == thread->tid) 402 return thread__get(thread); 403 404 if (thread->pid_ == -1) 405 return NULL; 406 407 return machine__find_thread(machine, thread->pid_, thread->pid_); 408 } 409 410 int thread__memcpy(struct thread *thread, struct machine *machine, 411 void *buf, u64 ip, int len, bool *is64bit) 412 { 413 u8 cpumode = PERF_RECORD_MISC_USER; 414 struct addr_location al; 415 long offset; 416 417 if (machine__kernel_ip(machine, ip)) 418 cpumode = PERF_RECORD_MISC_KERNEL; 419 420 if (!thread__find_map(thread, cpumode, ip, &al) || !al.map->dso || 421 al.map->dso->data.status == DSO_DATA_STATUS_ERROR || 422 map__load(al.map) < 0) 423 return -1; 424 425 offset = al.map->map_ip(al.map, ip); 426 if (is64bit) 427 *is64bit = al.map->dso->is_64_bit; 428 429 return dso__data_read_offset(al.map->dso, machine, offset, buf, len); 430 } 431