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