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 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 static int __thread__set_namespaces(struct thread *thread, u64 timestamp, 145 struct namespaces_event *event) 146 { 147 struct namespaces *new, *curr = thread__namespaces(thread); 148 149 new = namespaces__new(event); 150 if (!new) 151 return -ENOMEM; 152 153 list_add(&new->list, &thread->namespaces_list); 154 155 if (timestamp && curr) { 156 /* 157 * setns syscall must have changed few or all the namespaces 158 * of this thread. Update end time for the namespaces 159 * previously used. 160 */ 161 curr = list_next_entry(new, list); 162 curr->end_time = timestamp; 163 } 164 165 return 0; 166 } 167 168 int thread__set_namespaces(struct thread *thread, u64 timestamp, 169 struct namespaces_event *event) 170 { 171 int ret; 172 173 down_write(&thread->namespaces_lock); 174 ret = __thread__set_namespaces(thread, timestamp, event); 175 up_write(&thread->namespaces_lock); 176 return ret; 177 } 178 179 struct comm *thread__comm(const struct thread *thread) 180 { 181 if (list_empty(&thread->comm_list)) 182 return NULL; 183 184 return list_first_entry(&thread->comm_list, struct comm, list); 185 } 186 187 struct comm *thread__exec_comm(const struct thread *thread) 188 { 189 struct comm *comm, *last = NULL; 190 191 list_for_each_entry(comm, &thread->comm_list, list) { 192 if (comm->exec) 193 return comm; 194 last = comm; 195 } 196 197 return last; 198 } 199 200 static int ____thread__set_comm(struct thread *thread, const char *str, 201 u64 timestamp, bool exec) 202 { 203 struct comm *new, *curr = thread__comm(thread); 204 205 /* Override the default :tid entry */ 206 if (!thread->comm_set) { 207 int err = comm__override(curr, str, timestamp, exec); 208 if (err) 209 return err; 210 } else { 211 new = comm__new(str, timestamp, exec); 212 if (!new) 213 return -ENOMEM; 214 list_add(&new->list, &thread->comm_list); 215 216 if (exec) 217 unwind__flush_access(thread); 218 } 219 220 thread->comm_set = true; 221 222 return 0; 223 } 224 225 int __thread__set_comm(struct thread *thread, const char *str, u64 timestamp, 226 bool exec) 227 { 228 int ret; 229 230 down_write(&thread->comm_lock); 231 ret = ____thread__set_comm(thread, str, timestamp, exec); 232 up_write(&thread->comm_lock); 233 return ret; 234 } 235 236 int thread__set_comm_from_proc(struct thread *thread) 237 { 238 char path[64]; 239 char *comm = NULL; 240 size_t sz; 241 int err = -1; 242 243 if (!(snprintf(path, sizeof(path), "%d/task/%d/comm", 244 thread->pid_, thread->tid) >= (int)sizeof(path)) && 245 procfs__read_str(path, &comm, &sz) == 0) { 246 comm[sz - 1] = '\0'; 247 err = thread__set_comm(thread, comm, 0); 248 } 249 250 return err; 251 } 252 253 static const char *__thread__comm_str(const struct thread *thread) 254 { 255 const struct comm *comm = thread__comm(thread); 256 257 if (!comm) 258 return NULL; 259 260 return comm__str(comm); 261 } 262 263 const char *thread__comm_str(const struct thread *thread) 264 { 265 const char *str; 266 267 down_read((struct rw_semaphore *)&thread->comm_lock); 268 str = __thread__comm_str(thread); 269 up_read((struct rw_semaphore *)&thread->comm_lock); 270 271 return str; 272 } 273 274 /* CHECKME: it should probably better return the max comm len from its comm list */ 275 int thread__comm_len(struct thread *thread) 276 { 277 if (!thread->comm_len) { 278 const char *comm = thread__comm_str(thread); 279 if (!comm) 280 return 0; 281 thread->comm_len = strlen(comm); 282 } 283 284 return thread->comm_len; 285 } 286 287 size_t thread__fprintf(struct thread *thread, FILE *fp) 288 { 289 return fprintf(fp, "Thread %d %s\n", thread->tid, thread__comm_str(thread)) + 290 map_groups__fprintf(thread->mg, fp); 291 } 292 293 int thread__insert_map(struct thread *thread, struct map *map) 294 { 295 int ret; 296 297 ret = unwind__prepare_access(thread, map, NULL); 298 if (ret) 299 return ret; 300 301 map_groups__fixup_overlappings(thread->mg, map, stderr); 302 map_groups__insert(thread->mg, map); 303 304 return 0; 305 } 306 307 static int __thread__prepare_access(struct thread *thread) 308 { 309 bool initialized = false; 310 int err = 0; 311 struct maps *maps = &thread->mg->maps; 312 struct map *map; 313 314 down_read(&maps->lock); 315 316 for (map = maps__first(maps); map; map = map__next(map)) { 317 err = unwind__prepare_access(thread, map, &initialized); 318 if (err || initialized) 319 break; 320 } 321 322 up_read(&maps->lock); 323 324 return err; 325 } 326 327 static int thread__prepare_access(struct thread *thread) 328 { 329 int err = 0; 330 331 if (dwarf_callchain_users) 332 err = __thread__prepare_access(thread); 333 334 return err; 335 } 336 337 static int thread__clone_map_groups(struct thread *thread, 338 struct thread *parent, 339 bool do_maps_clone) 340 { 341 /* This is new thread, we share map groups for process. */ 342 if (thread->pid_ == parent->pid_) 343 return thread__prepare_access(thread); 344 345 if (thread->mg == parent->mg) { 346 pr_debug("broken map groups on thread %d/%d parent %d/%d\n", 347 thread->pid_, thread->tid, parent->pid_, parent->tid); 348 return 0; 349 } 350 /* But this one is new process, copy maps. */ 351 return do_maps_clone ? map_groups__clone(thread, parent->mg) : 0; 352 } 353 354 int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp, bool do_maps_clone) 355 { 356 if (parent->comm_set) { 357 const char *comm = thread__comm_str(parent); 358 int err; 359 if (!comm) 360 return -ENOMEM; 361 err = thread__set_comm(thread, comm, timestamp); 362 if (err) 363 return err; 364 } 365 366 thread->ppid = parent->tid; 367 return thread__clone_map_groups(thread, parent, do_maps_clone); 368 } 369 370 void thread__find_cpumode_addr_location(struct thread *thread, u64 addr, 371 struct addr_location *al) 372 { 373 size_t i; 374 const u8 cpumodes[] = { 375 PERF_RECORD_MISC_USER, 376 PERF_RECORD_MISC_KERNEL, 377 PERF_RECORD_MISC_GUEST_USER, 378 PERF_RECORD_MISC_GUEST_KERNEL 379 }; 380 381 for (i = 0; i < ARRAY_SIZE(cpumodes); i++) { 382 thread__find_symbol(thread, cpumodes[i], addr, al); 383 if (al->map) 384 break; 385 } 386 } 387 388 struct thread *thread__main_thread(struct machine *machine, struct thread *thread) 389 { 390 if (thread->pid_ == thread->tid) 391 return thread__get(thread); 392 393 if (thread->pid_ == -1) 394 return NULL; 395 396 return machine__find_thread(machine, thread->pid_, thread->pid_); 397 } 398 399 int thread__memcpy(struct thread *thread, struct machine *machine, 400 void *buf, u64 ip, int len, bool *is64bit) 401 { 402 u8 cpumode = PERF_RECORD_MISC_USER; 403 struct addr_location al; 404 long offset; 405 406 if (machine__kernel_ip(machine, ip)) 407 cpumode = PERF_RECORD_MISC_KERNEL; 408 409 if (!thread__find_map(thread, cpumode, ip, &al) || !al.map->dso || 410 al.map->dso->data.status == DSO_DATA_STATUS_ERROR || 411 map__load(al.map) < 0) 412 return -1; 413 414 offset = al.map->map_ip(al.map, ip); 415 if (is64bit) 416 *is64bit = al.map->dso->is_64_bit; 417 418 return dso__data_read_offset(al.map->dso, machine, offset, buf, len); 419 } 420