1 // SPDX-License-Identifier: GPL-2.0 2 #include <errno.h> 3 #include <stdlib.h> 4 #include <stdio.h> 5 #include <string.h> 6 #include <linux/kernel.h> 7 #include <linux/zalloc.h> 8 #include "dso.h" 9 #include "session.h" 10 #include "thread.h" 11 #include "thread-stack.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_maps(struct thread *thread, struct machine *machine) 23 { 24 pid_t pid = thread__pid(thread); 25 26 if (pid == thread__tid(thread) || pid == -1) { 27 thread__set_maps(thread, maps__new(machine)); 28 } else { 29 struct thread *leader = __machine__findnew_thread(machine, pid, pid); 30 31 if (leader) { 32 thread__set_maps(thread, maps__get(thread__maps(leader))); 33 thread__put(leader); 34 } 35 } 36 37 return thread__maps(thread) ? 0 : -1; 38 } 39 40 struct thread *thread__new(pid_t pid, pid_t tid) 41 { 42 char *comm_str; 43 struct comm *comm; 44 RC_STRUCT(thread) *_thread = zalloc(sizeof(*_thread)); 45 struct thread *thread; 46 47 if (ADD_RC_CHK(thread, _thread) != NULL) { 48 thread__set_pid(thread, pid); 49 thread__set_tid(thread, tid); 50 thread__set_ppid(thread, -1); 51 thread__set_cpu(thread, -1); 52 thread__set_guest_cpu(thread, -1); 53 thread__set_lbr_stitch_enable(thread, false); 54 INIT_LIST_HEAD(thread__namespaces_list(thread)); 55 INIT_LIST_HEAD(thread__comm_list(thread)); 56 init_rwsem(thread__namespaces_lock(thread)); 57 init_rwsem(thread__comm_lock(thread)); 58 59 comm_str = malloc(32); 60 if (!comm_str) 61 goto err_thread; 62 63 snprintf(comm_str, 32, ":%d", tid); 64 comm = comm__new(comm_str, 0, false); 65 free(comm_str); 66 if (!comm) 67 goto err_thread; 68 69 list_add(&comm->list, thread__comm_list(thread)); 70 refcount_set(thread__refcnt(thread), 1); 71 /* Thread holds first ref to nsdata. */ 72 RC_CHK_ACCESS(thread)->nsinfo = nsinfo__new(pid); 73 srccode_state_init(thread__srccode_state(thread)); 74 } 75 76 return thread; 77 78 err_thread: 79 free(thread); 80 return NULL; 81 } 82 83 void thread__delete(struct thread *thread) 84 { 85 struct namespaces *namespaces, *tmp_namespaces; 86 struct comm *comm, *tmp_comm; 87 88 thread_stack__free(thread); 89 90 if (thread__maps(thread)) { 91 maps__put(thread__maps(thread)); 92 thread__set_maps(thread, NULL); 93 } 94 down_write(thread__namespaces_lock(thread)); 95 list_for_each_entry_safe(namespaces, tmp_namespaces, 96 thread__namespaces_list(thread), list) { 97 list_del_init(&namespaces->list); 98 namespaces__free(namespaces); 99 } 100 up_write(thread__namespaces_lock(thread)); 101 102 down_write(thread__comm_lock(thread)); 103 list_for_each_entry_safe(comm, tmp_comm, thread__comm_list(thread), list) { 104 list_del_init(&comm->list); 105 comm__free(comm); 106 } 107 up_write(thread__comm_lock(thread)); 108 109 nsinfo__zput(RC_CHK_ACCESS(thread)->nsinfo); 110 srccode_state_free(thread__srccode_state(thread)); 111 112 exit_rwsem(thread__namespaces_lock(thread)); 113 exit_rwsem(thread__comm_lock(thread)); 114 thread__free_stitch_list(thread); 115 RC_CHK_FREE(thread); 116 } 117 118 struct thread *thread__get(struct thread *thread) 119 { 120 struct thread *result; 121 122 if (RC_CHK_GET(result, thread)) 123 refcount_inc(thread__refcnt(thread)); 124 125 return result; 126 } 127 128 void thread__put(struct thread *thread) 129 { 130 if (thread && refcount_dec_and_test(thread__refcnt(thread))) 131 thread__delete(thread); 132 else 133 RC_CHK_PUT(thread); 134 } 135 136 static struct namespaces *__thread__namespaces(struct thread *thread) 137 { 138 if (list_empty(thread__namespaces_list(thread))) 139 return NULL; 140 141 return list_first_entry(thread__namespaces_list(thread), struct namespaces, list); 142 } 143 144 struct namespaces *thread__namespaces(struct thread *thread) 145 { 146 struct namespaces *ns; 147 148 down_read(thread__namespaces_lock(thread)); 149 ns = __thread__namespaces(thread); 150 up_read(thread__namespaces_lock(thread)); 151 152 return ns; 153 } 154 155 static int __thread__set_namespaces(struct thread *thread, u64 timestamp, 156 struct perf_record_namespaces *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(thread)); 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 perf_record_namespaces *event) 181 { 182 int ret; 183 184 down_write(thread__namespaces_lock(thread)); 185 ret = __thread__set_namespaces(thread, timestamp, event); 186 up_write(thread__namespaces_lock(thread)); 187 return ret; 188 } 189 190 struct comm *thread__comm(struct thread *thread) 191 { 192 if (list_empty(thread__comm_list(thread))) 193 return NULL; 194 195 return list_first_entry(thread__comm_list(thread), struct comm, list); 196 } 197 198 struct comm *thread__exec_comm(struct thread *thread) 199 { 200 struct comm *comm, *last = NULL, *second_last = NULL; 201 202 list_for_each_entry(comm, thread__comm_list(thread), list) { 203 if (comm->exec) 204 return comm; 205 second_last = last; 206 last = comm; 207 } 208 209 /* 210 * 'last' with no start time might be the parent's comm of a synthesized 211 * thread (created by processing a synthesized fork event). For a main 212 * thread, that is very probably wrong. Prefer a later comm to avoid 213 * that case. 214 */ 215 if (second_last && !last->start && thread__pid(thread) == thread__tid(thread)) 216 return second_last; 217 218 return last; 219 } 220 221 static int ____thread__set_comm(struct thread *thread, const char *str, 222 u64 timestamp, bool exec) 223 { 224 struct comm *new, *curr = thread__comm(thread); 225 226 /* Override the default :tid entry */ 227 if (!thread__comm_set(thread)) { 228 int err = comm__override(curr, str, timestamp, exec); 229 if (err) 230 return err; 231 } else { 232 new = comm__new(str, timestamp, exec); 233 if (!new) 234 return -ENOMEM; 235 list_add(&new->list, thread__comm_list(thread)); 236 237 if (exec) 238 unwind__flush_access(thread__maps(thread)); 239 } 240 241 thread__set_comm_set(thread, true); 242 243 return 0; 244 } 245 246 int __thread__set_comm(struct thread *thread, const char *str, u64 timestamp, 247 bool exec) 248 { 249 int ret; 250 251 down_write(thread__comm_lock(thread)); 252 ret = ____thread__set_comm(thread, str, timestamp, exec); 253 up_write(thread__comm_lock(thread)); 254 return ret; 255 } 256 257 int thread__set_comm_from_proc(struct thread *thread) 258 { 259 char path[64]; 260 char *comm = NULL; 261 size_t sz; 262 int err = -1; 263 264 if (!(snprintf(path, sizeof(path), "%d/task/%d/comm", 265 thread__pid(thread), thread__tid(thread)) >= (int)sizeof(path)) && 266 procfs__read_str(path, &comm, &sz) == 0) { 267 comm[sz - 1] = '\0'; 268 err = thread__set_comm(thread, comm, 0); 269 } 270 271 return err; 272 } 273 274 static const char *__thread__comm_str(struct thread *thread) 275 { 276 const struct comm *comm = thread__comm(thread); 277 278 if (!comm) 279 return NULL; 280 281 return comm__str(comm); 282 } 283 284 const char *thread__comm_str(struct thread *thread) 285 { 286 const char *str; 287 288 down_read(thread__comm_lock(thread)); 289 str = __thread__comm_str(thread); 290 up_read(thread__comm_lock(thread)); 291 292 return str; 293 } 294 295 static int __thread__comm_len(struct thread *thread, const char *comm) 296 { 297 if (!comm) 298 return 0; 299 thread__set_comm_len(thread, strlen(comm)); 300 301 return thread__var_comm_len(thread); 302 } 303 304 /* CHECKME: it should probably better return the max comm len from its comm list */ 305 int thread__comm_len(struct thread *thread) 306 { 307 int comm_len = thread__var_comm_len(thread); 308 309 if (!comm_len) { 310 const char *comm; 311 312 down_read(thread__comm_lock(thread)); 313 comm = __thread__comm_str(thread); 314 comm_len = __thread__comm_len(thread, comm); 315 up_read(thread__comm_lock(thread)); 316 } 317 318 return comm_len; 319 } 320 321 size_t thread__fprintf(struct thread *thread, FILE *fp) 322 { 323 return fprintf(fp, "Thread %d %s\n", thread__tid(thread), thread__comm_str(thread)) + 324 maps__fprintf(thread__maps(thread), fp); 325 } 326 327 int thread__insert_map(struct thread *thread, struct map *map) 328 { 329 int ret; 330 331 ret = unwind__prepare_access(thread__maps(thread), map, NULL); 332 if (ret) 333 return ret; 334 335 maps__fixup_overlappings(thread__maps(thread), map, stderr); 336 return maps__insert(thread__maps(thread), map); 337 } 338 339 static int __thread__prepare_access(struct thread *thread) 340 { 341 bool initialized = false; 342 int err = 0; 343 struct maps *maps = thread__maps(thread); 344 struct map_rb_node *rb_node; 345 346 down_read(maps__lock(maps)); 347 348 maps__for_each_entry(maps, rb_node) { 349 err = unwind__prepare_access(thread__maps(thread), rb_node->map, &initialized); 350 if (err || initialized) 351 break; 352 } 353 354 up_read(maps__lock(maps)); 355 356 return err; 357 } 358 359 static int thread__prepare_access(struct thread *thread) 360 { 361 int err = 0; 362 363 if (dwarf_callchain_users) 364 err = __thread__prepare_access(thread); 365 366 return err; 367 } 368 369 static int thread__clone_maps(struct thread *thread, struct thread *parent, bool do_maps_clone) 370 { 371 /* This is new thread, we share map groups for process. */ 372 if (thread__pid(thread) == thread__pid(parent)) 373 return thread__prepare_access(thread); 374 375 if (thread__maps(thread) == thread__maps(parent)) { 376 pr_debug("broken map groups on thread %d/%d parent %d/%d\n", 377 thread__pid(thread), thread__tid(thread), 378 thread__pid(parent), thread__tid(parent)); 379 return 0; 380 } 381 /* But this one is new process, copy maps. */ 382 return do_maps_clone ? maps__clone(thread, thread__maps(parent)) : 0; 383 } 384 385 int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp, bool do_maps_clone) 386 { 387 if (thread__comm_set(parent)) { 388 const char *comm = thread__comm_str(parent); 389 int err; 390 if (!comm) 391 return -ENOMEM; 392 err = thread__set_comm(thread, comm, timestamp); 393 if (err) 394 return err; 395 } 396 397 thread__set_ppid(thread, thread__tid(parent)); 398 return thread__clone_maps(thread, parent, do_maps_clone); 399 } 400 401 void thread__find_cpumode_addr_location(struct thread *thread, u64 addr, 402 struct addr_location *al) 403 { 404 size_t i; 405 const u8 cpumodes[] = { 406 PERF_RECORD_MISC_USER, 407 PERF_RECORD_MISC_KERNEL, 408 PERF_RECORD_MISC_GUEST_USER, 409 PERF_RECORD_MISC_GUEST_KERNEL 410 }; 411 412 for (i = 0; i < ARRAY_SIZE(cpumodes); i++) { 413 thread__find_symbol(thread, cpumodes[i], addr, al); 414 if (al->map) 415 break; 416 } 417 } 418 419 struct thread *thread__main_thread(struct machine *machine, struct thread *thread) 420 { 421 if (thread__pid(thread) == thread__tid(thread)) 422 return thread__get(thread); 423 424 if (thread__pid(thread) == -1) 425 return NULL; 426 427 return machine__find_thread(machine, thread__pid(thread), thread__pid(thread)); 428 } 429 430 int thread__memcpy(struct thread *thread, struct machine *machine, 431 void *buf, u64 ip, int len, bool *is64bit) 432 { 433 u8 cpumode = PERF_RECORD_MISC_USER; 434 struct addr_location al; 435 struct dso *dso; 436 long offset; 437 438 if (machine__kernel_ip(machine, ip)) 439 cpumode = PERF_RECORD_MISC_KERNEL; 440 441 addr_location__init(&al); 442 if (!thread__find_map(thread, cpumode, ip, &al)) { 443 addr_location__exit(&al); 444 return -1; 445 } 446 447 dso = map__dso(al.map); 448 449 if (!dso || dso->data.status == DSO_DATA_STATUS_ERROR || map__load(al.map) < 0) { 450 addr_location__exit(&al); 451 return -1; 452 } 453 454 offset = map__map_ip(al.map, ip); 455 if (is64bit) 456 *is64bit = dso->is_64_bit; 457 458 addr_location__exit(&al); 459 460 return dso__data_read_offset(dso, machine, offset, buf, len); 461 } 462 463 void thread__free_stitch_list(struct thread *thread) 464 { 465 struct lbr_stitch *lbr_stitch = thread__lbr_stitch(thread); 466 struct stitch_list *pos, *tmp; 467 468 if (!lbr_stitch) 469 return; 470 471 list_for_each_entry_safe(pos, tmp, &lbr_stitch->lists, node) { 472 list_del_init(&pos->node); 473 free(pos); 474 } 475 476 list_for_each_entry_safe(pos, tmp, &lbr_stitch->free_lists, node) { 477 list_del_init(&pos->node); 478 free(pos); 479 } 480 481 zfree(&lbr_stitch->prev_lbr_cursor); 482 free(thread__lbr_stitch(thread)); 483 thread__set_lbr_stitch(thread, NULL); 484 } 485