1 // SPDX-License-Identifier: GPL-2.0 2 #include "util.h" 3 #include "debug.h" 4 #include "event.h" 5 #include <api/fs/fs.h> 6 #include <sys/stat.h> 7 #include <sys/utsname.h> 8 #include <dirent.h> 9 #include <fcntl.h> 10 #include <inttypes.h> 11 #include <signal.h> 12 #include <stdio.h> 13 #include <stdlib.h> 14 #include <string.h> 15 #include <errno.h> 16 #include <limits.h> 17 #include <linux/capability.h> 18 #include <linux/kernel.h> 19 #include <linux/log2.h> 20 #include <linux/time64.h> 21 #include <linux/overflow.h> 22 #include <unistd.h> 23 #include "cap.h" 24 #include "strlist.h" 25 #include "string2.h" 26 27 /* 28 * XXX We need to find a better place for these things... 29 */ 30 31 const char *input_name; 32 33 bool perf_singlethreaded = true; 34 35 void perf_set_singlethreaded(void) 36 { 37 perf_singlethreaded = true; 38 } 39 40 void perf_set_multithreaded(void) 41 { 42 perf_singlethreaded = false; 43 } 44 45 int sysctl_perf_event_max_stack = PERF_MAX_STACK_DEPTH; 46 int sysctl_perf_event_max_contexts_per_stack = PERF_MAX_CONTEXTS_PER_STACK; 47 48 int sysctl__max_stack(void) 49 { 50 int value; 51 52 if (sysctl__read_int("kernel/perf_event_max_stack", &value) == 0) 53 sysctl_perf_event_max_stack = value; 54 55 if (sysctl__read_int("kernel/perf_event_max_contexts_per_stack", &value) == 0) 56 sysctl_perf_event_max_contexts_per_stack = value; 57 58 return sysctl_perf_event_max_stack; 59 } 60 61 bool sysctl__nmi_watchdog_enabled(void) 62 { 63 static bool cached; 64 static bool nmi_watchdog; 65 int value; 66 67 if (cached) 68 return nmi_watchdog; 69 70 if (sysctl__read_int("kernel/nmi_watchdog", &value) < 0) 71 return false; 72 73 nmi_watchdog = (value > 0) ? true : false; 74 cached = true; 75 76 return nmi_watchdog; 77 } 78 79 bool test_attr__enabled; 80 81 bool perf_host = true; 82 bool perf_guest = false; 83 84 void event_attr_init(struct perf_event_attr *attr) 85 { 86 if (!perf_host) 87 attr->exclude_host = 1; 88 if (!perf_guest) 89 attr->exclude_guest = 1; 90 /* to capture ABI version */ 91 attr->size = sizeof(*attr); 92 } 93 94 int mkdir_p(char *path, mode_t mode) 95 { 96 struct stat st; 97 int err; 98 char *d = path; 99 100 if (*d != '/') 101 return -1; 102 103 if (stat(path, &st) == 0) 104 return 0; 105 106 while (*++d == '/'); 107 108 while ((d = strchr(d, '/'))) { 109 *d = '\0'; 110 err = stat(path, &st) && mkdir(path, mode); 111 *d++ = '/'; 112 if (err) 113 return -1; 114 while (*d == '/') 115 ++d; 116 } 117 return (stat(path, &st) && mkdir(path, mode)) ? -1 : 0; 118 } 119 120 static bool match_pat(char *file, const char **pat) 121 { 122 int i = 0; 123 124 if (!pat) 125 return true; 126 127 while (pat[i]) { 128 if (strglobmatch(file, pat[i])) 129 return true; 130 131 i++; 132 } 133 134 return false; 135 } 136 137 /* 138 * The depth specify how deep the removal will go. 139 * 0 - will remove only files under the 'path' directory 140 * 1 .. x - will dive in x-level deep under the 'path' directory 141 * 142 * If specified the pat is array of string patterns ended with NULL, 143 * which are checked upon every file/directory found. Only matching 144 * ones are removed. 145 * 146 * The function returns: 147 * 0 on success 148 * -1 on removal failure with errno set 149 * -2 on pattern failure 150 */ 151 static int rm_rf_depth_pat(const char *path, int depth, const char **pat) 152 { 153 DIR *dir; 154 int ret; 155 struct dirent *d; 156 char namebuf[PATH_MAX]; 157 struct stat statbuf; 158 159 /* Do not fail if there's no file. */ 160 ret = lstat(path, &statbuf); 161 if (ret) 162 return 0; 163 164 /* Try to remove any file we get. */ 165 if (!(statbuf.st_mode & S_IFDIR)) 166 return unlink(path); 167 168 /* We have directory in path. */ 169 dir = opendir(path); 170 if (dir == NULL) 171 return -1; 172 173 while ((d = readdir(dir)) != NULL && !ret) { 174 175 if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, "..")) 176 continue; 177 178 if (!match_pat(d->d_name, pat)) { 179 ret = -2; 180 break; 181 } 182 183 scnprintf(namebuf, sizeof(namebuf), "%s/%s", 184 path, d->d_name); 185 186 /* We have to check symbolic link itself */ 187 ret = lstat(namebuf, &statbuf); 188 if (ret < 0) { 189 pr_debug("stat failed: %s\n", namebuf); 190 break; 191 } 192 193 if (S_ISDIR(statbuf.st_mode)) 194 ret = depth ? rm_rf_depth_pat(namebuf, depth - 1, pat) : 0; 195 else 196 ret = unlink(namebuf); 197 } 198 closedir(dir); 199 200 if (ret < 0) 201 return ret; 202 203 return rmdir(path); 204 } 205 206 static int rm_rf_a_kcore_dir(const char *path, const char *name) 207 { 208 char kcore_dir_path[PATH_MAX]; 209 const char *pat[] = { 210 "kcore", 211 "kallsyms", 212 "modules", 213 NULL, 214 }; 215 216 snprintf(kcore_dir_path, sizeof(kcore_dir_path), "%s/%s", path, name); 217 218 return rm_rf_depth_pat(kcore_dir_path, 0, pat); 219 } 220 221 static bool kcore_dir_filter(const char *name __maybe_unused, struct dirent *d) 222 { 223 const char *pat[] = { 224 "kcore_dir", 225 "kcore_dir__[1-9]*", 226 NULL, 227 }; 228 229 return match_pat(d->d_name, pat); 230 } 231 232 static int rm_rf_kcore_dir(const char *path) 233 { 234 struct strlist *kcore_dirs; 235 struct str_node *nd; 236 int ret; 237 238 kcore_dirs = lsdir(path, kcore_dir_filter); 239 240 if (!kcore_dirs) 241 return 0; 242 243 strlist__for_each_entry(nd, kcore_dirs) { 244 ret = rm_rf_a_kcore_dir(path, nd->s); 245 if (ret) 246 return ret; 247 } 248 249 strlist__delete(kcore_dirs); 250 251 return 0; 252 } 253 254 int rm_rf_perf_data(const char *path) 255 { 256 const char *pat[] = { 257 "data", 258 "data.*", 259 NULL, 260 }; 261 262 rm_rf_kcore_dir(path); 263 264 return rm_rf_depth_pat(path, 0, pat); 265 } 266 267 int rm_rf(const char *path) 268 { 269 return rm_rf_depth_pat(path, INT_MAX, NULL); 270 } 271 272 /* A filter which removes dot files */ 273 bool lsdir_no_dot_filter(const char *name __maybe_unused, struct dirent *d) 274 { 275 return d->d_name[0] != '.'; 276 } 277 278 /* lsdir reads a directory and store it in strlist */ 279 struct strlist *lsdir(const char *name, 280 bool (*filter)(const char *, struct dirent *)) 281 { 282 struct strlist *list = NULL; 283 DIR *dir; 284 struct dirent *d; 285 286 dir = opendir(name); 287 if (!dir) 288 return NULL; 289 290 list = strlist__new(NULL, NULL); 291 if (!list) { 292 errno = ENOMEM; 293 goto out; 294 } 295 296 while ((d = readdir(dir)) != NULL) { 297 if (!filter || filter(name, d)) 298 strlist__add(list, d->d_name); 299 } 300 301 out: 302 closedir(dir); 303 return list; 304 } 305 306 size_t hex_width(u64 v) 307 { 308 size_t n = 1; 309 310 while ((v >>= 4)) 311 ++n; 312 313 return n; 314 } 315 316 int perf_event_paranoid(void) 317 { 318 int value; 319 320 if (sysctl__read_int("kernel/perf_event_paranoid", &value)) 321 return INT_MAX; 322 323 return value; 324 } 325 326 bool perf_event_paranoid_check(int max_level) 327 { 328 return perf_cap__capable(CAP_SYS_ADMIN) || 329 perf_cap__capable(CAP_PERFMON) || 330 perf_event_paranoid() <= max_level; 331 } 332 333 static int 334 fetch_ubuntu_kernel_version(unsigned int *puint) 335 { 336 ssize_t len; 337 size_t line_len = 0; 338 char *ptr, *line = NULL; 339 int version, patchlevel, sublevel, err; 340 FILE *vsig; 341 342 if (!puint) 343 return 0; 344 345 vsig = fopen("/proc/version_signature", "r"); 346 if (!vsig) { 347 pr_debug("Open /proc/version_signature failed: %s\n", 348 strerror(errno)); 349 return -1; 350 } 351 352 len = getline(&line, &line_len, vsig); 353 fclose(vsig); 354 err = -1; 355 if (len <= 0) { 356 pr_debug("Reading from /proc/version_signature failed: %s\n", 357 strerror(errno)); 358 goto errout; 359 } 360 361 ptr = strrchr(line, ' '); 362 if (!ptr) { 363 pr_debug("Parsing /proc/version_signature failed: %s\n", line); 364 goto errout; 365 } 366 367 err = sscanf(ptr + 1, "%d.%d.%d", 368 &version, &patchlevel, &sublevel); 369 if (err != 3) { 370 pr_debug("Unable to get kernel version from /proc/version_signature '%s'\n", 371 line); 372 goto errout; 373 } 374 375 *puint = (version << 16) + (patchlevel << 8) + sublevel; 376 err = 0; 377 errout: 378 free(line); 379 return err; 380 } 381 382 int 383 fetch_kernel_version(unsigned int *puint, char *str, 384 size_t str_size) 385 { 386 struct utsname utsname; 387 int version, patchlevel, sublevel, err; 388 bool int_ver_ready = false; 389 390 if (access("/proc/version_signature", R_OK) == 0) 391 if (!fetch_ubuntu_kernel_version(puint)) 392 int_ver_ready = true; 393 394 if (uname(&utsname)) 395 return -1; 396 397 if (str && str_size) { 398 strncpy(str, utsname.release, str_size); 399 str[str_size - 1] = '\0'; 400 } 401 402 if (!puint || int_ver_ready) 403 return 0; 404 405 err = sscanf(utsname.release, "%d.%d.%d", 406 &version, &patchlevel, &sublevel); 407 408 if (err != 3) { 409 pr_debug("Unable to get kernel version from uname '%s'\n", 410 utsname.release); 411 return -1; 412 } 413 414 *puint = (version << 16) + (patchlevel << 8) + sublevel; 415 return 0; 416 } 417 418 int perf_tip(char **strp, const char *dirpath) 419 { 420 struct strlist *tips; 421 struct str_node *node; 422 struct strlist_config conf = { 423 .dirname = dirpath, 424 .file_only = true, 425 }; 426 int ret = 0; 427 428 *strp = NULL; 429 tips = strlist__new("tips.txt", &conf); 430 if (tips == NULL) 431 return -errno; 432 433 if (strlist__nr_entries(tips) == 0) 434 goto out; 435 436 node = strlist__entry(tips, random() % strlist__nr_entries(tips)); 437 if (asprintf(strp, "Tip: %s", node->s) < 0) 438 ret = -ENOMEM; 439 440 out: 441 strlist__delete(tips); 442 443 return ret; 444 } 445 446 char *perf_exe(char *buf, int len) 447 { 448 int n = readlink("/proc/self/exe", buf, len); 449 if (n > 0) { 450 buf[n] = 0; 451 return buf; 452 } 453 return strcpy(buf, "perf"); 454 } 455 456 void perf_debuginfod_setup(struct perf_debuginfod *di) 457 { 458 /* 459 * By default '!di->set' we clear DEBUGINFOD_URLS, so debuginfod 460 * processing is not triggered, otherwise we set it to 'di->urls' 461 * value. If 'di->urls' is "system" we keep DEBUGINFOD_URLS value. 462 */ 463 if (!di->set) 464 setenv("DEBUGINFOD_URLS", "", 1); 465 else if (di->urls && strcmp(di->urls, "system")) 466 setenv("DEBUGINFOD_URLS", di->urls, 1); 467 468 pr_debug("DEBUGINFOD_URLS=%s\n", getenv("DEBUGINFOD_URLS")); 469 470 #ifndef HAVE_DEBUGINFOD_SUPPORT 471 if (di->set) 472 pr_warning("WARNING: debuginfod support requested, but perf is not built with it\n"); 473 #endif 474 } 475 476 /* 477 * Return a new filename prepended with task's root directory if it's in 478 * a chroot. Callers should free the returned string. 479 */ 480 char *filename_with_chroot(int pid, const char *filename) 481 { 482 char buf[PATH_MAX]; 483 char proc_root[32]; 484 char *new_name = NULL; 485 int ret; 486 487 scnprintf(proc_root, sizeof(proc_root), "/proc/%d/root", pid); 488 ret = readlink(proc_root, buf, sizeof(buf) - 1); 489 if (ret <= 0) 490 return NULL; 491 492 /* readlink(2) does not append a null byte to buf */ 493 buf[ret] = '\0'; 494 495 if (!strcmp(buf, "/")) 496 return NULL; 497 498 if (strstr(buf, "(deleted)")) 499 return NULL; 500 501 if (asprintf(&new_name, "%s/%s", buf, filename) < 0) 502 return NULL; 503 504 return new_name; 505 } 506 507 /* 508 * Reallocate an array *arr of size *arr_sz so that it is big enough to contain 509 * x elements of size msz, initializing new entries to *init_val or zero if 510 * init_val is NULL 511 */ 512 int do_realloc_array_as_needed(void **arr, size_t *arr_sz, size_t x, size_t msz, const void *init_val) 513 { 514 size_t new_sz = *arr_sz; 515 void *new_arr; 516 size_t i; 517 518 if (!new_sz) 519 new_sz = msz >= 64 ? 1 : roundup(64, msz); /* Start with at least 64 bytes */ 520 while (x >= new_sz) { 521 if (check_mul_overflow(new_sz, (size_t)2, &new_sz)) 522 return -ENOMEM; 523 } 524 if (new_sz == *arr_sz) 525 return 0; 526 new_arr = calloc(new_sz, msz); 527 if (!new_arr) 528 return -ENOMEM; 529 if (*arr_sz) 530 memcpy(new_arr, *arr, *arr_sz * msz); 531 if (init_val) { 532 for (i = *arr_sz; i < new_sz; i++) 533 memcpy(new_arr + (i * msz), init_val, msz); 534 } 535 *arr = new_arr; 536 *arr_sz = new_sz; 537 return 0; 538 } 539 540 #ifndef HAVE_SCHED_GETCPU_SUPPORT 541 int sched_getcpu(void) 542 { 543 #ifdef __NR_getcpu 544 unsigned int cpu; 545 int err = syscall(__NR_getcpu, &cpu, NULL, NULL); 546 547 if (!err) 548 return cpu; 549 #else 550 errno = ENOSYS; 551 #endif 552 return -1; 553 } 554 #endif 555 556 #ifndef HAVE_SCANDIRAT_SUPPORT 557 int scandirat(int dirfd, const char *dirp, 558 struct dirent ***namelist, 559 int (*filter)(const struct dirent *), 560 int (*compar)(const struct dirent **, const struct dirent **)) 561 { 562 char path[PATH_MAX]; 563 int err, fd = openat(dirfd, dirp, O_PATH); 564 565 if (fd < 0) 566 return fd; 567 568 snprintf(path, sizeof(path), "/proc/%d/fd/%d", getpid(), fd); 569 err = scandir(path, namelist, filter, compar); 570 close(fd); 571 return err; 572 } 573 #endif 574