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