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