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