580 lines · c
1// SPDX-License-Identifier: GPL-2.02#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 31const char *input_name;32 33bool perf_singlethreaded = true;34 35void perf_set_singlethreaded(void)36{37 perf_singlethreaded = true;38}39 40void perf_set_multithreaded(void)41{42 perf_singlethreaded = false;43}44 45int sysctl_perf_event_max_stack = PERF_MAX_STACK_DEPTH;46int sysctl_perf_event_max_contexts_per_stack = PERF_MAX_CONTEXTS_PER_STACK;47 48int 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 61bool 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 79bool test_attr__enabled;80 81bool perf_host = true;82bool perf_guest = false;83 84void 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 94int 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 120static 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' directory140 * 1 .. x - will dive in x-level deep under the 'path' directory141 *142 * If specified the pat is array of string patterns ended with NULL,143 * which are checked upon every file/directory found. Only matching144 * ones are removed.145 *146 * The function returns:147 * 0 on success148 * -1 on removal failure with errno set149 * -2 on pattern failure150 */151static 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 else196 ret = unlink(namebuf);197 }198 closedir(dir);199 200 if (ret < 0)201 return ret;202 203 return rmdir(path);204}205 206static 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 221static 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 232static 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 254int 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 267int 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 */273bool 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 */279struct 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 301out:302 closedir(dir);303 return list;304}305 306size_t hex_width(u64 v)307{308 size_t n = 1;309 310 while ((v >>= 4))311 ++n;312 313 return n;314}315 316int 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 326bool perf_event_paranoid_check(int max_level)327{328 bool used_root;329 330 if (perf_cap__capable(CAP_SYS_ADMIN, &used_root))331 return true;332 333 if (!used_root && perf_cap__capable(CAP_PERFMON, &used_root))334 return true;335 336 return perf_event_paranoid() <= max_level;337}338 339static int340fetch_ubuntu_kernel_version(unsigned int *puint)341{342 ssize_t len;343 size_t line_len = 0;344 char *ptr, *line = NULL;345 int version, patchlevel, sublevel, err;346 FILE *vsig;347 348 if (!puint)349 return 0;350 351 vsig = fopen("/proc/version_signature", "r");352 if (!vsig) {353 pr_debug("Open /proc/version_signature failed: %s\n",354 strerror(errno));355 return -1;356 }357 358 len = getline(&line, &line_len, vsig);359 fclose(vsig);360 err = -1;361 if (len <= 0) {362 pr_debug("Reading from /proc/version_signature failed: %s\n",363 strerror(errno));364 goto errout;365 }366 367 ptr = strrchr(line, ' ');368 if (!ptr) {369 pr_debug("Parsing /proc/version_signature failed: %s\n", line);370 goto errout;371 }372 373 err = sscanf(ptr + 1, "%d.%d.%d",374 &version, &patchlevel, &sublevel);375 if (err != 3) {376 pr_debug("Unable to get kernel version from /proc/version_signature '%s'\n",377 line);378 goto errout;379 }380 381 *puint = (version << 16) + (patchlevel << 8) + sublevel;382 err = 0;383errout:384 free(line);385 return err;386}387 388int389fetch_kernel_version(unsigned int *puint, char *str,390 size_t str_size)391{392 struct utsname utsname;393 int version, patchlevel, sublevel, err;394 bool int_ver_ready = false;395 396 if (access("/proc/version_signature", R_OK) == 0)397 if (!fetch_ubuntu_kernel_version(puint))398 int_ver_ready = true;399 400 if (uname(&utsname))401 return -1;402 403 if (str && str_size) {404 strncpy(str, utsname.release, str_size);405 str[str_size - 1] = '\0';406 }407 408 if (!puint || int_ver_ready)409 return 0;410 411 err = sscanf(utsname.release, "%d.%d.%d",412 &version, &patchlevel, &sublevel);413 414 if (err != 3) {415 pr_debug("Unable to get kernel version from uname '%s'\n",416 utsname.release);417 return -1;418 }419 420 *puint = (version << 16) + (patchlevel << 8) + sublevel;421 return 0;422}423 424int perf_tip(char **strp, const char *dirpath)425{426 struct strlist *tips;427 struct str_node *node;428 struct strlist_config conf = {429 .dirname = dirpath,430 .file_only = true,431 };432 int ret = 0;433 434 *strp = NULL;435 tips = strlist__new("tips.txt", &conf);436 if (tips == NULL)437 return -errno;438 439 if (strlist__nr_entries(tips) == 0)440 goto out;441 442 node = strlist__entry(tips, random() % strlist__nr_entries(tips));443 if (asprintf(strp, "Tip: %s", node->s) < 0)444 ret = -ENOMEM;445 446out:447 strlist__delete(tips);448 449 return ret;450}451 452char *perf_exe(char *buf, int len)453{454 int n = readlink("/proc/self/exe", buf, len);455 if (n > 0) {456 buf[n] = 0;457 return buf;458 }459 return strcpy(buf, "perf");460}461 462void perf_debuginfod_setup(struct perf_debuginfod *di)463{464 /*465 * By default '!di->set' we clear DEBUGINFOD_URLS, so debuginfod466 * processing is not triggered, otherwise we set it to 'di->urls'467 * value. If 'di->urls' is "system" we keep DEBUGINFOD_URLS value.468 */469 if (!di->set)470 setenv("DEBUGINFOD_URLS", "", 1);471 else if (di->urls && strcmp(di->urls, "system"))472 setenv("DEBUGINFOD_URLS", di->urls, 1);473 474 pr_debug("DEBUGINFOD_URLS=%s\n", getenv("DEBUGINFOD_URLS"));475 476#ifndef HAVE_DEBUGINFOD_SUPPORT477 if (di->set)478 pr_warning("WARNING: debuginfod support requested, but perf is not built with it\n");479#endif480}481 482/*483 * Return a new filename prepended with task's root directory if it's in484 * a chroot. Callers should free the returned string.485 */486char *filename_with_chroot(int pid, const char *filename)487{488 char buf[PATH_MAX];489 char proc_root[32];490 char *new_name = NULL;491 int ret;492 493 scnprintf(proc_root, sizeof(proc_root), "/proc/%d/root", pid);494 ret = readlink(proc_root, buf, sizeof(buf) - 1);495 if (ret <= 0)496 return NULL;497 498 /* readlink(2) does not append a null byte to buf */499 buf[ret] = '\0';500 501 if (!strcmp(buf, "/"))502 return NULL;503 504 if (strstr(buf, "(deleted)"))505 return NULL;506 507 if (asprintf(&new_name, "%s/%s", buf, filename) < 0)508 return NULL;509 510 return new_name;511}512 513/*514 * Reallocate an array *arr of size *arr_sz so that it is big enough to contain515 * x elements of size msz, initializing new entries to *init_val or zero if516 * init_val is NULL517 */518int do_realloc_array_as_needed(void **arr, size_t *arr_sz, size_t x, size_t msz, const void *init_val)519{520 size_t new_sz = *arr_sz;521 void *new_arr;522 size_t i;523 524 if (!new_sz)525 new_sz = msz >= 64 ? 1 : roundup(64, msz); /* Start with at least 64 bytes */526 while (x >= new_sz) {527 if (check_mul_overflow(new_sz, (size_t)2, &new_sz))528 return -ENOMEM;529 }530 if (new_sz == *arr_sz)531 return 0;532 new_arr = calloc(new_sz, msz);533 if (!new_arr)534 return -ENOMEM;535 if (*arr_sz)536 memcpy(new_arr, *arr, *arr_sz * msz);537 if (init_val) {538 for (i = *arr_sz; i < new_sz; i++)539 memcpy(new_arr + (i * msz), init_val, msz);540 }541 *arr = new_arr;542 *arr_sz = new_sz;543 return 0;544}545 546#ifndef HAVE_SCHED_GETCPU_SUPPORT547int sched_getcpu(void)548{549#ifdef __NR_getcpu550 unsigned int cpu;551 int err = syscall(__NR_getcpu, &cpu, NULL, NULL);552 553 if (!err)554 return cpu;555#else556 errno = ENOSYS;557#endif558 return -1;559}560#endif561 562#ifndef HAVE_SCANDIRAT_SUPPORT563int scandirat(int dirfd, const char *dirp,564 struct dirent ***namelist,565 int (*filter)(const struct dirent *),566 int (*compar)(const struct dirent **, const struct dirent **))567{568 char path[PATH_MAX];569 int err, fd = openat(dirfd, dirp, O_PATH);570 571 if (fd < 0)572 return fd;573 574 snprintf(path, sizeof(path), "/proc/%d/fd/%d", getpid(), fd);575 err = scandir(path, namelist, filter, compar);576 close(fd);577 return err;578}579#endif580