575 lines · c
1// SPDX-License-Identifier: GPL-2.02#include <linux/compiler.h>3#include <linux/kernel.h>4#include <linux/string.h>5#include <linux/zalloc.h>6#include <linux/err.h>7#include <sys/types.h>8#include <sys/stat.h>9#include <errno.h>10#include <fcntl.h>11#include <unistd.h>12#include <string.h>13#include <asm/bug.h>14#include <dirent.h>15 16#include "data.h"17#include "util.h" // rm_rf_perf_data()18#include "debug.h"19#include "header.h"20#include "rlimit.h"21#include <internal/lib.h>22 23static void close_dir(struct perf_data_file *files, int nr)24{25 while (--nr >= 0) {26 close(files[nr].fd);27 zfree(&files[nr].path);28 }29 free(files);30}31 32void perf_data__close_dir(struct perf_data *data)33{34 close_dir(data->dir.files, data->dir.nr);35}36 37int perf_data__create_dir(struct perf_data *data, int nr)38{39 enum rlimit_action set_rlimit = NO_CHANGE;40 struct perf_data_file *files = NULL;41 int i, ret;42 43 if (WARN_ON(!data->is_dir))44 return -EINVAL;45 46 files = zalloc(nr * sizeof(*files));47 if (!files)48 return -ENOMEM;49 50 for (i = 0; i < nr; i++) {51 struct perf_data_file *file = &files[i];52 53 ret = asprintf(&file->path, "%s/data.%d", data->path, i);54 if (ret < 0) {55 ret = -ENOMEM;56 goto out_err;57 }58 59retry_open:60 ret = open(file->path, O_RDWR|O_CREAT|O_TRUNC, S_IRUSR|S_IWUSR);61 if (ret < 0) {62 /*63 * If using parallel threads to collect data,64 * perf record needs at least 6 fds per CPU.65 * When we run out of them try to increase the limits.66 */67 if (errno == EMFILE && rlimit__increase_nofile(&set_rlimit))68 goto retry_open;69 70 ret = -errno;71 goto out_err;72 }73 set_rlimit = NO_CHANGE;74 75 file->fd = ret;76 }77 78 data->dir.version = PERF_DIR_VERSION;79 data->dir.files = files;80 data->dir.nr = nr;81 return 0;82 83out_err:84 close_dir(files, i);85 return ret;86}87 88int perf_data__open_dir(struct perf_data *data)89{90 struct perf_data_file *files = NULL;91 struct dirent *dent;92 int ret = -1;93 DIR *dir;94 int nr = 0;95 96 /*97 * Directory containing a single regular perf data file which is already98 * open, means there is nothing more to do here.99 */100 if (perf_data__is_single_file(data))101 return 0;102 103 if (WARN_ON(!data->is_dir))104 return -EINVAL;105 106 /* The version is provided by DIR_FORMAT feature. */107 if (WARN_ON(data->dir.version != PERF_DIR_VERSION))108 return -1;109 110 dir = opendir(data->path);111 if (!dir)112 return -EINVAL;113 114 while ((dent = readdir(dir)) != NULL) {115 struct perf_data_file *file;116 char path[PATH_MAX];117 struct stat st;118 119 snprintf(path, sizeof(path), "%s/%s", data->path, dent->d_name);120 if (stat(path, &st))121 continue;122 123 if (!S_ISREG(st.st_mode) || strncmp(dent->d_name, "data.", 5))124 continue;125 126 ret = -ENOMEM;127 128 file = realloc(files, (nr + 1) * sizeof(*files));129 if (!file)130 goto out_err;131 132 files = file;133 file = &files[nr++];134 135 file->path = strdup(path);136 if (!file->path)137 goto out_err;138 139 ret = open(file->path, O_RDONLY);140 if (ret < 0)141 goto out_err;142 143 file->fd = ret;144 file->size = st.st_size;145 }146 147 closedir(dir);148 if (!files)149 return -EINVAL;150 151 data->dir.files = files;152 data->dir.nr = nr;153 return 0;154 155out_err:156 closedir(dir);157 close_dir(files, nr);158 return ret;159}160 161int perf_data__update_dir(struct perf_data *data)162{163 int i;164 165 if (WARN_ON(!data->is_dir))166 return -EINVAL;167 168 for (i = 0; i < data->dir.nr; i++) {169 struct perf_data_file *file = &data->dir.files[i];170 struct stat st;171 172 if (fstat(file->fd, &st))173 return -1;174 175 file->size = st.st_size;176 }177 178 return 0;179}180 181static bool check_pipe(struct perf_data *data)182{183 struct stat st;184 bool is_pipe = false;185 int fd = perf_data__is_read(data) ?186 STDIN_FILENO : STDOUT_FILENO;187 188 if (!data->path) {189 if (!fstat(fd, &st) && S_ISFIFO(st.st_mode))190 is_pipe = true;191 } else {192 if (!strcmp(data->path, "-"))193 is_pipe = true;194 }195 196 if (is_pipe) {197 if (data->use_stdio) {198 const char *mode;199 200 mode = perf_data__is_read(data) ? "r" : "w";201 data->file.fptr = fdopen(fd, mode);202 203 if (data->file.fptr == NULL) {204 data->file.fd = fd;205 data->use_stdio = false;206 }207 208 /*209 * When is_pipe and data->file.fd is given, use given fd210 * instead of STDIN_FILENO or STDOUT_FILENO211 */212 } else if (data->file.fd <= 0) {213 data->file.fd = fd;214 }215 }216 217 return data->is_pipe = is_pipe;218}219 220static int check_backup(struct perf_data *data)221{222 struct stat st;223 224 if (perf_data__is_read(data))225 return 0;226 227 if (!stat(data->path, &st) && st.st_size) {228 char oldname[PATH_MAX];229 int ret;230 231 snprintf(oldname, sizeof(oldname), "%s.old",232 data->path);233 234 ret = rm_rf_perf_data(oldname);235 if (ret) {236 pr_err("Can't remove old data: %s (%s)\n",237 ret == -2 ?238 "Unknown file found" : strerror(errno),239 oldname);240 return -1;241 }242 243 if (rename(data->path, oldname)) {244 pr_err("Can't move data: %s (%s to %s)\n",245 strerror(errno),246 data->path, oldname);247 return -1;248 }249 }250 251 return 0;252}253 254static bool is_dir(struct perf_data *data)255{256 struct stat st;257 258 if (stat(data->path, &st))259 return false;260 261 return (st.st_mode & S_IFMT) == S_IFDIR;262}263 264static int open_file_read(struct perf_data *data)265{266 int flags = data->in_place_update ? O_RDWR : O_RDONLY;267 struct stat st;268 int fd;269 char sbuf[STRERR_BUFSIZE];270 271 fd = open(data->file.path, flags);272 if (fd < 0) {273 int err = errno;274 275 pr_err("failed to open %s: %s", data->file.path,276 str_error_r(err, sbuf, sizeof(sbuf)));277 if (err == ENOENT && !strcmp(data->file.path, "perf.data"))278 pr_err(" (try 'perf record' first)");279 pr_err("\n");280 return -err;281 }282 283 if (fstat(fd, &st) < 0)284 goto out_close;285 286 if (!data->force && st.st_uid && (st.st_uid != geteuid())) {287 pr_err("File %s not owned by current user or root (use -f to override)\n",288 data->file.path);289 goto out_close;290 }291 292 if (!st.st_size) {293 pr_info("zero-sized data (%s), nothing to do!\n",294 data->file.path);295 goto out_close;296 }297 298 data->file.size = st.st_size;299 return fd;300 301 out_close:302 close(fd);303 return -1;304}305 306static int open_file_write(struct perf_data *data)307{308 int fd;309 char sbuf[STRERR_BUFSIZE];310 311 fd = open(data->file.path, O_CREAT|O_RDWR|O_TRUNC|O_CLOEXEC,312 S_IRUSR|S_IWUSR);313 314 if (fd < 0)315 pr_err("failed to open %s : %s\n", data->file.path,316 str_error_r(errno, sbuf, sizeof(sbuf)));317 318 return fd;319}320 321static int open_file(struct perf_data *data)322{323 int fd;324 325 fd = perf_data__is_read(data) ?326 open_file_read(data) : open_file_write(data);327 328 if (fd < 0) {329 zfree(&data->file.path);330 return -1;331 }332 333 data->file.fd = fd;334 return 0;335}336 337static int open_file_dup(struct perf_data *data)338{339 data->file.path = strdup(data->path);340 if (!data->file.path)341 return -ENOMEM;342 343 return open_file(data);344}345 346static int open_dir(struct perf_data *data)347{348 int ret;349 350 /*351 * So far we open only the header, so we can read the data version and352 * layout.353 */354 if (asprintf(&data->file.path, "%s/data", data->path) < 0)355 return -1;356 357 if (perf_data__is_write(data) &&358 mkdir(data->path, S_IRWXU) < 0)359 return -1;360 361 ret = open_file(data);362 363 /* Cleanup whatever we managed to create so far. */364 if (ret && perf_data__is_write(data))365 rm_rf_perf_data(data->path);366 367 return ret;368}369 370int perf_data__open(struct perf_data *data)371{372 if (check_pipe(data))373 return 0;374 375 /* currently it allows stdio for pipe only */376 data->use_stdio = false;377 378 if (!data->path)379 data->path = "perf.data";380 381 if (check_backup(data))382 return -1;383 384 if (perf_data__is_read(data))385 data->is_dir = is_dir(data);386 387 return perf_data__is_dir(data) ?388 open_dir(data) : open_file_dup(data);389}390 391void perf_data__close(struct perf_data *data)392{393 if (perf_data__is_dir(data))394 perf_data__close_dir(data);395 396 zfree(&data->file.path);397 398 if (data->use_stdio)399 fclose(data->file.fptr);400 else401 close(data->file.fd);402}403 404ssize_t perf_data__read(struct perf_data *data, void *buf, size_t size)405{406 if (data->use_stdio) {407 if (fread(buf, size, 1, data->file.fptr) == 1)408 return size;409 return feof(data->file.fptr) ? 0 : -1;410 }411 return readn(data->file.fd, buf, size);412}413 414ssize_t perf_data_file__write(struct perf_data_file *file,415 void *buf, size_t size)416{417 return writen(file->fd, buf, size);418}419 420ssize_t perf_data__write(struct perf_data *data,421 void *buf, size_t size)422{423 if (data->use_stdio) {424 if (fwrite(buf, size, 1, data->file.fptr) == 1)425 return size;426 return -1;427 }428 return perf_data_file__write(&data->file, buf, size);429}430 431int perf_data__switch(struct perf_data *data,432 const char *postfix,433 size_t pos, bool at_exit,434 char **new_filepath)435{436 int ret;437 438 if (perf_data__is_read(data))439 return -EINVAL;440 441 if (asprintf(new_filepath, "%s.%s", data->path, postfix) < 0)442 return -ENOMEM;443 444 /*445 * Only fire a warning, don't return error, continue fill446 * original file.447 */448 if (rename(data->path, *new_filepath))449 pr_warning("Failed to rename %s to %s\n", data->path, *new_filepath);450 451 if (!at_exit) {452 close(data->file.fd);453 ret = perf_data__open(data);454 if (ret < 0)455 goto out;456 457 if (lseek(data->file.fd, pos, SEEK_SET) == (off_t)-1) {458 ret = -errno;459 pr_debug("Failed to lseek to %zu: %s",460 pos, strerror(errno));461 goto out;462 }463 }464 ret = data->file.fd;465out:466 return ret;467}468 469unsigned long perf_data__size(struct perf_data *data)470{471 u64 size = data->file.size;472 int i;473 474 if (perf_data__is_single_file(data))475 return size;476 477 for (i = 0; i < data->dir.nr; i++) {478 struct perf_data_file *file = &data->dir.files[i];479 480 size += file->size;481 }482 483 return size;484}485 486int perf_data__make_kcore_dir(struct perf_data *data, char *buf, size_t buf_sz)487{488 int ret;489 490 if (!data->is_dir)491 return -1;492 493 ret = snprintf(buf, buf_sz, "%s/kcore_dir", data->path);494 if (ret < 0 || (size_t)ret >= buf_sz)495 return -1;496 497 return mkdir(buf, S_IRWXU);498}499 500bool has_kcore_dir(const char *path)501{502 struct dirent *d = ERR_PTR(-EINVAL);503 const char *name = "kcore_dir";504 DIR *dir = opendir(path);505 size_t n = strlen(name);506 bool result = false;507 508 if (dir) {509 while (d && !result) {510 d = readdir(dir);511 result = d ? strncmp(d->d_name, name, n) : false;512 }513 closedir(dir);514 }515 516 return result;517}518 519char *perf_data__kallsyms_name(struct perf_data *data)520{521 char *kallsyms_name;522 struct stat st;523 524 if (!data->is_dir)525 return NULL;526 527 if (asprintf(&kallsyms_name, "%s/kcore_dir/kallsyms", data->path) < 0)528 return NULL;529 530 if (stat(kallsyms_name, &st)) {531 free(kallsyms_name);532 return NULL;533 }534 535 return kallsyms_name;536}537 538char *perf_data__guest_kallsyms_name(struct perf_data *data, pid_t machine_pid)539{540 char *kallsyms_name;541 struct stat st;542 543 if (!data->is_dir)544 return NULL;545 546 if (asprintf(&kallsyms_name, "%s/kcore_dir__%d/kallsyms", data->path, machine_pid) < 0)547 return NULL;548 549 if (stat(kallsyms_name, &st)) {550 free(kallsyms_name);551 return NULL;552 }553 554 return kallsyms_name;555}556 557bool is_perf_data(const char *path)558{559 bool ret = false;560 FILE *file;561 u64 magic;562 563 file = fopen(path, "r");564 if (!file)565 return false;566 567 if (fread(&magic, 1, 8, file) < 8)568 goto out;569 570 ret = is_perf_magic(magic);571out:572 fclose(file);573 return ret;574}575