linux/tools/perf/util/data.c
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   1// SPDX-License-Identifier: GPL-2.0
   2#include <linux/compiler.h>
   3#include <linux/kernel.h>
   4#include <linux/string.h>
   5#include <linux/zalloc.h>
   6#include <sys/types.h>
   7#include <sys/stat.h>
   8#include <errno.h>
   9#include <fcntl.h>
  10#include <unistd.h>
  11#include <string.h>
  12#include <asm/bug.h>
  13#include <dirent.h>
  14
  15#include "data.h"
  16#include "util.h" // rm_rf_perf_data()
  17#include "debug.h"
  18#include "header.h"
  19#include <internal/lib.h>
  20
  21static void close_dir(struct perf_data_file *files, int nr)
  22{
  23        while (--nr >= 0) {
  24                close(files[nr].fd);
  25                zfree(&files[nr].path);
  26        }
  27        free(files);
  28}
  29
  30void perf_data__close_dir(struct perf_data *data)
  31{
  32        close_dir(data->dir.files, data->dir.nr);
  33}
  34
  35int perf_data__create_dir(struct perf_data *data, int nr)
  36{
  37        struct perf_data_file *files = NULL;
  38        int i, ret;
  39
  40        if (WARN_ON(!data->is_dir))
  41                return -EINVAL;
  42
  43        files = zalloc(nr * sizeof(*files));
  44        if (!files)
  45                return -ENOMEM;
  46
  47        data->dir.version = PERF_DIR_VERSION;
  48        data->dir.files   = files;
  49        data->dir.nr      = nr;
  50
  51        for (i = 0; i < nr; i++) {
  52                struct perf_data_file *file = &files[i];
  53
  54                ret = asprintf(&file->path, "%s/data.%d", data->path, i);
  55                if (ret < 0)
  56                        goto out_err;
  57
  58                ret = open(file->path, O_RDWR|O_CREAT|O_TRUNC, S_IRUSR|S_IWUSR);
  59                if (ret < 0)
  60                        goto out_err;
  61
  62                file->fd = ret;
  63        }
  64
  65        return 0;
  66
  67out_err:
  68        close_dir(files, i);
  69        return ret;
  70}
  71
  72int perf_data__open_dir(struct perf_data *data)
  73{
  74        struct perf_data_file *files = NULL;
  75        struct dirent *dent;
  76        int ret = -1;
  77        DIR *dir;
  78        int nr = 0;
  79
  80        /*
  81         * Directory containing a single regular perf data file which is already
  82         * open, means there is nothing more to do here.
  83         */
  84        if (perf_data__is_single_file(data))
  85                return 0;
  86
  87        if (WARN_ON(!data->is_dir))
  88                return -EINVAL;
  89
  90        /* The version is provided by DIR_FORMAT feature. */
  91        if (WARN_ON(data->dir.version != PERF_DIR_VERSION))
  92                return -1;
  93
  94        dir = opendir(data->path);
  95        if (!dir)
  96                return -EINVAL;
  97
  98        while ((dent = readdir(dir)) != NULL) {
  99                struct perf_data_file *file;
 100                char path[PATH_MAX];
 101                struct stat st;
 102
 103                snprintf(path, sizeof(path), "%s/%s", data->path, dent->d_name);
 104                if (stat(path, &st))
 105                        continue;
 106
 107                if (!S_ISREG(st.st_mode) || strncmp(dent->d_name, "data.", 5))
 108                        continue;
 109
 110                ret = -ENOMEM;
 111
 112                file = realloc(files, (nr + 1) * sizeof(*files));
 113                if (!file)
 114                        goto out_err;
 115
 116                files = file;
 117                file = &files[nr++];
 118
 119                file->path = strdup(path);
 120                if (!file->path)
 121                        goto out_err;
 122
 123                ret = open(file->path, O_RDONLY);
 124                if (ret < 0)
 125                        goto out_err;
 126
 127                file->fd = ret;
 128                file->size = st.st_size;
 129        }
 130
 131        if (!files)
 132                return -EINVAL;
 133
 134        data->dir.files = files;
 135        data->dir.nr    = nr;
 136        return 0;
 137
 138out_err:
 139        close_dir(files, nr);
 140        return ret;
 141}
 142
 143int perf_data__update_dir(struct perf_data *data)
 144{
 145        int i;
 146
 147        if (WARN_ON(!data->is_dir))
 148                return -EINVAL;
 149
 150        for (i = 0; i < data->dir.nr; i++) {
 151                struct perf_data_file *file = &data->dir.files[i];
 152                struct stat st;
 153
 154                if (fstat(file->fd, &st))
 155                        return -1;
 156
 157                file->size = st.st_size;
 158        }
 159
 160        return 0;
 161}
 162
 163static bool check_pipe(struct perf_data *data)
 164{
 165        struct stat st;
 166        bool is_pipe = false;
 167        int fd = perf_data__is_read(data) ?
 168                 STDIN_FILENO : STDOUT_FILENO;
 169
 170        if (!data->path) {
 171                if (!fstat(fd, &st) && S_ISFIFO(st.st_mode))
 172                        is_pipe = true;
 173        } else {
 174                if (!strcmp(data->path, "-"))
 175                        is_pipe = true;
 176        }
 177
 178        if (is_pipe) {
 179                if (data->use_stdio) {
 180                        const char *mode;
 181
 182                        mode = perf_data__is_read(data) ? "r" : "w";
 183                        data->file.fptr = fdopen(fd, mode);
 184
 185                        if (data->file.fptr == NULL) {
 186                                data->file.fd = fd;
 187                                data->use_stdio = false;
 188                        }
 189                } else {
 190                        data->file.fd = fd;
 191                }
 192        }
 193
 194        return data->is_pipe = is_pipe;
 195}
 196
 197static int check_backup(struct perf_data *data)
 198{
 199        struct stat st;
 200
 201        if (perf_data__is_read(data))
 202                return 0;
 203
 204        if (!stat(data->path, &st) && st.st_size) {
 205                char oldname[PATH_MAX];
 206                int ret;
 207
 208                snprintf(oldname, sizeof(oldname), "%s.old",
 209                         data->path);
 210
 211                ret = rm_rf_perf_data(oldname);
 212                if (ret) {
 213                        pr_err("Can't remove old data: %s (%s)\n",
 214                               ret == -2 ?
 215                               "Unknown file found" : strerror(errno),
 216                               oldname);
 217                        return -1;
 218                }
 219
 220                if (rename(data->path, oldname)) {
 221                        pr_err("Can't move data: %s (%s to %s)\n",
 222                               strerror(errno),
 223                               data->path, oldname);
 224                        return -1;
 225                }
 226        }
 227
 228        return 0;
 229}
 230
 231static bool is_dir(struct perf_data *data)
 232{
 233        struct stat st;
 234
 235        if (stat(data->path, &st))
 236                return false;
 237
 238        return (st.st_mode & S_IFMT) == S_IFDIR;
 239}
 240
 241static int open_file_read(struct perf_data *data)
 242{
 243        int flags = data->in_place_update ? O_RDWR : O_RDONLY;
 244        struct stat st;
 245        int fd;
 246        char sbuf[STRERR_BUFSIZE];
 247
 248        fd = open(data->file.path, flags);
 249        if (fd < 0) {
 250                int err = errno;
 251
 252                pr_err("failed to open %s: %s", data->file.path,
 253                        str_error_r(err, sbuf, sizeof(sbuf)));
 254                if (err == ENOENT && !strcmp(data->file.path, "perf.data"))
 255                        pr_err("  (try 'perf record' first)");
 256                pr_err("\n");
 257                return -err;
 258        }
 259
 260        if (fstat(fd, &st) < 0)
 261                goto out_close;
 262
 263        if (!data->force && st.st_uid && (st.st_uid != geteuid())) {
 264                pr_err("File %s not owned by current user or root (use -f to override)\n",
 265                       data->file.path);
 266                goto out_close;
 267        }
 268
 269        if (!st.st_size) {
 270                pr_info("zero-sized data (%s), nothing to do!\n",
 271                        data->file.path);
 272                goto out_close;
 273        }
 274
 275        data->file.size = st.st_size;
 276        return fd;
 277
 278 out_close:
 279        close(fd);
 280        return -1;
 281}
 282
 283static int open_file_write(struct perf_data *data)
 284{
 285        int fd;
 286        char sbuf[STRERR_BUFSIZE];
 287
 288        fd = open(data->file.path, O_CREAT|O_RDWR|O_TRUNC|O_CLOEXEC,
 289                  S_IRUSR|S_IWUSR);
 290
 291        if (fd < 0)
 292                pr_err("failed to open %s : %s\n", data->file.path,
 293                        str_error_r(errno, sbuf, sizeof(sbuf)));
 294
 295        return fd;
 296}
 297
 298static int open_file(struct perf_data *data)
 299{
 300        int fd;
 301
 302        fd = perf_data__is_read(data) ?
 303             open_file_read(data) : open_file_write(data);
 304
 305        if (fd < 0) {
 306                zfree(&data->file.path);
 307                return -1;
 308        }
 309
 310        data->file.fd = fd;
 311        return 0;
 312}
 313
 314static int open_file_dup(struct perf_data *data)
 315{
 316        data->file.path = strdup(data->path);
 317        if (!data->file.path)
 318                return -ENOMEM;
 319
 320        return open_file(data);
 321}
 322
 323static int open_dir(struct perf_data *data)
 324{
 325        int ret;
 326
 327        /*
 328         * So far we open only the header, so we can read the data version and
 329         * layout.
 330         */
 331        if (asprintf(&data->file.path, "%s/data", data->path) < 0)
 332                return -1;
 333
 334        if (perf_data__is_write(data) &&
 335            mkdir(data->path, S_IRWXU) < 0)
 336                return -1;
 337
 338        ret = open_file(data);
 339
 340        /* Cleanup whatever we managed to create so far. */
 341        if (ret && perf_data__is_write(data))
 342                rm_rf_perf_data(data->path);
 343
 344        return ret;
 345}
 346
 347int perf_data__open(struct perf_data *data)
 348{
 349        if (check_pipe(data))
 350                return 0;
 351
 352        /* currently it allows stdio for pipe only */
 353        data->use_stdio = false;
 354
 355        if (!data->path)
 356                data->path = "perf.data";
 357
 358        if (check_backup(data))
 359                return -1;
 360
 361        if (perf_data__is_read(data))
 362                data->is_dir = is_dir(data);
 363
 364        return perf_data__is_dir(data) ?
 365               open_dir(data) : open_file_dup(data);
 366}
 367
 368void perf_data__close(struct perf_data *data)
 369{
 370        if (perf_data__is_dir(data))
 371                perf_data__close_dir(data);
 372
 373        zfree(&data->file.path);
 374
 375        if (data->use_stdio)
 376                fclose(data->file.fptr);
 377        else
 378                close(data->file.fd);
 379}
 380
 381ssize_t perf_data__read(struct perf_data *data, void *buf, size_t size)
 382{
 383        if (data->use_stdio) {
 384                if (fread(buf, size, 1, data->file.fptr) == 1)
 385                        return size;
 386                return feof(data->file.fptr) ? 0 : -1;
 387        }
 388        return readn(data->file.fd, buf, size);
 389}
 390
 391ssize_t perf_data_file__write(struct perf_data_file *file,
 392                              void *buf, size_t size)
 393{
 394        return writen(file->fd, buf, size);
 395}
 396
 397ssize_t perf_data__write(struct perf_data *data,
 398                              void *buf, size_t size)
 399{
 400        if (data->use_stdio) {
 401                if (fwrite(buf, size, 1, data->file.fptr) == 1)
 402                        return size;
 403                return -1;
 404        }
 405        return perf_data_file__write(&data->file, buf, size);
 406}
 407
 408int perf_data__switch(struct perf_data *data,
 409                           const char *postfix,
 410                           size_t pos, bool at_exit,
 411                           char **new_filepath)
 412{
 413        int ret;
 414
 415        if (check_pipe(data))
 416                return -EINVAL;
 417        if (perf_data__is_read(data))
 418                return -EINVAL;
 419
 420        if (asprintf(new_filepath, "%s.%s", data->path, postfix) < 0)
 421                return -ENOMEM;
 422
 423        /*
 424         * Only fire a warning, don't return error, continue fill
 425         * original file.
 426         */
 427        if (rename(data->path, *new_filepath))
 428                pr_warning("Failed to rename %s to %s\n", data->path, *new_filepath);
 429
 430        if (!at_exit) {
 431                close(data->file.fd);
 432                ret = perf_data__open(data);
 433                if (ret < 0)
 434                        goto out;
 435
 436                if (lseek(data->file.fd, pos, SEEK_SET) == (off_t)-1) {
 437                        ret = -errno;
 438                        pr_debug("Failed to lseek to %zu: %s",
 439                                 pos, strerror(errno));
 440                        goto out;
 441                }
 442        }
 443        ret = data->file.fd;
 444out:
 445        return ret;
 446}
 447
 448unsigned long perf_data__size(struct perf_data *data)
 449{
 450        u64 size = data->file.size;
 451        int i;
 452
 453        if (perf_data__is_single_file(data))
 454                return size;
 455
 456        for (i = 0; i < data->dir.nr; i++) {
 457                struct perf_data_file *file = &data->dir.files[i];
 458
 459                size += file->size;
 460        }
 461
 462        return size;
 463}
 464
 465int perf_data__make_kcore_dir(struct perf_data *data, char *buf, size_t buf_sz)
 466{
 467        int ret;
 468
 469        if (!data->is_dir)
 470                return -1;
 471
 472        ret = snprintf(buf, buf_sz, "%s/kcore_dir", data->path);
 473        if (ret < 0 || (size_t)ret >= buf_sz)
 474                return -1;
 475
 476        return mkdir(buf, S_IRWXU);
 477}
 478
 479char *perf_data__kallsyms_name(struct perf_data *data)
 480{
 481        char *kallsyms_name;
 482        struct stat st;
 483
 484        if (!data->is_dir)
 485                return NULL;
 486
 487        if (asprintf(&kallsyms_name, "%s/kcore_dir/kallsyms", data->path) < 0)
 488                return NULL;
 489
 490        if (stat(kallsyms_name, &st)) {
 491                free(kallsyms_name);
 492                return NULL;
 493        }
 494
 495        return kallsyms_name;
 496}
 497
 498bool is_perf_data(const char *path)
 499{
 500        bool ret = false;
 501        FILE *file;
 502        u64 magic;
 503
 504        file = fopen(path, "r");
 505        if (!file)
 506                return false;
 507
 508        if (fread(&magic, 1, 8, file) < 8)
 509                goto out;
 510
 511        ret = is_perf_magic(magic);
 512out:
 513        fclose(file);
 514        return ret;
 515}
 516