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