tools/perf/util/data.c

   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
  21 static 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
  30 void perf_data__close_dir(struct perf_data *data)
  31 {
  32         close_dir(data->dir.files, data->dir.nr);
  33 }
  34
  35 int 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
  66 out_err:
  67         close_dir(files, i);
  68         return ret;
  69 }
  70
  71 int 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
 137 out_err:
 138         close_dir(files, nr);
 139         return ret;
 140 }
 141
 142 int 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
 162 static 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                 if (data->use_stdio) {
 179                         const char *mode;
 180
 181                         mode = perf_data__is_read(data) ? "r" : "w";
 182                         data->file.fptr = fdopen(fd, mode);
 183
 184                         if (data->file.fptr == NULL) {
 185                                 data->file.fd = fd;
 186                                 data->use_stdio = false;
 187                         }
 188                 } else {
 189                         data->file.fd = fd;
 190                 }
 191         }
 192
 193         return data->is_pipe = is_pipe;
 194 }
 195
 196 static int check_backup(struct perf_data *data)
 197 {
 198         struct stat st;
 199
 200         if (perf_data__is_read(data))
 201                 return 0;
 202
 203         if (!stat(data->path, &st) && st.st_size) {
 204                 char oldname[PATH_MAX];
 205                 int ret;
 206
 207                 snprintf(oldname, sizeof(oldname), "%s.old",
 208                          data->path);
 209
 210                 ret = rm_rf_perf_data(oldname);
 211                 if (ret) {
 212                         pr_err("Can't remove old data: %s (%s)\n",
 213                                ret == -2 ?
 214                                "Unknown file found" : strerror(errno),
 215                                oldname);
 216                         return -1;
 217                 }
 218
 219                 if (rename(data->path, oldname)) {
 220                         pr_err("Can't move data: %s (%s to %s)\n",
 221                                strerror(errno),
 222                                data->path, oldname);
 223                         return -1;
 224                 }
 225         }
 226
 227         return 0;
 228 }
 229
 230 static bool is_dir(struct perf_data *data)
 231 {
 232         struct stat st;
 233
 234         if (stat(data->path, &st))
 235                 return false;
 236
 237         return (st.st_mode & S_IFMT) == S_IFDIR;
 238 }
 239
 240 static int open_file_read(struct perf_data *data)
 241 {
 242         struct stat st;
 243         int fd;
 244         char sbuf[STRERR_BUFSIZE];
 245
 246         fd = open(data->file.path, O_RDONLY);
 247         if (fd < 0) {
 248                 int err = errno;
 249
 250                 pr_err("failed to open %s: %s", data->file.path,
 251                         str_error_r(err, sbuf, sizeof(sbuf)));
 252                 if (err == ENOENT && !strcmp(data->file.path, "perf.data"))
 253                         pr_err("  (try 'perf record' first)");
 254                 pr_err("\n");
 255                 return -err;
 256         }
 257
 258         if (fstat(fd, &st) < 0)
 259                 goto out_close;
 260
 261         if (!data->force && st.st_uid && (st.st_uid != geteuid())) {
 262                 pr_err("File %s not owned by current user or root (use -f to override)\n",
 263                        data->file.path);
 264                 goto out_close;
 265         }
 266
 267         if (!st.st_size) {
 268                 pr_info("zero-sized data (%s), nothing to do!\n",
 269                         data->file.path);
 270                 goto out_close;
 271         }
 272
 273         data->file.size = st.st_size;
 274         return fd;
 275
 276  out_close:
 277         close(fd);
 278         return -1;
 279 }
 280
 281 static int open_file_write(struct perf_data *data)
 282 {
 283         int fd;
 284         char sbuf[STRERR_BUFSIZE];
 285
 286         fd = open(data->file.path, O_CREAT|O_RDWR|O_TRUNC|O_CLOEXEC,
 287                   S_IRUSR|S_IWUSR);
 288
 289         if (fd < 0)
 290                 pr_err("failed to open %s : %s\n", data->file.path,
 291                         str_error_r(errno, sbuf, sizeof(sbuf)));
 292
 293         return fd;
 294 }
 295
 296 static int open_file(struct perf_data *data)
 297 {
 298         int fd;
 299
 300         fd = perf_data__is_read(data) ?
 301              open_file_read(data) : open_file_write(data);
 302
 303         if (fd < 0) {
 304                 zfree(&data->file.path);
 305                 return -1;
 306         }
 307
 308         data->file.fd = fd;
 309         return 0;
 310 }
 311
 312 static int open_file_dup(struct perf_data *data)
 313 {
 314         data->file.path = strdup(data->path);
 315         if (!data->file.path)
 316                 return -ENOMEM;
 317
 318         return open_file(data);
 319 }
 320
 321 static int open_dir(struct perf_data *data)
 322 {
 323         int ret;
 324
 325         /*
 326          * So far we open only the header, so we can read the data version and
 327          * layout.
 328          */
 329         if (asprintf(&data->file.path, "%s/data", data->path) < 0)
 330                 return -1;
 331
 332         if (perf_data__is_write(data) &&
 333             mkdir(data->path, S_IRWXU) < 0)
 334                 return -1;
 335
 336         ret = open_file(data);
 337
 338         /* Cleanup whatever we managed to create so far. */
 339         if (ret && perf_data__is_write(data))
 340                 rm_rf_perf_data(data->path);
 341
 342         return ret;
 343 }
 344
 345 int perf_data__open(struct perf_data *data)
 346 {
 347         if (check_pipe(data))
 348                 return 0;
 349
 350         /* currently it allows stdio for pipe only */
 351         data->use_stdio = false;
 352
 353         if (!data->path)
 354                 data->path = "perf.data";
 355
 356         if (check_backup(data))
 357                 return -1;
 358
 359         if (perf_data__is_read(data))
 360                 data->is_dir = is_dir(data);
 361
 362         return perf_data__is_dir(data) ?
 363                open_dir(data) : open_file_dup(data);
 364 }
 365
 366 void perf_data__close(struct perf_data *data)
 367 {
 368         if (perf_data__is_dir(data))
 369                 perf_data__close_dir(data);
 370
 371         zfree(&data->file.path);
 372
 373         if (data->use_stdio)
 374                 fclose(data->file.fptr);
 375         else
 376                 close(data->file.fd);
 377 }
 378
 379 ssize_t perf_data__read(struct perf_data *data, void *buf, size_t size)
 380 {
 381         if (data->use_stdio) {
 382                 if (fread(buf, size, 1, data->file.fptr) == 1)
 383                         return size;
 384                 return feof(data->file.fptr) ? 0 : -1;
 385         }
 386         return readn(data->file.fd, buf, size);
 387 }
 388
 389 ssize_t perf_data_file__write(struct perf_data_file *file,
 390                               void *buf, size_t size)
 391 {
 392         return writen(file->fd, buf, size);
 393 }
 394
 395 ssize_t perf_data__write(struct perf_data *data,
 396                               void *buf, size_t size)
 397 {
 398         if (data->use_stdio) {
 399                 if (fwrite(buf, size, 1, data->file.fptr) == 1)
 400                         return size;
 401                 return -1;
 402         }
 403         return perf_data_file__write(&data->file, buf, size);
 404 }
 405
 406 int perf_data__switch(struct perf_data *data,
 407                            const char *postfix,
 408                            size_t pos, bool at_exit,
 409                            char **new_filepath)
 410 {
 411         int ret;
 412
 413         if (check_pipe(data))
 414                 return -EINVAL;
 415         if (perf_data__is_read(data))
 416                 return -EINVAL;
 417
 418         if (asprintf(new_filepath, "%s.%s", data->path, postfix) < 0)
 419                 return -ENOMEM;
 420
 421         /*
 422          * Only fire a warning, don't return error, continue fill
 423          * original file.
 424          */
 425         if (rename(data->path, *new_filepath))
 426                 pr_warning("Failed to rename %s to %s\n", data->path, *new_filepath);
 427
 428         if (!at_exit) {
 429                 close(data->file.fd);
 430                 ret = perf_data__open(data);
 431                 if (ret < 0)
 432                         goto out;
 433
 434                 if (lseek(data->file.fd, pos, SEEK_SET) == (off_t)-1) {
 435                         ret = -errno;
 436                         pr_debug("Failed to lseek to %zu: %s",
 437                                  pos, strerror(errno));
 438                         goto out;
 439                 }
 440         }
 441         ret = data->file.fd;
 442 out:
 443         return ret;
 444 }
 445
 446 unsigned long perf_data__size(struct perf_data *data)
 447 {
 448         u64 size = data->file.size;
 449         int i;
 450
 451         if (perf_data__is_single_file(data))
 452                 return size;
 453
 454         for (i = 0; i < data->dir.nr; i++) {
 455                 struct perf_data_file *file = &data->dir.files[i];
 456
 457                 size += file->size;
 458         }
 459
 460         return size;
 461 }
 462
 463 int perf_data__make_kcore_dir(struct perf_data *data, char *buf, size_t buf_sz)
 464 {
 465         int ret;
 466
 467         if (!data->is_dir)
 468                 return -1;
 469
 470         ret = snprintf(buf, buf_sz, "%s/kcore_dir", data->path);
 471         if (ret < 0 || (size_t)ret >= buf_sz)
 472                 return -1;
 473
 474         return mkdir(buf, S_IRWXU);
 475 }
 476
 477 char *perf_data__kallsyms_name(struct perf_data *data)
 478 {
 479         char *kallsyms_name;
 480         struct stat st;
 481
 482         if (!data->is_dir)
 483                 return NULL;
 484
 485         if (asprintf(&kallsyms_name, "%s/kcore_dir/kallsyms", data->path) < 0)
 486                 return NULL;
 487
 488         if (stat(kallsyms_name, &st)) {
 489                 free(kallsyms_name);
 490                 return NULL;
 491         }
 492
 493         return kallsyms_name;
 494 }
 495
 496 bool is_perf_data(const char *path)
 497 {
 498         bool ret = false;
 499         FILE *file;
 500         u64 magic;
 501
 502         file = fopen(path, "r");
 503         if (!file)
 504                 return false;
 505
 506         if (fread(&magic, 1, 8, file) < 8)
 507                 goto out;
 508
 509         ret = is_perf_magic(magic);
 510 out:
 511         fclose(file);
 512         return ret;
 513 }