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                 data->file.fd = fd;
 179
 180         return data->is_pipe = is_pipe;
 181 }
 182
 183 static 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
 217 static 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
 227 static 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
 268 static 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
 283 static 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
 299 static 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
 308 static 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
 332 int 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
 350 void 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
 359 ssize_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
 365 ssize_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
 371 int 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;
 407 out:
 408         return ret;
 409 }
 410
 411 unsigned 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
 428 int 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
 442 char *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 }