src/bin/lttng-crash/lttng-crash.c

   1 /*
   2  * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
   3  * Copyright (C) 2014 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License, version 2 only,
   7  * as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along
  15  * with this program; if not, write to the Free Software Foundation, Inc.,
  16  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  17  */
  18
  19 #include <getopt.h>
  20 #include <signal.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <sys/stat.h>
  25 #include <sys/types.h>
  26 #include <sys/stat.h>
  27 #include <sys/mman.h>
  28 #include <fcntl.h>
  29 #include <sys/wait.h>
  30 #include <unistd.h>
  31 #include <ctype.h>
  32 #include <dirent.h>
  33 #include <byteswap.h>
  34 #include <inttypes.h>
  35 #include <stdbool.h>
  36
  37 #include <version.h>
  38 #include <lttng/lttng.h>
  39 #include <common/common.h>
  40 #include <common/utils.h>
  41
  42 #define DEFAULT_VIEWER "babeltrace"
  43
  44 #define COPY_BUFLEN             4096
  45 #define RB_CRASH_DUMP_ABI_LEN   32
  46
  47 #define RB_CRASH_DUMP_ABI_MAGIC_LEN     16
  48
  49 /*
  50  * The 128-bit magic number is xor'd in the process data so it does not
  51  * cause a false positive when searching for buffers by scanning memory.
  52  * The actual magic number is:
  53  *   0x17, 0x7B, 0xF1, 0x77, 0xBF, 0x17, 0x7B, 0xF1,
  54  *   0x77, 0xBF, 0x17, 0x7B, 0xF1, 0x77, 0xBF, 0x17,
  55  */
  56 #define RB_CRASH_DUMP_ABI_MAGIC_XOR                                     \
  57         {                                                               \
  58                 0x17 ^ 0xFF, 0x7B ^ 0xFF, 0xF1 ^ 0xFF, 0x77 ^ 0xFF,     \
  59                 0xBF ^ 0xFF, 0x17 ^ 0xFF, 0x7B ^ 0xFF, 0xF1 ^ 0xFF,     \
  60                 0x77 ^ 0xFF, 0xBF ^ 0xFF, 0x17 ^ 0xFF, 0x7B ^ 0xFF,     \
  61                 0xF1 ^ 0xFF, 0x77 ^ 0xFF, 0xBF ^ 0xFF, 0x17 ^ 0xFF,     \
  62         }
  63
  64 /*
  65  * Non-static to ensure the compiler does not optimize away the xor.
  66  */
  67 uint8_t lttng_crash_expected_magic_xor[] = RB_CRASH_DUMP_ABI_MAGIC_XOR;
  68
  69 #define RB_CRASH_ENDIAN                 0x1234
  70 #define RB_CRASH_ENDIAN_REVERSE         0x3412
  71
  72 enum lttng_crash_type {
  73         LTTNG_CRASH_TYPE_UST = 0,
  74         LTTNG_CRASH_TYPE_KERNEL = 1,
  75 };
  76
  77 /* LTTng ring buffer defines (copied) */
  78
  79 #define HALF_ULONG_BITS(wl)     (((wl) * CHAR_BIT) >> 1)
  80
  81 #define SB_ID_OFFSET_SHIFT(wl)  (HALF_ULONG_BITS(wl) + 1)
  82 #define SB_ID_OFFSET_COUNT(wl)  (1UL << SB_ID_OFFSET_SHIFT(wl))
  83 #define SB_ID_OFFSET_MASK(wl)   (~(SB_ID_OFFSET_COUNT(wl) - 1))
  84 /*
  85  * Lowest bit of top word half belongs to noref. Used only for overwrite mode.
  86  */
  87 #define SB_ID_NOREF_SHIFT(wl)   (SB_ID_OFFSET_SHIFT(wl) - 1)
  88 #define SB_ID_NOREF_COUNT(wl)   (1UL << SB_ID_NOREF_SHIFT(wl))
  89 #define SB_ID_NOREF_MASK(wl)    SB_ID_NOREF_COUNT(wl)
  90 /*
  91  * In overwrite mode: lowest half of word is used for index.
  92  * Limit of 2^16 subbuffers per buffer on 32-bit, 2^32 on 64-bit.
  93  * In producer-consumer mode: whole word used for index.
  94  */
  95 #define SB_ID_INDEX_SHIFT(wl)   0
  96 #define SB_ID_INDEX_COUNT(wl)   (1UL << SB_ID_INDEX_SHIFT(wl))
  97 #define SB_ID_INDEX_MASK(wl)    (SB_ID_NOREF_COUNT(wl) - 1)
  98
  99 enum rb_modes {
 100         RING_BUFFER_OVERWRITE = 0,      /* Overwrite when buffer full */
 101         RING_BUFFER_DISCARD = 1,        /* Discard when buffer full */
 102 };
 103
 104 struct crash_abi_unknown {
 105         uint8_t magic[RB_CRASH_DUMP_ABI_MAGIC_LEN];
 106         uint64_t mmap_length;   /* Overall length of crash record */
 107         uint16_t endian;        /*
 108                                  * { 0x12, 0x34 }: big endian
 109                                  * { 0x34, 0x12 }: little endian
 110                                  */
 111         uint16_t major;         /* Major number. */
 112         uint16_t minor;         /* Minor number. */
 113         uint8_t word_size;      /* Word size (bytes). */
 114         uint8_t layout_type;    /* enum lttng_crash_layout */
 115 } __attribute__((packed));
 116
 117 struct crash_abi_0_0 {
 118         struct crash_abi_unknown parent;
 119
 120         struct {
 121                 uint32_t prod_offset;
 122                 uint32_t consumed_offset;
 123                 uint32_t commit_hot_array;
 124                 uint32_t commit_hot_seq;
 125                 uint32_t buf_wsb_array;
 126                 uint32_t buf_wsb_id;
 127                 uint32_t sb_array;
 128                 uint32_t sb_array_shmp_offset;
 129                 uint32_t sb_backend_p_offset;
 130                 uint32_t content_size;
 131                 uint32_t packet_size;
 132         } __attribute__((packed)) offset;
 133         struct {
 134                 uint8_t prod_offset;
 135                 uint8_t consumed_offset;
 136                 uint8_t commit_hot_seq;
 137                 uint8_t buf_wsb_id;
 138                 uint8_t sb_array_shmp_offset;
 139                 uint8_t sb_backend_p_offset;
 140                 uint8_t content_size;
 141                 uint8_t packet_size;
 142         } __attribute__((packed)) length;
 143         struct {
 144                 uint32_t commit_hot_array;
 145                 uint32_t buf_wsb_array;
 146                 uint32_t sb_array;
 147         } __attribute__((packed)) stride;
 148
 149         uint64_t buf_size;      /* Size of the buffer */
 150         uint64_t subbuf_size;   /* Sub-buffer size */
 151         uint64_t num_subbuf;    /* Number of sub-buffers for writer */
 152         uint32_t mode;          /* Buffer mode: 0: overwrite, 1: discard */
 153 } __attribute__((packed));
 154
 155 struct lttng_crash_layout {
 156         struct {
 157                 int prod_offset, consumed_offset,
 158                         commit_hot_array, commit_hot_seq,
 159                         buf_wsb_array, buf_wsb_id,
 160                         sb_array, sb_array_shmp_offset,
 161                         sb_backend_p_offset, content_size,
 162                         packet_size;
 163         } offset;
 164         struct {
 165                 int prod_offset, consumed_offset,
 166                         commit_hot_seq, buf_wsb_id,
 167                         sb_array_shmp_offset, sb_backend_p_offset,
 168                         content_size, packet_size;
 169         } length;
 170         struct {
 171                 int commit_hot_array, buf_wsb_array, sb_array;
 172         } stride;
 173
 174         int reverse_byte_order;
 175         int word_size;
 176
 177         uint64_t mmap_length;   /* Length of crash record */
 178         uint64_t buf_size;      /* Size of the buffer */
 179         uint64_t subbuf_size;   /* Sub-buffer size */
 180         uint64_t num_subbuf;    /* Number of sub-buffers for writer */
 181         uint32_t mode;          /* Buffer mode: 0: overwrite, 1: discard */
 182 };
 183
 184 /* Variables */
 185 static char *progname,
 186         *opt_viewer_path = NULL,
 187         *opt_output_path = NULL;
 188
 189 static char *input_path;
 190
 191 int lttng_opt_quiet, lttng_opt_verbose, lttng_opt_mi;
 192
 193 enum {
 194         OPT_DUMP_OPTIONS,
 195 };
 196
 197 /* Getopt options. No first level command. */
 198 static struct option long_options[] = {
 199         { "version",            0, NULL, 'V' },
 200         { "help",               0, NULL, 'h' },
 201         { "verbose",            0, NULL, 'v' },
 202         { "viewer",             1, NULL, 'e' },
 203         { "extract",            1, NULL, 'x' },
 204         { "list-options",       0, NULL, OPT_DUMP_OPTIONS },
 205         { NULL, 0, NULL, 0 },
 206 };
 207
 208 static void usage(void)
 209 {
 210         int ret = utils_show_man_page(1, "lttng-crash");
 211
 212         if (ret) {
 213                 ERR("Cannot view man page lttng-crash(1)");
 214                 perror("exec");
 215                 exit(EXIT_FAILURE);
 216         }
 217 }
 218
 219 static void version(FILE *ofp)
 220 {
 221         fprintf(ofp, "%s (LTTng Crash Trace Viewer) " VERSION " - " VERSION_NAME
 222 "%s%s\n",
 223                         progname,
 224                         GIT_VERSION[0] == '\0' ? "" : " - " GIT_VERSION,
 225                         EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " EXTRA_VERSION_NAME);
 226 }
 227
 228 /*
 229  *  list_options
 230  *
 231  *  List options line by line. This is mostly for bash auto completion and to
 232  *  avoid difficult parsing.
 233  */
 234 static void list_options(FILE *ofp)
 235 {
 236         int i = 0;
 237         struct option *option = NULL;
 238
 239         option = &long_options[i];
 240         while (option->name != NULL) {
 241                 fprintf(ofp, "--%s\n", option->name);
 242
 243                 if (isprint(option->val)) {
 244                         fprintf(ofp, "-%c\n", option->val);
 245                 }
 246
 247                 i++;
 248                 option = &long_options[i];
 249         }
 250 }
 251
 252 /*
 253  * Parse command line arguments.
 254  *
 255  * Return 0 if OK, else -1
 256  */
 257 static int parse_args(int argc, char **argv)
 258 {
 259         int opt, ret = 0;
 260
 261         if (argc < 2) {
 262                 usage();
 263                 exit(EXIT_FAILURE);
 264         }
 265
 266         while ((opt = getopt_long(argc, argv, "+Vhve:x:", long_options, NULL)) != -1) {
 267                 switch (opt) {
 268                 case 'V':
 269                         version(stdout);
 270                         ret = 1;
 271                         goto end;
 272                 case 'h':
 273                         usage();
 274                         ret = 1;
 275                         goto end;
 276                 case 'v':
 277                         /* There is only 3 possible level of verbosity. (-vvv) */
 278                         if (lttng_opt_verbose < 3) {
 279                                 lttng_opt_verbose += 1;
 280                         }
 281                         break;
 282                 case 'e':
 283                         free(opt_viewer_path);
 284                         opt_viewer_path = strdup(optarg);
 285                         break;
 286                 case 'x':
 287                         free(opt_output_path);
 288                         opt_output_path = strdup(optarg);
 289                         break;
 290                 case OPT_DUMP_OPTIONS:
 291                         list_options(stdout);
 292                         ret = 1;
 293                         goto end;
 294                 default:
 295                         ERR("Unknown command-line option");
 296                         goto error;
 297                 }
 298         }
 299
 300         if (!opt_viewer_path) {
 301                 opt_viewer_path = DEFAULT_VIEWER;
 302         }
 303
 304         /* No leftovers, or more than one input path, print usage and quit */
 305         if (argc - optind != 1) {
 306                 ERR("Command-line error: Specify exactly one input path");
 307                 goto error;
 308         }
 309
 310         input_path = argv[optind];
 311 end:
 312         return ret;
 313
 314 error:
 315         return -1;
 316 }
 317
 318 static
 319 int copy_file(const char *file_dest, const char *file_src)
 320 {
 321         int fd_src = -1, fd_dest = -1;
 322         ssize_t readlen, writelen;
 323         char buf[COPY_BUFLEN];
 324         int ret;
 325
 326         DBG("Copy metadata file '%s' into '%s'", file_src, file_dest);
 327
 328         fd_src = open(file_src, O_RDONLY);
 329         if (fd_src < 0) {
 330                 PERROR("Error opening %s for reading", file_src);
 331                 ret = -errno;
 332                 goto error;
 333         }
 334         fd_dest = open(file_dest, O_RDWR | O_CREAT | O_EXCL,
 335                         S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
 336         if (fd_dest < 0) {
 337                 PERROR("Error opening %s for writing", file_dest);
 338                 ret = -errno;
 339                 goto error;
 340         }
 341
 342         for (;;) {
 343                 readlen = lttng_read(fd_src, buf, COPY_BUFLEN);
 344                 if (readlen < 0) {
 345                         PERROR("Error reading input file");
 346                         ret = -1;
 347                         goto error;
 348                 }
 349                 if (!readlen) {
 350                         break;
 351                 }
 352                 writelen = lttng_write(fd_dest, buf, readlen);
 353                 if (writelen < readlen) {
 354                         PERROR("Error writing to output file");
 355                         ret = -1;
 356                         goto error;
 357                 }
 358         }
 359
 360         ret = 0;
 361 error:
 362         if (fd_src >= 0) {
 363                 if (close(fd_src) < 0) {
 364                         PERROR("Error closing %s", file_src);
 365                 }
 366         }
 367
 368         if (fd_dest >= 0) {
 369                 if (close(fd_dest) < 0) {
 370                         PERROR("Error closing %s", file_dest);
 371                 }
 372         }
 373         return ret;
 374 }
 375
 376 static
 377 uint64_t _crash_get_field(const struct lttng_crash_layout *layout,
 378                 const char *ptr, size_t size)
 379 {
 380         switch (size) {
 381         case 1: return *(uint8_t *) ptr;
 382         case 2: if (layout->reverse_byte_order) {
 383                         return __bswap_16(*(uint16_t *) ptr);
 384                 } else {
 385                         return *(uint16_t *) ptr;
 386
 387                 }
 388         case 4: if (layout->reverse_byte_order) {
 389                         return __bswap_32(*(uint32_t *) ptr);
 390                 } else {
 391                         return *(uint32_t *) ptr;
 392
 393                 }
 394         case 8: if (layout->reverse_byte_order) {
 395                         return __bswap_64(*(uint64_t *) ptr);
 396                 } else {
 397                         return *(uint64_t *) ptr;
 398                 }
 399         default:
 400                 abort();
 401                 return -1;
 402         }
 403
 404 }
 405
 406 #define crash_get_field(layout, map, name)                              \
 407         _crash_get_field(layout, (map) + (layout)->offset.name,         \
 408                 layout->length.name)
 409
 410 #define crash_get_array_field(layout, map, array_name, idx, field_name) \
 411         _crash_get_field(layout,                                        \
 412                 (map) + (layout)->offset.array_name                     \
 413                         + (idx * (layout)->stride.array_name)           \
 414                         + (layout)->offset.field_name,                  \
 415                 (layout)->length.field_name)
 416
 417 #define crash_get_hdr_raw_field(layout, hdr, name)      ((hdr)->name)
 418
 419 #define crash_get_hdr_field(layout, hdr, name)                          \
 420         _crash_get_field(layout, (const char *) &(hdr)->name,           \
 421                 sizeof((hdr)->name))
 422
 423 #define crash_get_layout(layout, hdr, name)                             \
 424         do {                                                            \
 425                 (layout)->name = crash_get_hdr_field(layout, hdr,       \
 426                                         name);                          \
 427                 DBG("layout.%s = %" PRIu64, #name,                      \
 428                         (uint64_t) (layout)->name);                     \
 429         } while (0)
 430
 431 static
 432 int get_crash_layout_0_0(struct lttng_crash_layout *layout,
 433                 char *map)
 434 {
 435         const struct crash_abi_0_0 *abi = (const struct crash_abi_0_0 *) map;
 436
 437         crash_get_layout(layout, abi, offset.prod_offset);
 438         crash_get_layout(layout, abi, offset.consumed_offset);
 439         crash_get_layout(layout, abi, offset.commit_hot_array);
 440         crash_get_layout(layout, abi, offset.commit_hot_seq);
 441         crash_get_layout(layout, abi, offset.buf_wsb_array);
 442         crash_get_layout(layout, abi, offset.buf_wsb_id);
 443         crash_get_layout(layout, abi, offset.sb_array);
 444         crash_get_layout(layout, abi, offset.sb_array_shmp_offset);
 445         crash_get_layout(layout, abi, offset.sb_backend_p_offset);
 446         crash_get_layout(layout, abi, offset.content_size);
 447         crash_get_layout(layout, abi, offset.packet_size);
 448
 449         crash_get_layout(layout, abi, length.prod_offset);
 450         crash_get_layout(layout, abi, length.consumed_offset);
 451         crash_get_layout(layout, abi, length.commit_hot_seq);
 452         crash_get_layout(layout, abi, length.buf_wsb_id);
 453         crash_get_layout(layout, abi, length.sb_array_shmp_offset);
 454         crash_get_layout(layout, abi, length.sb_backend_p_offset);
 455         crash_get_layout(layout, abi, length.content_size);
 456         crash_get_layout(layout, abi, length.packet_size);
 457
 458         crash_get_layout(layout, abi, stride.commit_hot_array);
 459         crash_get_layout(layout, abi, stride.buf_wsb_array);
 460         crash_get_layout(layout, abi, stride.sb_array);
 461
 462         crash_get_layout(layout, abi, buf_size);
 463         crash_get_layout(layout, abi, subbuf_size);
 464         crash_get_layout(layout, abi, num_subbuf);
 465         crash_get_layout(layout, abi, mode);
 466
 467         return 0;
 468 }
 469
 470 static
 471 void print_dbg_magic(const uint8_t *magic)
 472 {
 473         DBG("magic: 0x%X%X%X%X%X%X%X%X%X%X%X%X%X%X%X%X",
 474                 magic[0], magic[1], magic[2], magic[3],
 475                 magic[4], magic[5], magic[6], magic[7],
 476                 magic[8], magic[9], magic[10], magic[11],
 477                 magic[12], magic[13], magic[14], magic[15]);
 478 }
 479
 480 static
 481 int check_magic(const uint8_t *magic)
 482 {
 483         int i;
 484
 485         for (i = 0; i < RB_CRASH_DUMP_ABI_MAGIC_LEN; i++) {
 486                 if ((magic[i] ^ 0xFF) != lttng_crash_expected_magic_xor[i]) {
 487                         return -1;
 488                 }
 489         }
 490         return 0;
 491 }
 492
 493 static
 494 int get_crash_layout(struct lttng_crash_layout *layout, int fd)
 495 {
 496         char *map;
 497         int ret = 0, unmapret;
 498         const uint8_t *magic;
 499         uint64_t mmap_length;
 500         uint16_t major, minor;
 501         uint8_t word_size;
 502         const struct crash_abi_unknown *abi;
 503         uint16_t endian;
 504         enum lttng_crash_type layout_type;
 505
 506         map = mmap(NULL, RB_CRASH_DUMP_ABI_LEN, PROT_READ, MAP_PRIVATE,
 507                 fd, 0);
 508         if (map == MAP_FAILED) {
 509                 PERROR("Mapping file");
 510                 return -1;
 511         }
 512         abi = (const struct crash_abi_unknown *) map;
 513         magic = crash_get_hdr_raw_field(layout, abi, magic);
 514         print_dbg_magic(magic);
 515         if (check_magic(magic)) {
 516                 DBG("Unknown magic number");
 517                 ret = 1;        /* positive return value, skip */
 518                 goto end;
 519         }
 520         endian = crash_get_hdr_field(layout, abi, endian);
 521         switch (endian) {
 522         case RB_CRASH_ENDIAN:
 523                 break;
 524         case RB_CRASH_ENDIAN_REVERSE:
 525                 layout->reverse_byte_order = 1;
 526                 break;
 527         default:
 528                 DBG("Unknown endianness value: 0x%X", (unsigned int) endian);
 529                 ret = 1;        /* positive return value, skip */
 530                 goto end;
 531         }
 532         layout_type = (enum lttng_crash_type) crash_get_hdr_field(layout, abi, layout_type);
 533         switch (layout_type) {
 534         case LTTNG_CRASH_TYPE_UST:
 535                 break;
 536         case LTTNG_CRASH_TYPE_KERNEL:
 537                 ERR("lttng-modules buffer layout support not implemented");
 538                 ret = 1;        /* positive return value, skip */
 539                 goto end;
 540         default:
 541                 ERR("Unknown layout type %u", (unsigned int) layout_type);
 542                 ret = 1;        /* positive return value, skip */
 543                 goto end;
 544         }
 545         mmap_length = crash_get_hdr_field(layout, abi, mmap_length);
 546         DBG("mmap_length: %" PRIu64, mmap_length);
 547         layout->mmap_length = mmap_length;
 548         major = crash_get_hdr_field(layout, abi, major);
 549         DBG("major: %u", major);
 550         minor = crash_get_hdr_field(layout, abi, minor);
 551         DBG("minor: %u", minor);
 552         word_size = crash_get_hdr_field(layout, abi, word_size);
 553         DBG("word_size: %u", word_size);
 554         switch (major) {
 555         case 0:
 556                 switch (minor) {
 557                 case 0:
 558                         ret = get_crash_layout_0_0(layout, map);
 559                         if (ret)
 560                                 goto end;
 561                         break;
 562                 default:
 563                         ret = -1;
 564                         ERR("Unsupported crash ABI %u.%u\n", major, minor);
 565                         goto end;
 566                 }
 567                 break;
 568         default:
 569                 ERR("Unsupported crash ABI %u.%u\n", major, minor);
 570                 ret = -1;
 571                 goto end;
 572         }
 573         layout->word_size = word_size;
 574 end:
 575         unmapret = munmap(map, RB_CRASH_DUMP_ABI_LEN);
 576         if (unmapret) {
 577                 PERROR("munmap");
 578         }
 579         return ret;
 580 }
 581
 582 /* buf_trunc mask selects only the buffer number. */
 583 static inline
 584 uint64_t buf_trunc(uint64_t offset, uint64_t buf_size)
 585 {
 586         return offset & ~(buf_size - 1);
 587 }
 588
 589 /* subbuf_trunc mask selects the subbuffer number. */
 590 static inline
 591 uint64_t subbuf_trunc(uint64_t offset, uint64_t subbuf_size)
 592 {
 593         return offset & ~(subbuf_size - 1);
 594 }
 595
 596 /* buf_offset mask selects only the offset within the current buffer. */
 597 static inline
 598 uint64_t buf_offset(uint64_t offset, uint64_t buf_size)
 599 {
 600         return offset & (buf_size - 1);
 601 }
 602
 603 /* subbuf_offset mask selects the offset within the current subbuffer. */
 604 static inline
 605 uint64_t subbuf_offset(uint64_t offset, uint64_t subbuf_size)
 606 {
 607         return offset & (subbuf_size - 1);
 608 }
 609
 610 /* subbuf_index returns the index of the current subbuffer within the buffer. */
 611 static inline
 612 uint64_t subbuf_index(uint64_t offset, uint64_t buf_size, uint64_t subbuf_size)
 613 {
 614         return buf_offset(offset, buf_size) / subbuf_size;
 615 }
 616
 617 static inline
 618 uint64_t subbuffer_id_get_index(uint32_t mode, uint64_t id,
 619                 unsigned int wl)
 620 {
 621         if (mode == RING_BUFFER_OVERWRITE)
 622                 return id & SB_ID_INDEX_MASK(wl);
 623         else
 624                 return id;
 625 }
 626
 627 static
 628 int copy_crash_subbuf(const struct lttng_crash_layout *layout,
 629                 int fd_dest, char *buf, uint64_t offset)
 630 {
 631         uint64_t buf_size, subbuf_size, num_subbuf, sbidx, id,
 632                 sb_bindex, rpages_offset, p_offset, seq_cc,
 633                 committed, commit_count_mask, consumed_cur,
 634                 packet_size;
 635         char *subbuf_ptr;
 636         ssize_t writelen;
 637
 638         /*
 639          * Get the current subbuffer by applying the proper mask to
 640          * "offset", and looking up the subbuf location within the
 641          * source file buf.
 642          */
 643
 644         buf_size = layout->buf_size;
 645         subbuf_size = layout->subbuf_size;
 646         num_subbuf = layout->num_subbuf;
 647
 648         switch (layout->word_size) {
 649         case 4: commit_count_mask = 0xFFFFFFFFULL / num_subbuf;
 650                 break;
 651         case 8: commit_count_mask = 0xFFFFFFFFFFFFFFFFULL / num_subbuf;
 652                 break;
 653         default:
 654                 ERR("Unsupported word size: %u",
 655                         (unsigned int) layout->word_size);
 656                 return -EINVAL;
 657         }
 658
 659         DBG("Copy crash subbuffer at offset %" PRIu64, offset);
 660         sbidx = subbuf_index(offset, buf_size, subbuf_size);
 661
 662         /*
 663          * Find where the seq cc is located. Compute length of data to
 664          * copy.
 665          */
 666         seq_cc = crash_get_array_field(layout, buf, commit_hot_array,
 667                 sbidx, commit_hot_seq);
 668         consumed_cur = crash_get_field(layout, buf, consumed_offset);
 669
 670         /*
 671          * Check that the buffer we are getting is after or at
 672          * consumed_cur position.
 673          */
 674         if ((long) subbuf_trunc(offset, subbuf_size)
 675                         - (long) subbuf_trunc(consumed_cur, subbuf_size) < 0) {
 676                 DBG("No data: position is before consumed_cur");
 677                 goto nodata;
 678         }
 679
 680         /*
 681          * Check if subbuffer has been fully committed.
 682          */
 683         if (((seq_cc - subbuf_size) & commit_count_mask)
 684                         - (buf_trunc(offset, buf_size) / num_subbuf)
 685                         == 0) {
 686                 committed = subbuf_size;
 687         } else {
 688                 committed = subbuf_offset(seq_cc, subbuf_size);
 689                 if (!committed) {
 690                         DBG("No data committed, seq_cc: %" PRIu64, seq_cc);
 691                         goto nodata;
 692                 }
 693         }
 694
 695         /* Find actual physical offset in subbuffer table */
 696         id = crash_get_array_field(layout, buf, buf_wsb_array,
 697                 sbidx, buf_wsb_id);
 698         sb_bindex = subbuffer_id_get_index(layout->mode, id,
 699                 layout->word_size);
 700         rpages_offset = crash_get_array_field(layout, buf, sb_array,
 701                 sb_bindex, sb_array_shmp_offset);
 702         p_offset = crash_get_field(layout, buf + rpages_offset,
 703                 sb_backend_p_offset);
 704         subbuf_ptr = buf + p_offset;
 705
 706         if (committed == subbuf_size) {
 707                 /*
 708                  * Packet header can be used.
 709                  */
 710                 if (layout->length.packet_size) {
 711                         memcpy(&packet_size,
 712                                 subbuf_ptr + layout->offset.packet_size,
 713                                 layout->length.packet_size);
 714                         if (layout->reverse_byte_order) {
 715                                 packet_size = __bswap_64(packet_size);
 716                         }
 717                         packet_size /= CHAR_BIT;
 718                 } else {
 719                         packet_size = subbuf_size;
 720                 }
 721         } else {
 722                 uint64_t patch_size;
 723
 724                 /*
 725                  * Find where to patch the sub-buffer header with actual
 726                  * readable data len and packet len, derived from seq
 727                  * cc. Patch it in our in-memory copy.
 728                  */
 729                 patch_size = committed * CHAR_BIT;
 730                 if (layout->reverse_byte_order) {
 731                         patch_size = __bswap_64(patch_size);
 732                 }
 733                 if (layout->length.content_size) {
 734                         memcpy(subbuf_ptr + layout->offset.content_size,
 735                                 &patch_size, layout->length.content_size);
 736                 }
 737                 if (layout->length.packet_size) {
 738                         memcpy(subbuf_ptr + layout->offset.packet_size,
 739                                 &patch_size, layout->length.packet_size);
 740                 }
 741                 packet_size = committed;
 742         }
 743
 744         /*
 745          * Copy packet into fd_dest.
 746          */
 747         writelen = lttng_write(fd_dest, subbuf_ptr, packet_size);
 748         if (writelen < packet_size) {
 749                 PERROR("Error writing to output file");
 750                 return -1;
 751         }
 752         DBG("Copied %" PRIu64 " bytes of data", packet_size);
 753         return 0;
 754
 755 nodata:
 756         return -ENODATA;
 757 }
 758
 759 static
 760 int copy_crash_data(const struct lttng_crash_layout *layout, int fd_dest,
 761                 int fd_src)
 762 {
 763         char *buf;
 764         int ret = 0, has_data = 0;
 765         struct stat statbuf;
 766         size_t src_file_len;
 767         uint64_t prod_offset, consumed_offset;
 768         uint64_t offset, subbuf_size;
 769         ssize_t readlen;
 770
 771         ret = fstat(fd_src, &statbuf);
 772         if (ret) {
 773                 return ret;
 774         }
 775         src_file_len = layout->mmap_length;
 776         buf = zmalloc(src_file_len);
 777         if (!buf) {
 778                 return -1;
 779         }
 780         readlen = lttng_read(fd_src, buf, src_file_len);
 781         if (readlen < 0) {
 782                 PERROR("Error reading input file");
 783                 ret = -1;
 784                 goto end;
 785         }
 786
 787         prod_offset = crash_get_field(layout, buf, prod_offset);
 788         DBG("prod_offset: 0x%" PRIx64, prod_offset);
 789         consumed_offset = crash_get_field(layout, buf, consumed_offset);
 790         DBG("consumed_offset: 0x%" PRIx64, consumed_offset);
 791         subbuf_size = layout->subbuf_size;
 792
 793         for (offset = consumed_offset; offset < prod_offset;
 794                         offset += subbuf_size) {
 795                 ret = copy_crash_subbuf(layout, fd_dest, buf, offset);
 796                 if (!ret) {
 797                         has_data = 1;
 798                 }
 799                 if (ret) {
 800                         goto end;
 801                 }
 802         }
 803 end:
 804         free(buf);
 805         if (ret && ret != -ENODATA) {
 806                 return ret;
 807         }
 808         if (has_data) {
 809                 return 0;
 810         } else {
 811                 return -ENODATA;
 812         }
 813 }
 814
 815 static
 816 int extract_file(int output_dir_fd, const char *output_file,
 817                 int input_dir_fd, const char *input_file)
 818 {
 819         int fd_dest, fd_src, ret = 0, closeret;
 820         struct lttng_crash_layout layout;
 821
 822         layout.reverse_byte_order = 0;  /* For reading magic number */
 823
 824         DBG("Extract file '%s'", input_file);
 825         fd_src = openat(input_dir_fd, input_file, O_RDONLY);
 826         if (fd_src < 0) {
 827                 PERROR("Error opening '%s' for reading",
 828                         input_file);
 829                 ret = -1;
 830                 goto end;
 831         }
 832
 833         /* Query the crash ABI layout */
 834         ret = get_crash_layout(&layout, fd_src);
 835         if (ret) {
 836                 goto close_src;
 837         }
 838
 839         fd_dest = openat(output_dir_fd, output_file,
 840                         O_RDWR | O_CREAT | O_EXCL,
 841                         S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
 842         if (fd_dest < 0) {
 843                 PERROR("Error opening '%s' for writing",
 844                         output_file);
 845                 ret = -1;
 846                 goto close_src;
 847         }
 848
 849         ret = copy_crash_data(&layout, fd_dest, fd_src);
 850         if (ret) {
 851                 goto close_dest;
 852         }
 853
 854 close_dest:
 855         closeret = close(fd_dest);
 856         if (closeret) {
 857                 PERROR("close");
 858         }
 859         if (ret == -ENODATA) {
 860                 closeret = unlinkat(output_dir_fd, output_file, 0);
 861                 if (closeret) {
 862                         PERROR("unlinkat");
 863                 }
 864         }
 865 close_src:
 866         closeret = close(fd_src);
 867         if (closeret) {
 868                 PERROR("close");
 869         }
 870 end:
 871         return ret;
 872 }
 873
 874 static
 875 int extract_all_files(const char *output_path,
 876                 const char *input_path)
 877 {
 878         DIR *input_dir, *output_dir;
 879         int input_dir_fd, output_dir_fd, ret = 0, closeret;
 880         struct dirent *entry;   /* input */
 881
 882         /* Open input directory */
 883         input_dir = opendir(input_path);
 884         if (!input_dir) {
 885                 PERROR("Cannot open '%s' path", input_path);
 886                 return -1;
 887         }
 888         input_dir_fd = dirfd(input_dir);
 889         if (input_dir_fd < 0) {
 890                 PERROR("dirfd");
 891                 return -1;
 892         }
 893
 894         /* Open output directory */
 895         output_dir = opendir(output_path);
 896         if (!output_dir) {
 897                 PERROR("Cannot open '%s' path", output_path);
 898                 return -1;
 899         }
 900         output_dir_fd = dirfd(output_dir);
 901         if (output_dir_fd < 0) {
 902                 PERROR("dirfd");
 903                 return -1;
 904         }
 905
 906         while ((entry = readdir(input_dir))) {
 907                 if (!strcmp(entry->d_name, ".")
 908                                 || !strcmp(entry->d_name, ".."))
 909                         continue;
 910                 ret = extract_file(output_dir_fd, entry->d_name,
 911                         input_dir_fd, entry->d_name);
 912                 if (ret == -ENODATA) {
 913                         DBG("No data in file '%s', skipping", entry->d_name);
 914                         ret = 0;
 915                         continue;
 916                 } else if (ret < 0) {
 917                         break;
 918                 } else if (ret > 0) {
 919                         DBG("Skipping file '%s'", entry->d_name);
 920                         ret = 0;
 921                         continue;
 922                 }
 923         }
 924         closeret = closedir(output_dir);
 925         if (closeret) {
 926                 PERROR("closedir");
 927         }
 928         closeret = closedir(input_dir);
 929         if (closeret) {
 930                 PERROR("closedir");
 931         }
 932         return ret;
 933 }
 934
 935 static
 936 int extract_one_trace(const char *output_path,
 937                 const char *input_path)
 938 {
 939         char dest[PATH_MAX], src[PATH_MAX];
 940         int ret;
 941
 942         DBG("Extract crash trace '%s' into '%s'", input_path, output_path);
 943
 944         /* Copy metadata */
 945         strncpy(dest, output_path, PATH_MAX);
 946         dest[PATH_MAX - 1] = '\0';
 947         strncat(dest, "/metadata", PATH_MAX - strlen(dest) - 1);
 948
 949         strncpy(src, input_path, PATH_MAX);
 950         src[PATH_MAX - 1] = '\0';
 951         strncat(src, "/metadata", PATH_MAX - strlen(dest) - 1);
 952
 953         ret = copy_file(dest, src);
 954         if (ret) {
 955                 return ret;
 956         }
 957
 958         /* Extract each other file that has expected header */
 959         return extract_all_files(output_path, input_path);
 960 }
 961
 962 static
 963 int extract_trace_recursive(const char *output_path,
 964                 const char *input_path)
 965 {
 966         DIR *dir;
 967         int dir_fd, ret = 0, closeret;
 968         struct dirent *entry;
 969         size_t path_len;
 970         int has_warning = 0;
 971
 972         /* Open directory */
 973         dir = opendir(input_path);
 974         if (!dir) {
 975                 PERROR("Cannot open '%s' path", input_path);
 976                 return -1;
 977         }
 978
 979         path_len = strlen(input_path);
 980
 981         dir_fd = dirfd(dir);
 982         if (dir_fd < 0) {
 983                 PERROR("dirfd");
 984                 return -1;
 985         }
 986
 987         while ((entry = readdir(dir))) {
 988                 struct stat st;
 989                 size_t name_len;
 990                 char filename[PATH_MAX];
 991
 992                 if (!strcmp(entry->d_name, ".")
 993                                 || !strcmp(entry->d_name, "..")) {
 994                         continue;
 995                 }
 996
 997                 name_len = strlen(entry->d_name);
 998                 if (path_len + name_len + 2 > sizeof(filename)) {
 999                         ERR("Failed to remove file: path name too long (%s/%s)",
1000                                 input_path, entry->d_name);
1001                         continue;
1002                 }
1003
1004                 if (snprintf(filename, sizeof(filename), "%s/%s",
1005                                 input_path, entry->d_name) < 0) {
1006                         ERR("Failed to format path.");
1007                         continue;
1008                 }
1009
1010                 if (stat(filename, &st)) {
1011                         PERROR("stat");
1012                         continue;
1013                 }
1014
1015                 if (S_ISDIR(st.st_mode)) {
1016                         char output_subpath[PATH_MAX];
1017                         char input_subpath[PATH_MAX];
1018
1019                         strncpy(output_subpath, output_path,
1020                                 sizeof(output_subpath));
1021                         output_subpath[sizeof(output_subpath) - 1] = '\0';
1022                         strncat(output_subpath, "/",
1023                                 sizeof(output_subpath) - strlen(output_subpath) - 1);
1024                         strncat(output_subpath, entry->d_name,
1025                                 sizeof(output_subpath) - strlen(output_subpath) - 1);
1026
1027                         ret = mkdir(output_subpath, S_IRWXU | S_IRWXG);
1028                         if (ret) {
1029                                 PERROR("mkdir");
1030                                 has_warning = 1;
1031                                 goto end;
1032                         }
1033
1034                         strncpy(input_subpath, input_path,
1035                                 sizeof(input_subpath));
1036                         input_subpath[sizeof(input_subpath) - 1] = '\0';
1037                         strncat(input_subpath, "/",
1038                                 sizeof(input_subpath) - strlen(input_subpath) - 1);
1039                         strncat(input_subpath, entry->d_name,
1040                                 sizeof(input_subpath) - strlen(input_subpath) - 1);
1041
1042                         ret = extract_trace_recursive(output_subpath,
1043                                 input_subpath);
1044                         if (ret) {
1045                                 has_warning = 1;
1046                         }
1047                 } else if (S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)) {
1048                         if (!strcmp(entry->d_name, "metadata")) {
1049                                 ret = extract_one_trace(output_path,
1050                                         input_path);
1051                                 if (ret) {
1052                                         WARN("Error extracting trace '%s', continuing anyway.",
1053                                                 input_path);
1054                                         has_warning = 1;
1055                                 }
1056                         }
1057                 } else {
1058                         has_warning = 1;
1059                         goto end;
1060                 }
1061         }
1062 end:
1063         closeret = closedir(dir);
1064         if (closeret) {
1065                 PERROR("closedir");
1066         }
1067         return has_warning;
1068 }
1069
1070 static
1071 int delete_dir_recursive(const char *path)
1072 {
1073         DIR *dir;
1074         int dir_fd, ret = 0, closeret;
1075         size_t path_len;
1076         struct dirent *entry;
1077
1078         /* Open trace directory */
1079         dir = opendir(path);
1080         if (!dir) {
1081                 PERROR("Cannot open '%s' path", path);
1082                 ret = -errno;
1083                 goto end;
1084         }
1085
1086         path_len = strlen(path);
1087
1088         dir_fd = dirfd(dir);
1089         if (dir_fd < 0) {
1090                 PERROR("dirfd");
1091                 ret = -errno;
1092                 goto end;
1093         }
1094
1095         while ((entry = readdir(dir))) {
1096                 struct stat st;
1097                 size_t name_len;
1098                 char filename[PATH_MAX];
1099
1100                 if (!strcmp(entry->d_name, ".")
1101                                 || !strcmp(entry->d_name, "..")) {
1102                         continue;
1103                 }
1104
1105                 name_len = strlen(entry->d_name);
1106                 if (path_len + name_len + 2 > sizeof(filename)) {
1107                         ERR("Failed to remove file: path name too long (%s/%s)",
1108                                 path, entry->d_name);
1109                         continue;
1110                 }
1111
1112                 if (snprintf(filename, sizeof(filename), "%s/%s",
1113                                 path, entry->d_name) < 0) {
1114                         ERR("Failed to format path.");
1115                         continue;
1116                 }
1117
1118                 if (stat(filename, &st)) {
1119                         PERROR("stat");
1120                         continue;
1121                 }
1122
1123                 if (S_ISDIR(st.st_mode)) {
1124                         char *subpath = zmalloc(PATH_MAX);
1125
1126                         if (!subpath) {
1127                                 PERROR("zmalloc path");
1128                                 ret = -1;
1129                                 goto end;
1130                         }
1131                         strncpy(subpath, path, PATH_MAX);
1132                         subpath[PATH_MAX - 1] = '\0';
1133                         strncat(subpath, "/",
1134                                         PATH_MAX - strlen(subpath) - 1);
1135                         strncat(subpath, entry->d_name,
1136                                         PATH_MAX - strlen(subpath) - 1);
1137
1138                         ret = delete_dir_recursive(subpath);
1139                         free(subpath);
1140                         if (ret) {
1141                                 /* Error occurred, abort traversal. */
1142                                 goto end;
1143                         }
1144                 } else if (S_ISREG(st.st_mode)) {
1145                         ret = unlinkat(dir_fd, entry->d_name, 0);
1146                         if (ret) {
1147                                 PERROR("Unlinking '%s'", entry->d_name);
1148                                 goto end;
1149                         }
1150                 } else {
1151                         ret = -EINVAL;
1152                         goto end;
1153                 }
1154         }
1155 end:
1156         if (!ret) {
1157                 ret = rmdir(path);
1158                 if (ret) {
1159                         PERROR("rmdir '%s'", path);
1160                 }
1161         }
1162         closeret = closedir(dir);
1163         if (closeret) {
1164                 PERROR("closedir");
1165         }
1166         return ret;
1167 }
1168
1169 static
1170 int view_trace(const char *viewer_path, const char *trace_path)
1171 {
1172         pid_t pid;
1173
1174         pid = fork();
1175         if (pid < 0) {
1176                 /* Error */
1177                 PERROR("fork");
1178                 return -1;
1179         } else if (pid > 0) {
1180                 /* Parent */
1181                 int status;
1182
1183                 pid = waitpid(pid, &status, 0);
1184                 if (pid < 0 || !WIFEXITED(status)) {
1185                         return -1;
1186                 }
1187         } else {
1188                 /* Child */
1189                 int ret;
1190
1191                 ret = execlp(viewer_path, viewer_path,
1192                         trace_path, (char *) NULL);
1193                 if (ret) {
1194                         PERROR("execlp");
1195                         exit(EXIT_FAILURE);
1196                 }
1197                 exit(EXIT_SUCCESS);     /* Never reached */
1198         }
1199         return 0;
1200 }
1201
1202 /*
1203  *  main
1204  */
1205 int main(int argc, char *argv[])
1206 {
1207         int ret;
1208         bool has_warning = false;
1209         const char *output_path = NULL;
1210         char tmppath[] = "/tmp/lttng-crash-XXXXXX";
1211
1212         progname = argv[0] ? argv[0] : "lttng-crash";
1213
1214         ret = parse_args(argc, argv);
1215         if (ret > 0) {
1216                 goto end;
1217         } else if (ret < 0) {
1218                 has_warning = true;
1219                 goto end;
1220         }
1221
1222         if (opt_output_path) {
1223                 output_path = opt_output_path;
1224                 ret = mkdir(output_path, S_IRWXU | S_IRWXG);
1225                 if (ret) {
1226                         PERROR("mkdir");
1227                         has_warning = true;
1228                         goto end;
1229                 }
1230         } else {
1231                 output_path = mkdtemp(tmppath);
1232                 if (!output_path) {
1233                         PERROR("mkdtemp");
1234                         has_warning = true;
1235                         goto end;
1236                 }
1237         }
1238
1239         ret = extract_trace_recursive(output_path, input_path);
1240         if (ret < 0) {
1241                 has_warning = true;
1242                 goto end;
1243         } else if (ret > 0) {
1244                 /* extract_trace_recursive reported a warning. */
1245                 has_warning = true;
1246         }
1247         if (!opt_output_path) {
1248                 /* View trace */
1249                 ret = view_trace(opt_viewer_path, output_path);
1250                 if (ret) {
1251                         has_warning = true;
1252                 }
1253                 /* unlink temporary trace */
1254                 ret = delete_dir_recursive(output_path);
1255                 if (ret) {
1256                         has_warning = true;
1257                 }
1258         }
1259 end:
1260         exit(has_warning ? EXIT_FAILURE : EXIT_SUCCESS);
1261 }