bin: compile lttng-crash as a C++
authorSimon Marchi <simon.marchi@efficios.com>
Fri, 3 Sep 2021 21:31:29 +0000 (17:31 -0400)
committerJérémie Galarneau <jeremie.galarneau@efficios.com>
Wed, 17 Nov 2021 23:29:24 +0000 (18:29 -0500)
Same as the previous commits, but change lttng-crash to be a C++
program.

Change-Id: Ia487e12d2db07e2cd091637d38669289bcaff5d4
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
src/bin/lttng-crash/Makefile.am
src/bin/lttng-crash/lttng-crash.c [deleted file]
src/bin/lttng-crash/lttng-crash.cpp [new file with mode: 0644]

index 9c320bb151f171be9b7728f0033eb9aa71f05d67..b4231f3e99e739ca5a47bddd39987f918e0fab9c 100644 (file)
@@ -8,7 +8,7 @@ endif
 
 bin_PROGRAMS = lttng-crash
 
-lttng_crash_SOURCES = lttng-crash.c
+lttng_crash_SOURCES = lttng-crash.cpp
 
 lttng_crash_LDADD = $(top_builddir)/src/common/libcommon.la \
                        $(top_builddir)/src/common/config/libconfig.la
diff --git a/src/bin/lttng-crash/lttng-crash.c b/src/bin/lttng-crash/lttng-crash.c
deleted file mode 100644 (file)
index a4b6a93..0000000
+++ /dev/null
@@ -1,1269 +0,0 @@
-/*
- * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
- * Copyright (C) 2014 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * SPDX-License-Identifier: GPL-2.0-only
- *
- */
-
-#include <getopt.h>
-#include <signal.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/stat.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <sys/mman.h>
-#include <fcntl.h>
-#include <sys/wait.h>
-#include <unistd.h>
-#include <ctype.h>
-#include <dirent.h>
-#include <common/compat/endian.h>
-#include <inttypes.h>
-#include <stdbool.h>
-
-#include <version.h>
-#include <lttng/lttng.h>
-#include <common/common.h>
-#include <common/spawn-viewer.h>
-#include <common/utils.h>
-
-#define COPY_BUFLEN            4096
-#define RB_CRASH_DUMP_ABI_LEN  32
-
-#define RB_CRASH_DUMP_ABI_MAGIC_LEN    16
-
-/*
- * The 128-bit magic number is xor'd in the process data so it does not
- * cause a false positive when searching for buffers by scanning memory.
- * The actual magic number is:
- *   0x17, 0x7B, 0xF1, 0x77, 0xBF, 0x17, 0x7B, 0xF1,
- *   0x77, 0xBF, 0x17, 0x7B, 0xF1, 0x77, 0xBF, 0x17,
- */
-#define RB_CRASH_DUMP_ABI_MAGIC_XOR                                    \
-       {                                                               \
-               0x17 ^ 0xFF, 0x7B ^ 0xFF, 0xF1 ^ 0xFF, 0x77 ^ 0xFF,     \
-               0xBF ^ 0xFF, 0x17 ^ 0xFF, 0x7B ^ 0xFF, 0xF1 ^ 0xFF,     \
-               0x77 ^ 0xFF, 0xBF ^ 0xFF, 0x17 ^ 0xFF, 0x7B ^ 0xFF,     \
-               0xF1 ^ 0xFF, 0x77 ^ 0xFF, 0xBF ^ 0xFF, 0x17 ^ 0xFF,     \
-       }
-
-static const char *help_msg =
-#ifdef LTTNG_EMBED_HELP
-#include <lttng-crash.1.h>
-#else
-NULL
-#endif
-;
-
-/*
- * Non-static to ensure the compiler does not optimize away the xor.
- */
-uint8_t lttng_crash_expected_magic_xor[] = RB_CRASH_DUMP_ABI_MAGIC_XOR;
-
-#define RB_CRASH_ENDIAN                        0x1234
-#define RB_CRASH_ENDIAN_REVERSE                0x3412
-
-enum lttng_crash_type {
-       LTTNG_CRASH_TYPE_UST = 0,
-       LTTNG_CRASH_TYPE_KERNEL = 1,
-};
-
-/* LTTng ring buffer defines (copied) */
-
-#define HALF_ULONG_BITS(wl)    (((wl) * CHAR_BIT) >> 1)
-
-#define SB_ID_OFFSET_SHIFT(wl) (HALF_ULONG_BITS(wl) + 1)
-#define SB_ID_OFFSET_COUNT(wl) (1UL << SB_ID_OFFSET_SHIFT(wl))
-#define SB_ID_OFFSET_MASK(wl)  (~(SB_ID_OFFSET_COUNT(wl) - 1))
-/*
- * Lowest bit of top word half belongs to noref. Used only for overwrite mode.
- */
-#define SB_ID_NOREF_SHIFT(wl)  (SB_ID_OFFSET_SHIFT(wl) - 1)
-#define SB_ID_NOREF_COUNT(wl)  (1UL << SB_ID_NOREF_SHIFT(wl))
-#define SB_ID_NOREF_MASK(wl)   SB_ID_NOREF_COUNT(wl)
-/*
- * In overwrite mode: lowest half of word is used for index.
- * Limit of 2^16 subbuffers per buffer on 32-bit, 2^32 on 64-bit.
- * In producer-consumer mode: whole word used for index.
- */
-#define SB_ID_INDEX_SHIFT(wl)  0
-#define SB_ID_INDEX_COUNT(wl)  (1UL << SB_ID_INDEX_SHIFT(wl))
-#define SB_ID_INDEX_MASK(wl)   (SB_ID_NOREF_COUNT(wl) - 1)
-
-enum rb_modes {
-       RING_BUFFER_OVERWRITE = 0,      /* Overwrite when buffer full */
-       RING_BUFFER_DISCARD = 1,        /* Discard when buffer full */
-};
-
-struct crash_abi_unknown {
-       uint8_t magic[RB_CRASH_DUMP_ABI_MAGIC_LEN];
-       uint64_t mmap_length;   /* Overall length of crash record */
-       uint16_t endian;        /*
-                                * { 0x12, 0x34 }: big endian
-                                * { 0x34, 0x12 }: little endian
-                                */
-       uint16_t major;         /* Major number. */
-       uint16_t minor;         /* Minor number. */
-       uint8_t word_size;      /* Word size (bytes). */
-       uint8_t layout_type;    /* enum lttng_crash_layout */
-} __attribute__((packed));
-
-struct crash_abi_0_0 {
-       struct crash_abi_unknown parent;
-
-       struct {
-               uint32_t prod_offset;
-               uint32_t consumed_offset;
-               uint32_t commit_hot_array;
-               uint32_t commit_hot_seq;
-               uint32_t buf_wsb_array;
-               uint32_t buf_wsb_id;
-               uint32_t sb_array;
-               uint32_t sb_array_shmp_offset;
-               uint32_t sb_backend_p_offset;
-               uint32_t content_size;
-               uint32_t packet_size;
-       } __attribute__((packed)) offset;
-       struct {
-               uint8_t prod_offset;
-               uint8_t consumed_offset;
-               uint8_t commit_hot_seq;
-               uint8_t buf_wsb_id;
-               uint8_t sb_array_shmp_offset;
-               uint8_t sb_backend_p_offset;
-               uint8_t content_size;
-               uint8_t packet_size;
-       } __attribute__((packed)) length;
-       struct {
-               uint32_t commit_hot_array;
-               uint32_t buf_wsb_array;
-               uint32_t sb_array;
-       } __attribute__((packed)) stride;
-
-       uint64_t buf_size;      /* Size of the buffer */
-       uint64_t subbuf_size;   /* Sub-buffer size */
-       uint64_t num_subbuf;    /* Number of sub-buffers for writer */
-       uint32_t mode;          /* Buffer mode: 0: overwrite, 1: discard */
-} __attribute__((packed));
-
-struct lttng_crash_layout {
-       struct {
-               int prod_offset, consumed_offset,
-                       commit_hot_array, commit_hot_seq,
-                       buf_wsb_array, buf_wsb_id,
-                       sb_array, sb_array_shmp_offset,
-                       sb_backend_p_offset, content_size,
-                       packet_size;
-       } offset;
-       struct {
-               int prod_offset, consumed_offset,
-                       commit_hot_seq, buf_wsb_id,
-                       sb_array_shmp_offset, sb_backend_p_offset,
-                       content_size, packet_size;
-       } length;
-       struct {
-               int commit_hot_array, buf_wsb_array, sb_array;
-       } stride;
-
-       int reverse_byte_order;
-       int word_size;
-
-       uint64_t mmap_length;   /* Length of crash record */
-       uint64_t buf_size;      /* Size of the buffer */
-       uint64_t subbuf_size;   /* Sub-buffer size */
-       uint64_t num_subbuf;    /* Number of sub-buffers for writer */
-       uint32_t mode;          /* Buffer mode: 0: overwrite, 1: discard */
-};
-
-/* Variables */
-static const char *progname;
-static char *opt_viewer_path = NULL;
-static char *opt_output_path = NULL;
-
-static char *the_input_path;
-
-int lttng_opt_quiet, lttng_opt_verbose, lttng_opt_mi;
-
-enum {
-       OPT_DUMP_OPTIONS,
-};
-
-/* Getopt options. No first level command. */
-static struct option long_options[] = {
-       { "version",            0, NULL, 'V' },
-       { "help",               0, NULL, 'h' },
-       { "verbose",            0, NULL, 'v' },
-       { "viewer",             1, NULL, 'e' },
-       { "extract",            1, NULL, 'x' },
-       { "list-options",       0, NULL, OPT_DUMP_OPTIONS },
-       { NULL, 0, NULL, 0 },
-};
-
-static void usage(void)
-{
-       int ret = utils_show_help(1, "lttng-crash", help_msg);
-
-       if (ret) {
-               ERR("Cannot show --help for `lttng-crash`");
-               perror("exec");
-               exit(EXIT_FAILURE);
-       }
-}
-
-static void version(FILE *ofp)
-{
-       fprintf(ofp, "%s (LTTng Crash Trace Viewer) " VERSION " - " VERSION_NAME
-                       "%s%s\n",
-                       progname,
-                       GIT_VERSION[0] == '\0' ? "" : " - " GIT_VERSION,
-                       EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " EXTRA_VERSION_NAME);
-}
-
-/*
- *  list_options
- *
- *  List options line by line. This is mostly for bash auto completion and to
- *  avoid difficult parsing.
- */
-static void list_options(FILE *ofp)
-{
-       int i = 0;
-       struct option *option = NULL;
-
-       option = &long_options[i];
-       while (option->name != NULL) {
-               fprintf(ofp, "--%s\n", option->name);
-
-               if (isprint(option->val)) {
-                       fprintf(ofp, "-%c\n", option->val);
-               }
-
-               i++;
-               option = &long_options[i];
-       }
-}
-
-/*
- * Parse command line arguments.
- *
- * Return 0 if OK, else -1
- */
-static int parse_args(int argc, char **argv)
-{
-       int opt, ret = 0;
-
-       if (argc < 2) {
-               usage();
-               exit(EXIT_FAILURE);
-       }
-
-       while ((opt = getopt_long(argc, argv, "+Vhve:x:", long_options, NULL)) != -1) {
-               switch (opt) {
-               case 'V':
-                       version(stdout);
-                       ret = 1;
-                       goto end;
-               case 'h':
-                       usage();
-                       ret = 1;
-                       goto end;
-               case 'v':
-                       /* There is only 3 possible level of verbosity. (-vvv) */
-                       if (lttng_opt_verbose < 3) {
-                               lttng_opt_verbose += 1;
-                       }
-                       break;
-               case 'e':
-                       free(opt_viewer_path);
-                       opt_viewer_path = strdup(optarg);
-                       break;
-               case 'x':
-                       free(opt_output_path);
-                       opt_output_path = strdup(optarg);
-                       break;
-               case OPT_DUMP_OPTIONS:
-                       list_options(stdout);
-                       ret = 1;
-                       goto end;
-               default:
-                       ERR("Unknown command-line option");
-                       goto error;
-               }
-       }
-
-       /* No leftovers, or more than one input path, print usage and quit */
-       if (argc - optind != 1) {
-               ERR("Command-line error: Specify exactly one input path");
-               goto error;
-       }
-
-       the_input_path = argv[optind];
-end:
-       return ret;
-
-error:
-       return -1;
-}
-
-static
-int copy_file(const char *file_dest, const char *file_src)
-{
-       int fd_src = -1, fd_dest = -1;
-       ssize_t readlen, writelen;
-       char buf[COPY_BUFLEN];
-       int ret;
-
-       DBG("Copy metadata file '%s' into '%s'", file_src, file_dest);
-
-       fd_src = open(file_src, O_RDONLY);
-       if (fd_src < 0) {
-               PERROR("Error opening %s for reading", file_src);
-               ret = -errno;
-               goto error;
-       }
-       fd_dest = open(file_dest, O_RDWR | O_CREAT | O_EXCL,
-                       S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
-       if (fd_dest < 0) {
-               PERROR("Error opening %s for writing", file_dest);
-               ret = -errno;
-               goto error;
-       }
-
-       for (;;) {
-               readlen = lttng_read(fd_src, buf, COPY_BUFLEN);
-               if (readlen < 0) {
-                       PERROR("Error reading input file");
-                       ret = -1;
-                       goto error;
-               }
-               if (!readlen) {
-                       break;
-               }
-               writelen = lttng_write(fd_dest, buf, readlen);
-               if (writelen < readlen) {
-                       PERROR("Error writing to output file");
-                       ret = -1;
-                       goto error;
-               }
-       }
-
-       ret = 0;
-error:
-       if (fd_src >= 0) {
-               if (close(fd_src) < 0) {
-                       PERROR("Error closing %s", file_src);
-               }
-       }
-
-       if (fd_dest >= 0) {
-               if (close(fd_dest) < 0) {
-                       PERROR("Error closing %s", file_dest);
-               }
-       }
-       return ret;
-}
-
-static
-uint64_t _crash_get_field(const struct lttng_crash_layout *layout,
-               const char *ptr, size_t size)
-{
-       switch (size) {
-       case 1: return *(uint8_t *) ptr;
-       case 2: if (layout->reverse_byte_order) {
-                       return bswap_16(*(uint16_t *) ptr);
-               } else {
-                       return *(uint16_t *) ptr;
-
-               }
-       case 4: if (layout->reverse_byte_order) {
-                       return bswap_32(*(uint32_t *) ptr);
-               } else {
-                       return *(uint32_t *) ptr;
-
-               }
-       case 8: if (layout->reverse_byte_order) {
-                       return bswap_64(*(uint64_t *) ptr);
-               } else {
-                       return *(uint64_t *) ptr;
-               }
-       default:
-               abort();
-               return -1;
-       }
-
-}
-
-#define crash_get_field(layout, map, name)                             \
-       _crash_get_field(layout, (map) + (layout)->offset.name,         \
-               layout->length.name)
-
-#define crash_get_array_field(layout, map, array_name, idx, field_name)        \
-       _crash_get_field(layout,                                        \
-               (map) + (layout)->offset.array_name                     \
-                       + (idx * (layout)->stride.array_name)           \
-                       + (layout)->offset.field_name,                  \
-               (layout)->length.field_name)
-
-#define crash_get_hdr_raw_field(layout, hdr, name)     ((hdr)->name)
-
-#define crash_get_hdr_field(layout, hdr, name)                         \
-       _crash_get_field(layout, (const char *) &(hdr)->name,           \
-               sizeof((hdr)->name))
-
-#define crash_get_layout(layout, hdr, name)                            \
-       do {                                                            \
-               (layout)->name = crash_get_hdr_field(layout, hdr,       \
-                                       name);                          \
-               DBG("layout.%s = %" PRIu64, #name,                      \
-                       (uint64_t) (layout)->name);                     \
-       } while (0)
-
-static
-int get_crash_layout_0_0(struct lttng_crash_layout *layout,
-               char *map)
-{
-       const struct crash_abi_0_0 *abi = (const struct crash_abi_0_0 *) map;
-
-       crash_get_layout(layout, abi, offset.prod_offset);
-       crash_get_layout(layout, abi, offset.consumed_offset);
-       crash_get_layout(layout, abi, offset.commit_hot_array);
-       crash_get_layout(layout, abi, offset.commit_hot_seq);
-       crash_get_layout(layout, abi, offset.buf_wsb_array);
-       crash_get_layout(layout, abi, offset.buf_wsb_id);
-       crash_get_layout(layout, abi, offset.sb_array);
-       crash_get_layout(layout, abi, offset.sb_array_shmp_offset);
-       crash_get_layout(layout, abi, offset.sb_backend_p_offset);
-       crash_get_layout(layout, abi, offset.content_size);
-       crash_get_layout(layout, abi, offset.packet_size);
-
-       crash_get_layout(layout, abi, length.prod_offset);
-       crash_get_layout(layout, abi, length.consumed_offset);
-       crash_get_layout(layout, abi, length.commit_hot_seq);
-       crash_get_layout(layout, abi, length.buf_wsb_id);
-       crash_get_layout(layout, abi, length.sb_array_shmp_offset);
-       crash_get_layout(layout, abi, length.sb_backend_p_offset);
-       crash_get_layout(layout, abi, length.content_size);
-       crash_get_layout(layout, abi, length.packet_size);
-
-       crash_get_layout(layout, abi, stride.commit_hot_array);
-       crash_get_layout(layout, abi, stride.buf_wsb_array);
-       crash_get_layout(layout, abi, stride.sb_array);
-
-       crash_get_layout(layout, abi, buf_size);
-       crash_get_layout(layout, abi, subbuf_size);
-       crash_get_layout(layout, abi, num_subbuf);
-       crash_get_layout(layout, abi, mode);
-
-       return 0;
-}
-
-static
-void print_dbg_magic(const uint8_t *magic)
-{
-       DBG("magic: 0x%X%X%X%X%X%X%X%X%X%X%X%X%X%X%X%X",
-               magic[0], magic[1], magic[2], magic[3],
-               magic[4], magic[5], magic[6], magic[7],
-               magic[8], magic[9], magic[10], magic[11],
-               magic[12], magic[13], magic[14], magic[15]);
-}
-
-static
-int check_magic(const uint8_t *magic)
-{
-       int i;
-
-       for (i = 0; i < RB_CRASH_DUMP_ABI_MAGIC_LEN; i++) {
-               if ((magic[i] ^ 0xFF) != lttng_crash_expected_magic_xor[i]) {
-                       return -1;
-               }
-       }
-       return 0;
-}
-
-static
-int get_crash_layout(struct lttng_crash_layout *layout, int fd,
-               const char *input_file)
-{
-       char *map;
-       int ret = 0, unmapret;
-       const uint8_t *magic;
-       uint64_t mmap_length;
-       uint16_t major, minor;
-       uint8_t word_size;
-       const struct crash_abi_unknown *abi;
-       uint16_t endian;
-       enum lttng_crash_type layout_type;
-       struct stat stat;
-
-       ret = fstat(fd, &stat);
-       if (ret < 0) {
-               PERROR("Failed to fstat '%s'", input_file);
-               return -1;
-       }
-       if (stat.st_size < RB_CRASH_DUMP_ABI_LEN) {
-               ERR("File '%s' truncated: file length of %" PRIi64
-                               " bytes does not meet the minimal expected "
-                               "length of %d bytes",
-                               input_file, (int64_t) stat.st_size,
-                               RB_CRASH_DUMP_ABI_LEN);
-               return -1;
-       }
-       map = mmap(NULL, RB_CRASH_DUMP_ABI_LEN, PROT_READ, MAP_PRIVATE,
-               fd, 0);
-       if (map == MAP_FAILED) {
-               PERROR("Mapping file");
-               return -1;
-       }
-       abi = (const struct crash_abi_unknown *) map;
-       magic = crash_get_hdr_raw_field(layout, abi, magic);
-       print_dbg_magic(magic);
-       if (check_magic(magic)) {
-               DBG("Unknown magic number");
-               ret = 1;        /* positive return value, skip */
-               goto end;
-       }
-       endian = crash_get_hdr_field(layout, abi, endian);
-       switch (endian) {
-       case RB_CRASH_ENDIAN:
-               break;
-       case RB_CRASH_ENDIAN_REVERSE:
-               layout->reverse_byte_order = 1;
-               break;
-       default:
-               DBG("Unknown endianness value: 0x%X", (unsigned int) endian);
-               ret = 1;        /* positive return value, skip */
-               goto end;
-       }
-       layout_type = (enum lttng_crash_type) crash_get_hdr_field(layout, abi, layout_type);
-       switch (layout_type) {
-       case LTTNG_CRASH_TYPE_UST:
-               break;
-       case LTTNG_CRASH_TYPE_KERNEL:
-               ERR("lttng-modules buffer layout support not implemented");
-               ret = 1;        /* positive return value, skip */
-               goto end;
-       default:
-               ERR("Unknown layout type %u", (unsigned int) layout_type);
-               ret = 1;        /* positive return value, skip */
-               goto end;
-       }
-       mmap_length = crash_get_hdr_field(layout, abi, mmap_length);
-       DBG("mmap_length: %" PRIu64, mmap_length);
-       layout->mmap_length = mmap_length;
-       major = crash_get_hdr_field(layout, abi, major);
-       DBG("major: %u", major);
-       minor = crash_get_hdr_field(layout, abi, minor);
-       DBG("minor: %u", minor);
-       word_size = crash_get_hdr_field(layout, abi, word_size);
-       DBG("word_size: %u", word_size);
-       switch (major) {
-       case 0:
-               switch (minor) {
-               case 0:
-                       ret = get_crash_layout_0_0(layout, map);
-                       if (ret)
-                               goto end;
-                       break;
-               default:
-                       ret = -1;
-                       ERR("Unsupported crash ABI %u.%u\n", major, minor);
-                       goto end;
-               }
-               break;
-       default:
-               ERR("Unsupported crash ABI %u.%u\n", major, minor);
-               ret = -1;
-               goto end;
-       }
-       layout->word_size = word_size;
-end:
-       unmapret = munmap(map, RB_CRASH_DUMP_ABI_LEN);
-       if (unmapret) {
-               PERROR("munmap");
-       }
-       return ret;
-}
-
-/* buf_trunc mask selects only the buffer number. */
-static inline
-uint64_t buf_trunc(uint64_t offset, uint64_t buf_size)
-{
-       return offset & ~(buf_size - 1);
-}
-
-/* subbuf_trunc mask selects the subbuffer number. */
-static inline
-uint64_t subbuf_trunc(uint64_t offset, uint64_t subbuf_size)
-{
-       return offset & ~(subbuf_size - 1);
-}
-
-/* buf_offset mask selects only the offset within the current buffer. */
-static inline
-uint64_t buf_offset(uint64_t offset, uint64_t buf_size)
-{
-       return offset & (buf_size - 1);
-}
-
-/* subbuf_offset mask selects the offset within the current subbuffer. */
-static inline
-uint64_t subbuf_offset(uint64_t offset, uint64_t subbuf_size)
-{
-       return offset & (subbuf_size - 1);
-}
-
-/* subbuf_index returns the index of the current subbuffer within the buffer. */
-static inline
-uint64_t subbuf_index(uint64_t offset, uint64_t buf_size, uint64_t subbuf_size)
-{
-       return buf_offset(offset, buf_size) / subbuf_size;
-}
-
-static inline
-uint64_t subbuffer_id_get_index(uint32_t mode, uint64_t id,
-               unsigned int wl)
-{
-       if (mode == RING_BUFFER_OVERWRITE)
-               return id & SB_ID_INDEX_MASK(wl);
-       else
-               return id;
-}
-
-static
-int copy_crash_subbuf(const struct lttng_crash_layout *layout,
-               int fd_dest, char *buf, uint64_t offset)
-{
-       uint64_t buf_size, subbuf_size, num_subbuf, sbidx, id,
-               sb_bindex, rpages_offset, p_offset, seq_cc,
-               committed, commit_count_mask, consumed_cur,
-               packet_size;
-       char *subbuf_ptr;
-       ssize_t writelen;
-
-       /*
-        * Get the current subbuffer by applying the proper mask to
-        * "offset", and looking up the subbuf location within the
-        * source file buf.
-        */
-
-       buf_size = layout->buf_size;
-       subbuf_size = layout->subbuf_size;
-       num_subbuf = layout->num_subbuf;
-
-       switch (layout->word_size) {
-       case 4: commit_count_mask = 0xFFFFFFFFULL / num_subbuf;
-               break;
-       case 8: commit_count_mask = 0xFFFFFFFFFFFFFFFFULL / num_subbuf;
-               break;
-       default:
-               ERR("Unsupported word size: %u",
-                       (unsigned int) layout->word_size);
-               return -EINVAL;
-       }
-
-       DBG("Copy crash subbuffer at offset %" PRIu64, offset);
-       sbidx = subbuf_index(offset, buf_size, subbuf_size);
-
-       /*
-        * Find where the seq cc is located. Compute length of data to
-        * copy.
-        */
-       seq_cc = crash_get_array_field(layout, buf, commit_hot_array,
-               sbidx, commit_hot_seq);
-       consumed_cur = crash_get_field(layout, buf, consumed_offset);
-
-       /*
-        * Check that the buffer we are getting is after or at
-        * consumed_cur position.
-        */
-       if ((long) subbuf_trunc(offset, subbuf_size)
-                       - (long) subbuf_trunc(consumed_cur, subbuf_size) < 0) {
-               DBG("No data: position is before consumed_cur");
-               goto nodata;
-       }
-
-       /*
-        * Check if subbuffer has been fully committed.
-        */
-       if (((seq_cc - subbuf_size) & commit_count_mask)
-                       - (buf_trunc(offset, buf_size) / num_subbuf)
-                       == 0) {
-               committed = subbuf_size;
-       } else {
-               committed = subbuf_offset(seq_cc, subbuf_size);
-               if (!committed) {
-                       DBG("No data committed, seq_cc: %" PRIu64, seq_cc);
-                       goto nodata;
-               }
-       }
-
-       /* Find actual physical offset in subbuffer table */
-       id = crash_get_array_field(layout, buf, buf_wsb_array,
-               sbidx, buf_wsb_id);
-       sb_bindex = subbuffer_id_get_index(layout->mode, id,
-               layout->word_size);
-       rpages_offset = crash_get_array_field(layout, buf, sb_array,
-               sb_bindex, sb_array_shmp_offset);
-       p_offset = crash_get_field(layout, buf + rpages_offset,
-               sb_backend_p_offset);
-       subbuf_ptr = buf + p_offset;
-
-       if (committed == subbuf_size) {
-               /*
-                * Packet header can be used.
-                */
-               if (layout->length.packet_size) {
-                       memcpy(&packet_size,
-                               subbuf_ptr + layout->offset.packet_size,
-                               layout->length.packet_size);
-                       if (layout->reverse_byte_order) {
-                               packet_size = bswap_64(packet_size);
-                       }
-                       packet_size /= CHAR_BIT;
-               } else {
-                       packet_size = subbuf_size;
-               }
-       } else {
-               uint64_t patch_size;
-
-               /*
-                * Find where to patch the sub-buffer header with actual
-                * readable data len and packet len, derived from seq
-                * cc. Patch it in our in-memory copy.
-                */
-               patch_size = committed * CHAR_BIT;
-               if (layout->reverse_byte_order) {
-                       patch_size = bswap_64(patch_size);
-               }
-               if (layout->length.content_size) {
-                       memcpy(subbuf_ptr + layout->offset.content_size,
-                               &patch_size, layout->length.content_size);
-               }
-               if (layout->length.packet_size) {
-                       memcpy(subbuf_ptr + layout->offset.packet_size,
-                               &patch_size, layout->length.packet_size);
-               }
-               packet_size = committed;
-       }
-
-       /*
-        * Copy packet into fd_dest.
-        */
-       writelen = lttng_write(fd_dest, subbuf_ptr, packet_size);
-       if (writelen < packet_size) {
-               PERROR("Error writing to output file");
-               return -1;
-       }
-       DBG("Copied %" PRIu64 " bytes of data", packet_size);
-       return 0;
-
-nodata:
-       return -ENODATA;
-}
-
-static
-int copy_crash_data(const struct lttng_crash_layout *layout, int fd_dest,
-               int fd_src)
-{
-       char *buf;
-       int ret = 0, has_data = 0;
-       struct stat statbuf;
-       size_t src_file_len;
-       uint64_t prod_offset, consumed_offset;
-       uint64_t offset, subbuf_size;
-       ssize_t readlen;
-
-       ret = fstat(fd_src, &statbuf);
-       if (ret) {
-               return ret;
-       }
-       src_file_len = layout->mmap_length;
-       buf = zmalloc(src_file_len);
-       if (!buf) {
-               return -1;
-       }
-       readlen = lttng_read(fd_src, buf, src_file_len);
-       if (readlen < 0) {
-               PERROR("Error reading input file");
-               ret = -1;
-               goto end;
-       }
-
-       prod_offset = crash_get_field(layout, buf, prod_offset);
-       DBG("prod_offset: 0x%" PRIx64, prod_offset);
-       consumed_offset = crash_get_field(layout, buf, consumed_offset);
-       DBG("consumed_offset: 0x%" PRIx64, consumed_offset);
-       subbuf_size = layout->subbuf_size;
-
-       for (offset = consumed_offset; offset < prod_offset;
-                       offset += subbuf_size) {
-               ret = copy_crash_subbuf(layout, fd_dest, buf, offset);
-               if (!ret) {
-                       has_data = 1;
-               }
-               if (ret) {
-                       goto end;
-               }
-       }
-end:
-       free(buf);
-       if (ret && ret != -ENODATA) {
-               return ret;
-       }
-       if (has_data) {
-               return 0;
-       } else {
-               return -ENODATA;
-       }
-}
-
-static
-int extract_file(int output_dir_fd, const char *output_file,
-               int input_dir_fd, const char *input_file)
-{
-       int fd_dest, fd_src, ret = 0, closeret;
-       struct lttng_crash_layout layout;
-
-       layout.reverse_byte_order = 0;  /* For reading magic number */
-
-       DBG("Extract file '%s'", input_file);
-       fd_src = openat(input_dir_fd, input_file, O_RDONLY);
-       if (fd_src < 0) {
-               PERROR("Error opening '%s' for reading",
-                       input_file);
-               ret = -1;
-               goto end;
-       }
-
-       /* Query the crash ABI layout */
-       ret = get_crash_layout(&layout, fd_src, input_file);
-       if (ret) {
-               goto close_src;
-       }
-
-       fd_dest = openat(output_dir_fd, output_file,
-                       O_RDWR | O_CREAT | O_EXCL,
-                       S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
-       if (fd_dest < 0) {
-               PERROR("Error opening '%s' for writing",
-                       output_file);
-               ret = -1;
-               goto close_src;
-       }
-
-       ret = copy_crash_data(&layout, fd_dest, fd_src);
-       if (ret) {
-               goto close_dest;
-       }
-
-close_dest:
-       closeret = close(fd_dest);
-       if (closeret) {
-               PERROR("close");
-       }
-       if (ret == -ENODATA) {
-               closeret = unlinkat(output_dir_fd, output_file, 0);
-               if (closeret) {
-                       PERROR("unlinkat");
-               }
-       }
-close_src:
-       closeret = close(fd_src);
-       if (closeret) {
-               PERROR("close");
-       }
-end:
-       return ret;
-}
-
-static
-int extract_all_files(const char *output_path,
-               const char *input_path)
-{
-       DIR *input_dir, *output_dir;
-       int input_dir_fd, output_dir_fd, ret = 0, closeret;
-       struct dirent *entry;   /* input */
-
-       /* Open input directory */
-       input_dir = opendir(input_path);
-       if (!input_dir) {
-               PERROR("Cannot open '%s' path", input_path);
-               return -1;
-       }
-       input_dir_fd = dirfd(input_dir);
-       if (input_dir_fd < 0) {
-               PERROR("dirfd");
-               return -1;
-       }
-
-       /* Open output directory */
-       output_dir = opendir(output_path);
-       if (!output_dir) {
-               PERROR("Cannot open '%s' path", output_path);
-               return -1;
-       }
-       output_dir_fd = dirfd(output_dir);
-       if (output_dir_fd < 0) {
-               PERROR("dirfd");
-               return -1;
-       }
-
-       while ((entry = readdir(input_dir))) {
-               if (!strcmp(entry->d_name, ".")
-                               || !strcmp(entry->d_name, ".."))
-                       continue;
-               ret = extract_file(output_dir_fd, entry->d_name,
-                       input_dir_fd, entry->d_name);
-               if (ret == -ENODATA) {
-                       DBG("No data in file '%s', skipping", entry->d_name);
-                       ret = 0;
-                       continue;
-               } else if (ret < 0) {
-                       break;
-               } else if (ret > 0) {
-                       DBG("Skipping file '%s'", entry->d_name);
-                       ret = 0;
-                       continue;
-               }
-       }
-       closeret = closedir(output_dir);
-       if (closeret) {
-               PERROR("closedir");
-       }
-       closeret = closedir(input_dir);
-       if (closeret) {
-               PERROR("closedir");
-       }
-       return ret;
-}
-
-static
-int extract_one_trace(const char *output_path,
-               const char *input_path)
-{
-       char dest[PATH_MAX], src[PATH_MAX];
-       int ret;
-
-       DBG("Extract crash trace '%s' into '%s'", input_path, output_path);
-
-       /* Copy metadata */
-       strncpy(dest, output_path, PATH_MAX);
-       dest[PATH_MAX - 1] = '\0';
-       strncat(dest, "/metadata", PATH_MAX - strlen(dest) - 1);
-
-       strncpy(src, input_path, PATH_MAX);
-       src[PATH_MAX - 1] = '\0';
-       strncat(src, "/metadata", PATH_MAX - strlen(dest) - 1);
-
-       ret = copy_file(dest, src);
-       if (ret) {
-               return ret;
-       }
-
-       /* Extract each other file that has expected header */
-       return extract_all_files(output_path, input_path);
-}
-
-static
-int extract_trace_recursive(const char *output_path,
-               const char *input_path)
-{
-       DIR *dir;
-       int dir_fd, ret = 0, closeret;
-       struct dirent *entry;
-       size_t path_len;
-       int has_warning = 0;
-
-       /* Open directory */
-       dir = opendir(input_path);
-       if (!dir) {
-               PERROR("Cannot open '%s' path", input_path);
-               return -1;
-       }
-
-       path_len = strlen(input_path);
-
-       dir_fd = dirfd(dir);
-       if (dir_fd < 0) {
-               PERROR("dirfd");
-               return -1;
-       }
-
-       while ((entry = readdir(dir))) {
-               struct stat st;
-               size_t name_len;
-               char filename[PATH_MAX];
-
-               if (!strcmp(entry->d_name, ".")
-                               || !strcmp(entry->d_name, "..")) {
-                       continue;
-               }
-
-               name_len = strlen(entry->d_name);
-               if (path_len + name_len + 2 > sizeof(filename)) {
-                       ERR("Failed to remove file: path name too long (%s/%s)",
-                               input_path, entry->d_name);
-                       continue;
-               }
-
-               if (snprintf(filename, sizeof(filename), "%s/%s",
-                               input_path, entry->d_name) < 0) {
-                       ERR("Failed to format path.");
-                       continue;
-               }
-
-               if (stat(filename, &st)) {
-                       PERROR("stat");
-                       continue;
-               }
-
-               if (S_ISDIR(st.st_mode)) {
-                       char output_subpath[PATH_MAX];
-                       char input_subpath[PATH_MAX];
-
-                       strncpy(output_subpath, output_path,
-                               sizeof(output_subpath));
-                       output_subpath[sizeof(output_subpath) - 1] = '\0';
-                       strncat(output_subpath, "/",
-                               sizeof(output_subpath) - strlen(output_subpath) - 1);
-                       strncat(output_subpath, entry->d_name,
-                               sizeof(output_subpath) - strlen(output_subpath) - 1);
-
-                       ret = mkdir(output_subpath, S_IRWXU | S_IRWXG);
-                       if (ret) {
-                               PERROR("mkdir");
-                               has_warning = 1;
-                               goto end;
-                       }
-
-                       strncpy(input_subpath, input_path,
-                               sizeof(input_subpath));
-                       input_subpath[sizeof(input_subpath) - 1] = '\0';
-                       strncat(input_subpath, "/",
-                               sizeof(input_subpath) - strlen(input_subpath) - 1);
-                       strncat(input_subpath, entry->d_name,
-                               sizeof(input_subpath) - strlen(input_subpath) - 1);
-
-                       ret = extract_trace_recursive(output_subpath,
-                               input_subpath);
-                       if (ret) {
-                               has_warning = 1;
-                       }
-               } else if (S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)) {
-                       if (!strcmp(entry->d_name, "metadata")) {
-                               ret = extract_one_trace(output_path,
-                                       input_path);
-                               if (ret) {
-                                       WARN("Error extracting trace '%s', continuing anyway.",
-                                               input_path);
-                                       has_warning = 1;
-                               }
-                       }
-               } else {
-                       has_warning = 1;
-                       goto end;
-               }
-       }
-end:
-       closeret = closedir(dir);
-       if (closeret) {
-               PERROR("closedir");
-       }
-       return has_warning;
-}
-
-static
-int delete_dir_recursive(const char *path)
-{
-       DIR *dir;
-       int dir_fd, ret = 0, closeret;
-       size_t path_len;
-       struct dirent *entry;
-
-       /* Open trace directory */
-       dir = opendir(path);
-       if (!dir) {
-               PERROR("Cannot open '%s' path", path);
-               ret = -errno;
-               goto end_no_closedir;
-       }
-
-       path_len = strlen(path);
-
-       dir_fd = dirfd(dir);
-       if (dir_fd < 0) {
-               PERROR("dirfd");
-               ret = -errno;
-               goto end;
-       }
-
-       while ((entry = readdir(dir))) {
-               struct stat st;
-               size_t name_len;
-               char filename[PATH_MAX];
-
-               if (!strcmp(entry->d_name, ".")
-                               || !strcmp(entry->d_name, "..")) {
-                       continue;
-               }
-
-               name_len = strlen(entry->d_name);
-               if (path_len + name_len + 2 > sizeof(filename)) {
-                       ERR("Failed to remove file: path name too long (%s/%s)",
-                               path, entry->d_name);
-                       continue;
-               }
-
-               if (snprintf(filename, sizeof(filename), "%s/%s",
-                               path, entry->d_name) < 0) {
-                       ERR("Failed to format path.");
-                       continue;
-               }
-
-               if (stat(filename, &st)) {
-                       PERROR("stat");
-                       continue;
-               }
-
-               if (S_ISDIR(st.st_mode)) {
-                       char *subpath = zmalloc(PATH_MAX);
-
-                       if (!subpath) {
-                               PERROR("zmalloc path");
-                               ret = -1;
-                               goto end;
-                       }
-                       strncpy(subpath, path, PATH_MAX);
-                       subpath[PATH_MAX - 1] = '\0';
-                       strncat(subpath, "/",
-                                       PATH_MAX - strlen(subpath) - 1);
-                       strncat(subpath, entry->d_name,
-                                       PATH_MAX - strlen(subpath) - 1);
-
-                       ret = delete_dir_recursive(subpath);
-                       free(subpath);
-                       if (ret) {
-                               /* Error occurred, abort traversal. */
-                               goto end;
-                       }
-               } else if (S_ISREG(st.st_mode)) {
-                       ret = unlinkat(dir_fd, entry->d_name, 0);
-                       if (ret) {
-                               PERROR("Unlinking '%s'", entry->d_name);
-                               goto end;
-                       }
-               } else {
-                       ret = -EINVAL;
-                       goto end;
-               }
-       }
-end:
-       if (!ret) {
-               ret = rmdir(path);
-               if (ret) {
-                       PERROR("rmdir '%s'", path);
-               }
-       }
-       closeret = closedir(dir);
-       if (closeret) {
-               PERROR("closedir");
-       }
-end_no_closedir:
-       return ret;
-}
-
-static
-int view_trace(const char *trace_path, char *viewer_path)
-{
-       pid_t pid;
-
-       pid = fork();
-       if (pid < 0) {
-               /* Error */
-               PERROR("fork");
-               return -1;
-       } else if (pid > 0) {
-               /* Parent */
-               int status;
-
-               pid = waitpid(pid, &status, 0);
-               if (pid < 0 || !WIFEXITED(status)) {
-                       return -1;
-               }
-       } else {
-               /* Child */
-               int ret;
-
-               ret = spawn_viewer(trace_path, viewer_path, false);
-               if (ret) {
-                       exit(EXIT_FAILURE);
-               }
-               /* Never reached */
-               exit(EXIT_SUCCESS);
-       }
-       return 0;
-}
-
-/*
- *  main
- */
-int main(int argc, char *argv[])
-{
-       int ret;
-       bool has_warning = false;
-       const char *output_path = NULL;
-       char tmppath[] = "/tmp/lttng-crash-XXXXXX";
-
-       progname = argv[0] ? argv[0] : "lttng-crash";
-
-       ret = parse_args(argc, argv);
-       if (ret > 0) {
-               goto end;
-       } else if (ret < 0) {
-               has_warning = true;
-               goto end;
-       }
-
-       if (opt_output_path) {
-               output_path = opt_output_path;
-               ret = mkdir(output_path, S_IRWXU | S_IRWXG);
-               if (ret) {
-                       PERROR("mkdir");
-                       has_warning = true;
-                       goto end;
-               }
-       } else {
-               output_path = mkdtemp(tmppath);
-               if (!output_path) {
-                       PERROR("mkdtemp");
-                       has_warning = true;
-                       goto end;
-               }
-       }
-
-       ret = extract_trace_recursive(output_path, the_input_path);
-       if (ret < 0) {
-               has_warning = true;
-               goto end;
-       } else if (ret > 0) {
-               /* extract_trace_recursive reported a warning. */
-               has_warning = true;
-       }
-       if (!opt_output_path) {
-               /* View trace */
-               ret = view_trace(output_path, opt_viewer_path);
-               if (ret) {
-                       has_warning = true;
-               }
-               /* unlink temporary trace */
-               ret = delete_dir_recursive(output_path);
-               if (ret) {
-                       has_warning = true;
-               }
-       }
-end:
-       exit(has_warning ? EXIT_FAILURE : EXIT_SUCCESS);
-}
diff --git a/src/bin/lttng-crash/lttng-crash.cpp b/src/bin/lttng-crash/lttng-crash.cpp
new file mode 100644 (file)
index 0000000..3f5ea37
--- /dev/null
@@ -0,0 +1,1269 @@
+/*
+ * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
+ * Copyright (C) 2014 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-only
+ *
+ */
+
+#include <getopt.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <fcntl.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <ctype.h>
+#include <dirent.h>
+#include <common/compat/endian.h>
+#include <inttypes.h>
+#include <stdbool.h>
+
+#include <version.h>
+#include <lttng/lttng.h>
+#include <common/common.h>
+#include <common/spawn-viewer.h>
+#include <common/utils.h>
+
+#define COPY_BUFLEN            4096
+#define RB_CRASH_DUMP_ABI_LEN  32
+
+#define RB_CRASH_DUMP_ABI_MAGIC_LEN    16
+
+/*
+ * The 128-bit magic number is xor'd in the process data so it does not
+ * cause a false positive when searching for buffers by scanning memory.
+ * The actual magic number is:
+ *   0x17, 0x7B, 0xF1, 0x77, 0xBF, 0x17, 0x7B, 0xF1,
+ *   0x77, 0xBF, 0x17, 0x7B, 0xF1, 0x77, 0xBF, 0x17,
+ */
+#define RB_CRASH_DUMP_ABI_MAGIC_XOR                                    \
+       {                                                               \
+               0x17 ^ 0xFF, 0x7B ^ 0xFF, 0xF1 ^ 0xFF, 0x77 ^ 0xFF,     \
+               0xBF ^ 0xFF, 0x17 ^ 0xFF, 0x7B ^ 0xFF, 0xF1 ^ 0xFF,     \
+               0x77 ^ 0xFF, 0xBF ^ 0xFF, 0x17 ^ 0xFF, 0x7B ^ 0xFF,     \
+               0xF1 ^ 0xFF, 0x77 ^ 0xFF, 0xBF ^ 0xFF, 0x17 ^ 0xFF,     \
+       }
+
+static const char *help_msg =
+#ifdef LTTNG_EMBED_HELP
+#include <lttng-crash.1.h>
+#else
+NULL
+#endif
+;
+
+/*
+ * Non-static to ensure the compiler does not optimize away the xor.
+ */
+uint8_t lttng_crash_expected_magic_xor[] = RB_CRASH_DUMP_ABI_MAGIC_XOR;
+
+#define RB_CRASH_ENDIAN                        0x1234
+#define RB_CRASH_ENDIAN_REVERSE                0x3412
+
+enum lttng_crash_type {
+       LTTNG_CRASH_TYPE_UST = 0,
+       LTTNG_CRASH_TYPE_KERNEL = 1,
+};
+
+/* LTTng ring buffer defines (copied) */
+
+#define HALF_ULONG_BITS(wl)    (((wl) * CHAR_BIT) >> 1)
+
+#define SB_ID_OFFSET_SHIFT(wl) (HALF_ULONG_BITS(wl) + 1)
+#define SB_ID_OFFSET_COUNT(wl) (1UL << SB_ID_OFFSET_SHIFT(wl))
+#define SB_ID_OFFSET_MASK(wl)  (~(SB_ID_OFFSET_COUNT(wl) - 1))
+/*
+ * Lowest bit of top word half belongs to noref. Used only for overwrite mode.
+ */
+#define SB_ID_NOREF_SHIFT(wl)  (SB_ID_OFFSET_SHIFT(wl) - 1)
+#define SB_ID_NOREF_COUNT(wl)  (1UL << SB_ID_NOREF_SHIFT(wl))
+#define SB_ID_NOREF_MASK(wl)   SB_ID_NOREF_COUNT(wl)
+/*
+ * In overwrite mode: lowest half of word is used for index.
+ * Limit of 2^16 subbuffers per buffer on 32-bit, 2^32 on 64-bit.
+ * In producer-consumer mode: whole word used for index.
+ */
+#define SB_ID_INDEX_SHIFT(wl)  0
+#define SB_ID_INDEX_COUNT(wl)  (1UL << SB_ID_INDEX_SHIFT(wl))
+#define SB_ID_INDEX_MASK(wl)   (SB_ID_NOREF_COUNT(wl) - 1)
+
+enum rb_modes {
+       RING_BUFFER_OVERWRITE = 0,      /* Overwrite when buffer full */
+       RING_BUFFER_DISCARD = 1,        /* Discard when buffer full */
+};
+
+struct crash_abi_unknown {
+       uint8_t magic[RB_CRASH_DUMP_ABI_MAGIC_LEN];
+       uint64_t mmap_length;   /* Overall length of crash record */
+       uint16_t endian;        /*
+                                * { 0x12, 0x34 }: big endian
+                                * { 0x34, 0x12 }: little endian
+                                */
+       uint16_t major;         /* Major number. */
+       uint16_t minor;         /* Minor number. */
+       uint8_t word_size;      /* Word size (bytes). */
+       uint8_t layout_type;    /* enum lttng_crash_layout */
+} __attribute__((packed));
+
+struct crash_abi_0_0 {
+       struct crash_abi_unknown parent;
+
+       struct {
+               uint32_t prod_offset;
+               uint32_t consumed_offset;
+               uint32_t commit_hot_array;
+               uint32_t commit_hot_seq;
+               uint32_t buf_wsb_array;
+               uint32_t buf_wsb_id;
+               uint32_t sb_array;
+               uint32_t sb_array_shmp_offset;
+               uint32_t sb_backend_p_offset;
+               uint32_t content_size;
+               uint32_t packet_size;
+       } __attribute__((packed)) offset;
+       struct {
+               uint8_t prod_offset;
+               uint8_t consumed_offset;
+               uint8_t commit_hot_seq;
+               uint8_t buf_wsb_id;
+               uint8_t sb_array_shmp_offset;
+               uint8_t sb_backend_p_offset;
+               uint8_t content_size;
+               uint8_t packet_size;
+       } __attribute__((packed)) length;
+       struct {
+               uint32_t commit_hot_array;
+               uint32_t buf_wsb_array;
+               uint32_t sb_array;
+       } __attribute__((packed)) stride;
+
+       uint64_t buf_size;      /* Size of the buffer */
+       uint64_t subbuf_size;   /* Sub-buffer size */
+       uint64_t num_subbuf;    /* Number of sub-buffers for writer */
+       uint32_t mode;          /* Buffer mode: 0: overwrite, 1: discard */
+} __attribute__((packed));
+
+struct lttng_crash_layout {
+       struct {
+               int prod_offset, consumed_offset,
+                       commit_hot_array, commit_hot_seq,
+                       buf_wsb_array, buf_wsb_id,
+                       sb_array, sb_array_shmp_offset,
+                       sb_backend_p_offset, content_size,
+                       packet_size;
+       } offset;
+       struct {
+               int prod_offset, consumed_offset,
+                       commit_hot_seq, buf_wsb_id,
+                       sb_array_shmp_offset, sb_backend_p_offset,
+                       content_size, packet_size;
+       } length;
+       struct {
+               int commit_hot_array, buf_wsb_array, sb_array;
+       } stride;
+
+       int reverse_byte_order;
+       int word_size;
+
+       uint64_t mmap_length;   /* Length of crash record */
+       uint64_t buf_size;      /* Size of the buffer */
+       uint64_t subbuf_size;   /* Sub-buffer size */
+       uint64_t num_subbuf;    /* Number of sub-buffers for writer */
+       uint32_t mode;          /* Buffer mode: 0: overwrite, 1: discard */
+};
+
+/* Variables */
+static const char *progname;
+static char *opt_viewer_path = NULL;
+static char *opt_output_path = NULL;
+
+static char *the_input_path;
+
+int lttng_opt_quiet, lttng_opt_verbose, lttng_opt_mi;
+
+enum {
+       OPT_DUMP_OPTIONS,
+};
+
+/* Getopt options. No first level command. */
+static struct option long_options[] = {
+       { "version",            0, NULL, 'V' },
+       { "help",               0, NULL, 'h' },
+       { "verbose",            0, NULL, 'v' },
+       { "viewer",             1, NULL, 'e' },
+       { "extract",            1, NULL, 'x' },
+       { "list-options",       0, NULL, OPT_DUMP_OPTIONS },
+       { NULL, 0, NULL, 0 },
+};
+
+static void usage(void)
+{
+       int ret = utils_show_help(1, "lttng-crash", help_msg);
+
+       if (ret) {
+               ERR("Cannot show --help for `lttng-crash`");
+               perror("exec");
+               exit(EXIT_FAILURE);
+       }
+}
+
+static void version(FILE *ofp)
+{
+       fprintf(ofp, "%s (LTTng Crash Trace Viewer) " VERSION " - " VERSION_NAME
+                       "%s%s\n",
+                       progname,
+                       GIT_VERSION[0] == '\0' ? "" : " - " GIT_VERSION,
+                       EXTRA_VERSION_NAME[0] == '\0' ? "" : " - " EXTRA_VERSION_NAME);
+}
+
+/*
+ *  list_options
+ *
+ *  List options line by line. This is mostly for bash auto completion and to
+ *  avoid difficult parsing.
+ */
+static void list_options(FILE *ofp)
+{
+       int i = 0;
+       struct option *option = NULL;
+
+       option = &long_options[i];
+       while (option->name != NULL) {
+               fprintf(ofp, "--%s\n", option->name);
+
+               if (isprint(option->val)) {
+                       fprintf(ofp, "-%c\n", option->val);
+               }
+
+               i++;
+               option = &long_options[i];
+       }
+}
+
+/*
+ * Parse command line arguments.
+ *
+ * Return 0 if OK, else -1
+ */
+static int parse_args(int argc, char **argv)
+{
+       int opt, ret = 0;
+
+       if (argc < 2) {
+               usage();
+               exit(EXIT_FAILURE);
+       }
+
+       while ((opt = getopt_long(argc, argv, "+Vhve:x:", long_options, NULL)) != -1) {
+               switch (opt) {
+               case 'V':
+                       version(stdout);
+                       ret = 1;
+                       goto end;
+               case 'h':
+                       usage();
+                       ret = 1;
+                       goto end;
+               case 'v':
+                       /* There is only 3 possible level of verbosity. (-vvv) */
+                       if (lttng_opt_verbose < 3) {
+                               lttng_opt_verbose += 1;
+                       }
+                       break;
+               case 'e':
+                       free(opt_viewer_path);
+                       opt_viewer_path = strdup(optarg);
+                       break;
+               case 'x':
+                       free(opt_output_path);
+                       opt_output_path = strdup(optarg);
+                       break;
+               case OPT_DUMP_OPTIONS:
+                       list_options(stdout);
+                       ret = 1;
+                       goto end;
+               default:
+                       ERR("Unknown command-line option");
+                       goto error;
+               }
+       }
+
+       /* No leftovers, or more than one input path, print usage and quit */
+       if (argc - optind != 1) {
+               ERR("Command-line error: Specify exactly one input path");
+               goto error;
+       }
+
+       the_input_path = argv[optind];
+end:
+       return ret;
+
+error:
+       return -1;
+}
+
+static
+int copy_file(const char *file_dest, const char *file_src)
+{
+       int fd_src = -1, fd_dest = -1;
+       ssize_t readlen, writelen;
+       char buf[COPY_BUFLEN];
+       int ret;
+
+       DBG("Copy metadata file '%s' into '%s'", file_src, file_dest);
+
+       fd_src = open(file_src, O_RDONLY);
+       if (fd_src < 0) {
+               PERROR("Error opening %s for reading", file_src);
+               ret = -errno;
+               goto error;
+       }
+       fd_dest = open(file_dest, O_RDWR | O_CREAT | O_EXCL,
+                       S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
+       if (fd_dest < 0) {
+               PERROR("Error opening %s for writing", file_dest);
+               ret = -errno;
+               goto error;
+       }
+
+       for (;;) {
+               readlen = lttng_read(fd_src, buf, COPY_BUFLEN);
+               if (readlen < 0) {
+                       PERROR("Error reading input file");
+                       ret = -1;
+                       goto error;
+               }
+               if (!readlen) {
+                       break;
+               }
+               writelen = lttng_write(fd_dest, buf, readlen);
+               if (writelen < readlen) {
+                       PERROR("Error writing to output file");
+                       ret = -1;
+                       goto error;
+               }
+       }
+
+       ret = 0;
+error:
+       if (fd_src >= 0) {
+               if (close(fd_src) < 0) {
+                       PERROR("Error closing %s", file_src);
+               }
+       }
+
+       if (fd_dest >= 0) {
+               if (close(fd_dest) < 0) {
+                       PERROR("Error closing %s", file_dest);
+               }
+       }
+       return ret;
+}
+
+static
+uint64_t _crash_get_field(const struct lttng_crash_layout *layout,
+               const char *ptr, size_t size)
+{
+       switch (size) {
+       case 1: return *(uint8_t *) ptr;
+       case 2: if (layout->reverse_byte_order) {
+                       return bswap_16(*(uint16_t *) ptr);
+               } else {
+                       return *(uint16_t *) ptr;
+
+               }
+       case 4: if (layout->reverse_byte_order) {
+                       return bswap_32(*(uint32_t *) ptr);
+               } else {
+                       return *(uint32_t *) ptr;
+
+               }
+       case 8: if (layout->reverse_byte_order) {
+                       return bswap_64(*(uint64_t *) ptr);
+               } else {
+                       return *(uint64_t *) ptr;
+               }
+       default:
+               abort();
+               return -1;
+       }
+
+}
+
+#define crash_get_field(layout, map, name)                             \
+       _crash_get_field(layout, (map) + (layout)->offset.name,         \
+               layout->length.name)
+
+#define crash_get_array_field(layout, map, array_name, idx, field_name)        \
+       _crash_get_field(layout,                                        \
+               (map) + (layout)->offset.array_name                     \
+                       + (idx * (layout)->stride.array_name)           \
+                       + (layout)->offset.field_name,                  \
+               (layout)->length.field_name)
+
+#define crash_get_hdr_raw_field(layout, hdr, name)     ((hdr)->name)
+
+#define crash_get_hdr_field(layout, hdr, name)                         \
+       _crash_get_field(layout, (const char *) &(hdr)->name,           \
+               sizeof((hdr)->name))
+
+#define crash_get_layout(layout, hdr, name)                            \
+       do {                                                            \
+               (layout)->name = crash_get_hdr_field(layout, hdr,       \
+                                       name);                          \
+               DBG("layout.%s = %" PRIu64, #name,                      \
+                       (uint64_t) (layout)->name);                     \
+       } while (0)
+
+static
+int get_crash_layout_0_0(struct lttng_crash_layout *layout,
+               char *map)
+{
+       const struct crash_abi_0_0 *abi = (const struct crash_abi_0_0 *) map;
+
+       crash_get_layout(layout, abi, offset.prod_offset);
+       crash_get_layout(layout, abi, offset.consumed_offset);
+       crash_get_layout(layout, abi, offset.commit_hot_array);
+       crash_get_layout(layout, abi, offset.commit_hot_seq);
+       crash_get_layout(layout, abi, offset.buf_wsb_array);
+       crash_get_layout(layout, abi, offset.buf_wsb_id);
+       crash_get_layout(layout, abi, offset.sb_array);
+       crash_get_layout(layout, abi, offset.sb_array_shmp_offset);
+       crash_get_layout(layout, abi, offset.sb_backend_p_offset);
+       crash_get_layout(layout, abi, offset.content_size);
+       crash_get_layout(layout, abi, offset.packet_size);
+
+       crash_get_layout(layout, abi, length.prod_offset);
+       crash_get_layout(layout, abi, length.consumed_offset);
+       crash_get_layout(layout, abi, length.commit_hot_seq);
+       crash_get_layout(layout, abi, length.buf_wsb_id);
+       crash_get_layout(layout, abi, length.sb_array_shmp_offset);
+       crash_get_layout(layout, abi, length.sb_backend_p_offset);
+       crash_get_layout(layout, abi, length.content_size);
+       crash_get_layout(layout, abi, length.packet_size);
+
+       crash_get_layout(layout, abi, stride.commit_hot_array);
+       crash_get_layout(layout, abi, stride.buf_wsb_array);
+       crash_get_layout(layout, abi, stride.sb_array);
+
+       crash_get_layout(layout, abi, buf_size);
+       crash_get_layout(layout, abi, subbuf_size);
+       crash_get_layout(layout, abi, num_subbuf);
+       crash_get_layout(layout, abi, mode);
+
+       return 0;
+}
+
+static
+void print_dbg_magic(const uint8_t *magic)
+{
+       DBG("magic: 0x%X%X%X%X%X%X%X%X%X%X%X%X%X%X%X%X",
+               magic[0], magic[1], magic[2], magic[3],
+               magic[4], magic[5], magic[6], magic[7],
+               magic[8], magic[9], magic[10], magic[11],
+               magic[12], magic[13], magic[14], magic[15]);
+}
+
+static
+int check_magic(const uint8_t *magic)
+{
+       int i;
+
+       for (i = 0; i < RB_CRASH_DUMP_ABI_MAGIC_LEN; i++) {
+               if ((magic[i] ^ 0xFF) != lttng_crash_expected_magic_xor[i]) {
+                       return -1;
+               }
+       }
+       return 0;
+}
+
+static
+int get_crash_layout(struct lttng_crash_layout *layout, int fd,
+               const char *input_file)
+{
+       char *map;
+       int ret = 0, unmapret;
+       const uint8_t *magic;
+       uint64_t mmap_length;
+       uint16_t major, minor;
+       uint8_t word_size;
+       const struct crash_abi_unknown *abi;
+       uint16_t endian;
+       enum lttng_crash_type layout_type;
+       struct stat stat;
+
+       ret = fstat(fd, &stat);
+       if (ret < 0) {
+               PERROR("Failed to fstat '%s'", input_file);
+               return -1;
+       }
+       if (stat.st_size < RB_CRASH_DUMP_ABI_LEN) {
+               ERR("File '%s' truncated: file length of %" PRIi64
+                               " bytes does not meet the minimal expected "
+                               "length of %d bytes",
+                               input_file, (int64_t) stat.st_size,
+                               RB_CRASH_DUMP_ABI_LEN);
+               return -1;
+       }
+       map = (char *) mmap(NULL, RB_CRASH_DUMP_ABI_LEN, PROT_READ, MAP_PRIVATE,
+               fd, 0);
+       if (map == MAP_FAILED) {
+               PERROR("Mapping file");
+               return -1;
+       }
+       abi = (const struct crash_abi_unknown *) map;
+       magic = crash_get_hdr_raw_field(layout, abi, magic);
+       print_dbg_magic(magic);
+       if (check_magic(magic)) {
+               DBG("Unknown magic number");
+               ret = 1;        /* positive return value, skip */
+               goto end;
+       }
+       endian = crash_get_hdr_field(layout, abi, endian);
+       switch (endian) {
+       case RB_CRASH_ENDIAN:
+               break;
+       case RB_CRASH_ENDIAN_REVERSE:
+               layout->reverse_byte_order = 1;
+               break;
+       default:
+               DBG("Unknown endianness value: 0x%X", (unsigned int) endian);
+               ret = 1;        /* positive return value, skip */
+               goto end;
+       }
+       layout_type = (enum lttng_crash_type) crash_get_hdr_field(layout, abi, layout_type);
+       switch (layout_type) {
+       case LTTNG_CRASH_TYPE_UST:
+               break;
+       case LTTNG_CRASH_TYPE_KERNEL:
+               ERR("lttng-modules buffer layout support not implemented");
+               ret = 1;        /* positive return value, skip */
+               goto end;
+       default:
+               ERR("Unknown layout type %u", (unsigned int) layout_type);
+               ret = 1;        /* positive return value, skip */
+               goto end;
+       }
+       mmap_length = crash_get_hdr_field(layout, abi, mmap_length);
+       DBG("mmap_length: %" PRIu64, mmap_length);
+       layout->mmap_length = mmap_length;
+       major = crash_get_hdr_field(layout, abi, major);
+       DBG("major: %u", major);
+       minor = crash_get_hdr_field(layout, abi, minor);
+       DBG("minor: %u", minor);
+       word_size = crash_get_hdr_field(layout, abi, word_size);
+       DBG("word_size: %u", word_size);
+       switch (major) {
+       case 0:
+               switch (minor) {
+               case 0:
+                       ret = get_crash_layout_0_0(layout, map);
+                       if (ret)
+                               goto end;
+                       break;
+               default:
+                       ret = -1;
+                       ERR("Unsupported crash ABI %u.%u\n", major, minor);
+                       goto end;
+               }
+               break;
+       default:
+               ERR("Unsupported crash ABI %u.%u\n", major, minor);
+               ret = -1;
+               goto end;
+       }
+       layout->word_size = word_size;
+end:
+       unmapret = munmap(map, RB_CRASH_DUMP_ABI_LEN);
+       if (unmapret) {
+               PERROR("munmap");
+       }
+       return ret;
+}
+
+/* buf_trunc mask selects only the buffer number. */
+static inline
+uint64_t buf_trunc(uint64_t offset, uint64_t buf_size)
+{
+       return offset & ~(buf_size - 1);
+}
+
+/* subbuf_trunc mask selects the subbuffer number. */
+static inline
+uint64_t subbuf_trunc(uint64_t offset, uint64_t subbuf_size)
+{
+       return offset & ~(subbuf_size - 1);
+}
+
+/* buf_offset mask selects only the offset within the current buffer. */
+static inline
+uint64_t buf_offset(uint64_t offset, uint64_t buf_size)
+{
+       return offset & (buf_size - 1);
+}
+
+/* subbuf_offset mask selects the offset within the current subbuffer. */
+static inline
+uint64_t subbuf_offset(uint64_t offset, uint64_t subbuf_size)
+{
+       return offset & (subbuf_size - 1);
+}
+
+/* subbuf_index returns the index of the current subbuffer within the buffer. */
+static inline
+uint64_t subbuf_index(uint64_t offset, uint64_t buf_size, uint64_t subbuf_size)
+{
+       return buf_offset(offset, buf_size) / subbuf_size;
+}
+
+static inline
+uint64_t subbuffer_id_get_index(uint32_t mode, uint64_t id,
+               unsigned int wl)
+{
+       if (mode == RING_BUFFER_OVERWRITE)
+               return id & SB_ID_INDEX_MASK(wl);
+       else
+               return id;
+}
+
+static
+int copy_crash_subbuf(const struct lttng_crash_layout *layout,
+               int fd_dest, char *buf, uint64_t offset)
+{
+       uint64_t buf_size, subbuf_size, num_subbuf, sbidx, id,
+               sb_bindex, rpages_offset, p_offset, seq_cc,
+               committed, commit_count_mask, consumed_cur,
+               packet_size;
+       char *subbuf_ptr;
+       ssize_t writelen;
+
+       /*
+        * Get the current subbuffer by applying the proper mask to
+        * "offset", and looking up the subbuf location within the
+        * source file buf.
+        */
+
+       buf_size = layout->buf_size;
+       subbuf_size = layout->subbuf_size;
+       num_subbuf = layout->num_subbuf;
+
+       switch (layout->word_size) {
+       case 4: commit_count_mask = 0xFFFFFFFFULL / num_subbuf;
+               break;
+       case 8: commit_count_mask = 0xFFFFFFFFFFFFFFFFULL / num_subbuf;
+               break;
+       default:
+               ERR("Unsupported word size: %u",
+                       (unsigned int) layout->word_size);
+               return -EINVAL;
+       }
+
+       DBG("Copy crash subbuffer at offset %" PRIu64, offset);
+       sbidx = subbuf_index(offset, buf_size, subbuf_size);
+
+       /*
+        * Find where the seq cc is located. Compute length of data to
+        * copy.
+        */
+       seq_cc = crash_get_array_field(layout, buf, commit_hot_array,
+               sbidx, commit_hot_seq);
+       consumed_cur = crash_get_field(layout, buf, consumed_offset);
+
+       /*
+        * Check that the buffer we are getting is after or at
+        * consumed_cur position.
+        */
+       if ((long) subbuf_trunc(offset, subbuf_size)
+                       - (long) subbuf_trunc(consumed_cur, subbuf_size) < 0) {
+               DBG("No data: position is before consumed_cur");
+               goto nodata;
+       }
+
+       /*
+        * Check if subbuffer has been fully committed.
+        */
+       if (((seq_cc - subbuf_size) & commit_count_mask)
+                       - (buf_trunc(offset, buf_size) / num_subbuf)
+                       == 0) {
+               committed = subbuf_size;
+       } else {
+               committed = subbuf_offset(seq_cc, subbuf_size);
+               if (!committed) {
+                       DBG("No data committed, seq_cc: %" PRIu64, seq_cc);
+                       goto nodata;
+               }
+       }
+
+       /* Find actual physical offset in subbuffer table */
+       id = crash_get_array_field(layout, buf, buf_wsb_array,
+               sbidx, buf_wsb_id);
+       sb_bindex = subbuffer_id_get_index(layout->mode, id,
+               layout->word_size);
+       rpages_offset = crash_get_array_field(layout, buf, sb_array,
+               sb_bindex, sb_array_shmp_offset);
+       p_offset = crash_get_field(layout, buf + rpages_offset,
+               sb_backend_p_offset);
+       subbuf_ptr = buf + p_offset;
+
+       if (committed == subbuf_size) {
+               /*
+                * Packet header can be used.
+                */
+               if (layout->length.packet_size) {
+                       memcpy(&packet_size,
+                               subbuf_ptr + layout->offset.packet_size,
+                               layout->length.packet_size);
+                       if (layout->reverse_byte_order) {
+                               packet_size = bswap_64(packet_size);
+                       }
+                       packet_size /= CHAR_BIT;
+               } else {
+                       packet_size = subbuf_size;
+               }
+       } else {
+               uint64_t patch_size;
+
+               /*
+                * Find where to patch the sub-buffer header with actual
+                * readable data len and packet len, derived from seq
+                * cc. Patch it in our in-memory copy.
+                */
+               patch_size = committed * CHAR_BIT;
+               if (layout->reverse_byte_order) {
+                       patch_size = bswap_64(patch_size);
+               }
+               if (layout->length.content_size) {
+                       memcpy(subbuf_ptr + layout->offset.content_size,
+                               &patch_size, layout->length.content_size);
+               }
+               if (layout->length.packet_size) {
+                       memcpy(subbuf_ptr + layout->offset.packet_size,
+                               &patch_size, layout->length.packet_size);
+               }
+               packet_size = committed;
+       }
+
+       /*
+        * Copy packet into fd_dest.
+        */
+       writelen = lttng_write(fd_dest, subbuf_ptr, packet_size);
+       if (writelen < packet_size) {
+               PERROR("Error writing to output file");
+               return -1;
+       }
+       DBG("Copied %" PRIu64 " bytes of data", packet_size);
+       return 0;
+
+nodata:
+       return -ENODATA;
+}
+
+static
+int copy_crash_data(const struct lttng_crash_layout *layout, int fd_dest,
+               int fd_src)
+{
+       char *buf;
+       int ret = 0, has_data = 0;
+       struct stat statbuf;
+       size_t src_file_len;
+       uint64_t prod_offset, consumed_offset;
+       uint64_t offset, subbuf_size;
+       ssize_t readlen;
+
+       ret = fstat(fd_src, &statbuf);
+       if (ret) {
+               return ret;
+       }
+       src_file_len = layout->mmap_length;
+       buf = (char *) zmalloc(src_file_len);
+       if (!buf) {
+               return -1;
+       }
+       readlen = lttng_read(fd_src, buf, src_file_len);
+       if (readlen < 0) {
+               PERROR("Error reading input file");
+               ret = -1;
+               goto end;
+       }
+
+       prod_offset = crash_get_field(layout, buf, prod_offset);
+       DBG("prod_offset: 0x%" PRIx64, prod_offset);
+       consumed_offset = crash_get_field(layout, buf, consumed_offset);
+       DBG("consumed_offset: 0x%" PRIx64, consumed_offset);
+       subbuf_size = layout->subbuf_size;
+
+       for (offset = consumed_offset; offset < prod_offset;
+                       offset += subbuf_size) {
+               ret = copy_crash_subbuf(layout, fd_dest, buf, offset);
+               if (!ret) {
+                       has_data = 1;
+               }
+               if (ret) {
+                       goto end;
+               }
+       }
+end:
+       free(buf);
+       if (ret && ret != -ENODATA) {
+               return ret;
+       }
+       if (has_data) {
+               return 0;
+       } else {
+               return -ENODATA;
+       }
+}
+
+static
+int extract_file(int output_dir_fd, const char *output_file,
+               int input_dir_fd, const char *input_file)
+{
+       int fd_dest, fd_src, ret = 0, closeret;
+       struct lttng_crash_layout layout;
+
+       layout.reverse_byte_order = 0;  /* For reading magic number */
+
+       DBG("Extract file '%s'", input_file);
+       fd_src = openat(input_dir_fd, input_file, O_RDONLY);
+       if (fd_src < 0) {
+               PERROR("Error opening '%s' for reading",
+                       input_file);
+               ret = -1;
+               goto end;
+       }
+
+       /* Query the crash ABI layout */
+       ret = get_crash_layout(&layout, fd_src, input_file);
+       if (ret) {
+               goto close_src;
+       }
+
+       fd_dest = openat(output_dir_fd, output_file,
+                       O_RDWR | O_CREAT | O_EXCL,
+                       S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
+       if (fd_dest < 0) {
+               PERROR("Error opening '%s' for writing",
+                       output_file);
+               ret = -1;
+               goto close_src;
+       }
+
+       ret = copy_crash_data(&layout, fd_dest, fd_src);
+       if (ret) {
+               goto close_dest;
+       }
+
+close_dest:
+       closeret = close(fd_dest);
+       if (closeret) {
+               PERROR("close");
+       }
+       if (ret == -ENODATA) {
+               closeret = unlinkat(output_dir_fd, output_file, 0);
+               if (closeret) {
+                       PERROR("unlinkat");
+               }
+       }
+close_src:
+       closeret = close(fd_src);
+       if (closeret) {
+               PERROR("close");
+       }
+end:
+       return ret;
+}
+
+static
+int extract_all_files(const char *output_path,
+               const char *input_path)
+{
+       DIR *input_dir, *output_dir;
+       int input_dir_fd, output_dir_fd, ret = 0, closeret;
+       struct dirent *entry;   /* input */
+
+       /* Open input directory */
+       input_dir = opendir(input_path);
+       if (!input_dir) {
+               PERROR("Cannot open '%s' path", input_path);
+               return -1;
+       }
+       input_dir_fd = dirfd(input_dir);
+       if (input_dir_fd < 0) {
+               PERROR("dirfd");
+               return -1;
+       }
+
+       /* Open output directory */
+       output_dir = opendir(output_path);
+       if (!output_dir) {
+               PERROR("Cannot open '%s' path", output_path);
+               return -1;
+       }
+       output_dir_fd = dirfd(output_dir);
+       if (output_dir_fd < 0) {
+               PERROR("dirfd");
+               return -1;
+       }
+
+       while ((entry = readdir(input_dir))) {
+               if (!strcmp(entry->d_name, ".")
+                               || !strcmp(entry->d_name, ".."))
+                       continue;
+               ret = extract_file(output_dir_fd, entry->d_name,
+                       input_dir_fd, entry->d_name);
+               if (ret == -ENODATA) {
+                       DBG("No data in file '%s', skipping", entry->d_name);
+                       ret = 0;
+                       continue;
+               } else if (ret < 0) {
+                       break;
+               } else if (ret > 0) {
+                       DBG("Skipping file '%s'", entry->d_name);
+                       ret = 0;
+                       continue;
+               }
+       }
+       closeret = closedir(output_dir);
+       if (closeret) {
+               PERROR("closedir");
+       }
+       closeret = closedir(input_dir);
+       if (closeret) {
+               PERROR("closedir");
+       }
+       return ret;
+}
+
+static
+int extract_one_trace(const char *output_path,
+               const char *input_path)
+{
+       char dest[PATH_MAX], src[PATH_MAX];
+       int ret;
+
+       DBG("Extract crash trace '%s' into '%s'", input_path, output_path);
+
+       /* Copy metadata */
+       strncpy(dest, output_path, PATH_MAX);
+       dest[PATH_MAX - 1] = '\0';
+       strncat(dest, "/metadata", PATH_MAX - strlen(dest) - 1);
+
+       strncpy(src, input_path, PATH_MAX);
+       src[PATH_MAX - 1] = '\0';
+       strncat(src, "/metadata", PATH_MAX - strlen(dest) - 1);
+
+       ret = copy_file(dest, src);
+       if (ret) {
+               return ret;
+       }
+
+       /* Extract each other file that has expected header */
+       return extract_all_files(output_path, input_path);
+}
+
+static
+int extract_trace_recursive(const char *output_path,
+               const char *input_path)
+{
+       DIR *dir;
+       int dir_fd, ret = 0, closeret;
+       struct dirent *entry;
+       size_t path_len;
+       int has_warning = 0;
+
+       /* Open directory */
+       dir = opendir(input_path);
+       if (!dir) {
+               PERROR("Cannot open '%s' path", input_path);
+               return -1;
+       }
+
+       path_len = strlen(input_path);
+
+       dir_fd = dirfd(dir);
+       if (dir_fd < 0) {
+               PERROR("dirfd");
+               return -1;
+       }
+
+       while ((entry = readdir(dir))) {
+               struct stat st;
+               size_t name_len;
+               char filename[PATH_MAX];
+
+               if (!strcmp(entry->d_name, ".")
+                               || !strcmp(entry->d_name, "..")) {
+                       continue;
+               }
+
+               name_len = strlen(entry->d_name);
+               if (path_len + name_len + 2 > sizeof(filename)) {
+                       ERR("Failed to remove file: path name too long (%s/%s)",
+                               input_path, entry->d_name);
+                       continue;
+               }
+
+               if (snprintf(filename, sizeof(filename), "%s/%s",
+                               input_path, entry->d_name) < 0) {
+                       ERR("Failed to format path.");
+                       continue;
+               }
+
+               if (stat(filename, &st)) {
+                       PERROR("stat");
+                       continue;
+               }
+
+               if (S_ISDIR(st.st_mode)) {
+                       char output_subpath[PATH_MAX];
+                       char input_subpath[PATH_MAX];
+
+                       strncpy(output_subpath, output_path,
+                               sizeof(output_subpath));
+                       output_subpath[sizeof(output_subpath) - 1] = '\0';
+                       strncat(output_subpath, "/",
+                               sizeof(output_subpath) - strlen(output_subpath) - 1);
+                       strncat(output_subpath, entry->d_name,
+                               sizeof(output_subpath) - strlen(output_subpath) - 1);
+
+                       ret = mkdir(output_subpath, S_IRWXU | S_IRWXG);
+                       if (ret) {
+                               PERROR("mkdir");
+                               has_warning = 1;
+                               goto end;
+                       }
+
+                       strncpy(input_subpath, input_path,
+                               sizeof(input_subpath));
+                       input_subpath[sizeof(input_subpath) - 1] = '\0';
+                       strncat(input_subpath, "/",
+                               sizeof(input_subpath) - strlen(input_subpath) - 1);
+                       strncat(input_subpath, entry->d_name,
+                               sizeof(input_subpath) - strlen(input_subpath) - 1);
+
+                       ret = extract_trace_recursive(output_subpath,
+                               input_subpath);
+                       if (ret) {
+                               has_warning = 1;
+                       }
+               } else if (S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)) {
+                       if (!strcmp(entry->d_name, "metadata")) {
+                               ret = extract_one_trace(output_path,
+                                       input_path);
+                               if (ret) {
+                                       WARN("Error extracting trace '%s', continuing anyway.",
+                                               input_path);
+                                       has_warning = 1;
+                               }
+                       }
+               } else {
+                       has_warning = 1;
+                       goto end;
+               }
+       }
+end:
+       closeret = closedir(dir);
+       if (closeret) {
+               PERROR("closedir");
+       }
+       return has_warning;
+}
+
+static
+int delete_dir_recursive(const char *path)
+{
+       DIR *dir;
+       int dir_fd, ret = 0, closeret;
+       size_t path_len;
+       struct dirent *entry;
+
+       /* Open trace directory */
+       dir = opendir(path);
+       if (!dir) {
+               PERROR("Cannot open '%s' path", path);
+               ret = -errno;
+               goto end_no_closedir;
+       }
+
+       path_len = strlen(path);
+
+       dir_fd = dirfd(dir);
+       if (dir_fd < 0) {
+               PERROR("dirfd");
+               ret = -errno;
+               goto end;
+       }
+
+       while ((entry = readdir(dir))) {
+               struct stat st;
+               size_t name_len;
+               char filename[PATH_MAX];
+
+               if (!strcmp(entry->d_name, ".")
+                               || !strcmp(entry->d_name, "..")) {
+                       continue;
+               }
+
+               name_len = strlen(entry->d_name);
+               if (path_len + name_len + 2 > sizeof(filename)) {
+                       ERR("Failed to remove file: path name too long (%s/%s)",
+                               path, entry->d_name);
+                       continue;
+               }
+
+               if (snprintf(filename, sizeof(filename), "%s/%s",
+                               path, entry->d_name) < 0) {
+                       ERR("Failed to format path.");
+                       continue;
+               }
+
+               if (stat(filename, &st)) {
+                       PERROR("stat");
+                       continue;
+               }
+
+               if (S_ISDIR(st.st_mode)) {
+                       char *subpath = (char *) zmalloc(PATH_MAX);
+
+                       if (!subpath) {
+                               PERROR("zmalloc path");
+                               ret = -1;
+                               goto end;
+                       }
+                       strncpy(subpath, path, PATH_MAX);
+                       subpath[PATH_MAX - 1] = '\0';
+                       strncat(subpath, "/",
+                                       PATH_MAX - strlen(subpath) - 1);
+                       strncat(subpath, entry->d_name,
+                                       PATH_MAX - strlen(subpath) - 1);
+
+                       ret = delete_dir_recursive(subpath);
+                       free(subpath);
+                       if (ret) {
+                               /* Error occurred, abort traversal. */
+                               goto end;
+                       }
+               } else if (S_ISREG(st.st_mode)) {
+                       ret = unlinkat(dir_fd, entry->d_name, 0);
+                       if (ret) {
+                               PERROR("Unlinking '%s'", entry->d_name);
+                               goto end;
+                       }
+               } else {
+                       ret = -EINVAL;
+                       goto end;
+               }
+       }
+end:
+       if (!ret) {
+               ret = rmdir(path);
+               if (ret) {
+                       PERROR("rmdir '%s'", path);
+               }
+       }
+       closeret = closedir(dir);
+       if (closeret) {
+               PERROR("closedir");
+       }
+end_no_closedir:
+       return ret;
+}
+
+static
+int view_trace(const char *trace_path, char *viewer_path)
+{
+       pid_t pid;
+
+       pid = fork();
+       if (pid < 0) {
+               /* Error */
+               PERROR("fork");
+               return -1;
+       } else if (pid > 0) {
+               /* Parent */
+               int status;
+
+               pid = waitpid(pid, &status, 0);
+               if (pid < 0 || !WIFEXITED(status)) {
+                       return -1;
+               }
+       } else {
+               /* Child */
+               int ret;
+
+               ret = spawn_viewer(trace_path, viewer_path, false);
+               if (ret) {
+                       exit(EXIT_FAILURE);
+               }
+               /* Never reached */
+               exit(EXIT_SUCCESS);
+       }
+       return 0;
+}
+
+/*
+ *  main
+ */
+int main(int argc, char *argv[])
+{
+       int ret;
+       bool has_warning = false;
+       const char *output_path = NULL;
+       char tmppath[] = "/tmp/lttng-crash-XXXXXX";
+
+       progname = argv[0] ? argv[0] : "lttng-crash";
+
+       ret = parse_args(argc, argv);
+       if (ret > 0) {
+               goto end;
+       } else if (ret < 0) {
+               has_warning = true;
+               goto end;
+       }
+
+       if (opt_output_path) {
+               output_path = opt_output_path;
+               ret = mkdir(output_path, S_IRWXU | S_IRWXG);
+               if (ret) {
+                       PERROR("mkdir");
+                       has_warning = true;
+                       goto end;
+               }
+       } else {
+               output_path = mkdtemp(tmppath);
+               if (!output_path) {
+                       PERROR("mkdtemp");
+                       has_warning = true;
+                       goto end;
+               }
+       }
+
+       ret = extract_trace_recursive(output_path, the_input_path);
+       if (ret < 0) {
+               has_warning = true;
+               goto end;
+       } else if (ret > 0) {
+               /* extract_trace_recursive reported a warning. */
+               has_warning = true;
+       }
+       if (!opt_output_path) {
+               /* View trace */
+               ret = view_trace(output_path, opt_viewer_path);
+               if (ret) {
+                       has_warning = true;
+               }
+               /* unlink temporary trace */
+               ret = delete_dir_recursive(output_path);
+               if (ret) {
+                       has_warning = true;
+               }
+       }
+end:
+       exit(has_warning ? EXIT_FAILURE : EXIT_SUCCESS);
+}
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