diff options
Diffstat (limited to 'libbacktrace/macho.c')
| -rw-r--r-- | libbacktrace/macho.c | 1355 |
1 files changed, 1355 insertions, 0 deletions
diff --git a/libbacktrace/macho.c b/libbacktrace/macho.c new file mode 100644 index 0000000..66e101e --- /dev/null +++ b/libbacktrace/macho.c @@ -0,0 +1,1355 @@ +/* elf.c -- Get debug data from a Mach-O file for backtraces. + Copyright (C) 2020-2021 Free Software Foundation, Inc. + Written by Ian Lance Taylor, Google. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are +met: + + (1) Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + + (2) Redistributions in binary form must reproduce the above copyright + notice, this list of conditions and the following disclaimer in + the documentation and/or other materials provided with the + distribution. + + (3) The name of the author may not be used to + endorse or promote products derived from this software without + specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR +IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED +WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE +DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, +INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES +(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR +SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, +STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING +IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +POSSIBILITY OF SUCH DAMAGE. */ + +#include "config.h" + +#include <sys/types.h> +#include <dirent.h> +#include <stdlib.h> +#include <string.h> + +#ifdef HAVE_MACH_O_DYLD_H +#include <mach-o/dyld.h> +#endif + +#include "backtrace.h" +#include "internal.h" + +/* Mach-O file header for a 32-bit executable. */ + +struct macho_header_32 +{ + uint32_t magic; /* Magic number (MACH_O_MAGIC_32) */ + uint32_t cputype; /* CPU type */ + uint32_t cpusubtype; /* CPU subtype */ + uint32_t filetype; /* Type of file (object, executable) */ + uint32_t ncmds; /* Number of load commands */ + uint32_t sizeofcmds; /* Total size of load commands */ + uint32_t flags; /* Flags for special features */ +}; + +/* Mach-O file header for a 64-bit executable. */ + +struct macho_header_64 +{ + uint32_t magic; /* Magic number (MACH_O_MAGIC_64) */ + uint32_t cputype; /* CPU type */ + uint32_t cpusubtype; /* CPU subtype */ + uint32_t filetype; /* Type of file (object, executable) */ + uint32_t ncmds; /* Number of load commands */ + uint32_t sizeofcmds; /* Total size of load commands */ + uint32_t flags; /* Flags for special features */ + uint32_t reserved; /* Reserved */ +}; + +/* Mach-O file header for a fat executable. */ + +struct macho_header_fat +{ + uint32_t magic; /* Magic number (MACH_O_MH_(MAGIC|CIGAM)_FAT(_64)?) */ + uint32_t nfat_arch; /* Number of components */ +}; + +/* Values for the header magic field. */ + +#define MACH_O_MH_MAGIC_32 0xfeedface +#define MACH_O_MH_MAGIC_64 0xfeedfacf +#define MACH_O_MH_MAGIC_FAT 0xcafebabe +#define MACH_O_MH_CIGAM_FAT 0xbebafeca +#define MACH_O_MH_MAGIC_FAT_64 0xcafebabf +#define MACH_O_MH_CIGAM_FAT_64 0xbfbafeca + +/* Value for the header filetype field. */ + +#define MACH_O_MH_EXECUTE 0x02 +#define MACH_O_MH_DYLIB 0x06 +#define MACH_O_MH_DSYM 0x0a + +/* A component of a fat file. A fat file starts with a + macho_header_fat followed by nfat_arch instances of this + struct. */ + +struct macho_fat_arch +{ + uint32_t cputype; /* CPU type */ + uint32_t cpusubtype; /* CPU subtype */ + uint32_t offset; /* File offset of this entry */ + uint32_t size; /* Size of this entry */ + uint32_t align; /* Alignment of this entry */ +}; + +/* A component of a 64-bit fat file. This is used if the magic field + is MAGIC_FAT_64. This is only used when some file size or file + offset is too large to represent in the 32-bit format. */ + +struct macho_fat_arch_64 +{ + uint32_t cputype; /* CPU type */ + uint32_t cpusubtype; /* CPU subtype */ + uint64_t offset; /* File offset of this entry */ + uint64_t size; /* Size of this entry */ + uint32_t align; /* Alignment of this entry */ + uint32_t reserved; /* Reserved */ +}; + +/* Values for the fat_arch cputype field (and the header cputype + field). */ + +#define MACH_O_CPU_ARCH_ABI64 0x01000000 + +#define MACH_O_CPU_TYPE_X86 7 +#define MACH_O_CPU_TYPE_ARM 12 +#define MACH_O_CPU_TYPE_PPC 18 + +#define MACH_O_CPU_TYPE_X86_64 (MACH_O_CPU_TYPE_X86 | MACH_O_CPU_ARCH_ABI64) +#define MACH_O_CPU_TYPE_ARM64 (MACH_O_CPU_TYPE_ARM | MACH_O_CPU_ARCH_ABI64) +#define MACH_O_CPU_TYPE_PPC64 (MACH_O_CPU_TYPE_PPC | MACH_O_CPU_ARCH_ABI64) + +/* The header of a load command. */ + +struct macho_load_command +{ + uint32_t cmd; /* The type of load command */ + uint32_t cmdsize; /* Size in bytes of the entire command */ +}; + +/* Values for the load_command cmd field. */ + +#define MACH_O_LC_SEGMENT 0x01 +#define MACH_O_LC_SYMTAB 0x02 +#define MACH_O_LC_SEGMENT_64 0x19 +#define MACH_O_LC_UUID 0x1b + +/* The length of a section of segment name. */ + +#define MACH_O_NAMELEN (16) + +/* LC_SEGMENT load command. */ + +struct macho_segment_command +{ + uint32_t cmd; /* The type of load command (LC_SEGMENT) */ + uint32_t cmdsize; /* Size in bytes of the entire command */ + char segname[MACH_O_NAMELEN]; /* Segment name */ + uint32_t vmaddr; /* Virtual memory address */ + uint32_t vmsize; /* Virtual memory size */ + uint32_t fileoff; /* Offset of data to be mapped */ + uint32_t filesize; /* Size of data in file */ + uint32_t maxprot; /* Maximum permitted virtual protection */ + uint32_t initprot; /* Initial virtual memory protection */ + uint32_t nsects; /* Number of sections in this segment */ + uint32_t flags; /* Flags */ +}; + +/* LC_SEGMENT_64 load command. */ + +struct macho_segment_64_command +{ + uint32_t cmd; /* The type of load command (LC_SEGMENT) */ + uint32_t cmdsize; /* Size in bytes of the entire command */ + char segname[MACH_O_NAMELEN]; /* Segment name */ + uint64_t vmaddr; /* Virtual memory address */ + uint64_t vmsize; /* Virtual memory size */ + uint64_t fileoff; /* Offset of data to be mapped */ + uint64_t filesize; /* Size of data in file */ + uint32_t maxprot; /* Maximum permitted virtual protection */ + uint32_t initprot; /* Initial virtual memory protection */ + uint32_t nsects; /* Number of sections in this segment */ + uint32_t flags; /* Flags */ +}; + +/* LC_SYMTAB load command. */ + +struct macho_symtab_command +{ + uint32_t cmd; /* The type of load command (LC_SEGMENT) */ + uint32_t cmdsize; /* Size in bytes of the entire command */ + uint32_t symoff; /* File offset of symbol table */ + uint32_t nsyms; /* Number of symbols */ + uint32_t stroff; /* File offset of string table */ + uint32_t strsize; /* String table size */ +}; + +/* The length of a Mach-O uuid. */ + +#define MACH_O_UUID_LEN (16) + +/* LC_UUID load command. */ + +struct macho_uuid_command +{ + uint32_t cmd; /* Type of load command (LC_UUID) */ + uint32_t cmdsize; /* Size in bytes of command */ + unsigned char uuid[MACH_O_UUID_LEN]; /* UUID */ +}; + +/* 32-bit section header within a LC_SEGMENT segment. */ + +struct macho_section +{ + char sectname[MACH_O_NAMELEN]; /* Section name */ + char segment[MACH_O_NAMELEN]; /* Segment of this section */ + uint32_t addr; /* Address in memory */ + uint32_t size; /* Section size */ + uint32_t offset; /* File offset */ + uint32_t align; /* Log2 of section alignment */ + uint32_t reloff; /* File offset of relocations */ + uint32_t nreloc; /* Number of relocs for this section */ + uint32_t flags; /* Flags */ + uint32_t reserved1; + uint32_t reserved2; +}; + +/* 64-bit section header within a LC_SEGMENT_64 segment. */ + +struct macho_section_64 +{ + char sectname[MACH_O_NAMELEN]; /* Section name */ + char segment[MACH_O_NAMELEN]; /* Segment of this section */ + uint64_t addr; /* Address in memory */ + uint64_t size; /* Section size */ + uint32_t offset; /* File offset */ + uint32_t align; /* Log2 of section alignment */ + uint32_t reloff; /* File offset of section relocations */ + uint32_t nreloc; /* Number of relocs for this section */ + uint32_t flags; /* Flags */ + uint32_t reserved1; + uint32_t reserved2; + uint32_t reserved3; +}; + +/* 32-bit symbol data. */ + +struct macho_nlist +{ + uint32_t n_strx; /* Index of name in string table */ + uint8_t n_type; /* Type flag */ + uint8_t n_sect; /* Section number */ + uint16_t n_desc; /* Stabs description field */ + uint32_t n_value; /* Value */ +}; + +/* 64-bit symbol data. */ + +struct macho_nlist_64 +{ + uint32_t n_strx; /* Index of name in string table */ + uint8_t n_type; /* Type flag */ + uint8_t n_sect; /* Section number */ + uint16_t n_desc; /* Stabs description field */ + uint64_t n_value; /* Value */ +}; + +/* Value found in nlist n_type field. */ + +#define MACH_O_N_EXT 0x01 /* Extern symbol */ +#define MACH_O_N_ABS 0x02 /* Absolute symbol */ +#define MACH_O_N_SECT 0x0e /* Defined in section */ + +#define MACH_O_N_TYPE 0x0e /* Mask for type bits */ +#define MACH_O_N_STAB 0xe0 /* Stabs debugging symbol */ + +/* Information we keep for a Mach-O symbol. */ + +struct macho_symbol +{ + const char *name; /* Symbol name */ + uintptr_t address; /* Symbol address */ +}; + +/* Information to pass to macho_syminfo. */ + +struct macho_syminfo_data +{ + struct macho_syminfo_data *next; /* Next module */ + struct macho_symbol *symbols; /* Symbols sorted by address */ + size_t count; /* Number of symbols */ +}; + +/* Names of sections, indexed by enum dwarf_section in internal.h. */ + +static const char * const dwarf_section_names[DEBUG_MAX] = +{ + "__debug_info", + "__debug_line", + "__debug_abbrev", + "__debug_ranges", + "__debug_str", + "", /* DEBUG_ADDR */ + "__debug_str_offs", + "", /* DEBUG_LINE_STR */ + "__debug_rnglists" +}; + +/* Forward declaration. */ + +static int macho_add (struct backtrace_state *, const char *, int, off_t, + const unsigned char *, uintptr_t, int, + backtrace_error_callback, void *, fileline *, int *); + +/* A dummy callback function used when we can't find any debug info. */ + +static int +macho_nodebug (struct backtrace_state *state ATTRIBUTE_UNUSED, + uintptr_t pc ATTRIBUTE_UNUSED, + backtrace_full_callback callback ATTRIBUTE_UNUSED, + backtrace_error_callback error_callback, void *data) +{ + error_callback (data, "no debug info in Mach-O executable", -1); + return 0; +} + +/* A dummy callback function used when we can't find a symbol + table. */ + +static void +macho_nosyms (struct backtrace_state *state ATTRIBUTE_UNUSED, + uintptr_t addr ATTRIBUTE_UNUSED, + backtrace_syminfo_callback callback ATTRIBUTE_UNUSED, + backtrace_error_callback error_callback, void *data) +{ + error_callback (data, "no symbol table in Mach-O executable", -1); +} + +/* Add a single DWARF section to DWARF_SECTIONS, if we need the + section. Returns 1 on success, 0 on failure. */ + +static int +macho_add_dwarf_section (struct backtrace_state *state, int descriptor, + const char *sectname, uint32_t offset, uint64_t size, + backtrace_error_callback error_callback, void *data, + struct dwarf_sections *dwarf_sections) +{ + int i; + + for (i = 0; i < (int) DEBUG_MAX; ++i) + { + if (dwarf_section_names[i][0] != '\0' + && strncmp (sectname, dwarf_section_names[i], MACH_O_NAMELEN) == 0) + { + struct backtrace_view section_view; + + /* FIXME: Perhaps it would be better to try to use a single + view to read all the DWARF data, as we try to do for + ELF. */ + + if (!backtrace_get_view (state, descriptor, offset, size, + error_callback, data, §ion_view)) + return 0; + dwarf_sections->data[i] = (const unsigned char *) section_view.data; + dwarf_sections->size[i] = size; + break; + } + } + return 1; +} + +/* Collect DWARF sections from a DWARF segment. Returns 1 on success, + 0 on failure. */ + +static int +macho_add_dwarf_segment (struct backtrace_state *state, int descriptor, + off_t offset, unsigned int cmd, const char *psecs, + size_t sizesecs, unsigned int nsects, + backtrace_error_callback error_callback, void *data, + struct dwarf_sections *dwarf_sections) +{ + size_t sec_header_size; + size_t secoffset; + unsigned int i; + + switch (cmd) + { + case MACH_O_LC_SEGMENT: + sec_header_size = sizeof (struct macho_section); + break; + case MACH_O_LC_SEGMENT_64: + sec_header_size = sizeof (struct macho_section_64); + break; + default: + abort (); + } + + secoffset = 0; + for (i = 0; i < nsects; ++i) + { + if (secoffset + sec_header_size > sizesecs) + { + error_callback (data, "section overflow withing segment", 0); + return 0; + } + + switch (cmd) + { + case MACH_O_LC_SEGMENT: + { + struct macho_section section; + + memcpy (§ion, psecs + secoffset, sizeof section); + macho_add_dwarf_section (state, descriptor, section.sectname, + offset + section.offset, section.size, + error_callback, data, dwarf_sections); + } + break; + + case MACH_O_LC_SEGMENT_64: + { + struct macho_section_64 section; + + memcpy (§ion, psecs + secoffset, sizeof section); + macho_add_dwarf_section (state, descriptor, section.sectname, + offset + section.offset, section.size, + error_callback, data, dwarf_sections); + } + break; + + default: + abort (); + } + + secoffset += sec_header_size; + } + + return 1; +} + +/* Compare struct macho_symbol for qsort. */ + +static int +macho_symbol_compare (const void *v1, const void *v2) +{ + const struct macho_symbol *m1 = (const struct macho_symbol *) v1; + const struct macho_symbol *m2 = (const struct macho_symbol *) v2; + + if (m1->address < m2->address) + return -1; + else if (m1->address > m2->address) + return 1; + else + return 0; +} + +/* Compare an address against a macho_symbol for bsearch. We allocate + one extra entry in the array so that this can safely look at the + next entry. */ + +static int +macho_symbol_search (const void *vkey, const void *ventry) +{ + const uintptr_t *key = (const uintptr_t *) vkey; + const struct macho_symbol *entry = (const struct macho_symbol *) ventry; + uintptr_t addr; + + addr = *key; + if (addr < entry->address) + return -1; + else if (entry->name[0] == '\0' + && entry->address == ~(uintptr_t) 0) + return -1; + else if ((entry + 1)->name[0] == '\0' + && (entry + 1)->address == ~(uintptr_t) 0) + return -1; + else if (addr >= (entry + 1)->address) + return 1; + else + return 0; +} + +/* Return whether the symbol type field indicates a symbol table entry + that we care about: a function or data symbol. */ + +static int +macho_defined_symbol (uint8_t type) +{ + if ((type & MACH_O_N_STAB) != 0) + return 0; + if ((type & MACH_O_N_EXT) != 0) + return 0; + switch (type & MACH_O_N_TYPE) + { + case MACH_O_N_ABS: + return 1; + case MACH_O_N_SECT: + return 1; + default: + return 0; + } +} + +/* Add symbol table information for a Mach-O file. */ + +static int +macho_add_symtab (struct backtrace_state *state, int descriptor, + uintptr_t base_address, int is_64, + off_t symoff, unsigned int nsyms, off_t stroff, + unsigned int strsize, + backtrace_error_callback error_callback, void *data) +{ + size_t symsize; + struct backtrace_view sym_view; + int sym_view_valid; + struct backtrace_view str_view; + int str_view_valid; + size_t ndefs; + size_t symtaboff; + unsigned int i; + size_t macho_symbol_size; + struct macho_symbol *macho_symbols; + unsigned int j; + struct macho_syminfo_data *sdata; + + sym_view_valid = 0; + str_view_valid = 0; + macho_symbol_size = 0; + macho_symbols = NULL; + + if (is_64) + symsize = sizeof (struct macho_nlist_64); + else + symsize = sizeof (struct macho_nlist); + + if (!backtrace_get_view (state, descriptor, symoff, nsyms * symsize, + error_callback, data, &sym_view)) + goto fail; + sym_view_valid = 1; + + if (!backtrace_get_view (state, descriptor, stroff, strsize, + error_callback, data, &str_view)) + return 0; + str_view_valid = 1; + + ndefs = 0; + symtaboff = 0; + for (i = 0; i < nsyms; ++i, symtaboff += symsize) + { + if (is_64) + { + struct macho_nlist_64 nlist; + + memcpy (&nlist, (const char *) sym_view.data + symtaboff, + sizeof nlist); + if (macho_defined_symbol (nlist.n_type)) + ++ndefs; + } + else + { + struct macho_nlist nlist; + + memcpy (&nlist, (const char *) sym_view.data + symtaboff, + sizeof nlist); + if (macho_defined_symbol (nlist.n_type)) + ++ndefs; + } + } + + /* Add 1 to ndefs to make room for a sentinel. */ + macho_symbol_size = (ndefs + 1) * sizeof (struct macho_symbol); + macho_symbols = ((struct macho_symbol *) + backtrace_alloc (state, macho_symbol_size, error_callback, + data)); + if (macho_symbols == NULL) + goto fail; + + j = 0; + symtaboff = 0; + for (i = 0; i < nsyms; ++i, symtaboff += symsize) + { + uint32_t strx; + uint64_t value; + const char *name; + + strx = 0; + value = 0; + if (is_64) + { + struct macho_nlist_64 nlist; + + memcpy (&nlist, (const char *) sym_view.data + symtaboff, + sizeof nlist); + if (!macho_defined_symbol (nlist.n_type)) + continue; + + strx = nlist.n_strx; + value = nlist.n_value; + } + else + { + struct macho_nlist nlist; + + memcpy (&nlist, (const char *) sym_view.data + symtaboff, + sizeof nlist); + if (!macho_defined_symbol (nlist.n_type)) + continue; + + strx = nlist.n_strx; + value = nlist.n_value; + } + + if (strx >= strsize) + { + error_callback (data, "symbol string index out of range", 0); + goto fail; + } + + name = (const char *) str_view.data + strx; + if (name[0] == '_') + ++name; + macho_symbols[j].name = name; + macho_symbols[j].address = value + base_address; + ++j; + } + + sdata = ((struct macho_syminfo_data *) + backtrace_alloc (state, sizeof *sdata, error_callback, data)); + if (sdata == NULL) + goto fail; + + /* We need to keep the string table since it holds the names, but we + can release the symbol table. */ + + backtrace_release_view (state, &sym_view, error_callback, data); + sym_view_valid = 0; + str_view_valid = 0; + + /* Add a trailing sentinel symbol. */ + macho_symbols[j].name = ""; + macho_symbols[j].address = ~(uintptr_t) 0; + + backtrace_qsort (macho_symbols, ndefs + 1, sizeof (struct macho_symbol), + macho_symbol_compare); + + sdata->next = NULL; + sdata->symbols = macho_symbols; + sdata->count = ndefs; + + if (!state->threaded) + { + struct macho_syminfo_data **pp; + + for (pp = (struct macho_syminfo_data **) (void *) &state->syminfo_data; + *pp != NULL; + pp = &(*pp)->next) + ; + *pp = sdata; + } + else + { + while (1) + { + struct macho_syminfo_data **pp; + + pp = (struct macho_syminfo_data **) (void *) &state->syminfo_data; + + while (1) + { + struct macho_syminfo_data *p; + + p = backtrace_atomic_load_pointer (pp); + + if (p == NULL) + break; + + pp = &p->next; + } + + if (__sync_bool_compare_and_swap (pp, NULL, sdata)) + break; + } + } + + return 1; + + fail: + if (macho_symbols != NULL) + backtrace_free (state, macho_symbols, macho_symbol_size, + error_callback, data); + if (sym_view_valid) + backtrace_release_view (state, &sym_view, error_callback, data); + if (str_view_valid) + backtrace_release_view (state, &str_view, error_callback, data); + return 0; +} + +/* Return the symbol name and value for an ADDR. */ + +static void +macho_syminfo (struct backtrace_state *state, uintptr_t addr, + backtrace_syminfo_callback callback, + backtrace_error_callback error_callback ATTRIBUTE_UNUSED, + void *data) +{ + struct macho_syminfo_data *sdata; + struct macho_symbol *sym; + + sym = NULL; + if (!state->threaded) + { + for (sdata = (struct macho_syminfo_data *) state->syminfo_data; + sdata != NULL; + sdata = sdata->next) + { + sym = ((struct macho_symbol *) + bsearch (&addr, sdata->symbols, sdata->count, + sizeof (struct macho_symbol), macho_symbol_search)); + if (sym != NULL) + break; + } + } + else + { + struct macho_syminfo_data **pp; + + pp = (struct macho_syminfo_data **) (void *) &state->syminfo_data; + while (1) + { + sdata = backtrace_atomic_load_pointer (pp); + if (sdata == NULL) + break; + + sym = ((struct macho_symbol *) + bsearch (&addr, sdata->symbols, sdata->count, + sizeof (struct macho_symbol), macho_symbol_search)); + if (sym != NULL) + break; + + pp = &sdata->next; + } + } + + if (sym == NULL) + callback (data, addr, NULL, 0, 0); + else + callback (data, addr, sym->name, sym->address, 0); +} + +/* Look through a fat file to find the relevant executable. Returns 1 + on success, 0 on failure (in both cases descriptor is closed). */ + +static int +macho_add_fat (struct backtrace_state *state, const char *filename, + int descriptor, int swapped, off_t offset, + const unsigned char *match_uuid, uintptr_t base_address, + int skip_symtab, uint32_t nfat_arch, int is_64, + backtrace_error_callback error_callback, void *data, + fileline *fileline_fn, int *found_sym) +{ + int arch_view_valid; + unsigned int cputype; + size_t arch_size; + struct backtrace_view arch_view; + unsigned int i; + + arch_view_valid = 0; + +#if defined (__x86_64__) + cputype = MACH_O_CPU_TYPE_X86_64; +#elif defined (__i386__) + cputype = MACH_O_CPU_TYPE_X86; +#elif defined (__aarch64__) + cputype = MACH_O_CPU_TYPE_ARM64; +#elif defined (__arm__) + cputype = MACH_O_CPU_TYPE_ARM; +#elif defined (__ppc__) + cputype = MACH_O_CPU_TYPE_PPC; +#elif defined (__ppc64__) + cputype = MACH_O_CPU_TYPE_PPC64; +#else + error_callback (data, "unknown Mach-O architecture", 0); + goto fail; +#endif + + if (is_64) + arch_size = sizeof (struct macho_fat_arch_64); + else + arch_size = sizeof (struct macho_fat_arch); + + if (!backtrace_get_view (state, descriptor, offset, + nfat_arch * arch_size, + error_callback, data, &arch_view)) + goto fail; + + for (i = 0; i < nfat_arch; ++i) + { + uint32_t fcputype; + uint64_t foffset; + + if (is_64) + { + struct macho_fat_arch_64 fat_arch_64; + + memcpy (&fat_arch_64, + (const char *) arch_view.data + i * arch_size, + arch_size); + fcputype = fat_arch_64.cputype; + foffset = fat_arch_64.offset; + if (swapped) + { + fcputype = __builtin_bswap32 (fcputype); + foffset = __builtin_bswap64 (foffset); + } + } + else + { + struct macho_fat_arch fat_arch_32; + + memcpy (&fat_arch_32, + (const char *) arch_view.data + i * arch_size, + arch_size); + fcputype = fat_arch_32.cputype; + foffset = (uint64_t) fat_arch_32.offset; + if (swapped) + { + fcputype = __builtin_bswap32 (fcputype); + foffset = (uint64_t) __builtin_bswap32 ((uint32_t) foffset); + } + } + + if (fcputype == cputype) + { + /* FIXME: What about cpusubtype? */ + backtrace_release_view (state, &arch_view, error_callback, data); + return macho_add (state, filename, descriptor, foffset, match_uuid, + base_address, skip_symtab, error_callback, data, + fileline_fn, found_sym); + } + } + + error_callback (data, "could not find executable in fat file", 0); + + fail: + if (arch_view_valid) + backtrace_release_view (state, &arch_view, error_callback, data); + if (descriptor != -1) + backtrace_close (descriptor, error_callback, data); + return 0; +} + +/* Look for the dsym file for FILENAME. This is called if FILENAME + does not have debug info or a symbol table. Returns 1 on success, + 0 on failure. */ + +static int +macho_add_dsym (struct backtrace_state *state, const char *filename, + uintptr_t base_address, const unsigned char *uuid, + backtrace_error_callback error_callback, void *data, + fileline* fileline_fn) +{ + const char *p; + const char *dirname; + char *diralc; + size_t dirnamelen; + const char *basename; + size_t basenamelen; + const char *dsymsuffixdir; + size_t dsymsuffixdirlen; + size_t dsymlen; + char *dsym; + char *ps; + int d; + int does_not_exist; + int dummy_found_sym; + + diralc = NULL; + dirnamelen = 0; + dsym = NULL; + dsymlen = 0; + + p = strrchr (filename, '/'); + if (p == NULL) + { + dirname = "."; + dirnamelen = 1; + basename = filename; + basenamelen = strlen (basename); + diralc = NULL; + } + else + { + dirnamelen = p - filename; + diralc = backtrace_alloc (state, dirnamelen + 1, error_callback, data); + if (diralc == NULL) + goto fail; + memcpy (diralc, filename, dirnamelen); + diralc[dirnamelen] = '\0'; + dirname = diralc; + basename = p + 1; + basenamelen = strlen (basename); + } + + dsymsuffixdir = ".dSYM/Contents/Resources/DWARF/"; + dsymsuffixdirlen = strlen (dsymsuffixdir); + + dsymlen = (dirnamelen + + 1 + + basenamelen + + dsymsuffixdirlen + + basenamelen + + 1); + dsym = backtrace_alloc (state, dsymlen, error_callback, data); + if (dsym == NULL) + goto fail; + + ps = dsym; + memcpy (ps, dirname, dirnamelen); + ps += dirnamelen; + *ps++ = '/'; + memcpy (ps, basename, basenamelen); + ps += basenamelen; + memcpy (ps, dsymsuffixdir, dsymsuffixdirlen); + ps += dsymsuffixdirlen; + memcpy (ps, basename, basenamelen); + ps += basenamelen; + *ps = '\0'; + + if (diralc != NULL) + { + backtrace_free (state, diralc, dirnamelen + 1, error_callback, data); + diralc = NULL; + } + + d = backtrace_open (dsym, error_callback, data, &does_not_exist); + if (d < 0) + { + /* The file does not exist, so we can't read the debug info. + Just return success. */ + backtrace_free (state, dsym, dsymlen, error_callback, data); + return 1; + } + + if (!macho_add (state, dsym, d, 0, uuid, base_address, 1, + error_callback, data, fileline_fn, &dummy_found_sym)) + goto fail; + + backtrace_free (state, dsym, dsymlen, error_callback, data); + + return 1; + + fail: + if (dsym != NULL) + backtrace_free (state, dsym, dsymlen, error_callback, data); + if (diralc != NULL) + backtrace_free (state, diralc, dirnamelen, error_callback, data); + return 0; +} + +/* Add the backtrace data for a Macho-O file. Returns 1 on success, 0 + on failure (in both cases descriptor is closed). + + FILENAME: the name of the executable. + DESCRIPTOR: an open descriptor for the executable, closed here. + OFFSET: the offset within the file of this executable, for fat files. + MATCH_UUID: if not NULL, UUID that must match. + BASE_ADDRESS: the load address of the executable. + SKIP_SYMTAB: if non-zero, ignore the symbol table; used for dSYM files. + FILELINE_FN: set to the fileline function, by backtrace_dwarf_add. + FOUND_SYM: set to non-zero if we found the symbol table. +*/ + +static int +macho_add (struct backtrace_state *state, const char *filename, int descriptor, + off_t offset, const unsigned char *match_uuid, + uintptr_t base_address, int skip_symtab, + backtrace_error_callback error_callback, void *data, + fileline *fileline_fn, int *found_sym) +{ + struct backtrace_view header_view; + struct macho_header_32 header; + off_t hdroffset; + int is_64; + struct backtrace_view cmds_view; + int cmds_view_valid; + struct dwarf_sections dwarf_sections; + int have_dwarf; + unsigned char uuid[MACH_O_UUID_LEN]; + int have_uuid; + size_t cmdoffset; + unsigned int i; + + *found_sym = 0; + + cmds_view_valid = 0; + + /* The 32-bit and 64-bit file headers start out the same, so we can + just always read the 32-bit version. A fat header is shorter but + it will always be followed by data, so it's OK to read extra. */ + + if (!backtrace_get_view (state, descriptor, offset, + sizeof (struct macho_header_32), + error_callback, data, &header_view)) + goto fail; + + memcpy (&header, header_view.data, sizeof header); + + backtrace_release_view (state, &header_view, error_callback, data); + + switch (header.magic) + { + case MACH_O_MH_MAGIC_32: + is_64 = 0; + hdroffset = offset + sizeof (struct macho_header_32); + break; + case MACH_O_MH_MAGIC_64: + is_64 = 1; + hdroffset = offset + sizeof (struct macho_header_64); + break; + case MACH_O_MH_MAGIC_FAT: + case MACH_O_MH_MAGIC_FAT_64: + { + struct macho_header_fat fat_header; + + hdroffset = offset + sizeof (struct macho_header_fat); + memcpy (&fat_header, &header, sizeof fat_header); + return macho_add_fat (state, filename, descriptor, 0, hdroffset, + match_uuid, base_address, skip_symtab, + fat_header.nfat_arch, + header.magic == MACH_O_MH_MAGIC_FAT_64, + error_callback, data, fileline_fn, found_sym); + } + case MACH_O_MH_CIGAM_FAT: + case MACH_O_MH_CIGAM_FAT_64: + { + struct macho_header_fat fat_header; + uint32_t nfat_arch; + + hdroffset = offset + sizeof (struct macho_header_fat); + memcpy (&fat_header, &header, sizeof fat_header); + nfat_arch = __builtin_bswap32 (fat_header.nfat_arch); + return macho_add_fat (state, filename, descriptor, 1, hdroffset, + match_uuid, base_address, skip_symtab, + nfat_arch, + header.magic == MACH_O_MH_CIGAM_FAT_64, + error_callback, data, fileline_fn, found_sym); + } + default: + error_callback (data, "executable file is not in Mach-O format", 0); + goto fail; + } + + switch (header.filetype) + { + case MACH_O_MH_EXECUTE: + case MACH_O_MH_DYLIB: + case MACH_O_MH_DSYM: + break; + default: + error_callback (data, "executable file is not an executable", 0); + goto fail; + } + + if (!backtrace_get_view (state, descriptor, hdroffset, header.sizeofcmds, + error_callback, data, &cmds_view)) + goto fail; + cmds_view_valid = 1; + + memset (&dwarf_sections, 0, sizeof dwarf_sections); + have_dwarf = 0; + memset (&uuid, 0, sizeof uuid); + have_uuid = 0; + + cmdoffset = 0; + for (i = 0; i < header.ncmds; ++i) + { + const char *pcmd; + struct macho_load_command load_command; + + if (cmdoffset + sizeof load_command > header.sizeofcmds) + break; + + pcmd = (const char *) cmds_view.data + cmdoffset; + memcpy (&load_command, pcmd, sizeof load_command); + + switch (load_command.cmd) + { + case MACH_O_LC_SEGMENT: + { + struct macho_segment_command segcmd; + + memcpy (&segcmd, pcmd, sizeof segcmd); + if (memcmp (segcmd.segname, + "__DWARF\0\0\0\0\0\0\0\0\0", + MACH_O_NAMELEN) == 0) + { + if (!macho_add_dwarf_segment (state, descriptor, offset, + load_command.cmd, + pcmd + sizeof segcmd, + (load_command.cmdsize + - sizeof segcmd), + segcmd.nsects, error_callback, + data, &dwarf_sections)) + goto fail; + have_dwarf = 1; + } + } + break; + + case MACH_O_LC_SEGMENT_64: + { + struct macho_segment_64_command segcmd; + + memcpy (&segcmd, pcmd, sizeof segcmd); + if (memcmp (segcmd.segname, + "__DWARF\0\0\0\0\0\0\0\0\0", + MACH_O_NAMELEN) == 0) + { + if (!macho_add_dwarf_segment (state, descriptor, offset, + load_command.cmd, + pcmd + sizeof segcmd, + (load_command.cmdsize + - sizeof segcmd), + segcmd.nsects, error_callback, + data, &dwarf_sections)) + goto fail; + have_dwarf = 1; + } + } + break; + + case MACH_O_LC_SYMTAB: + if (!skip_symtab) + { + struct macho_symtab_command symcmd; + + memcpy (&symcmd, pcmd, sizeof symcmd); + if (!macho_add_symtab (state, descriptor, base_address, is_64, + offset + symcmd.symoff, symcmd.nsyms, + offset + symcmd.stroff, symcmd.strsize, + error_callback, data)) + goto fail; + + *found_sym = 1; + } + break; + + case MACH_O_LC_UUID: + { + struct macho_uuid_command uuidcmd; + + memcpy (&uuidcmd, pcmd, sizeof uuidcmd); + memcpy (&uuid[0], &uuidcmd.uuid[0], MACH_O_UUID_LEN); + have_uuid = 1; + } + break; + + default: + break; + } + + cmdoffset += load_command.cmdsize; + } + + if (!backtrace_close (descriptor, error_callback, data)) + goto fail; + descriptor = -1; + + backtrace_release_view (state, &cmds_view, error_callback, data); + cmds_view_valid = 0; + + if (match_uuid != NULL) + { + /* If we don't have a UUID, or it doesn't match, just ignore + this file. */ + if (!have_uuid + || memcmp (match_uuid, &uuid[0], MACH_O_UUID_LEN) != 0) + return 1; + } + + if (have_dwarf) + { + int is_big_endian; + + is_big_endian = 0; +#if defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) +#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ + is_big_endian = 1; +#endif +#endif + + if (!backtrace_dwarf_add (state, base_address, &dwarf_sections, + is_big_endian, NULL, error_callback, data, + fileline_fn, NULL)) + goto fail; + } + + if (!have_dwarf && have_uuid) + { + if (!macho_add_dsym (state, filename, base_address, &uuid[0], + error_callback, data, fileline_fn)) + goto fail; + } + + return 1; + + fail: + if (cmds_view_valid) + backtrace_release_view (state, &cmds_view, error_callback, data); + if (descriptor != -1) + backtrace_close (descriptor, error_callback, data); + return 0; +} + +#ifdef HAVE_MACH_O_DYLD_H + +/* Initialize the backtrace data we need from a Mach-O executable + using the dyld support functions. This closes descriptor. */ + +int +backtrace_initialize (struct backtrace_state *state, const char *filename, + int descriptor, backtrace_error_callback error_callback, + void *data, fileline *fileline_fn) +{ + uint32_t c; + uint32_t i; + int closed_descriptor; + int found_sym; + fileline macho_fileline_fn; + + closed_descriptor = 0; + found_sym = 0; + macho_fileline_fn = macho_nodebug; + + c = _dyld_image_count (); + for (i = 0; i < c; ++i) + { + uintptr_t base_address; + const char *name; + int d; + fileline mff; + int mfs; + + name = _dyld_get_image_name (i); + if (name == NULL) + continue; + + if (strcmp (name, filename) == 0 && !closed_descriptor) + { + d = descriptor; + closed_descriptor = 1; + } + else + { + int does_not_exist; + + d = backtrace_open (name, error_callback, data, &does_not_exist); + if (d < 0) + continue; + } + + base_address = _dyld_get_image_vmaddr_slide (i); + + mff = macho_nodebug; + if (!macho_add (state, name, d, 0, NULL, base_address, 0, + error_callback, data, &mff, &mfs)) + return 0; + + if (mff != macho_nodebug) + macho_fileline_fn = mff; + if (mfs) + found_sym = 1; + } + + if (!closed_descriptor) + backtrace_close (descriptor, error_callback, data); + + if (!state->threaded) + { + if (found_sym) + state->syminfo_fn = macho_syminfo; + else if (state->syminfo_fn == NULL) + state->syminfo_fn = macho_nosyms; + } + else + { + if (found_sym) + backtrace_atomic_store_pointer (&state->syminfo_fn, macho_syminfo); + else + (void) __sync_bool_compare_and_swap (&state->syminfo_fn, NULL, + macho_nosyms); + } + + if (!state->threaded) + *fileline_fn = state->fileline_fn; + else + *fileline_fn = backtrace_atomic_load_pointer (&state->fileline_fn); + + if (*fileline_fn == NULL || *fileline_fn == macho_nodebug) + *fileline_fn = macho_fileline_fn; + + return 1; +} + +#else /* !defined (HAVE_MACH_O_DYLD_H) */ + +/* Initialize the backtrace data we need from a Mach-O executable + without using the dyld support functions. This closes + descriptor. */ + +int +backtrace_initialize (struct backtrace_state *state, const char *filename, + int descriptor, backtrace_error_callback error_callback, + void *data, fileline *fileline_fn) +{ + fileline macho_fileline_fn; + int found_sym; + + macho_fileline_fn = macho_nodebug; + if (!macho_add (state, filename, descriptor, 0, NULL, 0, 0, + error_callback, data, &macho_fileline_fn, &found_sym)) + return 0; + + if (!state->threaded) + { + if (found_sym) + state->syminfo_fn = macho_syminfo; + else if (state->syminfo_fn == NULL) + state->syminfo_fn = macho_nosyms; + } + else + { + if (found_sym) + backtrace_atomic_store_pointer (&state->syminfo_fn, macho_syminfo); + else + (void) __sync_bool_compare_and_swap (&state->syminfo_fn, NULL, + macho_nosyms); + } + + if (!state->threaded) + *fileline_fn = state->fileline_fn; + else + *fileline_fn = backtrace_atomic_load_pointer (&state->fileline_fn); + + if (*fileline_fn == NULL || *fileline_fn == macho_nodebug) + *fileline_fn = macho_fileline_fn; + + return 1; +} + +#endif /* !defined (HAVE_MACH_O_DYLD_H) */ |