diff options
Diffstat (limited to 'gcc-4.8.1/libbacktrace/elf.c')
| -rw-r--r-- | gcc-4.8.1/libbacktrace/elf.c | 904 |
1 files changed, 0 insertions, 904 deletions
diff --git a/gcc-4.8.1/libbacktrace/elf.c b/gcc-4.8.1/libbacktrace/elf.c deleted file mode 100644 index ef9bcdfb4..000000000 --- a/gcc-4.8.1/libbacktrace/elf.c +++ /dev/null @@ -1,904 +0,0 @@ -/* elf.c -- Get debug data from an ELF file for backtraces. - Copyright (C) 2012-2013 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 <stdlib.h> -#include <string.h> -#include <sys/types.h> - -#ifdef HAVE_DL_ITERATE_PHDR -#include <link.h> -#endif - -#include "backtrace.h" -#include "internal.h" - -#ifndef HAVE_DL_ITERATE_PHDR - -/* Dummy version of dl_iterate_phdr for systems that don't have it. */ - -#define dl_phdr_info x_dl_phdr_info -#define dl_iterate_phdr x_dl_iterate_phdr - -struct dl_phdr_info -{ - uintptr_t dlpi_addr; - const char *dlpi_name; -}; - -static int -dl_iterate_phdr (int (*callback) (struct dl_phdr_info *, - size_t, void *) ATTRIBUTE_UNUSED, - void *data ATTRIBUTE_UNUSED) -{ - return 0; -} - -#endif /* ! defined (HAVE_DL_ITERATE_PHDR) */ - -/* The configure script must tell us whether we are 32-bit or 64-bit - ELF. We could make this code test and support either possibility, - but there is no point. This code only works for the currently - running executable, which means that we know the ELF mode at - configure mode. */ - -#if BACKTRACE_ELF_SIZE != 32 && BACKTRACE_ELF_SIZE != 64 -#error "Unknown BACKTRACE_ELF_SIZE" -#endif - -/* <link.h> might #include <elf.h> which might define our constants - with slightly different values. Undefine them to be safe. */ - -#undef EI_NIDENT -#undef EI_MAG0 -#undef EI_MAG1 -#undef EI_MAG2 -#undef EI_MAG3 -#undef EI_CLASS -#undef EI_DATA -#undef EI_VERSION -#undef ELF_MAG0 -#undef ELF_MAG1 -#undef ELF_MAG2 -#undef ELF_MAG3 -#undef ELFCLASS32 -#undef ELFCLASS64 -#undef ELFDATA2LSB -#undef ELFDATA2MSB -#undef EV_CURRENT -#undef SHN_LORESERVE -#undef SHN_XINDEX -#undef SHT_SYMTAB -#undef SHT_STRTAB -#undef SHT_DYNSYM -#undef STT_FUNC - -/* Basic types. */ - -typedef uint16_t b_elf_half; /* Elf_Half. */ -typedef uint32_t b_elf_word; /* Elf_Word. */ -typedef int32_t b_elf_sword; /* Elf_Sword. */ - -#if BACKTRACE_ELF_SIZE == 32 - -typedef uint32_t b_elf_addr; /* Elf_Addr. */ -typedef uint32_t b_elf_off; /* Elf_Off. */ - -typedef uint32_t b_elf_wxword; /* 32-bit Elf_Word, 64-bit ELF_Xword. */ - -#else - -typedef uint64_t b_elf_addr; /* Elf_Addr. */ -typedef uint64_t b_elf_off; /* Elf_Off. */ -typedef uint64_t b_elf_xword; /* Elf_Xword. */ -typedef int64_t b_elf_sxword; /* Elf_Sxword. */ - -typedef uint64_t b_elf_wxword; /* 32-bit Elf_Word, 64-bit ELF_Xword. */ - -#endif - -/* Data structures and associated constants. */ - -#define EI_NIDENT 16 - -typedef struct { - unsigned char e_ident[EI_NIDENT]; /* ELF "magic number" */ - b_elf_half e_type; /* Identifies object file type */ - b_elf_half e_machine; /* Specifies required architecture */ - b_elf_word e_version; /* Identifies object file version */ - b_elf_addr e_entry; /* Entry point virtual address */ - b_elf_off e_phoff; /* Program header table file offset */ - b_elf_off e_shoff; /* Section header table file offset */ - b_elf_word e_flags; /* Processor-specific flags */ - b_elf_half e_ehsize; /* ELF header size in bytes */ - b_elf_half e_phentsize; /* Program header table entry size */ - b_elf_half e_phnum; /* Program header table entry count */ - b_elf_half e_shentsize; /* Section header table entry size */ - b_elf_half e_shnum; /* Section header table entry count */ - b_elf_half e_shstrndx; /* Section header string table index */ -} b_elf_ehdr; /* Elf_Ehdr. */ - -#define EI_MAG0 0 -#define EI_MAG1 1 -#define EI_MAG2 2 -#define EI_MAG3 3 -#define EI_CLASS 4 -#define EI_DATA 5 -#define EI_VERSION 6 - -#define ELFMAG0 0x7f -#define ELFMAG1 'E' -#define ELFMAG2 'L' -#define ELFMAG3 'F' - -#define ELFCLASS32 1 -#define ELFCLASS64 2 - -#define ELFDATA2LSB 1 -#define ELFDATA2MSB 2 - -#define EV_CURRENT 1 - -typedef struct { - b_elf_word sh_name; /* Section name, index in string tbl */ - b_elf_word sh_type; /* Type of section */ - b_elf_wxword sh_flags; /* Miscellaneous section attributes */ - b_elf_addr sh_addr; /* Section virtual addr at execution */ - b_elf_off sh_offset; /* Section file offset */ - b_elf_wxword sh_size; /* Size of section in bytes */ - b_elf_word sh_link; /* Index of another section */ - b_elf_word sh_info; /* Additional section information */ - b_elf_wxword sh_addralign; /* Section alignment */ - b_elf_wxword sh_entsize; /* Entry size if section holds table */ -} b_elf_shdr; /* Elf_Shdr. */ - -#define SHN_LORESERVE 0xFF00 /* Begin range of reserved indices */ -#define SHN_XINDEX 0xFFFF /* Section index is held elsewhere */ - -#define SHT_SYMTAB 2 -#define SHT_STRTAB 3 -#define SHT_DYNSYM 11 - -#if BACKTRACE_ELF_SIZE == 32 - -typedef struct -{ - b_elf_word st_name; /* Symbol name, index in string tbl */ - b_elf_addr st_value; /* Symbol value */ - b_elf_word st_size; /* Symbol size */ - unsigned char st_info; /* Symbol binding and type */ - unsigned char st_other; /* Visibility and other data */ - b_elf_half st_shndx; /* Symbol section index */ -} b_elf_sym; /* Elf_Sym. */ - -#else /* BACKTRACE_ELF_SIZE != 32 */ - -typedef struct -{ - b_elf_word st_name; /* Symbol name, index in string tbl */ - unsigned char st_info; /* Symbol binding and type */ - unsigned char st_other; /* Visibility and other data */ - b_elf_half st_shndx; /* Symbol section index */ - b_elf_addr st_value; /* Symbol value */ - b_elf_xword st_size; /* Symbol size */ -} b_elf_sym; /* Elf_Sym. */ - -#endif /* BACKTRACE_ELF_SIZE != 32 */ - -#define STT_FUNC 2 - -/* An index of ELF sections we care about. */ - -enum debug_section -{ - DEBUG_INFO, - DEBUG_LINE, - DEBUG_ABBREV, - DEBUG_RANGES, - DEBUG_STR, - DEBUG_MAX -}; - -/* Names of sections, indexed by enum elf_section. */ - -static const char * const debug_section_names[DEBUG_MAX] = -{ - ".debug_info", - ".debug_line", - ".debug_abbrev", - ".debug_ranges", - ".debug_str" -}; - -/* Information we gather for the sections we care about. */ - -struct debug_section_info -{ - /* Section file offset. */ - off_t offset; - /* Section size. */ - size_t size; - /* Section contents, after read from file. */ - const unsigned char *data; -}; - -/* Information we keep for an ELF symbol. */ - -struct elf_symbol -{ - /* The name of the symbol. */ - const char *name; - /* The address of the symbol. */ - uintptr_t address; - /* The size of the symbol. */ - size_t size; -}; - -/* Information to pass to elf_syminfo. */ - -struct elf_syminfo_data -{ - /* Symbols for the next module. */ - struct elf_syminfo_data *next; - /* The ELF symbols, sorted by address. */ - struct elf_symbol *symbols; - /* The number of symbols. */ - size_t count; -}; - -/* A dummy callback function used when we can't find any debug info. */ - -static int -elf_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 ELF executable", -1); - return 0; -} - -/* A dummy callback function used when we can't find a symbol - table. */ - -static void -elf_nosyms (struct backtrace_state *state ATTRIBUTE_UNUSED, - uintptr_t pc ATTRIBUTE_UNUSED, - backtrace_syminfo_callback callback ATTRIBUTE_UNUSED, - backtrace_error_callback error_callback, void *data) -{ - error_callback (data, "no symbol table in ELF executable", -1); -} - -/* Compare struct elf_symbol for qsort. */ - -static int -elf_symbol_compare (const void *v1, const void *v2) -{ - const struct elf_symbol *e1 = (const struct elf_symbol *) v1; - const struct elf_symbol *e2 = (const struct elf_symbol *) v2; - - if (e1->address < e2->address) - return -1; - else if (e1->address > e2->address) - return 1; - else - return 0; -} - -/* Compare a PC against an elf_symbol for bsearch. We allocate one - extra entry in the array so that this can look safely at the next - entry. */ - -static int -elf_symbol_search (const void *vkey, const void *ventry) -{ - const uintptr_t *key = (const uintptr_t *) vkey; - const struct elf_symbol *entry = (const struct elf_symbol *) ventry; - uintptr_t pc; - - pc = *key; - if (pc < entry->address) - return -1; - else if (pc >= entry->address + entry->size) - return 1; - else - return 0; -} - -/* Initialize the symbol table info for elf_syminfo. */ - -static int -elf_initialize_syminfo (struct backtrace_state *state, - const unsigned char *symtab_data, size_t symtab_size, - const unsigned char *strtab, size_t strtab_size, - backtrace_error_callback error_callback, - void *data, struct elf_syminfo_data *sdata) -{ - size_t sym_count; - const b_elf_sym *sym; - size_t elf_symbol_count; - size_t elf_symbol_size; - struct elf_symbol *elf_symbols; - size_t i; - unsigned int j; - - sym_count = symtab_size / sizeof (b_elf_sym); - - /* We only care about function symbols. Count them. */ - sym = (const b_elf_sym *) symtab_data; - elf_symbol_count = 0; - for (i = 0; i < sym_count; ++i, ++sym) - { - if ((sym->st_info & 0xf) == STT_FUNC) - ++elf_symbol_count; - } - - elf_symbol_size = elf_symbol_count * sizeof (struct elf_symbol); - elf_symbols = ((struct elf_symbol *) - backtrace_alloc (state, elf_symbol_size, error_callback, - data)); - if (elf_symbols == NULL) - return 0; - - sym = (const b_elf_sym *) symtab_data; - j = 0; - for (i = 0; i < sym_count; ++i, ++sym) - { - if ((sym->st_info & 0xf) != STT_FUNC) - continue; - if (sym->st_name >= strtab_size) - { - error_callback (data, "symbol string index out of range", 0); - backtrace_free (state, elf_symbols, elf_symbol_size, error_callback, - data); - return 0; - } - elf_symbols[j].name = (const char *) strtab + sym->st_name; - elf_symbols[j].address = sym->st_value; - elf_symbols[j].size = sym->st_size; - ++j; - } - - qsort (elf_symbols, elf_symbol_count, sizeof (struct elf_symbol), - elf_symbol_compare); - - sdata->next = NULL; - sdata->symbols = elf_symbols; - sdata->count = elf_symbol_count; - - return 1; -} - -/* Add EDATA to the list in STATE. */ - -static void -elf_add_syminfo_data (struct backtrace_state *state, - struct elf_syminfo_data *edata) -{ - if (!state->threaded) - { - struct elf_syminfo_data **pp; - - for (pp = (struct elf_syminfo_data **) (void *) &state->syminfo_data; - *pp != NULL; - pp = &(*pp)->next) - ; - *pp = edata; - } - else - { - while (1) - { - struct elf_syminfo_data **pp; - - pp = (struct elf_syminfo_data **) (void *) &state->syminfo_data; - - while (1) - { - struct elf_syminfo_data *p; - - /* Atomic load. */ - p = *pp; - while (!__sync_bool_compare_and_swap (pp, p, p)) - p = *pp; - - if (p == NULL) - break; - - pp = &p->next; - } - - if (__sync_bool_compare_and_swap (pp, NULL, edata)) - break; - } - } -} - -/* Return the symbol name and value for a PC. */ - -static void -elf_syminfo (struct backtrace_state *state, uintptr_t pc, - backtrace_syminfo_callback callback, - backtrace_error_callback error_callback ATTRIBUTE_UNUSED, - void *data) -{ - struct elf_syminfo_data *edata; - struct elf_symbol *sym; - - edata = (struct elf_syminfo_data *) state->syminfo_data; - sym = ((struct elf_symbol *) - bsearch (&pc, edata->symbols, edata->count, - sizeof (struct elf_symbol), elf_symbol_search)); - if (sym == NULL) - callback (data, pc, NULL, 0); - else - callback (data, pc, sym->name, sym->address); -} - -/* Add the backtrace data for one ELF file. */ - -static int -elf_add (struct backtrace_state *state, int descriptor, uintptr_t base_address, - backtrace_error_callback error_callback, void *data, - fileline *fileline_fn, int *found_sym, int *found_dwarf) -{ - struct backtrace_view ehdr_view; - b_elf_ehdr ehdr; - off_t shoff; - unsigned int shnum; - unsigned int shstrndx; - struct backtrace_view shdrs_view; - int shdrs_view_valid; - const b_elf_shdr *shdrs; - const b_elf_shdr *shstrhdr; - size_t shstr_size; - off_t shstr_off; - struct backtrace_view names_view; - int names_view_valid; - const char *names; - unsigned int symtab_shndx; - unsigned int dynsym_shndx; - unsigned int i; - struct debug_section_info sections[DEBUG_MAX]; - struct backtrace_view symtab_view; - int symtab_view_valid; - struct backtrace_view strtab_view; - int strtab_view_valid; - off_t min_offset; - off_t max_offset; - struct backtrace_view debug_view; - int debug_view_valid; - - *found_sym = 0; - *found_dwarf = 0; - - shdrs_view_valid = 0; - names_view_valid = 0; - symtab_view_valid = 0; - strtab_view_valid = 0; - debug_view_valid = 0; - - if (!backtrace_get_view (state, descriptor, 0, sizeof ehdr, error_callback, - data, &ehdr_view)) - goto fail; - - memcpy (&ehdr, ehdr_view.data, sizeof ehdr); - - backtrace_release_view (state, &ehdr_view, error_callback, data); - - if (ehdr.e_ident[EI_MAG0] != ELFMAG0 - || ehdr.e_ident[EI_MAG1] != ELFMAG1 - || ehdr.e_ident[EI_MAG2] != ELFMAG2 - || ehdr.e_ident[EI_MAG3] != ELFMAG3) - { - error_callback (data, "executable file is not ELF", 0); - goto fail; - } - if (ehdr.e_ident[EI_VERSION] != EV_CURRENT) - { - error_callback (data, "executable file is unrecognized ELF version", 0); - goto fail; - } - -#if BACKTRACE_ELF_SIZE == 32 -#define BACKTRACE_ELFCLASS ELFCLASS32 -#else -#define BACKTRACE_ELFCLASS ELFCLASS64 -#endif - - if (ehdr.e_ident[EI_CLASS] != BACKTRACE_ELFCLASS) - { - error_callback (data, "executable file is unexpected ELF class", 0); - goto fail; - } - - if (ehdr.e_ident[EI_DATA] != ELFDATA2LSB - && ehdr.e_ident[EI_DATA] != ELFDATA2MSB) - { - error_callback (data, "executable file has unknown endianness", 0); - goto fail; - } - - shoff = ehdr.e_shoff; - shnum = ehdr.e_shnum; - shstrndx = ehdr.e_shstrndx; - - if ((shnum == 0 || shstrndx == SHN_XINDEX) - && shoff != 0) - { - struct backtrace_view shdr_view; - const b_elf_shdr *shdr; - - if (!backtrace_get_view (state, descriptor, shoff, sizeof shdr, - error_callback, data, &shdr_view)) - goto fail; - - shdr = (const b_elf_shdr *) shdr_view.data; - - if (shnum == 0) - shnum = shdr->sh_size; - - if (shstrndx == SHN_XINDEX) - { - shstrndx = shdr->sh_link; - - /* Versions of the GNU binutils between 2.12 and 2.18 did - not handle objects with more than SHN_LORESERVE sections - correctly. All large section indexes were offset by - 0x100. There is more information at - http://sourceware.org/bugzilla/show_bug.cgi?id-5900 . - Fortunately these object files are easy to detect, as the - GNU binutils always put the section header string table - near the end of the list of sections. Thus if the - section header string table index is larger than the - number of sections, then we know we have to subtract - 0x100 to get the real section index. */ - if (shstrndx >= shnum && shstrndx >= SHN_LORESERVE + 0x100) - shstrndx -= 0x100; - } - - backtrace_release_view (state, &shdr_view, error_callback, data); - } - - /* To translate PC to file/line when using DWARF, we need to find - the .debug_info and .debug_line sections. */ - - /* Read the section headers, skipping the first one. */ - - if (!backtrace_get_view (state, descriptor, shoff + sizeof (b_elf_shdr), - (shnum - 1) * sizeof (b_elf_shdr), - error_callback, data, &shdrs_view)) - goto fail; - shdrs_view_valid = 1; - shdrs = (const b_elf_shdr *) shdrs_view.data; - - /* Read the section names. */ - - shstrhdr = &shdrs[shstrndx - 1]; - shstr_size = shstrhdr->sh_size; - shstr_off = shstrhdr->sh_offset; - - if (!backtrace_get_view (state, descriptor, shstr_off, shstr_size, - error_callback, data, &names_view)) - goto fail; - names_view_valid = 1; - names = (const char *) names_view.data; - - symtab_shndx = 0; - dynsym_shndx = 0; - - memset (sections, 0, sizeof sections); - - /* Look for the symbol table. */ - for (i = 1; i < shnum; ++i) - { - const b_elf_shdr *shdr; - unsigned int sh_name; - const char *name; - int j; - - shdr = &shdrs[i - 1]; - - if (shdr->sh_type == SHT_SYMTAB) - symtab_shndx = i; - else if (shdr->sh_type == SHT_DYNSYM) - dynsym_shndx = i; - - sh_name = shdr->sh_name; - if (sh_name >= shstr_size) - { - error_callback (data, "ELF section name out of range", 0); - goto fail; - } - - name = names + sh_name; - - for (j = 0; j < (int) DEBUG_MAX; ++j) - { - if (strcmp (name, debug_section_names[j]) == 0) - { - sections[j].offset = shdr->sh_offset; - sections[j].size = shdr->sh_size; - break; - } - } - } - - if (symtab_shndx == 0) - symtab_shndx = dynsym_shndx; - if (symtab_shndx != 0) - { - const b_elf_shdr *symtab_shdr; - unsigned int strtab_shndx; - const b_elf_shdr *strtab_shdr; - struct elf_syminfo_data *sdata; - - symtab_shdr = &shdrs[symtab_shndx - 1]; - strtab_shndx = symtab_shdr->sh_link; - if (strtab_shndx >= shnum) - { - error_callback (data, - "ELF symbol table strtab link out of range", 0); - goto fail; - } - strtab_shdr = &shdrs[strtab_shndx - 1]; - - if (!backtrace_get_view (state, descriptor, symtab_shdr->sh_offset, - symtab_shdr->sh_size, error_callback, data, - &symtab_view)) - goto fail; - symtab_view_valid = 1; - - if (!backtrace_get_view (state, descriptor, strtab_shdr->sh_offset, - strtab_shdr->sh_size, error_callback, data, - &strtab_view)) - goto fail; - strtab_view_valid = 1; - - sdata = ((struct elf_syminfo_data *) - backtrace_alloc (state, sizeof *sdata, error_callback, data)); - if (sdata == NULL) - goto fail; - - if (!elf_initialize_syminfo (state, - symtab_view.data, symtab_shdr->sh_size, - strtab_view.data, strtab_shdr->sh_size, - error_callback, data, sdata)) - { - backtrace_free (state, sdata, sizeof *sdata, error_callback, data); - goto fail; - } - - /* We no longer need the symbol table, but we hold on to the - string table permanently. */ - backtrace_release_view (state, &symtab_view, error_callback, data); - - *found_sym = 1; - - elf_add_syminfo_data (state, sdata); - } - - /* FIXME: Need to handle compressed debug sections. */ - - backtrace_release_view (state, &shdrs_view, error_callback, data); - shdrs_view_valid = 0; - backtrace_release_view (state, &names_view, error_callback, data); - names_view_valid = 0; - - /* Read all the debug sections in a single view, since they are - probably adjacent in the file. We never release this view. */ - - min_offset = 0; - max_offset = 0; - for (i = 0; i < (int) DEBUG_MAX; ++i) - { - off_t end; - - if (min_offset == 0 || sections[i].offset < min_offset) - min_offset = sections[i].offset; - end = sections[i].offset + sections[i].size; - if (end > max_offset) - max_offset = end; - } - if (min_offset == 0 || max_offset == 0) - { - if (!backtrace_close (descriptor, error_callback, data)) - goto fail; - *fileline_fn = elf_nodebug; - return 1; - } - - if (!backtrace_get_view (state, descriptor, min_offset, - max_offset - min_offset, - error_callback, data, &debug_view)) - goto fail; - debug_view_valid = 1; - - /* We've read all we need from the executable. */ - if (!backtrace_close (descriptor, error_callback, data)) - goto fail; - descriptor = -1; - - for (i = 0; i < (int) DEBUG_MAX; ++i) - sections[i].data = ((const unsigned char *) debug_view.data - + (sections[i].offset - min_offset)); - - if (!backtrace_dwarf_add (state, base_address, - sections[DEBUG_INFO].data, - sections[DEBUG_INFO].size, - sections[DEBUG_LINE].data, - sections[DEBUG_LINE].size, - sections[DEBUG_ABBREV].data, - sections[DEBUG_ABBREV].size, - sections[DEBUG_RANGES].data, - sections[DEBUG_RANGES].size, - sections[DEBUG_STR].data, - sections[DEBUG_STR].size, - ehdr.e_ident[EI_DATA] == ELFDATA2MSB, - error_callback, data, fileline_fn)) - goto fail; - - *found_dwarf = 1; - - return 1; - - fail: - if (shdrs_view_valid) - backtrace_release_view (state, &shdrs_view, error_callback, data); - if (names_view_valid) - backtrace_release_view (state, &names_view, error_callback, data); - if (symtab_view_valid) - backtrace_release_view (state, &symtab_view, error_callback, data); - if (strtab_view_valid) - backtrace_release_view (state, &strtab_view, error_callback, data); - if (debug_view_valid) - backtrace_release_view (state, &debug_view, error_callback, data); - if (descriptor != -1) - backtrace_close (descriptor, error_callback, data); - return 0; -} - -/* Data passed to phdr_callback. */ - -struct phdr_data -{ - struct backtrace_state *state; - backtrace_error_callback error_callback; - void *data; - fileline *fileline_fn; - int *found_sym; - int *found_dwarf; -}; - -/* Callback passed to dl_iterate_phdr. Load debug info from shared - libraries. */ - -static int -phdr_callback (struct dl_phdr_info *info, size_t size ATTRIBUTE_UNUSED, - void *pdata) -{ - struct phdr_data *pd = (struct phdr_data *) pdata; - int descriptor; - int does_not_exist; - fileline elf_fileline_fn; - int found_dwarf; - - /* There is not much we can do if we don't have the module name. If - the base address is 0, this is probably the executable, which we - already loaded. */ - if (info->dlpi_name == NULL - || info->dlpi_name[0] == '\0' - || info->dlpi_addr == 0) - return 0; - - descriptor = backtrace_open (info->dlpi_name, pd->error_callback, pd->data, - &does_not_exist); - if (descriptor < 0) - return 0; - - if (elf_add (pd->state, descriptor, info->dlpi_addr, pd->error_callback, - pd->data, &elf_fileline_fn, pd->found_sym, &found_dwarf)) - { - if (found_dwarf) - { - *pd->found_dwarf = 1; - *pd->fileline_fn = elf_fileline_fn; - } - } - - return 0; -} - -/* Initialize the backtrace data we need from an ELF executable. At - the ELF level, all we need to do is find the debug info - sections. */ - -int -backtrace_initialize (struct backtrace_state *state, int descriptor, - backtrace_error_callback error_callback, - void *data, fileline *fileline_fn) -{ - int found_sym; - int found_dwarf; - syminfo elf_syminfo_fn; - fileline elf_fileline_fn; - struct phdr_data pd; - - if (!elf_add (state, descriptor, 0, error_callback, data, &elf_fileline_fn, - &found_sym, &found_dwarf)) - return 0; - - pd.state = state; - pd.error_callback = error_callback; - pd.data = data; - pd.fileline_fn = fileline_fn; - pd.found_sym = &found_sym; - pd.found_dwarf = &found_dwarf; - - dl_iterate_phdr (phdr_callback, (void *) &pd); - - elf_syminfo_fn = found_sym ? elf_syminfo : elf_nosyms; - if (!state->threaded) - { - if (state->syminfo_fn == NULL || found_sym) - state->syminfo_fn = elf_syminfo_fn; - } - else - { - __sync_bool_compare_and_swap (&state->syminfo_fn, NULL, elf_syminfo_fn); - if (found_sym) - __sync_bool_compare_and_swap (&state->syminfo_fn, elf_nosyms, - elf_syminfo_fn); - } - - if (!state->threaded) - { - if (state->fileline_fn == NULL || state->fileline_fn == elf_nodebug) - *fileline_fn = elf_fileline_fn; - } - else - { - fileline current_fn; - - /* Atomic load. */ - current_fn = state->fileline_fn; - while (!__sync_bool_compare_and_swap (&state->fileline_fn, current_fn, - current_fn)) - current_fn = state->fileline_fn; - if (current_fn == NULL || current_fn == elf_nodebug) - *fileline_fn = elf_fileline_fn; - } - - return 1; -} |