125b3c049e70834cf33790a28643ab058b507b35cBen Cheng/* Find an ELF file for a module from its build ID. 203333823c75a1c1887e923828113a1b0fd12020cElliott Hughes Copyright (C) 2007-2010, 2014 Red Hat, Inc. 303333823c75a1c1887e923828113a1b0fd12020cElliott Hughes This file is part of elfutils. 425b3c049e70834cf33790a28643ab058b507b35cBen Cheng 503333823c75a1c1887e923828113a1b0fd12020cElliott Hughes This file is free software; you can redistribute it and/or modify 603333823c75a1c1887e923828113a1b0fd12020cElliott Hughes it under the terms of either 725b3c049e70834cf33790a28643ab058b507b35cBen Cheng 803333823c75a1c1887e923828113a1b0fd12020cElliott Hughes * the GNU Lesser General Public License as published by the Free 903333823c75a1c1887e923828113a1b0fd12020cElliott Hughes Software Foundation; either version 3 of the License, or (at 1003333823c75a1c1887e923828113a1b0fd12020cElliott Hughes your option) any later version 1103333823c75a1c1887e923828113a1b0fd12020cElliott Hughes 1203333823c75a1c1887e923828113a1b0fd12020cElliott Hughes or 1303333823c75a1c1887e923828113a1b0fd12020cElliott Hughes 1403333823c75a1c1887e923828113a1b0fd12020cElliott Hughes * the GNU General Public License as published by the Free 1503333823c75a1c1887e923828113a1b0fd12020cElliott Hughes Software Foundation; either version 2 of the License, or (at 1603333823c75a1c1887e923828113a1b0fd12020cElliott Hughes your option) any later version 1703333823c75a1c1887e923828113a1b0fd12020cElliott Hughes 1803333823c75a1c1887e923828113a1b0fd12020cElliott Hughes or both in parallel, as here. 1903333823c75a1c1887e923828113a1b0fd12020cElliott Hughes 2003333823c75a1c1887e923828113a1b0fd12020cElliott Hughes elfutils is distributed in the hope that it will be useful, but 2125b3c049e70834cf33790a28643ab058b507b35cBen Cheng WITHOUT ANY WARRANTY; without even the implied warranty of 2225b3c049e70834cf33790a28643ab058b507b35cBen Cheng MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 2325b3c049e70834cf33790a28643ab058b507b35cBen Cheng General Public License for more details. 2425b3c049e70834cf33790a28643ab058b507b35cBen Cheng 2503333823c75a1c1887e923828113a1b0fd12020cElliott Hughes You should have received copies of the GNU General Public License and 2603333823c75a1c1887e923828113a1b0fd12020cElliott Hughes the GNU Lesser General Public License along with this program. If 2703333823c75a1c1887e923828113a1b0fd12020cElliott Hughes not, see <http://www.gnu.org/licenses/>. */ 2825b3c049e70834cf33790a28643ab058b507b35cBen Cheng 2925b3c049e70834cf33790a28643ab058b507b35cBen Cheng#include "libdwflP.h" 3025b3c049e70834cf33790a28643ab058b507b35cBen Cheng#include <inttypes.h> 3125b3c049e70834cf33790a28643ab058b507b35cBen Cheng#include <fcntl.h> 3225b3c049e70834cf33790a28643ab058b507b35cBen Cheng#include <unistd.h> 3325b3c049e70834cf33790a28643ab058b507b35cBen Cheng 3425b3c049e70834cf33790a28643ab058b507b35cBen Cheng 3525b3c049e70834cf33790a28643ab058b507b35cBen Chengint 3625b3c049e70834cf33790a28643ab058b507b35cBen Chenginternal_function 3703333823c75a1c1887e923828113a1b0fd12020cElliott Hughes__libdwfl_open_by_build_id (Dwfl_Module *mod, bool debug, char **file_name, 3803333823c75a1c1887e923828113a1b0fd12020cElliott Hughes const size_t id_len, const uint8_t *id) 3925b3c049e70834cf33790a28643ab058b507b35cBen Cheng{ 4025b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Search debuginfo_path directories' .build-id/ subdirectories. */ 4125b3c049e70834cf33790a28643ab058b507b35cBen Cheng 4225b3c049e70834cf33790a28643ab058b507b35cBen Cheng char id_name[sizeof "/.build-id/" + 1 + id_len * 2 + sizeof ".debug" - 1]; 4325b3c049e70834cf33790a28643ab058b507b35cBen Cheng strcpy (id_name, "/.build-id/"); 4425b3c049e70834cf33790a28643ab058b507b35cBen Cheng int n = snprintf (&id_name[sizeof "/.build-id/" - 1], 4525b3c049e70834cf33790a28643ab058b507b35cBen Cheng 4, "%02" PRIx8 "/", (uint8_t) id[0]); 4625b3c049e70834cf33790a28643ab058b507b35cBen Cheng assert (n == 3); 4725b3c049e70834cf33790a28643ab058b507b35cBen Cheng for (size_t i = 1; i < id_len; ++i) 4825b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 4925b3c049e70834cf33790a28643ab058b507b35cBen Cheng n = snprintf (&id_name[sizeof "/.build-id/" - 1 + 3 + (i - 1) * 2], 5025b3c049e70834cf33790a28643ab058b507b35cBen Cheng 3, "%02" PRIx8, (uint8_t) id[i]); 5125b3c049e70834cf33790a28643ab058b507b35cBen Cheng assert (n == 2); 5225b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 5325b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (debug) 5425b3c049e70834cf33790a28643ab058b507b35cBen Cheng strcpy (&id_name[sizeof "/.build-id/" - 1 + 3 + (id_len - 1) * 2], 5525b3c049e70834cf33790a28643ab058b507b35cBen Cheng ".debug"); 5625b3c049e70834cf33790a28643ab058b507b35cBen Cheng 5725b3c049e70834cf33790a28643ab058b507b35cBen Cheng const Dwfl_Callbacks *const cb = mod->dwfl->callbacks; 5825b3c049e70834cf33790a28643ab058b507b35cBen Cheng char *path = strdupa ((cb->debuginfo_path ? *cb->debuginfo_path : NULL) 5925b3c049e70834cf33790a28643ab058b507b35cBen Cheng ?: DEFAULT_DEBUGINFO_PATH); 6025b3c049e70834cf33790a28643ab058b507b35cBen Cheng 6125b3c049e70834cf33790a28643ab058b507b35cBen Cheng int fd = -1; 6225b3c049e70834cf33790a28643ab058b507b35cBen Cheng char *dir; 6325b3c049e70834cf33790a28643ab058b507b35cBen Cheng while (fd < 0 && (dir = strsep (&path, ":")) != NULL) 6425b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 6525b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (dir[0] == '+' || dir[0] == '-') 6625b3c049e70834cf33790a28643ab058b507b35cBen Cheng ++dir; 6725b3c049e70834cf33790a28643ab058b507b35cBen Cheng 6825b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Only absolute directory names are useful to us. */ 6925b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (dir[0] != '/') 7025b3c049e70834cf33790a28643ab058b507b35cBen Cheng continue; 7125b3c049e70834cf33790a28643ab058b507b35cBen Cheng 7225b3c049e70834cf33790a28643ab058b507b35cBen Cheng size_t dirlen = strlen (dir); 7325b3c049e70834cf33790a28643ab058b507b35cBen Cheng char *name = malloc (dirlen + sizeof id_name); 7425b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (unlikely (name == NULL)) 7525b3c049e70834cf33790a28643ab058b507b35cBen Cheng break; 7625b3c049e70834cf33790a28643ab058b507b35cBen Cheng memcpy (mempcpy (name, dir, dirlen), id_name, sizeof id_name); 7725b3c049e70834cf33790a28643ab058b507b35cBen Cheng 7825b3c049e70834cf33790a28643ab058b507b35cBen Cheng fd = TEMP_FAILURE_RETRY (open64 (name, O_RDONLY)); 7925b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (fd >= 0) 8025b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 8125b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (*file_name != NULL) 8225b3c049e70834cf33790a28643ab058b507b35cBen Cheng free (*file_name); 8325b3c049e70834cf33790a28643ab058b507b35cBen Cheng *file_name = canonicalize_file_name (name); 8425b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (*file_name == NULL) 8525b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 8625b3c049e70834cf33790a28643ab058b507b35cBen Cheng *file_name = name; 8725b3c049e70834cf33790a28643ab058b507b35cBen Cheng name = NULL; 8825b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 8925b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 9025b3c049e70834cf33790a28643ab058b507b35cBen Cheng free (name); 9125b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 9225b3c049e70834cf33790a28643ab058b507b35cBen Cheng 9325b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* If we simply found nothing, clear errno. If we had some other error 9425b3c049e70834cf33790a28643ab058b507b35cBen Cheng with the file, report that. Possibly this should treat other errors 9525b3c049e70834cf33790a28643ab058b507b35cBen Cheng like ENOENT too. But ignoring all errors could mask some that should 9625b3c049e70834cf33790a28643ab058b507b35cBen Cheng be reported. */ 9725b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (fd < 0 && errno == ENOENT) 9825b3c049e70834cf33790a28643ab058b507b35cBen Cheng errno = 0; 9925b3c049e70834cf33790a28643ab058b507b35cBen Cheng 10025b3c049e70834cf33790a28643ab058b507b35cBen Cheng return fd; 10125b3c049e70834cf33790a28643ab058b507b35cBen Cheng} 10225b3c049e70834cf33790a28643ab058b507b35cBen Cheng 10325b3c049e70834cf33790a28643ab058b507b35cBen Chengint 10403333823c75a1c1887e923828113a1b0fd12020cElliott Hughesinternal_function 10503333823c75a1c1887e923828113a1b0fd12020cElliott Hughes__libdwfl_open_mod_by_build_id (Dwfl_Module *mod, bool debug, char **file_name) 10603333823c75a1c1887e923828113a1b0fd12020cElliott Hughes{ 10703333823c75a1c1887e923828113a1b0fd12020cElliott Hughes /* If *FILE_NAME was primed into the module, leave it there 10803333823c75a1c1887e923828113a1b0fd12020cElliott Hughes as the fallback when we have nothing to offer. */ 10903333823c75a1c1887e923828113a1b0fd12020cElliott Hughes errno = 0; 11003333823c75a1c1887e923828113a1b0fd12020cElliott Hughes if (mod->build_id_len <= 0) 11103333823c75a1c1887e923828113a1b0fd12020cElliott Hughes return -1; 11203333823c75a1c1887e923828113a1b0fd12020cElliott Hughes 11303333823c75a1c1887e923828113a1b0fd12020cElliott Hughes const size_t id_len = mod->build_id_len; 11403333823c75a1c1887e923828113a1b0fd12020cElliott Hughes const uint8_t *id = mod->build_id_bits; 11503333823c75a1c1887e923828113a1b0fd12020cElliott Hughes 11603333823c75a1c1887e923828113a1b0fd12020cElliott Hughes return __libdwfl_open_by_build_id (mod, debug, file_name, id_len, id); 11703333823c75a1c1887e923828113a1b0fd12020cElliott Hughes} 11803333823c75a1c1887e923828113a1b0fd12020cElliott Hughes 11903333823c75a1c1887e923828113a1b0fd12020cElliott Hughesint 12025b3c049e70834cf33790a28643ab058b507b35cBen Chengdwfl_build_id_find_elf (Dwfl_Module *mod, 12125b3c049e70834cf33790a28643ab058b507b35cBen Cheng void **userdata __attribute__ ((unused)), 12225b3c049e70834cf33790a28643ab058b507b35cBen Cheng const char *modname __attribute__ ((unused)), 12325b3c049e70834cf33790a28643ab058b507b35cBen Cheng Dwarf_Addr base __attribute__ ((unused)), 12425b3c049e70834cf33790a28643ab058b507b35cBen Cheng char **file_name, Elf **elfp) 12525b3c049e70834cf33790a28643ab058b507b35cBen Cheng{ 12625b3c049e70834cf33790a28643ab058b507b35cBen Cheng *elfp = NULL; 12703333823c75a1c1887e923828113a1b0fd12020cElliott Hughes if (mod->is_executable && mod->dwfl->executable_for_core != NULL) 12803333823c75a1c1887e923828113a1b0fd12020cElliott Hughes { 12903333823c75a1c1887e923828113a1b0fd12020cElliott Hughes /* When dwfl_core_file_report was called with a non-NULL executable file 13003333823c75a1c1887e923828113a1b0fd12020cElliott Hughes name this callback will replace the Dwfl_Module main.name with the 13103333823c75a1c1887e923828113a1b0fd12020cElliott Hughes recorded executable file when MOD was identified as main executable 13203333823c75a1c1887e923828113a1b0fd12020cElliott Hughes (which then triggers opening and reporting of the executable). */ 13303333823c75a1c1887e923828113a1b0fd12020cElliott Hughes int fd = open64 (mod->dwfl->executable_for_core, O_RDONLY); 13403333823c75a1c1887e923828113a1b0fd12020cElliott Hughes if (fd >= 0) 13503333823c75a1c1887e923828113a1b0fd12020cElliott Hughes { 13603333823c75a1c1887e923828113a1b0fd12020cElliott Hughes *file_name = strdup (mod->dwfl->executable_for_core); 13703333823c75a1c1887e923828113a1b0fd12020cElliott Hughes if (*file_name != NULL) 13803333823c75a1c1887e923828113a1b0fd12020cElliott Hughes return fd; 13903333823c75a1c1887e923828113a1b0fd12020cElliott Hughes else 14003333823c75a1c1887e923828113a1b0fd12020cElliott Hughes close (fd); 14103333823c75a1c1887e923828113a1b0fd12020cElliott Hughes } 14203333823c75a1c1887e923828113a1b0fd12020cElliott Hughes } 14303333823c75a1c1887e923828113a1b0fd12020cElliott Hughes int fd = __libdwfl_open_mod_by_build_id (mod, false, file_name); 14425b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (fd >= 0) 14525b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 14625b3c049e70834cf33790a28643ab058b507b35cBen Cheng Dwfl_Error error = __libdw_open_file (&fd, elfp, true, false); 14725b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (error != DWFL_E_NOERROR) 14825b3c049e70834cf33790a28643ab058b507b35cBen Cheng __libdwfl_seterrno (error); 14925b3c049e70834cf33790a28643ab058b507b35cBen Cheng else if (__libdwfl_find_build_id (mod, false, *elfp) == 2) 15025b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 15125b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* This is a backdoor signal to short-circuit the ID refresh. */ 15225b3c049e70834cf33790a28643ab058b507b35cBen Cheng mod->main.valid = true; 15325b3c049e70834cf33790a28643ab058b507b35cBen Cheng return fd; 15425b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 15525b3c049e70834cf33790a28643ab058b507b35cBen Cheng else 15625b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 15725b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* This file does not contain the ID it should! */ 15825b3c049e70834cf33790a28643ab058b507b35cBen Cheng elf_end (*elfp); 15925b3c049e70834cf33790a28643ab058b507b35cBen Cheng *elfp = NULL; 16025b3c049e70834cf33790a28643ab058b507b35cBen Cheng close (fd); 16125b3c049e70834cf33790a28643ab058b507b35cBen Cheng fd = -1; 16225b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 16325b3c049e70834cf33790a28643ab058b507b35cBen Cheng free (*file_name); 16425b3c049e70834cf33790a28643ab058b507b35cBen Cheng *file_name = NULL; 16525b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 16625b3c049e70834cf33790a28643ab058b507b35cBen Cheng else if (errno == 0 && mod->build_id_len > 0) 16725b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Setting this with no file yet loaded is a marker that 16825b3c049e70834cf33790a28643ab058b507b35cBen Cheng the build ID is authoritative even if we also know a 16925b3c049e70834cf33790a28643ab058b507b35cBen Cheng putative *FILE_NAME. */ 17025b3c049e70834cf33790a28643ab058b507b35cBen Cheng mod->main.valid = true; 17125b3c049e70834cf33790a28643ab058b507b35cBen Cheng 17225b3c049e70834cf33790a28643ab058b507b35cBen Cheng return fd; 17325b3c049e70834cf33790a28643ab058b507b35cBen Cheng} 17425b3c049e70834cf33790a28643ab058b507b35cBen ChengINTDEF (dwfl_build_id_find_elf) 175