Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 1 | /* Find the debuginfo file for a module from its build ID. |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame^] | 2 | Copyright (C) 2007, 2009, 2014 Red Hat, Inc. |
| 3 | This file is part of elfutils. |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 4 | |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame^] | 5 | This file is free software; you can redistribute it and/or modify |
| 6 | it under the terms of either |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 7 | |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame^] | 8 | * the GNU Lesser General Public License as published by the Free |
| 9 | Software Foundation; either version 3 of the License, or (at |
| 10 | your option) any later version |
| 11 | |
| 12 | or |
| 13 | |
| 14 | * the GNU General Public License as published by the Free |
| 15 | Software Foundation; either version 2 of the License, or (at |
| 16 | your option) any later version |
| 17 | |
| 18 | or both in parallel, as here. |
| 19 | |
| 20 | elfutils is distributed in the hope that it will be useful, but |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 21 | WITHOUT ANY WARRANTY; without even the implied warranty of |
| 22 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 23 | General Public License for more details. |
| 24 | |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame^] | 25 | You should have received copies of the GNU General Public License and |
| 26 | the GNU Lesser General Public License along with this program. If |
| 27 | not, see <http://www.gnu.org/licenses/>. */ |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 28 | |
| 29 | #include "libdwflP.h" |
| 30 | #include <unistd.h> |
| 31 | |
| 32 | |
| 33 | int |
| 34 | dwfl_build_id_find_debuginfo (Dwfl_Module *mod, |
| 35 | void **userdata __attribute__ ((unused)), |
| 36 | const char *modname __attribute__ ((unused)), |
| 37 | Dwarf_Addr base __attribute__ ((unused)), |
| 38 | const char *file __attribute__ ((unused)), |
| 39 | const char *debuglink __attribute__ ((unused)), |
| 40 | GElf_Word crc __attribute__ ((unused)), |
| 41 | char **debuginfo_file_name) |
| 42 | { |
| 43 | int fd = -1; |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame^] | 44 | |
| 45 | /* Are we looking for a separate debug file for the main file or for |
| 46 | an alternate (dwz multi) debug file? Alternatively we could check |
| 47 | whether the dwbias == -1. */ |
| 48 | if (mod->dw != NULL) |
| 49 | { |
| 50 | const void *build_id; |
| 51 | const char *altname; |
| 52 | ssize_t build_id_len = INTUSE(dwelf_dwarf_gnu_debugaltlink) (mod->dw, |
| 53 | &altname, |
| 54 | &build_id); |
| 55 | if (build_id_len > 0) |
| 56 | fd = __libdwfl_open_by_build_id (mod, true, debuginfo_file_name, |
| 57 | build_id_len, build_id); |
| 58 | |
| 59 | if (fd >= 0) |
| 60 | { |
| 61 | /* We need to open an Elf handle on the file so we can check its |
| 62 | build ID note for validation. Backdoor the handle into the |
| 63 | module data structure since we had to open it early anyway. */ |
| 64 | Dwfl_Error error = __libdw_open_file (&fd, &mod->alt_elf, |
| 65 | true, false); |
| 66 | if (error != DWFL_E_NOERROR) |
| 67 | __libdwfl_seterrno (error); |
| 68 | else |
| 69 | { |
| 70 | const void *alt_build_id; |
| 71 | ssize_t alt_len = INTUSE(dwelf_elf_gnu_build_id) (mod->alt_elf, |
| 72 | &alt_build_id); |
| 73 | if (alt_len > 0 && alt_len == build_id_len |
| 74 | && memcmp (build_id, alt_build_id, alt_len) == 0) |
| 75 | return fd; |
| 76 | else |
| 77 | { |
| 78 | /* A mismatch! */ |
| 79 | elf_end (mod->alt_elf); |
| 80 | mod->alt_elf = NULL; |
| 81 | close (fd); |
| 82 | fd = -1; |
| 83 | } |
| 84 | free (*debuginfo_file_name); |
| 85 | *debuginfo_file_name = NULL; |
| 86 | errno = 0; |
| 87 | } |
| 88 | } |
| 89 | return fd; |
| 90 | } |
| 91 | |
| 92 | /* We don't even have the Dwarf yet and it isn't in the main file. |
| 93 | Try to find separate debug file now using the module build id. */ |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 94 | const unsigned char *bits; |
| 95 | GElf_Addr vaddr; |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame^] | 96 | |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 97 | if (INTUSE(dwfl_module_build_id) (mod, &bits, &vaddr) > 0) |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame^] | 98 | fd = __libdwfl_open_mod_by_build_id (mod, true, debuginfo_file_name); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 99 | if (fd >= 0) |
| 100 | { |
| 101 | /* We need to open an Elf handle on the file so we can check its |
| 102 | build ID note for validation. Backdoor the handle into the |
| 103 | module data structure since we had to open it early anyway. */ |
| 104 | Dwfl_Error error = __libdw_open_file (&fd, &mod->debug.elf, true, false); |
| 105 | if (error != DWFL_E_NOERROR) |
| 106 | __libdwfl_seterrno (error); |
| 107 | else if (likely (__libdwfl_find_build_id (mod, false, |
| 108 | mod->debug.elf) == 2)) |
| 109 | { |
| 110 | /* Also backdoor the gratuitous flag. */ |
| 111 | mod->debug.valid = true; |
| 112 | return fd; |
| 113 | } |
| 114 | else |
| 115 | { |
| 116 | /* A mismatch! */ |
| 117 | elf_end (mod->debug.elf); |
| 118 | mod->debug.elf = NULL; |
| 119 | close (fd); |
| 120 | fd = -1; |
| 121 | } |
| 122 | free (*debuginfo_file_name); |
| 123 | *debuginfo_file_name = NULL; |
| 124 | errno = 0; |
| 125 | } |
| 126 | return fd; |
| 127 | } |
| 128 | INTDEF (dwfl_build_id_find_debuginfo) |