1 /* Return build ID information for a module. 2 Copyright (C) 2007-2010, 2014 Red Hat, Inc. 3 This file is part of elfutils. 4 5 This file is free software; you can redistribute it and/or modify 6 it under the terms of either 7 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 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 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/>. */ 28 29 #include "libdwflP.h" 30 31 static int 32 found_build_id (Dwfl_Module *mod, bool set, 33 const void *bits, int len, GElf_Addr vaddr) 34 { 35 if (!set) 36 /* When checking bits, we do not compare VADDR because the 37 address found in a debuginfo file may not match the main 38 file as modified by prelink. */ 39 return 1 + (mod->build_id_len == len 40 && !memcmp (bits, mod->build_id_bits, len)); 41 42 void *copy = malloc (len); 43 if (unlikely (copy == NULL)) 44 { 45 __libdwfl_seterrno (DWFL_E_NOMEM); 46 return -1; 47 } 48 49 mod->build_id_bits = memcpy (copy, bits, len); 50 mod->build_id_vaddr = vaddr; 51 mod->build_id_len = len; 52 return len; 53 } 54 55 int 56 internal_function 57 __libdwfl_find_build_id (Dwfl_Module *mod, bool set, Elf *elf) 58 { 59 const void *build_id_bits; 60 GElf_Addr build_id_elfaddr; 61 int build_id_len; 62 63 /* For mod == NULL use dwelf_elf_gnu_build_id directly. */ 64 assert (mod != NULL); 65 66 int result = __libdwfl_find_elf_build_id (mod, elf, &build_id_bits, 67 &build_id_elfaddr, &build_id_len); 68 if (result <= 0) 69 return result; 70 71 GElf_Addr build_id_vaddr = build_id_elfaddr + (build_id_elfaddr != 0 72 ? mod->main_bias : 0); 73 return found_build_id (mod, set, build_id_bits, build_id_len, build_id_vaddr); 74 } 75 76 int 77 dwfl_module_build_id (Dwfl_Module *mod, 78 const unsigned char **bits, GElf_Addr *vaddr) 79 { 80 if (mod == NULL) 81 return -1; 82 83 if (mod->build_id_len == 0 && mod->main.elf != NULL) 84 { 85 /* We have the file, but have not examined it yet. */ 86 int result = __libdwfl_find_build_id (mod, true, mod->main.elf); 87 if (result <= 0) 88 { 89 mod->build_id_len = -1; /* Cache negative result. */ 90 return result; 91 } 92 } 93 94 if (mod->build_id_len <= 0) 95 return 0; 96 97 *bits = mod->build_id_bits; 98 *vaddr = mod->build_id_vaddr; 99 return mod->build_id_len; 100 } 101 INTDEF (dwfl_module_build_id) 102 NEW_VERSION (dwfl_module_build_id, ELFUTILS_0.138) 103 104 #ifdef SYMBOL_VERSIONING 105 COMPAT_VERSION (dwfl_module_build_id, ELFUTILS_0.130, vaddr_at_end) 106 107 int 108 _compat_vaddr_at_end_dwfl_module_build_id (Dwfl_Module *mod, 109 const unsigned char **bits, 110 GElf_Addr *vaddr) 111 { 112 int result = INTUSE(dwfl_module_build_id) (mod, bits, vaddr); 113 if (result > 0) 114 *vaddr += (result + 3) & -4; 115 return result; 116 } 117 #endif 118
