1 /* Return build ID information for a module. 2 Copyright (C) 2007, 2008 Red Hat, Inc. 3 This file is part of Red Hat elfutils. 4 5 Red Hat elfutils is free software; you can redistribute it and/or modify 6 it under the terms of the GNU General Public License as published by the 7 Free Software Foundation; version 2 of the License. 8 9 Red Hat elfutils is distributed in the hope that it will be useful, but 10 WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 General Public License for more details. 13 14 You should have received a copy of the GNU General Public License along 15 with Red Hat elfutils; if not, write to the Free Software Foundation, 16 Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. 17 18 In addition, as a special exception, Red Hat, Inc. gives You the 19 additional right to link the code of Red Hat elfutils with code licensed 20 under any Open Source Initiative certified open source license 21 (http://www.opensource.org/licenses/index.php) which requires the 22 distribution of source code with any binary distribution and to 23 distribute linked combinations of the two. Non-GPL Code permitted under 24 this exception must only link to the code of Red Hat elfutils through 25 those well defined interfaces identified in the file named EXCEPTION 26 found in the source code files (the "Approved Interfaces"). The files 27 of Non-GPL Code may instantiate templates or use macros or inline 28 functions from the Approved Interfaces without causing the resulting 29 work to be covered by the GNU General Public License. Only Red Hat, 30 Inc. may make changes or additions to the list of Approved Interfaces. 31 Red Hat's grant of this exception is conditioned upon your not adding 32 any new exceptions. If you wish to add a new Approved Interface or 33 exception, please contact Red Hat. You must obey the GNU General Public 34 License in all respects for all of the Red Hat elfutils code and other 35 code used in conjunction with Red Hat elfutils except the Non-GPL Code 36 covered by this exception. If you modify this file, you may extend this 37 exception to your version of the file, but you are not obligated to do 38 so. If you do not wish to provide this exception without modification, 39 you must delete this exception statement from your version and license 40 this file solely under the GPL without exception. 41 42 Red Hat elfutils is an included package of the Open Invention Network. 43 An included package of the Open Invention Network is a package for which 44 Open Invention Network licensees cross-license their patents. No patent 45 license is granted, either expressly or impliedly, by designation as an 46 included package. Should you wish to participate in the Open Invention 47 Network licensing program, please visit www.openinventionnetwork.com 48 <http://www.openinventionnetwork.com>. */ 49 50 #include "libdwflP.h" 51 52 static int 53 found_build_id (Dwfl_Module *mod, bool set, 54 const void *bits, int len, GElf_Addr vaddr) 55 { 56 if (!set) 57 /* When checking bits, we do not compare VADDR because the 58 address found in a debuginfo file may not match the main 59 file as modified by prelink. */ 60 return 1 + (mod->build_id_len == len 61 && !memcmp (bits, mod->build_id_bits, len)); 62 63 void *copy = malloc (len); 64 if (unlikely (copy == NULL)) 65 { 66 __libdwfl_seterrno (DWFL_E_NOMEM); 67 return -1; 68 } 69 70 mod->build_id_bits = memcpy (copy, bits, len); 71 mod->build_id_vaddr = vaddr; 72 mod->build_id_len = len; 73 return len; 74 } 75 76 #define NO_VADDR ((GElf_Addr) -1l) 77 78 static int 79 check_notes (Dwfl_Module *mod, bool set, Elf_Data *data, GElf_Addr data_vaddr) 80 { 81 size_t pos = 0; 82 GElf_Nhdr nhdr; 83 size_t name_pos; 84 size_t desc_pos; 85 while ((pos = gelf_getnote (data, pos, &nhdr, &name_pos, &desc_pos)) > 0) 86 if (nhdr.n_type == NT_GNU_BUILD_ID 87 && nhdr.n_namesz == sizeof "GNU" && !memcmp (data->d_buf + name_pos, 88 "GNU", sizeof "GNU")) 89 return found_build_id (mod, set, 90 data->d_buf + desc_pos, nhdr.n_descsz, 91 data_vaddr == NO_VADDR ? 0 92 : data_vaddr + desc_pos); 93 return 0; 94 } 95 96 int 97 internal_function 98 __libdwfl_find_build_id (Dwfl_Module *mod, bool set, Elf *elf) 99 { 100 int result = 0; 101 102 Elf_Scn *scn = elf_nextscn (elf, NULL); 103 104 if (scn == NULL) 105 { 106 /* No sections, have to look for phdrs. */ 107 GElf_Ehdr ehdr_mem; 108 GElf_Ehdr *ehdr = gelf_getehdr (elf, &ehdr_mem); 109 if (unlikely (ehdr == NULL)) 110 { 111 __libdwfl_seterrno (DWFL_E_LIBELF); 112 return -1; 113 } 114 for (uint_fast16_t i = 0; result == 0 && i < ehdr_mem.e_phnum; ++i) 115 { 116 GElf_Phdr phdr_mem; 117 GElf_Phdr *phdr = gelf_getphdr (elf, i, &phdr_mem); 118 if (likely (phdr != NULL) && phdr->p_type == PT_NOTE) 119 result = check_notes (mod, set, 120 elf_getdata_rawchunk (elf, 121 phdr->p_offset, 122 phdr->p_filesz, 123 ELF_T_NHDR), 124 phdr->p_vaddr + mod->main.bias); 125 } 126 } 127 else 128 do 129 { 130 GElf_Shdr shdr_mem; 131 GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem); 132 if (likely (shdr != NULL) && shdr->sh_type == SHT_NOTE) 133 result = check_notes (mod, set, elf_getdata (scn, NULL), 134 (shdr->sh_flags & SHF_ALLOC) 135 ? shdr->sh_addr + mod->main.bias : NO_VADDR); 136 } 137 while (result == 0 && (scn = elf_nextscn (elf, scn)) != NULL); 138 139 return result; 140 } 141 142 /* ANDROID_CHANGE_BEGIN */ 143 #if 0 144 int 145 __dwfl_module_build_id (Dwfl_Module *mod, 146 const unsigned char **bits, GElf_Addr *vaddr) 147 #else 148 int 149 dwfl_module_build_id (Dwfl_Module *mod, 150 const unsigned char **bits, GElf_Addr *vaddr) 151 #endif 152 /* ANDROID_CHANGE_END */ 153 { 154 if (mod == NULL) 155 return -1; 156 157 if (mod->build_id_len == 0 && mod->main.elf != NULL) 158 { 159 /* We have the file, but have not examined it yet. */ 160 int result = __libdwfl_find_build_id (mod, true, mod->main.elf); 161 if (result <= 0) 162 { 163 mod->build_id_len = -1; /* Cache negative result. */ 164 return result; 165 } 166 } 167 168 if (mod->build_id_len <= 0) 169 return 0; 170 171 *bits = mod->build_id_bits; 172 *vaddr = mod->build_id_vaddr; 173 return mod->build_id_len; 174 } 175 176 /* ANDROID_CHANGE_BEGIN */ 177 #if 0 178 extern __typeof__ (dwfl_module_build_id) INTUSE(dwfl_module_build_id) 179 __attribute__ ((alias ("__dwfl_module_build_id"))); 180 asm (".symver " 181 "__dwfl_module_build_id, dwfl_module_build_id@@ELFUTILS_0.138"); 182 183 int 184 _BUG_COMPAT_dwfl_module_build_id (Dwfl_Module *mod, 185 const unsigned char **bits, GElf_Addr *vaddr) 186 { 187 int result = INTUSE(dwfl_module_build_id) (mod, bits, vaddr); 188 if (result > 0) 189 *vaddr += (result + 3) & -4; 190 return result; 191 } 192 asm (".symver " 193 "_BUG_COMPAT_dwfl_module_build_id, dwfl_module_build_id (at) ELFUTILS_0.130"); 194 #endif 195 /* ANDROID_CHANGE_END */ 196
