1 /* Returns the file name and crc stored in the .gnu_debuglink if found. 2 Copyright (C) 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 #ifdef HAVE_CONFIG_H 30 # include <config.h> 31 #endif 32 33 #include "libdwelfP.h" 34 35 const char * 36 dwelf_elf_gnu_debuglink (Elf *elf, GElf_Word *crc) 37 { 38 size_t shstrndx; 39 if (elf_getshdrstrndx (elf, &shstrndx) < 0) 40 return NULL; 41 42 Elf_Scn *scn = NULL; 43 while ((scn = elf_nextscn (elf, scn)) != NULL) 44 { 45 GElf_Shdr shdr_mem; 46 GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem); 47 if (shdr == NULL) 48 return NULL; 49 50 const char *name = elf_strptr (elf, shstrndx, shdr->sh_name); 51 if (name == NULL) 52 return NULL; 53 54 if (!strcmp (name, ".gnu_debuglink")) 55 break; 56 } 57 58 if (scn == NULL) 59 return NULL; 60 61 /* Found the .gnu_debuglink section. Extract its contents. */ 62 Elf_Data *rawdata = elf_rawdata (scn, NULL); 63 if (rawdata == NULL || rawdata->d_buf == NULL) 64 return NULL; 65 66 /* The CRC comes after the zero-terminated file name, 67 (aligned up to 4 bytes) at the end of the section data. */ 68 if (rawdata->d_size <= sizeof *crc 69 || memchr (rawdata->d_buf, '\0', rawdata->d_size - sizeof *crc) == NULL) 70 return NULL; 71 72 Elf_Data crcdata = 73 { 74 .d_type = ELF_T_WORD, 75 .d_buf = crc, 76 .d_size = sizeof *crc, 77 .d_version = EV_CURRENT, 78 }; 79 Elf_Data conv = 80 { 81 .d_type = ELF_T_WORD, 82 .d_buf = rawdata->d_buf + rawdata->d_size - sizeof *crc, 83 .d_size = sizeof *crc, 84 .d_version = EV_CURRENT, 85 }; 86 87 GElf_Ehdr ehdr_mem; 88 GElf_Ehdr *ehdr = gelf_getehdr (elf, &ehdr_mem); 89 if (ehdr == NULL) 90 return NULL; 91 92 Elf_Data *d = gelf_xlatetom (elf, &crcdata, &conv, ehdr->e_ident[EI_DATA]); 93 if (d == NULL) 94 return NULL; 95 assert (d == &crcdata); 96 97 return rawdata->d_buf; 98 } 99 INTDEF(dwelf_elf_gnu_debuglink) 100
