Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 1 | /* Return string pointer from string section. |
| 2 | Copyright (C) 1998, 1999, 2000, 2001, 2002, 2004, 2008, 2009 Red Hat, Inc. |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame^] | 3 | This file is part of elfutils. |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 4 | Contributed by Ulrich Drepper <drepper@redhat.com>, 1998. |
| 5 | |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame^] | 6 | This file is free software; you can redistribute it and/or modify |
| 7 | it under the terms of either |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 8 | |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame^] | 9 | * the GNU Lesser General Public License as published by the Free |
| 10 | Software Foundation; either version 3 of the License, or (at |
| 11 | your option) any later version |
| 12 | |
| 13 | or |
| 14 | |
| 15 | * the GNU General Public License as published by the Free |
| 16 | Software Foundation; either version 2 of the License, or (at |
| 17 | your option) any later version |
| 18 | |
| 19 | or both in parallel, as here. |
| 20 | |
| 21 | elfutils is distributed in the hope that it will be useful, but |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 22 | WITHOUT ANY WARRANTY; without even the implied warranty of |
| 23 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 24 | General Public License for more details. |
| 25 | |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame^] | 26 | You should have received copies of the GNU General Public License and |
| 27 | the GNU Lesser General Public License along with this program. If |
| 28 | not, see <http://www.gnu.org/licenses/>. */ |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 29 | |
| 30 | #ifdef HAVE_CONFIG_H |
| 31 | # include <config.h> |
| 32 | #endif |
| 33 | |
| 34 | #include <libelf.h> |
| 35 | #include <stddef.h> |
| 36 | |
| 37 | #include "libelfP.h" |
| 38 | |
| 39 | |
| 40 | char * |
| 41 | elf_strptr (elf, idx, offset) |
| 42 | Elf *elf; |
| 43 | size_t idx; |
| 44 | size_t offset; |
| 45 | { |
| 46 | if (elf == NULL) |
| 47 | return NULL; |
| 48 | |
| 49 | if (elf->kind != ELF_K_ELF) |
| 50 | { |
| 51 | __libelf_seterrno (ELF_E_INVALID_HANDLE); |
| 52 | return NULL; |
| 53 | } |
| 54 | |
| 55 | rwlock_rdlock (elf->lock); |
| 56 | |
| 57 | char *result = NULL; |
| 58 | Elf_Scn *strscn; |
| 59 | |
| 60 | /* Find the section in the list. */ |
| 61 | Elf_ScnList *runp = (elf->class == ELFCLASS32 |
| 62 | || (offsetof (struct Elf, state.elf32.scns) |
| 63 | == offsetof (struct Elf, state.elf64.scns)) |
| 64 | ? &elf->state.elf32.scns : &elf->state.elf64.scns); |
| 65 | while (1) |
| 66 | { |
| 67 | if (idx < runp->max) |
| 68 | { |
| 69 | if (idx < runp->cnt) |
| 70 | strscn = &runp->data[idx]; |
| 71 | else |
| 72 | { |
| 73 | __libelf_seterrno (ELF_E_INVALID_INDEX); |
| 74 | goto out; |
| 75 | } |
| 76 | break; |
| 77 | } |
| 78 | |
| 79 | idx -= runp->max; |
| 80 | |
| 81 | runp = runp->next; |
| 82 | if (runp == NULL) |
| 83 | { |
| 84 | __libelf_seterrno (ELF_E_INVALID_INDEX); |
| 85 | goto out; |
| 86 | } |
| 87 | } |
| 88 | |
| 89 | if (elf->class == ELFCLASS32) |
| 90 | { |
| 91 | if (unlikely (strscn->shdr.e32->sh_type != SHT_STRTAB)) |
| 92 | { |
| 93 | /* This is no string section. */ |
| 94 | __libelf_seterrno (ELF_E_INVALID_SECTION); |
| 95 | goto out; |
| 96 | } |
| 97 | |
| 98 | if (unlikely (offset >= strscn->shdr.e32->sh_size)) |
| 99 | { |
| 100 | /* The given offset is too big, it is beyond this section. */ |
| 101 | __libelf_seterrno (ELF_E_OFFSET_RANGE); |
| 102 | goto out; |
| 103 | } |
| 104 | } |
| 105 | else |
| 106 | { |
| 107 | if (unlikely (strscn->shdr.e64->sh_type != SHT_STRTAB)) |
| 108 | { |
| 109 | /* This is no string section. */ |
| 110 | __libelf_seterrno (ELF_E_INVALID_SECTION); |
| 111 | goto out; |
| 112 | } |
| 113 | |
| 114 | if (unlikely (offset >= strscn->shdr.e64->sh_size)) |
| 115 | { |
| 116 | /* The given offset is too big, it is beyond this section. */ |
| 117 | __libelf_seterrno (ELF_E_OFFSET_RANGE); |
| 118 | goto out; |
| 119 | } |
| 120 | } |
| 121 | |
| 122 | if (strscn->rawdata_base == NULL && ! strscn->data_read) |
| 123 | { |
| 124 | rwlock_unlock (elf->lock); |
| 125 | rwlock_wrlock (elf->lock); |
| 126 | if (strscn->rawdata_base == NULL && ! strscn->data_read |
| 127 | /* Read the section data. */ |
| 128 | && __libelf_set_rawdata_wrlock (strscn) != 0) |
| 129 | goto out; |
| 130 | } |
| 131 | |
| 132 | if (likely (strscn->rawdata_base != NULL)) |
| 133 | // XXX Is this correct if a file is read and then new data is added |
| 134 | // XXX to the string section? Likely needs to check offset against |
| 135 | // XXX size of rawdata_base buffer and then iterate over rest of the |
| 136 | // XXX list. |
| 137 | result = &strscn->rawdata_base[offset]; |
| 138 | else |
| 139 | { |
| 140 | /* This is a file which is currently created. Use the list of |
| 141 | data blocks. */ |
| 142 | struct Elf_Data_List *dl = &strscn->data_list; |
| 143 | while (dl != NULL) |
| 144 | { |
| 145 | if (offset >= (size_t) dl->data.d.d_off |
| 146 | && offset < dl->data.d.d_off + dl->data.d.d_size) |
| 147 | { |
| 148 | result = (char *) dl->data.d.d_buf + (offset - dl->data.d.d_off); |
| 149 | break; |
| 150 | } |
| 151 | |
| 152 | dl = dl->next; |
| 153 | } |
| 154 | } |
| 155 | |
| 156 | out: |
| 157 | rwlock_unlock (elf->lock); |
| 158 | |
| 159 | return result; |
| 160 | } |
| 161 | INTDEF(elf_strptr) |