1/* Return string pointer from string section. 2 Copyright (C) 1998, 1999, 2000, 2001, 2002, 2004, 2008, 2009 Red Hat, Inc. 3 This file is part of Red Hat elfutils. 4 Contributed by Ulrich Drepper <drepper@redhat.com>, 1998. 5 6 Red Hat elfutils is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by the 8 Free Software Foundation; version 2 of the License. 9 10 Red Hat elfutils is distributed in the hope that it will be useful, but 11 WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 General Public License for more details. 14 15 You should have received a copy of the GNU General Public License along 16 with Red Hat elfutils; if not, write to the Free Software Foundation, 17 Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. 18 19 In addition, as a special exception, Red Hat, Inc. gives You the 20 additional right to link the code of Red Hat elfutils with code licensed 21 under any Open Source Initiative certified open source license 22 (http://www.opensource.org/licenses/index.php) which requires the 23 distribution of source code with any binary distribution and to 24 distribute linked combinations of the two. Non-GPL Code permitted under 25 this exception must only link to the code of Red Hat elfutils through 26 those well defined interfaces identified in the file named EXCEPTION 27 found in the source code files (the "Approved Interfaces"). The files 28 of Non-GPL Code may instantiate templates or use macros or inline 29 functions from the Approved Interfaces without causing the resulting 30 work to be covered by the GNU General Public License. Only Red Hat, 31 Inc. may make changes or additions to the list of Approved Interfaces. 32 Red Hat's grant of this exception is conditioned upon your not adding 33 any new exceptions. If you wish to add a new Approved Interface or 34 exception, please contact Red Hat. You must obey the GNU General Public 35 License in all respects for all of the Red Hat elfutils code and other 36 code used in conjunction with Red Hat elfutils except the Non-GPL Code 37 covered by this exception. If you modify this file, you may extend this 38 exception to your version of the file, but you are not obligated to do 39 so. If you do not wish to provide this exception without modification, 40 you must delete this exception statement from your version and license 41 this file solely under the GPL without exception. 42 43 Red Hat elfutils is an included package of the Open Invention Network. 44 An included package of the Open Invention Network is a package for which 45 Open Invention Network licensees cross-license their patents. No patent 46 license is granted, either expressly or impliedly, by designation as an 47 included package. Should you wish to participate in the Open Invention 48 Network licensing program, please visit www.openinventionnetwork.com 49 <http://www.openinventionnetwork.com>. */ 50 51#ifdef HAVE_CONFIG_H 52# include <config.h> 53#endif 54 55#include <libelf.h> 56#include <stddef.h> 57 58#include "libelfP.h" 59 60 61char * 62elf_strptr (elf, idx, offset) 63 Elf *elf; 64 size_t idx; 65 size_t offset; 66{ 67 if (elf == NULL) 68 return NULL; 69 70 if (elf->kind != ELF_K_ELF) 71 { 72 __libelf_seterrno (ELF_E_INVALID_HANDLE); 73 return NULL; 74 } 75 76 rwlock_rdlock (elf->lock); 77 78 char *result = NULL; 79 Elf_Scn *strscn; 80 81 /* Find the section in the list. */ 82 Elf_ScnList *runp = (elf->class == ELFCLASS32 83 || (offsetof (struct Elf, state.elf32.scns) 84 == offsetof (struct Elf, state.elf64.scns)) 85 ? &elf->state.elf32.scns : &elf->state.elf64.scns); 86 while (1) 87 { 88 if (idx < runp->max) 89 { 90 if (idx < runp->cnt) 91 strscn = &runp->data[idx]; 92 else 93 { 94 __libelf_seterrno (ELF_E_INVALID_INDEX); 95 goto out; 96 } 97 break; 98 } 99 100 idx -= runp->max; 101 102 runp = runp->next; 103 if (runp == NULL) 104 { 105 __libelf_seterrno (ELF_E_INVALID_INDEX); 106 goto out; 107 } 108 } 109 110 if (elf->class == ELFCLASS32) 111 { 112 if (unlikely (strscn->shdr.e32->sh_type != SHT_STRTAB)) 113 { 114 /* This is no string section. */ 115 __libelf_seterrno (ELF_E_INVALID_SECTION); 116 goto out; 117 } 118 119 if (unlikely (offset >= strscn->shdr.e32->sh_size)) 120 { 121 /* The given offset is too big, it is beyond this section. */ 122 __libelf_seterrno (ELF_E_OFFSET_RANGE); 123 goto out; 124 } 125 } 126 else 127 { 128 if (unlikely (strscn->shdr.e64->sh_type != SHT_STRTAB)) 129 { 130 /* This is no string section. */ 131 __libelf_seterrno (ELF_E_INVALID_SECTION); 132 goto out; 133 } 134 135 if (unlikely (offset >= strscn->shdr.e64->sh_size)) 136 { 137 /* The given offset is too big, it is beyond this section. */ 138 __libelf_seterrno (ELF_E_OFFSET_RANGE); 139 goto out; 140 } 141 } 142 143 if (strscn->rawdata_base == NULL && ! strscn->data_read) 144 { 145 rwlock_unlock (elf->lock); 146 rwlock_wrlock (elf->lock); 147 if (strscn->rawdata_base == NULL && ! strscn->data_read 148 /* Read the section data. */ 149 && __libelf_set_rawdata_wrlock (strscn) != 0) 150 goto out; 151 } 152 153 if (likely (strscn->rawdata_base != NULL)) 154 // XXX Is this correct if a file is read and then new data is added 155 // XXX to the string section? Likely needs to check offset against 156 // XXX size of rawdata_base buffer and then iterate over rest of the 157 // XXX list. 158 result = &strscn->rawdata_base[offset]; 159 else 160 { 161 /* This is a file which is currently created. Use the list of 162 data blocks. */ 163 struct Elf_Data_List *dl = &strscn->data_list; 164 while (dl != NULL) 165 { 166 if (offset >= (size_t) dl->data.d.d_off 167 && offset < dl->data.d.d_off + dl->data.d.d_size) 168 { 169 result = (char *) dl->data.d.d_buf + (offset - dl->data.d.d_off); 170 break; 171 } 172 173 dl = dl->next; 174 } 175 } 176 177 out: 178 rwlock_unlock (elf->lock); 179 180 return result; 181} 182INTDEF(elf_strptr) 183