1 /* Get symbol information and separate section index from symbol table 2 at the given index. 3 Copyright (C) 2000, 2001, 2002 Red Hat, Inc. 4 This file is part of Red Hat elfutils. 5 Written by Ulrich Drepper <drepper (at) redhat.com>, 2000. 6 7 Red Hat elfutils is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by the 9 Free Software Foundation; version 2 of the License. 10 11 Red Hat elfutils is distributed in the hope that it will be useful, but 12 WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 General Public License for more details. 15 16 You should have received a copy of the GNU General Public License along 17 with Red Hat elfutils; if not, write to the Free Software Foundation, 18 Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. 19 20 In addition, as a special exception, Red Hat, Inc. gives You the 21 additional right to link the code of Red Hat elfutils with code licensed 22 under any Open Source Initiative certified open source license 23 (http://www.opensource.org/licenses/index.php) which requires the 24 distribution of source code with any binary distribution and to 25 distribute linked combinations of the two. Non-GPL Code permitted under 26 this exception must only link to the code of Red Hat elfutils through 27 those well defined interfaces identified in the file named EXCEPTION 28 found in the source code files (the "Approved Interfaces"). The files 29 of Non-GPL Code may instantiate templates or use macros or inline 30 functions from the Approved Interfaces without causing the resulting 31 work to be covered by the GNU General Public License. Only Red Hat, 32 Inc. may make changes or additions to the list of Approved Interfaces. 33 Red Hat's grant of this exception is conditioned upon your not adding 34 any new exceptions. If you wish to add a new Approved Interface or 35 exception, please contact Red Hat. You must obey the GNU General Public 36 License in all respects for all of the Red Hat elfutils code and other 37 code used in conjunction with Red Hat elfutils except the Non-GPL Code 38 covered by this exception. If you modify this file, you may extend this 39 exception to your version of the file, but you are not obligated to do 40 so. If you do not wish to provide this exception without modification, 41 you must delete this exception statement from your version and license 42 this file solely under the GPL without exception. 43 44 Red Hat elfutils is an included package of the Open Invention Network. 45 An included package of the Open Invention Network is a package for which 46 Open Invention Network licensees cross-license their patents. No patent 47 license is granted, either expressly or impliedly, by designation as an 48 included package. Should you wish to participate in the Open Invention 49 Network licensing program, please visit www.openinventionnetwork.com 50 <http://www.openinventionnetwork.com>. */ 51 52 #ifdef HAVE_CONFIG_H 53 # include <config.h> 54 #endif 55 56 #include <assert.h> 57 #include <gelf.h> 58 #include <string.h> 59 60 #include "libelfP.h" 61 62 63 GElf_Sym * 64 gelf_getsymshndx (symdata, shndxdata, ndx, dst, dstshndx) 65 Elf_Data *symdata; 66 Elf_Data *shndxdata; 67 int ndx; 68 GElf_Sym *dst; 69 Elf32_Word *dstshndx; 70 { 71 Elf_Data_Scn *symdata_scn = (Elf_Data_Scn *) symdata; 72 Elf_Data_Scn *shndxdata_scn = (Elf_Data_Scn *) shndxdata; 73 GElf_Sym *result = NULL; 74 Elf32_Word shndx = 0; 75 76 if (symdata == NULL) 77 return NULL; 78 79 if (unlikely (symdata->d_type != ELF_T_SYM) 80 || (likely (shndxdata_scn != NULL) 81 && unlikely (shndxdata->d_type != ELF_T_WORD))) 82 { 83 __libelf_seterrno (ELF_E_INVALID_HANDLE); 84 return NULL; 85 } 86 87 rwlock_rdlock (symdata_scn->s->elf->lock); 88 89 /* The user is not required to pass a data descriptor for an extended 90 section index table. */ 91 if (likely (shndxdata_scn != NULL)) 92 { 93 if (unlikely ((ndx + 1) * sizeof (Elf32_Word) > shndxdata_scn->d.d_size)) 94 { 95 __libelf_seterrno (ELF_E_INVALID_INDEX); 96 goto out; 97 } 98 99 shndx = ((Elf32_Word *) shndxdata_scn->d.d_buf)[ndx]; 100 } 101 102 /* This is the one place where we have to take advantage of the fact 103 that an `Elf_Data' pointer is also a pointer to `Elf_Data_Scn'. 104 The interface is broken so that it requires this hack. */ 105 if (symdata_scn->s->elf->class == ELFCLASS32) 106 { 107 Elf32_Sym *src; 108 109 /* Here it gets a bit more complicated. The format of the symbol 110 table entries has to be adopted. The user better has provided 111 a buffer where we can store the information. While copying the 112 data we are converting the format. */ 113 if (unlikely ((ndx + 1) * sizeof (Elf32_Sym) > symdata->d_size)) 114 { 115 __libelf_seterrno (ELF_E_INVALID_INDEX); 116 goto out; 117 } 118 119 src = &((Elf32_Sym *) symdata->d_buf)[ndx]; 120 121 /* This might look like a simple copy operation but it's 122 not. There are zero- and sign-extensions going on. */ 123 #define COPY(name) \ 124 dst->name = src->name 125 COPY (st_name); 126 /* Please note that we can simply copy the `st_info' element since 127 the definitions of ELFxx_ST_BIND and ELFxx_ST_TYPE are the same 128 for the 64 bit variant. */ 129 COPY (st_info); 130 COPY (st_other); 131 COPY (st_shndx); 132 COPY (st_value); 133 COPY (st_size); 134 } 135 else 136 { 137 /* If this is a 64 bit object it's easy. */ 138 assert (sizeof (GElf_Sym) == sizeof (Elf64_Sym)); 139 140 /* The data is already in the correct form. Just make sure the 141 index is OK. */ 142 if (unlikely ((ndx + 1) * sizeof (GElf_Sym) > symdata->d_size)) 143 { 144 __libelf_seterrno (ELF_E_INVALID_INDEX); 145 goto out; 146 } 147 148 *dst = ((GElf_Sym *) symdata->d_buf)[ndx]; 149 } 150 151 /* Now we can store the section index. */ 152 if (dstshndx != NULL) 153 *dstshndx = shndx; 154 155 result = dst; 156 157 out: 158 rwlock_unlock (symdata_scn->s->elf->lock); 159 160 return result; 161 } 162
