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1 : : /* Get symbol information and separate section index from symbol table 2 : : at the given index. 3 : : Copyright (C) 2000, 2001, 2002, 2005, 2009, 2014, 2015 Red Hat, Inc. 4 : : This file is part of elfutils. 5 : : Written by Ulrich Drepper <drepper@redhat.com>, 2000. 6 : : 7 : : This file is free software; you can redistribute it and/or modify 8 : : it under the terms of either 9 : : 10 : : * the GNU Lesser General Public License as published by the Free 11 : : Software Foundation; either version 3 of the License, or (at 12 : : your option) any later version 13 : : 14 : : or 15 : : 16 : : * the GNU General Public License as published by the Free 17 : : Software Foundation; either version 2 of the License, or (at 18 : : your option) any later version 19 : : 20 : : or both in parallel, as here. 21 : : 22 : : elfutils is distributed in the hope that it will be useful, but 23 : : WITHOUT ANY WARRANTY; without even the implied warranty of 24 : : MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 25 : : General Public License for more details. 26 : : 27 : : You should have received copies of the GNU General Public License and 28 : : the GNU Lesser General Public License along with this program. If 29 : : not, see <http://www.gnu.org/licenses/>. */ 30 : : 31 : : #ifdef HAVE_CONFIG_H 32 : : # include <config.h> 33 : : #endif 34 : : 35 : : #include <assert.h> 36 : : #include <gelf.h> 37 : : #include <string.h> 38 : : 39 : : #include "libelfP.h" 40 : : 41 : : 42 : : GElf_Sym * 43 : 35029178 : gelf_getsymshndx (Elf_Data *symdata, Elf_Data *shndxdata, int ndx, 44 : : GElf_Sym *dst, Elf32_Word *dstshndx) 45 : : { 46 : 35029178 : Elf_Data_Scn *symdata_scn = (Elf_Data_Scn *) symdata; 47 : 35029178 : Elf_Data_Scn *shndxdata_scn = (Elf_Data_Scn *) shndxdata; 48 : 35029178 : GElf_Sym *result = NULL; 49 : 35029178 : Elf32_Word shndx = 0; 50 : : 51 [ - + ]: 35029178 : if (symdata == NULL) 52 : : return NULL; 53 : : 54 [ + - ]: 35029178 : if (unlikely (symdata->d_type != ELF_T_SYM) 55 [ + + ]: 35029178 : || (likely (shndxdata_scn != NULL) 56 [ - + ]: 176004 : && unlikely (shndxdata->d_type != ELF_T_WORD))) 57 : : { 58 : 0 : __libelf_seterrno (ELF_E_INVALID_HANDLE); 59 : 0 : return NULL; 60 : : } 61 : : 62 : 35029178 : rwlock_rdlock (symdata_scn->s->elf->lock); 63 : : 64 : : /* The user is not required to pass a data descriptor for an extended 65 : : section index table. */ 66 [ + + ]: 35029178 : if (likely (shndxdata_scn != NULL)) 67 : : { 68 [ - + ]: 176004 : if (INVALID_NDX (ndx, Elf32_Word, &shndxdata_scn->d)) 69 : : { 70 : 0 : __libelf_seterrno (ELF_E_INVALID_INDEX); 71 : 0 : goto out; 72 : : } 73 : : 74 : 176004 : shndx = ((Elf32_Word *) shndxdata_scn->d.d_buf)[ndx]; 75 : : } 76 : : 77 : : /* This is the one place where we have to take advantage of the fact 78 : : that an `Elf_Data' pointer is also a pointer to `Elf_Data_Scn'. 79 : : The interface is broken so that it requires this hack. */ 80 [ + + ]: 35029178 : if (symdata_scn->s->elf->class == ELFCLASS32) 81 : : { 82 : 602982 : Elf32_Sym *src; 83 : : 84 : : /* Here it gets a bit more complicated. The format of the symbol 85 : : table entries has to be adopted. The user better has provided 86 : : a buffer where we can store the information. While copying the 87 : : data we are converting the format. */ 88 [ - + ]: 602982 : if (INVALID_NDX (ndx, Elf32_Sym, symdata)) 89 : : { 90 : 0 : __libelf_seterrno (ELF_E_INVALID_INDEX); 91 : 0 : goto out; 92 : : } 93 : : 94 : 602982 : src = &((Elf32_Sym *) symdata->d_buf)[ndx]; 95 : : 96 : : /* This might look like a simple copy operation but it's 97 : : not. There are zero- and sign-extensions going on. */ 98 : : #define COPY(name) \ 99 : : dst->name = src->name 100 : 602982 : COPY (st_name); 101 : : /* Please note that we can simply copy the `st_info' element since 102 : : the definitions of ELFxx_ST_BIND and ELFxx_ST_TYPE are the same 103 : : for the 64 bit variant. */ 104 : 602982 : COPY (st_info); 105 : 602982 : COPY (st_other); 106 : 602982 : COPY (st_shndx); 107 : 602982 : COPY (st_value); 108 : 602982 : COPY (st_size); 109 : : } 110 : : else 111 : : { 112 : : /* If this is a 64 bit object it's easy. */ 113 : 34426196 : assert (sizeof (GElf_Sym) == sizeof (Elf64_Sym)); 114 : : 115 : : /* The data is already in the correct form. Just make sure the 116 : : index is OK. */ 117 [ - + ]: 34426196 : if (INVALID_NDX (ndx, GElf_Sym, symdata)) 118 : : { 119 : 0 : __libelf_seterrno (ELF_E_INVALID_INDEX); 120 : 0 : goto out; 121 : : } 122 : : 123 : 34426196 : *dst = ((GElf_Sym *) symdata->d_buf)[ndx]; 124 : : } 125 : : 126 : : /* Now we can store the section index. */ 127 [ + - ]: 35029178 : if (dstshndx != NULL) 128 : 35029178 : *dstshndx = shndx; 129 : : 130 : : result = dst; 131 : : 132 : 35029178 : out: 133 : 35029178 : rwlock_unlock (symdata_scn->s->elf->lock); 134 : : 135 : 35029178 : return result; 136 : : }