1 /* Get information from auxiliary vector at the given index. 2 Copyright (C) 2007 Red Hat, Inc. 3 This file is part of Red Hat elfutils. 4 5 Red Hat elfutils is free software; you can redistribute it and/or modify 6 it under the terms of the GNU General Public License as published by the 7 Free Software Foundation; version 2 of the License. 8 9 Red Hat elfutils is distributed in the hope that it will be useful, but 10 WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 General Public License for more details. 13 14 You should have received a copy of the GNU General Public License along 15 with Red Hat elfutils; if not, write to the Free Software Foundation, 16 Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. 17 18 In addition, as a special exception, Red Hat, Inc. gives You the 19 additional right to link the code of Red Hat elfutils with code licensed 20 under any Open Source Initiative certified open source license 21 (http://www.opensource.org/licenses/index.php) which requires the 22 distribution of source code with any binary distribution and to 23 distribute linked combinations of the two. Non-GPL Code permitted under 24 this exception must only link to the code of Red Hat elfutils through 25 those well defined interfaces identified in the file named EXCEPTION 26 found in the source code files (the "Approved Interfaces"). The files 27 of Non-GPL Code may instantiate templates or use macros or inline 28 functions from the Approved Interfaces without causing the resulting 29 work to be covered by the GNU General Public License. Only Red Hat, 30 Inc. may make changes or additions to the list of Approved Interfaces. 31 Red Hat's grant of this exception is conditioned upon your not adding 32 any new exceptions. If you wish to add a new Approved Interface or 33 exception, please contact Red Hat. You must obey the GNU General Public 34 License in all respects for all of the Red Hat elfutils code and other 35 code used in conjunction with Red Hat elfutils except the Non-GPL Code 36 covered by this exception. If you modify this file, you may extend this 37 exception to your version of the file, but you are not obligated to do 38 so. If you do not wish to provide this exception without modification, 39 you must delete this exception statement from your version and license 40 this file solely under the GPL without exception. 41 42 Red Hat elfutils is an included package of the Open Invention Network. 43 An included package of the Open Invention Network is a package for which 44 Open Invention Network licensees cross-license their patents. No patent 45 license is granted, either expressly or impliedly, by designation as an 46 included package. Should you wish to participate in the Open Invention 47 Network licensing program, please visit www.openinventionnetwork.com 48 <http://www.openinventionnetwork.com>. */ 49 50 #ifdef HAVE_CONFIG_H 51 # include <config.h> 52 #endif 53 54 #include <assert.h> 55 #include <gelf.h> 56 #include <string.h> 57 58 #include "libelfP.h" 59 60 61 GElf_auxv_t * 62 gelf_getauxv (data, ndx, dst) 63 Elf_Data *data; 64 int ndx; 65 GElf_auxv_t *dst; 66 { 67 Elf_Data_Scn *data_scn = (Elf_Data_Scn *) data; 68 GElf_auxv_t *result = NULL; 69 Elf *elf; 70 71 if (data_scn == NULL) 72 return NULL; 73 74 if (unlikely (data_scn->d.d_type != ELF_T_AUXV)) 75 { 76 __libelf_seterrno (ELF_E_INVALID_HANDLE); 77 return NULL; 78 } 79 80 elf = data_scn->s->elf; 81 82 rwlock_rdlock (elf->lock); 83 84 /* This is the one place where we have to take advantage of the fact 85 that an `Elf_Data' pointer is also a pointer to `Elf_Data_Scn'. 86 The interface is broken so that it requires this hack. */ 87 if (elf->class == ELFCLASS32) 88 { 89 Elf32_auxv_t *src; 90 91 /* Here it gets a bit more complicated. The format of the vector 92 entries has to be converted. The user better have provided a 93 buffer where we can store the information. While copying the data 94 we convert the format. */ 95 if (unlikely ((ndx + 1) * sizeof (Elf32_auxv_t) > data_scn->d.d_size)) 96 { 97 __libelf_seterrno (ELF_E_INVALID_INDEX); 98 goto out; 99 } 100 101 src = &((Elf32_auxv_t *) data_scn->d.d_buf)[ndx]; 102 103 /* This might look like a simple copy operation but it's 104 not. There are zero- and sign-extensions going on. */ 105 dst->a_type = src->a_type; 106 dst->a_un.a_val = src->a_un.a_val; 107 } 108 else 109 { 110 /* If this is a 64 bit object it's easy. */ 111 assert (sizeof (GElf_auxv_t) == sizeof (Elf64_auxv_t)); 112 113 /* The data is already in the correct form. Just make sure the 114 index is OK. */ 115 if (unlikely ((ndx + 1) * sizeof (GElf_auxv_t) > data_scn->d.d_size)) 116 { 117 __libelf_seterrno (ELF_E_INVALID_INDEX); 118 goto out; 119 } 120 121 *dst = ((GElf_auxv_t *) data_scn->d.d_buf)[ndx]; 122 } 123 124 result = dst; 125 126 out: 127 rwlock_unlock (elf->lock); 128 129 return result; 130 } 131
