Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 1 | /* Get information from dynamic table at the given index. |
| 2 | Copyright (C) 2000, 2001, 2002 Red Hat, Inc. |
| 3 | This file is part of Red Hat elfutils. |
| 4 | Written by Ulrich Drepper <drepper@redhat.com>, 2000. |
| 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 <assert.h> |
| 56 | #include <gelf.h> |
| 57 | #include <string.h> |
| 58 | |
| 59 | #include "libelfP.h" |
| 60 | |
| 61 | |
| 62 | GElf_Dyn * |
| 63 | gelf_getdyn (data, ndx, dst) |
| 64 | Elf_Data *data; |
| 65 | int ndx; |
| 66 | GElf_Dyn *dst; |
| 67 | { |
| 68 | Elf_Data_Scn *data_scn = (Elf_Data_Scn *) data; |
| 69 | GElf_Dyn *result = NULL; |
| 70 | Elf *elf; |
| 71 | |
| 72 | if (data_scn == NULL) |
| 73 | return NULL; |
| 74 | |
| 75 | if (unlikely (data_scn->d.d_type != ELF_T_DYN)) |
| 76 | { |
| 77 | __libelf_seterrno (ELF_E_INVALID_HANDLE); |
| 78 | return NULL; |
| 79 | } |
| 80 | |
| 81 | elf = data_scn->s->elf; |
| 82 | |
| 83 | rwlock_rdlock (elf->lock); |
| 84 | |
| 85 | /* This is the one place where we have to take advantage of the fact |
| 86 | that an `Elf_Data' pointer is also a pointer to `Elf_Data_Scn'. |
| 87 | The interface is broken so that it requires this hack. */ |
| 88 | if (elf->class == ELFCLASS32) |
| 89 | { |
| 90 | Elf32_Dyn *src; |
| 91 | |
| 92 | /* Here it gets a bit more complicated. The format of the symbol |
| 93 | table entries has to be adopted. The user better has provided |
| 94 | a buffer where we can store the information. While copying the |
| 95 | data we are converting the format. */ |
| 96 | if (unlikely ((ndx + 1) * sizeof (Elf32_Dyn) > data_scn->d.d_size)) |
| 97 | { |
| 98 | __libelf_seterrno (ELF_E_INVALID_INDEX); |
| 99 | goto out; |
| 100 | } |
| 101 | |
| 102 | src = &((Elf32_Dyn *) data_scn->d.d_buf)[ndx]; |
| 103 | |
| 104 | /* This might look like a simple copy operation but it's |
| 105 | not. There are zero- and sign-extensions going on. */ |
| 106 | dst->d_tag = src->d_tag; |
| 107 | /* It OK to copy `d_val' since `d_ptr' has the same size. */ |
| 108 | dst->d_un.d_val = src->d_un.d_val; |
| 109 | } |
| 110 | else |
| 111 | { |
| 112 | /* If this is a 64 bit object it's easy. */ |
| 113 | assert (sizeof (GElf_Dyn) == sizeof (Elf64_Dyn)); |
| 114 | |
| 115 | /* The data is already in the correct form. Just make sure the |
| 116 | index is OK. */ |
| 117 | if (unlikely ((ndx + 1) * sizeof (GElf_Dyn) > data_scn->d.d_size)) |
| 118 | { |
| 119 | __libelf_seterrno (ELF_E_INVALID_INDEX); |
| 120 | goto out; |
| 121 | } |
| 122 | |
| 123 | *dst = ((GElf_Dyn *) data_scn->d.d_buf)[ndx]; |
| 124 | } |
| 125 | |
| 126 | result = dst; |
| 127 | |
| 128 | out: |
| 129 | rwlock_unlock (elf->lock); |
| 130 | |
| 131 | return result; |
| 132 | } |