Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame] | 1 | /* Get information from dynamic table at the given index. |
Jakub Jelinek | a903962 | 2014-01-17 20:38:01 +0100 | [diff] [blame] | 2 | Copyright (C) 2000, 2001, 2002, 2005, 2009, 2014 Red Hat, Inc. |
Mark Wielaard | de2ed97 | 2012-06-05 17:15:16 +0200 | [diff] [blame] | 3 | This file is part of elfutils. |
Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame] | 4 | Written by Ulrich Drepper <drepper@redhat.com>, 2000. |
| 5 | |
Mark Wielaard | de2ed97 | 2012-06-05 17:15:16 +0200 | [diff] [blame] | 6 | This file is free software; you can redistribute it and/or modify |
| 7 | it under the terms of either |
Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame] | 8 | |
Mark Wielaard | de2ed97 | 2012-06-05 17:15:16 +0200 | [diff] [blame] | 9 | * the GNU Lesser General Public License as published by the Free |
| 10 | Software Foundation; either version 3 of the License, or (at |
| 11 | your option) any later version |
| 12 | |
| 13 | or |
| 14 | |
| 15 | * the GNU General Public License as published by the Free |
| 16 | Software Foundation; either version 2 of the License, or (at |
| 17 | your option) any later version |
| 18 | |
| 19 | or both in parallel, as here. |
| 20 | |
| 21 | elfutils is distributed in the hope that it will be useful, but |
Ulrich Drepper | 361df7d | 2006-04-04 21:38:57 +0000 | [diff] [blame] | 22 | WITHOUT ANY WARRANTY; without even the implied warranty of |
| 23 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 24 | General Public License for more details. |
Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame] | 25 | |
Mark Wielaard | de2ed97 | 2012-06-05 17:15:16 +0200 | [diff] [blame] | 26 | You should have received copies of the GNU General Public License and |
| 27 | the GNU Lesser General Public License along with this program. If |
| 28 | not, see <http://www.gnu.org/licenses/>. */ |
Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame] | 29 | |
| 30 | #ifdef HAVE_CONFIG_H |
| 31 | # include <config.h> |
| 32 | #endif |
| 33 | |
| 34 | #include <assert.h> |
| 35 | #include <gelf.h> |
| 36 | #include <string.h> |
| 37 | |
| 38 | #include "libelfP.h" |
| 39 | |
| 40 | |
| 41 | GElf_Dyn * |
| 42 | gelf_getdyn (data, ndx, dst) |
| 43 | Elf_Data *data; |
| 44 | int ndx; |
| 45 | GElf_Dyn *dst; |
| 46 | { |
| 47 | Elf_Data_Scn *data_scn = (Elf_Data_Scn *) data; |
| 48 | GElf_Dyn *result = NULL; |
| 49 | Elf *elf; |
| 50 | |
| 51 | if (data_scn == NULL) |
| 52 | return NULL; |
| 53 | |
| 54 | if (unlikely (data_scn->d.d_type != ELF_T_DYN)) |
| 55 | { |
| 56 | __libelf_seterrno (ELF_E_INVALID_HANDLE); |
| 57 | return NULL; |
| 58 | } |
| 59 | |
| 60 | elf = data_scn->s->elf; |
| 61 | |
Roland McGrath | b4d6f0f | 2008-08-25 22:55:17 +0000 | [diff] [blame] | 62 | rwlock_rdlock (elf->lock); |
Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame] | 63 | |
| 64 | /* This is the one place where we have to take advantage of the fact |
| 65 | that an `Elf_Data' pointer is also a pointer to `Elf_Data_Scn'. |
| 66 | The interface is broken so that it requires this hack. */ |
| 67 | if (elf->class == ELFCLASS32) |
| 68 | { |
| 69 | Elf32_Dyn *src; |
| 70 | |
| 71 | /* Here it gets a bit more complicated. The format of the symbol |
| 72 | table entries has to be adopted. The user better has provided |
| 73 | a buffer where we can store the information. While copying the |
| 74 | data we are converting the format. */ |
Jakub Jelinek | a903962 | 2014-01-17 20:38:01 +0100 | [diff] [blame] | 75 | if (INVALID_NDX (ndx, Elf32_Dyn, &data_scn->d)) |
Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame] | 76 | { |
| 77 | __libelf_seterrno (ELF_E_INVALID_INDEX); |
| 78 | goto out; |
| 79 | } |
| 80 | |
| 81 | src = &((Elf32_Dyn *) data_scn->d.d_buf)[ndx]; |
| 82 | |
| 83 | /* This might look like a simple copy operation but it's |
| 84 | not. There are zero- and sign-extensions going on. */ |
| 85 | dst->d_tag = src->d_tag; |
| 86 | /* It OK to copy `d_val' since `d_ptr' has the same size. */ |
| 87 | dst->d_un.d_val = src->d_un.d_val; |
| 88 | } |
| 89 | else |
| 90 | { |
| 91 | /* If this is a 64 bit object it's easy. */ |
| 92 | assert (sizeof (GElf_Dyn) == sizeof (Elf64_Dyn)); |
| 93 | |
| 94 | /* The data is already in the correct form. Just make sure the |
| 95 | index is OK. */ |
Jakub Jelinek | a903962 | 2014-01-17 20:38:01 +0100 | [diff] [blame] | 96 | if (INVALID_NDX (ndx, GElf_Dyn, &data_scn->d)) |
Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame] | 97 | { |
| 98 | __libelf_seterrno (ELF_E_INVALID_INDEX); |
| 99 | goto out; |
| 100 | } |
| 101 | |
| 102 | *dst = ((GElf_Dyn *) data_scn->d.d_buf)[ndx]; |
| 103 | } |
| 104 | |
| 105 | result = dst; |
| 106 | |
| 107 | out: |
Roland McGrath | b4d6f0f | 2008-08-25 22:55:17 +0000 | [diff] [blame] | 108 | rwlock_unlock (elf->lock); |
Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame] | 109 | |
| 110 | return result; |
| 111 | } |