Roland McGrath | cb6d865 | 2007-08-23 08:10:54 +0000 | [diff] [blame] | 1 | /* Get information from auxiliary vector at the given index. |
| 2 | Copyright (C) 2007 Red Hat, Inc. |
Mark Wielaard | de2ed97 | 2012-06-05 17:15:16 +0200 | [diff] [blame] | 3 | This file is part of elfutils. |
Roland McGrath | cb6d865 | 2007-08-23 08:10:54 +0000 | [diff] [blame] | 4 | |
Mark Wielaard | de2ed97 | 2012-06-05 17:15:16 +0200 | [diff] [blame] | 5 | This file is free software; you can redistribute it and/or modify |
| 6 | it under the terms of either |
Roland McGrath | cb6d865 | 2007-08-23 08:10:54 +0000 | [diff] [blame] | 7 | |
Mark Wielaard | de2ed97 | 2012-06-05 17:15:16 +0200 | [diff] [blame] | 8 | * the GNU Lesser General Public License as published by the Free |
| 9 | Software Foundation; either version 3 of the License, or (at |
| 10 | your option) any later version |
| 11 | |
| 12 | or |
| 13 | |
| 14 | * the GNU General Public License as published by the Free |
| 15 | Software Foundation; either version 2 of the License, or (at |
| 16 | your option) any later version |
| 17 | |
| 18 | or both in parallel, as here. |
| 19 | |
| 20 | elfutils is distributed in the hope that it will be useful, but |
Roland McGrath | cb6d865 | 2007-08-23 08:10:54 +0000 | [diff] [blame] | 21 | WITHOUT ANY WARRANTY; without even the implied warranty of |
| 22 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 23 | General Public License for more details. |
| 24 | |
Mark Wielaard | de2ed97 | 2012-06-05 17:15:16 +0200 | [diff] [blame] | 25 | You should have received copies of the GNU General Public License and |
| 26 | the GNU Lesser General Public License along with this program. If |
| 27 | not, see <http://www.gnu.org/licenses/>. */ |
Roland McGrath | cb6d865 | 2007-08-23 08:10:54 +0000 | [diff] [blame] | 28 | |
| 29 | #ifdef HAVE_CONFIG_H |
| 30 | # include <config.h> |
| 31 | #endif |
| 32 | |
| 33 | #include <assert.h> |
| 34 | #include <gelf.h> |
| 35 | #include <string.h> |
| 36 | |
| 37 | #include "libelfP.h" |
| 38 | |
| 39 | |
| 40 | GElf_auxv_t * |
| 41 | gelf_getauxv (data, ndx, dst) |
| 42 | Elf_Data *data; |
| 43 | int ndx; |
| 44 | GElf_auxv_t *dst; |
| 45 | { |
| 46 | Elf_Data_Scn *data_scn = (Elf_Data_Scn *) data; |
| 47 | GElf_auxv_t *result = NULL; |
| 48 | Elf *elf; |
| 49 | |
| 50 | if (data_scn == NULL) |
| 51 | return NULL; |
| 52 | |
| 53 | if (unlikely (data_scn->d.d_type != ELF_T_AUXV)) |
| 54 | { |
| 55 | __libelf_seterrno (ELF_E_INVALID_HANDLE); |
| 56 | return NULL; |
| 57 | } |
| 58 | |
| 59 | elf = data_scn->s->elf; |
| 60 | |
Roland McGrath | b4d6f0f | 2008-08-25 22:55:17 +0000 | [diff] [blame] | 61 | rwlock_rdlock (elf->lock); |
Roland McGrath | cb6d865 | 2007-08-23 08:10:54 +0000 | [diff] [blame] | 62 | |
| 63 | /* This is the one place where we have to take advantage of the fact |
| 64 | that an `Elf_Data' pointer is also a pointer to `Elf_Data_Scn'. |
| 65 | The interface is broken so that it requires this hack. */ |
| 66 | if (elf->class == ELFCLASS32) |
| 67 | { |
| 68 | Elf32_auxv_t *src; |
| 69 | |
| 70 | /* Here it gets a bit more complicated. The format of the vector |
| 71 | entries has to be converted. The user better have provided a |
| 72 | buffer where we can store the information. While copying the data |
| 73 | we convert the format. */ |
| 74 | if (unlikely ((ndx + 1) * sizeof (Elf32_auxv_t) > data_scn->d.d_size)) |
| 75 | { |
| 76 | __libelf_seterrno (ELF_E_INVALID_INDEX); |
| 77 | goto out; |
| 78 | } |
| 79 | |
| 80 | src = &((Elf32_auxv_t *) data_scn->d.d_buf)[ndx]; |
| 81 | |
| 82 | /* This might look like a simple copy operation but it's |
| 83 | not. There are zero- and sign-extensions going on. */ |
| 84 | dst->a_type = src->a_type; |
| 85 | dst->a_un.a_val = src->a_un.a_val; |
| 86 | } |
| 87 | else |
| 88 | { |
| 89 | /* If this is a 64 bit object it's easy. */ |
| 90 | assert (sizeof (GElf_auxv_t) == sizeof (Elf64_auxv_t)); |
| 91 | |
| 92 | /* The data is already in the correct form. Just make sure the |
| 93 | index is OK. */ |
| 94 | if (unlikely ((ndx + 1) * sizeof (GElf_auxv_t) > data_scn->d.d_size)) |
| 95 | { |
| 96 | __libelf_seterrno (ELF_E_INVALID_INDEX); |
| 97 | goto out; |
| 98 | } |
| 99 | |
| 100 | *dst = ((GElf_auxv_t *) data_scn->d.d_buf)[ndx]; |
| 101 | } |
| 102 | |
| 103 | result = dst; |
| 104 | |
| 105 | out: |
Roland McGrath | b4d6f0f | 2008-08-25 22:55:17 +0000 | [diff] [blame] | 106 | rwlock_unlock (elf->lock); |
Roland McGrath | cb6d865 | 2007-08-23 08:10:54 +0000 | [diff] [blame] | 107 | |
| 108 | return result; |
| 109 | } |