Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame^] | 1 | /* Get symbol information from symbol table at the given index. |
| 2 | Copyright (C) 1999, 2000, 2001, 2002 Red Hat, Inc. |
| 3 | Written by Ulrich Drepper <drepper@redhat.com>, 1999. |
| 4 | |
| 5 | This program is free software; you can redistribute it and/or modify |
| 6 | it under the terms of the GNU General Public License as published by |
| 7 | the Free Software Foundation, version 2. |
| 8 | |
| 9 | This program is distributed in the hope that it will be useful, |
| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | GNU General Public License for more details. |
| 13 | |
| 14 | You should have received a copy of the GNU General Public License |
| 15 | along with this program; if not, write to the Free Software Foundation, |
| 16 | Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ |
| 17 | |
| 18 | #ifdef HAVE_CONFIG_H |
| 19 | # include <config.h> |
| 20 | #endif |
| 21 | |
| 22 | #include <assert.h> |
| 23 | #include <gelf.h> |
| 24 | #include <string.h> |
| 25 | |
| 26 | #include "libelfP.h" |
| 27 | |
| 28 | |
| 29 | GElf_Sym * |
| 30 | gelf_getsym (data, ndx, dst) |
| 31 | Elf_Data *data; |
| 32 | int ndx; |
| 33 | GElf_Sym *dst; |
| 34 | { |
| 35 | Elf_Data_Scn *data_scn = (Elf_Data_Scn *) data; |
| 36 | GElf_Sym *result = NULL; |
| 37 | |
| 38 | if (data == NULL) |
| 39 | return NULL; |
| 40 | |
| 41 | if (unlikely (data->d_type != ELF_T_SYM)) |
| 42 | { |
| 43 | __libelf_seterrno (ELF_E_INVALID_HANDLE); |
| 44 | return NULL; |
| 45 | } |
| 46 | |
| 47 | rwlock_rdlock (data_scn->s->elf->lock); |
| 48 | |
| 49 | /* This is the one place where we have to take advantage of the fact |
| 50 | that an `Elf_Data' pointer is also a pointer to `Elf_Data_Scn'. |
| 51 | The interface is broken so that it requires this hack. */ |
| 52 | if (data_scn->s->elf->class == ELFCLASS32) |
| 53 | { |
| 54 | Elf32_Sym *src; |
| 55 | |
| 56 | /* Here it gets a bit more complicated. The format of the symbol |
| 57 | table entries has to be adopted. The user better has provided |
| 58 | a buffer where we can store the information. While copying the |
| 59 | data we are converting the format. */ |
| 60 | if (unlikely ((ndx + 1) * sizeof (Elf32_Sym) > data->d_size)) |
| 61 | { |
| 62 | __libelf_seterrno (ELF_E_INVALID_INDEX); |
| 63 | goto out; |
| 64 | } |
| 65 | |
| 66 | src = &((Elf32_Sym *) data->d_buf)[ndx]; |
| 67 | |
| 68 | /* This might look like a simple copy operation but it's |
| 69 | not. There are zero- and sign-extensions going on. */ |
| 70 | #define COPY(name) \ |
| 71 | dst->name = src->name |
| 72 | COPY (st_name); |
| 73 | /* Please note that we can simply copy the `st_info' element since |
| 74 | the definitions of ELFxx_ST_BIND and ELFxx_ST_TYPE are the same |
| 75 | for the 64 bit variant. */ |
| 76 | COPY (st_info); |
| 77 | COPY (st_other); |
| 78 | COPY (st_shndx); |
| 79 | COPY (st_value); |
| 80 | COPY (st_size); |
| 81 | } |
| 82 | else |
| 83 | { |
| 84 | /* If this is a 64 bit object it's easy. */ |
| 85 | assert (sizeof (GElf_Sym) == sizeof (Elf64_Sym)); |
| 86 | |
| 87 | /* The data is already in the correct form. Just make sure the |
| 88 | index is OK. */ |
| 89 | if (unlikely ((ndx + 1) * sizeof (GElf_Sym) > data->d_size)) |
| 90 | { |
| 91 | __libelf_seterrno (ELF_E_INVALID_INDEX); |
| 92 | goto out; |
| 93 | } |
| 94 | |
| 95 | *dst = ((GElf_Sym *) data->d_buf)[ndx]; |
| 96 | } |
| 97 | |
| 98 | result = dst; |
| 99 | |
| 100 | out: |
| 101 | rwlock_unlock (data_scn->s->elf->lock); |
| 102 | |
| 103 | return result; |
| 104 | } |
| 105 | INTDEF(gelf_getsym) |