Retro68/libelf/src/gelf_getdyn.c

109 lines
3.0 KiB
C

/* Get information from dynamic table at the given index.
Copyright (C) 2000, 2001, 2002, 2005, 2009, 2014, 2015 Red Hat, Inc.
This file is part of elfutils.
Written by Ulrich Drepper <drepper@redhat.com>, 2000.
This file is free software; you can redistribute it and/or modify
it under the terms of either
* the GNU Lesser General Public License as published by the Free
Software Foundation; either version 3 of the License, or (at
your option) any later version
or
* the GNU General Public License as published by the Free
Software Foundation; either version 2 of the License, or (at
your option) any later version
or both in parallel, as here.
elfutils is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received copies of the GNU General Public License and
the GNU Lesser General Public License along with this program. If
not, see <http://www.gnu.org/licenses/>. */
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <assert.h>
#include <gelf.h>
#include <string.h>
#include "libelfP.h"
GElf_Dyn *
gelf_getdyn (Elf_Data *data, int ndx, GElf_Dyn *dst)
{
Elf_Data_Scn *data_scn = (Elf_Data_Scn *) data;
GElf_Dyn *result = NULL;
Elf *elf;
if (data_scn == NULL)
return NULL;
if (unlikely (data_scn->d.d_type != ELF_T_DYN))
{
__libelf_seterrno (ELF_E_INVALID_HANDLE);
return NULL;
}
elf = data_scn->s->elf;
rwlock_rdlock (elf->lock);
/* This is the one place where we have to take advantage of the fact
that an `Elf_Data' pointer is also a pointer to `Elf_Data_Scn'.
The interface is broken so that it requires this hack. */
if (elf->class == ELFCLASS32)
{
Elf32_Dyn *src;
/* Here it gets a bit more complicated. The format of the symbol
table entries has to be adopted. The user better has provided
a buffer where we can store the information. While copying the
data we are converting the format. */
if (INVALID_NDX (ndx, Elf32_Dyn, &data_scn->d))
{
__libelf_seterrno (ELF_E_INVALID_INDEX);
goto out;
}
src = &((Elf32_Dyn *) data_scn->d.d_buf)[ndx];
/* This might look like a simple copy operation but it's
not. There are zero- and sign-extensions going on. */
dst->d_tag = src->d_tag;
/* It OK to copy `d_val' since `d_ptr' has the same size. */
dst->d_un.d_val = src->d_un.d_val;
}
else
{
/* If this is a 64 bit object it's easy. */
assert (sizeof (GElf_Dyn) == sizeof (Elf64_Dyn));
/* The data is already in the correct form. Just make sure the
index is OK. */
if (INVALID_NDX (ndx, GElf_Dyn, &data_scn->d))
{
__libelf_seterrno (ELF_E_INVALID_INDEX);
goto out;
}
*dst = ((GElf_Dyn *) data_scn->d.d_buf)[ndx];
}
result = dst;
out:
rwlock_unlock (elf->lock);
return result;
}