diff options
Diffstat (limited to 'libelf/gelf_getauxv.c')
| -rw-r--r-- | libelf/gelf_getauxv.c | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/libelf/gelf_getauxv.c b/libelf/gelf_getauxv.c new file mode 100644 index 0000000..036bdcc --- /dev/null +++ b/libelf/gelf_getauxv.c @@ -0,0 +1,130 @@ +/* Get information from auxiliary vector at the given index. + Copyright (C) 2007 Red Hat, Inc. + This file is part of Red Hat elfutils. + + Red Hat elfutils is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by the + Free Software Foundation; version 2 of the License. + + Red Hat 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 a copy of the GNU General Public License along + with Red Hat elfutils; if not, write to the Free Software Foundation, + Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. + + In addition, as a special exception, Red Hat, Inc. gives You the + additional right to link the code of Red Hat elfutils with code licensed + under any Open Source Initiative certified open source license + (http://www.opensource.org/licenses/index.php) which requires the + distribution of source code with any binary distribution and to + distribute linked combinations of the two. Non-GPL Code permitted under + this exception must only link to the code of Red Hat elfutils through + those well defined interfaces identified in the file named EXCEPTION + found in the source code files (the "Approved Interfaces"). The files + of Non-GPL Code may instantiate templates or use macros or inline + functions from the Approved Interfaces without causing the resulting + work to be covered by the GNU General Public License. Only Red Hat, + Inc. may make changes or additions to the list of Approved Interfaces. + Red Hat's grant of this exception is conditioned upon your not adding + any new exceptions. If you wish to add a new Approved Interface or + exception, please contact Red Hat. You must obey the GNU General Public + License in all respects for all of the Red Hat elfutils code and other + code used in conjunction with Red Hat elfutils except the Non-GPL Code + covered by this exception. If you modify this file, you may extend this + exception to your version of the file, but you are not obligated to do + so. If you do not wish to provide this exception without modification, + you must delete this exception statement from your version and license + this file solely under the GPL without exception. + + Red Hat elfutils is an included package of the Open Invention Network. + An included package of the Open Invention Network is a package for which + Open Invention Network licensees cross-license their patents. No patent + license is granted, either expressly or impliedly, by designation as an + included package. Should you wish to participate in the Open Invention + Network licensing program, please visit www.openinventionnetwork.com + <http://www.openinventionnetwork.com>. */ + +#ifdef HAVE_CONFIG_H +# include <config.h> +#endif + +#include <assert.h> +#include <gelf.h> +#include <string.h> + +#include "libelfP.h" + + +GElf_auxv_t * +gelf_getauxv (data, ndx, dst) + Elf_Data *data; + int ndx; + GElf_auxv_t *dst; +{ + Elf_Data_Scn *data_scn = (Elf_Data_Scn *) data; + GElf_auxv_t *result = NULL; + Elf *elf; + + if (data_scn == NULL) + return NULL; + + if (unlikely (data_scn->d.d_type != ELF_T_AUXV)) + { + __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_auxv_t *src; + + /* Here it gets a bit more complicated. The format of the vector + entries has to be converted. The user better have provided a + buffer where we can store the information. While copying the data + we convert the format. */ + if (unlikely ((ndx + 1) * sizeof (Elf32_auxv_t) > data_scn->d.d_size)) + { + __libelf_seterrno (ELF_E_INVALID_INDEX); + goto out; + } + + src = &((Elf32_auxv_t *) 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->a_type = src->a_type; + dst->a_un.a_val = src->a_un.a_val; + } + else + { + /* If this is a 64 bit object it's easy. */ + assert (sizeof (GElf_auxv_t) == sizeof (Elf64_auxv_t)); + + /* The data is already in the correct form. Just make sure the + index is OK. */ + if (unlikely ((ndx + 1) * sizeof (GElf_auxv_t) > data_scn->d.d_size)) + { + __libelf_seterrno (ELF_E_INVALID_INDEX); + goto out; + } + + *dst = ((GElf_auxv_t *) data_scn->d.d_buf)[ndx]; + } + + result = dst; + + out: + rwlock_unlock (elf->lock); + + return result; +} |