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https://github.com/JakeHillion/drgn.git
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1cedca8ff4
Based on: c950e8a9 config: Fix spec file, add manpages and new GFDL license. With the following patches: configure: Add --disable-programs configure: Add --disable-shared configure: Fix -D_FORTIFY_SOURCE=2 check when CFLAGS contains -Wno-error libcpu: compile i386_lex.c with -Wno-implicit-fallthrough The plan is to stop relying on the distribution's version of elfutils and instead ship our own. This gives us freedom to assume that we're using the latest version and even ship our own patches (starting with a few build system improvements). More details are in scripts/update-elfutils.sh, which was used to generate this commit.
117 lines
3.2 KiB
C
117 lines
3.2 KiB
C
/* Get note information at the supplied offset.
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Copyright (C) 2007, 2014, 2015, 2018 Red Hat, Inc.
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This file is part of elfutils.
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This file is free software; you can redistribute it and/or modify
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it under the terms of either
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* the GNU Lesser General Public License as published by the Free
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Software Foundation; either version 3 of the License, or (at
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your option) any later version
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or
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* the GNU General Public License as published by the Free
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Software Foundation; either version 2 of the License, or (at
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your option) any later version
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or both in parallel, as here.
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elfutils is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received copies of the GNU General Public License and
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the GNU Lesser General Public License along with this program. If
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not, see <http://www.gnu.org/licenses/>. */
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#ifdef HAVE_CONFIG_H
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# include <config.h>
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#endif
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#include <assert.h>
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#include <gelf.h>
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#include <string.h>
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#include "libelfP.h"
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size_t
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gelf_getnote (Elf_Data *data, size_t offset, GElf_Nhdr *result,
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size_t *name_offset, size_t *desc_offset)
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{
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if (data == NULL)
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return 0;
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if (unlikely (data->d_type != ELF_T_NHDR && data->d_type != ELF_T_NHDR8))
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{
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__libelf_seterrno (ELF_E_INVALID_HANDLE);
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return 0;
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}
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/* It's easy to handle this type. It has the same size for 32 and
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64 bit objects. */
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assert (sizeof (GElf_Nhdr) == sizeof (Elf32_Nhdr));
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assert (sizeof (GElf_Nhdr) == sizeof (Elf64_Nhdr));
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rwlock_rdlock (((Elf_Data_Scn *) data)->s->elf->lock);
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/* The data is already in the correct form. Just make sure the
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offset is OK. */
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if (unlikely (offset > data->d_size
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|| data->d_size - offset < sizeof (GElf_Nhdr)))
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{
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__libelf_seterrno (ELF_E_OFFSET_RANGE);
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offset = 0;
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}
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else
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{
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const GElf_Nhdr *n = data->d_buf + offset;
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offset += sizeof *n;
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if (offset > data->d_size)
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offset = 0;
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else
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{
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/* This is slightly tricky, offset is guaranteed to be 4
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byte aligned, which is what we need for the name_offset.
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And normally desc_offset is also 4 byte aligned, but not
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for GNU Property notes, then it should be 8. So align
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the offset, after adding the namesz, and include padding
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in descsz to get to the end. */
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*name_offset = offset;
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if (n->n_namesz > data->d_size
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|| offset > data->d_size - n->n_namesz)
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offset = 0;
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else
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{
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offset += n->n_namesz;
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/* Include padding. Check below for overflow. */
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GElf_Word descsz = (data->d_type == ELF_T_NHDR8
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? NOTE_ALIGN8 (n->n_descsz)
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: NOTE_ALIGN4 (n->n_descsz));
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if (data->d_type == ELF_T_NHDR8)
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offset = NOTE_ALIGN8 (offset);
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else
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offset = NOTE_ALIGN4 (offset);
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if (unlikely (offset > data->d_size
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|| data->d_size - offset < descsz
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|| (descsz == 0 && n->n_descsz != 0)))
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offset = 0;
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else
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{
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*desc_offset = offset;
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offset += descsz;
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*result = *n;
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}
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}
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}
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}
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rwlock_unlock (((Elf_Data_Scn *) data)->s->elf->lock);
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return offset;
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}
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