Coverage Report

Created: 2023-03-26 07:38

/src/libbpf/elfutils/libelf/gelf_getnote.c
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Source (jump to first uncovered line)
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/* 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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0
{
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0
  if (data == NULL)
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0
    return 0;
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  if (unlikely (data->d_type != ELF_T_NHDR && data->d_type != ELF_T_NHDR8))
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0
    {
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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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0
    {
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      __libelf_seterrno (ELF_E_OFFSET_RANGE);
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      offset = 0;
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0
    }
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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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0
      else
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0
  {
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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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0
    if (n->n_namesz > data->d_size
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0
        || 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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0
}