Squashed 'third_party/elfutils/' content from commit 555e15e
Change-Id: I61cde98949e47e5c8c09c33260de17f30921be79
git-subtree-dir: third_party/elfutils
git-subtree-split: 555e15ebe8bf1eb33d00747173cfc80cc65648a4
diff --git a/libelf/gelf_getnote.c b/libelf/gelf_getnote.c
new file mode 100644
index 0000000..c75edda
--- /dev/null
+++ b/libelf/gelf_getnote.c
@@ -0,0 +1,100 @@
+/* Get note information at the supplied offset.
+ Copyright (C) 2007, 2014, 2015 Red Hat, Inc.
+ This file is part of elfutils.
+
+ 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"
+
+size_t
+gelf_getnote (Elf_Data *data, size_t offset, GElf_Nhdr *result,
+ size_t *name_offset, size_t *desc_offset)
+{
+ if (data == NULL)
+ return 0;
+
+ if (unlikely (data->d_type != ELF_T_NHDR))
+ {
+ __libelf_seterrno (ELF_E_INVALID_HANDLE);
+ return 0;
+ }
+
+ /* It's easy to handle this type. It has the same size for 32 and
+ 64 bit objects. */
+ assert (sizeof (GElf_Nhdr) == sizeof (Elf32_Nhdr));
+ assert (sizeof (GElf_Nhdr) == sizeof (Elf64_Nhdr));
+
+ rwlock_rdlock (((Elf_Data_Scn *) data)->s->elf->lock);
+
+ /* The data is already in the correct form. Just make sure the
+ offset is OK. */
+ if (unlikely (offset > data->d_size
+ || data->d_size - offset < sizeof (GElf_Nhdr)))
+ {
+ __libelf_seterrno (ELF_E_OFFSET_RANGE);
+ offset = 0;
+ }
+ else
+ {
+ const GElf_Nhdr *n = data->d_buf + offset;
+ offset += sizeof *n;
+
+ /* Include padding. Check below for overflow. */
+ GElf_Word namesz = NOTE_ALIGN (n->n_namesz);
+ GElf_Word descsz = NOTE_ALIGN (n->n_descsz);
+
+ if (unlikely (offset > data->d_size
+ || data->d_size - offset < namesz
+ || (namesz == 0 && n->n_namesz != 0)))
+ offset = 0;
+ else
+ {
+ *name_offset = offset;
+ offset += namesz;
+ if (unlikely (offset > data->d_size
+ || data->d_size - offset < descsz
+ || (descsz == 0 && n->n_descsz != 0)))
+ offset = 0;
+ else
+ {
+ *desc_offset = offset;
+ offset += descsz;
+ *result = *n;
+ }
+ }
+ }
+
+ rwlock_unlock (((Elf_Data_Scn *) data)->s->elf->lock);
+
+ return offset;
+}