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/elf_newdata.c b/libelf/elf_newdata.c
new file mode 100644
index 0000000..f6609a8
--- /dev/null
+++ b/libelf/elf_newdata.c
@@ -0,0 +1,136 @@
+/* Create new, empty section data.
+ Copyright (C) 1998, 1999, 2000, 2001, 2002, 2015 Red Hat, Inc.
+ This file is part of elfutils.
+ Contributed by Ulrich Drepper <drepper@redhat.com>, 1998.
+
+ 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 <stddef.h>
+#include <stdlib.h>
+
+#include "libelfP.h"
+
+
+Elf_Data *
+elf_newdata (Elf_Scn *scn)
+{
+ Elf_Data_List *result = NULL;
+
+ if (scn == NULL)
+ return NULL;
+
+ if (unlikely (scn->index == 0))
+ {
+ /* It is not allowed to add something to the 0th section. */
+ __libelf_seterrno (ELF_E_NOT_NUL_SECTION);
+ return NULL;
+ }
+
+ if (scn->elf->class == ELFCLASS32
+ || (offsetof (struct Elf, state.elf32.ehdr)
+ == offsetof (struct Elf, state.elf64.ehdr))
+ ? scn->elf->state.elf32.ehdr == NULL
+ : scn->elf->state.elf64.ehdr == NULL)
+ {
+ __libelf_seterrno (ELF_E_WRONG_ORDER_EHDR);
+ return NULL;
+ }
+
+ rwlock_wrlock (scn->elf->lock);
+
+ /* data_read is set when data has been read from the ELF image or
+ when a new section has been created by elf_newscn. If data has
+ been read from the ELF image, then rawdata_base will point to raw
+ data. If data_read has been set by elf_newscn, then rawdata_base
+ will be NULL. data_list_rear will be set by elf_getdata if the
+ data has been converted, or by this function, elf_newdata, when
+ new data has been added.
+
+ Currently elf_getdata and elf_update rely on the fact that when
+ data_list_read is not NULL all they have to do is walk the data
+ list. They will ignore any (unread) raw data in that case.
+
+ So we need to make sure the data list is setup if there is
+ already data available. */
+ if (scn->data_read
+ && scn->rawdata_base != NULL
+ && scn->data_list_rear == NULL)
+ __libelf_set_data_list_rdlock (scn, 1);
+
+ if (scn->data_read && scn->data_list_rear == NULL)
+ {
+ /* This means the section was created by the user and this is the
+ first data. */
+ result = &scn->data_list;
+ result->flags = ELF_F_DIRTY;
+ }
+ else
+ {
+ /* It would be more efficient to create new data without
+ reading/converting the data from the file. But then we
+ have to remember this. Currently elf_getdata and
+ elf_update rely on the fact that they don't have to
+ load/convert any data if data_list_rear is set. */
+ if (scn->data_read == 0)
+ {
+ if (__libelf_set_rawdata_wrlock (scn) != 0)
+ /* Something went wrong. The error value is already set. */
+ goto out;
+ __libelf_set_data_list_rdlock (scn, 1);
+ }
+
+ /* Create a new, empty data descriptor. */
+ result = (Elf_Data_List *) calloc (1, sizeof (Elf_Data_List));
+ if (result == NULL)
+ {
+ __libelf_seterrno (ELF_E_NOMEM);
+ goto out;
+ }
+
+ result->flags = ELF_F_DIRTY | ELF_F_MALLOCED;
+ }
+
+ /* Set the predefined values. */
+ result->data.d.d_version = __libelf_version;
+
+ result->data.s = scn;
+
+ /* Add to the end of the list. */
+ if (scn->data_list_rear != NULL)
+ scn->data_list_rear->next = result;
+
+ scn->data_list_rear = result;
+
+ out:
+ rwlock_unlock (scn->elf->lock);
+
+ /* Please note that the following is thread safe and is also defined
+ for RESULT == NULL since it still return NULL. */
+ return &result->data.d;
+}