Rewrite abi-note.S in C.

Using C code allows the compiler to add target specific object file
markings based on CFLAGS.

The arm specific abi-note.S is removed and similar object file fix
up will be avoided on AArch64 with standard branch protection.

1 files changed, 77 insertions, 0 deletions

diff --git a/csu/abi-note.c b/csu/abi-note.c
new file mode 100644
index 0000000000..8febf4cac0
--- /dev/null
+++ b/csu/abi-note.c
@@ -0,0 +1,77 @@
+/* Special .init and .fini section support.
+   Copyright (C) 1997-2020 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   In addition to the permissions in the GNU Lesser General Public
+   License, the Free Software Foundation gives you unlimited
+   permission to link the compiled version of this file with other
+   programs, and to distribute those programs without any restriction
+   coming from the use of this file.  (The Lesser General Public
+   License restrictions do apply in other respects; for example, they
+   cover modification of the file, and distribution when not linked
+   into another program.)
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+/* Define an ELF note identifying the operating-system ABI that the
+   executable was created for.  The ELF note information identifies a
+   particular OS or coordinated development effort within which the
+   ELF header's e_machine value plus (for dynamically linked programs)
+   the PT_INTERP dynamic linker name and DT_NEEDED shared library
+   names fully identify the runtime environment required by an
+   executable.
+
+   The general format of ELF notes is as follows.
+   Offsets and lengths are bytes or (parenthetical references) to the
+   values in other fields.
+
+offset	length	contents
+0	4	length of name
+4	4	length of data
+8	4	note type
+12	(0)	vendor name
+		- null-terminated ASCII string, padded to 4-byte alignment
+12+(0)	(4)	note data,
+
+   The GNU project and cooperating development efforts (including the
+   Linux community) use note type 1 and a vendor name string of "GNU"
+   for a note descriptor that indicates ABI requirements.  The note data
+   is four 32-bit words.  The first of these is an operating system
+   number (0=Linux, 1=Hurd, 2=Solaris, ...) and the remaining three
+   identify the earliest release of that OS that supports this ABI.
+   See abi-tags (top level) for details. */
+
+#include <link.h>
+#include <stdint.h>
+#include <config.h>
+#include <abi-tag.h>		/* OS-specific ABI tag value */
+
+/* The linker (GNU ld 2.8 and later) recognizes an allocated section whose
+   name begins with `.note' and creates a PT_NOTE program header entry
+   pointing at it. */
+
+__attribute__ ((used, aligned (4), section (".note.ABI-tag")))
+static const struct
+{
+  ElfW(Nhdr) nhdr;
+  char name[4];
+  int32_t desc[4];
+} __abi_tag = {
+  { .n_namesz = sizeof __abi_tag.name,
+    .n_descsz = sizeof __abi_tag.desc,
+    .n_type = 1 },
+  "GNU",
+  { __ABI_TAG_OS, __ABI_TAG_VERSION }
+};