PATCH: Add x32 dl-machine.h

["H.J. Lu" <hongjiu dot lu at intel dot com>]

Hi,

This patch adds sysdeps/x86_64/x32/dl-machine.h.  It redeines
ARCH_LA_PLTENTER, ARCH_LA_PLTEXIT and RTLD_START.  The main
differences in RTLD_START is x32 are  a 32-bit environment and
it doesn't have 32bit push/pop.  Tested on Linux/x32.  OK to install?

Thanks.


H.J.
---
	* sysdeps/x86_64/x32/dl-machine.h: New file.

diff --git a/sysdeps/x86_64/x32/dl-machine.h b/sysdeps/x86_64/x32/dl-machine.h
new file mode 100644
index 0000000..94d3c0b
--- /dev/null
+++ b/sysdeps/x86_64/x32/dl-machine.h
@@ -0,0 +1,85 @@
+/* Machine-dependent ELF dynamic relocation inline functions.  x32 version.
+   Copyright (C) 2012 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.
+
+   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
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sysdeps/x86_64/dl-machine.h>
+
+#ifndef x32_dl_machine_h
+#define x32_dl_machine_h
+
+#undef ARCH_LA_PLTENTER
+#undef ARCH_LA_PLTEXIT
+#undef RTLD_START
+
+/* Names of the architecture-specific auditing callback functions.  */
+#define ARCH_LA_PLTENTER x32_gnu_pltenter
+#define ARCH_LA_PLTEXIT x32_gnu_pltexit
+
+/* Initial entry point code for the dynamic linker.
+   The C function `_dl_start' is the real entry point;
+   its return value is the user program's entry point.  */
+#define RTLD_START asm ("\n\
+.text\n\
+	.align 16\n\
+.globl _start\n\
+.globl _dl_start_user\n\
+_start:\n\
+	movl %esp, %edi\n\
+	call _dl_start\n\
+_dl_start_user:\n\
+	# Save the user entry point address in %r12.\n\
+	movl %eax, %r12d\n\
+	# See if we were run as a command with the executable file\n\
+	# name as an extra leading argument.\n\
+	movl _dl_skip_args(%rip), %eax\n\
+	# Pop the original argument count.\n\
+	movl (%rsp), %edx\n\
+	addl $4,%esp\n\
+	# Adjust the stack pointer to skip _dl_skip_args words.\n\
+	lea (%rsp,%rax,4), %esp\n\
+	# Subtract _dl_skip_args from argc.\n\
+	subl %eax, %edx\n\
+	# Push argc back on the stack.\n\
+	subl $4,%esp\n\
+	movl %edx, (%rsp)\n\
+	# Call _dl_init (struct link_map *main_map, int argc, char **argv, char **env)\n\
+	# argc -> rsi\n\
+	movl %edx, %esi\n\
+	# Save %rsp value in %r13.\n\
+	movl %esp, %r13d\n\
+	# And align stack for the _dl_init_internal call. \n\
+	and $-16, %esp\n\
+	# _dl_loaded -> rdi\n\
+	movl _rtld_local(%rip), %edi\n\
+	# env -> rcx\n\
+	lea 8(%r13,%rdx,4), %ecx\n\
+	# argv -> rdx\n\
+	lea 4(%r13), %edx\n\
+	# Clear %rbp to mark outermost frame obviously even for constructors.\n\
+	xorl %ebp, %ebp\n\
+	# Call the function to run the initializers.\n\
+	call _dl_init_internal@PLT\n\
+	# Pass our finalizer function to the user in %rdx, as per ELF ABI.\n\
+	lea _dl_fini(%rip), %edx\n\
+	# And make sure %rsp points to argc stored on the stack.\n\
+	movl %r13d, %esp\n\
+	# Jump to the user's entry point.\n\
+	jmp *%r12\n\
+.previous\n\
+");
+
+#endif /* !x32_dl_machine_h */