Update.

2002-08-31  Andreas Jaeger  <aj@suse.de>

	* sysdeps/unix/sysv/linux/x86_64/Makefile (sysdep_routines): Add
	__start_context.

	* sysdeps/unix/sysv/linux/x86_64/__start_context.S: New file.

	* sysdeps/unix/sysv/linux/x86_64/makecontext.c: New file.

	* sysdeps/unix/sysv/linux/x86_64/ucontext_i.h: Add defines for
	registers used for passing args.

	* sysdeps/unix/sysv/linux/x86_64/swapcontext.S: Save and restore
	all needed registers.

	* sysdeps/unix/sysv/linux/x86_64/setcontext.S: Restore all
	registers.

	* sysdeps/unix/sysv/linux/x86_64/getcontext.S: Save all needed
	registers.

1 files changed, 48 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/x86_64/__start_context.S b/sysdeps/unix/sysv/linux/x86_64/__start_context.S
new file mode 100644
index 0000000000..ad4502ca0a
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86_64/__start_context.S
@@ -0,0 +1,48 @@
+/* Copyright (C) 2002 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Andreas Jaeger <aj@suse.de>, 2002.
+
+   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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <sysdep.h>
+
+/* This is the helper code which gets called if a function which is
+   registered with 'makecontext' returns.  In this case we have to
+   install the context listed in the uc_link element of the context
+   'makecontext' manipulated at the time of the 'makecontext' call.
+   If the pointer is NULL the process must terminate.  */
+
+
+ENTRY(__start_context)
+	/* This removes the parameters passed to the function given to
+	   'makecontext' from the stack.  RBX contains the address
+	   on the stack pointer for the next context.  */
+	movq	%rbx, %rsp
+
+	popq	%rdi			/* This is the next context.  */
+	testq	%rdi, %rdi
+	je	2f			/* If it is zero exit.  */
+
+	call	JUMPTARGET(__setcontext)
+	/* If this returns (which can happen if the syscall fails) we'll
+	   exit the program with the return error value (-1).  */
+
+2:	movq	%rax,%rdi
+	call	JUMPTARGET(exit)
+	/* The 'exit' call should never return.  In case it does cause
+	   the process to terminate.  */
+	hlt
+END(__start_context)