From: Andreas Jaeger <aj@suse.de>
Date: Mon, 22 Apr 2002 05:58:12 +0000 (+0000)
Subject: Use %rdi as temp register instead of destroying %rbx.
X-Git-Tag: cvs/glibc-2-3~838
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=04d12383c83e8cba07b96289d313ebad7d0c6ea7;p=thirdparty%2Fglibc.git

Use %rdi as temp register instead of destroying %rbx.
---

diff --git a/sysdeps/unix/sysv/linux/x86_64/vfork.S b/sysdeps/unix/sysv/linux/x86_64/vfork.S
index 0b5a90a6c81..79f3260efc7 100644
--- a/sysdeps/unix/sysv/linux/x86_64/vfork.S
+++ b/sysdeps/unix/sysv/linux/x86_64/vfork.S
@@ -1,4 +1,4 @@
-/* Copyright (C) 2001 Free Software Foundation, Inc.
+/* Copyright (C) 2001, 2002 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
@@ -27,8 +27,9 @@
 
 ENTRY (__vfork)
 
-	/* Pop the return PC value into RBX.  */
-	popq	%rbx
+	/* Pop the return PC value into RDI.  We need a register that
+	   is preserved by the syscall and that we're allowed to destroy. */
+	popq %rdi
 
 	/* Stuff the syscall number in RAX and enter into the kernel.  */
 	movl	$SYS_ify (vfork), %eax
@@ -37,11 +38,11 @@ ENTRY (__vfork)
 	jae	.Lerror		/* Branch forward if it failed.  */
 
 	/* Jump to the return PC.  */
-	jmp	*%rbx
+	jmp	*%rdi
 
 .Lerror:
 	/* Push back the return PC.  */
-	pushq	%rbx
+	pushq	%rdi
 	jmp	SYSCALL_ERROR_LABEL
 
 .Lpseudo_end: