Simplify fork/vfork logic: the kernel has handled returning zero in the child

for a long time, so there's no need to test the second return register here
in the asm stub.

ok and testing of many archs by krw@ miod@

2 files changed, 3 insertions, 15 deletions

diff --git a/lib/libc/arch/i386/sys/Ovfork.S b/lib/libc/arch/i386/sys/Ovfork.S
index 984c26c3cb0..aad09330695 100644
--- a/lib/libc/arch/i386/sys/Ovfork.S
+++ b/lib/libc/arch/i386/sys/Ovfork.S
@@ -1,4 +1,4 @@
-/*	$OpenBSD: Ovfork.S,v 1.7 2012/08/22 17:19:34 pascal Exp $ */
+/*	$OpenBSD: Ovfork.S,v 1.8 2015/03/31 04:32:01 guenther Exp $ */
 /*-
  * Copyright (c) 1990 The Regents of the University of California.
  * All rights reserved.
@@ -33,20 +33,11 @@
 
 #include "SYS.h"
 
-/*
- * pid = vfork();
- *
- * %edx == 0 in parent process, %edx == 1 in child process.
- * %eax == pid of child in parent, %eax == pid of parent in child.
- *
- */
 SYSENTRY(vfork)
 	popl	%ecx		/* my rta into ecx */
 	movl	$(SYS_vfork),%eax
 	int	$0x80
 	jc	err
-	decl	%edx
-	andl	%edx,%eax
 	jmp	*%ecx
 err:
 #ifdef __PIC__
diff --git a/lib/libc/arch/i386/sys/fork.S b/lib/libc/arch/i386/sys/fork.S
index e8850dd5b5c..205ae5942c1 100644
--- a/lib/libc/arch/i386/sys/fork.S
+++ b/lib/libc/arch/i386/sys/fork.S
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fork.S,v 1.4 2005/08/07 11:30:38 espie Exp $ */
+/*	$OpenBSD: fork.S,v 1.5 2015/03/31 04:32:01 guenther Exp $ */
 /*-
  * Copyright (c) 1990 The Regents of the University of California.
  * All rights reserved.
@@ -33,7 +33,4 @@
 
 #include "SYS.h"
 
-SYSCALL(fork)
-	decl	%edx	/* from 1 to 0 in child, 0 to -1 in parent */
-	andl	%edx,%eax
-	ret		/* pid = fork(); */
+RSYSCALL(fork)