From 5d2472cf83a9ceb2b002dee59100ca3fbe7b9311 Mon Sep 17 00:00:00 2001
From: David McCullough <davidm@snapgear.com>
Date: Mon, 25 Jun 2001 04:11:28 +0000
Subject: Fixed vfork so the child doesn't trash the parents return address.

---
 libc/sysdeps/linux/m68k/Makefile |  4 ++--
 libc/sysdeps/linux/m68k/vfork.S  | 33 +++++++++++++++++++++++++++++++++
 libc/sysdeps/linux/m68k/vfork.c  | 25 -------------------------
 3 files changed, 35 insertions(+), 27 deletions(-)
 create mode 100644 libc/sysdeps/linux/m68k/vfork.S
 delete mode 100644 libc/sysdeps/linux/m68k/vfork.c

diff --git a/libc/sysdeps/linux/m68k/Makefile b/libc/sysdeps/linux/m68k/Makefile
index 3ca165344..9c929ec11 100644
--- a/libc/sysdeps/linux/m68k/Makefile
+++ b/libc/sysdeps/linux/m68k/Makefile
@@ -29,10 +29,10 @@ ASFLAGS=$(CFLAGS)
 CRT0=crt0.S
 CRT0_OBJ=$(patsubst %.S,%.o, $(CRT0))
 
-SSRC=setjmp.S # longjmp.S _start.S clone.S
+SSRC=setjmp.S vfork.S # longjmp.S _start.S clone.S
 SOBJS=$(patsubst %.S,%.o, $(SSRC))
 
-CSRC=ptrace.c vfork.c
+CSRC=ptrace.c
 COBJS=$(patsubst %.c,%.o, $(CSRC))
 
 OBJS=$(SOBJS) $(MOBJ) $(COBJS)
diff --git a/libc/sysdeps/linux/m68k/vfork.S b/libc/sysdeps/linux/m68k/vfork.S
new file mode 100644
index 000000000..ba3a67203
--- /dev/null
+++ b/libc/sysdeps/linux/m68k/vfork.S
@@ -0,0 +1,33 @@
+
+#include <asm/unistd.h>
+
+#ifndef __NR_vfork
+#define __NR_vfork __NR_fork /* uClinux-2.0 only has fork which is vfork */
+#endif
+
+#define IMM #
+
+	.text
+	.align 2
+	.globl errno
+	.globl vfork
+	.type	 vfork,@function
+vfork:
+	movl	%sp@+, %a1               /* save the return address for later */
+	movl	IMM __NR_vfork,%d0
+	trap	#0
+	movl	IMM -4097, %d1
+	cmpl 	%d0, %d1
+	bcs     fix_errno
+	jmp		%a1@                     /* don't return,  just jmp directly */
+fix_errno:
+	negl	%d0
+#ifndef __PIC__
+	movl	errno, %a0
+#else
+	movl	errno@GOT(%a5), %a0
+#endif
+	movl	%d0, %a0@
+	movl	IMM -1, %d0
+	jmp		%a1@                     /* don't return,  just jmp directly */
+
diff --git a/libc/sysdeps/linux/m68k/vfork.c b/libc/sysdeps/linux/m68k/vfork.c
deleted file mode 100644
index 9edcb650d..000000000
--- a/libc/sysdeps/linux/m68k/vfork.c
+++ /dev/null
@@ -1,25 +0,0 @@
-/* orginally from include/unistd.h, written by ndf@linux.mit.edu> */
-#include <unistd.h>
-#include <sys/types.h>
-#include <asm/unistd.h>
-
-#ifndef __NR_vfork
-#define __NR_vfork __NR_fork /* uClinux-2.0 only has fork which is vfork */
-#endif
-
-pid_t vfork(void)
-{
-    pid_t __res;
-	__asm__ __volatile__ ("movel %1,%%d0;"
-		"trap  #0;"
-		"movel %%d0,%0"
-		: "=d" (__res)
-		: "0" (__NR_vfork)
-		: "%d0");
-	if (__res >= (unsigned long)-4096) {
-	    errno = -__res;
-		__res = (pid_t)-1;
-	}
-    return(__res);
-}
-
-- 
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