initial import of NetBSD tree

1 files changed, 72 insertions, 0 deletions

diff --git a/lib/libc/arch/vax/sys/Ovfork.S b/lib/libc/arch/vax/sys/Ovfork.S
new file mode 100644
index 00000000000..8ed3bc3bfc0
--- /dev/null
+++ b/lib/libc/arch/vax/sys/Ovfork.S
@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 1983, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(SYSLIBC_SCCS) && !defined(lint)
+	/* .asciz "@(#)Ovfork.s	8.1 (Berkeley) 6/4/93" */
+	.asciz "$NetBSD: Ovfork.S,v 1.1 1995/04/17 12:23:56 ragge Exp $"
+#endif /* SYSLIBC_SCCS and not lint */
+
+/*
+ * @(#)vfork.s	4.1 (Berkeley) 12/21/80
+ * C library -- vfork
+ */
+
+#include "SYS.h"
+
+/*
+ * pid = vfork();
+ *
+ * r1 == 0 in parent process, r1 == 1 in child process.
+ * r0 == pid of child in parent, r0 == pid of parent in child.
+ *
+ * trickery here, due to keith sklower, uses ret to clear the stack,
+ * and then returns with a jump indirect, since only one person can return
+ * with a ret off this stack... we do the ret before we vfork!
+ */
+
+ENTRY(vfork)
+	movl	16(fp),r2	# save return address before we smash it
+	movab	here,16(fp)
+	ret
+here:
+	chmk	$ SYS_vfork
+	bcs	err		# if failed, set errno and return -1
+	/* this next trick is Chris Torek's fault */
+	mnegl	r1,r1		# r1 = 0xffffffff if child, 0 if parent
+	bicl2	r1,r0		# r0 &= ~r1, i.e., 0 if child, else unchanged
+	jmp	(r2)
+
+err:
+	movl	r0,_errno
+	mnegl	$1,r0
+	jmp	(r2)