the 5.1 era tfork syscall claws its way out of the grave. we failed to

fully deprecate it (notably the go port was still using it as of 5.3)
so to give users a little more time to update, __tfork51 lives again.
okish deraadt guenther

3 files changed, 36 insertions, 4 deletions

diff --git a/sys/kern/kern_fork.c b/sys/kern/kern_fork.c
index b3e658c3692..02bc078a951 100644
--- a/sys/kern/kern_fork.c
+++ b/sys/kern/kern_fork.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_fork.c,v 1.144 2013/03/02 07:05:17 guenther Exp $	*/
+/*	$OpenBSD: kern_fork.c,v 1.145 2013/03/14 21:38:22 tedu Exp $	*/
 /*	$NetBSD: kern_fork.c,v 1.29 1996/02/09 18:59:34 christos Exp $	*/
 
 /*
@@ -141,6 +141,31 @@ sys___tfork(struct proc *p, void *v, register_t *retval)
 	    tfork_child_return, param.tf_tcb, retval, NULL));
 }
 
+#ifdef COMPAT_O51
+int
+compat_o51_sys___tfork(struct proc *p, void *v, register_t *retval)
+{
+	struct compat_o51_sys___tfork_args /* {
+		syscallarg(struct __tfork51) *param;
+	} */ *uap = v;
+	struct __tfork51 param;
+	int flags;
+	int error;
+
+	if ((error = copyin(SCARG(uap, param), &param, sizeof(param))))
+		return (error);
+
+	if (param.tf_flags != 0)
+		return (EINVAL);
+
+	flags = FORK_TFORK | FORK_THREAD | FORK_SIGHAND | FORK_SHAREVM
+	    | FORK_NOZOMBIE | FORK_SHAREFILES;
+
+	return (fork1(p, 0, flags, NULL, param.tf_tid, tfork_child_return,
+	    param.tf_tcb, retval, NULL));
+}
+#endif
+
 void
 tfork_child_return(void *arg)
 {
diff --git a/sys/kern/syscalls.master b/sys/kern/syscalls.master
index 90e0271a650..fe0a69928aa 100644
--- a/sys/kern/syscalls.master
+++ b/sys/kern/syscalls.master
@@ -1,4 +1,4 @@
-;	$OpenBSD: syscalls.master,v 1.127 2013/03/02 07:05:18 guenther Exp $
+;	$OpenBSD: syscalls.master,v 1.128 2013/03/14 21:38:22 tedu Exp $
 ;	$NetBSD: syscalls.master,v 1.32 1996/04/23 10:24:21 mycroft Exp $
 
 ;	@(#)syscalls.master	8.2 (Berkeley) 1/13/94
@@ -564,6 +564,6 @@
 			    const struct timespec *times, int flag); }
 327	STD		{ int sys_futimens(int fd, \
 			    const struct timespec *times); }
-328	OBSOL		otfork51
+328	COMPAT_O51	{ int sys___tfork(struct __tfork51 *param); }
 329	STD NOLOCK	{ void sys___set_tcb(void *tcb); }
 330	STD NOLOCK	{ void *sys___get_tcb(void); }
diff --git a/sys/sys/unistd.h b/sys/sys/unistd.h
index 94db8ac5021..609bebe8692 100644
--- a/sys/sys/unistd.h
+++ b/sys/sys/unistd.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: unistd.h,v 1.25 2013/03/02 07:05:18 guenther Exp $	*/
+/*	$OpenBSD: unistd.h,v 1.26 2013/03/14 21:38:22 tedu Exp $	*/
 /*	$NetBSD: unistd.h,v 1.10 1994/06/29 06:46:06 cgd Exp $	*/
 
 /*
@@ -65,6 +65,13 @@ struct __tfork {
 	pid_t	*tf_tid;
 	void	*tf_stack;
 };
+
+/* COMPAT_O51 */
+struct __tfork51 {
+	void	*tf_tcb;
+	pid_t	*tf_tid;
+	int	tf_flags;
+};
 #endif
 
 /* the pathconf(2) variable values are part of the ABI */