from netbsd:

Only expect vm_fork() to return if __FORK_BRAINDAMAGE is defined.
Use splstatclock() rather than splhigh() in one place.
Eliminate unused third arg to vm_fork().

diff --git a/sys/kern/kern_fork.c b/sys/kern/kern_fork.c
index c7fd5d6..1beb55b 100644 (file)
--- a/sys/kern/kern_fork.c
+++ b/sys/kern/kern_fork.c
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_fork.c,v 1.25 1995/10/07 06:28:15 mycroft Exp $   */
+/*     $NetBSD: kern_fork.c,v 1.27 1995/12/10 08:26:02 mycroft Exp $   */
 
 /*
  * Copyright (c) 1982, 1986, 1989, 1991, 1993
@@ -53,7 +53,9 @@
 #include <sys/acct.h>
 #include <sys/ktrace.h>
 
-/* ARGSUSED */
+int    nprocs = 1;             /* process 0 */
+
+int
 sys_fork(p, v, retval)
        struct proc *p;
        void *v;
@@ -63,7 +65,7 @@ sys_fork(p, v, retval)
        return (fork1(p, 0, retval));
 }
 
-/* ARGSUSED */
+int
 sys_vfork(p, v, retval)
        struct proc *p;
        void *v;
@@ -73,8 +75,7 @@ sys_vfork(p, v, retval)
        return (fork1(p, 1, retval));
 }
 
-int    nprocs = 1;             /* process 0 */
-
+int
 fork1(p1, isvfork, retval)
        register struct proc *p1;
        int isvfork;
@@ -237,23 +238,33 @@ again:
         * from being swapped.
         */
        p1->p_holdcnt++;
+
+#ifdef __FORK_BRAINDAMAGE
        /*
         * Set return values for child before vm_fork,
         * so they can be copied to child stack.
-        * We return parent pid, and mark as child in retval[1].
+        * We return 0, rather than the traditional behaviour of modifying the
+        * return value in the system call stub.
         * NOTE: the kernel stack may be at a different location in the child
         * process, and thus addresses of automatic variables (including retval)
         * may be invalid after vm_fork returns in the child process.
         */
-       retval[0] = p1->p_pid;
+       retval[0] = 0;
        retval[1] = 1;
-       if (vm_fork(p1, p2, isvfork))
+       if (vm_fork(p1, p2))
                return (0);
+#else
+       /*
+        * Finish creating the child process.  It will return through a
+        * different path later.
+        */
+       vm_fork(p1, p2);
+#endif
 
        /*
         * Make child runnable, set start time, and add to run queue.
         */
-       (void) splhigh();
+       (void) splstatclock();
        p2->p_stats->p_start = time;
        p2->p_acflag = AFORK;
        p2->p_stat = SRUN;