Let fork1, uvm_fork, and cpu_fork take a function/argument pair as argument,

instead of doing fork1, cpu_set_kpc. This lets us retire cpu_set_kpc and
avoid a multiprocessor race.

This commit breaks vax because it doesn't look like any other arch, someone
working on vax might want to look at this and try to adapt the code to be
more like the rest of the world.

Idea and uvm parts from NetBSD.

2 files changed, 14 insertions, 20 deletions

diff --git a/sys/uvm/uvm_extern.h b/sys/uvm/uvm_extern.h
index 249713f25f6..c294b3d2987 100644
--- a/sys/uvm/uvm_extern.h
+++ b/sys/uvm/uvm_extern.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_extern.h,v 1.27 2001/11/06 13:36:52 art Exp $	*/
+/*	$OpenBSD: uvm_extern.h,v 1.28 2001/11/06 18:41:10 art Exp $	*/
 /*	$NetBSD: uvm_extern.h,v 1.48 2000/08/12 22:41:55 thorpej Exp $	*/
 
 /*
@@ -426,17 +426,6 @@ struct core;
 
 #ifdef _KERNEL
 
-/* vm_machdep.c */
-void		vmapbuf __P((struct buf *, vsize_t));
-void		vunmapbuf __P((struct buf *, vsize_t));
-void		pagemove __P((caddr_t, caddr_t, size_t));
-#ifndef	cpu_swapin
-void		cpu_swapin __P((struct proc *));
-#endif
-#ifndef	cpu_swapout
-void		cpu_swapout __P((struct proc *));
-#endif
-
 /* uvm_aobj.c */
 struct uvm_object	*uao_create __P((vsize_t, int));
 void			uao_detach __P((struct uvm_object *));
@@ -454,7 +443,7 @@ int			uvm_fault __P((vm_map_t, vaddr_t,
 void			uvm_chgkprot __P((caddr_t, size_t, int));
 #endif
 void			uvm_fork __P((struct proc *, struct proc *, boolean_t,
-			    void *, size_t));
+			    void *, size_t, void (*)(void *), void *));
 void			uvm_exit __P((struct proc *));
 void			uvm_init_limits __P((struct proc *));
 boolean_t		uvm_kernacc __P((caddr_t, size_t, int));
@@ -581,7 +570,8 @@ void		swstrategy __P((struct buf *));
 void		vmapbuf __P((struct buf *, vsize_t));
 void		vunmapbuf __P((struct buf *, vsize_t));
 void		pagemove __P((caddr_t, caddr_t, size_t));
-void		cpu_fork __P((struct proc *, struct proc *, void *, size_t));
+void		cpu_fork __P((struct proc *, struct proc *, void *, size_t,
+			void (*)(void *), void *));
 #ifndef	cpu_swapin
 void		cpu_swapin __P((struct proc *));
 #endif
diff --git a/sys/uvm/uvm_glue.c b/sys/uvm/uvm_glue.c
index ba10fa92b50..95f24367cc1 100644
--- a/sys/uvm/uvm_glue.c
+++ b/sys/uvm/uvm_glue.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_glue.c,v 1.23 2001/11/06 13:36:52 art Exp $	*/
+/*	$OpenBSD: uvm_glue.c,v 1.24 2001/11/06 18:41:10 art Exp $	*/
 /*	$NetBSD: uvm_glue.c,v 1.40 2000/08/21 02:29:32 thorpej Exp $	*/
 
 /* 
@@ -265,11 +265,13 @@ uvm_vsunlock(p, addr, len)
  *   than just hang
  */
 void
-uvm_fork(p1, p2, shared, stack, stacksize)
+uvm_fork(p1, p2, shared, stack, stacksize, func, arg)
 	struct proc *p1, *p2;
 	boolean_t shared;
 	void *stack;
 	size_t stacksize;
+	void (*func) __P((void *));
+	void *arg;
 {
 	struct user *up = p2->p_addr;
 	int rv;
@@ -306,11 +308,13 @@ uvm_fork(p1, p2, shared, stack, stacksize)
 	 (caddr_t)&up->u_stats.pstat_startcopy));
 	
 	/*
-	 * cpu_fork will copy and update the kernel stack and pcb, and make
-	 * the child ready to run.  The child will exit directly to user
-	 * mode on its first time slice, and will not return here.
+	 * cpu_fork() copy and update the pcb, and make the child ready
+	 * to run.  If this is a normal user fork, the child will exit
+	 * directly to user mode via child_return() on its first time
+	 * slice and will not return here.  If this is a kernel thread,
+	 * the specified entry point will be executed.
 	 */
-	cpu_fork(p1, p2, stack, stacksize);
+	cpu_fork(p1, p2, stack, stacksize, func, arg);
 }
 
 /*