From 0411e090837b2cc273ac2c5eb2ab4466fb70ad20 Mon Sep 17 00:00:00 2001
From: guenther <guenther@openbsd.org>
Date: Sat, 3 May 2014 22:44:36 +0000
Subject: [PATCH] Move the u-area allocation and pmap-magic logic to its own
 function uvm_uarea_alloc()

function name from NetBSD; arm testing by miod@
---
 sys/kern/kern_fork.c |  7 ++-----
 sys/uvm/uvm_extern.h |  3 ++-
 sys/uvm/uvm_glue.c   | 31 +++++++++++++++++++++++--------
 3 files changed, 27 insertions(+), 14 deletions(-)

diff --git a/sys/kern/kern_fork.c b/sys/kern/kern_fork.c
index bad4221d5d5..da052e891ff 100644
--- a/sys/kern/kern_fork.c
+++ b/sys/kern/kern_fork.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_fork.c,v 1.163 2014/04/18 11:51:17 guenther Exp $	*/
+/*	$OpenBSD: kern_fork.c,v 1.164 2014/05/03 22:44:36 guenther Exp $	*/
 /*	$NetBSD: kern_fork.c,v 1.29 1996/02/09 18:59:34 christos Exp $	*/
 
 /*
@@ -287,10 +287,7 @@ fork1(struct proc *curp, int flags, void *stack, pid_t *tidptr,
 		}
 	}
 
-	uaddr = uvm_km_kmemalloc_pla(kernel_map, uvm.kernel_object, USPACE,
-	    USPACE_ALIGN, UVM_KMF_ZERO,
-	    no_constraint.ucr_low, no_constraint.ucr_high,
-	    0, 0, USPACE/PAGE_SIZE);
+	uaddr = uvm_uarea_alloc();
 	if (uaddr == 0) {
 		if ((flags & FORK_THREAD) == 0) {
 			(void)chgproccnt(uid, -1);
diff --git a/sys/uvm/uvm_extern.h b/sys/uvm/uvm_extern.h
index 06919d70979..d6eae9c297f 100644
--- a/sys/uvm/uvm_extern.h
+++ b/sys/uvm/uvm_extern.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_extern.h,v 1.112 2014/04/03 21:40:10 tedu Exp $	*/
+/*	$OpenBSD: uvm_extern.h,v 1.113 2014/05/03 22:44:36 guenther Exp $	*/
 /*	$NetBSD: uvm_extern.h,v 1.57 2001/03/09 01:02:12 chs Exp $	*/
 
 /*
@@ -513,6 +513,7 @@ int			uvm_fault(vm_map_t, vaddr_t,
 #if defined(KGDB)
 void			uvm_chgkprot(caddr_t, size_t, int);
 #endif
+vaddr_t			uvm_uarea_alloc(void);
 void			uvm_fork(struct proc *, struct proc *, boolean_t,
 			    void *, size_t, void (*)(void *), void *);
 void			uvm_exit(struct proc *);
diff --git a/sys/uvm/uvm_glue.c b/sys/uvm/uvm_glue.c
index ffb283f22c1..324794c09e3 100644
--- a/sys/uvm/uvm_glue.c
+++ b/sys/uvm/uvm_glue.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_glue.c,v 1.62 2014/04/13 23:14:15 tedu Exp $	*/
+/*	$OpenBSD: uvm_glue.c,v 1.63 2014/05/03 22:44:36 guenther Exp $	*/
 /*	$NetBSD: uvm_glue.c,v 1.44 2001/02/06 19:54:44 eeh Exp $	*/
 
 /* 
@@ -293,12 +293,32 @@ uvm_vsunlock_device(struct proc *p, void *addr, size_t len, void *map)
 	uvm_km_free(kernel_map, kva, sz);
 }
 
+/*
+ * uvm_uarea_alloc: allocate the u-area for a new thread
+ */
+vaddr_t
+uvm_uarea_alloc(void)
+{
+	vaddr_t uaddr;
+
+	uaddr = uvm_km_kmemalloc_pla(kernel_map, uvm.kernel_object, USPACE,
+	    USPACE_ALIGN, UVM_KMF_ZERO,
+	    no_constraint.ucr_low, no_constraint.ucr_high,
+	    0, 0, USPACE/PAGE_SIZE);
+ 
+#ifdef PMAP_UAREA
+	/* Tell the pmap this is a u-area mapping */
+	if (uaddr != 0)
+		PMAP_UAREA(uaddr);
+#endif
+
+       return (uaddr);
+}
+
 /*
  * uvm_fork: fork a virtual address space
  *
  * - the address space is copied as per parent map's inherit values
- * - a new "user" structure is allocated for the child process
- *	[filled in by MD layer...]
  * - if specified, the child gets a new user stack described by
  *	stack and stacksize
  * - NOTE: the kernel stack may be at a different location in the child
@@ -318,11 +338,6 @@ uvm_fork(struct proc *p1, struct proc *p2, boolean_t shared, void *stack,
 	} else
 		p2->p_vmspace = uvmspace_fork(p1->p_vmspace); /* fork vmspace */
 
-#ifdef PMAP_UAREA
-	/* Tell the pmap this is a u-area mapping */
-	PMAP_UAREA((vaddr_t)p2->p_addr);
-#endif
-
 	/*
 	 * 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
-- 
2.20.1