Apply by doing:
	cd /usr/src
	patch -p0 < 012_uvm.patch
And then rebuild your kernel.

Index: sys/uvm/uvm_glue.c
===================================================================
RCS file: /cvs/src/sys/uvm/uvm_glue.c,v
retrieving revision 1.34
retrieving revision 1.34.2.1
diff -u -r1.34 -r1.34.2.1
--- sys/uvm/uvm_glue.c	2003/01/29 22:57:10	1.34
+++ sys/uvm/uvm_glue.c	2003/11/20 22:43:16	1.34.2.1
@@ -223,6 +223,8 @@
 	map = &p->p_vmspace->vm_map;
 	start = trunc_page((vaddr_t)addr);
 	end = round_page((vaddr_t)addr + len);
+	if (end <= start)
+		return (EINVAL);
 
 	rv = uvm_fault_wire(map, start, end, access_type);
 
@@ -242,8 +244,14 @@
 	caddr_t	addr;
 	size_t	len;
 {
-	uvm_fault_unwire(&p->p_vmspace->vm_map, trunc_page((vaddr_t)addr),
-		round_page((vaddr_t)addr + len));
+	vaddr_t start, end;
+
+	start = trunc_page((vaddr_t)addr);
+	end = round_page((vaddr_t)addr + len);
+	if (end <= start)
+		return;
+
+	uvm_fault_unwire(&p->p_vmspace->vm_map, start, end);
 }
 
 /*