From c0959978ecbcbb27e7c2ec8cbef299264d2c18f8 Mon Sep 17 00:00:00 2001
From: "Jayachandran C." <jchandra@FreeBSD.org>
Date: Mon, 17 Oct 2011 05:42:53 +0000
Subject: [PATCH] Fix for crash on MIPS /dev/mem read.

Reading /dev/mem in 64 bit kernel crashes.  This is because the page
used to call uiomove_fromphys() from memrw() does not have md.pv_list
initialized correctly.

The fix is to call pmap_page_init() on the page to initialize it.
---
 sys/mips/mips/mem.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sys/mips/mips/mem.c b/sys/mips/mips/mem.c
index 7529a9ed503..d40c424888a 100644
--- a/sys/mips/mips/mem.c
+++ b/sys/mips/mips/mem.c
@@ -87,6 +87,7 @@ memrw(struct cdev *dev, struct uio *uio, int flags)
 
 	GIANT_REQUIRED;
 
+	pmap_page_init(&m);
 	while (uio->uio_resid > 0 && !error) {
 		iov = uio->uio_iov;
 		if (iov->iov_len == 0) {