From: Samuel Thibault <samuel.thibault@eu.citrix.com>
Subject: [PATCH] minios: clear FB content
Date: Thu, 8 May 2008 15:34:26 +0100
Message-ID: <20080508143426.GM4365@implementation.uk.xensource.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Return-path: <xen-devel-bounces@lists.xensource.com>
Content-Disposition: inline
List-Unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
List-Post: <mailto:xen-devel@lists.xensource.com>
List-Help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-Subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
Sender: xen-devel-bounces@lists.xensource.com
Errors-To: xen-devel-bounces@lists.xensource.com
To: xen-devel@lists.xensource.com
List-Id: xen-devel@lists.xenproject.org

minios: clear FB content since _xmalloc may return non-zeroed memory (in
debug mode, notably).

Signed-off-by: Samuel Thibault <samuel.thibault@eu.citrix.com>

diff -r 2223ed7635d4 extras/mini-os/kernel.c
--- a/extras/mini-os/kernel.c	Thu May 08 13:59:03 2008 +0100
+++ b/extras/mini-os/kernel.c	Thu May 08 15:34:59 2008 +0100
@@ -302,13 +302,10 @@
 
     memsize = n * PAGE_SIZE;
     fb = _xmalloc(memsize, PAGE_SIZE);
+    memset(fb, 0, memsize);
     mfns = xmalloc_array(unsigned long, n);
-    for (i = 0; i < n; i++) {
-        /* trigger CoW */
-        ((char *) fb) [i * PAGE_SIZE] = 0;
-        barrier();
+    for (i = 0; i < n; i++)
         mfns[i] = virtual_to_mfn((char *) fb + i * PAGE_SIZE);
-    }
     fb_dev = init_fbfront(NULL, mfns, WIDTH, HEIGHT, DEPTH, line_length, n);
     xfree(mfns);
     if (!fb_dev) {