From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755150AbZIPDIJ (ORCPT ); Tue, 15 Sep 2009 23:08:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755124AbZIPDHt (ORCPT ); Tue, 15 Sep 2009 23:07:49 -0400 Received: from mga14.intel.com ([143.182.124.37]:7197 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752978AbZIPDHd (ORCPT ); Tue, 15 Sep 2009 23:07:33 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.44,394,1249282800"; d="scan'208";a="188105378" Message-Id: <20090916030604.070487909@intel.com> References: <20090916030009.585103525@intel.com> User-Agent: quilt/0.46-1 Date: Wed, 16 Sep 2009 11:00:10 +0800 From: Wu Fengguang To: Andrew Morton To: KAMEZAWA Hiroyuki CC: Benjamin Herrenschmidt , Andi Kleen , Christoph Lameter , Ingo Molnar , Tejun Heo , Nick Piggin , Wu Fengguang Cc: LKML , linux-mm@kvack.org Subject: [PATCH 1/4] devmem: fix kmem write bug on memory holes Content-Disposition: inline; filename=vwrite-fix.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org write_kmem() used to assume vwrite() always return the full buffer length. However now vwrite() could return 0 to indicate memory hole. This creates a bug that "buf" is not advanced accordingly. Fix it to simply ignore the return value, hence the memory hole. CC: Andi Kleen CC: Benjamin Herrenschmidt CC: Christoph Lameter CC: Ingo Molnar CC: Tejun Heo CC: Nick Piggin CC: KAMEZAWA Hiroyuki Signed-off-by: Wu Fengguang --- drivers/char/mem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- linux-mm.orig/drivers/char/mem.c 2009-09-16 10:41:10.000000000 +0800 +++ linux-mm/drivers/char/mem.c 2009-09-16 10:48:16.000000000 +0800 @@ -548,7 +548,7 @@ static ssize_t write_kmem(struct file * free_page((unsigned long)kbuf); return -EFAULT; } - sz = vwrite(kbuf, (char *)p, sz); + vwrite(kbuf, (char *)p, sz); count -= sz; buf += sz; virtr += sz; --