From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754562AbZIPBv7 (ORCPT ); Tue, 15 Sep 2009 21:51:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754468AbZIPBvm (ORCPT ); Tue, 15 Sep 2009 21:51:42 -0400 Received: from mga14.intel.com ([143.182.124.37]:51194 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753073AbZIPBvg (ORCPT ); Tue, 15 Sep 2009 21:51:36 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.44,394,1249282800"; d="scan'208";a="188088268" Message-Id: <20090916014958.836124324@intel.com> References: <20090916013939.656308742@intel.com> User-Agent: quilt/0.46-1 Date: Wed, 16 Sep 2009 09:39:41 +0800 From: Wu Fengguang To: Andrew Morton To: KAMEZAWA Hiroyuki CC: Benjamin Herrenschmidt , Greg Kroah-Hartman , Hugh Dickins , Wu Fengguang CC: Christoph Lameter CC: Ingo Molnar CC: Tejun Heo CC: Nick Piggin Cc: LKML , linux-mm@kvack.org Subject: [PATCH 2/3] devmem: check vmalloc address on kmem read/write Content-Disposition: inline; filename=vmalloc-addr-fix.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: KAMEZAWA Hiroyuki Otherwise vmalloc_to_page() will BUG(). This also makes the kmem read/write implementation aligned with mem(4): "References to nonexistent locations cause errors to be returned." Here we return -ENXIO (inspired by Hugh) if no bytes have been transfered to/from user space, otherwise return partial read/write results. CC: Greg Kroah-Hartman CC: Hugh Dickins Signed-off-by: KAMEZAWA Hiroyuki Signed-off-by: Wu Fengguang --- drivers/char/mem.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- linux-mm.orig/drivers/char/mem.c 2009-09-16 08:52:17.000000000 +0800 +++ linux-mm/drivers/char/mem.c 2009-09-16 09:15:03.000000000 +0800 @@ -443,6 +443,10 @@ static ssize_t read_kmem(struct file *fi return -ENOMEM; while (count > 0) { sz = size_inside_page(p, count); + if (!is_vmalloc_or_module_addr((void *)p)) { + err = -ENXIO; + break; + } err = vread(kbuf, (char *)p, sz); if (err) break; @@ -543,6 +547,10 @@ static ssize_t write_kmem(struct file * unsigned long sz = size_inside_page(p, count); unsigned long n; + if (!is_vmalloc_or_module_addr((void *)p)) { + err = -ENXIO; + break; + } n = copy_from_user(kbuf, buf, sz); if (n) { err = -EFAULT; --