From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753179AbbBJRF1 (ORCPT ); Tue, 10 Feb 2015 12:05:27 -0500 Received: from cdptpa-outbound-snat.email.rr.com ([107.14.166.227]:28822 "EHLO cdptpa-oedge-vip.email.rr.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752283AbbBJREK (ORCPT ); Tue, 10 Feb 2015 12:04:10 -0500 Message-Id: <20150210170407.854141610@goodmis.org> User-Agent: quilt/0.61-1 Date: Tue, 10 Feb 2015 12:02:26 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , , Stephen Boyd , Lime Yang , Vikram Mulukutla Subject: [for-next][PATCH 5/5] tracing: Fix unmapping loop in tracing_mark_write References: <20150210170221.012858236@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Disposition: inline; filename=0005-tracing-Fix-unmapping-loop-in-tracing_mark_write.patch X-RR-Connecting-IP: 107.14.168.130:25 X-Cloudmark-Score: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vikram Mulukutla Commit 6edb2a8a385f0cdef51dae37ff23e74d76d8a6ce introduced an array map_pages that contains the addresses returned by kmap_atomic. However, when unmapping those pages, map_pages[0] is unmapped before map_pages[1], breaking the nesting requirement as specified in the documentation for kmap_atomic/kunmap_atomic. This was caught by the highmem debug code present in kunmap_atomic. Fix the loop to do the unmapping properly. Link: http://lkml.kernel.org/r/1418871056-6614-1-git-send-email-markivx@codeaurora.org Cc: stable@vger.kernel.org # 3.5+ Reviewed-by: Stephen Boyd Reported-by: Lime Yang Signed-off-by: Vikram Mulukutla Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 5afce60e1b68..2078b86750e0 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4928,7 +4928,7 @@ tracing_mark_write(struct file *filp, const char __user *ubuf, *fpos += written; out_unlock: - for (i = 0; i < nr_pages; i++){ + for (i = nr_pages - 1; i >= 0; i--) { kunmap_atomic(map_page[i]); put_page(pages[i]); } -- 2.1.4