From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755644AbbDJObK (ORCPT ); Fri, 10 Apr 2015 10:31:10 -0400 Received: from bes.se.axis.com ([195.60.68.10]:34876 "EHLO bes.se.axis.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755163AbbDJObI convert rfc822-to-8bit (ORCPT ); Fri, 10 Apr 2015 10:31:08 -0400 From: Lars Persson To: Ralf Baechle CC: Lars Persson , "paul.burton@imgtec.com" , "linux-mips@linux-mips.org" , "linux-kernel@vger.kernel.org" Date: Fri, 10 Apr 2015 16:31:06 +0200 Subject: Re: [PATCH] MIPS: Fix HIGHMEM crash in __update_cache(). Thread-Topic: [PATCH] MIPS: Fix HIGHMEM crash in __update_cache(). Thread-Index: AdBzmvm8a+fz1qvEQYCdvuRdV6M/VA== Message-ID: <675481A1-B1B2-47BF-9AF9-2E7773497FEA@axis.com> References: <1428672084-20676-1-git-send-email-larper@axis.com> <20150410134711.GC21107@linux-mips.org> In-Reply-To: <20150410134711.GC21107@linux-mips.org> Accept-Language: en-US, sv-SE Content-Language: sv-SE X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US, sv-SE Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ralf, I came to think that also non-executable mappings for highmem pages could reach the flushing code in __update_cache() and trigger an OOPS. Until the highmem patches are merged we should block highmem pages in __update_cache(). Could you add this to the patch ? Sent from my iPhone > 10 apr 2015 kl. 15:47 skrev Ralf Baechle : > >> On Fri, Apr 10, 2015 at 03:21:24PM +0200, Lars Persson wrote: >> >> Commit 8b5fe5e54b47 ("MIPS: Fix race condition in lazy cache flushing.") >> triggered NULL pointer dereferences on systems with HIGHMEM. >> >> The problem was caused by not clearing the PG_dcache_dirty flag in >> flush_icache_page() and thus we enter __update_cache() that lacks >> support for HIGHMEM. > > Thanks, I've folded this patch into the original 8b5fe5e54b47 commit. > > Ralf