From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-vc0-f206.google.com (mail-vc0-f206.google.com [209.85.220.206]) by kanga.kvack.org (Postfix) with ESMTP id 4D76F6B0035 for ; Mon, 28 Oct 2013 11:24:01 -0400 (EDT) Received: by mail-vc0-f206.google.com with SMTP id ht10so44315vcb.5 for ; Mon, 28 Oct 2013 08:24:01 -0700 (PDT) Received: from psmtp.com ([74.125.245.125]) by mx.google.com with SMTP id gn4si9385600pbc.171.2013.10.27.05.50.47 for ; Sun, 27 Oct 2013 05:50:48 -0700 (PDT) Date: Sun, 27 Oct 2013 14:50:36 +0200 From: Aaro Koskinen Subject: Re: ARM/kirkwood: v3.12-rc6: kernel BUG at mm/util.c:390! Message-ID: <20131027125036.GJ17447@blackmetal.musicnaut.iki.fi> References: <20131024200730.GB17447@blackmetal.musicnaut.iki.fi> <20131026143617.GA14034@mudshark.cambridge.arm.com> <20131027195115.208f40f3@tom-ThinkPad-T410> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131027195115.208f40f3@tom-ThinkPad-T410> Sender: owner-linux-mm@kvack.org List-ID: To: Ming Lei Cc: Will Deacon , Russell King - ARM Linux , gmbnomis@gmail.com, catalin.marinas@arm.com, "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "linux-arm-kernel@lists.infradead.org" , Andrew Morton , FUJITA Tomonori , Tejun Heo , "James E.J. Bottomley" , Jens Axboe Hi, On Sun, Oct 27, 2013 at 07:51:15PM +0800, Ming Lei wrote: > On Sat, 26 Oct 2013 15:36:17 +0100 > Will Deacon wrote: > > > On Thu, Oct 24, 2013 at 09:07:30PM +0100, Aaro Koskinen wrote: > > > > > [ 36.477203] Backtrace: > > > [ 36.535603] [] (page_mapping+0x0/0x50) from [] (flush_kernel_dcache_page+0x14/0x98) > > > [ 36.661070] [] (flush_kernel_dcache_page+0x0/0x98) from [] (sg_miter_stop+0xc8/0x10c) > > > [ 36.792813] r4:df8a9a64 r3:00000003 > > > [ 36.857524] [] (sg_miter_stop+0x0/0x10c) from [] (sg_miter_next+0x14/0x13c) > > > > ... assumedly for scatter/gather DMA. How is your block driver allocating > > its buffers? If you're using the DMA API, I can't see how this would happen. > > Lots of SCSI commands(inquiry, ...) pass kmalloc buffer to block layer, > then the sg buffer copy helpers and flush_kernel_dcache_page() may see > slab page. > > That has been here from commit b1adaf65ba03( [SCSI] block: add sg buffer copy > helper functions). On ARM v3.9 or older kernels do not trigger this BUG, at seems it only started to appear with the following commit (bisected): commit 1bc39742aab09248169ef9d3727c9def3528b3f3 Author: Simon Baatz Date: Mon Jun 10 21:10:12 2013 +0100 ARM: 7755/1: handle user space mapped pages in flush_kernel_dcache_page A. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org