From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750835AbWDITMc (ORCPT ); Sun, 9 Apr 2006 15:12:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750774AbWDITMc (ORCPT ); Sun, 9 Apr 2006 15:12:32 -0400 Received: from srv5.dvmed.net ([207.36.208.214]:22434 "EHLO mail.dvmed.net") by vger.kernel.org with ESMTP id S1750835AbWDITMc (ORCPT ); Sun, 9 Apr 2006 15:12:32 -0400 Message-ID: <44395C98.7010208@garzik.org> Date: Sun, 09 Apr 2006 15:12:24 -0400 From: Jeff Garzik User-Agent: Thunderbird 1.5 (X11/20060313) MIME-Version: 1.0 To: Andrew Morton CC: Nick Orlov , linux-kernel@vger.kernel.org, axboe@suse.de, James.Bottomley@SteelEye.com Subject: Re: 2.6.17-rc1-mm2: badness in 3w_xxxx driver References: <20060409182306.GA4680@nickolas.homeunix.com> <20060409113240.630b9a24.akpm@osdl.org> In-Reply-To: <20060409113240.630b9a24.akpm@osdl.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Score: -3.8 (---) X-Spam-Report: SpamAssassin version 3.1.1 on srv5.dvmed.net summary: Content analysis details: (-3.8 points, 5.0 required) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andrew Morton wrote: > Nick Orlov wrote: >> The following patch: x86-kmap_atomic-debugging.patch exposed a badness >> in 3w_xxx driver. > > Sweet, thanks. > >> I'm getting a lot of: >> >> Apr 9 13:00:04 nickolas kernel: kmap_atomic: local irqs are enabled while using KM_IRQn >> Apr 9 13:00:04 nickolas kernel: show_trace+0x13/0x20 dump_stack+0x1e/0x20 >> Apr 9 13:00:04 nickolas kernel: kmap_atomic+0x79/0xe0 tw_transfer_internal+0x85/0xa0 >> Apr 9 13:00:04 nickolas kernel: tw_interrupt+0x3fe/0x820 handle_IRQ_event+0x3e/0x80 >> Apr 9 13:00:04 nickolas kernel: __do_IRQ+0x90/0x100 do_IRQ+0x26/0x40 >> Apr 9 13:00:04 nickolas kernel: common_interrupt+0x1a/0x20 cpu_idle+0x4d/0xb0 >> Apr 9 13:00:04 nickolas kernel: start_secondary+0x24c/0x4b0 <00000000> 0x0 >> Apr 9 13:00:04 nickolas kernel: 0xc214ffb4 >> >> I'm running 32 bit kernel on AMD64x2 w/ HIGHMEM enabled. >> I think this is an old bug since the 3w_xxxx.c has not been changed for >> a long time (at least since 2.6.16-rc1-mm4). >> >> Please let me know if you want me to try some patches. >> > > > From: Andrew Morton > > We must disable local IRQs while holding KM_IRQ0 or KM_IRQ1. Otherwise, an > IRQ handler could use those kmap slots while this code is using them, > resulting in memory corruption. > > Thanks to Nick Orlov for reporting. > > Cc: > Cc: James Bottomley > Signed-off-by: Andrew Morton > --- > > drivers/scsi/3w-xxxx.c | 3 +++ > 1 files changed, 3 insertions(+) > > diff -puN drivers/scsi/3w-xxxx.c~3ware-kmap_atomic-fix drivers/scsi/3w-xxxx.c > --- devel/drivers/scsi/3w-xxxx.c~3ware-kmap_atomic-fix 2006-04-09 11:28:08.000000000 -0700 > +++ devel-akpm/drivers/scsi/3w-xxxx.c 2006-04-09 11:29:21.000000000 -0700 > @@ -1508,10 +1508,12 @@ static void tw_transfer_internal(TW_Devi > struct scsi_cmnd *cmd = tw_dev->srb[request_id]; > void *buf; > unsigned int transfer_len; > + unsigned long flags = 0; > > if (cmd->use_sg) { > struct scatterlist *sg = > (struct scatterlist *)cmd->request_buffer; > + local_irq_save(flags); > buf = kmap_atomic(sg->page, KM_IRQ0) + sg->offset; > transfer_len = min(sg->length, len); > } else { > @@ -1526,6 +1528,7 @@ static void tw_transfer_internal(TW_Devi > > sg = (struct scatterlist *)cmd->request_buffer; > kunmap_atomic(buf - sg->offset, KM_IRQ0); > + local_irq_restore(flags); ACK. Though please make sure the active maintainer is CC'd on this... There is even a helpful MAINTAINERS entry for this driver. Jeff