From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750831AbWDISeM (ORCPT ); Sun, 9 Apr 2006 14:34:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750814AbWDISeL (ORCPT ); Sun, 9 Apr 2006 14:34:11 -0400 Received: from smtp.osdl.org ([65.172.181.4]:62336 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1750803AbWDISeK (ORCPT ); Sun, 9 Apr 2006 14:34:10 -0400 Date: Sun, 9 Apr 2006 11:32:40 -0700 From: Andrew Morton To: Nick Orlov Cc: linux-kernel@vger.kernel.org, axboe@suse.de, James.Bottomley@SteelEye.com Subject: Re: 2.6.17-rc1-mm2: badness in 3w_xxxx driver Message-Id: <20060409113240.630b9a24.akpm@osdl.org> In-Reply-To: <20060409182306.GA4680@nickolas.homeunix.com> References: <20060409182306.GA4680@nickolas.homeunix.com> X-Mailer: Sylpheed version 1.0.4 (GTK+ 1.2.10; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org 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); } } _