Return-path: Received: from charlotte.tuxdriver.com ([70.61.120.58]:34723 "EHLO smtp.tuxdriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755193AbZEFSQN (ORCPT ); Wed, 6 May 2009 14:16:13 -0400 Date: Wed, 6 May 2009 14:03:53 -0400 From: "John W. Linville" To: Greg KH Cc: Eric Valette , Larry Finger , FUJITA Tomonori , linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org Subject: Re: DMA debug trace pointing to rtl8187 Message-ID: <20090506180353.GD30070@tuxdriver.com> References: <49FDB9F8.3080400@free.fr> <20090506133131F.fujita.tomonori@lab.ntt.co.jp> <4A012FC8.3020304@free.fr> <20090506064513.GA7460@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20090506064513.GA7460@kroah.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: On Tue, May 05, 2009 at 11:45:13PM -0700, Greg KH wrote: > On Wed, May 06, 2009 at 08:35:52AM +0200, Eric Valette wrote: > > FUJITA Tomonori wrote: > > > CC'ed linux-usb, > > > > > > The ehci_hcd driver uses buffers on the stack for DMA? > > > > > > On Sun, 03 May 2009 17:36:24 +0200 > > > Eric Valette wrote: > > > > > >> ------------[ cut here ]------------ > > >> > > >> WARNING: at /usr/src/linux-2.6.22.9/lib/dma-debug.c:609 > > > > > > Hmm, the kernel version is wired. lib/dma-debug.c was added in > > > 2.6.30-rc. > > > > No that's the file path. I use ketchup to apply patches... > > > > > > > >> check_for_stack+0x6b/0x8b() > > >> Hardware name: P5W DH Deluxe > > >> > > >> ehci_hcd 0000:00:1d.7: DMA-API: device driver maps memory fromstack > > >> [addr=ffff88007fa79968] > > >> Modules linked in: > > >> > > >> Pid: 297, comm: khubd Not tainted 2.6.30-rc4-git1 #32 > > > > Here is the real version. > > The problem is in the rtl8187 driver. > > They are calling usb_control_msg and passing a pointer to a buffer on > the stack. See drivers/net/wireless/rtl818x/rtl8187.h for where the > problem happens in numerous places. > > Also it looks like rtl8225_write_8051() is incorrect. You are passing a > pointer to a variable that was passed as an argument. I don't know > where that is supposed to be on, somewhere on the stack I guess. > > Larry, care to fix this up? I just sent '[RFT] rtl8187: use DMA-aware buffers with usb_control_msg' as a parallel reply to this message. It is pretty ugly w.r.t. kmalloc failures, but it might be worth testing just to see if it helps the problem at hand...? John -- John W. Linville Someday the world will need a hero, and you linville@tuxdriver.com might be all we have. Be ready.