Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753875Ab0L1OtJ (ORCPT ); Tue, 28 Dec 2010 09:49:09 -0500 Received: from mail-iy0-f194.google.com ([209.85.210.194]:48221 "EHLO mail-iy0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753796Ab0L1OtH (ORCPT ); Tue, 28 Dec 2010 09:49:07 -0500 MIME-Version: 1.0 X-Originating-IP: [93.172.188.89] In-Reply-To: References: <1292870624-25450-1-git-send-email-felipe.contreras@nokia.com> <1293452486-notmuch-felipe.contreras@nokia.com> From: Ohad Ben-Cohen Date: Tue, 28 Dec 2010 16:48:46 +0200 Message-ID: Subject: Re: [PATCH v2] staging: tidspbridge: protect dmm_map properly To: Felipe Contreras Cc: Felipe Contreras , linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, greg@kroah.com, omar.ramirez@ti.com, fernando.lugo@ti.com, nm@ti.com, ameya.palande@nokia.com, h-kanigeri2@ti.com Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 923 Lines: 20 On Tue, Dec 28, 2010 at 2:12 PM, Felipe Contreras wrote: > On Tue, Dec 28, 2010 at 12:56 PM, Ohad Ben-Cohen wrote: >> I still don't know how exactly you triggered the bug: is gst-dsp >> multithreaded ? and one of its threads invoked proc_un_map() while >> another thread called proc_begin_dma() ? > > I haven't investigated why that happens Btw, I still think you should look into this. The kernel panic will be solved, but you may still have a race there that can lead to data corruption: if proc_un_map will be fast enough, it will acquire the proc_lock mutex before proc_begin_dma(), and then you will miss a cache operation. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/