From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 392B5C34047 for ; Wed, 19 Feb 2020 09:28:04 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0D6232064C for ; Wed, 19 Feb 2020 09:28:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="NsrFkCxB"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="Ps8pNHJp" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0D6232064C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Ost01iuzs6rG3ZdCC7N25DlyLBv6BrZFBWJ4ta3WpaU=; b=NsrFkCxBOcsM8V mrHGY/8LhsBQjpjTaANHuvEZC40nLl+kMpEAzKfLym6tR25HFrHxOsV9xUwvb7mEnJCuIEkbQZcTp xUNuOnJhZVwWW5ytjQDjWKRSNxJ3WGdzGqjZKdKdGg0fI9zqsuDjUez93QOKDfX+3d39DMpkg0UTu 4bhlfdst274en+nb4NDtre//VFuaxGhEb2Ix55vaISSh5IeS5yh7iKFhW5BbZH1u0LNwoWDODcNAN mmmg/buyELJXzXBUmJGSspZlJ39clQml6XCufs5woYKJ/rEOAIJ/Vd3Yhrm9w6p9b1r2ZvWebkeO0 LpDPrGfpBu80h/biEK4A==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1j4LeB-0003qm-5J; Wed, 19 Feb 2020 09:27:59 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1j4Le7-0003qK-Or for linux-arm-kernel@lists.infradead.org; Wed, 19 Feb 2020 09:27:57 +0000 Received: from localhost (unknown [106.201.32.165]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 849AA2064C; Wed, 19 Feb 2020 09:27:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582104475; bh=9kyEssX5GEbwlVExA9JUPsMK72bF0lQACS2bjDvlqvE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Ps8pNHJpu5H+1dtWXtP1nZ/vMn+PISHycpZFQKHsacq25au3EysOMbcLKDHH3BAd2 y73T6NuhAIbWZ8PVVOg4Zm8zeE8VZvgaMlmRXAXSZpaYiONEGAhq11oUnKgpObKaGa nfYJZdekeW4qPjWgALR9BhLDf5iJ6mdLxnWo5SC4= Date: Wed, 19 Feb 2020 14:57:51 +0530 From: Vinod Koul To: Geert Uytterhoeven Subject: Re: [PATCH] dmaengine: coh901318: Fix a double lock bug in dma_tc_handle() Message-ID: <20200219092751.GH2618@vkoul-mobl> References: <20200217144050.3i4ymbytogod4ijn@kili.mountain> <20200219091754.GE2618@vkoul-mobl> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200219_012755_830214_8D69B83B X-CRM114-Status: GOOD ( 17.35 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Linus Walleij , kernel-janitors@vger.kernel.org, Jia-Ju Bai , Linux ARM , dmaengine , Dan Williams , Dan Carpenter Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 19-02-20, 10:20, Geert Uytterhoeven wrote: > Hi Vinod, > > On Wed, Feb 19, 2020 at 10:18 AM Vinod Koul wrote: > > On 17-02-20, 23:24, Geert Uytterhoeven wrote: > > > On Mon, Feb 17, 2020 at 3:41 PM Dan Carpenter wrote: > > > > The caller is already holding the lock so this will deadlock. > > > > > > > > Fixes: 0b58828c923e ("DMAENGINE: COH 901 318 remove irq counting") > > > > Signed-off-by: Dan Carpenter > > > > --- > > > > This is the second double lock bug found using static analysis. The > > > > previous one was commit 627469e4445b ("dmaengine: coh901318: Fix a > > > > double-lock bug"). > > > > > > > > The fact that this has been broken for ten years suggests that no one > > > > has the hardware. > > > > > > Or this only runs CONFIG_SMP=n kernels? > > > This seems to be used in arch/arm/boot/dts/ste-u300.dts only, and > > > CONFIG_ARCH_U300 is a ARCH_MULTI_V5 platform, which looks like > > > it doesn't support SMP? > > > > Should we drop the driver then..? > > Why? Because spinlocks are no-ops on SMP=n, and spinlock bugs thus don't > affect the single platform using the driver? That doesn't answer the question if anyone has a hardware and we have users :) Sorry I should have written better about hardware and testing rather than cryptic reply which may have suggested about SMP :) -- ~Vinod _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel