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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 3C688C18E5A for ; Tue, 10 Mar 2020 13:02:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 14B41208E4 for ; Tue, 10 Mar 2020 13:02:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583845335; bh=vTWBqDRsC/tFRPDMOCq60Nxj2V6mOLrWJm0saUVbkdQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=nkASJWQW2rztvm9fANkkuRj4tY4G/XW4aB2VOKb++bvCvrjjRsTbmUUDvdpAa1oWa c+pmsZLqhIo2rNSefs9Qhq6/l4pq83+vqqkaCFUKW7mKm6mxwUyvP5FrTgDBu8y0kh LvL5G66VZcyYD0kfjlOlJQ3Ot2nOaFMOYHOvDIx0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728937AbgCJNCN (ORCPT ); Tue, 10 Mar 2020 09:02:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:44314 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730372AbgCJNCL (ORCPT ); Tue, 10 Mar 2020 09:02:11 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 8E173208E4; Tue, 10 Mar 2020 13:02:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583845331; bh=vTWBqDRsC/tFRPDMOCq60Nxj2V6mOLrWJm0saUVbkdQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BUf4LIz2rCGH+OI0w7J6oTH19U/i88akmZsa/yB2S4/dBx0dgTjeygmDzxfDJi4gm IWxM3SeCjeugb5bkfJjHpsORBYd3SwA3gP+XMLTXAhS5r84Li44kFvm8pNfl6nROlw uqnMAJXTW2CMsJcGf5RyT6wcRt9Ltu+TL8R4VdNc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dmitry Osipenko , Jon Hunter , Vinod Koul Subject: [PATCH 5.5 117/189] dmaengine: tegra-apb: Prevent race conditions of tasklet vs free list Date: Tue, 10 Mar 2020 13:39:14 +0100 Message-Id: <20200310123651.562676947@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200310123639.608886314@linuxfoundation.org> References: <20200310123639.608886314@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dmitry Osipenko commit c33ee1301c393a241d6424e36eff1071811b1064 upstream. The interrupt handler puts a half-completed DMA descriptor on a free list and then schedules tasklet to process bottom half of the descriptor that executes client's callback, this creates possibility to pick up the busy descriptor from the free list. Thus, let's disallow descriptor's re-use until it is fully processed. Signed-off-by: Dmitry Osipenko Acked-by: Jon Hunter Cc: Link: https://lore.kernel.org/r/20200209163356.6439-3-digetx@gmail.com Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman --- drivers/dma/tegra20-apb-dma.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/dma/tegra20-apb-dma.c +++ b/drivers/dma/tegra20-apb-dma.c @@ -281,7 +281,7 @@ static struct tegra_dma_desc *tegra_dma_ /* Do not allocate if desc are waiting for ack */ list_for_each_entry(dma_desc, &tdc->free_dma_desc, node) { - if (async_tx_test_ack(&dma_desc->txd)) { + if (async_tx_test_ack(&dma_desc->txd) && !dma_desc->cb_count) { list_del(&dma_desc->node); spin_unlock_irqrestore(&tdc->lock, flags); dma_desc->txd.flags = 0;