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 4BE08C18E5B for ; Tue, 10 Mar 2020 12:52:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1852524693 for ; Tue, 10 Mar 2020 12:52:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583844754; bh=vTWBqDRsC/tFRPDMOCq60Nxj2V6mOLrWJm0saUVbkdQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=XaXUrgPlwsaPu8BwoCwFSpadiMFJH1RgxxpRoRrEWbtRnZnYGoGGp+UpDLRiHE1fx glwUM/m+gOFbbrhDJLxXe1B2/DKFRmKrcVLtEGBrz6SQSwXky2sOz5FTb+B4u1BlHD k8zu6Mui6PlYIfaq4YGlmCwgv1a9fhdA9JTzPsRI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729073AbgCJMwc (ORCPT ); Tue, 10 Mar 2020 08:52:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:58168 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729057AbgCJMw2 (ORCPT ); Tue, 10 Mar 2020 08:52:28 -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 A428220674; Tue, 10 Mar 2020 12:52:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583844748; bh=vTWBqDRsC/tFRPDMOCq60Nxj2V6mOLrWJm0saUVbkdQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XCHu0GA3XnaRxOFBItUrK76AA0q9izLx5YvPlHnevFMijXprQEswpFnwevXcSSozx 8gpKAoUdzdEfWdu9di7ffn677zUAL9OgrknaMGsN7/at07ObGtHfwioVxuznivD9PK 5iPat5XUbvS06e2G1McnPc3ikuZqAhVZUaaVcDD8= 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 5.4 103/168] dmaengine: tegra-apb: Prevent race conditions of tasklet vs free list Date: Tue, 10 Mar 2020 13:39:09 +0100 Message-Id: <20200310123645.807416745@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200310123635.322799692@linuxfoundation.org> References: <20200310123635.322799692@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;