From patchwork Tue Mar 10 12:39:09 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 229741 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=ham 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 C9ECBC10F27 for ; Tue, 10 Mar 2020 12:52:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9E7BE2253D for ; Tue, 10 Mar 2020 12:52:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583844750; bh=vTWBqDRsC/tFRPDMOCq60Nxj2V6mOLrWJm0saUVbkdQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=siwjS1ZPcSK0ZQcp89CBLPYUD0VeGW/pdOsbh+oMMFhRY9RU+G7qA1NZJ8/etyNTM fNjv8HuzlrKtOIvfNLOxr7KWPsEKFwZD5dWuXHfeRR1gaNyaVCSLwKp7YRX4O7ty+o sPM83inhLMq0CMUjNJHn5m233hXJ76dNGizLBARY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728513AbgCJMwa (ORCPT ); Tue, 10 Mar 2020 08:52:30 -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 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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;