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 C876CC18E5B for ; Tue, 10 Mar 2020 13:02:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A12E82469C for ; Tue, 10 Mar 2020 13:02:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583845336; bh=vTWBqDRsC/tFRPDMOCq60Nxj2V6mOLrWJm0saUVbkdQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=I6eBjgwyGxqP5NPUjsleODZgiYcJfVXTLdZDpq6FBqahlWRPGEVkqn04x6xSzsrb5 5wSmeLGXxdbEuQZnfw92kfxPYLAN+WCa91JAnFY8E30AUw0bTVgnyemDDFlbTa/3tM TW93i06Q/22APPy4PyvBfkXKr/Fd2KyyAHlyfKq0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730027AbgCJNCM (ORCPT ); Tue, 10 Mar 2020 09:02:12 -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: 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;