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 70E81C18E5C for ; Tue, 10 Mar 2020 13:16:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4086020873 for ; Tue, 10 Mar 2020 13:16:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583846176; bh=FLADw+GKBExK9ezf3kJ+0wVCGT6MykYNqQ0rey0KKok=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=KZ69EK9P/rZWUEAt+gd7opkRB2cVBRCgJOsVDONzZAxvX2ZUuuI9atcDnp+RGy+Qt aIyic57HhFHS+kTMwKTjHrXB/+Q1XcYPRhw+q4/7AQQAOedJ6jwkNTJ0d6IyRDnKxN BYCkImCzcJ9jsb0zHPZ4XWMNLDmeQ/qOtfNSIP2M= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731748AbgCJNNm (ORCPT ); Tue, 10 Mar 2020 09:13:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:36384 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731722AbgCJNNd (ORCPT ); Tue, 10 Mar 2020 09:13:33 -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 34FA220409; Tue, 10 Mar 2020 13:13:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583846012; bh=FLADw+GKBExK9ezf3kJ+0wVCGT6MykYNqQ0rey0KKok=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kQCoSWXfKsXbXdACrz1kOxN1hZVYiuIUlCeIw7SdDJU7FZCTPrtgipdJugYvxv2eO jEdr+z0AEVObokV6tcPUtawYILCvKfwX4QgR7pDdaHM/2KvUzqjt0HidENplXYbVKV o6vl7eIZ1srJvIIRgEQb87UGpydalZYqJ8auaLWA= 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 4.19 54/86] dmaengine: tegra-apb: Prevent race conditions of tasklet vs free list Date: Tue, 10 Mar 2020 13:45:18 +0100 Message-Id: <20200310124533.710299227@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200310124530.808338541@linuxfoundation.org> References: <20200310124530.808338541@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 @@ -288,7 +288,7 @@ 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;