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 6D71EC10F27 for ; Tue, 10 Mar 2020 13:10:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3BE7724693 for ; Tue, 10 Mar 2020 13:10:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583845814; bh=FLADw+GKBExK9ezf3kJ+0wVCGT6MykYNqQ0rey0KKok=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=0w6qccXBjawRds2P34Z+QH6/91n2fcOFon72f0Kwur0/Dlzjoe7YsVypbii4CvLfM x21H7Do1e4ooYdj+iuSxe3fI7tutuWXYHRTp//ezzG+DQXnpEjGoqNNKZ6eh45bnOR jvvd1uOwBl0ChkX/eRfj24zkuS7Juo9vwjH4fI94= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730980AbgCJNKM (ORCPT ); Tue, 10 Mar 2020 09:10:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:59248 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730947AbgCJNKJ (ORCPT ); Tue, 10 Mar 2020 09:10:09 -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 46D2C246D9; Tue, 10 Mar 2020 13:10:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583845808; bh=FLADw+GKBExK9ezf3kJ+0wVCGT6MykYNqQ0rey0KKok=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=n6M/4ZaOUyBWycx1ajxa1CMOhseGrTH3Kub1R9SlF2BP3i8H6QANpYer9XsM9NCY8 PdyKxpEGt4OSVBf0YkRqZxfGdIKG2uhSef6InmLakNusMJAiKiwjVuvFK3Q90GQ0Rd UIWUIl5TiuXzYC0byFHb7KOndM0U3dLXPQ+d9q+s= 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 4.14 108/126] dmaengine: tegra-apb: Prevent race conditions of tasklet vs free list Date: Tue, 10 Mar 2020 13:42:09 +0100 Message-Id: <20200310124210.489864389@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200310124203.704193207@linuxfoundation.org> References: <20200310124203.704193207@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;