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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 81CB8C4332F for ; Mon, 14 Nov 2022 13:08:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237879AbiKNNIt (ORCPT ); Mon, 14 Nov 2022 08:08:49 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36214 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237814AbiKNNIr (ORCPT ); Mon, 14 Nov 2022 08:08:47 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 71E84765F for ; Mon, 14 Nov 2022 05:08:42 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 0D5936109A for ; Mon, 14 Nov 2022 13:08:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1CA01C433D6; Mon, 14 Nov 2022 13:08:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1668431321; bh=J8FeYCzhsj9DawneU/nb6hHSr9nNVxC2e3w/I0oE91o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VF41Gubq17pI1uJtupWw33cU2EBY5TQ4ZTY7Y2xVx6mMniUnmKw1tFrWmV1/BVec4 TRcS8f0RFCQ2Q8H6TD7/x6SJOFqTJvEr84qw8z2iBn9DoK/pMemVUNhn7ki7MeBcUA STEkA0DU42GjnwykD5gQnTzxYsZzeuY7YfGa9f1Y= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Peter Rosin , Tudor Ambarus , Nicolas Ferre , Vinod Koul Subject: [PATCH 6.0 183/190] dmaengine: at_hdmac: Fix concurrency over the active list Date: Mon, 14 Nov 2022 13:46:47 +0100 Message-Id: <20221114124506.884497044@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221114124458.806324402@linuxfoundation.org> References: <20221114124458.806324402@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Tudor Ambarus commit 03ed9ba357cc78116164b90b87f45eacab60b561 upstream. The tasklet (atc_advance_work()) did not held the channel lock when retrieving the first active descriptor, causing concurrency problems if issue_pending() was called in between. If issue_pending() was called exactly after the lock was released in the tasklet (atc_advance_work()), atc_chain_complete() could complete a descriptor for which the controller has not yet raised an interrupt. Fixes: dc78baa2b90b ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller") Reported-by: Peter Rosin Signed-off-by: Tudor Ambarus Cc: stable@vger.kernel.org Link: https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.se/ Acked-by: Nicolas Ferre Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.com Link: https://lore.kernel.org/r/20221025090306.297886-11-tudor.ambarus@microchip.com Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman --- drivers/dma/at_hdmac.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) --- a/drivers/dma/at_hdmac.c +++ b/drivers/dma/at_hdmac.c @@ -462,8 +462,6 @@ atc_chain_complete(struct at_dma_chan *a if (!atc_chan_is_cyclic(atchan)) dma_cookie_complete(txd); - /* Remove transfer node from the active list. */ - list_del_init(&desc->desc_node); spin_unlock_irqrestore(&atchan->lock, flags); dma_descriptor_unmap(txd); @@ -495,6 +493,7 @@ atc_chain_complete(struct at_dma_chan *a */ static void atc_advance_work(struct at_dma_chan *atchan) { + struct at_desc *desc; unsigned long flags; dev_vdbg(chan2dev(&atchan->chan_common), "advance_work\n"); @@ -502,9 +501,12 @@ static void atc_advance_work(struct at_d spin_lock_irqsave(&atchan->lock, flags); if (atc_chan_is_enabled(atchan) || list_empty(&atchan->active_list)) return spin_unlock_irqrestore(&atchan->lock, flags); - spin_unlock_irqrestore(&atchan->lock, flags); - atc_chain_complete(atchan, atc_first_active(atchan)); + desc = atc_first_active(atchan); + /* Remove the transfer node from the active list. */ + list_del_init(&desc->desc_node); + spin_unlock_irqrestore(&atchan->lock, flags); + atc_chain_complete(atchan, desc); /* advance work */ spin_lock_irqsave(&atchan->lock, flags);