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 E15CBC4332F for ; Mon, 14 Nov 2022 11:15:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236415AbiKNLPD (ORCPT ); Mon, 14 Nov 2022 06:15:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42034 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236691AbiKNLOj (ORCPT ); Mon, 14 Nov 2022 06:14:39 -0500 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 72C99222AC for ; Mon, 14 Nov 2022 03:10:09 -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 sin.source.kernel.org (Postfix) with ESMTPS id DBE97CE0EEA for ; Mon, 14 Nov 2022 11:10:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A3476C433C1; Mon, 14 Nov 2022 11:10:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1668424204; bh=Cb51Ss18A8vIdI/nW+J0iZNXVY2nsc2Ly2MeDwL31zI=; h=Subject:To:Cc:From:Date:From; b=oyJrxctgLf+9crt58O003xxpeA8JUCzhq0FY+TZD8drX7a57G0Nf/OoVi95tF+zvR 73V2ZtPIP7TiSEbS2RZPVUfFSN/EpbvpRJ2Ce+KOhWXa12QBFL4008pK9/9QXqLhwr 7h35Nq6dF1MXI35b2Zs+vPhqhW1f5RbaWUhvUqjg= Subject: FAILED: patch "[PATCH] dmaengine: at_hdmac: Fix concurrency over the active list" failed to apply to 4.19-stable tree To: tudor.ambarus@microchip.com, nicolas.ferre@microchip.com, peda@axentia.se, vkoul@kernel.org Cc: From: Date: Mon, 14 Nov 2022 12:09:49 +0100 Message-ID: <166842418960193@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . Possible dependencies: 03ed9ba357cc ("dmaengine: at_hdmac: Fix concurrency over the active list") 6ba826cbb57d ("dmaengine: at_hdmac: Free the memset buf without holding the chan lock") 06988949df8c ("dmaengine: at_hdmac: Fix concurrency over descriptor") c6babed879fb ("dmaengine: at_hdmac: Fix concurrency problems by removing atc_complete_all()") 078a6506141a ("dmaengine: at_hdmac: Fix deadlocks") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 03ed9ba357cc78116164b90b87f45eacab60b561 Mon Sep 17 00:00:00 2001 From: Tudor Ambarus Date: Tue, 25 Oct 2022 12:02:44 +0300 Subject: [PATCH] dmaengine: at_hdmac: Fix concurrency over the active list 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 diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c index 0fb44f622d35..b53a9fc15dd9 100644 --- a/drivers/dma/at_hdmac.c +++ b/drivers/dma/at_hdmac.c @@ -462,8 +462,6 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc) 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 *atchan, struct at_desc *desc) */ 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_dma_chan *atchan) 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);