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=-5.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 C6ECDECE561 for ; Mon, 24 Sep 2018 12:28:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8E7ED214AB for ; Mon, 24 Sep 2018 12:28:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8E7ED214AB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387614AbeIXSam (ORCPT ); Mon, 24 Sep 2018 14:30:42 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:57502 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733078AbeIXSal (ORCPT ); Mon, 24 Sep 2018 14:30:41 -0400 Received: from localhost (ip-213-127-77-73.ip.prioritytelecom.net [213.127.77.73]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 281671018; Mon, 24 Sep 2018 12:28:46 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, John Keeping , Vinod Koul , Sasha Levin Subject: [PATCH 4.18 037/235] dmaengine: pl330: fix irq race with terminate_all Date: Mon, 24 Sep 2018 13:50:23 +0200 Message-Id: <20180924113108.737341785@linuxfoundation.org> X-Mailer: git-send-email 2.19.0 In-Reply-To: <20180924113103.999624566@linuxfoundation.org> References: <20180924113103.999624566@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review 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 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: John Keeping [ Upstream commit e49756544a21f5625b379b3871d27d8500764670 ] In pl330_update() when checking if a channel has been aborted, the channel's lock is not taken, only the overall pl330_dmac lock. But in pl330_terminate_all() the aborted flag (req_running==-1) is set under the channel lock and not the pl330_dmac lock. With threaded interrupts, this leads to a potential race: pl330_terminate_all pl330_update ------------------- ------------ lock channel entry lock pl330 _stop channel unlock pl330 lock pl330 check req_running != -1 req_running = -1 _start channel Signed-off-by: John Keeping Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/dma/pl330.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/drivers/dma/pl330.c +++ b/drivers/dma/pl330.c @@ -2257,13 +2257,14 @@ static int pl330_terminate_all(struct dm pm_runtime_get_sync(pl330->ddma.dev); spin_lock_irqsave(&pch->lock, flags); + spin_lock(&pl330->lock); _stop(pch->thread); - spin_unlock(&pl330->lock); - pch->thread->req[0].desc = NULL; pch->thread->req[1].desc = NULL; pch->thread->req_running = -1; + spin_unlock(&pl330->lock); + power_down = pch->active; pch->active = false;