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=-2.6 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, 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 5E0A2ECDFB3 for ; Tue, 17 Jul 2018 10:48:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 70EB120864 for ; Tue, 17 Jul 2018 10:48:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=metanate.com header.i=@metanate.com header.b="OAf3/P8i" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 70EB120864 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=metanate.com 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 S1730252AbeGQLUL (ORCPT ); Tue, 17 Jul 2018 07:20:11 -0400 Received: from dougal.metanate.com ([90.155.101.14]:57070 "EHLO metanate.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729717AbeGQLUL (ORCPT ); Tue, 17 Jul 2018 07:20:11 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=simple/simple; d=metanate.com; s=stronger; h=Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: MIME-Version:Content-Type:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:In-Reply-To:References:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=kd1R/D0rhEllo6mHo7rjn1kFe39t23TsCXZO2SFjQGI=; b=OAf3/P8i/i2H/YvRfC9Gf8RLup xF6CfmciPtrJL5AlXW9rSTxXrRG+vZ2I5yZnqcJFwkeHCmRkJLajI2GUd0nNOJLNmq32zpjx0yGq2 OSyX+cNysG/lx/dutyIMEbz65W7N4xbhOODZHQS6/QXdcxk1Y9Gt9kgbumgdKMtHwel4/ChX62ixW C0SdowhAoPaYwZPQg9TZIe3KQXkqh4O1Pt3GFsd29kKRjRhbiCKvSioW5TXVBtI9+O+Q+z3GiXU5/ BhfyPZt4ADSPp7Nxak3/743A4UsaFDcvPM/OL/0rZ4NWcpHLJF+e8aCp65rEBCIc7yP6DBTnGUpRy 8SqRan/w==; Received: from johnkeeping.plus.com ([81.174.171.191] helo=localhost.localdomain) by shrek.metanate.com with esmtpsa (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.90_1) (envelope-from ) id 1ffNWQ-000447-Mx; Tue, 17 Jul 2018 11:47:59 +0100 From: John Keeping To: dmaengine@vger.kernel.org Cc: Vinod Koul , Dan Williams , linux-kernel@vger.kernel.org, John Keeping Subject: [PATCH] dmaengine: pl330: fix irq race with terminate_all Date: Tue, 17 Jul 2018 11:48:16 +0100 Message-Id: <20180717104816.17044-1-john@metanate.com> X-Mailer: git-send-email 2.18.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- drivers/dma/pl330.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c index 370df2e74ddd..88750a34e859 100644 --- a/drivers/dma/pl330.c +++ b/drivers/dma/pl330.c @@ -2256,13 +2256,14 @@ static int pl330_terminate_all(struct dma_chan *chan) 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; -- 2.18.0