From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: 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 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> In-Reply-To: <20180924113103.999624566@linuxfoundation.org> References: <20180924113103.999624566@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 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;