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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 87B5FC3A5A5 for ; Tue, 3 Sep 2019 16:32:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5BF0B238C7 for ; Tue, 3 Sep 2019 16:32:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567528338; bh=WG6uoZmxjfAMieB1hpPCkzQG0SYx+aPlTDuHzoGfSrQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=je8vhqm53Y5VXcOFS3oJx1y2TJnIXQwAt7+L7awpfPNpIG1W7zj7B3mewXUrwURMt 65YTOoeXKzfL4U7t1ZbST/SKr8gyjgAHInLGtLHwodF9nbcQS7BqHHxOYmLFKIHbp/ xyWFi0fP5v8nT8+rj4rCqvL1k/Im8Cd3t9Qr8U/8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729499AbfICQcR (ORCPT ); Tue, 3 Sep 2019 12:32:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:55654 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727069AbfICQcM (ORCPT ); Tue, 3 Sep 2019 12:32:12 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id F155E2343A; Tue, 3 Sep 2019 16:32:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567528332; bh=WG6uoZmxjfAMieB1hpPCkzQG0SYx+aPlTDuHzoGfSrQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wFYVmPzOyQlXoAIe6NC0ZRfHzRXIYqZ7OMl666m40GM/YNLqY1AP4fd1LbRjjtiM+ eGJpduduePWnyNwKH70EngrkA5d5VjUMdWVbwZgpmb24B1+wtNG/sVdctENmdQFzPn kIgPZHsdYBa0EZEjVt2P2XbNkEVlI2hs6NUrWiwE= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Halil Pasic , Marc Hartmayer , Cornelia Huck , Heiko Carstens , Sasha Levin , linux-s390@vger.kernel.org, virtualization@lists.linux-foundation.org, kvm@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 162/167] virtio/s390: fix race on airq_areas[] Date: Tue, 3 Sep 2019 12:25:14 -0400 Message-Id: <20190903162519.7136-162-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190903162519.7136-1-sashal@kernel.org> References: <20190903162519.7136-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Halil Pasic [ Upstream commit 4f419eb14272e0698e8c55bb5f3f266cc2a21c81 ] The access to airq_areas was racy ever since the adapter interrupts got introduced to virtio-ccw, but since commit 39c7dcb15892 ("virtio/s390: make airq summary indicators DMA") this became an issue in practice as well. Namely before that commit the airq_info that got overwritten was still functional. After that commit however the two infos share a summary_indicator, which aggravates the situation. Which means auto-online mechanism occasionally hangs the boot with virtio_blk. Signed-off-by: Halil Pasic Reported-by: Marc Hartmayer Reviewed-by: Cornelia Huck Cc: stable@vger.kernel.org Fixes: 96b14536d935 ("virtio-ccw: virtio-ccw adapter interrupt support.") Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin --- drivers/s390/virtio/virtio_ccw.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c index ec54538f7ae1c..67efdf25657f3 100644 --- a/drivers/s390/virtio/virtio_ccw.c +++ b/drivers/s390/virtio/virtio_ccw.c @@ -132,6 +132,7 @@ struct airq_info { struct airq_iv *aiv; }; static struct airq_info *airq_areas[MAX_AIRQ_AREAS]; +static DEFINE_MUTEX(airq_areas_lock); #define CCW_CMD_SET_VQ 0x13 #define CCW_CMD_VDEV_RESET 0x33 @@ -244,9 +245,11 @@ static unsigned long get_airq_indicator(struct virtqueue *vqs[], int nvqs, unsigned long bit, flags; for (i = 0; i < MAX_AIRQ_AREAS && !indicator_addr; i++) { + mutex_lock(&airq_areas_lock); if (!airq_areas[i]) airq_areas[i] = new_airq_info(); info = airq_areas[i]; + mutex_unlock(&airq_areas_lock); if (!info) return 0; write_lock_irqsave(&info->lock, flags); -- 2.20.1