From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751475AbbCJWvm (ORCPT ); Tue, 10 Mar 2015 18:51:42 -0400 Received: from p3plsmtps2ded03.prod.phx3.secureserver.net ([208.109.80.60]:34805 "EHLO p3plsmtps2ded03.prod.phx3.secureserver.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750971AbbCJWvh (ORCPT ); Tue, 10 Mar 2015 18:51:37 -0400 x-originating-ip: 72.167.245.219 From: "K. Y. Srinivasan" To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, devel@linuxdriverproject.org, olaf@aepfle.de, apw@canonical.com, vkuznets@redhat.com Cc: "K. Y. Srinivasan" Subject: [PATCH 2/7] Drivers: hv: hv_balloon: keep locks balanced on add_memory() failure Date: Tue, 10 Mar 2015 17:07:27 -0700 Message-Id: <1426032452-4429-2-git-send-email-kys@microsoft.com> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1426032452-4429-1-git-send-email-kys@microsoft.com> References: <1426032393-4387-1-git-send-email-kys@microsoft.com> <1426032452-4429-1-git-send-email-kys@microsoft.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vitaly Kuznetsov When add_memory() fails the following BUG is observed: [ 743.646107] hv_balloon: hot_add memory failed error is -17 [ 743.679973] [ 743.680930] ===================================== [ 743.680930] [ BUG: bad unlock balance detected! ] [ 743.680930] 3.19.0-rc5_bug1131426+ #552 Not tainted [ 743.680930] ------------------------------------- [ 743.680930] kworker/0:2/255 is trying to release lock (&dm_device.ha_region_mutex) at: [ 743.680930] [] mutex_unlock+0xe/0x10 [ 743.680930] but there are no more locks to release! This happens as we don't acquire ha_region_mutex and hot_add_req() expects us to as it does unconditional mutex_unlock(). Acquire the lock on the error path. Signed-off-by: Vitaly Kuznetsov Acked-by: Jason Wang Signed-off-by: K. Y. Srinivasan --- drivers/hv/hv_balloon.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c index c5bb872..f1f17c5 100644 --- a/drivers/hv/hv_balloon.c +++ b/drivers/hv/hv_balloon.c @@ -652,6 +652,7 @@ static void hv_mem_hot_add(unsigned long start, unsigned long size, } has->ha_end_pfn -= HA_CHUNK; has->covered_end_pfn -= processed_pfn; + mutex_lock(&dm_device.ha_region_mutex); break; } -- 1.7.4.1