From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752047AbeCOCpf (ORCPT ); Wed, 14 Mar 2018 22:45:35 -0400 Received: from out1-smtp.messagingengine.com ([66.111.4.25]:55961 "EHLO out1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751488AbeCOCpe (ORCPT ); Wed, 14 Mar 2018 22:45:34 -0400 X-ME-Sender: From: Simon Gaiser To: xen-devel@lists.xenproject.org Cc: Simon Gaiser , Boris Ostrovsky , Juergen Gross , linux-kernel@vger.kernel.org Subject: [PATCH v2 2/3] xen: xenbus: Catch closing of non existent transactions Date: Thu, 15 Mar 2018 03:43:21 +0100 Message-Id: <20180315024322.27429-2-simon@invisiblethingslab.com> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180315024322.27429-1-simon@invisiblethingslab.com> References: <20180315024322.27429-1-simon@invisiblethingslab.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Users of the xenbus functions should never close a non existent transaction (for example by trying to closing the same transaction twice) but better catch it in xs_request_exit() than to corrupt the reference counter. Signed-off-by: Simon Gaiser --- drivers/xen/xenbus/xenbus_xs.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c index 3f3b29398ab8..49a3874ae6bb 100644 --- a/drivers/xen/xenbus/xenbus_xs.c +++ b/drivers/xen/xenbus/xenbus_xs.c @@ -140,7 +140,9 @@ void xs_request_exit(struct xb_req_data *req) spin_lock(&xs_state_lock); xs_state_users--; if ((req->type == XS_TRANSACTION_START && req->msg.type == XS_ERROR) || - req->type == XS_TRANSACTION_END) + (req->type == XS_TRANSACTION_END && + !WARN_ON_ONCE(req->msg.type == XS_ERROR && + !strcmp(req->body, "ENOENT")))) xs_state_users--; spin_unlock(&xs_state_lock); -- 2.16.2