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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 54ECFC2BAEE for ; Tue, 24 Mar 2020 13:33:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2372120775 for ; Tue, 24 Mar 2020 13:33:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585056824; bh=hcTIdJiCXvD/krcQTIT1ht5ObWgrP9GQXXZnj8Jlw7w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=UMPp0bgOvRbORWrU1gFW1Kl7BW8VRVS1w68KWI4mm9NZhdPwS72Km6ITnWWLvBWIF NADSUffnU0XB9/pl/p2C4VPAbyGSrcR2dn9Afjr/tvgO2lyq+QGQdwFtx3o/9D51sE V7ORfZIJZdiGtoVhIxAfW43laje41BmVInCXk5B8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727567AbgCXNMT (ORCPT ); Tue, 24 Mar 2020 09:12:19 -0400 Received: from mail.kernel.org ([198.145.29.99]:58024 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727561AbgCXNMS (ORCPT ); Tue, 24 Mar 2020 09:12:18 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 90B6620775; Tue, 24 Mar 2020 13:12:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585055538; bh=hcTIdJiCXvD/krcQTIT1ht5ObWgrP9GQXXZnj8Jlw7w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Gw0kWMMJ8rAwgqEHDzEI2JG5fnBiD55PBKvchp8lyYHuikqPpZrdMGxyI3HNrclRL 7fyE+yX0jIJCAECVtkkpf/GfCJBB6kUBHBjlI1sh6Q3JEF7zY1XFYzzbJpFXHExhG8 K0IoGmD57+a5Oqd2ka7dCKbxrT9gTkLsCWR+dXrc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dongli Zhang , Julien Grall , Boris Ostrovsky , Sasha Levin Subject: [PATCH 4.19 17/65] xenbus: req->err should be updated before req->state Date: Tue, 24 Mar 2020 14:10:38 +0100 Message-Id: <20200324130759.134090166@linuxfoundation.org> X-Mailer: git-send-email 2.25.2 In-Reply-To: <20200324130756.679112147@linuxfoundation.org> References: <20200324130756.679112147@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Dongli Zhang [ Upstream commit 8130b9d5b5abf26f9927b487c15319a187775f34 ] This patch adds the barrier to guarantee that req->err is always updated before req->state. Otherwise, read_reply() would not return ERR_PTR(req->err) but req->body, when process_writes()->xb_write() is failed. Signed-off-by: Dongli Zhang Link: https://lore.kernel.org/r/20200303221423.21962-2-dongli.zhang@oracle.com Reviewed-by: Julien Grall Signed-off-by: Boris Ostrovsky Signed-off-by: Sasha Levin --- drivers/xen/xenbus/xenbus_comms.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/xen/xenbus/xenbus_comms.c b/drivers/xen/xenbus/xenbus_comms.c index 852ed161fc2a7..eb5151fc8efab 100644 --- a/drivers/xen/xenbus/xenbus_comms.c +++ b/drivers/xen/xenbus/xenbus_comms.c @@ -397,6 +397,8 @@ static int process_writes(void) if (state.req->state == xb_req_state_aborted) kfree(state.req); else { + /* write err, then update state */ + virt_wmb(); state.req->state = xb_req_state_got_reply; wake_up(&state.req->wq); } -- 2.20.1