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 22ED1C43331 for ; Tue, 24 Mar 2020 13:16:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E72D0206F6 for ; Tue, 24 Mar 2020 13:16:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585055804; bh=hcTIdJiCXvD/krcQTIT1ht5ObWgrP9GQXXZnj8Jlw7w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=zSKtl7wGXar3fx+q0oQsbEG0r8qI6GC4N2NHF02cxKQJ7RvnT69BaMhgO3gOkBbhL DcIbj+vFYsDMdoo6/S7f7s/XROckyzzGfspRhHC0X58gi/+RUqNjdC0wOzsyLEz2WK YUs0n2XeXuoKTi/UVi+8sIn47id93G6z2N3MaPBo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727989AbgCXNQm (ORCPT ); Tue, 24 Mar 2020 09:16:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:36232 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727490AbgCXNQj (ORCPT ); Tue, 24 Mar 2020 09:16:39 -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 74B1E206F6; Tue, 24 Mar 2020 13:16:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585055798; bh=hcTIdJiCXvD/krcQTIT1ht5ObWgrP9GQXXZnj8Jlw7w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=s6c1CbAMFpFEMIWQWSceNbypgkpL6/EHr9eFeDlQOD4iPDAkSuoJTzXj3gpdFL4yK 0MG8VjZh8tm0GoWt6Gpl8XGDVDB1S2GODF3HZ85Vcfe4jJa97rq2wJxLgM5SSabeV+ bJmg2h8kefyezjVeHRWrfuBXEYQvudXbdq91f50o= 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 5.4 032/102] xenbus: req->err should be updated before req->state Date: Tue, 24 Mar 2020 14:10:24 +0100 Message-Id: <20200324130809.899629569@linuxfoundation.org> X-Mailer: git-send-email 2.25.2 In-Reply-To: <20200324130806.544601211@linuxfoundation.org> References: <20200324130806.544601211@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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