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=ham 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 8716EC5ACBF for ; Mon, 16 Mar 2020 02:34:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 52E29206EB for ; Mon, 16 Mar 2020 02:34:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584326094; bh=hcTIdJiCXvD/krcQTIT1ht5ObWgrP9GQXXZnj8Jlw7w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=zzBLZrpSPgca9rjF8Fh2YNVjvFwZ62JZtswiw3UZ4BHt//BVIGAr8UcTmX2n/7H/z +SiuUjak1z7I/bKAI3WPPZG18RpNEzhpCQkz0+/Kdxfao99KiHJ8pjIq9m4rxu3fyb PbKP7xUxHutqHjRAZJX1asRTIizhSxPJ17UthDXA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730011AbgCPCex (ORCPT ); Sun, 15 Mar 2020 22:34:53 -0400 Received: from mail.kernel.org ([198.145.29.99]:38698 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729968AbgCPCeu (ORCPT ); Sun, 15 Mar 2020 22:34:50 -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 727082073C; Mon, 16 Mar 2020 02:34:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584326090; bh=hcTIdJiCXvD/krcQTIT1ht5ObWgrP9GQXXZnj8Jlw7w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FVrWJWsf2thcl4fJ/bYAYPKJbgm0Y3chNwaVfoU3U+SPm5AND1KrVQ1zNVB2eflcX EI2xUmD8/Bau520OnUBZuDWD3BsECy++/cN4BWlS/77EfaWQrxchNEIXhMoVPEJZmk fT9ReKimjgRmjt84zkcCrsuy0GKSNUhzqLlzbfIg= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Dongli Zhang , Julien Grall , Boris Ostrovsky , Sasha Levin , xen-devel@lists.xenproject.org Subject: [PATCH AUTOSEL 5.4 33/35] xenbus: req->err should be updated before req->state Date: Sun, 15 Mar 2020 22:34:09 -0400 Message-Id: <20200316023411.1263-33-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200316023411.1263-1-sashal@kernel.org> References: <20200316023411.1263-1-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: 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