From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754325AbcCRXix (ORCPT ); Fri, 18 Mar 2016 19:38:53 -0400 Received: from p3plsmtps2ded02.prod.phx3.secureserver.net ([208.109.80.59]:32967 "EHLO p3plsmtps2ded02.prod.phx3.secureserver.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753734AbcCRXht (ORCPT ); Fri, 18 Mar 2016 19:37:49 -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, jasowang@redhat.c Cc: "K. Y. Srinivasan" , stable@vger.kernel.org Subject: [PATCH 3/5] Drivers: hv: vmbus: Fix a bug in hv_need_to_signal_on_read() Date: Fri, 18 Mar 2016 18:14:23 -0700 Message-Id: <1458350065-32666-3-git-send-email-kys@microsoft.com> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1458350065-32666-1-git-send-email-kys@microsoft.com> References: <1458350038-32624-1-git-send-email-kys@microsoft.com> <1458350065-32666-1-git-send-email-kys@microsoft.com> X-CMAE-Envelope: MS4wfLxMxcSAot9D0tWUOd/oWYp7kZF0nhizmZI7Do/QcwCxqs3BIBkhyzd3RHN6cQg+1oxQtqXvVFyXQ8vaQIS4cRLuNV6wnsr9xHdwtLtpB8B6p5V+LHJk dAd4QyT3EbTZbLCr2aNYbN6x6d1w7GxHX9YZIN3mu06NwVEwnF6oYImNljGJEpjhHz6DggkmDPdhidPOmX2kmRShfTDZk7yYGrzdeY3CXShpN7WYocTzmbbM 2BYGBOqfWRLVJvK1SdZy/8p8kY2+Pv85cMfYNTf9pUGjMkxR5BqvdZAQF4G0cdgri3K698RjwkHwxVJpMiskWyHdt2UfakZbjgxm9vDveokVENpGvYAfi3gH 7fQ7CX7d0Y+VEt/zpZVeJZ5MzmjWlngwHRYPYw/30w+CdY8/xVXWV0tJdU/bkOLuSAJ29AFMSut4B7t0ipVxLen8b2Q4eQ== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We need to issue a full memory barrier prior making a signalling decision. Signed-off-by: K. Y. Srinivasan Cc: stable@vger.kernel.org --- drivers/hv/ring_buffer.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c index 2919395..67dc245 100644 --- a/drivers/hv/ring_buffer.c +++ b/drivers/hv/ring_buffer.c @@ -104,6 +104,7 @@ static bool hv_need_to_signal_on_read(struct hv_ring_buffer_info *rbi) u32 cur_write_sz; u32 pending_sz; + mb(); pending_sz = READ_ONCE(rbi->ring_buffer->pending_send_sz); /* If the other end is not blocked on write don't bother. */ if (pending_sz == 0) -- 1.7.4.1