From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932279AbcCWXSQ (ORCPT ); Wed, 23 Mar 2016 19:18:16 -0400 Received: from p3plsmtps2ded03.prod.phx3.secureserver.net ([208.109.80.60]:44591 "EHLO p3plsmtps2ded03.prod.phx3.secureserver.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752752AbcCWXRD (ORCPT ); Wed, 23 Mar 2016 19:17:03 -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.com Cc: "K. Y. Srinivasan" , stable@vger.kernel.org Subject: [PATCH 3/7] Drivers: hv: vmbus: Fix a bug in hv_need_to_signal_on_read() Date: Wed, 23 Mar 2016 17:53:53 -0700 Message-Id: <1458780837-4367-3-git-send-email-kys@microsoft.com> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1458780837-4367-1-git-send-email-kys@microsoft.com> References: <1458780816-4328-1-git-send-email-kys@microsoft.com> <1458780837-4367-1-git-send-email-kys@microsoft.com> X-CMAE-Envelope: MS4wfLWDK2bxfk0YqyO38VH2AsySrTZuW+XvUGqUVJIQninVp2mLCnicItGxl71mi32hGXItMv7z7GtQkN+iC6bX5lQqaNJuxYXna7lPPbqzPR63FG6niZ3F tdf1zUmNF0vC0amlnfIb0BLjG8ML8EpXmQHSynAu6bmpUozpbJZG8Zv+3CsGCfUDO0FaxwnAF0r574FlQUxVqAZ0qhWv285afLlH0r2YOvdQnWIT+dllXFOr wLKK1AS/XP+D+r2H4dDjwRvfkHIDnX9NNbmPv6C5jNTQ6tAUyd40n0wFQN0LRTC3gRJDqjmXkR1jl+6AOfsZTHY9SCH6G27uNjGG5492eJyKTZoTRMLQL5Sx EUCyjuQ+vVwVlQO5fbAJPxvb9v3fKY0IqD/z1vtr4bbJ7TQZCEJD6gCuXNSb2xQCqRPFWzt3UjgODaQ4/VWzasVvygZlrw== 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