From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751505AbdKYTXJ (ORCPT ); Sat, 25 Nov 2017 14:23:09 -0500 Received: from shards.monkeyblade.net ([184.105.139.130]:53990 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751024AbdKYTXH (ORCPT ); Sat, 25 Nov 2017 14:23:07 -0500 Date: Sun, 26 Nov 2017 04:22:21 +0900 (KST) Message-Id: <20171126.042221.596692527873080042.davem@davemloft.net> To: jhansen@vmware.com Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, gregkh@linuxfoundation.org, pv-drivers@vmware.com Subject: Re: [PATCH v2] VSOCK: Don't call vsock_stream_has_data in atomic context From: David Miller In-Reply-To: <1511533528-5253-1-git-send-email-jhansen@vmware.com> References: <1511533528-5253-1-git-send-email-jhansen@vmware.com> X-Mailer: Mew version 6.7 on Emacs 25.3 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Sat, 25 Nov 2017 11:23:03 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jorgen Hansen Date: Fri, 24 Nov 2017 06:25:28 -0800 > When using the host personality, VMCI will grab a mutex for any > queue pair access. In the detach callback for the vmci vsock > transport, we call vsock_stream_has_data while holding a spinlock, > and vsock_stream_has_data will access a queue pair. > > To avoid this, we can simply omit calling vsock_stream_has_data > for host side queue pairs, since the QPs are empty per default > when the guest has detached. > > This bug affects users of VMware Workstation using kernel version > 4.4 and later. > > Testing: Ran vsock tests between guest and host, and verified that > with this change, the host isn't calling vsock_stream_has_data > during detach. Ran mixedTest between guest and host using both > guest and host as server. > > v2: Rebased on top of recent change to sk_state values > Reviewed-by: Adit Ranadive > Reviewed-by: Aditya Sarwade > Reviewed-by: Stefan Hajnoczi > Signed-off-by: Jorgen Hansen Applied, thank you.