From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757990Ab0LHBiK (ORCPT ); Tue, 7 Dec 2010 20:38:10 -0500 Received: from kroah.org ([198.145.64.141]:48934 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757248Ab0LHBBH (ORCPT ); Tue, 7 Dec 2010 20:01:07 -0500 X-Mailbox-Line: From gregkh@clark.site Tue Dec 7 16:57:33 2010 Message-Id: <20101208005733.478414057@clark.site> User-Agent: quilt/0.48-11.2 Date: Tue, 07 Dec 2010 16:58:18 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Ian Campbell , Jeremy Fitzhardinge Subject: [121/289] xen: ensure that all event channels start off bound to VCPU 0 In-Reply-To: <20101208005821.GA2922@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.36-stable review patch. If anyone has any objections, please let us know. ------------------ From: Ian Campbell commit b0097adeec27e30223c989561ab0f7aa60d1fe93 upstream. All event channels startbound to VCPU 0 so ensure that cpu_evtchn_mask is initialised to reflect this. Otherwise there is a race after registering an event channel but before the affinity is explicitly set where the event channel can be delivered. If this happens then the event channel remains pending in the L1 (evtchn_pending) array but is cleared in L2 (evtchn_pending_sel), this means the event channel cannot be reraised until another event channel happens to trigger the same L2 entry on that VCPU. sizeof(cpu_evtchn_mask(0))==sizeof(unsigned long*) which is not correct, and causes only the first 32 or 64 event channels (depending on architecture) to be initially bound to VCPU0. Use sizeof(struct cpu_evtchn_s) instead. Signed-off-by: Ian Campbell Cc: Jeremy Fitzhardinge Signed-off-by: Greg Kroah-Hartman --- drivers/xen/events.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/xen/events.c +++ b/drivers/xen/events.c @@ -261,7 +261,7 @@ static void init_evtchn_cpu_bindings(voi } #endif - memset(cpu_evtchn_mask(0), ~0, sizeof(cpu_evtchn_mask(0))); + memset(cpu_evtchn_mask(0), ~0, sizeof(struct cpu_evtchn_s)); } static inline void clear_evtchn(int port)