Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758988Ab3IHDtm (ORCPT ); Sat, 7 Sep 2013 23:49:42 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:56071 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756915Ab3IHDTE (ORCPT ); Sat, 7 Sep 2013 23:19:04 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Konrad Rzeszutek Wilk" , "David Vrabel" Date: Sun, 08 Sep 2013 03:52:01 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [080/121] xen/events: initialize local per-cpu mask for all possible events In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.101 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1771 Lines: 47 3.2.51-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: David Vrabel commit 84ca7a8e45dafb49cd5ca90a343ba033e2885c17 upstream. The sizeof() argument in init_evtchn_cpu_bindings() is incorrect resulting in only the first 64 (or 32 in 32-bit guests) ports having their bindings being initialized to VCPU 0. In most cases this does not cause a problem as request_irq() will set the irq affinity which will set the correct local per-cpu mask. However, if the request_irq() is called on a VCPU other than 0, there is a window between the unmasking of the event and the affinity being set were an event may be lost because it is not locally unmasked on any VCPU. If request_irq() is called on VCPU 0 then local irqs are disabled during the window and the race does not occur. Fix this by initializing all NR_EVENT_CHANNEL bits in the local per-cpu masks. Signed-off-by: David Vrabel Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Ben Hutchings --- drivers/xen/events.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/xen/events.c +++ b/drivers/xen/events.c @@ -316,7 +316,7 @@ static void init_evtchn_cpu_bindings(voi for_each_possible_cpu(i) memset(per_cpu(cpu_evtchn_mask, i), - (i == 0) ? ~0 : 0, sizeof(*per_cpu(cpu_evtchn_mask, i))); + (i == 0) ? ~0 : 0, NR_EVENT_CHANNELS/8); } static inline void clear_evtchn(int port) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/