From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:34951 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751662AbcIINnO (ORCPT ); Fri, 9 Sep 2016 09:43:14 -0400 Subject: Patch "[PATCH 097/135] Drivers: hv: vmbus: avoid infinite loop in" has been added to the 4.4-stable tree To: vkuznets@redhat.com, alexander.levin@verizon.com, gregkh@linuxfoundation.org, kys@microsoft.com Cc: , From: Date: Fri, 09 Sep 2016 15:38:30 +0200 Message-ID: <147342831023051@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled [PATCH 097/135] Drivers: hv: vmbus: avoid infinite loop in to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: 0097-Drivers-hv-vmbus-avoid-infinite-loop-in-init_vp_inde.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 864900991b27198b2006f7e8abc50599ea923968 Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Wed, 27 Jan 2016 22:29:34 -0800 Subject: [PATCH 097/135] Drivers: hv: vmbus: avoid infinite loop in init_vp_index() [ Upstream commit 79fd8e706637a5c7c41f9498fe0fbfb437abfdc8 ] When we pick a CPU to use for a new subchannel we try find a non-used one on the appropriate NUMA node, we keep track of them with the primary->alloced_cpus_in_node mask. Under normal circumstances we don't run out of available CPUs but it is possible when we we don't initialize some cpus in Linux, e.g. when we boot with 'nr_cpus=' limitation. Avoid the infinite loop in init_vp_index() by checking that we still have non-used CPUs in the alloced_cpus_in_node mask and resetting it in case we don't. Signed-off-by: Vitaly Kuznetsov Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/hv/channel_mgmt.c | 11 +++++++++++ 1 file changed, 11 insertions(+) --- a/drivers/hv/channel_mgmt.c +++ b/drivers/hv/channel_mgmt.c @@ -459,6 +459,17 @@ static void init_vp_index(struct vmbus_c cpumask_of_node(primary->numa_node)); cur_cpu = -1; + + /* + * Normally Hyper-V host doesn't create more subchannels than there + * are VCPUs on the node but it is possible when not all present VCPUs + * on the node are initialized by guest. Clear the alloced_cpus_in_node + * to start over. + */ + if (cpumask_equal(&primary->alloced_cpus_in_node, + cpumask_of_node(primary->numa_node))) + cpumask_clear(&primary->alloced_cpus_in_node); + while (true) { cur_cpu = cpumask_next(cur_cpu, &available_mask); if (cur_cpu >= nr_cpu_ids) { Patches currently in stable-queue which might be from vkuznets@redhat.com are queue-4.4/0038-drivers-hv-cleanup-synic-msrs-if-vmbus-connect-faile.patch queue-4.4/0097-Drivers-hv-vmbus-avoid-infinite-loop-in-init_vp_inde.patch queue-4.4/0118-clocksource-Allow-unregistering-the-watchdog.patch queue-4.4/0099-Drivers-hv-vmbus-don-t-manipulate-with-clocksources-.patch queue-4.4/0127-x86-hyperv-Avoid-reporting-bogus-NMI-status-for-Gen2.patch queue-4.4/0098-Drivers-hv-vmbus-avoid-scheduling-in-interrupt-conte.patch