From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:38720 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966861AbdEWOsD (ORCPT ); Tue, 23 May 2017 10:48:03 -0400 Subject: Patch "powerpc/sysfs: Fix reference leak of cpu device_nodes present at boot" has been added to the 4.11-stable tree To: tyreld@linux.vnet.ibm.com, gregkh@linuxfoundation.org, mpe@ellerman.id.au Cc: , From: Date: Tue, 23 May 2017 16:45:55 +0200 Message-ID: <149555075510892@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 powerpc/sysfs: Fix reference leak of cpu device_nodes present at boot to the 4.11-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: powerpc-sysfs-fix-reference-leak-of-cpu-device_nodes-present-at-boot.patch and it can be found in the queue-4.11 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From e76ca27790a514590af782f83f6eae49e0ccf8c9 Mon Sep 17 00:00:00 2001 From: Tyrel Datwyler Date: Mon, 17 Apr 2017 20:24:39 -0400 Subject: powerpc/sysfs: Fix reference leak of cpu device_nodes present at boot From: Tyrel Datwyler commit e76ca27790a514590af782f83f6eae49e0ccf8c9 upstream. For CPUs present at boot each logical CPU acquires a reference to the associated device node of the core. This happens in register_cpu() which is called by topology_init(). The result of this is that we end up with a reference held by each thread of the core. However, these references are never freed if the CPU core is DLPAR removed. This patch fixes the reference leaks by acquiring and releasing the references in the CPU hotplug callbacks un/register_cpu_online(). With this patch symmetric reference counting is observed with both CPUs present at boot, and those DLPAR added after boot. Fixes: f86e4718f24b ("driver/core: cpu: initialize of_node in cpu's device struture") Signed-off-by: Tyrel Datwyler Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/kernel/sysfs.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/arch/powerpc/kernel/sysfs.c +++ b/arch/powerpc/kernel/sysfs.c @@ -710,6 +710,10 @@ static int register_cpu_online(unsigned struct device_attribute *attrs, *pmc_attrs; int i, nattrs; + /* For cpus present at boot a reference was already grabbed in register_cpu() */ + if (!s->of_node) + s->of_node = of_get_cpu_node(cpu, NULL); + #ifdef CONFIG_PPC64 if (cpu_has_feature(CPU_FTR_SMT)) device_create_file(s, &dev_attr_smt_snooze_delay); @@ -864,6 +868,8 @@ static int unregister_cpu_online(unsigne } #endif cacheinfo_cpu_offline(cpu); + of_node_put(s->of_node); + s->of_node = NULL; #endif /* CONFIG_HOTPLUG_CPU */ return 0; } Patches currently in stable-queue which might be from tyreld@linux.vnet.ibm.com are queue-4.11/powerpc-sysfs-fix-reference-leak-of-cpu-device_nodes-present-at-boot.patch queue-4.11/of-fix-cpus-reference-leak-in-of_numa_parse_cpu_nodes.patch queue-4.11/powerpc-pseries-fix-of_node_put-underflow-during-dlpar-remove.patch