Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751145AbaJIELC (ORCPT ); Thu, 9 Oct 2014 00:11:02 -0400 Received: from szxga01-in.huawei.com ([119.145.14.64]:51785 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750705AbaJIEKx (ORCPT ); Thu, 9 Oct 2014 00:10:53 -0400 Message-ID: <54360ABF.9030302@huawei.com> Date: Thu, 9 Oct 2014 12:10:39 +0800 From: Xishi Qiu User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:12.0) Gecko/20120428 Thunderbird/12.0.1 MIME-Version: 1.0 To: Yasuaki Ishimatsu CC: , , , , Subject: Re: [PATCH] driver/base/node: remove unnecessary kfree of node struct from unregister_one_node References: <542E750B.4000508@jp.fujitsu.com> In-Reply-To: <542E750B.4000508@jp.fujitsu.com> Content-Type: text/plain; charset="ISO-2022-JP" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.25.179] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2014/10/3 18:06, Yasuaki Ishimatsu wrote: > Commit 92d585ef067d ("numa: fix NULL pointer access and memory > leak in unregister_one_node()") added kfree() of node struct in > unregister_one_node(). But node struct is freed by node_device_release() > which is called in unregister_node(). So by adding the kfree(), Hi, Is this path? unregister_node() device_unregister() device_del() bus_remove_device() device_release_driver() __device_release_driver() devres_release_all() release_nodes() dr->node.release(dev, dr->data); then which function is be called? Thanks, Xishi Qiu > node struct is freed two times. > > While hot removing memory, the commit leads the following BUG_ON(): > > kernel BUG at mm/slub.c:3346! > invalid opcode: 0000 [#1] SMP > [...] > Call Trace: > [...] unregister_one_node > [...] try_offline_node > [...] remove_memory > [...] acpi_memory_device_remove > [...] acpi_bus_trim > [...] acpi_bus_trim > [...] acpi_device_hotplug > [...] acpi_hotplug_work_fn > [...] process_one_work > [...] worker_thread > [...] ? rescuer_thread > [...] kthread > [...] ? kthread_create_on_node > [...] ret_from_fork > [...] ? kthread_create_on_node > > This patch removes unnecessary kfree() from unregister_one_node(). > > Signed-off-by: Yasuaki Ishimatsu > Cc: Xishi Qiu > Cc: Greg Kroah-Hartman > Cc: Andrew Morton > Cc: stable@vger.kernel.org # v3.16+ > Fixes: 92d585ef067d "numa: fix NULL pointer access and memory leak in unregister_one_node()" > --- > drivers/base/node.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/drivers/base/node.c b/drivers/base/node.c > index c6d3ae0..d51c49c 100644 > --- a/drivers/base/node.c > +++ b/drivers/base/node.c > @@ -603,7 +603,6 @@ void unregister_one_node(int nid) > return; > > unregister_node(node_devices[nid]); > - kfree(node_devices[nid]); > node_devices[nid] = NULL; > } > -- 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/