linux-kernel - Re: [PATCH v4] x86, hotplug: fix llc shared map unreleased during cpu hotplug

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <54180A36.7040504@gmail.com>
Date:	Tue, 16 Sep 2014 18:00:22 +0800
From:	Wanpeng Li <kernellwp@...il.com>
To:	Ingo Molnar <mingo@...nel.org>,
	Wanpeng Li <wanpeng.li@...ux.intel.com>
CC:	Ingo Molnar <mingo@...hat.com>, hpa@...or.com,
	Peter Zijlstra <peterz@...radead.org>, x86@...nel.org,
	Borislav Petkov <bp@...en8.de>,
	Yasuaki Ishimatsu <isimatu.yasuaki@...fujitsu.com>,
	David Rientjes <rientjes@...gle.com>,
	Prarit Bhargava <prarit@...hat.com>,
	Steven Rostedt <srostedt@...hat.com>,
	Jan Kiszka <jan.kiszka@...mens.com>,
	Toshi Kani <toshi.kani@...com>, linux-kernel@...r.kernel.org,
	Zhang Yang <yang.z.zhang@...el.com>
Subject: Re: [PATCH v4] x86, hotplug: fix llc shared map unreleased during
 cpu hotplug

于 14-9-16 下午5:01, Ingo Molnar 写道:
> * Wanpeng Li <wanpeng.li@...ux.intel.com> wrote:
>
>> Hi Ingo,
>> On Thu, Sep 04, 2014 at 04:56:41PM +0800, Wanpeng Li wrote:
>>> On Thu, Sep 04, 2014 at 07:20:34AM +0200, Ingo Molnar wrote:
>>>> * Wanpeng Li <wanpeng.li@...ux.intel.com> wrote:
>>>>
>>>>> BUG: unable to handle kernel NULL pointer dereference at 0000000000000004
>>>>> IP: [..] find_busiest_group
>>>>> PGD 5a9d5067 PUD 13067 PMD 0
>>>>> Oops: 0000 [#3] SMP
>>>>> [...]
>>>>> Call Trace:
>>>>> load_balance
>>>>> ? _raw_spin_unlock_irqrestore
>>>>> idle_balance
>>>>> __schedule
>>>>> schedule
>>>>> schedule_timeout
>>>>> ? lock_timer_base
>>>>> schedule_timeout_uninterruptible
>>>>> msleep
>>>>> lock_device_hotplug_sysfs
>>>>> online_store
>>>>> dev_attr_store
>>>>> sysfs_write_file
>>>>> vfs_write
>>>>> SyS_write
>>>>> system_call_fastpath
>>>>>
>>>>> Last level cache shared map is built during cpu up and build sched domain
>>>>> routine takes advantage of it to setup sched domain cpu topology, however,
>>>>> llc shared map is unreleased during cpu disable which lead to invalid sched
>>>>> domain cpu topology. This patch fix it by release llc shared map correctly
>>>>> during cpu disable.
>>>> Very little is said in this changelog about how the bug was
>>>> found, how likely it is to occur for others, what systems are
>>>> affected, etc.
>>> This bug can be triggered by hot add and remove large number of xen
>>> domain0's vcpus repeated.
>>>
>> If I need to send a new version of the patch or you can pick the patch
>> w/ the updated changelog for me? ;-)
> Please send a fresh new version, maintainers trying to splice &
> dice patches and changelogs is an unrobust approach prone to
> mistakes.

Ok, I will send out a new version tomorrow. ;-)

Regards,
Wanpeng Li

>
> Thanks,
>
> 	Ingo
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@...r.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/