Re: [PATCH V2] x86/numa: kernel stack corruption fix

From: Xishi Qiu
Date: Tue Apr 07 2015 - 22:58:47 EST


On 2015/4/8 10:18, Baoquan He wrote:

> On 04/08/15 at 09:59am, Xishi Qiu wrote:
>> On 2015/4/8 9:46, Dave Young wrote:
>>
>>>>>
>>>>> - /* Mark all kernel nodes. */
>>>>> + /*
>>>>> + * Mark all kernel nodes.
>>>>> + *
>>>>> + * In case booting with mem=nn[kMG] or in kdump kernel, numa_meminfo
>>>>
>>>> Hi Dave,
>>>>
>>>> It should both set mem=xx and numa=off, then numa_meminfo may not include all
>>>> the memblock.reserved memory, right?
>>>
>>> Yasuaki Ishimatsu suggests to remove numa=off in comment because in theory there's such
>>> possiblity that it may happen even without numa=off. Just consider the non-snb board..
>>>
>>> Thanks
>>> Dave
>>>
>>
>> Hi Dave,
>>
>> I made a mistake, when numa is on, numa_meminfo is from SRAT, but it will be cut
>> in numa_cleanup_meminfo(), so the bug is not related to numa on/off. Your comment
>> is right.
>
> Hi Xishi,
>
>>From code flow it's exact as you said. And if remove numa=off bug should
> be reproduced alwasy. I talked to Dave, he said error didn't occur when
> he remove numa=off. That is too weird.
>

Hi Baoquan,

May be it wrote over end of numa mask bitmap, but the stack can still run,
so there is no Call Trace.
How about add some printk to see if it has written over?

Thanks,
Xishi Qiu

> Thanks
> Baoquan >
>>
>>> .
>>>
>>
>>
>>
>
> .
>



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