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Subject: Re: [mm] b1f0502d04: INFO:trying_to_register_non-static_key
To:     David Rientjes <rientjes@google.com>
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From:   Laurent Dufour <ldufour@linux.vnet.ibm.com>
Date:   Wed, 28 Mar 2018 15:30:08 +0200
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On 26/03/2018 00:10, David Rientjes wrote:
> On Wed, 21 Mar 2018, Laurent Dufour wrote:
> 
>> I found the root cause of this lockdep warning.
>>
>> In mmap_region(), unmap_region() may be called while vma_link() has not been
>> called. This happens during the error path if call_mmap() failed.
>>
>> The only to fix that particular case is to call
>> seqcount_init(&vma->vm_sequence) when initializing the vma in mmap_region().
>>
> 
> Ack, although that would require a fixup to dup_mmap() as well.

You're right, I'll fix that too.

Thanks a lot.
Laurent.