Re: [PATCH 3/3] prctl_set_mm: downgrade mmap_sem to read lock

[Kirill Tkhai]

On 30.04.2019 12:08, Cyrill Gorcunov wrote:
> On Tue, Apr 30, 2019 at 11:55:45AM +0300, Kirill Tkhai wrote:
>>> -	up_write(&mm->mmap_sem);
>>> +	spin_unlock(&mm->arg_lock);
>>> +	up_read(&mm->mmap_sem);
>>>  	return error;
>>
>> Hm, shouldn't spin_lock()/spin_unlock() pair go as a fixup to existing code
>> in a separate patch? 
>>
>> Without them, the existing code has a problem at least in get_mm_cmdline().
> 
> Seems reasonable to merge it into patch 1.

Sounds sensibly.