Re: [PATCH V3] futex: add futex_q static initializer

[Darren Hart <dvhart@linux.intel.com>]

On 11/08/2010 01:48 PM, Thomas Gleixner wrote:
> On Mon, 8 Nov 2010, Darren Hart wrote:

>>   /*
>>    * Hash buckets are shared by all the futex_keys that hash to the same
>>    * location.  Each key may have multiple futex_q structures, one for each task
>> @@ -1751,7 +1757,6 @@ static int futex_wait_setup(u32 __user *uaddr, u32 val, unsigned int flags,
>>   	 * rare, but normal.
>>   	 */
>>   retry:
>> -	q->key = FUTEX_KEY_INIT;
>
> You sure about that one in the retry path ?
>
>> @@ -1906,11 +1907,7 @@ static int futex_lock_pi(u32 __user *uaddr, unsigned int flags, int detect,
>>   		hrtimer_set_expires(&to->timer, *time);
>>   	}
>>
>> -	q.pi_state = NULL;
>> -	q.rt_waiter = NULL;
>> -	q.requeue_pi_key = NULL;
>>   retry:
>> -	q.key = FUTEX_KEY_INIT;
>
> Ditto

Yes, these are fine. get_futex_key (called immediately after retry: in 
both cases) will set the mm or inode or error out. On error we return 
immediately. No need to zero both.ptr.

Thanks,

-- 
Darren Hart
Embedded Linux Kernel