On 08/21/2013 12:19 AM, Darren Hart wrote:
> HopingOn Tue, 2013-08-20 at 11:07 +0800, Chen Gang wrote:
>
>
> Hi Chen,
>
>> rt_mutex_finish_proxy_lock() can return failure code (e.g. -EINTR,
>> -ETIMEDOUT).
>>
>> Original implementation has already noticed about it, but not check it
>> before next work.
>>
>> Also let coments within 80 columns to pass "./scripts/checkpatch.pl".
>>
>>
>> Signed-off-by: Chen Gang <gang.c...@asianux.com>
>> ---
>> kernel/futex.c | 30 ++++++++++++++++--------------
>> 1 files changed, 16 insertions(+), 14 deletions(-)
>>
>> diff --git a/kernel/futex.c b/kernel/futex.c
>> index c3a1a55..1a94e7d 100644
>> --- a/kernel/futex.c
>> +++ b/kernel/futex.c
>> @@ -2373,21 +2373,23 @@ static int futex_wait_requeue_pi(u32 __user *uaddr,
>> unsigned int flags,
>> ret = rt_mutex_finish_proxy_lock(pi_mutex, to, &rt_waiter, 1);
>> debug_rt_mutex_free_waiter(&rt_waiter);
>>
>> - spin_lock(q.lock_ptr);
>> - /*
>> - * Fixup the pi_state owner and possibly acquire the lock if we
>> - * haven't already.
>> - */
>> - res = fixup_owner(uaddr2, &q, !ret);
>
>
> This call catches a corner case which appears to be skipped now. Or am I
> missing how you accounted for that?
>
>
Pardon ?
Hmm... this patch lets related code block in "if(!ret) {...}", should
not remove any code.
Please help check again for whether what I have done is correct or not.
Thanks.
>> - /*
>> - * If fixup_owner() returned an error, proprogate that. If it
>> - * acquired the lock, clear -ETIMEDOUT or -EINTR.
>> - */
>> - if (res)
>> - ret = (res < 0) ? res : 0;
>> + if (!ret) {
>> + spin_lock(q.lock_ptr);
>> + /*
>> + * Fixup the pi_state owner and possibly acquire the
>> + * lock if we haven't already.
>> + */
>> + res = fixup_owner(uaddr2, &q, !ret);
>> + /*
>> + * If fixup_owner() returned an error, proprogate that.
>> + * If it acquired the lock, clear -ETIMEDOUT or -EINTR.
>> + */
>> + if (res)
>> + ret = (res < 0) ? res : 0;
>>
>> - /* Unqueue and drop the lock. */
>> - unqueue_me_pi(&q);
>> + /* Unqueue and drop the lock. */
>> + unqueue_me_pi(&q);
>> + }
>> }
>>
>> /*
>
> Thanks,
>
--
Chen Gang
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