Re: [PATCH v2] nptl: Handle spurious EINTR when thread cancellation is disabled (BZ#29029)

[Adhemerval Zanella <adhemerval.zanella@linaro.org>]

On 19/04/2022 09:46, Szabolcs Nagy wrote:
> The 04/19/2022 09:30, Adhemerval Zanella wrote:
>> Do this fix the intermittent issue you are seeing:
>>
> 
> yes, this seems to fix the issue.

Thanks, I think this is obvious enough since it is essentially the old
code (sorry about trying to be clever here).  I will fix it upstream and
backport to affected releases as well.

> 
>> diff --git a/nptl/pthread_cancel.c b/nptl/pthread_cancel.c
>> index c76882e279..e67b2df5cc 100644
>> --- a/nptl/pthread_cancel.c
>> +++ b/nptl/pthread_cancel.c
>> @@ -121,6 +121,7 @@ __pthread_cancel (pthread_t th)
>>    int newval;
>>    do
>>      {
>> +    again:
>>        newval = oldval | CANCELING_BITMASK | CANCELED_BITMASK;
>>        if (oldval == newval)
>>         break;
>> @@ -134,7 +135,7 @@ __pthread_cancel (pthread_t th)
>>           int newval2 = oldval | CANCELING_BITMASK;
>>           if (!atomic_compare_exchange_weak_acquire (&pd->cancelhandling,
>>                                                      &oldval, newval2))
>> -           continue;
>> +           goto again;
>>  
>>           if (pd == THREAD_SELF)
>>             /* This is not merely an optimization: An application may
>>
>>