Re: [PATCH 08/11] nptl: Move cancel state out of cancelhandling

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

On 26/05/2021 15:20, Florian Weimer wrote:
> * Adhemerval Zanella via Libc-alpha:
> 
>> diff --git a/nptl/descr.h b/nptl/descr.h
>> index a120365f88..a3084fdf60 100644
>> --- a/nptl/descr.h
>> +++ b/nptl/descr.h
> 
>> @@ -407,6 +401,10 @@ struct pthread
>>    /* Used on strsignal.  */
>>    struct tls_internal_t tls_state;
>>  
>> +  /* Thread cancel state (PTHREAD_CANCEL_ENABLE or
>> +     PTHREAD_CANCEL_DISABLE).  */
>> +  unsigned char cancelstate;
> 
> You could move this into the padding after the c11 flag, I think.

Right, I moved to below c11.  What kind of constraint we have for the
'struct pthread' regarding its internal member layout? We have a couple
of unused fields and might be good to clean them up.

> 
> I think there is an implied dependency on PTHREAD_CANCEL_ENABLE == 0 in
> __tls_init_tp and somewhere in pthread_create.  Maybe add a static
> assert for PTHREAD_CANCEL_ENABLE == 0?

I think it would be better to add an initialization on __tls_init_tp,
similar to get_cached_stack.  It would be better if we consolidate
the 'struct pthread' initialization in a common place.