Re: [PATCH 1/3] glibc: Perform rseq registration at C startup and thread creation (v21)

From: Florian Weimer
Date: Wed Jun 24 2020 - 15:12:10 EST


* Mathieu Desnoyers:

>> I'm still worried that __rseq_static_assert and __rseq_alignof will show
>> up in the UAPI with textually different definitions. (This does not
>> apply to __rseq_tls_model_ie.)
>
> What makes this worry not apply to __rseq_tls_model_ie ?

It's not needed by the kernel header because it doesn't contain a
__rseq_abi declaration.

>>
>> Is my worry unfounded?
>
> So AFAIU you worry that eventually sys/rseq.h and linux/rseq.h carry different
> definitions of __rseq_static_assert and __rseq_alignof.
>
> Indeed, I did not surround those #define with #ifndef/#endif. Maybe we should ?
>
> Just in case the definitions end up being different (worse case scenario), we
> should expect their behavior to be pretty much equivalent. So going for the
> following should address your concern I think:

I think we should keep things simple on the glibc side for now and do
this changes to the kernel headers first.

Thanks,
Florian