Re: [PATCH 1/2] KVM: selftests: Make rseq compatible with glibc-2.35

From: Florian Weimer
Date: Tue Aug 09 2022 - 03:16:56 EST


* Gavin Shan:

>> __builtin_thread_pointer doesn't work on all architectures/GCC
>> versions.
>> Is this a problem for selftests?
>>
>
> It's a problem as the test case is running on all architectures. I think I
> need introduce our own __builtin_thread_pointer() for where it's not
> supported: (1) PowerPC (2) x86 without GCC 11
>
> Please let me know if I still have missed cases where
> __buitin_thread_pointer() isn't supported?

As far as I know, these are the two outliers that also have rseq
support. The list is a bit longer if we also consider non-rseq
architectures (csky, hppa, ia64, m68k, microblaze, sparc, don't know
about the Linux architectures without glibc support).

Thanks,
Florian