Hi Florian,
On 8/9/22 5:16 PM, Florian Weimer wrote:
__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).
For kvm/selftests, there are 3 architectures involved actually. So we
just need consider 4 cases: aarch64, x86, s390 and other. For other
case, we just use __builtin_thread_pointer() to maintain code's
integrity, but it's not called at all.
I think kvm/selftest is always relying on glibc if I'm correct.
Thanks,
Gavin
