----- Gavin Shan <gshan@xxxxxxxxxx> wrote: > 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. All those are handled in the rseq selftests and in librseq. Why duplicate all that logic again? Thanks, Mathieu > > Thanks, > Gavin > -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com