On Sun, May 17, 2020 at 7:45 PM Qian Cai <cai@xxxxxx> wrote: > > With Clang 9.0.1, > > return array->value + array->elem_size * (index & array->index_mask); > > but array->value is, > > char value[0] __aligned(8); This, and ptrs and pptrs, should be flexible arrays. But they are in a union, and unions don't support flexible arrays. Putting each of them into anonymous struct field also doesn't work: /data/users/andriin/linux/include/linux/bpf.h:820:18: error: flexible array member in a struct with no named members struct { void *ptrs[] __aligned(8); }; So it probably has to stay this way. Is there a way to silence UBSAN for this particular case?