On Tue, 2 Feb 2021 at 00:27, Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx> wrote: > > On Mon, Feb 1, 2021 at 7:00 AM Brendan Jackman <jackmanb@xxxxxxxxxx> wrote: > > + > > +SEC("fentry/bpf_fentry_test1") > > +int BPF_PROG(sub, int x) > > +{ > > + int a = 0; > > + int b = __sync_fetch_and_add(&a, 1); > > It probably needs ENABLE_ATOMICS_TESTS ? > > Otherwise clang without -mcpu=v3 will complain: > "fatal error: error in backend: Invalid usage of the XADD return value" Ah yep of course, thanks for spotting. v3 incoming...