Re: [PATCH bpf-next v2] bpf: Propagate memory bounds to registers in atomics w/ BPF_FETCH

[Alexei Starovoitov]

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"