Re: [PATCH bpf-next] selftests/bpf: Wait for the struct_ops map to be freed in assoc_in_timer

[Qiliang Yuan <odys.yuan@gmail.com>]

On Fri, Oct 9, 2026 at 02:36 AM bot+bpf-ci@kernel.org wrote:
> Should the late dissociation be fixed in bpf_struct_ops_map_free() instead
> of only making the test wait longer, for example with a grace period after
> bpf_struct_ops_map_dissoc_progs() or by dissociating before the call_rcu()?
>
> If the flakiness started with 5db69b0fbdc8, is the Fixes: tag pointing at
> the right commit?

Yes to both. With the window widened, a timer callback of the struct_ops
prog returns into the freed trampoline and the kernel hits an int3 Oops,
on the first run.

v2 [1] frees the map after a grace period that follows clearing the
association, since dissociating before the call_rcu() would take a mutex
where bpf_map_put() may run in softirq. It adds a test that catches the
map being freed under a running .test_1, and keeps the test fix of v1
with Fixes pointing at 5db69b0fbdc8.

[1] https://lore.kernel.org/r/20261010-selftests-bpf-struct-ops-assoc-timer-v2-0-d7a43896dbf1@gmail.com

Thanks,
Qiliang