Re: [PATCH] bpf/perf: Fix suspicious RCU usage in get_callchain_entry()

[Qing Wang]

On Wed, 04 Feb 2026 at 08:04, Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx> wrote:
> rcu_read_lock/unlock is not called when may_fault == false because in
> that case BPF program is already running within rcu_read_lock/unlock
> region. So I'm not sure this patch fixes anything really. And even
> with trace_in, if we cann rcu_read_lock/unlock one extra time it
> shouldn't be a problem, no?

Thanks for your review, I agree with you. My patch is incorrect and there was a patch series [0]
to fix it.

    [0] https://lore.kernel.org/bpf/fb745675-e25c-4dcc-be4b-4a4411056755@xxxxxxxxx/T/#mc0fc5e0fec2e6456f72f402308fd4e397ba19d09

Let's forget my patch.

Thanks,
Qing.