Re: [PATCH] bpf: fix rq lock recursion issue

["Toke Høiland-Jørgensen" <toke@redhat.com>]

Satya Durga Srinivasu Prabhala <quic_satyap@quicinc.com> writes:

> Below recursion is observed in a rare scenario where __schedule()
> takes rq lock, at around same time task's affinity is being changed,
> bpf function for tracing sched_switch calls migrate_enabled(),
> checks for affinity change (cpus_ptr != cpus_mask) lands into
> __set_cpus_allowed_ptr which tries acquire rq lock and causing the
> recursion bug.

So this only affects tracing programs that attach to tasks that can have
their affinity changed? Or do we need to review migrate_enable() vs
preempt_enable() for networking hooks as well?

-Toke