Re: [patch part-II V2 01/13] context_tracking: Ensure that the critical path cannot be instrumented

Thomas Gleixner
2020-03-09T14:41:27Z

Frederic Weisbecker <frederic@kernel.org> writes:
> On Sun, Mar 08, 2020 at 11:24:00PM +0100, Thomas Gleixner wrote:
>> context tracking lacks a few protection mechanisms against instrumentation:
>>
>> - While the core functions are marked NOKPROBE they lack protection
>> against function tracing which is required as the function entry/exit
>> points can be utilized by BPF.
>
> Just to clarify things up: IIUC, BPF scripts can be called from the
> function graph tracer hooks, and that BPF code uses RCU, right?

At least at the moment.