Re: [RFC perf,bpf 1/5] perf, bpf: Introduce PERF_RECORD_BPF_EVENT

From: Song Liu
Date: Fri Nov 09 2018 - 13:50:43 EST




> On Nov 9, 2018, at 9:08 AM, David Ahern <dsahern@xxxxxxxxx> wrote:
>
> On 11/8/18 11:49 AM, Song Liu wrote:
>> Could you please point me to more information about the use cases you worry
>> about? I am more than happy to optimize the logic for those use cases.
>
> bpf load and unload as just another tracepoint to throw into a set of
> events that are monitored. As mentioned before auditing the loads and
> unloads is one example.

For the tracepoint approach, we need similar synchronous logic in perf to
process BPF load/unload events. If we agree this is the right direction,
I will modify the set with tracepoints.

>
> And that brings up another comment: Why are you adding a PERF_RECORD_*
> rather than a tracepoint? From what I can see the PERF_RECORD_BPF_EVENT
> definition does not include the who is loading / unloading a bpf
> program. That is important information as well.

bpf_prog_info has "__u32 created_by_uid;" in it, so it is not really needed
in current version.

Thanks,
Song