Re: [PATCH v2 10/15] tools/rv: Add BPF monitors

[John Ogness]

On 2026-10-19, Gabriele Monaco <gmonaco@xxxxxxxxxx> wrote:
>> @gmonaco: There should be clean glob-friendly RV bpf_trace_printk
>> strings so that filters can be easily and reliably set up.
>
> If I leave the LTL header unmodified, you'd get something like:
>
>   rv: sleep: <comm>[<pid>] violation detected
>
> It should be glob-friendly enough, but I'll try it out.

If transition-events will also be included (should be optional for
performance reasons), a better format may be:

  rv: violation: sleep: <comm>[<pid>] <violation text>

  rv: event: sleep: <comm>[<pid>] <event text>

> I wonder if string matching brings additional overhead (trace_printk
> itself does, if I recall correctly), but that's probably rather minor.

For production environments, I expect that trace_printk's are only
occurring for violations, in which case the cost of a string compare
will probably be irrelevant.

Are these trace_printk's available without getting the scary kernel
warning when kernel code uses trace_printk()? We do want RV support to
be enabled in production kernels.

John