Re: [PATCH 2/4] tracing/user_events: Introduce multi-format events

From: Steven Rostedt
Date: Fri Jan 26 2024 - 15:04:52 EST


On Fri, 26 Jan 2024 11:10:07 -0800
Beau Belgrave <beaub@xxxxxxxxxxxxxxxxxxx> wrote:

> > OK, so the each different event has suffixed name. But this will
> > introduce non C-variable name.
> >
> > Steve, do you think your library can handle these symbols? It will
> > be something like "event:[1]" as the event name.
> > Personally I like "event.1" style. (of course we need to ensure the
> > user given event name is NOT including such suffix numbers)
> >
>
> Just to clarify around events including a suffix number. This is why
> multi-events use "user_events_multi" system name and the single-events
> using just "user_events".
>
> Even if a user program did include a suffix, the suffix would still get
> appended. An example is "test" vs "test:[0]" using multi-format would
> result in two tracepoints ("test:[0]" and "test:[0]:[1]" respectively
> (assuming these are the first multi-events on the system).
>
> I'm with you, we really don't want any spoofing or squatting possible.
> By using different system names and always appending the suffix I
> believe covers this.
>
> Looking forward to hearing Steven's thoughts on this as well.

I'm leaning towards Masami's suggestion to use dots, as that won't conflict
with special characters from bash, as '[' and ']' do.

-- Steve