Re: [PATCH v2 2/4] libtracefs: Implement tracefs_kprobe_raw()

[Steven Rostedt <rostedt@goodmis.org>]

On Wed, 30 Jun 2021 22:46:19 +0300
"Yordan Karadzhov (VMware)" <y.karadz@gmail.com> wrote:

> > +int tracefs_kprobe_raw(const char *system, const char *event,
> > +		       const char *addr, const char *format)
> > +{
> > +	char *str;
> > +	int ret;
> > +
> > +	errno = EBADMSG;
> > +	if (!addr || !format)
> > +		return -1;
> > +
> > +	if (!event)
> > +		event = addr;
> > +
> > +	if (system)
> > +		ret = asprintf(&str, "p:%s/%s %s %s\n",
> > +			       system, event, addr, format);
> > +	else
> > +		ret = asprintf(&str, "p:%s %s %s\n",
> > +			       event, addr, format);  
> 
> I wonder what will be the way to register a "return value" ("r:") 
> kprobe. Do you consider having a separate API for them?

Yes, I was thinking about having a "tracefs_kretprobe_raw()" as well.

I also thought of adding a flag in the parameter, but thought that a
separate function would be better instead.

I wanted to play with this interface before creating the retprobe one.
If you are happy with the current design, I can add that too.

-- Steve