Re: [PATCH 3/5] v2 seccomp_filters: Enable ftrace-based system call filtering

* Steven Rostedt [off-list ref] wrote:

On Mon, 2011-05-16 at 18:52 +0200, Ingo Molnar wrote:

quoted

* Steven Rostedt [off-list ref] wrote:

quoted

I'm a bit nervous about the 'active' role of (trace_)events, because of the 
way multiple callbacks can be registered. How would:

	err = event_x();
	if (err == -EACCESS) {

be handled? [...]

The default behavior would be something obvious: to trigger all callbacks and 
use the first non-zero return value.

But how do we know which callback that was from? There's no ordering of what 
callbacks are called first.

We do not have to know that - nor do the calling sites care in general. Do you 
have some specific usecase in mind where the identity of the callback that 
generates a match matters?

Thanks,

	Ingo