Re: [PATCH v3] kprobes: Disable Kprobe when ftrace arming fails

From: Ingo Molnar
Date: Mon Mar 23 2015 - 09:34:52 EST



* Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:

> On Mon, 23 Mar 2015 13:39:55 +0100
> Petr Mladek <pmladek@xxxxxxx> wrote:
>
>
> > > wth is a 'universe' in this context?
> >
> > We use the term "universe" to define whether the system or task uses
> > original or patched functions. It is especially important for patches
> > that modify semantic of functions. They need more complex consistency
> > model. It defines when it is safe time for the system or task to start
> > using the new functions (switch to the new universe).
> >
> > In theory, different tasks might be in more universes if more patches are
> > being applied. In practice, we deal with only two universes. The trick is
> > that we allow to add new patch only when the whole system has switched
> > to the previous one.
> >
>
> Is this terminology documented anywhere upstream yet?

Even if it was documented (it isn't), it's pretty weird terminology -
please use clearer formulations, like 'patched function' or 'unpatched
function' or 'function with pending patch'. No need to redefine
existing words in a weird fashion just to create the appearance of
being special ...

Thanks,

Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/