Re: [RFC PATCH 2/2] livepatch: Clear relocation targets on a module removal

From: Jiri Kosina
Date: Thu Sep 05 2019 - 07:19:26 EST


On Thu, 5 Sep 2019, Petr Mladek wrote:

> > I don't have a number, but it's very common to patch a function which
> > uses jump labels or alternatives.
>
> Really? My impression is that both alternatives and jump_labels
> are used in hot paths. I would expect them mostly in core code
> that is always loaded.
>
> Alternatives are often used in assembly that we are not able
> to livepatch anyway.
>
> Or are they spread widely via some macros or inlined functions?

All the indirect jumps are turned into alternatives when retpolines are in
place.

--
Jiri Kosina
SUSE Labs