Re: [PATCH 2/2] ppc64le live patch: get rid of mini stack frame

From: Petr Mladek
Date: Thu Mar 10 2016 - 07:25:26 EST


On Wed 2016-03-09 18:30:17, Torsten Duwe wrote:
> After the mini stack frame is no longer required for TOC storage, it can
> be eliminated iff the functionality of klp_return_helper, which required
> a stack frame for the extra return address previously, is carried out
> by the replacement function now. This requires _every_ live patch replacement
> function to execute the following (or similar) sequence of machine instructions
> just before every return to the original caller:

I have thought about it and it is a nono from my point of view.
It is too error prone, especially that there are functions that
call return on several locations.

Best Regards,
Petr