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

On Thu 2016-03-10 13:25:08, Petr Mladek wrote:

On Wed 2016-03-09 18:30:17, Torsten Duwe wrote:

quoted

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.

BTW: How is this solved in kretprobes? Or is it easier there?

Best Regards,
Petr