[PATCH v3] kernel/module_64.c: Add REL24 relocation support of livepatch symbols

[Josh Poimboeuf]

On Fri, Nov 10, 2017 at 01:06:25PM +1100, Balbir Singh wrote:
> On Fri, Nov 10, 2017 at 2:19 AM, Josh Poimboeuf <jpoimboe at redhat.com> wrote:
> > FWIW, I think it won't matter anyway.  I'm currently pursuing the option
> > of inserting nops after local calls, because it has less runtime
> > complexity than using a stub.
> >
> > I think I've figured out a way to do it with a GCC plugin, but if that
> > doesn't work I'll try the asm listing sed approach suggested by Michael.
> >
> 
> A plugin that runs for the new kernel with the patch? Just for
> specific files involved in the patch?

The plugin will affect the code generation of all functions in the patch
module.  So all calls in all replacement functions will have the nops.

Here's a prototype (not yet fully tested):

  https://github.com/jpoimboe/kpatch/blob/TODO-ppc-fix/kpatch-build/gcc-plugins/ppc64le-plugin.c

-- 
Josh