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

[Michael Ellerman]

Josh Poimboeuf <jpoimboe at redhat.com> writes:

> 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

Nice.

cheers