Re: [RFC PATCH] ftrace: Skip __fentry__ location of overridden weak functions

On Fri, 7 Jun 2024 17:02:28 +0200
Peter Zijlstra [off-list ref] wrote:

quoted

There may be following resolutions:  

Oh gawd, sodding weak functions again.

I would suggest changing scipts/kallsyms.c to emit readily identifiable
symbol names for all the weak junk, eg:

  __weak_junk_NNNNN

That instantly fixes the immediate problem and Steve's horrid hack can
go away.

Right. And when I wrote that hack, I specifically said this should be
fixed in kallsyms, and preferably at build time, as that's when the
weak functions should all be resolved.

-- Steve

Additionally, I would add a boot up pass that would INT3 fill all such
functions and remove/invalidate all
static_call/static_jump/fentry/alternative entry that is inside of them.