Re: objtool warnings for kernel/trace/trace_selftest_dynamic.o

From: Andi Kleen
Date: Mon Dec 17 2018 - 16:03:38 EST

> > That seems weird.
> >
> > Are you sure it's not just because they are empty? AFAIK
> > gcc doesn't necessarily generate frame pointers for empty functions.
> I suspected that it was because they're empty, however I didn't see this
> warning for other leaf functions. The sancov plugin is presumably
> taking care of adding frame pointers where needed. Also, adding

That would surprise me.

> -mno-omit-leaf-frame-pointer didn't fix it.
> And anyway I confirmed that it was fixed by removing __noclone.

So this is with a plugin?

Maybe the plugin does something wrong?

I thought this was just a standard build.

I'm not sure the problem is well enough understood yet
to really do anything.

Do you have a simple standalone test case to show the compiler behavior?