Re: [PATCH v3 5/6] x86/ftrace: Use text_poke()

From: Jiri Kosina
Date: Tue Jan 28 2020 - 19:47:03 EST


On Tue, 28 Jan 2020, Josh Poimboeuf wrote:

> > Anyway, I think that we might make your life easier with using the
> > proposed -Wsuggest-attribute=noreturn.
>
> Maybe. Though if I understand correctly, this doesn't help for any of
> the new warnings because they're for static functions, and this only
> warns about global functions.

Could you please provide a pointer where those have been
reported/analyzed?

For the cases I've seen so far, it has always been gcc deciding under
certain circumstances not to propagate __attribute__((__noreturn__)) from
callee to caller even in the cases when caller unconditionally called
callee.

AFAIU, the behavior is (and always will) be dependent on the state of gcc
optimizations, and therefore I don't see any other way than adding
__noreturn anotation transitively everywhere in order to silence objtool.

So those cases have to be fixed anyway.

What are the other cases please? Either I have completely missed those, or
they haven't been mentioned in this thread.

Thanks,

--
Jiri Kosina
SUSE Labs