Re: [PATCH 2/3] objtool: Ignore retpoline alternatives

From: David Woodhouse
Date: Thu Jan 11 2018 - 12:57:20 EST


On Thu, 2018-01-11 at 09:29 -0800, Linus Torvalds wrote:
>
> That, btw, is also why it's pointless to make the small numbers
> "bigger". Using "1122" as a label is actively worse than just using
> "1".

Actually in macros I don't think that's entirely true (depending on the
assembler/preprocessor behaviour, which is often surprising).

You want to use labels in macros which are not going to conflict with
what the human has typed into their .S file. If they have code along
the lines of

 jnz 1f
INVOKE_MACRO
1:

... then you surely don't want to be using the label '1' in your macro.

I'm fairly sure that's true if you're using CPP macros (which we seem
to do most of the time even in .S files). It might actually DTRT if you
are using .macro; I'm not sure.

So I will go back to numeric labels, as I said. But not '1:'. :)

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