Re: [tip: objtool/urgent] objtool: Consolidate annotation macros
From: Ingo Molnar
Date: Wed Dec 03 2025 - 13:48:10 EST
* Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> On Wed, 3 Dec 2025 at 08:57, Ingo Molnar <mingo@xxxxxxxxxx> wrote:
> >
> > Find below a diff of the arch/x86/kernel/process.s output
> > of your tree versus current tip:objtool/urgent.
>
> Yeah, just a single example would have been sufficient, ie a simple
>
> Turn
>
> 911:
> .pushsection .discard.annotate_insn,"M", @progbits, 8
> .long 911b - .
> .long 1
> .popsection
> jmp __x86_return_thunk
>
> Into
>
> 911: .pushsection ".discard.annotate_insn", "M", @progbits, 8;
> .long 911b - .; .long 1; .popsection
> jmp __x86_return_thunk
I ended up rebasing the commit after all and added your example,
because seeing it written out triggered further enhancements:
> and btw, the quotes around the section name are not necessary afaik.
>
> Also, I have to say that being mergeable is a bit annoying here:
> without that, we could drop the "@progbits, 8" parts too which is just
> strange noise. Is the mergeability really a win? Because I'd assume
> that it's never *actually* merged, since the expression "911b-." ends
> up being a unique value?
>
> What am I missing? It *feels* like this should just all be
>
> 911: .pushsection .discard.annotate_insn ; .long 911b - .;
> .long 1; .popsection
> jmp __x86_return_thunk
>
> instead. But it's entirely possible I'm not seeing the reason here...
Thanks,
Ingo