linux-kernel - Re: [tip: objtool/core] objtool/klp: Add --debug option to show cloning decisions

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Message-ID: <20251031202526.GB2486902@ax162>
Date: Fri, 31 Oct 2025 16:25:26 -0400
From: Nathan Chancellor <nathan@...nel.org>
To: Josh Poimboeuf <jpoimboe@...nel.org>
Cc: Borislav Petkov <bp@...en8.de>, linux-kernel@...r.kernel.org,
	linux-tip-commits@...r.kernel.org, Petr Mladek <pmladek@...e.com>,
	Joe Lawrence <joe.lawrence@...hat.com>, x86@...nel.org
Subject: Re: [tip: objtool/core] objtool/klp: Add --debug option to show
 cloning decisions

On Fri, Oct 31, 2025 at 09:11:44AM -0700, Josh Poimboeuf wrote:
> On Fri, Oct 31, 2025 at 03:21:00PM +0100, Borislav Petkov wrote:
> > On Fri, Oct 31, 2025 at 10:09:44AM -0400, Nathan Chancellor wrote:
> > > Yeah, that looks good to me and matches the workaround that Peter did in
> > > include/linux/compiler-clang.h. If cleanup is going to be used more in
> > > objtool, it might be worth taking that approach there too like:
> > > 
> > >   #ifdef __clang__
> > >   #define __cleanup(func) __maybe_unused __attribute__((__cleanup__(func)))
> > >   #else
> > >   #define __cleanup(func) __attribute__((__cleanup__(func)))
> > >   #endif
> > 
> > LGTM.
> > 
> > I'll wait for the objool-er folks to lemme know what they want before
> > I productize it.
> > 
> > Thx Nathan!
> 
> How about __maybe_unused unconditionally without the #ifdef damage?

Yeah I had only suggested that to mirror the kernel but fundamentally,
GCC already treats it that way so I don't think there is any harm in
just doing this unconditionally.

Nathan