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Date:   Tue, 1 Mar 2022 15:19:49 +0100 (CET)
From:   Miroslav Benes <mbenes@suse.cz>
To:     Josh Poimboeuf <jpoimboe@redhat.com>
cc:     Peter Zijlstra <peterz@infradead.org>, x86@kernel.org,
        joao@overdrivepizza.com, hjl.tools@gmail.com,
        andrew.cooper3@citrix.com, linux-kernel@vger.kernel.org,
        ndesaulniers@google.com, keescook@chromium.org,
        samitolvanen@google.com, mark.rutland@arm.com,
        alyssa.milburn@intel.com
Subject: Re: [PATCH 21/29] objtool: Rename --duplicate to --lto
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On Mon, 28 Feb 2022, Josh Poimboeuf wrote:

> On Mon, Feb 28, 2022 at 09:09:34PM +0100, Peter Zijlstra wrote:
> > > So how about we just get rid of the magical --vmlinux and --lto options
> > > altogether, and make --noinstr additive, like all the other options?
> > >
> > >   A) legacy mode:
> > >      .o files: objtool check [--module]
> > >       vmlinux: N/A
> > >        module: N/A
> > >
> > >   B) CONFIG_NOINSTR_VALIDATION=y && !(CONFIG_X86_KERNEL_IBT=y || CONFIG_LTO=y):
> > >      .o files: objtool check [--module]
> > >       vmlinux: objtool check --noinstr-only
> > >        module: objtool check --module --noinstr-only
> > >
> > >   C) CONFIG_X86_KERNEL_IBT=y || CONFIG_LTO=y:
> > >      .o files: N/A
> > >       vmlinux: objtool check --noinstr
> > >        module: objtool check --module --noinstr
> > 
> > I like the --noinstr-only thing. But I think I still like a flag to
> > differentiate between TU/.o file and vmlinux/whole-module invocation.
> 
> I'm missing why that would still be useful.
> 
> > Anyway, you ok with me cleaning this up later, in a separate series?
> 
> Sure.  It's already less than ideal today anyway, with '--vmlinux' and
> '--duplicate'.

Since I always have hard times to figure out different passes and options 
of objtool, could you add the above description (its final version) to 
tools/objtool/Documentation/ as a part of the cleanup series, please?

Miroslav