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Date:   Wed, 24 Aug 2022 17:38:26 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     Borislav Petkov <bp@alien8.de>
Cc:     X86 ML <x86@kernel.org>, Michael Matz <matz@suse.de>,
        linux-toolchains@vger.kernel.org,
        LKML <linux-kernel@vger.kernel.org>,
        Josh Poimboeuf <jpoimboe@redhat.com>
Subject: Re: [PATCH] x86/sev: Mark snp_abort() noreturn
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References: <20220824152420.20547-1-bp@alien8.de>
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On Wed, Aug 24, 2022 at 05:24:20PM +0200, Borislav Petkov wrote:
> From: Borislav Petkov <bp@suse.de>
> 
> Mark both the function prototype and definition as noreturn in order to
> prevent the compiler from doing transformations which confuse objtool
> like so:
> 
>   vmlinux.o: warning: objtool: sme_enable+0x71: unreachable instruction
> 
> This triggers with gcc-12.

You'll probably also have to add it to the
objtool/check.c:global_noreturn[] list, for the case where objtool fails
to recognise it as noreturn.