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Date:   Sat, 9 Jul 2022 23:57:14 +0200
From:   Borislav Petkov <bp@alien8.de>
To:     "H. Peter Anvin" <hpa@zytor.com>
Cc:     "Jason A. Donenfeld" <Jason@zx2c4.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, X86 ML <x86@kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Andy Lutomirski <luto@kernel.org>
Subject: Re: [PATCH tip v8] x86/setup: Use rng seeds from setup_data
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References: <20220707000852.523788-1-Jason@zx2c4.com>
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 <ddba81dd-cc92-699c-5274-785396a17fb5@zytor.com>
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 <191d8f96-7573-bd0e-9ca4-3fc22c5c9a49@zytor.com>
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On Sat, Jul 09, 2022 at 02:45:24PM -0700, H. Peter Anvin wrote:
> On 7/9/22 02:49, Borislav Petkov wrote:
> > On Fri, Jul 08, 2022 at 06:51:16PM -0700, H. Peter Anvin wrote:
> > > #define SETUP_ENUM_MAX	SETUP_RNG_SEED
> > > #define SETUP_INDIRECT	(1<<31)
> > > #define SETUP_TYPE_MAX	(SETUP_ENUM_MAX | SETUP_INDIRECT)
> > 
> > Wait, if we get to add a new number, SETUP_ENUM_MAX and thus
> > SETUP_TYPE_MAX will change. And they're uapi too...
> 
> Talking API here rather than ABI, i.e. the semantics of those symbols.

Sure but do we worry about some userspace including those headers and
relying on the SETUP_ENUM_MAX number?

Or is userspace required to be recompiled against newer uapi headers?

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette