Re: [PATCH] crypto: x86/curve25519 - fix cpu feature checking logic in mod_exit

From: Hangbin Liu <liuhangbin@gmail.com>
To: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Linux Crypto Mailing List <linux-crypto@vger.kernel.org>,
	Herbert Xu <herbert@gondor.apana.org.au>,
	Netdev <netdev@vger.kernel.org>, stable <stable@vger.kernel.org>
Subject: Re: [PATCH] crypto: x86/curve25519 - fix cpu feature checking logic in mod_exit
Date: Thu, 3 Jun 2021 22:06:56 +0800	[thread overview]
Message-ID: <CAPwn2JQh2ahvSwJiuMNSeoVe7czM1x=Pt5jyXQBVxpPb5PbU1A@mail.gmail.com> (raw)
In-Reply-To: <CAHmME9qXTYVLenPBfq2xpfq=DSJAsdUwSqP4Fzc=0YP6kW+QsQ@mail.gmail.com>

On Thu, Jun 3, 2021 at 6:24 PM Jason A. Donenfeld <Jason@zx2c4.com> wrote:
> >         if (IS_REACHABLE(CONFIG_CRYPTO_KPP) &&
> > -           (boot_cpu_has(X86_FEATURE_BMI2) || boot_cpu_has(X86_FEATURE_ADX)))
> > +           static_branch_likely(&curve25519_use_bmi2_adx))
> >                 crypto_unregister_kpp(&curve25519_alg);
> >  }
>
> Looks like the error is actually that the `||` should be a `&&`. But
> if you'd like to branch on that static key instead, that's fine.

Yes, the code would be shorter by checking the static key :)

Thanks
hangbin