From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18])
	(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
	(No client certificate requested)
	by smtp.subspace.kernel.org (Postfix) with ESMTPS id 01BDE3EDE4D
	for <linux-kernel@vger.kernel.org>; Thu, 23 Jul 2026 07:59:00 +0000 (UTC)
Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18
ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;
	t=1784793542; cv=none; b=Di9zZX2/6cvxApcnXizaqE1z7Dtn5HP4USRcJIxQpfQxsHiThusjGkj7eLKRQd0glMW1ibPCZju6m9YkwW75BI7vptHyqrXVriB6DDHKkjNPZ1p0X6RGYvxfFNxV+06FQVL7ArCGRn+VMK5DWsGTvugwaqdu5eKmdI0F+fCImA8=
ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org;
	s=arc-20240116; t=1784793542; c=relaxed/simple;
	bh=iQuhBExkXwoTed5Ff9du5z+kBL7x/In2ZB9F6nL7QuA=;
	h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version:
	 Content-Type:Content-Disposition:In-Reply-To; b=DDClrJYg5Xla7hjWgJ4oer+yBZPUSFr4OLxQQbf6VnraDVJ82zFzJnluHqY8mQBTpMrCccw0mHrdJensgUq4BDH9MXkKRTmMdQYHG67aYKlohC5diB84a/hgH66tcCiYni3zZwvZ/QIWSMCvT2IR+pXTokSkxUm5uAHNzBYO6ZY=
ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Drwg8wOw; arc=none smtp.client-ip=100.103.45.18
Authentication-Results: smtp.subspace.kernel.org;
	dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Drwg8wOw"
Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8E6621F000E9;
	Thu, 23 Jul 2026 07:58:58 +0000 (UTC)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org;
	s=k20260515; t=1784793540;
	bh=W7A6iHIAXOEMl4f8tOlEiILGykzWa6dqSRG5DnecYIY=;
	h=Date:From:To:Cc:Subject:References:In-Reply-To;
	b=Drwg8wOwcZUNM+iibPgobMqG/5zugnRe9iGqj+RX8mMfJWZc/Pt6xowhjCU3yGA6I
	 Bl7hWdmeD0GSKFmf6DD3HKH5SclppHtzuihMX83a3j9FJgzLnPEXz6WsTMJwPicXqZ
	 XSh8wMe9NZ7F3mVpeIXsx4QXhI4yfAlofZbjy3f1Q5DzVDQOFx9fnwMmtsBgy2AyM3
	 S9vs52w/cO0t66fThifhtmISbCul/UQSGe6Z693cllUbDcSza+vZf7NYCQ7I28QdLf
	 dB6X14RTfrK2tugCYxFZedIGY5sCmBUFlf4JAHObKR6FXra/0bjtPl7oK4VdbwAbLH
	 IDKwB53QWZngA==
Date: Thu, 23 Jul 2026 09:58:55 +0200
From: Ingo Molnar <mingo@kernel.org>
To: Thorsten Blum <thorsten.blum@linux.dev>
Cc: Thomas Gleixner <tglx@kernel.org>, Ingo Molnar <mingo@redhat.com>,
	Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org,
	"H. Peter Anvin" <hpa@zytor.com>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86/purgatory: Return bool from verify_sha256_digest()
Message-ID: <amHJv5VB7lL3OvEZ@gmail.com>
References: <20260722162245.156368-2-thorsten.blum@linux.dev>
Precedence: bulk
X-Mailing-List: linux-kernel@vger.kernel.org
List-Id: <linux-kernel.vger.kernel.org>
List-Subscribe: <mailto:linux-kernel+subscribe@vger.kernel.org>
List-Unsubscribe: <mailto:linux-kernel+unsubscribe@vger.kernel.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20260722162245.156368-2-thorsten.blum@linux.dev>


* Thorsten Blum <thorsten.blum@linux.dev> wrote:

> -	if (memcmp(digest, purgatory_sha256_digest, sizeof(digest)))
> -		return 1;
> -
> -	return 0;
> +	return memcmp(digest, purgatory_sha256_digest, sizeof(digest)) == 0;

Could you please write this as !memcmp()? The == 0 variant is
quite a bad pattern for such a long line, as it's far easier
to miss during review than a ! unary operator...

Just like here:

> +	if (!verify_sha256_digest()) {

Thanks,

	Ingo