From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.alien8.de (mail.alien8.de [65.109.113.108]) (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 3DFD42D4816 for ; Wed, 20 Aug 2025 10:08:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=65.109.113.108 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755684522; cv=none; b=msO2tLap9o5+ulPEsSR+hSRPllwwN3zEs/p8seiXRAQDlBCF4feiDJoDswWQRTvmTW08hheeq4Fk5nr2VvH2jdXgrInrHCQ8JwH5rGXkUIBhMtARQoc9LJFDODwXCPI7++PtQWWCF495/8gYoeshNg+Y6obrOF5ZWVW6UzDFWME= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755684522; c=relaxed/simple; bh=mwTP7TXo7bhpX8PXSFHrgLv6FCeN0wiH8F/6+WtedzM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ovNU4AlQ0AtAQ1haNjALrlPRUZbQp1V3DQx7hHy+f6mD+e1IBRQIJIS2Q7cm+ZholJRU+wWnSyCFyEeBZHzB201jB0rcMwrEIBsv3cQmo/lO+iY/XifWZsUBYStTZ6OOknG3ZVn8L7fiHzLP5r8jIfg2Mx6oyvEt5LM6EkOT7gs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=alien8.de; spf=pass smtp.mailfrom=alien8.de; dkim=pass (4096-bit key) header.d=alien8.de header.i=@alien8.de header.b=ZaTG3BvN; arc=none smtp.client-ip=65.109.113.108 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=alien8.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=alien8.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (4096-bit key) header.d=alien8.de header.i=@alien8.de header.b="ZaTG3BvN" Received: from localhost (localhost.localdomain [127.0.0.1]) by mail.alien8.de (SuperMail on ZX Spectrum 128k) with ESMTP id 0097A40E0286; Wed, 20 Aug 2025 10:08:38 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at mail.alien8.de Authentication-Results: mail.alien8.de (amavisd-new); dkim=pass (4096-bit key) header.d=alien8.de Received: from mail.alien8.de ([127.0.0.1]) by localhost (mail.alien8.de [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id PUkKV75C_p3f; Wed, 20 Aug 2025 10:08:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=alien8; t=1755684515; bh=npNf42C7Vj4TBsjN4PzadidMVWGU5giR5QJBdLC8SCM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ZaTG3BvNQN/31hOAOfJCdItO2aq9kizZxFa0HBpj8cUkXrhyqK8u+5kLatn2LuVBE F+aWjokpoRK3ECr7GI2Woo2UfXkuZp/JqeYULK7C1uzlSwlFJHqkXf55Lbo+tXecGD EkVHARrXTAMlY40HjE+V7ACgzS9tZFlZFQyk9mfuP1QOG0Sy1EETeecElBaZD1uWtD ociqsNu2h2T4XomuQrqFX8JI7hU0derOIrdq53eTFSmTLprIV895wgOobSS2u/dvc4 iBMJwvuvOJEgltR1b5aOVn7tQBEMFdwww3PdTsWlpO88szTd423BSzCzBy1B6NXe69 5zrCI6hpP6vGCz6PV7pYVBlkG+o2aH+gMEKjMLOVZPMcVF35bVzv4B6i+dM2CRty60 0dsUzlN9vwgkUPHBH+iv92wH6w+N8dsMytRA2SFi1UTLnW5QfRF/uQK+mqa2X6lQ1h kovB8YXcWdvQiJ7lD18dhemAFEjGvclKl+i0OIlsI/NirAGuPY0F8LLZwz4o9zzip2 pdyYd3X7LkOtvZlMHS46IJXqO1KH+62OkXTL6bl6Z1Vs26tt14qN/QtA171zJWGNfO 5U4ZcTIA5zKVMax6QbLMY4Sae0+sEM2nXdUJpLMkcA+nXQZ3o241glB7WdK7ZLLVqu r9O0WOEP52oXEBJ1W4Z/Ljes= Received: from zn.tnic (pd953092e.dip0.t-ipconnect.de [217.83.9.46]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature ECDSA (P-256) server-digest SHA256) (No client certificate requested) by mail.alien8.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 8558840E0232; Wed, 20 Aug 2025 10:08:17 +0000 (UTC) Date: Wed, 20 Aug 2025 12:08:12 +0200 From: Borislav Petkov To: Marcos Del Sol Vives Cc: "Ahmed S. Darwish" , linux-kernel@vger.kernel.org, Thomas Gleixner , Ingo Molnar , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Brian Gerst , Uros Bizjak , Ard Biesheuvel , David Kaplan , Kees Cook , "Peter Zijlstra (Intel)" , Andrew Cooper , Oleg Nesterov , "Xin Li (Intel)" , Sabyrzhan Tasbolatov Subject: Re: [PATCH] x86: add hintable NOPs emulation Message-ID: <20250820100812.GFaKWejCFMSAS6QIfS@fat_crate.local> References: <20250820013452.495481-1-marcos@orca.pet> <2cd7b099-095d-405c-a7d9-b0f1f72184c2@orca.pet> <20250820094347.GDaKWY02hR3AAoT7la@fat_crate.local> <20250820095556.GEaKWbrMh24T7jTfBg@fat_crate.local> <3db7d599-c2a7-4bec-94b1-4872649dde8d@orca.pet> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <3db7d599-c2a7-4bec-94b1-4872649dde8d@orca.pet> On Wed, Aug 20, 2025 at 12:01:30PM +0200, Marcos Del Sol Vives wrote: > Please define "once". Once per what? Per boot? Per executable? Per process? pr_err_once(). Per boot. > Once per boot would mean they'd need to reboot to see if any other executables > are affected. We'll cross that bridge when we get to it. > (again, like IOPL emulation which was already deemed okay a couple years ago > and merged into the kernel) When it is flooding dmesg for no good reason, I wouldn't mind toning that down too. IOW, I wanna see a real, actual use case which justifies flooding dmesg. If you don't have one, then we'll do it only when it is really warranted. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette