From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 48057C001DE for ; Fri, 28 Jul 2023 16:03:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232261AbjG1QDb (ORCPT ); Fri, 28 Jul 2023 12:03:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49156 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236783AbjG1QC5 (ORCPT ); Fri, 28 Jul 2023 12:02:57 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AF32F2109; Fri, 28 Jul 2023 09:02:56 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 4BC6162199; Fri, 28 Jul 2023 16:02:56 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CE414C433C7; Fri, 28 Jul 2023 16:02:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1690560175; bh=5+J+83TIFs9lZ6wTmxsZgXtKL3q38n2yCo3y8qTZ7N8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=jvO9hazSNAGUk8tEio79eCKsYssfSy0geDTTQuH3rVlrLBw9BRzr2W8FKEp1g6GE7 xyyV6wG+/gEhhnojSaYN0xZGYJ7TNz41xrH/5namT+MasnVI6q+netdOigN1p2F8Xs UiajqzXuIHzaW/VQWNXZVjdeHLaWRINZKoWv20D+yd69SZLrcXxn7/VhnVnC6azcV0 uakFy04j7DDn+wgdzr/6qhCxnzBm56Z8AETjHGHt12OebNyGVCIjmiqGlIPoZKq+mE Ysaqt3HMjsRuQ585YU8rA70URXv7n98gIUhFEAPZW6v4toNlPHr90hL3YQ7Jn0OGn5 bbUw1+uTfxHCg== Date: Fri, 28 Jul 2023 11:02:47 -0500 From: Josh Poimboeuf To: Valentin Schneider Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-doc@vger.kernel.org, kvm@vger.kernel.org, linux-mm@kvack.org, bpf@vger.kernel.org, x86@kernel.org, rcu@vger.kernel.org, linux-kselftest@vger.kernel.org, Josh Poimboeuf , Steven Rostedt , Masami Hiramatsu , Jonathan Corbet , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Paolo Bonzini , Wanpeng Li , Vitaly Kuznetsov , Andy Lutomirski , Peter Zijlstra , Frederic Weisbecker , "Paul E. McKenney" , Neeraj Upadhyay , Joel Fernandes , Josh Triplett , Boqun Feng , Mathieu Desnoyers , Lai Jiangshan , Zqiang , Andrew Morton , Uladzislau Rezki , Christoph Hellwig , Lorenzo Stoakes , Jason Baron , Kees Cook , Sami Tolvanen , Ard Biesheuvel , Nicholas Piggin , Juerg Haefliger , Nicolas Saenz Julienne , "Kirill A. Shutemov" , Nadav Amit , Dan Carpenter , Chuang Wang , Yang Jihong , Petr Mladek , "Jason A. Donenfeld" , Song Liu , Julian Pidancet , Tom Lendacky , Dionna Glaze , Thomas =?utf-8?Q?Wei=C3=9Fschuh?= , Juri Lelli , Daniel Bristot de Oliveira , Marcelo Tosatti , Yair Podemsky Subject: Re: [RFC PATCH v2 12/20] objtool: Warn about non __ro_after_init static key usage in .noinstr Message-ID: <20230728160247.multb2csnpa22fgx@treble> References: <20230720163056.2564824-1-vschneid@redhat.com> <20230720163056.2564824-13-vschneid@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20230720163056.2564824-13-vschneid@redhat.com> Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Thu, Jul 20, 2023 at 05:30:48PM +0100, Valentin Schneider wrote: > Later commits will depend on having no runtime-mutable text in early entry > code. (ab)use the .noinstr section as a marker of early entry code and warn > about static keys used in it that can be flipped at runtime. Similar to my comment on patch 13, this could also use a short justification for adding the feature, i.e. why runtime-mutable text isn't going to be allowed in .noinstr. Also, please add a short description of the warning (and why it exists) to tools/objtool/Documentation/objtool.txt. -- Josh