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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id DE662C0015E for ; Fri, 28 Jul 2023 16:03:40 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 390218D0002; Fri, 28 Jul 2023 12:03:40 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 3400B8D0001; Fri, 28 Jul 2023 12:03:40 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2085F8D0002; Fri, 28 Jul 2023 12:03:40 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 111418D0001 for ; Fri, 28 Jul 2023 12:03:40 -0400 (EDT) Received: from smtpin27.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 94D99140681 for ; Fri, 28 Jul 2023 16:03:39 +0000 (UTC) X-FDA: 81061490958.27.E76E186 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf18.hostedemail.com (Postfix) with ESMTP id 4B8821C0154 for ; Fri, 28 Jul 2023 16:02:56 +0000 (UTC) Authentication-Results: imf18.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=jvO9hazS; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf18.hostedemail.com: domain of jpoimboe@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=jpoimboe@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1690560177; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=159Dty1hYL8oTIor9q/do4QgsrGD5rOacyW4EAPbdRA=; b=IKc3k8pVc8S80JXz7JEbGr/qTJsgSY1k6lw/dK90+2oPzc19ttbOUULx3ESSKqhhIGEnZC USNW2g/EHKF6NZmfYoybXgPLMJATW2AqIPPuexjzIX0DnBuZrf5EEjoYHKHdZaVgy4Ysmg uSDdcfgZjeXoUVbWmSYEwpF3/2+Z3ME= ARC-Authentication-Results: i=1; imf18.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=jvO9hazS; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf18.hostedemail.com: domain of jpoimboe@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=jpoimboe@kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1690560177; a=rsa-sha256; cv=none; b=cpNnaAxKwp7IFqrVSkm6f7mJ8JQnsYGL8nelv+p//QNhnpu0PlOG/uXf6ZSVB2xQ17f5rA Ph/wfdchgzY3ZA4lRH3EwSSHzJMfbgLo0RTdivzJtqq6MleBdzDKrv7KcF55IDoA13uqe7 me9Rsbqi4NuPnxWtPwiGCXqV8FMpjnQ= 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 454F162196; 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> X-Rspam-User: X-Stat-Signature: 6uimb8udsky447tgihwxrmej9ebbr8hq X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 4B8821C0154 X-HE-Tag: 1690560176-621064 X-HE-Meta: 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 sreN9O9k aaCvLhVk+sIgqrWQWF2XgjlxwXu1P3LTfeGUEriLqSm1nX+MvAtmzQ7VoAJrCiOmuF4fEwdZ7Fpw2UVWx/vMlE5VvW4szMFlKvHLOd88AsFfwB2US5FQR+2deNB/F3H1FHksWh1GACKEmdAiJ1oaKuWkdwuEf2qdoLJ3vy1Tjta4FQFsIldy5cbzNd5PAVA7HBHqSqcpW0srV5ProjVpzw7Tj/z+w2KxxqLrHwJ8p1sQmMjkH2Hx5dHD+Wby0+kYb+xhW1NaP5hsKFQvas2JzQFunvHUNz9yXtPjw2HI2taCKnWMM92lOf4o4MOvbMI+B4gJjih1BEfeSn0xk9ekdbVVQtlN7AIXfwehChqDnkF1smo8PpF4wcIsZfz+B0VD24RtNzcA/yvUhJwuv7WGXqz4iIQ== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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