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 X-Spam-Level: X-Spam-Status: No, score=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4A80EC28D14 for ; Tue, 2 Mar 2021 09:49:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0E7EE64E56 for ; Tue, 2 Mar 2021 09:49:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1382620AbhCBJkT (ORCPT ); Tue, 2 Mar 2021 04:40:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55980 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240744AbhCBJUk (ORCPT ); Tue, 2 Mar 2021 04:20:40 -0500 Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1B88DC061756 for ; Tue, 2 Mar 2021 01:20:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=n+hLSIAYyK/Uw/x0vonbD56+QIeIjoNQnAuL5VLwhr8=; b=uaRamYrLoO9Guter62fKCGRifG 1skDMBpJeYua+A7KjKaxANLB6rG+AET3Xi/wN8GomdciRG02iVDPsVmRuH3eJVo9bGS5Z6eXqP7OP 8UBVAkDhHDeUwr1V2nIqZoUUtxZjqf8xIneX591HJsowXDlYxZTSfe5Fss1zmE1g03O8s0SiP5NM8 dSEg0NBEvdiMT/y8FF98Vz8N6Eg0SPthoPxPKBywJkPFLaVS1zavqqbCwaCkS5PdMQX2r5puzFKEg LZdHs3L09LwfHxjVI/EtlUJelp1pE9wzkqHOvmAs5coFsYBouZIOLyWB/nCfdsbbESIsqOh0RG3WU X47R9Vrg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1lH1C1-0001Kx-Uw; Tue, 02 Mar 2021 09:19:50 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id D6DFF30018A; Tue, 2 Mar 2021 10:19:47 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id C033E234E17C3; Tue, 2 Mar 2021 10:19:47 +0100 (CET) Date: Tue, 2 Mar 2021 10:19:47 +0100 From: Peter Zijlstra To: Steven Rostedt Cc: Sami Tolvanen , kernel test robot , Kees Cook , LKML , lkp@lists.01.org, kernel test robot Subject: Re: [x86, build] 6dafca9780: WARNING:at_arch/x86/kernel/ftrace.c:#ftrace_verify_code Message-ID: References: <20210301074027.GD12822@xsang-OptiPlex-9020> <20210301184524.7aa05ac1@gandalf.local.home> <20210301201526.65ce7f1c@oasis.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210301201526.65ce7f1c@oasis.local.home> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 01, 2021 at 08:15:26PM -0500, Steven Rostedt wrote: > diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c > index 7edbd5ee5ed4..e8afc765e00a 100644 > --- a/arch/x86/kernel/ftrace.c > +++ b/arch/x86/kernel/ftrace.c > @@ -36,6 +36,7 @@ > #ifdef CONFIG_DYNAMIC_FTRACE > > static int ftrace_poke_late = 0; > +static const char p6_nop[] = { P6_NOP5 }; I don't understand this approach, why not simply rewrite all the nops at boot and not worry about it when modifying the code later?