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=-5.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=no 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 4D8E2C433DF for ; Wed, 22 Jul 2020 19:11:22 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0BDFF2065D for ; Wed, 22 Jul 2020 19:11:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="ChRxce5K" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0BDFF2065D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=5h9qaKiENTwuj8k3Y49tYbyW22C4ll5XI/Rgh5dPm5Y=; b=ChRxce5KEOzP6YS4GC+rZh5a8 XXCrLMynECByujF4gAEErKyX0iho8TT9HcdVVbaE2DZB4ei9FLSp09VnqpEJLWSE3G9eAGBgM5Xck VIVY2PDkoGlFlX60oToGde64TPwgSB+BfG/hkFHacPB1do9ysUBgxEt5ypOOEOC/rLyHrPF7xzhAi Tebe2ZTfH60g5ph/0kfJ8MzG3Gm8wtkdvdj6UDjNCqBMa9T4y0cqKpGL21GBcEOr80LJHQrXYc7HH venVHcVwHJKR/M9jxAo5wrSeWiDfsJuzO1gliVK11BWGmqcx4/CfmEpSKVP8fisGHXdYoBWYQFDgC 50XNJDHVw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jyK7h-00061y-Va; Wed, 22 Jul 2020 19:09:50 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jyK7f-00060Y-8N for linux-arm-kernel@lists.infradead.org; Wed, 22 Jul 2020 19:09:48 +0000 Received: from oasis.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D81D320714; Wed, 22 Jul 2020 19:09:44 +0000 (UTC) Date: Wed, 22 Jul 2020 15:09:43 -0400 From: Steven Rostedt To: Peter Zijlstra Subject: Re: [RFC][PATCH] objtool,x86_64: Replace recordmcount with objtool Message-ID: <20200722150943.53046592@oasis.local.home> In-Reply-To: <20200722184137.GP10769@hirez.programming.kicks-ass.net> References: <20200624203200.78870-1-samitolvanen@google.com> <20200624203200.78870-5-samitolvanen@google.com> <20200624212737.GV4817@hirez.programming.kicks-ass.net> <20200624214530.GA120457@google.com> <20200625074530.GW4817@hirez.programming.kicks-ass.net> <20200625161503.GB173089@google.com> <20200625200235.GQ4781@hirez.programming.kicks-ass.net> <20200625224042.GA169781@google.com> <20200626112931.GF4817@hirez.programming.kicks-ass.net> <20200722135542.41127cc4@oasis.local.home> <20200722184137.GP10769@hirez.programming.kicks-ass.net> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200722_150947_484050_40D38EE7 X-CRM114-Status: GOOD ( 12.91 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arch@vger.kernel.org, x86@kernel.org, Kees Cook , "Paul E. McKenney" , kernel-hardening@lists.openwall.com, Greg Kroah-Hartman , Masahiro Yamada , linux-kbuild@vger.kernel.org, Nick Desaulniers , linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Josh Poimboeuf , Sami Tolvanen , linux-pci@vger.kernel.org, Will Deacon , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, 22 Jul 2020 20:41:37 +0200 Peter Zijlstra wrote: > > That said, Andi Kleen added an option to gcc called -mnop-mcount which > > will have gcc do both create the mcount section and convert the calls > > into nops. When doing so, it defines CC_USING_NOP_MCOUNT which will > > tell ftrace to expect the calls to already be converted. > > That seems like the much easier solution, then we can forget about > recordmcount / objtool entirely for this. Of course that was only for some gcc compilers, and I'm not sure if clang can do this. Or do you just see all compilers doing this in the future, and not worrying about record-mcount at all, and bothering with objtool? -- Steve _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel