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=-4.0 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 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 EA0E5C433EB for ; Wed, 22 Jul 2020 23:57:47 +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 B722C20727 for ; Wed, 22 Jul 2020 23:57:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="L3/j0tCy" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B722C20727 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.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:In-Reply-To:MIME-Version:References: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=DA1/me5Sw8lKazIYLZb86JA0mqp5ii5Q8rS8c4dlqF4=; b=L3/j0tCy+7vBOKo7anoI2UDOm qa1HHCgKGmtWkk7wti44CCyuN/XygTr3sk3+ISY04rLmcqlAkDXQG3WQYHLkQm6zxRog6XF/jL4mm rW4dk3P8zsezT7K0xFOrJ3y+xlEFPERqNdQ8KahMM8hVhKD9YD0LB9eGHMscyE+xDsYSU/TXhPBP/ 2/YAWwWl6rqtt9OYCcZhlsDZPfJHUHdUF+3UQjvHWMneKKhDGnfl951+4PMBRTJsj6faxJ5+Eh4ou qPPsX+UJRTZvwlP2IeMHNyWrDpUVIMevzlZp5W/Bo1R0F1d5JWZuHRnSLtlWCmZFDHqBfXue0iXbx I8vvjxRQA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jyOb7-0007r4-Ju; Wed, 22 Jul 2020 23:56:29 +0000 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 1jyOb0-0007ot-PD; Wed, 22 Jul 2020 23:56:23 +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 A4C193060EF; Thu, 23 Jul 2020 01:56:20 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 8E31729BEC9E1; Thu, 23 Jul 2020 01:56:20 +0200 (CEST) Date: Thu, 23 Jul 2020 01:56:20 +0200 From: Peter Zijlstra To: Steven Rostedt Subject: Re: [RFC][PATCH] objtool,x86_64: Replace recordmcount with objtool Message-ID: <20200722235620.GR10769@hirez.programming.kicks-ass.net> References: <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> <20200722150943.53046592@oasis.local.home> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200722150943.53046592@oasis.local.home> 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, Jul 22, 2020 at 03:09:43PM -0400, Steven Rostedt wrote: > 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? I got the GCC version wrong :/ Both -mnop-mcount and -mrecord-mcount landed in GCC-5, where our minimum GCC is now at 4.9. Anyway, what do you prefer, I suppose I can make objtool whatever we need, that patch is trivial. Simply recording the sites and not rewriting them should be simple enough. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel