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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 08437C46464 for ; Tue, 14 Aug 2018 02:03:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B08082174B for ; Tue, 14 Aug 2018 02:03:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B08082174B 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-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729383AbeHNEsM (ORCPT ); Tue, 14 Aug 2018 00:48:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:42776 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725829AbeHNEsM (ORCPT ); Tue, 14 Aug 2018 00:48:12 -0400 Received: from vmware.local.home (cpe-66-24-56-78.stny.res.rr.com [66.24.56.78]) (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 C3A5A21745; Tue, 14 Aug 2018 02:03:16 +0000 (UTC) Date: Mon, 13 Aug 2018 22:03:15 -0400 From: Steven Rostedt To: Julien Thierry Cc: Torsten Duwe , Will Deacon , Catalin Marinas , Ingo Molnar , Ard Biesheuvel , Arnd Bergmann , AKASHI Takahiro , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, live-patching@vger.kernel.org Subject: Re: [PATCH 1/3] arm64: implement ftrace with regs Message-ID: <20180813220315.6e8dfc9c@vmware.local.home> In-Reply-To: <2b5c1092-2cc0-00ec-ba3d-341dc61452b4@arm.com> References: <20180810160043.9E45568C76@newverein.lst.de> <20180810160223.D360D68C76@newverein.lst.de> <2b5c1092-2cc0-00ec-ba3d-341dc61452b4@arm.com> X-Mailer: Claws Mail 3.15.1 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 13 Aug 2018 11:54:06 +0100 Julien Thierry wrote: > > --- a/arch/arm64/Makefile > > +++ b/arch/arm64/Makefile > > @@ -78,6 +78,15 @@ ifeq ($(CONFIG_ARM64_MODULE_PLTS),y) > > KBUILD_LDFLAGS_MODULE += -T $(srctree)/arch/arm64/kernel/module.lds > > endif > > > > +ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS > > + CC_FLAGS_FTRACE := -fpatchable-function-entry=2 > > + KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY > > + ifeq ($(call cc-option,-fpatchable-function-entry=2),) > > + $(warning Cannot use CONFIG_DYNAMIC_FTRACE_WITH_REGS: \ > > + -fpatchable-function-entry not supported by compiler) > > Shouldn't this be an error? The option -fpatchable-function-entry has > been added to the CC_FLAGS_FTRACE, so any call to the compiler is gonna > break anyway. Or am I missing something? I'm guessing this adds a more informative message on that error. One will know why -fpatchable-function-entry was added to the CFLAGS. I'm for more informative error messages being a victim of poor error messages causing me to dig deep into the guts of the build infrastructure to figure out simple issues. -- Steve