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=-3.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 92A0EC04AB1 for ; Fri, 10 May 2019 02:30:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 673562183F for ; Fri, 10 May 2019 02:30:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726946AbfEJCaz (ORCPT ); Thu, 9 May 2019 22:30:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:52076 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726839AbfEJCay (ORCPT ); Thu, 9 May 2019 22:30:54 -0400 Received: from gandalf.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 F40EB217F5; Fri, 10 May 2019 02:30:52 +0000 (UTC) Date: Thu, 9 May 2019 22:30:51 -0400 From: Steven Rostedt To: Josh Poimboeuf Cc: LKML , Linus Torvalds , Peter Zijlstra , Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" , Jiri Kosina , Miroslav Benes , Petr Mladek , Joe Lawrence , live-patching@vger.kernel.org, x86@kernel.org, Borislav Petkov Subject: Re: [RFC][PATCH] ftrace/x86: Remove mcount support Message-ID: <20190509223051.710a8f4e@gandalf.local.home> In-Reply-To: <20190509201430.2eabpqjv2kw7dwnv@treble> References: <20190509154902.34ea14f8@gandalf.local.home> <20190509201430.2eabpqjv2kw7dwnv@treble> X-Mailer: Claws Mail 3.17.3 (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 Thu, 9 May 2019 15:14:30 -0500 Josh Poimboeuf wrote: > > Signed-off-by: Steven Rostedt (VMware) > > --- > > arch/x86/include/asm/ftrace.h | 8 +++---- > > arch/x86/include/asm/livepatch.h | 3 --- > > arch/x86/kernel/ftrace_32.S | 36 +++++--------------------------- > > arch/x86/kernel/ftrace_64.S | 28 +------------------------ > > 4 files changed, 9 insertions(+), 66 deletions(-) > > I was wondering why you didn't do s/mcount/fentry/ everywhere, but I > guess it's because mcount is still used by other arches, so it still has > a generic meaning tree-wide, right? Yes, fentry works nicely when you have a single instruction that pushes the return address on the stack and then jumps to another location. It's much trickier to implement with link registers. There's a few different implementations for other archs, but mcount happens to be the one supported by most. > > Anyway it's nice to finally see this cruft disappear. > > Acked-by: Josh Poimboeuf Thanks! -- Steve