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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 05C29C34047 for ; Wed, 19 Feb 2020 15:36:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D7ABD24671 for ; Wed, 19 Feb 2020 15:36:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726794AbgBSPgS (ORCPT ); Wed, 19 Feb 2020 10:36:18 -0500 Received: from mail.kernel.org ([198.145.29.99]:42162 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726645AbgBSPgS (ORCPT ); Wed, 19 Feb 2020 10:36:18 -0500 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 403CE2465D; Wed, 19 Feb 2020 15:36:16 +0000 (UTC) Date: Wed, 19 Feb 2020 10:36:14 -0500 From: Steven Rostedt To: Peter Zijlstra Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, mingo@kernel.org, joel@joelfernandes.org, gregkh@linuxfoundation.org, gustavo@embeddedor.com, tglx@linutronix.de, paulmck@kernel.org, josh@joshtriplett.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, luto@kernel.org, tony.luck@intel.com, frederic@kernel.org, dan.carpenter@oracle.com, mhiramat@kernel.org Subject: Re: [PATCH v3 04/22] x86/doublefault: Make memmove() notrace/NOKPROBE Message-ID: <20200219103614.2299ff61@gandalf.local.home> In-Reply-To: <20200219150744.604459293@infradead.org> References: <20200219144724.800607165@infradead.org> <20200219150744.604459293@infradead.org> 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 Wed, 19 Feb 2020 15:47:28 +0100 Peter Zijlstra wrote: > --- a/arch/x86/lib/memcpy_32.c > +++ b/arch/x86/lib/memcpy_32.c > @@ -21,7 +21,7 @@ __visible void *memset(void *s, int c, s > } > EXPORT_SYMBOL(memset); > > -__visible void *memmove(void *dest, const void *src, size_t n) > +__visible notrace void *memmove(void *dest, const void *src, size_t n) > { > int d0,d1,d2,d3,d4,d5; > char *ret = dest; > @@ -207,3 +207,8 @@ __visible void *memmove(void *dest, cons > > } > EXPORT_SYMBOL(memmove); Hmm, for things like this, which is adding notrace because of a single instance of it (although it is fine to trace in any other instance), it would be nice to have a gcc helper that could call "memmove+5" which would skip the tracing portion. -- Steve