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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C07EAC4332F for ; Sun, 5 Nov 2023 17:26:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229529AbjKER0W (ORCPT ); Sun, 5 Nov 2023 12:26:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52070 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229445AbjKER0T (ORCPT ); Sun, 5 Nov 2023 12:26:19 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1615AC5; Sun, 5 Nov 2023 09:26:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=VZvehqzmYfdKM74gw2bH42XgavIBzXX1XLduCUr0/Wg=; b=fM/RAP1TLr0PusgCJzr2HIanH3 +3yAPvHpA6a+RDrBtCIBv1gYHkRYFVPVzS8RE05WCpl/UEnAvoqM3iiFaLRm4jR19YfroPbrnzSA9 oJ2iLNvwxknV1xzPNiagLOEY98tceQkBZoMydZWolPBWJ5aPM/fc5Y5I55xxWBjYZkeJCZ9/4VoWT sybSV8dVHNwdRyt+38tjZK4jBdt4YQMcaqjs4v7qXaBCH/nbC9kbtlbeo2SSGMfExst+9u52mpdTi +ihJZJvwDn1LsmgOoEyyFk5G4H63OZwgfCKPiy0VuFFx2ZvAk2f59lwmzkS0N5WWRcrJ1fVZ0TWg2 JqVFeuqQ==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1qzgsS-0011Dy-DX; Sun, 05 Nov 2023 17:25:37 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id B2ABA300326; Sun, 5 Nov 2023 18:25:36 +0100 (CET) Date: Sun, 5 Nov 2023 18:25:36 +0100 From: Peter Zijlstra To: "Masami Hiramatsu (Google)" Cc: Alexei Starovoitov , Steven Rostedt , Florent Revest , linux-trace-kernel@vger.kernel.org, LKML , Martin KaFai Lau , bpf , Sven Schnelle , Alexei Starovoitov , Jiri Olsa , Arnaldo Carvalho de Melo , Daniel Borkmann , Alan Maguire , Mark Rutland , Thomas Gleixner , Guo Ren Subject: Re: [RFC PATCH 24/32] x86/ftrace: Enable HAVE_FUNCTION_GRAPH_FREGS Message-ID: <20231105172536.GA7124@noisy.programming.kicks-ass.net> References: <169920038849.482486.15796387219966662967.stgit@devnote2> <169920068069.482486.6540417903833579700.stgit@devnote2> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <169920068069.482486.6540417903833579700.stgit@devnote2> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 06, 2023 at 01:11:21AM +0900, Masami Hiramatsu (Google) wrote: > From: Masami Hiramatsu (Google) > > Support HAVE_FUNCTION_GRAPH_FREGS on x86-64, which saves ftrace_regs > on the stack in ftrace_graph return trampoline so that the callbacks > can access registers via ftrace_regs APIs. What is ftrace_regs ? If I look at arch/x86/include/asm/ftrace.h it's a pointless wrapper around pt_regs. Can we please remove the pointless wrappery and call it what it is?