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=-0.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 EE9C1C04A6B for ; Mon, 6 May 2019 17:06:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C5A402087F for ; Mon, 6 May 2019 17:06:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726411AbfEFRGs (ORCPT ); Mon, 6 May 2019 13:06:48 -0400 Received: from mail.kernel.org ([198.145.29.99]:56362 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726386AbfEFRGr (ORCPT ); Mon, 6 May 2019 13:06:47 -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 994A7206A3; Mon, 6 May 2019 17:06:44 +0000 (UTC) Date: Mon, 6 May 2019 13:06:43 -0400 From: Steven Rostedt To: Linus Torvalds Cc: Peter Zijlstra , Andy Lutomirski , Linux List Kernel Mailing , Ingo Molnar , Andrew Morton , Andy Lutomirski , Nicolai Stange , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , "the arch/x86 maintainers" , Josh Poimboeuf , Jiri Kosina , Miroslav Benes , Petr Mladek , Joe Lawrence , Shuah Khan , Konrad Rzeszutek Wilk , Tim Chen , Sebastian Andrzej Siewior , Mimi Zohar , Juergen Gross , Nick Desaulniers , Nayna Jain , Masahiro Yamada , Joerg Roedel , "open list:KERNEL SELFTEST FRAMEWORK" , stable Subject: Re: [RFC][PATCH 1/2] x86: Allow breakpoints to emulate call functions Message-ID: <20190506130643.62c35eeb@gandalf.local.home> In-Reply-To: References: <20190502181811.GY2623@hirez.programming.kicks-ass.net> <20190502202146.GZ2623@hirez.programming.kicks-ass.net> <20190502185225.0cdfc8bc@gandalf.local.home> <20190502193129.664c5b2e@gandalf.local.home> <20190502195052.0af473cf@gandalf.local.home> <20190503092959.GB2623@hirez.programming.kicks-ass.net> <20190503092247.20cc1ff0@gandalf.local.home> <2045370D-38D8-406C-9E94-C1D483E232C9@amacapital.net> <20190506081951.GJ2606@hirez.programming.kicks-ass.net> <20190506095631.6f71ad7c@gandalf.local.home> 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: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Mon, 6 May 2019 09:17:19 -0700 Linus Torvalds wrote: > So what is it that doesn't actually work? I've looked at the patch > even more, and I can't for the life of me see how it wouldn't work. > > Of course, I didn't test any of the actual ftrace parts, since I > short-circuited them intentionally with the above test function hack. > I have no idea what the semantics for those > ftrace_location(ip)/is_ftrace_caller(ip) cases are supposed to be, I > only tested that yes, the infrastructure clearly emulates a call > instruction. Can you try booting with: CONFIG_KPROBE_EVENTS=y CONFIG_UPROBE_EVENTS=y CONFIG_DYNAMIC_EVENTS=y CONFIG_PROBE_EVENTS=y CONFIG_DYNAMIC_FTRACE=y CONFIG_DYNAMIC_FTRACE_WITH_REGS=y CONFIG_FUNCTION_PROFILER=y CONFIG_FTRACE_MCOUNT_RECORD=y CONFIG_FTRACE_SELFTEST=y CONFIG_FTRACE_STARTUP_TEST=y CONFIG_TRACEPOINT_BENCHMARK=y CONFIG_RING_BUFFER_BENCHMARK=y CONFIG_RING_BUFFER_STARTUP_TEST=y And see if it boots? -- Steve