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=-6.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS 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 97B2CC433C1 for ; Thu, 25 Mar 2021 03:26:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 682CF61A12 for ; Thu, 25 Mar 2021 03:26:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231835AbhCYDZz (ORCPT ); Wed, 24 Mar 2021 23:25:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:37634 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230525AbhCYDZa (ORCPT ); Wed, 24 Mar 2021 23:25:30 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 296B2619EE; Thu, 25 Mar 2021 03:25:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1616642730; bh=G2jMw/CxVhfwI+lARDiDkf9hXk+3Sq4LeL7ZRcjEp2M=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=eNcEUmR2so623VmkdCpmgRtK9S9J3v06vWus15G3OkV+vvnQM9LBDAmT3EZsmnhfz vVObW9w5GtqYAKWalpubKZ3M8OuQrUlHYAFJq1FQPo9lbVI8VGdajY4H3ve30v55CF +UwOiHkj4Ejoiy4AuEmwyP1JXevHrqJtPUf6HNHOsNisNr/tDxPeUIVbkucVzbHJzR iFEX3/hlGARhPw6sjXSlkUSJSCPdYCtaz6q4/68BBoAMuGUeOSZZDjIOl/Xdl2KUMC ZpGUdlC/rmlrbbjn/NKQAQRPF1efzen4VYc49FQsgudctSfeVRkMK2n6ix7voPk4xe H0jHfcSdNgHGQ== Date: Thu, 25 Mar 2021 12:25:24 +0900 From: Masami Hiramatsu To: Steven Rostedt Cc: Josh Poimboeuf , Peter Zijlstra , Ingo Molnar , X86 ML , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, tglx@linutronix.de, kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar Subject: Re: [PATCH -tip v4 10/12] x86/kprobes: Push a fake return address at kretprobe_trampoline Message-Id: <20210325122524.91bca1233c0c254fdc0678fc@kernel.org> In-Reply-To: <20210324202613.7cad6f4f@oasis.local.home> References: <161639518354.895304.15627519393073806809.stgit@devnote2> <161639530062.895304.16962383429668412873.stgit@devnote2> <20210323223007.GG4746@worktop.programming.kicks-ass.net> <20210324104058.7c06aaeb0408e24db6ba46f8@kernel.org> <20210324160143.wd43zribpeop2czn@treble> <20210325084741.74bdb2b1d2ed00fe68840cea@kernel.org> <20210324202613.7cad6f4f@oasis.local.home> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Wed, 24 Mar 2021 20:26:13 -0400 Steven Rostedt wrote: > On Thu, 25 Mar 2021 08:47:41 +0900 > Masami Hiramatsu wrote: > > > > I think the REGS and REGS_PARTIAL cases can also be affected by function > > > graph tracing. So should they use the generic unwind_recover_ret_addr() > > > instead of unwind_recover_kretprobe()? > > > > Yes, but I'm not sure this parameter can be applied. > > For example, it passed "state->sp - sizeof(unsigned long)" as where the > > return address stored address. Is that same on ftrace graph too? > > Stack traces on the return side of function graph tracer has never > worked. It's on my todo list, because that's one of the requirements to > get right if we every manage to combine kretprobe and function graph > tracers together. OK, then at this point let's just fix the kretprobe side. Thanks, > > -- Steve -- Masami Hiramatsu