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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, 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 D67A3C433DB for ; Thu, 25 Mar 2021 00:27:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B143761A1F for ; Thu, 25 Mar 2021 00:27:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239235AbhCYA0c (ORCPT ); Wed, 24 Mar 2021 20:26:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:45090 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232029AbhCYA0S (ORCPT ); Wed, 24 Mar 2021 20:26:18 -0400 Received: from oasis.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 B3F6361A1A; Thu, 25 Mar 2021 00:26:15 +0000 (UTC) Date: Wed, 24 Mar 2021 20:26:13 -0400 From: Steven Rostedt To: Masami Hiramatsu 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: <20210324202613.7cad6f4f@oasis.local.home> In-Reply-To: <20210325084741.74bdb2b1d2ed00fe68840cea@kernel.org> 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> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.33; 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: linux-kernel@vger.kernel.org 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. -- Steve From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Rostedt Date: Thu, 25 Mar 2021 00:26:13 +0000 Subject: Re: [PATCH -tip v4 10/12] x86/kprobes: Push a fake return address at kretprobe_trampoline Message-Id: <20210324202613.7cad6f4f@oasis.local.home> List-Id: 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> In-Reply-To: <20210325084741.74bdb2b1d2ed00fe68840cea@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Masami Hiramatsu 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 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. -- Steve