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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,T_DKIMWL_WL_HIGH, URIBL_BLOCKED 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 10781C04AB3 for ; Wed, 29 May 2019 06:47:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D7E43216FD for ; Wed, 29 May 2019 06:47:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559112467; bh=xY1iAw/2N4nKPDxFqUZ+osggFL15pR2wiUbf/oD2RJI=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=2PIBAnHpNnCuptevndJnQPf64emKwfbBvjsxh7OlumzN6SieJXJ40UgZvVuZ2b3ZH QAgJmZML8GCm9DSjMrBrlvAKpTe/VSoojTnI3ZBXUd8jUh3PeFVHZ+g/iIlkQeAmFg 9Bf7wVDAqAQInzDkOxA8PV+fE2KQNdalp2o0O5Mw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726189AbfE2Grr (ORCPT ); Wed, 29 May 2019 02:47:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:37736 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725879AbfE2Grq (ORCPT ); Wed, 29 May 2019 02:47:46 -0400 Received: from devnote2 (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (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 03B5621670; Wed, 29 May 2019 06:47:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559112465; bh=xY1iAw/2N4nKPDxFqUZ+osggFL15pR2wiUbf/oD2RJI=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=w+twq5wTNZfl465wcH4n7a5RMmightjumKr9p8BTphVOKp9KUxlJgWOXG/gDiayIf ZlKk8OU+2oZat/FweumICAtZTk3F6og/XJlgpovEvLTGoCSf9t0duNxsWgH2qHZ3i7 xzetlptWYSWG0g3Km8R4pndBXghTAxZ08x/ZZ3WU= Date: Wed, 29 May 2019 15:47:40 +0900 From: Masami Hiramatsu To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Andrew Morton , Thomas Gleixner , Peter Zijlstra , Josh Poimboeuf , Frederic Weisbecker , Joel Fernandes , Andy Lutomirski , Mark Rutland , Namhyung Kim , "Frank Ch. Eigler" Subject: Re: [RFC][PATCH 00/14 v2] function_graph: Rewrite to allow multiple users Message-Id: <20190529154740.016517ff9225680f64961097@kernel.org> In-Reply-To: <20190522104027.1b2aabd8@gandalf.local.home> References: <20190520142001.270067280@goodmis.org> <20190522231955.72899b0d606adb919e8716ff@kernel.org> <20190522104027.1b2aabd8@gandalf.local.home> X-Mailer: Sylpheed 3.5.1 (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, 22 May 2019 10:40:27 -0400 Steven Rostedt wrote: > On Wed, 22 May 2019 23:19:55 +0900 > Masami Hiramatsu wrote: > > > > void *fgraph_reserve_data(int size_in_bytes) > > > > > > Allows the entry function to reserve up to 4 words of data on > > > the shadow stack. On success, a pointer to the contents is returned. > > > This may be only called once per entry function. > > > > > > void *fgraph_retrieve_data(void) > > > > > > Allows the return function to retrieve the reserved data that was > > > allocated by the entry function. > > > > Nice! this seems good for kretprobe too. I'll review and try to port > > kretprobe on this framework. > > If you rather pull from my git repo and not download all the patches, > they are currently available in my ftrace/fgraph-multi branch. Hi Steve, I found that these interfaces seem tightly coupled with fgraph_ops. But that cause a problem when I'm using it from kretprobe. kretprobe has 2 handlers, entry handler and return handler, and both need pt_regs. But fgraph_ops's entryfunc and retfunc do not pass the pt_regs. That is the biggest issue for me on these APIs. Can we expand fgraph_ops with regs parameter? Thank you, -- Masami Hiramatsu