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=-2.2 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 AA4CFC04A6B for ; Fri, 10 May 2019 12:17:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7A91820896 for ; Fri, 10 May 2019 12:17:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="NGB6qFBt" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727291AbfEJMR5 (ORCPT ); Fri, 10 May 2019 08:17:57 -0400 Received: from merlin.infradead.org ([205.233.59.134]:38110 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727071AbfEJMR5 (ORCPT ); Fri, 10 May 2019 08:17:57 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.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:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=Zhu4heSzSl0zciCgHpqHGoWkGn39CgR6C2tptsMuYBM=; b=NGB6qFBt2V87eP39aFFQk44sG a1MQSCehHjm4bl0/c9oF9zFoQVP5qo5An72Q+stfXEUeRP6B1tX+JW20CZDdPUSSJXvNKhvjfvAGM gKxwWvJggOF/QrQllumc6FPxSjgDRLT1JeZFF+ECEKD2gfBADPwKAtRDXmsBqu8Xmj2a2nDbBe7Zw C7QAPemxyDPP9US4Vb+ObnU37O2j/yZT2ZfNwpFOz7r2UBZTccJ70hCMz77IvmRmew+FvQQ7Kjiob gPxPNEvdQtPXzJ6M72/5UmG5eeZ3cXboeJXR7q1CNNUKVoHNlv3TSnALh2+6C28w/yemcF/v2SZzi X8RLN0Img==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1hP4Sn-0005Xp-Rz; Fri, 10 May 2019 12:17:22 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 544722029F1F3; Fri, 10 May 2019 14:17:20 +0200 (CEST) Date: Fri, 10 May 2019 14:17:20 +0200 From: Peter Zijlstra To: Masami Hiramatsu Cc: Steven Rostedt , Andy Lutomirski , Josh Poimboeuf , linux-kernel@vger.kernel.org, Linus Torvalds , Ingo Molnar , Andrew Morton , Andy Lutomirski , Nicolai Stange , Thomas Gleixner , Borislav Petkov , "H. Peter Anvin" , x86@kernel.org, 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 , linux-kselftest@vger.kernel.org Subject: Re: [PATCH 2/4] x86/kprobes: Fix frame pointer annotations Message-ID: <20190510121720.GT2589@hirez.programming.kicks-ass.net> References: <20190508115416.nblx7c2kocidpytm@treble> <20190508120416.GL2589@hirez.programming.kicks-ass.net> <20190508124248.u5ukpbhnh4wpiccq@treble> <20190508153907.GM2589@hirez.programming.kicks-ass.net> <20190508184848.qerg3flv3ej3xsev@treble> <20190509102030.dfa62e058f09d0d8cbdd6053@kernel.org> <20190509081431.GO2589@hirez.programming.kicks-ass.net> <81170F0B-A2BB-4CD6-A1B5-5E7E0DDBC282@amacapital.net> <20190509174316.pzuakeu657g3fnlm@home.goodmis.org> <20190510122103.5a7bc5416b7af96b27d4fab4@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190510122103.5a7bc5416b7af96b27d4fab4@kernel.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 10, 2019 at 12:21:03PM +0900, Masami Hiramatsu wrote: > Yes, optprobe also has to save and restore the flags. > Above trampline is for kretprobe, which is placed at the function return, so > we don't have to care about flags. Sure, optprobe is actually special here, because it branches out at 'random' places and does indeed need to preserve flags. But both ftrace and retprobes are at C function call boundaries. Preserving flags doesn't make sense.