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=-6.5 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 74DAFC07E99 for ; Fri, 9 Jul 2021 14:55:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 58E03613BD for ; Fri, 9 Jul 2021 14:55:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232374AbhGIO6T (ORCPT ); Fri, 9 Jul 2021 10:58:19 -0400 Received: from mail.kernel.org ([198.145.29.99]:44368 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231972AbhGIO6T (ORCPT ); Fri, 9 Jul 2021 10:58:19 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 47D0661242; Fri, 9 Jul 2021 14:55:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625842536; bh=Q2WG2NG1T89ViRXSnVoTpzh42KcKP8D2yuxnM2NHFLk=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=fBhhIzyyAoLntM8rT07BquH3igKKEvTX2kQj+DWRV+X4ADbvirwhloSDGtaFij3Ik n17gc+bDJLT826iPEC1EWuvqRvCH4uTMUj18U/KoZVMyraHebRg6vZE1E6ZsycgDxE RN9bo82HHDyppAnO5bYXlUmWHG0lKG6k8rCKSkJlVXyMHSLmjTsgqdLkIU5cHsOUfK O+fpPhhJ1l/y3pxcuOe/DreJxFv53TURXVuN91GnShGLXnBLhwtp5LfJ18rwDDSoSa SAP2UWPWvCRCqxEcolzKaWZGu4fCA2RLPRWf3M98wCU2DctHXgUbVGzyvTPo8CH30j QG9NG40CposHw== Date: Fri, 9 Jul 2021 23:55:31 +0900 From: Masami Hiramatsu To: Ingo Molnar Cc: Steven Rostedt , Josh Poimboeuf , X86 ML , Daniel Xu , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, Thomas Gleixner , Borislav Petkov , Peter Zijlstra , kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar , Andrii Nakryiko Subject: Re: [PATCH -tip v8 10/13] x86/kprobes: Push a fake return address at kretprobe_trampoline Message-Id: <20210709235531.527d5cbb59c5669eed885b32@kernel.org> In-Reply-To: References: <162399992186.506599.8457763707951687195.stgit@devnote2> <162400001661.506599.5153975410607447958.stgit@devnote2> 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 Mon, 5 Jul 2021 10:17:26 +0200 Ingo Molnar wrote: > > * Masami Hiramatsu wrote: > > > + /* Replace fake return address with real one. */ > > + *frame_pointer = kretprobe_trampoline_handler(regs, frame_pointer); > > + /* > > + * Move flags to sp so that kretprobe_trapmoline can return > > + * right after popf. > > What is a trapmoline? This means kretprobe_trampoline() code. > > Also, in the x86 code we capitalize register and instruction names so that > they are more distinctive and easier to read in the flow of English text. OK, let me update it. Thank you, > > Thanks, > > Ingo -- Masami Hiramatsu