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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=unavailable 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 B40BAC10F00 for ; Fri, 22 Feb 2019 19:39:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 808882070B for ; Fri, 22 Feb 2019 19:39:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726672AbfBVTjd (ORCPT ); Fri, 22 Feb 2019 14:39:33 -0500 Received: from mail.kernel.org ([198.145.29.99]:34956 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726086AbfBVTjc (ORCPT ); Fri, 22 Feb 2019 14:39:32 -0500 Received: from gandalf.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 DCA3F20700; Fri, 22 Feb 2019 19:39:30 +0000 (UTC) Date: Fri, 22 Feb 2019 14:39:29 -0500 From: Steven Rostedt To: Alexei Starovoitov Cc: Linus Torvalds , Masami Hiramatsu , Andy Lutomirski , Linux List Kernel Mailing , Ingo Molnar , Andrew Morton , stable , Changbin Du , Jann Horn , Kees Cook , Andy Lutomirski , daniel@iogearbox.net, netdev@vger.kernel.org, bpf@vger.kernel.org Subject: Re: [PATCH 1/2 v2] kprobe: Do not use uaccess functions to access kernel memory that can fault Message-ID: <20190222143911.617604af@gandalf.local.home> In-Reply-To: <20190222193456.5vqppubzrcx5wsul@ast-mbp.dhcp.thefacebook.com> References: <20190219111802.1d6dbaa3@gandalf.local.home> <20190219140330.5dd9e876@gandalf.local.home> <20190220171019.5e81a4946b56982f324f7c45@kernel.org> <20190220094926.0ab575b3@gandalf.local.home> <20190222172745.2c7205d62003c0a858e33278@kernel.org> <20190222173509.88489b7c5d1bf0e2ec2382ee@kernel.org> <20190222192703.epvgxghwybte7gxs@ast-mbp.dhcp.thefacebook.com> <20190222143026.17d6f0f6@gandalf.local.home> <20190222193456.5vqppubzrcx5wsul@ast-mbp.dhcp.thefacebook.com> X-Mailer: Claws Mail 3.16.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 22 Feb 2019 11:34:58 -0800 Alexei Starovoitov wrote: > so you're saying you will break existing kprobe scripts? Yes we may. > I don't think it's a good idea. > It's not acceptable to break bpf_probe_read uapi. Then you may need to add more code to determine if the address is user space or not in the kernel, and then go the appropriate route, before calling probe_kernel_read(). -- Steve