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,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, 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 B73E0C43381 for ; Fri, 22 Feb 2019 21:59:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 857432075C for ; Fri, 22 Feb 2019 21:59:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="Po2mNkob" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726384AbfBVV7b (ORCPT ); Fri, 22 Feb 2019 16:59:31 -0500 Received: from mail-lf1-f65.google.com ([209.85.167.65]:40522 "EHLO mail-lf1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726019AbfBVV7a (ORCPT ); Fri, 22 Feb 2019 16:59:30 -0500 Received: by mail-lf1-f65.google.com with SMTP id t14so2841975lfk.7 for ; Fri, 22 Feb 2019 13:59:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=inGp63CnkQPGym5+zaHGFM1K173YzJRg3qyu/avVomA=; b=Po2mNkobwlHker/hG/WZJJNGd+vAIrgxgBuQa408gySq/P7Su/1AyIszKrUH/AWfWJ V7g3ut1/pzDwvsmIWtas1+dKpqGuzH3hvjjpTai4gEjacHpLTYoLLtKMNAw/2qmocFNk pA6VCjKTIuSGj0yWkT6srpr/n2/BU+GqWO/j0= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=inGp63CnkQPGym5+zaHGFM1K173YzJRg3qyu/avVomA=; b=LztmOOqMwtOO0mzaInnGHDDSoQqTuACJ0YWIkySBd/FHlnND7vHXSYUwej08GjQPsU LSCeiZKff5po4C0PQT837IqvgvbhYF5gG5SnZlLr553iuDm/zMnC+LM4/eGrOJ3Ej2oC k4NWkbZu+yjfT0FRhTH527HoQQvWdRQBnSHZmW68bEgAgvStcZVeNjKCvA1oA8pGSTBL rcR8wajbCASsSsjuLL+PcJQVhpaq+X3BccYGv6buvCzzZ8DieOlwPXRehaBFiMUDSmZl yP8p3vQFpbHZqtDODVJA5aoIjwhg6DKuM9j2TZaGQrrfUetf400jjKjsTW3SL17XyMit 1UJg== X-Gm-Message-State: AHQUAubdfs2z756mCFjdjtslZue1q8qTdGaLtSTNCw1Q5tsvd0NCGYSq 6alFRiVy7FKK98wpsRr4iyqlPktDUWU= X-Google-Smtp-Source: AHgI3IZE5i6fkQoyK7ZMBoQDrrRj4vuSwZ4XWsRe8X9rq6YSB4gQ07DkwD+a+2LKgwiMx9H4CzlMzw== X-Received: by 2002:ac2:4317:: with SMTP id l23mr2452913lfh.98.1550872768437; Fri, 22 Feb 2019 13:59:28 -0800 (PST) Received: from mail-lj1-f179.google.com (mail-lj1-f179.google.com. [209.85.208.179]) by smtp.gmail.com with ESMTPSA id p76sm980323lja.0.2019.02.22.13.59.27 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 22 Feb 2019 13:59:27 -0800 (PST) Received: by mail-lj1-f179.google.com with SMTP id d24so2573795ljc.12 for ; Fri, 22 Feb 2019 13:59:27 -0800 (PST) X-Received: by 2002:a2e:6e09:: with SMTP id j9-v6mr3445351ljc.118.1550872766956; Fri, 22 Feb 2019 13:59:26 -0800 (PST) MIME-Version: 1.0 References: <20190222192703.epvgxghwybte7gxs@ast-mbp.dhcp.thefacebook.com> <20190222.133842.1637029078039923178.davem@davemloft.net> In-Reply-To: <20190222.133842.1637029078039923178.davem@davemloft.net> From: Linus Torvalds Date: Fri, 22 Feb 2019 13:59:10 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 1/2 v2] kprobe: Do not use uaccess functions to access kernel memory that can fault To: David Miller Cc: Alexei Starovoitov , Masami Hiramatsu , Steven Rostedt , Andy Lutomirski , Linux List Kernel Mailing , Ingo Molnar , Andrew Morton , stable , Changbin Du , Jann Horn , Kees Cook , Andrew Lutomirski , Daniel Borkmann , Netdev , bpf@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 22, 2019 at 1:38 PM David Miller wrote: > > Don't be surprised if we see more separation like this in the future too. Yes, with the whole meltdown fiasco, there's actually more pressure to add more support for separation of kernel/user address spaces. As Andy pointed out, it's been discussed as a future wish-list for x86-64 too. But yeah, right now the *common* architectures all distinguish kernel and user space by pointers (ie x86-64, arm64 and powerpc). Linus