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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT 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 1DFEDC10F0B for ; Tue, 26 Feb 2019 03:57:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D4BD0217F5 for ; Tue, 26 Feb 2019 03:57:47 +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="CQq89mON" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726443AbfBZD5q (ORCPT ); Mon, 25 Feb 2019 22:57:46 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:58090 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725877AbfBZD5q (ORCPT ); Mon, 25 Feb 2019 22:57:46 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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=Quv3YfUmhrPNUMCgAXXUle+etixw9QKj9S3s9u17QdU=; b=CQq89mONXp+sgS1IH4jU4x/7M z9uV/INOoRLO9uYreGt8k7cDCF8YIM9b5VWF+OwyJs3EHLAzJzh9zox8WCMv29TfhKvQxy4Q4biIk jDDI3AuENHo11s2dqIWs/XWIUwZqF3/G4ER3vz7edVpga0Ovx/z3JcB6JTzpLFbzUo1soZvLkG/XM vfhz+DCCLyPXuTx3rdtNV+dZG/ds8CNAQHuAY7PYJREjEzD8giMzTvEHPjTyQ9UgzX2zMH5m/R/Tj QvgVTL2OH17oIiTHHyMUmouGNwhPaKgAoVOSKkCnzpbXkzBricMsGMjNQc1K/0HlXL8OjPDZgnOlA p+SR/DuRA==; Received: from hch by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1gyTsD-0006Xg-Df; Tue, 26 Feb 2019 03:57:41 +0000 Date: Mon, 25 Feb 2019 19:57:41 -0800 From: Christoph Hellwig To: Linus Torvalds Cc: David Miller , 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 Subject: Re: [PATCH 1/2 v2] kprobe: Do not use uaccess functions to access kernel memory that can fault Message-ID: <20190226035741.GA14994@infradead.org> References: <20190222192703.epvgxghwybte7gxs@ast-mbp.dhcp.thefacebook.com> <20190222.133842.1637029078039923178.davem@davemloft.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.2 (2017-12-15) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html 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 01:59:10PM -0800, Linus Torvalds wrote: > 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. S/390 is another example. I've also proposed a RISC-V extension for it, including prototypes for Rocketchip and Qemu, and a Linux kernel support, but it didn't go any way.