Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753678AbdCIX0G (ORCPT ); Thu, 9 Mar 2017 18:26:06 -0500 Received: from mail-io0-f169.google.com ([209.85.223.169]:33230 "EHLO mail-io0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752501AbdCIX0E (ORCPT ); Thu, 9 Mar 2017 18:26:04 -0500 MIME-Version: 1.0 In-Reply-To: <20170309224820.5invcnhvr2tl3ges@pd.tnic> References: <58C157E6.1010909@iogearbox.net> <58C19607.6000605@iogearbox.net> <58C19F67.3040509@iogearbox.net> <58C1C9DC.7070509@iogearbox.net> <20170309215547.jmdzznlkzaxwu2pf@pd.tnic> <20170309220732.ufqoqlawktsi2gao@pd.tnic> <58C1D305.8090802@iogearbox.net> <20170309224820.5invcnhvr2tl3ges@pd.tnic> From: Linus Torvalds Date: Thu, 9 Mar 2017 15:26:02 -0800 X-Google-Sender-Auth: xbzKNMHlo0wknVhAfsQw3AhYFQI Message-ID: Subject: Re: [net/bpf] 3051bf36c2 BUG: unable to handle kernel paging request at 0000a7cf To: Borislav Petkov Cc: Daniel Borkmann , Thomas Gleixner , Kees Cook , Laura Abbott , Ingo Molnar , Peter Anvin , Fengguang Wu , Network Development , LKML , LKP , ast@fb.com, "the arch/x86 maintainers" , "David S. Miller" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 822 Lines: 20 On Thu, Mar 9, 2017 at 2:48 PM, Borislav Petkov wrote: > > I guess we could return to doing boot_cpu_has() in __flush_tlb_all() > then. I mean, the timing-sensitivity argument is meh - killing global > TLB entries a bit faster doesn't bring me a whole lot when I have to go > and walk pagetable and reestablish them, which is the real price to pay > anyway. So should all of commit ("c109bf95992b x86/cpufeature: Remove cpu_has_pge") just be reverted (and then marked for stable)? Or do we have some alternate plan? This has apparently been going on for a long while (it got merged into 4.7), but presumably it only actually _matters_ if lguest is enabled and used and we've triggered that lguest_arch_host_init() code. Maybe it's the lguest games with PGE that need to be removed? Linus