Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753225AbeADVqs (ORCPT + 1 other); Thu, 4 Jan 2018 16:46:48 -0500 Received: from Galois.linutronix.de ([146.0.238.70]:43209 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751952AbeADVqr (ORCPT ); Thu, 4 Jan 2018 16:46:47 -0500 Date: Thu, 4 Jan 2018 22:46:44 +0100 (CET) From: Thomas Gleixner To: Dave Hansen cc: linux-kernel@vger.kernel.org, x86@kernel.org, moritz.lipp@iaik.tugraz.at, daniel.gruss@iaik.tugraz.at, michael.schwarz@iaik.tugraz.at, richard.fellner@student.tugraz.at, luto@kernel.org, torvalds@linux-foundation.org, keescook@google.com, hughd@google.com Subject: Re: [PATCH] x86/doc: add PTI description In-Reply-To: <20180104205458.6E55ED20@viggo.jf.intel.com> Message-ID: References: <20180104205458.6E55ED20@viggo.jf.intel.com> User-Agent: Alpine 2.20 (DEB 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: On Thu, 4 Jan 2018, Dave Hansen wrote: > > - pti= [X86_64] > + pti= [X86_64] Disable Page Table Isolation of user and That description is definitely wrong.... > + kernel address spaces. Disabling this feature > + removes hardening, but improves performance of > + system calls and interrupts. > + > Control user/kernel address space isolation: > on - enable > off - disable > auto - default setting > > + nopti [X86_64] > + Equivalent to pti=off > + > pty.legacy_count= > [KNL] Number of legacy pty's. Overwrites compiled-in > default number. Thanks, tglx