Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753423AbbLNUBm (ORCPT ); Mon, 14 Dec 2015 15:01:42 -0500 Received: from www.linutronix.de ([62.245.132.108]:36605 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750801AbbLNUBl (ORCPT ); Mon, 14 Dec 2015 15:01:41 -0500 Date: Mon, 14 Dec 2015 21:00:52 +0100 (CET) From: Thomas Gleixner To: Dave Hansen cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org, dave.hansen@linux.intel.com Subject: Re: [PATCH 24/32] x86, pkeys: actually enable Memory Protection Keys in CPU In-Reply-To: <20151214190622.8DAD0692@viggo.jf.intel.com> Message-ID: References: <20151214190542.39C4886D@viggo.jf.intel.com> <20151214190622.8DAD0692@viggo.jf.intel.com> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) 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,URIBL_BLOCKED=0.001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1092 Lines: 26 On Mon, 14 Dec 2015, Dave Hansen wrote: > This sets the bit in 'cr4' to actually enable the protection > keys feature. We also include a boot-time disable for the > feature "nopku". > > Seting X86_CR4_PKE will cause the X86_FEATURE_OSPKE cpuid > bit to appear set. At this point in boot, identify_cpu() > has already run the actual CPUID instructions and populated > the "cpu features" structures. We need to go back and > re-run identify_cpu() to make sure it gets updated values. > > We *could* simply re-populate the 11th word of the cpuid > data, but this is probably quick enough. > > Also note that with the cpu_has() check and X86_FEATURE_PKU > present in disabled-features.h, we do not need an #ifdef > for setup_pku(). > > Signed-off-by: Dave Hansen Reviewed-by: Thomas Gleixner -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/