From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752164AbbI1TSa (ORCPT ); Mon, 28 Sep 2015 15:18:30 -0400 Received: from mga02.intel.com ([134.134.136.20]:16244 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751829AbbI1TSY (ORCPT ); Mon, 28 Sep 2015 15:18:24 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.17,604,1437462000"; d="scan'208";a="814722978" Subject: [PATCH 17/25] x86, pkeys: dump PKRU with other kernel registers To: dave@sr71.net Cc: borntraeger@de.ibm.com, x86@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, dave.hansen@linux.intel.com From: Dave Hansen Date: Mon, 28 Sep 2015 12:18:24 -0700 References: <20150928191817.035A64E2@viggo.jf.intel.com> In-Reply-To: <20150928191817.035A64E2@viggo.jf.intel.com> Message-Id: <20150928191824.88E91D56@viggo.jf.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dave Hansen I'm a bit ambivalent about whether this is needed or not. Protection Keys never affect kernel mappings. But, they can affect whether the kernel will fault when it touches a user mapping. But, the kernel doesn't touch user mappings without some careful choreography and these accesses don't generally result in oopses. Signed-off-by: Dave Hansen --- b/arch/x86/kernel/process_64.c | 2 ++ 1 file changed, 2 insertions(+) diff -puN arch/x86/kernel/process_64.c~pkeys-30-kernel-error-dumps arch/x86/kernel/process_64.c --- a/arch/x86/kernel/process_64.c~pkeys-30-kernel-error-dumps 2015-09-28 11:39:48.695307824 -0700 +++ b/arch/x86/kernel/process_64.c 2015-09-28 11:39:48.698307960 -0700 @@ -116,6 +116,8 @@ void __show_regs(struct pt_regs *regs, i printk(KERN_DEFAULT "DR0: %016lx DR1: %016lx DR2: %016lx\n", d0, d1, d2); printk(KERN_DEFAULT "DR3: %016lx DR6: %016lx DR7: %016lx\n", d3, d6, d7); + if (boot_cpu_has(X86_FEATURE_OSPKE)) + printk(KERN_DEFAULT "PKRU: %08x\n", read_pkru()); } void release_thread(struct task_struct *dead_task) _