Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S941487AbcLXBi4 (ORCPT ); Fri, 23 Dec 2016 20:38:56 -0500 Received: from mga01.intel.com ([192.55.52.88]:32340 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751671AbcLXBiZ (ORCPT ); Fri, 23 Dec 2016 20:38:25 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.33,396,1477983600"; d="scan'208";a="45999344" From: Ricardo Neri To: Ingo Molnar , Thomas Gleixner , Borislav Petkov , Andy Lutomirski , Peter Zijlstra Cc: linux-kernel@vger.kernel.org, x86@kernel.org, , , Ricardo Neri , Andrew Morton , "H . Peter Anvin" , Brian Gerst , Chen Yucong , Chris Metcalf , Dave Hansen , Fenghua Yu , Huang Rui , Jiri Slaby , Jonathan Corbet , "Michael S . Tsirkin" , Paul Gortmaker , "Ravi V . Shankar" , Shuah Khan , Vlastimil Babka , Tony Luck , Paolo Bonzini , "Liang Z . Li" , Alexandre Julliard , Stas Sergeev Subject: [v2 6/7] x86/traps: Fixup general protection faults caused by UMIP Date: Fri, 23 Dec 2016 17:37:44 -0800 Message-Id: <20161224013745.108716-7-ricardo.neri-calderon@linux.intel.com> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20161224013745.108716-1-ricardo.neri-calderon@linux.intel.com> References: <20161224013745.108716-1-ricardo.neri-calderon@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2141 Lines: 61 If the User-Mode Instruction Prevention CPU feature is available and enabled, a general protection fault will be issued if the instructions sgdt, sldt, sidt, str or smsw are executed from user-mode context (CPL > 0). If the fault was caused by any of the instructions protected by UMIP, fixup_umip_exceptino will emulate dummy results for these instructions. Cc: Andy Lutomirski Cc: Andrew Morton Cc: H. Peter Anvin Cc: Borislav Petkov Cc: Brian Gerst Cc: Chen Yucong Cc: Chris Metcalf Cc: Dave Hansen Cc: Fenghua Yu Cc: Huang Rui Cc: Jiri Slaby Cc: Jonathan Corbet Cc: Michael S. Tsirkin Cc: Paul Gortmaker Cc: Peter Zijlstra Cc: Ravi V. Shankar Cc: Shuah Khan Cc: Vlastimil Babka Cc: Tony Luck Cc: Paolo Bonzini Cc: Liang Z. Li Cc: Alexandre Julliard Cc: Stas Sergeev Cc: x86@kernel.org Cc: linux-msdos@vger.kernel.org Signed-off-by: Ricardo Neri --- arch/x86/kernel/traps.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index bf0c6d0..5044fb3 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -64,6 +64,7 @@ #include #include #include +#include #ifdef CONFIG_X86_64 #include @@ -491,6 +492,9 @@ do_general_protection(struct pt_regs *regs, long error_code) RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU"); cond_local_irq_enable(regs); + if (user_mode(regs) && !fixup_umip_exception(regs)) + return; + if (v8086_mode(regs)) { local_irq_enable(); handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code); -- 2.9.3