From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756104AbdLOTC5 (ORCPT ); Fri, 15 Dec 2017 14:02:57 -0500 Received: from terminus.zytor.com ([65.50.211.136]:44041 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755848AbdLOTCw (ORCPT ); Fri, 15 Dec 2017 14:02:52 -0500 Date: Fri, 15 Dec 2017 10:34:12 -0800 From: tip-bot for Andy Lutomirski Message-ID: Cc: linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, David.Laight@aculab.com, tglx@linutronix.de, mingo@kernel.org, kirill@shutemov.name, bp@alien8.de, kirill.shutemov@linux.intel.com, dave.hansen@intel.com, keescook@chromium.org, hpa@zytor.com, luto@kernel.org, peterz@infradead.org, brgerst@gmail.com Reply-To: linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, David.Laight@aculab.com, tglx@linutronix.de, kirill@shutemov.name, mingo@kernel.org, bp@alien8.de, kirill.shutemov@linux.intel.com, dave.hansen@intel.com, keescook@chromium.org, hpa@zytor.com, luto@kernel.org, brgerst@gmail.com, peterz@infradead.org In-Reply-To: <24c898b4f44fdf8c22d93703850fb384ef87cfdc.1513035461.git.luto@kernel.org> References: <24c898b4f44fdf8c22d93703850fb384ef87cfdc.1513035461.git.luto@kernel.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/urgent] x86/espfix/64: Fix espfix double-fault handling on 5-level systems Git-Commit-ID: c739f930be1dd5fd949030e3475a884fe06dae9b X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: c739f930be1dd5fd949030e3475a884fe06dae9b Gitweb: https://git.kernel.org/tip/c739f930be1dd5fd949030e3475a884fe06dae9b Author: Andy Lutomirski AuthorDate: Tue, 12 Dec 2017 07:56:36 -0800 Committer: Ingo Molnar CommitDate: Fri, 15 Dec 2017 16:58:53 +0100 x86/espfix/64: Fix espfix double-fault handling on 5-level systems Using PGDIR_SHIFT to identify espfix64 addresses on 5-level systems was wrong, and it resulted in panics due to unhandled double faults. Use P4D_SHIFT instead, which is correct on 4-level and 5-level machines. This fixes a panic when running x86 selftests on 5-level machines. Signed-off-by: Andy Lutomirski Acked-by: Kirill A. Shutemov Cc: Borislav Petkov Cc: Brian Gerst Cc: Dave Hansen Cc: David Laight Cc: Kees Cook Cc: Kirill A. Shutemov Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: stable@vger.kernel.org Fixes: 1d33b219563f ("x86/espfix: Add support for 5-level paging") Link: http://lkml.kernel.org/r/24c898b4f44fdf8c22d93703850fb384ef87cfdc.1513035461.git.luto@kernel.org Signed-off-by: Ingo Molnar --- arch/x86/kernel/traps.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index b7b0f74..c751518 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -355,7 +355,7 @@ dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code) * * No need for ist_enter here because we don't use RCU. */ - if (((long)regs->sp >> PGDIR_SHIFT) == ESPFIX_PGD_ENTRY && + if (((long)regs->sp >> P4D_SHIFT) == ESPFIX_PGD_ENTRY && regs->cs == __KERNEL_CS && regs->ip == (unsigned long)native_irq_return_iret) {