From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934889AbcI2SYp (ORCPT ); Thu, 29 Sep 2016 14:24:45 -0400 Received: from terminus.zytor.com ([198.137.202.10]:52396 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934559AbcI2SYg (ORCPT ); Thu, 29 Sep 2016 14:24:36 -0400 Date: Thu, 29 Sep 2016 11:21:42 -0700 From: tip-bot for Andy Lutomirski Message-ID: Cc: linux-kernel@vger.kernel.org, jpoimboe@redhat.com, peterz@infradead.org, tglx@linutronix.de, torvalds@linux-foundation.org, bp@suse.de, dvlasenk@redhat.com, brgerst@gmail.com, hpa@zytor.com, bp@alien8.de, mingo@kernel.org, luto@kernel.org Reply-To: peterz@infradead.org, tglx@linutronix.de, linux-kernel@vger.kernel.org, jpoimboe@redhat.com, dvlasenk@redhat.com, brgerst@gmail.com, bp@alien8.de, hpa@zytor.com, mingo@kernel.org, luto@kernel.org, torvalds@linux-foundation.org, bp@suse.de In-Reply-To: <43a20f81fb504013bf613913dc25574b45336a61.1475091074.git.luto@kernel.org> References: <43a20f81fb504013bf613913dc25574b45336a61.1475091074.git.luto@kernel.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/urgent] x86/init: Fix cr4_init_shadow() on CR4-less machines Git-Commit-ID: e1bfc11c5a6f40222a698a818dc269113245820e 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: e1bfc11c5a6f40222a698a818dc269113245820e Gitweb: http://git.kernel.org/tip/e1bfc11c5a6f40222a698a818dc269113245820e Author: Andy Lutomirski AuthorDate: Wed, 28 Sep 2016 12:34:14 -0700 Committer: Ingo Molnar CommitDate: Thu, 29 Sep 2016 19:08:30 +0200 x86/init: Fix cr4_init_shadow() on CR4-less machines cr4_init_shadow() will panic on 486-like machines without CR4. Fix it using __read_cr4_safe(). Reported-by: david@saggiorato.net Signed-off-by: Andy Lutomirski Reviewed-by: Borislav Petkov Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: stable@vger.kernel.org Fixes: 1e02ce4cccdc ("x86: Store a per-cpu shadow copy of CR4") Link: http://lkml.kernel.org/r/43a20f81fb504013bf613913dc25574b45336a61.1475091074.git.luto@kernel.org Signed-off-by: Ingo Molnar --- arch/x86/include/asm/tlbflush.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h index 6fa8594..dee8a70 100644 --- a/arch/x86/include/asm/tlbflush.h +++ b/arch/x86/include/asm/tlbflush.h @@ -81,7 +81,7 @@ DECLARE_PER_CPU_SHARED_ALIGNED(struct tlb_state, cpu_tlbstate); /* Initialize cr4 shadow for this CPU. */ static inline void cr4_init_shadow(void) { - this_cpu_write(cpu_tlbstate.cr4, __read_cr4()); + this_cpu_write(cpu_tlbstate.cr4, __read_cr4_safe()); } /* Set in this cpu's CR4. */