From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:44921 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751774AbcJDIUr (ORCPT ); Tue, 4 Oct 2016 04:20:47 -0400 Subject: Patch "x86/init: Fix cr4_init_shadow() on CR4-less machines" has been added to the 4.4-stable tree To: luto@kernel.org, bp@alien8.de, bp@suse.de, brgerst@gmail.com, dvlasenk@redhat.com, gregkh@linuxfoundation.org, hpa@zytor.com, jpoimboe@redhat.com, mingo@kernel.org, peterz@infradead.org, tglx@linutronix.de, torvalds@linux-foundation.org Cc: , From: Date: Tue, 04 Oct 2016 10:17:02 +0200 Message-ID: <147556902290131@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled x86/init: Fix cr4_init_shadow() on CR4-less machines to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: x86-init-fix-cr4_init_shadow-on-cr4-less-machines.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From e1bfc11c5a6f40222a698a818dc269113245820e Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Wed, 28 Sep 2016 12:34:14 -0700 Subject: x86/init: Fix cr4_init_shadow() on CR4-less machines From: Andy Lutomirski commit e1bfc11c5a6f40222a698a818dc269113245820e upstream. 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 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 Signed-off-by: Greg Kroah-Hartman --- arch/x86/include/asm/tlbflush.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/x86/include/asm/tlbflush.h +++ b/arch/x86/include/asm/tlbflush.h @@ -32,7 +32,7 @@ DECLARE_PER_CPU_SHARED_ALIGNED(struct tl /* 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. */ Patches currently in stable-queue which might be from luto@kernel.org are queue-4.4/x86-init-fix-cr4_init_shadow-on-cr4-less-machines.patch queue-4.4/x86-boot-initialize-fpu-and-x86_feature_always-even-if-we-don-t-have-cpuid.patch