Commit-ID: e1bfc11c5a6f40222a698a818dc269113245820e Gitweb: http://git.kernel.org/tip/e1bfc11c5a6f40222a698a818dc269113245820e Author: Andy Lutomirski <l...@kernel.org> AuthorDate: Wed, 28 Sep 2016 12:34:14 -0700 Committer: Ingo Molnar <mi...@kernel.org> 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: da...@saggiorato.net Signed-off-by: Andy Lutomirski <l...@kernel.org> Reviewed-by: Borislav Petkov <b...@suse.de> Cc: Borislav Petkov <b...@alien8.de> Cc: Brian Gerst <brge...@gmail.com> Cc: Denys Vlasenko <dvlas...@redhat.com> Cc: H. Peter Anvin <h...@zytor.com> Cc: Josh Poimboeuf <jpoim...@redhat.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Cc: sta...@vger.kernel.org Fixes: 1e02ce4cccdc ("x86: Store a per-cpu shadow copy of CR4") Link: http://lkml.kernel.org/r/43a20f81fb504013bf613913dc25574b45336a61.1475091074.git.l...@kernel.org Signed-off-by: Ingo Molnar <mi...@kernel.org> --- 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. */