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. */
