x86/asm/64: Clear AC on NMI entries
This closes a hole in our SMAP implementation.
This patch comes from grsecurity. Good catch!
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/314cc9f294e8f14ed85485727556ad4f15bb1659.1502159503.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index d271fb7..6d078b8 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1211,6 +1211,8 @@
* other IST entries.
*/
+ ASM_CLAC
+
/* Use %rdx as our temp variable throughout */
pushq %rdx