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authorAndy Lutomirski <luto@kernel.org>2016-09-28 12:34:14 -0700
committerIngo Molnar <mingo@kernel.org>2016-09-29 19:08:30 +0200
commite1bfc11c5a6f40222a698a818dc269113245820e (patch)
treeb6a55b3ed54de70282b676db15103fec1efbc052
parent8ab293e3a1376574e11f9059c09cc0db212546cb (diff)
downloadlinux-sh-e1bfc11c5a6f40222a698a818dc269113245820e.tar.gz
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 <luto@kernel.org> Reviewed-by: Borislav Petkov <bp@suse.de> 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 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 <mingo@kernel.org>
-rw-r--r--arch/x86/include/asm/tlbflush.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h
index 6fa85944af83..dee8a70382ba 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. */