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authorAndy Lutomirski <luto@kernel.org>2016-09-28 12:34:14 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-10-07 15:23:40 +0200
commit6c0db7437f4d0a0ce9dcbecb811275d034b11b96 (patch)
tree8d2b1f0aa0ae2fa726a7e38dd0c4f6d01a2a1f0a /arch/x86/include
parent7677956e4094595732df548681ea9c4d66821bdb (diff)
x86/init: Fix cr4_init_shadow() on CR4-less machines
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 <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> 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/include')
-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 3142218e546f..6433e28dc9c8 100644
--- a/arch/x86/include/asm/tlbflush.h
+++ b/arch/x86/include/asm/tlbflush.h
@@ -32,7 +32,7 @@ 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. */