Re: [PATCH 1/3] x86/init: Fix cr4_init_shadow() on CR4-less machines
From: Borislav Petkov <bp@alien8.de>
Date: 2016-09-29 11:44:55
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On Wed, Sep 28, 2016 at 12:34:14PM -0700, Andy Lutomirski wrote:
quoted hunk ↗ jump to hunk
cr4_init_shadow() will panic on 486-like machines without CR4. Fix it using __read_cr4_safe(). Cc: stable@vger.kernel.org Reported-by: david@saggiorato.net Fixes: 1e02ce4cccdc ("x86: Store a per-cpu shadow copy of CR4") Signed-off-by: Andy Lutomirski <luto@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 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. */--
Reviewed-by: Borislav Petkov <redacted>
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Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply.
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