WARN if the IA32_FEATURE_CONTROL MSR is somehow left unlocked now that CPU initialization unconditionally locks the MSR. Reviewed-by: Borislav Petkov <bp@xxxxxxx> Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> --- arch/x86/kernel/cpu/mce/intel.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/cpu/mce/intel.c b/arch/x86/kernel/cpu/mce/intel.c index 3e5b29acd301..5abc55a67fce 100644 --- a/arch/x86/kernel/cpu/mce/intel.c +++ b/arch/x86/kernel/cpu/mce/intel.c @@ -119,11 +119,10 @@ static bool lmce_supported(void) * generate a #GP fault. */ rdmsrl(MSR_IA32_FEATURE_CONTROL, tmp); - if ((tmp & (FEAT_CTL_LOCKED | FEAT_CTL_LMCE_ENABLED)) == - (FEAT_CTL_LOCKED | FEAT_CTL_LMCE_ENABLED)) - return true; + if (WARN_ON_ONCE(!(tmp & FEAT_CTL_LOCKED))) + return false; - return false; + return tmp & FEAT_CTL_LMCE_ENABLED; } bool mce_intel_cmci_poll(void) -- 2.24.0
