Commit 6d527ceb authored by Sean Christopherson's avatar Sean Christopherson Committed by Borislav Petkov
Browse files

x86/mce: WARN once if IA32_FEAT_CTL MSR is left unlocked 



WARN if the IA32_FEAT_CTL MSR is somehow left unlocked now that CPU
initialization unconditionally locks the MSR.

Signed-off-by: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20191221044513.21680-6-sean.j.christopherson@intel.com
parent 1db2a6e1

arch/x86/kernel/cpu/mce/intel.c

+6 −5
Original line number Diff line number Diff line
@@ -116,14 +116,15 @@ static bool lmce_supported(void) 
	/*

	 * BIOS should indicate support for LMCE by setting bit 20 in

	 * IA32_FEAT_CTL without which touching MCG_EXT_CTL will generate a #GP

	 * fault.

	 * fault.  The MSR must also be locked for LMCE_ENABLED to take effect.

	 * WARN if the MSR isn't locked as init_ia32_feat_ctl() unconditionally

	 * locks the MSR in the event that it wasn't already locked by BIOS.

	 */

	rdmsrl(MSR_IA32_FEAT_CTL, 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 tmp & FEAT_CTL_LMCE_ENABLED;

}



bool mce_intel_cmci_poll(void)

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