Commit 925946cf authored by Tony Luck's avatar Tony Luck Committed by Borislav Petkov
Browse files

x86/mce: Change default MCE logger to check mce->kflags 



Instead of keeping count of how many handlers are registered on the
MCE notifier chain and printing if below some magic value, look at
mce->kflags to see if anyone claims to have handled/logged this error.

 [ bp: Do not print ->kflags in __print_mce(). ]

Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Tested-by: default avatarTony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20200214222720.13168-6-tony.luck@intel.com
parent 23ba710a

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

+3 −16
Original line number Diff line number Diff line
@@ -158,29 +158,17 @@ void mce_log(struct mce *m) 
}

EXPORT_SYMBOL_GPL(mce_log);



/*

 * We run the default notifier if we have only the UC, the first and the

 * default notifier registered. I.e., the mandatory NUM_DEFAULT_NOTIFIERS

 * notifiers registered on the chain.

 */

#define NUM_DEFAULT_NOTIFIERS	3

static atomic_t num_notifiers;



void mce_register_decode_chain(struct notifier_block *nb)

{

	if (WARN_ON(nb->priority > MCE_PRIO_MCELOG && nb->priority < MCE_PRIO_EDAC))

		return;



	atomic_inc(&num_notifiers);



	blocking_notifier_chain_register(&x86_mce_decoder_chain, nb);

}

EXPORT_SYMBOL_GPL(mce_register_decode_chain);



void mce_unregister_decode_chain(struct notifier_block *nb)

{

	atomic_dec(&num_notifiers);



	blocking_notifier_chain_unregister(&x86_mce_decoder_chain, nb);

}

EXPORT_SYMBOL_GPL(mce_unregister_decode_chain);
@@ -263,6 +251,7 @@ static void __print_mce(struct mce *m) 
	}



	pr_cont("\n");



	/*

	 * Note this output is parsed by external tools and old fields

	 * should not be changed.
@@ -602,9 +591,7 @@ static int mce_default_notifier(struct notifier_block *nb, unsigned long val, 
	if (!m)

		return NOTIFY_DONE;



	if (atomic_read(&num_notifiers) > NUM_DEFAULT_NOTIFIERS)

		return NOTIFY_DONE;



	if (!m->kflags)

		__print_mce(m);



	return NOTIFY_DONE;