From b3029f49b4cae58e779212b3678805f5bd4a496d Mon Sep 17 00:00:00 2001 From: Tony Luck Date: Mon, 6 Jul 2020 22:13:31 +0800 Subject: [PATCH 2027/2944] x86/mce: Change default MCE logger to check mce->kflags fix #29415191 commit 925946cfa715a5a71639528f82b98e58f14dd4cb upstream 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: Tony Luck Signed-off-by: Borislav Petkov Tested-by: Tony Luck Link: https://lkml.kernel.org/r/20200214222720.13168-6-tony.luck@intel.com Signed-off-by: Youquan Song Signed-off-by: Wetp Zhang Reviewed-by: Artie Ding --- arch/x86/kernel/cpu/mcheck/mce.c | 19 +++---------------- 1 file changed, 3 insertions(+), 16 deletions(-) diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index f0484ff..a2d22be 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -154,29 +154,17 @@ void mce_inject_log(struct mce *m) static struct notifier_block mce_srao_nb; -/* - * We run the default notifier if we have only the SRAO, 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); @@ -259,6 +247,7 @@ 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. @@ -634,10 +623,8 @@ 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; - - __print_mce(m); + if (!m->kflags) + __print_mce(m); return NOTIFY_DONE; } -- 1.8.3.1