From: Borislav Petkov <[email protected]> Change the MCE decoding flow to issue the trace_mce_record() tracepoint only when there's no decoder registered on the decoder chain. If there is, it will do some massaging on the MCE info before issuing it through the tracepoint.
Signed-off-by: Borislav Petkov <[email protected]> --- arch/x86/include/asm/mce.h | 4 +++- arch/x86/kernel/cpu/mcheck/mce.c | 9 ++++++++- 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h index 181264989db5..ba4c99ace544 100644 --- a/arch/x86/include/asm/mce.h +++ b/arch/x86/include/asm/mce.h @@ -146,6 +146,7 @@ struct mca_config { bool ser; bool recovery; bool bios_cmci_threshold; + bool has_decoder; u8 banks; s8 bootlog; int tolerant; @@ -195,7 +196,8 @@ enum mce_notifier_prios { MCE_PRIO_SRAO = INT_MAX - 1, MCE_PRIO_EXTLOG = INT_MAX - 2, MCE_PRIO_NFIT = INT_MAX - 3, - MCE_PRIO_EDAC = INT_MAX - 4, + MCE_PRIO_DECODER = INT_MAX - 4, + MCE_PRIO_EDAC = INT_MAX - 5, MCE_PRIO_MCELOG = 1, MCE_PRIO_LOWEST = 0, }; diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index 3b413065c613..dcf75f40e031 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -163,6 +163,9 @@ void mce_register_decode_chain(struct notifier_block *nb) atomic_inc(&num_notifiers); + if (nb->priority == MCE_PRIO_DECODER) + mca_cfg.has_decoder = true; + blocking_notifier_chain_register(&x86_mce_decoder_chain, nb); } EXPORT_SYMBOL_GPL(mce_register_decode_chain); @@ -171,6 +174,9 @@ void mce_unregister_decode_chain(struct notifier_block *nb) { atomic_dec(&num_notifiers); + if (nb->priority == MCE_PRIO_DECODER) + mca_cfg.has_decoder = false; + blocking_notifier_chain_unregister(&x86_mce_decoder_chain, nb); } EXPORT_SYMBOL_GPL(mce_unregister_decode_chain); @@ -557,7 +563,8 @@ static int mce_first_notifier(struct notifier_block *nb, unsigned long val, return NOTIFY_STOP; /* Emit the trace record: */ - trace_mce_record(m); + if (!mca_cfg.has_decoder) + trace_mce_record(m); set_bit(0, &mce_need_notify); -- 2.13.0
