The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 5d96c9342c23ee1d084802dcf064caa67ecaa45b Mon Sep 17 00:00:00 2001

From: Vishal Verma vishal.l.verma@intel.com Date: Thu, 25 Oct 2018 18:37:28 -0600 Subject: [PATCH] acpi/nfit, x86/mce: Handle only uncorrectable machine checks

The MCE handler for nfit devices is called for memory errors on a Non-Volatile DIMM and adds the error location to a 'badblocks' list. This list is used by the various NVDIMM drivers to avoid consuming known poison locations during IO.

The MCE handler gets called for both corrected and uncorrectable errors. Until now, both kinds of errors have been added to the badblocks list. However, corrected memory errors indicate that the problem has already been fixed by hardware, and the resulting interrupt is merely a notification to Linux.

As far as future accesses to that location are concerned, it is perfectly fine to use, and thus doesn't need to be included in the above badblocks list.

Add a check in the nfit MCE handler to filter out corrected mce events, and only process uncorrectable errors.

Fixes: 6839a6d96f4e ("nfit: do an ARS scrub on hitting a latent media error") Reported-by: Omar Avelar omar.avelar@intel.com Signed-off-by: Vishal Verma vishal.l.verma@intel.com Signed-off-by: Borislav Petkov bp@suse.de CC: Arnd Bergmann arnd@arndb.de CC: Dan Williams dan.j.williams@intel.com CC: Dave Jiang dave.jiang@intel.com CC: elliott@hpe.com CC: "H. Peter Anvin" hpa@zytor.com CC: Ingo Molnar mingo@redhat.com CC: Len Brown lenb@kernel.org CC: linux-acpi@vger.kernel.org CC: linux-edac linux-edac@vger.kernel.org CC: linux-nvdimm@lists.01.org CC: Qiuxu Zhuo qiuxu.zhuo@intel.com CC: "Rafael J. Wysocki" rjw@rjwysocki.net CC: Ross Zwisler zwisler@kernel.org CC: stable stable@vger.kernel.org CC: Thomas Gleixner tglx@linutronix.de CC: Tony Luck tony.luck@intel.com CC: x86-ml x86@kernel.org CC: Yazen Ghannam yazen.ghannam@amd.com Link: http://lkml.kernel.org/r/20181026003729.8420-1-vishal.l.verma@intel.com

diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h index 4da9b1c58d28..dbd9fe2f6163 100644 --- a/arch/x86/include/asm/mce.h +++ b/arch/x86/include/asm/mce.h @@ -221,6 +221,7 @@ static inline void mce_hygon_feature_init(struct cpuinfo_x86 *c) { return mce_am

int mce_available(struct cpuinfo_x86 *c); bool mce_is_memory_error(struct mce *m); +bool mce_is_correctable(struct mce *m);

DECLARE_PER_CPU(unsigned, mce_exception_count); DECLARE_PER_CPU(unsigned, mce_poll_count); diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index 8c66d2fc8f81..77527b8ea982 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -534,7 +534,7 @@ bool mce_is_memory_error(struct mce *m) } EXPORT_SYMBOL_GPL(mce_is_memory_error);

-static bool mce_is_correctable(struct mce *m) +bool mce_is_correctable(struct mce *m) { if (m->cpuvendor == X86_VENDOR_AMD && m->status & MCI_STATUS_DEFERRED) return false; @@ -547,6 +547,7 @@ static bool mce_is_correctable(struct mce *m)

return true; } +EXPORT_SYMBOL_GPL(mce_is_correctable);

static bool cec_add_mce(struct mce *m) { diff --git a/drivers/acpi/nfit/mce.c b/drivers/acpi/nfit/mce.c index e9626bf6ca29..7a51707f87e9 100644 --- a/drivers/acpi/nfit/mce.c +++ b/drivers/acpi/nfit/mce.c @@ -25,8 +25,8 @@ static int nfit_handle_mce(struct notifier_block *nb, unsigned long val, struct acpi_nfit_desc *acpi_desc; struct nfit_spa *nfit_spa;

- /* We only care about memory errors */ - if (!mce_is_memory_error(mce)) + /* We only care about uncorrectable memory errors */ + if (!mce_is_memory_error(mce) || mce_is_correctable(mce)) return NOTIFY_DONE;

/*