4.18-stable review patch. If anyone has any objections, please let me know.
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From: Vishal Verma vishal.l.verma@intel.com
commit 5d96c9342c23ee1d084802dcf064caa67ecaa45b upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/include/asm/mce.h | 1 + arch/x86/kernel/cpu/mcheck/mce.c | 3 ++- drivers/acpi/nfit/mce.c | 4 ++-- 3 files changed, 5 insertions(+), 3 deletions(-)
--- a/arch/x86/include/asm/mce.h +++ b/arch/x86/include/asm/mce.h @@ -216,6 +216,7 @@ static inline int umc_normaddr_to_sysadd
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); --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -538,7 +538,7 @@ 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; @@ -548,6 +548,7 @@ static bool mce_is_correctable(struct mc
return true; } +EXPORT_SYMBOL_GPL(mce_is_correctable);
static bool cec_add_mce(struct mce *m) { --- a/drivers/acpi/nfit/mce.c +++ b/drivers/acpi/nfit/mce.c @@ -25,8 +25,8 @@ static int nfit_handle_mce(struct notifi 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;
/*