From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg Kroah-Hartman Subject: [PATCH 4.18 073/171] acpi/nfit, x86/mce: Handle only uncorrectable machine checks Date: Mon, 19 Nov 2018 17:27:49 +0100 Message-ID: <20181119162631.442303192@linuxfoundation.org> References: <20181119162618.909354448@linuxfoundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20181119162618.909354448@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Omar Avelar , Vishal Verma , Borislav Petkov , Arnd Bergmann , Dan Williams , Dave Jiang , elliott@hpe.com, "H. Peter Anvin" , Ingo Molnar , Len Brown , linux-acpi@vger.kernel.org, linux-edac , linux-nvdimm@lists.01.org, Qiuxu Zhuo , "Rafael J. Wysocki" , Ross Zwisler , Thomas Gleixner , Tony Luck , x86-ml , Yazen Ghannam List-Id: linux-acpi@vger.kernel.org 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Vishal Verma 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 Signed-off-by: Vishal Verma Signed-off-by: Borislav Petkov CC: Arnd Bergmann CC: Dan Williams CC: Dave Jiang CC: elliott@hpe.com CC: "H. Peter Anvin" CC: Ingo Molnar CC: Len Brown CC: linux-acpi@vger.kernel.org CC: linux-edac CC: linux-nvdimm@lists.01.org CC: Qiuxu Zhuo CC: "Rafael J. Wysocki" CC: Ross Zwisler CC: stable CC: Thomas Gleixner CC: Tony Luck CC: x86-ml CC: Yazen Ghannam Link: http://lkml.kernel.org/r/20181026003729.8420-1-vishal.l.verma@intel.com Signed-off-by: Greg Kroah-Hartman --- 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; /*