From 1d1dd2011adca8fa1e0715a83fc751eae31acf1d Mon Sep 17 00:00:00 2001 From: Tony Luck Date: Fri, 25 May 2018 14:41:39 -0700 Subject: [PATCH] x86/mce: Improve error message when kernel cannot recover commit c7d606f560e4c698884697fef503e4abacdd8c25 upstream. Since we added support to add recovery from some errors inside the kernel in: commit b2f9d678e28c ("x86/mce: Check for faults tagged in EXTABLE_CLASS_FAULT exception table entries") we have done a less than stellar job at reporting the cause of recoverable machine checks that occur in other parts of the kernel. The user just gets the unhelpful message: mce: [Hardware Error]: Machine check: Action required: unknown MCACOD doubly unhelpful when they check the manual for the reported IA32_MSR_STATUS.MCACOD and see that it is listed as one of the standard recoverable values. Add an extra rule to the MCE severity table to catch this case and report it as: mce: [Hardware Error]: Machine check: Data load in unrecoverable area of kernel Fixes: b2f9d678e28c ("x86/mce: Check for faults tagged in EXTABLE_CLASS_FAULT exception table entries") Signed-off-by: Tony Luck Signed-off-by: Thomas Gleixner Cc: Qiuxu Zhuo Cc: Ashok Raj Cc: stable@vger.kernel.org # 4.6+ Cc: Dan Williams Cc: Borislav Petkov Link: https://lkml.kernel.org/r/4cc7c465150a9a48b8b9f45d0b840278e77eb9b5.1527283897.git.tony.luck@intel.com Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/mcheck/mce-severity.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/x86/kernel/cpu/mcheck/mce-severity.c b/arch/x86/kernel/cpu/mcheck/mce-severity.c index 4b8187639c2d..c51353569492 100644 --- a/arch/x86/kernel/cpu/mcheck/mce-severity.c +++ b/arch/x86/kernel/cpu/mcheck/mce-severity.c @@ -143,6 +143,11 @@ static struct severity { SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR|MCI_ADDR|MCACOD, MCI_UC_SAR|MCI_ADDR|MCACOD_INSTR), USER ), + MCESEV( + PANIC, "Data load in unrecoverable area of kernel", + SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR|MCI_ADDR|MCACOD, MCI_UC_SAR|MCI_ADDR|MCACOD_DATA), + KERNEL + ), #endif MCESEV( PANIC, "Action required: unknown MCACOD",