4.17-stable review patch. If anyone has any objections, please let me know.
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From: Tony Luck tony.luck@intel.com
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 tony.luck@intel.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Cc: Qiuxu Zhuo qiuxu.zhuo@intel.com Cc: Ashok Raj ashok.raj@intel.com Cc: stable@vger.kernel.org # 4.6+ Cc: Dan Williams dan.j.williams@intel.com Cc: Borislav Petkov bp@suse.de Link: https://lkml.kernel.org/r/4cc7c465150a9a48b8b9f45d0b840278e77eb9b5.152728389... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/kernel/cpu/mcheck/mce-severity.c | 5 +++++ 1 file changed, 5 insertions(+)
--- a/arch/x86/kernel/cpu/mcheck/mce-severity.c +++ b/arch/x86/kernel/cpu/mcheck/mce-severity.c @@ -160,6 +160,11 @@ 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",