Fix machine check recovery for instruction fault on Sandy Bridge

[Unchanged since last posted - except to add Boris' Acked-by
since after further discussion his nitpick didn't warrant a change. Ready for x86/mce branch ... and if possible to move to Linus in this merge window]

This patch series adds a workaround for some strange asymmetry between how machine checks are reported for data and instruction fetches. For instruction fetch error the processor does not set the EIPV bit in the MCG_STATUS register on the affected processor, leading us to believe that the cs/ip values saved on the stack are not associated with the machine check ... which in turn makes us unable to determine whether the machine check was taken in kernel or user mode. The workaround is to fake the presence of the EIPV bit for this error on this processor model. Not pretty, but avoids having to make special cases later in the code.

Tony Luck (2):
x86/mce: Move MCACOD defines from mce-severity.c to <asm/mce.h> x86/mce: Add quirk for instruction recovery on Sandy Bridge
processors

 arch/x86/include/asm/mce.h                |  8 ++++++
 arch/x86/kernel/cpu/mcheck/mce-severity.c |  7 -----
 arch/x86/kernel/cpu/mcheck/mce.c          | 43 ++++++++++++++++++++++++++++---
 3 files changed, 48 insertions(+), 10 deletions(-)

1.7.10.2.552.gaa3bb87