On Fri, Dec 11, 2015 at 2:45 PM, Luck, Tony <tony.l...@intel.com> wrote: >>> But a machine check safe copy_from_user() would be useful >>> current generation cpus that broadcast all the time. >> >> Fair enough. > > Thanks for spending the time to look at this. Coaxing me to re-write the > tail of do_machine_check() has made that code much better. Too many > years of one patch on top of another without looking at the whole context. > > Cogitate on this series over the weekend and see if you can give me > an Acked-by or Reviewed-by (I'll be adding a #define for BIT(63)).
I can't review the MCE decoding part, because I don't understand it nearly well enough. The interaction with the core fault handling looks fine, modulo any need to bikeshed on the macro naming (which I'll refrain from doing). I still think it would be better if you get rid of BIT(63) and use a pair of landing pads, though. They could be as simple as: .Lpage_fault_goes_here: xorq %rax, %rax jmp .Lbad .Lmce_goes_here: /* set high bit of rax or whatever */ /* fall through */ .Lbad: /* deal with it */ That way the magic is isolated to the function that needs the magic. Also, at least renaming the macro to EXTABLE_MC_PA_IN_AX might be nice. It'll keep future users honest. Maybe some day there'll be a PA_IN_AX flag, and, heck, maybe some day there'll be ways to get info for non-MCE faults delivered through fixup_exception. --Andy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/