On Friday 25 January 2008 09:38:38 Nick Piggin wrote: > On Friday 25 January 2008 19:15, Jan Beulich wrote: > > Actually, another thought: permitting (and handling) spurious faults for > > kernel mappings conflicts with NMI handling, i.e. great care would be > > needed to ensure the NMI path cannot touch any such mapping. So > > even the present Xen/Linux Dom0 implementation may have some > > (perhaps unlikely) problems here, and it would get worse if we added > > e.g. a virtual watchdog NMI (something I am considering, which would > > then extend the problem to DomU-s). > > Can you explain how they conflict?
NMI is blocked by the hardware until IRET and when a page fault happens inside the NMI handler the early IRET unblocks it and then NMIs can nest, which will lead to stack corruption. -Andi -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
