x86_64/HOTPLUG_CPU: NULL dereference doesn't #PF with init_level4_pgt

[Zwane Mwaikambo]

NULL dereferences don't cause a page fault if the 4th level pagetable 
being used is init_level4_pgt because we never zap_low_mappings. Since 
the idle thread uses init_level4_pgt any bad dereferences happening there 
(e.g. from interrupts) won't cause a fault. Andi would you be fine with 
switching the idle threads to a different level4?

Thanks,
	Zwane

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/