Three interrupt related fixes for X86: - Move disabling of the local APIC after invoking fixup_irqs() to ensure that interrupts which are incoming are noted in the IRR and not ignored. - Unbreak affinity setting. The rework of the entry code reused the regular exception entry code for device interrupts. The vector number is pushed into the errorcode slot on the stack which is then lifted into an argument and set to -1 because that's regs->orig_ax which is used in quite some places to check whether the entry came from a syscall. But it was overlooked that orig_ax is used in the affinity cleanup code to validate whether the interrupt has arrived on the new target. It turned out that this vector check is pointless because interrupts are never moved from one vector to another on the same CPU. That check is a historical leftover from the time where x86 supported multi-CPU affinities, but not longer needed with the now strict single CPU affinity. Famous last words ... - Add a missing check for an empty cpumask into the matrix allocator. The affinity change added a warning to catch the case where an interrupt is moved on the same CPU to a different vector. This triggers because a condition with an empty cpumask returns an assignment from the allocator as the allocator uses for_each_cpu() without checking the cpumask for being empty. The historical inconsistent for_each_cpu() behaviour of ignoring the cpumask and unconditionally claiming that CPU0 is in the mask striked again. Sigh.