On Sat, 2018-02-03 at 07:17:50 UTC, Nicholas Piggin wrote: > The soft IRQ masking code has to hard-disable interrupts in cases > where the exception is not cleared by the masked handler. External > interrupts used this approach for soft masking. Now recently PMU > interrupts do the same thing. > > The soft IRQ masking code additionally allowed for interrupt handlers > to hard-enable interrupts after soft-disabling them. The idea is to > allow PMU interrupts through to profile interrupt handlers. > > So when interrupts are being replayed when there is a pending > interrupt that requires hard-disabling, there is a test to prevent > those handlers from hard-enabling them if there is a pending external > interrupt. may_hard_irq_enable() handles this. > > After f442d00480 ("powerpc/64s: Add support to mask perf interrupts > and replay them"), may_hard_irq_enable() could prematurely enable > MSR[EE] when a PMU exception exists, which would result in the > interrupt firing again while masked, and MSR[EE] being disabled again. > > I haven't seen that this could cause a serious problem, but it's > more consistent to handle these soft-masked interrupts in the same > way. So introduce a define for all types of interrupts that require > MSR[EE] masking in their soft-disable handlers, and use that in > may_hard_irq_enable(). > > Cc: Madhavan Srinivasan <ma...@linux.vnet.ibm.com> > Signed-off-by: Nicholas Piggin <npig...@gmail.com> > Reviewed-by: Madhavan Srinivasan <ma...@linux.vnet.ibm.com>
Applied to powerpc fixes, thanks. https://git.kernel.org/powerpc/c/6cc3f91bf69fc8c1719704607474f9 cheers