From: Thomas Gleixner tglx@linutronix.de
[ Upstream commit df4393424af3fbdcd5c404077176082a8ce459c4 ]
There is an issue with threaded interrupts which are marked ONESHOT and using the fasteoi handler:
if (IS_ONESHOT()) mask_irq(); .... cond_unmask_eoi_irq() chip->irq_eoi(); if (setaffinity_pending) { mask_ioapic(); ... move_affinity(); unmask_ioapic(); }
So if setaffinity is pending the interrupt will be moved and then unconditionally unmasked at the ioapic level, which is wrong in two aspects:
1) It should be kept masked up to the point where the threaded handler finished.
2) The physical chip state and the software masked state are inconsistent
Guard both the mask and the unmask with a check for the software masked state. If the line is marked masked then the ioapic line is also masked, so both mask_ioapic() and unmask_ioapic() can be skipped safely.
Signed-off-by: Thomas Gleixner tglx@linutronix.de Cc: Andy Shevchenko andy.shevchenko@gmail.com Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Peter Zijlstra peterz@infradead.org Cc: Sebastian Siewior bigeasy@linutronix.de Fixes: 3aa551c9b4c4 ("genirq: add threaded interrupt handler support") Link: https://lkml.kernel.org/r/20191017101938.321393687@linutronix.de Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/kernel/apic/io_apic.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index 4d5e8ff3b5e5..5e8fc9809da3 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -1710,9 +1710,10 @@ static bool io_apic_level_ack_pending(struct mp_chip_data *data)
static inline bool ioapic_irqd_mask(struct irq_data *data) { - /* If we are moving the irq we need to mask it */ + /* If we are moving the IRQ we need to mask it */ if (unlikely(irqd_is_setaffinity_pending(data))) { - mask_ioapic_irq(data); + if (!irqd_irq_masked(data)) + mask_ioapic_irq(data); return true; } return false; @@ -1749,7 +1750,9 @@ static inline void ioapic_irqd_unmask(struct irq_data *data, bool masked) */ if (!io_apic_level_ack_pending(data->chip_data)) irq_move_masked_irq(data); - unmask_ioapic_irq(data); + /* If the IRQ is masked in the core, leave it: */ + if (!irqd_irq_masked(data)) + unmask_ioapic_irq(data); } } #else