diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2020-03-06 14:03:46 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-03-08 11:06:41 +0100 |
| commit | da90921acc62c71d27729ae211ccfda5370bf75b (patch) | |
| tree | fb26cfaf7dd63e0092d50824c2b2b8af93056b53 /kernel/irq/resend.c | |
| parent | 1f85b1f5e1f5541272abedc19ba7b6c5b564c228 (diff) | |
| download | lwn-da90921acc62c71d27729ae211ccfda5370bf75b.tar.gz lwn-da90921acc62c71d27729ae211ccfda5370bf75b.zip | |
genirq: Sanitize state handling in check_irq_resend()
The code sets IRQS_REPLAY unconditionally whether the resend happens or
not. That doesn't have bad side effects right now, but inconsistent state
is always a latent source of problems.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lkml.kernel.org/r/20200306130623.882129117@linutronix.de
Diffstat (limited to 'kernel/irq/resend.c')
| -rw-r--r-- | kernel/irq/resend.c | 22 |
1 files changed, 14 insertions, 8 deletions
diff --git a/kernel/irq/resend.c b/kernel/irq/resend.c index a21fc4eeedc7..bef72dcfb79b 100644 --- a/kernel/irq/resend.c +++ b/kernel/irq/resend.c @@ -93,6 +93,8 @@ static int irq_sw_resend(struct irq_desc *desc) */ int check_irq_resend(struct irq_desc *desc) { + int err = 0; + /* * We do not resend level type interrupts. Level type interrupts * are resent by hardware when they are still active. Clear the @@ -106,13 +108,17 @@ int check_irq_resend(struct irq_desc *desc) if (desc->istate & IRQS_REPLAY) return -EBUSY; - if (desc->istate & IRQS_PENDING) { - desc->istate &= ~IRQS_PENDING; - desc->istate |= IRQS_REPLAY; + if (!(desc->istate & IRQS_PENDING)) + return 0; - if (!desc->irq_data.chip->irq_retrigger || - !desc->irq_data.chip->irq_retrigger(&desc->irq_data)) - return irq_sw_resend(desc); - } - return 0; + desc->istate &= ~IRQS_PENDING; + + if (!desc->irq_data.chip->irq_retrigger || + !desc->irq_data.chip->irq_retrigger(&desc->irq_data)) + err = irq_sw_resend(desc); + + /* If the retrigger was successfull, mark it with the REPLAY bit */ + if (!err) + desc->istate |= IRQS_REPLAY; + return err; } |