diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2012-11-23 10:08:44 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2012-12-11 12:25:30 +0100 |
| commit | e716efde75267eab919cdb2bef5b2cb77f305326 (patch) | |
| tree | 7af4b7266b29a7a0268fcf68cb5f3a8c23405dd3 | |
| parent | 04aa530ec04f61875b99c12721162e2964e3318c (diff) | |
| download | lwn-e716efde75267eab919cdb2bef5b2cb77f305326.tar.gz lwn-e716efde75267eab919cdb2bef5b2cb77f305326.zip | |
genirq: Avoid deadlock in spurious handling
commit 52553ddf(genirq: fix regression in irqfixup, irqpoll)
introduced a potential deadlock by calling the action handler with the
irq descriptor lock held.
Remove the call and let the handling code run even for an interrupt
where only a single action is registered. That matches the goal of
the above commit and avoids the deadlock.
Document the confusing action = desc->action reload in the handling
loop while at it.
Reported-and-tested-by: "Wang, Warner" <warner.wang@hp.com>
Tested-by: Edward Donovan <edward.donovan@numble.net>
Cc: "Wang, Song-Bo (Stoney)" <song-bo.wang@hp.com>
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| -rw-r--r-- | kernel/irq/spurious.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c index 611cd6003c45..7b5f012bde9d 100644 --- a/kernel/irq/spurious.c +++ b/kernel/irq/spurious.c @@ -80,13 +80,11 @@ static int try_one_irq(int irq, struct irq_desc *desc, bool force) /* * All handlers must agree on IRQF_SHARED, so we test just the - * first. Check for action->next as well. + * first. */ action = desc->action; if (!action || !(action->flags & IRQF_SHARED) || - (action->flags & __IRQF_TIMER) || - (action->handler(irq, action->dev_id) == IRQ_HANDLED) || - !action->next) + (action->flags & __IRQF_TIMER)) goto out; /* Already running on another processor */ @@ -104,6 +102,7 @@ static int try_one_irq(int irq, struct irq_desc *desc, bool force) do { if (handle_irq_event(desc) == IRQ_HANDLED) ret = IRQ_HANDLED; + /* Make sure that there is still a valid action */ action = desc->action; } while ((desc->istate & IRQS_PENDING) && action); desc->istate &= ~IRQS_POLL_INPROGRESS; |