Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Fix crash with irqpoll due to the IRQF_IRQPOLL flag testing
With irqpoll enabled, trying to test the IRQF_IRQPOLL flag in the
actions would cause a NULL pointer dereference if no action was
installed (for example, the driver might have been unloaded with
interrupts still pending).
So be a bit more careful about testing the flag by making sure to test
for that case.
(The actual _change_ is trivial, the patch is more than a one-liner
because I rewrote the testing to also be much more readable.
Original (discarded) bugfix by Bernhard Walle.
Cc: Bernhard Walle <bwalle@suse.de>
Tested-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+37
-9
+37
-9
kernel/irq/spurious.c
+37
-9
kernel/irq/spurious.c
···
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}
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}
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+
static inline int try_misrouted_irq(unsigned int irq, struct irq_desc *desc, irqreturn_t action_ret)
139
+
{
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+
struct irqaction *action;
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+
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+
if (!irqfixup)
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return 0;
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+
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+
/* We didn't actually handle the IRQ - see if it was misrouted? */
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+
if (action_ret == IRQ_NONE)
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return 1;
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+
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/*
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* But for 'irqfixup == 2' we also do it for handled interrupts if
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+
* they are marked as IRQF_IRQPOLL (or for irq zero, which is the
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* traditional PC timer interrupt.. Legacy)
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+
*/
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if (irqfixup < 2)
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return 0;
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+
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+
if (!irq)
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return 1;
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+
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+
/*
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* Since we don't get the descriptor lock, "action" can
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* change under us. We don't really care, but we don't
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* want to follow a NULL pointer. So tell the compiler to
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* just load it once by using a barrier.
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+
*/
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action = desc->action;
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barrier();
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return action && (action->flags & IRQF_IRQPOLL);
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+
}
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+
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void note_interrupt(unsigned int irq, struct irq_desc *desc,
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irqreturn_t action_ret)
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{
···
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report_bad_irq(irq, desc, action_ret);
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}
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146
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-
if (unlikely(irqfixup)) {
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-
/* Don't punish working computers */
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-
if ((irqfixup == 2 && ((irq == 0) ||
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-
(desc->action->flags & IRQF_IRQPOLL))) ||
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-
action_ret == IRQ_NONE) {
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-
int ok = misrouted_irq(irq);
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-
if (action_ret == IRQ_NONE)
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-
desc->irqs_unhandled -= ok;
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-
}
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+
if (unlikely(try_misrouted_irq(irq, desc, action_ret))) {
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+
int ok = misrouted_irq(irq);
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+
if (action_ret == IRQ_NONE)
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+
desc->irqs_unhandled -= ok;
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151
}
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desc->irq_count++;