1774250a20
[ Upstream commit 56c6be35fcbed54279df0a2c9e60480a61841d6f ]
As &hc->lock is acquired by both timer _hfcpci_softirq() and hardirq
hfcpci_int(), the timer should disable irq before lock acquisition
otherwise deadlock could happen if the timmer is preemtped by the hadr irq.
Possible deadlock scenario:
hfcpci_softirq() (timer)
-> _hfcpci_softirq()
-> spin_lock(&hc->lock);
<irq interruption>
-> hfcpci_int()
-> spin_lock(&hc->lock); (deadlock here)
This flaw was found by an experimental static analysis tool I am developing
for irq-related deadlock.
The tentative patch fixes the potential deadlock by spin_lock_irq()
in timer.
Fixes:
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Makefile |