linux/kernel/irq
Ido Yariv 550acb1926 genirq: Fix race condition when stopping the irq thread
In irq_wait_for_interrupt(), the should_stop member is verified before
setting the task's state to TASK_INTERRUPTIBLE and calling schedule().
In case kthread_stop sets should_stop and wakes up the process after
should_stop is checked by the irq thread but before the task's state
is changed, the irq thread might never exit:

kthread_stop                    irq_wait_for_interrupt
------------                    ----------------------

                                 ...
...                              while (!kthread_should_stop()) {
kthread->should_stop = 1;
wake_up_process(k);
wait_for_completion(&kthread->exited);
...
                                     set_current_state(TASK_INTERRUPTIBLE);

                                     ...

                                     schedule();
                                 }

Fix this by checking if the thread should stop after modifying the
task's state.

[ tglx: Simplified it a bit ]

Signed-off-by: Ido Yariv <ido@wizery.com>
Link: http://lkml.kernel.org/r/1322740508-22640-1-git-send-email-ido@wizery.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@kernel.org
2011-12-02 11:54:24 +01:00
..
Kconfig irq: add irq_domain translation infrastructure 2011-07-28 01:32:04 -06:00
Makefile irq: add irq_domain translation infrastructure 2011-07-28 01:32:04 -06:00
autoprobe.c
chip.c genirq: Add support for per-cpu dev_id interrupts 2011-10-03 15:35:26 +02:00
debug.h
devres.c
dummychip.c
generic-chip.c kernel: Fix files explicitly needing EXPORT_SYMBOL infrastructure 2011-10-31 19:30:05 -04:00
handle.c
internals.h genirq: Add support for per-cpu dev_id interrupts 2011-10-03 15:35:26 +02:00
irqdesc.c irq: don't put module.h into irq.h for tracking irqgen modules. 2011-10-31 19:32:35 -04:00
irqdomain.c irq: support domains with non-zero hwirq base 2011-10-31 14:03:23 +01:00
manage.c genirq: Fix race condition when stopping the irq thread 2011-12-02 11:54:24 +01:00
migration.c
pm.c genirq: Add IRQF_RESUME_EARLY and resume such IRQs earlier 2011-10-17 11:42:49 +02:00
proc.c
resend.c
settings.h genirq: Add support for per-cpu dev_id interrupts 2011-10-03 15:35:26 +02:00
spurious.c genirq: fix regression in irqfixup, irqpoll 2011-11-28 08:43:09 -08:00