rtmutex: Warn if trylock is called from hard/softirq context

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rt_mutex_trylock() must be called from thread context. It can be
called from atomic regions (preemption or interrupts disabled), but
not from hard/softirq/nmi context. Add a warning to alert abusers.

The reasons for this are:

    1) There is a potential deadlock in the slowpath

    2) Another cpu which blocks on the rtmutex will boost the task
       which allegedly locked the rtmutex, but that cannot work
       because the hard/softirq context borrows the task context.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>

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Thomas Gleixner 2015-05-13 22:49:12 +02:00

parent a22e5f579b

commit 6ce47fd961

1 changed files with 7 additions and 0 deletions

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kernel/locking/rtmutex.c

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