completion: Use lockdep_assert_RT_in_threaded_ctx() in complete_all() (8bf6c677) · Commits · 戴 / test

The warning was intended to spot complete_all() users from hardirq context on PREEMPT_RT. The warning as-is will also trigger in interrupt handlers, which are threaded on PREEMPT_RT, which was not intended. Use lockdep_assert_RT_in_threaded_ctx() which triggers in non-preemptive context on PREEMPT_RT. Fixes: ("completion: Use simple wait queues") Reported-by:

kernel test robot <rong.a.chen@intel.com> Suggested-by:

Peter Zijlstra <peterz@infradead.org> Signed-off-by:

Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by:

Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200323152019.4qjwluldohuh3by5@linutronix.de

include/linux/lockdep.h

+15 −0

Original line number	Diff line number	Diff line
		@@ -711,6 +711,21 @@ do { \
		# define lockdep_assert_in_irq() do { } while (0)
		#endif

		#ifdef CONFIG_PROVE_RAW_LOCK_NESTING

		# define lockdep_assert_RT_in_threaded_ctx() do { \
		WARN_ONCE(debug_locks && !current->lockdep_recursion && \
		current->hardirq_context && \
		!(current->hardirq_threaded \|\| current->irq_config), \
		"Not in threaded context on PREEMPT_RT as expected\n"); \
		} while (0)

		#else

		# define lockdep_assert_RT_in_threaded_ctx() do { } while (0)

		#endif

		#ifdef CONFIG_LOCKDEP
		void lockdep_rcu_suspicious(const char file, const int line, const char s);
		#else

kernel/sched/completion.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -58,7 +58,7 @@ void complete_all(struct completion *x)
		{
		unsigned long flags;

		WARN_ON(irqs_disabled());
		lockdep_assert_RT_in_threaded_ctx();

		raw_spin_lock_irqsave(&x->wait.lock, flags);
		x->done = UINT_MAX;

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