Commit 9a019db0 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

locking/lockdep: Improve 'invalid wait context' splat 



The 'invalid wait context' splat doesn't print all the information
required to reconstruct / validate the error, specifically the
irq-context state is missing.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent a13f58a0

kernel/locking/lockdep.c

+31 −20
Original line number Diff line number Diff line
@@ -3952,10 +3952,36 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this, 
	return ret;

}



static inline short task_wait_context(struct task_struct *curr)

{

	/*

	 * Set appropriate wait type for the context; for IRQs we have to take

	 * into account force_irqthread as that is implied by PREEMPT_RT.

	 */

	if (curr->hardirq_context) {

		/*

		 * Check if force_irqthreads will run us threaded.

		 */

		if (curr->hardirq_threaded || curr->irq_config)

			return LD_WAIT_CONFIG;



		return LD_WAIT_SPIN;

	} else if (curr->softirq_context) {

		/*

		 * Softirqs are always threaded.

		 */

		return LD_WAIT_CONFIG;

	}



	return LD_WAIT_MAX;

}



static int

print_lock_invalid_wait_context(struct task_struct *curr,

				struct held_lock *hlock)

{

	short curr_inner;



	if (!debug_locks_off())

		return 0;

	if (debug_locks_silent)
@@ -3971,6 +3997,10 @@ print_lock_invalid_wait_context(struct task_struct *curr, 
	print_lock(hlock);



	pr_warn("other info that might help us debug this:\n");



	curr_inner = task_wait_context(curr);

	pr_warn("context-{%d:%d}\n", curr_inner, curr_inner);



	lockdep_print_held_locks(curr);



	pr_warn("stack backtrace:\n");
@@ -4017,26 +4047,7 @@ static int check_wait_context(struct task_struct *curr, struct held_lock *next) 
	}

	depth++;



	/*

	 * Set appropriate wait type for the context; for IRQs we have to take

	 * into account force_irqthread as that is implied by PREEMPT_RT.

	 */

	if (curr->hardirq_context) {

		/*

		 * Check if force_irqthreads will run us threaded.

		 */

		if (curr->hardirq_threaded || curr->irq_config)

			curr_inner = LD_WAIT_CONFIG;

		else

			curr_inner = LD_WAIT_SPIN;

	} else if (curr->softirq_context) {

		/*

		 * Softirqs are always threaded.

		 */

		curr_inner = LD_WAIT_CONFIG;

	} else {

		curr_inner = LD_WAIT_MAX;

	}

	curr_inner = task_wait_context(curr);



	for (; depth < curr->lockdep_depth; depth++) {

		struct held_lock *prev = curr->held_locks + depth;