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Commit 91f65fac authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Joerg Roedel
Browse files

iommu/amd: Fix amd_iommu_free_device() 



put_device_state_wait() doesn't loop on the condition and a spurious
wakeup will have it free the device state even though there might still
be references out to it.

Fix this by using 'normal' wait primitives.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent e36f014e

drivers/iommu/amd_iommu_v2.c

+7 −13
Original line number Original line Diff line number Diff line
@@ -151,18 +151,6 @@ static void put_device_state(struct device_state *dev_state) 
		wake_up(&dev_state->wq);

		wake_up(&dev_state->wq);

}

}





static void put_device_state_wait(struct device_state *dev_state)

{

	DEFINE_WAIT(wait);



	prepare_to_wait(&dev_state->wq, &wait, TASK_UNINTERRUPTIBLE);

	if (!atomic_dec_and_test(&dev_state->count))

		schedule();

	finish_wait(&dev_state->wq, &wait);



	free_device_state(dev_state);

}



/* Must be called under dev_state->lock */

/* Must be called under dev_state->lock */

static struct pasid_state **__get_pasid_state_ptr(struct device_state *dev_state,

static struct pasid_state **__get_pasid_state_ptr(struct device_state *dev_state,

						  int pasid, bool alloc)

						  int pasid, bool alloc)
@@ -851,7 +839,13 @@ void amd_iommu_free_device(struct pci_dev *pdev) 
	/* Get rid of any remaining pasid states */

	/* Get rid of any remaining pasid states */

	free_pasid_states(dev_state);

	free_pasid_states(dev_state);





	put_device_state_wait(dev_state);

	put_device_state(dev_state);

	/*

	 * Wait until the last reference is dropped before freeing

	 * the device state.

	 */

	wait_event(dev_state->wq, !atomic_read(&dev_state->count));

	free_device_state(dev_state);

}

}

EXPORT_SYMBOL(amd_iommu_free_device);

EXPORT_SYMBOL(amd_iommu_free_device);