Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit ee0c6bfb authored by Dan Carpenter's avatar Dan Carpenter Committed by Eric Anholt
Browse files

drm/i915: take struct_mutex in i915_dma_cleanup() 

intel_cleanup_ring_buffer() calls drm_gem_object_unreference() (as
opposed to drm_gem_object_unreference_unlocked()) so it needs to be
called with "struct_mutex" held.  If we don't hold the lock, it triggers
a BUG_ON(!mutex_is_locked(&dev->struct_mutex));

I also audited the other places that call intel_cleanup_ring_buffer()
and they all hold the lock so they're OK.

This was introduced in: 8187a2b7 "drm/i915: introduce
intel_ring_buffer structure (V2)" and it's a regression from v2.6.34.

Addresses: https://bugzilla.kernel.org/show_bug.cgi?id=16247



Signed-off-by: default avatarDan Carpenter <error27@gmail.com>
Reported-by: default avatarBenny Halevy <bhalevy@panasas.com>
Tested-by: default avatarBenny Halevy <bhalevy@panasas.com>
Signed-off-by: default avatarEric Anholt <eric@anholt.net>
parent 2d1c9752

drivers/gpu/drm/i915/i915_dma.c

+2 −0
Original line number Diff line number Diff line
@@ -128,9 +128,11 @@ static int i915_dma_cleanup(struct drm_device * dev) 
	if (dev->irq_enabled)

		drm_irq_uninstall(dev);



	mutex_lock(&dev->struct_mutex);

	intel_cleanup_ring_buffer(dev, &dev_priv->render_ring);

	if (HAS_BSD(dev))

		intel_cleanup_ring_buffer(dev, &dev_priv->bsd_ring);

	mutex_unlock(&dev->struct_mutex);



	/* Clear the HWS virtual address at teardown */

	if (I915_NEED_GFX_HWS(dev))