Op 26-06-13 04:14, Seung-Woo Kim schreef:
From: YoungJun Cho yj44.cho@samsung.com
The drm_gem_mmap_obj() has to be protected with dev->struct_mutex, but some caller functions do not. So it adds mutex lock to missing callers and adds WARN_ON assertion whether drm_gem_mmap_obj() is called with mutex lock or not.
Signed-off-by: YoungJun Cho yj44.cho@samsung.com Signed-off-by: Seung-Woo Kim sw0312.kim@samsung.com Signed-off-by: Kyungmin Park kyungmin.park@samsung.com CC: Laurent Pinchart laurent.pinchart+renesas@ideasonboard.com CC: Rob Clark robdclark@gmail.com
This patch is based on drm-next branch.
drivers/gpu/drm/drm_gem.c | 4 ++++ drivers/gpu/drm/drm_gem_cma_helper.c | 3 +++ drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c | 3 +++ 3 files changed, 10 insertions(+), 0 deletions(-)
diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index 4321713..b19bba0 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -661,6 +661,8 @@ EXPORT_SYMBOL(drm_gem_vm_close);
- the GEM object is not looked up based on its fake offset. To implement the
- DRM mmap operation, drivers should use the drm_gem_mmap() function.
- NOTE: This function has to be protected with dev->struct_mutex
*/
- Return 0 or success or -EINVAL if the object size is smaller than the VMA
- size, or if no gem_vm_ops are provided.
@@ -669,6 +671,8 @@ int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size, { struct drm_device *dev = obj->dev;
- WARN_ON(!mutex_is_locked(&dev->struct_mutex));
Please don't use mutex_is_locked, use lockdep_assert_held, so the cost only exists when PROVE_LOCKING is used..
I know some current code does it wrong, but that is the correct function to use.
~Maarten