From 29d08b3efddca628b0360411ab2b85f7b1723f48 Mon Sep 17 00:00:00 2001 From: Dave Airlie Date: Mon, 27 Sep 2010 16:17:17 +1000 Subject: drm/gem: handlecount isn't really a kref so don't make it one. There were lots of places being inconsistent since handle count looked like a kref but it really wasn't. Fix this my just making handle count an atomic on the object, and have it increase the normal object kref. Now i915/radeon/nouveau drivers can drop the normal reference on userspace object creation, and have the handle hold it. This patch fixes a memory leak or corruption on unload, because the driver had no way of knowing if a handle had been actually added for this object, and the fbcon object needed to know this to clean itself up properly. Reviewed-by: Chris Wilson Signed-off-by: Dave Airlie --- include/drm/drmP.h | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) (limited to 'include/drm') diff --git a/include/drm/drmP.h b/include/drm/drmP.h index 774e1d49509..07e4726a4ee 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -612,7 +612,7 @@ struct drm_gem_object { struct kref refcount; /** Handle count of this object. Each handle also holds a reference */ - struct kref handlecount; + atomic_t handle_count; /* number of handles on this object */ /** Related drm device */ struct drm_device *dev; @@ -1461,7 +1461,7 @@ struct drm_gem_object *drm_gem_object_alloc(struct drm_device *dev, size_t size); int drm_gem_object_init(struct drm_device *dev, struct drm_gem_object *obj, size_t size); -void drm_gem_object_handle_free(struct kref *kref); +void drm_gem_object_handle_free(struct drm_gem_object *obj); void drm_gem_vm_open(struct vm_area_struct *vma); void drm_gem_vm_close(struct vm_area_struct *vma); int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma); @@ -1496,7 +1496,7 @@ static inline void drm_gem_object_handle_reference(struct drm_gem_object *obj) { drm_gem_object_reference(obj); - kref_get(&obj->handlecount); + atomic_inc(&obj->handle_count); } static inline void @@ -1505,12 +1505,15 @@ drm_gem_object_handle_unreference(struct drm_gem_object *obj) if (obj == NULL) return; + if (atomic_read(&obj->handle_count) == 0) + return; /* * Must bump handle count first as this may be the last * ref, in which case the object would disappear before we * checked for a name */ - kref_put(&obj->handlecount, drm_gem_object_handle_free); + if (atomic_dec_and_test(&obj->handle_count)) + drm_gem_object_handle_free(obj); drm_gem_object_unreference(obj); } @@ -1520,12 +1523,17 @@ drm_gem_object_handle_unreference_unlocked(struct drm_gem_object *obj) if (obj == NULL) return; + if (atomic_read(&obj->handle_count) == 0) + return; + /* * Must bump handle count first as this may be the last * ref, in which case the object would disappear before we * checked for a name */ - kref_put(&obj->handlecount, drm_gem_object_handle_free); + + if (atomic_dec_and_test(&obj->handle_count)) + drm_gem_object_handle_free(obj); drm_gem_object_unreference_unlocked(obj); } -- cgit v1.2.3-18-g5258