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| author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2018-03-22 09:02:33 +0100 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2018-03-26 17:42:06 +0200 |
| commit | 3903117609f40a0bc21b8c48533ac07a574c4cdc (patch) | |
| tree | 2de4db493464148719b73231d6480b081de8b1ed | |
| parent | 3f07f28b9712605d1adb589344ced72e8397dc8a (diff) | |
| download | linux-3903117609f40a0bc21b8c48533ac07a574c4cdc.tar.bz2 | |
drm/gem: Document that handle_create must be the last step
It published the gem object to userspace, by that point other threads
can guess the id and start using it. And gem IDs are _very_ easy to
guess (it's just an idr).
Since gem objects is the only thing we allow drivers to create
themselves (all the kms/prime/syncobj stuff is handled by the core) no
other functions seem to be in need of this clarification.
Motivated by reviewing the xen-front kms driver.
Cc: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180322080233.17266-1-daniel.vetter@ffwll.ch
| -rw-r--r-- | drivers/gpu/drm/drm_gem.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index 4975ba9a7bc8..4a16d7b26c89 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -436,9 +436,12 @@ err_unref: * @obj: object to register * @handlep: pionter to return the created handle to the caller * - * Create a handle for this object. This adds a handle reference - * to the object, which includes a regular reference count. Callers - * will likely want to dereference the object afterwards. + * Create a handle for this object. This adds a handle reference to the object, + * which includes a regular reference count. Callers will likely want to + * dereference the object afterwards. + * + * Since this publishes @obj to userspace it must be fully set up by this point, + * drivers must call this last in their buffer object creation callbacks. */ int drm_gem_handle_create(struct drm_file *file_priv, struct drm_gem_object *obj, |