diff options
| author | Anusha Srivatsa <asrivats@redhat.com> | 2025-03-31 11:15:26 -0400 |
|---|---|---|
| committer | Maxime Ripard <mripard@kernel.org> | 2025-04-01 16:58:04 +0200 |
| commit | dcba396f69073d4ea8c04374fdd207e67e5b5a94 (patch) | |
| tree | 7c7d5e6aeded8b9a21e1b840db63a20b022d3039 /include/drm | |
| parent | ed9c594d495deb676825489032cee0a03ce29bf9 (diff) | |
drm/panel: Add refcount support
Allocate panel via reference counting. Add _get() and _put() helper
functions to ensure panel allocations are refcounted. Avoid use after
free by ensuring panel pointer is valid and can be usable till the last
reference is put.
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Anusha Srivatsa <asrivats@redhat.com>
Link: https://lore.kernel.org/r/20250331-b4-panel-refcounting-v4-2-dad50c60c6c9@redhat.com
Signed-off-by: Maxime Ripard <mripard@kernel.org>
Diffstat (limited to 'include/drm')
| -rw-r--r-- | include/drm/drm_panel.h | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h index 415e85e8b76a..31d84f901c51 100644 --- a/include/drm/drm_panel.h +++ b/include/drm/drm_panel.h @@ -28,6 +28,7 @@ #include <linux/errno.h> #include <linux/list.h> #include <linux/mutex.h> +#include <linux/kref.h> struct backlight_device; struct dentry; @@ -266,6 +267,17 @@ struct drm_panel { * If true then the panel has been enabled. */ bool enabled; + + /** + * @container: Pointer to the private driver struct embedding this + * @struct drm_panel. + */ + void *container; + + /** + * @refcount: reference count of users referencing this panel. + */ + struct kref refcount; }; void *__devm_drm_panel_alloc(struct device *dev, size_t size, size_t offset, @@ -282,6 +294,10 @@ void *__devm_drm_panel_alloc(struct device *dev, size_t size, size_t offset, * @connector_type: the connector type (DRM_MODE_CONNECTOR_*) corresponding to * the panel interface * + * The reference count of the returned panel is initialized to 1. This + * reference will be automatically dropped via devm (by calling + * drm_panel_put()) when @dev is removed. + * * Returns: * Pointer to container structure embedding the panel, ERR_PTR on failure. */ @@ -294,6 +310,9 @@ void drm_panel_init(struct drm_panel *panel, struct device *dev, const struct drm_panel_funcs *funcs, int connector_type); +struct drm_panel *drm_panel_get(struct drm_panel *panel); +void drm_panel_put(struct drm_panel *panel); + void drm_panel_add(struct drm_panel *panel); void drm_panel_remove(struct drm_panel *panel); |