Unverified Commit ed9c594d authored by Anusha Srivatsa's avatar Anusha Srivatsa Committed by Maxime Ripard
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drm/panel: Add new helpers for refcounted panel allocatons 



Introduce reference counted allocations for panels to avoid
use-after-free. The patch adds the macro devm_drm_bridge_alloc()
to allocate a new refcounted panel. Followed the documentation for
drmm_encoder_alloc() and devm_drm_dev_alloc and other similar
implementations for this purpose.

Reviewed-by: default avatarMaxime Ripard <mripard@kernel.org>
Signed-off-by: default avatarAnusha Srivatsa <asrivats@redhat.com>
Link: https://lore.kernel.org/r/20250331-b4-panel-refcounting-v4-1-dad50c60c6c9@redhat.com


Signed-off-by: default avatarMaxime Ripard <mripard@kernel.org>
parent 65931bbc

drivers/gpu/drm/drm_panel.c

+25 −0
Original line number Diff line number Diff line
@@ -355,6 +355,31 @@ struct drm_panel *of_drm_find_panel(const struct device_node *np) 
}

EXPORT_SYMBOL(of_drm_find_panel);



void *__devm_drm_panel_alloc(struct device *dev, size_t size, size_t offset,

			     const struct drm_panel_funcs *funcs,

			     int connector_type)

{

	void *container;

	struct drm_panel *panel;



	if (!funcs) {

		dev_warn(dev, "Missing funcs pointer\n");

		return ERR_PTR(-EINVAL);

	}



	container = devm_kzalloc(dev, size, GFP_KERNEL);

	if (!container)

		return ERR_PTR(-ENOMEM);



	panel = container + offset;

	panel->funcs = funcs;



	drm_panel_init(panel, dev, funcs, connector_type);



	return container;

}

EXPORT_SYMBOL(__devm_drm_panel_alloc);



/**

 * of_drm_get_panel_orientation - look up the orientation of the panel through

 * the "rotation" binding from a device tree node

include/drm/drm_panel.h

+22 −0
Original line number Diff line number Diff line
@@ -268,6 +268,28 @@ struct drm_panel { 
	bool enabled;

};



void *__devm_drm_panel_alloc(struct device *dev, size_t size, size_t offset,

			     const struct drm_panel_funcs *funcs,

			     int connector_type);



/**

 * devm_drm_panel_alloc - Allocate and initialize a refcounted panel.

 *

 * @dev: struct device of the panel device

 * @type: the type of the struct which contains struct &drm_panel

 * @member: the name of the &drm_panel within @type

 * @funcs: callbacks for this panel

 * @connector_type: the connector type (DRM_MODE_CONNECTOR_*) corresponding to

 * the panel interface

 *

 * Returns:

 * Pointer to container structure embedding the panel, ERR_PTR on failure.

 */

#define devm_drm_panel_alloc(dev, type, member, funcs, connector_type) \

	((type *)__devm_drm_panel_alloc(dev, sizeof(type), \

					offsetof(type, member), funcs, \

					connector_type))



void drm_panel_init(struct drm_panel *panel, struct device *dev,

		    const struct drm_panel_funcs *funcs,

		    int connector_type);