From ed9c594d495deb676825489032cee0a03ce29bf9 Mon Sep 17 00:00:00 2001 From: Anusha Srivatsa Date: Mon, 31 Mar 2025 11:15:25 -0400 Subject: [PATCH] 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: Maxime Ripard Signed-off-by: Anusha Srivatsa Link: https://lore.kernel.org/r/20250331-b4-panel-refcounting-v4-1-dad50c60c6c9@redhat.com Signed-off-by: Maxime Ripard --- drivers/gpu/drm/drm_panel.c | 25 +++++++++++++++++++++++++ include/drm/drm_panel.h | 22 ++++++++++++++++++++++ 2 files changed, 47 insertions(+) diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c index c627e42a7ce7..bdeab5710ee3 100644 --- a/drivers/gpu/drm/drm_panel.c +++ b/drivers/gpu/drm/drm_panel.c @@ -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 diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h index a9c042c8dea1..415e85e8b76a 100644 --- a/include/drm/drm_panel.h +++ b/include/drm/drm_panel.h @@ -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); -- 2.25.1