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 <mrip...@kernel.org>
Signed-off-by: Anusha Srivatsa <asriv...@redhat.com>
---
v4: Remove documentation about refcounting in this patch, it is
not used yet.
v3: Remove include. Fix typos. Code style corrections (Luca)
- Move the documentation to the main helper instead of in returns
(Maxime)
v2: Better documentation for connector_type field - follow drm_panel_init
documentation. (Luca)
- Clarify the refcount initialisation in comments.(Maxime)
- Correct the documentation of the return type (Maxime)
---
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
c627e42a7ce70459f50eb5095fffc806ca45dabf..bdeab5710ee324dc1742fbc77582250960556308
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
a9c042c8dea1a82ef979c7a68204e0b55483fc28..415e85e8b76a15679f59c944ea152367dc3e0488
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);
--
2.48.1
