audio: don't override the "const" attribute

Using a type-cast to override a "const" attribute and modify read-
only data is unsafe. Add a writable pointer to struct
comp_driver_info instead and use it when creating component drivers
dynamically.

Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>

Author: lyakh

src/audio/component.c

@@ -13,6 +13,7 @@
 #include <rtos/alloc.h>
 #include <rtos/cache.h>
 #include <sof/lib/memory.h> /* for SHARED_DATA */
+#include <sof/lib/uuid.h>
 #include <sof/list.h>
 #include <rtos/sof.h>
 #include <rtos/string.h>
@@ -63,6 +64,36 @@ void comp_unregister(struct comp_driver_info *drv)
 	k_spin_unlock(&drivers->lock, key);
 }
 
+int comp_set_adapter_ops(const struct comp_driver *drv, const struct module_interface *ops)
+{
+	struct comp_driver_list *drivers = comp_drivers_get();
+	struct list_item *clist;
+
+	/* The list is only modified in IPC context, and we're in IPC context too */
+	list_for_item(clist, &drivers->list) {
+		struct comp_driver_info *info = container_of(clist, struct comp_driver_info, list);
+
+		if (!memcmp(info->drv->uid, drv->uid, UUID_SIZE)) {
+			/*
+			 * This function should only be called for dynamically
+			 * loaded component drivers and their driver info cannot
+			 * be NULL. Do a sanity check.
+			 */
+			if (!info->adapter_ops) {
+				tr_err(&comp_tr, "NULL adapter ops ptr for %pU!",
+				       info->drv->tctx->uuid_p);
+				return -EINVAL;
+			}
+
+			tr_dbg(&comp_tr, "update uuid %pU", info->drv->tctx->uuid_p);
+			*info->adapter_ops = ops;
+			return 0;
+		}
+	}
+
+	return -ENODEV;
+}
+
 /* NOTE: Keep the component state diagram up to date:
  * sof-docs/developer_guides/firmware/components/images/comp-dev-states.pu
  */

src/include/sof/audio/component.h

@@ -594,8 +594,9 @@ struct comp_driver {
 
 /** \brief Holds constant pointer to component driver */
 struct comp_driver_info {
-	const struct comp_driver *drv;	/**< pointer to component driver */
-	struct list_item list;		/**< list of component drivers */
+	const struct comp_driver *drv;			/**< pointer to component driver */
+	const struct module_interface **adapter_ops;	/**< pointer for updating ops */
+	struct list_item list;				/**< list of component drivers */
 };
 
 #define COMP_PROCESSING_DOMAIN_LL 0
@@ -968,6 +969,15 @@ int comp_register(struct comp_driver_info *drv);
  */
 void comp_unregister(struct comp_driver_info *drv);
 
+/**
+ * Set adapter ops for a dynamically created driver.
+ *
+ * @param drv Component driver to update.
+ * @param ops Module interface operations.
+ * @return 0 or a negative error code
+ */
+int comp_set_adapter_ops(const struct comp_driver *drv, const struct module_interface *ops);
+
 /** @}*/
 
 /**

src/library_manager/lib_manager.c

@@ -518,17 +518,19 @@ static struct comp_dev *lib_manager_module_create(const struct comp_driver *drv,
 	/* Intel modules expects DW size here */
 	mod_cfg.size = args->size >> 2;
 
-	((struct comp_driver *)drv)->adapter_ops = native_system_agent_start(module_entry_point,
-									     module_id,	instance_id,
-									     0, log_handle,
-									     &mod_cfg);
+	const struct module_interface *ops = native_system_agent_start(module_entry_point,
+								       module_id, instance_id,
+								       0, log_handle, &mod_cfg);
 
-	if (!drv->adapter_ops) {
+	if (!ops) {
 		lib_manager_free_module(module_id);
 		tr_err(&lib_manager_tr, "native_system_agent_start failed!");
 		return NULL;
 	}
 
+	if (comp_set_adapter_ops(drv, ops) < 0)
+		return NULL;
+
 	dev = module_adapter_new(drv, config, spec);
 	if (!dev)
 		lib_manager_free_module(module_id);
@@ -662,6 +664,7 @@ int lib_manager_register_module(const uint32_t component_id)
 
 	/* Fill the new_drv_info structure with already known parameters */
 	new_drv_info->drv = drv;
+	new_drv_info->adapter_ops = &drv->adapter_ops;
 
 	/* Register new driver in the list */
 	ret = comp_register(new_drv_info);