devlink: protect devlink param list by instance lock

Commit 1d18bb1a4ddd ("devlink: allow registering parameters after
the instance") as the subject implies introduced possibility to register
devlink params even for already registered devlink instance. This is a
bit problematic, as the consistency or params list was originally
secured by the fact it is static during devlink lifetime. So in order to
protect the params list, take devlink instance lock during the params
operations. Introduce unlocked function variants and use them in drivers
in locked context. Put lock assertions to appropriate places.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Tested-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 53 insertions, 24 deletions

diff --git a/net/devlink/leftover.c b/net/devlink/leftover.c
index 512ed4ccbdc71..bd4c5d2dd6122 100644
--- a/net/devlink/leftover.c
+++ b/net/devlink/leftover.c
@@ -10832,7 +10832,7 @@ static void devlink_param_unregister(struct devlink *devlink,
 }
 
 /**
- *	devlink_params_register - register configuration parameters
+ *	devl_params_register - register configuration parameters
  *
  *	@devlink: devlink
  *	@params: configuration parameters array
@@ -10840,13 +10840,15 @@ static void devlink_param_unregister(struct devlink *devlink,
  *
  *	Register the configuration parameters supported by the driver.
  */
-int devlink_params_register(struct devlink *devlink,
-			    const struct devlink_param *params,
-			    size_t params_count)
+int devl_params_register(struct devlink *devlink,
+			 const struct devlink_param *params,
+			 size_t params_count)
 {
 	const struct devlink_param *param = params;
 	int i, err;
 
+	lockdep_assert_held(&devlink->lock);
+
 	for (i = 0; i < params_count; i++, param++) {
 		err = devlink_param_register(devlink, param);
 		if (err)
@@ -10862,29 +10864,54 @@ rollback:
 		devlink_param_unregister(devlink, param);
 	return err;
 }
+EXPORT_SYMBOL_GPL(devl_params_register);
+
+int devlink_params_register(struct devlink *devlink,
+			    const struct devlink_param *params,
+			    size_t params_count)
+{
+	int err;
+
+	devl_lock(devlink);
+	err = devl_params_register(devlink, params, params_count);
+	devl_unlock(devlink);
+	return err;
+}
 EXPORT_SYMBOL_GPL(devlink_params_register);
 
 /**
- *	devlink_params_unregister - unregister configuration parameters
+ *	devl_params_unregister - unregister configuration parameters
  *	@devlink: devlink
  *	@params: configuration parameters to unregister
  *	@params_count: number of parameters provided
  */
-void devlink_params_unregister(struct devlink *devlink,
-			       const struct devlink_param *params,
-			       size_t params_count)
+void devl_params_unregister(struct devlink *devlink,
+			    const struct devlink_param *params,
+			    size_t params_count)
 {
 	const struct devlink_param *param = params;
 	int i;
 
+	lockdep_assert_held(&devlink->lock);
+
 	for (i = 0; i < params_count; i++, param++)
 		devlink_param_unregister(devlink, param);
 }
+EXPORT_SYMBOL_GPL(devl_params_unregister);
+
+void devlink_params_unregister(struct devlink *devlink,
+			       const struct devlink_param *params,
+			       size_t params_count)
+{
+	devl_lock(devlink);
+	devl_params_unregister(devlink, params, params_count);
+	devl_unlock(devlink);
+}
 EXPORT_SYMBOL_GPL(devlink_params_unregister);
 
 /**
- *	devlink_param_driverinit_value_get - get configuration parameter
- *					     value for driver initializing
+ *	devl_param_driverinit_value_get - get configuration parameter
+ *					  value for driver initializing
  *
  *	@devlink: devlink
  *	@param_id: parameter ID
@@ -10893,11 +10920,13 @@ EXPORT_SYMBOL_GPL(devlink_params_unregister);
  *	This function should be used by the driver to get driverinit
  *	configuration for initialization after reload command.
  */
-int devlink_param_driverinit_value_get(struct devlink *devlink, u32 param_id,
-				       union devlink_param_value *init_val)
+int devl_param_driverinit_value_get(struct devlink *devlink, u32 param_id,
+				    union devlink_param_value *init_val)
 {
 	struct devlink_param_item *param_item;
 
+	lockdep_assert_held(&devlink->lock);
+
 	if (WARN_ON(!devlink_reload_supported(devlink->ops)))
 		return -EOPNOTSUPP;
 
@@ -10919,12 +10948,12 @@ int devlink_param_driverinit_value_get(struct devlink *devlink, u32 param_id,
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(devlink_param_driverinit_value_get);
+EXPORT_SYMBOL_GPL(devl_param_driverinit_value_get);
 
 /**
- *	devlink_param_driverinit_value_set - set value of configuration
- *					     parameter for driverinit
- *					     configuration mode
+ *	devl_param_driverinit_value_set - set value of configuration
+ *					  parameter for driverinit
+ *					  configuration mode
  *
  *	@devlink: devlink
  *	@param_id: parameter ID
@@ -10933,8 +10962,8 @@ EXPORT_SYMBOL_GPL(devlink_param_driverinit_value_get);
  *	This function should be used by the driver to set driverinit
  *	configuration mode default value.
  */
-void devlink_param_driverinit_value_set(struct devlink *devlink, u32 param_id,
-					union devlink_param_value init_val)
+void devl_param_driverinit_value_set(struct devlink *devlink, u32 param_id,
+				     union devlink_param_value init_val)
 {
 	struct devlink_param_item *param_item;
 
@@ -10954,12 +10983,12 @@ void devlink_param_driverinit_value_set(struct devlink *devlink, u32 param_id,
 
 	devlink_param_notify(devlink, 0, param_item, DEVLINK_CMD_PARAM_NEW);
 }
-EXPORT_SYMBOL_GPL(devlink_param_driverinit_value_set);
+EXPORT_SYMBOL_GPL(devl_param_driverinit_value_set);
 
 /**
- *	devlink_param_value_changed - notify devlink on a parameter's value
- *				      change. Should be called by the driver
- *				      right after the change.
+ *	devl_param_value_changed - notify devlink on a parameter's value
+ *				   change. Should be called by the driver
+ *				   right after the change.
  *
  *	@devlink: devlink
  *	@param_id: parameter ID
@@ -10968,7 +10997,7 @@ EXPORT_SYMBOL_GPL(devlink_param_driverinit_value_set);
  *	change, excluding driverinit configuration mode.
  *	For driverinit configuration mode driver should use the function
  */
-void devlink_param_value_changed(struct devlink *devlink, u32 param_id)
+void devl_param_value_changed(struct devlink *devlink, u32 param_id)
 {
 	struct devlink_param_item *param_item;
 
@@ -10977,7 +11006,7 @@ void devlink_param_value_changed(struct devlink *devlink, u32 param_id)
 
 	devlink_param_notify(devlink, 0, param_item, DEVLINK_CMD_PARAM_NEW);
 }
-EXPORT_SYMBOL_GPL(devlink_param_value_changed);
+EXPORT_SYMBOL_GPL(devl_param_value_changed);
 
 /**
  * devl_region_create - create a new address region