module: add module_param_unsafe and module_param_named_unsafe

Add the helpers to be used by modules wishing to expose unsafe debugging
or testing module parameters that taint the kernel when set.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Jon Mason <jon.mason@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

include/linux/moduleparam.h

@@ -122,6 +122,12 @@ struct kparam_array
 #define module_param(name, type, perm)				\
 	module_param_named(name, name, type, perm)
 
+/**
+ * module_param_unsafe - same as module_param but taints kernel
+ */
+#define module_param_unsafe(name, type, perm)			\
+	module_param_named_unsafe(name, name, type, perm)
+
 /**
  * module_param_named - typesafe helper for a renamed module/cmdline parameter
  * @name: a valid C identifier which is the parameter name.
@@ -138,6 +144,14 @@ struct kparam_array
 	module_param_cb(name, &param_ops_##type, &value, perm);		   \
 	__MODULE_PARM_TYPE(name, #type)
 
+/**
+ * module_param_named_unsafe - same as module_param_named but taints kernel
+ */
+#define module_param_named_unsafe(name, value, type, perm)		\
+	param_check_##type(name, &(value));				\
+	module_param_cb_unsafe(name, &param_ops_##type, &value, perm);	\
+	__MODULE_PARM_TYPE(name, #type)
+
 /**
  * module_param_cb - general callback for a module/cmdline parameter
  * @name: a valid C identifier which is the parameter name.
@@ -149,6 +163,10 @@ struct kparam_array
 #define module_param_cb(name, ops, arg, perm)				      \
 	__module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, -1, 0)
 
+#define module_param_cb_unsafe(name, ops, arg, perm)			      \
+	__module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, -1,    \
+			    KERNEL_PARAM_FL_UNSAFE)
+
 /**
  * <level>_param_cb - general callback for a module/cmdline parameter
  *                    to be evaluated before certain initcall level