[PATCH 3/4] module: add module_param_unsafe and module_param_named_unsafe

Jani Nikula
2014-08-11T13:57:36Z

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>
---
include/linux/moduleparam.h | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)

diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h
index 1e3ffb839daa..9531f9f9729e 100644
--- a/include/linux/moduleparam.h
+++ b/include/linux/moduleparam.h
@@ -123,6 +123,12 @@ struct kparam_array
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.
* @value: the actual lvalue to alter.
@@ -139,6 +145,14 @@ struct kparam_array
__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.
* @ops: the set & get operations for this parameter.
@@ -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
--
1.9.1