Merge branch 'params' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus

* 'params' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus: (22 commits)
  param: don't deref arg in __same_type() checks
  param: update drivers/acpi/debug.c to new scheme
  param: use module_param in drivers/message/fusion/mptbase.c
  ide: use module_param_named rather than module_param_call
  param: update drivers/char/ipmi/ipmi_watchdog.c to new scheme
  param: lock if_sdio's lbs_helper_name and lbs_fw_name against sysfs changes.
  param: lock myri10ge_fw_name against sysfs changes.
  param: simple locking for sysfs-writable charp parameters
  param: remove unnecessary writable charp
  param: add kerneldoc to moduleparam.h
  param: locking for kernel parameters
  param: make param sections const.
  param: use free hook for charp (fix leak of charp parameters)
  param: add a free hook to kernel_param_ops.
  param: silence .init.text references from param ops
  Add param ops struct for hvc_iucv driver.
  nfs: update for module_param_named API change
  AppArmor: update for module_param_named API change
  param: use ops in struct kernel_param, rather than get and set fns directly
  param: move the EXPORT_SYMBOL to after the definitions.
  ...

1 files changed, 221 insertions, 67 deletions

diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h
index 82a9124f7d75..9d2f1837b3d8 100644
--- a/include/linux/moduleparam.h
+++ b/include/linux/moduleparam.h
@@ -31,20 +31,23 @@ static const char __module_cat(name,__LINE__)[]				  \
 
 struct kernel_param;
 
-/* Returns 0, or -errno.  arg is in kp->arg. */
-typedef int (*param_set_fn)(const char *val, struct kernel_param *kp);
-/* Returns length written or -errno.  Buffer is 4k (ie. be short!) */
-typedef int (*param_get_fn)(char *buffer, struct kernel_param *kp);
+struct kernel_param_ops {
+	/* Returns 0, or -errno.  arg is in kp->arg. */
+	int (*set)(const char *val, const struct kernel_param *kp);
+	/* Returns length written or -errno.  Buffer is 4k (ie. be short!) */
+	int (*get)(char *buffer, const struct kernel_param *kp);
+	/* Optional function to free kp->arg when module unloaded. */
+	void (*free)(void *arg);
+};
 
 /* Flag bits for kernel_param.flags */
 #define KPARAM_ISBOOL		2
 
 struct kernel_param {
 	const char *name;
+	const struct kernel_param_ops *ops;
 	u16 perm;
 	u16 flags;
-	param_set_fn set;
-	param_get_fn get;
 	union {
 		void *arg;
 		const struct kparam_string *str;
@@ -63,12 +66,67 @@ struct kparam_array
 {
 	unsigned int max;
 	unsigned int *num;
-	param_set_fn set;
-	param_get_fn get;
+	const struct kernel_param_ops *ops;
 	unsigned int elemsize;
 	void *elem;
 };
 
+/**
+ * module_param - typesafe helper for a module/cmdline parameter
+ * @value: the variable to alter, and exposed parameter name.
+ * @type: the type of the parameter
+ * @perm: visibility in sysfs.
+ *
+ * @value becomes the module parameter, or (prefixed by KBUILD_MODNAME and a
+ * ".") the kernel commandline parameter.  Note that - is changed to _, so
+ * the user can use "foo-bar=1" even for variable "foo_bar".
+ *
+ * @perm is 0 if the the variable is not to appear in sysfs, or 0444
+ * for world-readable, 0644 for root-writable, etc.  Note that if it
+ * is writable, you may need to use kparam_block_sysfs_write() around
+ * accesses (esp. charp, which can be kfreed when it changes).
+ *
+ * The @type is simply pasted to refer to a param_ops_##type and a
+ * param_check_##type: for convenience many standard types are provided but
+ * you can create your own by defining those variables.
+ *
+ * Standard types are:
+ *	byte, short, ushort, int, uint, long, ulong
+ *	charp: a character pointer
+ *	bool: a bool, values 0/1, y/n, Y/N.
+ *	invbool: the above, only sense-reversed (N = true).
+ */
+#define module_param(name, type, perm)				\
+	module_param_named(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.
+ * @type: the type of the parameter
+ * @perm: visibility in sysfs.
+ *
+ * Usually it's a good idea to have variable names and user-exposed names the
+ * same, but that's harder if the variable must be non-static or is inside a
+ * structure.  This allows exposure under a different name.
+ */
+#define module_param_named(name, value, type, perm)			   \
+	param_check_##type(name, &(value));				   \
+	module_param_cb(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.
+ * @perm: visibility in sysfs.
+ *
+ * The ops can have NULL set or get functions.
+ */
+#define module_param_cb(name, ops, arg, perm)				      \
+	__module_param_call(MODULE_PARAM_PREFIX,			      \
+			    name, ops, arg, __same_type((arg), bool *), perm)
+
 /* On alpha, ia64 and ppc64 relocations to global data cannot go into
    read-only sections (which is part of respective UNIX ABI on these
    platforms). So 'const' makes no sense and even causes compile failures
@@ -80,10 +138,8 @@ struct kparam_array
 #endif
 
 /* This is the fundamental function for registering boot/module
-   parameters.  perm sets the visibility in sysfs: 000 means it's
-   not there, read bits mean it's readable, write bits mean it's
-   writable. */
-#define __module_param_call(prefix, name, set, get, arg, isbool, perm)	\
+   parameters. */
+#define __module_param_call(prefix, name, ops, arg, isbool, perm)	\
 	/* Default value instead of permissions? */			\
 	static int __param_perm_check_##name __attribute__((unused)) =	\
 	BUILD_BUG_ON_ZERO((perm) < 0 || (perm) > 0777 || ((perm) & 2))	\
@@ -92,31 +148,87 @@ struct kparam_array
 	static struct kernel_param __moduleparam_const __param_##name	\
 	__used								\
     __attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \
-	= { __param_str_##name, perm, isbool ? KPARAM_ISBOOL : 0,	\
-	    set, get, { arg } }
+	= { __param_str_##name, ops, perm, isbool ? KPARAM_ISBOOL : 0,	\
+	    { arg } }
+
+/* Obsolete - use module_param_cb() */
+#define module_param_call(name, set, get, arg, perm)			\
+	static struct kernel_param_ops __param_ops_##name =		\
+		 { (void *)set, (void *)get };				\
+	__module_param_call(MODULE_PARAM_PREFIX,			\
+			    name, &__param_ops_##name, arg,		\
+			    __same_type(arg, bool *),			\
+			    (perm) + sizeof(__check_old_set_param(set))*0)
+
+/* We don't get oldget: it's often a new-style param_get_uint, etc. */
+static inline int
+__check_old_set_param(int (*oldset)(const char *, struct kernel_param *))
+{
+	return 0;
+}
 
-#define module_param_call(name, set, get, arg, perm)			      \
-	__module_param_call(MODULE_PARAM_PREFIX,			      \
-			    name, set, get, arg,			      \
-			    __same_type(*(arg), bool), perm)
+/**
+ * kparam_block_sysfs_write - make sure a parameter isn't written via sysfs.
+ * @name: the name of the parameter
+ *
+ * There's no point blocking write on a paramter that isn't writable via sysfs!
+ */
+#define kparam_block_sysfs_write(name)			\
+	do {						\
+		BUG_ON(!(__param_##name.perm & 0222));	\
+		__kernel_param_lock();			\
+	} while (0)
 
-/* Helper functions: type is byte, short, ushort, int, uint, long,
-   ulong, charp, bool or invbool, or XXX if you define param_get_XXX,
-   param_set_XXX and param_check_XXX. */
-#define module_param_named(name, value, type, perm)			   \
-	param_check_##type(name, &(value));				   \
-	module_param_call(name, param_set_##type, param_get_##type, &value, perm); \
-	__MODULE_PARM_TYPE(name, #type)
+/**
+ * kparam_unblock_sysfs_write - allows sysfs to write to a parameter again.
+ * @name: the name of the parameter
+ */
+#define kparam_unblock_sysfs_write(name)		\
+	do {						\
+		BUG_ON(!(__param_##name.perm & 0222));	\
+		__kernel_param_unlock();		\
+	} while (0)
 
-#define module_param(name, type, perm)				\
-	module_param_named(name, name, type, perm)
+/**
+ * kparam_block_sysfs_read - make sure a parameter isn't read via sysfs.
+ * @name: the name of the parameter
+ *
+ * This also blocks sysfs writes.
+ */
+#define kparam_block_sysfs_read(name)			\
+	do {						\
+		BUG_ON(!(__param_##name.perm & 0444));	\
+		__kernel_param_lock();			\
+	} while (0)
+
+/**
+ * kparam_unblock_sysfs_read - allows sysfs to read a parameter again.
+ * @name: the name of the parameter
+ */
+#define kparam_unblock_sysfs_read(name)			\
+	do {						\
+		BUG_ON(!(__param_##name.perm & 0444));	\
+		__kernel_param_unlock();		\
+	} while (0)
+
+#ifdef CONFIG_SYSFS
+extern void __kernel_param_lock(void);
+extern void __kernel_param_unlock(void);
+#else
+static inline void __kernel_param_lock(void)
+{
+}
+static inline void __kernel_param_unlock(void)
+{
+}
+#endif
 
 #ifndef MODULE
 /**
  * core_param - define a historical core kernel parameter.
  * @name: the name of the cmdline and sysfs parameter (often the same as var)
  * @var: the variable
- * @type: the type (for param_set_##type and param_get_##type)
+ * @type: the type of the parameter
  * @perm: visibility in sysfs
  *
  * core_param is just like module_param(), but cannot be modular and
@@ -126,23 +238,32 @@ struct kparam_array
  */
 #define core_param(name, var, type, perm)				\
 	param_check_##type(name, &(var));				\
-	__module_param_call("", name, param_set_##type, param_get_##type, \
+	__module_param_call("", name, &param_ops_##type,		\
 			    &var, __same_type(var, bool), perm)
 #endif /* !MODULE */
 
-/* Actually copy string: maxlen param is usually sizeof(string). */
+/**
+ * module_param_string - a char array parameter
+ * @name: the name of the parameter
+ * @string: the string variable
+ * @len: the maximum length of the string, incl. terminator
+ * @perm: visibility in sysfs.
+ *
+ * This actually copies the string when it's set (unlike type charp).
+ * @len is usually just sizeof(string).
+ */
 #define module_param_string(name, string, len, perm)			\
 	static const struct kparam_string __param_string_##name		\
 		= { len, string };					\
 	__module_param_call(MODULE_PARAM_PREFIX, name,			\
-			    param_set_copystring, param_get_string,	\
+			    &param_ops_string,				\
 			    .str = &__param_string_##name, 0, perm);	\
 	__MODULE_PARM_TYPE(name, "string")
 
 /* Called on module insert or kernel boot */
 extern int parse_args(const char *name,
 		      char *args,
-		      struct kernel_param *params,
+		      const struct kernel_param *params,
 		      unsigned num,
 		      int (*unknown)(char *param, char *val));
 
@@ -162,72 +283,105 @@ static inline void destroy_params(const struct kernel_param *params,
 #define __param_check(name, p, type) \
 	static inline type *__check_##name(void) { return(p); }
 
-extern int param_set_byte(const char *val, struct kernel_param *kp);
-extern int param_get_byte(char *buffer, struct kernel_param *kp);
+extern struct kernel_param_ops param_ops_byte;
+extern int param_set_byte(const char *val, const struct kernel_param *kp);
+extern int param_get_byte(char *buffer, const struct kernel_param *kp);
 #define param_check_byte(name, p) __param_check(name, p, unsigned char)
 
-extern int param_set_short(const char *val, struct kernel_param *kp);
-extern int param_get_short(char *buffer, struct kernel_param *kp);
+extern struct kernel_param_ops param_ops_short;
+extern int param_set_short(const char *val, const struct kernel_param *kp);
+extern int param_get_short(char *buffer, const struct kernel_param *kp);
 #define param_check_short(name, p) __param_check(name, p, short)
 
-extern int param_set_ushort(const char *val, struct kernel_param *kp);
-extern int param_get_ushort(char *buffer, struct kernel_param *kp);
+extern struct kernel_param_ops param_ops_ushort;
+extern int param_set_ushort(const char *val, const struct kernel_param *kp);
+extern int param_get_ushort(char *buffer, const struct kernel_param *kp);
 #define param_check_ushort(name, p) __param_check(name, p, unsigned short)
 
-extern int param_set_int(const char *val, struct kernel_param *kp);
-extern int param_get_int(char *buffer, struct kernel_param *kp);
+extern struct kernel_param_ops param_ops_int;
+extern int param_set_int(const char *val, const struct kernel_param *kp);
+extern int param_get_int(char *buffer, const struct kernel_param *kp);
 #define param_check_int(name, p) __param_check(name, p, int)
 
-extern int param_set_uint(const char *val, struct kernel_param *kp);
-extern int param_get_uint(char *buffer, struct kernel_param *kp);
+extern struct kernel_param_ops param_ops_uint;
+extern int param_set_uint(const char *val, const struct kernel_param *kp);
+extern int param_get_uint(char *buffer, const struct kernel_param *kp);
 #define param_check_uint(name, p) __param_check(name, p, unsigned int)
 
-extern int param_set_long(const char *val, struct kernel_param *kp);
-extern int param_get_long(char *buffer, struct kernel_param *kp);
+extern struct kernel_param_ops param_ops_long;
+extern int param_set_long(const char *val, const struct kernel_param *kp);
+extern int param_get_long(char *buffer, const struct kernel_param *kp);
 #define param_check_long(name, p) __param_check(name, p, long)
 
-extern int param_set_ulong(const char *val, struct kernel_param *kp);
-extern int param_get_ulong(char *buffer, struct kernel_param *kp);
+extern struct kernel_param_ops param_ops_ulong;
+extern int param_set_ulong(const char *val, const struct kernel_param *kp);
+extern int param_get_ulong(char *buffer, const struct kernel_param *kp);
 #define param_check_ulong(name, p) __param_check(name, p, unsigned long)
 
-extern int param_set_charp(const char *val, struct kernel_param *kp);
-extern int param_get_charp(char *buffer, struct kernel_param *kp);
+extern struct kernel_param_ops param_ops_charp;
+extern int param_set_charp(const char *val, const struct kernel_param *kp);
+extern int param_get_charp(char *buffer, const struct kernel_param *kp);
 #define param_check_charp(name, p) __param_check(name, p, char *)
 
 /* For historical reasons "bool" parameters can be (unsigned) "int". */
-extern int param_set_bool(const char *val, struct kernel_param *kp);
-extern int param_get_bool(char *buffer, struct kernel_param *kp);
+extern struct kernel_param_ops param_ops_bool;
+extern int param_set_bool(const char *val, const struct kernel_param *kp);
+extern int param_get_bool(char *buffer, const struct kernel_param *kp);
 #define param_check_bool(name, p)					\
 	static inline void __check_##name(void)				\
 	{								\
-		BUILD_BUG_ON(!__same_type(*(p), bool) &&		\
-			     !__same_type(*(p), unsigned int) &&	\
-			     !__same_type(*(p), int));			\
+		BUILD_BUG_ON(!__same_type((p), bool *) &&		\
+			     !__same_type((p), unsigned int *) &&	\
+			     !__same_type((p), int *));			\
 	}
 
-extern int param_set_invbool(const char *val, struct kernel_param *kp);
-extern int param_get_invbool(char *buffer, struct kernel_param *kp);
+extern struct kernel_param_ops param_ops_invbool;
+extern int param_set_invbool(const char *val, const struct kernel_param *kp);
+extern int param_get_invbool(char *buffer, const struct kernel_param *kp);
 #define param_check_invbool(name, p) __param_check(name, p, bool)
 
-/* Comma-separated array: *nump is set to number they actually specified. */
+/**
+ * module_param_array - a parameter which is an array of some type
+ * @name: the name of the array variable
+ * @type: the type, as per module_param()
+ * @nump: optional pointer filled in with the number written
+ * @perm: visibility in sysfs
+ *
+ * Input and output are as comma-separated values.  Commas inside values
+ * don't work properly (eg. an array of charp).
+ *
+ * ARRAY_SIZE(@name) is used to determine the number of elements in the
+ * array, so the definition must be visible.
+ */
+#define module_param_array(name, type, nump, perm)		\
+	module_param_array_named(name, name, type, nump, perm)
+
+/**
+ * module_param_array_named - renamed parameter which is an array of some type
+ * @name: a valid C identifier which is the parameter name
+ * @array: the name of the array variable
+ * @type: the type, as per module_param()
+ * @nump: optional pointer filled in with the number written
+ * @perm: visibility in sysfs
+ *
+ * This exposes a different name than the actual variable name.  See
+ * module_param_named() for why this might be necessary.
+ */
 #define module_param_array_named(name, array, type, nump, perm)		\
 	static const struct kparam_array __param_arr_##name		\
-	= { ARRAY_SIZE(array), nump, param_set_##type, param_get_##type,\
+	= { ARRAY_SIZE(array), nump, &param_ops_##type,			\
 	    sizeof(array[0]), array };					\
 	__module_param_call(MODULE_PARAM_PREFIX, name,			\
-			    param_array_set, param_array_get,		\
+			    &param_array_ops,				\
 			    .arr = &__param_arr_##name,			\
 			    __same_type(array[0], bool), perm);		\
 	__MODULE_PARM_TYPE(name, "array of " #type)
 
-#define module_param_array(name, type, nump, perm)		\
-	module_param_array_named(name, name, type, nump, perm)
-
-extern int param_array_set(const char *val, struct kernel_param *kp);
-extern int param_array_get(char *buffer, struct kernel_param *kp);
+extern struct kernel_param_ops param_array_ops;
 
-extern int param_set_copystring(const char *val, struct kernel_param *kp);
-extern int param_get_string(char *buffer, struct kernel_param *kp);
+extern struct kernel_param_ops param_ops_string;
+extern int param_set_copystring(const char *val, const struct kernel_param *);
+extern int param_get_string(char *buffer, const struct kernel_param *kp);
 
 /* for exporting parameters in /sys/parameters */
 
@@ -235,13 +389,13 @@ struct module;
 
 #if defined(CONFIG_SYSFS) && defined(CONFIG_MODULES)
 extern int module_param_sysfs_setup(struct module *mod,
-				    struct kernel_param *kparam,
+				    const struct kernel_param *kparam,
 				    unsigned int num_params);
 
 extern void module_param_sysfs_remove(struct module *mod);
 #else
 static inline int module_param_sysfs_setup(struct module *mod,
-			     struct kernel_param *kparam,
+			     const struct kernel_param *kparam,
 			     unsigned int num_params)
 {
 	return 0;