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)