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![Rusty Russell](/assets/img/avatar_default.png)
gcc allows this when arg is a function, but sparse complains: drivers/char/ipmi/ipmi_watchdog.c:303:1: error: cannot dereference this type drivers/char/ipmi/ipmi_watchdog.c:307:1: error: cannot dereference this type drivers/char/ipmi/ipmi_watchdog.c:311:1: error: cannot dereference this type Reported-by: Randy Dunlap <randy.dunlap@oracle.com> Tested-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
408 lines
14 KiB
C
408 lines
14 KiB
C
#ifndef _LINUX_MODULE_PARAMS_H
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#define _LINUX_MODULE_PARAMS_H
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/* (C) Copyright 2001, 2002 Rusty Russell IBM Corporation */
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#include <linux/init.h>
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#include <linux/stringify.h>
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#include <linux/kernel.h>
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/* You can override this manually, but generally this should match the
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module name. */
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#ifdef MODULE
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#define MODULE_PARAM_PREFIX /* empty */
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#else
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#define MODULE_PARAM_PREFIX KBUILD_MODNAME "."
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#endif
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/* Chosen so that structs with an unsigned long line up. */
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#define MAX_PARAM_PREFIX_LEN (64 - sizeof(unsigned long))
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#ifdef MODULE
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#define ___module_cat(a,b) __mod_ ## a ## b
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#define __module_cat(a,b) ___module_cat(a,b)
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#define __MODULE_INFO(tag, name, info) \
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static const char __module_cat(name,__LINE__)[] \
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__used \
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__attribute__((section(".modinfo"),unused)) = __stringify(tag) "=" info
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#else /* !MODULE */
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#define __MODULE_INFO(tag, name, info)
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#endif
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#define __MODULE_PARM_TYPE(name, _type) \
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__MODULE_INFO(parmtype, name##type, #name ":" _type)
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struct kernel_param;
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struct kernel_param_ops {
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/* Returns 0, or -errno. arg is in kp->arg. */
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int (*set)(const char *val, const struct kernel_param *kp);
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/* Returns length written or -errno. Buffer is 4k (ie. be short!) */
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int (*get)(char *buffer, const struct kernel_param *kp);
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/* Optional function to free kp->arg when module unloaded. */
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void (*free)(void *arg);
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};
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/* Flag bits for kernel_param.flags */
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#define KPARAM_ISBOOL 2
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struct kernel_param {
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const char *name;
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const struct kernel_param_ops *ops;
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u16 perm;
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u16 flags;
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union {
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void *arg;
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const struct kparam_string *str;
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const struct kparam_array *arr;
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};
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};
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/* Special one for strings we want to copy into */
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struct kparam_string {
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unsigned int maxlen;
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char *string;
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};
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/* Special one for arrays */
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struct kparam_array
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{
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unsigned int max;
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unsigned int *num;
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const struct kernel_param_ops *ops;
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unsigned int elemsize;
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void *elem;
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};
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/**
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* module_param - typesafe helper for a module/cmdline parameter
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* @value: the variable to alter, and exposed parameter name.
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* @type: the type of the parameter
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* @perm: visibility in sysfs.
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*
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* @value becomes the module parameter, or (prefixed by KBUILD_MODNAME and a
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* ".") the kernel commandline parameter. Note that - is changed to _, so
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* the user can use "foo-bar=1" even for variable "foo_bar".
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*
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* @perm is 0 if the the variable is not to appear in sysfs, or 0444
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* for world-readable, 0644 for root-writable, etc. Note that if it
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* is writable, you may need to use kparam_block_sysfs_write() around
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* accesses (esp. charp, which can be kfreed when it changes).
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*
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* The @type is simply pasted to refer to a param_ops_##type and a
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* param_check_##type: for convenience many standard types are provided but
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* you can create your own by defining those variables.
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*
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* Standard types are:
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* byte, short, ushort, int, uint, long, ulong
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* charp: a character pointer
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* bool: a bool, values 0/1, y/n, Y/N.
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* invbool: the above, only sense-reversed (N = true).
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*/
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#define module_param(name, type, perm) \
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module_param_named(name, name, type, perm)
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/**
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* module_param_named - typesafe helper for a renamed module/cmdline parameter
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* @name: a valid C identifier which is the parameter name.
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* @value: the actual lvalue to alter.
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* @type: the type of the parameter
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* @perm: visibility in sysfs.
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*
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* Usually it's a good idea to have variable names and user-exposed names the
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* same, but that's harder if the variable must be non-static or is inside a
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* structure. This allows exposure under a different name.
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*/
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#define module_param_named(name, value, type, perm) \
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param_check_##type(name, &(value)); \
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module_param_cb(name, ¶m_ops_##type, &value, perm); \
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__MODULE_PARM_TYPE(name, #type)
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/**
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* module_param_cb - general callback for a module/cmdline parameter
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* @name: a valid C identifier which is the parameter name.
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* @ops: the set & get operations for this parameter.
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* @perm: visibility in sysfs.
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*
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* The ops can have NULL set or get functions.
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*/
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#define module_param_cb(name, ops, arg, perm) \
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__module_param_call(MODULE_PARAM_PREFIX, \
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name, ops, arg, __same_type((arg), bool *), perm)
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/* On alpha, ia64 and ppc64 relocations to global data cannot go into
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read-only sections (which is part of respective UNIX ABI on these
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platforms). So 'const' makes no sense and even causes compile failures
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with some compilers. */
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#if defined(CONFIG_ALPHA) || defined(CONFIG_IA64) || defined(CONFIG_PPC64)
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#define __moduleparam_const
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#else
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#define __moduleparam_const const
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#endif
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/* This is the fundamental function for registering boot/module
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parameters. */
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#define __module_param_call(prefix, name, ops, arg, isbool, perm) \
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/* Default value instead of permissions? */ \
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static int __param_perm_check_##name __attribute__((unused)) = \
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BUILD_BUG_ON_ZERO((perm) < 0 || (perm) > 0777 || ((perm) & 2)) \
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+ BUILD_BUG_ON_ZERO(sizeof(""prefix) > MAX_PARAM_PREFIX_LEN); \
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static const char __param_str_##name[] = prefix #name; \
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static struct kernel_param __moduleparam_const __param_##name \
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__used \
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__attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \
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= { __param_str_##name, ops, perm, isbool ? KPARAM_ISBOOL : 0, \
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{ arg } }
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/* Obsolete - use module_param_cb() */
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#define module_param_call(name, set, get, arg, perm) \
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static struct kernel_param_ops __param_ops_##name = \
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{ (void *)set, (void *)get }; \
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__module_param_call(MODULE_PARAM_PREFIX, \
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name, &__param_ops_##name, arg, \
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__same_type(arg, bool *), \
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(perm) + sizeof(__check_old_set_param(set))*0)
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/* We don't get oldget: it's often a new-style param_get_uint, etc. */
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static inline int
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__check_old_set_param(int (*oldset)(const char *, struct kernel_param *))
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{
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return 0;
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}
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/**
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* kparam_block_sysfs_write - make sure a parameter isn't written via sysfs.
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* @name: the name of the parameter
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*
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* There's no point blocking write on a paramter that isn't writable via sysfs!
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*/
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#define kparam_block_sysfs_write(name) \
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do { \
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BUG_ON(!(__param_##name.perm & 0222)); \
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__kernel_param_lock(); \
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} while (0)
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/**
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* kparam_unblock_sysfs_write - allows sysfs to write to a parameter again.
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* @name: the name of the parameter
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*/
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#define kparam_unblock_sysfs_write(name) \
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do { \
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BUG_ON(!(__param_##name.perm & 0222)); \
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__kernel_param_unlock(); \
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} while (0)
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/**
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* kparam_block_sysfs_read - make sure a parameter isn't read via sysfs.
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* @name: the name of the parameter
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*
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* This also blocks sysfs writes.
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*/
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#define kparam_block_sysfs_read(name) \
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do { \
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BUG_ON(!(__param_##name.perm & 0444)); \
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__kernel_param_lock(); \
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} while (0)
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/**
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* kparam_unblock_sysfs_read - allows sysfs to read a parameter again.
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* @name: the name of the parameter
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*/
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#define kparam_unblock_sysfs_read(name) \
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do { \
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BUG_ON(!(__param_##name.perm & 0444)); \
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__kernel_param_unlock(); \
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} while (0)
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#ifdef CONFIG_SYSFS
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extern void __kernel_param_lock(void);
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extern void __kernel_param_unlock(void);
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#else
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static inline void __kernel_param_lock(void)
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{
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}
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static inline void __kernel_param_unlock(void)
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{
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}
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#endif
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#ifndef MODULE
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/**
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* core_param - define a historical core kernel parameter.
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* @name: the name of the cmdline and sysfs parameter (often the same as var)
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* @var: the variable
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* @type: the type of the parameter
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* @perm: visibility in sysfs
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*
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* core_param is just like module_param(), but cannot be modular and
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* doesn't add a prefix (such as "printk."). This is for compatibility
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* with __setup(), and it makes sense as truly core parameters aren't
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* tied to the particular file they're in.
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*/
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#define core_param(name, var, type, perm) \
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param_check_##type(name, &(var)); \
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__module_param_call("", name, ¶m_ops_##type, \
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&var, __same_type(var, bool), perm)
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#endif /* !MODULE */
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/**
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* module_param_string - a char array parameter
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* @name: the name of the parameter
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* @string: the string variable
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* @len: the maximum length of the string, incl. terminator
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* @perm: visibility in sysfs.
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*
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* This actually copies the string when it's set (unlike type charp).
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* @len is usually just sizeof(string).
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*/
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#define module_param_string(name, string, len, perm) \
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static const struct kparam_string __param_string_##name \
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= { len, string }; \
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__module_param_call(MODULE_PARAM_PREFIX, name, \
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¶m_ops_string, \
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.str = &__param_string_##name, 0, perm); \
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__MODULE_PARM_TYPE(name, "string")
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/* Called on module insert or kernel boot */
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extern int parse_args(const char *name,
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char *args,
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const struct kernel_param *params,
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unsigned num,
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int (*unknown)(char *param, char *val));
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/* Called by module remove. */
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#ifdef CONFIG_SYSFS
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extern void destroy_params(const struct kernel_param *params, unsigned num);
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#else
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static inline void destroy_params(const struct kernel_param *params,
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unsigned num)
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{
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}
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#endif /* !CONFIG_SYSFS */
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/* All the helper functions */
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/* The macros to do compile-time type checking stolen from Jakub
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Jelinek, who IIRC came up with this idea for the 2.4 module init code. */
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#define __param_check(name, p, type) \
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static inline type *__check_##name(void) { return(p); }
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extern struct kernel_param_ops param_ops_byte;
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extern int param_set_byte(const char *val, const struct kernel_param *kp);
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extern int param_get_byte(char *buffer, const struct kernel_param *kp);
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#define param_check_byte(name, p) __param_check(name, p, unsigned char)
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extern struct kernel_param_ops param_ops_short;
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extern int param_set_short(const char *val, const struct kernel_param *kp);
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extern int param_get_short(char *buffer, const struct kernel_param *kp);
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#define param_check_short(name, p) __param_check(name, p, short)
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extern struct kernel_param_ops param_ops_ushort;
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extern int param_set_ushort(const char *val, const struct kernel_param *kp);
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extern int param_get_ushort(char *buffer, const struct kernel_param *kp);
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#define param_check_ushort(name, p) __param_check(name, p, unsigned short)
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extern struct kernel_param_ops param_ops_int;
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extern int param_set_int(const char *val, const struct kernel_param *kp);
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extern int param_get_int(char *buffer, const struct kernel_param *kp);
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#define param_check_int(name, p) __param_check(name, p, int)
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extern struct kernel_param_ops param_ops_uint;
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extern int param_set_uint(const char *val, const struct kernel_param *kp);
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extern int param_get_uint(char *buffer, const struct kernel_param *kp);
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#define param_check_uint(name, p) __param_check(name, p, unsigned int)
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extern struct kernel_param_ops param_ops_long;
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extern int param_set_long(const char *val, const struct kernel_param *kp);
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extern int param_get_long(char *buffer, const struct kernel_param *kp);
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#define param_check_long(name, p) __param_check(name, p, long)
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extern struct kernel_param_ops param_ops_ulong;
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extern int param_set_ulong(const char *val, const struct kernel_param *kp);
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extern int param_get_ulong(char *buffer, const struct kernel_param *kp);
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#define param_check_ulong(name, p) __param_check(name, p, unsigned long)
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extern struct kernel_param_ops param_ops_charp;
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extern int param_set_charp(const char *val, const struct kernel_param *kp);
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extern int param_get_charp(char *buffer, const struct kernel_param *kp);
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#define param_check_charp(name, p) __param_check(name, p, char *)
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/* For historical reasons "bool" parameters can be (unsigned) "int". */
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extern struct kernel_param_ops param_ops_bool;
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extern int param_set_bool(const char *val, const struct kernel_param *kp);
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extern int param_get_bool(char *buffer, const struct kernel_param *kp);
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#define param_check_bool(name, p) \
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static inline void __check_##name(void) \
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{ \
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BUILD_BUG_ON(!__same_type((p), bool *) && \
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!__same_type((p), unsigned int *) && \
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!__same_type((p), int *)); \
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}
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extern struct kernel_param_ops param_ops_invbool;
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extern int param_set_invbool(const char *val, const struct kernel_param *kp);
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extern int param_get_invbool(char *buffer, const struct kernel_param *kp);
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#define param_check_invbool(name, p) __param_check(name, p, bool)
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/**
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* module_param_array - a parameter which is an array of some type
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* @name: the name of the array variable
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* @type: the type, as per module_param()
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* @nump: optional pointer filled in with the number written
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* @perm: visibility in sysfs
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*
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* Input and output are as comma-separated values. Commas inside values
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* don't work properly (eg. an array of charp).
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*
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* ARRAY_SIZE(@name) is used to determine the number of elements in the
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* array, so the definition must be visible.
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*/
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#define module_param_array(name, type, nump, perm) \
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module_param_array_named(name, name, type, nump, perm)
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/**
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* module_param_array_named - renamed parameter which is an array of some type
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* @name: a valid C identifier which is the parameter name
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* @array: the name of the array variable
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* @type: the type, as per module_param()
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* @nump: optional pointer filled in with the number written
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* @perm: visibility in sysfs
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*
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* This exposes a different name than the actual variable name. See
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* module_param_named() for why this might be necessary.
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*/
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#define module_param_array_named(name, array, type, nump, perm) \
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static const struct kparam_array __param_arr_##name \
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= { ARRAY_SIZE(array), nump, ¶m_ops_##type, \
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sizeof(array[0]), array }; \
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__module_param_call(MODULE_PARAM_PREFIX, name, \
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¶m_array_ops, \
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.arr = &__param_arr_##name, \
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__same_type(array[0], bool), perm); \
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__MODULE_PARM_TYPE(name, "array of " #type)
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extern struct kernel_param_ops param_array_ops;
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extern struct kernel_param_ops param_ops_string;
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extern int param_set_copystring(const char *val, const struct kernel_param *);
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extern int param_get_string(char *buffer, const struct kernel_param *kp);
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/* for exporting parameters in /sys/parameters */
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struct module;
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#if defined(CONFIG_SYSFS) && defined(CONFIG_MODULES)
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extern int module_param_sysfs_setup(struct module *mod,
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const struct kernel_param *kparam,
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unsigned int num_params);
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extern void module_param_sysfs_remove(struct module *mod);
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#else
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static inline int module_param_sysfs_setup(struct module *mod,
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const struct kernel_param *kparam,
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unsigned int num_params)
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{
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return 0;
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}
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static inline void module_param_sysfs_remove(struct module *mod)
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{ }
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#endif
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#endif /* _LINUX_MODULE_PARAMS_H */
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