projects/linux·blob v4.10-rc7 · refs

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1#ifndef _LINUX_MODULE_PARAMS_H
2#define _LINUX_MODULE_PARAMS_H
3/* (C) Copyright 2001, 2002 Rusty Russell IBM Corporation */
4#include <linux/init.h>
5#include <linux/stringify.h>
6#include <linux/kernel.h>
7
8/* You can override this manually, but generally this should match the
9 module name. */
10#ifdef MODULE
11#define MODULE_PARAM_PREFIX /* empty */
12#else
13#define MODULE_PARAM_PREFIX KBUILD_MODNAME "."
14#endif
15
16/* Chosen so that structs with an unsigned long line up. */
17#define MAX_PARAM_PREFIX_LEN (64 - sizeof(unsigned long))
18
19#ifdef MODULE
20#define __MODULE_INFO(tag, name, info) \
21static const char __UNIQUE_ID(name)[] \
22 __used __attribute__((section(".modinfo"), unused, aligned(1))) \
23 = __stringify(tag) "=" info
24#else /* !MODULE */
25/* This struct is here for syntactic coherency, it is not used */
26#define __MODULE_INFO(tag, name, info) \
27 struct __UNIQUE_ID(name) {}
28#endif
29#define __MODULE_PARM_TYPE(name, _type) \
30 __MODULE_INFO(parmtype, name##type, #name ":" _type)
31
32/* One for each parameter, describing how to use it. Some files do
33 multiple of these per line, so can't just use MODULE_INFO. */
34#define MODULE_PARM_DESC(_parm, desc) \
35 __MODULE_INFO(parm, _parm, #_parm ":" desc)
36
37struct kernel_param;
38
39/*
40 * Flags available for kernel_param_ops
41 *
42 * NOARG - the parameter allows for no argument (foo instead of foo=1)
43 */
44enum {
45 KERNEL_PARAM_OPS_FL_NOARG = (1 << 0)
46};
47
48struct kernel_param_ops {
49 /* How the ops should behave */
50 unsigned int flags;
51 /* Returns 0, or -errno. arg is in kp->arg. */
52 int (*set)(const char *val, const struct kernel_param *kp);
53 /* Returns length written or -errno. Buffer is 4k (ie. be short!) */
54 int (*get)(char *buffer, const struct kernel_param *kp);
55 /* Optional function to free kp->arg when module unloaded. */
56 void (*free)(void *arg);
57};
58
59/*
60 * Flags available for kernel_param
61 *
62 * UNSAFE - the parameter is dangerous and setting it will taint the kernel
63 */
64enum {
65 KERNEL_PARAM_FL_UNSAFE = (1 << 0)
66};
67
68struct kernel_param {
69 const char *name;
70 struct module *mod;
71 const struct kernel_param_ops *ops;
72 const u16 perm;
73 s8 level;
74 u8 flags;
75 union {
76 void *arg;
77 const struct kparam_string *str;
78 const struct kparam_array *arr;
79 };
80};
81
82extern const struct kernel_param __start___param[], __stop___param[];
83
84/* Special one for strings we want to copy into */
85struct kparam_string {
86 unsigned int maxlen;
87 char *string;
88};
89
90/* Special one for arrays */
91struct kparam_array
92{
93 unsigned int max;
94 unsigned int elemsize;
95 unsigned int *num;
96 const struct kernel_param_ops *ops;
97 void *elem;
98};
99
100/**
101 * module_param - typesafe helper for a module/cmdline parameter
102 * @value: the variable to alter, and exposed parameter name.
103 * @type: the type of the parameter
104 * @perm: visibility in sysfs.
105 *
106 * @value becomes the module parameter, or (prefixed by KBUILD_MODNAME and a
107 * ".") the kernel commandline parameter. Note that - is changed to _, so
108 * the user can use "foo-bar=1" even for variable "foo_bar".
109 *
110 * @perm is 0 if the the variable is not to appear in sysfs, or 0444
111 * for world-readable, 0644 for root-writable, etc. Note that if it
112 * is writable, you may need to use kernel_param_lock() around
113 * accesses (esp. charp, which can be kfreed when it changes).
114 *
115 * The @type is simply pasted to refer to a param_ops_##type and a
116 * param_check_##type: for convenience many standard types are provided but
117 * you can create your own by defining those variables.
118 *
119 * Standard types are:
120 * byte, short, ushort, int, uint, long, ulong
121 * charp: a character pointer
122 * bool: a bool, values 0/1, y/n, Y/N.
123 * invbool: the above, only sense-reversed (N = true).
124 */
125#define module_param(name, type, perm) \
126 module_param_named(name, name, type, perm)
127
128/**
129 * module_param_unsafe - same as module_param but taints kernel
130 */
131#define module_param_unsafe(name, type, perm) \
132 module_param_named_unsafe(name, name, type, perm)
133
134/**
135 * module_param_named - typesafe helper for a renamed module/cmdline parameter
136 * @name: a valid C identifier which is the parameter name.
137 * @value: the actual lvalue to alter.
138 * @type: the type of the parameter
139 * @perm: visibility in sysfs.
140 *
141 * Usually it's a good idea to have variable names and user-exposed names the
142 * same, but that's harder if the variable must be non-static or is inside a
143 * structure. This allows exposure under a different name.
144 */
145#define module_param_named(name, value, type, perm) \
146 param_check_##type(name, &(value)); \
147 module_param_cb(name, &param_ops_##type, &value, perm); \
148 __MODULE_PARM_TYPE(name, #type)
149
150/**
151 * module_param_named_unsafe - same as module_param_named but taints kernel
152 */
153#define module_param_named_unsafe(name, value, type, perm) \
154 param_check_##type(name, &(value)); \
155 module_param_cb_unsafe(name, &param_ops_##type, &value, perm); \
156 __MODULE_PARM_TYPE(name, #type)
157
158/**
159 * module_param_cb - general callback for a module/cmdline parameter
160 * @name: a valid C identifier which is the parameter name.
161 * @ops: the set & get operations for this parameter.
162 * @perm: visibility in sysfs.
163 *
164 * The ops can have NULL set or get functions.
165 */
166#define module_param_cb(name, ops, arg, perm) \
167 __module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, -1, 0)
168
169#define module_param_cb_unsafe(name, ops, arg, perm) \
170 __module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, -1, \
171 KERNEL_PARAM_FL_UNSAFE)
172
173/**
174 * <level>_param_cb - general callback for a module/cmdline parameter
175 * to be evaluated before certain initcall level
176 * @name: a valid C identifier which is the parameter name.
177 * @ops: the set & get operations for this parameter.
178 * @perm: visibility in sysfs.
179 *
180 * The ops can have NULL set or get functions.
181 */
182#define __level_param_cb(name, ops, arg, perm, level) \
183 __module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, level, 0)
184
185#define core_param_cb(name, ops, arg, perm) \
186 __level_param_cb(name, ops, arg, perm, 1)
187
188#define postcore_param_cb(name, ops, arg, perm) \
189 __level_param_cb(name, ops, arg, perm, 2)
190
191#define arch_param_cb(name, ops, arg, perm) \
192 __level_param_cb(name, ops, arg, perm, 3)
193
194#define subsys_param_cb(name, ops, arg, perm) \
195 __level_param_cb(name, ops, arg, perm, 4)
196
197#define fs_param_cb(name, ops, arg, perm) \
198 __level_param_cb(name, ops, arg, perm, 5)
199
200#define device_param_cb(name, ops, arg, perm) \
201 __level_param_cb(name, ops, arg, perm, 6)
202
203#define late_param_cb(name, ops, arg, perm) \
204 __level_param_cb(name, ops, arg, perm, 7)
205
206/* On alpha, ia64 and ppc64 relocations to global data cannot go into
207 read-only sections (which is part of respective UNIX ABI on these
208 platforms). So 'const' makes no sense and even causes compile failures
209 with some compilers. */
210#if defined(CONFIG_ALPHA) || defined(CONFIG_IA64) || defined(CONFIG_PPC64)
211#define __moduleparam_const
212#else
213#define __moduleparam_const const
214#endif
215
216/* This is the fundamental function for registering boot/module
217 parameters. */
218#define __module_param_call(prefix, name, ops, arg, perm, level, flags) \
219 /* Default value instead of permissions? */ \
220 static const char __param_str_##name[] = prefix #name; \
221 static struct kernel_param __moduleparam_const __param_##name \
222 __used \
223 __attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \
224 = { __param_str_##name, THIS_MODULE, ops, \
225 VERIFY_OCTAL_PERMISSIONS(perm), level, flags, { arg } }
226
227/* Obsolete - use module_param_cb() */
228#define module_param_call(name, set, get, arg, perm) \
229 static const struct kernel_param_ops __param_ops_##name = \
230 { .flags = 0, (void *)set, (void *)get }; \
231 __module_param_call(MODULE_PARAM_PREFIX, \
232 name, &__param_ops_##name, arg, \
233 (perm) + sizeof(__check_old_set_param(set))*0, -1, 0)
234
235/* We don't get oldget: it's often a new-style param_get_uint, etc. */
236static inline int
237__check_old_set_param(int (*oldset)(const char *, struct kernel_param *))
238{
239 return 0;
240}
241
242#ifdef CONFIG_SYSFS
243extern void kernel_param_lock(struct module *mod);
244extern void kernel_param_unlock(struct module *mod);
245#else
246static inline void kernel_param_lock(struct module *mod)
247{
248}
249static inline void kernel_param_unlock(struct module *mod)
250{
251}
252#endif
253
254#ifndef MODULE
255/**
256 * core_param - define a historical core kernel parameter.
257 * @name: the name of the cmdline and sysfs parameter (often the same as var)
258 * @var: the variable
259 * @type: the type of the parameter
260 * @perm: visibility in sysfs
261 *
262 * core_param is just like module_param(), but cannot be modular and
263 * doesn't add a prefix (such as "printk."). This is for compatibility
264 * with __setup(), and it makes sense as truly core parameters aren't
265 * tied to the particular file they're in.
266 */
267#define core_param(name, var, type, perm) \
268 param_check_##type(name, &(var)); \
269 __module_param_call("", name, &param_ops_##type, &var, perm, -1, 0)
270
271/**
272 * core_param_unsafe - same as core_param but taints kernel
273 */
274#define core_param_unsafe(name, var, type, perm) \
275 param_check_##type(name, &(var)); \
276 __module_param_call("", name, &param_ops_##type, &var, perm, \
277 -1, KERNEL_PARAM_FL_UNSAFE)
278
279#endif /* !MODULE */
280
281/**
282 * module_param_string - a char array parameter
283 * @name: the name of the parameter
284 * @string: the string variable
285 * @len: the maximum length of the string, incl. terminator
286 * @perm: visibility in sysfs.
287 *
288 * This actually copies the string when it's set (unlike type charp).
289 * @len is usually just sizeof(string).
290 */
291#define module_param_string(name, string, len, perm) \
292 static const struct kparam_string __param_string_##name \
293 = { len, string }; \
294 __module_param_call(MODULE_PARAM_PREFIX, name, \
295 &param_ops_string, \
296 .str = &__param_string_##name, perm, -1, 0);\
297 __MODULE_PARM_TYPE(name, "string")
298
299/**
300 * parameq - checks if two parameter names match
301 * @name1: parameter name 1
302 * @name2: parameter name 2
303 *
304 * Returns true if the two parameter names are equal.
305 * Dashes (-) are considered equal to underscores (_).
306 */
307extern bool parameq(const char *name1, const char *name2);
308
309/**
310 * parameqn - checks if two parameter names match
311 * @name1: parameter name 1
312 * @name2: parameter name 2
313 * @n: the length to compare
314 *
315 * Similar to parameq(), except it compares @n characters.
316 */
317extern bool parameqn(const char *name1, const char *name2, size_t n);
318
319/* Called on module insert or kernel boot */
320extern char *parse_args(const char *name,
321 char *args,
322 const struct kernel_param *params,
323 unsigned num,
324 s16 level_min,
325 s16 level_max,
326 void *arg,
327 int (*unknown)(char *param, char *val,
328 const char *doing, void *arg));
329
330/* Called by module remove. */
331#ifdef CONFIG_SYSFS
332extern void destroy_params(const struct kernel_param *params, unsigned num);
333#else
334static inline void destroy_params(const struct kernel_param *params,
335 unsigned num)
336{
337}
338#endif /* !CONFIG_SYSFS */
339
340/* All the helper functions */
341/* The macros to do compile-time type checking stolen from Jakub
342 Jelinek, who IIRC came up with this idea for the 2.4 module init code. */
343#define __param_check(name, p, type) \
344 static inline type __always_unused *__check_##name(void) { return(p); }
345
346extern const struct kernel_param_ops param_ops_byte;
347extern int param_set_byte(const char *val, const struct kernel_param *kp);
348extern int param_get_byte(char *buffer, const struct kernel_param *kp);
349#define param_check_byte(name, p) __param_check(name, p, unsigned char)
350
351extern const struct kernel_param_ops param_ops_short;
352extern int param_set_short(const char *val, const struct kernel_param *kp);
353extern int param_get_short(char *buffer, const struct kernel_param *kp);
354#define param_check_short(name, p) __param_check(name, p, short)
355
356extern const struct kernel_param_ops param_ops_ushort;
357extern int param_set_ushort(const char *val, const struct kernel_param *kp);
358extern int param_get_ushort(char *buffer, const struct kernel_param *kp);
359#define param_check_ushort(name, p) __param_check(name, p, unsigned short)
360
361extern const struct kernel_param_ops param_ops_int;
362extern int param_set_int(const char *val, const struct kernel_param *kp);
363extern int param_get_int(char *buffer, const struct kernel_param *kp);
364#define param_check_int(name, p) __param_check(name, p, int)
365
366extern const struct kernel_param_ops param_ops_uint;
367extern int param_set_uint(const char *val, const struct kernel_param *kp);
368extern int param_get_uint(char *buffer, const struct kernel_param *kp);
369#define param_check_uint(name, p) __param_check(name, p, unsigned int)
370
371extern const struct kernel_param_ops param_ops_long;
372extern int param_set_long(const char *val, const struct kernel_param *kp);
373extern int param_get_long(char *buffer, const struct kernel_param *kp);
374#define param_check_long(name, p) __param_check(name, p, long)
375
376extern const struct kernel_param_ops param_ops_ulong;
377extern int param_set_ulong(const char *val, const struct kernel_param *kp);
378extern int param_get_ulong(char *buffer, const struct kernel_param *kp);
379#define param_check_ulong(name, p) __param_check(name, p, unsigned long)
380
381extern const struct kernel_param_ops param_ops_ullong;
382extern int param_set_ullong(const char *val, const struct kernel_param *kp);
383extern int param_get_ullong(char *buffer, const struct kernel_param *kp);
384#define param_check_ullong(name, p) __param_check(name, p, unsigned long long)
385
386extern const struct kernel_param_ops param_ops_charp;
387extern int param_set_charp(const char *val, const struct kernel_param *kp);
388extern int param_get_charp(char *buffer, const struct kernel_param *kp);
389extern void param_free_charp(void *arg);
390#define param_check_charp(name, p) __param_check(name, p, char *)
391
392/* We used to allow int as well as bool. We're taking that away! */
393extern const struct kernel_param_ops param_ops_bool;
394extern int param_set_bool(const char *val, const struct kernel_param *kp);
395extern int param_get_bool(char *buffer, const struct kernel_param *kp);
396#define param_check_bool(name, p) __param_check(name, p, bool)
397
398extern const struct kernel_param_ops param_ops_bool_enable_only;
399extern int param_set_bool_enable_only(const char *val,
400 const struct kernel_param *kp);
401/* getter is the same as for the regular bool */
402#define param_check_bool_enable_only param_check_bool
403
404extern const struct kernel_param_ops param_ops_invbool;
405extern int param_set_invbool(const char *val, const struct kernel_param *kp);
406extern int param_get_invbool(char *buffer, const struct kernel_param *kp);
407#define param_check_invbool(name, p) __param_check(name, p, bool)
408
409/* An int, which can only be set like a bool (though it shows as an int). */
410extern const struct kernel_param_ops param_ops_bint;
411extern int param_set_bint(const char *val, const struct kernel_param *kp);
412#define param_get_bint param_get_int
413#define param_check_bint param_check_int
414
415/**
416 * module_param_array - a parameter which is an array of some type
417 * @name: the name of the array variable
418 * @type: the type, as per module_param()
419 * @nump: optional pointer filled in with the number written
420 * @perm: visibility in sysfs
421 *
422 * Input and output are as comma-separated values. Commas inside values
423 * don't work properly (eg. an array of charp).
424 *
425 * ARRAY_SIZE(@name) is used to determine the number of elements in the
426 * array, so the definition must be visible.
427 */
428#define module_param_array(name, type, nump, perm) \
429 module_param_array_named(name, name, type, nump, perm)
430
431/**
432 * module_param_array_named - renamed parameter which is an array of some type
433 * @name: a valid C identifier which is the parameter name
434 * @array: the name of the array variable
435 * @type: the type, as per module_param()
436 * @nump: optional pointer filled in with the number written
437 * @perm: visibility in sysfs
438 *
439 * This exposes a different name than the actual variable name. See
440 * module_param_named() for why this might be necessary.
441 */
442#define module_param_array_named(name, array, type, nump, perm) \
443 param_check_##type(name, &(array)[0]); \
444 static const struct kparam_array __param_arr_##name \
445 = { .max = ARRAY_SIZE(array), .num = nump, \
446 .ops = &param_ops_##type, \
447 .elemsize = sizeof(array[0]), .elem = array }; \
448 __module_param_call(MODULE_PARAM_PREFIX, name, \
449 &param_array_ops, \
450 .arr = &__param_arr_##name, \
451 perm, -1, 0); \
452 __MODULE_PARM_TYPE(name, "array of " #type)
453
454extern const struct kernel_param_ops param_array_ops;
455
456extern const struct kernel_param_ops param_ops_string;
457extern int param_set_copystring(const char *val, const struct kernel_param *);
458extern int param_get_string(char *buffer, const struct kernel_param *kp);
459
460/* for exporting parameters in /sys/module/.../parameters */
461
462struct module;
463
464#if defined(CONFIG_SYSFS) && defined(CONFIG_MODULES)
465extern int module_param_sysfs_setup(struct module *mod,
466 const struct kernel_param *kparam,
467 unsigned int num_params);
468
469extern void module_param_sysfs_remove(struct module *mod);
470#else
471static inline int module_param_sysfs_setup(struct module *mod,
472 const struct kernel_param *kparam,
473 unsigned int num_params)
474{
475 return 0;
476}
477
478static inline void module_param_sysfs_remove(struct module *mod)
479{ }
480#endif
481
482#endif /* _LINUX_MODULE_PARAMS_H */