Linux/module.h 常用头文件

/*

*写内核驱动的时候 必须加载这个头文件，作用是动态的将模块加载到内核中去

*常用的宏定义如 MODULE_LICESENCE(),MODULE_AUTHOR(),等在此文件中

*而且 kobject，kset结构体题及其操作函数也在这个结构体中，，，其实学习头文件最好的方法就是仔细的看头文件--看看有哪些功能就好用的时候再查阅

*

*

*/

#ifndef _LINUX_MODULE_H

#define _LINUX_MODULE_H
/*
 * Dynamic loading of modules into the kernel.
 *
 * Rewritten by Richard Henderson <[e-mail]> Dec 1996
 * Rewritten again by Rusty Russell, 2002
 */
#include <linux/list.h>
#include <linux/stat.h>
#include <linux/compiler.h>
#include <linux/cache.h>
#include <linux/kmod.h>
#include <linux/elf.h>
#include <linux/stringify.h>
#include <linux/kobject.h>
#include <linux/moduleparam.h>
#include <linux/tracepoint.h>


#include <linux/percpu.h>
#include <asm/module.h>


#include <trace/events/module.h>


/* Not Yet Implemented */
#define MODULE_SUPPORTED_DEVICE(name)


/* Some toolchains use a `_' prefix for all user symbols. */
#ifdef CONFIG_SYMBOL_PREFIX
#define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
#else
#define MODULE_SYMBOL_PREFIX ""
#endif


#define MODULE_NAME_LEN MAX_PARAM_PREFIX_LEN


struct kernel_symbol
{
unsigned long value;
const char *name;
};


struct modversion_info
{
unsigned long crc;
char name[MODULE_NAME_LEN];
};


struct module;


struct module_attribute {
        struct attribute attr;
        ssize_t (*show)(struct module_attribute *, struct module *, char *);
        ssize_t (*store)(struct module_attribute *, struct module *,
const char *, size_t count);
void (*setup)(struct module *, const char *);
int (*test)(struct module *);
void (*free)(struct module *);
};


struct module_version_attribute {
struct module_attribute mattr;
const char *module_name;
const char *version;
} __attribute__ ((__aligned__(sizeof(void *))));


struct module_kobject
{
struct kobject kobj;
struct module *mod;
struct kobject *drivers_dir;
struct module_param_attrs *mp;
};


/* These are either module local, or the kernel's dummy ones. */
extern int init_module(void);
extern void cleanup_module(void);


/* Archs provide a method of finding the correct exception table. */
struct exception_table_entry;


const struct exception_table_entry *
search_extable(const struct exception_table_entry *first,
      const struct exception_table_entry *last,
      unsigned long value);
void sort_extable(struct exception_table_entry *start,
 struct exception_table_entry *finish);
void sort_main_extable(void);
void trim_init_extable(struct module *m);


#ifdef MODULE
#define MODULE_GENERIC_TABLE(gtype,name)\
extern const struct gtype##_id __mod_##gtype##_table\
  __attribute__ ((unused, alias(__stringify(name))))


extern struct module __this_module;
#define THIS_MODULE (&__this_module)
#else  /* !MODULE */
#define MODULE_GENERIC_TABLE(gtype,name)
#define THIS_MODULE ((struct module *)0)
#endif


/* Generic info of form tag = "info" */
#define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info)


/* For userspace: you can also call me... */
#define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)


/*
 * The following license idents are currently accepted as indicating free
 * software modules
 *
 *"GPL" [GNU Public License v2 or later]
 *"GPL v2" [GNU Public License v2]
 *"GPL and additional rights"[GNU Public License v2 rights and more]
 *"Dual BSD/GPL"[GNU Public License v2
 *or BSD license choice]
 *"Dual MIT/GPL"[GNU Public License v2
 *or MIT license choice]
 *"Dual MPL/GPL"[GNU Public License v2
 *or Mozilla license choice]
 *
 * The following other idents are available
 *
 *"Proprietary"[Non free products]
 *
 * There are dual licensed components, but when running with Linux it is the
 * GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL
 * is a GPL combined work.
 *
 * This exists for several reasons
 * 1.So modinfo can show license info for users wanting to vet their setup 
 *is free
 * 2.So the community can ignore bug reports including proprietary modules
 * 3.So vendors can do likewise based on their own policies
 */
#define MODULE_LICENSE(_license) MODULE_INFO(license, _license)


/*
 * Author(s), use "Name <email>" or just "Name", for multiple
 * authors use multiple MODULE_AUTHOR() statements/lines.
 */
#define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
  
/* What your module does. */
#define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)


/* One for each parameter, describing how to use it.  Some files do
   multiple of these per line, so can't just use MODULE_INFO. */
#define MODULE_PARM_DESC(_parm, desc) \
__MODULE_INFO(parm, _parm, #_parm ":" desc)


#define MODULE_DEVICE_TABLE(type,name)\
  MODULE_GENERIC_TABLE(type##_device,name)


/* Version of form [<epoch>:]<version>[-<extra-version>].
   Or for CVS/RCS ID version, everything but the number is stripped.
  <epoch>: A (small) unsigned integer which allows you to start versions
           anew. If not mentioned, it's zero.  eg. "2:1.0" is after
  "1:2.0".
  <version>: The <version> may contain only alphanumerics and the
           character `.'.  Ordered by numeric sort for numeric parts,
  ascii sort for ascii parts (as per RPM or DEB algorithm).
  <extraversion>: Like <version>, but inserted for local
           customizations, eg "rh3" or "rusty1".


  Using this automatically adds a checksum of the .c files and the
  local headers in "srcversion".
*/


#if defined(MODULE) || !defined(CONFIG_SYSFS)
#define MODULE_VERSION(_version) MODULE_INFO(version, _version)
#else
#define MODULE_VERSION(_version)\
extern ssize_t __modver_version_show(struct module_attribute *,\
    struct module *, char *);\
static struct module_version_attribute __modver_version_attr\
__used \
    __attribute__ ((__section__ ("__modver"),aligned(sizeof(void *)))) \
= {\
.mattr = {\
.attr= {\
.name= "version",\
.mode= S_IRUGO,\
},\
.show= __modver_version_show,\
},\
.module_name = KBUILD_MODNAME,\
.version = _version,\
}
#endif


/* Optional firmware file (or files) needed by the module
 * format is simply firmware file name.  Multiple firmware
 * files require multiple MODULE_FIRMWARE() specifiers */
#define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)


/* Given an address, look for it in the exception tables */
const struct exception_table_entry *search_exception_tables(unsigned long add);


struct notifier_block;


#ifdef CONFIG_MODULES


extern int modules_disabled; /* for sysctl */
/* Get/put a kernel symbol (calls must be symmetric) */
void *__symbol_get(const char *symbol);
void *__symbol_get_gpl(const char *symbol);
#define symbol_get(x) ((typeof(&x))(__symbol_get(MODULE_SYMBOL_PREFIX #x)))


/* modules using other modules: kdb wants to see this. */
struct module_use {
struct list_head source_list;
struct list_head target_list;
struct module *source, *target;
};


#ifndef __GENKSYMS__
#ifdef CONFIG_MODVERSIONS
/* Mark the CRC weak since genksyms apparently decides not to
 * generate a checksums for some symbols */
#define __CRC_SYMBOL(sym, sec)\
extern void *__crc_##sym __attribute__((weak));\
static const unsigned long __kcrctab_##sym\
__used \
__attribute__((section("__kcrctab" sec), unused))\
= (unsigned long) &__crc_##sym;
#else
#define __CRC_SYMBOL(sym, sec)
#endif


/* For every exported symbol, place a struct in the __ksymtab section */
#define __EXPORT_SYMBOL(sym, sec)\
extern typeof(sym) sym;\
__CRC_SYMBOL(sym, sec)\
static const char __kstrtab_##sym[]\
__attribute__((section("__ksymtab_strings"), aligned(1))) \
= MODULE_SYMBOL_PREFIX #sym;                    \
static const struct kernel_symbol __ksymtab_##sym\
__used \
__attribute__((section("__ksymtab" sec), unused))\
= { (unsigned long)&sym, __kstrtab_##sym }


#define EXPORT_SYMBOL(sym)\
__EXPORT_SYMBOL(sym, "")


#define EXPORT_SYMBOL_GPL(sym)\
__EXPORT_SYMBOL(sym, "_gpl")


#define EXPORT_SYMBOL_GPL_FUTURE(sym)\
__EXPORT_SYMBOL(sym, "_gpl_future")




#ifdef CONFIG_UNUSED_SYMBOLS
#define EXPORT_UNUSED_SYMBOL(sym) __EXPORT_SYMBOL(sym, "_unused")
#define EXPORT_UNUSED_SYMBOL_GPL(sym) __EXPORT_SYMBOL(sym, "_unused_gpl")
#else
#define EXPORT_UNUSED_SYMBOL(sym)
#define EXPORT_UNUSED_SYMBOL_GPL(sym)
#endif


#endif


enum module_state
{
MODULE_STATE_LIVE,
MODULE_STATE_COMING,
MODULE_STATE_GOING,
};


struct module
{
enum module_state state;


/* Member of list of modules */
struct list_head list;


/* Unique handle for this module */
char name[MODULE_NAME_LEN];


/* Sysfs stuff. */
struct module_kobject mkobj;
struct module_attribute *modinfo_attrs;
const char *version;
const char *srcversion;
struct kobject *holders_dir;


/* Exported symbols */
const struct kernel_symbol *syms;
const unsigned long *crcs;
unsigned int num_syms;


/* Kernel parameters. */
struct kernel_param *kp;
unsigned int num_kp;


/* GPL-only exported symbols. */
unsigned int num_gpl_syms;
const struct kernel_symbol *gpl_syms;
const unsigned long *gpl_crcs;


#ifdef CONFIG_UNUSED_SYMBOLS
/* unused exported symbols. */
const struct kernel_symbol *unused_syms;
const unsigned long *unused_crcs;
unsigned int num_unused_syms;


/* GPL-only, unused exported symbols. */
unsigned int num_unused_gpl_syms;
const struct kernel_symbol *unused_gpl_syms;
const unsigned long *unused_gpl_crcs;
#endif


/* symbols that will be GPL-only in the near future. */
const struct kernel_symbol *gpl_future_syms;
const unsigned long *gpl_future_crcs;
unsigned int num_gpl_future_syms;


/* Exception table */
unsigned int num_exentries;
struct exception_table_entry *extable;


/* Startup function. */
int (*init)(void);


/* If this is non-NULL, vfree after init() returns */
void *module_init;


/* Here is the actual code + data, vfree'd on unload. */
void *module_core;


/* Here are the sizes of the init and core sections */
unsigned int init_size, core_size;


/* The size of the executable code in each section.  */
unsigned int init_text_size, core_text_size;


/* Size of RO sections of the module (text+rodata) */
unsigned int init_ro_size, core_ro_size;


/* Arch-specific module values */
struct mod_arch_specific arch;


unsigned int taints;/* same bits as kernel:tainted */


#ifdef CONFIG_GENERIC_BUG
/* Support for BUG */
unsigned num_bugs;
struct list_head bug_list;
struct bug_entry *bug_table;
#endif


#ifdef CONFIG_KALLSYMS
/*
* We keep the symbol and string tables for kallsyms.
* The core_* fields below are temporary, loader-only (they
* could really be discarded after module init).
*/
Elf_Sym *symtab, *core_symtab;
unsigned int num_symtab, core_num_syms;
char *strtab, *core_strtab;


/* Section attributes */
struct module_sect_attrs *sect_attrs;


/* Notes attributes */
struct module_notes_attrs *notes_attrs;
#endif


#ifdef CONFIG_SMP
/* Per-cpu data. */
void __percpu *percpu;
unsigned int percpu_size;
#endif


/* The command line arguments (may be mangled).  People like
  keeping pointers to this stuff */
char *args;
#ifdef CONFIG_TRACEPOINTS
struct tracepoint * const *tracepoints_ptrs;
unsigned int num_tracepoints;
#endif
#ifdef HAVE_JUMP_LABEL
struct jump_entry *jump_entries;
unsigned int num_jump_entries;
#endif
#ifdef CONFIG_TRACING
const char **trace_bprintk_fmt_start;
unsigned int num_trace_bprintk_fmt;
#endif
#ifdef CONFIG_EVENT_TRACING
struct ftrace_event_call **trace_events;
unsigned int num_trace_events;
#endif
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
unsigned long *ftrace_callsites;
unsigned int num_ftrace_callsites;
#endif


#ifdef CONFIG_MODULE_UNLOAD
/* What modules depend on me? */
struct list_head source_list;
/* What modules do I depend on? */
struct list_head target_list;


/* Who is waiting for us to be unloaded */
struct task_struct *waiter;


/* Destruction function. */
void (*exit)(void);


struct module_ref {
unsigned int incs;
unsigned int decs;
} __percpu *refptr;
#endif


#ifdef CONFIG_CONSTRUCTORS
/* Constructor functions. */
ctor_fn_t *ctors;
unsigned int num_ctors;
#endif
};
#ifndef MODULE_ARCH_INIT
#define MODULE_ARCH_INIT {}
#endif


extern struct mutex module_mutex;


/* FIXME: It'd be nice to isolate modules during init, too, so they
   aren't used before they (may) fail.  But presently too much code
   (IDE & SCSI) require entry into the module during init.*/
static inline int module_is_live(struct module *mod)
{
return mod->state != MODULE_STATE_GOING;
}


struct module *__module_text_address(unsigned long addr);
struct module *__module_address(unsigned long addr);
bool is_module_address(unsigned long addr);
bool is_module_percpu_address(unsigned long addr);
bool is_module_text_address(unsigned long addr);


static inline int within_module_core(unsigned long addr, struct module *mod)
{
return (unsigned long)mod->module_core <= addr &&
      addr < (unsigned long)mod->module_core + mod->core_size;
}


static inline int within_module_init(unsigned long addr, struct module *mod)
{
return (unsigned long)mod->module_init <= addr &&
      addr < (unsigned long)mod->module_init + mod->init_size;
}


/* Search for module by name: must hold module_mutex. */
struct module *find_module(const char *name);


struct symsearch {
const struct kernel_symbol *start, *stop;
const unsigned long *crcs;
enum {
NOT_GPL_ONLY,
GPL_ONLY,
WILL_BE_GPL_ONLY,
} licence;
bool unused;
};


/* Search for an exported symbol by name. */
const struct kernel_symbol *find_symbol(const char *name,
struct module **owner,
const unsigned long **crc,
bool gplok,
bool warn);


/* Walk the exported symbol table */
bool each_symbol(bool (*fn)(const struct symsearch *arr, struct module *owner,
   unsigned int symnum, void *data), void *data);


/* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
   symnum out of range. */
int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
char *name, char *module_name, int *exported);


/* Look for this name: can be of form module:name. */
unsigned long module_kallsyms_lookup_name(const char *name);


int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
    struct module *, unsigned long),
  void *data);


extern void __module_put_and_exit(struct module *mod, long code)
__attribute__((noreturn));
#define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code);


#ifdef CONFIG_MODULE_UNLOAD
unsigned int module_refcount(struct module *mod);
void __symbol_put(const char *symbol);
#define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x)
void symbol_put_addr(void *addr);


/* Sometimes we know we already have a refcount, and it's easier not
   to handle the error case (which only happens with rmmod --wait). */
static inline void __module_get(struct module *module)
{
if (module) {
preempt_disable();
__this_cpu_inc(module->refptr->incs);
trace_module_get(module, _THIS_IP_);
preempt_enable();
}
}


static inline int try_module_get(struct module *module)
{
int ret = 1;


if (module) {
preempt_disable();


if (likely(module_is_live(module))) {
__this_cpu_inc(module->refptr->incs);
trace_module_get(module, _THIS_IP_);
} else
ret = 0;


preempt_enable();
}
return ret;
}


extern void module_put(struct module *module);


#else /*!CONFIG_MODULE_UNLOAD*/
static inline int try_module_get(struct module *module)
{
return !module || module_is_live(module);
}
static inline void module_put(struct module *module)
{
}
static inline void __module_get(struct module *module)
{
}
#define symbol_put(x) do { } while(0)
#define symbol_put_addr(p) do { } while(0)


#endif /* CONFIG_MODULE_UNLOAD */
int ref_module(struct module *a, struct module *b);


/* This is a #define so the string doesn't get put in every .o file */
#define module_name(mod)\
({\
struct module *__mod = (mod);\
__mod ? __mod->name : "kernel";\
})


/* For kallsyms to ask for address resolution.  namebuf should be at
 * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
 * found, otherwise NULL. */
const char *module_address_lookup(unsigned long addr,
   unsigned long *symbolsize,
   unsigned long *offset,
   char **modname,
   char *namebuf);
int lookup_module_symbol_name(unsigned long addr, char *symname);
int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);


/* For extable.c to search modules' exception tables. */
const struct exception_table_entry *search_module_extables(unsigned long addr);


int register_module_notifier(struct notifier_block * nb);
int unregister_module_notifier(struct notifier_block * nb);


extern void print_modules(void);


extern void module_update_tracepoints(void);
extern int module_get_iter_tracepoints(struct tracepoint_iter *iter);


#else /* !CONFIG_MODULES... */
#define EXPORT_SYMBOL(sym)
#define EXPORT_SYMBOL_GPL(sym)
#define EXPORT_SYMBOL_GPL_FUTURE(sym)
#define EXPORT_UNUSED_SYMBOL(sym)
#define EXPORT_UNUSED_SYMBOL_GPL(sym)


/* Given an address, look for it in the exception tables. */
static inline const struct exception_table_entry *
search_module_extables(unsigned long addr)
{
return NULL;
}


static inline struct module *__module_address(unsigned long addr)
{
return NULL;
}


static inline struct module *__module_text_address(unsigned long addr)
{
return NULL;
}


static inline bool is_module_address(unsigned long addr)
{
return false;
}


static inline bool is_module_percpu_address(unsigned long addr)
{
return false;
}


static inline bool is_module_text_address(unsigned long addr)
{
return false;
}


/* Get/put a kernel symbol (calls should be symmetric) */
#define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
#define symbol_put(x) do { } while(0)
#define symbol_put_addr(x) do { } while(0)


static inline void __module_get(struct module *module)
{
}


static inline int try_module_get(struct module *module)
{
return 1;
}


static inline void module_put(struct module *module)
{
}


#define module_name(mod) "kernel"


/* For kallsyms to ask for address resolution.  NULL means not found. */
static inline const char *module_address_lookup(unsigned long addr,
 unsigned long *symbolsize,
 unsigned long *offset,
 char **modname,
 char *namebuf)
{
return NULL;
}


static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
{
return -ERANGE;
}


static inline int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
{
return -ERANGE;
}


static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
char *type, char *name,
char *module_name, int *exported)
{
return -ERANGE;
}


static inline unsigned long module_kallsyms_lookup_name(const char *name)
{
return 0;
}


static inline int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
  struct module *,
  unsigned long),
void *data)
{
return 0;
}


static inline int register_module_notifier(struct notifier_block * nb)
{
/* no events will happen anyway, so this can always succeed */
return 0;
}


static inline int unregister_module_notifier(struct notifier_block * nb)
{
return 0;
}


#define module_put_and_exit(code) do_exit(code)


static inline void print_modules(void)
{
}


static inline void module_update_tracepoints(void)
{
}


static inline int module_get_iter_tracepoints(struct tracepoint_iter *iter)
{
return 0;
}
#endif /* CONFIG_MODULES */


#ifdef CONFIG_SYSFS
extern struct kset *module_kset;
extern struct kobj_type module_ktype;
extern int module_sysfs_initialized;
#endif /* CONFIG_SYSFS */


#define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)


/* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */


#define __MODULE_STRING(x) __stringify(x)


#ifdef CONFIG_DEBUG_SET_MODULE_RONX
extern void set_all_modules_text_rw(void);
extern void set_all_modules_text_ro(void);
#else
static inline void set_all_modules_text_rw(void) { }
static inline void set_all_modules_text_ro(void) { }
#endif


#ifdef CONFIG_GENERIC_BUG
void module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *,
struct module *);
void module_bug_cleanup(struct module *);


#else/* !CONFIG_GENERIC_BUG */


static inline void module_bug_finalize(const Elf_Ehdr *hdr,
const Elf_Shdr *sechdrs,
struct module *mod)
{
}
static inline void module_bug_cleanup(struct module *mod) {}
#endif/* CONFIG_GENERIC_BUG */


#endif /* _LINUX_MODULE_H */