module.h

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#ifndef _LINUX_MODULE_H
#define _LINUX_MODULE_H
/*
 * Dynamic loading of modules into the kernel.
 *
 * Rewritten by Richard Henderson <[email protected]> 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/export.h>

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

/* In stripped ARM and x86-64 modules, ~ is surprisingly rare. */
#define MODULE_SIG_STRING "~Module signature appended~\n"

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

#define MODULE_NAME_LEN MAX_PARAM_PREFIX_LEN

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

struct module;

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

struct module_attribute {
    struct attribute attr;
    ssize_t (*show)(struct module_attribute *, struct module_kobject *,
            char *);
    ssize_t (*store)(struct module_attribute *, struct module_kobject *,
             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 *))));

extern ssize_t __modver_version_show(struct module_attribute *,
                     struct module_kobject *, char *);

extern struct module_attribute module_uevent;

/* 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))))

#else  /* !MODULE */
#define MODULE_GENERIC_TABLE(gtype,name)
#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)

#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)                    \
    static struct module_version_attribute ___modver_attr = {   \
        .mattr  = {                     \
            .attr   = {                 \
                .name   = "version",            \
                .mode   = S_IRUGO,          \
            },                      \
            .show   = __modver_version_show,        \
        },                          \
        .module_name    = KBUILD_MODNAME,           \
        .version    = _version,             \
    };                              \
    static const struct module_version_attribute            \
    __used __attribute__ ((__section__ ("__modver")))       \
    * __moduleparam_const __modver_attr = &___modver_attr
#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;
};

enum module_state
{
    MODULE_STATE_LIVE,
    MODULE_STATE_COMING,
    MODULE_STATE_GOING,
};

struct module_ref {
    unsigned long incs;
    unsigned long decs;
} __attribute((aligned(2 * sizeof(unsigned long))));

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

#ifdef CONFIG_MODULE_SIG
    /* Signature was verified. */
    bool sig_ok;
#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

    /* The command line arguments (may be mangled).  People like
       keeping pointers to this stuff */
    char *args;

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

#ifdef CONFIG_TRACEPOINTS
    unsigned int num_tracepoints;
    struct tracepoint * const *tracepoints_ptrs;
#endif
#ifdef HAVE_JUMP_LABEL
    struct jump_entry *jump_entries;
    unsigned int num_jump_entries;
#endif
#ifdef CONFIG_TRACING
    unsigned int num_trace_bprintk_fmt;
    const char **trace_bprintk_fmt_start;
#endif
#ifdef CONFIG_EVENT_TRACING
    struct ftrace_event_call **trace_events;
    unsigned int num_trace_events;
#endif
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
    unsigned int num_ftrace_callsites;
    unsigned long *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 __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_section(bool (*fn)(const struct symsearch *arr,
                    struct module *owner,
                    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 long 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). */
extern void __module_get(struct module *module);

/* This is the Right Way to get a module: if it fails, it's being removed,
 * so pretend it's not there. */
extern bool try_module_get(struct module *module);

extern void module_put(struct module *module);

#else 
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);

#else /* !CONFIG_MODULES... */

/* 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)
{
}
#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 */