LXR linux-old/include/linux/module.h

   1/*
   2 * Dynamic loading of modules into the kernel.
   3 *
   4 * Rewritten by Richard Henderson <rth@tamu.edu> Dec 1996
   5 */
   6
   7#ifndef _LINUX_MODULE_H
   8#define _LINUX_MODULE_H
   9
  10#include <linux/config.h>
  11#include <linux/spinlock.h>
  12#include <linux/list.h>
  13
  14#ifdef __GENKSYMS__
  15#  define _set_ver(sym) sym
  16#  undef  MODVERSIONS
  17#  define MODVERSIONS
  18#else /* ! __GENKSYMS__ */
  19# if !defined(MODVERSIONS) && defined(EXPORT_SYMTAB)
  20#   define _set_ver(sym) sym
  21#   include <linux/modversions.h>
  22# endif
  23#endif /* __GENKSYMS__ */
  24
  25#include <asm/atomic.h>
  26
  27/* Don't need to bring in all of uaccess.h just for this decl.  */
  28struct exception_table_entry;
  29
  30/* Used by get_kernel_syms, which is obsolete.  */
  31struct kernel_sym
  32{
  33        unsigned long value;
  34        char name[60];          /* should have been 64-sizeof(long); oh well */
  35};
  36
  37struct module_symbol
  38{
  39        unsigned long value;
  40        const char *name;
  41};
  42
  43struct module_ref
  44{
  45        struct module *dep;     /* "parent" pointer */
  46        struct module *ref;     /* "child" pointer */
  47        struct module_ref *next_ref;
  48};
  49
  50/* TBD */
  51struct module_persist;
  52
  53struct module
  54{
  55        unsigned long size_of_struct;   /* == sizeof(module) */
  56        struct module *next;
  57        const char *name;
  58        unsigned long size;
  59
  60        union
  61        {
  62                atomic_t usecount;
  63                long pad;
  64        } uc;                           /* Needs to keep its size - so says rth */
  65
  66        unsigned long flags;            /* AUTOCLEAN et al */
  67
  68        unsigned nsyms;
  69        unsigned ndeps;
  70
  71        struct module_symbol *syms;
  72        struct module_ref *deps;
  73        struct module_ref *refs;
  74        int (*init)(void);
  75        void (*cleanup)(void);
  76        const struct exception_table_entry *ex_table_start;
  77        const struct exception_table_entry *ex_table_end;
  78#ifdef __alpha__
  79        unsigned long gp;
  80#endif
  81        /* Members past this point are extensions to the basic
  82           module support and are optional.  Use mod_member_present()
  83           to examine them.  */
  84        const struct module_persist *persist_start;
  85        const struct module_persist *persist_end;
  86        int (*can_unload)(void);
  87        int runsize;                    /* In modutils, not currently used */
  88        const char *kallsyms_start;     /* All symbols for kernel debugging */
  89        const char *kallsyms_end;
  90        const char *archdata_start;     /* arch specific data for module */
  91        const char *archdata_end;
  92        const char *kernel_data;        /* Reserved for kernel internal use */
  93};
  94
  95struct module_info
  96{
  97        unsigned long addr;
  98        unsigned long size;
  99        unsigned long flags;
 100        long usecount;
 101};
 102
 103/* Bits of module.flags.  */
 104
 105#define MOD_UNINITIALIZED       0
 106#define MOD_RUNNING             1
 107#define MOD_DELETED             2
 108#define MOD_AUTOCLEAN           4
 109#define MOD_VISITED             8
 110#define MOD_USED_ONCE           16
 111#define MOD_JUST_FREED          32
 112#define MOD_INITIALIZING        64
 113
 114/* Values for query_module's which.  */
 115
 116#define QM_MODULES      1
 117#define QM_DEPS         2
 118#define QM_REFS         3
 119#define QM_SYMBOLS      4
 120#define QM_INFO         5
 121
 122/* Can the module be queried? */
 123#define MOD_CAN_QUERY(mod) (((mod)->flags & (MOD_RUNNING | MOD_INITIALIZING)) && !((mod)->flags & MOD_DELETED))
 124
 125/* When struct module is extended, we must test whether the new member
 126   is present in the header received from insmod before we can use it.  
 127   This function returns true if the member is present.  */
 128
 129#define mod_member_present(mod,member)                                  \
 130        ((unsigned long)(&((struct module *)0L)->member + 1)            \
 131         <= (mod)->size_of_struct)
 132
 133/*
 134 * Ditto for archdata.  Assumes mod->archdata_start and mod->archdata_end
 135 * are validated elsewhere.
 136 */
 137#define mod_archdata_member_present(mod, type, member)                  \
 138        (((unsigned long)(&((type *)0L)->member) +                      \
 139          sizeof(((type *)0L)->member)) <=                              \
 140         ((mod)->archdata_end - (mod)->archdata_start))
 141         
 142
 143/* Check if an address p with number of entries n is within the body of module m */
 144#define mod_bound(p, n, m) ((unsigned long)(p) >= ((unsigned long)(m) + ((m)->size_of_struct)) && \
 145                 (unsigned long)((p)+(n)) <= (unsigned long)(m) + (m)->size)
 146
 147/* Backwards compatibility definition.  */
 148
 149#define GET_USE_COUNT(module)   (atomic_read(&(module)->uc.usecount))
 150
 151/* Poke the use count of a module.  */
 152
 153#define __MOD_INC_USE_COUNT(mod)                                        \
 154        (atomic_inc(&(mod)->uc.usecount), (mod)->flags |= MOD_VISITED|MOD_USED_ONCE)
 155#define __MOD_DEC_USE_COUNT(mod)                                        \
 156        (atomic_dec(&(mod)->uc.usecount), (mod)->flags |= MOD_VISITED)
 157#define __MOD_IN_USE(mod)                                               \
 158        (mod_member_present((mod), can_unload) && (mod)->can_unload     \
 159         ? (mod)->can_unload() : atomic_read(&(mod)->uc.usecount))
 160
 161/* Indirect stringification.  */
 162
 163#define __MODULE_STRING_1(x)    #x
 164#define __MODULE_STRING(x)      __MODULE_STRING_1(x)
 165
 166/* Generic inter module communication.
 167 *
 168 * NOTE: This interface is intended for small amounts of data that are
 169 *       passed between two objects and either or both of the objects
 170 *       might be compiled as modules.  Do not over use this interface.
 171 *
 172 *       If more than two objects need to communicate then you probably
 173 *       need a specific interface instead of abusing this generic
 174 *       interface.  If both objects are *always* built into the kernel
 175 *       then a global extern variable is good enough, you do not need
 176 *       this interface.
 177 *
 178 * Keith Owens <kaos@ocs.com.au> 28 Oct 2000.
 179 */
 180
 181#ifdef __KERNEL__
 182#define HAVE_INTER_MODULE
 183extern void inter_module_register(const char *, struct module *, const void *);
 184extern void inter_module_unregister(const char *);
 185extern const void *inter_module_get(const char *);
 186extern const void *inter_module_get_request(const char *, const char *);
 187extern void inter_module_put(const char *);
 188
 189struct inter_module_entry {
 190        struct list_head list;
 191        const char *im_name;
 192        struct module *owner;
 193        const void *userdata;
 194};
 195
 196extern int try_inc_mod_count(struct module *mod);
 197#endif /* __KERNEL__ */
 198
 199#if defined(MODULE) && !defined(__GENKSYMS__)
 200
 201/* Embedded module documentation macros.  */
 202
 203/* For documentation purposes only.  */
 204
 205#define MODULE_AUTHOR(name)                                                \
 206const char __module_author[] __attribute__((section(".modinfo"))) =        \
 207"author=" name
 208
 209#define MODULE_DESCRIPTION(desc)                                           \
 210const char __module_description[] __attribute__((section(".modinfo"))) =   \
 211"description=" desc
 212
 213/* Could potentially be used by kmod...  */
 214
 215#define MODULE_SUPPORTED_DEVICE(dev)                                       \
 216const char __module_device[] __attribute__((section(".modinfo"))) =        \
 217"device=" dev
 218
 219/* Used to verify parameters given to the module.  The TYPE arg should
 220   be a string in the following format:
 221        [min[-max]]{b,h,i,l,s}
 222   The MIN and MAX specifiers delimit the length of the array.  If MAX
 223   is omitted, it defaults to MIN; if both are omitted, the default is 1.
 224   The final character is a type specifier:
 225        b       byte
 226        h       short
 227        i       int
 228        l       long
 229        s       string
 230*/
 231
 232#define MODULE_PARM(var,type)                   \
 233const char __module_parm_##var[]                \
 234__attribute__((section(".modinfo"))) =          \
 235"parm_" __MODULE_STRING(var) "=" type
 236
 237#define MODULE_PARM_DESC(var,desc)              \
 238const char __module_parm_desc_##var[]           \
 239__attribute__((section(".modinfo"))) =          \
 240"parm_desc_" __MODULE_STRING(var) "=" desc
 241
 242/*
 243 * MODULE_DEVICE_TABLE exports information about devices
 244 * currently supported by this module.  A device type, such as PCI,
 245 * is a C-like identifier passed as the first arg to this macro.
 246 * The second macro arg is the variable containing the device
 247 * information being made public.
 248 *
 249 * The following is a list of known device types (arg 1),
 250 * and the C types which are to be passed as arg 2.
 251 * pci - struct pci_device_id - List of PCI ids supported by this module
 252 * isapnp - struct isapnp_device_id - List of ISA PnP ids supported by this module
 253 * usb - struct usb_device_id - List of USB ids supported by this module
 254 */
 255#define MODULE_GENERIC_TABLE(gtype,name)        \
 256static const unsigned long __module_##gtype##_size \
 257  __attribute__ ((unused)) = sizeof(struct gtype##_id); \
 258static const struct gtype##_id * __module_##gtype##_table \
 259  __attribute__ ((unused)) = name
 260
 261/*
 262 * The following license idents are currently accepted as indicating free
 263 * software modules
 264 *
 265 *      "GPL"                           [GNU Public License v2 or later]
 266 *      "GPL and additional rights"     [GNU Public License v2 rights and more]
 267 *      "Dual BSD/GPL"                  [GNU Public License v2 or BSD license choice]
 268 *      "Dual MPL/GPL"                  [GNU Public License v2 or Mozilla license choice]
 269 *
 270 * The following other idents are available
 271 *
 272 *      "Proprietary"                   [Non free products]
 273 *
 274 * There are dual licensed components, but when running with Linux it is the
 275 * GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL
 276 * is a GPL combined work.
 277 *
 278 * This exists for several reasons
 279 * 1.   So modinfo can show license info for users wanting to vet their setup 
 280 *      is free
 281 * 2.   So the community can ignore bug reports including proprietary modules
 282 * 3.   So vendors can do likewise based on their own policies
 283 */
 284 
 285#define MODULE_LICENSE(license)         \
 286static const char __module_license[] __attribute__((section(".modinfo"))) =   \
 287"license=" license
 288
 289/* Define the module variable, and usage macros.  */
 290extern struct module __this_module;
 291
 292#define THIS_MODULE             (&__this_module)
 293#define MOD_INC_USE_COUNT       __MOD_INC_USE_COUNT(THIS_MODULE)
 294#define MOD_DEC_USE_COUNT       __MOD_DEC_USE_COUNT(THIS_MODULE)
 295#define MOD_IN_USE              __MOD_IN_USE(THIS_MODULE)
 296
 297#include <linux/version.h>
 298static const char __module_kernel_version[] __attribute__((section(".modinfo"))) =
 299"kernel_version=" UTS_RELEASE;
 300#ifdef MODVERSIONS
 301static const char __module_using_checksums[] __attribute__((section(".modinfo"))) =
 302"using_checksums=1";
 303#endif
 304
 305#else /* MODULE */
 306
 307#define MODULE_AUTHOR(name)
 308#define MODULE_LICENSE(license)
 309#define MODULE_DESCRIPTION(desc)
 310#define MODULE_SUPPORTED_DEVICE(name)
 311#define MODULE_PARM(var,type)
 312#define MODULE_PARM_DESC(var,desc)
 313
 314/* Create a dummy reference to the table to suppress gcc unused warnings.  Put
 315 * the reference in the .data.exit section which is discarded when code is built
 316 * in, so the reference does not bloat the running kernel.  Note: cannot be
 317 * const, other exit data may be writable.
 318 */
 319#define MODULE_GENERIC_TABLE(gtype,name) \
 320static const struct gtype##_id * __module_##gtype##_table \
 321  __attribute__ ((unused, __section__(".data.exit"))) = name
 322
 323#ifndef __GENKSYMS__
 324
 325#define THIS_MODULE             NULL
 326#define MOD_INC_USE_COUNT       do { } while (0)
 327#define MOD_DEC_USE_COUNT       do { } while (0)
 328#define MOD_IN_USE              1
 329
 330extern struct module *module_list;
 331
 332#endif /* !__GENKSYMS__ */
 333
 334#endif /* MODULE */
 335
 336#define MODULE_DEVICE_TABLE(type,name)          \
 337  MODULE_GENERIC_TABLE(type##_device,name)
 338
 339/* Export a symbol either from the kernel or a module.
 340
 341   In the kernel, the symbol is added to the kernel's global symbol table.
 342
 343   In a module, it controls which variables are exported.  If no
 344   variables are explicitly exported, the action is controled by the
 345   insmod -[xX] flags.  Otherwise, only the variables listed are exported.
 346   This obviates the need for the old register_symtab() function.  */
 347
 348#if defined(__GENKSYMS__)
 349
 350/* We want the EXPORT_SYMBOL tag left intact for recognition.  */
 351
 352#elif !defined(AUTOCONF_INCLUDED)
 353
 354#define __EXPORT_SYMBOL(sym,str)   error config_must_be_included_before_module
 355#define EXPORT_SYMBOL(var)         error config_must_be_included_before_module
 356#define EXPORT_SYMBOL_NOVERS(var)  error config_must_be_included_before_module
 357#define EXPORT_SYMBOL_GPL(var)  error config_must_be_included_before_module
 358
 359#elif !defined(CONFIG_MODULES)
 360
 361#define __EXPORT_SYMBOL(sym,str)
 362#define EXPORT_SYMBOL(var)
 363#define EXPORT_SYMBOL_NOVERS(var)
 364#define EXPORT_SYMBOL_GPL(var)
 365
 366#elif !defined(EXPORT_SYMTAB)
 367
 368#define __EXPORT_SYMBOL(sym,str)   error this_object_must_be_defined_as_export_objs_in_the_Makefile
 369#define EXPORT_SYMBOL(var)         error this_object_must_be_defined_as_export_objs_in_the_Makefile
 370#define EXPORT_SYMBOL_NOVERS(var)  error this_object_must_be_defined_as_export_objs_in_the_Makefile
 371#define EXPORT_SYMBOL_GPL(var)  error this_object_must_be_defined_as_export_objs_in_the_Makefile
 372
 373#else
 374
 375#define __EXPORT_SYMBOL(sym, str)                       \
 376const char __kstrtab_##sym[]                            \
 377__attribute__((section(".kstrtab"))) = str;             \
 378const struct module_symbol __ksymtab_##sym              \
 379__attribute__((section("__ksymtab"))) =                 \
 380{ (unsigned long)&sym, __kstrtab_##sym }
 381
 382#define __EXPORT_SYMBOL_GPL(sym, str)                   \
 383const char __kstrtab_##sym[]                            \
 384__attribute__((section(".kstrtab"))) = "GPLONLY_" str;  \
 385const struct module_symbol __ksymtab_##sym              \
 386__attribute__((section("__ksymtab"))) =                 \
 387{ (unsigned long)&sym, __kstrtab_##sym }
 388
 389#if defined(MODVERSIONS) || !defined(CONFIG_MODVERSIONS)
 390#define EXPORT_SYMBOL(var)  __EXPORT_SYMBOL(var, __MODULE_STRING(var))
 391#define EXPORT_SYMBOL_GPL(var)  __EXPORT_SYMBOL_GPL(var, __MODULE_STRING(var))
 392#else
 393#define EXPORT_SYMBOL(var)  __EXPORT_SYMBOL(var, __MODULE_STRING(__VERSIONED_SYMBOL(var)))
 394#define EXPORT_SYMBOL_GPL(var)  __EXPORT_SYMBOL(var, __MODULE_STRING(__VERSIONED_SYMBOL(var)))
 395#endif
 396
 397#define EXPORT_SYMBOL_NOVERS(var)  __EXPORT_SYMBOL(var, __MODULE_STRING(var))
 398
 399#endif /* __GENKSYMS__ */
 400
 401#ifdef MODULE
 402/* Force a module to export no symbols.  */
 403#define EXPORT_NO_SYMBOLS  __asm__(".section __ksymtab\n.previous")
 404#else
 405#define EXPORT_NO_SYMBOLS
 406#endif /* MODULE */
 407
 408#ifdef CONFIG_MODULES
 409#define SET_MODULE_OWNER(some_struct) do { (some_struct)->owner = THIS_MODULE; } while (0)
 410#else
 411#define SET_MODULE_OWNER(some_struct) do { } while (0)
 412#endif
 413
 414#endif /* _LINUX_MODULE_H */
 415