module: trim exception table on init free.
[deliverable/linux.git] / include / linux / module.h
1 #ifndef _LINUX_MODULE_H
2 #define _LINUX_MODULE_H
3 /*
4 * Dynamic loading of modules into the kernel.
5 *
6 * Rewritten by Richard Henderson <rth@tamu.edu> Dec 1996
7 * Rewritten again by Rusty Russell, 2002
8 */
9 #include <linux/list.h>
10 #include <linux/stat.h>
11 #include <linux/compiler.h>
12 #include <linux/cache.h>
13 #include <linux/kmod.h>
14 #include <linux/elf.h>
15 #include <linux/stringify.h>
16 #include <linux/kobject.h>
17 #include <linux/moduleparam.h>
18 #include <linux/marker.h>
19 #include <linux/tracepoint.h>
20 #include <asm/local.h>
21
22 #include <asm/module.h>
23
24 /* Not Yet Implemented */
25 #define MODULE_SUPPORTED_DEVICE(name)
26
27 /* some toolchains uses a `_' prefix for all user symbols */
28 #ifndef MODULE_SYMBOL_PREFIX
29 #define MODULE_SYMBOL_PREFIX ""
30 #endif
31
32 #define MODULE_NAME_LEN MAX_PARAM_PREFIX_LEN
33
34 struct kernel_symbol
35 {
36 unsigned long value;
37 const char *name;
38 };
39
40 struct modversion_info
41 {
42 unsigned long crc;
43 char name[MODULE_NAME_LEN];
44 };
45
46 struct module;
47
48 struct module_attribute {
49 struct attribute attr;
50 ssize_t (*show)(struct module_attribute *, struct module *, char *);
51 ssize_t (*store)(struct module_attribute *, struct module *,
52 const char *, size_t count);
53 void (*setup)(struct module *, const char *);
54 int (*test)(struct module *);
55 void (*free)(struct module *);
56 };
57
58 struct module_kobject
59 {
60 struct kobject kobj;
61 struct module *mod;
62 struct kobject *drivers_dir;
63 struct module_param_attrs *mp;
64 };
65
66 /* These are either module local, or the kernel's dummy ones. */
67 extern int init_module(void);
68 extern void cleanup_module(void);
69
70 /* Archs provide a method of finding the correct exception table. */
71 struct exception_table_entry;
72
73 const struct exception_table_entry *
74 search_extable(const struct exception_table_entry *first,
75 const struct exception_table_entry *last,
76 unsigned long value);
77 void sort_extable(struct exception_table_entry *start,
78 struct exception_table_entry *finish);
79 void sort_main_extable(void);
80 void trim_init_extable(struct module *m);
81
82 #ifdef MODULE
83 #define MODULE_GENERIC_TABLE(gtype,name) \
84 extern const struct gtype##_id __mod_##gtype##_table \
85 __attribute__ ((unused, alias(__stringify(name))))
86
87 extern struct module __this_module;
88 #define THIS_MODULE (&__this_module)
89 #else /* !MODULE */
90 #define MODULE_GENERIC_TABLE(gtype,name)
91 #define THIS_MODULE ((struct module *)0)
92 #endif
93
94 /* Generic info of form tag = "info" */
95 #define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info)
96
97 /* For userspace: you can also call me... */
98 #define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)
99
100 /*
101 * The following license idents are currently accepted as indicating free
102 * software modules
103 *
104 * "GPL" [GNU Public License v2 or later]
105 * "GPL v2" [GNU Public License v2]
106 * "GPL and additional rights" [GNU Public License v2 rights and more]
107 * "Dual BSD/GPL" [GNU Public License v2
108 * or BSD license choice]
109 * "Dual MIT/GPL" [GNU Public License v2
110 * or MIT license choice]
111 * "Dual MPL/GPL" [GNU Public License v2
112 * or Mozilla license choice]
113 *
114 * The following other idents are available
115 *
116 * "Proprietary" [Non free products]
117 *
118 * There are dual licensed components, but when running with Linux it is the
119 * GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL
120 * is a GPL combined work.
121 *
122 * This exists for several reasons
123 * 1. So modinfo can show license info for users wanting to vet their setup
124 * is free
125 * 2. So the community can ignore bug reports including proprietary modules
126 * 3. So vendors can do likewise based on their own policies
127 */
128 #define MODULE_LICENSE(_license) MODULE_INFO(license, _license)
129
130 /* Author, ideally of form NAME[, NAME]*[ and NAME] */
131 #define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
132
133 /* What your module does. */
134 #define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
135
136 /* One for each parameter, describing how to use it. Some files do
137 multiple of these per line, so can't just use MODULE_INFO. */
138 #define MODULE_PARM_DESC(_parm, desc) \
139 __MODULE_INFO(parm, _parm, #_parm ":" desc)
140
141 #define MODULE_DEVICE_TABLE(type,name) \
142 MODULE_GENERIC_TABLE(type##_device,name)
143
144 /* Version of form [<epoch>:]<version>[-<extra-version>].
145 Or for CVS/RCS ID version, everything but the number is stripped.
146 <epoch>: A (small) unsigned integer which allows you to start versions
147 anew. If not mentioned, it's zero. eg. "2:1.0" is after
148 "1:2.0".
149 <version>: The <version> may contain only alphanumerics and the
150 character `.'. Ordered by numeric sort for numeric parts,
151 ascii sort for ascii parts (as per RPM or DEB algorithm).
152 <extraversion>: Like <version>, but inserted for local
153 customizations, eg "rh3" or "rusty1".
154
155 Using this automatically adds a checksum of the .c files and the
156 local headers in "srcversion".
157 */
158 #define MODULE_VERSION(_version) MODULE_INFO(version, _version)
159
160 /* Optional firmware file (or files) needed by the module
161 * format is simply firmware file name. Multiple firmware
162 * files require multiple MODULE_FIRMWARE() specifiers */
163 #define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
164
165 /* Given an address, look for it in the exception tables */
166 const struct exception_table_entry *search_exception_tables(unsigned long add);
167
168 struct notifier_block;
169
170 #ifdef CONFIG_MODULES
171
172 /* Get/put a kernel symbol (calls must be symmetric) */
173 void *__symbol_get(const char *symbol);
174 void *__symbol_get_gpl(const char *symbol);
175 #define symbol_get(x) ((typeof(&x))(__symbol_get(MODULE_SYMBOL_PREFIX #x)))
176
177 #ifndef __GENKSYMS__
178 #ifdef CONFIG_MODVERSIONS
179 /* Mark the CRC weak since genksyms apparently decides not to
180 * generate a checksums for some symbols */
181 #define __CRC_SYMBOL(sym, sec) \
182 extern void *__crc_##sym __attribute__((weak)); \
183 static const unsigned long __kcrctab_##sym \
184 __used \
185 __attribute__((section("__kcrctab" sec), unused)) \
186 = (unsigned long) &__crc_##sym;
187 #else
188 #define __CRC_SYMBOL(sym, sec)
189 #endif
190
191 /* For every exported symbol, place a struct in the __ksymtab section */
192 #define __EXPORT_SYMBOL(sym, sec) \
193 extern typeof(sym) sym; \
194 __CRC_SYMBOL(sym, sec) \
195 static const char __kstrtab_##sym[] \
196 __attribute__((section("__ksymtab_strings"), aligned(1))) \
197 = MODULE_SYMBOL_PREFIX #sym; \
198 static const struct kernel_symbol __ksymtab_##sym \
199 __used \
200 __attribute__((section("__ksymtab" sec), unused)) \
201 = { (unsigned long)&sym, __kstrtab_##sym }
202
203 #define EXPORT_SYMBOL(sym) \
204 __EXPORT_SYMBOL(sym, "")
205
206 #define EXPORT_SYMBOL_GPL(sym) \
207 __EXPORT_SYMBOL(sym, "_gpl")
208
209 #define EXPORT_SYMBOL_GPL_FUTURE(sym) \
210 __EXPORT_SYMBOL(sym, "_gpl_future")
211
212
213 #ifdef CONFIG_UNUSED_SYMBOLS
214 #define EXPORT_UNUSED_SYMBOL(sym) __EXPORT_SYMBOL(sym, "_unused")
215 #define EXPORT_UNUSED_SYMBOL_GPL(sym) __EXPORT_SYMBOL(sym, "_unused_gpl")
216 #else
217 #define EXPORT_UNUSED_SYMBOL(sym)
218 #define EXPORT_UNUSED_SYMBOL_GPL(sym)
219 #endif
220
221 #endif
222
223 enum module_state
224 {
225 MODULE_STATE_LIVE,
226 MODULE_STATE_COMING,
227 MODULE_STATE_GOING,
228 };
229
230 struct module
231 {
232 enum module_state state;
233
234 /* Member of list of modules */
235 struct list_head list;
236
237 /* Unique handle for this module */
238 char name[MODULE_NAME_LEN];
239
240 /* Sysfs stuff. */
241 struct module_kobject mkobj;
242 struct module_attribute *modinfo_attrs;
243 const char *version;
244 const char *srcversion;
245 struct kobject *holders_dir;
246
247 /* Exported symbols */
248 const struct kernel_symbol *syms;
249 const unsigned long *crcs;
250 unsigned int num_syms;
251
252 /* Kernel parameters. */
253 struct kernel_param *kp;
254 unsigned int num_kp;
255
256 /* GPL-only exported symbols. */
257 unsigned int num_gpl_syms;
258 const struct kernel_symbol *gpl_syms;
259 const unsigned long *gpl_crcs;
260
261 #ifdef CONFIG_UNUSED_SYMBOLS
262 /* unused exported symbols. */
263 const struct kernel_symbol *unused_syms;
264 const unsigned long *unused_crcs;
265 unsigned int num_unused_syms;
266
267 /* GPL-only, unused exported symbols. */
268 unsigned int num_unused_gpl_syms;
269 const struct kernel_symbol *unused_gpl_syms;
270 const unsigned long *unused_gpl_crcs;
271 #endif
272
273 /* symbols that will be GPL-only in the near future. */
274 const struct kernel_symbol *gpl_future_syms;
275 const unsigned long *gpl_future_crcs;
276 unsigned int num_gpl_future_syms;
277
278 /* Exception table */
279 unsigned int num_exentries;
280 struct exception_table_entry *extable;
281
282 /* Startup function. */
283 int (*init)(void);
284
285 /* If this is non-NULL, vfree after init() returns */
286 void *module_init;
287
288 /* Here is the actual code + data, vfree'd on unload. */
289 void *module_core;
290
291 /* Here are the sizes of the init and core sections */
292 unsigned int init_size, core_size;
293
294 /* The size of the executable code in each section. */
295 unsigned int init_text_size, core_text_size;
296
297 /* Arch-specific module values */
298 struct mod_arch_specific arch;
299
300 unsigned int taints; /* same bits as kernel:tainted */
301
302 #ifdef CONFIG_GENERIC_BUG
303 /* Support for BUG */
304 unsigned num_bugs;
305 struct list_head bug_list;
306 struct bug_entry *bug_table;
307 #endif
308
309 #ifdef CONFIG_KALLSYMS
310 /* We keep the symbol and string tables for kallsyms. */
311 Elf_Sym *symtab;
312 unsigned int num_symtab;
313 char *strtab;
314
315 /* Section attributes */
316 struct module_sect_attrs *sect_attrs;
317
318 /* Notes attributes */
319 struct module_notes_attrs *notes_attrs;
320 #endif
321
322 /* Per-cpu data. */
323 void *percpu;
324
325 /* The command line arguments (may be mangled). People like
326 keeping pointers to this stuff */
327 char *args;
328 #ifdef CONFIG_MARKERS
329 struct marker *markers;
330 unsigned int num_markers;
331 #endif
332 #ifdef CONFIG_TRACEPOINTS
333 struct tracepoint *tracepoints;
334 unsigned int num_tracepoints;
335 #endif
336
337 #ifdef CONFIG_TRACING
338 const char **trace_bprintk_fmt_start;
339 unsigned int num_trace_bprintk_fmt;
340 #endif
341 #ifdef CONFIG_EVENT_TRACING
342 struct ftrace_event_call *trace_events;
343 unsigned int num_trace_events;
344 #endif
345 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
346 unsigned long *ftrace_callsites;
347 unsigned int num_ftrace_callsites;
348 #endif
349
350 #ifdef CONFIG_MODULE_UNLOAD
351 /* What modules depend on me? */
352 struct list_head modules_which_use_me;
353
354 /* Who is waiting for us to be unloaded */
355 struct task_struct *waiter;
356
357 /* Destruction function. */
358 void (*exit)(void);
359
360 #ifdef CONFIG_SMP
361 char *refptr;
362 #else
363 local_t ref;
364 #endif
365 #endif
366 };
367 #ifndef MODULE_ARCH_INIT
368 #define MODULE_ARCH_INIT {}
369 #endif
370
371 extern struct mutex module_mutex;
372
373 /* FIXME: It'd be nice to isolate modules during init, too, so they
374 aren't used before they (may) fail. But presently too much code
375 (IDE & SCSI) require entry into the module during init.*/
376 static inline int module_is_live(struct module *mod)
377 {
378 return mod->state != MODULE_STATE_GOING;
379 }
380
381 struct module *__module_text_address(unsigned long addr);
382 struct module *__module_address(unsigned long addr);
383 bool is_module_address(unsigned long addr);
384 bool is_module_text_address(unsigned long addr);
385
386 static inline int within_module_core(unsigned long addr, struct module *mod)
387 {
388 return (unsigned long)mod->module_core <= addr &&
389 addr < (unsigned long)mod->module_core + mod->core_size;
390 }
391
392 static inline int within_module_init(unsigned long addr, struct module *mod)
393 {
394 return (unsigned long)mod->module_init <= addr &&
395 addr < (unsigned long)mod->module_init + mod->init_size;
396 }
397
398 /* Search for module by name: must hold module_mutex. */
399 struct module *find_module(const char *name);
400
401 struct symsearch {
402 const struct kernel_symbol *start, *stop;
403 const unsigned long *crcs;
404 enum {
405 NOT_GPL_ONLY,
406 GPL_ONLY,
407 WILL_BE_GPL_ONLY,
408 } licence;
409 bool unused;
410 };
411
412 /* Search for an exported symbol by name. */
413 const struct kernel_symbol *find_symbol(const char *name,
414 struct module **owner,
415 const unsigned long **crc,
416 bool gplok,
417 bool warn);
418
419 /* Walk the exported symbol table */
420 bool each_symbol(bool (*fn)(const struct symsearch *arr, struct module *owner,
421 unsigned int symnum, void *data), void *data);
422
423 /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
424 symnum out of range. */
425 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
426 char *name, char *module_name, int *exported);
427
428 /* Look for this name: can be of form module:name. */
429 unsigned long module_kallsyms_lookup_name(const char *name);
430
431 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
432 struct module *, unsigned long),
433 void *data);
434
435 extern void __module_put_and_exit(struct module *mod, long code)
436 __attribute__((noreturn));
437 #define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code);
438
439 #ifdef CONFIG_MODULE_UNLOAD
440 unsigned int module_refcount(struct module *mod);
441 void __symbol_put(const char *symbol);
442 #define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x)
443 void symbol_put_addr(void *addr);
444
445 static inline local_t *__module_ref_addr(struct module *mod, int cpu)
446 {
447 #ifdef CONFIG_SMP
448 return (local_t *) (mod->refptr + per_cpu_offset(cpu));
449 #else
450 return &mod->ref;
451 #endif
452 }
453
454 /* Sometimes we know we already have a refcount, and it's easier not
455 to handle the error case (which only happens with rmmod --wait). */
456 static inline void __module_get(struct module *module)
457 {
458 if (module) {
459 local_inc(__module_ref_addr(module, get_cpu()));
460 put_cpu();
461 }
462 }
463
464 static inline int try_module_get(struct module *module)
465 {
466 int ret = 1;
467
468 if (module) {
469 unsigned int cpu = get_cpu();
470 if (likely(module_is_live(module)))
471 local_inc(__module_ref_addr(module, cpu));
472 else
473 ret = 0;
474 put_cpu();
475 }
476 return ret;
477 }
478
479 extern void module_put(struct module *module);
480
481 #else /*!CONFIG_MODULE_UNLOAD*/
482 static inline int try_module_get(struct module *module)
483 {
484 return !module || module_is_live(module);
485 }
486 static inline void module_put(struct module *module)
487 {
488 }
489 static inline void __module_get(struct module *module)
490 {
491 }
492 #define symbol_put(x) do { } while(0)
493 #define symbol_put_addr(p) do { } while(0)
494
495 #endif /* CONFIG_MODULE_UNLOAD */
496 int use_module(struct module *a, struct module *b);
497
498 /* This is a #define so the string doesn't get put in every .o file */
499 #define module_name(mod) \
500 ({ \
501 struct module *__mod = (mod); \
502 __mod ? __mod->name : "kernel"; \
503 })
504
505 /* For kallsyms to ask for address resolution. namebuf should be at
506 * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
507 * found, otherwise NULL. */
508 const char *module_address_lookup(unsigned long addr,
509 unsigned long *symbolsize,
510 unsigned long *offset,
511 char **modname,
512 char *namebuf);
513 int lookup_module_symbol_name(unsigned long addr, char *symname);
514 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
515
516 /* For extable.c to search modules' exception tables. */
517 const struct exception_table_entry *search_module_extables(unsigned long addr);
518
519 int register_module_notifier(struct notifier_block * nb);
520 int unregister_module_notifier(struct notifier_block * nb);
521
522 extern void print_modules(void);
523
524 extern void module_update_markers(void);
525
526 extern void module_update_tracepoints(void);
527 extern int module_get_iter_tracepoints(struct tracepoint_iter *iter);
528
529 #else /* !CONFIG_MODULES... */
530 #define EXPORT_SYMBOL(sym)
531 #define EXPORT_SYMBOL_GPL(sym)
532 #define EXPORT_SYMBOL_GPL_FUTURE(sym)
533 #define EXPORT_UNUSED_SYMBOL(sym)
534 #define EXPORT_UNUSED_SYMBOL_GPL(sym)
535
536 /* Given an address, look for it in the exception tables. */
537 static inline const struct exception_table_entry *
538 search_module_extables(unsigned long addr)
539 {
540 return NULL;
541 }
542
543 static inline struct module *__module_address(unsigned long addr)
544 {
545 return NULL;
546 }
547
548 static inline struct module *__module_text_address(unsigned long addr)
549 {
550 return NULL;
551 }
552
553 static inline bool is_module_address(unsigned long addr)
554 {
555 return false;
556 }
557
558 static inline bool is_module_text_address(unsigned long addr)
559 {
560 return false;
561 }
562
563 /* Get/put a kernel symbol (calls should be symmetric) */
564 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
565 #define symbol_put(x) do { } while(0)
566 #define symbol_put_addr(x) do { } while(0)
567
568 static inline void __module_get(struct module *module)
569 {
570 }
571
572 static inline int try_module_get(struct module *module)
573 {
574 return 1;
575 }
576
577 static inline void module_put(struct module *module)
578 {
579 }
580
581 #define module_name(mod) "kernel"
582
583 /* For kallsyms to ask for address resolution. NULL means not found. */
584 static inline const char *module_address_lookup(unsigned long addr,
585 unsigned long *symbolsize,
586 unsigned long *offset,
587 char **modname,
588 char *namebuf)
589 {
590 return NULL;
591 }
592
593 static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
594 {
595 return -ERANGE;
596 }
597
598 static inline int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
599 {
600 return -ERANGE;
601 }
602
603 static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
604 char *type, char *name,
605 char *module_name, int *exported)
606 {
607 return -ERANGE;
608 }
609
610 static inline unsigned long module_kallsyms_lookup_name(const char *name)
611 {
612 return 0;
613 }
614
615 static inline int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
616 struct module *,
617 unsigned long),
618 void *data)
619 {
620 return 0;
621 }
622
623 static inline int register_module_notifier(struct notifier_block * nb)
624 {
625 /* no events will happen anyway, so this can always succeed */
626 return 0;
627 }
628
629 static inline int unregister_module_notifier(struct notifier_block * nb)
630 {
631 return 0;
632 }
633
634 #define module_put_and_exit(code) do_exit(code)
635
636 static inline void print_modules(void)
637 {
638 }
639
640 static inline void module_update_markers(void)
641 {
642 }
643
644 static inline void module_update_tracepoints(void)
645 {
646 }
647
648 static inline int module_get_iter_tracepoints(struct tracepoint_iter *iter)
649 {
650 return 0;
651 }
652
653 #endif /* CONFIG_MODULES */
654
655 struct device_driver;
656 #ifdef CONFIG_SYSFS
657 struct module;
658
659 extern struct kset *module_kset;
660 extern struct kobj_type module_ktype;
661 extern int module_sysfs_initialized;
662
663 int mod_sysfs_init(struct module *mod);
664 int mod_sysfs_setup(struct module *mod,
665 struct kernel_param *kparam,
666 unsigned int num_params);
667 int module_add_modinfo_attrs(struct module *mod);
668 void module_remove_modinfo_attrs(struct module *mod);
669
670 #else /* !CONFIG_SYSFS */
671
672 static inline int mod_sysfs_init(struct module *mod)
673 {
674 return 0;
675 }
676
677 static inline int mod_sysfs_setup(struct module *mod,
678 struct kernel_param *kparam,
679 unsigned int num_params)
680 {
681 return 0;
682 }
683
684 static inline int module_add_modinfo_attrs(struct module *mod)
685 {
686 return 0;
687 }
688
689 static inline void module_remove_modinfo_attrs(struct module *mod)
690 { }
691
692 #endif /* CONFIG_SYSFS */
693
694 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
695
696 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
697
698 #define __MODULE_STRING(x) __stringify(x)
699
700 #endif /* _LINUX_MODULE_H */
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