tracing: Remove side effect from module tracepoints that caused a GPF
[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/tracepoint.h>
19
20 #include <linux/percpu.h>
21 #include <asm/module.h>
22
23 #include <trace/events/module.h>
24
25 /* Not Yet Implemented */
26 #define MODULE_SUPPORTED_DEVICE(name)
27
28 /* Some toolchains use a `_' prefix for all user symbols. */
29 #ifdef CONFIG_SYMBOL_PREFIX
30 #define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
31 #else
32 #define MODULE_SYMBOL_PREFIX ""
33 #endif
34
35 #define MODULE_NAME_LEN MAX_PARAM_PREFIX_LEN
36
37 struct kernel_symbol
38 {
39 unsigned long value;
40 const char *name;
41 };
42
43 struct modversion_info
44 {
45 unsigned long crc;
46 char name[MODULE_NAME_LEN];
47 };
48
49 struct module;
50
51 struct module_attribute {
52 struct attribute attr;
53 ssize_t (*show)(struct module_attribute *, struct module *, char *);
54 ssize_t (*store)(struct module_attribute *, struct module *,
55 const char *, size_t count);
56 void (*setup)(struct module *, const char *);
57 int (*test)(struct module *);
58 void (*free)(struct module *);
59 };
60
61 struct module_kobject
62 {
63 struct kobject kobj;
64 struct module *mod;
65 struct kobject *drivers_dir;
66 struct module_param_attrs *mp;
67 };
68
69 /* These are either module local, or the kernel's dummy ones. */
70 extern int init_module(void);
71 extern void cleanup_module(void);
72
73 /* Archs provide a method of finding the correct exception table. */
74 struct exception_table_entry;
75
76 const struct exception_table_entry *
77 search_extable(const struct exception_table_entry *first,
78 const struct exception_table_entry *last,
79 unsigned long value);
80 void sort_extable(struct exception_table_entry *start,
81 struct exception_table_entry *finish);
82 void sort_main_extable(void);
83 void trim_init_extable(struct module *m);
84
85 #ifdef MODULE
86 #define MODULE_GENERIC_TABLE(gtype,name) \
87 extern const struct gtype##_id __mod_##gtype##_table \
88 __attribute__ ((unused, alias(__stringify(name))))
89
90 extern struct module __this_module;
91 #define THIS_MODULE (&__this_module)
92 #else /* !MODULE */
93 #define MODULE_GENERIC_TABLE(gtype,name)
94 #define THIS_MODULE ((struct module *)0)
95 #endif
96
97 /* Generic info of form tag = "info" */
98 #define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info)
99
100 /* For userspace: you can also call me... */
101 #define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)
102
103 /*
104 * The following license idents are currently accepted as indicating free
105 * software modules
106 *
107 * "GPL" [GNU Public License v2 or later]
108 * "GPL v2" [GNU Public License v2]
109 * "GPL and additional rights" [GNU Public License v2 rights and more]
110 * "Dual BSD/GPL" [GNU Public License v2
111 * or BSD license choice]
112 * "Dual MIT/GPL" [GNU Public License v2
113 * or MIT license choice]
114 * "Dual MPL/GPL" [GNU Public License v2
115 * or Mozilla license choice]
116 *
117 * The following other idents are available
118 *
119 * "Proprietary" [Non free products]
120 *
121 * There are dual licensed components, but when running with Linux it is the
122 * GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL
123 * is a GPL combined work.
124 *
125 * This exists for several reasons
126 * 1. So modinfo can show license info for users wanting to vet their setup
127 * is free
128 * 2. So the community can ignore bug reports including proprietary modules
129 * 3. So vendors can do likewise based on their own policies
130 */
131 #define MODULE_LICENSE(_license) MODULE_INFO(license, _license)
132
133 /*
134 * Author(s), use "Name <email>" or just "Name", for multiple
135 * authors use multiple MODULE_AUTHOR() statements/lines.
136 */
137 #define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
138
139 /* What your module does. */
140 #define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
141
142 /* One for each parameter, describing how to use it. Some files do
143 multiple of these per line, so can't just use MODULE_INFO. */
144 #define MODULE_PARM_DESC(_parm, desc) \
145 __MODULE_INFO(parm, _parm, #_parm ":" desc)
146
147 #define MODULE_DEVICE_TABLE(type,name) \
148 MODULE_GENERIC_TABLE(type##_device,name)
149
150 /* Version of form [<epoch>:]<version>[-<extra-version>].
151 Or for CVS/RCS ID version, everything but the number is stripped.
152 <epoch>: A (small) unsigned integer which allows you to start versions
153 anew. If not mentioned, it's zero. eg. "2:1.0" is after
154 "1:2.0".
155 <version>: The <version> may contain only alphanumerics and the
156 character `.'. Ordered by numeric sort for numeric parts,
157 ascii sort for ascii parts (as per RPM or DEB algorithm).
158 <extraversion>: Like <version>, but inserted for local
159 customizations, eg "rh3" or "rusty1".
160
161 Using this automatically adds a checksum of the .c files and the
162 local headers in "srcversion".
163 */
164 #define MODULE_VERSION(_version) MODULE_INFO(version, _version)
165
166 /* Optional firmware file (or files) needed by the module
167 * format is simply firmware file name. Multiple firmware
168 * files require multiple MODULE_FIRMWARE() specifiers */
169 #define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
170
171 /* Given an address, look for it in the exception tables */
172 const struct exception_table_entry *search_exception_tables(unsigned long add);
173
174 struct notifier_block;
175
176 #ifdef CONFIG_MODULES
177
178 extern int modules_disabled; /* for sysctl */
179 /* Get/put a kernel symbol (calls must be symmetric) */
180 void *__symbol_get(const char *symbol);
181 void *__symbol_get_gpl(const char *symbol);
182 #define symbol_get(x) ((typeof(&x))(__symbol_get(MODULE_SYMBOL_PREFIX #x)))
183
184 #ifndef __GENKSYMS__
185 #ifdef CONFIG_MODVERSIONS
186 /* Mark the CRC weak since genksyms apparently decides not to
187 * generate a checksums for some symbols */
188 #define __CRC_SYMBOL(sym, sec) \
189 extern void *__crc_##sym __attribute__((weak)); \
190 static const unsigned long __kcrctab_##sym \
191 __used \
192 __attribute__((section("__kcrctab" sec), unused)) \
193 = (unsigned long) &__crc_##sym;
194 #else
195 #define __CRC_SYMBOL(sym, sec)
196 #endif
197
198 /* For every exported symbol, place a struct in the __ksymtab section */
199 #define __EXPORT_SYMBOL(sym, sec) \
200 extern typeof(sym) sym; \
201 __CRC_SYMBOL(sym, sec) \
202 static const char __kstrtab_##sym[] \
203 __attribute__((section("__ksymtab_strings"), aligned(1))) \
204 = MODULE_SYMBOL_PREFIX #sym; \
205 static const struct kernel_symbol __ksymtab_##sym \
206 __used \
207 __attribute__((section("__ksymtab" sec), unused)) \
208 = { (unsigned long)&sym, __kstrtab_##sym }
209
210 #define EXPORT_SYMBOL(sym) \
211 __EXPORT_SYMBOL(sym, "")
212
213 #define EXPORT_SYMBOL_GPL(sym) \
214 __EXPORT_SYMBOL(sym, "_gpl")
215
216 #define EXPORT_SYMBOL_GPL_FUTURE(sym) \
217 __EXPORT_SYMBOL(sym, "_gpl_future")
218
219
220 #ifdef CONFIG_UNUSED_SYMBOLS
221 #define EXPORT_UNUSED_SYMBOL(sym) __EXPORT_SYMBOL(sym, "_unused")
222 #define EXPORT_UNUSED_SYMBOL_GPL(sym) __EXPORT_SYMBOL(sym, "_unused_gpl")
223 #else
224 #define EXPORT_UNUSED_SYMBOL(sym)
225 #define EXPORT_UNUSED_SYMBOL_GPL(sym)
226 #endif
227
228 #endif
229
230 enum module_state
231 {
232 MODULE_STATE_LIVE,
233 MODULE_STATE_COMING,
234 MODULE_STATE_GOING,
235 };
236
237 struct module
238 {
239 enum module_state state;
240
241 /* Member of list of modules */
242 struct list_head list;
243
244 /* Unique handle for this module */
245 char name[MODULE_NAME_LEN];
246
247 /* Sysfs stuff. */
248 struct module_kobject mkobj;
249 struct module_attribute *modinfo_attrs;
250 const char *version;
251 const char *srcversion;
252 struct kobject *holders_dir;
253
254 /* Exported symbols */
255 const struct kernel_symbol *syms;
256 const unsigned long *crcs;
257 unsigned int num_syms;
258
259 /* Kernel parameters. */
260 struct kernel_param *kp;
261 unsigned int num_kp;
262
263 /* GPL-only exported symbols. */
264 unsigned int num_gpl_syms;
265 const struct kernel_symbol *gpl_syms;
266 const unsigned long *gpl_crcs;
267
268 #ifdef CONFIG_UNUSED_SYMBOLS
269 /* unused exported symbols. */
270 const struct kernel_symbol *unused_syms;
271 const unsigned long *unused_crcs;
272 unsigned int num_unused_syms;
273
274 /* GPL-only, unused exported symbols. */
275 unsigned int num_unused_gpl_syms;
276 const struct kernel_symbol *unused_gpl_syms;
277 const unsigned long *unused_gpl_crcs;
278 #endif
279
280 /* symbols that will be GPL-only in the near future. */
281 const struct kernel_symbol *gpl_future_syms;
282 const unsigned long *gpl_future_crcs;
283 unsigned int num_gpl_future_syms;
284
285 /* Exception table */
286 unsigned int num_exentries;
287 struct exception_table_entry *extable;
288
289 /* Startup function. */
290 int (*init)(void);
291
292 /* If this is non-NULL, vfree after init() returns */
293 void *module_init;
294
295 /* Here is the actual code + data, vfree'd on unload. */
296 void *module_core;
297
298 /* Here are the sizes of the init and core sections */
299 unsigned int init_size, core_size;
300
301 /* The size of the executable code in each section. */
302 unsigned int init_text_size, core_text_size;
303
304 /* Arch-specific module values */
305 struct mod_arch_specific arch;
306
307 unsigned int taints; /* same bits as kernel:tainted */
308
309 #ifdef CONFIG_GENERIC_BUG
310 /* Support for BUG */
311 unsigned num_bugs;
312 struct list_head bug_list;
313 struct bug_entry *bug_table;
314 #endif
315
316 #ifdef CONFIG_KALLSYMS
317 /*
318 * We keep the symbol and string tables for kallsyms.
319 * The core_* fields below are temporary, loader-only (they
320 * could really be discarded after module init).
321 */
322 Elf_Sym *symtab, *core_symtab;
323 unsigned int num_symtab, core_num_syms;
324 char *strtab, *core_strtab;
325
326 /* Section attributes */
327 struct module_sect_attrs *sect_attrs;
328
329 /* Notes attributes */
330 struct module_notes_attrs *notes_attrs;
331 #endif
332
333 /* Per-cpu data. */
334 void *percpu;
335
336 /* The command line arguments (may be mangled). People like
337 keeping pointers to this stuff */
338 char *args;
339 #ifdef CONFIG_TRACEPOINTS
340 struct tracepoint *tracepoints;
341 unsigned int num_tracepoints;
342 #endif
343
344 #ifdef CONFIG_TRACING
345 const char **trace_bprintk_fmt_start;
346 unsigned int num_trace_bprintk_fmt;
347 #endif
348 #ifdef CONFIG_EVENT_TRACING
349 struct ftrace_event_call *trace_events;
350 unsigned int num_trace_events;
351 #endif
352 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
353 unsigned long *ftrace_callsites;
354 unsigned int num_ftrace_callsites;
355 #endif
356
357 #ifdef CONFIG_MODULE_UNLOAD
358 /* What modules depend on me? */
359 struct list_head modules_which_use_me;
360
361 /* Who is waiting for us to be unloaded */
362 struct task_struct *waiter;
363
364 /* Destruction function. */
365 void (*exit)(void);
366
367 struct module_ref {
368 int count;
369 } __percpu *refptr;
370 #endif
371
372 #ifdef CONFIG_CONSTRUCTORS
373 /* Constructor functions. */
374 ctor_fn_t *ctors;
375 unsigned int num_ctors;
376 #endif
377 };
378 #ifndef MODULE_ARCH_INIT
379 #define MODULE_ARCH_INIT {}
380 #endif
381
382 extern struct mutex module_mutex;
383
384 /* FIXME: It'd be nice to isolate modules during init, too, so they
385 aren't used before they (may) fail. But presently too much code
386 (IDE & SCSI) require entry into the module during init.*/
387 static inline int module_is_live(struct module *mod)
388 {
389 return mod->state != MODULE_STATE_GOING;
390 }
391
392 struct module *__module_text_address(unsigned long addr);
393 struct module *__module_address(unsigned long addr);
394 bool is_module_address(unsigned long addr);
395 bool is_module_text_address(unsigned long addr);
396
397 static inline int within_module_core(unsigned long addr, struct module *mod)
398 {
399 return (unsigned long)mod->module_core <= addr &&
400 addr < (unsigned long)mod->module_core + mod->core_size;
401 }
402
403 static inline int within_module_init(unsigned long addr, struct module *mod)
404 {
405 return (unsigned long)mod->module_init <= addr &&
406 addr < (unsigned long)mod->module_init + mod->init_size;
407 }
408
409 /* Search for module by name: must hold module_mutex. */
410 struct module *find_module(const char *name);
411
412 struct symsearch {
413 const struct kernel_symbol *start, *stop;
414 const unsigned long *crcs;
415 enum {
416 NOT_GPL_ONLY,
417 GPL_ONLY,
418 WILL_BE_GPL_ONLY,
419 } licence;
420 bool unused;
421 };
422
423 /* Search for an exported symbol by name. */
424 const struct kernel_symbol *find_symbol(const char *name,
425 struct module **owner,
426 const unsigned long **crc,
427 bool gplok,
428 bool warn);
429
430 /* Walk the exported symbol table */
431 bool each_symbol(bool (*fn)(const struct symsearch *arr, struct module *owner,
432 unsigned int symnum, void *data), void *data);
433
434 /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
435 symnum out of range. */
436 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
437 char *name, char *module_name, int *exported);
438
439 /* Look for this name: can be of form module:name. */
440 unsigned long module_kallsyms_lookup_name(const char *name);
441
442 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
443 struct module *, unsigned long),
444 void *data);
445
446 extern void __module_put_and_exit(struct module *mod, long code)
447 __attribute__((noreturn));
448 #define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code);
449
450 #ifdef CONFIG_MODULE_UNLOAD
451 unsigned int module_refcount(struct module *mod);
452 void __symbol_put(const char *symbol);
453 #define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x)
454 void symbol_put_addr(void *addr);
455
456 /* Sometimes we know we already have a refcount, and it's easier not
457 to handle the error case (which only happens with rmmod --wait). */
458 static inline void __module_get(struct module *module)
459 {
460 if (module) {
461 preempt_disable();
462 __this_cpu_inc(module->refptr->count);
463 trace_module_get(module, _THIS_IP_);
464 preempt_enable();
465 }
466 }
467
468 static inline int try_module_get(struct module *module)
469 {
470 int ret = 1;
471
472 if (module) {
473 preempt_disable();
474
475 if (likely(module_is_live(module))) {
476 __this_cpu_inc(module->refptr->count);
477 trace_module_get(module, _THIS_IP_);
478 }
479 else
480 ret = 0;
481
482 preempt_enable();
483 }
484 return ret;
485 }
486
487 extern void module_put(struct module *module);
488
489 #else /*!CONFIG_MODULE_UNLOAD*/
490 static inline int try_module_get(struct module *module)
491 {
492 return !module || module_is_live(module);
493 }
494 static inline void module_put(struct module *module)
495 {
496 }
497 static inline void __module_get(struct module *module)
498 {
499 }
500 #define symbol_put(x) do { } while(0)
501 #define symbol_put_addr(p) do { } while(0)
502
503 #endif /* CONFIG_MODULE_UNLOAD */
504 int use_module(struct module *a, struct module *b);
505
506 /* This is a #define so the string doesn't get put in every .o file */
507 #define module_name(mod) \
508 ({ \
509 struct module *__mod = (mod); \
510 __mod ? __mod->name : "kernel"; \
511 })
512
513 /* For kallsyms to ask for address resolution. namebuf should be at
514 * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
515 * found, otherwise NULL. */
516 const char *module_address_lookup(unsigned long addr,
517 unsigned long *symbolsize,
518 unsigned long *offset,
519 char **modname,
520 char *namebuf);
521 int lookup_module_symbol_name(unsigned long addr, char *symname);
522 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
523
524 /* For extable.c to search modules' exception tables. */
525 const struct exception_table_entry *search_module_extables(unsigned long addr);
526
527 int register_module_notifier(struct notifier_block * nb);
528 int unregister_module_notifier(struct notifier_block * nb);
529
530 extern void print_modules(void);
531
532 extern void module_update_tracepoints(void);
533 extern int module_get_iter_tracepoints(struct tracepoint_iter *iter);
534
535 #else /* !CONFIG_MODULES... */
536 #define EXPORT_SYMBOL(sym)
537 #define EXPORT_SYMBOL_GPL(sym)
538 #define EXPORT_SYMBOL_GPL_FUTURE(sym)
539 #define EXPORT_UNUSED_SYMBOL(sym)
540 #define EXPORT_UNUSED_SYMBOL_GPL(sym)
541
542 /* Given an address, look for it in the exception tables. */
543 static inline const struct exception_table_entry *
544 search_module_extables(unsigned long addr)
545 {
546 return NULL;
547 }
548
549 static inline struct module *__module_address(unsigned long addr)
550 {
551 return NULL;
552 }
553
554 static inline struct module *__module_text_address(unsigned long addr)
555 {
556 return NULL;
557 }
558
559 static inline bool is_module_address(unsigned long addr)
560 {
561 return false;
562 }
563
564 static inline bool is_module_text_address(unsigned long addr)
565 {
566 return false;
567 }
568
569 /* Get/put a kernel symbol (calls should be symmetric) */
570 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); })
571 #define symbol_put(x) do { } while(0)
572 #define symbol_put_addr(x) do { } while(0)
573
574 static inline void __module_get(struct module *module)
575 {
576 }
577
578 static inline int try_module_get(struct module *module)
579 {
580 return 1;
581 }
582
583 static inline void module_put(struct module *module)
584 {
585 }
586
587 #define module_name(mod) "kernel"
588
589 /* For kallsyms to ask for address resolution. NULL means not found. */
590 static inline const char *module_address_lookup(unsigned long addr,
591 unsigned long *symbolsize,
592 unsigned long *offset,
593 char **modname,
594 char *namebuf)
595 {
596 return NULL;
597 }
598
599 static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
600 {
601 return -ERANGE;
602 }
603
604 static inline int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
605 {
606 return -ERANGE;
607 }
608
609 static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
610 char *type, char *name,
611 char *module_name, int *exported)
612 {
613 return -ERANGE;
614 }
615
616 static inline unsigned long module_kallsyms_lookup_name(const char *name)
617 {
618 return 0;
619 }
620
621 static inline int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
622 struct module *,
623 unsigned long),
624 void *data)
625 {
626 return 0;
627 }
628
629 static inline int register_module_notifier(struct notifier_block * nb)
630 {
631 /* no events will happen anyway, so this can always succeed */
632 return 0;
633 }
634
635 static inline int unregister_module_notifier(struct notifier_block * nb)
636 {
637 return 0;
638 }
639
640 #define module_put_and_exit(code) do_exit(code)
641
642 static inline void print_modules(void)
643 {
644 }
645
646 static inline void module_update_tracepoints(void)
647 {
648 }
649
650 static inline int module_get_iter_tracepoints(struct tracepoint_iter *iter)
651 {
652 return 0;
653 }
654
655 #endif /* CONFIG_MODULES */
656
657 struct device_driver;
658 #ifdef CONFIG_SYSFS
659 struct module;
660
661 extern struct kset *module_kset;
662 extern struct kobj_type module_ktype;
663 extern int module_sysfs_initialized;
664
665 int mod_sysfs_init(struct module *mod);
666 int mod_sysfs_setup(struct module *mod,
667 struct kernel_param *kparam,
668 unsigned int num_params);
669 int module_add_modinfo_attrs(struct module *mod);
670 void module_remove_modinfo_attrs(struct module *mod);
671
672 #else /* !CONFIG_SYSFS */
673
674 static inline int mod_sysfs_init(struct module *mod)
675 {
676 return 0;
677 }
678
679 static inline int mod_sysfs_setup(struct module *mod,
680 struct kernel_param *kparam,
681 unsigned int num_params)
682 {
683 return 0;
684 }
685
686 static inline int module_add_modinfo_attrs(struct module *mod)
687 {
688 return 0;
689 }
690
691 static inline void module_remove_modinfo_attrs(struct module *mod)
692 { }
693
694 #endif /* CONFIG_SYSFS */
695
696 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
697
698 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
699
700 #define __MODULE_STRING(x) __stringify(x)
701
702
703 #ifdef CONFIG_GENERIC_BUG
704 int module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *,
705 struct module *);
706 void module_bug_cleanup(struct module *);
707
708 #else /* !CONFIG_GENERIC_BUG */
709
710 static inline int module_bug_finalize(const Elf_Ehdr *hdr,
711 const Elf_Shdr *sechdrs,
712 struct module *mod)
713 {
714 return 0;
715 }
716 static inline void module_bug_cleanup(struct module *mod) {}
717 #endif /* CONFIG_GENERIC_BUG */
718
719 #endif /* _LINUX_MODULE_H */
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