xref: /linux/include/linux/module.h (revision 136114e0abf03005e182d75761ab694648e6d388)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Dynamic loading of modules into the kernel.
4  *
5  * Rewritten by Richard Henderson <rth@tamu.edu> Dec 1996
6  * Rewritten again by Rusty Russell, 2002
7  */
8 
9 #ifndef _LINUX_MODULE_H
10 #define _LINUX_MODULE_H
11 
12 #include <linux/list.h>
13 #include <linux/stat.h>
14 #include <linux/buildid.h>
15 #include <linux/compiler.h>
16 #include <linux/cache.h>
17 #include <linux/cleanup.h>
18 #include <linux/kmod.h>
19 #include <linux/init.h>
20 #include <linux/elf.h>
21 #include <linux/stringify.h>
22 #include <linux/kobject.h>
23 #include <linux/moduleparam.h>
24 #include <linux/jump_label.h>
25 #include <linux/export.h>
26 #include <linux/rbtree_latch.h>
27 #include <linux/error-injection.h>
28 #include <linux/tracepoint-defs.h>
29 #include <linux/srcu.h>
30 #include <linux/static_call_types.h>
31 #include <linux/dynamic_debug.h>
32 
33 #include <linux/percpu.h>
34 #include <asm/module.h>
35 
36 #define MODULE_NAME_LEN __MODULE_NAME_LEN
37 
38 struct modversion_info {
39 	unsigned long crc;
40 	char name[MODULE_NAME_LEN];
41 };
42 
43 struct module;
44 struct exception_table_entry;
45 
46 struct module_kobject {
47 	struct kobject kobj;
48 	struct module *mod;
49 	struct kobject *drivers_dir;
50 	struct module_param_attrs *mp;
51 	struct completion *kobj_completion;
52 } __randomize_layout;
53 
54 struct module_attribute {
55 	struct attribute attr;
56 	ssize_t (*show)(const struct module_attribute *, struct module_kobject *,
57 			char *);
58 	ssize_t (*store)(const struct module_attribute *, struct module_kobject *,
59 			 const char *, size_t count);
60 	void (*setup)(struct module *, const char *);
61 	int (*test)(struct module *);
62 	void (*free)(struct module *);
63 };
64 
65 struct module_version_attribute {
66 	struct module_attribute mattr;
67 	const char *module_name;
68 	const char *version;
69 };
70 
71 extern ssize_t __modver_version_show(const struct module_attribute *,
72 				     struct module_kobject *, char *);
73 
74 extern const struct module_attribute module_uevent;
75 
76 /* These are either module local, or the kernel's dummy ones. */
77 extern int init_module(void);
78 extern void cleanup_module(void);
79 
80 #ifndef MODULE
81 /**
82  * module_init() - driver initialization entry point
83  * @x: function to be run at kernel boot time or module insertion
84  *
85  * module_init() will either be called during do_initcalls() (if
86  * builtin) or at module insertion time (if a module).  There can only
87  * be one per module.
88  */
89 #define module_init(x)	__initcall(x);
90 
91 /**
92  * module_exit() - driver exit entry point
93  * @x: function to be run when driver is removed
94  *
95  * module_exit() will wrap the driver clean-up code
96  * with cleanup_module() when used with rmmod when
97  * the driver is a module.  If the driver is statically
98  * compiled into the kernel, module_exit() has no effect.
99  * There can only be one per module.
100  */
101 #define module_exit(x)	__exitcall(x);
102 
103 #else /* MODULE */
104 
105 /*
106  * In most cases loadable modules do not need custom
107  * initcall levels. There are still some valid cases where
108  * a driver may be needed early if built in, and does not
109  * matter when built as a loadable module. Like bus
110  * snooping debug drivers.
111  */
112 #define early_initcall(fn)		module_init(fn)
113 #define core_initcall(fn)		module_init(fn)
114 #define core_initcall_sync(fn)		module_init(fn)
115 #define postcore_initcall(fn)		module_init(fn)
116 #define postcore_initcall_sync(fn)	module_init(fn)
117 #define arch_initcall(fn)		module_init(fn)
118 #define subsys_initcall(fn)		module_init(fn)
119 #define subsys_initcall_sync(fn)	module_init(fn)
120 #define fs_initcall(fn)			module_init(fn)
121 #define fs_initcall_sync(fn)		module_init(fn)
122 #define rootfs_initcall(fn)		module_init(fn)
123 #define device_initcall(fn)		module_init(fn)
124 #define device_initcall_sync(fn)	module_init(fn)
125 #define late_initcall(fn)		module_init(fn)
126 #define late_initcall_sync(fn)		module_init(fn)
127 
128 #define console_initcall(fn)		module_init(fn)
129 
130 /* Each module must use one module_init(). */
131 #define module_init(initfn)					\
132 	static inline initcall_t __maybe_unused __inittest(void)		\
133 	{ return initfn; }					\
134 	int init_module(void) __copy(initfn)			\
135 		__attribute__((alias(#initfn)));		\
136 	___ADDRESSABLE(init_module, __initdata);
137 
138 /* This is only required if you want to be unloadable. */
139 #define module_exit(exitfn)					\
140 	static inline exitcall_t __maybe_unused __exittest(void)		\
141 	{ return exitfn; }					\
142 	void cleanup_module(void) __copy(exitfn)		\
143 		__attribute__((alias(#exitfn)));		\
144 	___ADDRESSABLE(cleanup_module, __exitdata);
145 
146 #endif
147 
148 /* This means "can be init if no module support, otherwise module load
149    may call it." */
150 #ifdef CONFIG_MODULES
151 #define __init_or_module
152 #define __initdata_or_module
153 #define __initconst_or_module
154 #else
155 #define __init_or_module __init
156 #define __initdata_or_module __initdata
157 #define __initconst_or_module __initconst
158 #endif /*CONFIG_MODULES*/
159 
160 struct module_kobject *lookup_or_create_module_kobject(const char *name);
161 
162 /* For userspace: you can also call me... */
163 #define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)
164 
165 /* Soft module dependencies. See man modprobe.d for details.
166  * Example: MODULE_SOFTDEP("pre: module-foo module-bar post: module-baz")
167  */
168 #define MODULE_SOFTDEP(_softdep) MODULE_INFO(softdep, _softdep)
169 
170 /*
171  * Weak module dependencies. See man modprobe.d for details.
172  * Example: MODULE_WEAKDEP("module-foo")
173  */
174 #define MODULE_WEAKDEP(_weakdep) MODULE_INFO(weakdep, _weakdep)
175 
176 /*
177  * MODULE_FILE is used for generating modules.builtin
178  * So, make it no-op when this is being built as a module
179  */
180 #ifdef MODULE
181 #define MODULE_FILE
182 #else
183 #define MODULE_FILE	MODULE_INFO(file, KBUILD_MODFILE);
184 #endif
185 
186 /*
187  * The following license idents are currently accepted as indicating free
188  * software modules
189  *
190  *	"GPL"				[GNU Public License v2]
191  *	"GPL v2"			[GNU Public License v2]
192  *	"GPL and additional rights"	[GNU Public License v2 rights and more]
193  *	"Dual BSD/GPL"			[GNU Public License v2
194  *					 or BSD license choice]
195  *	"Dual MIT/GPL"			[GNU Public License v2
196  *					 or MIT license choice]
197  *	"Dual MPL/GPL"			[GNU Public License v2
198  *					 or Mozilla license choice]
199  *
200  * The following other idents are available
201  *
202  *	"Proprietary"			[Non free products]
203  *
204  * Both "GPL v2" and "GPL" (the latter also in dual licensed strings) are
205  * merely stating that the module is licensed under the GPL v2, but are not
206  * telling whether "GPL v2 only" or "GPL v2 or later". The reason why there
207  * are two variants is a historic and failed attempt to convey more
208  * information in the MODULE_LICENSE string. For module loading the
209  * "only/or later" distinction is completely irrelevant and does neither
210  * replace the proper license identifiers in the corresponding source file
211  * nor amends them in any way. The sole purpose is to make the
212  * 'Proprietary' flagging work and to refuse to bind symbols which are
213  * exported with EXPORT_SYMBOL_GPL when a non free module is loaded.
214  *
215  * In the same way "BSD" is not a clear license information. It merely
216  * states, that the module is licensed under one of the compatible BSD
217  * license variants. The detailed and correct license information is again
218  * to be found in the corresponding source files.
219  *
220  * There are dual licensed components, but when running with Linux it is the
221  * GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL
222  * is a GPL combined work.
223  *
224  * This exists for several reasons
225  * 1.	So modinfo can show license info for users wanting to vet their setup
226  *	is free
227  * 2.	So the community can ignore bug reports including proprietary modules
228  * 3.	So vendors can do likewise based on their own policies
229  */
230 #define MODULE_LICENSE(_license) MODULE_FILE MODULE_INFO(license, _license)
231 
232 /*
233  * Author(s), use "Name <email>" or just "Name", for multiple
234  * authors use multiple MODULE_AUTHOR() statements/lines.
235  */
236 #define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
237 
238 /* What your module does. */
239 #define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
240 
241 /*
242  * Format: __mod_device_table__kmod_<modname>__<type>__<name>
243  * Parts of the string `__kmod_` and `__` are used as delimiters when parsing
244  * a symbol in file2alias.c
245  */
246 #define __mod_device_table(type, name)	\
247 	__PASTE(__mod_device_table__,	\
248 	__PASTE(kmod_,			\
249 	__PASTE(__KBUILD_MODNAME,	\
250 	__PASTE(__,			\
251 	__PASTE(type,			\
252 	__PASTE(__, name))))))
253 
254 /* Creates an alias so file2alias.c can find device table. */
255 #define MODULE_DEVICE_TABLE(type, name)					\
256 static typeof(name) __mod_device_table(type, name)			\
257   __attribute__ ((used, alias(__stringify(name))))
258 
259 /* Version of form [<epoch>:]<version>[-<extra-version>].
260  * Or for CVS/RCS ID version, everything but the number is stripped.
261  * <epoch>: A (small) unsigned integer which allows you to start versions
262  * anew. If not mentioned, it's zero.  eg. "2:1.0" is after
263  * "1:2.0".
264 
265  * <version>: The <version> may contain only alphanumerics and the
266  * character `.'.  Ordered by numeric sort for numeric parts,
267  * ascii sort for ascii parts (as per RPM or DEB algorithm).
268 
269  * <extraversion>: Like <version>, but inserted for local
270  * customizations, eg "rh3" or "rusty1".
271 
272  * Using this automatically adds a checksum of the .c files and the
273  * local headers in "srcversion".
274  */
275 
276 #if defined(MODULE) || !defined(CONFIG_SYSFS)
277 #define MODULE_VERSION(_version) MODULE_INFO(version, _version)
278 #else
279 #define MODULE_VERSION(_version)					\
280 	MODULE_INFO(version, _version);					\
281 	static const struct module_version_attribute __modver_attr	\
282 		__used __section("__modver")				\
283 		__aligned(__alignof__(struct module_version_attribute)) \
284 		= {							\
285 			.mattr	= {					\
286 				.attr	= {				\
287 					.name	= "version",		\
288 					.mode	= S_IRUGO,		\
289 				},					\
290 				.show	= __modver_version_show,	\
291 			},						\
292 			.module_name	= KBUILD_MODNAME,		\
293 			.version	= _version,			\
294 		}
295 #endif
296 
297 /* Optional firmware file (or files) needed by the module
298  * format is simply firmware file name.  Multiple firmware
299  * files require multiple MODULE_FIRMWARE() specifiers */
300 #define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
301 
302 #define MODULE_IMPORT_NS(ns)	MODULE_INFO(import_ns, ns)
303 
304 struct notifier_block;
305 
306 enum module_state {
307 	MODULE_STATE_LIVE,	/* Normal state. */
308 	MODULE_STATE_COMING,	/* Full formed, running module_init. */
309 	MODULE_STATE_GOING,	/* Going away. */
310 	MODULE_STATE_UNFORMED,	/* Still setting it up. */
311 };
312 
313 struct mod_tree_node {
314 	struct module *mod;
315 	struct latch_tree_node node;
316 };
317 
318 enum mod_mem_type {
319 	MOD_TEXT = 0,
320 	MOD_DATA,
321 	MOD_RODATA,
322 	MOD_RO_AFTER_INIT,
323 	MOD_INIT_TEXT,
324 	MOD_INIT_DATA,
325 	MOD_INIT_RODATA,
326 
327 	MOD_MEM_NUM_TYPES,
328 	MOD_INVALID = -1,
329 };
330 
331 #define mod_mem_type_is_init(type)	\
332 	((type) == MOD_INIT_TEXT ||	\
333 	 (type) == MOD_INIT_DATA ||	\
334 	 (type) == MOD_INIT_RODATA)
335 
336 #define mod_mem_type_is_core(type) (!mod_mem_type_is_init(type))
337 
338 #define mod_mem_type_is_text(type)	\
339 	 ((type) == MOD_TEXT ||		\
340 	  (type) == MOD_INIT_TEXT)
341 
342 #define mod_mem_type_is_data(type) (!mod_mem_type_is_text(type))
343 
344 #define mod_mem_type_is_core_data(type)	\
345 	(mod_mem_type_is_core(type) &&	\
346 	 mod_mem_type_is_data(type))
347 
348 #define for_each_mod_mem_type(type)			\
349 	for (enum mod_mem_type (type) = 0;		\
350 	     (type) < MOD_MEM_NUM_TYPES; (type)++)
351 
352 #define for_class_mod_mem_type(type, class)		\
353 	for_each_mod_mem_type(type)			\
354 		if (mod_mem_type_is_##class(type))
355 
356 struct module_memory {
357 	void *base;
358 	bool is_rox;
359 	unsigned int size;
360 
361 #ifdef CONFIG_MODULES_TREE_LOOKUP
362 	struct mod_tree_node mtn;
363 #endif
364 };
365 
366 #ifdef CONFIG_MODULES_TREE_LOOKUP
367 /* Only touch one cacheline for common rbtree-for-core-layout case. */
368 #define __module_memory_align ____cacheline_aligned
369 #else
370 #define __module_memory_align
371 #endif
372 
373 struct mod_kallsyms {
374 	Elf_Sym *symtab;
375 	unsigned int num_symtab;
376 	char *strtab;
377 	char *typetab;
378 };
379 
380 #ifdef CONFIG_LIVEPATCH
381 /**
382  * struct klp_modinfo - ELF information preserved from the livepatch module
383  *
384  * @hdr: ELF header
385  * @sechdrs: Section header table
386  * @secstrings: String table for the section headers
387  * @symndx: The symbol table section index
388  */
389 struct klp_modinfo {
390 	Elf_Ehdr hdr;
391 	Elf_Shdr *sechdrs;
392 	char *secstrings;
393 	unsigned int symndx;
394 };
395 #endif
396 
397 struct module {
398 	enum module_state state;
399 
400 	/* Member of list of modules */
401 	struct list_head list;
402 
403 	/* Unique handle for this module */
404 	char name[MODULE_NAME_LEN];
405 
406 #ifdef CONFIG_STACKTRACE_BUILD_ID
407 	/* Module build ID */
408 	unsigned char build_id[BUILD_ID_SIZE_MAX];
409 #endif
410 
411 	/* Sysfs stuff. */
412 	struct module_kobject mkobj;
413 	struct module_attribute *modinfo_attrs;
414 	const char *version;
415 	const char *srcversion;
416 	struct kobject *holders_dir;
417 
418 	/* Exported symbols */
419 	const struct kernel_symbol *syms;
420 	const u32 *crcs;
421 	unsigned int num_syms;
422 
423 #ifdef CONFIG_ARCH_USES_CFI_TRAPS
424 	s32 *kcfi_traps;
425 	s32 *kcfi_traps_end;
426 #endif
427 
428 	/* Kernel parameters. */
429 #ifdef CONFIG_SYSFS
430 	struct mutex param_lock;
431 #endif
432 	struct kernel_param *kp;
433 	unsigned int num_kp;
434 
435 	/* GPL-only exported symbols. */
436 	unsigned int num_gpl_syms;
437 	const struct kernel_symbol *gpl_syms;
438 	const u32 *gpl_crcs;
439 	bool using_gplonly_symbols;
440 
441 #ifdef CONFIG_MODULE_SIG
442 	/* Signature was verified. */
443 	bool sig_ok;
444 #endif
445 
446 	bool async_probe_requested;
447 
448 	/* Exception table */
449 	unsigned int num_exentries;
450 	struct exception_table_entry *extable;
451 
452 	/* Startup function. */
453 	int (*init)(void);
454 
455 	struct module_memory mem[MOD_MEM_NUM_TYPES] __module_memory_align;
456 
457 	/* Arch-specific module values */
458 	struct mod_arch_specific arch;
459 
460 	unsigned long taints;	/* same bits as kernel:taint_flags */
461 
462 #ifdef CONFIG_GENERIC_BUG
463 	/* Support for BUG */
464 	unsigned num_bugs;
465 	struct list_head bug_list;
466 	struct bug_entry *bug_table;
467 #endif
468 
469 #ifdef CONFIG_KALLSYMS
470 	/* Protected by RCU and/or module_mutex: use rcu_dereference() */
471 	struct mod_kallsyms __rcu *kallsyms;
472 	struct mod_kallsyms core_kallsyms;
473 
474 	/* Section attributes */
475 	struct module_sect_attrs *sect_attrs;
476 
477 	/* Notes attributes */
478 	struct module_notes_attrs *notes_attrs;
479 #endif
480 
481 	/* The command line arguments (may be mangled).  People like
482 	   keeping pointers to this stuff */
483 	char *args;
484 
485 #ifdef CONFIG_SMP
486 	/* Per-cpu data. */
487 	void __percpu *percpu;
488 	unsigned int percpu_size;
489 #endif
490 	void *noinstr_text_start;
491 	unsigned int noinstr_text_size;
492 
493 #ifdef CONFIG_TRACEPOINTS
494 	unsigned int num_tracepoints;
495 	tracepoint_ptr_t *tracepoints_ptrs;
496 #endif
497 #ifdef CONFIG_TREE_SRCU
498 	unsigned int num_srcu_structs;
499 	struct srcu_struct **srcu_struct_ptrs;
500 #endif
501 #ifdef CONFIG_BPF_EVENTS
502 	unsigned int num_bpf_raw_events;
503 	struct bpf_raw_event_map *bpf_raw_events;
504 #endif
505 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
506 	unsigned int btf_data_size;
507 	unsigned int btf_base_data_size;
508 	void *btf_data;
509 	void *btf_base_data;
510 #endif
511 #ifdef CONFIG_JUMP_LABEL
512 	struct jump_entry *jump_entries;
513 	unsigned int num_jump_entries;
514 #endif
515 #ifdef CONFIG_TRACING
516 	unsigned int num_trace_bprintk_fmt;
517 	const char **trace_bprintk_fmt_start;
518 #endif
519 #ifdef CONFIG_EVENT_TRACING
520 	struct trace_event_call **trace_events;
521 	unsigned int num_trace_events;
522 	struct trace_eval_map **trace_evals;
523 	unsigned int num_trace_evals;
524 #endif
525 #ifdef CONFIG_DYNAMIC_FTRACE
526 	unsigned int num_ftrace_callsites;
527 	unsigned long *ftrace_callsites;
528 #endif
529 #ifdef CONFIG_KPROBES
530 	void *kprobes_text_start;
531 	unsigned int kprobes_text_size;
532 	unsigned long *kprobe_blacklist;
533 	unsigned int num_kprobe_blacklist;
534 #endif
535 #ifdef CONFIG_HAVE_STATIC_CALL_INLINE
536 	int num_static_call_sites;
537 	struct static_call_site *static_call_sites;
538 #endif
539 #if IS_ENABLED(CONFIG_KUNIT)
540 	int num_kunit_init_suites;
541 	struct kunit_suite **kunit_init_suites;
542 	int num_kunit_suites;
543 	struct kunit_suite **kunit_suites;
544 #endif
545 
546 
547 #ifdef CONFIG_LIVEPATCH
548 	bool klp; /* Is this a livepatch module? */
549 	bool klp_alive;
550 
551 	/* ELF information */
552 	struct klp_modinfo *klp_info;
553 #endif
554 
555 #ifdef CONFIG_PRINTK_INDEX
556 	unsigned int printk_index_size;
557 	struct pi_entry **printk_index_start;
558 #endif
559 
560 #ifdef CONFIG_MODULE_UNLOAD
561 	/* What modules depend on me? */
562 	struct list_head source_list;
563 	/* What modules do I depend on? */
564 	struct list_head target_list;
565 
566 	/* Destruction function. */
567 	void (*exit)(void);
568 
569 	atomic_t refcnt;
570 #endif
571 
572 #ifdef CONFIG_CONSTRUCTORS
573 	/* Constructor functions. */
574 	ctor_fn_t *ctors;
575 	unsigned int num_ctors;
576 #endif
577 
578 #ifdef CONFIG_FUNCTION_ERROR_INJECTION
579 	struct error_injection_entry *ei_funcs;
580 	unsigned int num_ei_funcs;
581 #endif
582 #ifdef CONFIG_DYNAMIC_DEBUG_CORE
583 	struct _ddebug_info dyndbg_info;
584 #endif
585 } ____cacheline_aligned __randomize_layout;
586 #ifndef MODULE_ARCH_INIT
587 #define MODULE_ARCH_INIT {}
588 #endif
589 
590 #ifdef CONFIG_MODULES
591 
592 /* Get/put a kernel symbol (calls must be symmetric) */
593 void *__symbol_get(const char *symbol);
594 void *__symbol_get_gpl(const char *symbol);
595 #define symbol_get(x)	({ \
596 	static const char __notrim[] \
597 		__used __section(".no_trim_symbol") = __stringify(x); \
598 	(typeof(&x))(__symbol_get(__stringify(x))); })
599 
600 #ifndef HAVE_ARCH_KALLSYMS_SYMBOL_VALUE
kallsyms_symbol_value(const Elf_Sym * sym)601 static inline unsigned long kallsyms_symbol_value(const Elf_Sym *sym)
602 {
603 	return sym->st_value;
604 }
605 #endif
606 
607 /* FIXME: It'd be nice to isolate modules during init, too, so they
608    aren't used before they (may) fail.  But presently too much code
609    (IDE & SCSI) require entry into the module during init.*/
module_is_live(struct module * mod)610 static inline bool module_is_live(struct module *mod)
611 {
612 	return mod->state != MODULE_STATE_GOING;
613 }
614 
module_is_coming(struct module * mod)615 static inline bool module_is_coming(struct module *mod)
616 {
617         return mod->state == MODULE_STATE_COMING;
618 }
619 
620 struct module *__module_text_address(unsigned long addr);
621 struct module *__module_address(unsigned long addr);
622 bool is_module_address(unsigned long addr);
623 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr);
624 bool is_module_percpu_address(unsigned long addr);
625 bool is_module_text_address(unsigned long addr);
626 
within_module_mem_type(unsigned long addr,const struct module * mod,enum mod_mem_type type)627 static inline bool within_module_mem_type(unsigned long addr,
628 					  const struct module *mod,
629 					  enum mod_mem_type type)
630 {
631 	unsigned long base, size;
632 
633 	base = (unsigned long)mod->mem[type].base;
634 	size = mod->mem[type].size;
635 	return addr - base < size;
636 }
637 
within_module_core(unsigned long addr,const struct module * mod)638 static inline bool within_module_core(unsigned long addr,
639 				      const struct module *mod)
640 {
641 	for_class_mod_mem_type(type, core) {
642 		if (within_module_mem_type(addr, mod, type))
643 			return true;
644 	}
645 	return false;
646 }
647 
within_module_init(unsigned long addr,const struct module * mod)648 static inline bool within_module_init(unsigned long addr,
649 				      const struct module *mod)
650 {
651 	for_class_mod_mem_type(type, init) {
652 		if (within_module_mem_type(addr, mod, type))
653 			return true;
654 	}
655 	return false;
656 }
657 
within_module(unsigned long addr,const struct module * mod)658 static inline bool within_module(unsigned long addr, const struct module *mod)
659 {
660 	return within_module_init(addr, mod) || within_module_core(addr, mod);
661 }
662 
663 /* Search for module by name: must be in a RCU critical section. */
664 struct module *find_module(const char *name);
665 
666 extern void __noreturn __module_put_and_kthread_exit(struct module *mod,
667 			long code);
668 #define module_put_and_kthread_exit(code) __module_put_and_kthread_exit(THIS_MODULE, code)
669 
670 #ifdef CONFIG_MODULE_UNLOAD
671 int module_refcount(struct module *mod);
672 void __symbol_put(const char *symbol);
673 #define symbol_put(x) __symbol_put(__stringify(x))
674 void symbol_put_addr(void *addr);
675 
676 /* Sometimes we know we already have a refcount, and it's easier not
677    to handle the error case (which only happens with rmmod --wait). */
678 extern void __module_get(struct module *module);
679 
680 /**
681  * try_module_get() - take module refcount unless module is being removed
682  * @module: the module we should check for
683  *
684  * Only try to get a module reference count if the module is not being removed.
685  * This call will fail if the module is in the process of being removed.
686  *
687  * Care must also be taken to ensure the module exists and is alive prior to
688  * usage of this call. This can be gauranteed through two means:
689  *
690  * 1) Direct protection: you know an earlier caller must have increased the
691  *    module reference through __module_get(). This can typically be achieved
692  *    by having another entity other than the module itself increment the
693  *    module reference count.
694  *
695  * 2) Implied protection: there is an implied protection against module
696  *    removal. An example of this is the implied protection used by kernfs /
697  *    sysfs. The sysfs store / read file operations are guaranteed to exist
698  *    through the use of kernfs's active reference (see kernfs_active()) and a
699  *    sysfs / kernfs file removal cannot happen unless the same file is not
700  *    active. Therefore, if a sysfs file is being read or written to the module
701  *    which created it must still exist. It is therefore safe to use
702  *    try_module_get() on module sysfs store / read ops.
703  *
704  * One of the real values to try_module_get() is the module_is_live() check
705  * which ensures that the caller of try_module_get() can yield to userspace
706  * module removal requests and gracefully fail if the module is on its way out.
707  *
708  * Returns true if the reference count was successfully incremented.
709  */
710 extern bool try_module_get(struct module *module);
711 
712 /**
713  * module_put() - release a reference count to a module
714  * @module: the module we should release a reference count for
715  *
716  * If you successfully bump a reference count to a module with try_module_get(),
717  * when you are finished you must call module_put() to release that reference
718  * count.
719  */
720 extern void module_put(struct module *module);
721 
722 #else /*!CONFIG_MODULE_UNLOAD*/
try_module_get(struct module * module)723 static inline bool try_module_get(struct module *module)
724 {
725 	return !module || module_is_live(module);
726 }
module_put(struct module * module)727 static inline void module_put(struct module *module)
728 {
729 }
__module_get(struct module * module)730 static inline void __module_get(struct module *module)
731 {
732 }
733 #define symbol_put(x) do { } while (0)
734 #define symbol_put_addr(p) do { } while (0)
735 
736 #endif /* CONFIG_MODULE_UNLOAD */
737 
738 /* This is a #define so the string doesn't get put in every .o file */
739 #define module_name(mod)			\
740 ({						\
741 	struct module *__mod = (mod);		\
742 	__mod ? __mod->name : "kernel";		\
743 })
744 
module_buildid(struct module * mod)745 static inline const unsigned char *module_buildid(struct module *mod)
746 {
747 #ifdef CONFIG_STACKTRACE_BUILD_ID
748 	return mod->build_id;
749 #else
750 	return NULL;
751 #endif
752 }
753 
754 /* Dereference module function descriptor */
755 void *dereference_module_function_descriptor(struct module *mod, void *ptr);
756 
757 int register_module_notifier(struct notifier_block *nb);
758 int unregister_module_notifier(struct notifier_block *nb);
759 
760 extern void print_modules(void);
761 
module_requested_async_probing(struct module * module)762 static inline bool module_requested_async_probing(struct module *module)
763 {
764 	return module && module->async_probe_requested;
765 }
766 
is_livepatch_module(struct module * mod)767 static inline bool is_livepatch_module(struct module *mod)
768 {
769 #ifdef CONFIG_LIVEPATCH
770 	return mod->klp;
771 #else
772 	return false;
773 #endif
774 }
775 
776 void module_for_each_mod(int(*func)(struct module *mod, void *data), void *data);
777 
778 #else /* !CONFIG_MODULES... */
779 
__module_address(unsigned long addr)780 static inline struct module *__module_address(unsigned long addr)
781 {
782 	return NULL;
783 }
784 
__module_text_address(unsigned long addr)785 static inline struct module *__module_text_address(unsigned long addr)
786 {
787 	return NULL;
788 }
789 
is_module_address(unsigned long addr)790 static inline bool is_module_address(unsigned long addr)
791 {
792 	return false;
793 }
794 
is_module_percpu_address(unsigned long addr)795 static inline bool is_module_percpu_address(unsigned long addr)
796 {
797 	return false;
798 }
799 
__is_module_percpu_address(unsigned long addr,unsigned long * can_addr)800 static inline bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
801 {
802 	return false;
803 }
804 
is_module_text_address(unsigned long addr)805 static inline bool is_module_text_address(unsigned long addr)
806 {
807 	return false;
808 }
809 
within_module_core(unsigned long addr,const struct module * mod)810 static inline bool within_module_core(unsigned long addr,
811 				      const struct module *mod)
812 {
813 	return false;
814 }
815 
within_module_init(unsigned long addr,const struct module * mod)816 static inline bool within_module_init(unsigned long addr,
817 				      const struct module *mod)
818 {
819 	return false;
820 }
821 
within_module(unsigned long addr,const struct module * mod)822 static inline bool within_module(unsigned long addr, const struct module *mod)
823 {
824 	return false;
825 }
826 
827 /* Get/put a kernel symbol (calls should be symmetric) */
828 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak,visibility("hidden"))); &(x); })
829 #define symbol_put(x) do { } while (0)
830 #define symbol_put_addr(x) do { } while (0)
831 
__module_get(struct module * module)832 static inline void __module_get(struct module *module)
833 {
834 }
835 
try_module_get(struct module * module)836 static inline bool try_module_get(struct module *module)
837 {
838 	return true;
839 }
840 
module_put(struct module * module)841 static inline void module_put(struct module *module)
842 {
843 }
844 
845 #define module_name(mod) "kernel"
846 
register_module_notifier(struct notifier_block * nb)847 static inline int register_module_notifier(struct notifier_block *nb)
848 {
849 	/* no events will happen anyway, so this can always succeed */
850 	return 0;
851 }
852 
unregister_module_notifier(struct notifier_block * nb)853 static inline int unregister_module_notifier(struct notifier_block *nb)
854 {
855 	return 0;
856 }
857 
858 #define module_put_and_kthread_exit(code) kthread_exit(code)
859 
print_modules(void)860 static inline void print_modules(void)
861 {
862 }
863 
module_requested_async_probing(struct module * module)864 static inline bool module_requested_async_probing(struct module *module)
865 {
866 	return false;
867 }
868 
869 
870 /* Dereference module function descriptor */
871 static inline
dereference_module_function_descriptor(struct module * mod,void * ptr)872 void *dereference_module_function_descriptor(struct module *mod, void *ptr)
873 {
874 	return ptr;
875 }
876 
module_is_coming(struct module * mod)877 static inline bool module_is_coming(struct module *mod)
878 {
879 	return false;
880 }
881 
module_for_each_mod(int (* func)(struct module * mod,void * data),void * data)882 static inline void module_for_each_mod(int(*func)(struct module *mod, void *data), void *data)
883 {
884 }
885 #endif /* CONFIG_MODULES */
886 
887 #ifdef CONFIG_SYSFS
888 extern struct kset *module_kset;
889 extern const struct kobj_type module_ktype;
890 #endif /* CONFIG_SYSFS */
891 
892 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
893 
894 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
895 
896 #define __MODULE_STRING(x) __stringify(x)
897 
898 #ifdef CONFIG_GENERIC_BUG
899 void module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *,
900 			 struct module *);
901 void module_bug_cleanup(struct module *);
902 
903 #else	/* !CONFIG_GENERIC_BUG */
904 
module_bug_finalize(const Elf_Ehdr * hdr,const Elf_Shdr * sechdrs,struct module * mod)905 static inline void module_bug_finalize(const Elf_Ehdr *hdr,
906 					const Elf_Shdr *sechdrs,
907 					struct module *mod)
908 {
909 }
module_bug_cleanup(struct module * mod)910 static inline void module_bug_cleanup(struct module *mod) {}
911 #endif	/* CONFIG_GENERIC_BUG */
912 
913 #ifdef CONFIG_MITIGATION_RETPOLINE
914 extern bool retpoline_module_ok(bool has_retpoline);
915 #else
retpoline_module_ok(bool has_retpoline)916 static inline bool retpoline_module_ok(bool has_retpoline)
917 {
918 	return true;
919 }
920 #endif
921 
922 #ifdef CONFIG_MODULE_SIG
923 bool is_module_sig_enforced(void);
924 
925 void set_module_sig_enforced(void);
926 
module_sig_ok(struct module * module)927 static inline bool module_sig_ok(struct module *module)
928 {
929 	return module->sig_ok;
930 }
931 #else	/* !CONFIG_MODULE_SIG */
is_module_sig_enforced(void)932 static inline bool is_module_sig_enforced(void)
933 {
934 	return false;
935 }
936 
set_module_sig_enforced(void)937 static inline void set_module_sig_enforced(void)
938 {
939 }
940 
module_sig_ok(struct module * module)941 static inline bool module_sig_ok(struct module *module)
942 {
943 	return true;
944 }
945 #endif	/* CONFIG_MODULE_SIG */
946 
947 #if defined(CONFIG_MODULES) && defined(CONFIG_KALLSYMS)
948 int module_kallsyms_on_each_symbol(const char *modname,
949 				   int (*fn)(void *, const char *, unsigned long),
950 				   void *data);
951 
952 /* For kallsyms to ask for address resolution.  namebuf should be at
953  * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
954  * found, otherwise NULL.
955  */
956 int module_address_lookup(unsigned long addr,
957 			  unsigned long *symbolsize,
958 			  unsigned long *offset,
959 			  char **modname, const unsigned char **modbuildid,
960 			  char *namebuf);
961 int lookup_module_symbol_name(unsigned long addr, char *symname);
962 int lookup_module_symbol_attrs(unsigned long addr,
963 			       unsigned long *size,
964 			       unsigned long *offset,
965 			       char *modname,
966 			       char *name);
967 
968 /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
969  * symnum out of range.
970  */
971 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
972 		       char *name, char *module_name, int *exported);
973 
974 /* Look for this name: can be of form module:name. */
975 unsigned long module_kallsyms_lookup_name(const char *name);
976 
977 unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name);
978 
979 #else	/* CONFIG_MODULES && CONFIG_KALLSYMS */
980 
module_kallsyms_on_each_symbol(const char * modname,int (* fn)(void *,const char *,unsigned long),void * data)981 static inline int module_kallsyms_on_each_symbol(const char *modname,
982 						 int (*fn)(void *, const char *, unsigned long),
983 						 void *data)
984 {
985 	return -EOPNOTSUPP;
986 }
987 
988 /* For kallsyms to ask for address resolution.  NULL means not found. */
module_address_lookup(unsigned long addr,unsigned long * symbolsize,unsigned long * offset,char ** modname,const unsigned char ** modbuildid,char * namebuf)989 static inline int module_address_lookup(unsigned long addr,
990 						unsigned long *symbolsize,
991 						unsigned long *offset,
992 						char **modname,
993 						const unsigned char **modbuildid,
994 						char *namebuf)
995 {
996 	return 0;
997 }
998 
lookup_module_symbol_name(unsigned long addr,char * symname)999 static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
1000 {
1001 	return -ERANGE;
1002 }
1003 
module_get_kallsym(unsigned int symnum,unsigned long * value,char * type,char * name,char * module_name,int * exported)1004 static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
1005 				     char *type, char *name,
1006 				     char *module_name, int *exported)
1007 {
1008 	return -ERANGE;
1009 }
1010 
module_kallsyms_lookup_name(const char * name)1011 static inline unsigned long module_kallsyms_lookup_name(const char *name)
1012 {
1013 	return 0;
1014 }
1015 
find_kallsyms_symbol_value(struct module * mod,const char * name)1016 static inline unsigned long find_kallsyms_symbol_value(struct module *mod,
1017 						       const char *name)
1018 {
1019 	return 0;
1020 }
1021 
1022 #endif  /* CONFIG_MODULES && CONFIG_KALLSYMS */
1023 
1024 /* Define __free(module_put) macro for struct module *. */
1025 DEFINE_FREE(module_put, struct module *, if (_T) module_put(_T))
1026 
1027 #endif /* _LINUX_MODULE_H */
1028