xref: /linux-6.15/include/linux/module.h (revision 8341eee8)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Dynamic loading of modules into the kernel.
4  *
5  * Rewritten by Richard Henderson <[email protected]> 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/kmod.h>
18 #include <linux/init.h>
19 #include <linux/elf.h>
20 #include <linux/stringify.h>
21 #include <linux/kobject.h>
22 #include <linux/moduleparam.h>
23 #include <linux/jump_label.h>
24 #include <linux/export.h>
25 #include <linux/rbtree_latch.h>
26 #include <linux/error-injection.h>
27 #include <linux/tracepoint-defs.h>
28 #include <linux/srcu.h>
29 #include <linux/static_call_types.h>
30 #include <linux/dynamic_debug.h>
31 
32 #include <linux/percpu.h>
33 #include <asm/module.h>
34 
35 #define MODULE_NAME_LEN MAX_PARAM_PREFIX_LEN
36 
37 struct modversion_info {
38 	unsigned long crc;
39 	char name[MODULE_NAME_LEN];
40 };
41 
42 struct module;
43 struct exception_table_entry;
44 
45 struct module_kobject {
46 	struct kobject kobj;
47 	struct module *mod;
48 	struct kobject *drivers_dir;
49 	struct module_param_attrs *mp;
50 	struct completion *kobj_completion;
51 } __randomize_layout;
52 
53 struct module_attribute {
54 	struct attribute attr;
55 	ssize_t (*show)(struct module_attribute *, struct module_kobject *,
56 			char *);
57 	ssize_t (*store)(struct module_attribute *, struct module_kobject *,
58 			 const char *, size_t count);
59 	void (*setup)(struct module *, const char *);
60 	int (*test)(struct module *);
61 	void (*free)(struct module *);
62 };
63 
64 struct module_version_attribute {
65 	struct module_attribute mattr;
66 	const char *module_name;
67 	const char *version;
68 };
69 
70 extern ssize_t __modver_version_show(struct module_attribute *,
71 				     struct module_kobject *, char *);
72 
73 extern struct module_attribute module_uevent;
74 
75 /* These are either module local, or the kernel's dummy ones. */
76 extern int init_module(void);
77 extern void cleanup_module(void);
78 
79 #ifndef MODULE
80 /**
81  * module_init() - driver initialization entry point
82  * @x: function to be run at kernel boot time or module insertion
83  *
84  * module_init() will either be called during do_initcalls() (if
85  * builtin) or at module insertion time (if a module).  There can only
86  * be one per module.
87  */
88 #define module_init(x)	__initcall(x);
89 
90 /**
91  * module_exit() - driver exit entry point
92  * @x: function to be run when driver is removed
93  *
94  * module_exit() will wrap the driver clean-up code
95  * with cleanup_module() when used with rmmod when
96  * the driver is a module.  If the driver is statically
97  * compiled into the kernel, module_exit() has no effect.
98  * There can only be one per module.
99  */
100 #define module_exit(x)	__exitcall(x);
101 
102 #else /* MODULE */
103 
104 /*
105  * In most cases loadable modules do not need custom
106  * initcall levels. There are still some valid cases where
107  * a driver may be needed early if built in, and does not
108  * matter when built as a loadable module. Like bus
109  * snooping debug drivers.
110  */
111 #define early_initcall(fn)		module_init(fn)
112 #define core_initcall(fn)		module_init(fn)
113 #define core_initcall_sync(fn)		module_init(fn)
114 #define postcore_initcall(fn)		module_init(fn)
115 #define postcore_initcall_sync(fn)	module_init(fn)
116 #define arch_initcall(fn)		module_init(fn)
117 #define subsys_initcall(fn)		module_init(fn)
118 #define subsys_initcall_sync(fn)	module_init(fn)
119 #define fs_initcall(fn)			module_init(fn)
120 #define fs_initcall_sync(fn)		module_init(fn)
121 #define rootfs_initcall(fn)		module_init(fn)
122 #define device_initcall(fn)		module_init(fn)
123 #define device_initcall_sync(fn)	module_init(fn)
124 #define late_initcall(fn)		module_init(fn)
125 #define late_initcall_sync(fn)		module_init(fn)
126 
127 #define console_initcall(fn)		module_init(fn)
128 
129 /* Each module must use one module_init(). */
130 #define module_init(initfn)					\
131 	static inline initcall_t __maybe_unused __inittest(void)		\
132 	{ return initfn; }					\
133 	int init_module(void) __copy(initfn)			\
134 		__attribute__((alias(#initfn)));		\
135 	___ADDRESSABLE(init_module, __initdata);
136 
137 /* This is only required if you want to be unloadable. */
138 #define module_exit(exitfn)					\
139 	static inline exitcall_t __maybe_unused __exittest(void)		\
140 	{ return exitfn; }					\
141 	void cleanup_module(void) __copy(exitfn)		\
142 		__attribute__((alias(#exitfn)));		\
143 	___ADDRESSABLE(cleanup_module, __exitdata);
144 
145 #endif
146 
147 /* This means "can be init if no module support, otherwise module load
148    may call it." */
149 #ifdef CONFIG_MODULES
150 #define __init_or_module
151 #define __initdata_or_module
152 #define __initconst_or_module
153 #define __INIT_OR_MODULE	.text
154 #define __INITDATA_OR_MODULE	.data
155 #define __INITRODATA_OR_MODULE	.section ".rodata","a",%progbits
156 #else
157 #define __init_or_module __init
158 #define __initdata_or_module __initdata
159 #define __initconst_or_module __initconst
160 #define __INIT_OR_MODULE __INIT
161 #define __INITDATA_OR_MODULE __INITDATA
162 #define __INITRODATA_OR_MODULE __INITRODATA
163 #endif /*CONFIG_MODULES*/
164 
165 /* Generic info of form tag = "info" */
166 #define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info)
167 
168 /* For userspace: you can also call me... */
169 #define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)
170 
171 /* Soft module dependencies. See man modprobe.d for details.
172  * Example: MODULE_SOFTDEP("pre: module-foo module-bar post: module-baz")
173  */
174 #define MODULE_SOFTDEP(_softdep) MODULE_INFO(softdep, _softdep)
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 #ifdef MODULE
242 /* Creates an alias so file2alias.c can find device table. */
243 #define MODULE_DEVICE_TABLE(type, name)					\
244 extern typeof(name) __mod_##type##__##name##_device_table		\
245   __attribute__ ((unused, alias(__stringify(name))))
246 #else  /* !MODULE */
247 #define MODULE_DEVICE_TABLE(type, name)
248 #endif
249 
250 /* Version of form [<epoch>:]<version>[-<extra-version>].
251  * Or for CVS/RCS ID version, everything but the number is stripped.
252  * <epoch>: A (small) unsigned integer which allows you to start versions
253  * anew. If not mentioned, it's zero.  eg. "2:1.0" is after
254  * "1:2.0".
255 
256  * <version>: The <version> may contain only alphanumerics and the
257  * character `.'.  Ordered by numeric sort for numeric parts,
258  * ascii sort for ascii parts (as per RPM or DEB algorithm).
259 
260  * <extraversion>: Like <version>, but inserted for local
261  * customizations, eg "rh3" or "rusty1".
262 
263  * Using this automatically adds a checksum of the .c files and the
264  * local headers in "srcversion".
265  */
266 
267 #if defined(MODULE) || !defined(CONFIG_SYSFS)
268 #define MODULE_VERSION(_version) MODULE_INFO(version, _version)
269 #else
270 #define MODULE_VERSION(_version)					\
271 	MODULE_INFO(version, _version);					\
272 	static struct module_version_attribute __modver_attr		\
273 		__used __section("__modver")				\
274 		__aligned(__alignof__(struct module_version_attribute)) \
275 		= {							\
276 			.mattr	= {					\
277 				.attr	= {				\
278 					.name	= "version",		\
279 					.mode	= S_IRUGO,		\
280 				},					\
281 				.show	= __modver_version_show,	\
282 			},						\
283 			.module_name	= KBUILD_MODNAME,		\
284 			.version	= _version,			\
285 		}
286 #endif
287 
288 /* Optional firmware file (or files) needed by the module
289  * format is simply firmware file name.  Multiple firmware
290  * files require multiple MODULE_FIRMWARE() specifiers */
291 #define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
292 
293 #define MODULE_IMPORT_NS(ns)	MODULE_INFO(import_ns, __stringify(ns))
294 
295 struct notifier_block;
296 
297 #ifdef CONFIG_MODULES
298 
299 extern int modules_disabled; /* for sysctl */
300 /* Get/put a kernel symbol (calls must be symmetric) */
301 void *__symbol_get(const char *symbol);
302 void *__symbol_get_gpl(const char *symbol);
303 #define symbol_get(x) ((typeof(&x))(__symbol_get(__stringify(x))))
304 
305 /* modules using other modules: kdb wants to see this. */
306 struct module_use {
307 	struct list_head source_list;
308 	struct list_head target_list;
309 	struct module *source, *target;
310 };
311 
312 enum module_state {
313 	MODULE_STATE_LIVE,	/* Normal state. */
314 	MODULE_STATE_COMING,	/* Full formed, running module_init. */
315 	MODULE_STATE_GOING,	/* Going away. */
316 	MODULE_STATE_UNFORMED,	/* Still setting it up. */
317 };
318 
319 struct mod_tree_node {
320 	struct module *mod;
321 	struct latch_tree_node node;
322 };
323 
324 enum mod_mem_type {
325 	MOD_TEXT = 0,
326 	MOD_DATA,
327 	MOD_RODATA,
328 	MOD_RO_AFTER_INIT,
329 	MOD_INIT_TEXT,
330 	MOD_INIT_DATA,
331 	MOD_INIT_RODATA,
332 
333 	MOD_MEM_NUM_TYPES,
334 	MOD_INVALID = -1,
335 };
336 
337 #define mod_mem_type_is_init(type)	\
338 	((type) == MOD_INIT_TEXT ||	\
339 	 (type) == MOD_INIT_DATA ||	\
340 	 (type) == MOD_INIT_RODATA)
341 
342 #define mod_mem_type_is_core(type) (!mod_mem_type_is_init(type))
343 
344 #define mod_mem_type_is_text(type)	\
345 	 ((type) == MOD_TEXT ||		\
346 	  (type) == MOD_INIT_TEXT)
347 
348 #define mod_mem_type_is_data(type) (!mod_mem_type_is_text(type))
349 
350 #define mod_mem_type_is_core_data(type)	\
351 	(mod_mem_type_is_core(type) &&	\
352 	 mod_mem_type_is_data(type))
353 
354 #define for_each_mod_mem_type(type)			\
355 	for (enum mod_mem_type (type) = 0;		\
356 	     (type) < MOD_MEM_NUM_TYPES; (type)++)
357 
358 #define for_class_mod_mem_type(type, class)		\
359 	for_each_mod_mem_type(type)			\
360 		if (mod_mem_type_is_##class(type))
361 
362 struct module_memory {
363 	void *base;
364 	unsigned int size;
365 
366 #ifdef CONFIG_MODULES_TREE_LOOKUP
367 	struct mod_tree_node mtn;
368 #endif
369 };
370 
371 #ifdef CONFIG_MODULES_TREE_LOOKUP
372 /* Only touch one cacheline for common rbtree-for-core-layout case. */
373 #define __module_memory_align ____cacheline_aligned
374 #else
375 #define __module_memory_align
376 #endif
377 
378 struct mod_kallsyms {
379 	Elf_Sym *symtab;
380 	unsigned int num_symtab;
381 	char *strtab;
382 	char *typetab;
383 };
384 
385 #ifdef CONFIG_LIVEPATCH
386 /**
387  * struct klp_modinfo - ELF information preserved from the livepatch module
388  *
389  * @hdr: ELF header
390  * @sechdrs: Section header table
391  * @secstrings: String table for the section headers
392  * @symndx: The symbol table section index
393  */
394 struct klp_modinfo {
395 	Elf_Ehdr hdr;
396 	Elf_Shdr *sechdrs;
397 	char *secstrings;
398 	unsigned int symndx;
399 };
400 #endif
401 
402 struct module {
403 	enum module_state state;
404 
405 	/* Member of list of modules */
406 	struct list_head list;
407 
408 	/* Unique handle for this module */
409 	char name[MODULE_NAME_LEN];
410 
411 #ifdef CONFIG_STACKTRACE_BUILD_ID
412 	/* Module build ID */
413 	unsigned char build_id[BUILD_ID_SIZE_MAX];
414 #endif
415 
416 	/* Sysfs stuff. */
417 	struct module_kobject mkobj;
418 	struct module_attribute *modinfo_attrs;
419 	const char *version;
420 	const char *srcversion;
421 	struct kobject *holders_dir;
422 
423 	/* Exported symbols */
424 	const struct kernel_symbol *syms;
425 	const s32 *crcs;
426 	unsigned int num_syms;
427 
428 #ifdef CONFIG_ARCH_USES_CFI_TRAPS
429 	s32 *kcfi_traps;
430 	s32 *kcfi_traps_end;
431 #endif
432 
433 	/* Kernel parameters. */
434 #ifdef CONFIG_SYSFS
435 	struct mutex param_lock;
436 #endif
437 	struct kernel_param *kp;
438 	unsigned int num_kp;
439 
440 	/* GPL-only exported symbols. */
441 	unsigned int num_gpl_syms;
442 	const struct kernel_symbol *gpl_syms;
443 	const s32 *gpl_crcs;
444 	bool using_gplonly_symbols;
445 
446 #ifdef CONFIG_MODULE_SIG
447 	/* Signature was verified. */
448 	bool sig_ok;
449 #endif
450 
451 	bool async_probe_requested;
452 
453 	/* Exception table */
454 	unsigned int num_exentries;
455 	struct exception_table_entry *extable;
456 
457 	/* Startup function. */
458 	int (*init)(void);
459 
460 	struct module_memory mem[MOD_MEM_NUM_TYPES] __module_memory_align;
461 
462 	/* Arch-specific module values */
463 	struct mod_arch_specific arch;
464 
465 	unsigned long taints;	/* same bits as kernel:taint_flags */
466 
467 #ifdef CONFIG_GENERIC_BUG
468 	/* Support for BUG */
469 	unsigned num_bugs;
470 	struct list_head bug_list;
471 	struct bug_entry *bug_table;
472 #endif
473 
474 #ifdef CONFIG_KALLSYMS
475 	/* Protected by RCU and/or module_mutex: use rcu_dereference() */
476 	struct mod_kallsyms __rcu *kallsyms;
477 	struct mod_kallsyms core_kallsyms;
478 
479 	/* Section attributes */
480 	struct module_sect_attrs *sect_attrs;
481 
482 	/* Notes attributes */
483 	struct module_notes_attrs *notes_attrs;
484 #endif
485 
486 	/* The command line arguments (may be mangled).  People like
487 	   keeping pointers to this stuff */
488 	char *args;
489 
490 #ifdef CONFIG_SMP
491 	/* Per-cpu data. */
492 	void __percpu *percpu;
493 	unsigned int percpu_size;
494 #endif
495 	void *noinstr_text_start;
496 	unsigned int noinstr_text_size;
497 
498 #ifdef CONFIG_TRACEPOINTS
499 	unsigned int num_tracepoints;
500 	tracepoint_ptr_t *tracepoints_ptrs;
501 #endif
502 #ifdef CONFIG_TREE_SRCU
503 	unsigned int num_srcu_structs;
504 	struct srcu_struct **srcu_struct_ptrs;
505 #endif
506 #ifdef CONFIG_BPF_EVENTS
507 	unsigned int num_bpf_raw_events;
508 	struct bpf_raw_event_map *bpf_raw_events;
509 #endif
510 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
511 	unsigned int btf_data_size;
512 	unsigned int btf_base_data_size;
513 	void *btf_data;
514 	void *btf_base_data;
515 #endif
516 #ifdef CONFIG_JUMP_LABEL
517 	struct jump_entry *jump_entries;
518 	unsigned int num_jump_entries;
519 #endif
520 #ifdef CONFIG_TRACING
521 	unsigned int num_trace_bprintk_fmt;
522 	const char **trace_bprintk_fmt_start;
523 #endif
524 #ifdef CONFIG_EVENT_TRACING
525 	struct trace_event_call **trace_events;
526 	unsigned int num_trace_events;
527 	struct trace_eval_map **trace_evals;
528 	unsigned int num_trace_evals;
529 #endif
530 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
531 	unsigned int num_ftrace_callsites;
532 	unsigned long *ftrace_callsites;
533 #endif
534 #ifdef CONFIG_KPROBES
535 	void *kprobes_text_start;
536 	unsigned int kprobes_text_size;
537 	unsigned long *kprobe_blacklist;
538 	unsigned int num_kprobe_blacklist;
539 #endif
540 #ifdef CONFIG_HAVE_STATIC_CALL_INLINE
541 	int num_static_call_sites;
542 	struct static_call_site *static_call_sites;
543 #endif
544 #if IS_ENABLED(CONFIG_KUNIT)
545 	int num_kunit_init_suites;
546 	struct kunit_suite **kunit_init_suites;
547 	int num_kunit_suites;
548 	struct kunit_suite **kunit_suites;
549 #endif
550 
551 
552 #ifdef CONFIG_LIVEPATCH
553 	bool klp; /* Is this a livepatch module? */
554 	bool klp_alive;
555 
556 	/* ELF information */
557 	struct klp_modinfo *klp_info;
558 #endif
559 
560 #ifdef CONFIG_PRINTK_INDEX
561 	unsigned int printk_index_size;
562 	struct pi_entry **printk_index_start;
563 #endif
564 
565 #ifdef CONFIG_MODULE_UNLOAD
566 	/* What modules depend on me? */
567 	struct list_head source_list;
568 	/* What modules do I depend on? */
569 	struct list_head target_list;
570 
571 	/* Destruction function. */
572 	void (*exit)(void);
573 
574 	atomic_t refcnt;
575 #endif
576 
577 #ifdef CONFIG_CONSTRUCTORS
578 	/* Constructor functions. */
579 	ctor_fn_t *ctors;
580 	unsigned int num_ctors;
581 #endif
582 
583 #ifdef CONFIG_FUNCTION_ERROR_INJECTION
584 	struct error_injection_entry *ei_funcs;
585 	unsigned int num_ei_funcs;
586 #endif
587 #ifdef CONFIG_DYNAMIC_DEBUG_CORE
588 	struct _ddebug_info dyndbg_info;
589 #endif
590 } ____cacheline_aligned __randomize_layout;
591 #ifndef MODULE_ARCH_INIT
592 #define MODULE_ARCH_INIT {}
593 #endif
594 
595 #ifndef HAVE_ARCH_KALLSYMS_SYMBOL_VALUE
596 static inline unsigned long kallsyms_symbol_value(const Elf_Sym *sym)
597 {
598 	return sym->st_value;
599 }
600 #endif
601 
602 /* FIXME: It'd be nice to isolate modules during init, too, so they
603    aren't used before they (may) fail.  But presently too much code
604    (IDE & SCSI) require entry into the module during init.*/
605 static inline bool module_is_live(struct module *mod)
606 {
607 	return mod->state != MODULE_STATE_GOING;
608 }
609 
610 static inline bool module_is_coming(struct module *mod)
611 {
612         return mod->state == MODULE_STATE_COMING;
613 }
614 
615 struct module *__module_text_address(unsigned long addr);
616 struct module *__module_address(unsigned long addr);
617 bool is_module_address(unsigned long addr);
618 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr);
619 bool is_module_percpu_address(unsigned long addr);
620 bool is_module_text_address(unsigned long addr);
621 
622 static inline bool within_module_mem_type(unsigned long addr,
623 					  const struct module *mod,
624 					  enum mod_mem_type type)
625 {
626 	unsigned long base, size;
627 
628 	base = (unsigned long)mod->mem[type].base;
629 	size = mod->mem[type].size;
630 	return addr - base < size;
631 }
632 
633 static inline bool within_module_core(unsigned long addr,
634 				      const struct module *mod)
635 {
636 	for_class_mod_mem_type(type, core) {
637 		if (within_module_mem_type(addr, mod, type))
638 			return true;
639 	}
640 	return false;
641 }
642 
643 static inline bool within_module_init(unsigned long addr,
644 				      const struct module *mod)
645 {
646 	for_class_mod_mem_type(type, init) {
647 		if (within_module_mem_type(addr, mod, type))
648 			return true;
649 	}
650 	return false;
651 }
652 
653 static inline bool within_module(unsigned long addr, const struct module *mod)
654 {
655 	return within_module_init(addr, mod) || within_module_core(addr, mod);
656 }
657 
658 /* Search for module by name: must be in a RCU-sched critical section. */
659 struct module *find_module(const char *name);
660 
661 extern void __noreturn __module_put_and_kthread_exit(struct module *mod,
662 			long code);
663 #define module_put_and_kthread_exit(code) __module_put_and_kthread_exit(THIS_MODULE, code)
664 
665 #ifdef CONFIG_MODULE_UNLOAD
666 int module_refcount(struct module *mod);
667 void __symbol_put(const char *symbol);
668 #define symbol_put(x) __symbol_put(__stringify(x))
669 void symbol_put_addr(void *addr);
670 
671 /* Sometimes we know we already have a refcount, and it's easier not
672    to handle the error case (which only happens with rmmod --wait). */
673 extern void __module_get(struct module *module);
674 
675 /**
676  * try_module_get() - take module refcount unless module is being removed
677  * @module: the module we should check for
678  *
679  * Only try to get a module reference count if the module is not being removed.
680  * This call will fail if the module is in the process of being removed.
681  *
682  * Care must also be taken to ensure the module exists and is alive prior to
683  * usage of this call. This can be gauranteed through two means:
684  *
685  * 1) Direct protection: you know an earlier caller must have increased the
686  *    module reference through __module_get(). This can typically be achieved
687  *    by having another entity other than the module itself increment the
688  *    module reference count.
689  *
690  * 2) Implied protection: there is an implied protection against module
691  *    removal. An example of this is the implied protection used by kernfs /
692  *    sysfs. The sysfs store / read file operations are guaranteed to exist
693  *    through the use of kernfs's active reference (see kernfs_active()) and a
694  *    sysfs / kernfs file removal cannot happen unless the same file is not
695  *    active. Therefore, if a sysfs file is being read or written to the module
696  *    which created it must still exist. It is therefore safe to use
697  *    try_module_get() on module sysfs store / read ops.
698  *
699  * One of the real values to try_module_get() is the module_is_live() check
700  * which ensures that the caller of try_module_get() can yield to userspace
701  * module removal requests and gracefully fail if the module is on its way out.
702  *
703  * Returns true if the reference count was successfully incremented.
704  */
705 extern bool try_module_get(struct module *module);
706 
707 /**
708  * module_put() - release a reference count to a module
709  * @module: the module we should release a reference count for
710  *
711  * If you successfully bump a reference count to a module with try_module_get(),
712  * when you are finished you must call module_put() to release that reference
713  * count.
714  */
715 extern void module_put(struct module *module);
716 
717 #else /*!CONFIG_MODULE_UNLOAD*/
718 static inline bool try_module_get(struct module *module)
719 {
720 	return !module || module_is_live(module);
721 }
722 static inline void module_put(struct module *module)
723 {
724 }
725 static inline void __module_get(struct module *module)
726 {
727 }
728 #define symbol_put(x) do { } while (0)
729 #define symbol_put_addr(p) do { } while (0)
730 
731 #endif /* CONFIG_MODULE_UNLOAD */
732 
733 /* This is a #define so the string doesn't get put in every .o file */
734 #define module_name(mod)			\
735 ({						\
736 	struct module *__mod = (mod);		\
737 	__mod ? __mod->name : "kernel";		\
738 })
739 
740 /* Dereference module function descriptor */
741 void *dereference_module_function_descriptor(struct module *mod, void *ptr);
742 
743 int register_module_notifier(struct notifier_block *nb);
744 int unregister_module_notifier(struct notifier_block *nb);
745 
746 extern void print_modules(void);
747 
748 static inline bool module_requested_async_probing(struct module *module)
749 {
750 	return module && module->async_probe_requested;
751 }
752 
753 static inline bool is_livepatch_module(struct module *mod)
754 {
755 #ifdef CONFIG_LIVEPATCH
756 	return mod->klp;
757 #else
758 	return false;
759 #endif
760 }
761 
762 void set_module_sig_enforced(void);
763 
764 #else /* !CONFIG_MODULES... */
765 
766 static inline struct module *__module_address(unsigned long addr)
767 {
768 	return NULL;
769 }
770 
771 static inline struct module *__module_text_address(unsigned long addr)
772 {
773 	return NULL;
774 }
775 
776 static inline bool is_module_address(unsigned long addr)
777 {
778 	return false;
779 }
780 
781 static inline bool is_module_percpu_address(unsigned long addr)
782 {
783 	return false;
784 }
785 
786 static inline bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
787 {
788 	return false;
789 }
790 
791 static inline bool is_module_text_address(unsigned long addr)
792 {
793 	return false;
794 }
795 
796 static inline bool within_module_core(unsigned long addr,
797 				      const struct module *mod)
798 {
799 	return false;
800 }
801 
802 static inline bool within_module_init(unsigned long addr,
803 				      const struct module *mod)
804 {
805 	return false;
806 }
807 
808 static inline bool within_module(unsigned long addr, const struct module *mod)
809 {
810 	return false;
811 }
812 
813 /* Get/put a kernel symbol (calls should be symmetric) */
814 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak,visibility("hidden"))); &(x); })
815 #define symbol_put(x) do { } while (0)
816 #define symbol_put_addr(x) do { } while (0)
817 
818 static inline void __module_get(struct module *module)
819 {
820 }
821 
822 static inline bool try_module_get(struct module *module)
823 {
824 	return true;
825 }
826 
827 static inline void module_put(struct module *module)
828 {
829 }
830 
831 #define module_name(mod) "kernel"
832 
833 static inline int register_module_notifier(struct notifier_block *nb)
834 {
835 	/* no events will happen anyway, so this can always succeed */
836 	return 0;
837 }
838 
839 static inline int unregister_module_notifier(struct notifier_block *nb)
840 {
841 	return 0;
842 }
843 
844 #define module_put_and_kthread_exit(code) kthread_exit(code)
845 
846 static inline void print_modules(void)
847 {
848 }
849 
850 static inline bool module_requested_async_probing(struct module *module)
851 {
852 	return false;
853 }
854 
855 
856 static inline void set_module_sig_enforced(void)
857 {
858 }
859 
860 /* Dereference module function descriptor */
861 static inline
862 void *dereference_module_function_descriptor(struct module *mod, void *ptr)
863 {
864 	return ptr;
865 }
866 
867 static inline bool module_is_coming(struct module *mod)
868 {
869 	return false;
870 }
871 #endif /* CONFIG_MODULES */
872 
873 #ifdef CONFIG_SYSFS
874 extern struct kset *module_kset;
875 extern const struct kobj_type module_ktype;
876 #endif /* CONFIG_SYSFS */
877 
878 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
879 
880 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
881 
882 #define __MODULE_STRING(x) __stringify(x)
883 
884 #ifdef CONFIG_GENERIC_BUG
885 void module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *,
886 			 struct module *);
887 void module_bug_cleanup(struct module *);
888 
889 #else	/* !CONFIG_GENERIC_BUG */
890 
891 static inline void module_bug_finalize(const Elf_Ehdr *hdr,
892 					const Elf_Shdr *sechdrs,
893 					struct module *mod)
894 {
895 }
896 static inline void module_bug_cleanup(struct module *mod) {}
897 #endif	/* CONFIG_GENERIC_BUG */
898 
899 #ifdef CONFIG_MITIGATION_RETPOLINE
900 extern bool retpoline_module_ok(bool has_retpoline);
901 #else
902 static inline bool retpoline_module_ok(bool has_retpoline)
903 {
904 	return true;
905 }
906 #endif
907 
908 #ifdef CONFIG_MODULE_SIG
909 bool is_module_sig_enforced(void);
910 
911 static inline bool module_sig_ok(struct module *module)
912 {
913 	return module->sig_ok;
914 }
915 #else	/* !CONFIG_MODULE_SIG */
916 static inline bool is_module_sig_enforced(void)
917 {
918 	return false;
919 }
920 
921 static inline bool module_sig_ok(struct module *module)
922 {
923 	return true;
924 }
925 #endif	/* CONFIG_MODULE_SIG */
926 
927 #if defined(CONFIG_MODULES) && defined(CONFIG_KALLSYMS)
928 int module_kallsyms_on_each_symbol(const char *modname,
929 				   int (*fn)(void *, const char *, unsigned long),
930 				   void *data);
931 
932 /* For kallsyms to ask for address resolution.  namebuf should be at
933  * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
934  * found, otherwise NULL.
935  */
936 int module_address_lookup(unsigned long addr,
937 			  unsigned long *symbolsize,
938 			  unsigned long *offset,
939 			  char **modname, const unsigned char **modbuildid,
940 			  char *namebuf);
941 int lookup_module_symbol_name(unsigned long addr, char *symname);
942 int lookup_module_symbol_attrs(unsigned long addr,
943 			       unsigned long *size,
944 			       unsigned long *offset,
945 			       char *modname,
946 			       char *name);
947 
948 /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
949  * symnum out of range.
950  */
951 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
952 		       char *name, char *module_name, int *exported);
953 
954 /* Look for this name: can be of form module:name. */
955 unsigned long module_kallsyms_lookup_name(const char *name);
956 
957 unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name);
958 
959 #else	/* CONFIG_MODULES && CONFIG_KALLSYMS */
960 
961 static inline int module_kallsyms_on_each_symbol(const char *modname,
962 						 int (*fn)(void *, const char *, unsigned long),
963 						 void *data)
964 {
965 	return -EOPNOTSUPP;
966 }
967 
968 /* For kallsyms to ask for address resolution.  NULL means not found. */
969 static inline int module_address_lookup(unsigned long addr,
970 						unsigned long *symbolsize,
971 						unsigned long *offset,
972 						char **modname,
973 						const unsigned char **modbuildid,
974 						char *namebuf)
975 {
976 	return 0;
977 }
978 
979 static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
980 {
981 	return -ERANGE;
982 }
983 
984 static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
985 				     char *type, char *name,
986 				     char *module_name, int *exported)
987 {
988 	return -ERANGE;
989 }
990 
991 static inline unsigned long module_kallsyms_lookup_name(const char *name)
992 {
993 	return 0;
994 }
995 
996 static inline unsigned long find_kallsyms_symbol_value(struct module *mod,
997 						       const char *name)
998 {
999 	return 0;
1000 }
1001 
1002 #endif  /* CONFIG_MODULES && CONFIG_KALLSYMS */
1003 
1004 #endif /* _LINUX_MODULE_H */
1005