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/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 	void *btf_data;
513 #endif
514 #ifdef CONFIG_JUMP_LABEL
515 	struct jump_entry *jump_entries;
516 	unsigned int num_jump_entries;
517 #endif
518 #ifdef CONFIG_TRACING
519 	unsigned int num_trace_bprintk_fmt;
520 	const char **trace_bprintk_fmt_start;
521 #endif
522 #ifdef CONFIG_EVENT_TRACING
523 	struct trace_event_call **trace_events;
524 	unsigned int num_trace_events;
525 	struct trace_eval_map **trace_evals;
526 	unsigned int num_trace_evals;
527 #endif
528 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
529 	unsigned int num_ftrace_callsites;
530 	unsigned long *ftrace_callsites;
531 #endif
532 #ifdef CONFIG_KPROBES
533 	void *kprobes_text_start;
534 	unsigned int kprobes_text_size;
535 	unsigned long *kprobe_blacklist;
536 	unsigned int num_kprobe_blacklist;
537 #endif
538 #ifdef CONFIG_HAVE_STATIC_CALL_INLINE
539 	int num_static_call_sites;
540 	struct static_call_site *static_call_sites;
541 #endif
542 #if IS_ENABLED(CONFIG_KUNIT)
543 	int num_kunit_suites;
544 	struct kunit_suite **kunit_suites;
545 #endif
546 
547 
548 #ifdef CONFIG_LIVEPATCH
549 	bool klp; /* Is this a livepatch module? */
550 	bool klp_alive;
551 
552 	/* ELF information */
553 	struct klp_modinfo *klp_info;
554 #endif
555 
556 #ifdef CONFIG_PRINTK_INDEX
557 	unsigned int printk_index_size;
558 	struct pi_entry **printk_index_start;
559 #endif
560 
561 #ifdef CONFIG_MODULE_UNLOAD
562 	/* What modules depend on me? */
563 	struct list_head source_list;
564 	/* What modules do I depend on? */
565 	struct list_head target_list;
566 
567 	/* Destruction function. */
568 	void (*exit)(void);
569 
570 	atomic_t refcnt;
571 #endif
572 
573 #ifdef CONFIG_CONSTRUCTORS
574 	/* Constructor functions. */
575 	ctor_fn_t *ctors;
576 	unsigned int num_ctors;
577 #endif
578 
579 #ifdef CONFIG_FUNCTION_ERROR_INJECTION
580 	struct error_injection_entry *ei_funcs;
581 	unsigned int num_ei_funcs;
582 #endif
583 #ifdef CONFIG_DYNAMIC_DEBUG_CORE
584 	struct _ddebug_info dyndbg_info;
585 #endif
586 } ____cacheline_aligned __randomize_layout;
587 #ifndef MODULE_ARCH_INIT
588 #define MODULE_ARCH_INIT {}
589 #endif
590 
591 #ifndef HAVE_ARCH_KALLSYMS_SYMBOL_VALUE
kallsyms_symbol_value(const Elf_Sym * sym)592 static inline unsigned long kallsyms_symbol_value(const Elf_Sym *sym)
593 {
594 	return sym->st_value;
595 }
596 #endif
597 
598 /* FIXME: It'd be nice to isolate modules during init, too, so they
599    aren't used before they (may) fail.  But presently too much code
600    (IDE & SCSI) require entry into the module during init.*/
module_is_live(struct module * mod)601 static inline bool module_is_live(struct module *mod)
602 {
603 	return mod->state != MODULE_STATE_GOING;
604 }
605 
606 struct module *__module_text_address(unsigned long addr);
607 struct module *__module_address(unsigned long addr);
608 bool is_module_address(unsigned long addr);
609 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr);
610 bool is_module_percpu_address(unsigned long addr);
611 bool is_module_text_address(unsigned long addr);
612 
within_module_mem_type(unsigned long addr,const struct module * mod,enum mod_mem_type type)613 static inline bool within_module_mem_type(unsigned long addr,
614 					  const struct module *mod,
615 					  enum mod_mem_type type)
616 {
617 	unsigned long base, size;
618 
619 	base = (unsigned long)mod->mem[type].base;
620 	size = mod->mem[type].size;
621 	return addr - base < size;
622 }
623 
within_module_core(unsigned long addr,const struct module * mod)624 static inline bool within_module_core(unsigned long addr,
625 				      const struct module *mod)
626 {
627 	for_class_mod_mem_type(type, core) {
628 		if (within_module_mem_type(addr, mod, type))
629 			return true;
630 	}
631 	return false;
632 }
633 
within_module_init(unsigned long addr,const struct module * mod)634 static inline bool within_module_init(unsigned long addr,
635 				      const struct module *mod)
636 {
637 	for_class_mod_mem_type(type, init) {
638 		if (within_module_mem_type(addr, mod, type))
639 			return true;
640 	}
641 	return false;
642 }
643 
within_module(unsigned long addr,const struct module * mod)644 static inline bool within_module(unsigned long addr, const struct module *mod)
645 {
646 	return within_module_init(addr, mod) || within_module_core(addr, mod);
647 }
648 
649 /* Search for module by name: must be in a RCU-sched critical section. */
650 struct module *find_module(const char *name);
651 
652 extern void __noreturn __module_put_and_kthread_exit(struct module *mod,
653 			long code);
654 #define module_put_and_kthread_exit(code) __module_put_and_kthread_exit(THIS_MODULE, code)
655 
656 #ifdef CONFIG_MODULE_UNLOAD
657 int module_refcount(struct module *mod);
658 void __symbol_put(const char *symbol);
659 #define symbol_put(x) __symbol_put(__stringify(x))
660 void symbol_put_addr(void *addr);
661 
662 /* Sometimes we know we already have a refcount, and it's easier not
663    to handle the error case (which only happens with rmmod --wait). */
664 extern void __module_get(struct module *module);
665 
666 /**
667  * try_module_get() - take module refcount unless module is being removed
668  * @module: the module we should check for
669  *
670  * Only try to get a module reference count if the module is not being removed.
671  * This call will fail if the module is already being removed.
672  *
673  * Care must also be taken to ensure the module exists and is alive prior to
674  * usage of this call. This can be gauranteed through two means:
675  *
676  * 1) Direct protection: you know an earlier caller must have increased the
677  *    module reference through __module_get(). This can typically be achieved
678  *    by having another entity other than the module itself increment the
679  *    module reference count.
680  *
681  * 2) Implied protection: there is an implied protection against module
682  *    removal. An example of this is the implied protection used by kernfs /
683  *    sysfs. The sysfs store / read file operations are guaranteed to exist
684  *    through the use of kernfs's active reference (see kernfs_active()) and a
685  *    sysfs / kernfs file removal cannot happen unless the same file is not
686  *    active. Therefore, if a sysfs file is being read or written to the module
687  *    which created it must still exist. It is therefore safe to use
688  *    try_module_get() on module sysfs store / read ops.
689  *
690  * One of the real values to try_module_get() is the module_is_live() check
691  * which ensures that the caller of try_module_get() can yield to userspace
692  * module removal requests and gracefully fail if the module is on its way out.
693  *
694  * Returns true if the reference count was successfully incremented.
695  */
696 extern bool try_module_get(struct module *module);
697 
698 /**
699  * module_put() - release a reference count to a module
700  * @module: the module we should release a reference count for
701  *
702  * If you successfully bump a reference count to a module with try_module_get(),
703  * when you are finished you must call module_put() to release that reference
704  * count.
705  */
706 extern void module_put(struct module *module);
707 
708 #else /*!CONFIG_MODULE_UNLOAD*/
try_module_get(struct module * module)709 static inline bool try_module_get(struct module *module)
710 {
711 	return !module || module_is_live(module);
712 }
module_put(struct module * module)713 static inline void module_put(struct module *module)
714 {
715 }
__module_get(struct module * module)716 static inline void __module_get(struct module *module)
717 {
718 }
719 #define symbol_put(x) do { } while (0)
720 #define symbol_put_addr(p) do { } while (0)
721 
722 #endif /* CONFIG_MODULE_UNLOAD */
723 
724 /* This is a #define so the string doesn't get put in every .o file */
725 #define module_name(mod)			\
726 ({						\
727 	struct module *__mod = (mod);		\
728 	__mod ? __mod->name : "kernel";		\
729 })
730 
731 /* Dereference module function descriptor */
732 void *dereference_module_function_descriptor(struct module *mod, void *ptr);
733 
734 int register_module_notifier(struct notifier_block *nb);
735 int unregister_module_notifier(struct notifier_block *nb);
736 
737 extern void print_modules(void);
738 
module_requested_async_probing(struct module * module)739 static inline bool module_requested_async_probing(struct module *module)
740 {
741 	return module && module->async_probe_requested;
742 }
743 
is_livepatch_module(struct module * mod)744 static inline bool is_livepatch_module(struct module *mod)
745 {
746 #ifdef CONFIG_LIVEPATCH
747 	return mod->klp;
748 #else
749 	return false;
750 #endif
751 }
752 
753 void set_module_sig_enforced(void);
754 
755 #else /* !CONFIG_MODULES... */
756 
__module_address(unsigned long addr)757 static inline struct module *__module_address(unsigned long addr)
758 {
759 	return NULL;
760 }
761 
__module_text_address(unsigned long addr)762 static inline struct module *__module_text_address(unsigned long addr)
763 {
764 	return NULL;
765 }
766 
is_module_address(unsigned long addr)767 static inline bool is_module_address(unsigned long addr)
768 {
769 	return false;
770 }
771 
is_module_percpu_address(unsigned long addr)772 static inline bool is_module_percpu_address(unsigned long addr)
773 {
774 	return false;
775 }
776 
__is_module_percpu_address(unsigned long addr,unsigned long * can_addr)777 static inline bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
778 {
779 	return false;
780 }
781 
is_module_text_address(unsigned long addr)782 static inline bool is_module_text_address(unsigned long addr)
783 {
784 	return false;
785 }
786 
within_module_core(unsigned long addr,const struct module * mod)787 static inline bool within_module_core(unsigned long addr,
788 				      const struct module *mod)
789 {
790 	return false;
791 }
792 
within_module_init(unsigned long addr,const struct module * mod)793 static inline bool within_module_init(unsigned long addr,
794 				      const struct module *mod)
795 {
796 	return false;
797 }
798 
within_module(unsigned long addr,const struct module * mod)799 static inline bool within_module(unsigned long addr, const struct module *mod)
800 {
801 	return false;
802 }
803 
804 /* Get/put a kernel symbol (calls should be symmetric) */
805 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak,visibility("hidden"))); &(x); })
806 #define symbol_put(x) do { } while (0)
807 #define symbol_put_addr(x) do { } while (0)
808 
__module_get(struct module * module)809 static inline void __module_get(struct module *module)
810 {
811 }
812 
try_module_get(struct module * module)813 static inline bool try_module_get(struct module *module)
814 {
815 	return true;
816 }
817 
module_put(struct module * module)818 static inline void module_put(struct module *module)
819 {
820 }
821 
822 #define module_name(mod) "kernel"
823 
register_module_notifier(struct notifier_block * nb)824 static inline int register_module_notifier(struct notifier_block *nb)
825 {
826 	/* no events will happen anyway, so this can always succeed */
827 	return 0;
828 }
829 
unregister_module_notifier(struct notifier_block * nb)830 static inline int unregister_module_notifier(struct notifier_block *nb)
831 {
832 	return 0;
833 }
834 
835 #define module_put_and_kthread_exit(code) kthread_exit(code)
836 
print_modules(void)837 static inline void print_modules(void)
838 {
839 }
840 
module_requested_async_probing(struct module * module)841 static inline bool module_requested_async_probing(struct module *module)
842 {
843 	return false;
844 }
845 
846 
set_module_sig_enforced(void)847 static inline void set_module_sig_enforced(void)
848 {
849 }
850 
851 /* Dereference module function descriptor */
852 static inline
dereference_module_function_descriptor(struct module * mod,void * ptr)853 void *dereference_module_function_descriptor(struct module *mod, void *ptr)
854 {
855 	return ptr;
856 }
857 
858 #endif /* CONFIG_MODULES */
859 
860 #ifdef CONFIG_SYSFS
861 extern struct kset *module_kset;
862 extern const struct kobj_type module_ktype;
863 #endif /* CONFIG_SYSFS */
864 
865 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
866 
867 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
868 
869 #define __MODULE_STRING(x) __stringify(x)
870 
871 #ifdef CONFIG_GENERIC_BUG
872 void module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *,
873 			 struct module *);
874 void module_bug_cleanup(struct module *);
875 
876 #else	/* !CONFIG_GENERIC_BUG */
877 
module_bug_finalize(const Elf_Ehdr * hdr,const Elf_Shdr * sechdrs,struct module * mod)878 static inline void module_bug_finalize(const Elf_Ehdr *hdr,
879 					const Elf_Shdr *sechdrs,
880 					struct module *mod)
881 {
882 }
module_bug_cleanup(struct module * mod)883 static inline void module_bug_cleanup(struct module *mod) {}
884 #endif	/* CONFIG_GENERIC_BUG */
885 
886 #ifdef CONFIG_RETPOLINE
887 extern bool retpoline_module_ok(bool has_retpoline);
888 #else
retpoline_module_ok(bool has_retpoline)889 static inline bool retpoline_module_ok(bool has_retpoline)
890 {
891 	return true;
892 }
893 #endif
894 
895 #ifdef CONFIG_MODULE_SIG
896 bool is_module_sig_enforced(void);
897 
module_sig_ok(struct module * module)898 static inline bool module_sig_ok(struct module *module)
899 {
900 	return module->sig_ok;
901 }
902 #else	/* !CONFIG_MODULE_SIG */
is_module_sig_enforced(void)903 static inline bool is_module_sig_enforced(void)
904 {
905 	return false;
906 }
907 
module_sig_ok(struct module * module)908 static inline bool module_sig_ok(struct module *module)
909 {
910 	return true;
911 }
912 #endif	/* CONFIG_MODULE_SIG */
913 
914 #if defined(CONFIG_MODULES) && defined(CONFIG_KALLSYMS)
915 int module_kallsyms_on_each_symbol(const char *modname,
916 				   int (*fn)(void *, const char *, unsigned long),
917 				   void *data);
918 
919 /* For kallsyms to ask for address resolution.  namebuf should be at
920  * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
921  * found, otherwise NULL.
922  */
923 const char *module_address_lookup(unsigned long addr,
924 				  unsigned long *symbolsize,
925 				  unsigned long *offset,
926 				  char **modname, const unsigned char **modbuildid,
927 				  char *namebuf);
928 int lookup_module_symbol_name(unsigned long addr, char *symname);
929 int lookup_module_symbol_attrs(unsigned long addr,
930 			       unsigned long *size,
931 			       unsigned long *offset,
932 			       char *modname,
933 			       char *name);
934 
935 /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
936  * symnum out of range.
937  */
938 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
939 		       char *name, char *module_name, int *exported);
940 
941 /* Look for this name: can be of form module:name. */
942 unsigned long module_kallsyms_lookup_name(const char *name);
943 
944 unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name);
945 
946 #else	/* CONFIG_MODULES && CONFIG_KALLSYMS */
947 
module_kallsyms_on_each_symbol(const char * modname,int (* fn)(void *,const char *,unsigned long),void * data)948 static inline int module_kallsyms_on_each_symbol(const char *modname,
949 						 int (*fn)(void *, const char *, unsigned long),
950 						 void *data)
951 {
952 	return -EOPNOTSUPP;
953 }
954 
955 /* 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)956 static inline const char *module_address_lookup(unsigned long addr,
957 						unsigned long *symbolsize,
958 						unsigned long *offset,
959 						char **modname,
960 						const unsigned char **modbuildid,
961 						char *namebuf)
962 {
963 	return NULL;
964 }
965 
lookup_module_symbol_name(unsigned long addr,char * symname)966 static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
967 {
968 	return -ERANGE;
969 }
970 
module_get_kallsym(unsigned int symnum,unsigned long * value,char * type,char * name,char * module_name,int * exported)971 static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
972 				     char *type, char *name,
973 				     char *module_name, int *exported)
974 {
975 	return -ERANGE;
976 }
977 
module_kallsyms_lookup_name(const char * name)978 static inline unsigned long module_kallsyms_lookup_name(const char *name)
979 {
980 	return 0;
981 }
982 
find_kallsyms_symbol_value(struct module * mod,const char * name)983 static inline unsigned long find_kallsyms_symbol_value(struct module *mod,
984 						       const char *name)
985 {
986 	return 0;
987 }
988 
989 #endif  /* CONFIG_MODULES && CONFIG_KALLSYMS */
990 
991 #endif /* _LINUX_MODULE_H */
992