xref: /openbmc/linux/include/linux/module.h (revision 098c0a373cdd51d3a735da7394acd6e57fae45a0)
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 struct module_kobject *lookup_or_create_module_kobject(const char *name);
166 
167 /* Generic info of form tag = "info" */
168 #define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info)
169 
170 /* For userspace: you can also call me... */
171 #define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)
172 
173 /* Soft module dependencies. See man modprobe.d for details.
174  * Example: MODULE_SOFTDEP("pre: module-foo module-bar post: module-baz")
175  */
176 #define MODULE_SOFTDEP(_softdep) MODULE_INFO(softdep, _softdep)
177 
178 /*
179  * MODULE_FILE is used for generating modules.builtin
180  * So, make it no-op when this is being built as a module
181  */
182 #ifdef MODULE
183 #define MODULE_FILE
184 #else
185 #define MODULE_FILE	MODULE_INFO(file, KBUILD_MODFILE);
186 #endif
187 
188 /*
189  * The following license idents are currently accepted as indicating free
190  * software modules
191  *
192  *	"GPL"				[GNU Public License v2]
193  *	"GPL v2"			[GNU Public License v2]
194  *	"GPL and additional rights"	[GNU Public License v2 rights and more]
195  *	"Dual BSD/GPL"			[GNU Public License v2
196  *					 or BSD license choice]
197  *	"Dual MIT/GPL"			[GNU Public License v2
198  *					 or MIT license choice]
199  *	"Dual MPL/GPL"			[GNU Public License v2
200  *					 or Mozilla license choice]
201  *
202  * The following other idents are available
203  *
204  *	"Proprietary"			[Non free products]
205  *
206  * Both "GPL v2" and "GPL" (the latter also in dual licensed strings) are
207  * merely stating that the module is licensed under the GPL v2, but are not
208  * telling whether "GPL v2 only" or "GPL v2 or later". The reason why there
209  * are two variants is a historic and failed attempt to convey more
210  * information in the MODULE_LICENSE string. For module loading the
211  * "only/or later" distinction is completely irrelevant and does neither
212  * replace the proper license identifiers in the corresponding source file
213  * nor amends them in any way. The sole purpose is to make the
214  * 'Proprietary' flagging work and to refuse to bind symbols which are
215  * exported with EXPORT_SYMBOL_GPL when a non free module is loaded.
216  *
217  * In the same way "BSD" is not a clear license information. It merely
218  * states, that the module is licensed under one of the compatible BSD
219  * license variants. The detailed and correct license information is again
220  * to be found in the corresponding source files.
221  *
222  * There are dual licensed components, but when running with Linux it is the
223  * GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL
224  * is a GPL combined work.
225  *
226  * This exists for several reasons
227  * 1.	So modinfo can show license info for users wanting to vet their setup
228  *	is free
229  * 2.	So the community can ignore bug reports including proprietary modules
230  * 3.	So vendors can do likewise based on their own policies
231  */
232 #define MODULE_LICENSE(_license) MODULE_FILE MODULE_INFO(license, _license)
233 
234 /*
235  * Author(s), use "Name <email>" or just "Name", for multiple
236  * authors use multiple MODULE_AUTHOR() statements/lines.
237  */
238 #define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
239 
240 /* What your module does. */
241 #define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
242 
243 #ifdef MODULE
244 /* Creates an alias so file2alias.c can find device table. */
245 #define MODULE_DEVICE_TABLE(type, name)					\
246 extern typeof(name) __mod_##type##__##name##_device_table		\
247   __attribute__ ((unused, alias(__stringify(name))))
248 #else  /* !MODULE */
249 #define MODULE_DEVICE_TABLE(type, name)
250 #endif
251 
252 /* Version of form [<epoch>:]<version>[-<extra-version>].
253  * Or for CVS/RCS ID version, everything but the number is stripped.
254  * <epoch>: A (small) unsigned integer which allows you to start versions
255  * anew. If not mentioned, it's zero.  eg. "2:1.0" is after
256  * "1:2.0".
257 
258  * <version>: The <version> may contain only alphanumerics and the
259  * character `.'.  Ordered by numeric sort for numeric parts,
260  * ascii sort for ascii parts (as per RPM or DEB algorithm).
261 
262  * <extraversion>: Like <version>, but inserted for local
263  * customizations, eg "rh3" or "rusty1".
264 
265  * Using this automatically adds a checksum of the .c files and the
266  * local headers in "srcversion".
267  */
268 
269 #if defined(MODULE) || !defined(CONFIG_SYSFS)
270 #define MODULE_VERSION(_version) MODULE_INFO(version, _version)
271 #else
272 #define MODULE_VERSION(_version)					\
273 	MODULE_INFO(version, _version);					\
274 	static struct module_version_attribute __modver_attr		\
275 		__used __section("__modver")				\
276 		__aligned(__alignof__(struct module_version_attribute)) \
277 		= {							\
278 			.mattr	= {					\
279 				.attr	= {				\
280 					.name	= "version",		\
281 					.mode	= S_IRUGO,		\
282 				},					\
283 				.show	= __modver_version_show,	\
284 			},						\
285 			.module_name	= KBUILD_MODNAME,		\
286 			.version	= _version,			\
287 		}
288 #endif
289 
290 /* Optional firmware file (or files) needed by the module
291  * format is simply firmware file name.  Multiple firmware
292  * files require multiple MODULE_FIRMWARE() specifiers */
293 #define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
294 
295 #define MODULE_IMPORT_NS(ns)	MODULE_INFO(import_ns, __stringify(ns))
296 
297 struct notifier_block;
298 
299 #ifdef CONFIG_MODULES
300 
301 extern int modules_disabled; /* for sysctl */
302 /* Get/put a kernel symbol (calls must be symmetric) */
303 void *__symbol_get(const char *symbol);
304 void *__symbol_get_gpl(const char *symbol);
305 #define symbol_get(x) ((typeof(&x))(__symbol_get(__stringify(x))))
306 
307 /* modules using other modules: kdb wants to see this. */
308 struct module_use {
309 	struct list_head source_list;
310 	struct list_head target_list;
311 	struct module *source, *target;
312 };
313 
314 enum module_state {
315 	MODULE_STATE_LIVE,	/* Normal state. */
316 	MODULE_STATE_COMING,	/* Full formed, running module_init. */
317 	MODULE_STATE_GOING,	/* Going away. */
318 	MODULE_STATE_UNFORMED,	/* Still setting it up. */
319 };
320 
321 struct mod_tree_node {
322 	struct module *mod;
323 	struct latch_tree_node node;
324 };
325 
326 enum mod_mem_type {
327 	MOD_TEXT = 0,
328 	MOD_DATA,
329 	MOD_RODATA,
330 	MOD_RO_AFTER_INIT,
331 	MOD_INIT_TEXT,
332 	MOD_INIT_DATA,
333 	MOD_INIT_RODATA,
334 
335 	MOD_MEM_NUM_TYPES,
336 	MOD_INVALID = -1,
337 };
338 
339 #define mod_mem_type_is_init(type)	\
340 	((type) == MOD_INIT_TEXT ||	\
341 	 (type) == MOD_INIT_DATA ||	\
342 	 (type) == MOD_INIT_RODATA)
343 
344 #define mod_mem_type_is_core(type) (!mod_mem_type_is_init(type))
345 
346 #define mod_mem_type_is_text(type)	\
347 	 ((type) == MOD_TEXT ||		\
348 	  (type) == MOD_INIT_TEXT)
349 
350 #define mod_mem_type_is_data(type) (!mod_mem_type_is_text(type))
351 
352 #define mod_mem_type_is_core_data(type)	\
353 	(mod_mem_type_is_core(type) &&	\
354 	 mod_mem_type_is_data(type))
355 
356 #define for_each_mod_mem_type(type)			\
357 	for (enum mod_mem_type (type) = 0;		\
358 	     (type) < MOD_MEM_NUM_TYPES; (type)++)
359 
360 #define for_class_mod_mem_type(type, class)		\
361 	for_each_mod_mem_type(type)			\
362 		if (mod_mem_type_is_##class(type))
363 
364 struct module_memory {
365 	void *base;
366 	unsigned int size;
367 
368 #ifdef CONFIG_MODULES_TREE_LOOKUP
369 	struct mod_tree_node mtn;
370 #endif
371 };
372 
373 #ifdef CONFIG_MODULES_TREE_LOOKUP
374 /* Only touch one cacheline for common rbtree-for-core-layout case. */
375 #define __module_memory_align ____cacheline_aligned
376 #else
377 #define __module_memory_align
378 #endif
379 
380 struct mod_kallsyms {
381 	Elf_Sym *symtab;
382 	unsigned int num_symtab;
383 	char *strtab;
384 	char *typetab;
385 };
386 
387 #ifdef CONFIG_LIVEPATCH
388 /**
389  * struct klp_modinfo - ELF information preserved from the livepatch module
390  *
391  * @hdr: ELF header
392  * @sechdrs: Section header table
393  * @secstrings: String table for the section headers
394  * @symndx: The symbol table section index
395  */
396 struct klp_modinfo {
397 	Elf_Ehdr hdr;
398 	Elf_Shdr *sechdrs;
399 	char *secstrings;
400 	unsigned int symndx;
401 };
402 #endif
403 
404 struct module {
405 	enum module_state state;
406 
407 	/* Member of list of modules */
408 	struct list_head list;
409 
410 	/* Unique handle for this module */
411 	char name[MODULE_NAME_LEN];
412 
413 #ifdef CONFIG_STACKTRACE_BUILD_ID
414 	/* Module build ID */
415 	unsigned char build_id[BUILD_ID_SIZE_MAX];
416 #endif
417 
418 	/* Sysfs stuff. */
419 	struct module_kobject mkobj;
420 	struct module_attribute *modinfo_attrs;
421 	const char *version;
422 	const char *srcversion;
423 	struct kobject *holders_dir;
424 
425 	/* Exported symbols */
426 	const struct kernel_symbol *syms;
427 	const s32 *crcs;
428 	unsigned int num_syms;
429 
430 #ifdef CONFIG_ARCH_USES_CFI_TRAPS
431 	s32 *kcfi_traps;
432 	s32 *kcfi_traps_end;
433 #endif
434 
435 	/* Kernel parameters. */
436 #ifdef CONFIG_SYSFS
437 	struct mutex param_lock;
438 #endif
439 	struct kernel_param *kp;
440 	unsigned int num_kp;
441 
442 	/* GPL-only exported symbols. */
443 	unsigned int num_gpl_syms;
444 	const struct kernel_symbol *gpl_syms;
445 	const s32 *gpl_crcs;
446 	bool using_gplonly_symbols;
447 
448 #ifdef CONFIG_MODULE_SIG
449 	/* Signature was verified. */
450 	bool sig_ok;
451 #endif
452 
453 	bool async_probe_requested;
454 
455 	/* Exception table */
456 	unsigned int num_exentries;
457 	struct exception_table_entry *extable;
458 
459 	/* Startup function. */
460 	int (*init)(void);
461 
462 	struct module_memory mem[MOD_MEM_NUM_TYPES] __module_memory_align;
463 
464 	/* Arch-specific module values */
465 	struct mod_arch_specific arch;
466 
467 	unsigned long taints;	/* same bits as kernel:taint_flags */
468 
469 #ifdef CONFIG_GENERIC_BUG
470 	/* Support for BUG */
471 	unsigned num_bugs;
472 	struct list_head bug_list;
473 	struct bug_entry *bug_table;
474 #endif
475 
476 #ifdef CONFIG_KALLSYMS
477 	/* Protected by RCU and/or module_mutex: use rcu_dereference() */
478 	struct mod_kallsyms __rcu *kallsyms;
479 	struct mod_kallsyms core_kallsyms;
480 
481 	/* Section attributes */
482 	struct module_sect_attrs *sect_attrs;
483 
484 	/* Notes attributes */
485 	struct module_notes_attrs *notes_attrs;
486 #endif
487 
488 	/* The command line arguments (may be mangled).  People like
489 	   keeping pointers to this stuff */
490 	char *args;
491 
492 #ifdef CONFIG_SMP
493 	/* Per-cpu data. */
494 	void __percpu *percpu;
495 	unsigned int percpu_size;
496 #endif
497 	void *noinstr_text_start;
498 	unsigned int noinstr_text_size;
499 
500 #ifdef CONFIG_TRACEPOINTS
501 	unsigned int num_tracepoints;
502 	tracepoint_ptr_t *tracepoints_ptrs;
503 #endif
504 #ifdef CONFIG_TREE_SRCU
505 	unsigned int num_srcu_structs;
506 	struct srcu_struct **srcu_struct_ptrs;
507 #endif
508 #ifdef CONFIG_BPF_EVENTS
509 	unsigned int num_bpf_raw_events;
510 	struct bpf_raw_event_map *bpf_raw_events;
511 #endif
512 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
513 	unsigned int btf_data_size;
514 	void *btf_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_suites;
546 	struct kunit_suite **kunit_suites;
547 #endif
548 
549 
550 #ifdef CONFIG_LIVEPATCH
551 	bool klp; /* Is this a livepatch module? */
552 	bool klp_alive;
553 
554 	/* ELF information */
555 	struct klp_modinfo *klp_info;
556 #endif
557 
558 #ifdef CONFIG_PRINTK_INDEX
559 	unsigned int printk_index_size;
560 	struct pi_entry **printk_index_start;
561 #endif
562 
563 #ifdef CONFIG_MODULE_UNLOAD
564 	/* What modules depend on me? */
565 	struct list_head source_list;
566 	/* What modules do I depend on? */
567 	struct list_head target_list;
568 
569 	/* Destruction function. */
570 	void (*exit)(void);
571 
572 	atomic_t refcnt;
573 #endif
574 
575 #ifdef CONFIG_MITIGATION_ITS
576 	int its_num_pages;
577 	void **its_page_array;
578 #endif
579 
580 #ifdef CONFIG_CONSTRUCTORS
581 	/* Constructor functions. */
582 	ctor_fn_t *ctors;
583 	unsigned int num_ctors;
584 #endif
585 
586 #ifdef CONFIG_FUNCTION_ERROR_INJECTION
587 	struct error_injection_entry *ei_funcs;
588 	unsigned int num_ei_funcs;
589 #endif
590 #ifdef CONFIG_DYNAMIC_DEBUG_CORE
591 	struct _ddebug_info dyndbg_info;
592 #endif
593 } ____cacheline_aligned __randomize_layout;
594 #ifndef MODULE_ARCH_INIT
595 #define MODULE_ARCH_INIT {}
596 #endif
597 
598 #ifndef HAVE_ARCH_KALLSYMS_SYMBOL_VALUE
kallsyms_symbol_value(const Elf_Sym * sym)599 static inline unsigned long kallsyms_symbol_value(const Elf_Sym *sym)
600 {
601 	return sym->st_value;
602 }
603 #endif
604 
605 /* FIXME: It'd be nice to isolate modules during init, too, so they
606    aren't used before they (may) fail.  But presently too much code
607    (IDE & SCSI) require entry into the module during init.*/
module_is_live(struct module * mod)608 static inline bool module_is_live(struct module *mod)
609 {
610 	return mod->state != MODULE_STATE_GOING;
611 }
612 
613 struct module *__module_text_address(unsigned long addr);
614 struct module *__module_address(unsigned long addr);
615 bool is_module_address(unsigned long addr);
616 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr);
617 bool is_module_percpu_address(unsigned long addr);
618 bool is_module_text_address(unsigned long addr);
619 
within_module_mem_type(unsigned long addr,const struct module * mod,enum mod_mem_type type)620 static inline bool within_module_mem_type(unsigned long addr,
621 					  const struct module *mod,
622 					  enum mod_mem_type type)
623 {
624 	unsigned long base, size;
625 
626 	base = (unsigned long)mod->mem[type].base;
627 	size = mod->mem[type].size;
628 	return addr - base < size;
629 }
630 
within_module_core(unsigned long addr,const struct module * mod)631 static inline bool within_module_core(unsigned long addr,
632 				      const struct module *mod)
633 {
634 	for_class_mod_mem_type(type, core) {
635 		if (within_module_mem_type(addr, mod, type))
636 			return true;
637 	}
638 	return false;
639 }
640 
within_module_init(unsigned long addr,const struct module * mod)641 static inline bool within_module_init(unsigned long addr,
642 				      const struct module *mod)
643 {
644 	for_class_mod_mem_type(type, init) {
645 		if (within_module_mem_type(addr, mod, type))
646 			return true;
647 	}
648 	return false;
649 }
650 
within_module(unsigned long addr,const struct module * mod)651 static inline bool within_module(unsigned long addr, const struct module *mod)
652 {
653 	return within_module_init(addr, mod) || within_module_core(addr, mod);
654 }
655 
656 /* Search for module by name: must be in a RCU-sched critical section. */
657 struct module *find_module(const char *name);
658 
659 extern void __noreturn __module_put_and_kthread_exit(struct module *mod,
660 			long code);
661 #define module_put_and_kthread_exit(code) __module_put_and_kthread_exit(THIS_MODULE, code)
662 
663 #ifdef CONFIG_MODULE_UNLOAD
664 int module_refcount(struct module *mod);
665 void __symbol_put(const char *symbol);
666 #define symbol_put(x) __symbol_put(__stringify(x))
667 void symbol_put_addr(void *addr);
668 
669 /* Sometimes we know we already have a refcount, and it's easier not
670    to handle the error case (which only happens with rmmod --wait). */
671 extern void __module_get(struct module *module);
672 
673 /**
674  * try_module_get() - take module refcount unless module is being removed
675  * @module: the module we should check for
676  *
677  * Only try to get a module reference count if the module is not being removed.
678  * This call will fail if the module is already being removed.
679  *
680  * Care must also be taken to ensure the module exists and is alive prior to
681  * usage of this call. This can be gauranteed through two means:
682  *
683  * 1) Direct protection: you know an earlier caller must have increased the
684  *    module reference through __module_get(). This can typically be achieved
685  *    by having another entity other than the module itself increment the
686  *    module reference count.
687  *
688  * 2) Implied protection: there is an implied protection against module
689  *    removal. An example of this is the implied protection used by kernfs /
690  *    sysfs. The sysfs store / read file operations are guaranteed to exist
691  *    through the use of kernfs's active reference (see kernfs_active()) and a
692  *    sysfs / kernfs file removal cannot happen unless the same file is not
693  *    active. Therefore, if a sysfs file is being read or written to the module
694  *    which created it must still exist. It is therefore safe to use
695  *    try_module_get() on module sysfs store / read ops.
696  *
697  * One of the real values to try_module_get() is the module_is_live() check
698  * which ensures that the caller of try_module_get() can yield to userspace
699  * module removal requests and gracefully fail if the module is on its way out.
700  *
701  * Returns true if the reference count was successfully incremented.
702  */
703 extern bool try_module_get(struct module *module);
704 
705 /**
706  * module_put() - release a reference count to a module
707  * @module: the module we should release a reference count for
708  *
709  * If you successfully bump a reference count to a module with try_module_get(),
710  * when you are finished you must call module_put() to release that reference
711  * count.
712  */
713 extern void module_put(struct module *module);
714 
715 #else /*!CONFIG_MODULE_UNLOAD*/
try_module_get(struct module * module)716 static inline bool try_module_get(struct module *module)
717 {
718 	return !module || module_is_live(module);
719 }
module_put(struct module * module)720 static inline void module_put(struct module *module)
721 {
722 }
__module_get(struct module * module)723 static inline void __module_get(struct module *module)
724 {
725 }
726 #define symbol_put(x) do { } while (0)
727 #define symbol_put_addr(p) do { } while (0)
728 
729 #endif /* CONFIG_MODULE_UNLOAD */
730 
731 /* This is a #define so the string doesn't get put in every .o file */
732 #define module_name(mod)			\
733 ({						\
734 	struct module *__mod = (mod);		\
735 	__mod ? __mod->name : "kernel";		\
736 })
737 
738 /* Dereference module function descriptor */
739 void *dereference_module_function_descriptor(struct module *mod, void *ptr);
740 
741 int register_module_notifier(struct notifier_block *nb);
742 int unregister_module_notifier(struct notifier_block *nb);
743 
744 extern void print_modules(void);
745 
module_requested_async_probing(struct module * module)746 static inline bool module_requested_async_probing(struct module *module)
747 {
748 	return module && module->async_probe_requested;
749 }
750 
is_livepatch_module(struct module * mod)751 static inline bool is_livepatch_module(struct module *mod)
752 {
753 #ifdef CONFIG_LIVEPATCH
754 	return mod->klp;
755 #else
756 	return false;
757 #endif
758 }
759 
760 void set_module_sig_enforced(void);
761 
762 #else /* !CONFIG_MODULES... */
763 
__module_address(unsigned long addr)764 static inline struct module *__module_address(unsigned long addr)
765 {
766 	return NULL;
767 }
768 
__module_text_address(unsigned long addr)769 static inline struct module *__module_text_address(unsigned long addr)
770 {
771 	return NULL;
772 }
773 
is_module_address(unsigned long addr)774 static inline bool is_module_address(unsigned long addr)
775 {
776 	return false;
777 }
778 
is_module_percpu_address(unsigned long addr)779 static inline bool is_module_percpu_address(unsigned long addr)
780 {
781 	return false;
782 }
783 
__is_module_percpu_address(unsigned long addr,unsigned long * can_addr)784 static inline bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
785 {
786 	return false;
787 }
788 
is_module_text_address(unsigned long addr)789 static inline bool is_module_text_address(unsigned long addr)
790 {
791 	return false;
792 }
793 
within_module_core(unsigned long addr,const struct module * mod)794 static inline bool within_module_core(unsigned long addr,
795 				      const struct module *mod)
796 {
797 	return false;
798 }
799 
within_module_init(unsigned long addr,const struct module * mod)800 static inline bool within_module_init(unsigned long addr,
801 				      const struct module *mod)
802 {
803 	return false;
804 }
805 
within_module(unsigned long addr,const struct module * mod)806 static inline bool within_module(unsigned long addr, const struct module *mod)
807 {
808 	return false;
809 }
810 
811 /* Get/put a kernel symbol (calls should be symmetric) */
812 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak,visibility("hidden"))); &(x); })
813 #define symbol_put(x) do { } while (0)
814 #define symbol_put_addr(x) do { } while (0)
815 
__module_get(struct module * module)816 static inline void __module_get(struct module *module)
817 {
818 }
819 
try_module_get(struct module * module)820 static inline bool try_module_get(struct module *module)
821 {
822 	return true;
823 }
824 
module_put(struct module * module)825 static inline void module_put(struct module *module)
826 {
827 }
828 
829 #define module_name(mod) "kernel"
830 
register_module_notifier(struct notifier_block * nb)831 static inline int register_module_notifier(struct notifier_block *nb)
832 {
833 	/* no events will happen anyway, so this can always succeed */
834 	return 0;
835 }
836 
unregister_module_notifier(struct notifier_block * nb)837 static inline int unregister_module_notifier(struct notifier_block *nb)
838 {
839 	return 0;
840 }
841 
842 #define module_put_and_kthread_exit(code) kthread_exit(code)
843 
print_modules(void)844 static inline void print_modules(void)
845 {
846 }
847 
module_requested_async_probing(struct module * module)848 static inline bool module_requested_async_probing(struct module *module)
849 {
850 	return false;
851 }
852 
853 
set_module_sig_enforced(void)854 static inline void set_module_sig_enforced(void)
855 {
856 }
857 
858 /* Dereference module function descriptor */
859 static inline
dereference_module_function_descriptor(struct module * mod,void * ptr)860 void *dereference_module_function_descriptor(struct module *mod, void *ptr)
861 {
862 	return ptr;
863 }
864 
865 #endif /* CONFIG_MODULES */
866 
867 #ifdef CONFIG_SYSFS
868 extern struct kset *module_kset;
869 extern const struct kobj_type module_ktype;
870 #endif /* CONFIG_SYSFS */
871 
872 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
873 
874 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
875 
876 #define __MODULE_STRING(x) __stringify(x)
877 
878 #ifdef CONFIG_GENERIC_BUG
879 void module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *,
880 			 struct module *);
881 void module_bug_cleanup(struct module *);
882 
883 #else	/* !CONFIG_GENERIC_BUG */
884 
module_bug_finalize(const Elf_Ehdr * hdr,const Elf_Shdr * sechdrs,struct module * mod)885 static inline void module_bug_finalize(const Elf_Ehdr *hdr,
886 					const Elf_Shdr *sechdrs,
887 					struct module *mod)
888 {
889 }
module_bug_cleanup(struct module * mod)890 static inline void module_bug_cleanup(struct module *mod) {}
891 #endif	/* CONFIG_GENERIC_BUG */
892 
893 #ifdef CONFIG_RETPOLINE
894 extern bool retpoline_module_ok(bool has_retpoline);
895 #else
retpoline_module_ok(bool has_retpoline)896 static inline bool retpoline_module_ok(bool has_retpoline)
897 {
898 	return true;
899 }
900 #endif
901 
902 #ifdef CONFIG_MODULE_SIG
903 bool is_module_sig_enforced(void);
904 
module_sig_ok(struct module * module)905 static inline bool module_sig_ok(struct module *module)
906 {
907 	return module->sig_ok;
908 }
909 #else	/* !CONFIG_MODULE_SIG */
is_module_sig_enforced(void)910 static inline bool is_module_sig_enforced(void)
911 {
912 	return false;
913 }
914 
module_sig_ok(struct module * module)915 static inline bool module_sig_ok(struct module *module)
916 {
917 	return true;
918 }
919 #endif	/* CONFIG_MODULE_SIG */
920 
921 #if defined(CONFIG_MODULES) && defined(CONFIG_KALLSYMS)
922 int module_kallsyms_on_each_symbol(const char *modname,
923 				   int (*fn)(void *, const char *, unsigned long),
924 				   void *data);
925 
926 /* For kallsyms to ask for address resolution.  namebuf should be at
927  * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
928  * found, otherwise NULL.
929  */
930 const char *module_address_lookup(unsigned long addr,
931 				  unsigned long *symbolsize,
932 				  unsigned long *offset,
933 				  char **modname, const unsigned char **modbuildid,
934 				  char *namebuf);
935 int lookup_module_symbol_name(unsigned long addr, char *symname);
936 int lookup_module_symbol_attrs(unsigned long addr,
937 			       unsigned long *size,
938 			       unsigned long *offset,
939 			       char *modname,
940 			       char *name);
941 
942 /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
943  * symnum out of range.
944  */
945 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
946 		       char *name, char *module_name, int *exported);
947 
948 /* Look for this name: can be of form module:name. */
949 unsigned long module_kallsyms_lookup_name(const char *name);
950 
951 unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name);
952 
953 #else	/* CONFIG_MODULES && CONFIG_KALLSYMS */
954 
module_kallsyms_on_each_symbol(const char * modname,int (* fn)(void *,const char *,unsigned long),void * data)955 static inline int module_kallsyms_on_each_symbol(const char *modname,
956 						 int (*fn)(void *, const char *, unsigned long),
957 						 void *data)
958 {
959 	return -EOPNOTSUPP;
960 }
961 
962 /* 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)963 static inline const char *module_address_lookup(unsigned long addr,
964 						unsigned long *symbolsize,
965 						unsigned long *offset,
966 						char **modname,
967 						const unsigned char **modbuildid,
968 						char *namebuf)
969 {
970 	return NULL;
971 }
972 
lookup_module_symbol_name(unsigned long addr,char * symname)973 static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
974 {
975 	return -ERANGE;
976 }
977 
module_get_kallsym(unsigned int symnum,unsigned long * value,char * type,char * name,char * module_name,int * exported)978 static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
979 				     char *type, char *name,
980 				     char *module_name, int *exported)
981 {
982 	return -ERANGE;
983 }
984 
module_kallsyms_lookup_name(const char * name)985 static inline unsigned long module_kallsyms_lookup_name(const char *name)
986 {
987 	return 0;
988 }
989 
find_kallsyms_symbol_value(struct module * mod,const char * name)990 static inline unsigned long find_kallsyms_symbol_value(struct module *mod,
991 						       const char *name)
992 {
993 	return 0;
994 }
995 
996 #endif  /* CONFIG_MODULES && CONFIG_KALLSYMS */
997 
998 #endif /* _LINUX_MODULE_H */
999