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