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 /* 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 * Weak module dependencies. See man modprobe.d for details.
178 * Example: MODULE_WEAKDEP("module-foo")
179 */
180 #define MODULE_WEAKDEP(_weakdep) MODULE_INFO(weakdep, _weakdep)
181
182 /*
183 * MODULE_FILE is used for generating modules.builtin
184 * So, make it no-op when this is being built as a module
185 */
186 #ifdef MODULE
187 #define MODULE_FILE
188 #else
189 #define MODULE_FILE MODULE_INFO(file, KBUILD_MODFILE);
190 #endif
191
192 /*
193 * The following license idents are currently accepted as indicating free
194 * software modules
195 *
196 * "GPL" [GNU Public License v2]
197 * "GPL v2" [GNU Public License v2]
198 * "GPL and additional rights" [GNU Public License v2 rights and more]
199 * "Dual BSD/GPL" [GNU Public License v2
200 * or BSD license choice]
201 * "Dual MIT/GPL" [GNU Public License v2
202 * or MIT license choice]
203 * "Dual MPL/GPL" [GNU Public License v2
204 * or Mozilla license choice]
205 *
206 * The following other idents are available
207 *
208 * "Proprietary" [Non free products]
209 *
210 * Both "GPL v2" and "GPL" (the latter also in dual licensed strings) are
211 * merely stating that the module is licensed under the GPL v2, but are not
212 * telling whether "GPL v2 only" or "GPL v2 or later". The reason why there
213 * are two variants is a historic and failed attempt to convey more
214 * information in the MODULE_LICENSE string. For module loading the
215 * "only/or later" distinction is completely irrelevant and does neither
216 * replace the proper license identifiers in the corresponding source file
217 * nor amends them in any way. The sole purpose is to make the
218 * 'Proprietary' flagging work and to refuse to bind symbols which are
219 * exported with EXPORT_SYMBOL_GPL when a non free module is loaded.
220 *
221 * In the same way "BSD" is not a clear license information. It merely
222 * states, that the module is licensed under one of the compatible BSD
223 * license variants. The detailed and correct license information is again
224 * to be found in the corresponding source files.
225 *
226 * There are dual licensed components, but when running with Linux it is the
227 * GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL
228 * is a GPL combined work.
229 *
230 * This exists for several reasons
231 * 1. So modinfo can show license info for users wanting to vet their setup
232 * is free
233 * 2. So the community can ignore bug reports including proprietary modules
234 * 3. So vendors can do likewise based on their own policies
235 */
236 #define MODULE_LICENSE(_license) MODULE_FILE MODULE_INFO(license, _license)
237
238 /*
239 * Author(s), use "Name <email>" or just "Name", for multiple
240 * authors use multiple MODULE_AUTHOR() statements/lines.
241 */
242 #define MODULE_AUTHOR(_author) MODULE_INFO(author, _author)
243
244 /* What your module does. */
245 #define MODULE_DESCRIPTION(_description) MODULE_INFO(description, _description)
246
247 #ifdef MODULE
248 /* Creates an alias so file2alias.c can find device table. */
249 #define MODULE_DEVICE_TABLE(type, name) \
250 extern typeof(name) __mod_device_table__##type##__##name \
251 __attribute__ ((unused, alias(__stringify(name))))
252 #else /* !MODULE */
253 #define MODULE_DEVICE_TABLE(type, name)
254 #endif
255
256 /* Version of form [<epoch>:]<version>[-<extra-version>].
257 * Or for CVS/RCS ID version, everything but the number is stripped.
258 * <epoch>: A (small) unsigned integer which allows you to start versions
259 * anew. If not mentioned, it's zero. eg. "2:1.0" is after
260 * "1:2.0".
261
262 * <version>: The <version> may contain only alphanumerics and the
263 * character `.'. Ordered by numeric sort for numeric parts,
264 * ascii sort for ascii parts (as per RPM or DEB algorithm).
265
266 * <extraversion>: Like <version>, but inserted for local
267 * customizations, eg "rh3" or "rusty1".
268
269 * Using this automatically adds a checksum of the .c files and the
270 * local headers in "srcversion".
271 */
272
273 #if defined(MODULE) || !defined(CONFIG_SYSFS)
274 #define MODULE_VERSION(_version) MODULE_INFO(version, _version)
275 #else
276 #define MODULE_VERSION(_version) \
277 MODULE_INFO(version, _version); \
278 static const struct module_version_attribute __modver_attr \
279 __used __section("__modver") \
280 __aligned(__alignof__(struct module_version_attribute)) \
281 = { \
282 .mattr = { \
283 .attr = { \
284 .name = "version", \
285 .mode = S_IRUGO, \
286 }, \
287 .show = __modver_version_show, \
288 }, \
289 .module_name = KBUILD_MODNAME, \
290 .version = _version, \
291 }
292 #endif
293
294 /* Optional firmware file (or files) needed by the module
295 * format is simply firmware file name. Multiple firmware
296 * files require multiple MODULE_FIRMWARE() specifiers */
297 #define MODULE_FIRMWARE(_firmware) MODULE_INFO(firmware, _firmware)
298
299 #define MODULE_IMPORT_NS(ns) MODULE_INFO(import_ns, ns)
300
301 struct notifier_block;
302
303 #ifdef CONFIG_MODULES
304
305 extern int modules_disabled; /* for sysctl */
306 /* Get/put a kernel symbol (calls must be symmetric) */
307 void *__symbol_get(const char *symbol);
308 void *__symbol_get_gpl(const char *symbol);
309 #define symbol_get(x) ({ \
310 static const char __notrim[] \
311 __used __section(".no_trim_symbol") = __stringify(x); \
312 (typeof(&x))(__symbol_get(__stringify(x))); })
313
314 /* modules using other modules: kdb wants to see this. */
315 struct module_use {
316 struct list_head source_list;
317 struct list_head target_list;
318 struct module *source, *target;
319 };
320
321 enum module_state {
322 MODULE_STATE_LIVE, /* Normal state. */
323 MODULE_STATE_COMING, /* Full formed, running module_init. */
324 MODULE_STATE_GOING, /* Going away. */
325 MODULE_STATE_UNFORMED, /* Still setting it up. */
326 };
327
328 struct mod_tree_node {
329 struct module *mod;
330 struct latch_tree_node node;
331 };
332
333 enum mod_mem_type {
334 MOD_TEXT = 0,
335 MOD_DATA,
336 MOD_RODATA,
337 MOD_RO_AFTER_INIT,
338 MOD_INIT_TEXT,
339 MOD_INIT_DATA,
340 MOD_INIT_RODATA,
341
342 MOD_MEM_NUM_TYPES,
343 MOD_INVALID = -1,
344 };
345
346 #define mod_mem_type_is_init(type) \
347 ((type) == MOD_INIT_TEXT || \
348 (type) == MOD_INIT_DATA || \
349 (type) == MOD_INIT_RODATA)
350
351 #define mod_mem_type_is_core(type) (!mod_mem_type_is_init(type))
352
353 #define mod_mem_type_is_text(type) \
354 ((type) == MOD_TEXT || \
355 (type) == MOD_INIT_TEXT)
356
357 #define mod_mem_type_is_data(type) (!mod_mem_type_is_text(type))
358
359 #define mod_mem_type_is_core_data(type) \
360 (mod_mem_type_is_core(type) && \
361 mod_mem_type_is_data(type))
362
363 #define for_each_mod_mem_type(type) \
364 for (enum mod_mem_type (type) = 0; \
365 (type) < MOD_MEM_NUM_TYPES; (type)++)
366
367 #define for_class_mod_mem_type(type, class) \
368 for_each_mod_mem_type(type) \
369 if (mod_mem_type_is_##class(type))
370
371 struct module_memory {
372 void *base;
373 void *rw_copy;
374 bool is_rox;
375 unsigned int size;
376
377 #ifdef CONFIG_MODULES_TREE_LOOKUP
378 struct mod_tree_node mtn;
379 #endif
380 };
381
382 #ifdef CONFIG_MODULES_TREE_LOOKUP
383 /* Only touch one cacheline for common rbtree-for-core-layout case. */
384 #define __module_memory_align ____cacheline_aligned
385 #else
386 #define __module_memory_align
387 #endif
388
389 struct mod_kallsyms {
390 Elf_Sym *symtab;
391 unsigned int num_symtab;
392 char *strtab;
393 char *typetab;
394 };
395
396 #ifdef CONFIG_LIVEPATCH
397 /**
398 * struct klp_modinfo - ELF information preserved from the livepatch module
399 *
400 * @hdr: ELF header
401 * @sechdrs: Section header table
402 * @secstrings: String table for the section headers
403 * @symndx: The symbol table section index
404 */
405 struct klp_modinfo {
406 Elf_Ehdr hdr;
407 Elf_Shdr *sechdrs;
408 char *secstrings;
409 unsigned int symndx;
410 };
411 #endif
412
413 struct module {
414 enum module_state state;
415
416 /* Member of list of modules */
417 struct list_head list;
418
419 /* Unique handle for this module */
420 char name[MODULE_NAME_LEN];
421
422 #ifdef CONFIG_STACKTRACE_BUILD_ID
423 /* Module build ID */
424 unsigned char build_id[BUILD_ID_SIZE_MAX];
425 #endif
426
427 /* Sysfs stuff. */
428 struct module_kobject mkobj;
429 struct module_attribute *modinfo_attrs;
430 const char *version;
431 const char *srcversion;
432 struct kobject *holders_dir;
433
434 /* Exported symbols */
435 const struct kernel_symbol *syms;
436 const u32 *crcs;
437 unsigned int num_syms;
438
439 #ifdef CONFIG_ARCH_USES_CFI_TRAPS
440 s32 *kcfi_traps;
441 s32 *kcfi_traps_end;
442 #endif
443
444 /* Kernel parameters. */
445 #ifdef CONFIG_SYSFS
446 struct mutex param_lock;
447 #endif
448 struct kernel_param *kp;
449 unsigned int num_kp;
450
451 /* GPL-only exported symbols. */
452 unsigned int num_gpl_syms;
453 const struct kernel_symbol *gpl_syms;
454 const u32 *gpl_crcs;
455 bool using_gplonly_symbols;
456
457 #ifdef CONFIG_MODULE_SIG
458 /* Signature was verified. */
459 bool sig_ok;
460 #endif
461
462 bool async_probe_requested;
463
464 /* Exception table */
465 unsigned int num_exentries;
466 struct exception_table_entry *extable;
467
468 /* Startup function. */
469 int (*init)(void);
470
471 struct module_memory mem[MOD_MEM_NUM_TYPES] __module_memory_align;
472
473 /* Arch-specific module values */
474 struct mod_arch_specific arch;
475
476 unsigned long taints; /* same bits as kernel:taint_flags */
477
478 #ifdef CONFIG_GENERIC_BUG
479 /* Support for BUG */
480 unsigned num_bugs;
481 struct list_head bug_list;
482 struct bug_entry *bug_table;
483 #endif
484
485 #ifdef CONFIG_KALLSYMS
486 /* Protected by RCU and/or module_mutex: use rcu_dereference() */
487 struct mod_kallsyms __rcu *kallsyms;
488 struct mod_kallsyms core_kallsyms;
489
490 /* Section attributes */
491 struct module_sect_attrs *sect_attrs;
492
493 /* Notes attributes */
494 struct module_notes_attrs *notes_attrs;
495 #endif
496
497 /* The command line arguments (may be mangled). People like
498 keeping pointers to this stuff */
499 char *args;
500
501 #ifdef CONFIG_SMP
502 /* Per-cpu data. */
503 void __percpu *percpu;
504 unsigned int percpu_size;
505 #endif
506 void *noinstr_text_start;
507 unsigned int noinstr_text_size;
508
509 #ifdef CONFIG_TRACEPOINTS
510 unsigned int num_tracepoints;
511 tracepoint_ptr_t *tracepoints_ptrs;
512 #endif
513 #ifdef CONFIG_TREE_SRCU
514 unsigned int num_srcu_structs;
515 struct srcu_struct **srcu_struct_ptrs;
516 #endif
517 #ifdef CONFIG_BPF_EVENTS
518 unsigned int num_bpf_raw_events;
519 struct bpf_raw_event_map *bpf_raw_events;
520 #endif
521 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
522 unsigned int btf_data_size;
523 unsigned int btf_base_data_size;
524 void *btf_data;
525 void *btf_base_data;
526 #endif
527 #ifdef CONFIG_JUMP_LABEL
528 struct jump_entry *jump_entries;
529 unsigned int num_jump_entries;
530 #endif
531 #ifdef CONFIG_TRACING
532 unsigned int num_trace_bprintk_fmt;
533 const char **trace_bprintk_fmt_start;
534 #endif
535 #ifdef CONFIG_EVENT_TRACING
536 struct trace_event_call **trace_events;
537 unsigned int num_trace_events;
538 struct trace_eval_map **trace_evals;
539 unsigned int num_trace_evals;
540 #endif
541 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
542 unsigned int num_ftrace_callsites;
543 unsigned long *ftrace_callsites;
544 #endif
545 #ifdef CONFIG_KPROBES
546 void *kprobes_text_start;
547 unsigned int kprobes_text_size;
548 unsigned long *kprobe_blacklist;
549 unsigned int num_kprobe_blacklist;
550 #endif
551 #ifdef CONFIG_HAVE_STATIC_CALL_INLINE
552 int num_static_call_sites;
553 struct static_call_site *static_call_sites;
554 #endif
555 #if IS_ENABLED(CONFIG_KUNIT)
556 int num_kunit_init_suites;
557 struct kunit_suite **kunit_init_suites;
558 int num_kunit_suites;
559 struct kunit_suite **kunit_suites;
560 #endif
561
562
563 #ifdef CONFIG_LIVEPATCH
564 bool klp; /* Is this a livepatch module? */
565 bool klp_alive;
566
567 /* ELF information */
568 struct klp_modinfo *klp_info;
569 #endif
570
571 #ifdef CONFIG_PRINTK_INDEX
572 unsigned int printk_index_size;
573 struct pi_entry **printk_index_start;
574 #endif
575
576 #ifdef CONFIG_MODULE_UNLOAD
577 /* What modules depend on me? */
578 struct list_head source_list;
579 /* What modules do I depend on? */
580 struct list_head target_list;
581
582 /* Destruction function. */
583 void (*exit)(void);
584
585 atomic_t refcnt;
586 #endif
587
588 #ifdef CONFIG_CONSTRUCTORS
589 /* Constructor functions. */
590 ctor_fn_t *ctors;
591 unsigned int num_ctors;
592 #endif
593
594 #ifdef CONFIG_FUNCTION_ERROR_INJECTION
595 struct error_injection_entry *ei_funcs;
596 unsigned int num_ei_funcs;
597 #endif
598 #ifdef CONFIG_DYNAMIC_DEBUG_CORE
599 struct _ddebug_info dyndbg_info;
600 #endif
601 } ____cacheline_aligned __randomize_layout;
602 #ifndef MODULE_ARCH_INIT
603 #define MODULE_ARCH_INIT {}
604 #endif
605
606 #ifndef HAVE_ARCH_KALLSYMS_SYMBOL_VALUE
kallsyms_symbol_value(const Elf_Sym * sym)607 static inline unsigned long kallsyms_symbol_value(const Elf_Sym *sym)
608 {
609 return sym->st_value;
610 }
611 #endif
612
613 /* FIXME: It'd be nice to isolate modules during init, too, so they
614 aren't used before they (may) fail. But presently too much code
615 (IDE & SCSI) require entry into the module during init.*/
module_is_live(struct module * mod)616 static inline bool module_is_live(struct module *mod)
617 {
618 return mod->state != MODULE_STATE_GOING;
619 }
620
module_is_coming(struct module * mod)621 static inline bool module_is_coming(struct module *mod)
622 {
623 return mod->state == MODULE_STATE_COMING;
624 }
625
626 struct module *__module_text_address(unsigned long addr);
627 struct module *__module_address(unsigned long addr);
628 bool is_module_address(unsigned long addr);
629 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr);
630 bool is_module_percpu_address(unsigned long addr);
631 bool is_module_text_address(unsigned long addr);
632
within_module_mem_type(unsigned long addr,const struct module * mod,enum mod_mem_type type)633 static inline bool within_module_mem_type(unsigned long addr,
634 const struct module *mod,
635 enum mod_mem_type type)
636 {
637 unsigned long base, size;
638
639 base = (unsigned long)mod->mem[type].base;
640 size = mod->mem[type].size;
641 return addr - base < size;
642 }
643
within_module_core(unsigned long addr,const struct module * mod)644 static inline bool within_module_core(unsigned long addr,
645 const struct module *mod)
646 {
647 for_class_mod_mem_type(type, core) {
648 if (within_module_mem_type(addr, mod, type))
649 return true;
650 }
651 return false;
652 }
653
within_module_init(unsigned long addr,const struct module * mod)654 static inline bool within_module_init(unsigned long addr,
655 const struct module *mod)
656 {
657 for_class_mod_mem_type(type, init) {
658 if (within_module_mem_type(addr, mod, type))
659 return true;
660 }
661 return false;
662 }
663
within_module(unsigned long addr,const struct module * mod)664 static inline bool within_module(unsigned long addr, const struct module *mod)
665 {
666 return within_module_init(addr, mod) || within_module_core(addr, mod);
667 }
668
669 /* Search for module by name: must be in a RCU-sched critical section. */
670 struct module *find_module(const char *name);
671
672 extern void __noreturn __module_put_and_kthread_exit(struct module *mod,
673 long code);
674 #define module_put_and_kthread_exit(code) __module_put_and_kthread_exit(THIS_MODULE, code)
675
676 #ifdef CONFIG_MODULE_UNLOAD
677 int module_refcount(struct module *mod);
678 void __symbol_put(const char *symbol);
679 #define symbol_put(x) __symbol_put(__stringify(x))
680 void symbol_put_addr(void *addr);
681
682 /* Sometimes we know we already have a refcount, and it's easier not
683 to handle the error case (which only happens with rmmod --wait). */
684 extern void __module_get(struct module *module);
685
686 /**
687 * try_module_get() - take module refcount unless module is being removed
688 * @module: the module we should check for
689 *
690 * Only try to get a module reference count if the module is not being removed.
691 * This call will fail if the module is in the process of being removed.
692 *
693 * Care must also be taken to ensure the module exists and is alive prior to
694 * usage of this call. This can be gauranteed through two means:
695 *
696 * 1) Direct protection: you know an earlier caller must have increased the
697 * module reference through __module_get(). This can typically be achieved
698 * by having another entity other than the module itself increment the
699 * module reference count.
700 *
701 * 2) Implied protection: there is an implied protection against module
702 * removal. An example of this is the implied protection used by kernfs /
703 * sysfs. The sysfs store / read file operations are guaranteed to exist
704 * through the use of kernfs's active reference (see kernfs_active()) and a
705 * sysfs / kernfs file removal cannot happen unless the same file is not
706 * active. Therefore, if a sysfs file is being read or written to the module
707 * which created it must still exist. It is therefore safe to use
708 * try_module_get() on module sysfs store / read ops.
709 *
710 * One of the real values to try_module_get() is the module_is_live() check
711 * which ensures that the caller of try_module_get() can yield to userspace
712 * module removal requests and gracefully fail if the module is on its way out.
713 *
714 * Returns true if the reference count was successfully incremented.
715 */
716 extern bool try_module_get(struct module *module);
717
718 /**
719 * module_put() - release a reference count to a module
720 * @module: the module we should release a reference count for
721 *
722 * If you successfully bump a reference count to a module with try_module_get(),
723 * when you are finished you must call module_put() to release that reference
724 * count.
725 */
726 extern void module_put(struct module *module);
727
728 #else /*!CONFIG_MODULE_UNLOAD*/
try_module_get(struct module * module)729 static inline bool try_module_get(struct module *module)
730 {
731 return !module || module_is_live(module);
732 }
module_put(struct module * module)733 static inline void module_put(struct module *module)
734 {
735 }
__module_get(struct module * module)736 static inline void __module_get(struct module *module)
737 {
738 }
739 #define symbol_put(x) do { } while (0)
740 #define symbol_put_addr(p) do { } while (0)
741
742 #endif /* CONFIG_MODULE_UNLOAD */
743
744 /* This is a #define so the string doesn't get put in every .o file */
745 #define module_name(mod) \
746 ({ \
747 struct module *__mod = (mod); \
748 __mod ? __mod->name : "kernel"; \
749 })
750
751 /* Dereference module function descriptor */
752 void *dereference_module_function_descriptor(struct module *mod, void *ptr);
753
754 int register_module_notifier(struct notifier_block *nb);
755 int unregister_module_notifier(struct notifier_block *nb);
756
757 extern void print_modules(void);
758
module_requested_async_probing(struct module * module)759 static inline bool module_requested_async_probing(struct module *module)
760 {
761 return module && module->async_probe_requested;
762 }
763
is_livepatch_module(struct module * mod)764 static inline bool is_livepatch_module(struct module *mod)
765 {
766 #ifdef CONFIG_LIVEPATCH
767 return mod->klp;
768 #else
769 return false;
770 #endif
771 }
772
773 void set_module_sig_enforced(void);
774
775 void *__module_writable_address(struct module *mod, void *loc);
776
module_writable_address(struct module * mod,void * loc)777 static inline void *module_writable_address(struct module *mod, void *loc)
778 {
779 if (!IS_ENABLED(CONFIG_ARCH_HAS_EXECMEM_ROX) || !mod ||
780 mod->state != MODULE_STATE_UNFORMED)
781 return loc;
782 return __module_writable_address(mod, loc);
783 }
784
785 #else /* !CONFIG_MODULES... */
786
__module_address(unsigned long addr)787 static inline struct module *__module_address(unsigned long addr)
788 {
789 return NULL;
790 }
791
__module_text_address(unsigned long addr)792 static inline struct module *__module_text_address(unsigned long addr)
793 {
794 return NULL;
795 }
796
is_module_address(unsigned long addr)797 static inline bool is_module_address(unsigned long addr)
798 {
799 return false;
800 }
801
is_module_percpu_address(unsigned long addr)802 static inline bool is_module_percpu_address(unsigned long addr)
803 {
804 return false;
805 }
806
__is_module_percpu_address(unsigned long addr,unsigned long * can_addr)807 static inline bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
808 {
809 return false;
810 }
811
is_module_text_address(unsigned long addr)812 static inline bool is_module_text_address(unsigned long addr)
813 {
814 return false;
815 }
816
within_module_core(unsigned long addr,const struct module * mod)817 static inline bool within_module_core(unsigned long addr,
818 const struct module *mod)
819 {
820 return false;
821 }
822
within_module_init(unsigned long addr,const struct module * mod)823 static inline bool within_module_init(unsigned long addr,
824 const struct module *mod)
825 {
826 return false;
827 }
828
within_module(unsigned long addr,const struct module * mod)829 static inline bool within_module(unsigned long addr, const struct module *mod)
830 {
831 return false;
832 }
833
834 /* Get/put a kernel symbol (calls should be symmetric) */
835 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak,visibility("hidden"))); &(x); })
836 #define symbol_put(x) do { } while (0)
837 #define symbol_put_addr(x) do { } while (0)
838
__module_get(struct module * module)839 static inline void __module_get(struct module *module)
840 {
841 }
842
try_module_get(struct module * module)843 static inline bool try_module_get(struct module *module)
844 {
845 return true;
846 }
847
module_put(struct module * module)848 static inline void module_put(struct module *module)
849 {
850 }
851
852 #define module_name(mod) "kernel"
853
register_module_notifier(struct notifier_block * nb)854 static inline int register_module_notifier(struct notifier_block *nb)
855 {
856 /* no events will happen anyway, so this can always succeed */
857 return 0;
858 }
859
unregister_module_notifier(struct notifier_block * nb)860 static inline int unregister_module_notifier(struct notifier_block *nb)
861 {
862 return 0;
863 }
864
865 #define module_put_and_kthread_exit(code) kthread_exit(code)
866
print_modules(void)867 static inline void print_modules(void)
868 {
869 }
870
module_requested_async_probing(struct module * module)871 static inline bool module_requested_async_probing(struct module *module)
872 {
873 return false;
874 }
875
876
set_module_sig_enforced(void)877 static inline void set_module_sig_enforced(void)
878 {
879 }
880
881 /* Dereference module function descriptor */
882 static inline
dereference_module_function_descriptor(struct module * mod,void * ptr)883 void *dereference_module_function_descriptor(struct module *mod, void *ptr)
884 {
885 return ptr;
886 }
887
module_is_coming(struct module * mod)888 static inline bool module_is_coming(struct module *mod)
889 {
890 return false;
891 }
892
module_writable_address(struct module * mod,void * loc)893 static inline void *module_writable_address(struct module *mod, void *loc)
894 {
895 return loc;
896 }
897 #endif /* CONFIG_MODULES */
898
899 #ifdef CONFIG_SYSFS
900 extern struct kset *module_kset;
901 extern const struct kobj_type module_ktype;
902 #endif /* CONFIG_SYSFS */
903
904 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
905
906 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
907
908 #define __MODULE_STRING(x) __stringify(x)
909
910 #ifdef CONFIG_GENERIC_BUG
911 void module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *,
912 struct module *);
913 void module_bug_cleanup(struct module *);
914
915 #else /* !CONFIG_GENERIC_BUG */
916
module_bug_finalize(const Elf_Ehdr * hdr,const Elf_Shdr * sechdrs,struct module * mod)917 static inline void module_bug_finalize(const Elf_Ehdr *hdr,
918 const Elf_Shdr *sechdrs,
919 struct module *mod)
920 {
921 }
module_bug_cleanup(struct module * mod)922 static inline void module_bug_cleanup(struct module *mod) {}
923 #endif /* CONFIG_GENERIC_BUG */
924
925 #ifdef CONFIG_MITIGATION_RETPOLINE
926 extern bool retpoline_module_ok(bool has_retpoline);
927 #else
retpoline_module_ok(bool has_retpoline)928 static inline bool retpoline_module_ok(bool has_retpoline)
929 {
930 return true;
931 }
932 #endif
933
934 #ifdef CONFIG_MODULE_SIG
935 bool is_module_sig_enforced(void);
936
module_sig_ok(struct module * module)937 static inline bool module_sig_ok(struct module *module)
938 {
939 return module->sig_ok;
940 }
941 #else /* !CONFIG_MODULE_SIG */
is_module_sig_enforced(void)942 static inline bool is_module_sig_enforced(void)
943 {
944 return false;
945 }
946
module_sig_ok(struct module * module)947 static inline bool module_sig_ok(struct module *module)
948 {
949 return true;
950 }
951 #endif /* CONFIG_MODULE_SIG */
952
953 #if defined(CONFIG_MODULES) && defined(CONFIG_KALLSYMS)
954 int module_kallsyms_on_each_symbol(const char *modname,
955 int (*fn)(void *, const char *, unsigned long),
956 void *data);
957
958 /* For kallsyms to ask for address resolution. namebuf should be at
959 * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
960 * found, otherwise NULL.
961 */
962 int module_address_lookup(unsigned long addr,
963 unsigned long *symbolsize,
964 unsigned long *offset,
965 char **modname, const unsigned char **modbuildid,
966 char *namebuf);
967 int lookup_module_symbol_name(unsigned long addr, char *symname);
968 int lookup_module_symbol_attrs(unsigned long addr,
969 unsigned long *size,
970 unsigned long *offset,
971 char *modname,
972 char *name);
973
974 /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
975 * symnum out of range.
976 */
977 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
978 char *name, char *module_name, int *exported);
979
980 /* Look for this name: can be of form module:name. */
981 unsigned long module_kallsyms_lookup_name(const char *name);
982
983 unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name);
984
985 #else /* CONFIG_MODULES && CONFIG_KALLSYMS */
986
module_kallsyms_on_each_symbol(const char * modname,int (* fn)(void *,const char *,unsigned long),void * data)987 static inline int module_kallsyms_on_each_symbol(const char *modname,
988 int (*fn)(void *, const char *, unsigned long),
989 void *data)
990 {
991 return -EOPNOTSUPP;
992 }
993
994 /* 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)995 static inline int module_address_lookup(unsigned long addr,
996 unsigned long *symbolsize,
997 unsigned long *offset,
998 char **modname,
999 const unsigned char **modbuildid,
1000 char *namebuf)
1001 {
1002 return 0;
1003 }
1004
lookup_module_symbol_name(unsigned long addr,char * symname)1005 static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
1006 {
1007 return -ERANGE;
1008 }
1009
module_get_kallsym(unsigned int symnum,unsigned long * value,char * type,char * name,char * module_name,int * exported)1010 static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
1011 char *type, char *name,
1012 char *module_name, int *exported)
1013 {
1014 return -ERANGE;
1015 }
1016
module_kallsyms_lookup_name(const char * name)1017 static inline unsigned long module_kallsyms_lookup_name(const char *name)
1018 {
1019 return 0;
1020 }
1021
find_kallsyms_symbol_value(struct module * mod,const char * name)1022 static inline unsigned long find_kallsyms_symbol_value(struct module *mod,
1023 const char *name)
1024 {
1025 return 0;
1026 }
1027
1028 #endif /* CONFIG_MODULES && CONFIG_KALLSYMS */
1029
1030 #endif /* _LINUX_MODULE_H */
1031