1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * Dynamic loading of modules into the kernel.
4 *
5 * Rewritten by Richard Henderson <rth@tamu.edu> Dec 1996
6 * Rewritten again by Rusty Russell, 2002
7 */
8
9 #ifndef _LINUX_MODULE_H
10 #define _LINUX_MODULE_H
11
12 #include <linux/list.h>
13 #include <linux/stat.h>
14 #include <linux/buildid.h>
15 #include <linux/compiler.h>
16 #include <linux/cache.h>
17 #include <linux/kmod.h>
18 #include <linux/init.h>
19 #include <linux/elf.h>
20 #include <linux/stringify.h>
21 #include <linux/kobject.h>
22 #include <linux/moduleparam.h>
23 #include <linux/jump_label.h>
24 #include <linux/export.h>
25 #include <linux/rbtree_latch.h>
26 #include <linux/error-injection.h>
27 #include <linux/tracepoint-defs.h>
28 #include <linux/srcu.h>
29 #include <linux/static_call_types.h>
30 #include <linux/dynamic_debug.h>
31
32 #include <linux/percpu.h>
33 #include <asm/module.h>
34
35 #define MODULE_NAME_LEN MAX_PARAM_PREFIX_LEN
36
37 struct modversion_info {
38 unsigned long crc;
39 char name[MODULE_NAME_LEN];
40 };
41
42 struct module;
43 struct exception_table_entry;
44
45 struct module_kobject {
46 struct kobject kobj;
47 struct module *mod;
48 struct kobject *drivers_dir;
49 struct module_param_attrs *mp;
50 struct completion *kobj_completion;
51 } __randomize_layout;
52
53 struct module_attribute {
54 struct attribute attr;
55 ssize_t (*show)(struct module_attribute *, struct module_kobject *,
56 char *);
57 ssize_t (*store)(struct module_attribute *, struct module_kobject *,
58 const char *, size_t count);
59 void (*setup)(struct module *, const char *);
60 int (*test)(struct module *);
61 void (*free)(struct module *);
62 };
63
64 struct module_version_attribute {
65 struct module_attribute mattr;
66 const char *module_name;
67 const char *version;
68 };
69
70 extern ssize_t __modver_version_show(struct module_attribute *,
71 struct module_kobject *, char *);
72
73 extern struct module_attribute module_uevent;
74
75 /* These are either module local, or the kernel's dummy ones. */
76 extern int init_module(void);
77 extern void cleanup_module(void);
78
79 #ifndef MODULE
80 /**
81 * module_init() - driver initialization entry point
82 * @x: function to be run at kernel boot time or module insertion
83 *
84 * module_init() will either be called during do_initcalls() (if
85 * builtin) or at module insertion time (if a module). There can only
86 * be one per module.
87 */
88 #define module_init(x) __initcall(x);
89
90 /**
91 * module_exit() - driver exit entry point
92 * @x: function to be run when driver is removed
93 *
94 * module_exit() will wrap the driver clean-up code
95 * with cleanup_module() when used with rmmod when
96 * the driver is a module. If the driver is statically
97 * compiled into the kernel, module_exit() has no effect.
98 * There can only be one per module.
99 */
100 #define module_exit(x) __exitcall(x);
101
102 #else /* MODULE */
103
104 /*
105 * In most cases loadable modules do not need custom
106 * initcall levels. There are still some valid cases where
107 * a driver may be needed early if built in, and does not
108 * matter when built as a loadable module. Like bus
109 * snooping debug drivers.
110 */
111 #define early_initcall(fn) module_init(fn)
112 #define core_initcall(fn) module_init(fn)
113 #define core_initcall_sync(fn) module_init(fn)
114 #define postcore_initcall(fn) module_init(fn)
115 #define postcore_initcall_sync(fn) module_init(fn)
116 #define arch_initcall(fn) module_init(fn)
117 #define subsys_initcall(fn) module_init(fn)
118 #define subsys_initcall_sync(fn) module_init(fn)
119 #define fs_initcall(fn) module_init(fn)
120 #define fs_initcall_sync(fn) module_init(fn)
121 #define rootfs_initcall(fn) module_init(fn)
122 #define device_initcall(fn) module_init(fn)
123 #define device_initcall_sync(fn) module_init(fn)
124 #define late_initcall(fn) module_init(fn)
125 #define late_initcall_sync(fn) module_init(fn)
126
127 #define console_initcall(fn) module_init(fn)
128
129 /* Each module must use one module_init(). */
130 #define module_init(initfn) \
131 static inline initcall_t __maybe_unused __inittest(void) \
132 { return initfn; } \
133 int init_module(void) __copy(initfn) \
134 __attribute__((alias(#initfn))); \
135 ___ADDRESSABLE(init_module, __initdata);
136
137 /* This is only required if you want to be unloadable. */
138 #define module_exit(exitfn) \
139 static inline exitcall_t __maybe_unused __exittest(void) \
140 { return exitfn; } \
141 void cleanup_module(void) __copy(exitfn) \
142 __attribute__((alias(#exitfn))); \
143 ___ADDRESSABLE(cleanup_module, __exitdata);
144
145 #endif
146
147 /* This means "can be init if no module support, otherwise module load
148 may call it." */
149 #ifdef CONFIG_MODULES
150 #define __init_or_module
151 #define __initdata_or_module
152 #define __initconst_or_module
153 #define __INIT_OR_MODULE .text
154 #define __INITDATA_OR_MODULE .data
155 #define __INITRODATA_OR_MODULE .section ".rodata","a",%progbits
156 #else
157 #define __init_or_module __init
158 #define __initdata_or_module __initdata
159 #define __initconst_or_module __initconst
160 #define __INIT_OR_MODULE __INIT
161 #define __INITDATA_OR_MODULE __INITDATA
162 #define __INITRODATA_OR_MODULE __INITRODATA
163 #endif /*CONFIG_MODULES*/
164
165 /* Generic info of form tag = "info" */
166 #define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info)
167
168 /* For userspace: you can also call me... */
169 #define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)
170
171 /* Soft module dependencies. See man modprobe.d for details.
172 * Example: MODULE_SOFTDEP("pre: module-foo module-bar post: module-baz")
173 */
174 #define MODULE_SOFTDEP(_softdep) MODULE_INFO(softdep, _softdep)
175
176 /*
177 * 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_##type##__##name##_device_table \
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 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, __stringify(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) ((typeof(&x))(__symbol_get(__stringify(x))))
310
311 /* modules using other modules: kdb wants to see this. */
312 struct module_use {
313 struct list_head source_list;
314 struct list_head target_list;
315 struct module *source, *target;
316 };
317
318 enum module_state {
319 MODULE_STATE_LIVE, /* Normal state. */
320 MODULE_STATE_COMING, /* Full formed, running module_init. */
321 MODULE_STATE_GOING, /* Going away. */
322 MODULE_STATE_UNFORMED, /* Still setting it up. */
323 };
324
325 struct mod_tree_node {
326 struct module *mod;
327 struct latch_tree_node node;
328 };
329
330 enum mod_mem_type {
331 MOD_TEXT = 0,
332 MOD_DATA,
333 MOD_RODATA,
334 MOD_RO_AFTER_INIT,
335 MOD_INIT_TEXT,
336 MOD_INIT_DATA,
337 MOD_INIT_RODATA,
338
339 MOD_MEM_NUM_TYPES,
340 MOD_INVALID = -1,
341 };
342
343 #define mod_mem_type_is_init(type) \
344 ((type) == MOD_INIT_TEXT || \
345 (type) == MOD_INIT_DATA || \
346 (type) == MOD_INIT_RODATA)
347
348 #define mod_mem_type_is_core(type) (!mod_mem_type_is_init(type))
349
350 #define mod_mem_type_is_text(type) \
351 ((type) == MOD_TEXT || \
352 (type) == MOD_INIT_TEXT)
353
354 #define mod_mem_type_is_data(type) (!mod_mem_type_is_text(type))
355
356 #define mod_mem_type_is_core_data(type) \
357 (mod_mem_type_is_core(type) && \
358 mod_mem_type_is_data(type))
359
360 #define for_each_mod_mem_type(type) \
361 for (enum mod_mem_type (type) = 0; \
362 (type) < MOD_MEM_NUM_TYPES; (type)++)
363
364 #define for_class_mod_mem_type(type, class) \
365 for_each_mod_mem_type(type) \
366 if (mod_mem_type_is_##class(type))
367
368 struct module_memory {
369 void *base;
370 unsigned int size;
371
372 #ifdef CONFIG_MODULES_TREE_LOOKUP
373 struct mod_tree_node mtn;
374 #endif
375 };
376
377 #ifdef CONFIG_MODULES_TREE_LOOKUP
378 /* Only touch one cacheline for common rbtree-for-core-layout case. */
379 #define __module_memory_align ____cacheline_aligned
380 #else
381 #define __module_memory_align
382 #endif
383
384 struct mod_kallsyms {
385 Elf_Sym *symtab;
386 unsigned int num_symtab;
387 char *strtab;
388 char *typetab;
389 };
390
391 #ifdef CONFIG_LIVEPATCH
392 /**
393 * struct klp_modinfo - ELF information preserved from the livepatch module
394 *
395 * @hdr: ELF header
396 * @sechdrs: Section header table
397 * @secstrings: String table for the section headers
398 * @symndx: The symbol table section index
399 */
400 struct klp_modinfo {
401 Elf_Ehdr hdr;
402 Elf_Shdr *sechdrs;
403 char *secstrings;
404 unsigned int symndx;
405 };
406 #endif
407
408 struct module {
409 enum module_state state;
410
411 /* Member of list of modules */
412 struct list_head list;
413
414 /* Unique handle for this module */
415 char name[MODULE_NAME_LEN];
416
417 #ifdef CONFIG_STACKTRACE_BUILD_ID
418 /* Module build ID */
419 unsigned char build_id[BUILD_ID_SIZE_MAX];
420 #endif
421
422 /* Sysfs stuff. */
423 struct module_kobject mkobj;
424 struct module_attribute *modinfo_attrs;
425 const char *version;
426 const char *srcversion;
427 struct kobject *holders_dir;
428
429 /* Exported symbols */
430 const struct kernel_symbol *syms;
431 const s32 *crcs;
432 unsigned int num_syms;
433
434 #ifdef CONFIG_ARCH_USES_CFI_TRAPS
435 s32 *kcfi_traps;
436 s32 *kcfi_traps_end;
437 #endif
438
439 /* Kernel parameters. */
440 #ifdef CONFIG_SYSFS
441 struct mutex param_lock;
442 #endif
443 struct kernel_param *kp;
444 unsigned int num_kp;
445
446 /* GPL-only exported symbols. */
447 unsigned int num_gpl_syms;
448 const struct kernel_symbol *gpl_syms;
449 const s32 *gpl_crcs;
450 bool using_gplonly_symbols;
451
452 #ifdef CONFIG_MODULE_SIG
453 /* Signature was verified. */
454 bool sig_ok;
455 #endif
456
457 bool async_probe_requested;
458
459 /* Exception table */
460 unsigned int num_exentries;
461 struct exception_table_entry *extable;
462
463 /* Startup function. */
464 int (*init)(void);
465
466 struct module_memory mem[MOD_MEM_NUM_TYPES] __module_memory_align;
467
468 /* Arch-specific module values */
469 struct mod_arch_specific arch;
470
471 unsigned long taints; /* same bits as kernel:taint_flags */
472
473 #ifdef CONFIG_GENERIC_BUG
474 /* Support for BUG */
475 unsigned num_bugs;
476 struct list_head bug_list;
477 struct bug_entry *bug_table;
478 #endif
479
480 #ifdef CONFIG_KALLSYMS
481 /* Protected by RCU and/or module_mutex: use rcu_dereference() */
482 struct mod_kallsyms __rcu *kallsyms;
483 struct mod_kallsyms core_kallsyms;
484
485 /* Section attributes */
486 struct module_sect_attrs *sect_attrs;
487
488 /* Notes attributes */
489 struct module_notes_attrs *notes_attrs;
490 #endif
491
492 /* The command line arguments (may be mangled). People like
493 keeping pointers to this stuff */
494 char *args;
495
496 #ifdef CONFIG_SMP
497 /* Per-cpu data. */
498 void __percpu *percpu;
499 unsigned int percpu_size;
500 #endif
501 void *noinstr_text_start;
502 unsigned int noinstr_text_size;
503
504 #ifdef CONFIG_TRACEPOINTS
505 unsigned int num_tracepoints;
506 tracepoint_ptr_t *tracepoints_ptrs;
507 #endif
508 #ifdef CONFIG_TREE_SRCU
509 unsigned int num_srcu_structs;
510 struct srcu_struct **srcu_struct_ptrs;
511 #endif
512 #ifdef CONFIG_BPF_EVENTS
513 unsigned int num_bpf_raw_events;
514 struct bpf_raw_event_map *bpf_raw_events;
515 #endif
516 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
517 unsigned int btf_data_size;
518 unsigned int btf_base_data_size;
519 void *btf_data;
520 void *btf_base_data;
521 #endif
522 #ifdef CONFIG_JUMP_LABEL
523 struct jump_entry *jump_entries;
524 unsigned int num_jump_entries;
525 #endif
526 #ifdef CONFIG_TRACING
527 unsigned int num_trace_bprintk_fmt;
528 const char **trace_bprintk_fmt_start;
529 #endif
530 #ifdef CONFIG_EVENT_TRACING
531 struct trace_event_call **trace_events;
532 unsigned int num_trace_events;
533 struct trace_eval_map **trace_evals;
534 unsigned int num_trace_evals;
535 #endif
536 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
537 unsigned int num_ftrace_callsites;
538 unsigned long *ftrace_callsites;
539 #endif
540 #ifdef CONFIG_KPROBES
541 void *kprobes_text_start;
542 unsigned int kprobes_text_size;
543 unsigned long *kprobe_blacklist;
544 unsigned int num_kprobe_blacklist;
545 #endif
546 #ifdef CONFIG_HAVE_STATIC_CALL_INLINE
547 int num_static_call_sites;
548 struct static_call_site *static_call_sites;
549 #endif
550 #if IS_ENABLED(CONFIG_KUNIT)
551 int num_kunit_init_suites;
552 struct kunit_suite **kunit_init_suites;
553 int num_kunit_suites;
554 struct kunit_suite **kunit_suites;
555 #endif
556
557
558 #ifdef CONFIG_LIVEPATCH
559 bool klp; /* Is this a livepatch module? */
560 bool klp_alive;
561
562 /* ELF information */
563 struct klp_modinfo *klp_info;
564 #endif
565
566 #ifdef CONFIG_PRINTK_INDEX
567 unsigned int printk_index_size;
568 struct pi_entry **printk_index_start;
569 #endif
570
571 #ifdef CONFIG_MODULE_UNLOAD
572 /* What modules depend on me? */
573 struct list_head source_list;
574 /* What modules do I depend on? */
575 struct list_head target_list;
576
577 /* Destruction function. */
578 void (*exit)(void);
579
580 atomic_t refcnt;
581 #endif
582
583 #ifdef CONFIG_CONSTRUCTORS
584 /* Constructor functions. */
585 ctor_fn_t *ctors;
586 unsigned int num_ctors;
587 #endif
588
589 #ifdef CONFIG_FUNCTION_ERROR_INJECTION
590 struct error_injection_entry *ei_funcs;
591 unsigned int num_ei_funcs;
592 #endif
593 #ifdef CONFIG_DYNAMIC_DEBUG_CORE
594 struct _ddebug_info dyndbg_info;
595 #endif
596 } ____cacheline_aligned __randomize_layout;
597 #ifndef MODULE_ARCH_INIT
598 #define MODULE_ARCH_INIT {}
599 #endif
600
601 #ifndef HAVE_ARCH_KALLSYMS_SYMBOL_VALUE
kallsyms_symbol_value(const Elf_Sym * sym)602 static inline unsigned long kallsyms_symbol_value(const Elf_Sym *sym)
603 {
604 return sym->st_value;
605 }
606 #endif
607
608 /* FIXME: It'd be nice to isolate modules during init, too, so they
609 aren't used before they (may) fail. But presently too much code
610 (IDE & SCSI) require entry into the module during init.*/
module_is_live(struct module * mod)611 static inline bool module_is_live(struct module *mod)
612 {
613 return mod->state != MODULE_STATE_GOING;
614 }
615
module_is_coming(struct module * mod)616 static inline bool module_is_coming(struct module *mod)
617 {
618 return mod->state == MODULE_STATE_COMING;
619 }
620
621 struct module *__module_text_address(unsigned long addr);
622 struct module *__module_address(unsigned long addr);
623 bool is_module_address(unsigned long addr);
624 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr);
625 bool is_module_percpu_address(unsigned long addr);
626 bool is_module_text_address(unsigned long addr);
627
within_module_mem_type(unsigned long addr,const struct module * mod,enum mod_mem_type type)628 static inline bool within_module_mem_type(unsigned long addr,
629 const struct module *mod,
630 enum mod_mem_type type)
631 {
632 unsigned long base, size;
633
634 base = (unsigned long)mod->mem[type].base;
635 size = mod->mem[type].size;
636 return addr - base < size;
637 }
638
within_module_core(unsigned long addr,const struct module * mod)639 static inline bool within_module_core(unsigned long addr,
640 const struct module *mod)
641 {
642 for_class_mod_mem_type(type, core) {
643 if (within_module_mem_type(addr, mod, type))
644 return true;
645 }
646 return false;
647 }
648
within_module_init(unsigned long addr,const struct module * mod)649 static inline bool within_module_init(unsigned long addr,
650 const struct module *mod)
651 {
652 for_class_mod_mem_type(type, init) {
653 if (within_module_mem_type(addr, mod, type))
654 return true;
655 }
656 return false;
657 }
658
within_module(unsigned long addr,const struct module * mod)659 static inline bool within_module(unsigned long addr, const struct module *mod)
660 {
661 return within_module_init(addr, mod) || within_module_core(addr, mod);
662 }
663
664 /* Search for module by name: must be in a RCU-sched critical section. */
665 struct module *find_module(const char *name);
666
667 extern void __noreturn __module_put_and_kthread_exit(struct module *mod,
668 long code);
669 #define module_put_and_kthread_exit(code) __module_put_and_kthread_exit(THIS_MODULE, code)
670
671 #ifdef CONFIG_MODULE_UNLOAD
672 int module_refcount(struct module *mod);
673 void __symbol_put(const char *symbol);
674 #define symbol_put(x) __symbol_put(__stringify(x))
675 void symbol_put_addr(void *addr);
676
677 /* Sometimes we know we already have a refcount, and it's easier not
678 to handle the error case (which only happens with rmmod --wait). */
679 extern void __module_get(struct module *module);
680
681 /**
682 * try_module_get() - take module refcount unless module is being removed
683 * @module: the module we should check for
684 *
685 * Only try to get a module reference count if the module is not being removed.
686 * This call will fail if the module is in the process of being removed.
687 *
688 * Care must also be taken to ensure the module exists and is alive prior to
689 * usage of this call. This can be gauranteed through two means:
690 *
691 * 1) Direct protection: you know an earlier caller must have increased the
692 * module reference through __module_get(). This can typically be achieved
693 * by having another entity other than the module itself increment the
694 * module reference count.
695 *
696 * 2) Implied protection: there is an implied protection against module
697 * removal. An example of this is the implied protection used by kernfs /
698 * sysfs. The sysfs store / read file operations are guaranteed to exist
699 * through the use of kernfs's active reference (see kernfs_active()) and a
700 * sysfs / kernfs file removal cannot happen unless the same file is not
701 * active. Therefore, if a sysfs file is being read or written to the module
702 * which created it must still exist. It is therefore safe to use
703 * try_module_get() on module sysfs store / read ops.
704 *
705 * One of the real values to try_module_get() is the module_is_live() check
706 * which ensures that the caller of try_module_get() can yield to userspace
707 * module removal requests and gracefully fail if the module is on its way out.
708 *
709 * Returns true if the reference count was successfully incremented.
710 */
711 extern bool try_module_get(struct module *module);
712
713 /**
714 * module_put() - release a reference count to a module
715 * @module: the module we should release a reference count for
716 *
717 * If you successfully bump a reference count to a module with try_module_get(),
718 * when you are finished you must call module_put() to release that reference
719 * count.
720 */
721 extern void module_put(struct module *module);
722
723 #else /*!CONFIG_MODULE_UNLOAD*/
try_module_get(struct module * module)724 static inline bool try_module_get(struct module *module)
725 {
726 return !module || module_is_live(module);
727 }
module_put(struct module * module)728 static inline void module_put(struct module *module)
729 {
730 }
__module_get(struct module * module)731 static inline void __module_get(struct module *module)
732 {
733 }
734 #define symbol_put(x) do { } while (0)
735 #define symbol_put_addr(p) do { } while (0)
736
737 #endif /* CONFIG_MODULE_UNLOAD */
738
739 /* This is a #define so the string doesn't get put in every .o file */
740 #define module_name(mod) \
741 ({ \
742 struct module *__mod = (mod); \
743 __mod ? __mod->name : "kernel"; \
744 })
745
746 /* Dereference module function descriptor */
747 void *dereference_module_function_descriptor(struct module *mod, void *ptr);
748
749 int register_module_notifier(struct notifier_block *nb);
750 int unregister_module_notifier(struct notifier_block *nb);
751
752 extern void print_modules(void);
753
module_requested_async_probing(struct module * module)754 static inline bool module_requested_async_probing(struct module *module)
755 {
756 return module && module->async_probe_requested;
757 }
758
is_livepatch_module(struct module * mod)759 static inline bool is_livepatch_module(struct module *mod)
760 {
761 #ifdef CONFIG_LIVEPATCH
762 return mod->klp;
763 #else
764 return false;
765 #endif
766 }
767
768 void set_module_sig_enforced(void);
769
770 #else /* !CONFIG_MODULES... */
771
__module_address(unsigned long addr)772 static inline struct module *__module_address(unsigned long addr)
773 {
774 return NULL;
775 }
776
__module_text_address(unsigned long addr)777 static inline struct module *__module_text_address(unsigned long addr)
778 {
779 return NULL;
780 }
781
is_module_address(unsigned long addr)782 static inline bool is_module_address(unsigned long addr)
783 {
784 return false;
785 }
786
is_module_percpu_address(unsigned long addr)787 static inline bool is_module_percpu_address(unsigned long addr)
788 {
789 return false;
790 }
791
__is_module_percpu_address(unsigned long addr,unsigned long * can_addr)792 static inline bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
793 {
794 return false;
795 }
796
is_module_text_address(unsigned long addr)797 static inline bool is_module_text_address(unsigned long addr)
798 {
799 return false;
800 }
801
within_module_core(unsigned long addr,const struct module * mod)802 static inline bool within_module_core(unsigned long addr,
803 const struct module *mod)
804 {
805 return false;
806 }
807
within_module_init(unsigned long addr,const struct module * mod)808 static inline bool within_module_init(unsigned long addr,
809 const struct module *mod)
810 {
811 return false;
812 }
813
within_module(unsigned long addr,const struct module * mod)814 static inline bool within_module(unsigned long addr, const struct module *mod)
815 {
816 return false;
817 }
818
819 /* Get/put a kernel symbol (calls should be symmetric) */
820 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak,visibility("hidden"))); &(x); })
821 #define symbol_put(x) do { } while (0)
822 #define symbol_put_addr(x) do { } while (0)
823
__module_get(struct module * module)824 static inline void __module_get(struct module *module)
825 {
826 }
827
try_module_get(struct module * module)828 static inline bool try_module_get(struct module *module)
829 {
830 return true;
831 }
832
module_put(struct module * module)833 static inline void module_put(struct module *module)
834 {
835 }
836
837 #define module_name(mod) "kernel"
838
register_module_notifier(struct notifier_block * nb)839 static inline int register_module_notifier(struct notifier_block *nb)
840 {
841 /* no events will happen anyway, so this can always succeed */
842 return 0;
843 }
844
unregister_module_notifier(struct notifier_block * nb)845 static inline int unregister_module_notifier(struct notifier_block *nb)
846 {
847 return 0;
848 }
849
850 #define module_put_and_kthread_exit(code) kthread_exit(code)
851
print_modules(void)852 static inline void print_modules(void)
853 {
854 }
855
module_requested_async_probing(struct module * module)856 static inline bool module_requested_async_probing(struct module *module)
857 {
858 return false;
859 }
860
861
set_module_sig_enforced(void)862 static inline void set_module_sig_enforced(void)
863 {
864 }
865
866 /* Dereference module function descriptor */
867 static inline
dereference_module_function_descriptor(struct module * mod,void * ptr)868 void *dereference_module_function_descriptor(struct module *mod, void *ptr)
869 {
870 return ptr;
871 }
872
module_is_coming(struct module * mod)873 static inline bool module_is_coming(struct module *mod)
874 {
875 return false;
876 }
877 #endif /* CONFIG_MODULES */
878
879 #ifdef CONFIG_SYSFS
880 extern struct kset *module_kset;
881 extern const struct kobj_type module_ktype;
882 #endif /* CONFIG_SYSFS */
883
884 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
885
886 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
887
888 #define __MODULE_STRING(x) __stringify(x)
889
890 #ifdef CONFIG_GENERIC_BUG
891 void module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *,
892 struct module *);
893 void module_bug_cleanup(struct module *);
894
895 #else /* !CONFIG_GENERIC_BUG */
896
module_bug_finalize(const Elf_Ehdr * hdr,const Elf_Shdr * sechdrs,struct module * mod)897 static inline void module_bug_finalize(const Elf_Ehdr *hdr,
898 const Elf_Shdr *sechdrs,
899 struct module *mod)
900 {
901 }
module_bug_cleanup(struct module * mod)902 static inline void module_bug_cleanup(struct module *mod) {}
903 #endif /* CONFIG_GENERIC_BUG */
904
905 #ifdef CONFIG_MITIGATION_RETPOLINE
906 extern bool retpoline_module_ok(bool has_retpoline);
907 #else
retpoline_module_ok(bool has_retpoline)908 static inline bool retpoline_module_ok(bool has_retpoline)
909 {
910 return true;
911 }
912 #endif
913
914 #ifdef CONFIG_MODULE_SIG
915 bool is_module_sig_enforced(void);
916
module_sig_ok(struct module * module)917 static inline bool module_sig_ok(struct module *module)
918 {
919 return module->sig_ok;
920 }
921 #else /* !CONFIG_MODULE_SIG */
is_module_sig_enforced(void)922 static inline bool is_module_sig_enforced(void)
923 {
924 return false;
925 }
926
module_sig_ok(struct module * module)927 static inline bool module_sig_ok(struct module *module)
928 {
929 return true;
930 }
931 #endif /* CONFIG_MODULE_SIG */
932
933 #if defined(CONFIG_MODULES) && defined(CONFIG_KALLSYMS)
934 int module_kallsyms_on_each_symbol(const char *modname,
935 int (*fn)(void *, const char *, unsigned long),
936 void *data);
937
938 /* For kallsyms to ask for address resolution. namebuf should be at
939 * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
940 * found, otherwise NULL.
941 */
942 int module_address_lookup(unsigned long addr,
943 unsigned long *symbolsize,
944 unsigned long *offset,
945 char **modname, const unsigned char **modbuildid,
946 char *namebuf);
947 int lookup_module_symbol_name(unsigned long addr, char *symname);
948 int lookup_module_symbol_attrs(unsigned long addr,
949 unsigned long *size,
950 unsigned long *offset,
951 char *modname,
952 char *name);
953
954 /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
955 * symnum out of range.
956 */
957 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
958 char *name, char *module_name, int *exported);
959
960 /* Look for this name: can be of form module:name. */
961 unsigned long module_kallsyms_lookup_name(const char *name);
962
963 unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name);
964
965 #else /* CONFIG_MODULES && CONFIG_KALLSYMS */
966
module_kallsyms_on_each_symbol(const char * modname,int (* fn)(void *,const char *,unsigned long),void * data)967 static inline int module_kallsyms_on_each_symbol(const char *modname,
968 int (*fn)(void *, const char *, unsigned long),
969 void *data)
970 {
971 return -EOPNOTSUPP;
972 }
973
974 /* 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)975 static inline int module_address_lookup(unsigned long addr,
976 unsigned long *symbolsize,
977 unsigned long *offset,
978 char **modname,
979 const unsigned char **modbuildid,
980 char *namebuf)
981 {
982 return 0;
983 }
984
lookup_module_symbol_name(unsigned long addr,char * symname)985 static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
986 {
987 return -ERANGE;
988 }
989
module_get_kallsym(unsigned int symnum,unsigned long * value,char * type,char * name,char * module_name,int * exported)990 static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
991 char *type, char *name,
992 char *module_name, int *exported)
993 {
994 return -ERANGE;
995 }
996
module_kallsyms_lookup_name(const char * name)997 static inline unsigned long module_kallsyms_lookup_name(const char *name)
998 {
999 return 0;
1000 }
1001
find_kallsyms_symbol_value(struct module * mod,const char * name)1002 static inline unsigned long find_kallsyms_symbol_value(struct module *mod,
1003 const char *name)
1004 {
1005 return 0;
1006 }
1007
1008 #endif /* CONFIG_MODULES && CONFIG_KALLSYMS */
1009
1010 #endif /* _LINUX_MODULE_H */
1011