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_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 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) ((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 void *rw_copy;
371 bool is_rox;
372 unsigned int size;
373
374 #ifdef CONFIG_MODULES_TREE_LOOKUP
375 struct mod_tree_node mtn;
376 #endif
377 };
378
379 #ifdef CONFIG_MODULES_TREE_LOOKUP
380 /* Only touch one cacheline for common rbtree-for-core-layout case. */
381 #define __module_memory_align ____cacheline_aligned
382 #else
383 #define __module_memory_align
384 #endif
385
386 struct mod_kallsyms {
387 Elf_Sym *symtab;
388 unsigned int num_symtab;
389 char *strtab;
390 char *typetab;
391 };
392
393 #ifdef CONFIG_LIVEPATCH
394 /**
395 * struct klp_modinfo - ELF information preserved from the livepatch module
396 *
397 * @hdr: ELF header
398 * @sechdrs: Section header table
399 * @secstrings: String table for the section headers
400 * @symndx: The symbol table section index
401 */
402 struct klp_modinfo {
403 Elf_Ehdr hdr;
404 Elf_Shdr *sechdrs;
405 char *secstrings;
406 unsigned int symndx;
407 };
408 #endif
409
410 struct module {
411 enum module_state state;
412
413 /* Member of list of modules */
414 struct list_head list;
415
416 /* Unique handle for this module */
417 char name[MODULE_NAME_LEN];
418
419 #ifdef CONFIG_STACKTRACE_BUILD_ID
420 /* Module build ID */
421 unsigned char build_id[BUILD_ID_SIZE_MAX];
422 #endif
423
424 /* Sysfs stuff. */
425 struct module_kobject mkobj;
426 struct module_attribute *modinfo_attrs;
427 const char *version;
428 const char *srcversion;
429 struct kobject *holders_dir;
430
431 /* Exported symbols */
432 const struct kernel_symbol *syms;
433 const s32 *crcs;
434 unsigned int num_syms;
435
436 #ifdef CONFIG_ARCH_USES_CFI_TRAPS
437 s32 *kcfi_traps;
438 s32 *kcfi_traps_end;
439 #endif
440
441 /* Kernel parameters. */
442 #ifdef CONFIG_SYSFS
443 struct mutex param_lock;
444 #endif
445 struct kernel_param *kp;
446 unsigned int num_kp;
447
448 /* GPL-only exported symbols. */
449 unsigned int num_gpl_syms;
450 const struct kernel_symbol *gpl_syms;
451 const s32 *gpl_crcs;
452 bool using_gplonly_symbols;
453
454 #ifdef CONFIG_MODULE_SIG
455 /* Signature was verified. */
456 bool sig_ok;
457 #endif
458
459 bool async_probe_requested;
460
461 /* Exception table */
462 unsigned int num_exentries;
463 struct exception_table_entry *extable;
464
465 /* Startup function. */
466 int (*init)(void);
467
468 struct module_memory mem[MOD_MEM_NUM_TYPES] __module_memory_align;
469
470 /* Arch-specific module values */
471 struct mod_arch_specific arch;
472
473 unsigned long taints; /* same bits as kernel:taint_flags */
474
475 #ifdef CONFIG_GENERIC_BUG
476 /* Support for BUG */
477 unsigned num_bugs;
478 struct list_head bug_list;
479 struct bug_entry *bug_table;
480 #endif
481
482 #ifdef CONFIG_KALLSYMS
483 /* Protected by RCU and/or module_mutex: use rcu_dereference() */
484 struct mod_kallsyms __rcu *kallsyms;
485 struct mod_kallsyms core_kallsyms;
486
487 /* Section attributes */
488 struct module_sect_attrs *sect_attrs;
489
490 /* Notes attributes */
491 struct module_notes_attrs *notes_attrs;
492 #endif
493
494 /* The command line arguments (may be mangled). People like
495 keeping pointers to this stuff */
496 char *args;
497
498 #ifdef CONFIG_SMP
499 /* Per-cpu data. */
500 void __percpu *percpu;
501 unsigned int percpu_size;
502 #endif
503 void *noinstr_text_start;
504 unsigned int noinstr_text_size;
505
506 #ifdef CONFIG_TRACEPOINTS
507 unsigned int num_tracepoints;
508 tracepoint_ptr_t *tracepoints_ptrs;
509 #endif
510 #ifdef CONFIG_TREE_SRCU
511 unsigned int num_srcu_structs;
512 struct srcu_struct **srcu_struct_ptrs;
513 #endif
514 #ifdef CONFIG_BPF_EVENTS
515 unsigned int num_bpf_raw_events;
516 struct bpf_raw_event_map *bpf_raw_events;
517 #endif
518 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
519 unsigned int btf_data_size;
520 unsigned int btf_base_data_size;
521 void *btf_data;
522 void *btf_base_data;
523 #endif
524 #ifdef CONFIG_JUMP_LABEL
525 struct jump_entry *jump_entries;
526 unsigned int num_jump_entries;
527 #endif
528 #ifdef CONFIG_TRACING
529 unsigned int num_trace_bprintk_fmt;
530 const char **trace_bprintk_fmt_start;
531 #endif
532 #ifdef CONFIG_EVENT_TRACING
533 struct trace_event_call **trace_events;
534 unsigned int num_trace_events;
535 struct trace_eval_map **trace_evals;
536 unsigned int num_trace_evals;
537 #endif
538 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
539 unsigned int num_ftrace_callsites;
540 unsigned long *ftrace_callsites;
541 #endif
542 #ifdef CONFIG_KPROBES
543 void *kprobes_text_start;
544 unsigned int kprobes_text_size;
545 unsigned long *kprobe_blacklist;
546 unsigned int num_kprobe_blacklist;
547 #endif
548 #ifdef CONFIG_HAVE_STATIC_CALL_INLINE
549 int num_static_call_sites;
550 struct static_call_site *static_call_sites;
551 #endif
552 #if IS_ENABLED(CONFIG_KUNIT)
553 int num_kunit_init_suites;
554 struct kunit_suite **kunit_init_suites;
555 int num_kunit_suites;
556 struct kunit_suite **kunit_suites;
557 #endif
558
559
560 #ifdef CONFIG_LIVEPATCH
561 bool klp; /* Is this a livepatch module? */
562 bool klp_alive;
563
564 /* ELF information */
565 struct klp_modinfo *klp_info;
566 #endif
567
568 #ifdef CONFIG_PRINTK_INDEX
569 unsigned int printk_index_size;
570 struct pi_entry **printk_index_start;
571 #endif
572
573 #ifdef CONFIG_MODULE_UNLOAD
574 /* What modules depend on me? */
575 struct list_head source_list;
576 /* What modules do I depend on? */
577 struct list_head target_list;
578
579 /* Destruction function. */
580 void (*exit)(void);
581
582 atomic_t refcnt;
583 #endif
584
585 #ifdef CONFIG_CONSTRUCTORS
586 /* Constructor functions. */
587 ctor_fn_t *ctors;
588 unsigned int num_ctors;
589 #endif
590
591 #ifdef CONFIG_FUNCTION_ERROR_INJECTION
592 struct error_injection_entry *ei_funcs;
593 unsigned int num_ei_funcs;
594 #endif
595 #ifdef CONFIG_DYNAMIC_DEBUG_CORE
596 struct _ddebug_info dyndbg_info;
597 #endif
598 } ____cacheline_aligned __randomize_layout;
599 #ifndef MODULE_ARCH_INIT
600 #define MODULE_ARCH_INIT {}
601 #endif
602
603 #ifndef HAVE_ARCH_KALLSYMS_SYMBOL_VALUE
kallsyms_symbol_value(const Elf_Sym * sym)604 static inline unsigned long kallsyms_symbol_value(const Elf_Sym *sym)
605 {
606 return sym->st_value;
607 }
608 #endif
609
610 /* FIXME: It'd be nice to isolate modules during init, too, so they
611 aren't used before they (may) fail. But presently too much code
612 (IDE & SCSI) require entry into the module during init.*/
module_is_live(struct module * mod)613 static inline bool module_is_live(struct module *mod)
614 {
615 return mod->state != MODULE_STATE_GOING;
616 }
617
module_is_coming(struct module * mod)618 static inline bool module_is_coming(struct module *mod)
619 {
620 return mod->state == MODULE_STATE_COMING;
621 }
622
623 struct module *__module_text_address(unsigned long addr);
624 struct module *__module_address(unsigned long addr);
625 bool is_module_address(unsigned long addr);
626 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr);
627 bool is_module_percpu_address(unsigned long addr);
628 bool is_module_text_address(unsigned long addr);
629
within_module_mem_type(unsigned long addr,const struct module * mod,enum mod_mem_type type)630 static inline bool within_module_mem_type(unsigned long addr,
631 const struct module *mod,
632 enum mod_mem_type type)
633 {
634 unsigned long base, size;
635
636 base = (unsigned long)mod->mem[type].base;
637 size = mod->mem[type].size;
638 return addr - base < size;
639 }
640
within_module_core(unsigned long addr,const struct module * mod)641 static inline bool within_module_core(unsigned long addr,
642 const struct module *mod)
643 {
644 for_class_mod_mem_type(type, core) {
645 if (within_module_mem_type(addr, mod, type))
646 return true;
647 }
648 return false;
649 }
650
within_module_init(unsigned long addr,const struct module * mod)651 static inline bool within_module_init(unsigned long addr,
652 const struct module *mod)
653 {
654 for_class_mod_mem_type(type, init) {
655 if (within_module_mem_type(addr, mod, type))
656 return true;
657 }
658 return false;
659 }
660
within_module(unsigned long addr,const struct module * mod)661 static inline bool within_module(unsigned long addr, const struct module *mod)
662 {
663 return within_module_init(addr, mod) || within_module_core(addr, mod);
664 }
665
666 /* Search for module by name: must be in a RCU-sched critical section. */
667 struct module *find_module(const char *name);
668
669 extern void __noreturn __module_put_and_kthread_exit(struct module *mod,
670 long code);
671 #define module_put_and_kthread_exit(code) __module_put_and_kthread_exit(THIS_MODULE, code)
672
673 #ifdef CONFIG_MODULE_UNLOAD
674 int module_refcount(struct module *mod);
675 void __symbol_put(const char *symbol);
676 #define symbol_put(x) __symbol_put(__stringify(x))
677 void symbol_put_addr(void *addr);
678
679 /* Sometimes we know we already have a refcount, and it's easier not
680 to handle the error case (which only happens with rmmod --wait). */
681 extern void __module_get(struct module *module);
682
683 /**
684 * try_module_get() - take module refcount unless module is being removed
685 * @module: the module we should check for
686 *
687 * Only try to get a module reference count if the module is not being removed.
688 * This call will fail if the module is in the process of being removed.
689 *
690 * Care must also be taken to ensure the module exists and is alive prior to
691 * usage of this call. This can be gauranteed through two means:
692 *
693 * 1) Direct protection: you know an earlier caller must have increased the
694 * module reference through __module_get(). This can typically be achieved
695 * by having another entity other than the module itself increment the
696 * module reference count.
697 *
698 * 2) Implied protection: there is an implied protection against module
699 * removal. An example of this is the implied protection used by kernfs /
700 * sysfs. The sysfs store / read file operations are guaranteed to exist
701 * through the use of kernfs's active reference (see kernfs_active()) and a
702 * sysfs / kernfs file removal cannot happen unless the same file is not
703 * active. Therefore, if a sysfs file is being read or written to the module
704 * which created it must still exist. It is therefore safe to use
705 * try_module_get() on module sysfs store / read ops.
706 *
707 * One of the real values to try_module_get() is the module_is_live() check
708 * which ensures that the caller of try_module_get() can yield to userspace
709 * module removal requests and gracefully fail if the module is on its way out.
710 *
711 * Returns true if the reference count was successfully incremented.
712 */
713 extern bool try_module_get(struct module *module);
714
715 /**
716 * module_put() - release a reference count to a module
717 * @module: the module we should release a reference count for
718 *
719 * If you successfully bump a reference count to a module with try_module_get(),
720 * when you are finished you must call module_put() to release that reference
721 * count.
722 */
723 extern void module_put(struct module *module);
724
725 #else /*!CONFIG_MODULE_UNLOAD*/
try_module_get(struct module * module)726 static inline bool try_module_get(struct module *module)
727 {
728 return !module || module_is_live(module);
729 }
module_put(struct module * module)730 static inline void module_put(struct module *module)
731 {
732 }
__module_get(struct module * module)733 static inline void __module_get(struct module *module)
734 {
735 }
736 #define symbol_put(x) do { } while (0)
737 #define symbol_put_addr(p) do { } while (0)
738
739 #endif /* CONFIG_MODULE_UNLOAD */
740
741 /* This is a #define so the string doesn't get put in every .o file */
742 #define module_name(mod) \
743 ({ \
744 struct module *__mod = (mod); \
745 __mod ? __mod->name : "kernel"; \
746 })
747
748 /* Dereference module function descriptor */
749 void *dereference_module_function_descriptor(struct module *mod, void *ptr);
750
751 int register_module_notifier(struct notifier_block *nb);
752 int unregister_module_notifier(struct notifier_block *nb);
753
754 extern void print_modules(void);
755
module_requested_async_probing(struct module * module)756 static inline bool module_requested_async_probing(struct module *module)
757 {
758 return module && module->async_probe_requested;
759 }
760
is_livepatch_module(struct module * mod)761 static inline bool is_livepatch_module(struct module *mod)
762 {
763 #ifdef CONFIG_LIVEPATCH
764 return mod->klp;
765 #else
766 return false;
767 #endif
768 }
769
770 void set_module_sig_enforced(void);
771
772 void *__module_writable_address(struct module *mod, void *loc);
773
module_writable_address(struct module * mod,void * loc)774 static inline void *module_writable_address(struct module *mod, void *loc)
775 {
776 if (!IS_ENABLED(CONFIG_ARCH_HAS_EXECMEM_ROX) || !mod)
777 return loc;
778 return __module_writable_address(mod, loc);
779 }
780
781 #else /* !CONFIG_MODULES... */
782
__module_address(unsigned long addr)783 static inline struct module *__module_address(unsigned long addr)
784 {
785 return NULL;
786 }
787
__module_text_address(unsigned long addr)788 static inline struct module *__module_text_address(unsigned long addr)
789 {
790 return NULL;
791 }
792
is_module_address(unsigned long addr)793 static inline bool is_module_address(unsigned long addr)
794 {
795 return false;
796 }
797
is_module_percpu_address(unsigned long addr)798 static inline bool is_module_percpu_address(unsigned long addr)
799 {
800 return false;
801 }
802
__is_module_percpu_address(unsigned long addr,unsigned long * can_addr)803 static inline bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
804 {
805 return false;
806 }
807
is_module_text_address(unsigned long addr)808 static inline bool is_module_text_address(unsigned long addr)
809 {
810 return false;
811 }
812
within_module_core(unsigned long addr,const struct module * mod)813 static inline bool within_module_core(unsigned long addr,
814 const struct module *mod)
815 {
816 return false;
817 }
818
within_module_init(unsigned long addr,const struct module * mod)819 static inline bool within_module_init(unsigned long addr,
820 const struct module *mod)
821 {
822 return false;
823 }
824
within_module(unsigned long addr,const struct module * mod)825 static inline bool within_module(unsigned long addr, const struct module *mod)
826 {
827 return false;
828 }
829
830 /* Get/put a kernel symbol (calls should be symmetric) */
831 #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak,visibility("hidden"))); &(x); })
832 #define symbol_put(x) do { } while (0)
833 #define symbol_put_addr(x) do { } while (0)
834
__module_get(struct module * module)835 static inline void __module_get(struct module *module)
836 {
837 }
838
try_module_get(struct module * module)839 static inline bool try_module_get(struct module *module)
840 {
841 return true;
842 }
843
module_put(struct module * module)844 static inline void module_put(struct module *module)
845 {
846 }
847
848 #define module_name(mod) "kernel"
849
register_module_notifier(struct notifier_block * nb)850 static inline int register_module_notifier(struct notifier_block *nb)
851 {
852 /* no events will happen anyway, so this can always succeed */
853 return 0;
854 }
855
unregister_module_notifier(struct notifier_block * nb)856 static inline int unregister_module_notifier(struct notifier_block *nb)
857 {
858 return 0;
859 }
860
861 #define module_put_and_kthread_exit(code) kthread_exit(code)
862
print_modules(void)863 static inline void print_modules(void)
864 {
865 }
866
module_requested_async_probing(struct module * module)867 static inline bool module_requested_async_probing(struct module *module)
868 {
869 return false;
870 }
871
872
set_module_sig_enforced(void)873 static inline void set_module_sig_enforced(void)
874 {
875 }
876
877 /* Dereference module function descriptor */
878 static inline
dereference_module_function_descriptor(struct module * mod,void * ptr)879 void *dereference_module_function_descriptor(struct module *mod, void *ptr)
880 {
881 return ptr;
882 }
883
module_is_coming(struct module * mod)884 static inline bool module_is_coming(struct module *mod)
885 {
886 return false;
887 }
888
module_writable_address(struct module * mod,void * loc)889 static inline void *module_writable_address(struct module *mod, void *loc)
890 {
891 return loc;
892 }
893 #endif /* CONFIG_MODULES */
894
895 #ifdef CONFIG_SYSFS
896 extern struct kset *module_kset;
897 extern const struct kobj_type module_ktype;
898 #endif /* CONFIG_SYSFS */
899
900 #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x)
901
902 /* BELOW HERE ALL THESE ARE OBSOLETE AND WILL VANISH */
903
904 #define __MODULE_STRING(x) __stringify(x)
905
906 #ifdef CONFIG_GENERIC_BUG
907 void module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *,
908 struct module *);
909 void module_bug_cleanup(struct module *);
910
911 #else /* !CONFIG_GENERIC_BUG */
912
module_bug_finalize(const Elf_Ehdr * hdr,const Elf_Shdr * sechdrs,struct module * mod)913 static inline void module_bug_finalize(const Elf_Ehdr *hdr,
914 const Elf_Shdr *sechdrs,
915 struct module *mod)
916 {
917 }
module_bug_cleanup(struct module * mod)918 static inline void module_bug_cleanup(struct module *mod) {}
919 #endif /* CONFIG_GENERIC_BUG */
920
921 #ifdef CONFIG_MITIGATION_RETPOLINE
922 extern bool retpoline_module_ok(bool has_retpoline);
923 #else
retpoline_module_ok(bool has_retpoline)924 static inline bool retpoline_module_ok(bool has_retpoline)
925 {
926 return true;
927 }
928 #endif
929
930 #ifdef CONFIG_MODULE_SIG
931 bool is_module_sig_enforced(void);
932
module_sig_ok(struct module * module)933 static inline bool module_sig_ok(struct module *module)
934 {
935 return module->sig_ok;
936 }
937 #else /* !CONFIG_MODULE_SIG */
is_module_sig_enforced(void)938 static inline bool is_module_sig_enforced(void)
939 {
940 return false;
941 }
942
module_sig_ok(struct module * module)943 static inline bool module_sig_ok(struct module *module)
944 {
945 return true;
946 }
947 #endif /* CONFIG_MODULE_SIG */
948
949 #if defined(CONFIG_MODULES) && defined(CONFIG_KALLSYMS)
950 int module_kallsyms_on_each_symbol(const char *modname,
951 int (*fn)(void *, const char *, unsigned long),
952 void *data);
953
954 /* For kallsyms to ask for address resolution. namebuf should be at
955 * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
956 * found, otherwise NULL.
957 */
958 int module_address_lookup(unsigned long addr,
959 unsigned long *symbolsize,
960 unsigned long *offset,
961 char **modname, const unsigned char **modbuildid,
962 char *namebuf);
963 int lookup_module_symbol_name(unsigned long addr, char *symname);
964 int lookup_module_symbol_attrs(unsigned long addr,
965 unsigned long *size,
966 unsigned long *offset,
967 char *modname,
968 char *name);
969
970 /* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
971 * symnum out of range.
972 */
973 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
974 char *name, char *module_name, int *exported);
975
976 /* Look for this name: can be of form module:name. */
977 unsigned long module_kallsyms_lookup_name(const char *name);
978
979 unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name);
980
981 #else /* CONFIG_MODULES && CONFIG_KALLSYMS */
982
module_kallsyms_on_each_symbol(const char * modname,int (* fn)(void *,const char *,unsigned long),void * data)983 static inline int module_kallsyms_on_each_symbol(const char *modname,
984 int (*fn)(void *, const char *, unsigned long),
985 void *data)
986 {
987 return -EOPNOTSUPP;
988 }
989
990 /* 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)991 static inline int module_address_lookup(unsigned long addr,
992 unsigned long *symbolsize,
993 unsigned long *offset,
994 char **modname,
995 const unsigned char **modbuildid,
996 char *namebuf)
997 {
998 return 0;
999 }
1000
lookup_module_symbol_name(unsigned long addr,char * symname)1001 static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
1002 {
1003 return -ERANGE;
1004 }
1005
module_get_kallsym(unsigned int symnum,unsigned long * value,char * type,char * name,char * module_name,int * exported)1006 static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
1007 char *type, char *name,
1008 char *module_name, int *exported)
1009 {
1010 return -ERANGE;
1011 }
1012
module_kallsyms_lookup_name(const char * name)1013 static inline unsigned long module_kallsyms_lookup_name(const char *name)
1014 {
1015 return 0;
1016 }
1017
find_kallsyms_symbol_value(struct module * mod,const char * name)1018 static inline unsigned long find_kallsyms_symbol_value(struct module *mod,
1019 const char *name)
1020 {
1021 return 0;
1022 }
1023
1024 #endif /* CONFIG_MODULES && CONFIG_KALLSYMS */
1025
1026 #endif /* _LINUX_MODULE_H */
1027