1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Copyright (C) 2002 Richard Henderson
4 * Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
5 * Copyright (C) 2023 Luis Chamberlain <mcgrof@kernel.org>
8 #define INCLUDE_VERMAGIC
10 #include <linux/export.h>
11 #include <linux/extable.h>
12 #include <linux/moduleloader.h>
13 #include <linux/module_signature.h>
14 #include <linux/trace_events.h>
15 #include <linux/init.h>
16 #include <linux/kallsyms.h>
17 #include <linux/buildid.h>
19 #include <linux/kernel.h>
20 #include <linux/kernel_read_file.h>
21 #include <linux/kstrtox.h>
22 #include <linux/slab.h>
23 #include <linux/vmalloc.h>
24 #include <linux/elf.h>
25 #include <linux/seq_file.h>
26 #include <linux/syscalls.h>
27 #include <linux/fcntl.h>
28 #include <linux/rcupdate.h>
29 #include <linux/capability.h>
30 #include <linux/cpu.h>
31 #include <linux/moduleparam.h>
32 #include <linux/errno.h>
33 #include <linux/err.h>
34 #include <linux/vermagic.h>
35 #include <linux/notifier.h>
36 #include <linux/sched.h>
37 #include <linux/device.h>
38 #include <linux/string.h>
39 #include <linux/mutex.h>
40 #include <linux/rculist.h>
41 #include <linux/uaccess.h>
42 #include <asm/cacheflush.h>
43 #include <linux/set_memory.h>
44 #include <asm/mmu_context.h>
45 #include <linux/license.h>
46 #include <asm/sections.h>
47 #include <linux/tracepoint.h>
48 #include <linux/ftrace.h>
49 #include <linux/livepatch.h>
50 #include <linux/async.h>
51 #include <linux/percpu.h>
52 #include <linux/kmemleak.h>
53 #include <linux/jump_label.h>
54 #include <linux/pfn.h>
55 #include <linux/bsearch.h>
56 #include <linux/dynamic_debug.h>
57 #include <linux/audit.h>
58 #include <linux/cfi.h>
59 #include <linux/debugfs.h>
60 #include <uapi/linux/module.h>
63 #define CREATE_TRACE_POINTS
64 #include <trace/events/module.h>
68 * 1) List of modules (also safely readable with preempt_disable),
69 * 2) module_use links,
70 * 3) mod_tree.addr_min/mod_tree.addr_max.
71 * (delete and add uses RCU list operations).
73 DEFINE_MUTEX(module_mutex);
76 /* Work queue for freeing init sections in success case */
77 static void do_free_init(struct work_struct *w);
78 static DECLARE_WORK(init_free_wq, do_free_init);
79 static LLIST_HEAD(init_free_list);
81 struct mod_tree_root mod_tree __cacheline_aligned = {
86 const struct kernel_symbol *start, *stop;
88 enum mod_license license;
92 * Bounds of module memory, for speeding up __module_address.
93 * Protected by module_mutex.
95 static void __mod_update_bounds(enum mod_mem_type type __maybe_unused, void *base,
96 unsigned int size, struct mod_tree_root *tree)
98 unsigned long min = (unsigned long)base;
99 unsigned long max = min + size;
101 #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
102 if (mod_mem_type_is_core_data(type)) {
103 if (min < tree->data_addr_min)
104 tree->data_addr_min = min;
105 if (max > tree->data_addr_max)
106 tree->data_addr_max = max;
110 if (min < tree->addr_min)
111 tree->addr_min = min;
112 if (max > tree->addr_max)
113 tree->addr_max = max;
116 static void mod_update_bounds(struct module *mod)
118 for_each_mod_mem_type(type) {
119 struct module_memory *mod_mem = &mod->mem[type];
122 __mod_update_bounds(type, mod_mem->base, mod_mem->size, &mod_tree);
126 /* Block module loading/unloading? */
127 int modules_disabled;
128 core_param(nomodule, modules_disabled, bint, 0);
130 /* Waiting for a module to finish initializing? */
131 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
133 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
135 int register_module_notifier(struct notifier_block *nb)
137 return blocking_notifier_chain_register(&module_notify_list, nb);
139 EXPORT_SYMBOL(register_module_notifier);
141 int unregister_module_notifier(struct notifier_block *nb)
143 return blocking_notifier_chain_unregister(&module_notify_list, nb);
145 EXPORT_SYMBOL(unregister_module_notifier);
148 * We require a truly strong try_module_get(): 0 means success.
149 * Otherwise an error is returned due to ongoing or failed
150 * initialization etc.
152 static inline int strong_try_module_get(struct module *mod)
154 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
155 if (mod && mod->state == MODULE_STATE_COMING)
157 if (try_module_get(mod))
163 static inline void add_taint_module(struct module *mod, unsigned flag,
164 enum lockdep_ok lockdep_ok)
166 add_taint(flag, lockdep_ok);
167 set_bit(flag, &mod->taints);
171 * A thread that wants to hold a reference to a module only while it
172 * is running can call this to safely exit.
174 void __noreturn __module_put_and_kthread_exit(struct module *mod, long code)
179 EXPORT_SYMBOL(__module_put_and_kthread_exit);
181 /* Find a module section: 0 means not found. */
182 static unsigned int find_sec(const struct load_info *info, const char *name)
186 for (i = 1; i < info->hdr->e_shnum; i++) {
187 Elf_Shdr *shdr = &info->sechdrs[i];
188 /* Alloc bit cleared means "ignore it." */
189 if ((shdr->sh_flags & SHF_ALLOC)
190 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
196 /* Find a module section, or NULL. */
197 static void *section_addr(const struct load_info *info, const char *name)
199 /* Section 0 has sh_addr 0. */
200 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
203 /* Find a module section, or NULL. Fill in number of "objects" in section. */
204 static void *section_objs(const struct load_info *info,
209 unsigned int sec = find_sec(info, name);
211 /* Section 0 has sh_addr 0 and sh_size 0. */
212 *num = info->sechdrs[sec].sh_size / object_size;
213 return (void *)info->sechdrs[sec].sh_addr;
216 /* Find a module section: 0 means not found. Ignores SHF_ALLOC flag. */
217 static unsigned int find_any_sec(const struct load_info *info, const char *name)
221 for (i = 1; i < info->hdr->e_shnum; i++) {
222 Elf_Shdr *shdr = &info->sechdrs[i];
223 if (strcmp(info->secstrings + shdr->sh_name, name) == 0)
230 * Find a module section, or NULL. Fill in number of "objects" in section.
231 * Ignores SHF_ALLOC flag.
233 static __maybe_unused void *any_section_objs(const struct load_info *info,
238 unsigned int sec = find_any_sec(info, name);
240 /* Section 0 has sh_addr 0 and sh_size 0. */
241 *num = info->sechdrs[sec].sh_size / object_size;
242 return (void *)info->sechdrs[sec].sh_addr;
245 #ifndef CONFIG_MODVERSIONS
246 #define symversion(base, idx) NULL
248 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
251 static const char *kernel_symbol_name(const struct kernel_symbol *sym)
253 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
254 return offset_to_ptr(&sym->name_offset);
260 static const char *kernel_symbol_namespace(const struct kernel_symbol *sym)
262 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
263 if (!sym->namespace_offset)
265 return offset_to_ptr(&sym->namespace_offset);
267 return sym->namespace;
271 int cmp_name(const void *name, const void *sym)
273 return strcmp(name, kernel_symbol_name(sym));
276 static bool find_exported_symbol_in_section(const struct symsearch *syms,
277 struct module *owner,
278 struct find_symbol_arg *fsa)
280 struct kernel_symbol *sym;
282 if (!fsa->gplok && syms->license == GPL_ONLY)
285 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
286 sizeof(struct kernel_symbol), cmp_name);
291 fsa->crc = symversion(syms->crcs, sym - syms->start);
293 fsa->license = syms->license;
299 * Find an exported symbol and return it, along with, (optional) crc and
300 * (optional) module which owns it. Needs preempt disabled or module_mutex.
302 bool find_symbol(struct find_symbol_arg *fsa)
304 static const struct symsearch arr[] = {
305 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
307 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
308 __start___kcrctab_gpl,
314 module_assert_mutex_or_preempt();
316 for (i = 0; i < ARRAY_SIZE(arr); i++)
317 if (find_exported_symbol_in_section(&arr[i], NULL, fsa))
320 list_for_each_entry_rcu(mod, &modules, list,
321 lockdep_is_held(&module_mutex)) {
322 struct symsearch arr[] = {
323 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
325 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
330 if (mod->state == MODULE_STATE_UNFORMED)
333 for (i = 0; i < ARRAY_SIZE(arr); i++)
334 if (find_exported_symbol_in_section(&arr[i], mod, fsa))
338 pr_debug("Failed to find symbol %s\n", fsa->name);
343 * Search for module by name: must hold module_mutex (or preempt disabled
344 * for read-only access).
346 struct module *find_module_all(const char *name, size_t len,
351 module_assert_mutex_or_preempt();
353 list_for_each_entry_rcu(mod, &modules, list,
354 lockdep_is_held(&module_mutex)) {
355 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
357 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
363 struct module *find_module(const char *name)
365 return find_module_all(name, strlen(name), false);
370 static inline void __percpu *mod_percpu(struct module *mod)
375 static int percpu_modalloc(struct module *mod, struct load_info *info)
377 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
378 unsigned long align = pcpusec->sh_addralign;
380 if (!pcpusec->sh_size)
383 if (align > PAGE_SIZE) {
384 pr_warn("%s: per-cpu alignment %li > %li\n",
385 mod->name, align, PAGE_SIZE);
389 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
391 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
392 mod->name, (unsigned long)pcpusec->sh_size);
395 mod->percpu_size = pcpusec->sh_size;
399 static void percpu_modfree(struct module *mod)
401 free_percpu(mod->percpu);
404 static unsigned int find_pcpusec(struct load_info *info)
406 return find_sec(info, ".data..percpu");
409 static void percpu_modcopy(struct module *mod,
410 const void *from, unsigned long size)
414 for_each_possible_cpu(cpu)
415 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
418 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
425 list_for_each_entry_rcu(mod, &modules, list) {
426 if (mod->state == MODULE_STATE_UNFORMED)
428 if (!mod->percpu_size)
430 for_each_possible_cpu(cpu) {
431 void *start = per_cpu_ptr(mod->percpu, cpu);
432 void *va = (void *)addr;
434 if (va >= start && va < start + mod->percpu_size) {
436 *can_addr = (unsigned long) (va - start);
437 *can_addr += (unsigned long)
438 per_cpu_ptr(mod->percpu,
452 * is_module_percpu_address() - test whether address is from module static percpu
453 * @addr: address to test
455 * Test whether @addr belongs to module static percpu area.
457 * Return: %true if @addr is from module static percpu area
459 bool is_module_percpu_address(unsigned long addr)
461 return __is_module_percpu_address(addr, NULL);
464 #else /* ... !CONFIG_SMP */
466 static inline void __percpu *mod_percpu(struct module *mod)
470 static int percpu_modalloc(struct module *mod, struct load_info *info)
472 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
473 if (info->sechdrs[info->index.pcpu].sh_size != 0)
477 static inline void percpu_modfree(struct module *mod)
480 static unsigned int find_pcpusec(struct load_info *info)
484 static inline void percpu_modcopy(struct module *mod,
485 const void *from, unsigned long size)
487 /* pcpusec should be 0, and size of that section should be 0. */
490 bool is_module_percpu_address(unsigned long addr)
495 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
500 #endif /* CONFIG_SMP */
502 #define MODINFO_ATTR(field) \
503 static void setup_modinfo_##field(struct module *mod, const char *s) \
505 mod->field = kstrdup(s, GFP_KERNEL); \
507 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
508 struct module_kobject *mk, char *buffer) \
510 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
512 static int modinfo_##field##_exists(struct module *mod) \
514 return mod->field != NULL; \
516 static void free_modinfo_##field(struct module *mod) \
521 static struct module_attribute modinfo_##field = { \
522 .attr = { .name = __stringify(field), .mode = 0444 }, \
523 .show = show_modinfo_##field, \
524 .setup = setup_modinfo_##field, \
525 .test = modinfo_##field##_exists, \
526 .free = free_modinfo_##field, \
529 MODINFO_ATTR(version);
530 MODINFO_ATTR(srcversion);
533 char name[MODULE_NAME_LEN + 1];
534 char taints[MODULE_FLAGS_BUF_SIZE];
535 } last_unloaded_module;
537 #ifdef CONFIG_MODULE_UNLOAD
539 EXPORT_TRACEPOINT_SYMBOL(module_get);
541 /* MODULE_REF_BASE is the base reference count by kmodule loader. */
542 #define MODULE_REF_BASE 1
544 /* Init the unload section of the module. */
545 static int module_unload_init(struct module *mod)
548 * Initialize reference counter to MODULE_REF_BASE.
549 * refcnt == 0 means module is going.
551 atomic_set(&mod->refcnt, MODULE_REF_BASE);
553 INIT_LIST_HEAD(&mod->source_list);
554 INIT_LIST_HEAD(&mod->target_list);
556 /* Hold reference count during initialization. */
557 atomic_inc(&mod->refcnt);
562 /* Does a already use b? */
563 static int already_uses(struct module *a, struct module *b)
565 struct module_use *use;
567 list_for_each_entry(use, &b->source_list, source_list) {
568 if (use->source == a)
571 pr_debug("%s does not use %s!\n", a->name, b->name);
577 * - we add 'a' as a "source", 'b' as a "target" of module use
578 * - the module_use is added to the list of 'b' sources (so
579 * 'b' can walk the list to see who sourced them), and of 'a'
580 * targets (so 'a' can see what modules it targets).
582 static int add_module_usage(struct module *a, struct module *b)
584 struct module_use *use;
586 pr_debug("Allocating new usage for %s.\n", a->name);
587 use = kmalloc(sizeof(*use), GFP_ATOMIC);
593 list_add(&use->source_list, &b->source_list);
594 list_add(&use->target_list, &a->target_list);
598 /* Module a uses b: caller needs module_mutex() */
599 static int ref_module(struct module *a, struct module *b)
603 if (b == NULL || already_uses(a, b))
606 /* If module isn't available, we fail. */
607 err = strong_try_module_get(b);
611 err = add_module_usage(a, b);
619 /* Clear the unload stuff of the module. */
620 static void module_unload_free(struct module *mod)
622 struct module_use *use, *tmp;
624 mutex_lock(&module_mutex);
625 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
626 struct module *i = use->target;
627 pr_debug("%s unusing %s\n", mod->name, i->name);
629 list_del(&use->source_list);
630 list_del(&use->target_list);
633 mutex_unlock(&module_mutex);
636 #ifdef CONFIG_MODULE_FORCE_UNLOAD
637 static inline int try_force_unload(unsigned int flags)
639 int ret = (flags & O_TRUNC);
641 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
645 static inline int try_force_unload(unsigned int flags)
649 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
651 /* Try to release refcount of module, 0 means success. */
652 static int try_release_module_ref(struct module *mod)
656 /* Try to decrement refcnt which we set at loading */
657 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
660 /* Someone can put this right now, recover with checking */
661 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
666 static int try_stop_module(struct module *mod, int flags, int *forced)
668 /* If it's not unused, quit unless we're forcing. */
669 if (try_release_module_ref(mod) != 0) {
670 *forced = try_force_unload(flags);
675 /* Mark it as dying. */
676 mod->state = MODULE_STATE_GOING;
682 * module_refcount() - return the refcount or -1 if unloading
683 * @mod: the module we're checking
686 * -1 if the module is in the process of unloading
687 * otherwise the number of references in the kernel to the module
689 int module_refcount(struct module *mod)
691 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
693 EXPORT_SYMBOL(module_refcount);
695 /* This exists whether we can unload or not */
696 static void free_module(struct module *mod);
698 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
702 char name[MODULE_NAME_LEN];
703 char buf[MODULE_FLAGS_BUF_SIZE];
706 if (!capable(CAP_SYS_MODULE) || modules_disabled)
709 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
711 name[MODULE_NAME_LEN-1] = '\0';
713 audit_log_kern_module(name);
715 if (mutex_lock_interruptible(&module_mutex) != 0)
718 mod = find_module(name);
724 if (!list_empty(&mod->source_list)) {
725 /* Other modules depend on us: get rid of them first. */
730 /* Doing init or already dying? */
731 if (mod->state != MODULE_STATE_LIVE) {
732 /* FIXME: if (force), slam module count damn the torpedoes */
733 pr_debug("%s already dying\n", mod->name);
738 /* If it has an init func, it must have an exit func to unload */
739 if (mod->init && !mod->exit) {
740 forced = try_force_unload(flags);
742 /* This module can't be removed */
748 ret = try_stop_module(mod, flags, &forced);
752 mutex_unlock(&module_mutex);
753 /* Final destruction now no one is using it. */
754 if (mod->exit != NULL)
756 blocking_notifier_call_chain(&module_notify_list,
757 MODULE_STATE_GOING, mod);
758 klp_module_going(mod);
759 ftrace_release_mod(mod);
761 async_synchronize_full();
763 /* Store the name and taints of the last unloaded module for diagnostic purposes */
764 strscpy(last_unloaded_module.name, mod->name, sizeof(last_unloaded_module.name));
765 strscpy(last_unloaded_module.taints, module_flags(mod, buf, false), sizeof(last_unloaded_module.taints));
768 /* someone could wait for the module in add_unformed_module() */
769 wake_up_all(&module_wq);
772 mutex_unlock(&module_mutex);
776 void __symbol_put(const char *symbol)
778 struct find_symbol_arg fsa = {
784 BUG_ON(!find_symbol(&fsa));
785 module_put(fsa.owner);
788 EXPORT_SYMBOL(__symbol_put);
790 /* Note this assumes addr is a function, which it currently always is. */
791 void symbol_put_addr(void *addr)
793 struct module *modaddr;
794 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
796 if (core_kernel_text(a))
800 * Even though we hold a reference on the module; we still need to
801 * disable preemption in order to safely traverse the data structure.
804 modaddr = __module_text_address(a);
809 EXPORT_SYMBOL_GPL(symbol_put_addr);
811 static ssize_t show_refcnt(struct module_attribute *mattr,
812 struct module_kobject *mk, char *buffer)
814 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
817 static struct module_attribute modinfo_refcnt =
818 __ATTR(refcnt, 0444, show_refcnt, NULL);
820 void __module_get(struct module *module)
824 atomic_inc(&module->refcnt);
825 trace_module_get(module, _RET_IP_);
829 EXPORT_SYMBOL(__module_get);
831 bool try_module_get(struct module *module)
837 /* Note: here, we can fail to get a reference */
838 if (likely(module_is_live(module) &&
839 atomic_inc_not_zero(&module->refcnt) != 0))
840 trace_module_get(module, _RET_IP_);
848 EXPORT_SYMBOL(try_module_get);
850 void module_put(struct module *module)
856 ret = atomic_dec_if_positive(&module->refcnt);
857 WARN_ON(ret < 0); /* Failed to put refcount */
858 trace_module_put(module, _RET_IP_);
862 EXPORT_SYMBOL(module_put);
864 #else /* !CONFIG_MODULE_UNLOAD */
865 static inline void module_unload_free(struct module *mod)
869 static int ref_module(struct module *a, struct module *b)
871 return strong_try_module_get(b);
874 static inline int module_unload_init(struct module *mod)
878 #endif /* CONFIG_MODULE_UNLOAD */
880 size_t module_flags_taint(unsigned long taints, char *buf)
885 for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
886 if (taint_flags[i].module && test_bit(i, &taints))
887 buf[l++] = taint_flags[i].c_true;
893 static ssize_t show_initstate(struct module_attribute *mattr,
894 struct module_kobject *mk, char *buffer)
896 const char *state = "unknown";
898 switch (mk->mod->state) {
899 case MODULE_STATE_LIVE:
902 case MODULE_STATE_COMING:
905 case MODULE_STATE_GOING:
911 return sprintf(buffer, "%s\n", state);
914 static struct module_attribute modinfo_initstate =
915 __ATTR(initstate, 0444, show_initstate, NULL);
917 static ssize_t store_uevent(struct module_attribute *mattr,
918 struct module_kobject *mk,
919 const char *buffer, size_t count)
923 rc = kobject_synth_uevent(&mk->kobj, buffer, count);
924 return rc ? rc : count;
927 struct module_attribute module_uevent =
928 __ATTR(uevent, 0200, NULL, store_uevent);
930 static ssize_t show_coresize(struct module_attribute *mattr,
931 struct module_kobject *mk, char *buffer)
933 unsigned int size = mk->mod->mem[MOD_TEXT].size;
935 if (!IS_ENABLED(CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC)) {
936 for_class_mod_mem_type(type, core_data)
937 size += mk->mod->mem[type].size;
939 return sprintf(buffer, "%u\n", size);
942 static struct module_attribute modinfo_coresize =
943 __ATTR(coresize, 0444, show_coresize, NULL);
945 #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
946 static ssize_t show_datasize(struct module_attribute *mattr,
947 struct module_kobject *mk, char *buffer)
949 unsigned int size = 0;
951 for_class_mod_mem_type(type, core_data)
952 size += mk->mod->mem[type].size;
953 return sprintf(buffer, "%u\n", size);
956 static struct module_attribute modinfo_datasize =
957 __ATTR(datasize, 0444, show_datasize, NULL);
960 static ssize_t show_initsize(struct module_attribute *mattr,
961 struct module_kobject *mk, char *buffer)
963 unsigned int size = 0;
965 for_class_mod_mem_type(type, init)
966 size += mk->mod->mem[type].size;
967 return sprintf(buffer, "%u\n", size);
970 static struct module_attribute modinfo_initsize =
971 __ATTR(initsize, 0444, show_initsize, NULL);
973 static ssize_t show_taint(struct module_attribute *mattr,
974 struct module_kobject *mk, char *buffer)
978 l = module_flags_taint(mk->mod->taints, buffer);
983 static struct module_attribute modinfo_taint =
984 __ATTR(taint, 0444, show_taint, NULL);
986 struct module_attribute *modinfo_attrs[] = {
992 #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
997 #ifdef CONFIG_MODULE_UNLOAD
1003 size_t modinfo_attrs_count = ARRAY_SIZE(modinfo_attrs);
1005 static const char vermagic[] = VERMAGIC_STRING;
1007 int try_to_force_load(struct module *mod, const char *reason)
1009 #ifdef CONFIG_MODULE_FORCE_LOAD
1010 if (!test_taint(TAINT_FORCED_MODULE))
1011 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1012 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1019 /* Parse tag=value strings from .modinfo section */
1020 char *module_next_tag_pair(char *string, unsigned long *secsize)
1022 /* Skip non-zero chars */
1025 if ((*secsize)-- <= 1)
1029 /* Skip any zero padding. */
1030 while (!string[0]) {
1032 if ((*secsize)-- <= 1)
1038 static char *get_next_modinfo(const struct load_info *info, const char *tag,
1042 unsigned int taglen = strlen(tag);
1043 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
1044 unsigned long size = infosec->sh_size;
1047 * get_modinfo() calls made before rewrite_section_headers()
1048 * must use sh_offset, as sh_addr isn't set!
1050 char *modinfo = (char *)info->hdr + infosec->sh_offset;
1053 size -= prev - modinfo;
1054 modinfo = module_next_tag_pair(prev, &size);
1057 for (p = modinfo; p; p = module_next_tag_pair(p, &size)) {
1058 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
1059 return p + taglen + 1;
1064 static char *get_modinfo(const struct load_info *info, const char *tag)
1066 return get_next_modinfo(info, tag, NULL);
1069 static int verify_namespace_is_imported(const struct load_info *info,
1070 const struct kernel_symbol *sym,
1073 const char *namespace;
1074 char *imported_namespace;
1076 namespace = kernel_symbol_namespace(sym);
1077 if (namespace && namespace[0]) {
1078 for_each_modinfo_entry(imported_namespace, info, "import_ns") {
1079 if (strcmp(namespace, imported_namespace) == 0)
1082 #ifdef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1087 "%s: module uses symbol (%s) from namespace %s, but does not import it.\n",
1088 mod->name, kernel_symbol_name(sym), namespace);
1089 #ifndef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1096 static bool inherit_taint(struct module *mod, struct module *owner, const char *name)
1098 if (!owner || !test_bit(TAINT_PROPRIETARY_MODULE, &owner->taints))
1101 if (mod->using_gplonly_symbols) {
1102 pr_err("%s: module using GPL-only symbols uses symbols %s from proprietary module %s.\n",
1103 mod->name, name, owner->name);
1107 if (!test_bit(TAINT_PROPRIETARY_MODULE, &mod->taints)) {
1108 pr_warn("%s: module uses symbols %s from proprietary module %s, inheriting taint.\n",
1109 mod->name, name, owner->name);
1110 set_bit(TAINT_PROPRIETARY_MODULE, &mod->taints);
1115 /* Resolve a symbol for this module. I.e. if we find one, record usage. */
1116 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1117 const struct load_info *info,
1121 struct find_symbol_arg fsa = {
1123 .gplok = !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)),
1129 * The module_mutex should not be a heavily contended lock;
1130 * if we get the occasional sleep here, we'll go an extra iteration
1131 * in the wait_event_interruptible(), which is harmless.
1133 sched_annotate_sleep();
1134 mutex_lock(&module_mutex);
1135 if (!find_symbol(&fsa))
1138 if (fsa.license == GPL_ONLY)
1139 mod->using_gplonly_symbols = true;
1141 if (!inherit_taint(mod, fsa.owner, name)) {
1146 if (!check_version(info, name, mod, fsa.crc)) {
1147 fsa.sym = ERR_PTR(-EINVAL);
1151 err = verify_namespace_is_imported(info, fsa.sym, mod);
1153 fsa.sym = ERR_PTR(err);
1157 err = ref_module(mod, fsa.owner);
1159 fsa.sym = ERR_PTR(err);
1164 /* We must make copy under the lock if we failed to get ref. */
1165 strncpy(ownername, module_name(fsa.owner), MODULE_NAME_LEN);
1167 mutex_unlock(&module_mutex);
1171 static const struct kernel_symbol *
1172 resolve_symbol_wait(struct module *mod,
1173 const struct load_info *info,
1176 const struct kernel_symbol *ksym;
1177 char owner[MODULE_NAME_LEN];
1179 if (wait_event_interruptible_timeout(module_wq,
1180 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1181 || PTR_ERR(ksym) != -EBUSY,
1183 pr_warn("%s: gave up waiting for init of module %s.\n",
1189 void __weak module_memfree(void *module_region)
1192 * This memory may be RO, and freeing RO memory in an interrupt is not
1193 * supported by vmalloc.
1195 WARN_ON(in_interrupt());
1196 vfree(module_region);
1199 void __weak module_arch_cleanup(struct module *mod)
1203 void __weak module_arch_freeing_init(struct module *mod)
1207 static bool mod_mem_use_vmalloc(enum mod_mem_type type)
1209 return IS_ENABLED(CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC) &&
1210 mod_mem_type_is_core_data(type);
1213 static void *module_memory_alloc(unsigned int size, enum mod_mem_type type)
1215 if (mod_mem_use_vmalloc(type))
1216 return vzalloc(size);
1217 return module_alloc(size);
1220 static void module_memory_free(void *ptr, enum mod_mem_type type)
1222 if (mod_mem_use_vmalloc(type))
1225 module_memfree(ptr);
1228 static void free_mod_mem(struct module *mod)
1230 for_each_mod_mem_type(type) {
1231 struct module_memory *mod_mem = &mod->mem[type];
1233 if (type == MOD_DATA)
1236 /* Free lock-classes; relies on the preceding sync_rcu(). */
1237 lockdep_free_key_range(mod_mem->base, mod_mem->size);
1239 module_memory_free(mod_mem->base, type);
1242 /* MOD_DATA hosts mod, so free it at last */
1243 lockdep_free_key_range(mod->mem[MOD_DATA].base, mod->mem[MOD_DATA].size);
1244 module_memory_free(mod->mem[MOD_DATA].base, MOD_DATA);
1247 /* Free a module, remove from lists, etc. */
1248 static void free_module(struct module *mod)
1250 trace_module_free(mod);
1252 mod_sysfs_teardown(mod);
1255 * We leave it in list to prevent duplicate loads, but make sure
1256 * that noone uses it while it's being deconstructed.
1258 mutex_lock(&module_mutex);
1259 mod->state = MODULE_STATE_UNFORMED;
1260 mutex_unlock(&module_mutex);
1262 /* Arch-specific cleanup. */
1263 module_arch_cleanup(mod);
1265 /* Module unload stuff */
1266 module_unload_free(mod);
1268 /* Free any allocated parameters. */
1269 destroy_params(mod->kp, mod->num_kp);
1271 if (is_livepatch_module(mod))
1272 free_module_elf(mod);
1274 /* Now we can delete it from the lists */
1275 mutex_lock(&module_mutex);
1276 /* Unlink carefully: kallsyms could be walking list. */
1277 list_del_rcu(&mod->list);
1278 mod_tree_remove(mod);
1279 /* Remove this module from bug list, this uses list_del_rcu */
1280 module_bug_cleanup(mod);
1281 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
1283 if (try_add_tainted_module(mod))
1284 pr_err("%s: adding tainted module to the unloaded tainted modules list failed.\n",
1286 mutex_unlock(&module_mutex);
1288 /* This may be empty, but that's OK */
1289 module_arch_freeing_init(mod);
1291 percpu_modfree(mod);
1296 void *__symbol_get(const char *symbol)
1298 struct find_symbol_arg fsa = {
1305 if (!find_symbol(&fsa) || strong_try_module_get(fsa.owner)) {
1310 return (void *)kernel_symbol_value(fsa.sym);
1312 EXPORT_SYMBOL_GPL(__symbol_get);
1315 * Ensure that an exported symbol [global namespace] does not already exist
1316 * in the kernel or in some other module's exported symbol table.
1318 * You must hold the module_mutex.
1320 static int verify_exported_symbols(struct module *mod)
1323 const struct kernel_symbol *s;
1325 const struct kernel_symbol *sym;
1328 { mod->syms, mod->num_syms },
1329 { mod->gpl_syms, mod->num_gpl_syms },
1332 for (i = 0; i < ARRAY_SIZE(arr); i++) {
1333 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1334 struct find_symbol_arg fsa = {
1335 .name = kernel_symbol_name(s),
1338 if (find_symbol(&fsa)) {
1339 pr_err("%s: exports duplicate symbol %s"
1341 mod->name, kernel_symbol_name(s),
1342 module_name(fsa.owner));
1350 static bool ignore_undef_symbol(Elf_Half emachine, const char *name)
1353 * On x86, PIC code and Clang non-PIC code may have call foo@PLT. GNU as
1354 * before 2.37 produces an unreferenced _GLOBAL_OFFSET_TABLE_ on x86-64.
1355 * i386 has a similar problem but may not deserve a fix.
1357 * If we ever have to ignore many symbols, consider refactoring the code to
1358 * only warn if referenced by a relocation.
1360 if (emachine == EM_386 || emachine == EM_X86_64)
1361 return !strcmp(name, "_GLOBAL_OFFSET_TABLE_");
1365 /* Change all symbols so that st_value encodes the pointer directly. */
1366 static int simplify_symbols(struct module *mod, const struct load_info *info)
1368 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
1369 Elf_Sym *sym = (void *)symsec->sh_addr;
1370 unsigned long secbase;
1373 const struct kernel_symbol *ksym;
1375 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
1376 const char *name = info->strtab + sym[i].st_name;
1378 switch (sym[i].st_shndx) {
1380 /* Ignore common symbols */
1381 if (!strncmp(name, "__gnu_lto", 9))
1385 * We compiled with -fno-common. These are not
1386 * supposed to happen.
1388 pr_debug("Common symbol: %s\n", name);
1389 pr_warn("%s: please compile with -fno-common\n",
1395 /* Don't need to do anything */
1396 pr_debug("Absolute symbol: 0x%08lx %s\n",
1397 (long)sym[i].st_value, name);
1401 /* Livepatch symbols are resolved by livepatch */
1405 ksym = resolve_symbol_wait(mod, info, name);
1406 /* Ok if resolved. */
1407 if (ksym && !IS_ERR(ksym)) {
1408 sym[i].st_value = kernel_symbol_value(ksym);
1412 /* Ok if weak or ignored. */
1414 (ELF_ST_BIND(sym[i].st_info) == STB_WEAK ||
1415 ignore_undef_symbol(info->hdr->e_machine, name)))
1418 ret = PTR_ERR(ksym) ?: -ENOENT;
1419 pr_warn("%s: Unknown symbol %s (err %d)\n",
1420 mod->name, name, ret);
1424 /* Divert to percpu allocation if a percpu var. */
1425 if (sym[i].st_shndx == info->index.pcpu)
1426 secbase = (unsigned long)mod_percpu(mod);
1428 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
1429 sym[i].st_value += secbase;
1437 static int apply_relocations(struct module *mod, const struct load_info *info)
1442 /* Now do relocations. */
1443 for (i = 1; i < info->hdr->e_shnum; i++) {
1444 unsigned int infosec = info->sechdrs[i].sh_info;
1446 /* Not a valid relocation section? */
1447 if (infosec >= info->hdr->e_shnum)
1450 /* Don't bother with non-allocated sections */
1451 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
1454 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
1455 err = klp_apply_section_relocs(mod, info->sechdrs,
1460 else if (info->sechdrs[i].sh_type == SHT_REL)
1461 err = apply_relocate(info->sechdrs, info->strtab,
1462 info->index.sym, i, mod);
1463 else if (info->sechdrs[i].sh_type == SHT_RELA)
1464 err = apply_relocate_add(info->sechdrs, info->strtab,
1465 info->index.sym, i, mod);
1472 /* Additional bytes needed by arch in front of individual sections */
1473 unsigned int __weak arch_mod_section_prepend(struct module *mod,
1474 unsigned int section)
1476 /* default implementation just returns zero */
1480 long module_get_offset_and_type(struct module *mod, enum mod_mem_type type,
1481 Elf_Shdr *sechdr, unsigned int section)
1484 long mask = ((unsigned long)(type) & SH_ENTSIZE_TYPE_MASK) << SH_ENTSIZE_TYPE_SHIFT;
1486 mod->mem[type].size += arch_mod_section_prepend(mod, section);
1487 offset = ALIGN(mod->mem[type].size, sechdr->sh_addralign ?: 1);
1488 mod->mem[type].size = offset + sechdr->sh_size;
1490 WARN_ON_ONCE(offset & mask);
1491 return offset | mask;
1494 static bool module_init_layout_section(const char *sname)
1496 #ifndef CONFIG_MODULE_UNLOAD
1497 if (module_exit_section(sname))
1500 return module_init_section(sname);
1503 static void __layout_sections(struct module *mod, struct load_info *info, bool is_init)
1507 static const unsigned long masks[][2] = {
1509 * NOTE: all executable code must be the first section
1510 * in this array; otherwise modify the text_size
1511 * finder in the two loops below
1513 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
1514 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
1515 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
1516 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
1517 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
1519 static const int core_m_to_mem_type[] = {
1526 static const int init_m_to_mem_type[] = {
1534 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1535 enum mod_mem_type type = is_init ? init_m_to_mem_type[m] : core_m_to_mem_type[m];
1537 for (i = 0; i < info->hdr->e_shnum; ++i) {
1538 Elf_Shdr *s = &info->sechdrs[i];
1539 const char *sname = info->secstrings + s->sh_name;
1541 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1542 || (s->sh_flags & masks[m][1])
1543 || s->sh_entsize != ~0UL
1544 || is_init != module_init_layout_section(sname))
1547 if (WARN_ON_ONCE(type == MOD_INVALID))
1550 s->sh_entsize = module_get_offset_and_type(mod, type, s, i);
1551 pr_debug("\t%s\n", sname);
1557 * Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
1558 * might -- code, read-only data, read-write data, small data. Tally
1559 * sizes, and place the offsets into sh_entsize fields: high bit means it
1562 static void layout_sections(struct module *mod, struct load_info *info)
1566 for (i = 0; i < info->hdr->e_shnum; i++)
1567 info->sechdrs[i].sh_entsize = ~0UL;
1569 pr_debug("Core section allocation order for %s:\n", mod->name);
1570 __layout_sections(mod, info, false);
1572 pr_debug("Init section allocation order for %s:\n", mod->name);
1573 __layout_sections(mod, info, true);
1576 static void module_license_taint_check(struct module *mod, const char *license)
1579 license = "unspecified";
1581 if (!license_is_gpl_compatible(license)) {
1582 if (!test_taint(TAINT_PROPRIETARY_MODULE))
1583 pr_warn("%s: module license '%s' taints kernel.\n",
1584 mod->name, license);
1585 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
1586 LOCKDEP_NOW_UNRELIABLE);
1590 static void setup_modinfo(struct module *mod, struct load_info *info)
1592 struct module_attribute *attr;
1595 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1597 attr->setup(mod, get_modinfo(info, attr->attr.name));
1601 static void free_modinfo(struct module *mod)
1603 struct module_attribute *attr;
1606 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1612 void * __weak module_alloc(unsigned long size)
1614 return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
1615 GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS,
1616 NUMA_NO_NODE, __builtin_return_address(0));
1619 bool __weak module_init_section(const char *name)
1621 return strstarts(name, ".init");
1624 bool __weak module_exit_section(const char *name)
1626 return strstarts(name, ".exit");
1629 static int validate_section_offset(struct load_info *info, Elf_Shdr *shdr)
1631 #if defined(CONFIG_64BIT)
1632 unsigned long long secend;
1634 unsigned long secend;
1638 * Check for both overflow and offset/size being
1641 secend = shdr->sh_offset + shdr->sh_size;
1642 if (secend < shdr->sh_offset || secend > info->len)
1649 * Check userspace passed ELF module against our expectations, and cache
1650 * useful variables for further processing as we go.
1652 * This does basic validity checks against section offsets and sizes, the
1653 * section name string table, and the indices used for it (sh_name).
1655 * As a last step, since we're already checking the ELF sections we cache
1656 * useful variables which will be used later for our convenience:
1658 * o pointers to section headers
1659 * o cache the modinfo symbol section
1660 * o cache the string symbol section
1661 * o cache the module section
1663 * As a last step we set info->mod to the temporary copy of the module in
1664 * info->hdr. The final one will be allocated in move_module(). Any
1665 * modifications we make to our copy of the module will be carried over
1666 * to the final minted module.
1668 static int elf_validity_cache_copy(struct load_info *info, int flags)
1671 Elf_Shdr *shdr, *strhdr;
1673 unsigned int num_mod_secs = 0, mod_idx;
1674 unsigned int num_info_secs = 0, info_idx;
1675 unsigned int num_sym_secs = 0, sym_idx;
1677 if (info->len < sizeof(*(info->hdr))) {
1678 pr_err("Invalid ELF header len %lu\n", info->len);
1682 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0) {
1683 pr_err("Invalid ELF header magic: != %s\n", ELFMAG);
1686 if (info->hdr->e_type != ET_REL) {
1687 pr_err("Invalid ELF header type: %u != %u\n",
1688 info->hdr->e_type, ET_REL);
1691 if (!elf_check_arch(info->hdr)) {
1692 pr_err("Invalid architecture in ELF header: %u\n",
1693 info->hdr->e_machine);
1696 if (!module_elf_check_arch(info->hdr)) {
1697 pr_err("Invalid module architecture in ELF header: %u\n",
1698 info->hdr->e_machine);
1701 if (info->hdr->e_shentsize != sizeof(Elf_Shdr)) {
1702 pr_err("Invalid ELF section header size\n");
1707 * e_shnum is 16 bits, and sizeof(Elf_Shdr) is
1708 * known and small. So e_shnum * sizeof(Elf_Shdr)
1709 * will not overflow unsigned long on any platform.
1711 if (info->hdr->e_shoff >= info->len
1712 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
1713 info->len - info->hdr->e_shoff)) {
1714 pr_err("Invalid ELF section header overflow\n");
1718 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
1721 * Verify if the section name table index is valid.
1723 if (info->hdr->e_shstrndx == SHN_UNDEF
1724 || info->hdr->e_shstrndx >= info->hdr->e_shnum) {
1725 pr_err("Invalid ELF section name index: %d || e_shstrndx (%d) >= e_shnum (%d)\n",
1726 info->hdr->e_shstrndx, info->hdr->e_shstrndx,
1727 info->hdr->e_shnum);
1731 strhdr = &info->sechdrs[info->hdr->e_shstrndx];
1732 err = validate_section_offset(info, strhdr);
1734 pr_err("Invalid ELF section hdr(type %u)\n", strhdr->sh_type);
1739 * The section name table must be NUL-terminated, as required
1740 * by the spec. This makes strcmp and pr_* calls that access
1741 * strings in the section safe.
1743 info->secstrings = (void *)info->hdr + strhdr->sh_offset;
1744 if (strhdr->sh_size == 0) {
1745 pr_err("empty section name table\n");
1748 if (info->secstrings[strhdr->sh_size - 1] != '\0') {
1749 pr_err("ELF Spec violation: section name table isn't null terminated\n");
1754 * The code assumes that section 0 has a length of zero and
1755 * an addr of zero, so check for it.
1757 if (info->sechdrs[0].sh_type != SHT_NULL
1758 || info->sechdrs[0].sh_size != 0
1759 || info->sechdrs[0].sh_addr != 0) {
1760 pr_err("ELF Spec violation: section 0 type(%d)!=SH_NULL or non-zero len or addr\n",
1761 info->sechdrs[0].sh_type);
1765 for (i = 1; i < info->hdr->e_shnum; i++) {
1766 shdr = &info->sechdrs[i];
1767 switch (shdr->sh_type) {
1772 if (shdr->sh_link == SHN_UNDEF
1773 || shdr->sh_link >= info->hdr->e_shnum) {
1774 pr_err("Invalid ELF sh_link!=SHN_UNDEF(%d) or (sh_link(%d) >= hdr->e_shnum(%d)\n",
1775 shdr->sh_link, shdr->sh_link,
1776 info->hdr->e_shnum);
1783 err = validate_section_offset(info, shdr);
1785 pr_err("Invalid ELF section in module (section %u type %u)\n",
1789 if (strcmp(info->secstrings + shdr->sh_name,
1790 ".gnu.linkonce.this_module") == 0) {
1793 } else if (strcmp(info->secstrings + shdr->sh_name,
1799 if (shdr->sh_flags & SHF_ALLOC) {
1800 if (shdr->sh_name >= strhdr->sh_size) {
1801 pr_err("Invalid ELF section name in module (section %u type %u)\n",
1810 if (num_info_secs > 1) {
1811 pr_err("Only one .modinfo section must exist.\n");
1813 } else if (num_info_secs == 1) {
1814 /* Try to find a name early so we can log errors with a module name */
1815 info->index.info = info_idx;
1816 info->name = get_modinfo(info, "name");
1819 if (num_sym_secs != 1) {
1820 pr_warn("%s: module has no symbols (stripped?)\n",
1821 info->name ?: "(missing .modinfo section or name field)");
1825 /* Sets internal symbols and strings. */
1826 info->index.sym = sym_idx;
1827 shdr = &info->sechdrs[sym_idx];
1828 info->index.str = shdr->sh_link;
1829 info->strtab = (char *)info->hdr + info->sechdrs[info->index.str].sh_offset;
1832 * The ".gnu.linkonce.this_module" ELF section is special. It is
1833 * what modpost uses to refer to __this_module and let's use rely
1834 * on THIS_MODULE to point to &__this_module properly. The kernel's
1835 * modpost declares it on each modules's *.mod.c file. If the struct
1836 * module of the kernel changes a full kernel rebuild is required.
1838 * We have a few expectaions for this special section, the following
1839 * code validates all this for us:
1841 * o Only one section must exist
1842 * o We expect the kernel to always have to allocate it: SHF_ALLOC
1843 * o The section size must match the kernel's run time's struct module
1846 if (num_mod_secs != 1) {
1847 pr_err("module %s: Only one .gnu.linkonce.this_module section must exist.\n",
1848 info->name ?: "(missing .modinfo section or name field)");
1852 shdr = &info->sechdrs[mod_idx];
1855 * This is already implied on the switch above, however let's be
1856 * pedantic about it.
1858 if (shdr->sh_type == SHT_NOBITS) {
1859 pr_err("module %s: .gnu.linkonce.this_module section must have a size set\n",
1860 info->name ?: "(missing .modinfo section or name field)");
1864 if (!(shdr->sh_flags & SHF_ALLOC)) {
1865 pr_err("module %s: .gnu.linkonce.this_module must occupy memory during process execution\n",
1866 info->name ?: "(missing .modinfo section or name field)");
1870 if (shdr->sh_size != sizeof(struct module)) {
1871 pr_err("module %s: .gnu.linkonce.this_module section size must match the kernel's built struct module size at run time\n",
1872 info->name ?: "(missing .modinfo section or name field)");
1876 info->index.mod = mod_idx;
1878 /* This is temporary: point mod into copy of data. */
1879 info->mod = (void *)info->hdr + shdr->sh_offset;
1882 * If we didn't load the .modinfo 'name' field earlier, fall back to
1883 * on-disk struct mod 'name' field.
1886 info->name = info->mod->name;
1888 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
1889 info->index.vers = 0; /* Pretend no __versions section! */
1891 info->index.vers = find_sec(info, "__versions");
1893 info->index.pcpu = find_pcpusec(info);
1901 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
1903 static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
1906 unsigned long n = min(len, COPY_CHUNK_SIZE);
1908 if (copy_from_user(dst, usrc, n) != 0)
1918 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
1920 if (!get_modinfo(info, "livepatch"))
1921 /* Nothing more to do */
1924 if (set_livepatch_module(mod))
1927 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
1932 static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
1934 if (retpoline_module_ok(get_modinfo(info, "retpoline")))
1937 pr_warn("%s: loading module not compiled with retpoline compiler.\n",
1941 /* Sets info->hdr and info->len. */
1942 static int copy_module_from_user(const void __user *umod, unsigned long len,
1943 struct load_info *info)
1948 if (info->len < sizeof(*(info->hdr)))
1951 err = security_kernel_load_data(LOADING_MODULE, true);
1955 /* Suck in entire file: we'll want most of it. */
1956 info->hdr = __vmalloc(info->len, GFP_KERNEL | __GFP_NOWARN);
1960 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
1965 err = security_kernel_post_load_data((char *)info->hdr, info->len,
1966 LOADING_MODULE, "init_module");
1974 static void free_copy(struct load_info *info, int flags)
1976 if (flags & MODULE_INIT_COMPRESSED_FILE)
1977 module_decompress_cleanup(info);
1982 static int rewrite_section_headers(struct load_info *info, int flags)
1986 /* This should always be true, but let's be sure. */
1987 info->sechdrs[0].sh_addr = 0;
1989 for (i = 1; i < info->hdr->e_shnum; i++) {
1990 Elf_Shdr *shdr = &info->sechdrs[i];
1993 * Mark all sections sh_addr with their address in the
1996 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2000 /* Track but don't keep modinfo and version sections. */
2001 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2002 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2008 * These calls taint the kernel depending certain module circumstances */
2009 static void module_augment_kernel_taints(struct module *mod, struct load_info *info)
2011 int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
2013 if (!get_modinfo(info, "intree")) {
2014 if (!test_taint(TAINT_OOT_MODULE))
2015 pr_warn("%s: loading out-of-tree module taints kernel.\n",
2017 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2020 check_modinfo_retpoline(mod, info);
2022 if (get_modinfo(info, "staging")) {
2023 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
2024 pr_warn("%s: module is from the staging directory, the quality "
2025 "is unknown, you have been warned.\n", mod->name);
2028 if (is_livepatch_module(mod)) {
2029 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
2030 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
2034 module_license_taint_check(mod, get_modinfo(info, "license"));
2036 if (get_modinfo(info, "test")) {
2037 if (!test_taint(TAINT_TEST))
2038 pr_warn("%s: loading test module taints kernel.\n",
2040 add_taint_module(mod, TAINT_TEST, LOCKDEP_STILL_OK);
2042 #ifdef CONFIG_MODULE_SIG
2043 mod->sig_ok = info->sig_ok;
2045 pr_notice_once("%s: module verification failed: signature "
2046 "and/or required key missing - tainting "
2047 "kernel\n", mod->name);
2048 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
2053 * ndiswrapper is under GPL by itself, but loads proprietary modules.
2054 * Don't use add_taint_module(), as it would prevent ndiswrapper from
2055 * using GPL-only symbols it needs.
2057 if (strcmp(mod->name, "ndiswrapper") == 0)
2058 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
2060 /* driverloader was caught wrongly pretending to be under GPL */
2061 if (strcmp(mod->name, "driverloader") == 0)
2062 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2063 LOCKDEP_NOW_UNRELIABLE);
2065 /* lve claims to be GPL but upstream won't provide source */
2066 if (strcmp(mod->name, "lve") == 0)
2067 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2068 LOCKDEP_NOW_UNRELIABLE);
2070 if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
2071 pr_warn("%s: module license taints kernel.\n", mod->name);
2075 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2077 const char *modmagic = get_modinfo(info, "vermagic");
2080 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
2083 /* This is allowed: modprobe --force will invalidate it. */
2085 err = try_to_force_load(mod, "bad vermagic");
2088 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2089 pr_err("%s: version magic '%s' should be '%s'\n",
2090 info->name, modmagic, vermagic);
2094 err = check_modinfo_livepatch(mod, info);
2101 static int find_module_sections(struct module *mod, struct load_info *info)
2103 mod->kp = section_objs(info, "__param",
2104 sizeof(*mod->kp), &mod->num_kp);
2105 mod->syms = section_objs(info, "__ksymtab",
2106 sizeof(*mod->syms), &mod->num_syms);
2107 mod->crcs = section_addr(info, "__kcrctab");
2108 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2109 sizeof(*mod->gpl_syms),
2110 &mod->num_gpl_syms);
2111 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2113 #ifdef CONFIG_CONSTRUCTORS
2114 mod->ctors = section_objs(info, ".ctors",
2115 sizeof(*mod->ctors), &mod->num_ctors);
2117 mod->ctors = section_objs(info, ".init_array",
2118 sizeof(*mod->ctors), &mod->num_ctors);
2119 else if (find_sec(info, ".init_array")) {
2121 * This shouldn't happen with same compiler and binutils
2122 * building all parts of the module.
2124 pr_warn("%s: has both .ctors and .init_array.\n",
2130 mod->noinstr_text_start = section_objs(info, ".noinstr.text", 1,
2131 &mod->noinstr_text_size);
2133 #ifdef CONFIG_TRACEPOINTS
2134 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2135 sizeof(*mod->tracepoints_ptrs),
2136 &mod->num_tracepoints);
2138 #ifdef CONFIG_TREE_SRCU
2139 mod->srcu_struct_ptrs = section_objs(info, "___srcu_struct_ptrs",
2140 sizeof(*mod->srcu_struct_ptrs),
2141 &mod->num_srcu_structs);
2143 #ifdef CONFIG_BPF_EVENTS
2144 mod->bpf_raw_events = section_objs(info, "__bpf_raw_tp_map",
2145 sizeof(*mod->bpf_raw_events),
2146 &mod->num_bpf_raw_events);
2148 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
2149 mod->btf_data = any_section_objs(info, ".BTF", 1, &mod->btf_data_size);
2151 #ifdef CONFIG_JUMP_LABEL
2152 mod->jump_entries = section_objs(info, "__jump_table",
2153 sizeof(*mod->jump_entries),
2154 &mod->num_jump_entries);
2156 #ifdef CONFIG_EVENT_TRACING
2157 mod->trace_events = section_objs(info, "_ftrace_events",
2158 sizeof(*mod->trace_events),
2159 &mod->num_trace_events);
2160 mod->trace_evals = section_objs(info, "_ftrace_eval_map",
2161 sizeof(*mod->trace_evals),
2162 &mod->num_trace_evals);
2164 #ifdef CONFIG_TRACING
2165 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2166 sizeof(*mod->trace_bprintk_fmt_start),
2167 &mod->num_trace_bprintk_fmt);
2169 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
2170 /* sechdrs[0].sh_size is always zero */
2171 mod->ftrace_callsites = section_objs(info, FTRACE_CALLSITE_SECTION,
2172 sizeof(*mod->ftrace_callsites),
2173 &mod->num_ftrace_callsites);
2175 #ifdef CONFIG_FUNCTION_ERROR_INJECTION
2176 mod->ei_funcs = section_objs(info, "_error_injection_whitelist",
2177 sizeof(*mod->ei_funcs),
2178 &mod->num_ei_funcs);
2180 #ifdef CONFIG_KPROBES
2181 mod->kprobes_text_start = section_objs(info, ".kprobes.text", 1,
2182 &mod->kprobes_text_size);
2183 mod->kprobe_blacklist = section_objs(info, "_kprobe_blacklist",
2184 sizeof(unsigned long),
2185 &mod->num_kprobe_blacklist);
2187 #ifdef CONFIG_PRINTK_INDEX
2188 mod->printk_index_start = section_objs(info, ".printk_index",
2189 sizeof(*mod->printk_index_start),
2190 &mod->printk_index_size);
2192 #ifdef CONFIG_HAVE_STATIC_CALL_INLINE
2193 mod->static_call_sites = section_objs(info, ".static_call_sites",
2194 sizeof(*mod->static_call_sites),
2195 &mod->num_static_call_sites);
2197 #if IS_ENABLED(CONFIG_KUNIT)
2198 mod->kunit_suites = section_objs(info, ".kunit_test_suites",
2199 sizeof(*mod->kunit_suites),
2200 &mod->num_kunit_suites);
2203 mod->extable = section_objs(info, "__ex_table",
2204 sizeof(*mod->extable), &mod->num_exentries);
2206 if (section_addr(info, "__obsparm"))
2207 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
2209 #ifdef CONFIG_DYNAMIC_DEBUG_CORE
2210 mod->dyndbg_info.descs = section_objs(info, "__dyndbg",
2211 sizeof(*mod->dyndbg_info.descs),
2212 &mod->dyndbg_info.num_descs);
2213 mod->dyndbg_info.classes = section_objs(info, "__dyndbg_classes",
2214 sizeof(*mod->dyndbg_info.classes),
2215 &mod->dyndbg_info.num_classes);
2221 static int move_module(struct module *mod, struct load_info *info)
2225 enum mod_mem_type t = 0;
2228 for_each_mod_mem_type(type) {
2229 if (!mod->mem[type].size) {
2230 mod->mem[type].base = NULL;
2233 mod->mem[type].size = PAGE_ALIGN(mod->mem[type].size);
2234 ptr = module_memory_alloc(mod->mem[type].size, type);
2236 * The pointer to these blocks of memory are stored on the module
2237 * structure and we keep that around so long as the module is
2238 * around. We only free that memory when we unload the module.
2239 * Just mark them as not being a leak then. The .init* ELF
2240 * sections *do* get freed after boot so we *could* treat them
2241 * slightly differently with kmemleak_ignore() and only grey
2242 * them out as they work as typical memory allocations which
2243 * *do* eventually get freed, but let's just keep things simple
2244 * and avoid *any* false positives.
2246 kmemleak_not_leak(ptr);
2251 memset(ptr, 0, mod->mem[type].size);
2252 mod->mem[type].base = ptr;
2255 /* Transfer each section which specifies SHF_ALLOC */
2256 pr_debug("Final section addresses for %s:\n", mod->name);
2257 for (i = 0; i < info->hdr->e_shnum; i++) {
2259 Elf_Shdr *shdr = &info->sechdrs[i];
2260 enum mod_mem_type type = shdr->sh_entsize >> SH_ENTSIZE_TYPE_SHIFT;
2262 if (!(shdr->sh_flags & SHF_ALLOC))
2265 dest = mod->mem[type].base + (shdr->sh_entsize & SH_ENTSIZE_OFFSET_MASK);
2267 if (shdr->sh_type != SHT_NOBITS) {
2269 * Our ELF checker already validated this, but let's
2270 * be pedantic and make the goal clearer. We actually
2271 * end up copying over all modifications made to the
2272 * userspace copy of the entire struct module.
2274 if (i == info->index.mod &&
2275 (WARN_ON_ONCE(shdr->sh_size != sizeof(struct module)))) {
2279 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2282 * Update the userspace copy's ELF section address to point to
2283 * our newly allocated memory as a pure convenience so that
2284 * users of info can keep taking advantage and using the newly
2285 * minted official memory area.
2287 shdr->sh_addr = (unsigned long)dest;
2288 pr_debug("\t0x%lx 0x%.8lx %s\n", (long)shdr->sh_addr,
2289 (long)shdr->sh_size, info->secstrings + shdr->sh_name);
2294 for (t--; t >= 0; t--)
2295 module_memory_free(mod->mem[t].base, t);
2299 static int check_export_symbol_versions(struct module *mod)
2301 #ifdef CONFIG_MODVERSIONS
2302 if ((mod->num_syms && !mod->crcs) ||
2303 (mod->num_gpl_syms && !mod->gpl_crcs)) {
2304 return try_to_force_load(mod,
2305 "no versions for exported symbols");
2311 static void flush_module_icache(const struct module *mod)
2314 * Flush the instruction cache, since we've played with text.
2315 * Do it before processing of module parameters, so the module
2316 * can provide parameter accessor functions of its own.
2318 for_each_mod_mem_type(type) {
2319 const struct module_memory *mod_mem = &mod->mem[type];
2321 if (mod_mem->size) {
2322 flush_icache_range((unsigned long)mod_mem->base,
2323 (unsigned long)mod_mem->base + mod_mem->size);
2328 bool __weak module_elf_check_arch(Elf_Ehdr *hdr)
2333 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
2341 /* module_blacklist is a comma-separated list of module names */
2342 static char *module_blacklist;
2343 static bool blacklisted(const char *module_name)
2348 if (!module_blacklist)
2351 for (p = module_blacklist; *p; p += len) {
2352 len = strcspn(p, ",");
2353 if (strlen(module_name) == len && !memcmp(module_name, p, len))
2360 core_param(module_blacklist, module_blacklist, charp, 0400);
2362 static struct module *layout_and_allocate(struct load_info *info, int flags)
2368 /* Allow arches to frob section contents and sizes. */
2369 err = module_frob_arch_sections(info->hdr, info->sechdrs,
2370 info->secstrings, info->mod);
2372 return ERR_PTR(err);
2374 err = module_enforce_rwx_sections(info->hdr, info->sechdrs,
2375 info->secstrings, info->mod);
2377 return ERR_PTR(err);
2379 /* We will do a special allocation for per-cpu sections later. */
2380 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
2383 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
2384 * layout_sections() can put it in the right place.
2385 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
2387 ndx = find_sec(info, ".data..ro_after_init");
2389 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
2391 * Mark the __jump_table section as ro_after_init as well: these data
2392 * structures are never modified, with the exception of entries that
2393 * refer to code in the __init section, which are annotated as such
2394 * at module load time.
2396 ndx = find_sec(info, "__jump_table");
2398 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
2401 * Determine total sizes, and put offsets in sh_entsize. For now
2402 * this is done generically; there doesn't appear to be any
2403 * special cases for the architectures.
2405 layout_sections(info->mod, info);
2406 layout_symtab(info->mod, info);
2408 /* Allocate and move to the final place */
2409 err = move_module(info->mod, info);
2411 return ERR_PTR(err);
2413 /* Module has been copied to its final place now: return it. */
2414 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2415 kmemleak_load_module(mod, info);
2419 /* mod is no longer valid after this! */
2420 static void module_deallocate(struct module *mod, struct load_info *info)
2422 percpu_modfree(mod);
2423 module_arch_freeing_init(mod);
2428 int __weak module_finalize(const Elf_Ehdr *hdr,
2429 const Elf_Shdr *sechdrs,
2435 static int post_relocation(struct module *mod, const struct load_info *info)
2437 /* Sort exception table now relocations are done. */
2438 sort_extable(mod->extable, mod->extable + mod->num_exentries);
2440 /* Copy relocated percpu area over. */
2441 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
2442 info->sechdrs[info->index.pcpu].sh_size);
2444 /* Setup kallsyms-specific fields. */
2445 add_kallsyms(mod, info);
2447 /* Arch-specific module finalizing. */
2448 return module_finalize(info->hdr, info->sechdrs, mod);
2451 /* Call module constructors. */
2452 static void do_mod_ctors(struct module *mod)
2454 #ifdef CONFIG_CONSTRUCTORS
2457 for (i = 0; i < mod->num_ctors; i++)
2462 /* For freeing module_init on success, in case kallsyms traversing */
2463 struct mod_initfree {
2464 struct llist_node node;
2470 static void do_free_init(struct work_struct *w)
2472 struct llist_node *pos, *n, *list;
2473 struct mod_initfree *initfree;
2475 list = llist_del_all(&init_free_list);
2479 llist_for_each_safe(pos, n, list) {
2480 initfree = container_of(pos, struct mod_initfree, node);
2481 module_memfree(initfree->init_text);
2482 module_memfree(initfree->init_data);
2483 module_memfree(initfree->init_rodata);
2488 #undef MODULE_PARAM_PREFIX
2489 #define MODULE_PARAM_PREFIX "module."
2490 /* Default value for module->async_probe_requested */
2491 static bool async_probe;
2492 module_param(async_probe, bool, 0644);
2495 * This is where the real work happens.
2497 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
2498 * helper command 'lx-symbols'.
2500 static noinline int do_init_module(struct module *mod)
2503 struct mod_initfree *freeinit;
2504 #if defined(CONFIG_MODULE_STATS)
2505 unsigned int text_size = 0, total_size = 0;
2507 for_each_mod_mem_type(type) {
2508 const struct module_memory *mod_mem = &mod->mem[type];
2509 if (mod_mem->size) {
2510 total_size += mod_mem->size;
2511 if (type == MOD_TEXT || type == MOD_INIT_TEXT)
2512 text_size += mod_mem->size;
2517 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
2522 freeinit->init_text = mod->mem[MOD_INIT_TEXT].base;
2523 freeinit->init_data = mod->mem[MOD_INIT_DATA].base;
2524 freeinit->init_rodata = mod->mem[MOD_INIT_RODATA].base;
2527 /* Start the module */
2528 if (mod->init != NULL)
2529 ret = do_one_initcall(mod->init);
2531 goto fail_free_freeinit;
2534 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
2535 "follow 0/-E convention\n"
2536 "%s: loading module anyway...\n",
2537 __func__, mod->name, ret, __func__);
2541 /* Now it's a first class citizen! */
2542 mod->state = MODULE_STATE_LIVE;
2543 blocking_notifier_call_chain(&module_notify_list,
2544 MODULE_STATE_LIVE, mod);
2546 /* Delay uevent until module has finished its init routine */
2547 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
2550 * We need to finish all async code before the module init sequence
2551 * is done. This has potential to deadlock if synchronous module
2552 * loading is requested from async (which is not allowed!).
2554 * See commit 0fdff3ec6d87 ("async, kmod: warn on synchronous
2555 * request_module() from async workers") for more details.
2557 if (!mod->async_probe_requested)
2558 async_synchronize_full();
2560 ftrace_free_mem(mod, mod->mem[MOD_INIT_TEXT].base,
2561 mod->mem[MOD_INIT_TEXT].base + mod->mem[MOD_INIT_TEXT].size);
2562 mutex_lock(&module_mutex);
2563 /* Drop initial reference. */
2565 trim_init_extable(mod);
2566 #ifdef CONFIG_KALLSYMS
2567 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
2568 rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
2570 module_enable_ro(mod, true);
2571 mod_tree_remove_init(mod);
2572 module_arch_freeing_init(mod);
2573 for_class_mod_mem_type(type, init) {
2574 mod->mem[type].base = NULL;
2575 mod->mem[type].size = 0;
2578 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
2579 /* .BTF is not SHF_ALLOC and will get removed, so sanitize pointer */
2580 mod->btf_data = NULL;
2583 * We want to free module_init, but be aware that kallsyms may be
2584 * walking this with preempt disabled. In all the failure paths, we
2585 * call synchronize_rcu(), but we don't want to slow down the success
2586 * path. module_memfree() cannot be called in an interrupt, so do the
2587 * work and call synchronize_rcu() in a work queue.
2589 * Note that module_alloc() on most architectures creates W+X page
2590 * mappings which won't be cleaned up until do_free_init() runs. Any
2591 * code such as mark_rodata_ro() which depends on those mappings to
2592 * be cleaned up needs to sync with the queued work - ie
2595 if (llist_add(&freeinit->node, &init_free_list))
2596 schedule_work(&init_free_wq);
2598 mutex_unlock(&module_mutex);
2599 wake_up_all(&module_wq);
2601 mod_stat_add_long(text_size, &total_text_size);
2602 mod_stat_add_long(total_size, &total_mod_size);
2604 mod_stat_inc(&modcount);
2611 /* Try to protect us from buggy refcounters. */
2612 mod->state = MODULE_STATE_GOING;
2615 blocking_notifier_call_chain(&module_notify_list,
2616 MODULE_STATE_GOING, mod);
2617 klp_module_going(mod);
2618 ftrace_release_mod(mod);
2620 wake_up_all(&module_wq);
2625 static int may_init_module(void)
2627 if (!capable(CAP_SYS_MODULE) || modules_disabled)
2633 /* Is this module of this name done loading? No locks held. */
2634 static bool finished_loading(const char *name)
2640 * The module_mutex should not be a heavily contended lock;
2641 * if we get the occasional sleep here, we'll go an extra iteration
2642 * in the wait_event_interruptible(), which is harmless.
2644 sched_annotate_sleep();
2645 mutex_lock(&module_mutex);
2646 mod = find_module_all(name, strlen(name), true);
2647 ret = !mod || mod->state == MODULE_STATE_LIVE
2648 || mod->state == MODULE_STATE_GOING;
2649 mutex_unlock(&module_mutex);
2654 /* Must be called with module_mutex held */
2655 static int module_patient_check_exists(const char *name,
2656 enum fail_dup_mod_reason reason)
2661 old = find_module_all(name, strlen(name), true);
2665 if (old->state == MODULE_STATE_COMING ||
2666 old->state == MODULE_STATE_UNFORMED) {
2667 /* Wait in case it fails to load. */
2668 mutex_unlock(&module_mutex);
2669 err = wait_event_interruptible(module_wq,
2670 finished_loading(name));
2671 mutex_lock(&module_mutex);
2675 /* The module might have gone in the meantime. */
2676 old = find_module_all(name, strlen(name), true);
2679 if (try_add_failed_module(name, reason))
2680 pr_warn("Could not add fail-tracking for module: %s\n", name);
2683 * We are here only when the same module was being loaded. Do
2684 * not try to load it again right now. It prevents long delays
2685 * caused by serialized module load failures. It might happen
2686 * when more devices of the same type trigger load of
2687 * a particular module.
2689 if (old && old->state == MODULE_STATE_LIVE)
2695 * We try to place it in the list now to make sure it's unique before
2696 * we dedicate too many resources. In particular, temporary percpu
2697 * memory exhaustion.
2699 static int add_unformed_module(struct module *mod)
2703 mod->state = MODULE_STATE_UNFORMED;
2705 mutex_lock(&module_mutex);
2706 err = module_patient_check_exists(mod->name, FAIL_DUP_MOD_LOAD);
2710 mod_update_bounds(mod);
2711 list_add_rcu(&mod->list, &modules);
2712 mod_tree_insert(mod);
2716 mutex_unlock(&module_mutex);
2720 static int complete_formation(struct module *mod, struct load_info *info)
2724 mutex_lock(&module_mutex);
2726 /* Find duplicate symbols (must be called under lock). */
2727 err = verify_exported_symbols(mod);
2731 /* These rely on module_mutex for list integrity. */
2732 module_bug_finalize(info->hdr, info->sechdrs, mod);
2733 module_cfi_finalize(info->hdr, info->sechdrs, mod);
2735 module_enable_ro(mod, false);
2736 module_enable_nx(mod);
2737 module_enable_x(mod);
2740 * Mark state as coming so strong_try_module_get() ignores us,
2741 * but kallsyms etc. can see us.
2743 mod->state = MODULE_STATE_COMING;
2744 mutex_unlock(&module_mutex);
2749 mutex_unlock(&module_mutex);
2753 static int prepare_coming_module(struct module *mod)
2757 ftrace_module_enable(mod);
2758 err = klp_module_coming(mod);
2762 err = blocking_notifier_call_chain_robust(&module_notify_list,
2763 MODULE_STATE_COMING, MODULE_STATE_GOING, mod);
2764 err = notifier_to_errno(err);
2766 klp_module_going(mod);
2771 static int unknown_module_param_cb(char *param, char *val, const char *modname,
2774 struct module *mod = arg;
2777 if (strcmp(param, "async_probe") == 0) {
2778 if (kstrtobool(val, &mod->async_probe_requested))
2779 mod->async_probe_requested = true;
2783 /* Check for magic 'dyndbg' arg */
2784 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
2786 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
2790 /* Module within temporary copy, this doesn't do any allocation */
2791 static int early_mod_check(struct load_info *info, int flags)
2796 * Now that we know we have the correct module name, check
2797 * if it's blacklisted.
2799 if (blacklisted(info->name)) {
2800 pr_err("Module %s is blacklisted\n", info->name);
2804 err = rewrite_section_headers(info, flags);
2808 /* Check module struct version now, before we try to use module. */
2809 if (!check_modstruct_version(info, info->mod))
2812 err = check_modinfo(info->mod, info, flags);
2816 mutex_lock(&module_mutex);
2817 err = module_patient_check_exists(info->mod->name, FAIL_DUP_MOD_BECOMING);
2818 mutex_unlock(&module_mutex);
2824 * Allocate and load the module: note that size of section 0 is always
2825 * zero, and we rely on this for optional sections.
2827 static int load_module(struct load_info *info, const char __user *uargs,
2831 bool module_allocated = false;
2836 * Do the signature check (if any) first. All that
2837 * the signature check needs is info->len, it does
2838 * not need any of the section info. That can be
2839 * set up later. This will minimize the chances
2840 * of a corrupt module causing problems before
2841 * we even get to the signature check.
2843 * The check will also adjust info->len by stripping
2844 * off the sig length at the end of the module, making
2845 * checks against info->len more correct.
2847 err = module_sig_check(info, flags);
2852 * Do basic sanity checks against the ELF header and
2853 * sections. Cache useful sections and set the
2854 * info->mod to the userspace passed struct module.
2856 err = elf_validity_cache_copy(info, flags);
2860 err = early_mod_check(info, flags);
2864 /* Figure out module layout, and allocate all the memory. */
2865 mod = layout_and_allocate(info, flags);
2871 module_allocated = true;
2873 audit_log_kern_module(mod->name);
2875 /* Reserve our place in the list. */
2876 err = add_unformed_module(mod);
2881 * We are tainting your kernel if your module gets into
2882 * the modules linked list somehow.
2884 module_augment_kernel_taints(mod, info);
2886 /* To avoid stressing percpu allocator, do this once we're unique. */
2887 err = percpu_modalloc(mod, info);
2891 /* Now module is in final location, initialize linked lists, etc. */
2892 err = module_unload_init(mod);
2896 init_param_lock(mod);
2899 * Now we've got everything in the final locations, we can
2900 * find optional sections.
2902 err = find_module_sections(mod, info);
2906 err = check_export_symbol_versions(mod);
2910 /* Set up MODINFO_ATTR fields */
2911 setup_modinfo(mod, info);
2913 /* Fix up syms, so that st_value is a pointer to location. */
2914 err = simplify_symbols(mod, info);
2918 err = apply_relocations(mod, info);
2922 err = post_relocation(mod, info);
2926 flush_module_icache(mod);
2928 /* Now copy in args */
2929 mod->args = strndup_user(uargs, ~0UL >> 1);
2930 if (IS_ERR(mod->args)) {
2931 err = PTR_ERR(mod->args);
2932 goto free_arch_cleanup;
2935 init_build_id(mod, info);
2937 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
2938 ftrace_module_init(mod);
2940 /* Finally it's fully formed, ready to start executing. */
2941 err = complete_formation(mod, info);
2943 goto ddebug_cleanup;
2945 err = prepare_coming_module(mod);
2949 mod->async_probe_requested = async_probe;
2951 /* Module is ready to execute: parsing args may do that. */
2952 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
2954 unknown_module_param_cb);
2955 if (IS_ERR(after_dashes)) {
2956 err = PTR_ERR(after_dashes);
2957 goto coming_cleanup;
2958 } else if (after_dashes) {
2959 pr_warn("%s: parameters '%s' after `--' ignored\n",
2960 mod->name, after_dashes);
2963 /* Link in to sysfs. */
2964 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
2966 goto coming_cleanup;
2968 if (is_livepatch_module(mod)) {
2969 err = copy_module_elf(mod, info);
2974 /* Get rid of temporary copy. */
2975 free_copy(info, flags);
2978 trace_module_load(mod);
2980 return do_init_module(mod);
2983 mod_sysfs_teardown(mod);
2985 mod->state = MODULE_STATE_GOING;
2986 destroy_params(mod->kp, mod->num_kp);
2987 blocking_notifier_call_chain(&module_notify_list,
2988 MODULE_STATE_GOING, mod);
2989 klp_module_going(mod);
2991 mod->state = MODULE_STATE_GOING;
2992 /* module_bug_cleanup needs module_mutex protection */
2993 mutex_lock(&module_mutex);
2994 module_bug_cleanup(mod);
2995 mutex_unlock(&module_mutex);
2998 ftrace_release_mod(mod);
3002 module_arch_cleanup(mod);
3006 module_unload_free(mod);
3008 mutex_lock(&module_mutex);
3009 /* Unlink carefully: kallsyms could be walking list. */
3010 list_del_rcu(&mod->list);
3011 mod_tree_remove(mod);
3012 wake_up_all(&module_wq);
3013 /* Wait for RCU-sched synchronizing before releasing mod->list. */
3015 mutex_unlock(&module_mutex);
3017 mod_stat_bump_invalid(info, flags);
3018 /* Free lock-classes; relies on the preceding sync_rcu() */
3019 for_class_mod_mem_type(type, core_data) {
3020 lockdep_free_key_range(mod->mem[type].base,
3021 mod->mem[type].size);
3024 module_deallocate(mod, info);
3027 * The info->len is always set. We distinguish between
3028 * failures once the proper module was allocated and
3031 if (!module_allocated)
3032 mod_stat_bump_becoming(info, flags);
3033 free_copy(info, flags);
3037 SYSCALL_DEFINE3(init_module, void __user *, umod,
3038 unsigned long, len, const char __user *, uargs)
3041 struct load_info info = { };
3043 err = may_init_module();
3047 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3050 err = copy_module_from_user(umod, len, &info);
3052 mod_stat_inc(&failed_kreads);
3053 mod_stat_add_long(len, &invalid_kread_bytes);
3057 return load_module(&info, uargs, 0);
3060 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3062 struct load_info info = { };
3067 err = may_init_module();
3071 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3073 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3074 |MODULE_INIT_IGNORE_VERMAGIC
3075 |MODULE_INIT_COMPRESSED_FILE))
3078 len = kernel_read_file_from_fd(fd, 0, &buf, INT_MAX, NULL,
3081 mod_stat_inc(&failed_kreads);
3082 mod_stat_add_long(len, &invalid_kread_bytes);
3086 if (flags & MODULE_INIT_COMPRESSED_FILE) {
3087 err = module_decompress(&info, buf, len);
3088 vfree(buf); /* compressed data is no longer needed */
3090 mod_stat_inc(&failed_decompress);
3091 mod_stat_add_long(len, &invalid_decompress_bytes);
3099 return load_module(&info, uargs, flags);
3102 /* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
3103 char *module_flags(struct module *mod, char *buf, bool show_state)
3107 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
3108 if (!mod->taints && !show_state)
3111 mod->state == MODULE_STATE_GOING ||
3112 mod->state == MODULE_STATE_COMING) {
3114 bx += module_flags_taint(mod->taints, buf + bx);
3115 /* Show a - for module-is-being-unloaded */
3116 if (mod->state == MODULE_STATE_GOING && show_state)
3118 /* Show a + for module-is-being-loaded */
3119 if (mod->state == MODULE_STATE_COMING && show_state)
3129 /* Given an address, look for it in the module exception tables. */
3130 const struct exception_table_entry *search_module_extables(unsigned long addr)
3132 const struct exception_table_entry *e = NULL;
3136 mod = __module_address(addr);
3140 if (!mod->num_exentries)
3143 e = search_extable(mod->extable,
3150 * Now, if we found one, we are running inside it now, hence
3151 * we cannot unload the module, hence no refcnt needed.
3157 * is_module_address() - is this address inside a module?
3158 * @addr: the address to check.
3160 * See is_module_text_address() if you simply want to see if the address
3161 * is code (not data).
3163 bool is_module_address(unsigned long addr)
3168 ret = __module_address(addr) != NULL;
3175 * __module_address() - get the module which contains an address.
3176 * @addr: the address.
3178 * Must be called with preempt disabled or module mutex held so that
3179 * module doesn't get freed during this.
3181 struct module *__module_address(unsigned long addr)
3185 if (addr >= mod_tree.addr_min && addr <= mod_tree.addr_max)
3188 #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
3189 if (addr >= mod_tree.data_addr_min && addr <= mod_tree.data_addr_max)
3196 module_assert_mutex_or_preempt();
3198 mod = mod_find(addr, &mod_tree);
3200 BUG_ON(!within_module(addr, mod));
3201 if (mod->state == MODULE_STATE_UNFORMED)
3208 * is_module_text_address() - is this address inside module code?
3209 * @addr: the address to check.
3211 * See is_module_address() if you simply want to see if the address is
3212 * anywhere in a module. See kernel_text_address() for testing if an
3213 * address corresponds to kernel or module code.
3215 bool is_module_text_address(unsigned long addr)
3220 ret = __module_text_address(addr) != NULL;
3227 * __module_text_address() - get the module whose code contains an address.
3228 * @addr: the address.
3230 * Must be called with preempt disabled or module mutex held so that
3231 * module doesn't get freed during this.
3233 struct module *__module_text_address(unsigned long addr)
3235 struct module *mod = __module_address(addr);
3237 /* Make sure it's within the text section. */
3238 if (!within_module_mem_type(addr, mod, MOD_TEXT) &&
3239 !within_module_mem_type(addr, mod, MOD_INIT_TEXT))
3245 /* Don't grab lock, we're oopsing. */
3246 void print_modules(void)
3249 char buf[MODULE_FLAGS_BUF_SIZE];
3251 printk(KERN_DEFAULT "Modules linked in:");
3252 /* Most callers should already have preempt disabled, but make sure */
3254 list_for_each_entry_rcu(mod, &modules, list) {
3255 if (mod->state == MODULE_STATE_UNFORMED)
3257 pr_cont(" %s%s", mod->name, module_flags(mod, buf, true));
3260 print_unloaded_tainted_modules();
3262 if (last_unloaded_module.name[0])
3263 pr_cont(" [last unloaded: %s%s]", last_unloaded_module.name,
3264 last_unloaded_module.taints);
3268 #ifdef CONFIG_MODULE_DEBUGFS
3269 struct dentry *mod_debugfs_root;
3271 static int module_debugfs_init(void)
3273 mod_debugfs_root = debugfs_create_dir("modules", NULL);
3276 module_init(module_debugfs_init);