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.
7 #define INCLUDE_VERMAGIC
9 #include <linux/export.h>
10 #include <linux/extable.h>
11 #include <linux/moduleloader.h>
12 #include <linux/module_signature.h>
13 #include <linux/trace_events.h>
14 #include <linux/init.h>
15 #include <linux/kallsyms.h>
16 #include <linux/buildid.h>
18 #include <linux/kernel.h>
19 #include <linux/kernel_read_file.h>
20 #include <linux/slab.h>
21 #include <linux/vmalloc.h>
22 #include <linux/elf.h>
23 #include <linux/seq_file.h>
24 #include <linux/syscalls.h>
25 #include <linux/fcntl.h>
26 #include <linux/rcupdate.h>
27 #include <linux/capability.h>
28 #include <linux/cpu.h>
29 #include <linux/moduleparam.h>
30 #include <linux/errno.h>
31 #include <linux/err.h>
32 #include <linux/vermagic.h>
33 #include <linux/notifier.h>
34 #include <linux/sched.h>
35 #include <linux/device.h>
36 #include <linux/string.h>
37 #include <linux/mutex.h>
38 #include <linux/rculist.h>
39 #include <linux/uaccess.h>
40 #include <asm/cacheflush.h>
41 #include <linux/set_memory.h>
42 #include <asm/mmu_context.h>
43 #include <linux/license.h>
44 #include <asm/sections.h>
45 #include <linux/tracepoint.h>
46 #include <linux/ftrace.h>
47 #include <linux/livepatch.h>
48 #include <linux/async.h>
49 #include <linux/percpu.h>
50 #include <linux/kmemleak.h>
51 #include <linux/jump_label.h>
52 #include <linux/pfn.h>
53 #include <linux/bsearch.h>
54 #include <linux/dynamic_debug.h>
55 #include <linux/audit.h>
56 #include <uapi/linux/module.h>
59 #define CREATE_TRACE_POINTS
60 #include <trace/events/module.h>
64 * 1) List of modules (also safely readable with preempt_disable),
65 * 2) module_use links,
66 * 3) mod_tree.addr_min/mod_tree.addr_max.
67 * (delete and add uses RCU list operations).
69 DEFINE_MUTEX(module_mutex);
72 /* Work queue for freeing init sections in success case */
73 static void do_free_init(struct work_struct *w);
74 static DECLARE_WORK(init_free_wq, do_free_init);
75 static LLIST_HEAD(init_free_list);
77 struct mod_tree_root mod_tree __cacheline_aligned = {
81 #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
82 struct mod_tree_root mod_data_tree __cacheline_aligned = {
87 #define module_addr_min mod_tree.addr_min
88 #define module_addr_max mod_tree.addr_max
91 const struct kernel_symbol *start, *stop;
93 enum mod_license license;
97 * Bounds of module text, for speeding up __module_address.
98 * Protected by module_mutex.
100 static void __mod_update_bounds(void *base, unsigned int size, struct mod_tree_root *tree)
102 unsigned long min = (unsigned long)base;
103 unsigned long max = min + size;
105 if (min < tree->addr_min)
106 tree->addr_min = min;
107 if (max > tree->addr_max)
108 tree->addr_max = max;
111 static void mod_update_bounds(struct module *mod)
113 __mod_update_bounds(mod->core_layout.base, mod->core_layout.size, &mod_tree);
114 if (mod->init_layout.size)
115 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size, &mod_tree);
116 #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
117 __mod_update_bounds(mod->data_layout.base, mod->data_layout.size, &mod_data_tree);
121 /* Block module loading/unloading? */
122 int modules_disabled;
123 core_param(nomodule, modules_disabled, bint, 0);
125 /* Waiting for a module to finish initializing? */
126 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
128 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
130 int register_module_notifier(struct notifier_block *nb)
132 return blocking_notifier_chain_register(&module_notify_list, nb);
134 EXPORT_SYMBOL(register_module_notifier);
136 int unregister_module_notifier(struct notifier_block *nb)
138 return blocking_notifier_chain_unregister(&module_notify_list, nb);
140 EXPORT_SYMBOL(unregister_module_notifier);
143 * We require a truly strong try_module_get(): 0 means success.
144 * Otherwise an error is returned due to ongoing or failed
145 * initialization etc.
147 static inline int strong_try_module_get(struct module *mod)
149 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
150 if (mod && mod->state == MODULE_STATE_COMING)
152 if (try_module_get(mod))
158 static inline void add_taint_module(struct module *mod, unsigned flag,
159 enum lockdep_ok lockdep_ok)
161 add_taint(flag, lockdep_ok);
162 set_bit(flag, &mod->taints);
166 * A thread that wants to hold a reference to a module only while it
167 * is running can call this to safely exit.
169 void __noreturn __module_put_and_kthread_exit(struct module *mod, long code)
174 EXPORT_SYMBOL(__module_put_and_kthread_exit);
176 /* Find a module section: 0 means not found. */
177 static unsigned int find_sec(const struct load_info *info, const char *name)
181 for (i = 1; i < info->hdr->e_shnum; i++) {
182 Elf_Shdr *shdr = &info->sechdrs[i];
183 /* Alloc bit cleared means "ignore it." */
184 if ((shdr->sh_flags & SHF_ALLOC)
185 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
191 /* Find a module section, or NULL. */
192 static void *section_addr(const struct load_info *info, const char *name)
194 /* Section 0 has sh_addr 0. */
195 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
198 /* Find a module section, or NULL. Fill in number of "objects" in section. */
199 static void *section_objs(const struct load_info *info,
204 unsigned int sec = find_sec(info, name);
206 /* Section 0 has sh_addr 0 and sh_size 0. */
207 *num = info->sechdrs[sec].sh_size / object_size;
208 return (void *)info->sechdrs[sec].sh_addr;
211 /* Find a module section: 0 means not found. Ignores SHF_ALLOC flag. */
212 static unsigned int find_any_sec(const struct load_info *info, const char *name)
216 for (i = 1; i < info->hdr->e_shnum; i++) {
217 Elf_Shdr *shdr = &info->sechdrs[i];
218 if (strcmp(info->secstrings + shdr->sh_name, name) == 0)
225 * Find a module section, or NULL. Fill in number of "objects" in section.
226 * Ignores SHF_ALLOC flag.
228 static __maybe_unused void *any_section_objs(const struct load_info *info,
233 unsigned int sec = find_any_sec(info, name);
235 /* Section 0 has sh_addr 0 and sh_size 0. */
236 *num = info->sechdrs[sec].sh_size / object_size;
237 return (void *)info->sechdrs[sec].sh_addr;
240 #ifndef CONFIG_MODVERSIONS
241 #define symversion(base, idx) NULL
243 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
246 static const char *kernel_symbol_name(const struct kernel_symbol *sym)
248 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
249 return offset_to_ptr(&sym->name_offset);
255 static const char *kernel_symbol_namespace(const struct kernel_symbol *sym)
257 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
258 if (!sym->namespace_offset)
260 return offset_to_ptr(&sym->namespace_offset);
262 return sym->namespace;
266 int cmp_name(const void *name, const void *sym)
268 return strcmp(name, kernel_symbol_name(sym));
271 static bool find_exported_symbol_in_section(const struct symsearch *syms,
272 struct module *owner,
273 struct find_symbol_arg *fsa)
275 struct kernel_symbol *sym;
277 if (!fsa->gplok && syms->license == GPL_ONLY)
280 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
281 sizeof(struct kernel_symbol), cmp_name);
286 fsa->crc = symversion(syms->crcs, sym - syms->start);
288 fsa->license = syms->license;
294 * Find an exported symbol and return it, along with, (optional) crc and
295 * (optional) module which owns it. Needs preempt disabled or module_mutex.
297 bool find_symbol(struct find_symbol_arg *fsa)
299 static const struct symsearch arr[] = {
300 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
302 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
303 __start___kcrctab_gpl,
309 module_assert_mutex_or_preempt();
311 for (i = 0; i < ARRAY_SIZE(arr); i++)
312 if (find_exported_symbol_in_section(&arr[i], NULL, fsa))
315 list_for_each_entry_rcu(mod, &modules, list,
316 lockdep_is_held(&module_mutex)) {
317 struct symsearch arr[] = {
318 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
320 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
325 if (mod->state == MODULE_STATE_UNFORMED)
328 for (i = 0; i < ARRAY_SIZE(arr); i++)
329 if (find_exported_symbol_in_section(&arr[i], mod, fsa))
333 pr_debug("Failed to find symbol %s\n", fsa->name);
338 * Search for module by name: must hold module_mutex (or preempt disabled
339 * for read-only access).
341 struct module *find_module_all(const char *name, size_t len,
346 module_assert_mutex_or_preempt();
348 list_for_each_entry_rcu(mod, &modules, list,
349 lockdep_is_held(&module_mutex)) {
350 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
352 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
358 struct module *find_module(const char *name)
360 return find_module_all(name, strlen(name), false);
365 static inline void __percpu *mod_percpu(struct module *mod)
370 static int percpu_modalloc(struct module *mod, struct load_info *info)
372 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
373 unsigned long align = pcpusec->sh_addralign;
375 if (!pcpusec->sh_size)
378 if (align > PAGE_SIZE) {
379 pr_warn("%s: per-cpu alignment %li > %li\n",
380 mod->name, align, PAGE_SIZE);
384 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
386 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
387 mod->name, (unsigned long)pcpusec->sh_size);
390 mod->percpu_size = pcpusec->sh_size;
394 static void percpu_modfree(struct module *mod)
396 free_percpu(mod->percpu);
399 static unsigned int find_pcpusec(struct load_info *info)
401 return find_sec(info, ".data..percpu");
404 static void percpu_modcopy(struct module *mod,
405 const void *from, unsigned long size)
409 for_each_possible_cpu(cpu)
410 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
413 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
420 list_for_each_entry_rcu(mod, &modules, list) {
421 if (mod->state == MODULE_STATE_UNFORMED)
423 if (!mod->percpu_size)
425 for_each_possible_cpu(cpu) {
426 void *start = per_cpu_ptr(mod->percpu, cpu);
427 void *va = (void *)addr;
429 if (va >= start && va < start + mod->percpu_size) {
431 *can_addr = (unsigned long) (va - start);
432 *can_addr += (unsigned long)
433 per_cpu_ptr(mod->percpu,
447 * is_module_percpu_address() - test whether address is from module static percpu
448 * @addr: address to test
450 * Test whether @addr belongs to module static percpu area.
452 * Return: %true if @addr is from module static percpu area
454 bool is_module_percpu_address(unsigned long addr)
456 return __is_module_percpu_address(addr, NULL);
459 #else /* ... !CONFIG_SMP */
461 static inline void __percpu *mod_percpu(struct module *mod)
465 static int percpu_modalloc(struct module *mod, struct load_info *info)
467 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
468 if (info->sechdrs[info->index.pcpu].sh_size != 0)
472 static inline void percpu_modfree(struct module *mod)
475 static unsigned int find_pcpusec(struct load_info *info)
479 static inline void percpu_modcopy(struct module *mod,
480 const void *from, unsigned long size)
482 /* pcpusec should be 0, and size of that section should be 0. */
485 bool is_module_percpu_address(unsigned long addr)
490 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
495 #endif /* CONFIG_SMP */
497 #define MODINFO_ATTR(field) \
498 static void setup_modinfo_##field(struct module *mod, const char *s) \
500 mod->field = kstrdup(s, GFP_KERNEL); \
502 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
503 struct module_kobject *mk, char *buffer) \
505 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
507 static int modinfo_##field##_exists(struct module *mod) \
509 return mod->field != NULL; \
511 static void free_modinfo_##field(struct module *mod) \
516 static struct module_attribute modinfo_##field = { \
517 .attr = { .name = __stringify(field), .mode = 0444 }, \
518 .show = show_modinfo_##field, \
519 .setup = setup_modinfo_##field, \
520 .test = modinfo_##field##_exists, \
521 .free = free_modinfo_##field, \
524 MODINFO_ATTR(version);
525 MODINFO_ATTR(srcversion);
528 char name[MODULE_NAME_LEN + 1];
529 char taints[MODULE_FLAGS_BUF_SIZE];
530 } last_unloaded_module;
532 #ifdef CONFIG_MODULE_UNLOAD
534 EXPORT_TRACEPOINT_SYMBOL(module_get);
536 /* MODULE_REF_BASE is the base reference count by kmodule loader. */
537 #define MODULE_REF_BASE 1
539 /* Init the unload section of the module. */
540 static int module_unload_init(struct module *mod)
543 * Initialize reference counter to MODULE_REF_BASE.
544 * refcnt == 0 means module is going.
546 atomic_set(&mod->refcnt, MODULE_REF_BASE);
548 INIT_LIST_HEAD(&mod->source_list);
549 INIT_LIST_HEAD(&mod->target_list);
551 /* Hold reference count during initialization. */
552 atomic_inc(&mod->refcnt);
557 /* Does a already use b? */
558 static int already_uses(struct module *a, struct module *b)
560 struct module_use *use;
562 list_for_each_entry(use, &b->source_list, source_list) {
563 if (use->source == a) {
564 pr_debug("%s uses %s!\n", a->name, b->name);
568 pr_debug("%s does not use %s!\n", a->name, b->name);
574 * - we add 'a' as a "source", 'b' as a "target" of module use
575 * - the module_use is added to the list of 'b' sources (so
576 * 'b' can walk the list to see who sourced them), and of 'a'
577 * targets (so 'a' can see what modules it targets).
579 static int add_module_usage(struct module *a, struct module *b)
581 struct module_use *use;
583 pr_debug("Allocating new usage for %s.\n", a->name);
584 use = kmalloc(sizeof(*use), GFP_ATOMIC);
590 list_add(&use->source_list, &b->source_list);
591 list_add(&use->target_list, &a->target_list);
595 /* Module a uses b: caller needs module_mutex() */
596 static int ref_module(struct module *a, struct module *b)
600 if (b == NULL || already_uses(a, b))
603 /* If module isn't available, we fail. */
604 err = strong_try_module_get(b);
608 err = add_module_usage(a, b);
616 /* Clear the unload stuff of the module. */
617 static void module_unload_free(struct module *mod)
619 struct module_use *use, *tmp;
621 mutex_lock(&module_mutex);
622 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
623 struct module *i = use->target;
624 pr_debug("%s unusing %s\n", mod->name, i->name);
626 list_del(&use->source_list);
627 list_del(&use->target_list);
630 mutex_unlock(&module_mutex);
633 #ifdef CONFIG_MODULE_FORCE_UNLOAD
634 static inline int try_force_unload(unsigned int flags)
636 int ret = (flags & O_TRUNC);
638 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
642 static inline int try_force_unload(unsigned int flags)
646 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
648 /* Try to release refcount of module, 0 means success. */
649 static int try_release_module_ref(struct module *mod)
653 /* Try to decrement refcnt which we set at loading */
654 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
657 /* Someone can put this right now, recover with checking */
658 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
663 static int try_stop_module(struct module *mod, int flags, int *forced)
665 /* If it's not unused, quit unless we're forcing. */
666 if (try_release_module_ref(mod) != 0) {
667 *forced = try_force_unload(flags);
672 /* Mark it as dying. */
673 mod->state = MODULE_STATE_GOING;
679 * module_refcount() - return the refcount or -1 if unloading
680 * @mod: the module we're checking
683 * -1 if the module is in the process of unloading
684 * otherwise the number of references in the kernel to the module
686 int module_refcount(struct module *mod)
688 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
690 EXPORT_SYMBOL(module_refcount);
692 /* This exists whether we can unload or not */
693 static void free_module(struct module *mod);
695 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
699 char name[MODULE_NAME_LEN];
700 char buf[MODULE_FLAGS_BUF_SIZE];
703 if (!capable(CAP_SYS_MODULE) || modules_disabled)
706 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
708 name[MODULE_NAME_LEN-1] = '\0';
710 audit_log_kern_module(name);
712 if (mutex_lock_interruptible(&module_mutex) != 0)
715 mod = find_module(name);
721 if (!list_empty(&mod->source_list)) {
722 /* Other modules depend on us: get rid of them first. */
727 /* Doing init or already dying? */
728 if (mod->state != MODULE_STATE_LIVE) {
729 /* FIXME: if (force), slam module count damn the torpedoes */
730 pr_debug("%s already dying\n", mod->name);
735 /* If it has an init func, it must have an exit func to unload */
736 if (mod->init && !mod->exit) {
737 forced = try_force_unload(flags);
739 /* This module can't be removed */
745 ret = try_stop_module(mod, flags, &forced);
749 mutex_unlock(&module_mutex);
750 /* Final destruction now no one is using it. */
751 if (mod->exit != NULL)
753 blocking_notifier_call_chain(&module_notify_list,
754 MODULE_STATE_GOING, mod);
755 klp_module_going(mod);
756 ftrace_release_mod(mod);
758 async_synchronize_full();
760 /* Store the name and taints of the last unloaded module for diagnostic purposes */
761 strscpy(last_unloaded_module.name, mod->name, sizeof(last_unloaded_module.name));
762 strscpy(last_unloaded_module.taints, module_flags(mod, buf, false), sizeof(last_unloaded_module.taints));
765 /* someone could wait for the module in add_unformed_module() */
766 wake_up_all(&module_wq);
769 mutex_unlock(&module_mutex);
773 void __symbol_put(const char *symbol)
775 struct find_symbol_arg fsa = {
781 BUG_ON(!find_symbol(&fsa));
782 module_put(fsa.owner);
785 EXPORT_SYMBOL(__symbol_put);
787 /* Note this assumes addr is a function, which it currently always is. */
788 void symbol_put_addr(void *addr)
790 struct module *modaddr;
791 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
793 if (core_kernel_text(a))
797 * Even though we hold a reference on the module; we still need to
798 * disable preemption in order to safely traverse the data structure.
801 modaddr = __module_text_address(a);
806 EXPORT_SYMBOL_GPL(symbol_put_addr);
808 static ssize_t show_refcnt(struct module_attribute *mattr,
809 struct module_kobject *mk, char *buffer)
811 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
814 static struct module_attribute modinfo_refcnt =
815 __ATTR(refcnt, 0444, show_refcnt, NULL);
817 void __module_get(struct module *module)
821 atomic_inc(&module->refcnt);
822 trace_module_get(module, _RET_IP_);
826 EXPORT_SYMBOL(__module_get);
828 bool try_module_get(struct module *module)
834 /* Note: here, we can fail to get a reference */
835 if (likely(module_is_live(module) &&
836 atomic_inc_not_zero(&module->refcnt) != 0))
837 trace_module_get(module, _RET_IP_);
845 EXPORT_SYMBOL(try_module_get);
847 void module_put(struct module *module)
853 ret = atomic_dec_if_positive(&module->refcnt);
854 WARN_ON(ret < 0); /* Failed to put refcount */
855 trace_module_put(module, _RET_IP_);
859 EXPORT_SYMBOL(module_put);
861 #else /* !CONFIG_MODULE_UNLOAD */
862 static inline void module_unload_free(struct module *mod)
866 static int ref_module(struct module *a, struct module *b)
868 return strong_try_module_get(b);
871 static inline int module_unload_init(struct module *mod)
875 #endif /* CONFIG_MODULE_UNLOAD */
877 size_t module_flags_taint(unsigned long taints, char *buf)
882 for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
883 if (taint_flags[i].module && test_bit(i, &taints))
884 buf[l++] = taint_flags[i].c_true;
890 static ssize_t show_initstate(struct module_attribute *mattr,
891 struct module_kobject *mk, char *buffer)
893 const char *state = "unknown";
895 switch (mk->mod->state) {
896 case MODULE_STATE_LIVE:
899 case MODULE_STATE_COMING:
902 case MODULE_STATE_GOING:
908 return sprintf(buffer, "%s\n", state);
911 static struct module_attribute modinfo_initstate =
912 __ATTR(initstate, 0444, show_initstate, NULL);
914 static ssize_t store_uevent(struct module_attribute *mattr,
915 struct module_kobject *mk,
916 const char *buffer, size_t count)
920 rc = kobject_synth_uevent(&mk->kobj, buffer, count);
921 return rc ? rc : count;
924 struct module_attribute module_uevent =
925 __ATTR(uevent, 0200, NULL, store_uevent);
927 static ssize_t show_coresize(struct module_attribute *mattr,
928 struct module_kobject *mk, char *buffer)
930 return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
933 static struct module_attribute modinfo_coresize =
934 __ATTR(coresize, 0444, show_coresize, NULL);
936 #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
937 static ssize_t show_datasize(struct module_attribute *mattr,
938 struct module_kobject *mk, char *buffer)
940 return sprintf(buffer, "%u\n", mk->mod->data_layout.size);
943 static struct module_attribute modinfo_datasize =
944 __ATTR(datasize, 0444, show_datasize, NULL);
947 static ssize_t show_initsize(struct module_attribute *mattr,
948 struct module_kobject *mk, char *buffer)
950 return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
953 static struct module_attribute modinfo_initsize =
954 __ATTR(initsize, 0444, show_initsize, NULL);
956 static ssize_t show_taint(struct module_attribute *mattr,
957 struct module_kobject *mk, char *buffer)
961 l = module_flags_taint(mk->mod->taints, buffer);
966 static struct module_attribute modinfo_taint =
967 __ATTR(taint, 0444, show_taint, NULL);
969 struct module_attribute *modinfo_attrs[] = {
975 #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
980 #ifdef CONFIG_MODULE_UNLOAD
986 size_t modinfo_attrs_count = ARRAY_SIZE(modinfo_attrs);
988 static const char vermagic[] = VERMAGIC_STRING;
990 int try_to_force_load(struct module *mod, const char *reason)
992 #ifdef CONFIG_MODULE_FORCE_LOAD
993 if (!test_taint(TAINT_FORCED_MODULE))
994 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
995 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1002 static char *get_modinfo(const struct load_info *info, const char *tag);
1003 static char *get_next_modinfo(const struct load_info *info, const char *tag,
1006 static int verify_namespace_is_imported(const struct load_info *info,
1007 const struct kernel_symbol *sym,
1010 const char *namespace;
1011 char *imported_namespace;
1013 namespace = kernel_symbol_namespace(sym);
1014 if (namespace && namespace[0]) {
1015 imported_namespace = get_modinfo(info, "import_ns");
1016 while (imported_namespace) {
1017 if (strcmp(namespace, imported_namespace) == 0)
1019 imported_namespace = get_next_modinfo(
1020 info, "import_ns", imported_namespace);
1022 #ifdef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1027 "%s: module uses symbol (%s) from namespace %s, but does not import it.\n",
1028 mod->name, kernel_symbol_name(sym), namespace);
1029 #ifndef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1036 static bool inherit_taint(struct module *mod, struct module *owner, const char *name)
1038 if (!owner || !test_bit(TAINT_PROPRIETARY_MODULE, &owner->taints))
1041 if (mod->using_gplonly_symbols) {
1042 pr_err("%s: module using GPL-only symbols uses symbols %s from proprietary module %s.\n",
1043 mod->name, name, owner->name);
1047 if (!test_bit(TAINT_PROPRIETARY_MODULE, &mod->taints)) {
1048 pr_warn("%s: module uses symbols %s from proprietary module %s, inheriting taint.\n",
1049 mod->name, name, owner->name);
1050 set_bit(TAINT_PROPRIETARY_MODULE, &mod->taints);
1055 /* Resolve a symbol for this module. I.e. if we find one, record usage. */
1056 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1057 const struct load_info *info,
1061 struct find_symbol_arg fsa = {
1063 .gplok = !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)),
1069 * The module_mutex should not be a heavily contended lock;
1070 * if we get the occasional sleep here, we'll go an extra iteration
1071 * in the wait_event_interruptible(), which is harmless.
1073 sched_annotate_sleep();
1074 mutex_lock(&module_mutex);
1075 if (!find_symbol(&fsa))
1078 if (fsa.license == GPL_ONLY)
1079 mod->using_gplonly_symbols = true;
1081 if (!inherit_taint(mod, fsa.owner, name)) {
1086 if (!check_version(info, name, mod, fsa.crc)) {
1087 fsa.sym = ERR_PTR(-EINVAL);
1091 err = verify_namespace_is_imported(info, fsa.sym, mod);
1093 fsa.sym = ERR_PTR(err);
1097 err = ref_module(mod, fsa.owner);
1099 fsa.sym = ERR_PTR(err);
1104 /* We must make copy under the lock if we failed to get ref. */
1105 strncpy(ownername, module_name(fsa.owner), MODULE_NAME_LEN);
1107 mutex_unlock(&module_mutex);
1111 static const struct kernel_symbol *
1112 resolve_symbol_wait(struct module *mod,
1113 const struct load_info *info,
1116 const struct kernel_symbol *ksym;
1117 char owner[MODULE_NAME_LEN];
1119 if (wait_event_interruptible_timeout(module_wq,
1120 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1121 || PTR_ERR(ksym) != -EBUSY,
1123 pr_warn("%s: gave up waiting for init of module %s.\n",
1129 void __weak module_memfree(void *module_region)
1132 * This memory may be RO, and freeing RO memory in an interrupt is not
1133 * supported by vmalloc.
1135 WARN_ON(in_interrupt());
1136 vfree(module_region);
1139 void __weak module_arch_cleanup(struct module *mod)
1143 void __weak module_arch_freeing_init(struct module *mod)
1147 static void cfi_cleanup(struct module *mod);
1149 /* Free a module, remove from lists, etc. */
1150 static void free_module(struct module *mod)
1152 trace_module_free(mod);
1154 mod_sysfs_teardown(mod);
1157 * We leave it in list to prevent duplicate loads, but make sure
1158 * that noone uses it while it's being deconstructed.
1160 mutex_lock(&module_mutex);
1161 mod->state = MODULE_STATE_UNFORMED;
1162 mutex_unlock(&module_mutex);
1164 /* Remove dynamic debug info */
1165 ddebug_remove_module(mod->name);
1167 /* Arch-specific cleanup. */
1168 module_arch_cleanup(mod);
1170 /* Module unload stuff */
1171 module_unload_free(mod);
1173 /* Free any allocated parameters. */
1174 destroy_params(mod->kp, mod->num_kp);
1176 if (is_livepatch_module(mod))
1177 free_module_elf(mod);
1179 /* Now we can delete it from the lists */
1180 mutex_lock(&module_mutex);
1181 /* Unlink carefully: kallsyms could be walking list. */
1182 list_del_rcu(&mod->list);
1183 mod_tree_remove(mod);
1184 /* Remove this module from bug list, this uses list_del_rcu */
1185 module_bug_cleanup(mod);
1186 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
1188 if (try_add_tainted_module(mod))
1189 pr_err("%s: adding tainted module to the unloaded tainted modules list failed.\n",
1191 mutex_unlock(&module_mutex);
1193 /* Clean up CFI for the module. */
1196 /* This may be empty, but that's OK */
1197 module_arch_freeing_init(mod);
1198 module_memfree(mod->init_layout.base);
1200 percpu_modfree(mod);
1202 /* Free lock-classes; relies on the preceding sync_rcu(). */
1203 lockdep_free_key_range(mod->data_layout.base, mod->data_layout.size);
1205 /* Finally, free the core (containing the module structure) */
1206 module_memfree(mod->core_layout.base);
1207 #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
1208 vfree(mod->data_layout.base);
1212 void *__symbol_get(const char *symbol)
1214 struct find_symbol_arg fsa = {
1221 if (!find_symbol(&fsa) || strong_try_module_get(fsa.owner)) {
1226 return (void *)kernel_symbol_value(fsa.sym);
1228 EXPORT_SYMBOL_GPL(__symbol_get);
1231 * Ensure that an exported symbol [global namespace] does not already exist
1232 * in the kernel or in some other module's exported symbol table.
1234 * You must hold the module_mutex.
1236 static int verify_exported_symbols(struct module *mod)
1239 const struct kernel_symbol *s;
1241 const struct kernel_symbol *sym;
1244 { mod->syms, mod->num_syms },
1245 { mod->gpl_syms, mod->num_gpl_syms },
1248 for (i = 0; i < ARRAY_SIZE(arr); i++) {
1249 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1250 struct find_symbol_arg fsa = {
1251 .name = kernel_symbol_name(s),
1254 if (find_symbol(&fsa)) {
1255 pr_err("%s: exports duplicate symbol %s"
1257 mod->name, kernel_symbol_name(s),
1258 module_name(fsa.owner));
1266 static bool ignore_undef_symbol(Elf_Half emachine, const char *name)
1269 * On x86, PIC code and Clang non-PIC code may have call foo@PLT. GNU as
1270 * before 2.37 produces an unreferenced _GLOBAL_OFFSET_TABLE_ on x86-64.
1271 * i386 has a similar problem but may not deserve a fix.
1273 * If we ever have to ignore many symbols, consider refactoring the code to
1274 * only warn if referenced by a relocation.
1276 if (emachine == EM_386 || emachine == EM_X86_64)
1277 return !strcmp(name, "_GLOBAL_OFFSET_TABLE_");
1281 /* Change all symbols so that st_value encodes the pointer directly. */
1282 static int simplify_symbols(struct module *mod, const struct load_info *info)
1284 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
1285 Elf_Sym *sym = (void *)symsec->sh_addr;
1286 unsigned long secbase;
1289 const struct kernel_symbol *ksym;
1291 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
1292 const char *name = info->strtab + sym[i].st_name;
1294 switch (sym[i].st_shndx) {
1296 /* Ignore common symbols */
1297 if (!strncmp(name, "__gnu_lto", 9))
1301 * We compiled with -fno-common. These are not
1302 * supposed to happen.
1304 pr_debug("Common symbol: %s\n", name);
1305 pr_warn("%s: please compile with -fno-common\n",
1311 /* Don't need to do anything */
1312 pr_debug("Absolute symbol: 0x%08lx\n",
1313 (long)sym[i].st_value);
1317 /* Livepatch symbols are resolved by livepatch */
1321 ksym = resolve_symbol_wait(mod, info, name);
1322 /* Ok if resolved. */
1323 if (ksym && !IS_ERR(ksym)) {
1324 sym[i].st_value = kernel_symbol_value(ksym);
1328 /* Ok if weak or ignored. */
1330 (ELF_ST_BIND(sym[i].st_info) == STB_WEAK ||
1331 ignore_undef_symbol(info->hdr->e_machine, name)))
1334 ret = PTR_ERR(ksym) ?: -ENOENT;
1335 pr_warn("%s: Unknown symbol %s (err %d)\n",
1336 mod->name, name, ret);
1340 /* Divert to percpu allocation if a percpu var. */
1341 if (sym[i].st_shndx == info->index.pcpu)
1342 secbase = (unsigned long)mod_percpu(mod);
1344 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
1345 sym[i].st_value += secbase;
1353 static int apply_relocations(struct module *mod, const struct load_info *info)
1358 /* Now do relocations. */
1359 for (i = 1; i < info->hdr->e_shnum; i++) {
1360 unsigned int infosec = info->sechdrs[i].sh_info;
1362 /* Not a valid relocation section? */
1363 if (infosec >= info->hdr->e_shnum)
1366 /* Don't bother with non-allocated sections */
1367 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
1370 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
1371 err = klp_apply_section_relocs(mod, info->sechdrs,
1376 else if (info->sechdrs[i].sh_type == SHT_REL)
1377 err = apply_relocate(info->sechdrs, info->strtab,
1378 info->index.sym, i, mod);
1379 else if (info->sechdrs[i].sh_type == SHT_RELA)
1380 err = apply_relocate_add(info->sechdrs, info->strtab,
1381 info->index.sym, i, mod);
1388 /* Additional bytes needed by arch in front of individual sections */
1389 unsigned int __weak arch_mod_section_prepend(struct module *mod,
1390 unsigned int section)
1392 /* default implementation just returns zero */
1396 /* Update size with this section: return offset. */
1397 long module_get_offset(struct module *mod, unsigned int *size,
1398 Elf_Shdr *sechdr, unsigned int section)
1402 *size += arch_mod_section_prepend(mod, section);
1403 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
1404 *size = ret + sechdr->sh_size;
1408 static bool module_init_layout_section(const char *sname)
1410 #ifndef CONFIG_MODULE_UNLOAD
1411 if (module_exit_section(sname))
1414 return module_init_section(sname);
1418 * Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
1419 * might -- code, read-only data, read-write data, small data. Tally
1420 * sizes, and place the offsets into sh_entsize fields: high bit means it
1423 static void layout_sections(struct module *mod, struct load_info *info)
1425 static unsigned long const masks[][2] = {
1427 * NOTE: all executable code must be the first section
1428 * in this array; otherwise modify the text_size
1429 * finder in the two loops below
1431 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
1432 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
1433 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
1434 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
1435 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
1439 for (i = 0; i < info->hdr->e_shnum; i++)
1440 info->sechdrs[i].sh_entsize = ~0UL;
1442 pr_debug("Core section allocation order:\n");
1443 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1444 for (i = 0; i < info->hdr->e_shnum; ++i) {
1445 Elf_Shdr *s = &info->sechdrs[i];
1446 const char *sname = info->secstrings + s->sh_name;
1447 unsigned int *sizep;
1449 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1450 || (s->sh_flags & masks[m][1])
1451 || s->sh_entsize != ~0UL
1452 || module_init_layout_section(sname))
1454 sizep = m ? &mod->data_layout.size : &mod->core_layout.size;
1455 s->sh_entsize = module_get_offset(mod, sizep, s, i);
1456 pr_debug("\t%s\n", sname);
1459 case 0: /* executable */
1460 mod->core_layout.size = strict_align(mod->core_layout.size);
1461 mod->core_layout.text_size = mod->core_layout.size;
1463 case 1: /* RO: text and ro-data */
1464 mod->data_layout.size = strict_align(mod->data_layout.size);
1465 mod->data_layout.ro_size = mod->data_layout.size;
1467 case 2: /* RO after init */
1468 mod->data_layout.size = strict_align(mod->data_layout.size);
1469 mod->data_layout.ro_after_init_size = mod->data_layout.size;
1471 case 4: /* whole core */
1472 mod->data_layout.size = strict_align(mod->data_layout.size);
1477 pr_debug("Init section allocation order:\n");
1478 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1479 for (i = 0; i < info->hdr->e_shnum; ++i) {
1480 Elf_Shdr *s = &info->sechdrs[i];
1481 const char *sname = info->secstrings + s->sh_name;
1483 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1484 || (s->sh_flags & masks[m][1])
1485 || s->sh_entsize != ~0UL
1486 || !module_init_layout_section(sname))
1488 s->sh_entsize = (module_get_offset(mod, &mod->init_layout.size, s, i)
1489 | INIT_OFFSET_MASK);
1490 pr_debug("\t%s\n", sname);
1493 case 0: /* executable */
1494 mod->init_layout.size = strict_align(mod->init_layout.size);
1495 mod->init_layout.text_size = mod->init_layout.size;
1497 case 1: /* RO: text and ro-data */
1498 mod->init_layout.size = strict_align(mod->init_layout.size);
1499 mod->init_layout.ro_size = mod->init_layout.size;
1503 * RO after init doesn't apply to init_layout (only
1504 * core_layout), so it just takes the value of ro_size.
1506 mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
1508 case 4: /* whole init */
1509 mod->init_layout.size = strict_align(mod->init_layout.size);
1515 static void set_license(struct module *mod, const char *license)
1518 license = "unspecified";
1520 if (!license_is_gpl_compatible(license)) {
1521 if (!test_taint(TAINT_PROPRIETARY_MODULE))
1522 pr_warn("%s: module license '%s' taints kernel.\n",
1523 mod->name, license);
1524 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
1525 LOCKDEP_NOW_UNRELIABLE);
1529 /* Parse tag=value strings from .modinfo section */
1530 static char *next_string(char *string, unsigned long *secsize)
1532 /* Skip non-zero chars */
1535 if ((*secsize)-- <= 1)
1539 /* Skip any zero padding. */
1540 while (!string[0]) {
1542 if ((*secsize)-- <= 1)
1548 static char *get_next_modinfo(const struct load_info *info, const char *tag,
1552 unsigned int taglen = strlen(tag);
1553 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
1554 unsigned long size = infosec->sh_size;
1557 * get_modinfo() calls made before rewrite_section_headers()
1558 * must use sh_offset, as sh_addr isn't set!
1560 char *modinfo = (char *)info->hdr + infosec->sh_offset;
1563 size -= prev - modinfo;
1564 modinfo = next_string(prev, &size);
1567 for (p = modinfo; p; p = next_string(p, &size)) {
1568 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
1569 return p + taglen + 1;
1574 static char *get_modinfo(const struct load_info *info, const char *tag)
1576 return get_next_modinfo(info, tag, NULL);
1579 static void setup_modinfo(struct module *mod, struct load_info *info)
1581 struct module_attribute *attr;
1584 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1586 attr->setup(mod, get_modinfo(info, attr->attr.name));
1590 static void free_modinfo(struct module *mod)
1592 struct module_attribute *attr;
1595 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1601 static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num)
1605 ddebug_add_module(debug, num, mod->name);
1608 static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug)
1611 ddebug_remove_module(mod->name);
1614 void * __weak module_alloc(unsigned long size)
1616 return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
1617 GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS,
1618 NUMA_NO_NODE, __builtin_return_address(0));
1621 bool __weak module_init_section(const char *name)
1623 return strstarts(name, ".init");
1626 bool __weak module_exit_section(const char *name)
1628 return strstarts(name, ".exit");
1631 static int validate_section_offset(struct load_info *info, Elf_Shdr *shdr)
1633 #if defined(CONFIG_64BIT)
1634 unsigned long long secend;
1636 unsigned long secend;
1640 * Check for both overflow and offset/size being
1643 secend = shdr->sh_offset + shdr->sh_size;
1644 if (secend < shdr->sh_offset || secend > info->len)
1651 * Sanity checks against invalid binaries, wrong arch, weird elf version.
1653 * Also do basic validity checks against section offsets and sizes, the
1654 * section name string table, and the indices used for it (sh_name).
1656 static int elf_validity_check(struct load_info *info)
1659 Elf_Shdr *shdr, *strhdr;
1662 if (info->len < sizeof(*(info->hdr))) {
1663 pr_err("Invalid ELF header len %lu\n", info->len);
1667 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0) {
1668 pr_err("Invalid ELF header magic: != %s\n", ELFMAG);
1671 if (info->hdr->e_type != ET_REL) {
1672 pr_err("Invalid ELF header type: %u != %u\n",
1673 info->hdr->e_type, ET_REL);
1676 if (!elf_check_arch(info->hdr)) {
1677 pr_err("Invalid architecture in ELF header: %u\n",
1678 info->hdr->e_machine);
1681 if (info->hdr->e_shentsize != sizeof(Elf_Shdr)) {
1682 pr_err("Invalid ELF section header size\n");
1687 * e_shnum is 16 bits, and sizeof(Elf_Shdr) is
1688 * known and small. So e_shnum * sizeof(Elf_Shdr)
1689 * will not overflow unsigned long on any platform.
1691 if (info->hdr->e_shoff >= info->len
1692 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
1693 info->len - info->hdr->e_shoff)) {
1694 pr_err("Invalid ELF section header overflow\n");
1698 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
1701 * Verify if the section name table index is valid.
1703 if (info->hdr->e_shstrndx == SHN_UNDEF
1704 || info->hdr->e_shstrndx >= info->hdr->e_shnum) {
1705 pr_err("Invalid ELF section name index: %d || e_shstrndx (%d) >= e_shnum (%d)\n",
1706 info->hdr->e_shstrndx, info->hdr->e_shstrndx,
1707 info->hdr->e_shnum);
1711 strhdr = &info->sechdrs[info->hdr->e_shstrndx];
1712 err = validate_section_offset(info, strhdr);
1714 pr_err("Invalid ELF section hdr(type %u)\n", strhdr->sh_type);
1719 * The section name table must be NUL-terminated, as required
1720 * by the spec. This makes strcmp and pr_* calls that access
1721 * strings in the section safe.
1723 info->secstrings = (void *)info->hdr + strhdr->sh_offset;
1724 if (strhdr->sh_size == 0) {
1725 pr_err("empty section name table\n");
1728 if (info->secstrings[strhdr->sh_size - 1] != '\0') {
1729 pr_err("ELF Spec violation: section name table isn't null terminated\n");
1734 * The code assumes that section 0 has a length of zero and
1735 * an addr of zero, so check for it.
1737 if (info->sechdrs[0].sh_type != SHT_NULL
1738 || info->sechdrs[0].sh_size != 0
1739 || info->sechdrs[0].sh_addr != 0) {
1740 pr_err("ELF Spec violation: section 0 type(%d)!=SH_NULL or non-zero len or addr\n",
1741 info->sechdrs[0].sh_type);
1745 for (i = 1; i < info->hdr->e_shnum; i++) {
1746 shdr = &info->sechdrs[i];
1747 switch (shdr->sh_type) {
1752 if (shdr->sh_link == SHN_UNDEF
1753 || shdr->sh_link >= info->hdr->e_shnum) {
1754 pr_err("Invalid ELF sh_link!=SHN_UNDEF(%d) or (sh_link(%d) >= hdr->e_shnum(%d)\n",
1755 shdr->sh_link, shdr->sh_link,
1756 info->hdr->e_shnum);
1761 err = validate_section_offset(info, shdr);
1763 pr_err("Invalid ELF section in module (section %u type %u)\n",
1768 if (shdr->sh_flags & SHF_ALLOC) {
1769 if (shdr->sh_name >= strhdr->sh_size) {
1770 pr_err("Invalid ELF section name in module (section %u type %u)\n",
1785 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
1787 static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
1790 unsigned long n = min(len, COPY_CHUNK_SIZE);
1792 if (copy_from_user(dst, usrc, n) != 0)
1802 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
1804 if (!get_modinfo(info, "livepatch"))
1805 /* Nothing more to do */
1808 if (set_livepatch_module(mod)) {
1809 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
1810 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
1815 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
1820 static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
1822 if (retpoline_module_ok(get_modinfo(info, "retpoline")))
1825 pr_warn("%s: loading module not compiled with retpoline compiler.\n",
1829 /* Sets info->hdr and info->len. */
1830 static int copy_module_from_user(const void __user *umod, unsigned long len,
1831 struct load_info *info)
1836 if (info->len < sizeof(*(info->hdr)))
1839 err = security_kernel_load_data(LOADING_MODULE, true);
1843 /* Suck in entire file: we'll want most of it. */
1844 info->hdr = __vmalloc(info->len, GFP_KERNEL | __GFP_NOWARN);
1848 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
1853 err = security_kernel_post_load_data((char *)info->hdr, info->len,
1854 LOADING_MODULE, "init_module");
1862 static void free_copy(struct load_info *info, int flags)
1864 if (flags & MODULE_INIT_COMPRESSED_FILE)
1865 module_decompress_cleanup(info);
1870 static int rewrite_section_headers(struct load_info *info, int flags)
1874 /* This should always be true, but let's be sure. */
1875 info->sechdrs[0].sh_addr = 0;
1877 for (i = 1; i < info->hdr->e_shnum; i++) {
1878 Elf_Shdr *shdr = &info->sechdrs[i];
1881 * Mark all sections sh_addr with their address in the
1884 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
1888 /* Track but don't keep modinfo and version sections. */
1889 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
1890 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
1896 * Set up our basic convenience variables (pointers to section headers,
1897 * search for module section index etc), and do some basic section
1900 * Set info->mod to the temporary copy of the module in info->hdr. The final one
1901 * will be allocated in move_module().
1903 static int setup_load_info(struct load_info *info, int flags)
1907 /* Try to find a name early so we can log errors with a module name */
1908 info->index.info = find_sec(info, ".modinfo");
1909 if (info->index.info)
1910 info->name = get_modinfo(info, "name");
1912 /* Find internal symbols and strings. */
1913 for (i = 1; i < info->hdr->e_shnum; i++) {
1914 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
1915 info->index.sym = i;
1916 info->index.str = info->sechdrs[i].sh_link;
1917 info->strtab = (char *)info->hdr
1918 + info->sechdrs[info->index.str].sh_offset;
1923 if (info->index.sym == 0) {
1924 pr_warn("%s: module has no symbols (stripped?)\n",
1925 info->name ?: "(missing .modinfo section or name field)");
1929 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
1930 if (!info->index.mod) {
1931 pr_warn("%s: No module found in object\n",
1932 info->name ?: "(missing .modinfo section or name field)");
1935 /* This is temporary: point mod into copy of data. */
1936 info->mod = (void *)info->hdr + info->sechdrs[info->index.mod].sh_offset;
1939 * If we didn't load the .modinfo 'name' field earlier, fall back to
1940 * on-disk struct mod 'name' field.
1943 info->name = info->mod->name;
1945 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
1946 info->index.vers = 0; /* Pretend no __versions section! */
1948 info->index.vers = find_sec(info, "__versions");
1950 info->index.pcpu = find_pcpusec(info);
1955 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
1957 const char *modmagic = get_modinfo(info, "vermagic");
1960 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
1963 /* This is allowed: modprobe --force will invalidate it. */
1965 err = try_to_force_load(mod, "bad vermagic");
1968 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
1969 pr_err("%s: version magic '%s' should be '%s'\n",
1970 info->name, modmagic, vermagic);
1974 if (!get_modinfo(info, "intree")) {
1975 if (!test_taint(TAINT_OOT_MODULE))
1976 pr_warn("%s: loading out-of-tree module taints kernel.\n",
1978 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
1981 check_modinfo_retpoline(mod, info);
1983 if (get_modinfo(info, "staging")) {
1984 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
1985 pr_warn("%s: module is from the staging directory, the quality "
1986 "is unknown, you have been warned.\n", mod->name);
1989 err = check_modinfo_livepatch(mod, info);
1993 /* Set up license info based on the info section */
1994 set_license(mod, get_modinfo(info, "license"));
1996 if (get_modinfo(info, "test")) {
1997 if (!test_taint(TAINT_TEST))
1998 pr_warn("%s: loading test module taints kernel.\n",
2000 add_taint_module(mod, TAINT_TEST, LOCKDEP_STILL_OK);
2006 static int find_module_sections(struct module *mod, struct load_info *info)
2008 mod->kp = section_objs(info, "__param",
2009 sizeof(*mod->kp), &mod->num_kp);
2010 mod->syms = section_objs(info, "__ksymtab",
2011 sizeof(*mod->syms), &mod->num_syms);
2012 mod->crcs = section_addr(info, "__kcrctab");
2013 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2014 sizeof(*mod->gpl_syms),
2015 &mod->num_gpl_syms);
2016 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2018 #ifdef CONFIG_CONSTRUCTORS
2019 mod->ctors = section_objs(info, ".ctors",
2020 sizeof(*mod->ctors), &mod->num_ctors);
2022 mod->ctors = section_objs(info, ".init_array",
2023 sizeof(*mod->ctors), &mod->num_ctors);
2024 else if (find_sec(info, ".init_array")) {
2026 * This shouldn't happen with same compiler and binutils
2027 * building all parts of the module.
2029 pr_warn("%s: has both .ctors and .init_array.\n",
2035 mod->noinstr_text_start = section_objs(info, ".noinstr.text", 1,
2036 &mod->noinstr_text_size);
2038 #ifdef CONFIG_TRACEPOINTS
2039 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2040 sizeof(*mod->tracepoints_ptrs),
2041 &mod->num_tracepoints);
2043 #ifdef CONFIG_TREE_SRCU
2044 mod->srcu_struct_ptrs = section_objs(info, "___srcu_struct_ptrs",
2045 sizeof(*mod->srcu_struct_ptrs),
2046 &mod->num_srcu_structs);
2048 #ifdef CONFIG_BPF_EVENTS
2049 mod->bpf_raw_events = section_objs(info, "__bpf_raw_tp_map",
2050 sizeof(*mod->bpf_raw_events),
2051 &mod->num_bpf_raw_events);
2053 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
2054 mod->btf_data = any_section_objs(info, ".BTF", 1, &mod->btf_data_size);
2056 #ifdef CONFIG_JUMP_LABEL
2057 mod->jump_entries = section_objs(info, "__jump_table",
2058 sizeof(*mod->jump_entries),
2059 &mod->num_jump_entries);
2061 #ifdef CONFIG_EVENT_TRACING
2062 mod->trace_events = section_objs(info, "_ftrace_events",
2063 sizeof(*mod->trace_events),
2064 &mod->num_trace_events);
2065 mod->trace_evals = section_objs(info, "_ftrace_eval_map",
2066 sizeof(*mod->trace_evals),
2067 &mod->num_trace_evals);
2069 #ifdef CONFIG_TRACING
2070 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2071 sizeof(*mod->trace_bprintk_fmt_start),
2072 &mod->num_trace_bprintk_fmt);
2074 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
2075 /* sechdrs[0].sh_size is always zero */
2076 mod->ftrace_callsites = section_objs(info, FTRACE_CALLSITE_SECTION,
2077 sizeof(*mod->ftrace_callsites),
2078 &mod->num_ftrace_callsites);
2080 #ifdef CONFIG_FUNCTION_ERROR_INJECTION
2081 mod->ei_funcs = section_objs(info, "_error_injection_whitelist",
2082 sizeof(*mod->ei_funcs),
2083 &mod->num_ei_funcs);
2085 #ifdef CONFIG_KPROBES
2086 mod->kprobes_text_start = section_objs(info, ".kprobes.text", 1,
2087 &mod->kprobes_text_size);
2088 mod->kprobe_blacklist = section_objs(info, "_kprobe_blacklist",
2089 sizeof(unsigned long),
2090 &mod->num_kprobe_blacklist);
2092 #ifdef CONFIG_PRINTK_INDEX
2093 mod->printk_index_start = section_objs(info, ".printk_index",
2094 sizeof(*mod->printk_index_start),
2095 &mod->printk_index_size);
2097 #ifdef CONFIG_HAVE_STATIC_CALL_INLINE
2098 mod->static_call_sites = section_objs(info, ".static_call_sites",
2099 sizeof(*mod->static_call_sites),
2100 &mod->num_static_call_sites);
2103 mod->kunit_suites = section_objs(info, ".kunit_test_suites",
2104 sizeof(*mod->kunit_suites),
2105 &mod->num_kunit_suites);
2108 mod->extable = section_objs(info, "__ex_table",
2109 sizeof(*mod->extable), &mod->num_exentries);
2111 if (section_addr(info, "__obsparm"))
2112 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
2114 info->debug = section_objs(info, "__dyndbg",
2115 sizeof(*info->debug), &info->num_debug);
2120 static int move_module(struct module *mod, struct load_info *info)
2125 /* Do the allocs. */
2126 ptr = module_alloc(mod->core_layout.size);
2128 * The pointer to this block is stored in the module structure
2129 * which is inside the block. Just mark it as not being a
2132 kmemleak_not_leak(ptr);
2136 memset(ptr, 0, mod->core_layout.size);
2137 mod->core_layout.base = ptr;
2139 if (mod->init_layout.size) {
2140 ptr = module_alloc(mod->init_layout.size);
2142 * The pointer to this block is stored in the module structure
2143 * which is inside the block. This block doesn't need to be
2144 * scanned as it contains data and code that will be freed
2145 * after the module is initialized.
2147 kmemleak_ignore(ptr);
2149 module_memfree(mod->core_layout.base);
2152 memset(ptr, 0, mod->init_layout.size);
2153 mod->init_layout.base = ptr;
2155 mod->init_layout.base = NULL;
2157 #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
2158 /* Do the allocs. */
2159 ptr = vzalloc(mod->data_layout.size);
2161 * The pointer to this block is stored in the module structure
2162 * which is inside the block. Just mark it as not being a
2165 kmemleak_not_leak(ptr);
2167 module_memfree(mod->core_layout.base);
2168 module_memfree(mod->init_layout.base);
2172 mod->data_layout.base = ptr;
2174 /* Transfer each section which specifies SHF_ALLOC */
2175 pr_debug("final section addresses:\n");
2176 for (i = 0; i < info->hdr->e_shnum; i++) {
2178 Elf_Shdr *shdr = &info->sechdrs[i];
2180 if (!(shdr->sh_flags & SHF_ALLOC))
2183 if (shdr->sh_entsize & INIT_OFFSET_MASK)
2184 dest = mod->init_layout.base
2185 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
2186 else if (!(shdr->sh_flags & SHF_EXECINSTR))
2187 dest = mod->data_layout.base + shdr->sh_entsize;
2189 dest = mod->core_layout.base + shdr->sh_entsize;
2191 if (shdr->sh_type != SHT_NOBITS)
2192 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2193 /* Update sh_addr to point to copy in image. */
2194 shdr->sh_addr = (unsigned long)dest;
2195 pr_debug("\t0x%lx %s\n",
2196 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
2202 static int check_module_license_and_versions(struct module *mod)
2204 int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
2207 * ndiswrapper is under GPL by itself, but loads proprietary modules.
2208 * Don't use add_taint_module(), as it would prevent ndiswrapper from
2209 * using GPL-only symbols it needs.
2211 if (strcmp(mod->name, "ndiswrapper") == 0)
2212 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
2214 /* driverloader was caught wrongly pretending to be under GPL */
2215 if (strcmp(mod->name, "driverloader") == 0)
2216 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2217 LOCKDEP_NOW_UNRELIABLE);
2219 /* lve claims to be GPL but upstream won't provide source */
2220 if (strcmp(mod->name, "lve") == 0)
2221 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2222 LOCKDEP_NOW_UNRELIABLE);
2224 if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
2225 pr_warn("%s: module license taints kernel.\n", mod->name);
2227 #ifdef CONFIG_MODVERSIONS
2228 if ((mod->num_syms && !mod->crcs) ||
2229 (mod->num_gpl_syms && !mod->gpl_crcs)) {
2230 return try_to_force_load(mod,
2231 "no versions for exported symbols");
2237 static void flush_module_icache(const struct module *mod)
2240 * Flush the instruction cache, since we've played with text.
2241 * Do it before processing of module parameters, so the module
2242 * can provide parameter accessor functions of its own.
2244 if (mod->init_layout.base)
2245 flush_icache_range((unsigned long)mod->init_layout.base,
2246 (unsigned long)mod->init_layout.base
2247 + mod->init_layout.size);
2248 flush_icache_range((unsigned long)mod->core_layout.base,
2249 (unsigned long)mod->core_layout.base + mod->core_layout.size);
2252 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
2260 /* module_blacklist is a comma-separated list of module names */
2261 static char *module_blacklist;
2262 static bool blacklisted(const char *module_name)
2267 if (!module_blacklist)
2270 for (p = module_blacklist; *p; p += len) {
2271 len = strcspn(p, ",");
2272 if (strlen(module_name) == len && !memcmp(module_name, p, len))
2279 core_param(module_blacklist, module_blacklist, charp, 0400);
2281 static struct module *layout_and_allocate(struct load_info *info, int flags)
2287 err = check_modinfo(info->mod, info, flags);
2289 return ERR_PTR(err);
2291 /* Allow arches to frob section contents and sizes. */
2292 err = module_frob_arch_sections(info->hdr, info->sechdrs,
2293 info->secstrings, info->mod);
2295 return ERR_PTR(err);
2297 err = module_enforce_rwx_sections(info->hdr, info->sechdrs,
2298 info->secstrings, info->mod);
2300 return ERR_PTR(err);
2302 /* We will do a special allocation for per-cpu sections later. */
2303 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
2306 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
2307 * layout_sections() can put it in the right place.
2308 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
2310 ndx = find_sec(info, ".data..ro_after_init");
2312 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
2314 * Mark the __jump_table section as ro_after_init as well: these data
2315 * structures are never modified, with the exception of entries that
2316 * refer to code in the __init section, which are annotated as such
2317 * at module load time.
2319 ndx = find_sec(info, "__jump_table");
2321 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
2324 * Determine total sizes, and put offsets in sh_entsize. For now
2325 * this is done generically; there doesn't appear to be any
2326 * special cases for the architectures.
2328 layout_sections(info->mod, info);
2329 layout_symtab(info->mod, info);
2331 /* Allocate and move to the final place */
2332 err = move_module(info->mod, info);
2334 return ERR_PTR(err);
2336 /* Module has been copied to its final place now: return it. */
2337 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2338 kmemleak_load_module(mod, info);
2342 /* mod is no longer valid after this! */
2343 static void module_deallocate(struct module *mod, struct load_info *info)
2345 percpu_modfree(mod);
2346 module_arch_freeing_init(mod);
2347 module_memfree(mod->init_layout.base);
2348 module_memfree(mod->core_layout.base);
2349 #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
2350 vfree(mod->data_layout.base);
2354 int __weak module_finalize(const Elf_Ehdr *hdr,
2355 const Elf_Shdr *sechdrs,
2361 static int post_relocation(struct module *mod, const struct load_info *info)
2363 /* Sort exception table now relocations are done. */
2364 sort_extable(mod->extable, mod->extable + mod->num_exentries);
2366 /* Copy relocated percpu area over. */
2367 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
2368 info->sechdrs[info->index.pcpu].sh_size);
2370 /* Setup kallsyms-specific fields. */
2371 add_kallsyms(mod, info);
2373 /* Arch-specific module finalizing. */
2374 return module_finalize(info->hdr, info->sechdrs, mod);
2377 /* Is this module of this name done loading? No locks held. */
2378 static bool finished_loading(const char *name)
2384 * The module_mutex should not be a heavily contended lock;
2385 * if we get the occasional sleep here, we'll go an extra iteration
2386 * in the wait_event_interruptible(), which is harmless.
2388 sched_annotate_sleep();
2389 mutex_lock(&module_mutex);
2390 mod = find_module_all(name, strlen(name), true);
2391 ret = !mod || mod->state == MODULE_STATE_LIVE;
2392 mutex_unlock(&module_mutex);
2397 /* Call module constructors. */
2398 static void do_mod_ctors(struct module *mod)
2400 #ifdef CONFIG_CONSTRUCTORS
2403 for (i = 0; i < mod->num_ctors; i++)
2408 /* For freeing module_init on success, in case kallsyms traversing */
2409 struct mod_initfree {
2410 struct llist_node node;
2414 static void do_free_init(struct work_struct *w)
2416 struct llist_node *pos, *n, *list;
2417 struct mod_initfree *initfree;
2419 list = llist_del_all(&init_free_list);
2423 llist_for_each_safe(pos, n, list) {
2424 initfree = container_of(pos, struct mod_initfree, node);
2425 module_memfree(initfree->module_init);
2430 #undef MODULE_PARAM_PREFIX
2431 #define MODULE_PARAM_PREFIX "module."
2432 /* Default value for module->async_probe_requested */
2433 static bool async_probe;
2434 module_param(async_probe, bool, 0644);
2437 * This is where the real work happens.
2439 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
2440 * helper command 'lx-symbols'.
2442 static noinline int do_init_module(struct module *mod)
2445 struct mod_initfree *freeinit;
2447 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
2452 freeinit->module_init = mod->init_layout.base;
2455 /* Start the module */
2456 if (mod->init != NULL)
2457 ret = do_one_initcall(mod->init);
2459 goto fail_free_freeinit;
2462 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
2463 "follow 0/-E convention\n"
2464 "%s: loading module anyway...\n",
2465 __func__, mod->name, ret, __func__);
2469 /* Now it's a first class citizen! */
2470 mod->state = MODULE_STATE_LIVE;
2471 blocking_notifier_call_chain(&module_notify_list,
2472 MODULE_STATE_LIVE, mod);
2474 /* Delay uevent until module has finished its init routine */
2475 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
2478 * We need to finish all async code before the module init sequence
2479 * is done. This has potential to deadlock if synchronous module
2480 * loading is requested from async (which is not allowed!).
2482 * See commit 0fdff3ec6d87 ("async, kmod: warn on synchronous
2483 * request_module() from async workers") for more details.
2485 if (!mod->async_probe_requested)
2486 async_synchronize_full();
2488 ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base +
2489 mod->init_layout.size);
2490 mutex_lock(&module_mutex);
2491 /* Drop initial reference. */
2493 trim_init_extable(mod);
2494 #ifdef CONFIG_KALLSYMS
2495 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
2496 rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
2498 module_enable_ro(mod, true);
2499 mod_tree_remove_init(mod);
2500 module_arch_freeing_init(mod);
2501 mod->init_layout.base = NULL;
2502 mod->init_layout.size = 0;
2503 mod->init_layout.ro_size = 0;
2504 mod->init_layout.ro_after_init_size = 0;
2505 mod->init_layout.text_size = 0;
2506 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
2507 /* .BTF is not SHF_ALLOC and will get removed, so sanitize pointer */
2508 mod->btf_data = NULL;
2511 * We want to free module_init, but be aware that kallsyms may be
2512 * walking this with preempt disabled. In all the failure paths, we
2513 * call synchronize_rcu(), but we don't want to slow down the success
2514 * path. module_memfree() cannot be called in an interrupt, so do the
2515 * work and call synchronize_rcu() in a work queue.
2517 * Note that module_alloc() on most architectures creates W+X page
2518 * mappings which won't be cleaned up until do_free_init() runs. Any
2519 * code such as mark_rodata_ro() which depends on those mappings to
2520 * be cleaned up needs to sync with the queued work - ie
2523 if (llist_add(&freeinit->node, &init_free_list))
2524 schedule_work(&init_free_wq);
2526 mutex_unlock(&module_mutex);
2527 wake_up_all(&module_wq);
2534 /* Try to protect us from buggy refcounters. */
2535 mod->state = MODULE_STATE_GOING;
2538 blocking_notifier_call_chain(&module_notify_list,
2539 MODULE_STATE_GOING, mod);
2540 klp_module_going(mod);
2541 ftrace_release_mod(mod);
2543 wake_up_all(&module_wq);
2547 static int may_init_module(void)
2549 if (!capable(CAP_SYS_MODULE) || modules_disabled)
2556 * We try to place it in the list now to make sure it's unique before
2557 * we dedicate too many resources. In particular, temporary percpu
2558 * memory exhaustion.
2560 static int add_unformed_module(struct module *mod)
2565 mod->state = MODULE_STATE_UNFORMED;
2568 mutex_lock(&module_mutex);
2569 old = find_module_all(mod->name, strlen(mod->name), true);
2571 if (old->state != MODULE_STATE_LIVE) {
2572 /* Wait in case it fails to load. */
2573 mutex_unlock(&module_mutex);
2574 err = wait_event_interruptible(module_wq,
2575 finished_loading(mod->name));
2583 mod_update_bounds(mod);
2584 list_add_rcu(&mod->list, &modules);
2585 mod_tree_insert(mod);
2589 mutex_unlock(&module_mutex);
2594 static int complete_formation(struct module *mod, struct load_info *info)
2598 mutex_lock(&module_mutex);
2600 /* Find duplicate symbols (must be called under lock). */
2601 err = verify_exported_symbols(mod);
2605 /* This relies on module_mutex for list integrity. */
2606 module_bug_finalize(info->hdr, info->sechdrs, mod);
2608 if (module_check_misalignment(mod))
2609 goto out_misaligned;
2611 module_enable_ro(mod, false);
2612 module_enable_nx(mod);
2613 module_enable_x(mod);
2616 * Mark state as coming so strong_try_module_get() ignores us,
2617 * but kallsyms etc. can see us.
2619 mod->state = MODULE_STATE_COMING;
2620 mutex_unlock(&module_mutex);
2627 mutex_unlock(&module_mutex);
2631 static int prepare_coming_module(struct module *mod)
2635 ftrace_module_enable(mod);
2636 err = klp_module_coming(mod);
2640 err = blocking_notifier_call_chain_robust(&module_notify_list,
2641 MODULE_STATE_COMING, MODULE_STATE_GOING, mod);
2642 err = notifier_to_errno(err);
2644 klp_module_going(mod);
2649 static int unknown_module_param_cb(char *param, char *val, const char *modname,
2652 struct module *mod = arg;
2655 if (strcmp(param, "async_probe") == 0) {
2656 if (strtobool(val, &mod->async_probe_requested))
2657 mod->async_probe_requested = true;
2661 /* Check for magic 'dyndbg' arg */
2662 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
2664 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
2668 static void cfi_init(struct module *mod);
2671 * Allocate and load the module: note that size of section 0 is always
2672 * zero, and we rely on this for optional sections.
2674 static int load_module(struct load_info *info, const char __user *uargs,
2682 * Do the signature check (if any) first. All that
2683 * the signature check needs is info->len, it does
2684 * not need any of the section info. That can be
2685 * set up later. This will minimize the chances
2686 * of a corrupt module causing problems before
2687 * we even get to the signature check.
2689 * The check will also adjust info->len by stripping
2690 * off the sig length at the end of the module, making
2691 * checks against info->len more correct.
2693 err = module_sig_check(info, flags);
2698 * Do basic sanity checks against the ELF header and
2701 err = elf_validity_check(info);
2706 * Everything checks out, so set up the section info
2707 * in the info structure.
2709 err = setup_load_info(info, flags);
2714 * Now that we know we have the correct module name, check
2715 * if it's blacklisted.
2717 if (blacklisted(info->name)) {
2719 pr_err("Module %s is blacklisted\n", info->name);
2723 err = rewrite_section_headers(info, flags);
2727 /* Check module struct version now, before we try to use module. */
2728 if (!check_modstruct_version(info, info->mod)) {
2733 /* Figure out module layout, and allocate all the memory. */
2734 mod = layout_and_allocate(info, flags);
2740 audit_log_kern_module(mod->name);
2742 /* Reserve our place in the list. */
2743 err = add_unformed_module(mod);
2747 #ifdef CONFIG_MODULE_SIG
2748 mod->sig_ok = info->sig_ok;
2750 pr_notice_once("%s: module verification failed: signature "
2751 "and/or required key missing - tainting "
2752 "kernel\n", mod->name);
2753 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
2757 /* To avoid stressing percpu allocator, do this once we're unique. */
2758 err = percpu_modalloc(mod, info);
2762 /* Now module is in final location, initialize linked lists, etc. */
2763 err = module_unload_init(mod);
2767 init_param_lock(mod);
2770 * Now we've got everything in the final locations, we can
2771 * find optional sections.
2773 err = find_module_sections(mod, info);
2777 err = check_module_license_and_versions(mod);
2781 /* Set up MODINFO_ATTR fields */
2782 setup_modinfo(mod, info);
2784 /* Fix up syms, so that st_value is a pointer to location. */
2785 err = simplify_symbols(mod, info);
2789 err = apply_relocations(mod, info);
2793 err = post_relocation(mod, info);
2797 flush_module_icache(mod);
2799 /* Setup CFI for the module. */
2802 /* Now copy in args */
2803 mod->args = strndup_user(uargs, ~0UL >> 1);
2804 if (IS_ERR(mod->args)) {
2805 err = PTR_ERR(mod->args);
2806 goto free_arch_cleanup;
2809 init_build_id(mod, info);
2810 dynamic_debug_setup(mod, info->debug, info->num_debug);
2812 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
2813 ftrace_module_init(mod);
2815 /* Finally it's fully formed, ready to start executing. */
2816 err = complete_formation(mod, info);
2818 goto ddebug_cleanup;
2820 err = prepare_coming_module(mod);
2824 mod->async_probe_requested = async_probe;
2826 /* Module is ready to execute: parsing args may do that. */
2827 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
2829 unknown_module_param_cb);
2830 if (IS_ERR(after_dashes)) {
2831 err = PTR_ERR(after_dashes);
2832 goto coming_cleanup;
2833 } else if (after_dashes) {
2834 pr_warn("%s: parameters '%s' after `--' ignored\n",
2835 mod->name, after_dashes);
2838 /* Link in to sysfs. */
2839 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
2841 goto coming_cleanup;
2843 if (is_livepatch_module(mod)) {
2844 err = copy_module_elf(mod, info);
2849 /* Get rid of temporary copy. */
2850 free_copy(info, flags);
2853 trace_module_load(mod);
2855 return do_init_module(mod);
2858 mod_sysfs_teardown(mod);
2860 mod->state = MODULE_STATE_GOING;
2861 destroy_params(mod->kp, mod->num_kp);
2862 blocking_notifier_call_chain(&module_notify_list,
2863 MODULE_STATE_GOING, mod);
2864 klp_module_going(mod);
2866 mod->state = MODULE_STATE_GOING;
2867 /* module_bug_cleanup needs module_mutex protection */
2868 mutex_lock(&module_mutex);
2869 module_bug_cleanup(mod);
2870 mutex_unlock(&module_mutex);
2873 ftrace_release_mod(mod);
2874 dynamic_debug_remove(mod, info->debug);
2879 module_arch_cleanup(mod);
2883 module_unload_free(mod);
2885 mutex_lock(&module_mutex);
2886 /* Unlink carefully: kallsyms could be walking list. */
2887 list_del_rcu(&mod->list);
2888 mod_tree_remove(mod);
2889 wake_up_all(&module_wq);
2890 /* Wait for RCU-sched synchronizing before releasing mod->list. */
2892 mutex_unlock(&module_mutex);
2894 /* Free lock-classes; relies on the preceding sync_rcu() */
2895 lockdep_free_key_range(mod->data_layout.base, mod->data_layout.size);
2897 module_deallocate(mod, info);
2899 free_copy(info, flags);
2903 SYSCALL_DEFINE3(init_module, void __user *, umod,
2904 unsigned long, len, const char __user *, uargs)
2907 struct load_info info = { };
2909 err = may_init_module();
2913 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
2916 err = copy_module_from_user(umod, len, &info);
2920 return load_module(&info, uargs, 0);
2923 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
2925 struct load_info info = { };
2930 err = may_init_module();
2934 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
2936 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
2937 |MODULE_INIT_IGNORE_VERMAGIC
2938 |MODULE_INIT_COMPRESSED_FILE))
2941 len = kernel_read_file_from_fd(fd, 0, &buf, INT_MAX, NULL,
2946 if (flags & MODULE_INIT_COMPRESSED_FILE) {
2947 err = module_decompress(&info, buf, len);
2948 vfree(buf); /* compressed data is no longer needed */
2956 return load_module(&info, uargs, flags);
2959 static inline int within(unsigned long addr, void *start, unsigned long size)
2961 return ((void *)addr >= start && (void *)addr < start + size);
2964 static void cfi_init(struct module *mod)
2966 #ifdef CONFIG_CFI_CLANG
2968 #ifdef CONFIG_MODULE_UNLOAD
2972 rcu_read_lock_sched();
2973 mod->cfi_check = (cfi_check_fn)
2974 find_kallsyms_symbol_value(mod, "__cfi_check");
2975 init = (initcall_t *)
2976 find_kallsyms_symbol_value(mod, "__cfi_jt_init_module");
2977 /* Fix init/exit functions to point to the CFI jump table */
2980 #ifdef CONFIG_MODULE_UNLOAD
2981 exit = (exitcall_t *)
2982 find_kallsyms_symbol_value(mod, "__cfi_jt_cleanup_module");
2986 rcu_read_unlock_sched();
2988 cfi_module_add(mod, mod_tree.addr_min);
2992 static void cfi_cleanup(struct module *mod)
2994 #ifdef CONFIG_CFI_CLANG
2995 cfi_module_remove(mod, mod_tree.addr_min);
2999 /* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
3000 char *module_flags(struct module *mod, char *buf, bool show_state)
3004 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
3005 if (!mod->taints && !show_state)
3008 mod->state == MODULE_STATE_GOING ||
3009 mod->state == MODULE_STATE_COMING) {
3011 bx += module_flags_taint(mod->taints, buf + bx);
3012 /* Show a - for module-is-being-unloaded */
3013 if (mod->state == MODULE_STATE_GOING && show_state)
3015 /* Show a + for module-is-being-loaded */
3016 if (mod->state == MODULE_STATE_COMING && show_state)
3026 /* Given an address, look for it in the module exception tables. */
3027 const struct exception_table_entry *search_module_extables(unsigned long addr)
3029 const struct exception_table_entry *e = NULL;
3033 mod = __module_address(addr);
3037 if (!mod->num_exentries)
3040 e = search_extable(mod->extable,
3047 * Now, if we found one, we are running inside it now, hence
3048 * we cannot unload the module, hence no refcnt needed.
3054 * is_module_address() - is this address inside a module?
3055 * @addr: the address to check.
3057 * See is_module_text_address() if you simply want to see if the address
3058 * is code (not data).
3060 bool is_module_address(unsigned long addr)
3065 ret = __module_address(addr) != NULL;
3072 * __module_address() - get the module which contains an address.
3073 * @addr: the address.
3075 * Must be called with preempt disabled or module mutex held so that
3076 * module doesn't get freed during this.
3078 struct module *__module_address(unsigned long addr)
3081 struct mod_tree_root *tree;
3083 if (addr >= mod_tree.addr_min && addr <= mod_tree.addr_max)
3085 #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
3086 else if (addr >= mod_data_tree.addr_min && addr <= mod_data_tree.addr_max)
3087 tree = &mod_data_tree;
3092 module_assert_mutex_or_preempt();
3094 mod = mod_find(addr, tree);
3096 BUG_ON(!within_module(addr, mod));
3097 if (mod->state == MODULE_STATE_UNFORMED)
3104 * is_module_text_address() - is this address inside module code?
3105 * @addr: the address to check.
3107 * See is_module_address() if you simply want to see if the address is
3108 * anywhere in a module. See kernel_text_address() for testing if an
3109 * address corresponds to kernel or module code.
3111 bool is_module_text_address(unsigned long addr)
3116 ret = __module_text_address(addr) != NULL;
3123 * __module_text_address() - get the module whose code contains an address.
3124 * @addr: the address.
3126 * Must be called with preempt disabled or module mutex held so that
3127 * module doesn't get freed during this.
3129 struct module *__module_text_address(unsigned long addr)
3131 struct module *mod = __module_address(addr);
3133 /* Make sure it's within the text section. */
3134 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
3135 && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
3141 /* Don't grab lock, we're oopsing. */
3142 void print_modules(void)
3145 char buf[MODULE_FLAGS_BUF_SIZE];
3147 printk(KERN_DEFAULT "Modules linked in:");
3148 /* Most callers should already have preempt disabled, but make sure */
3150 list_for_each_entry_rcu(mod, &modules, list) {
3151 if (mod->state == MODULE_STATE_UNFORMED)
3153 pr_cont(" %s%s", mod->name, module_flags(mod, buf, true));
3156 print_unloaded_tainted_modules();
3158 if (last_unloaded_module.name[0])
3159 pr_cont(" [last unloaded: %s%s]", last_unloaded_module.name,
3160 last_unloaded_module.taints);