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 <linux/cfi.h>
57 #include <uapi/linux/module.h>
60 #define CREATE_TRACE_POINTS
61 #include <trace/events/module.h>
65 * 1) List of modules (also safely readable with preempt_disable),
66 * 2) module_use links,
67 * 3) mod_tree.addr_min/mod_tree.addr_max.
68 * (delete and add uses RCU list operations).
70 DEFINE_MUTEX(module_mutex);
73 /* Work queue for freeing init sections in success case */
74 static void do_free_init(struct work_struct *w);
75 static DECLARE_WORK(init_free_wq, do_free_init);
76 static LLIST_HEAD(init_free_list);
78 struct mod_tree_root mod_tree __cacheline_aligned = {
82 #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
83 struct mod_tree_root mod_data_tree __cacheline_aligned = {
89 const struct kernel_symbol *start, *stop;
91 enum mod_license license;
95 * Bounds of module text, for speeding up __module_address.
96 * Protected by module_mutex.
98 static void __mod_update_bounds(void *base, unsigned int size, struct mod_tree_root *tree)
100 unsigned long min = (unsigned long)base;
101 unsigned long max = min + size;
103 if (min < tree->addr_min)
104 tree->addr_min = min;
105 if (max > tree->addr_max)
106 tree->addr_max = max;
109 static void mod_update_bounds(struct module *mod)
111 __mod_update_bounds(mod->core_layout.base, mod->core_layout.size, &mod_tree);
112 if (mod->init_layout.size)
113 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size, &mod_tree);
114 #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
115 __mod_update_bounds(mod->data_layout.base, mod->data_layout.size, &mod_data_tree);
119 /* Block module loading/unloading? */
120 int modules_disabled;
121 core_param(nomodule, modules_disabled, bint, 0);
123 /* Waiting for a module to finish initializing? */
124 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
126 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
128 int register_module_notifier(struct notifier_block *nb)
130 return blocking_notifier_chain_register(&module_notify_list, nb);
132 EXPORT_SYMBOL(register_module_notifier);
134 int unregister_module_notifier(struct notifier_block *nb)
136 return blocking_notifier_chain_unregister(&module_notify_list, nb);
138 EXPORT_SYMBOL(unregister_module_notifier);
141 * We require a truly strong try_module_get(): 0 means success.
142 * Otherwise an error is returned due to ongoing or failed
143 * initialization etc.
145 static inline int strong_try_module_get(struct module *mod)
147 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
148 if (mod && mod->state == MODULE_STATE_COMING)
150 if (try_module_get(mod))
156 static inline void add_taint_module(struct module *mod, unsigned flag,
157 enum lockdep_ok lockdep_ok)
159 add_taint(flag, lockdep_ok);
160 set_bit(flag, &mod->taints);
164 * A thread that wants to hold a reference to a module only while it
165 * is running can call this to safely exit.
167 void __noreturn __module_put_and_kthread_exit(struct module *mod, long code)
172 EXPORT_SYMBOL(__module_put_and_kthread_exit);
174 /* Find a module section: 0 means not found. */
175 static unsigned int find_sec(const struct load_info *info, const char *name)
179 for (i = 1; i < info->hdr->e_shnum; i++) {
180 Elf_Shdr *shdr = &info->sechdrs[i];
181 /* Alloc bit cleared means "ignore it." */
182 if ((shdr->sh_flags & SHF_ALLOC)
183 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
189 /* Find a module section, or NULL. */
190 static void *section_addr(const struct load_info *info, const char *name)
192 /* Section 0 has sh_addr 0. */
193 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
196 /* Find a module section, or NULL. Fill in number of "objects" in section. */
197 static void *section_objs(const struct load_info *info,
202 unsigned int sec = find_sec(info, name);
204 /* Section 0 has sh_addr 0 and sh_size 0. */
205 *num = info->sechdrs[sec].sh_size / object_size;
206 return (void *)info->sechdrs[sec].sh_addr;
209 /* Find a module section: 0 means not found. Ignores SHF_ALLOC flag. */
210 static unsigned int find_any_sec(const struct load_info *info, const char *name)
214 for (i = 1; i < info->hdr->e_shnum; i++) {
215 Elf_Shdr *shdr = &info->sechdrs[i];
216 if (strcmp(info->secstrings + shdr->sh_name, name) == 0)
223 * Find a module section, or NULL. Fill in number of "objects" in section.
224 * Ignores SHF_ALLOC flag.
226 static __maybe_unused void *any_section_objs(const struct load_info *info,
231 unsigned int sec = find_any_sec(info, name);
233 /* Section 0 has sh_addr 0 and sh_size 0. */
234 *num = info->sechdrs[sec].sh_size / object_size;
235 return (void *)info->sechdrs[sec].sh_addr;
238 #ifndef CONFIG_MODVERSIONS
239 #define symversion(base, idx) NULL
241 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
244 static const char *kernel_symbol_name(const struct kernel_symbol *sym)
246 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
247 return offset_to_ptr(&sym->name_offset);
253 static const char *kernel_symbol_namespace(const struct kernel_symbol *sym)
255 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
256 if (!sym->namespace_offset)
258 return offset_to_ptr(&sym->namespace_offset);
260 return sym->namespace;
264 int cmp_name(const void *name, const void *sym)
266 return strcmp(name, kernel_symbol_name(sym));
269 static bool find_exported_symbol_in_section(const struct symsearch *syms,
270 struct module *owner,
271 struct find_symbol_arg *fsa)
273 struct kernel_symbol *sym;
275 if (!fsa->gplok && syms->license == GPL_ONLY)
278 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
279 sizeof(struct kernel_symbol), cmp_name);
284 fsa->crc = symversion(syms->crcs, sym - syms->start);
286 fsa->license = syms->license;
292 * Find an exported symbol and return it, along with, (optional) crc and
293 * (optional) module which owns it. Needs preempt disabled or module_mutex.
295 bool find_symbol(struct find_symbol_arg *fsa)
297 static const struct symsearch arr[] = {
298 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
300 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
301 __start___kcrctab_gpl,
307 module_assert_mutex_or_preempt();
309 for (i = 0; i < ARRAY_SIZE(arr); i++)
310 if (find_exported_symbol_in_section(&arr[i], NULL, fsa))
313 list_for_each_entry_rcu(mod, &modules, list,
314 lockdep_is_held(&module_mutex)) {
315 struct symsearch arr[] = {
316 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
318 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
323 if (mod->state == MODULE_STATE_UNFORMED)
326 for (i = 0; i < ARRAY_SIZE(arr); i++)
327 if (find_exported_symbol_in_section(&arr[i], mod, fsa))
331 pr_debug("Failed to find symbol %s\n", fsa->name);
336 * Search for module by name: must hold module_mutex (or preempt disabled
337 * for read-only access).
339 struct module *find_module_all(const char *name, size_t len,
344 module_assert_mutex_or_preempt();
346 list_for_each_entry_rcu(mod, &modules, list,
347 lockdep_is_held(&module_mutex)) {
348 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
350 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
356 struct module *find_module(const char *name)
358 return find_module_all(name, strlen(name), false);
363 static inline void __percpu *mod_percpu(struct module *mod)
368 static int percpu_modalloc(struct module *mod, struct load_info *info)
370 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
371 unsigned long align = pcpusec->sh_addralign;
373 if (!pcpusec->sh_size)
376 if (align > PAGE_SIZE) {
377 pr_warn("%s: per-cpu alignment %li > %li\n",
378 mod->name, align, PAGE_SIZE);
382 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
384 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
385 mod->name, (unsigned long)pcpusec->sh_size);
388 mod->percpu_size = pcpusec->sh_size;
392 static void percpu_modfree(struct module *mod)
394 free_percpu(mod->percpu);
397 static unsigned int find_pcpusec(struct load_info *info)
399 return find_sec(info, ".data..percpu");
402 static void percpu_modcopy(struct module *mod,
403 const void *from, unsigned long size)
407 for_each_possible_cpu(cpu)
408 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
411 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
418 list_for_each_entry_rcu(mod, &modules, list) {
419 if (mod->state == MODULE_STATE_UNFORMED)
421 if (!mod->percpu_size)
423 for_each_possible_cpu(cpu) {
424 void *start = per_cpu_ptr(mod->percpu, cpu);
425 void *va = (void *)addr;
427 if (va >= start && va < start + mod->percpu_size) {
429 *can_addr = (unsigned long) (va - start);
430 *can_addr += (unsigned long)
431 per_cpu_ptr(mod->percpu,
445 * is_module_percpu_address() - test whether address is from module static percpu
446 * @addr: address to test
448 * Test whether @addr belongs to module static percpu area.
450 * Return: %true if @addr is from module static percpu area
452 bool is_module_percpu_address(unsigned long addr)
454 return __is_module_percpu_address(addr, NULL);
457 #else /* ... !CONFIG_SMP */
459 static inline void __percpu *mod_percpu(struct module *mod)
463 static int percpu_modalloc(struct module *mod, struct load_info *info)
465 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
466 if (info->sechdrs[info->index.pcpu].sh_size != 0)
470 static inline void percpu_modfree(struct module *mod)
473 static unsigned int find_pcpusec(struct load_info *info)
477 static inline void percpu_modcopy(struct module *mod,
478 const void *from, unsigned long size)
480 /* pcpusec should be 0, and size of that section should be 0. */
483 bool is_module_percpu_address(unsigned long addr)
488 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
493 #endif /* CONFIG_SMP */
495 #define MODINFO_ATTR(field) \
496 static void setup_modinfo_##field(struct module *mod, const char *s) \
498 mod->field = kstrdup(s, GFP_KERNEL); \
500 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
501 struct module_kobject *mk, char *buffer) \
503 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
505 static int modinfo_##field##_exists(struct module *mod) \
507 return mod->field != NULL; \
509 static void free_modinfo_##field(struct module *mod) \
514 static struct module_attribute modinfo_##field = { \
515 .attr = { .name = __stringify(field), .mode = 0444 }, \
516 .show = show_modinfo_##field, \
517 .setup = setup_modinfo_##field, \
518 .test = modinfo_##field##_exists, \
519 .free = free_modinfo_##field, \
522 MODINFO_ATTR(version);
523 MODINFO_ATTR(srcversion);
526 char name[MODULE_NAME_LEN + 1];
527 char taints[MODULE_FLAGS_BUF_SIZE];
528 } last_unloaded_module;
530 #ifdef CONFIG_MODULE_UNLOAD
532 EXPORT_TRACEPOINT_SYMBOL(module_get);
534 /* MODULE_REF_BASE is the base reference count by kmodule loader. */
535 #define MODULE_REF_BASE 1
537 /* Init the unload section of the module. */
538 static int module_unload_init(struct module *mod)
541 * Initialize reference counter to MODULE_REF_BASE.
542 * refcnt == 0 means module is going.
544 atomic_set(&mod->refcnt, MODULE_REF_BASE);
546 INIT_LIST_HEAD(&mod->source_list);
547 INIT_LIST_HEAD(&mod->target_list);
549 /* Hold reference count during initialization. */
550 atomic_inc(&mod->refcnt);
555 /* Does a already use b? */
556 static int already_uses(struct module *a, struct module *b)
558 struct module_use *use;
560 list_for_each_entry(use, &b->source_list, source_list) {
561 if (use->source == a) {
562 pr_debug("%s uses %s!\n", a->name, b->name);
566 pr_debug("%s does not use %s!\n", a->name, b->name);
572 * - we add 'a' as a "source", 'b' as a "target" of module use
573 * - the module_use is added to the list of 'b' sources (so
574 * 'b' can walk the list to see who sourced them), and of 'a'
575 * targets (so 'a' can see what modules it targets).
577 static int add_module_usage(struct module *a, struct module *b)
579 struct module_use *use;
581 pr_debug("Allocating new usage for %s.\n", a->name);
582 use = kmalloc(sizeof(*use), GFP_ATOMIC);
588 list_add(&use->source_list, &b->source_list);
589 list_add(&use->target_list, &a->target_list);
593 /* Module a uses b: caller needs module_mutex() */
594 static int ref_module(struct module *a, struct module *b)
598 if (b == NULL || already_uses(a, b))
601 /* If module isn't available, we fail. */
602 err = strong_try_module_get(b);
606 err = add_module_usage(a, b);
614 /* Clear the unload stuff of the module. */
615 static void module_unload_free(struct module *mod)
617 struct module_use *use, *tmp;
619 mutex_lock(&module_mutex);
620 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
621 struct module *i = use->target;
622 pr_debug("%s unusing %s\n", mod->name, i->name);
624 list_del(&use->source_list);
625 list_del(&use->target_list);
628 mutex_unlock(&module_mutex);
631 #ifdef CONFIG_MODULE_FORCE_UNLOAD
632 static inline int try_force_unload(unsigned int flags)
634 int ret = (flags & O_TRUNC);
636 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
640 static inline int try_force_unload(unsigned int flags)
644 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
646 /* Try to release refcount of module, 0 means success. */
647 static int try_release_module_ref(struct module *mod)
651 /* Try to decrement refcnt which we set at loading */
652 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
655 /* Someone can put this right now, recover with checking */
656 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
661 static int try_stop_module(struct module *mod, int flags, int *forced)
663 /* If it's not unused, quit unless we're forcing. */
664 if (try_release_module_ref(mod) != 0) {
665 *forced = try_force_unload(flags);
670 /* Mark it as dying. */
671 mod->state = MODULE_STATE_GOING;
677 * module_refcount() - return the refcount or -1 if unloading
678 * @mod: the module we're checking
681 * -1 if the module is in the process of unloading
682 * otherwise the number of references in the kernel to the module
684 int module_refcount(struct module *mod)
686 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
688 EXPORT_SYMBOL(module_refcount);
690 /* This exists whether we can unload or not */
691 static void free_module(struct module *mod);
693 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
697 char name[MODULE_NAME_LEN];
698 char buf[MODULE_FLAGS_BUF_SIZE];
701 if (!capable(CAP_SYS_MODULE) || modules_disabled)
704 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
706 name[MODULE_NAME_LEN-1] = '\0';
708 audit_log_kern_module(name);
710 if (mutex_lock_interruptible(&module_mutex) != 0)
713 mod = find_module(name);
719 if (!list_empty(&mod->source_list)) {
720 /* Other modules depend on us: get rid of them first. */
725 /* Doing init or already dying? */
726 if (mod->state != MODULE_STATE_LIVE) {
727 /* FIXME: if (force), slam module count damn the torpedoes */
728 pr_debug("%s already dying\n", mod->name);
733 /* If it has an init func, it must have an exit func to unload */
734 if (mod->init && !mod->exit) {
735 forced = try_force_unload(flags);
737 /* This module can't be removed */
743 ret = try_stop_module(mod, flags, &forced);
747 mutex_unlock(&module_mutex);
748 /* Final destruction now no one is using it. */
749 if (mod->exit != NULL)
751 blocking_notifier_call_chain(&module_notify_list,
752 MODULE_STATE_GOING, mod);
753 klp_module_going(mod);
754 ftrace_release_mod(mod);
756 async_synchronize_full();
758 /* Store the name and taints of the last unloaded module for diagnostic purposes */
759 strscpy(last_unloaded_module.name, mod->name, sizeof(last_unloaded_module.name));
760 strscpy(last_unloaded_module.taints, module_flags(mod, buf, false), sizeof(last_unloaded_module.taints));
763 /* someone could wait for the module in add_unformed_module() */
764 wake_up_all(&module_wq);
767 mutex_unlock(&module_mutex);
771 void __symbol_put(const char *symbol)
773 struct find_symbol_arg fsa = {
779 BUG_ON(!find_symbol(&fsa));
780 module_put(fsa.owner);
783 EXPORT_SYMBOL(__symbol_put);
785 /* Note this assumes addr is a function, which it currently always is. */
786 void symbol_put_addr(void *addr)
788 struct module *modaddr;
789 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
791 if (core_kernel_text(a))
795 * Even though we hold a reference on the module; we still need to
796 * disable preemption in order to safely traverse the data structure.
799 modaddr = __module_text_address(a);
804 EXPORT_SYMBOL_GPL(symbol_put_addr);
806 static ssize_t show_refcnt(struct module_attribute *mattr,
807 struct module_kobject *mk, char *buffer)
809 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
812 static struct module_attribute modinfo_refcnt =
813 __ATTR(refcnt, 0444, show_refcnt, NULL);
815 void __module_get(struct module *module)
819 atomic_inc(&module->refcnt);
820 trace_module_get(module, _RET_IP_);
824 EXPORT_SYMBOL(__module_get);
826 bool try_module_get(struct module *module)
832 /* Note: here, we can fail to get a reference */
833 if (likely(module_is_live(module) &&
834 atomic_inc_not_zero(&module->refcnt) != 0))
835 trace_module_get(module, _RET_IP_);
843 EXPORT_SYMBOL(try_module_get);
845 void module_put(struct module *module)
851 ret = atomic_dec_if_positive(&module->refcnt);
852 WARN_ON(ret < 0); /* Failed to put refcount */
853 trace_module_put(module, _RET_IP_);
857 EXPORT_SYMBOL(module_put);
859 #else /* !CONFIG_MODULE_UNLOAD */
860 static inline void module_unload_free(struct module *mod)
864 static int ref_module(struct module *a, struct module *b)
866 return strong_try_module_get(b);
869 static inline int module_unload_init(struct module *mod)
873 #endif /* CONFIG_MODULE_UNLOAD */
875 size_t module_flags_taint(unsigned long taints, char *buf)
880 for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
881 if (taint_flags[i].module && test_bit(i, &taints))
882 buf[l++] = taint_flags[i].c_true;
888 static ssize_t show_initstate(struct module_attribute *mattr,
889 struct module_kobject *mk, char *buffer)
891 const char *state = "unknown";
893 switch (mk->mod->state) {
894 case MODULE_STATE_LIVE:
897 case MODULE_STATE_COMING:
900 case MODULE_STATE_GOING:
906 return sprintf(buffer, "%s\n", state);
909 static struct module_attribute modinfo_initstate =
910 __ATTR(initstate, 0444, show_initstate, NULL);
912 static ssize_t store_uevent(struct module_attribute *mattr,
913 struct module_kobject *mk,
914 const char *buffer, size_t count)
918 rc = kobject_synth_uevent(&mk->kobj, buffer, count);
919 return rc ? rc : count;
922 struct module_attribute module_uevent =
923 __ATTR(uevent, 0200, NULL, store_uevent);
925 static ssize_t show_coresize(struct module_attribute *mattr,
926 struct module_kobject *mk, char *buffer)
928 return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
931 static struct module_attribute modinfo_coresize =
932 __ATTR(coresize, 0444, show_coresize, NULL);
934 #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
935 static ssize_t show_datasize(struct module_attribute *mattr,
936 struct module_kobject *mk, char *buffer)
938 return sprintf(buffer, "%u\n", mk->mod->data_layout.size);
941 static struct module_attribute modinfo_datasize =
942 __ATTR(datasize, 0444, show_datasize, NULL);
945 static ssize_t show_initsize(struct module_attribute *mattr,
946 struct module_kobject *mk, char *buffer)
948 return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
951 static struct module_attribute modinfo_initsize =
952 __ATTR(initsize, 0444, show_initsize, NULL);
954 static ssize_t show_taint(struct module_attribute *mattr,
955 struct module_kobject *mk, char *buffer)
959 l = module_flags_taint(mk->mod->taints, buffer);
964 static struct module_attribute modinfo_taint =
965 __ATTR(taint, 0444, show_taint, NULL);
967 struct module_attribute *modinfo_attrs[] = {
973 #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
978 #ifdef CONFIG_MODULE_UNLOAD
984 size_t modinfo_attrs_count = ARRAY_SIZE(modinfo_attrs);
986 static const char vermagic[] = VERMAGIC_STRING;
988 int try_to_force_load(struct module *mod, const char *reason)
990 #ifdef CONFIG_MODULE_FORCE_LOAD
991 if (!test_taint(TAINT_FORCED_MODULE))
992 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
993 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1000 static char *get_modinfo(const struct load_info *info, const char *tag);
1001 static char *get_next_modinfo(const struct load_info *info, const char *tag,
1004 static int verify_namespace_is_imported(const struct load_info *info,
1005 const struct kernel_symbol *sym,
1008 const char *namespace;
1009 char *imported_namespace;
1011 namespace = kernel_symbol_namespace(sym);
1012 if (namespace && namespace[0]) {
1013 imported_namespace = get_modinfo(info, "import_ns");
1014 while (imported_namespace) {
1015 if (strcmp(namespace, imported_namespace) == 0)
1017 imported_namespace = get_next_modinfo(
1018 info, "import_ns", imported_namespace);
1020 #ifdef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1025 "%s: module uses symbol (%s) from namespace %s, but does not import it.\n",
1026 mod->name, kernel_symbol_name(sym), namespace);
1027 #ifndef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1034 static bool inherit_taint(struct module *mod, struct module *owner, const char *name)
1036 if (!owner || !test_bit(TAINT_PROPRIETARY_MODULE, &owner->taints))
1039 if (mod->using_gplonly_symbols) {
1040 pr_err("%s: module using GPL-only symbols uses symbols %s from proprietary module %s.\n",
1041 mod->name, name, owner->name);
1045 if (!test_bit(TAINT_PROPRIETARY_MODULE, &mod->taints)) {
1046 pr_warn("%s: module uses symbols %s from proprietary module %s, inheriting taint.\n",
1047 mod->name, name, owner->name);
1048 set_bit(TAINT_PROPRIETARY_MODULE, &mod->taints);
1053 /* Resolve a symbol for this module. I.e. if we find one, record usage. */
1054 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1055 const struct load_info *info,
1059 struct find_symbol_arg fsa = {
1061 .gplok = !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)),
1067 * The module_mutex should not be a heavily contended lock;
1068 * if we get the occasional sleep here, we'll go an extra iteration
1069 * in the wait_event_interruptible(), which is harmless.
1071 sched_annotate_sleep();
1072 mutex_lock(&module_mutex);
1073 if (!find_symbol(&fsa))
1076 if (fsa.license == GPL_ONLY)
1077 mod->using_gplonly_symbols = true;
1079 if (!inherit_taint(mod, fsa.owner, name)) {
1084 if (!check_version(info, name, mod, fsa.crc)) {
1085 fsa.sym = ERR_PTR(-EINVAL);
1089 err = verify_namespace_is_imported(info, fsa.sym, mod);
1091 fsa.sym = ERR_PTR(err);
1095 err = ref_module(mod, fsa.owner);
1097 fsa.sym = ERR_PTR(err);
1102 /* We must make copy under the lock if we failed to get ref. */
1103 strncpy(ownername, module_name(fsa.owner), MODULE_NAME_LEN);
1105 mutex_unlock(&module_mutex);
1109 static const struct kernel_symbol *
1110 resolve_symbol_wait(struct module *mod,
1111 const struct load_info *info,
1114 const struct kernel_symbol *ksym;
1115 char owner[MODULE_NAME_LEN];
1117 if (wait_event_interruptible_timeout(module_wq,
1118 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1119 || PTR_ERR(ksym) != -EBUSY,
1121 pr_warn("%s: gave up waiting for init of module %s.\n",
1127 void __weak module_memfree(void *module_region)
1130 * This memory may be RO, and freeing RO memory in an interrupt is not
1131 * supported by vmalloc.
1133 WARN_ON(in_interrupt());
1134 vfree(module_region);
1137 void __weak module_arch_cleanup(struct module *mod)
1141 void __weak module_arch_freeing_init(struct module *mod)
1145 /* Free a module, remove from lists, etc. */
1146 static void free_module(struct module *mod)
1148 trace_module_free(mod);
1150 mod_sysfs_teardown(mod);
1153 * We leave it in list to prevent duplicate loads, but make sure
1154 * that noone uses it while it's being deconstructed.
1156 mutex_lock(&module_mutex);
1157 mod->state = MODULE_STATE_UNFORMED;
1158 mutex_unlock(&module_mutex);
1160 /* Remove dynamic debug info */
1161 ddebug_remove_module(mod->name);
1163 /* Arch-specific cleanup. */
1164 module_arch_cleanup(mod);
1166 /* Module unload stuff */
1167 module_unload_free(mod);
1169 /* Free any allocated parameters. */
1170 destroy_params(mod->kp, mod->num_kp);
1172 if (is_livepatch_module(mod))
1173 free_module_elf(mod);
1175 /* Now we can delete it from the lists */
1176 mutex_lock(&module_mutex);
1177 /* Unlink carefully: kallsyms could be walking list. */
1178 list_del_rcu(&mod->list);
1179 mod_tree_remove(mod);
1180 /* Remove this module from bug list, this uses list_del_rcu */
1181 module_bug_cleanup(mod);
1182 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
1184 if (try_add_tainted_module(mod))
1185 pr_err("%s: adding tainted module to the unloaded tainted modules list failed.\n",
1187 mutex_unlock(&module_mutex);
1189 /* This may be empty, but that's OK */
1190 module_arch_freeing_init(mod);
1191 module_memfree(mod->init_layout.base);
1193 percpu_modfree(mod);
1195 /* Free lock-classes; relies on the preceding sync_rcu(). */
1196 lockdep_free_key_range(mod->data_layout.base, mod->data_layout.size);
1198 /* Finally, free the core (containing the module structure) */
1199 module_memfree(mod->core_layout.base);
1200 #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
1201 vfree(mod->data_layout.base);
1205 void *__symbol_get(const char *symbol)
1207 struct find_symbol_arg fsa = {
1214 if (!find_symbol(&fsa) || strong_try_module_get(fsa.owner)) {
1219 return (void *)kernel_symbol_value(fsa.sym);
1221 EXPORT_SYMBOL_GPL(__symbol_get);
1224 * Ensure that an exported symbol [global namespace] does not already exist
1225 * in the kernel or in some other module's exported symbol table.
1227 * You must hold the module_mutex.
1229 static int verify_exported_symbols(struct module *mod)
1232 const struct kernel_symbol *s;
1234 const struct kernel_symbol *sym;
1237 { mod->syms, mod->num_syms },
1238 { mod->gpl_syms, mod->num_gpl_syms },
1241 for (i = 0; i < ARRAY_SIZE(arr); i++) {
1242 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1243 struct find_symbol_arg fsa = {
1244 .name = kernel_symbol_name(s),
1247 if (find_symbol(&fsa)) {
1248 pr_err("%s: exports duplicate symbol %s"
1250 mod->name, kernel_symbol_name(s),
1251 module_name(fsa.owner));
1259 static bool ignore_undef_symbol(Elf_Half emachine, const char *name)
1262 * On x86, PIC code and Clang non-PIC code may have call foo@PLT. GNU as
1263 * before 2.37 produces an unreferenced _GLOBAL_OFFSET_TABLE_ on x86-64.
1264 * i386 has a similar problem but may not deserve a fix.
1266 * If we ever have to ignore many symbols, consider refactoring the code to
1267 * only warn if referenced by a relocation.
1269 if (emachine == EM_386 || emachine == EM_X86_64)
1270 return !strcmp(name, "_GLOBAL_OFFSET_TABLE_");
1274 /* Change all symbols so that st_value encodes the pointer directly. */
1275 static int simplify_symbols(struct module *mod, const struct load_info *info)
1277 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
1278 Elf_Sym *sym = (void *)symsec->sh_addr;
1279 unsigned long secbase;
1282 const struct kernel_symbol *ksym;
1284 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
1285 const char *name = info->strtab + sym[i].st_name;
1287 switch (sym[i].st_shndx) {
1289 /* Ignore common symbols */
1290 if (!strncmp(name, "__gnu_lto", 9))
1294 * We compiled with -fno-common. These are not
1295 * supposed to happen.
1297 pr_debug("Common symbol: %s\n", name);
1298 pr_warn("%s: please compile with -fno-common\n",
1304 /* Don't need to do anything */
1305 pr_debug("Absolute symbol: 0x%08lx\n",
1306 (long)sym[i].st_value);
1310 /* Livepatch symbols are resolved by livepatch */
1314 ksym = resolve_symbol_wait(mod, info, name);
1315 /* Ok if resolved. */
1316 if (ksym && !IS_ERR(ksym)) {
1317 sym[i].st_value = kernel_symbol_value(ksym);
1321 /* Ok if weak or ignored. */
1323 (ELF_ST_BIND(sym[i].st_info) == STB_WEAK ||
1324 ignore_undef_symbol(info->hdr->e_machine, name)))
1327 ret = PTR_ERR(ksym) ?: -ENOENT;
1328 pr_warn("%s: Unknown symbol %s (err %d)\n",
1329 mod->name, name, ret);
1333 /* Divert to percpu allocation if a percpu var. */
1334 if (sym[i].st_shndx == info->index.pcpu)
1335 secbase = (unsigned long)mod_percpu(mod);
1337 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
1338 sym[i].st_value += secbase;
1346 static int apply_relocations(struct module *mod, const struct load_info *info)
1351 /* Now do relocations. */
1352 for (i = 1; i < info->hdr->e_shnum; i++) {
1353 unsigned int infosec = info->sechdrs[i].sh_info;
1355 /* Not a valid relocation section? */
1356 if (infosec >= info->hdr->e_shnum)
1359 /* Don't bother with non-allocated sections */
1360 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
1363 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
1364 err = klp_apply_section_relocs(mod, info->sechdrs,
1369 else if (info->sechdrs[i].sh_type == SHT_REL)
1370 err = apply_relocate(info->sechdrs, info->strtab,
1371 info->index.sym, i, mod);
1372 else if (info->sechdrs[i].sh_type == SHT_RELA)
1373 err = apply_relocate_add(info->sechdrs, info->strtab,
1374 info->index.sym, i, mod);
1381 /* Additional bytes needed by arch in front of individual sections */
1382 unsigned int __weak arch_mod_section_prepend(struct module *mod,
1383 unsigned int section)
1385 /* default implementation just returns zero */
1389 /* Update size with this section: return offset. */
1390 long module_get_offset(struct module *mod, unsigned int *size,
1391 Elf_Shdr *sechdr, unsigned int section)
1395 *size += arch_mod_section_prepend(mod, section);
1396 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
1397 *size = ret + sechdr->sh_size;
1401 static bool module_init_layout_section(const char *sname)
1403 #ifndef CONFIG_MODULE_UNLOAD
1404 if (module_exit_section(sname))
1407 return module_init_section(sname);
1411 * Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
1412 * might -- code, read-only data, read-write data, small data. Tally
1413 * sizes, and place the offsets into sh_entsize fields: high bit means it
1416 static void layout_sections(struct module *mod, struct load_info *info)
1418 static unsigned long const masks[][2] = {
1420 * NOTE: all executable code must be the first section
1421 * in this array; otherwise modify the text_size
1422 * finder in the two loops below
1424 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
1425 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
1426 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
1427 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
1428 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
1432 for (i = 0; i < info->hdr->e_shnum; i++)
1433 info->sechdrs[i].sh_entsize = ~0UL;
1435 pr_debug("Core section allocation order:\n");
1436 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1437 for (i = 0; i < info->hdr->e_shnum; ++i) {
1438 Elf_Shdr *s = &info->sechdrs[i];
1439 const char *sname = info->secstrings + s->sh_name;
1440 unsigned int *sizep;
1442 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1443 || (s->sh_flags & masks[m][1])
1444 || s->sh_entsize != ~0UL
1445 || module_init_layout_section(sname))
1447 sizep = m ? &mod->data_layout.size : &mod->core_layout.size;
1448 s->sh_entsize = module_get_offset(mod, sizep, s, i);
1449 pr_debug("\t%s\n", sname);
1452 case 0: /* executable */
1453 mod->core_layout.size = strict_align(mod->core_layout.size);
1454 mod->core_layout.text_size = mod->core_layout.size;
1456 case 1: /* RO: text and ro-data */
1457 mod->data_layout.size = strict_align(mod->data_layout.size);
1458 mod->data_layout.ro_size = mod->data_layout.size;
1460 case 2: /* RO after init */
1461 mod->data_layout.size = strict_align(mod->data_layout.size);
1462 mod->data_layout.ro_after_init_size = mod->data_layout.size;
1464 case 4: /* whole core */
1465 mod->data_layout.size = strict_align(mod->data_layout.size);
1470 pr_debug("Init section allocation order:\n");
1471 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1472 for (i = 0; i < info->hdr->e_shnum; ++i) {
1473 Elf_Shdr *s = &info->sechdrs[i];
1474 const char *sname = info->secstrings + s->sh_name;
1476 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1477 || (s->sh_flags & masks[m][1])
1478 || s->sh_entsize != ~0UL
1479 || !module_init_layout_section(sname))
1481 s->sh_entsize = (module_get_offset(mod, &mod->init_layout.size, s, i)
1482 | INIT_OFFSET_MASK);
1483 pr_debug("\t%s\n", sname);
1486 case 0: /* executable */
1487 mod->init_layout.size = strict_align(mod->init_layout.size);
1488 mod->init_layout.text_size = mod->init_layout.size;
1490 case 1: /* RO: text and ro-data */
1491 mod->init_layout.size = strict_align(mod->init_layout.size);
1492 mod->init_layout.ro_size = mod->init_layout.size;
1496 * RO after init doesn't apply to init_layout (only
1497 * core_layout), so it just takes the value of ro_size.
1499 mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
1501 case 4: /* whole init */
1502 mod->init_layout.size = strict_align(mod->init_layout.size);
1508 static void set_license(struct module *mod, const char *license)
1511 license = "unspecified";
1513 if (!license_is_gpl_compatible(license)) {
1514 if (!test_taint(TAINT_PROPRIETARY_MODULE))
1515 pr_warn("%s: module license '%s' taints kernel.\n",
1516 mod->name, license);
1517 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
1518 LOCKDEP_NOW_UNRELIABLE);
1522 /* Parse tag=value strings from .modinfo section */
1523 static char *next_string(char *string, unsigned long *secsize)
1525 /* Skip non-zero chars */
1528 if ((*secsize)-- <= 1)
1532 /* Skip any zero padding. */
1533 while (!string[0]) {
1535 if ((*secsize)-- <= 1)
1541 static char *get_next_modinfo(const struct load_info *info, const char *tag,
1545 unsigned int taglen = strlen(tag);
1546 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
1547 unsigned long size = infosec->sh_size;
1550 * get_modinfo() calls made before rewrite_section_headers()
1551 * must use sh_offset, as sh_addr isn't set!
1553 char *modinfo = (char *)info->hdr + infosec->sh_offset;
1556 size -= prev - modinfo;
1557 modinfo = next_string(prev, &size);
1560 for (p = modinfo; p; p = next_string(p, &size)) {
1561 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
1562 return p + taglen + 1;
1567 static char *get_modinfo(const struct load_info *info, const char *tag)
1569 return get_next_modinfo(info, tag, NULL);
1572 static void setup_modinfo(struct module *mod, struct load_info *info)
1574 struct module_attribute *attr;
1577 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1579 attr->setup(mod, get_modinfo(info, attr->attr.name));
1583 static void free_modinfo(struct module *mod)
1585 struct module_attribute *attr;
1588 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1594 static void dynamic_debug_setup(struct module *mod, struct _ddebug_info *dyndbg)
1596 if (!dyndbg->num_descs)
1598 ddebug_add_module(dyndbg, mod->name);
1601 static void dynamic_debug_remove(struct module *mod, struct _ddebug_info *dyndbg)
1603 if (dyndbg->num_descs)
1604 ddebug_remove_module(mod->name);
1607 void * __weak module_alloc(unsigned long size)
1609 return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
1610 GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS,
1611 NUMA_NO_NODE, __builtin_return_address(0));
1614 bool __weak module_init_section(const char *name)
1616 return strstarts(name, ".init");
1619 bool __weak module_exit_section(const char *name)
1621 return strstarts(name, ".exit");
1624 static int validate_section_offset(struct load_info *info, Elf_Shdr *shdr)
1626 #if defined(CONFIG_64BIT)
1627 unsigned long long secend;
1629 unsigned long secend;
1633 * Check for both overflow and offset/size being
1636 secend = shdr->sh_offset + shdr->sh_size;
1637 if (secend < shdr->sh_offset || secend > info->len)
1644 * Sanity checks against invalid binaries, wrong arch, weird elf version.
1646 * Also do basic validity checks against section offsets and sizes, the
1647 * section name string table, and the indices used for it (sh_name).
1649 static int elf_validity_check(struct load_info *info)
1652 Elf_Shdr *shdr, *strhdr;
1655 if (info->len < sizeof(*(info->hdr))) {
1656 pr_err("Invalid ELF header len %lu\n", info->len);
1660 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0) {
1661 pr_err("Invalid ELF header magic: != %s\n", ELFMAG);
1664 if (info->hdr->e_type != ET_REL) {
1665 pr_err("Invalid ELF header type: %u != %u\n",
1666 info->hdr->e_type, ET_REL);
1669 if (!elf_check_arch(info->hdr)) {
1670 pr_err("Invalid architecture in ELF header: %u\n",
1671 info->hdr->e_machine);
1674 if (!module_elf_check_arch(info->hdr)) {
1675 pr_err("Invalid module architecture in ELF header: %u\n",
1676 info->hdr->e_machine);
1679 if (info->hdr->e_shentsize != sizeof(Elf_Shdr)) {
1680 pr_err("Invalid ELF section header size\n");
1685 * e_shnum is 16 bits, and sizeof(Elf_Shdr) is
1686 * known and small. So e_shnum * sizeof(Elf_Shdr)
1687 * will not overflow unsigned long on any platform.
1689 if (info->hdr->e_shoff >= info->len
1690 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
1691 info->len - info->hdr->e_shoff)) {
1692 pr_err("Invalid ELF section header overflow\n");
1696 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
1699 * Verify if the section name table index is valid.
1701 if (info->hdr->e_shstrndx == SHN_UNDEF
1702 || info->hdr->e_shstrndx >= info->hdr->e_shnum) {
1703 pr_err("Invalid ELF section name index: %d || e_shstrndx (%d) >= e_shnum (%d)\n",
1704 info->hdr->e_shstrndx, info->hdr->e_shstrndx,
1705 info->hdr->e_shnum);
1709 strhdr = &info->sechdrs[info->hdr->e_shstrndx];
1710 err = validate_section_offset(info, strhdr);
1712 pr_err("Invalid ELF section hdr(type %u)\n", strhdr->sh_type);
1717 * The section name table must be NUL-terminated, as required
1718 * by the spec. This makes strcmp and pr_* calls that access
1719 * strings in the section safe.
1721 info->secstrings = (void *)info->hdr + strhdr->sh_offset;
1722 if (strhdr->sh_size == 0) {
1723 pr_err("empty section name table\n");
1726 if (info->secstrings[strhdr->sh_size - 1] != '\0') {
1727 pr_err("ELF Spec violation: section name table isn't null terminated\n");
1732 * The code assumes that section 0 has a length of zero and
1733 * an addr of zero, so check for it.
1735 if (info->sechdrs[0].sh_type != SHT_NULL
1736 || info->sechdrs[0].sh_size != 0
1737 || info->sechdrs[0].sh_addr != 0) {
1738 pr_err("ELF Spec violation: section 0 type(%d)!=SH_NULL or non-zero len or addr\n",
1739 info->sechdrs[0].sh_type);
1743 for (i = 1; i < info->hdr->e_shnum; i++) {
1744 shdr = &info->sechdrs[i];
1745 switch (shdr->sh_type) {
1750 if (shdr->sh_link == SHN_UNDEF
1751 || shdr->sh_link >= info->hdr->e_shnum) {
1752 pr_err("Invalid ELF sh_link!=SHN_UNDEF(%d) or (sh_link(%d) >= hdr->e_shnum(%d)\n",
1753 shdr->sh_link, shdr->sh_link,
1754 info->hdr->e_shnum);
1759 err = validate_section_offset(info, shdr);
1761 pr_err("Invalid ELF section in module (section %u type %u)\n",
1766 if (shdr->sh_flags & SHF_ALLOC) {
1767 if (shdr->sh_name >= strhdr->sh_size) {
1768 pr_err("Invalid ELF section name in module (section %u type %u)\n",
1783 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
1785 static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
1788 unsigned long n = min(len, COPY_CHUNK_SIZE);
1790 if (copy_from_user(dst, usrc, n) != 0)
1800 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
1802 if (!get_modinfo(info, "livepatch"))
1803 /* Nothing more to do */
1806 if (set_livepatch_module(mod)) {
1807 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
1808 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
1813 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
1818 static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
1820 if (retpoline_module_ok(get_modinfo(info, "retpoline")))
1823 pr_warn("%s: loading module not compiled with retpoline compiler.\n",
1827 /* Sets info->hdr and info->len. */
1828 static int copy_module_from_user(const void __user *umod, unsigned long len,
1829 struct load_info *info)
1834 if (info->len < sizeof(*(info->hdr)))
1837 err = security_kernel_load_data(LOADING_MODULE, true);
1841 /* Suck in entire file: we'll want most of it. */
1842 info->hdr = __vmalloc(info->len, GFP_KERNEL | __GFP_NOWARN);
1846 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
1851 err = security_kernel_post_load_data((char *)info->hdr, info->len,
1852 LOADING_MODULE, "init_module");
1860 static void free_copy(struct load_info *info, int flags)
1862 if (flags & MODULE_INIT_COMPRESSED_FILE)
1863 module_decompress_cleanup(info);
1868 static int rewrite_section_headers(struct load_info *info, int flags)
1872 /* This should always be true, but let's be sure. */
1873 info->sechdrs[0].sh_addr = 0;
1875 for (i = 1; i < info->hdr->e_shnum; i++) {
1876 Elf_Shdr *shdr = &info->sechdrs[i];
1879 * Mark all sections sh_addr with their address in the
1882 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
1886 /* Track but don't keep modinfo and version sections. */
1887 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
1888 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
1894 * Set up our basic convenience variables (pointers to section headers,
1895 * search for module section index etc), and do some basic section
1898 * Set info->mod to the temporary copy of the module in info->hdr. The final one
1899 * will be allocated in move_module().
1901 static int setup_load_info(struct load_info *info, int flags)
1905 /* Try to find a name early so we can log errors with a module name */
1906 info->index.info = find_sec(info, ".modinfo");
1907 if (info->index.info)
1908 info->name = get_modinfo(info, "name");
1910 /* Find internal symbols and strings. */
1911 for (i = 1; i < info->hdr->e_shnum; i++) {
1912 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
1913 info->index.sym = i;
1914 info->index.str = info->sechdrs[i].sh_link;
1915 info->strtab = (char *)info->hdr
1916 + info->sechdrs[info->index.str].sh_offset;
1921 if (info->index.sym == 0) {
1922 pr_warn("%s: module has no symbols (stripped?)\n",
1923 info->name ?: "(missing .modinfo section or name field)");
1927 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
1928 if (!info->index.mod) {
1929 pr_warn("%s: No module found in object\n",
1930 info->name ?: "(missing .modinfo section or name field)");
1933 /* This is temporary: point mod into copy of data. */
1934 info->mod = (void *)info->hdr + info->sechdrs[info->index.mod].sh_offset;
1937 * If we didn't load the .modinfo 'name' field earlier, fall back to
1938 * on-disk struct mod 'name' field.
1941 info->name = info->mod->name;
1943 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
1944 info->index.vers = 0; /* Pretend no __versions section! */
1946 info->index.vers = find_sec(info, "__versions");
1948 info->index.pcpu = find_pcpusec(info);
1953 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
1955 const char *modmagic = get_modinfo(info, "vermagic");
1958 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
1961 /* This is allowed: modprobe --force will invalidate it. */
1963 err = try_to_force_load(mod, "bad vermagic");
1966 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
1967 pr_err("%s: version magic '%s' should be '%s'\n",
1968 info->name, modmagic, vermagic);
1972 if (!get_modinfo(info, "intree")) {
1973 if (!test_taint(TAINT_OOT_MODULE))
1974 pr_warn("%s: loading out-of-tree module taints kernel.\n",
1976 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
1979 check_modinfo_retpoline(mod, info);
1981 if (get_modinfo(info, "staging")) {
1982 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
1983 pr_warn("%s: module is from the staging directory, the quality "
1984 "is unknown, you have been warned.\n", mod->name);
1987 err = check_modinfo_livepatch(mod, info);
1991 /* Set up license info based on the info section */
1992 set_license(mod, get_modinfo(info, "license"));
1994 if (get_modinfo(info, "test")) {
1995 if (!test_taint(TAINT_TEST))
1996 pr_warn("%s: loading test module taints kernel.\n",
1998 add_taint_module(mod, TAINT_TEST, LOCKDEP_STILL_OK);
2004 static int find_module_sections(struct module *mod, struct load_info *info)
2006 mod->kp = section_objs(info, "__param",
2007 sizeof(*mod->kp), &mod->num_kp);
2008 mod->syms = section_objs(info, "__ksymtab",
2009 sizeof(*mod->syms), &mod->num_syms);
2010 mod->crcs = section_addr(info, "__kcrctab");
2011 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2012 sizeof(*mod->gpl_syms),
2013 &mod->num_gpl_syms);
2014 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2016 #ifdef CONFIG_CONSTRUCTORS
2017 mod->ctors = section_objs(info, ".ctors",
2018 sizeof(*mod->ctors), &mod->num_ctors);
2020 mod->ctors = section_objs(info, ".init_array",
2021 sizeof(*mod->ctors), &mod->num_ctors);
2022 else if (find_sec(info, ".init_array")) {
2024 * This shouldn't happen with same compiler and binutils
2025 * building all parts of the module.
2027 pr_warn("%s: has both .ctors and .init_array.\n",
2033 mod->noinstr_text_start = section_objs(info, ".noinstr.text", 1,
2034 &mod->noinstr_text_size);
2036 #ifdef CONFIG_TRACEPOINTS
2037 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2038 sizeof(*mod->tracepoints_ptrs),
2039 &mod->num_tracepoints);
2041 #ifdef CONFIG_TREE_SRCU
2042 mod->srcu_struct_ptrs = section_objs(info, "___srcu_struct_ptrs",
2043 sizeof(*mod->srcu_struct_ptrs),
2044 &mod->num_srcu_structs);
2046 #ifdef CONFIG_BPF_EVENTS
2047 mod->bpf_raw_events = section_objs(info, "__bpf_raw_tp_map",
2048 sizeof(*mod->bpf_raw_events),
2049 &mod->num_bpf_raw_events);
2051 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
2052 mod->btf_data = any_section_objs(info, ".BTF", 1, &mod->btf_data_size);
2054 #ifdef CONFIG_JUMP_LABEL
2055 mod->jump_entries = section_objs(info, "__jump_table",
2056 sizeof(*mod->jump_entries),
2057 &mod->num_jump_entries);
2059 #ifdef CONFIG_EVENT_TRACING
2060 mod->trace_events = section_objs(info, "_ftrace_events",
2061 sizeof(*mod->trace_events),
2062 &mod->num_trace_events);
2063 mod->trace_evals = section_objs(info, "_ftrace_eval_map",
2064 sizeof(*mod->trace_evals),
2065 &mod->num_trace_evals);
2067 #ifdef CONFIG_TRACING
2068 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2069 sizeof(*mod->trace_bprintk_fmt_start),
2070 &mod->num_trace_bprintk_fmt);
2072 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
2073 /* sechdrs[0].sh_size is always zero */
2074 mod->ftrace_callsites = section_objs(info, FTRACE_CALLSITE_SECTION,
2075 sizeof(*mod->ftrace_callsites),
2076 &mod->num_ftrace_callsites);
2078 #ifdef CONFIG_FUNCTION_ERROR_INJECTION
2079 mod->ei_funcs = section_objs(info, "_error_injection_whitelist",
2080 sizeof(*mod->ei_funcs),
2081 &mod->num_ei_funcs);
2083 #ifdef CONFIG_KPROBES
2084 mod->kprobes_text_start = section_objs(info, ".kprobes.text", 1,
2085 &mod->kprobes_text_size);
2086 mod->kprobe_blacklist = section_objs(info, "_kprobe_blacklist",
2087 sizeof(unsigned long),
2088 &mod->num_kprobe_blacklist);
2090 #ifdef CONFIG_PRINTK_INDEX
2091 mod->printk_index_start = section_objs(info, ".printk_index",
2092 sizeof(*mod->printk_index_start),
2093 &mod->printk_index_size);
2095 #ifdef CONFIG_HAVE_STATIC_CALL_INLINE
2096 mod->static_call_sites = section_objs(info, ".static_call_sites",
2097 sizeof(*mod->static_call_sites),
2098 &mod->num_static_call_sites);
2100 #if IS_ENABLED(CONFIG_KUNIT)
2101 mod->kunit_suites = section_objs(info, ".kunit_test_suites",
2102 sizeof(*mod->kunit_suites),
2103 &mod->num_kunit_suites);
2106 mod->extable = section_objs(info, "__ex_table",
2107 sizeof(*mod->extable), &mod->num_exentries);
2109 if (section_addr(info, "__obsparm"))
2110 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
2112 info->dyndbg.descs = section_objs(info, "__dyndbg",
2113 sizeof(*info->dyndbg.descs), &info->dyndbg.num_descs);
2114 info->dyndbg.classes = section_objs(info, "__dyndbg_classes",
2115 sizeof(*info->dyndbg.classes), &info->dyndbg.num_classes);
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 bool __weak module_elf_check_arch(Elf_Ehdr *hdr)
2257 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
2265 /* module_blacklist is a comma-separated list of module names */
2266 static char *module_blacklist;
2267 static bool blacklisted(const char *module_name)
2272 if (!module_blacklist)
2275 for (p = module_blacklist; *p; p += len) {
2276 len = strcspn(p, ",");
2277 if (strlen(module_name) == len && !memcmp(module_name, p, len))
2284 core_param(module_blacklist, module_blacklist, charp, 0400);
2286 static struct module *layout_and_allocate(struct load_info *info, int flags)
2292 err = check_modinfo(info->mod, info, flags);
2294 return ERR_PTR(err);
2296 /* Allow arches to frob section contents and sizes. */
2297 err = module_frob_arch_sections(info->hdr, info->sechdrs,
2298 info->secstrings, info->mod);
2300 return ERR_PTR(err);
2302 err = module_enforce_rwx_sections(info->hdr, info->sechdrs,
2303 info->secstrings, info->mod);
2305 return ERR_PTR(err);
2307 /* We will do a special allocation for per-cpu sections later. */
2308 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
2311 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
2312 * layout_sections() can put it in the right place.
2313 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
2315 ndx = find_sec(info, ".data..ro_after_init");
2317 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
2319 * Mark the __jump_table section as ro_after_init as well: these data
2320 * structures are never modified, with the exception of entries that
2321 * refer to code in the __init section, which are annotated as such
2322 * at module load time.
2324 ndx = find_sec(info, "__jump_table");
2326 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
2329 * Determine total sizes, and put offsets in sh_entsize. For now
2330 * this is done generically; there doesn't appear to be any
2331 * special cases for the architectures.
2333 layout_sections(info->mod, info);
2334 layout_symtab(info->mod, info);
2336 /* Allocate and move to the final place */
2337 err = move_module(info->mod, info);
2339 return ERR_PTR(err);
2341 /* Module has been copied to its final place now: return it. */
2342 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2343 kmemleak_load_module(mod, info);
2347 /* mod is no longer valid after this! */
2348 static void module_deallocate(struct module *mod, struct load_info *info)
2350 percpu_modfree(mod);
2351 module_arch_freeing_init(mod);
2352 module_memfree(mod->init_layout.base);
2353 module_memfree(mod->core_layout.base);
2354 #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
2355 vfree(mod->data_layout.base);
2359 int __weak module_finalize(const Elf_Ehdr *hdr,
2360 const Elf_Shdr *sechdrs,
2366 static int post_relocation(struct module *mod, const struct load_info *info)
2368 /* Sort exception table now relocations are done. */
2369 sort_extable(mod->extable, mod->extable + mod->num_exentries);
2371 /* Copy relocated percpu area over. */
2372 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
2373 info->sechdrs[info->index.pcpu].sh_size);
2375 /* Setup kallsyms-specific fields. */
2376 add_kallsyms(mod, info);
2378 /* Arch-specific module finalizing. */
2379 return module_finalize(info->hdr, info->sechdrs, mod);
2382 /* Is this module of this name done loading? No locks held. */
2383 static bool finished_loading(const char *name)
2389 * The module_mutex should not be a heavily contended lock;
2390 * if we get the occasional sleep here, we'll go an extra iteration
2391 * in the wait_event_interruptible(), which is harmless.
2393 sched_annotate_sleep();
2394 mutex_lock(&module_mutex);
2395 mod = find_module_all(name, strlen(name), true);
2396 ret = !mod || mod->state == MODULE_STATE_LIVE;
2397 mutex_unlock(&module_mutex);
2402 /* Call module constructors. */
2403 static void do_mod_ctors(struct module *mod)
2405 #ifdef CONFIG_CONSTRUCTORS
2408 for (i = 0; i < mod->num_ctors; i++)
2413 /* For freeing module_init on success, in case kallsyms traversing */
2414 struct mod_initfree {
2415 struct llist_node node;
2419 static void do_free_init(struct work_struct *w)
2421 struct llist_node *pos, *n, *list;
2422 struct mod_initfree *initfree;
2424 list = llist_del_all(&init_free_list);
2428 llist_for_each_safe(pos, n, list) {
2429 initfree = container_of(pos, struct mod_initfree, node);
2430 module_memfree(initfree->module_init);
2435 #undef MODULE_PARAM_PREFIX
2436 #define MODULE_PARAM_PREFIX "module."
2437 /* Default value for module->async_probe_requested */
2438 static bool async_probe;
2439 module_param(async_probe, bool, 0644);
2442 * This is where the real work happens.
2444 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
2445 * helper command 'lx-symbols'.
2447 static noinline int do_init_module(struct module *mod)
2450 struct mod_initfree *freeinit;
2452 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
2457 freeinit->module_init = mod->init_layout.base;
2460 /* Start the module */
2461 if (mod->init != NULL)
2462 ret = do_one_initcall(mod->init);
2464 goto fail_free_freeinit;
2467 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
2468 "follow 0/-E convention\n"
2469 "%s: loading module anyway...\n",
2470 __func__, mod->name, ret, __func__);
2474 /* Now it's a first class citizen! */
2475 mod->state = MODULE_STATE_LIVE;
2476 blocking_notifier_call_chain(&module_notify_list,
2477 MODULE_STATE_LIVE, mod);
2479 /* Delay uevent until module has finished its init routine */
2480 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
2483 * We need to finish all async code before the module init sequence
2484 * is done. This has potential to deadlock if synchronous module
2485 * loading is requested from async (which is not allowed!).
2487 * See commit 0fdff3ec6d87 ("async, kmod: warn on synchronous
2488 * request_module() from async workers") for more details.
2490 if (!mod->async_probe_requested)
2491 async_synchronize_full();
2493 ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base +
2494 mod->init_layout.size);
2495 mutex_lock(&module_mutex);
2496 /* Drop initial reference. */
2498 trim_init_extable(mod);
2499 #ifdef CONFIG_KALLSYMS
2500 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
2501 rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
2503 module_enable_ro(mod, true);
2504 mod_tree_remove_init(mod);
2505 module_arch_freeing_init(mod);
2506 mod->init_layout.base = NULL;
2507 mod->init_layout.size = 0;
2508 mod->init_layout.ro_size = 0;
2509 mod->init_layout.ro_after_init_size = 0;
2510 mod->init_layout.text_size = 0;
2511 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
2512 /* .BTF is not SHF_ALLOC and will get removed, so sanitize pointer */
2513 mod->btf_data = NULL;
2516 * We want to free module_init, but be aware that kallsyms may be
2517 * walking this with preempt disabled. In all the failure paths, we
2518 * call synchronize_rcu(), but we don't want to slow down the success
2519 * path. module_memfree() cannot be called in an interrupt, so do the
2520 * work and call synchronize_rcu() in a work queue.
2522 * Note that module_alloc() on most architectures creates W+X page
2523 * mappings which won't be cleaned up until do_free_init() runs. Any
2524 * code such as mark_rodata_ro() which depends on those mappings to
2525 * be cleaned up needs to sync with the queued work - ie
2528 if (llist_add(&freeinit->node, &init_free_list))
2529 schedule_work(&init_free_wq);
2531 mutex_unlock(&module_mutex);
2532 wake_up_all(&module_wq);
2539 /* Try to protect us from buggy refcounters. */
2540 mod->state = MODULE_STATE_GOING;
2543 blocking_notifier_call_chain(&module_notify_list,
2544 MODULE_STATE_GOING, mod);
2545 klp_module_going(mod);
2546 ftrace_release_mod(mod);
2548 wake_up_all(&module_wq);
2552 static int may_init_module(void)
2554 if (!capable(CAP_SYS_MODULE) || modules_disabled)
2561 * We try to place it in the list now to make sure it's unique before
2562 * we dedicate too many resources. In particular, temporary percpu
2563 * memory exhaustion.
2565 static int add_unformed_module(struct module *mod)
2570 mod->state = MODULE_STATE_UNFORMED;
2573 mutex_lock(&module_mutex);
2574 old = find_module_all(mod->name, strlen(mod->name), true);
2576 if (old->state != MODULE_STATE_LIVE) {
2577 /* Wait in case it fails to load. */
2578 mutex_unlock(&module_mutex);
2579 err = wait_event_interruptible(module_wq,
2580 finished_loading(mod->name));
2588 mod_update_bounds(mod);
2589 list_add_rcu(&mod->list, &modules);
2590 mod_tree_insert(mod);
2594 mutex_unlock(&module_mutex);
2599 static int complete_formation(struct module *mod, struct load_info *info)
2603 mutex_lock(&module_mutex);
2605 /* Find duplicate symbols (must be called under lock). */
2606 err = verify_exported_symbols(mod);
2610 /* These rely on module_mutex for list integrity. */
2611 module_bug_finalize(info->hdr, info->sechdrs, mod);
2612 module_cfi_finalize(info->hdr, info->sechdrs, mod);
2614 if (module_check_misalignment(mod))
2615 goto out_misaligned;
2617 module_enable_ro(mod, false);
2618 module_enable_nx(mod);
2619 module_enable_x(mod);
2622 * Mark state as coming so strong_try_module_get() ignores us,
2623 * but kallsyms etc. can see us.
2625 mod->state = MODULE_STATE_COMING;
2626 mutex_unlock(&module_mutex);
2633 mutex_unlock(&module_mutex);
2637 static int prepare_coming_module(struct module *mod)
2641 ftrace_module_enable(mod);
2642 err = klp_module_coming(mod);
2646 err = blocking_notifier_call_chain_robust(&module_notify_list,
2647 MODULE_STATE_COMING, MODULE_STATE_GOING, mod);
2648 err = notifier_to_errno(err);
2650 klp_module_going(mod);
2655 static int unknown_module_param_cb(char *param, char *val, const char *modname,
2658 struct module *mod = arg;
2661 if (strcmp(param, "async_probe") == 0) {
2662 if (strtobool(val, &mod->async_probe_requested))
2663 mod->async_probe_requested = true;
2667 /* Check for magic 'dyndbg' arg */
2668 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
2670 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
2675 * Allocate and load the module: note that size of section 0 is always
2676 * zero, and we rely on this for optional sections.
2678 static int load_module(struct load_info *info, const char __user *uargs,
2686 * Do the signature check (if any) first. All that
2687 * the signature check needs is info->len, it does
2688 * not need any of the section info. That can be
2689 * set up later. This will minimize the chances
2690 * of a corrupt module causing problems before
2691 * we even get to the signature check.
2693 * The check will also adjust info->len by stripping
2694 * off the sig length at the end of the module, making
2695 * checks against info->len more correct.
2697 err = module_sig_check(info, flags);
2702 * Do basic sanity checks against the ELF header and
2705 err = elf_validity_check(info);
2710 * Everything checks out, so set up the section info
2711 * in the info structure.
2713 err = setup_load_info(info, flags);
2718 * Now that we know we have the correct module name, check
2719 * if it's blacklisted.
2721 if (blacklisted(info->name)) {
2723 pr_err("Module %s is blacklisted\n", info->name);
2727 err = rewrite_section_headers(info, flags);
2731 /* Check module struct version now, before we try to use module. */
2732 if (!check_modstruct_version(info, info->mod)) {
2737 /* Figure out module layout, and allocate all the memory. */
2738 mod = layout_and_allocate(info, flags);
2744 audit_log_kern_module(mod->name);
2746 /* Reserve our place in the list. */
2747 err = add_unformed_module(mod);
2751 #ifdef CONFIG_MODULE_SIG
2752 mod->sig_ok = info->sig_ok;
2754 pr_notice_once("%s: module verification failed: signature "
2755 "and/or required key missing - tainting "
2756 "kernel\n", mod->name);
2757 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
2761 /* To avoid stressing percpu allocator, do this once we're unique. */
2762 err = percpu_modalloc(mod, info);
2766 /* Now module is in final location, initialize linked lists, etc. */
2767 err = module_unload_init(mod);
2771 init_param_lock(mod);
2774 * Now we've got everything in the final locations, we can
2775 * find optional sections.
2777 err = find_module_sections(mod, info);
2781 err = check_module_license_and_versions(mod);
2785 /* Set up MODINFO_ATTR fields */
2786 setup_modinfo(mod, info);
2788 /* Fix up syms, so that st_value is a pointer to location. */
2789 err = simplify_symbols(mod, info);
2793 err = apply_relocations(mod, info);
2797 err = post_relocation(mod, info);
2801 flush_module_icache(mod);
2803 /* Now copy in args */
2804 mod->args = strndup_user(uargs, ~0UL >> 1);
2805 if (IS_ERR(mod->args)) {
2806 err = PTR_ERR(mod->args);
2807 goto free_arch_cleanup;
2810 init_build_id(mod, info);
2811 dynamic_debug_setup(mod, &info->dyndbg);
2813 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
2814 ftrace_module_init(mod);
2816 /* Finally it's fully formed, ready to start executing. */
2817 err = complete_formation(mod, info);
2819 goto ddebug_cleanup;
2821 err = prepare_coming_module(mod);
2825 mod->async_probe_requested = async_probe;
2827 /* Module is ready to execute: parsing args may do that. */
2828 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
2830 unknown_module_param_cb);
2831 if (IS_ERR(after_dashes)) {
2832 err = PTR_ERR(after_dashes);
2833 goto coming_cleanup;
2834 } else if (after_dashes) {
2835 pr_warn("%s: parameters '%s' after `--' ignored\n",
2836 mod->name, after_dashes);
2839 /* Link in to sysfs. */
2840 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
2842 goto coming_cleanup;
2844 if (is_livepatch_module(mod)) {
2845 err = copy_module_elf(mod, info);
2850 /* Get rid of temporary copy. */
2851 free_copy(info, flags);
2854 trace_module_load(mod);
2856 return do_init_module(mod);
2859 mod_sysfs_teardown(mod);
2861 mod->state = MODULE_STATE_GOING;
2862 destroy_params(mod->kp, mod->num_kp);
2863 blocking_notifier_call_chain(&module_notify_list,
2864 MODULE_STATE_GOING, mod);
2865 klp_module_going(mod);
2867 mod->state = MODULE_STATE_GOING;
2868 /* module_bug_cleanup needs module_mutex protection */
2869 mutex_lock(&module_mutex);
2870 module_bug_cleanup(mod);
2871 mutex_unlock(&module_mutex);
2874 ftrace_release_mod(mod);
2875 dynamic_debug_remove(mod, &info->dyndbg);
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 /* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
2965 char *module_flags(struct module *mod, char *buf, bool show_state)
2969 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
2970 if (!mod->taints && !show_state)
2973 mod->state == MODULE_STATE_GOING ||
2974 mod->state == MODULE_STATE_COMING) {
2976 bx += module_flags_taint(mod->taints, buf + bx);
2977 /* Show a - for module-is-being-unloaded */
2978 if (mod->state == MODULE_STATE_GOING && show_state)
2980 /* Show a + for module-is-being-loaded */
2981 if (mod->state == MODULE_STATE_COMING && show_state)
2991 /* Given an address, look for it in the module exception tables. */
2992 const struct exception_table_entry *search_module_extables(unsigned long addr)
2994 const struct exception_table_entry *e = NULL;
2998 mod = __module_address(addr);
3002 if (!mod->num_exentries)
3005 e = search_extable(mod->extable,
3012 * Now, if we found one, we are running inside it now, hence
3013 * we cannot unload the module, hence no refcnt needed.
3019 * is_module_address() - is this address inside a module?
3020 * @addr: the address to check.
3022 * See is_module_text_address() if you simply want to see if the address
3023 * is code (not data).
3025 bool is_module_address(unsigned long addr)
3030 ret = __module_address(addr) != NULL;
3037 * __module_address() - get the module which contains an address.
3038 * @addr: the address.
3040 * Must be called with preempt disabled or module mutex held so that
3041 * module doesn't get freed during this.
3043 struct module *__module_address(unsigned long addr)
3046 struct mod_tree_root *tree;
3048 if (addr >= mod_tree.addr_min && addr <= mod_tree.addr_max)
3050 #ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
3051 else if (addr >= mod_data_tree.addr_min && addr <= mod_data_tree.addr_max)
3052 tree = &mod_data_tree;
3057 module_assert_mutex_or_preempt();
3059 mod = mod_find(addr, tree);
3061 BUG_ON(!within_module(addr, mod));
3062 if (mod->state == MODULE_STATE_UNFORMED)
3069 * is_module_text_address() - is this address inside module code?
3070 * @addr: the address to check.
3072 * See is_module_address() if you simply want to see if the address is
3073 * anywhere in a module. See kernel_text_address() for testing if an
3074 * address corresponds to kernel or module code.
3076 bool is_module_text_address(unsigned long addr)
3081 ret = __module_text_address(addr) != NULL;
3088 * __module_text_address() - get the module whose code contains an address.
3089 * @addr: the address.
3091 * Must be called with preempt disabled or module mutex held so that
3092 * module doesn't get freed during this.
3094 struct module *__module_text_address(unsigned long addr)
3096 struct module *mod = __module_address(addr);
3098 /* Make sure it's within the text section. */
3099 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
3100 && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
3106 /* Don't grab lock, we're oopsing. */
3107 void print_modules(void)
3110 char buf[MODULE_FLAGS_BUF_SIZE];
3112 printk(KERN_DEFAULT "Modules linked in:");
3113 /* Most callers should already have preempt disabled, but make sure */
3115 list_for_each_entry_rcu(mod, &modules, list) {
3116 if (mod->state == MODULE_STATE_UNFORMED)
3118 pr_cont(" %s%s", mod->name, module_flags(mod, buf, true));
3121 print_unloaded_tainted_modules();
3123 if (last_unloaded_module.name[0])
3124 pr_cont(" [last unloaded: %s%s]", last_unloaded_module.name,
3125 last_unloaded_module.taints);