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.
8 #define INCLUDE_VERMAGIC
10 #include <linux/export.h>
11 #include <linux/extable.h>
12 #include <linux/moduleloader.h>
13 #include <linux/module_signature.h>
14 #include <linux/trace_events.h>
15 #include <linux/init.h>
16 #include <linux/kallsyms.h>
17 #include <linux/file.h>
19 #include <linux/sysfs.h>
20 #include <linux/kernel.h>
21 #include <linux/kernel_read_file.h>
22 #include <linux/slab.h>
23 #include <linux/vmalloc.h>
24 #include <linux/elf.h>
25 #include <linux/proc_fs.h>
26 #include <linux/security.h>
27 #include <linux/seq_file.h>
28 #include <linux/syscalls.h>
29 #include <linux/fcntl.h>
30 #include <linux/rcupdate.h>
31 #include <linux/capability.h>
32 #include <linux/cpu.h>
33 #include <linux/moduleparam.h>
34 #include <linux/errno.h>
35 #include <linux/err.h>
36 #include <linux/vermagic.h>
37 #include <linux/notifier.h>
38 #include <linux/sched.h>
39 #include <linux/device.h>
40 #include <linux/string.h>
41 #include <linux/mutex.h>
42 #include <linux/rculist.h>
43 #include <linux/uaccess.h>
44 #include <asm/cacheflush.h>
45 #include <linux/set_memory.h>
46 #include <asm/mmu_context.h>
47 #include <linux/license.h>
48 #include <asm/sections.h>
49 #include <linux/tracepoint.h>
50 #include <linux/ftrace.h>
51 #include <linux/livepatch.h>
52 #include <linux/async.h>
53 #include <linux/percpu.h>
54 #include <linux/kmemleak.h>
55 #include <linux/jump_label.h>
56 #include <linux/pfn.h>
57 #include <linux/bsearch.h>
58 #include <linux/dynamic_debug.h>
59 #include <linux/audit.h>
60 #include <uapi/linux/module.h>
61 #include "module-internal.h"
63 #define CREATE_TRACE_POINTS
64 #include <trace/events/module.h>
66 #ifndef ARCH_SHF_SMALL
67 #define ARCH_SHF_SMALL 0
71 * Modules' sections will be aligned on page boundaries
72 * to ensure complete separation of code and data, but
73 * only when CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y
75 #ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
76 # define debug_align(X) ALIGN(X, PAGE_SIZE)
78 # define debug_align(X) (X)
81 /* If this is set, the section belongs in the init part of the module */
82 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
86 * 1) List of modules (also safely readable with preempt_disable),
87 * 2) module_use links,
88 * 3) module_addr_min/module_addr_max.
89 * (delete and add uses RCU list operations). */
90 DEFINE_MUTEX(module_mutex);
91 EXPORT_SYMBOL_GPL(module_mutex);
92 static LIST_HEAD(modules);
94 /* Work queue for freeing init sections in success case */
95 static void do_free_init(struct work_struct *w);
96 static DECLARE_WORK(init_free_wq, do_free_init);
97 static LLIST_HEAD(init_free_list);
99 #ifdef CONFIG_MODULES_TREE_LOOKUP
102 * Use a latched RB-tree for __module_address(); this allows us to use
103 * RCU-sched lookups of the address from any context.
105 * This is conditional on PERF_EVENTS || TRACING because those can really hit
106 * __module_address() hard by doing a lot of stack unwinding; potentially from
110 static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
112 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
114 return (unsigned long)layout->base;
117 static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
119 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
121 return (unsigned long)layout->size;
124 static __always_inline bool
125 mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
127 return __mod_tree_val(a) < __mod_tree_val(b);
130 static __always_inline int
131 mod_tree_comp(void *key, struct latch_tree_node *n)
133 unsigned long val = (unsigned long)key;
134 unsigned long start, end;
136 start = __mod_tree_val(n);
140 end = start + __mod_tree_size(n);
147 static const struct latch_tree_ops mod_tree_ops = {
148 .less = mod_tree_less,
149 .comp = mod_tree_comp,
152 static struct mod_tree_root {
153 struct latch_tree_root root;
154 unsigned long addr_min;
155 unsigned long addr_max;
156 } mod_tree __cacheline_aligned = {
160 #define module_addr_min mod_tree.addr_min
161 #define module_addr_max mod_tree.addr_max
163 static noinline void __mod_tree_insert(struct mod_tree_node *node)
165 latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
168 static void __mod_tree_remove(struct mod_tree_node *node)
170 latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
174 * These modifications: insert, remove_init and remove; are serialized by the
177 static void mod_tree_insert(struct module *mod)
179 mod->core_layout.mtn.mod = mod;
180 mod->init_layout.mtn.mod = mod;
182 __mod_tree_insert(&mod->core_layout.mtn);
183 if (mod->init_layout.size)
184 __mod_tree_insert(&mod->init_layout.mtn);
187 static void mod_tree_remove_init(struct module *mod)
189 if (mod->init_layout.size)
190 __mod_tree_remove(&mod->init_layout.mtn);
193 static void mod_tree_remove(struct module *mod)
195 __mod_tree_remove(&mod->core_layout.mtn);
196 mod_tree_remove_init(mod);
199 static struct module *mod_find(unsigned long addr)
201 struct latch_tree_node *ltn;
203 ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
207 return container_of(ltn, struct mod_tree_node, node)->mod;
210 #else /* MODULES_TREE_LOOKUP */
212 static unsigned long module_addr_min = -1UL, module_addr_max = 0;
214 static void mod_tree_insert(struct module *mod) { }
215 static void mod_tree_remove_init(struct module *mod) { }
216 static void mod_tree_remove(struct module *mod) { }
218 static struct module *mod_find(unsigned long addr)
222 list_for_each_entry_rcu(mod, &modules, list,
223 lockdep_is_held(&module_mutex)) {
224 if (within_module(addr, mod))
231 #endif /* MODULES_TREE_LOOKUP */
234 * Bounds of module text, for speeding up __module_address.
235 * Protected by module_mutex.
237 static void __mod_update_bounds(void *base, unsigned int size)
239 unsigned long min = (unsigned long)base;
240 unsigned long max = min + size;
242 if (min < module_addr_min)
243 module_addr_min = min;
244 if (max > module_addr_max)
245 module_addr_max = max;
248 static void mod_update_bounds(struct module *mod)
250 __mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
251 if (mod->init_layout.size)
252 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
255 #ifdef CONFIG_KGDB_KDB
256 struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
257 #endif /* CONFIG_KGDB_KDB */
259 static void module_assert_mutex(void)
261 lockdep_assert_held(&module_mutex);
264 static void module_assert_mutex_or_preempt(void)
266 #ifdef CONFIG_LOCKDEP
267 if (unlikely(!debug_locks))
270 WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
271 !lockdep_is_held(&module_mutex));
275 static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
276 module_param(sig_enforce, bool_enable_only, 0644);
279 * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
280 * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
282 bool is_module_sig_enforced(void)
286 EXPORT_SYMBOL(is_module_sig_enforced);
288 void set_module_sig_enforced(void)
293 /* Block module loading/unloading? */
294 int modules_disabled = 0;
295 core_param(nomodule, modules_disabled, bint, 0);
297 /* Waiting for a module to finish initializing? */
298 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
300 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
302 int register_module_notifier(struct notifier_block *nb)
304 return blocking_notifier_chain_register(&module_notify_list, nb);
306 EXPORT_SYMBOL(register_module_notifier);
308 int unregister_module_notifier(struct notifier_block *nb)
310 return blocking_notifier_chain_unregister(&module_notify_list, nb);
312 EXPORT_SYMBOL(unregister_module_notifier);
315 * We require a truly strong try_module_get(): 0 means success.
316 * Otherwise an error is returned due to ongoing or failed
317 * initialization etc.
319 static inline int strong_try_module_get(struct module *mod)
321 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
322 if (mod && mod->state == MODULE_STATE_COMING)
324 if (try_module_get(mod))
330 static inline void add_taint_module(struct module *mod, unsigned flag,
331 enum lockdep_ok lockdep_ok)
333 add_taint(flag, lockdep_ok);
334 set_bit(flag, &mod->taints);
338 * A thread that wants to hold a reference to a module only while it
339 * is running can call this to safely exit. nfsd and lockd use this.
341 void __noreturn __module_put_and_exit(struct module *mod, long code)
346 EXPORT_SYMBOL(__module_put_and_exit);
348 /* Find a module section: 0 means not found. */
349 static unsigned int find_sec(const struct load_info *info, const char *name)
353 for (i = 1; i < info->hdr->e_shnum; i++) {
354 Elf_Shdr *shdr = &info->sechdrs[i];
355 /* Alloc bit cleared means "ignore it." */
356 if ((shdr->sh_flags & SHF_ALLOC)
357 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
363 /* Find a module section, or NULL. */
364 static void *section_addr(const struct load_info *info, const char *name)
366 /* Section 0 has sh_addr 0. */
367 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
370 /* Find a module section, or NULL. Fill in number of "objects" in section. */
371 static void *section_objs(const struct load_info *info,
376 unsigned int sec = find_sec(info, name);
378 /* Section 0 has sh_addr 0 and sh_size 0. */
379 *num = info->sechdrs[sec].sh_size / object_size;
380 return (void *)info->sechdrs[sec].sh_addr;
383 /* Provided by the linker */
384 extern const struct kernel_symbol __start___ksymtab[];
385 extern const struct kernel_symbol __stop___ksymtab[];
386 extern const struct kernel_symbol __start___ksymtab_gpl[];
387 extern const struct kernel_symbol __stop___ksymtab_gpl[];
388 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
389 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
390 extern const s32 __start___kcrctab[];
391 extern const s32 __start___kcrctab_gpl[];
392 extern const s32 __start___kcrctab_gpl_future[];
393 #ifdef CONFIG_UNUSED_SYMBOLS
394 extern const struct kernel_symbol __start___ksymtab_unused[];
395 extern const struct kernel_symbol __stop___ksymtab_unused[];
396 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
397 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
398 extern const s32 __start___kcrctab_unused[];
399 extern const s32 __start___kcrctab_unused_gpl[];
402 #ifndef CONFIG_MODVERSIONS
403 #define symversion(base, idx) NULL
405 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
408 static bool each_symbol_in_section(const struct symsearch *arr,
409 unsigned int arrsize,
410 struct module *owner,
411 bool (*fn)(const struct symsearch *syms,
412 struct module *owner,
418 for (j = 0; j < arrsize; j++) {
419 if (fn(&arr[j], owner, data))
426 /* Returns true as soon as fn returns true, otherwise false. */
427 static bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
428 struct module *owner,
433 static const struct symsearch arr[] = {
434 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
435 NOT_GPL_ONLY, false },
436 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
437 __start___kcrctab_gpl,
439 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
440 __start___kcrctab_gpl_future,
441 WILL_BE_GPL_ONLY, false },
442 #ifdef CONFIG_UNUSED_SYMBOLS
443 { __start___ksymtab_unused, __stop___ksymtab_unused,
444 __start___kcrctab_unused,
445 NOT_GPL_ONLY, true },
446 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
447 __start___kcrctab_unused_gpl,
452 module_assert_mutex_or_preempt();
454 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
457 list_for_each_entry_rcu(mod, &modules, list,
458 lockdep_is_held(&module_mutex)) {
459 struct symsearch arr[] = {
460 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
461 NOT_GPL_ONLY, false },
462 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
465 { mod->gpl_future_syms,
466 mod->gpl_future_syms + mod->num_gpl_future_syms,
467 mod->gpl_future_crcs,
468 WILL_BE_GPL_ONLY, false },
469 #ifdef CONFIG_UNUSED_SYMBOLS
471 mod->unused_syms + mod->num_unused_syms,
473 NOT_GPL_ONLY, true },
474 { mod->unused_gpl_syms,
475 mod->unused_gpl_syms + mod->num_unused_gpl_syms,
476 mod->unused_gpl_crcs,
481 if (mod->state == MODULE_STATE_UNFORMED)
484 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
490 struct find_symbol_arg {
497 struct module *owner;
499 const struct kernel_symbol *sym;
500 enum mod_license license;
503 static bool check_exported_symbol(const struct symsearch *syms,
504 struct module *owner,
505 unsigned int symnum, void *data)
507 struct find_symbol_arg *fsa = data;
510 if (syms->license == GPL_ONLY)
512 if (syms->license == WILL_BE_GPL_ONLY && fsa->warn) {
513 pr_warn("Symbol %s is being used by a non-GPL module, "
514 "which will not be allowed in the future\n",
519 #ifdef CONFIG_UNUSED_SYMBOLS
520 if (syms->unused && fsa->warn) {
521 pr_warn("Symbol %s is marked as UNUSED, however this module is "
522 "using it.\n", fsa->name);
523 pr_warn("This symbol will go away in the future.\n");
524 pr_warn("Please evaluate if this is the right api to use and "
525 "if it really is, submit a report to the linux kernel "
526 "mailing list together with submitting your code for "
532 fsa->crc = symversion(syms->crcs, symnum);
533 fsa->sym = &syms->start[symnum];
534 fsa->license = syms->license;
538 static unsigned long kernel_symbol_value(const struct kernel_symbol *sym)
540 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
541 return (unsigned long)offset_to_ptr(&sym->value_offset);
547 static const char *kernel_symbol_name(const struct kernel_symbol *sym)
549 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
550 return offset_to_ptr(&sym->name_offset);
556 static const char *kernel_symbol_namespace(const struct kernel_symbol *sym)
558 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
559 if (!sym->namespace_offset)
561 return offset_to_ptr(&sym->namespace_offset);
563 return sym->namespace;
567 static int cmp_name(const void *name, const void *sym)
569 return strcmp(name, kernel_symbol_name(sym));
572 static bool find_exported_symbol_in_section(const struct symsearch *syms,
573 struct module *owner,
576 struct find_symbol_arg *fsa = data;
577 struct kernel_symbol *sym;
579 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
580 sizeof(struct kernel_symbol), cmp_name);
582 if (sym != NULL && check_exported_symbol(syms, owner,
583 sym - syms->start, data))
589 /* Find an exported symbol and return it, along with, (optional) crc and
590 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
591 static const struct kernel_symbol *find_symbol(const char *name,
592 struct module **owner,
594 enum mod_license *license,
598 struct find_symbol_arg fsa;
604 if (each_symbol_section(find_exported_symbol_in_section, &fsa)) {
610 *license = fsa.license;
614 pr_debug("Failed to find symbol %s\n", name);
619 * Search for module by name: must hold module_mutex (or preempt disabled
620 * for read-only access).
622 static struct module *find_module_all(const char *name, size_t len,
627 module_assert_mutex_or_preempt();
629 list_for_each_entry_rcu(mod, &modules, list,
630 lockdep_is_held(&module_mutex)) {
631 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
633 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
639 struct module *find_module(const char *name)
641 module_assert_mutex();
642 return find_module_all(name, strlen(name), false);
644 EXPORT_SYMBOL_GPL(find_module);
648 static inline void __percpu *mod_percpu(struct module *mod)
653 static int percpu_modalloc(struct module *mod, struct load_info *info)
655 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
656 unsigned long align = pcpusec->sh_addralign;
658 if (!pcpusec->sh_size)
661 if (align > PAGE_SIZE) {
662 pr_warn("%s: per-cpu alignment %li > %li\n",
663 mod->name, align, PAGE_SIZE);
667 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
669 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
670 mod->name, (unsigned long)pcpusec->sh_size);
673 mod->percpu_size = pcpusec->sh_size;
677 static void percpu_modfree(struct module *mod)
679 free_percpu(mod->percpu);
682 static unsigned int find_pcpusec(struct load_info *info)
684 return find_sec(info, ".data..percpu");
687 static void percpu_modcopy(struct module *mod,
688 const void *from, unsigned long size)
692 for_each_possible_cpu(cpu)
693 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
696 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
703 list_for_each_entry_rcu(mod, &modules, list) {
704 if (mod->state == MODULE_STATE_UNFORMED)
706 if (!mod->percpu_size)
708 for_each_possible_cpu(cpu) {
709 void *start = per_cpu_ptr(mod->percpu, cpu);
710 void *va = (void *)addr;
712 if (va >= start && va < start + mod->percpu_size) {
714 *can_addr = (unsigned long) (va - start);
715 *can_addr += (unsigned long)
716 per_cpu_ptr(mod->percpu,
730 * is_module_percpu_address() - test whether address is from module static percpu
731 * @addr: address to test
733 * Test whether @addr belongs to module static percpu area.
735 * Return: %true if @addr is from module static percpu area
737 bool is_module_percpu_address(unsigned long addr)
739 return __is_module_percpu_address(addr, NULL);
742 #else /* ... !CONFIG_SMP */
744 static inline void __percpu *mod_percpu(struct module *mod)
748 static int percpu_modalloc(struct module *mod, struct load_info *info)
750 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
751 if (info->sechdrs[info->index.pcpu].sh_size != 0)
755 static inline void percpu_modfree(struct module *mod)
758 static unsigned int find_pcpusec(struct load_info *info)
762 static inline void percpu_modcopy(struct module *mod,
763 const void *from, unsigned long size)
765 /* pcpusec should be 0, and size of that section should be 0. */
768 bool is_module_percpu_address(unsigned long addr)
773 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
778 #endif /* CONFIG_SMP */
780 #define MODINFO_ATTR(field) \
781 static void setup_modinfo_##field(struct module *mod, const char *s) \
783 mod->field = kstrdup(s, GFP_KERNEL); \
785 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
786 struct module_kobject *mk, char *buffer) \
788 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
790 static int modinfo_##field##_exists(struct module *mod) \
792 return mod->field != NULL; \
794 static void free_modinfo_##field(struct module *mod) \
799 static struct module_attribute modinfo_##field = { \
800 .attr = { .name = __stringify(field), .mode = 0444 }, \
801 .show = show_modinfo_##field, \
802 .setup = setup_modinfo_##field, \
803 .test = modinfo_##field##_exists, \
804 .free = free_modinfo_##field, \
807 MODINFO_ATTR(version);
808 MODINFO_ATTR(srcversion);
810 static char last_unloaded_module[MODULE_NAME_LEN+1];
812 #ifdef CONFIG_MODULE_UNLOAD
814 EXPORT_TRACEPOINT_SYMBOL(module_get);
816 /* MODULE_REF_BASE is the base reference count by kmodule loader. */
817 #define MODULE_REF_BASE 1
819 /* Init the unload section of the module. */
820 static int module_unload_init(struct module *mod)
823 * Initialize reference counter to MODULE_REF_BASE.
824 * refcnt == 0 means module is going.
826 atomic_set(&mod->refcnt, MODULE_REF_BASE);
828 INIT_LIST_HEAD(&mod->source_list);
829 INIT_LIST_HEAD(&mod->target_list);
831 /* Hold reference count during initialization. */
832 atomic_inc(&mod->refcnt);
837 /* Does a already use b? */
838 static int already_uses(struct module *a, struct module *b)
840 struct module_use *use;
842 list_for_each_entry(use, &b->source_list, source_list) {
843 if (use->source == a) {
844 pr_debug("%s uses %s!\n", a->name, b->name);
848 pr_debug("%s does not use %s!\n", a->name, b->name);
854 * - we add 'a' as a "source", 'b' as a "target" of module use
855 * - the module_use is added to the list of 'b' sources (so
856 * 'b' can walk the list to see who sourced them), and of 'a'
857 * targets (so 'a' can see what modules it targets).
859 static int add_module_usage(struct module *a, struct module *b)
861 struct module_use *use;
863 pr_debug("Allocating new usage for %s.\n", a->name);
864 use = kmalloc(sizeof(*use), GFP_ATOMIC);
870 list_add(&use->source_list, &b->source_list);
871 list_add(&use->target_list, &a->target_list);
875 /* Module a uses b: caller needs module_mutex() */
876 static int ref_module(struct module *a, struct module *b)
880 if (b == NULL || already_uses(a, b))
883 /* If module isn't available, we fail. */
884 err = strong_try_module_get(b);
888 err = add_module_usage(a, b);
896 /* Clear the unload stuff of the module. */
897 static void module_unload_free(struct module *mod)
899 struct module_use *use, *tmp;
901 mutex_lock(&module_mutex);
902 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
903 struct module *i = use->target;
904 pr_debug("%s unusing %s\n", mod->name, i->name);
906 list_del(&use->source_list);
907 list_del(&use->target_list);
910 mutex_unlock(&module_mutex);
913 #ifdef CONFIG_MODULE_FORCE_UNLOAD
914 static inline int try_force_unload(unsigned int flags)
916 int ret = (flags & O_TRUNC);
918 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
922 static inline int try_force_unload(unsigned int flags)
926 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
928 /* Try to release refcount of module, 0 means success. */
929 static int try_release_module_ref(struct module *mod)
933 /* Try to decrement refcnt which we set at loading */
934 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
937 /* Someone can put this right now, recover with checking */
938 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
943 static int try_stop_module(struct module *mod, int flags, int *forced)
945 /* If it's not unused, quit unless we're forcing. */
946 if (try_release_module_ref(mod) != 0) {
947 *forced = try_force_unload(flags);
952 /* Mark it as dying. */
953 mod->state = MODULE_STATE_GOING;
959 * module_refcount() - return the refcount or -1 if unloading
960 * @mod: the module we're checking
963 * -1 if the module is in the process of unloading
964 * otherwise the number of references in the kernel to the module
966 int module_refcount(struct module *mod)
968 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
970 EXPORT_SYMBOL(module_refcount);
972 /* This exists whether we can unload or not */
973 static void free_module(struct module *mod);
975 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
979 char name[MODULE_NAME_LEN];
982 if (!capable(CAP_SYS_MODULE) || modules_disabled)
985 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
987 name[MODULE_NAME_LEN-1] = '\0';
989 audit_log_kern_module(name);
991 if (mutex_lock_interruptible(&module_mutex) != 0)
994 mod = find_module(name);
1000 if (!list_empty(&mod->source_list)) {
1001 /* Other modules depend on us: get rid of them first. */
1006 /* Doing init or already dying? */
1007 if (mod->state != MODULE_STATE_LIVE) {
1008 /* FIXME: if (force), slam module count damn the torpedoes */
1009 pr_debug("%s already dying\n", mod->name);
1014 /* If it has an init func, it must have an exit func to unload */
1015 if (mod->init && !mod->exit) {
1016 forced = try_force_unload(flags);
1018 /* This module can't be removed */
1024 /* Stop the machine so refcounts can't move and disable module. */
1025 ret = try_stop_module(mod, flags, &forced);
1029 mutex_unlock(&module_mutex);
1030 /* Final destruction now no one is using it. */
1031 if (mod->exit != NULL)
1033 blocking_notifier_call_chain(&module_notify_list,
1034 MODULE_STATE_GOING, mod);
1035 klp_module_going(mod);
1036 ftrace_release_mod(mod);
1038 async_synchronize_full();
1040 /* Store the name of the last unloaded module for diagnostic purposes */
1041 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
1044 /* someone could wait for the module in add_unformed_module() */
1045 wake_up_all(&module_wq);
1048 mutex_unlock(&module_mutex);
1052 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1054 struct module_use *use;
1055 int printed_something = 0;
1057 seq_printf(m, " %i ", module_refcount(mod));
1060 * Always include a trailing , so userspace can differentiate
1061 * between this and the old multi-field proc format.
1063 list_for_each_entry(use, &mod->source_list, source_list) {
1064 printed_something = 1;
1065 seq_printf(m, "%s,", use->source->name);
1068 if (mod->init != NULL && mod->exit == NULL) {
1069 printed_something = 1;
1070 seq_puts(m, "[permanent],");
1073 if (!printed_something)
1077 void __symbol_put(const char *symbol)
1079 struct module *owner;
1082 if (!find_symbol(symbol, &owner, NULL, NULL, true, false))
1087 EXPORT_SYMBOL(__symbol_put);
1089 /* Note this assumes addr is a function, which it currently always is. */
1090 void symbol_put_addr(void *addr)
1092 struct module *modaddr;
1093 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1095 if (core_kernel_text(a))
1099 * Even though we hold a reference on the module; we still need to
1100 * disable preemption in order to safely traverse the data structure.
1103 modaddr = __module_text_address(a);
1105 module_put(modaddr);
1108 EXPORT_SYMBOL_GPL(symbol_put_addr);
1110 static ssize_t show_refcnt(struct module_attribute *mattr,
1111 struct module_kobject *mk, char *buffer)
1113 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1116 static struct module_attribute modinfo_refcnt =
1117 __ATTR(refcnt, 0444, show_refcnt, NULL);
1119 void __module_get(struct module *module)
1123 atomic_inc(&module->refcnt);
1124 trace_module_get(module, _RET_IP_);
1128 EXPORT_SYMBOL(__module_get);
1130 bool try_module_get(struct module *module)
1136 /* Note: here, we can fail to get a reference */
1137 if (likely(module_is_live(module) &&
1138 atomic_inc_not_zero(&module->refcnt) != 0))
1139 trace_module_get(module, _RET_IP_);
1147 EXPORT_SYMBOL(try_module_get);
1149 void module_put(struct module *module)
1155 ret = atomic_dec_if_positive(&module->refcnt);
1156 WARN_ON(ret < 0); /* Failed to put refcount */
1157 trace_module_put(module, _RET_IP_);
1161 EXPORT_SYMBOL(module_put);
1163 #else /* !CONFIG_MODULE_UNLOAD */
1164 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1166 /* We don't know the usage count, or what modules are using. */
1167 seq_puts(m, " - -");
1170 static inline void module_unload_free(struct module *mod)
1174 static int ref_module(struct module *a, struct module *b)
1176 return strong_try_module_get(b);
1179 static inline int module_unload_init(struct module *mod)
1183 #endif /* CONFIG_MODULE_UNLOAD */
1185 static size_t module_flags_taint(struct module *mod, char *buf)
1190 for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
1191 if (taint_flags[i].module && test_bit(i, &mod->taints))
1192 buf[l++] = taint_flags[i].c_true;
1198 static ssize_t show_initstate(struct module_attribute *mattr,
1199 struct module_kobject *mk, char *buffer)
1201 const char *state = "unknown";
1203 switch (mk->mod->state) {
1204 case MODULE_STATE_LIVE:
1207 case MODULE_STATE_COMING:
1210 case MODULE_STATE_GOING:
1216 return sprintf(buffer, "%s\n", state);
1219 static struct module_attribute modinfo_initstate =
1220 __ATTR(initstate, 0444, show_initstate, NULL);
1222 static ssize_t store_uevent(struct module_attribute *mattr,
1223 struct module_kobject *mk,
1224 const char *buffer, size_t count)
1228 rc = kobject_synth_uevent(&mk->kobj, buffer, count);
1229 return rc ? rc : count;
1232 struct module_attribute module_uevent =
1233 __ATTR(uevent, 0200, NULL, store_uevent);
1235 static ssize_t show_coresize(struct module_attribute *mattr,
1236 struct module_kobject *mk, char *buffer)
1238 return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1241 static struct module_attribute modinfo_coresize =
1242 __ATTR(coresize, 0444, show_coresize, NULL);
1244 static ssize_t show_initsize(struct module_attribute *mattr,
1245 struct module_kobject *mk, char *buffer)
1247 return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1250 static struct module_attribute modinfo_initsize =
1251 __ATTR(initsize, 0444, show_initsize, NULL);
1253 static ssize_t show_taint(struct module_attribute *mattr,
1254 struct module_kobject *mk, char *buffer)
1258 l = module_flags_taint(mk->mod, buffer);
1263 static struct module_attribute modinfo_taint =
1264 __ATTR(taint, 0444, show_taint, NULL);
1266 static struct module_attribute *modinfo_attrs[] = {
1269 &modinfo_srcversion,
1274 #ifdef CONFIG_MODULE_UNLOAD
1280 static const char vermagic[] = VERMAGIC_STRING;
1282 static int try_to_force_load(struct module *mod, const char *reason)
1284 #ifdef CONFIG_MODULE_FORCE_LOAD
1285 if (!test_taint(TAINT_FORCED_MODULE))
1286 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1287 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1294 #ifdef CONFIG_MODVERSIONS
1296 static u32 resolve_rel_crc(const s32 *crc)
1298 return *(u32 *)((void *)crc + *crc);
1301 static int check_version(const struct load_info *info,
1302 const char *symname,
1306 Elf_Shdr *sechdrs = info->sechdrs;
1307 unsigned int versindex = info->index.vers;
1308 unsigned int i, num_versions;
1309 struct modversion_info *versions;
1311 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1315 /* No versions at all? modprobe --force does this. */
1317 return try_to_force_load(mod, symname) == 0;
1319 versions = (void *) sechdrs[versindex].sh_addr;
1320 num_versions = sechdrs[versindex].sh_size
1321 / sizeof(struct modversion_info);
1323 for (i = 0; i < num_versions; i++) {
1326 if (strcmp(versions[i].name, symname) != 0)
1329 if (IS_ENABLED(CONFIG_MODULE_REL_CRCS))
1330 crcval = resolve_rel_crc(crc);
1333 if (versions[i].crc == crcval)
1335 pr_debug("Found checksum %X vs module %lX\n",
1336 crcval, versions[i].crc);
1340 /* Broken toolchain. Warn once, then let it go.. */
1341 pr_warn_once("%s: no symbol version for %s\n", info->name, symname);
1345 pr_warn("%s: disagrees about version of symbol %s\n",
1346 info->name, symname);
1350 static inline int check_modstruct_version(const struct load_info *info,
1356 * Since this should be found in kernel (which can't be removed), no
1357 * locking is necessary -- use preempt_disable() to placate lockdep.
1360 if (!find_symbol("module_layout", NULL, &crc, NULL, true, false)) {
1365 return check_version(info, "module_layout", mod, crc);
1368 /* First part is kernel version, which we ignore if module has crcs. */
1369 static inline int same_magic(const char *amagic, const char *bmagic,
1373 amagic += strcspn(amagic, " ");
1374 bmagic += strcspn(bmagic, " ");
1376 return strcmp(amagic, bmagic) == 0;
1379 static inline int check_version(const struct load_info *info,
1380 const char *symname,
1387 static inline int check_modstruct_version(const struct load_info *info,
1393 static inline int same_magic(const char *amagic, const char *bmagic,
1396 return strcmp(amagic, bmagic) == 0;
1398 #endif /* CONFIG_MODVERSIONS */
1400 static char *get_modinfo(const struct load_info *info, const char *tag);
1401 static char *get_next_modinfo(const struct load_info *info, const char *tag,
1404 static int verify_namespace_is_imported(const struct load_info *info,
1405 const struct kernel_symbol *sym,
1408 const char *namespace;
1409 char *imported_namespace;
1411 namespace = kernel_symbol_namespace(sym);
1412 if (namespace && namespace[0]) {
1413 imported_namespace = get_modinfo(info, "import_ns");
1414 while (imported_namespace) {
1415 if (strcmp(namespace, imported_namespace) == 0)
1417 imported_namespace = get_next_modinfo(
1418 info, "import_ns", imported_namespace);
1420 #ifdef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1425 "%s: module uses symbol (%s) from namespace %s, but does not import it.\n",
1426 mod->name, kernel_symbol_name(sym), namespace);
1427 #ifndef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1434 static bool inherit_taint(struct module *mod, struct module *owner)
1436 if (!owner || !test_bit(TAINT_PROPRIETARY_MODULE, &owner->taints))
1439 if (mod->using_gplonly_symbols) {
1440 pr_err("%s: module using GPL-only symbols uses symbols from proprietary module %s.\n",
1441 mod->name, owner->name);
1445 if (!test_bit(TAINT_PROPRIETARY_MODULE, &mod->taints)) {
1446 pr_warn("%s: module uses symbols from proprietary module %s, inheriting taint.\n",
1447 mod->name, owner->name);
1448 set_bit(TAINT_PROPRIETARY_MODULE, &mod->taints);
1453 /* Resolve a symbol for this module. I.e. if we find one, record usage. */
1454 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1455 const struct load_info *info,
1459 struct module *owner;
1460 const struct kernel_symbol *sym;
1462 enum mod_license license;
1466 * The module_mutex should not be a heavily contended lock;
1467 * if we get the occasional sleep here, we'll go an extra iteration
1468 * in the wait_event_interruptible(), which is harmless.
1470 sched_annotate_sleep();
1471 mutex_lock(&module_mutex);
1472 sym = find_symbol(name, &owner, &crc, &license,
1473 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1477 if (license == GPL_ONLY)
1478 mod->using_gplonly_symbols = true;
1480 if (!inherit_taint(mod, owner)) {
1485 if (!check_version(info, name, mod, crc)) {
1486 sym = ERR_PTR(-EINVAL);
1490 err = verify_namespace_is_imported(info, sym, mod);
1496 err = ref_module(mod, owner);
1503 /* We must make copy under the lock if we failed to get ref. */
1504 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1506 mutex_unlock(&module_mutex);
1510 static const struct kernel_symbol *
1511 resolve_symbol_wait(struct module *mod,
1512 const struct load_info *info,
1515 const struct kernel_symbol *ksym;
1516 char owner[MODULE_NAME_LEN];
1518 if (wait_event_interruptible_timeout(module_wq,
1519 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1520 || PTR_ERR(ksym) != -EBUSY,
1522 pr_warn("%s: gave up waiting for init of module %s.\n",
1529 * /sys/module/foo/sections stuff
1530 * J. Corbet <corbet@lwn.net>
1534 #ifdef CONFIG_KALLSYMS
1535 static inline bool sect_empty(const Elf_Shdr *sect)
1537 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1540 struct module_sect_attr {
1541 struct bin_attribute battr;
1542 unsigned long address;
1545 struct module_sect_attrs {
1546 struct attribute_group grp;
1547 unsigned int nsections;
1548 struct module_sect_attr attrs[];
1551 #define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4))
1552 static ssize_t module_sect_read(struct file *file, struct kobject *kobj,
1553 struct bin_attribute *battr,
1554 char *buf, loff_t pos, size_t count)
1556 struct module_sect_attr *sattr =
1557 container_of(battr, struct module_sect_attr, battr);
1558 char bounce[MODULE_SECT_READ_SIZE + 1];
1565 * Since we're a binary read handler, we must account for the
1566 * trailing NUL byte that sprintf will write: if "buf" is
1567 * too small to hold the NUL, or the NUL is exactly the last
1568 * byte, the read will look like it got truncated by one byte.
1569 * Since there is no way to ask sprintf nicely to not write
1570 * the NUL, we have to use a bounce buffer.
1572 wrote = scnprintf(bounce, sizeof(bounce), "0x%px\n",
1573 kallsyms_show_value(file->f_cred)
1574 ? (void *)sattr->address : NULL);
1575 count = min(count, wrote);
1576 memcpy(buf, bounce, count);
1581 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1583 unsigned int section;
1585 for (section = 0; section < sect_attrs->nsections; section++)
1586 kfree(sect_attrs->attrs[section].battr.attr.name);
1590 static void add_sect_attrs(struct module *mod, const struct load_info *info)
1592 unsigned int nloaded = 0, i, size[2];
1593 struct module_sect_attrs *sect_attrs;
1594 struct module_sect_attr *sattr;
1595 struct bin_attribute **gattr;
1597 /* Count loaded sections and allocate structures */
1598 for (i = 0; i < info->hdr->e_shnum; i++)
1599 if (!sect_empty(&info->sechdrs[i]))
1601 size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded),
1602 sizeof(sect_attrs->grp.bin_attrs[0]));
1603 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.bin_attrs[0]);
1604 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1605 if (sect_attrs == NULL)
1608 /* Setup section attributes. */
1609 sect_attrs->grp.name = "sections";
1610 sect_attrs->grp.bin_attrs = (void *)sect_attrs + size[0];
1612 sect_attrs->nsections = 0;
1613 sattr = §_attrs->attrs[0];
1614 gattr = §_attrs->grp.bin_attrs[0];
1615 for (i = 0; i < info->hdr->e_shnum; i++) {
1616 Elf_Shdr *sec = &info->sechdrs[i];
1617 if (sect_empty(sec))
1619 sysfs_bin_attr_init(&sattr->battr);
1620 sattr->address = sec->sh_addr;
1621 sattr->battr.attr.name =
1622 kstrdup(info->secstrings + sec->sh_name, GFP_KERNEL);
1623 if (sattr->battr.attr.name == NULL)
1625 sect_attrs->nsections++;
1626 sattr->battr.read = module_sect_read;
1627 sattr->battr.size = MODULE_SECT_READ_SIZE;
1628 sattr->battr.attr.mode = 0400;
1629 *(gattr++) = &(sattr++)->battr;
1633 if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp))
1636 mod->sect_attrs = sect_attrs;
1639 free_sect_attrs(sect_attrs);
1642 static void remove_sect_attrs(struct module *mod)
1644 if (mod->sect_attrs) {
1645 sysfs_remove_group(&mod->mkobj.kobj,
1646 &mod->sect_attrs->grp);
1647 /* We are positive that no one is using any sect attrs
1648 * at this point. Deallocate immediately. */
1649 free_sect_attrs(mod->sect_attrs);
1650 mod->sect_attrs = NULL;
1655 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1658 struct module_notes_attrs {
1659 struct kobject *dir;
1661 struct bin_attribute attrs[];
1664 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1665 struct bin_attribute *bin_attr,
1666 char *buf, loff_t pos, size_t count)
1669 * The caller checked the pos and count against our size.
1671 memcpy(buf, bin_attr->private + pos, count);
1675 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1678 if (notes_attrs->dir) {
1680 sysfs_remove_bin_file(notes_attrs->dir,
1681 ¬es_attrs->attrs[i]);
1682 kobject_put(notes_attrs->dir);
1687 static void add_notes_attrs(struct module *mod, const struct load_info *info)
1689 unsigned int notes, loaded, i;
1690 struct module_notes_attrs *notes_attrs;
1691 struct bin_attribute *nattr;
1693 /* failed to create section attributes, so can't create notes */
1694 if (!mod->sect_attrs)
1697 /* Count notes sections and allocate structures. */
1699 for (i = 0; i < info->hdr->e_shnum; i++)
1700 if (!sect_empty(&info->sechdrs[i]) &&
1701 (info->sechdrs[i].sh_type == SHT_NOTE))
1707 notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes),
1709 if (notes_attrs == NULL)
1712 notes_attrs->notes = notes;
1713 nattr = ¬es_attrs->attrs[0];
1714 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1715 if (sect_empty(&info->sechdrs[i]))
1717 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1718 sysfs_bin_attr_init(nattr);
1719 nattr->attr.name = mod->sect_attrs->attrs[loaded].battr.attr.name;
1720 nattr->attr.mode = S_IRUGO;
1721 nattr->size = info->sechdrs[i].sh_size;
1722 nattr->private = (void *) info->sechdrs[i].sh_addr;
1723 nattr->read = module_notes_read;
1729 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1730 if (!notes_attrs->dir)
1733 for (i = 0; i < notes; ++i)
1734 if (sysfs_create_bin_file(notes_attrs->dir,
1735 ¬es_attrs->attrs[i]))
1738 mod->notes_attrs = notes_attrs;
1742 free_notes_attrs(notes_attrs, i);
1745 static void remove_notes_attrs(struct module *mod)
1747 if (mod->notes_attrs)
1748 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1753 static inline void add_sect_attrs(struct module *mod,
1754 const struct load_info *info)
1758 static inline void remove_sect_attrs(struct module *mod)
1762 static inline void add_notes_attrs(struct module *mod,
1763 const struct load_info *info)
1767 static inline void remove_notes_attrs(struct module *mod)
1770 #endif /* CONFIG_KALLSYMS */
1772 static void del_usage_links(struct module *mod)
1774 #ifdef CONFIG_MODULE_UNLOAD
1775 struct module_use *use;
1777 mutex_lock(&module_mutex);
1778 list_for_each_entry(use, &mod->target_list, target_list)
1779 sysfs_remove_link(use->target->holders_dir, mod->name);
1780 mutex_unlock(&module_mutex);
1784 static int add_usage_links(struct module *mod)
1787 #ifdef CONFIG_MODULE_UNLOAD
1788 struct module_use *use;
1790 mutex_lock(&module_mutex);
1791 list_for_each_entry(use, &mod->target_list, target_list) {
1792 ret = sysfs_create_link(use->target->holders_dir,
1793 &mod->mkobj.kobj, mod->name);
1797 mutex_unlock(&module_mutex);
1799 del_usage_links(mod);
1804 static void module_remove_modinfo_attrs(struct module *mod, int end);
1806 static int module_add_modinfo_attrs(struct module *mod)
1808 struct module_attribute *attr;
1809 struct module_attribute *temp_attr;
1813 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1814 (ARRAY_SIZE(modinfo_attrs) + 1)),
1816 if (!mod->modinfo_attrs)
1819 temp_attr = mod->modinfo_attrs;
1820 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1821 if (!attr->test || attr->test(mod)) {
1822 memcpy(temp_attr, attr, sizeof(*temp_attr));
1823 sysfs_attr_init(&temp_attr->attr);
1824 error = sysfs_create_file(&mod->mkobj.kobj,
1836 module_remove_modinfo_attrs(mod, --i);
1838 kfree(mod->modinfo_attrs);
1842 static void module_remove_modinfo_attrs(struct module *mod, int end)
1844 struct module_attribute *attr;
1847 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1848 if (end >= 0 && i > end)
1850 /* pick a field to test for end of list */
1851 if (!attr->attr.name)
1853 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1857 kfree(mod->modinfo_attrs);
1860 static void mod_kobject_put(struct module *mod)
1862 DECLARE_COMPLETION_ONSTACK(c);
1863 mod->mkobj.kobj_completion = &c;
1864 kobject_put(&mod->mkobj.kobj);
1865 wait_for_completion(&c);
1868 static int mod_sysfs_init(struct module *mod)
1871 struct kobject *kobj;
1873 if (!module_sysfs_initialized) {
1874 pr_err("%s: module sysfs not initialized\n", mod->name);
1879 kobj = kset_find_obj(module_kset, mod->name);
1881 pr_err("%s: module is already loaded\n", mod->name);
1887 mod->mkobj.mod = mod;
1889 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1890 mod->mkobj.kobj.kset = module_kset;
1891 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1894 mod_kobject_put(mod);
1896 /* delay uevent until full sysfs population */
1901 static int mod_sysfs_setup(struct module *mod,
1902 const struct load_info *info,
1903 struct kernel_param *kparam,
1904 unsigned int num_params)
1908 err = mod_sysfs_init(mod);
1912 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1913 if (!mod->holders_dir) {
1918 err = module_param_sysfs_setup(mod, kparam, num_params);
1920 goto out_unreg_holders;
1922 err = module_add_modinfo_attrs(mod);
1924 goto out_unreg_param;
1926 err = add_usage_links(mod);
1928 goto out_unreg_modinfo_attrs;
1930 add_sect_attrs(mod, info);
1931 add_notes_attrs(mod, info);
1933 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1936 out_unreg_modinfo_attrs:
1937 module_remove_modinfo_attrs(mod, -1);
1939 module_param_sysfs_remove(mod);
1941 kobject_put(mod->holders_dir);
1943 mod_kobject_put(mod);
1948 static void mod_sysfs_fini(struct module *mod)
1950 remove_notes_attrs(mod);
1951 remove_sect_attrs(mod);
1952 mod_kobject_put(mod);
1955 static void init_param_lock(struct module *mod)
1957 mutex_init(&mod->param_lock);
1959 #else /* !CONFIG_SYSFS */
1961 static int mod_sysfs_setup(struct module *mod,
1962 const struct load_info *info,
1963 struct kernel_param *kparam,
1964 unsigned int num_params)
1969 static void mod_sysfs_fini(struct module *mod)
1973 static void module_remove_modinfo_attrs(struct module *mod, int end)
1977 static void del_usage_links(struct module *mod)
1981 static void init_param_lock(struct module *mod)
1984 #endif /* CONFIG_SYSFS */
1986 static void mod_sysfs_teardown(struct module *mod)
1988 del_usage_links(mod);
1989 module_remove_modinfo_attrs(mod, -1);
1990 module_param_sysfs_remove(mod);
1991 kobject_put(mod->mkobj.drivers_dir);
1992 kobject_put(mod->holders_dir);
1993 mod_sysfs_fini(mod);
1997 * LKM RO/NX protection: protect module's text/ro-data
1998 * from modification and any data from execution.
2000 * General layout of module is:
2001 * [text] [read-only-data] [ro-after-init] [writable data]
2002 * text_size -----^ ^ ^ ^
2003 * ro_size ------------------------| | |
2004 * ro_after_init_size -----------------------------| |
2005 * size -----------------------------------------------------------|
2007 * These values are always page-aligned (as is base)
2011 * Since some arches are moving towards PAGE_KERNEL module allocations instead
2012 * of PAGE_KERNEL_EXEC, keep frob_text() and module_enable_x() outside of the
2013 * CONFIG_STRICT_MODULE_RWX block below because they are needed regardless of
2014 * whether we are strict.
2016 #ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
2017 static void frob_text(const struct module_layout *layout,
2018 int (*set_memory)(unsigned long start, int num_pages))
2020 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
2021 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
2022 set_memory((unsigned long)layout->base,
2023 layout->text_size >> PAGE_SHIFT);
2026 static void module_enable_x(const struct module *mod)
2028 frob_text(&mod->core_layout, set_memory_x);
2029 frob_text(&mod->init_layout, set_memory_x);
2031 #else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
2032 static void module_enable_x(const struct module *mod) { }
2033 #endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
2035 #ifdef CONFIG_STRICT_MODULE_RWX
2036 static void frob_rodata(const struct module_layout *layout,
2037 int (*set_memory)(unsigned long start, int num_pages))
2039 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
2040 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
2041 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
2042 set_memory((unsigned long)layout->base + layout->text_size,
2043 (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
2046 static void frob_ro_after_init(const struct module_layout *layout,
2047 int (*set_memory)(unsigned long start, int num_pages))
2049 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
2050 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
2051 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
2052 set_memory((unsigned long)layout->base + layout->ro_size,
2053 (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
2056 static void frob_writable_data(const struct module_layout *layout,
2057 int (*set_memory)(unsigned long start, int num_pages))
2059 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
2060 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
2061 BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
2062 set_memory((unsigned long)layout->base + layout->ro_after_init_size,
2063 (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
2066 static void module_enable_ro(const struct module *mod, bool after_init)
2068 if (!rodata_enabled)
2071 set_vm_flush_reset_perms(mod->core_layout.base);
2072 set_vm_flush_reset_perms(mod->init_layout.base);
2073 frob_text(&mod->core_layout, set_memory_ro);
2075 frob_rodata(&mod->core_layout, set_memory_ro);
2076 frob_text(&mod->init_layout, set_memory_ro);
2077 frob_rodata(&mod->init_layout, set_memory_ro);
2080 frob_ro_after_init(&mod->core_layout, set_memory_ro);
2083 static void module_enable_nx(const struct module *mod)
2085 frob_rodata(&mod->core_layout, set_memory_nx);
2086 frob_ro_after_init(&mod->core_layout, set_memory_nx);
2087 frob_writable_data(&mod->core_layout, set_memory_nx);
2088 frob_rodata(&mod->init_layout, set_memory_nx);
2089 frob_writable_data(&mod->init_layout, set_memory_nx);
2092 static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
2093 char *secstrings, struct module *mod)
2095 const unsigned long shf_wx = SHF_WRITE|SHF_EXECINSTR;
2098 for (i = 0; i < hdr->e_shnum; i++) {
2099 if ((sechdrs[i].sh_flags & shf_wx) == shf_wx) {
2100 pr_err("%s: section %s (index %d) has invalid WRITE|EXEC flags\n",
2101 mod->name, secstrings + sechdrs[i].sh_name, i);
2109 #else /* !CONFIG_STRICT_MODULE_RWX */
2110 static void module_enable_nx(const struct module *mod) { }
2111 static void module_enable_ro(const struct module *mod, bool after_init) {}
2112 static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
2113 char *secstrings, struct module *mod)
2117 #endif /* CONFIG_STRICT_MODULE_RWX */
2119 #ifdef CONFIG_LIVEPATCH
2121 * Persist Elf information about a module. Copy the Elf header,
2122 * section header table, section string table, and symtab section
2123 * index from info to mod->klp_info.
2125 static int copy_module_elf(struct module *mod, struct load_info *info)
2127 unsigned int size, symndx;
2130 size = sizeof(*mod->klp_info);
2131 mod->klp_info = kmalloc(size, GFP_KERNEL);
2132 if (mod->klp_info == NULL)
2136 size = sizeof(mod->klp_info->hdr);
2137 memcpy(&mod->klp_info->hdr, info->hdr, size);
2139 /* Elf section header table */
2140 size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
2141 mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL);
2142 if (mod->klp_info->sechdrs == NULL) {
2147 /* Elf section name string table */
2148 size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
2149 mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL);
2150 if (mod->klp_info->secstrings == NULL) {
2155 /* Elf symbol section index */
2156 symndx = info->index.sym;
2157 mod->klp_info->symndx = symndx;
2160 * For livepatch modules, core_kallsyms.symtab is a complete
2161 * copy of the original symbol table. Adjust sh_addr to point
2162 * to core_kallsyms.symtab since the copy of the symtab in module
2163 * init memory is freed at the end of do_init_module().
2165 mod->klp_info->sechdrs[symndx].sh_addr = \
2166 (unsigned long) mod->core_kallsyms.symtab;
2171 kfree(mod->klp_info->sechdrs);
2173 kfree(mod->klp_info);
2177 static void free_module_elf(struct module *mod)
2179 kfree(mod->klp_info->sechdrs);
2180 kfree(mod->klp_info->secstrings);
2181 kfree(mod->klp_info);
2183 #else /* !CONFIG_LIVEPATCH */
2184 static int copy_module_elf(struct module *mod, struct load_info *info)
2189 static void free_module_elf(struct module *mod)
2192 #endif /* CONFIG_LIVEPATCH */
2194 void __weak module_memfree(void *module_region)
2197 * This memory may be RO, and freeing RO memory in an interrupt is not
2198 * supported by vmalloc.
2200 WARN_ON(in_interrupt());
2201 vfree(module_region);
2204 void __weak module_arch_cleanup(struct module *mod)
2208 void __weak module_arch_freeing_init(struct module *mod)
2212 /* Free a module, remove from lists, etc. */
2213 static void free_module(struct module *mod)
2215 trace_module_free(mod);
2217 mod_sysfs_teardown(mod);
2219 /* We leave it in list to prevent duplicate loads, but make sure
2220 * that noone uses it while it's being deconstructed. */
2221 mutex_lock(&module_mutex);
2222 mod->state = MODULE_STATE_UNFORMED;
2223 mutex_unlock(&module_mutex);
2225 /* Remove dynamic debug info */
2226 ddebug_remove_module(mod->name);
2228 /* Arch-specific cleanup. */
2229 module_arch_cleanup(mod);
2231 /* Module unload stuff */
2232 module_unload_free(mod);
2234 /* Free any allocated parameters. */
2235 destroy_params(mod->kp, mod->num_kp);
2237 if (is_livepatch_module(mod))
2238 free_module_elf(mod);
2240 /* Now we can delete it from the lists */
2241 mutex_lock(&module_mutex);
2242 /* Unlink carefully: kallsyms could be walking list. */
2243 list_del_rcu(&mod->list);
2244 mod_tree_remove(mod);
2245 /* Remove this module from bug list, this uses list_del_rcu */
2246 module_bug_cleanup(mod);
2247 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2249 mutex_unlock(&module_mutex);
2251 /* This may be empty, but that's OK */
2252 module_arch_freeing_init(mod);
2253 module_memfree(mod->init_layout.base);
2255 percpu_modfree(mod);
2257 /* Free lock-classes; relies on the preceding sync_rcu(). */
2258 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
2260 /* Finally, free the core (containing the module structure) */
2261 module_memfree(mod->core_layout.base);
2264 void *__symbol_get(const char *symbol)
2266 struct module *owner;
2267 const struct kernel_symbol *sym;
2270 sym = find_symbol(symbol, &owner, NULL, NULL, true, true);
2271 if (sym && strong_try_module_get(owner))
2275 return sym ? (void *)kernel_symbol_value(sym) : NULL;
2277 EXPORT_SYMBOL_GPL(__symbol_get);
2280 * Ensure that an exported symbol [global namespace] does not already exist
2281 * in the kernel or in some other module's exported symbol table.
2283 * You must hold the module_mutex.
2285 static int verify_exported_symbols(struct module *mod)
2288 struct module *owner;
2289 const struct kernel_symbol *s;
2291 const struct kernel_symbol *sym;
2294 { mod->syms, mod->num_syms },
2295 { mod->gpl_syms, mod->num_gpl_syms },
2296 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2297 #ifdef CONFIG_UNUSED_SYMBOLS
2298 { mod->unused_syms, mod->num_unused_syms },
2299 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2303 for (i = 0; i < ARRAY_SIZE(arr); i++) {
2304 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2305 if (find_symbol(kernel_symbol_name(s), &owner, NULL,
2306 NULL, true, false)) {
2307 pr_err("%s: exports duplicate symbol %s"
2309 mod->name, kernel_symbol_name(s),
2310 module_name(owner));
2318 /* Change all symbols so that st_value encodes the pointer directly. */
2319 static int simplify_symbols(struct module *mod, const struct load_info *info)
2321 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2322 Elf_Sym *sym = (void *)symsec->sh_addr;
2323 unsigned long secbase;
2326 const struct kernel_symbol *ksym;
2328 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2329 const char *name = info->strtab + sym[i].st_name;
2331 switch (sym[i].st_shndx) {
2333 /* Ignore common symbols */
2334 if (!strncmp(name, "__gnu_lto", 9))
2337 /* We compiled with -fno-common. These are not
2338 supposed to happen. */
2339 pr_debug("Common symbol: %s\n", name);
2340 pr_warn("%s: please compile with -fno-common\n",
2346 /* Don't need to do anything */
2347 pr_debug("Absolute symbol: 0x%08lx\n",
2348 (long)sym[i].st_value);
2352 /* Livepatch symbols are resolved by livepatch */
2356 ksym = resolve_symbol_wait(mod, info, name);
2357 /* Ok if resolved. */
2358 if (ksym && !IS_ERR(ksym)) {
2359 sym[i].st_value = kernel_symbol_value(ksym);
2364 if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
2367 ret = PTR_ERR(ksym) ?: -ENOENT;
2368 pr_warn("%s: Unknown symbol %s (err %d)\n",
2369 mod->name, name, ret);
2373 /* Divert to percpu allocation if a percpu var. */
2374 if (sym[i].st_shndx == info->index.pcpu)
2375 secbase = (unsigned long)mod_percpu(mod);
2377 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2378 sym[i].st_value += secbase;
2386 static int apply_relocations(struct module *mod, const struct load_info *info)
2391 /* Now do relocations. */
2392 for (i = 1; i < info->hdr->e_shnum; i++) {
2393 unsigned int infosec = info->sechdrs[i].sh_info;
2395 /* Not a valid relocation section? */
2396 if (infosec >= info->hdr->e_shnum)
2399 /* Don't bother with non-allocated sections */
2400 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2403 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
2404 err = klp_apply_section_relocs(mod, info->sechdrs,
2409 else if (info->sechdrs[i].sh_type == SHT_REL)
2410 err = apply_relocate(info->sechdrs, info->strtab,
2411 info->index.sym, i, mod);
2412 else if (info->sechdrs[i].sh_type == SHT_RELA)
2413 err = apply_relocate_add(info->sechdrs, info->strtab,
2414 info->index.sym, i, mod);
2421 /* Additional bytes needed by arch in front of individual sections */
2422 unsigned int __weak arch_mod_section_prepend(struct module *mod,
2423 unsigned int section)
2425 /* default implementation just returns zero */
2429 /* Update size with this section: return offset. */
2430 static long get_offset(struct module *mod, unsigned int *size,
2431 Elf_Shdr *sechdr, unsigned int section)
2435 *size += arch_mod_section_prepend(mod, section);
2436 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2437 *size = ret + sechdr->sh_size;
2441 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2442 might -- code, read-only data, read-write data, small data. Tally
2443 sizes, and place the offsets into sh_entsize fields: high bit means it
2445 static void layout_sections(struct module *mod, struct load_info *info)
2447 static unsigned long const masks[][2] = {
2448 /* NOTE: all executable code must be the first section
2449 * in this array; otherwise modify the text_size
2450 * finder in the two loops below */
2451 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2452 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2453 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
2454 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2455 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2459 for (i = 0; i < info->hdr->e_shnum; i++)
2460 info->sechdrs[i].sh_entsize = ~0UL;
2462 pr_debug("Core section allocation order:\n");
2463 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2464 for (i = 0; i < info->hdr->e_shnum; ++i) {
2465 Elf_Shdr *s = &info->sechdrs[i];
2466 const char *sname = info->secstrings + s->sh_name;
2468 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2469 || (s->sh_flags & masks[m][1])
2470 || s->sh_entsize != ~0UL
2471 || module_init_section(sname))
2473 s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2474 pr_debug("\t%s\n", sname);
2477 case 0: /* executable */
2478 mod->core_layout.size = debug_align(mod->core_layout.size);
2479 mod->core_layout.text_size = mod->core_layout.size;
2481 case 1: /* RO: text and ro-data */
2482 mod->core_layout.size = debug_align(mod->core_layout.size);
2483 mod->core_layout.ro_size = mod->core_layout.size;
2485 case 2: /* RO after init */
2486 mod->core_layout.size = debug_align(mod->core_layout.size);
2487 mod->core_layout.ro_after_init_size = mod->core_layout.size;
2489 case 4: /* whole core */
2490 mod->core_layout.size = debug_align(mod->core_layout.size);
2495 pr_debug("Init section allocation order:\n");
2496 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2497 for (i = 0; i < info->hdr->e_shnum; ++i) {
2498 Elf_Shdr *s = &info->sechdrs[i];
2499 const char *sname = info->secstrings + s->sh_name;
2501 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2502 || (s->sh_flags & masks[m][1])
2503 || s->sh_entsize != ~0UL
2504 || !module_init_section(sname))
2506 s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
2507 | INIT_OFFSET_MASK);
2508 pr_debug("\t%s\n", sname);
2511 case 0: /* executable */
2512 mod->init_layout.size = debug_align(mod->init_layout.size);
2513 mod->init_layout.text_size = mod->init_layout.size;
2515 case 1: /* RO: text and ro-data */
2516 mod->init_layout.size = debug_align(mod->init_layout.size);
2517 mod->init_layout.ro_size = mod->init_layout.size;
2521 * RO after init doesn't apply to init_layout (only
2522 * core_layout), so it just takes the value of ro_size.
2524 mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
2526 case 4: /* whole init */
2527 mod->init_layout.size = debug_align(mod->init_layout.size);
2533 static void set_license(struct module *mod, const char *license)
2536 license = "unspecified";
2538 if (!license_is_gpl_compatible(license)) {
2539 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2540 pr_warn("%s: module license '%s' taints kernel.\n",
2541 mod->name, license);
2542 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2543 LOCKDEP_NOW_UNRELIABLE);
2547 /* Parse tag=value strings from .modinfo section */
2548 static char *next_string(char *string, unsigned long *secsize)
2550 /* Skip non-zero chars */
2553 if ((*secsize)-- <= 1)
2557 /* Skip any zero padding. */
2558 while (!string[0]) {
2560 if ((*secsize)-- <= 1)
2566 static char *get_next_modinfo(const struct load_info *info, const char *tag,
2570 unsigned int taglen = strlen(tag);
2571 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2572 unsigned long size = infosec->sh_size;
2575 * get_modinfo() calls made before rewrite_section_headers()
2576 * must use sh_offset, as sh_addr isn't set!
2578 char *modinfo = (char *)info->hdr + infosec->sh_offset;
2581 size -= prev - modinfo;
2582 modinfo = next_string(prev, &size);
2585 for (p = modinfo; p; p = next_string(p, &size)) {
2586 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2587 return p + taglen + 1;
2592 static char *get_modinfo(const struct load_info *info, const char *tag)
2594 return get_next_modinfo(info, tag, NULL);
2597 static void setup_modinfo(struct module *mod, struct load_info *info)
2599 struct module_attribute *attr;
2602 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2604 attr->setup(mod, get_modinfo(info, attr->attr.name));
2608 static void free_modinfo(struct module *mod)
2610 struct module_attribute *attr;
2613 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2619 #ifdef CONFIG_KALLSYMS
2621 /* Lookup exported symbol in given range of kernel_symbols */
2622 static const struct kernel_symbol *lookup_exported_symbol(const char *name,
2623 const struct kernel_symbol *start,
2624 const struct kernel_symbol *stop)
2626 return bsearch(name, start, stop - start,
2627 sizeof(struct kernel_symbol), cmp_name);
2630 static int is_exported(const char *name, unsigned long value,
2631 const struct module *mod)
2633 const struct kernel_symbol *ks;
2635 ks = lookup_exported_symbol(name, __start___ksymtab, __stop___ksymtab);
2637 ks = lookup_exported_symbol(name, mod->syms, mod->syms + mod->num_syms);
2639 return ks != NULL && kernel_symbol_value(ks) == value;
2643 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2645 const Elf_Shdr *sechdrs = info->sechdrs;
2647 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2648 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2653 if (sym->st_shndx == SHN_UNDEF)
2655 if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
2657 if (sym->st_shndx >= SHN_LORESERVE)
2659 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2661 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2662 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2663 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2665 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2670 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2671 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2676 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2683 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2684 unsigned int shnum, unsigned int pcpundx)
2686 const Elf_Shdr *sec;
2688 if (src->st_shndx == SHN_UNDEF
2689 || src->st_shndx >= shnum
2693 #ifdef CONFIG_KALLSYMS_ALL
2694 if (src->st_shndx == pcpundx)
2698 sec = sechdrs + src->st_shndx;
2699 if (!(sec->sh_flags & SHF_ALLOC)
2700 #ifndef CONFIG_KALLSYMS_ALL
2701 || !(sec->sh_flags & SHF_EXECINSTR)
2703 || (sec->sh_entsize & INIT_OFFSET_MASK))
2710 * We only allocate and copy the strings needed by the parts of symtab
2711 * we keep. This is simple, but has the effect of making multiple
2712 * copies of duplicates. We could be more sophisticated, see
2713 * linux-kernel thread starting with
2714 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2716 static void layout_symtab(struct module *mod, struct load_info *info)
2718 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2719 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2721 unsigned int i, nsrc, ndst, strtab_size = 0;
2723 /* Put symbol section at end of init part of module. */
2724 symsect->sh_flags |= SHF_ALLOC;
2725 symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2726 info->index.sym) | INIT_OFFSET_MASK;
2727 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2729 src = (void *)info->hdr + symsect->sh_offset;
2730 nsrc = symsect->sh_size / sizeof(*src);
2732 /* Compute total space required for the core symbols' strtab. */
2733 for (ndst = i = 0; i < nsrc; i++) {
2734 if (i == 0 || is_livepatch_module(mod) ||
2735 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2736 info->index.pcpu)) {
2737 strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2742 /* Append room for core symbols at end of core part. */
2743 info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
2744 info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
2745 mod->core_layout.size += strtab_size;
2746 info->core_typeoffs = mod->core_layout.size;
2747 mod->core_layout.size += ndst * sizeof(char);
2748 mod->core_layout.size = debug_align(mod->core_layout.size);
2750 /* Put string table section at end of init part of module. */
2751 strsect->sh_flags |= SHF_ALLOC;
2752 strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2753 info->index.str) | INIT_OFFSET_MASK;
2754 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2756 /* We'll tack temporary mod_kallsyms on the end. */
2757 mod->init_layout.size = ALIGN(mod->init_layout.size,
2758 __alignof__(struct mod_kallsyms));
2759 info->mod_kallsyms_init_off = mod->init_layout.size;
2760 mod->init_layout.size += sizeof(struct mod_kallsyms);
2761 info->init_typeoffs = mod->init_layout.size;
2762 mod->init_layout.size += nsrc * sizeof(char);
2763 mod->init_layout.size = debug_align(mod->init_layout.size);
2767 * We use the full symtab and strtab which layout_symtab arranged to
2768 * be appended to the init section. Later we switch to the cut-down
2771 static void add_kallsyms(struct module *mod, const struct load_info *info)
2773 unsigned int i, ndst;
2777 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2779 /* Set up to point into init section. */
2780 mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
2782 mod->kallsyms->symtab = (void *)symsec->sh_addr;
2783 mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2784 /* Make sure we get permanent strtab: don't use info->strtab. */
2785 mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2786 mod->kallsyms->typetab = mod->init_layout.base + info->init_typeoffs;
2789 * Now populate the cut down core kallsyms for after init
2790 * and set types up while we still have access to sections.
2792 mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
2793 mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
2794 mod->core_kallsyms.typetab = mod->core_layout.base + info->core_typeoffs;
2795 src = mod->kallsyms->symtab;
2796 for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2797 mod->kallsyms->typetab[i] = elf_type(src + i, info);
2798 if (i == 0 || is_livepatch_module(mod) ||
2799 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2800 info->index.pcpu)) {
2801 mod->core_kallsyms.typetab[ndst] =
2802 mod->kallsyms->typetab[i];
2804 dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
2805 s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2809 mod->core_kallsyms.num_symtab = ndst;
2812 static inline void layout_symtab(struct module *mod, struct load_info *info)
2816 static void add_kallsyms(struct module *mod, const struct load_info *info)
2819 #endif /* CONFIG_KALLSYMS */
2821 static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num)
2825 ddebug_add_module(debug, num, mod->name);
2828 static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug)
2831 ddebug_remove_module(mod->name);
2834 void * __weak module_alloc(unsigned long size)
2836 return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
2837 GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS,
2838 NUMA_NO_NODE, __builtin_return_address(0));
2841 bool __weak module_init_section(const char *name)
2843 return strstarts(name, ".init");
2846 bool __weak module_exit_section(const char *name)
2848 return strstarts(name, ".exit");
2851 #ifdef CONFIG_DEBUG_KMEMLEAK
2852 static void kmemleak_load_module(const struct module *mod,
2853 const struct load_info *info)
2857 /* only scan the sections containing data */
2858 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2860 for (i = 1; i < info->hdr->e_shnum; i++) {
2861 /* Scan all writable sections that's not executable */
2862 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2863 !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2864 (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2867 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2868 info->sechdrs[i].sh_size, GFP_KERNEL);
2872 static inline void kmemleak_load_module(const struct module *mod,
2873 const struct load_info *info)
2878 #ifdef CONFIG_MODULE_SIG
2879 static int module_sig_check(struct load_info *info, int flags)
2882 const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2884 const void *mod = info->hdr;
2887 * Require flags == 0, as a module with version information
2888 * removed is no longer the module that was signed
2891 info->len > markerlen &&
2892 memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2893 /* We truncate the module to discard the signature */
2894 info->len -= markerlen;
2895 err = mod_verify_sig(mod, info);
2897 info->sig_ok = true;
2903 * We don't permit modules to be loaded into the trusted kernels
2904 * without a valid signature on them, but if we're not enforcing,
2905 * certain errors are non-fatal.
2909 reason = "unsigned module";
2912 reason = "module with unsupported crypto";
2915 reason = "module with unavailable key";
2920 * All other errors are fatal, including lack of memory,
2921 * unparseable signatures, and signature check failures --
2922 * even if signatures aren't required.
2927 if (is_module_sig_enforced()) {
2928 pr_notice("%s: loading of %s is rejected\n", info->name, reason);
2929 return -EKEYREJECTED;
2932 return security_locked_down(LOCKDOWN_MODULE_SIGNATURE);
2934 #else /* !CONFIG_MODULE_SIG */
2935 static int module_sig_check(struct load_info *info, int flags)
2939 #endif /* !CONFIG_MODULE_SIG */
2941 /* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2942 static int elf_header_check(struct load_info *info)
2944 if (info->len < sizeof(*(info->hdr)))
2947 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2948 || info->hdr->e_type != ET_REL
2949 || !elf_check_arch(info->hdr)
2950 || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2953 if (info->hdr->e_shoff >= info->len
2954 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2955 info->len - info->hdr->e_shoff))
2961 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2963 static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
2966 unsigned long n = min(len, COPY_CHUNK_SIZE);
2968 if (copy_from_user(dst, usrc, n) != 0)
2978 #ifdef CONFIG_LIVEPATCH
2979 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2981 if (get_modinfo(info, "livepatch")) {
2983 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
2984 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
2990 #else /* !CONFIG_LIVEPATCH */
2991 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2993 if (get_modinfo(info, "livepatch")) {
2994 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
3001 #endif /* CONFIG_LIVEPATCH */
3003 static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
3005 if (retpoline_module_ok(get_modinfo(info, "retpoline")))
3008 pr_warn("%s: loading module not compiled with retpoline compiler.\n",
3012 /* Sets info->hdr and info->len. */
3013 static int copy_module_from_user(const void __user *umod, unsigned long len,
3014 struct load_info *info)
3019 if (info->len < sizeof(*(info->hdr)))
3022 err = security_kernel_load_data(LOADING_MODULE, true);
3026 /* Suck in entire file: we'll want most of it. */
3027 info->hdr = __vmalloc(info->len, GFP_KERNEL | __GFP_NOWARN);
3031 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
3036 err = security_kernel_post_load_data((char *)info->hdr, info->len,
3037 LOADING_MODULE, "init_module");
3045 static void free_copy(struct load_info *info)
3050 static int rewrite_section_headers(struct load_info *info, int flags)
3054 /* This should always be true, but let's be sure. */
3055 info->sechdrs[0].sh_addr = 0;
3057 for (i = 1; i < info->hdr->e_shnum; i++) {
3058 Elf_Shdr *shdr = &info->sechdrs[i];
3059 if (shdr->sh_type != SHT_NOBITS
3060 && info->len < shdr->sh_offset + shdr->sh_size) {
3061 pr_err("Module len %lu truncated\n", info->len);
3065 /* Mark all sections sh_addr with their address in the
3067 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
3069 #ifndef CONFIG_MODULE_UNLOAD
3070 /* Don't load .exit sections */
3071 if (module_exit_section(info->secstrings+shdr->sh_name))
3072 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
3076 /* Track but don't keep modinfo and version sections. */
3077 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
3078 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
3084 * Set up our basic convenience variables (pointers to section headers,
3085 * search for module section index etc), and do some basic section
3088 * Set info->mod to the temporary copy of the module in info->hdr. The final one
3089 * will be allocated in move_module().
3091 static int setup_load_info(struct load_info *info, int flags)
3095 /* Set up the convenience variables */
3096 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
3097 info->secstrings = (void *)info->hdr
3098 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
3100 /* Try to find a name early so we can log errors with a module name */
3101 info->index.info = find_sec(info, ".modinfo");
3102 if (info->index.info)
3103 info->name = get_modinfo(info, "name");
3105 /* Find internal symbols and strings. */
3106 for (i = 1; i < info->hdr->e_shnum; i++) {
3107 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
3108 info->index.sym = i;
3109 info->index.str = info->sechdrs[i].sh_link;
3110 info->strtab = (char *)info->hdr
3111 + info->sechdrs[info->index.str].sh_offset;
3116 if (info->index.sym == 0) {
3117 pr_warn("%s: module has no symbols (stripped?)\n",
3118 info->name ?: "(missing .modinfo section or name field)");
3122 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
3123 if (!info->index.mod) {
3124 pr_warn("%s: No module found in object\n",
3125 info->name ?: "(missing .modinfo section or name field)");
3128 /* This is temporary: point mod into copy of data. */
3129 info->mod = (void *)info->hdr + info->sechdrs[info->index.mod].sh_offset;
3132 * If we didn't load the .modinfo 'name' field earlier, fall back to
3133 * on-disk struct mod 'name' field.
3136 info->name = info->mod->name;
3138 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
3139 info->index.vers = 0; /* Pretend no __versions section! */
3141 info->index.vers = find_sec(info, "__versions");
3143 info->index.pcpu = find_pcpusec(info);
3148 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
3150 const char *modmagic = get_modinfo(info, "vermagic");
3153 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
3156 /* This is allowed: modprobe --force will invalidate it. */
3158 err = try_to_force_load(mod, "bad vermagic");
3161 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
3162 pr_err("%s: version magic '%s' should be '%s'\n",
3163 info->name, modmagic, vermagic);
3167 if (!get_modinfo(info, "intree")) {
3168 if (!test_taint(TAINT_OOT_MODULE))
3169 pr_warn("%s: loading out-of-tree module taints kernel.\n",
3171 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
3174 check_modinfo_retpoline(mod, info);
3176 if (get_modinfo(info, "staging")) {
3177 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
3178 pr_warn("%s: module is from the staging directory, the quality "
3179 "is unknown, you have been warned.\n", mod->name);
3182 err = check_modinfo_livepatch(mod, info);
3186 /* Set up license info based on the info section */
3187 set_license(mod, get_modinfo(info, "license"));
3192 static int find_module_sections(struct module *mod, struct load_info *info)
3194 mod->kp = section_objs(info, "__param",
3195 sizeof(*mod->kp), &mod->num_kp);
3196 mod->syms = section_objs(info, "__ksymtab",
3197 sizeof(*mod->syms), &mod->num_syms);
3198 mod->crcs = section_addr(info, "__kcrctab");
3199 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
3200 sizeof(*mod->gpl_syms),
3201 &mod->num_gpl_syms);
3202 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
3203 mod->gpl_future_syms = section_objs(info,
3204 "__ksymtab_gpl_future",
3205 sizeof(*mod->gpl_future_syms),
3206 &mod->num_gpl_future_syms);
3207 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
3209 #ifdef CONFIG_UNUSED_SYMBOLS
3210 mod->unused_syms = section_objs(info, "__ksymtab_unused",
3211 sizeof(*mod->unused_syms),
3212 &mod->num_unused_syms);
3213 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
3214 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
3215 sizeof(*mod->unused_gpl_syms),
3216 &mod->num_unused_gpl_syms);
3217 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
3219 #ifdef CONFIG_CONSTRUCTORS
3220 mod->ctors = section_objs(info, ".ctors",
3221 sizeof(*mod->ctors), &mod->num_ctors);
3223 mod->ctors = section_objs(info, ".init_array",
3224 sizeof(*mod->ctors), &mod->num_ctors);
3225 else if (find_sec(info, ".init_array")) {
3227 * This shouldn't happen with same compiler and binutils
3228 * building all parts of the module.
3230 pr_warn("%s: has both .ctors and .init_array.\n",
3236 mod->noinstr_text_start = section_objs(info, ".noinstr.text", 1,
3237 &mod->noinstr_text_size);
3239 #ifdef CONFIG_TRACEPOINTS
3240 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
3241 sizeof(*mod->tracepoints_ptrs),
3242 &mod->num_tracepoints);
3244 #ifdef CONFIG_TREE_SRCU
3245 mod->srcu_struct_ptrs = section_objs(info, "___srcu_struct_ptrs",
3246 sizeof(*mod->srcu_struct_ptrs),
3247 &mod->num_srcu_structs);
3249 #ifdef CONFIG_BPF_EVENTS
3250 mod->bpf_raw_events = section_objs(info, "__bpf_raw_tp_map",
3251 sizeof(*mod->bpf_raw_events),
3252 &mod->num_bpf_raw_events);
3254 #ifdef CONFIG_JUMP_LABEL
3255 mod->jump_entries = section_objs(info, "__jump_table",
3256 sizeof(*mod->jump_entries),
3257 &mod->num_jump_entries);
3259 #ifdef CONFIG_EVENT_TRACING
3260 mod->trace_events = section_objs(info, "_ftrace_events",
3261 sizeof(*mod->trace_events),
3262 &mod->num_trace_events);
3263 mod->trace_evals = section_objs(info, "_ftrace_eval_map",
3264 sizeof(*mod->trace_evals),
3265 &mod->num_trace_evals);
3267 #ifdef CONFIG_TRACING
3268 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
3269 sizeof(*mod->trace_bprintk_fmt_start),
3270 &mod->num_trace_bprintk_fmt);
3272 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
3273 /* sechdrs[0].sh_size is always zero */
3274 mod->ftrace_callsites = section_objs(info, FTRACE_CALLSITE_SECTION,
3275 sizeof(*mod->ftrace_callsites),
3276 &mod->num_ftrace_callsites);
3278 #ifdef CONFIG_FUNCTION_ERROR_INJECTION
3279 mod->ei_funcs = section_objs(info, "_error_injection_whitelist",
3280 sizeof(*mod->ei_funcs),
3281 &mod->num_ei_funcs);
3283 #ifdef CONFIG_KPROBES
3284 mod->kprobes_text_start = section_objs(info, ".kprobes.text", 1,
3285 &mod->kprobes_text_size);
3286 mod->kprobe_blacklist = section_objs(info, "_kprobe_blacklist",
3287 sizeof(unsigned long),
3288 &mod->num_kprobe_blacklist);
3290 #ifdef CONFIG_HAVE_STATIC_CALL_INLINE
3291 mod->static_call_sites = section_objs(info, ".static_call_sites",
3292 sizeof(*mod->static_call_sites),
3293 &mod->num_static_call_sites);
3295 mod->extable = section_objs(info, "__ex_table",
3296 sizeof(*mod->extable), &mod->num_exentries);
3298 if (section_addr(info, "__obsparm"))
3299 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
3301 info->debug = section_objs(info, "__dyndbg",
3302 sizeof(*info->debug), &info->num_debug);
3307 static int move_module(struct module *mod, struct load_info *info)
3312 /* Do the allocs. */
3313 ptr = module_alloc(mod->core_layout.size);
3315 * The pointer to this block is stored in the module structure
3316 * which is inside the block. Just mark it as not being a
3319 kmemleak_not_leak(ptr);
3323 memset(ptr, 0, mod->core_layout.size);
3324 mod->core_layout.base = ptr;
3326 if (mod->init_layout.size) {
3327 ptr = module_alloc(mod->init_layout.size);
3329 * The pointer to this block is stored in the module structure
3330 * which is inside the block. This block doesn't need to be
3331 * scanned as it contains data and code that will be freed
3332 * after the module is initialized.
3334 kmemleak_ignore(ptr);
3336 module_memfree(mod->core_layout.base);
3339 memset(ptr, 0, mod->init_layout.size);
3340 mod->init_layout.base = ptr;
3342 mod->init_layout.base = NULL;
3344 /* Transfer each section which specifies SHF_ALLOC */
3345 pr_debug("final section addresses:\n");
3346 for (i = 0; i < info->hdr->e_shnum; i++) {
3348 Elf_Shdr *shdr = &info->sechdrs[i];
3350 if (!(shdr->sh_flags & SHF_ALLOC))
3353 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3354 dest = mod->init_layout.base
3355 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3357 dest = mod->core_layout.base + shdr->sh_entsize;
3359 if (shdr->sh_type != SHT_NOBITS)
3360 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3361 /* Update sh_addr to point to copy in image. */
3362 shdr->sh_addr = (unsigned long)dest;
3363 pr_debug("\t0x%lx %s\n",
3364 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3370 static int check_module_license_and_versions(struct module *mod)
3372 int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
3375 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3376 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3377 * using GPL-only symbols it needs.
3379 if (strcmp(mod->name, "ndiswrapper") == 0)
3380 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3382 /* driverloader was caught wrongly pretending to be under GPL */
3383 if (strcmp(mod->name, "driverloader") == 0)
3384 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3385 LOCKDEP_NOW_UNRELIABLE);
3387 /* lve claims to be GPL but upstream won't provide source */
3388 if (strcmp(mod->name, "lve") == 0)
3389 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3390 LOCKDEP_NOW_UNRELIABLE);
3392 if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
3393 pr_warn("%s: module license taints kernel.\n", mod->name);
3395 #ifdef CONFIG_MODVERSIONS
3396 if ((mod->num_syms && !mod->crcs)
3397 || (mod->num_gpl_syms && !mod->gpl_crcs)
3398 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3399 #ifdef CONFIG_UNUSED_SYMBOLS
3400 || (mod->num_unused_syms && !mod->unused_crcs)
3401 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3404 return try_to_force_load(mod,
3405 "no versions for exported symbols");
3411 static void flush_module_icache(const struct module *mod)
3414 * Flush the instruction cache, since we've played with text.
3415 * Do it before processing of module parameters, so the module
3416 * can provide parameter accessor functions of its own.
3418 if (mod->init_layout.base)
3419 flush_icache_range((unsigned long)mod->init_layout.base,
3420 (unsigned long)mod->init_layout.base
3421 + mod->init_layout.size);
3422 flush_icache_range((unsigned long)mod->core_layout.base,
3423 (unsigned long)mod->core_layout.base + mod->core_layout.size);
3426 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3434 /* module_blacklist is a comma-separated list of module names */
3435 static char *module_blacklist;
3436 static bool blacklisted(const char *module_name)
3441 if (!module_blacklist)
3444 for (p = module_blacklist; *p; p += len) {
3445 len = strcspn(p, ",");
3446 if (strlen(module_name) == len && !memcmp(module_name, p, len))
3453 core_param(module_blacklist, module_blacklist, charp, 0400);
3455 static struct module *layout_and_allocate(struct load_info *info, int flags)
3461 err = check_modinfo(info->mod, info, flags);
3463 return ERR_PTR(err);
3465 /* Allow arches to frob section contents and sizes. */
3466 err = module_frob_arch_sections(info->hdr, info->sechdrs,
3467 info->secstrings, info->mod);
3469 return ERR_PTR(err);
3471 err = module_enforce_rwx_sections(info->hdr, info->sechdrs,
3472 info->secstrings, info->mod);
3474 return ERR_PTR(err);
3476 /* We will do a special allocation for per-cpu sections later. */
3477 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3480 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3481 * layout_sections() can put it in the right place.
3482 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3484 ndx = find_sec(info, ".data..ro_after_init");
3486 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3488 * Mark the __jump_table section as ro_after_init as well: these data
3489 * structures are never modified, with the exception of entries that
3490 * refer to code in the __init section, which are annotated as such
3491 * at module load time.
3493 ndx = find_sec(info, "__jump_table");
3495 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3497 /* Determine total sizes, and put offsets in sh_entsize. For now
3498 this is done generically; there doesn't appear to be any
3499 special cases for the architectures. */
3500 layout_sections(info->mod, info);
3501 layout_symtab(info->mod, info);
3503 /* Allocate and move to the final place */
3504 err = move_module(info->mod, info);
3506 return ERR_PTR(err);
3508 /* Module has been copied to its final place now: return it. */
3509 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3510 kmemleak_load_module(mod, info);
3514 /* mod is no longer valid after this! */
3515 static void module_deallocate(struct module *mod, struct load_info *info)
3517 percpu_modfree(mod);
3518 module_arch_freeing_init(mod);
3519 module_memfree(mod->init_layout.base);
3520 module_memfree(mod->core_layout.base);
3523 int __weak module_finalize(const Elf_Ehdr *hdr,
3524 const Elf_Shdr *sechdrs,
3530 static int post_relocation(struct module *mod, const struct load_info *info)
3532 /* Sort exception table now relocations are done. */
3533 sort_extable(mod->extable, mod->extable + mod->num_exentries);
3535 /* Copy relocated percpu area over. */
3536 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3537 info->sechdrs[info->index.pcpu].sh_size);
3539 /* Setup kallsyms-specific fields. */
3540 add_kallsyms(mod, info);
3542 /* Arch-specific module finalizing. */
3543 return module_finalize(info->hdr, info->sechdrs, mod);
3546 /* Is this module of this name done loading? No locks held. */
3547 static bool finished_loading(const char *name)
3553 * The module_mutex should not be a heavily contended lock;
3554 * if we get the occasional sleep here, we'll go an extra iteration
3555 * in the wait_event_interruptible(), which is harmless.
3557 sched_annotate_sleep();
3558 mutex_lock(&module_mutex);
3559 mod = find_module_all(name, strlen(name), true);
3560 ret = !mod || mod->state == MODULE_STATE_LIVE;
3561 mutex_unlock(&module_mutex);
3566 /* Call module constructors. */
3567 static void do_mod_ctors(struct module *mod)
3569 #ifdef CONFIG_CONSTRUCTORS
3572 for (i = 0; i < mod->num_ctors; i++)
3577 /* For freeing module_init on success, in case kallsyms traversing */
3578 struct mod_initfree {
3579 struct llist_node node;
3583 static void do_free_init(struct work_struct *w)
3585 struct llist_node *pos, *n, *list;
3586 struct mod_initfree *initfree;
3588 list = llist_del_all(&init_free_list);
3592 llist_for_each_safe(pos, n, list) {
3593 initfree = container_of(pos, struct mod_initfree, node);
3594 module_memfree(initfree->module_init);
3600 * This is where the real work happens.
3602 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3603 * helper command 'lx-symbols'.
3605 static noinline int do_init_module(struct module *mod)
3608 struct mod_initfree *freeinit;
3610 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3615 freeinit->module_init = mod->init_layout.base;
3618 * We want to find out whether @mod uses async during init. Clear
3619 * PF_USED_ASYNC. async_schedule*() will set it.
3621 current->flags &= ~PF_USED_ASYNC;
3624 /* Start the module */
3625 if (mod->init != NULL)
3626 ret = do_one_initcall(mod->init);
3628 goto fail_free_freeinit;
3631 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3632 "follow 0/-E convention\n"
3633 "%s: loading module anyway...\n",
3634 __func__, mod->name, ret, __func__);
3638 /* Now it's a first class citizen! */
3639 mod->state = MODULE_STATE_LIVE;
3640 blocking_notifier_call_chain(&module_notify_list,
3641 MODULE_STATE_LIVE, mod);
3644 * We need to finish all async code before the module init sequence
3645 * is done. This has potential to deadlock. For example, a newly
3646 * detected block device can trigger request_module() of the
3647 * default iosched from async probing task. Once userland helper
3648 * reaches here, async_synchronize_full() will wait on the async
3649 * task waiting on request_module() and deadlock.
3651 * This deadlock is avoided by perfomring async_synchronize_full()
3652 * iff module init queued any async jobs. This isn't a full
3653 * solution as it will deadlock the same if module loading from
3654 * async jobs nests more than once; however, due to the various
3655 * constraints, this hack seems to be the best option for now.
3656 * Please refer to the following thread for details.
3658 * http://thread.gmane.org/gmane.linux.kernel/1420814
3660 if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3661 async_synchronize_full();
3663 ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base +
3664 mod->init_layout.size);
3665 mutex_lock(&module_mutex);
3666 /* Drop initial reference. */
3668 trim_init_extable(mod);
3669 #ifdef CONFIG_KALLSYMS
3670 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3671 rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3673 module_enable_ro(mod, true);
3674 mod_tree_remove_init(mod);
3675 module_arch_freeing_init(mod);
3676 mod->init_layout.base = NULL;
3677 mod->init_layout.size = 0;
3678 mod->init_layout.ro_size = 0;
3679 mod->init_layout.ro_after_init_size = 0;
3680 mod->init_layout.text_size = 0;
3682 * We want to free module_init, but be aware that kallsyms may be
3683 * walking this with preempt disabled. In all the failure paths, we
3684 * call synchronize_rcu(), but we don't want to slow down the success
3685 * path. module_memfree() cannot be called in an interrupt, so do the
3686 * work and call synchronize_rcu() in a work queue.
3688 * Note that module_alloc() on most architectures creates W+X page
3689 * mappings which won't be cleaned up until do_free_init() runs. Any
3690 * code such as mark_rodata_ro() which depends on those mappings to
3691 * be cleaned up needs to sync with the queued work - ie
3694 if (llist_add(&freeinit->node, &init_free_list))
3695 schedule_work(&init_free_wq);
3697 mutex_unlock(&module_mutex);
3698 wake_up_all(&module_wq);
3705 /* Try to protect us from buggy refcounters. */
3706 mod->state = MODULE_STATE_GOING;
3709 blocking_notifier_call_chain(&module_notify_list,
3710 MODULE_STATE_GOING, mod);
3711 klp_module_going(mod);
3712 ftrace_release_mod(mod);
3714 wake_up_all(&module_wq);
3718 static int may_init_module(void)
3720 if (!capable(CAP_SYS_MODULE) || modules_disabled)
3727 * We try to place it in the list now to make sure it's unique before
3728 * we dedicate too many resources. In particular, temporary percpu
3729 * memory exhaustion.
3731 static int add_unformed_module(struct module *mod)
3736 mod->state = MODULE_STATE_UNFORMED;
3739 mutex_lock(&module_mutex);
3740 old = find_module_all(mod->name, strlen(mod->name), true);
3742 if (old->state != MODULE_STATE_LIVE) {
3743 /* Wait in case it fails to load. */
3744 mutex_unlock(&module_mutex);
3745 err = wait_event_interruptible(module_wq,
3746 finished_loading(mod->name));
3754 mod_update_bounds(mod);
3755 list_add_rcu(&mod->list, &modules);
3756 mod_tree_insert(mod);
3760 mutex_unlock(&module_mutex);
3765 static int complete_formation(struct module *mod, struct load_info *info)
3769 mutex_lock(&module_mutex);
3771 /* Find duplicate symbols (must be called under lock). */
3772 err = verify_exported_symbols(mod);
3776 /* This relies on module_mutex for list integrity. */
3777 module_bug_finalize(info->hdr, info->sechdrs, mod);
3779 module_enable_ro(mod, false);
3780 module_enable_nx(mod);
3781 module_enable_x(mod);
3783 /* Mark state as coming so strong_try_module_get() ignores us,
3784 * but kallsyms etc. can see us. */
3785 mod->state = MODULE_STATE_COMING;
3786 mutex_unlock(&module_mutex);
3791 mutex_unlock(&module_mutex);
3795 static int prepare_coming_module(struct module *mod)
3799 ftrace_module_enable(mod);
3800 err = klp_module_coming(mod);
3804 err = blocking_notifier_call_chain_robust(&module_notify_list,
3805 MODULE_STATE_COMING, MODULE_STATE_GOING, mod);
3806 err = notifier_to_errno(err);
3808 klp_module_going(mod);
3813 static int unknown_module_param_cb(char *param, char *val, const char *modname,
3816 struct module *mod = arg;
3819 if (strcmp(param, "async_probe") == 0) {
3820 mod->async_probe_requested = true;
3824 /* Check for magic 'dyndbg' arg */
3825 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3827 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3831 /* Allocate and load the module: note that size of section 0 is always
3832 zero, and we rely on this for optional sections. */
3833 static int load_module(struct load_info *info, const char __user *uargs,
3840 err = elf_header_check(info);
3842 pr_err("Module has invalid ELF header\n");
3846 err = setup_load_info(info, flags);
3850 if (blacklisted(info->name)) {
3852 pr_err("Module %s is blacklisted\n", info->name);
3856 err = module_sig_check(info, flags);
3860 err = rewrite_section_headers(info, flags);
3864 /* Check module struct version now, before we try to use module. */
3865 if (!check_modstruct_version(info, info->mod)) {
3870 /* Figure out module layout, and allocate all the memory. */
3871 mod = layout_and_allocate(info, flags);
3877 audit_log_kern_module(mod->name);
3879 /* Reserve our place in the list. */
3880 err = add_unformed_module(mod);
3884 #ifdef CONFIG_MODULE_SIG
3885 mod->sig_ok = info->sig_ok;
3887 pr_notice_once("%s: module verification failed: signature "
3888 "and/or required key missing - tainting "
3889 "kernel\n", mod->name);
3890 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3894 /* To avoid stressing percpu allocator, do this once we're unique. */
3895 err = percpu_modalloc(mod, info);
3899 /* Now module is in final location, initialize linked lists, etc. */
3900 err = module_unload_init(mod);
3904 init_param_lock(mod);
3906 /* Now we've got everything in the final locations, we can
3907 * find optional sections. */
3908 err = find_module_sections(mod, info);
3912 err = check_module_license_and_versions(mod);
3916 /* Set up MODINFO_ATTR fields */
3917 setup_modinfo(mod, info);
3919 /* Fix up syms, so that st_value is a pointer to location. */
3920 err = simplify_symbols(mod, info);
3924 err = apply_relocations(mod, info);
3928 err = post_relocation(mod, info);
3932 flush_module_icache(mod);
3934 /* Now copy in args */
3935 mod->args = strndup_user(uargs, ~0UL >> 1);
3936 if (IS_ERR(mod->args)) {
3937 err = PTR_ERR(mod->args);
3938 goto free_arch_cleanup;
3941 dynamic_debug_setup(mod, info->debug, info->num_debug);
3943 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3944 ftrace_module_init(mod);
3946 /* Finally it's fully formed, ready to start executing. */
3947 err = complete_formation(mod, info);
3949 goto ddebug_cleanup;
3951 err = prepare_coming_module(mod);
3955 /* Module is ready to execute: parsing args may do that. */
3956 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3958 unknown_module_param_cb);
3959 if (IS_ERR(after_dashes)) {
3960 err = PTR_ERR(after_dashes);
3961 goto coming_cleanup;
3962 } else if (after_dashes) {
3963 pr_warn("%s: parameters '%s' after `--' ignored\n",
3964 mod->name, after_dashes);
3967 /* Link in to sysfs. */
3968 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3970 goto coming_cleanup;
3972 if (is_livepatch_module(mod)) {
3973 err = copy_module_elf(mod, info);
3978 /* Get rid of temporary copy. */
3982 trace_module_load(mod);
3984 return do_init_module(mod);
3987 mod_sysfs_teardown(mod);
3989 mod->state = MODULE_STATE_GOING;
3990 destroy_params(mod->kp, mod->num_kp);
3991 blocking_notifier_call_chain(&module_notify_list,
3992 MODULE_STATE_GOING, mod);
3993 klp_module_going(mod);
3995 mod->state = MODULE_STATE_GOING;
3996 /* module_bug_cleanup needs module_mutex protection */
3997 mutex_lock(&module_mutex);
3998 module_bug_cleanup(mod);
3999 mutex_unlock(&module_mutex);
4002 ftrace_release_mod(mod);
4003 dynamic_debug_remove(mod, info->debug);
4007 module_arch_cleanup(mod);
4011 module_unload_free(mod);
4013 mutex_lock(&module_mutex);
4014 /* Unlink carefully: kallsyms could be walking list. */
4015 list_del_rcu(&mod->list);
4016 mod_tree_remove(mod);
4017 wake_up_all(&module_wq);
4018 /* Wait for RCU-sched synchronizing before releasing mod->list. */
4020 mutex_unlock(&module_mutex);
4022 /* Free lock-classes; relies on the preceding sync_rcu() */
4023 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
4025 module_deallocate(mod, info);
4031 SYSCALL_DEFINE3(init_module, void __user *, umod,
4032 unsigned long, len, const char __user *, uargs)
4035 struct load_info info = { };
4037 err = may_init_module();
4041 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
4044 err = copy_module_from_user(umod, len, &info);
4048 return load_module(&info, uargs, 0);
4051 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
4053 struct load_info info = { };
4057 err = may_init_module();
4061 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
4063 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
4064 |MODULE_INIT_IGNORE_VERMAGIC))
4067 err = kernel_read_file_from_fd(fd, 0, &hdr, INT_MAX, NULL,
4074 return load_module(&info, uargs, flags);
4077 static inline int within(unsigned long addr, void *start, unsigned long size)
4079 return ((void *)addr >= start && (void *)addr < start + size);
4082 #ifdef CONFIG_KALLSYMS
4084 * This ignores the intensely annoying "mapping symbols" found
4085 * in ARM ELF files: $a, $t and $d.
4087 static inline int is_arm_mapping_symbol(const char *str)
4089 if (str[0] == '.' && str[1] == 'L')
4091 return str[0] == '$' && strchr("axtd", str[1])
4092 && (str[2] == '\0' || str[2] == '.');
4095 static const char *kallsyms_symbol_name(struct mod_kallsyms *kallsyms, unsigned int symnum)
4097 return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
4101 * Given a module and address, find the corresponding symbol and return its name
4102 * while providing its size and offset if needed.
4104 static const char *find_kallsyms_symbol(struct module *mod,
4106 unsigned long *size,
4107 unsigned long *offset)
4109 unsigned int i, best = 0;
4110 unsigned long nextval, bestval;
4111 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4113 /* At worse, next value is at end of module */
4114 if (within_module_init(addr, mod))
4115 nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
4117 nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
4119 bestval = kallsyms_symbol_value(&kallsyms->symtab[best]);
4121 /* Scan for closest preceding symbol, and next symbol. (ELF
4122 starts real symbols at 1). */
4123 for (i = 1; i < kallsyms->num_symtab; i++) {
4124 const Elf_Sym *sym = &kallsyms->symtab[i];
4125 unsigned long thisval = kallsyms_symbol_value(sym);
4127 if (sym->st_shndx == SHN_UNDEF)
4130 /* We ignore unnamed symbols: they're uninformative
4131 * and inserted at a whim. */
4132 if (*kallsyms_symbol_name(kallsyms, i) == '\0'
4133 || is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms, i)))
4136 if (thisval <= addr && thisval > bestval) {
4140 if (thisval > addr && thisval < nextval)
4148 *size = nextval - bestval;
4150 *offset = addr - bestval;
4152 return kallsyms_symbol_name(kallsyms, best);
4155 void * __weak dereference_module_function_descriptor(struct module *mod,
4161 /* For kallsyms to ask for address resolution. NULL means not found. Careful
4162 * not to lock to avoid deadlock on oopses, simply disable preemption. */
4163 const char *module_address_lookup(unsigned long addr,
4164 unsigned long *size,
4165 unsigned long *offset,
4169 const char *ret = NULL;
4173 mod = __module_address(addr);
4176 *modname = mod->name;
4178 ret = find_kallsyms_symbol(mod, addr, size, offset);
4180 /* Make a copy in here where it's safe */
4182 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
4190 int lookup_module_symbol_name(unsigned long addr, char *symname)
4195 list_for_each_entry_rcu(mod, &modules, list) {
4196 if (mod->state == MODULE_STATE_UNFORMED)
4198 if (within_module(addr, mod)) {
4201 sym = find_kallsyms_symbol(mod, addr, NULL, NULL);
4205 strlcpy(symname, sym, KSYM_NAME_LEN);
4215 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
4216 unsigned long *offset, char *modname, char *name)
4221 list_for_each_entry_rcu(mod, &modules, list) {
4222 if (mod->state == MODULE_STATE_UNFORMED)
4224 if (within_module(addr, mod)) {
4227 sym = find_kallsyms_symbol(mod, addr, size, offset);
4231 strlcpy(modname, mod->name, MODULE_NAME_LEN);
4233 strlcpy(name, sym, KSYM_NAME_LEN);
4243 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
4244 char *name, char *module_name, int *exported)
4249 list_for_each_entry_rcu(mod, &modules, list) {
4250 struct mod_kallsyms *kallsyms;
4252 if (mod->state == MODULE_STATE_UNFORMED)
4254 kallsyms = rcu_dereference_sched(mod->kallsyms);
4255 if (symnum < kallsyms->num_symtab) {
4256 const Elf_Sym *sym = &kallsyms->symtab[symnum];
4258 *value = kallsyms_symbol_value(sym);
4259 *type = kallsyms->typetab[symnum];
4260 strlcpy(name, kallsyms_symbol_name(kallsyms, symnum), KSYM_NAME_LEN);
4261 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
4262 *exported = is_exported(name, *value, mod);
4266 symnum -= kallsyms->num_symtab;
4272 /* Given a module and name of symbol, find and return the symbol's value */
4273 static unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name)
4276 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4278 for (i = 0; i < kallsyms->num_symtab; i++) {
4279 const Elf_Sym *sym = &kallsyms->symtab[i];
4281 if (strcmp(name, kallsyms_symbol_name(kallsyms, i)) == 0 &&
4282 sym->st_shndx != SHN_UNDEF)
4283 return kallsyms_symbol_value(sym);
4288 /* Look for this name: can be of form module:name. */
4289 unsigned long module_kallsyms_lookup_name(const char *name)
4293 unsigned long ret = 0;
4295 /* Don't lock: we're in enough trouble already. */
4297 if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
4298 if ((mod = find_module_all(name, colon - name, false)) != NULL)
4299 ret = find_kallsyms_symbol_value(mod, colon+1);
4301 list_for_each_entry_rcu(mod, &modules, list) {
4302 if (mod->state == MODULE_STATE_UNFORMED)
4304 if ((ret = find_kallsyms_symbol_value(mod, name)) != 0)
4312 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
4313 struct module *, unsigned long),
4320 module_assert_mutex();
4322 list_for_each_entry(mod, &modules, list) {
4323 /* We hold module_mutex: no need for rcu_dereference_sched */
4324 struct mod_kallsyms *kallsyms = mod->kallsyms;
4326 if (mod->state == MODULE_STATE_UNFORMED)
4328 for (i = 0; i < kallsyms->num_symtab; i++) {
4329 const Elf_Sym *sym = &kallsyms->symtab[i];
4331 if (sym->st_shndx == SHN_UNDEF)
4334 ret = fn(data, kallsyms_symbol_name(kallsyms, i),
4335 mod, kallsyms_symbol_value(sym));
4342 #endif /* CONFIG_KALLSYMS */
4344 /* Maximum number of characters written by module_flags() */
4345 #define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
4347 /* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
4348 static char *module_flags(struct module *mod, char *buf)
4352 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
4354 mod->state == MODULE_STATE_GOING ||
4355 mod->state == MODULE_STATE_COMING) {
4357 bx += module_flags_taint(mod, buf + bx);
4358 /* Show a - for module-is-being-unloaded */
4359 if (mod->state == MODULE_STATE_GOING)
4361 /* Show a + for module-is-being-loaded */
4362 if (mod->state == MODULE_STATE_COMING)
4371 #ifdef CONFIG_PROC_FS
4372 /* Called by the /proc file system to return a list of modules. */
4373 static void *m_start(struct seq_file *m, loff_t *pos)
4375 mutex_lock(&module_mutex);
4376 return seq_list_start(&modules, *pos);
4379 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
4381 return seq_list_next(p, &modules, pos);
4384 static void m_stop(struct seq_file *m, void *p)
4386 mutex_unlock(&module_mutex);
4389 static int m_show(struct seq_file *m, void *p)
4391 struct module *mod = list_entry(p, struct module, list);
4392 char buf[MODULE_FLAGS_BUF_SIZE];
4395 /* We always ignore unformed modules. */
4396 if (mod->state == MODULE_STATE_UNFORMED)
4399 seq_printf(m, "%s %u",
4400 mod->name, mod->init_layout.size + mod->core_layout.size);
4401 print_unload_info(m, mod);
4403 /* Informative for users. */
4404 seq_printf(m, " %s",
4405 mod->state == MODULE_STATE_GOING ? "Unloading" :
4406 mod->state == MODULE_STATE_COMING ? "Loading" :
4408 /* Used by oprofile and other similar tools. */
4409 value = m->private ? NULL : mod->core_layout.base;
4410 seq_printf(m, " 0x%px", value);
4414 seq_printf(m, " %s", module_flags(mod, buf));
4420 /* Format: modulename size refcount deps address
4422 Where refcount is a number or -, and deps is a comma-separated list
4425 static const struct seq_operations modules_op = {
4433 * This also sets the "private" pointer to non-NULL if the
4434 * kernel pointers should be hidden (so you can just test
4435 * "m->private" to see if you should keep the values private).
4437 * We use the same logic as for /proc/kallsyms.
4439 static int modules_open(struct inode *inode, struct file *file)
4441 int err = seq_open(file, &modules_op);
4444 struct seq_file *m = file->private_data;
4445 m->private = kallsyms_show_value(file->f_cred) ? NULL : (void *)8ul;
4451 static const struct proc_ops modules_proc_ops = {
4452 .proc_flags = PROC_ENTRY_PERMANENT,
4453 .proc_open = modules_open,
4454 .proc_read = seq_read,
4455 .proc_lseek = seq_lseek,
4456 .proc_release = seq_release,
4459 static int __init proc_modules_init(void)
4461 proc_create("modules", 0, NULL, &modules_proc_ops);
4464 module_init(proc_modules_init);
4467 /* Given an address, look for it in the module exception tables. */
4468 const struct exception_table_entry *search_module_extables(unsigned long addr)
4470 const struct exception_table_entry *e = NULL;
4474 mod = __module_address(addr);
4478 if (!mod->num_exentries)
4481 e = search_extable(mod->extable,
4488 * Now, if we found one, we are running inside it now, hence
4489 * we cannot unload the module, hence no refcnt needed.
4495 * is_module_address - is this address inside a module?
4496 * @addr: the address to check.
4498 * See is_module_text_address() if you simply want to see if the address
4499 * is code (not data).
4501 bool is_module_address(unsigned long addr)
4506 ret = __module_address(addr) != NULL;
4513 * __module_address - get the module which contains an address.
4514 * @addr: the address.
4516 * Must be called with preempt disabled or module mutex held so that
4517 * module doesn't get freed during this.
4519 struct module *__module_address(unsigned long addr)
4523 if (addr < module_addr_min || addr > module_addr_max)
4526 module_assert_mutex_or_preempt();
4528 mod = mod_find(addr);
4530 BUG_ON(!within_module(addr, mod));
4531 if (mod->state == MODULE_STATE_UNFORMED)
4538 * is_module_text_address - is this address inside module code?
4539 * @addr: the address to check.
4541 * See is_module_address() if you simply want to see if the address is
4542 * anywhere in a module. See kernel_text_address() for testing if an
4543 * address corresponds to kernel or module code.
4545 bool is_module_text_address(unsigned long addr)
4550 ret = __module_text_address(addr) != NULL;
4557 * __module_text_address - get the module whose code contains an address.
4558 * @addr: the address.
4560 * Must be called with preempt disabled or module mutex held so that
4561 * module doesn't get freed during this.
4563 struct module *__module_text_address(unsigned long addr)
4565 struct module *mod = __module_address(addr);
4567 /* Make sure it's within the text section. */
4568 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
4569 && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
4575 /* Don't grab lock, we're oopsing. */
4576 void print_modules(void)
4579 char buf[MODULE_FLAGS_BUF_SIZE];
4581 printk(KERN_DEFAULT "Modules linked in:");
4582 /* Most callers should already have preempt disabled, but make sure */
4584 list_for_each_entry_rcu(mod, &modules, list) {
4585 if (mod->state == MODULE_STATE_UNFORMED)
4587 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4590 if (last_unloaded_module[0])
4591 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4595 #ifdef CONFIG_MODVERSIONS
4596 /* Generate the signature for all relevant module structures here.
4597 * If these change, we don't want to try to parse the module. */
4598 void module_layout(struct module *mod,
4599 struct modversion_info *ver,
4600 struct kernel_param *kp,
4601 struct kernel_symbol *ks,
4602 struct tracepoint * const *tp)
4605 EXPORT_SYMBOL(module_layout);