1 // SPDX-License-Identifier: GPL-2.0-or-later
3 Copyright (C) 2002 Richard Henderson
4 Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
7 #include <linux/export.h>
8 #include <linux/extable.h>
9 #include <linux/moduleloader.h>
10 #include <linux/module_signature.h>
11 #include <linux/trace_events.h>
12 #include <linux/init.h>
13 #include <linux/kallsyms.h>
14 #include <linux/file.h>
16 #include <linux/sysfs.h>
17 #include <linux/kernel.h>
18 #include <linux/slab.h>
19 #include <linux/vmalloc.h>
20 #include <linux/elf.h>
21 #include <linux/proc_fs.h>
22 #include <linux/security.h>
23 #include <linux/seq_file.h>
24 #include <linux/syscalls.h>
25 #include <linux/fcntl.h>
26 #include <linux/rcupdate.h>
27 #include <linux/capability.h>
28 #include <linux/cpu.h>
29 #include <linux/moduleparam.h>
30 #include <linux/errno.h>
31 #include <linux/err.h>
32 #include <linux/vermagic.h>
33 #include <linux/notifier.h>
34 #include <linux/sched.h>
35 #include <linux/device.h>
36 #include <linux/string.h>
37 #include <linux/mutex.h>
38 #include <linux/rculist.h>
39 #include <linux/uaccess.h>
40 #include <asm/cacheflush.h>
41 #include <linux/set_memory.h>
42 #include <asm/mmu_context.h>
43 #include <linux/license.h>
44 #include <asm/sections.h>
45 #include <linux/tracepoint.h>
46 #include <linux/ftrace.h>
47 #include <linux/livepatch.h>
48 #include <linux/async.h>
49 #include <linux/percpu.h>
50 #include <linux/kmemleak.h>
51 #include <linux/jump_label.h>
52 #include <linux/pfn.h>
53 #include <linux/bsearch.h>
54 #include <linux/dynamic_debug.h>
55 #include <linux/audit.h>
56 #include <uapi/linux/module.h>
57 #include "module-internal.h"
59 #define CREATE_TRACE_POINTS
60 #include <trace/events/module.h>
62 #ifndef ARCH_SHF_SMALL
63 #define ARCH_SHF_SMALL 0
67 * Modules' sections will be aligned on page boundaries
68 * to ensure complete separation of code and data, but
69 * only when CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y
71 #ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
72 # define debug_align(X) ALIGN(X, PAGE_SIZE)
74 # define debug_align(X) (X)
77 /* If this is set, the section belongs in the init part of the module */
78 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
82 * 1) List of modules (also safely readable with preempt_disable),
83 * 2) module_use links,
84 * 3) module_addr_min/module_addr_max.
85 * (delete and add uses RCU list operations). */
86 DEFINE_MUTEX(module_mutex);
87 EXPORT_SYMBOL_GPL(module_mutex);
88 static LIST_HEAD(modules);
90 /* Work queue for freeing init sections in success case */
91 static void do_free_init(struct work_struct *w);
92 static DECLARE_WORK(init_free_wq, do_free_init);
93 static LLIST_HEAD(init_free_list);
95 #ifdef CONFIG_MODULES_TREE_LOOKUP
98 * Use a latched RB-tree for __module_address(); this allows us to use
99 * RCU-sched lookups of the address from any context.
101 * This is conditional on PERF_EVENTS || TRACING because those can really hit
102 * __module_address() hard by doing a lot of stack unwinding; potentially from
106 static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
108 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
110 return (unsigned long)layout->base;
113 static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
115 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
117 return (unsigned long)layout->size;
120 static __always_inline bool
121 mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
123 return __mod_tree_val(a) < __mod_tree_val(b);
126 static __always_inline int
127 mod_tree_comp(void *key, struct latch_tree_node *n)
129 unsigned long val = (unsigned long)key;
130 unsigned long start, end;
132 start = __mod_tree_val(n);
136 end = start + __mod_tree_size(n);
143 static const struct latch_tree_ops mod_tree_ops = {
144 .less = mod_tree_less,
145 .comp = mod_tree_comp,
148 static struct mod_tree_root {
149 struct latch_tree_root root;
150 unsigned long addr_min;
151 unsigned long addr_max;
152 } mod_tree __cacheline_aligned = {
156 #define module_addr_min mod_tree.addr_min
157 #define module_addr_max mod_tree.addr_max
159 static noinline void __mod_tree_insert(struct mod_tree_node *node)
161 latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
164 static void __mod_tree_remove(struct mod_tree_node *node)
166 latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
170 * These modifications: insert, remove_init and remove; are serialized by the
173 static void mod_tree_insert(struct module *mod)
175 mod->core_layout.mtn.mod = mod;
176 mod->init_layout.mtn.mod = mod;
178 __mod_tree_insert(&mod->core_layout.mtn);
179 if (mod->init_layout.size)
180 __mod_tree_insert(&mod->init_layout.mtn);
183 static void mod_tree_remove_init(struct module *mod)
185 if (mod->init_layout.size)
186 __mod_tree_remove(&mod->init_layout.mtn);
189 static void mod_tree_remove(struct module *mod)
191 __mod_tree_remove(&mod->core_layout.mtn);
192 mod_tree_remove_init(mod);
195 static struct module *mod_find(unsigned long addr)
197 struct latch_tree_node *ltn;
199 ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
203 return container_of(ltn, struct mod_tree_node, node)->mod;
206 #else /* MODULES_TREE_LOOKUP */
208 static unsigned long module_addr_min = -1UL, module_addr_max = 0;
210 static void mod_tree_insert(struct module *mod) { }
211 static void mod_tree_remove_init(struct module *mod) { }
212 static void mod_tree_remove(struct module *mod) { }
214 static struct module *mod_find(unsigned long addr)
218 list_for_each_entry_rcu(mod, &modules, list,
219 lockdep_is_held(&module_mutex)) {
220 if (within_module(addr, mod))
227 #endif /* MODULES_TREE_LOOKUP */
230 * Bounds of module text, for speeding up __module_address.
231 * Protected by module_mutex.
233 static void __mod_update_bounds(void *base, unsigned int size)
235 unsigned long min = (unsigned long)base;
236 unsigned long max = min + size;
238 if (min < module_addr_min)
239 module_addr_min = min;
240 if (max > module_addr_max)
241 module_addr_max = max;
244 static void mod_update_bounds(struct module *mod)
246 __mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
247 if (mod->init_layout.size)
248 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
251 #ifdef CONFIG_KGDB_KDB
252 struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
253 #endif /* CONFIG_KGDB_KDB */
255 static void module_assert_mutex(void)
257 lockdep_assert_held(&module_mutex);
260 static void module_assert_mutex_or_preempt(void)
262 #ifdef CONFIG_LOCKDEP
263 if (unlikely(!debug_locks))
266 WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
267 !lockdep_is_held(&module_mutex));
271 #ifdef CONFIG_MODULE_SIG
272 static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
273 module_param(sig_enforce, bool_enable_only, 0644);
275 void set_module_sig_enforced(void)
280 #define sig_enforce false
284 * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
285 * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
287 bool is_module_sig_enforced(void)
291 EXPORT_SYMBOL(is_module_sig_enforced);
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.
736 * %true if @addr is from module static percpu area
738 bool is_module_percpu_address(unsigned long addr)
740 return __is_module_percpu_address(addr, NULL);
743 #else /* ... !CONFIG_SMP */
745 static inline void __percpu *mod_percpu(struct module *mod)
749 static int percpu_modalloc(struct module *mod, struct load_info *info)
751 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
752 if (info->sechdrs[info->index.pcpu].sh_size != 0)
756 static inline void percpu_modfree(struct module *mod)
759 static unsigned int find_pcpusec(struct load_info *info)
763 static inline void percpu_modcopy(struct module *mod,
764 const void *from, unsigned long size)
766 /* pcpusec should be 0, and size of that section should be 0. */
769 bool is_module_percpu_address(unsigned long addr)
774 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
779 #endif /* CONFIG_SMP */
781 #define MODINFO_ATTR(field) \
782 static void setup_modinfo_##field(struct module *mod, const char *s) \
784 mod->field = kstrdup(s, GFP_KERNEL); \
786 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
787 struct module_kobject *mk, char *buffer) \
789 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
791 static int modinfo_##field##_exists(struct module *mod) \
793 return mod->field != NULL; \
795 static void free_modinfo_##field(struct module *mod) \
800 static struct module_attribute modinfo_##field = { \
801 .attr = { .name = __stringify(field), .mode = 0444 }, \
802 .show = show_modinfo_##field, \
803 .setup = setup_modinfo_##field, \
804 .test = modinfo_##field##_exists, \
805 .free = free_modinfo_##field, \
808 MODINFO_ATTR(version);
809 MODINFO_ATTR(srcversion);
811 static char last_unloaded_module[MODULE_NAME_LEN+1];
813 #ifdef CONFIG_MODULE_UNLOAD
815 EXPORT_TRACEPOINT_SYMBOL(module_get);
817 /* MODULE_REF_BASE is the base reference count by kmodule loader. */
818 #define MODULE_REF_BASE 1
820 /* Init the unload section of the module. */
821 static int module_unload_init(struct module *mod)
824 * Initialize reference counter to MODULE_REF_BASE.
825 * refcnt == 0 means module is going.
827 atomic_set(&mod->refcnt, MODULE_REF_BASE);
829 INIT_LIST_HEAD(&mod->source_list);
830 INIT_LIST_HEAD(&mod->target_list);
832 /* Hold reference count during initialization. */
833 atomic_inc(&mod->refcnt);
838 /* Does a already use b? */
839 static int already_uses(struct module *a, struct module *b)
841 struct module_use *use;
843 list_for_each_entry(use, &b->source_list, source_list) {
844 if (use->source == a) {
845 pr_debug("%s uses %s!\n", a->name, b->name);
849 pr_debug("%s does not use %s!\n", a->name, b->name);
855 * - we add 'a' as a "source", 'b' as a "target" of module use
856 * - the module_use is added to the list of 'b' sources (so
857 * 'b' can walk the list to see who sourced them), and of 'a'
858 * targets (so 'a' can see what modules it targets).
860 static int add_module_usage(struct module *a, struct module *b)
862 struct module_use *use;
864 pr_debug("Allocating new usage for %s.\n", a->name);
865 use = kmalloc(sizeof(*use), GFP_ATOMIC);
871 list_add(&use->source_list, &b->source_list);
872 list_add(&use->target_list, &a->target_list);
876 /* Module a uses b: caller needs module_mutex() */
877 static int ref_module(struct module *a, struct module *b)
881 if (b == NULL || already_uses(a, b))
884 /* If module isn't available, we fail. */
885 err = strong_try_module_get(b);
889 err = add_module_usage(a, b);
897 /* Clear the unload stuff of the module. */
898 static void module_unload_free(struct module *mod)
900 struct module_use *use, *tmp;
902 mutex_lock(&module_mutex);
903 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
904 struct module *i = use->target;
905 pr_debug("%s unusing %s\n", mod->name, i->name);
907 list_del(&use->source_list);
908 list_del(&use->target_list);
911 mutex_unlock(&module_mutex);
914 #ifdef CONFIG_MODULE_FORCE_UNLOAD
915 static inline int try_force_unload(unsigned int flags)
917 int ret = (flags & O_TRUNC);
919 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
923 static inline int try_force_unload(unsigned int flags)
927 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
929 /* Try to release refcount of module, 0 means success. */
930 static int try_release_module_ref(struct module *mod)
934 /* Try to decrement refcnt which we set at loading */
935 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
938 /* Someone can put this right now, recover with checking */
939 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
944 static int try_stop_module(struct module *mod, int flags, int *forced)
946 /* If it's not unused, quit unless we're forcing. */
947 if (try_release_module_ref(mod) != 0) {
948 *forced = try_force_unload(flags);
953 /* Mark it as dying. */
954 mod->state = MODULE_STATE_GOING;
960 * module_refcount - return the refcount or -1 if unloading
962 * @mod: the module we're checking
965 * -1 if the module is in the process of unloading
966 * otherwise the number of references in the kernel to the module
968 int module_refcount(struct module *mod)
970 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
972 EXPORT_SYMBOL(module_refcount);
974 /* This exists whether we can unload or not */
975 static void free_module(struct module *mod);
977 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
981 char name[MODULE_NAME_LEN];
984 if (!capable(CAP_SYS_MODULE) || modules_disabled)
987 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
989 name[MODULE_NAME_LEN-1] = '\0';
991 audit_log_kern_module(name);
993 if (mutex_lock_interruptible(&module_mutex) != 0)
996 mod = find_module(name);
1002 if (!list_empty(&mod->source_list)) {
1003 /* Other modules depend on us: get rid of them first. */
1008 /* Doing init or already dying? */
1009 if (mod->state != MODULE_STATE_LIVE) {
1010 /* FIXME: if (force), slam module count damn the torpedoes */
1011 pr_debug("%s already dying\n", mod->name);
1016 /* If it has an init func, it must have an exit func to unload */
1017 if (mod->init && !mod->exit) {
1018 forced = try_force_unload(flags);
1020 /* This module can't be removed */
1026 /* Stop the machine so refcounts can't move and disable module. */
1027 ret = try_stop_module(mod, flags, &forced);
1031 mutex_unlock(&module_mutex);
1032 /* Final destruction now no one is using it. */
1033 if (mod->exit != NULL)
1035 blocking_notifier_call_chain(&module_notify_list,
1036 MODULE_STATE_GOING, mod);
1037 klp_module_going(mod);
1038 ftrace_release_mod(mod);
1040 async_synchronize_full();
1042 /* Store the name of the last unloaded module for diagnostic purposes */
1043 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
1046 /* someone could wait for the module in add_unformed_module() */
1047 wake_up_all(&module_wq);
1050 mutex_unlock(&module_mutex);
1054 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1056 struct module_use *use;
1057 int printed_something = 0;
1059 seq_printf(m, " %i ", module_refcount(mod));
1062 * Always include a trailing , so userspace can differentiate
1063 * between this and the old multi-field proc format.
1065 list_for_each_entry(use, &mod->source_list, source_list) {
1066 printed_something = 1;
1067 seq_printf(m, "%s,", use->source->name);
1070 if (mod->init != NULL && mod->exit == NULL) {
1071 printed_something = 1;
1072 seq_puts(m, "[permanent],");
1075 if (!printed_something)
1079 void __symbol_put(const char *symbol)
1081 struct module *owner;
1084 if (!find_symbol(symbol, &owner, NULL, NULL, true, false))
1089 EXPORT_SYMBOL(__symbol_put);
1091 /* Note this assumes addr is a function, which it currently always is. */
1092 void symbol_put_addr(void *addr)
1094 struct module *modaddr;
1095 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1097 if (core_kernel_text(a))
1101 * Even though we hold a reference on the module; we still need to
1102 * disable preemption in order to safely traverse the data structure.
1105 modaddr = __module_text_address(a);
1107 module_put(modaddr);
1110 EXPORT_SYMBOL_GPL(symbol_put_addr);
1112 static ssize_t show_refcnt(struct module_attribute *mattr,
1113 struct module_kobject *mk, char *buffer)
1115 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1118 static struct module_attribute modinfo_refcnt =
1119 __ATTR(refcnt, 0444, show_refcnt, NULL);
1121 void __module_get(struct module *module)
1125 atomic_inc(&module->refcnt);
1126 trace_module_get(module, _RET_IP_);
1130 EXPORT_SYMBOL(__module_get);
1132 bool try_module_get(struct module *module)
1138 /* Note: here, we can fail to get a reference */
1139 if (likely(module_is_live(module) &&
1140 atomic_inc_not_zero(&module->refcnt) != 0))
1141 trace_module_get(module, _RET_IP_);
1149 EXPORT_SYMBOL(try_module_get);
1151 void module_put(struct module *module)
1157 ret = atomic_dec_if_positive(&module->refcnt);
1158 WARN_ON(ret < 0); /* Failed to put refcount */
1159 trace_module_put(module, _RET_IP_);
1163 EXPORT_SYMBOL(module_put);
1165 #else /* !CONFIG_MODULE_UNLOAD */
1166 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1168 /* We don't know the usage count, or what modules are using. */
1169 seq_puts(m, " - -");
1172 static inline void module_unload_free(struct module *mod)
1176 static int ref_module(struct module *a, struct module *b)
1178 return strong_try_module_get(b);
1181 static inline int module_unload_init(struct module *mod)
1185 #endif /* CONFIG_MODULE_UNLOAD */
1187 static size_t module_flags_taint(struct module *mod, char *buf)
1192 for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
1193 if (taint_flags[i].module && test_bit(i, &mod->taints))
1194 buf[l++] = taint_flags[i].c_true;
1200 static ssize_t show_initstate(struct module_attribute *mattr,
1201 struct module_kobject *mk, char *buffer)
1203 const char *state = "unknown";
1205 switch (mk->mod->state) {
1206 case MODULE_STATE_LIVE:
1209 case MODULE_STATE_COMING:
1212 case MODULE_STATE_GOING:
1218 return sprintf(buffer, "%s\n", state);
1221 static struct module_attribute modinfo_initstate =
1222 __ATTR(initstate, 0444, show_initstate, NULL);
1224 static ssize_t store_uevent(struct module_attribute *mattr,
1225 struct module_kobject *mk,
1226 const char *buffer, size_t count)
1230 rc = kobject_synth_uevent(&mk->kobj, buffer, count);
1231 return rc ? rc : count;
1234 struct module_attribute module_uevent =
1235 __ATTR(uevent, 0200, NULL, store_uevent);
1237 static ssize_t show_coresize(struct module_attribute *mattr,
1238 struct module_kobject *mk, char *buffer)
1240 return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1243 static struct module_attribute modinfo_coresize =
1244 __ATTR(coresize, 0444, show_coresize, NULL);
1246 static ssize_t show_initsize(struct module_attribute *mattr,
1247 struct module_kobject *mk, char *buffer)
1249 return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1252 static struct module_attribute modinfo_initsize =
1253 __ATTR(initsize, 0444, show_initsize, NULL);
1255 static ssize_t show_taint(struct module_attribute *mattr,
1256 struct module_kobject *mk, char *buffer)
1260 l = module_flags_taint(mk->mod, buffer);
1265 static struct module_attribute modinfo_taint =
1266 __ATTR(taint, 0444, show_taint, NULL);
1268 static struct module_attribute *modinfo_attrs[] = {
1271 &modinfo_srcversion,
1276 #ifdef CONFIG_MODULE_UNLOAD
1282 static const char vermagic[] = VERMAGIC_STRING;
1284 static int try_to_force_load(struct module *mod, const char *reason)
1286 #ifdef CONFIG_MODULE_FORCE_LOAD
1287 if (!test_taint(TAINT_FORCED_MODULE))
1288 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1289 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1296 #ifdef CONFIG_MODVERSIONS
1298 static u32 resolve_rel_crc(const s32 *crc)
1300 return *(u32 *)((void *)crc + *crc);
1303 static int check_version(const struct load_info *info,
1304 const char *symname,
1308 Elf_Shdr *sechdrs = info->sechdrs;
1309 unsigned int versindex = info->index.vers;
1310 unsigned int i, num_versions;
1311 struct modversion_info *versions;
1313 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1317 /* No versions at all? modprobe --force does this. */
1319 return try_to_force_load(mod, symname) == 0;
1321 versions = (void *) sechdrs[versindex].sh_addr;
1322 num_versions = sechdrs[versindex].sh_size
1323 / sizeof(struct modversion_info);
1325 for (i = 0; i < num_versions; i++) {
1328 if (strcmp(versions[i].name, symname) != 0)
1331 if (IS_ENABLED(CONFIG_MODULE_REL_CRCS))
1332 crcval = resolve_rel_crc(crc);
1335 if (versions[i].crc == crcval)
1337 pr_debug("Found checksum %X vs module %lX\n",
1338 crcval, versions[i].crc);
1342 /* Broken toolchain. Warn once, then let it go.. */
1343 pr_warn_once("%s: no symbol version for %s\n", info->name, symname);
1347 pr_warn("%s: disagrees about version of symbol %s\n",
1348 info->name, symname);
1352 static inline int check_modstruct_version(const struct load_info *info,
1358 * Since this should be found in kernel (which can't be removed), no
1359 * locking is necessary -- use preempt_disable() to placate lockdep.
1362 if (!find_symbol("module_layout", NULL, &crc, NULL, true, false)) {
1367 return check_version(info, "module_layout", mod, crc);
1370 /* First part is kernel version, which we ignore if module has crcs. */
1371 static inline int same_magic(const char *amagic, const char *bmagic,
1375 amagic += strcspn(amagic, " ");
1376 bmagic += strcspn(bmagic, " ");
1378 return strcmp(amagic, bmagic) == 0;
1381 static inline int check_version(const struct load_info *info,
1382 const char *symname,
1389 static inline int check_modstruct_version(const struct load_info *info,
1395 static inline int same_magic(const char *amagic, const char *bmagic,
1398 return strcmp(amagic, bmagic) == 0;
1400 #endif /* CONFIG_MODVERSIONS */
1402 static char *get_modinfo(const struct load_info *info, const char *tag);
1403 static char *get_next_modinfo(const struct load_info *info, const char *tag,
1406 static int verify_namespace_is_imported(const struct load_info *info,
1407 const struct kernel_symbol *sym,
1410 const char *namespace;
1411 char *imported_namespace;
1413 namespace = kernel_symbol_namespace(sym);
1415 imported_namespace = get_modinfo(info, "import_ns");
1416 while (imported_namespace) {
1417 if (strcmp(namespace, imported_namespace) == 0)
1419 imported_namespace = get_next_modinfo(
1420 info, "import_ns", imported_namespace);
1422 #ifdef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1427 "%s: module uses symbol (%s) from namespace %s, but does not import it.\n",
1428 mod->name, kernel_symbol_name(sym), namespace);
1429 #ifndef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1436 static bool inherit_taint(struct module *mod, struct module *owner)
1438 if (!owner || !test_bit(TAINT_PROPRIETARY_MODULE, &owner->taints))
1441 if (mod->using_gplonly_symbols) {
1442 pr_err("%s: module using GPL-only symbols uses symbols from proprietary module %s.\n",
1443 mod->name, owner->name);
1447 if (!test_bit(TAINT_PROPRIETARY_MODULE, &mod->taints)) {
1448 pr_warn("%s: module uses symbols from proprietary module %s, inheriting taint.\n",
1449 mod->name, owner->name);
1450 set_bit(TAINT_PROPRIETARY_MODULE, &mod->taints);
1455 /* Resolve a symbol for this module. I.e. if we find one, record usage. */
1456 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1457 const struct load_info *info,
1461 struct module *owner;
1462 const struct kernel_symbol *sym;
1464 enum mod_license license;
1468 * The module_mutex should not be a heavily contended lock;
1469 * if we get the occasional sleep here, we'll go an extra iteration
1470 * in the wait_event_interruptible(), which is harmless.
1472 sched_annotate_sleep();
1473 mutex_lock(&module_mutex);
1474 sym = find_symbol(name, &owner, &crc, &license,
1475 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1479 if (license == GPL_ONLY)
1480 mod->using_gplonly_symbols = true;
1482 if (!inherit_taint(mod, owner)) {
1487 if (!check_version(info, name, mod, crc)) {
1488 sym = ERR_PTR(-EINVAL);
1492 err = verify_namespace_is_imported(info, sym, mod);
1498 err = ref_module(mod, owner);
1505 /* We must make copy under the lock if we failed to get ref. */
1506 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1508 mutex_unlock(&module_mutex);
1512 static const struct kernel_symbol *
1513 resolve_symbol_wait(struct module *mod,
1514 const struct load_info *info,
1517 const struct kernel_symbol *ksym;
1518 char owner[MODULE_NAME_LEN];
1520 if (wait_event_interruptible_timeout(module_wq,
1521 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1522 || PTR_ERR(ksym) != -EBUSY,
1524 pr_warn("%s: gave up waiting for init of module %s.\n",
1531 * /sys/module/foo/sections stuff
1532 * J. Corbet <corbet@lwn.net>
1536 #ifdef CONFIG_KALLSYMS
1537 static inline bool sect_empty(const Elf_Shdr *sect)
1539 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1542 struct module_sect_attr {
1543 struct bin_attribute battr;
1544 unsigned long address;
1547 struct module_sect_attrs {
1548 struct attribute_group grp;
1549 unsigned int nsections;
1550 struct module_sect_attr attrs[0];
1553 #define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4))
1554 static ssize_t module_sect_read(struct file *file, struct kobject *kobj,
1555 struct bin_attribute *battr,
1556 char *buf, loff_t pos, size_t count)
1558 struct module_sect_attr *sattr =
1559 container_of(battr, struct module_sect_attr, battr);
1560 char bounce[MODULE_SECT_READ_SIZE + 1];
1567 * Since we're a binary read handler, we must account for the
1568 * trailing NUL byte that sprintf will write: if "buf" is
1569 * too small to hold the NUL, or the NUL is exactly the last
1570 * byte, the read will look like it got truncated by one byte.
1571 * Since there is no way to ask sprintf nicely to not write
1572 * the NUL, we have to use a bounce buffer.
1574 wrote = scnprintf(bounce, sizeof(bounce), "0x%px\n",
1575 kallsyms_show_value(file->f_cred)
1576 ? (void *)sattr->address : NULL);
1577 count = min(count, wrote);
1578 memcpy(buf, bounce, count);
1583 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1585 unsigned int section;
1587 for (section = 0; section < sect_attrs->nsections; section++)
1588 kfree(sect_attrs->attrs[section].battr.attr.name);
1592 static void add_sect_attrs(struct module *mod, const struct load_info *info)
1594 unsigned int nloaded = 0, i, size[2];
1595 struct module_sect_attrs *sect_attrs;
1596 struct module_sect_attr *sattr;
1597 struct bin_attribute **gattr;
1599 /* Count loaded sections and allocate structures */
1600 for (i = 0; i < info->hdr->e_shnum; i++)
1601 if (!sect_empty(&info->sechdrs[i]))
1603 size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded),
1604 sizeof(sect_attrs->grp.bin_attrs[0]));
1605 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.bin_attrs[0]);
1606 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1607 if (sect_attrs == NULL)
1610 /* Setup section attributes. */
1611 sect_attrs->grp.name = "sections";
1612 sect_attrs->grp.bin_attrs = (void *)sect_attrs + size[0];
1614 sect_attrs->nsections = 0;
1615 sattr = §_attrs->attrs[0];
1616 gattr = §_attrs->grp.bin_attrs[0];
1617 for (i = 0; i < info->hdr->e_shnum; i++) {
1618 Elf_Shdr *sec = &info->sechdrs[i];
1619 if (sect_empty(sec))
1621 sysfs_bin_attr_init(&sattr->battr);
1622 sattr->address = sec->sh_addr;
1623 sattr->battr.attr.name =
1624 kstrdup(info->secstrings + sec->sh_name, GFP_KERNEL);
1625 if (sattr->battr.attr.name == NULL)
1627 sect_attrs->nsections++;
1628 sattr->battr.read = module_sect_read;
1629 sattr->battr.size = MODULE_SECT_READ_SIZE;
1630 sattr->battr.attr.mode = 0400;
1631 *(gattr++) = &(sattr++)->battr;
1635 if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp))
1638 mod->sect_attrs = sect_attrs;
1641 free_sect_attrs(sect_attrs);
1644 static void remove_sect_attrs(struct module *mod)
1646 if (mod->sect_attrs) {
1647 sysfs_remove_group(&mod->mkobj.kobj,
1648 &mod->sect_attrs->grp);
1649 /* We are positive that no one is using any sect attrs
1650 * at this point. Deallocate immediately. */
1651 free_sect_attrs(mod->sect_attrs);
1652 mod->sect_attrs = NULL;
1657 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1660 struct module_notes_attrs {
1661 struct kobject *dir;
1663 struct bin_attribute attrs[0];
1666 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1667 struct bin_attribute *bin_attr,
1668 char *buf, loff_t pos, size_t count)
1671 * The caller checked the pos and count against our size.
1673 memcpy(buf, bin_attr->private + pos, count);
1677 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1680 if (notes_attrs->dir) {
1682 sysfs_remove_bin_file(notes_attrs->dir,
1683 ¬es_attrs->attrs[i]);
1684 kobject_put(notes_attrs->dir);
1689 static void add_notes_attrs(struct module *mod, const struct load_info *info)
1691 unsigned int notes, loaded, i;
1692 struct module_notes_attrs *notes_attrs;
1693 struct bin_attribute *nattr;
1695 /* failed to create section attributes, so can't create notes */
1696 if (!mod->sect_attrs)
1699 /* Count notes sections and allocate structures. */
1701 for (i = 0; i < info->hdr->e_shnum; i++)
1702 if (!sect_empty(&info->sechdrs[i]) &&
1703 (info->sechdrs[i].sh_type == SHT_NOTE))
1709 notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes),
1711 if (notes_attrs == NULL)
1714 notes_attrs->notes = notes;
1715 nattr = ¬es_attrs->attrs[0];
1716 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1717 if (sect_empty(&info->sechdrs[i]))
1719 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1720 sysfs_bin_attr_init(nattr);
1721 nattr->attr.name = mod->sect_attrs->attrs[loaded].battr.attr.name;
1722 nattr->attr.mode = S_IRUGO;
1723 nattr->size = info->sechdrs[i].sh_size;
1724 nattr->private = (void *) info->sechdrs[i].sh_addr;
1725 nattr->read = module_notes_read;
1731 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1732 if (!notes_attrs->dir)
1735 for (i = 0; i < notes; ++i)
1736 if (sysfs_create_bin_file(notes_attrs->dir,
1737 ¬es_attrs->attrs[i]))
1740 mod->notes_attrs = notes_attrs;
1744 free_notes_attrs(notes_attrs, i);
1747 static void remove_notes_attrs(struct module *mod)
1749 if (mod->notes_attrs)
1750 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1755 static inline void add_sect_attrs(struct module *mod,
1756 const struct load_info *info)
1760 static inline void remove_sect_attrs(struct module *mod)
1764 static inline void add_notes_attrs(struct module *mod,
1765 const struct load_info *info)
1769 static inline void remove_notes_attrs(struct module *mod)
1772 #endif /* CONFIG_KALLSYMS */
1774 static void del_usage_links(struct module *mod)
1776 #ifdef CONFIG_MODULE_UNLOAD
1777 struct module_use *use;
1779 mutex_lock(&module_mutex);
1780 list_for_each_entry(use, &mod->target_list, target_list)
1781 sysfs_remove_link(use->target->holders_dir, mod->name);
1782 mutex_unlock(&module_mutex);
1786 static int add_usage_links(struct module *mod)
1789 #ifdef CONFIG_MODULE_UNLOAD
1790 struct module_use *use;
1792 mutex_lock(&module_mutex);
1793 list_for_each_entry(use, &mod->target_list, target_list) {
1794 ret = sysfs_create_link(use->target->holders_dir,
1795 &mod->mkobj.kobj, mod->name);
1799 mutex_unlock(&module_mutex);
1801 del_usage_links(mod);
1806 static void module_remove_modinfo_attrs(struct module *mod, int end);
1808 static int module_add_modinfo_attrs(struct module *mod)
1810 struct module_attribute *attr;
1811 struct module_attribute *temp_attr;
1815 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1816 (ARRAY_SIZE(modinfo_attrs) + 1)),
1818 if (!mod->modinfo_attrs)
1821 temp_attr = mod->modinfo_attrs;
1822 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1823 if (!attr->test || attr->test(mod)) {
1824 memcpy(temp_attr, attr, sizeof(*temp_attr));
1825 sysfs_attr_init(&temp_attr->attr);
1826 error = sysfs_create_file(&mod->mkobj.kobj,
1838 module_remove_modinfo_attrs(mod, --i);
1840 kfree(mod->modinfo_attrs);
1844 static void module_remove_modinfo_attrs(struct module *mod, int end)
1846 struct module_attribute *attr;
1849 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1850 if (end >= 0 && i > end)
1852 /* pick a field to test for end of list */
1853 if (!attr->attr.name)
1855 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1859 kfree(mod->modinfo_attrs);
1862 static void mod_kobject_put(struct module *mod)
1864 DECLARE_COMPLETION_ONSTACK(c);
1865 mod->mkobj.kobj_completion = &c;
1866 kobject_put(&mod->mkobj.kobj);
1867 wait_for_completion(&c);
1870 static int mod_sysfs_init(struct module *mod)
1873 struct kobject *kobj;
1875 if (!module_sysfs_initialized) {
1876 pr_err("%s: module sysfs not initialized\n", mod->name);
1881 kobj = kset_find_obj(module_kset, mod->name);
1883 pr_err("%s: module is already loaded\n", mod->name);
1889 mod->mkobj.mod = mod;
1891 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1892 mod->mkobj.kobj.kset = module_kset;
1893 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1896 mod_kobject_put(mod);
1902 static int mod_sysfs_setup(struct module *mod,
1903 const struct load_info *info,
1904 struct kernel_param *kparam,
1905 unsigned int num_params)
1909 err = mod_sysfs_init(mod);
1913 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1914 if (!mod->holders_dir) {
1919 err = module_param_sysfs_setup(mod, kparam, num_params);
1921 goto out_unreg_holders;
1923 err = module_add_modinfo_attrs(mod);
1925 goto out_unreg_param;
1927 err = add_usage_links(mod);
1929 goto out_unreg_modinfo_attrs;
1931 add_sect_attrs(mod, info);
1932 add_notes_attrs(mod, info);
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);
1996 #ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
1998 * LKM RO/NX protection: protect module's text/ro-data
1999 * from modification and any data from execution.
2001 * General layout of module is:
2002 * [text] [read-only-data] [ro-after-init] [writable data]
2003 * text_size -----^ ^ ^ ^
2004 * ro_size ------------------------| | |
2005 * ro_after_init_size -----------------------------| |
2006 * size -----------------------------------------------------------|
2008 * These values are always page-aligned (as is base)
2010 static void frob_text(const struct module_layout *layout,
2011 int (*set_memory)(unsigned long start, int num_pages))
2013 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
2014 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
2015 set_memory((unsigned long)layout->base,
2016 layout->text_size >> PAGE_SHIFT);
2019 #ifdef CONFIG_STRICT_MODULE_RWX
2020 static void frob_rodata(const struct module_layout *layout,
2021 int (*set_memory)(unsigned long start, int num_pages))
2023 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
2024 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
2025 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
2026 set_memory((unsigned long)layout->base + layout->text_size,
2027 (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
2030 static void frob_ro_after_init(const struct module_layout *layout,
2031 int (*set_memory)(unsigned long start, int num_pages))
2033 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
2034 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
2035 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
2036 set_memory((unsigned long)layout->base + layout->ro_size,
2037 (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
2040 static void frob_writable_data(const struct module_layout *layout,
2041 int (*set_memory)(unsigned long start, int num_pages))
2043 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
2044 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
2045 BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
2046 set_memory((unsigned long)layout->base + layout->ro_after_init_size,
2047 (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
2050 /* livepatching wants to disable read-only so it can frob module. */
2051 void module_disable_ro(const struct module *mod)
2053 if (!rodata_enabled)
2056 frob_text(&mod->core_layout, set_memory_rw);
2057 frob_rodata(&mod->core_layout, set_memory_rw);
2058 frob_ro_after_init(&mod->core_layout, set_memory_rw);
2059 frob_text(&mod->init_layout, set_memory_rw);
2060 frob_rodata(&mod->init_layout, set_memory_rw);
2063 void module_enable_ro(const struct module *mod, bool after_init)
2065 if (!rodata_enabled)
2068 set_vm_flush_reset_perms(mod->core_layout.base);
2069 set_vm_flush_reset_perms(mod->init_layout.base);
2070 frob_text(&mod->core_layout, set_memory_ro);
2072 frob_rodata(&mod->core_layout, set_memory_ro);
2073 frob_text(&mod->init_layout, set_memory_ro);
2074 frob_rodata(&mod->init_layout, set_memory_ro);
2077 frob_ro_after_init(&mod->core_layout, set_memory_ro);
2080 static void module_enable_nx(const struct module *mod)
2082 frob_rodata(&mod->core_layout, set_memory_nx);
2083 frob_ro_after_init(&mod->core_layout, set_memory_nx);
2084 frob_writable_data(&mod->core_layout, set_memory_nx);
2085 frob_rodata(&mod->init_layout, set_memory_nx);
2086 frob_writable_data(&mod->init_layout, set_memory_nx);
2089 /* Iterate through all modules and set each module's text as RW */
2090 void set_all_modules_text_rw(void)
2094 if (!rodata_enabled)
2097 mutex_lock(&module_mutex);
2098 list_for_each_entry_rcu(mod, &modules, list) {
2099 if (mod->state == MODULE_STATE_UNFORMED)
2102 frob_text(&mod->core_layout, set_memory_rw);
2103 frob_text(&mod->init_layout, set_memory_rw);
2105 mutex_unlock(&module_mutex);
2108 /* Iterate through all modules and set each module's text as RO */
2109 void set_all_modules_text_ro(void)
2113 if (!rodata_enabled)
2116 mutex_lock(&module_mutex);
2117 list_for_each_entry_rcu(mod, &modules, list) {
2119 * Ignore going modules since it's possible that ro
2120 * protection has already been disabled, otherwise we'll
2121 * run into protection faults at module deallocation.
2123 if (mod->state == MODULE_STATE_UNFORMED ||
2124 mod->state == MODULE_STATE_GOING)
2127 frob_text(&mod->core_layout, set_memory_ro);
2128 frob_text(&mod->init_layout, set_memory_ro);
2130 mutex_unlock(&module_mutex);
2132 #else /* !CONFIG_STRICT_MODULE_RWX */
2133 static void module_enable_nx(const struct module *mod) { }
2134 #endif /* CONFIG_STRICT_MODULE_RWX */
2135 static void module_enable_x(const struct module *mod)
2137 frob_text(&mod->core_layout, set_memory_x);
2138 frob_text(&mod->init_layout, set_memory_x);
2140 #else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
2141 static void module_enable_nx(const struct module *mod) { }
2142 static void module_enable_x(const struct module *mod) { }
2143 #endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
2146 #ifdef CONFIG_LIVEPATCH
2148 * Persist Elf information about a module. Copy the Elf header,
2149 * section header table, section string table, and symtab section
2150 * index from info to mod->klp_info.
2152 static int copy_module_elf(struct module *mod, struct load_info *info)
2154 unsigned int size, symndx;
2157 size = sizeof(*mod->klp_info);
2158 mod->klp_info = kmalloc(size, GFP_KERNEL);
2159 if (mod->klp_info == NULL)
2163 size = sizeof(mod->klp_info->hdr);
2164 memcpy(&mod->klp_info->hdr, info->hdr, size);
2166 /* Elf section header table */
2167 size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
2168 mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL);
2169 if (mod->klp_info->sechdrs == NULL) {
2174 /* Elf section name string table */
2175 size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
2176 mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL);
2177 if (mod->klp_info->secstrings == NULL) {
2182 /* Elf symbol section index */
2183 symndx = info->index.sym;
2184 mod->klp_info->symndx = symndx;
2187 * For livepatch modules, core_kallsyms.symtab is a complete
2188 * copy of the original symbol table. Adjust sh_addr to point
2189 * to core_kallsyms.symtab since the copy of the symtab in module
2190 * init memory is freed at the end of do_init_module().
2192 mod->klp_info->sechdrs[symndx].sh_addr = \
2193 (unsigned long) mod->core_kallsyms.symtab;
2198 kfree(mod->klp_info->sechdrs);
2200 kfree(mod->klp_info);
2204 static void free_module_elf(struct module *mod)
2206 kfree(mod->klp_info->sechdrs);
2207 kfree(mod->klp_info->secstrings);
2208 kfree(mod->klp_info);
2210 #else /* !CONFIG_LIVEPATCH */
2211 static int copy_module_elf(struct module *mod, struct load_info *info)
2216 static void free_module_elf(struct module *mod)
2219 #endif /* CONFIG_LIVEPATCH */
2221 void __weak module_memfree(void *module_region)
2224 * This memory may be RO, and freeing RO memory in an interrupt is not
2225 * supported by vmalloc.
2227 WARN_ON(in_interrupt());
2228 vfree(module_region);
2231 void __weak module_arch_cleanup(struct module *mod)
2235 void __weak module_arch_freeing_init(struct module *mod)
2239 /* Free a module, remove from lists, etc. */
2240 static void free_module(struct module *mod)
2242 trace_module_free(mod);
2244 mod_sysfs_teardown(mod);
2246 /* We leave it in list to prevent duplicate loads, but make sure
2247 * that noone uses it while it's being deconstructed. */
2248 mutex_lock(&module_mutex);
2249 mod->state = MODULE_STATE_UNFORMED;
2250 mutex_unlock(&module_mutex);
2252 /* Remove dynamic debug info */
2253 ddebug_remove_module(mod->name);
2255 /* Arch-specific cleanup. */
2256 module_arch_cleanup(mod);
2258 /* Module unload stuff */
2259 module_unload_free(mod);
2261 /* Free any allocated parameters. */
2262 destroy_params(mod->kp, mod->num_kp);
2264 if (is_livepatch_module(mod))
2265 free_module_elf(mod);
2267 /* Now we can delete it from the lists */
2268 mutex_lock(&module_mutex);
2269 /* Unlink carefully: kallsyms could be walking list. */
2270 list_del_rcu(&mod->list);
2271 mod_tree_remove(mod);
2272 /* Remove this module from bug list, this uses list_del_rcu */
2273 module_bug_cleanup(mod);
2274 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2276 mutex_unlock(&module_mutex);
2278 /* This may be empty, but that's OK */
2279 module_arch_freeing_init(mod);
2280 module_memfree(mod->init_layout.base);
2282 percpu_modfree(mod);
2284 /* Free lock-classes; relies on the preceding sync_rcu(). */
2285 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
2287 /* Finally, free the core (containing the module structure) */
2288 module_memfree(mod->core_layout.base);
2291 void *__symbol_get(const char *symbol)
2293 struct module *owner;
2294 enum mod_license license;
2295 const struct kernel_symbol *sym;
2298 sym = find_symbol(symbol, &owner, NULL, &license, true, true);
2301 if (license != GPL_ONLY) {
2302 pr_warn("failing symbol_get of non-GPLONLY symbol %s.\n",
2306 if (strong_try_module_get(owner))
2310 return sym ? (void *)kernel_symbol_value(sym) : NULL;
2315 EXPORT_SYMBOL_GPL(__symbol_get);
2318 * Ensure that an exported symbol [global namespace] does not already exist
2319 * in the kernel or in some other module's exported symbol table.
2321 * You must hold the module_mutex.
2323 static int verify_exported_symbols(struct module *mod)
2326 struct module *owner;
2327 const struct kernel_symbol *s;
2329 const struct kernel_symbol *sym;
2332 { mod->syms, mod->num_syms },
2333 { mod->gpl_syms, mod->num_gpl_syms },
2334 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2335 #ifdef CONFIG_UNUSED_SYMBOLS
2336 { mod->unused_syms, mod->num_unused_syms },
2337 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2341 for (i = 0; i < ARRAY_SIZE(arr); i++) {
2342 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2343 if (find_symbol(kernel_symbol_name(s), &owner, NULL,
2344 NULL, true, false)) {
2345 pr_err("%s: exports duplicate symbol %s"
2347 mod->name, kernel_symbol_name(s),
2348 module_name(owner));
2356 static bool ignore_undef_symbol(Elf_Half emachine, const char *name)
2359 * On x86, PIC code and Clang non-PIC code may have call foo@PLT. GNU as
2360 * before 2.37 produces an unreferenced _GLOBAL_OFFSET_TABLE_ on x86-64.
2361 * i386 has a similar problem but may not deserve a fix.
2363 * If we ever have to ignore many symbols, consider refactoring the code to
2364 * only warn if referenced by a relocation.
2366 if (emachine == EM_386 || emachine == EM_X86_64)
2367 return !strcmp(name, "_GLOBAL_OFFSET_TABLE_");
2371 /* Change all symbols so that st_value encodes the pointer directly. */
2372 static int simplify_symbols(struct module *mod, const struct load_info *info)
2374 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2375 Elf_Sym *sym = (void *)symsec->sh_addr;
2376 unsigned long secbase;
2379 const struct kernel_symbol *ksym;
2381 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2382 const char *name = info->strtab + sym[i].st_name;
2384 switch (sym[i].st_shndx) {
2386 /* Ignore common symbols */
2387 if (!strncmp(name, "__gnu_lto", 9))
2390 /* We compiled with -fno-common. These are not
2391 supposed to happen. */
2392 pr_debug("Common symbol: %s\n", name);
2393 pr_warn("%s: please compile with -fno-common\n",
2399 /* Don't need to do anything */
2400 pr_debug("Absolute symbol: 0x%08lx\n",
2401 (long)sym[i].st_value);
2405 /* Livepatch symbols are resolved by livepatch */
2409 ksym = resolve_symbol_wait(mod, info, name);
2410 /* Ok if resolved. */
2411 if (ksym && !IS_ERR(ksym)) {
2412 sym[i].st_value = kernel_symbol_value(ksym);
2416 /* Ok if weak or ignored. */
2418 (ELF_ST_BIND(sym[i].st_info) == STB_WEAK ||
2419 ignore_undef_symbol(info->hdr->e_machine, name)))
2422 ret = PTR_ERR(ksym) ?: -ENOENT;
2423 pr_warn("%s: Unknown symbol %s (err %d)\n",
2424 mod->name, name, ret);
2428 /* Divert to percpu allocation if a percpu var. */
2429 if (sym[i].st_shndx == info->index.pcpu)
2430 secbase = (unsigned long)mod_percpu(mod);
2432 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2433 sym[i].st_value += secbase;
2441 static int apply_relocations(struct module *mod, const struct load_info *info)
2446 /* Now do relocations. */
2447 for (i = 1; i < info->hdr->e_shnum; i++) {
2448 unsigned int infosec = info->sechdrs[i].sh_info;
2450 /* Not a valid relocation section? */
2451 if (infosec >= info->hdr->e_shnum)
2454 /* Don't bother with non-allocated sections */
2455 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2458 /* Livepatch relocation sections are applied by livepatch */
2459 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
2462 if (info->sechdrs[i].sh_type == SHT_REL)
2463 err = apply_relocate(info->sechdrs, info->strtab,
2464 info->index.sym, i, mod);
2465 else if (info->sechdrs[i].sh_type == SHT_RELA)
2466 err = apply_relocate_add(info->sechdrs, info->strtab,
2467 info->index.sym, i, mod);
2474 /* Additional bytes needed by arch in front of individual sections */
2475 unsigned int __weak arch_mod_section_prepend(struct module *mod,
2476 unsigned int section)
2478 /* default implementation just returns zero */
2482 /* Update size with this section: return offset. */
2483 static long get_offset(struct module *mod, unsigned int *size,
2484 Elf_Shdr *sechdr, unsigned int section)
2488 *size += arch_mod_section_prepend(mod, section);
2489 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2490 *size = ret + sechdr->sh_size;
2494 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2495 might -- code, read-only data, read-write data, small data. Tally
2496 sizes, and place the offsets into sh_entsize fields: high bit means it
2498 static void layout_sections(struct module *mod, struct load_info *info)
2500 static unsigned long const masks[][2] = {
2501 /* NOTE: all executable code must be the first section
2502 * in this array; otherwise modify the text_size
2503 * finder in the two loops below */
2504 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2505 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2506 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
2507 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2508 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2512 for (i = 0; i < info->hdr->e_shnum; i++)
2513 info->sechdrs[i].sh_entsize = ~0UL;
2515 pr_debug("Core section allocation order:\n");
2516 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2517 for (i = 0; i < info->hdr->e_shnum; ++i) {
2518 Elf_Shdr *s = &info->sechdrs[i];
2519 const char *sname = info->secstrings + s->sh_name;
2521 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2522 || (s->sh_flags & masks[m][1])
2523 || s->sh_entsize != ~0UL
2524 || strstarts(sname, ".init"))
2526 s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2527 pr_debug("\t%s\n", sname);
2530 case 0: /* executable */
2531 mod->core_layout.size = debug_align(mod->core_layout.size);
2532 mod->core_layout.text_size = mod->core_layout.size;
2534 case 1: /* RO: text and ro-data */
2535 mod->core_layout.size = debug_align(mod->core_layout.size);
2536 mod->core_layout.ro_size = mod->core_layout.size;
2538 case 2: /* RO after init */
2539 mod->core_layout.size = debug_align(mod->core_layout.size);
2540 mod->core_layout.ro_after_init_size = mod->core_layout.size;
2542 case 4: /* whole core */
2543 mod->core_layout.size = debug_align(mod->core_layout.size);
2548 pr_debug("Init section allocation order:\n");
2549 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2550 for (i = 0; i < info->hdr->e_shnum; ++i) {
2551 Elf_Shdr *s = &info->sechdrs[i];
2552 const char *sname = info->secstrings + s->sh_name;
2554 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2555 || (s->sh_flags & masks[m][1])
2556 || s->sh_entsize != ~0UL
2557 || !strstarts(sname, ".init"))
2559 s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
2560 | INIT_OFFSET_MASK);
2561 pr_debug("\t%s\n", sname);
2564 case 0: /* executable */
2565 mod->init_layout.size = debug_align(mod->init_layout.size);
2566 mod->init_layout.text_size = mod->init_layout.size;
2568 case 1: /* RO: text and ro-data */
2569 mod->init_layout.size = debug_align(mod->init_layout.size);
2570 mod->init_layout.ro_size = mod->init_layout.size;
2574 * RO after init doesn't apply to init_layout (only
2575 * core_layout), so it just takes the value of ro_size.
2577 mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
2579 case 4: /* whole init */
2580 mod->init_layout.size = debug_align(mod->init_layout.size);
2586 static void set_license(struct module *mod, const char *license)
2589 license = "unspecified";
2591 if (!license_is_gpl_compatible(license)) {
2592 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2593 pr_warn("%s: module license '%s' taints kernel.\n",
2594 mod->name, license);
2595 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2596 LOCKDEP_NOW_UNRELIABLE);
2600 /* Parse tag=value strings from .modinfo section */
2601 static char *next_string(char *string, unsigned long *secsize)
2603 /* Skip non-zero chars */
2606 if ((*secsize)-- <= 1)
2610 /* Skip any zero padding. */
2611 while (!string[0]) {
2613 if ((*secsize)-- <= 1)
2619 static char *get_next_modinfo(const struct load_info *info, const char *tag,
2623 unsigned int taglen = strlen(tag);
2624 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2625 unsigned long size = infosec->sh_size;
2628 * get_modinfo() calls made before rewrite_section_headers()
2629 * must use sh_offset, as sh_addr isn't set!
2631 char *modinfo = (char *)info->hdr + infosec->sh_offset;
2634 size -= prev - modinfo;
2635 modinfo = next_string(prev, &size);
2638 for (p = modinfo; p; p = next_string(p, &size)) {
2639 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2640 return p + taglen + 1;
2645 static char *get_modinfo(const struct load_info *info, const char *tag)
2647 return get_next_modinfo(info, tag, NULL);
2650 static void setup_modinfo(struct module *mod, struct load_info *info)
2652 struct module_attribute *attr;
2655 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2657 attr->setup(mod, get_modinfo(info, attr->attr.name));
2661 static void free_modinfo(struct module *mod)
2663 struct module_attribute *attr;
2666 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2672 #ifdef CONFIG_KALLSYMS
2674 /* Lookup exported symbol in given range of kernel_symbols */
2675 static const struct kernel_symbol *lookup_exported_symbol(const char *name,
2676 const struct kernel_symbol *start,
2677 const struct kernel_symbol *stop)
2679 return bsearch(name, start, stop - start,
2680 sizeof(struct kernel_symbol), cmp_name);
2683 static int is_exported(const char *name, unsigned long value,
2684 const struct module *mod)
2686 const struct kernel_symbol *ks;
2688 ks = lookup_exported_symbol(name, __start___ksymtab, __stop___ksymtab);
2690 ks = lookup_exported_symbol(name, mod->syms, mod->syms + mod->num_syms);
2692 return ks != NULL && kernel_symbol_value(ks) == value;
2696 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2698 const Elf_Shdr *sechdrs = info->sechdrs;
2700 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2701 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2706 if (sym->st_shndx == SHN_UNDEF)
2708 if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
2710 if (sym->st_shndx >= SHN_LORESERVE)
2712 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2714 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2715 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2716 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2718 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2723 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2724 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2729 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2736 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2737 unsigned int shnum, unsigned int pcpundx)
2739 const Elf_Shdr *sec;
2741 if (src->st_shndx == SHN_UNDEF
2742 || src->st_shndx >= shnum
2746 #ifdef CONFIG_KALLSYMS_ALL
2747 if (src->st_shndx == pcpundx)
2751 sec = sechdrs + src->st_shndx;
2752 if (!(sec->sh_flags & SHF_ALLOC)
2753 #ifndef CONFIG_KALLSYMS_ALL
2754 || !(sec->sh_flags & SHF_EXECINSTR)
2756 || (sec->sh_entsize & INIT_OFFSET_MASK))
2763 * We only allocate and copy the strings needed by the parts of symtab
2764 * we keep. This is simple, but has the effect of making multiple
2765 * copies of duplicates. We could be more sophisticated, see
2766 * linux-kernel thread starting with
2767 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2769 static void layout_symtab(struct module *mod, struct load_info *info)
2771 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2772 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2774 unsigned int i, nsrc, ndst, strtab_size = 0;
2776 /* Put symbol section at end of init part of module. */
2777 symsect->sh_flags |= SHF_ALLOC;
2778 symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2779 info->index.sym) | INIT_OFFSET_MASK;
2780 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2782 src = (void *)info->hdr + symsect->sh_offset;
2783 nsrc = symsect->sh_size / sizeof(*src);
2785 /* Compute total space required for the core symbols' strtab. */
2786 for (ndst = i = 0; i < nsrc; i++) {
2787 if (i == 0 || is_livepatch_module(mod) ||
2788 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2789 info->index.pcpu)) {
2790 strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2795 /* Append room for core symbols at end of core part. */
2796 info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
2797 info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
2798 mod->core_layout.size += strtab_size;
2799 info->core_typeoffs = mod->core_layout.size;
2800 mod->core_layout.size += ndst * sizeof(char);
2801 mod->core_layout.size = debug_align(mod->core_layout.size);
2803 /* Put string table section at end of init part of module. */
2804 strsect->sh_flags |= SHF_ALLOC;
2805 strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2806 info->index.str) | INIT_OFFSET_MASK;
2807 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2809 /* We'll tack temporary mod_kallsyms on the end. */
2810 mod->init_layout.size = ALIGN(mod->init_layout.size,
2811 __alignof__(struct mod_kallsyms));
2812 info->mod_kallsyms_init_off = mod->init_layout.size;
2813 mod->init_layout.size += sizeof(struct mod_kallsyms);
2814 info->init_typeoffs = mod->init_layout.size;
2815 mod->init_layout.size += nsrc * sizeof(char);
2816 mod->init_layout.size = debug_align(mod->init_layout.size);
2820 * We use the full symtab and strtab which layout_symtab arranged to
2821 * be appended to the init section. Later we switch to the cut-down
2824 static void add_kallsyms(struct module *mod, const struct load_info *info)
2826 unsigned int i, ndst;
2830 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2832 /* Set up to point into init section. */
2833 mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
2835 mod->kallsyms->symtab = (void *)symsec->sh_addr;
2836 mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2837 /* Make sure we get permanent strtab: don't use info->strtab. */
2838 mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2839 mod->kallsyms->typetab = mod->init_layout.base + info->init_typeoffs;
2842 * Now populate the cut down core kallsyms for after init
2843 * and set types up while we still have access to sections.
2845 mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
2846 mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
2847 mod->core_kallsyms.typetab = mod->core_layout.base + info->core_typeoffs;
2848 src = mod->kallsyms->symtab;
2849 for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2850 mod->kallsyms->typetab[i] = elf_type(src + i, info);
2851 if (i == 0 || is_livepatch_module(mod) ||
2852 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2853 info->index.pcpu)) {
2854 mod->core_kallsyms.typetab[ndst] =
2855 mod->kallsyms->typetab[i];
2857 dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
2858 s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2862 mod->core_kallsyms.num_symtab = ndst;
2865 static inline void layout_symtab(struct module *mod, struct load_info *info)
2869 static void add_kallsyms(struct module *mod, const struct load_info *info)
2872 #endif /* CONFIG_KALLSYMS */
2874 static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num)
2878 ddebug_add_module(debug, num, mod->name);
2881 static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug)
2884 ddebug_remove_module(mod->name);
2887 void * __weak module_alloc(unsigned long size)
2889 return vmalloc_exec(size);
2892 bool __weak module_exit_section(const char *name)
2894 return strstarts(name, ".exit");
2897 #ifdef CONFIG_DEBUG_KMEMLEAK
2898 static void kmemleak_load_module(const struct module *mod,
2899 const struct load_info *info)
2903 /* only scan the sections containing data */
2904 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2906 for (i = 1; i < info->hdr->e_shnum; i++) {
2907 /* Scan all writable sections that's not executable */
2908 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2909 !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2910 (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2913 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2914 info->sechdrs[i].sh_size, GFP_KERNEL);
2918 static inline void kmemleak_load_module(const struct module *mod,
2919 const struct load_info *info)
2924 #ifdef CONFIG_MODULE_SIG
2925 static int module_sig_check(struct load_info *info, int flags)
2928 const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2930 const void *mod = info->hdr;
2933 * Require flags == 0, as a module with version information
2934 * removed is no longer the module that was signed
2937 info->len > markerlen &&
2938 memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2939 /* We truncate the module to discard the signature */
2940 info->len -= markerlen;
2941 err = mod_verify_sig(mod, info);
2946 info->sig_ok = true;
2949 /* We don't permit modules to be loaded into trusted kernels
2950 * without a valid signature on them, but if we're not
2951 * enforcing, certain errors are non-fatal.
2954 reason = "unsigned module";
2957 reason = "module with unsupported crypto";
2960 reason = "module with unavailable key";
2963 /* All other errors are fatal, including nomem, unparseable
2964 * signatures and signature check failures - even if signatures
2971 if (is_module_sig_enforced()) {
2972 pr_notice("Loading of %s is rejected\n", reason);
2973 return -EKEYREJECTED;
2976 return security_locked_down(LOCKDOWN_MODULE_SIGNATURE);
2978 #else /* !CONFIG_MODULE_SIG */
2979 static int module_sig_check(struct load_info *info, int flags)
2983 #endif /* !CONFIG_MODULE_SIG */
2985 static int validate_section_offset(struct load_info *info, Elf_Shdr *shdr)
2987 unsigned long secend;
2990 * Check for both overflow and offset/size being
2993 secend = shdr->sh_offset + shdr->sh_size;
2994 if (secend < shdr->sh_offset || secend > info->len)
3001 * Sanity checks against invalid binaries, wrong arch, weird elf version.
3003 * Also do basic validity checks against section offsets and sizes, the
3004 * section name string table, and the indices used for it (sh_name).
3006 static int elf_validity_check(struct load_info *info)
3009 Elf_Shdr *shdr, *strhdr;
3012 if (info->len < sizeof(*(info->hdr)))
3015 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
3016 || info->hdr->e_type != ET_REL
3017 || !elf_check_arch(info->hdr)
3018 || info->hdr->e_shentsize != sizeof(Elf_Shdr))
3022 * e_shnum is 16 bits, and sizeof(Elf_Shdr) is
3023 * known and small. So e_shnum * sizeof(Elf_Shdr)
3024 * will not overflow unsigned long on any platform.
3026 if (info->hdr->e_shoff >= info->len
3027 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
3028 info->len - info->hdr->e_shoff))
3031 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
3034 * Verify if the section name table index is valid.
3036 if (info->hdr->e_shstrndx == SHN_UNDEF
3037 || info->hdr->e_shstrndx >= info->hdr->e_shnum)
3040 strhdr = &info->sechdrs[info->hdr->e_shstrndx];
3041 err = validate_section_offset(info, strhdr);
3046 * The section name table must be NUL-terminated, as required
3047 * by the spec. This makes strcmp and pr_* calls that access
3048 * strings in the section safe.
3050 info->secstrings = (void *)info->hdr + strhdr->sh_offset;
3051 if (info->secstrings[strhdr->sh_size - 1] != '\0')
3055 * The code assumes that section 0 has a length of zero and
3056 * an addr of zero, so check for it.
3058 if (info->sechdrs[0].sh_type != SHT_NULL
3059 || info->sechdrs[0].sh_size != 0
3060 || info->sechdrs[0].sh_addr != 0)
3063 for (i = 1; i < info->hdr->e_shnum; i++) {
3064 shdr = &info->sechdrs[i];
3065 switch (shdr->sh_type) {
3070 if (shdr->sh_link == SHN_UNDEF
3071 || shdr->sh_link >= info->hdr->e_shnum)
3075 err = validate_section_offset(info, shdr);
3077 pr_err("Invalid ELF section in module (section %u type %u)\n",
3082 if (shdr->sh_flags & SHF_ALLOC) {
3083 if (shdr->sh_name >= strhdr->sh_size) {
3084 pr_err("Invalid ELF section name in module (section %u type %u)\n",
3096 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
3098 static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
3101 unsigned long n = min(len, COPY_CHUNK_SIZE);
3103 if (copy_from_user(dst, usrc, n) != 0)
3113 #ifdef CONFIG_LIVEPATCH
3114 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
3116 if (get_modinfo(info, "livepatch")) {
3118 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
3119 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
3125 #else /* !CONFIG_LIVEPATCH */
3126 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
3128 if (get_modinfo(info, "livepatch")) {
3129 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
3136 #endif /* CONFIG_LIVEPATCH */
3138 static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
3140 if (retpoline_module_ok(get_modinfo(info, "retpoline")))
3143 pr_warn("%s: loading module not compiled with retpoline compiler.\n",
3147 /* Sets info->hdr and info->len. */
3148 static int copy_module_from_user(const void __user *umod, unsigned long len,
3149 struct load_info *info)
3154 if (info->len < sizeof(*(info->hdr)))
3157 err = security_kernel_load_data(LOADING_MODULE);
3161 /* Suck in entire file: we'll want most of it. */
3162 info->hdr = __vmalloc(info->len,
3163 GFP_KERNEL | __GFP_NOWARN, PAGE_KERNEL);
3167 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
3175 static void free_copy(struct load_info *info)
3180 static int rewrite_section_headers(struct load_info *info, int flags)
3184 /* This should always be true, but let's be sure. */
3185 info->sechdrs[0].sh_addr = 0;
3187 for (i = 1; i < info->hdr->e_shnum; i++) {
3188 Elf_Shdr *shdr = &info->sechdrs[i];
3190 /* Mark all sections sh_addr with their address in the
3192 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
3194 #ifndef CONFIG_MODULE_UNLOAD
3195 /* Don't load .exit sections */
3196 if (module_exit_section(info->secstrings+shdr->sh_name))
3197 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
3201 /* Track but don't keep modinfo and version sections. */
3202 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
3203 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
3209 * Set up our basic convenience variables (pointers to section headers,
3210 * search for module section index etc), and do some basic section
3213 * Set info->mod to the temporary copy of the module in info->hdr. The final one
3214 * will be allocated in move_module().
3216 static int setup_load_info(struct load_info *info, int flags)
3220 /* Try to find a name early so we can log errors with a module name */
3221 info->index.info = find_sec(info, ".modinfo");
3222 if (info->index.info)
3223 info->name = get_modinfo(info, "name");
3225 /* Find internal symbols and strings. */
3226 for (i = 1; i < info->hdr->e_shnum; i++) {
3227 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
3228 info->index.sym = i;
3229 info->index.str = info->sechdrs[i].sh_link;
3230 info->strtab = (char *)info->hdr
3231 + info->sechdrs[info->index.str].sh_offset;
3236 if (info->index.sym == 0) {
3237 pr_warn("%s: module has no symbols (stripped?)\n",
3238 info->name ?: "(missing .modinfo section or name field)");
3242 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
3243 if (!info->index.mod) {
3244 pr_warn("%s: No module found in object\n",
3245 info->name ?: "(missing .modinfo section or name field)");
3248 /* This is temporary: point mod into copy of data. */
3249 info->mod = (void *)info->hdr + info->sechdrs[info->index.mod].sh_offset;
3252 * If we didn't load the .modinfo 'name' field earlier, fall back to
3253 * on-disk struct mod 'name' field.
3256 info->name = info->mod->name;
3258 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
3259 info->index.vers = 0; /* Pretend no __versions section! */
3261 info->index.vers = find_sec(info, "__versions");
3263 info->index.pcpu = find_pcpusec(info);
3268 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
3270 const char *modmagic = get_modinfo(info, "vermagic");
3273 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
3276 /* This is allowed: modprobe --force will invalidate it. */
3278 err = try_to_force_load(mod, "bad vermagic");
3281 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
3282 pr_err("%s: version magic '%s' should be '%s'\n",
3283 info->name, modmagic, vermagic);
3287 if (!get_modinfo(info, "intree")) {
3288 if (!test_taint(TAINT_OOT_MODULE))
3289 pr_warn("%s: loading out-of-tree module taints kernel.\n",
3291 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
3294 check_modinfo_retpoline(mod, info);
3296 if (get_modinfo(info, "staging")) {
3297 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
3298 pr_warn("%s: module is from the staging directory, the quality "
3299 "is unknown, you have been warned.\n", mod->name);
3302 err = check_modinfo_livepatch(mod, info);
3306 /* Set up license info based on the info section */
3307 set_license(mod, get_modinfo(info, "license"));
3312 static int find_module_sections(struct module *mod, struct load_info *info)
3314 mod->kp = section_objs(info, "__param",
3315 sizeof(*mod->kp), &mod->num_kp);
3316 mod->syms = section_objs(info, "__ksymtab",
3317 sizeof(*mod->syms), &mod->num_syms);
3318 mod->crcs = section_addr(info, "__kcrctab");
3319 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
3320 sizeof(*mod->gpl_syms),
3321 &mod->num_gpl_syms);
3322 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
3323 mod->gpl_future_syms = section_objs(info,
3324 "__ksymtab_gpl_future",
3325 sizeof(*mod->gpl_future_syms),
3326 &mod->num_gpl_future_syms);
3327 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
3329 #ifdef CONFIG_UNUSED_SYMBOLS
3330 mod->unused_syms = section_objs(info, "__ksymtab_unused",
3331 sizeof(*mod->unused_syms),
3332 &mod->num_unused_syms);
3333 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
3334 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
3335 sizeof(*mod->unused_gpl_syms),
3336 &mod->num_unused_gpl_syms);
3337 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
3339 #ifdef CONFIG_CONSTRUCTORS
3340 mod->ctors = section_objs(info, ".ctors",
3341 sizeof(*mod->ctors), &mod->num_ctors);
3343 mod->ctors = section_objs(info, ".init_array",
3344 sizeof(*mod->ctors), &mod->num_ctors);
3345 else if (find_sec(info, ".init_array")) {
3347 * This shouldn't happen with same compiler and binutils
3348 * building all parts of the module.
3350 pr_warn("%s: has both .ctors and .init_array.\n",
3356 #ifdef CONFIG_TRACEPOINTS
3357 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
3358 sizeof(*mod->tracepoints_ptrs),
3359 &mod->num_tracepoints);
3361 #ifdef CONFIG_TREE_SRCU
3362 mod->srcu_struct_ptrs = section_objs(info, "___srcu_struct_ptrs",
3363 sizeof(*mod->srcu_struct_ptrs),
3364 &mod->num_srcu_structs);
3366 #ifdef CONFIG_BPF_EVENTS
3367 mod->bpf_raw_events = section_objs(info, "__bpf_raw_tp_map",
3368 sizeof(*mod->bpf_raw_events),
3369 &mod->num_bpf_raw_events);
3371 #ifdef CONFIG_JUMP_LABEL
3372 mod->jump_entries = section_objs(info, "__jump_table",
3373 sizeof(*mod->jump_entries),
3374 &mod->num_jump_entries);
3376 #ifdef CONFIG_EVENT_TRACING
3377 mod->trace_events = section_objs(info, "_ftrace_events",
3378 sizeof(*mod->trace_events),
3379 &mod->num_trace_events);
3380 mod->trace_evals = section_objs(info, "_ftrace_eval_map",
3381 sizeof(*mod->trace_evals),
3382 &mod->num_trace_evals);
3384 #ifdef CONFIG_TRACING
3385 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
3386 sizeof(*mod->trace_bprintk_fmt_start),
3387 &mod->num_trace_bprintk_fmt);
3389 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
3390 /* sechdrs[0].sh_size is always zero */
3391 mod->ftrace_callsites = section_objs(info, FTRACE_CALLSITE_SECTION,
3392 sizeof(*mod->ftrace_callsites),
3393 &mod->num_ftrace_callsites);
3395 #ifdef CONFIG_FUNCTION_ERROR_INJECTION
3396 mod->ei_funcs = section_objs(info, "_error_injection_whitelist",
3397 sizeof(*mod->ei_funcs),
3398 &mod->num_ei_funcs);
3400 mod->extable = section_objs(info, "__ex_table",
3401 sizeof(*mod->extable), &mod->num_exentries);
3403 if (section_addr(info, "__obsparm"))
3404 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
3406 info->debug = section_objs(info, "__verbose",
3407 sizeof(*info->debug), &info->num_debug);
3412 static int move_module(struct module *mod, struct load_info *info)
3417 /* Do the allocs. */
3418 ptr = module_alloc(mod->core_layout.size);
3420 * The pointer to this block is stored in the module structure
3421 * which is inside the block. Just mark it as not being a
3424 kmemleak_not_leak(ptr);
3428 memset(ptr, 0, mod->core_layout.size);
3429 mod->core_layout.base = ptr;
3431 if (mod->init_layout.size) {
3432 ptr = module_alloc(mod->init_layout.size);
3434 * The pointer to this block is stored in the module structure
3435 * which is inside the block. This block doesn't need to be
3436 * scanned as it contains data and code that will be freed
3437 * after the module is initialized.
3439 kmemleak_ignore(ptr);
3441 module_memfree(mod->core_layout.base);
3444 memset(ptr, 0, mod->init_layout.size);
3445 mod->init_layout.base = ptr;
3447 mod->init_layout.base = NULL;
3449 /* Transfer each section which specifies SHF_ALLOC */
3450 pr_debug("final section addresses:\n");
3451 for (i = 0; i < info->hdr->e_shnum; i++) {
3453 Elf_Shdr *shdr = &info->sechdrs[i];
3455 if (!(shdr->sh_flags & SHF_ALLOC))
3458 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3459 dest = mod->init_layout.base
3460 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3462 dest = mod->core_layout.base + shdr->sh_entsize;
3464 if (shdr->sh_type != SHT_NOBITS)
3465 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3466 /* Update sh_addr to point to copy in image. */
3467 shdr->sh_addr = (unsigned long)dest;
3468 pr_debug("\t0x%lx %s\n",
3469 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3475 static int check_module_license_and_versions(struct module *mod)
3477 int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
3480 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3481 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3482 * using GPL-only symbols it needs.
3484 if (strcmp(mod->name, "ndiswrapper") == 0)
3485 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3487 /* driverloader was caught wrongly pretending to be under GPL */
3488 if (strcmp(mod->name, "driverloader") == 0)
3489 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3490 LOCKDEP_NOW_UNRELIABLE);
3492 /* lve claims to be GPL but upstream won't provide source */
3493 if (strcmp(mod->name, "lve") == 0)
3494 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3495 LOCKDEP_NOW_UNRELIABLE);
3497 if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
3498 pr_warn("%s: module license taints kernel.\n", mod->name);
3500 #ifdef CONFIG_MODVERSIONS
3501 if ((mod->num_syms && !mod->crcs)
3502 || (mod->num_gpl_syms && !mod->gpl_crcs)
3503 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3504 #ifdef CONFIG_UNUSED_SYMBOLS
3505 || (mod->num_unused_syms && !mod->unused_crcs)
3506 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3509 return try_to_force_load(mod,
3510 "no versions for exported symbols");
3516 static void flush_module_icache(const struct module *mod)
3518 mm_segment_t old_fs;
3520 /* flush the icache in correct context */
3525 * Flush the instruction cache, since we've played with text.
3526 * Do it before processing of module parameters, so the module
3527 * can provide parameter accessor functions of its own.
3529 if (mod->init_layout.base)
3530 flush_icache_range((unsigned long)mod->init_layout.base,
3531 (unsigned long)mod->init_layout.base
3532 + mod->init_layout.size);
3533 flush_icache_range((unsigned long)mod->core_layout.base,
3534 (unsigned long)mod->core_layout.base + mod->core_layout.size);
3539 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3547 /* module_blacklist is a comma-separated list of module names */
3548 static char *module_blacklist;
3549 static bool blacklisted(const char *module_name)
3554 if (!module_blacklist)
3557 for (p = module_blacklist; *p; p += len) {
3558 len = strcspn(p, ",");
3559 if (strlen(module_name) == len && !memcmp(module_name, p, len))
3566 core_param(module_blacklist, module_blacklist, charp, 0400);
3568 static struct module *layout_and_allocate(struct load_info *info, int flags)
3574 err = check_modinfo(info->mod, info, flags);
3576 return ERR_PTR(err);
3578 /* Allow arches to frob section contents and sizes. */
3579 err = module_frob_arch_sections(info->hdr, info->sechdrs,
3580 info->secstrings, info->mod);
3582 return ERR_PTR(err);
3584 /* We will do a special allocation for per-cpu sections later. */
3585 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3588 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3589 * layout_sections() can put it in the right place.
3590 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3592 ndx = find_sec(info, ".data..ro_after_init");
3594 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3596 * Mark the __jump_table section as ro_after_init as well: these data
3597 * structures are never modified, with the exception of entries that
3598 * refer to code in the __init section, which are annotated as such
3599 * at module load time.
3601 ndx = find_sec(info, "__jump_table");
3603 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3605 /* Determine total sizes, and put offsets in sh_entsize. For now
3606 this is done generically; there doesn't appear to be any
3607 special cases for the architectures. */
3608 layout_sections(info->mod, info);
3609 layout_symtab(info->mod, info);
3611 /* Allocate and move to the final place */
3612 err = move_module(info->mod, info);
3614 return ERR_PTR(err);
3616 /* Module has been copied to its final place now: return it. */
3617 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3618 kmemleak_load_module(mod, info);
3622 /* mod is no longer valid after this! */
3623 static void module_deallocate(struct module *mod, struct load_info *info)
3625 percpu_modfree(mod);
3626 module_arch_freeing_init(mod);
3627 module_memfree(mod->init_layout.base);
3628 module_memfree(mod->core_layout.base);
3631 int __weak module_finalize(const Elf_Ehdr *hdr,
3632 const Elf_Shdr *sechdrs,
3638 static int post_relocation(struct module *mod, const struct load_info *info)
3640 /* Sort exception table now relocations are done. */
3641 sort_extable(mod->extable, mod->extable + mod->num_exentries);
3643 /* Copy relocated percpu area over. */
3644 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3645 info->sechdrs[info->index.pcpu].sh_size);
3647 /* Setup kallsyms-specific fields. */
3648 add_kallsyms(mod, info);
3650 /* Arch-specific module finalizing. */
3651 return module_finalize(info->hdr, info->sechdrs, mod);
3654 /* Is this module of this name done loading? No locks held. */
3655 static bool finished_loading(const char *name)
3661 * The module_mutex should not be a heavily contended lock;
3662 * if we get the occasional sleep here, we'll go an extra iteration
3663 * in the wait_event_interruptible(), which is harmless.
3665 sched_annotate_sleep();
3666 mutex_lock(&module_mutex);
3667 mod = find_module_all(name, strlen(name), true);
3668 ret = !mod || mod->state == MODULE_STATE_LIVE
3669 || mod->state == MODULE_STATE_GOING;
3670 mutex_unlock(&module_mutex);
3675 /* Call module constructors. */
3676 static void do_mod_ctors(struct module *mod)
3678 #ifdef CONFIG_CONSTRUCTORS
3681 for (i = 0; i < mod->num_ctors; i++)
3686 /* For freeing module_init on success, in case kallsyms traversing */
3687 struct mod_initfree {
3688 struct llist_node node;
3692 static void do_free_init(struct work_struct *w)
3694 struct llist_node *pos, *n, *list;
3695 struct mod_initfree *initfree;
3697 list = llist_del_all(&init_free_list);
3701 llist_for_each_safe(pos, n, list) {
3702 initfree = container_of(pos, struct mod_initfree, node);
3703 module_memfree(initfree->module_init);
3709 * This is where the real work happens.
3711 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3712 * helper command 'lx-symbols'.
3714 static noinline int do_init_module(struct module *mod)
3717 struct mod_initfree *freeinit;
3719 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3724 freeinit->module_init = mod->init_layout.base;
3727 /* Start the module */
3728 if (mod->init != NULL)
3729 ret = do_one_initcall(mod->init);
3731 goto fail_free_freeinit;
3734 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3735 "follow 0/-E convention\n"
3736 "%s: loading module anyway...\n",
3737 __func__, mod->name, ret, __func__);
3741 /* Now it's a first class citizen! */
3742 mod->state = MODULE_STATE_LIVE;
3743 blocking_notifier_call_chain(&module_notify_list,
3744 MODULE_STATE_LIVE, mod);
3746 /* Delay uevent until module has finished its init routine */
3747 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
3750 * We need to finish all async code before the module init sequence
3751 * is done. This has potential to deadlock if synchronous module
3752 * loading is requested from async (which is not allowed!).
3754 * See commit 0fdff3ec6d87 ("async, kmod: warn on synchronous
3755 * request_module() from async workers") for more details.
3757 if (!mod->async_probe_requested)
3758 async_synchronize_full();
3760 ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base +
3761 mod->init_layout.size);
3762 mutex_lock(&module_mutex);
3763 /* Drop initial reference. */
3765 trim_init_extable(mod);
3766 #ifdef CONFIG_KALLSYMS
3767 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3768 rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3770 module_enable_ro(mod, true);
3771 mod_tree_remove_init(mod);
3772 module_arch_freeing_init(mod);
3773 mod->init_layout.base = NULL;
3774 mod->init_layout.size = 0;
3775 mod->init_layout.ro_size = 0;
3776 mod->init_layout.ro_after_init_size = 0;
3777 mod->init_layout.text_size = 0;
3779 * We want to free module_init, but be aware that kallsyms may be
3780 * walking this with preempt disabled. In all the failure paths, we
3781 * call synchronize_rcu(), but we don't want to slow down the success
3782 * path. module_memfree() cannot be called in an interrupt, so do the
3783 * work and call synchronize_rcu() in a work queue.
3785 * Note that module_alloc() on most architectures creates W+X page
3786 * mappings which won't be cleaned up until do_free_init() runs. Any
3787 * code such as mark_rodata_ro() which depends on those mappings to
3788 * be cleaned up needs to sync with the queued work - ie
3791 if (llist_add(&freeinit->node, &init_free_list))
3792 schedule_work(&init_free_wq);
3794 mutex_unlock(&module_mutex);
3795 wake_up_all(&module_wq);
3802 /* Try to protect us from buggy refcounters. */
3803 mod->state = MODULE_STATE_GOING;
3806 blocking_notifier_call_chain(&module_notify_list,
3807 MODULE_STATE_GOING, mod);
3808 klp_module_going(mod);
3809 ftrace_release_mod(mod);
3811 wake_up_all(&module_wq);
3815 static int may_init_module(void)
3817 if (!capable(CAP_SYS_MODULE) || modules_disabled)
3824 * We try to place it in the list now to make sure it's unique before
3825 * we dedicate too many resources. In particular, temporary percpu
3826 * memory exhaustion.
3828 static int add_unformed_module(struct module *mod)
3833 mod->state = MODULE_STATE_UNFORMED;
3835 mutex_lock(&module_mutex);
3836 old = find_module_all(mod->name, strlen(mod->name), true);
3838 if (old->state == MODULE_STATE_COMING
3839 || old->state == MODULE_STATE_UNFORMED) {
3840 /* Wait in case it fails to load. */
3841 mutex_unlock(&module_mutex);
3842 err = wait_event_interruptible(module_wq,
3843 finished_loading(mod->name));
3847 /* The module might have gone in the meantime. */
3848 mutex_lock(&module_mutex);
3849 old = find_module_all(mod->name, strlen(mod->name),
3854 * We are here only when the same module was being loaded. Do
3855 * not try to load it again right now. It prevents long delays
3856 * caused by serialized module load failures. It might happen
3857 * when more devices of the same type trigger load of
3858 * a particular module.
3860 if (old && old->state == MODULE_STATE_LIVE)
3866 mod_update_bounds(mod);
3867 list_add_rcu(&mod->list, &modules);
3868 mod_tree_insert(mod);
3872 mutex_unlock(&module_mutex);
3877 static int complete_formation(struct module *mod, struct load_info *info)
3881 mutex_lock(&module_mutex);
3883 /* Find duplicate symbols (must be called under lock). */
3884 err = verify_exported_symbols(mod);
3888 /* This relies on module_mutex for list integrity. */
3889 module_bug_finalize(info->hdr, info->sechdrs, mod);
3891 module_enable_ro(mod, false);
3892 module_enable_nx(mod);
3893 module_enable_x(mod);
3895 /* Mark state as coming so strong_try_module_get() ignores us,
3896 * but kallsyms etc. can see us. */
3897 mod->state = MODULE_STATE_COMING;
3898 mutex_unlock(&module_mutex);
3903 mutex_unlock(&module_mutex);
3907 static int prepare_coming_module(struct module *mod)
3911 ftrace_module_enable(mod);
3912 err = klp_module_coming(mod);
3916 blocking_notifier_call_chain(&module_notify_list,
3917 MODULE_STATE_COMING, mod);
3921 static int unknown_module_param_cb(char *param, char *val, const char *modname,
3924 struct module *mod = arg;
3927 if (strcmp(param, "async_probe") == 0) {
3928 mod->async_probe_requested = true;
3932 /* Check for magic 'dyndbg' arg */
3933 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3935 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3939 /* Allocate and load the module: note that size of section 0 is always
3940 zero, and we rely on this for optional sections. */
3941 static int load_module(struct load_info *info, const char __user *uargs,
3949 * Do the signature check (if any) first. All that
3950 * the signature check needs is info->len, it does
3951 * not need any of the section info. That can be
3952 * set up later. This will minimize the chances
3953 * of a corrupt module causing problems before
3954 * we even get to the signature check.
3956 * The check will also adjust info->len by stripping
3957 * off the sig length at the end of the module, making
3958 * checks against info->len more correct.
3960 err = module_sig_check(info, flags);
3965 * Do basic sanity checks against the ELF header and
3968 err = elf_validity_check(info);
3970 pr_err("Module has invalid ELF structures\n");
3975 * Everything checks out, so set up the section info
3976 * in the info structure.
3978 err = setup_load_info(info, flags);
3983 * Now that we know we have the correct module name, check
3984 * if it's blacklisted.
3986 if (blacklisted(info->name)) {
3991 err = rewrite_section_headers(info, flags);
3995 /* Check module struct version now, before we try to use module. */
3996 if (!check_modstruct_version(info, info->mod)) {
4001 /* Figure out module layout, and allocate all the memory. */
4002 mod = layout_and_allocate(info, flags);
4008 audit_log_kern_module(mod->name);
4010 /* Reserve our place in the list. */
4011 err = add_unformed_module(mod);
4015 #ifdef CONFIG_MODULE_SIG
4016 mod->sig_ok = info->sig_ok;
4018 pr_notice_once("%s: module verification failed: signature "
4019 "and/or required key missing - tainting "
4020 "kernel\n", mod->name);
4021 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
4025 /* To avoid stressing percpu allocator, do this once we're unique. */
4026 err = percpu_modalloc(mod, info);
4030 /* Now module is in final location, initialize linked lists, etc. */
4031 err = module_unload_init(mod);
4035 init_param_lock(mod);
4037 /* Now we've got everything in the final locations, we can
4038 * find optional sections. */
4039 err = find_module_sections(mod, info);
4043 err = check_module_license_and_versions(mod);
4047 /* Set up MODINFO_ATTR fields */
4048 setup_modinfo(mod, info);
4050 /* Fix up syms, so that st_value is a pointer to location. */
4051 err = simplify_symbols(mod, info);
4055 err = apply_relocations(mod, info);
4059 err = post_relocation(mod, info);
4063 flush_module_icache(mod);
4065 /* Now copy in args */
4066 mod->args = strndup_user(uargs, ~0UL >> 1);
4067 if (IS_ERR(mod->args)) {
4068 err = PTR_ERR(mod->args);
4069 goto free_arch_cleanup;
4072 dynamic_debug_setup(mod, info->debug, info->num_debug);
4074 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
4075 ftrace_module_init(mod);
4077 /* Finally it's fully formed, ready to start executing. */
4078 err = complete_formation(mod, info);
4080 goto ddebug_cleanup;
4082 err = prepare_coming_module(mod);
4086 /* Module is ready to execute: parsing args may do that. */
4087 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
4089 unknown_module_param_cb);
4090 if (IS_ERR(after_dashes)) {
4091 err = PTR_ERR(after_dashes);
4092 goto coming_cleanup;
4093 } else if (after_dashes) {
4094 pr_warn("%s: parameters '%s' after `--' ignored\n",
4095 mod->name, after_dashes);
4098 /* Link in to sysfs. */
4099 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
4101 goto coming_cleanup;
4103 if (is_livepatch_module(mod)) {
4104 err = copy_module_elf(mod, info);
4109 /* Get rid of temporary copy. */
4113 trace_module_load(mod);
4115 return do_init_module(mod);
4118 mod_sysfs_teardown(mod);
4120 mod->state = MODULE_STATE_GOING;
4121 destroy_params(mod->kp, mod->num_kp);
4122 blocking_notifier_call_chain(&module_notify_list,
4123 MODULE_STATE_GOING, mod);
4124 klp_module_going(mod);
4126 mod->state = MODULE_STATE_GOING;
4127 /* module_bug_cleanup needs module_mutex protection */
4128 mutex_lock(&module_mutex);
4129 module_bug_cleanup(mod);
4130 mutex_unlock(&module_mutex);
4133 ftrace_release_mod(mod);
4134 dynamic_debug_remove(mod, info->debug);
4138 module_arch_cleanup(mod);
4142 module_unload_free(mod);
4144 mutex_lock(&module_mutex);
4145 /* Unlink carefully: kallsyms could be walking list. */
4146 list_del_rcu(&mod->list);
4147 mod_tree_remove(mod);
4148 wake_up_all(&module_wq);
4149 /* Wait for RCU-sched synchronizing before releasing mod->list. */
4151 mutex_unlock(&module_mutex);
4153 /* Free lock-classes; relies on the preceding sync_rcu() */
4154 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
4156 module_deallocate(mod, info);
4162 SYSCALL_DEFINE3(init_module, void __user *, umod,
4163 unsigned long, len, const char __user *, uargs)
4166 struct load_info info = { };
4168 err = may_init_module();
4172 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
4175 err = copy_module_from_user(umod, len, &info);
4179 return load_module(&info, uargs, 0);
4182 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
4184 struct load_info info = { };
4189 err = may_init_module();
4193 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
4195 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
4196 |MODULE_INIT_IGNORE_VERMAGIC))
4199 err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX,
4206 return load_module(&info, uargs, flags);
4209 static inline int within(unsigned long addr, void *start, unsigned long size)
4211 return ((void *)addr >= start && (void *)addr < start + size);
4214 #ifdef CONFIG_KALLSYMS
4216 * This ignores the intensely annoying "mapping symbols" found
4217 * in ARM ELF files: $a, $t and $d.
4219 static inline int is_arm_mapping_symbol(const char *str)
4221 if (str[0] == '.' && str[1] == 'L')
4223 return str[0] == '$' && strchr("axtd", str[1])
4224 && (str[2] == '\0' || str[2] == '.');
4227 static const char *kallsyms_symbol_name(struct mod_kallsyms *kallsyms, unsigned int symnum)
4229 return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
4233 * Given a module and address, find the corresponding symbol and return its name
4234 * while providing its size and offset if needed.
4236 static const char *find_kallsyms_symbol(struct module *mod,
4238 unsigned long *size,
4239 unsigned long *offset)
4241 unsigned int i, best = 0;
4242 unsigned long nextval, bestval;
4243 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4245 /* At worse, next value is at end of module */
4246 if (within_module_init(addr, mod))
4247 nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
4249 nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
4251 bestval = kallsyms_symbol_value(&kallsyms->symtab[best]);
4253 /* Scan for closest preceding symbol, and next symbol. (ELF
4254 starts real symbols at 1). */
4255 for (i = 1; i < kallsyms->num_symtab; i++) {
4256 const Elf_Sym *sym = &kallsyms->symtab[i];
4257 unsigned long thisval = kallsyms_symbol_value(sym);
4259 if (sym->st_shndx == SHN_UNDEF)
4262 /* We ignore unnamed symbols: they're uninformative
4263 * and inserted at a whim. */
4264 if (*kallsyms_symbol_name(kallsyms, i) == '\0'
4265 || is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms, i)))
4268 if (thisval <= addr && thisval > bestval) {
4272 if (thisval > addr && thisval < nextval)
4280 *size = nextval - bestval;
4282 *offset = addr - bestval;
4284 return kallsyms_symbol_name(kallsyms, best);
4287 void * __weak dereference_module_function_descriptor(struct module *mod,
4293 /* For kallsyms to ask for address resolution. NULL means not found. Careful
4294 * not to lock to avoid deadlock on oopses, simply disable preemption. */
4295 const char *module_address_lookup(unsigned long addr,
4296 unsigned long *size,
4297 unsigned long *offset,
4301 const char *ret = NULL;
4305 mod = __module_address(addr);
4308 *modname = mod->name;
4310 ret = find_kallsyms_symbol(mod, addr, size, offset);
4312 /* Make a copy in here where it's safe */
4314 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
4322 int lookup_module_symbol_name(unsigned long addr, char *symname)
4327 list_for_each_entry_rcu(mod, &modules, list) {
4328 if (mod->state == MODULE_STATE_UNFORMED)
4330 if (within_module(addr, mod)) {
4333 sym = find_kallsyms_symbol(mod, addr, NULL, NULL);
4337 strlcpy(symname, sym, KSYM_NAME_LEN);
4347 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
4348 unsigned long *offset, char *modname, char *name)
4353 list_for_each_entry_rcu(mod, &modules, list) {
4354 if (mod->state == MODULE_STATE_UNFORMED)
4356 if (within_module(addr, mod)) {
4359 sym = find_kallsyms_symbol(mod, addr, size, offset);
4363 strlcpy(modname, mod->name, MODULE_NAME_LEN);
4365 strlcpy(name, sym, KSYM_NAME_LEN);
4375 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
4376 char *name, char *module_name, int *exported)
4381 list_for_each_entry_rcu(mod, &modules, list) {
4382 struct mod_kallsyms *kallsyms;
4384 if (mod->state == MODULE_STATE_UNFORMED)
4386 kallsyms = rcu_dereference_sched(mod->kallsyms);
4387 if (symnum < kallsyms->num_symtab) {
4388 const Elf_Sym *sym = &kallsyms->symtab[symnum];
4390 *value = kallsyms_symbol_value(sym);
4391 *type = kallsyms->typetab[symnum];
4392 strlcpy(name, kallsyms_symbol_name(kallsyms, symnum), KSYM_NAME_LEN);
4393 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
4394 *exported = is_exported(name, *value, mod);
4398 symnum -= kallsyms->num_symtab;
4404 /* Given a module and name of symbol, find and return the symbol's value */
4405 static unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name)
4408 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4410 for (i = 0; i < kallsyms->num_symtab; i++) {
4411 const Elf_Sym *sym = &kallsyms->symtab[i];
4413 if (strcmp(name, kallsyms_symbol_name(kallsyms, i)) == 0 &&
4414 sym->st_shndx != SHN_UNDEF)
4415 return kallsyms_symbol_value(sym);
4420 /* Look for this name: can be of form module:name. */
4421 unsigned long module_kallsyms_lookup_name(const char *name)
4425 unsigned long ret = 0;
4427 /* Don't lock: we're in enough trouble already. */
4429 if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
4430 if ((mod = find_module_all(name, colon - name, false)) != NULL)
4431 ret = find_kallsyms_symbol_value(mod, colon+1);
4433 list_for_each_entry_rcu(mod, &modules, list) {
4434 if (mod->state == MODULE_STATE_UNFORMED)
4436 if ((ret = find_kallsyms_symbol_value(mod, name)) != 0)
4444 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
4445 struct module *, unsigned long),
4452 module_assert_mutex();
4454 list_for_each_entry(mod, &modules, list) {
4455 /* We hold module_mutex: no need for rcu_dereference_sched */
4456 struct mod_kallsyms *kallsyms = mod->kallsyms;
4458 if (mod->state == MODULE_STATE_UNFORMED)
4460 for (i = 0; i < kallsyms->num_symtab; i++) {
4461 const Elf_Sym *sym = &kallsyms->symtab[i];
4463 if (sym->st_shndx == SHN_UNDEF)
4466 ret = fn(data, kallsyms_symbol_name(kallsyms, i),
4467 mod, kallsyms_symbol_value(sym));
4474 #endif /* CONFIG_KALLSYMS */
4476 /* Maximum number of characters written by module_flags() */
4477 #define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
4479 /* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
4480 static char *module_flags(struct module *mod, char *buf)
4484 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
4486 mod->state == MODULE_STATE_GOING ||
4487 mod->state == MODULE_STATE_COMING) {
4489 bx += module_flags_taint(mod, buf + bx);
4490 /* Show a - for module-is-being-unloaded */
4491 if (mod->state == MODULE_STATE_GOING)
4493 /* Show a + for module-is-being-loaded */
4494 if (mod->state == MODULE_STATE_COMING)
4503 #ifdef CONFIG_PROC_FS
4504 /* Called by the /proc file system to return a list of modules. */
4505 static void *m_start(struct seq_file *m, loff_t *pos)
4507 mutex_lock(&module_mutex);
4508 return seq_list_start(&modules, *pos);
4511 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
4513 return seq_list_next(p, &modules, pos);
4516 static void m_stop(struct seq_file *m, void *p)
4518 mutex_unlock(&module_mutex);
4521 static int m_show(struct seq_file *m, void *p)
4523 struct module *mod = list_entry(p, struct module, list);
4524 char buf[MODULE_FLAGS_BUF_SIZE];
4527 /* We always ignore unformed modules. */
4528 if (mod->state == MODULE_STATE_UNFORMED)
4531 seq_printf(m, "%s %u",
4532 mod->name, mod->init_layout.size + mod->core_layout.size);
4533 print_unload_info(m, mod);
4535 /* Informative for users. */
4536 seq_printf(m, " %s",
4537 mod->state == MODULE_STATE_GOING ? "Unloading" :
4538 mod->state == MODULE_STATE_COMING ? "Loading" :
4540 /* Used by oprofile and other similar tools. */
4541 value = m->private ? NULL : mod->core_layout.base;
4542 seq_printf(m, " 0x%px", value);
4546 seq_printf(m, " %s", module_flags(mod, buf));
4552 /* Format: modulename size refcount deps address
4554 Where refcount is a number or -, and deps is a comma-separated list
4557 static const struct seq_operations modules_op = {
4565 * This also sets the "private" pointer to non-NULL if the
4566 * kernel pointers should be hidden (so you can just test
4567 * "m->private" to see if you should keep the values private).
4569 * We use the same logic as for /proc/kallsyms.
4571 static int modules_open(struct inode *inode, struct file *file)
4573 int err = seq_open(file, &modules_op);
4576 struct seq_file *m = file->private_data;
4577 m->private = kallsyms_show_value(file->f_cred) ? NULL : (void *)8ul;
4583 static const struct file_operations proc_modules_operations = {
4584 .open = modules_open,
4586 .llseek = seq_lseek,
4587 .release = seq_release,
4590 static int __init proc_modules_init(void)
4592 proc_create("modules", 0, NULL, &proc_modules_operations);
4595 module_init(proc_modules_init);
4598 /* Given an address, look for it in the module exception tables. */
4599 const struct exception_table_entry *search_module_extables(unsigned long addr)
4601 const struct exception_table_entry *e = NULL;
4605 mod = __module_address(addr);
4609 if (!mod->num_exentries)
4612 e = search_extable(mod->extable,
4619 * Now, if we found one, we are running inside it now, hence
4620 * we cannot unload the module, hence no refcnt needed.
4626 * is_module_address - is this address inside a module?
4627 * @addr: the address to check.
4629 * See is_module_text_address() if you simply want to see if the address
4630 * is code (not data).
4632 bool is_module_address(unsigned long addr)
4637 ret = __module_address(addr) != NULL;
4644 * __module_address - get the module which contains an address.
4645 * @addr: the address.
4647 * Must be called with preempt disabled or module mutex held so that
4648 * module doesn't get freed during this.
4650 struct module *__module_address(unsigned long addr)
4654 if (addr < module_addr_min || addr > module_addr_max)
4657 module_assert_mutex_or_preempt();
4659 mod = mod_find(addr);
4661 BUG_ON(!within_module(addr, mod));
4662 if (mod->state == MODULE_STATE_UNFORMED)
4669 * is_module_text_address - is this address inside module code?
4670 * @addr: the address to check.
4672 * See is_module_address() if you simply want to see if the address is
4673 * anywhere in a module. See kernel_text_address() for testing if an
4674 * address corresponds to kernel or module code.
4676 bool is_module_text_address(unsigned long addr)
4681 ret = __module_text_address(addr) != NULL;
4688 * __module_text_address - get the module whose code contains an address.
4689 * @addr: the address.
4691 * Must be called with preempt disabled or module mutex held so that
4692 * module doesn't get freed during this.
4694 struct module *__module_text_address(unsigned long addr)
4696 struct module *mod = __module_address(addr);
4698 /* Make sure it's within the text section. */
4699 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
4700 && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
4706 /* Don't grab lock, we're oopsing. */
4707 void print_modules(void)
4710 char buf[MODULE_FLAGS_BUF_SIZE];
4712 printk(KERN_DEFAULT "Modules linked in:");
4713 /* Most callers should already have preempt disabled, but make sure */
4715 list_for_each_entry_rcu(mod, &modules, list) {
4716 if (mod->state == MODULE_STATE_UNFORMED)
4718 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4721 if (last_unloaded_module[0])
4722 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4726 #ifdef CONFIG_MODVERSIONS
4727 /* Generate the signature for all relevant module structures here.
4728 * If these change, we don't want to try to parse the module. */
4729 void module_layout(struct module *mod,
4730 struct modversion_info *ver,
4731 struct kernel_param *kp,
4732 struct kernel_symbol *ks,
4733 struct tracepoint * const *tp)
4736 EXPORT_SYMBOL(module_layout);