1 // SPDX-License-Identifier: GPL-2.0-or-later
3 Copyright (C) 2002 Richard Henderson
4 Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
8 #define INCLUDE_VERMAGIC
10 #include <linux/export.h>
11 #include <linux/extable.h>
12 #include <linux/moduleloader.h>
13 #include <linux/module_signature.h>
14 #include <linux/trace_events.h>
15 #include <linux/init.h>
16 #include <linux/kallsyms.h>
17 #include <linux/file.h>
19 #include <linux/sysfs.h>
20 #include <linux/kernel.h>
21 #include <linux/kernel_read_file.h>
22 #include <linux/slab.h>
23 #include <linux/vmalloc.h>
24 #include <linux/elf.h>
25 #include <linux/proc_fs.h>
26 #include <linux/security.h>
27 #include <linux/seq_file.h>
28 #include <linux/syscalls.h>
29 #include <linux/fcntl.h>
30 #include <linux/rcupdate.h>
31 #include <linux/capability.h>
32 #include <linux/cpu.h>
33 #include <linux/moduleparam.h>
34 #include <linux/errno.h>
35 #include <linux/err.h>
36 #include <linux/vermagic.h>
37 #include <linux/notifier.h>
38 #include <linux/sched.h>
39 #include <linux/device.h>
40 #include <linux/string.h>
41 #include <linux/mutex.h>
42 #include <linux/rculist.h>
43 #include <linux/uaccess.h>
44 #include <asm/cacheflush.h>
45 #include <linux/set_memory.h>
46 #include <asm/mmu_context.h>
47 #include <linux/license.h>
48 #include <asm/sections.h>
49 #include <linux/tracepoint.h>
50 #include <linux/ftrace.h>
51 #include <linux/livepatch.h>
52 #include <linux/async.h>
53 #include <linux/percpu.h>
54 #include <linux/kmemleak.h>
55 #include <linux/jump_label.h>
56 #include <linux/pfn.h>
57 #include <linux/bsearch.h>
58 #include <linux/dynamic_debug.h>
59 #include <linux/audit.h>
60 #include <uapi/linux/module.h>
61 #include "module-internal.h"
63 #define CREATE_TRACE_POINTS
64 #include <trace/events/module.h>
66 #ifndef ARCH_SHF_SMALL
67 #define ARCH_SHF_SMALL 0
71 * Modules' sections will be aligned on page boundaries
72 * to ensure complete separation of code and data, but
73 * only when CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y
75 #ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
76 # define debug_align(X) ALIGN(X, PAGE_SIZE)
78 # define debug_align(X) (X)
81 /* If this is set, the section belongs in the init part of the module */
82 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
86 * 1) List of modules (also safely readable with preempt_disable),
87 * 2) module_use links,
88 * 3) module_addr_min/module_addr_max.
89 * (delete and add uses RCU list operations). */
90 DEFINE_MUTEX(module_mutex);
91 EXPORT_SYMBOL_GPL(module_mutex);
92 static LIST_HEAD(modules);
94 /* Work queue for freeing init sections in success case */
95 static void do_free_init(struct work_struct *w);
96 static DECLARE_WORK(init_free_wq, do_free_init);
97 static LLIST_HEAD(init_free_list);
99 #ifdef CONFIG_MODULES_TREE_LOOKUP
102 * Use a latched RB-tree for __module_address(); this allows us to use
103 * RCU-sched lookups of the address from any context.
105 * This is conditional on PERF_EVENTS || TRACING because those can really hit
106 * __module_address() hard by doing a lot of stack unwinding; potentially from
110 static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
112 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
114 return (unsigned long)layout->base;
117 static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
119 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
121 return (unsigned long)layout->size;
124 static __always_inline bool
125 mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
127 return __mod_tree_val(a) < __mod_tree_val(b);
130 static __always_inline int
131 mod_tree_comp(void *key, struct latch_tree_node *n)
133 unsigned long val = (unsigned long)key;
134 unsigned long start, end;
136 start = __mod_tree_val(n);
140 end = start + __mod_tree_size(n);
147 static const struct latch_tree_ops mod_tree_ops = {
148 .less = mod_tree_less,
149 .comp = mod_tree_comp,
152 static struct mod_tree_root {
153 struct latch_tree_root root;
154 unsigned long addr_min;
155 unsigned long addr_max;
156 } mod_tree __cacheline_aligned = {
160 #define module_addr_min mod_tree.addr_min
161 #define module_addr_max mod_tree.addr_max
163 static noinline void __mod_tree_insert(struct mod_tree_node *node)
165 latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
168 static void __mod_tree_remove(struct mod_tree_node *node)
170 latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
174 * These modifications: insert, remove_init and remove; are serialized by the
177 static void mod_tree_insert(struct module *mod)
179 mod->core_layout.mtn.mod = mod;
180 mod->init_layout.mtn.mod = mod;
182 __mod_tree_insert(&mod->core_layout.mtn);
183 if (mod->init_layout.size)
184 __mod_tree_insert(&mod->init_layout.mtn);
187 static void mod_tree_remove_init(struct module *mod)
189 if (mod->init_layout.size)
190 __mod_tree_remove(&mod->init_layout.mtn);
193 static void mod_tree_remove(struct module *mod)
195 __mod_tree_remove(&mod->core_layout.mtn);
196 mod_tree_remove_init(mod);
199 static struct module *mod_find(unsigned long addr)
201 struct latch_tree_node *ltn;
203 ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
207 return container_of(ltn, struct mod_tree_node, node)->mod;
210 #else /* MODULES_TREE_LOOKUP */
212 static unsigned long module_addr_min = -1UL, module_addr_max = 0;
214 static void mod_tree_insert(struct module *mod) { }
215 static void mod_tree_remove_init(struct module *mod) { }
216 static void mod_tree_remove(struct module *mod) { }
218 static struct module *mod_find(unsigned long addr)
222 list_for_each_entry_rcu(mod, &modules, list,
223 lockdep_is_held(&module_mutex)) {
224 if (within_module(addr, mod))
231 #endif /* MODULES_TREE_LOOKUP */
234 * Bounds of module text, for speeding up __module_address.
235 * Protected by module_mutex.
237 static void __mod_update_bounds(void *base, unsigned int size)
239 unsigned long min = (unsigned long)base;
240 unsigned long max = min + size;
242 if (min < module_addr_min)
243 module_addr_min = min;
244 if (max > module_addr_max)
245 module_addr_max = max;
248 static void mod_update_bounds(struct module *mod)
250 __mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
251 if (mod->init_layout.size)
252 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
255 #ifdef CONFIG_KGDB_KDB
256 struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
257 #endif /* CONFIG_KGDB_KDB */
259 static void module_assert_mutex(void)
261 lockdep_assert_held(&module_mutex);
264 static void module_assert_mutex_or_preempt(void)
266 #ifdef CONFIG_LOCKDEP
267 if (unlikely(!debug_locks))
270 WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
271 !lockdep_is_held(&module_mutex));
275 #ifdef CONFIG_MODULE_SIG
276 static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
277 module_param(sig_enforce, bool_enable_only, 0644);
279 void set_module_sig_enforced(void)
284 #define sig_enforce false
288 * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
289 * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
291 bool is_module_sig_enforced(void)
295 EXPORT_SYMBOL(is_module_sig_enforced);
297 /* Block module loading/unloading? */
298 int modules_disabled = 0;
299 core_param(nomodule, modules_disabled, bint, 0);
301 /* Waiting for a module to finish initializing? */
302 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
304 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
306 int register_module_notifier(struct notifier_block *nb)
308 return blocking_notifier_chain_register(&module_notify_list, nb);
310 EXPORT_SYMBOL(register_module_notifier);
312 int unregister_module_notifier(struct notifier_block *nb)
314 return blocking_notifier_chain_unregister(&module_notify_list, nb);
316 EXPORT_SYMBOL(unregister_module_notifier);
319 * We require a truly strong try_module_get(): 0 means success.
320 * Otherwise an error is returned due to ongoing or failed
321 * initialization etc.
323 static inline int strong_try_module_get(struct module *mod)
325 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
326 if (mod && mod->state == MODULE_STATE_COMING)
328 if (try_module_get(mod))
334 static inline void add_taint_module(struct module *mod, unsigned flag,
335 enum lockdep_ok lockdep_ok)
337 add_taint(flag, lockdep_ok);
338 set_bit(flag, &mod->taints);
342 * A thread that wants to hold a reference to a module only while it
343 * is running can call this to safely exit. nfsd and lockd use this.
345 void __noreturn __module_put_and_exit(struct module *mod, long code)
350 EXPORT_SYMBOL(__module_put_and_exit);
352 /* Find a module section: 0 means not found. */
353 static unsigned int find_sec(const struct load_info *info, const char *name)
357 for (i = 1; i < info->hdr->e_shnum; i++) {
358 Elf_Shdr *shdr = &info->sechdrs[i];
359 /* Alloc bit cleared means "ignore it." */
360 if ((shdr->sh_flags & SHF_ALLOC)
361 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
367 /* Find a module section, or NULL. */
368 static void *section_addr(const struct load_info *info, const char *name)
370 /* Section 0 has sh_addr 0. */
371 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
374 /* Find a module section, or NULL. Fill in number of "objects" in section. */
375 static void *section_objs(const struct load_info *info,
380 unsigned int sec = find_sec(info, name);
382 /* Section 0 has sh_addr 0 and sh_size 0. */
383 *num = info->sechdrs[sec].sh_size / object_size;
384 return (void *)info->sechdrs[sec].sh_addr;
387 /* Provided by the linker */
388 extern const struct kernel_symbol __start___ksymtab[];
389 extern const struct kernel_symbol __stop___ksymtab[];
390 extern const struct kernel_symbol __start___ksymtab_gpl[];
391 extern const struct kernel_symbol __stop___ksymtab_gpl[];
392 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
393 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
394 extern const s32 __start___kcrctab[];
395 extern const s32 __start___kcrctab_gpl[];
396 extern const s32 __start___kcrctab_gpl_future[];
397 #ifdef CONFIG_UNUSED_SYMBOLS
398 extern const struct kernel_symbol __start___ksymtab_unused[];
399 extern const struct kernel_symbol __stop___ksymtab_unused[];
400 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
401 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
402 extern const s32 __start___kcrctab_unused[];
403 extern const s32 __start___kcrctab_unused_gpl[];
406 #ifndef CONFIG_MODVERSIONS
407 #define symversion(base, idx) NULL
409 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
412 static bool each_symbol_in_section(const struct symsearch *arr,
413 unsigned int arrsize,
414 struct module *owner,
415 bool (*fn)(const struct symsearch *syms,
416 struct module *owner,
422 for (j = 0; j < arrsize; j++) {
423 if (fn(&arr[j], owner, data))
430 /* Returns true as soon as fn returns true, otherwise false. */
431 static bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
432 struct module *owner,
437 static const struct symsearch arr[] = {
438 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
439 NOT_GPL_ONLY, false },
440 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
441 __start___kcrctab_gpl,
443 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
444 __start___kcrctab_gpl_future,
445 WILL_BE_GPL_ONLY, false },
446 #ifdef CONFIG_UNUSED_SYMBOLS
447 { __start___ksymtab_unused, __stop___ksymtab_unused,
448 __start___kcrctab_unused,
449 NOT_GPL_ONLY, true },
450 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
451 __start___kcrctab_unused_gpl,
456 module_assert_mutex_or_preempt();
458 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
461 list_for_each_entry_rcu(mod, &modules, list,
462 lockdep_is_held(&module_mutex)) {
463 struct symsearch arr[] = {
464 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
465 NOT_GPL_ONLY, false },
466 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
469 { mod->gpl_future_syms,
470 mod->gpl_future_syms + mod->num_gpl_future_syms,
471 mod->gpl_future_crcs,
472 WILL_BE_GPL_ONLY, false },
473 #ifdef CONFIG_UNUSED_SYMBOLS
475 mod->unused_syms + mod->num_unused_syms,
477 NOT_GPL_ONLY, true },
478 { mod->unused_gpl_syms,
479 mod->unused_gpl_syms + mod->num_unused_gpl_syms,
480 mod->unused_gpl_crcs,
485 if (mod->state == MODULE_STATE_UNFORMED)
488 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
494 struct find_symbol_arg {
501 struct module *owner;
503 const struct kernel_symbol *sym;
504 enum mod_license license;
507 static bool check_exported_symbol(const struct symsearch *syms,
508 struct module *owner,
509 unsigned int symnum, void *data)
511 struct find_symbol_arg *fsa = data;
514 if (syms->license == GPL_ONLY)
516 if (syms->license == WILL_BE_GPL_ONLY && fsa->warn) {
517 pr_warn("Symbol %s is being used by a non-GPL module, "
518 "which will not be allowed in the future\n",
523 #ifdef CONFIG_UNUSED_SYMBOLS
524 if (syms->unused && fsa->warn) {
525 pr_warn("Symbol %s is marked as UNUSED, however this module is "
526 "using it.\n", fsa->name);
527 pr_warn("This symbol will go away in the future.\n");
528 pr_warn("Please evaluate if this is the right api to use and "
529 "if it really is, submit a report to the linux kernel "
530 "mailing list together with submitting your code for "
536 fsa->crc = symversion(syms->crcs, symnum);
537 fsa->sym = &syms->start[symnum];
538 fsa->license = syms->license;
542 static unsigned long kernel_symbol_value(const struct kernel_symbol *sym)
544 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
545 return (unsigned long)offset_to_ptr(&sym->value_offset);
551 static const char *kernel_symbol_name(const struct kernel_symbol *sym)
553 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
554 return offset_to_ptr(&sym->name_offset);
560 static const char *kernel_symbol_namespace(const struct kernel_symbol *sym)
562 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
563 if (!sym->namespace_offset)
565 return offset_to_ptr(&sym->namespace_offset);
567 return sym->namespace;
571 static int cmp_name(const void *name, const void *sym)
573 return strcmp(name, kernel_symbol_name(sym));
576 static bool find_exported_symbol_in_section(const struct symsearch *syms,
577 struct module *owner,
580 struct find_symbol_arg *fsa = data;
581 struct kernel_symbol *sym;
583 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
584 sizeof(struct kernel_symbol), cmp_name);
586 if (sym != NULL && check_exported_symbol(syms, owner,
587 sym - syms->start, data))
593 /* Find an exported symbol and return it, along with, (optional) crc and
594 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
595 static const struct kernel_symbol *find_symbol(const char *name,
596 struct module **owner,
598 enum mod_license *license,
602 struct find_symbol_arg fsa;
608 if (each_symbol_section(find_exported_symbol_in_section, &fsa)) {
614 *license = fsa.license;
618 pr_debug("Failed to find symbol %s\n", name);
623 * Search for module by name: must hold module_mutex (or preempt disabled
624 * for read-only access).
626 static struct module *find_module_all(const char *name, size_t len,
631 module_assert_mutex_or_preempt();
633 list_for_each_entry_rcu(mod, &modules, list,
634 lockdep_is_held(&module_mutex)) {
635 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
637 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
643 struct module *find_module(const char *name)
645 module_assert_mutex();
646 return find_module_all(name, strlen(name), false);
648 EXPORT_SYMBOL_GPL(find_module);
652 static inline void __percpu *mod_percpu(struct module *mod)
657 static int percpu_modalloc(struct module *mod, struct load_info *info)
659 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
660 unsigned long align = pcpusec->sh_addralign;
662 if (!pcpusec->sh_size)
665 if (align > PAGE_SIZE) {
666 pr_warn("%s: per-cpu alignment %li > %li\n",
667 mod->name, align, PAGE_SIZE);
671 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
673 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
674 mod->name, (unsigned long)pcpusec->sh_size);
677 mod->percpu_size = pcpusec->sh_size;
681 static void percpu_modfree(struct module *mod)
683 free_percpu(mod->percpu);
686 static unsigned int find_pcpusec(struct load_info *info)
688 return find_sec(info, ".data..percpu");
691 static void percpu_modcopy(struct module *mod,
692 const void *from, unsigned long size)
696 for_each_possible_cpu(cpu)
697 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
700 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
707 list_for_each_entry_rcu(mod, &modules, list) {
708 if (mod->state == MODULE_STATE_UNFORMED)
710 if (!mod->percpu_size)
712 for_each_possible_cpu(cpu) {
713 void *start = per_cpu_ptr(mod->percpu, cpu);
714 void *va = (void *)addr;
716 if (va >= start && va < start + mod->percpu_size) {
718 *can_addr = (unsigned long) (va - start);
719 *can_addr += (unsigned long)
720 per_cpu_ptr(mod->percpu,
734 * is_module_percpu_address - test whether address is from module static percpu
735 * @addr: address to test
737 * Test whether @addr belongs to module static percpu area.
740 * %true if @addr is from module static percpu area
742 bool is_module_percpu_address(unsigned long addr)
744 return __is_module_percpu_address(addr, NULL);
747 #else /* ... !CONFIG_SMP */
749 static inline void __percpu *mod_percpu(struct module *mod)
753 static int percpu_modalloc(struct module *mod, struct load_info *info)
755 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
756 if (info->sechdrs[info->index.pcpu].sh_size != 0)
760 static inline void percpu_modfree(struct module *mod)
763 static unsigned int find_pcpusec(struct load_info *info)
767 static inline void percpu_modcopy(struct module *mod,
768 const void *from, unsigned long size)
770 /* pcpusec should be 0, and size of that section should be 0. */
773 bool is_module_percpu_address(unsigned long addr)
778 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
783 #endif /* CONFIG_SMP */
785 #define MODINFO_ATTR(field) \
786 static void setup_modinfo_##field(struct module *mod, const char *s) \
788 mod->field = kstrdup(s, GFP_KERNEL); \
790 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
791 struct module_kobject *mk, char *buffer) \
793 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
795 static int modinfo_##field##_exists(struct module *mod) \
797 return mod->field != NULL; \
799 static void free_modinfo_##field(struct module *mod) \
804 static struct module_attribute modinfo_##field = { \
805 .attr = { .name = __stringify(field), .mode = 0444 }, \
806 .show = show_modinfo_##field, \
807 .setup = setup_modinfo_##field, \
808 .test = modinfo_##field##_exists, \
809 .free = free_modinfo_##field, \
812 MODINFO_ATTR(version);
813 MODINFO_ATTR(srcversion);
815 static char last_unloaded_module[MODULE_NAME_LEN+1];
817 #ifdef CONFIG_MODULE_UNLOAD
819 EXPORT_TRACEPOINT_SYMBOL(module_get);
821 /* MODULE_REF_BASE is the base reference count by kmodule loader. */
822 #define MODULE_REF_BASE 1
824 /* Init the unload section of the module. */
825 static int module_unload_init(struct module *mod)
828 * Initialize reference counter to MODULE_REF_BASE.
829 * refcnt == 0 means module is going.
831 atomic_set(&mod->refcnt, MODULE_REF_BASE);
833 INIT_LIST_HEAD(&mod->source_list);
834 INIT_LIST_HEAD(&mod->target_list);
836 /* Hold reference count during initialization. */
837 atomic_inc(&mod->refcnt);
842 /* Does a already use b? */
843 static int already_uses(struct module *a, struct module *b)
845 struct module_use *use;
847 list_for_each_entry(use, &b->source_list, source_list) {
848 if (use->source == a) {
849 pr_debug("%s uses %s!\n", a->name, b->name);
853 pr_debug("%s does not use %s!\n", a->name, b->name);
859 * - we add 'a' as a "source", 'b' as a "target" of module use
860 * - the module_use is added to the list of 'b' sources (so
861 * 'b' can walk the list to see who sourced them), and of 'a'
862 * targets (so 'a' can see what modules it targets).
864 static int add_module_usage(struct module *a, struct module *b)
866 struct module_use *use;
868 pr_debug("Allocating new usage for %s.\n", a->name);
869 use = kmalloc(sizeof(*use), GFP_ATOMIC);
875 list_add(&use->source_list, &b->source_list);
876 list_add(&use->target_list, &a->target_list);
880 /* Module a uses b: caller needs module_mutex() */
881 static int ref_module(struct module *a, struct module *b)
885 if (b == NULL || already_uses(a, b))
888 /* If module isn't available, we fail. */
889 err = strong_try_module_get(b);
893 err = add_module_usage(a, b);
901 /* Clear the unload stuff of the module. */
902 static void module_unload_free(struct module *mod)
904 struct module_use *use, *tmp;
906 mutex_lock(&module_mutex);
907 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
908 struct module *i = use->target;
909 pr_debug("%s unusing %s\n", mod->name, i->name);
911 list_del(&use->source_list);
912 list_del(&use->target_list);
915 mutex_unlock(&module_mutex);
918 #ifdef CONFIG_MODULE_FORCE_UNLOAD
919 static inline int try_force_unload(unsigned int flags)
921 int ret = (flags & O_TRUNC);
923 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
927 static inline int try_force_unload(unsigned int flags)
931 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
933 /* Try to release refcount of module, 0 means success. */
934 static int try_release_module_ref(struct module *mod)
938 /* Try to decrement refcnt which we set at loading */
939 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
942 /* Someone can put this right now, recover with checking */
943 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
948 static int try_stop_module(struct module *mod, int flags, int *forced)
950 /* If it's not unused, quit unless we're forcing. */
951 if (try_release_module_ref(mod) != 0) {
952 *forced = try_force_unload(flags);
957 /* Mark it as dying. */
958 mod->state = MODULE_STATE_GOING;
964 * module_refcount - return the refcount or -1 if unloading
966 * @mod: the module we're checking
969 * -1 if the module is in the process of unloading
970 * otherwise the number of references in the kernel to the module
972 int module_refcount(struct module *mod)
974 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
976 EXPORT_SYMBOL(module_refcount);
978 /* This exists whether we can unload or not */
979 static void free_module(struct module *mod);
981 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
985 char name[MODULE_NAME_LEN];
988 if (!capable(CAP_SYS_MODULE) || modules_disabled)
991 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
993 name[MODULE_NAME_LEN-1] = '\0';
995 audit_log_kern_module(name);
997 if (mutex_lock_interruptible(&module_mutex) != 0)
1000 mod = find_module(name);
1006 if (!list_empty(&mod->source_list)) {
1007 /* Other modules depend on us: get rid of them first. */
1012 /* Doing init or already dying? */
1013 if (mod->state != MODULE_STATE_LIVE) {
1014 /* FIXME: if (force), slam module count damn the torpedoes */
1015 pr_debug("%s already dying\n", mod->name);
1020 /* If it has an init func, it must have an exit func to unload */
1021 if (mod->init && !mod->exit) {
1022 forced = try_force_unload(flags);
1024 /* This module can't be removed */
1030 /* Stop the machine so refcounts can't move and disable module. */
1031 ret = try_stop_module(mod, flags, &forced);
1035 mutex_unlock(&module_mutex);
1036 /* Final destruction now no one is using it. */
1037 if (mod->exit != NULL)
1039 blocking_notifier_call_chain(&module_notify_list,
1040 MODULE_STATE_GOING, mod);
1041 klp_module_going(mod);
1042 ftrace_release_mod(mod);
1044 async_synchronize_full();
1046 /* Store the name of the last unloaded module for diagnostic purposes */
1047 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
1050 /* someone could wait for the module in add_unformed_module() */
1051 wake_up_all(&module_wq);
1054 mutex_unlock(&module_mutex);
1058 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1060 struct module_use *use;
1061 int printed_something = 0;
1063 seq_printf(m, " %i ", module_refcount(mod));
1066 * Always include a trailing , so userspace can differentiate
1067 * between this and the old multi-field proc format.
1069 list_for_each_entry(use, &mod->source_list, source_list) {
1070 printed_something = 1;
1071 seq_printf(m, "%s,", use->source->name);
1074 if (mod->init != NULL && mod->exit == NULL) {
1075 printed_something = 1;
1076 seq_puts(m, "[permanent],");
1079 if (!printed_something)
1083 void __symbol_put(const char *symbol)
1085 struct module *owner;
1088 if (!find_symbol(symbol, &owner, NULL, NULL, true, false))
1093 EXPORT_SYMBOL(__symbol_put);
1095 /* Note this assumes addr is a function, which it currently always is. */
1096 void symbol_put_addr(void *addr)
1098 struct module *modaddr;
1099 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1101 if (core_kernel_text(a))
1105 * Even though we hold a reference on the module; we still need to
1106 * disable preemption in order to safely traverse the data structure.
1109 modaddr = __module_text_address(a);
1111 module_put(modaddr);
1114 EXPORT_SYMBOL_GPL(symbol_put_addr);
1116 static ssize_t show_refcnt(struct module_attribute *mattr,
1117 struct module_kobject *mk, char *buffer)
1119 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1122 static struct module_attribute modinfo_refcnt =
1123 __ATTR(refcnt, 0444, show_refcnt, NULL);
1125 void __module_get(struct module *module)
1129 atomic_inc(&module->refcnt);
1130 trace_module_get(module, _RET_IP_);
1134 EXPORT_SYMBOL(__module_get);
1136 bool try_module_get(struct module *module)
1142 /* Note: here, we can fail to get a reference */
1143 if (likely(module_is_live(module) &&
1144 atomic_inc_not_zero(&module->refcnt) != 0))
1145 trace_module_get(module, _RET_IP_);
1153 EXPORT_SYMBOL(try_module_get);
1155 void module_put(struct module *module)
1161 ret = atomic_dec_if_positive(&module->refcnt);
1162 WARN_ON(ret < 0); /* Failed to put refcount */
1163 trace_module_put(module, _RET_IP_);
1167 EXPORT_SYMBOL(module_put);
1169 #else /* !CONFIG_MODULE_UNLOAD */
1170 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1172 /* We don't know the usage count, or what modules are using. */
1173 seq_puts(m, " - -");
1176 static inline void module_unload_free(struct module *mod)
1180 static int ref_module(struct module *a, struct module *b)
1182 return strong_try_module_get(b);
1185 static inline int module_unload_init(struct module *mod)
1189 #endif /* CONFIG_MODULE_UNLOAD */
1191 static size_t module_flags_taint(struct module *mod, char *buf)
1196 for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
1197 if (taint_flags[i].module && test_bit(i, &mod->taints))
1198 buf[l++] = taint_flags[i].c_true;
1204 static ssize_t show_initstate(struct module_attribute *mattr,
1205 struct module_kobject *mk, char *buffer)
1207 const char *state = "unknown";
1209 switch (mk->mod->state) {
1210 case MODULE_STATE_LIVE:
1213 case MODULE_STATE_COMING:
1216 case MODULE_STATE_GOING:
1222 return sprintf(buffer, "%s\n", state);
1225 static struct module_attribute modinfo_initstate =
1226 __ATTR(initstate, 0444, show_initstate, NULL);
1228 static ssize_t store_uevent(struct module_attribute *mattr,
1229 struct module_kobject *mk,
1230 const char *buffer, size_t count)
1234 rc = kobject_synth_uevent(&mk->kobj, buffer, count);
1235 return rc ? rc : count;
1238 struct module_attribute module_uevent =
1239 __ATTR(uevent, 0200, NULL, store_uevent);
1241 static ssize_t show_coresize(struct module_attribute *mattr,
1242 struct module_kobject *mk, char *buffer)
1244 return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1247 static struct module_attribute modinfo_coresize =
1248 __ATTR(coresize, 0444, show_coresize, NULL);
1250 static ssize_t show_initsize(struct module_attribute *mattr,
1251 struct module_kobject *mk, char *buffer)
1253 return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1256 static struct module_attribute modinfo_initsize =
1257 __ATTR(initsize, 0444, show_initsize, NULL);
1259 static ssize_t show_taint(struct module_attribute *mattr,
1260 struct module_kobject *mk, char *buffer)
1264 l = module_flags_taint(mk->mod, buffer);
1269 static struct module_attribute modinfo_taint =
1270 __ATTR(taint, 0444, show_taint, NULL);
1272 static struct module_attribute *modinfo_attrs[] = {
1275 &modinfo_srcversion,
1280 #ifdef CONFIG_MODULE_UNLOAD
1286 static const char vermagic[] = VERMAGIC_STRING;
1288 static int try_to_force_load(struct module *mod, const char *reason)
1290 #ifdef CONFIG_MODULE_FORCE_LOAD
1291 if (!test_taint(TAINT_FORCED_MODULE))
1292 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1293 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1300 #ifdef CONFIG_MODVERSIONS
1302 static u32 resolve_rel_crc(const s32 *crc)
1304 return *(u32 *)((void *)crc + *crc);
1307 static int check_version(const struct load_info *info,
1308 const char *symname,
1312 Elf_Shdr *sechdrs = info->sechdrs;
1313 unsigned int versindex = info->index.vers;
1314 unsigned int i, num_versions;
1315 struct modversion_info *versions;
1317 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1321 /* No versions at all? modprobe --force does this. */
1323 return try_to_force_load(mod, symname) == 0;
1325 versions = (void *) sechdrs[versindex].sh_addr;
1326 num_versions = sechdrs[versindex].sh_size
1327 / sizeof(struct modversion_info);
1329 for (i = 0; i < num_versions; i++) {
1332 if (strcmp(versions[i].name, symname) != 0)
1335 if (IS_ENABLED(CONFIG_MODULE_REL_CRCS))
1336 crcval = resolve_rel_crc(crc);
1339 if (versions[i].crc == crcval)
1341 pr_debug("Found checksum %X vs module %lX\n",
1342 crcval, versions[i].crc);
1346 /* Broken toolchain. Warn once, then let it go.. */
1347 pr_warn_once("%s: no symbol version for %s\n", info->name, symname);
1351 pr_warn("%s: disagrees about version of symbol %s\n",
1352 info->name, symname);
1356 static inline int check_modstruct_version(const struct load_info *info,
1362 * Since this should be found in kernel (which can't be removed), no
1363 * locking is necessary -- use preempt_disable() to placate lockdep.
1366 if (!find_symbol("module_layout", NULL, &crc, NULL, true, false)) {
1371 return check_version(info, "module_layout", mod, crc);
1374 /* First part is kernel version, which we ignore if module has crcs. */
1375 static inline int same_magic(const char *amagic, const char *bmagic,
1379 amagic += strcspn(amagic, " ");
1380 bmagic += strcspn(bmagic, " ");
1382 return strcmp(amagic, bmagic) == 0;
1385 static inline int check_version(const struct load_info *info,
1386 const char *symname,
1393 static inline int check_modstruct_version(const struct load_info *info,
1399 static inline int same_magic(const char *amagic, const char *bmagic,
1402 return strcmp(amagic, bmagic) == 0;
1404 #endif /* CONFIG_MODVERSIONS */
1406 static char *get_modinfo(const struct load_info *info, const char *tag);
1407 static char *get_next_modinfo(const struct load_info *info, const char *tag,
1410 static int verify_namespace_is_imported(const struct load_info *info,
1411 const struct kernel_symbol *sym,
1414 const char *namespace;
1415 char *imported_namespace;
1417 namespace = kernel_symbol_namespace(sym);
1418 if (namespace && namespace[0]) {
1419 imported_namespace = get_modinfo(info, "import_ns");
1420 while (imported_namespace) {
1421 if (strcmp(namespace, imported_namespace) == 0)
1423 imported_namespace = get_next_modinfo(
1424 info, "import_ns", imported_namespace);
1426 #ifdef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1431 "%s: module uses symbol (%s) from namespace %s, but does not import it.\n",
1432 mod->name, kernel_symbol_name(sym), namespace);
1433 #ifndef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1440 static bool inherit_taint(struct module *mod, struct module *owner)
1442 if (!owner || !test_bit(TAINT_PROPRIETARY_MODULE, &owner->taints))
1445 if (mod->using_gplonly_symbols) {
1446 pr_err("%s: module using GPL-only symbols uses symbols from proprietary module %s.\n",
1447 mod->name, owner->name);
1451 if (!test_bit(TAINT_PROPRIETARY_MODULE, &mod->taints)) {
1452 pr_warn("%s: module uses symbols from proprietary module %s, inheriting taint.\n",
1453 mod->name, owner->name);
1454 set_bit(TAINT_PROPRIETARY_MODULE, &mod->taints);
1459 /* Resolve a symbol for this module. I.e. if we find one, record usage. */
1460 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1461 const struct load_info *info,
1465 struct module *owner;
1466 const struct kernel_symbol *sym;
1468 enum mod_license license;
1472 * The module_mutex should not be a heavily contended lock;
1473 * if we get the occasional sleep here, we'll go an extra iteration
1474 * in the wait_event_interruptible(), which is harmless.
1476 sched_annotate_sleep();
1477 mutex_lock(&module_mutex);
1478 sym = find_symbol(name, &owner, &crc, &license,
1479 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1483 if (license == GPL_ONLY)
1484 mod->using_gplonly_symbols = true;
1486 if (!inherit_taint(mod, owner)) {
1491 if (!check_version(info, name, mod, crc)) {
1492 sym = ERR_PTR(-EINVAL);
1496 err = verify_namespace_is_imported(info, sym, mod);
1502 err = ref_module(mod, owner);
1509 /* We must make copy under the lock if we failed to get ref. */
1510 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1512 mutex_unlock(&module_mutex);
1516 static const struct kernel_symbol *
1517 resolve_symbol_wait(struct module *mod,
1518 const struct load_info *info,
1521 const struct kernel_symbol *ksym;
1522 char owner[MODULE_NAME_LEN];
1524 if (wait_event_interruptible_timeout(module_wq,
1525 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1526 || PTR_ERR(ksym) != -EBUSY,
1528 pr_warn("%s: gave up waiting for init of module %s.\n",
1535 * /sys/module/foo/sections stuff
1536 * J. Corbet <corbet@lwn.net>
1540 #ifdef CONFIG_KALLSYMS
1541 static inline bool sect_empty(const Elf_Shdr *sect)
1543 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1546 struct module_sect_attr {
1547 struct bin_attribute battr;
1548 unsigned long address;
1551 struct module_sect_attrs {
1552 struct attribute_group grp;
1553 unsigned int nsections;
1554 struct module_sect_attr attrs[];
1557 #define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4))
1558 static ssize_t module_sect_read(struct file *file, struct kobject *kobj,
1559 struct bin_attribute *battr,
1560 char *buf, loff_t pos, size_t count)
1562 struct module_sect_attr *sattr =
1563 container_of(battr, struct module_sect_attr, battr);
1564 char bounce[MODULE_SECT_READ_SIZE + 1];
1571 * Since we're a binary read handler, we must account for the
1572 * trailing NUL byte that sprintf will write: if "buf" is
1573 * too small to hold the NUL, or the NUL is exactly the last
1574 * byte, the read will look like it got truncated by one byte.
1575 * Since there is no way to ask sprintf nicely to not write
1576 * the NUL, we have to use a bounce buffer.
1578 wrote = scnprintf(bounce, sizeof(bounce), "0x%px\n",
1579 kallsyms_show_value(file->f_cred)
1580 ? (void *)sattr->address : NULL);
1581 count = min(count, wrote);
1582 memcpy(buf, bounce, count);
1587 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1589 unsigned int section;
1591 for (section = 0; section < sect_attrs->nsections; section++)
1592 kfree(sect_attrs->attrs[section].battr.attr.name);
1596 static void add_sect_attrs(struct module *mod, const struct load_info *info)
1598 unsigned int nloaded = 0, i, size[2];
1599 struct module_sect_attrs *sect_attrs;
1600 struct module_sect_attr *sattr;
1601 struct bin_attribute **gattr;
1603 /* Count loaded sections and allocate structures */
1604 for (i = 0; i < info->hdr->e_shnum; i++)
1605 if (!sect_empty(&info->sechdrs[i]))
1607 size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded),
1608 sizeof(sect_attrs->grp.bin_attrs[0]));
1609 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.bin_attrs[0]);
1610 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1611 if (sect_attrs == NULL)
1614 /* Setup section attributes. */
1615 sect_attrs->grp.name = "sections";
1616 sect_attrs->grp.bin_attrs = (void *)sect_attrs + size[0];
1618 sect_attrs->nsections = 0;
1619 sattr = §_attrs->attrs[0];
1620 gattr = §_attrs->grp.bin_attrs[0];
1621 for (i = 0; i < info->hdr->e_shnum; i++) {
1622 Elf_Shdr *sec = &info->sechdrs[i];
1623 if (sect_empty(sec))
1625 sysfs_bin_attr_init(&sattr->battr);
1626 sattr->address = sec->sh_addr;
1627 sattr->battr.attr.name =
1628 kstrdup(info->secstrings + sec->sh_name, GFP_KERNEL);
1629 if (sattr->battr.attr.name == NULL)
1631 sect_attrs->nsections++;
1632 sattr->battr.read = module_sect_read;
1633 sattr->battr.size = MODULE_SECT_READ_SIZE;
1634 sattr->battr.attr.mode = 0400;
1635 *(gattr++) = &(sattr++)->battr;
1639 if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp))
1642 mod->sect_attrs = sect_attrs;
1645 free_sect_attrs(sect_attrs);
1648 static void remove_sect_attrs(struct module *mod)
1650 if (mod->sect_attrs) {
1651 sysfs_remove_group(&mod->mkobj.kobj,
1652 &mod->sect_attrs->grp);
1653 /* We are positive that no one is using any sect attrs
1654 * at this point. Deallocate immediately. */
1655 free_sect_attrs(mod->sect_attrs);
1656 mod->sect_attrs = NULL;
1661 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1664 struct module_notes_attrs {
1665 struct kobject *dir;
1667 struct bin_attribute attrs[];
1670 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1671 struct bin_attribute *bin_attr,
1672 char *buf, loff_t pos, size_t count)
1675 * The caller checked the pos and count against our size.
1677 memcpy(buf, bin_attr->private + pos, count);
1681 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1684 if (notes_attrs->dir) {
1686 sysfs_remove_bin_file(notes_attrs->dir,
1687 ¬es_attrs->attrs[i]);
1688 kobject_put(notes_attrs->dir);
1693 static void add_notes_attrs(struct module *mod, const struct load_info *info)
1695 unsigned int notes, loaded, i;
1696 struct module_notes_attrs *notes_attrs;
1697 struct bin_attribute *nattr;
1699 /* failed to create section attributes, so can't create notes */
1700 if (!mod->sect_attrs)
1703 /* Count notes sections and allocate structures. */
1705 for (i = 0; i < info->hdr->e_shnum; i++)
1706 if (!sect_empty(&info->sechdrs[i]) &&
1707 (info->sechdrs[i].sh_type == SHT_NOTE))
1713 notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes),
1715 if (notes_attrs == NULL)
1718 notes_attrs->notes = notes;
1719 nattr = ¬es_attrs->attrs[0];
1720 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1721 if (sect_empty(&info->sechdrs[i]))
1723 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1724 sysfs_bin_attr_init(nattr);
1725 nattr->attr.name = mod->sect_attrs->attrs[loaded].battr.attr.name;
1726 nattr->attr.mode = S_IRUGO;
1727 nattr->size = info->sechdrs[i].sh_size;
1728 nattr->private = (void *) info->sechdrs[i].sh_addr;
1729 nattr->read = module_notes_read;
1735 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1736 if (!notes_attrs->dir)
1739 for (i = 0; i < notes; ++i)
1740 if (sysfs_create_bin_file(notes_attrs->dir,
1741 ¬es_attrs->attrs[i]))
1744 mod->notes_attrs = notes_attrs;
1748 free_notes_attrs(notes_attrs, i);
1751 static void remove_notes_attrs(struct module *mod)
1753 if (mod->notes_attrs)
1754 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1759 static inline void add_sect_attrs(struct module *mod,
1760 const struct load_info *info)
1764 static inline void remove_sect_attrs(struct module *mod)
1768 static inline void add_notes_attrs(struct module *mod,
1769 const struct load_info *info)
1773 static inline void remove_notes_attrs(struct module *mod)
1776 #endif /* CONFIG_KALLSYMS */
1778 static void del_usage_links(struct module *mod)
1780 #ifdef CONFIG_MODULE_UNLOAD
1781 struct module_use *use;
1783 mutex_lock(&module_mutex);
1784 list_for_each_entry(use, &mod->target_list, target_list)
1785 sysfs_remove_link(use->target->holders_dir, mod->name);
1786 mutex_unlock(&module_mutex);
1790 static int add_usage_links(struct module *mod)
1793 #ifdef CONFIG_MODULE_UNLOAD
1794 struct module_use *use;
1796 mutex_lock(&module_mutex);
1797 list_for_each_entry(use, &mod->target_list, target_list) {
1798 ret = sysfs_create_link(use->target->holders_dir,
1799 &mod->mkobj.kobj, mod->name);
1803 mutex_unlock(&module_mutex);
1805 del_usage_links(mod);
1810 static void module_remove_modinfo_attrs(struct module *mod, int end);
1812 static int module_add_modinfo_attrs(struct module *mod)
1814 struct module_attribute *attr;
1815 struct module_attribute *temp_attr;
1819 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1820 (ARRAY_SIZE(modinfo_attrs) + 1)),
1822 if (!mod->modinfo_attrs)
1825 temp_attr = mod->modinfo_attrs;
1826 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1827 if (!attr->test || attr->test(mod)) {
1828 memcpy(temp_attr, attr, sizeof(*temp_attr));
1829 sysfs_attr_init(&temp_attr->attr);
1830 error = sysfs_create_file(&mod->mkobj.kobj,
1842 module_remove_modinfo_attrs(mod, --i);
1844 kfree(mod->modinfo_attrs);
1848 static void module_remove_modinfo_attrs(struct module *mod, int end)
1850 struct module_attribute *attr;
1853 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1854 if (end >= 0 && i > end)
1856 /* pick a field to test for end of list */
1857 if (!attr->attr.name)
1859 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1863 kfree(mod->modinfo_attrs);
1866 static void mod_kobject_put(struct module *mod)
1868 DECLARE_COMPLETION_ONSTACK(c);
1869 mod->mkobj.kobj_completion = &c;
1870 kobject_put(&mod->mkobj.kobj);
1871 wait_for_completion(&c);
1874 static int mod_sysfs_init(struct module *mod)
1877 struct kobject *kobj;
1879 if (!module_sysfs_initialized) {
1880 pr_err("%s: module sysfs not initialized\n", mod->name);
1885 kobj = kset_find_obj(module_kset, mod->name);
1887 pr_err("%s: module is already loaded\n", mod->name);
1893 mod->mkobj.mod = mod;
1895 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1896 mod->mkobj.kobj.kset = module_kset;
1897 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1900 mod_kobject_put(mod);
1906 static int mod_sysfs_setup(struct module *mod,
1907 const struct load_info *info,
1908 struct kernel_param *kparam,
1909 unsigned int num_params)
1913 err = mod_sysfs_init(mod);
1917 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1918 if (!mod->holders_dir) {
1923 err = module_param_sysfs_setup(mod, kparam, num_params);
1925 goto out_unreg_holders;
1927 err = module_add_modinfo_attrs(mod);
1929 goto out_unreg_param;
1931 err = add_usage_links(mod);
1933 goto out_unreg_modinfo_attrs;
1935 add_sect_attrs(mod, info);
1936 add_notes_attrs(mod, info);
1940 out_unreg_modinfo_attrs:
1941 module_remove_modinfo_attrs(mod, -1);
1943 module_param_sysfs_remove(mod);
1945 kobject_put(mod->holders_dir);
1947 mod_kobject_put(mod);
1952 static void mod_sysfs_fini(struct module *mod)
1954 remove_notes_attrs(mod);
1955 remove_sect_attrs(mod);
1956 mod_kobject_put(mod);
1959 static void init_param_lock(struct module *mod)
1961 mutex_init(&mod->param_lock);
1963 #else /* !CONFIG_SYSFS */
1965 static int mod_sysfs_setup(struct module *mod,
1966 const struct load_info *info,
1967 struct kernel_param *kparam,
1968 unsigned int num_params)
1973 static void mod_sysfs_fini(struct module *mod)
1977 static void module_remove_modinfo_attrs(struct module *mod, int end)
1981 static void del_usage_links(struct module *mod)
1985 static void init_param_lock(struct module *mod)
1988 #endif /* CONFIG_SYSFS */
1990 static void mod_sysfs_teardown(struct module *mod)
1992 del_usage_links(mod);
1993 module_remove_modinfo_attrs(mod, -1);
1994 module_param_sysfs_remove(mod);
1995 kobject_put(mod->mkobj.drivers_dir);
1996 kobject_put(mod->holders_dir);
1997 mod_sysfs_fini(mod);
2001 * LKM RO/NX protection: protect module's text/ro-data
2002 * from modification and any data from execution.
2004 * General layout of module is:
2005 * [text] [read-only-data] [ro-after-init] [writable data]
2006 * text_size -----^ ^ ^ ^
2007 * ro_size ------------------------| | |
2008 * ro_after_init_size -----------------------------| |
2009 * size -----------------------------------------------------------|
2011 * These values are always page-aligned (as is base)
2015 * Since some arches are moving towards PAGE_KERNEL module allocations instead
2016 * of PAGE_KERNEL_EXEC, keep frob_text() and module_enable_x() outside of the
2017 * CONFIG_STRICT_MODULE_RWX block below because they are needed regardless of
2018 * whether we are strict.
2020 #ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
2021 static void frob_text(const struct module_layout *layout,
2022 int (*set_memory)(unsigned long start, int num_pages))
2024 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
2025 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
2026 set_memory((unsigned long)layout->base,
2027 layout->text_size >> PAGE_SHIFT);
2030 static void module_enable_x(const struct module *mod)
2032 frob_text(&mod->core_layout, set_memory_x);
2033 frob_text(&mod->init_layout, set_memory_x);
2035 #else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
2036 static void module_enable_x(const struct module *mod) { }
2037 #endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
2039 #ifdef CONFIG_STRICT_MODULE_RWX
2040 static void frob_rodata(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->text_size & (PAGE_SIZE-1));
2045 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
2046 set_memory((unsigned long)layout->base + layout->text_size,
2047 (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
2050 static void frob_ro_after_init(const struct module_layout *layout,
2051 int (*set_memory)(unsigned long start, int num_pages))
2053 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
2054 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
2055 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
2056 set_memory((unsigned long)layout->base + layout->ro_size,
2057 (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
2060 static void frob_writable_data(const struct module_layout *layout,
2061 int (*set_memory)(unsigned long start, int num_pages))
2063 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
2064 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
2065 BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
2066 set_memory((unsigned long)layout->base + layout->ro_after_init_size,
2067 (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
2070 static void module_enable_ro(const struct module *mod, bool after_init)
2072 if (!rodata_enabled)
2075 set_vm_flush_reset_perms(mod->core_layout.base);
2076 set_vm_flush_reset_perms(mod->init_layout.base);
2077 frob_text(&mod->core_layout, set_memory_ro);
2079 frob_rodata(&mod->core_layout, set_memory_ro);
2080 frob_text(&mod->init_layout, set_memory_ro);
2081 frob_rodata(&mod->init_layout, set_memory_ro);
2084 frob_ro_after_init(&mod->core_layout, set_memory_ro);
2087 static void module_enable_nx(const struct module *mod)
2089 frob_rodata(&mod->core_layout, set_memory_nx);
2090 frob_ro_after_init(&mod->core_layout, set_memory_nx);
2091 frob_writable_data(&mod->core_layout, set_memory_nx);
2092 frob_rodata(&mod->init_layout, set_memory_nx);
2093 frob_writable_data(&mod->init_layout, set_memory_nx);
2096 static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
2097 char *secstrings, struct module *mod)
2099 const unsigned long shf_wx = SHF_WRITE|SHF_EXECINSTR;
2102 for (i = 0; i < hdr->e_shnum; i++) {
2103 if ((sechdrs[i].sh_flags & shf_wx) == shf_wx) {
2104 pr_err("%s: section %s (index %d) has invalid WRITE|EXEC flags\n",
2105 mod->name, secstrings + sechdrs[i].sh_name, i);
2113 #else /* !CONFIG_STRICT_MODULE_RWX */
2114 static void module_enable_nx(const struct module *mod) { }
2115 static void module_enable_ro(const struct module *mod, bool after_init) {}
2116 static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
2117 char *secstrings, struct module *mod)
2121 #endif /* CONFIG_STRICT_MODULE_RWX */
2123 #ifdef CONFIG_LIVEPATCH
2125 * Persist Elf information about a module. Copy the Elf header,
2126 * section header table, section string table, and symtab section
2127 * index from info to mod->klp_info.
2129 static int copy_module_elf(struct module *mod, struct load_info *info)
2131 unsigned int size, symndx;
2134 size = sizeof(*mod->klp_info);
2135 mod->klp_info = kmalloc(size, GFP_KERNEL);
2136 if (mod->klp_info == NULL)
2140 size = sizeof(mod->klp_info->hdr);
2141 memcpy(&mod->klp_info->hdr, info->hdr, size);
2143 /* Elf section header table */
2144 size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
2145 mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL);
2146 if (mod->klp_info->sechdrs == NULL) {
2151 /* Elf section name string table */
2152 size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
2153 mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL);
2154 if (mod->klp_info->secstrings == NULL) {
2159 /* Elf symbol section index */
2160 symndx = info->index.sym;
2161 mod->klp_info->symndx = symndx;
2164 * For livepatch modules, core_kallsyms.symtab is a complete
2165 * copy of the original symbol table. Adjust sh_addr to point
2166 * to core_kallsyms.symtab since the copy of the symtab in module
2167 * init memory is freed at the end of do_init_module().
2169 mod->klp_info->sechdrs[symndx].sh_addr = \
2170 (unsigned long) mod->core_kallsyms.symtab;
2175 kfree(mod->klp_info->sechdrs);
2177 kfree(mod->klp_info);
2181 static void free_module_elf(struct module *mod)
2183 kfree(mod->klp_info->sechdrs);
2184 kfree(mod->klp_info->secstrings);
2185 kfree(mod->klp_info);
2187 #else /* !CONFIG_LIVEPATCH */
2188 static int copy_module_elf(struct module *mod, struct load_info *info)
2193 static void free_module_elf(struct module *mod)
2196 #endif /* CONFIG_LIVEPATCH */
2198 void __weak module_memfree(void *module_region)
2201 * This memory may be RO, and freeing RO memory in an interrupt is not
2202 * supported by vmalloc.
2204 WARN_ON(in_interrupt());
2205 vfree(module_region);
2208 void __weak module_arch_cleanup(struct module *mod)
2212 void __weak module_arch_freeing_init(struct module *mod)
2216 /* Free a module, remove from lists, etc. */
2217 static void free_module(struct module *mod)
2219 trace_module_free(mod);
2221 mod_sysfs_teardown(mod);
2223 /* We leave it in list to prevent duplicate loads, but make sure
2224 * that noone uses it while it's being deconstructed. */
2225 mutex_lock(&module_mutex);
2226 mod->state = MODULE_STATE_UNFORMED;
2227 mutex_unlock(&module_mutex);
2229 /* Remove dynamic debug info */
2230 ddebug_remove_module(mod->name);
2232 /* Arch-specific cleanup. */
2233 module_arch_cleanup(mod);
2235 /* Module unload stuff */
2236 module_unload_free(mod);
2238 /* Free any allocated parameters. */
2239 destroy_params(mod->kp, mod->num_kp);
2241 if (is_livepatch_module(mod))
2242 free_module_elf(mod);
2244 /* Now we can delete it from the lists */
2245 mutex_lock(&module_mutex);
2246 /* Unlink carefully: kallsyms could be walking list. */
2247 list_del_rcu(&mod->list);
2248 mod_tree_remove(mod);
2249 /* Remove this module from bug list, this uses list_del_rcu */
2250 module_bug_cleanup(mod);
2251 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2253 mutex_unlock(&module_mutex);
2255 /* This may be empty, but that's OK */
2256 module_arch_freeing_init(mod);
2257 module_memfree(mod->init_layout.base);
2259 percpu_modfree(mod);
2261 /* Free lock-classes; relies on the preceding sync_rcu(). */
2262 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
2264 /* Finally, free the core (containing the module structure) */
2265 module_memfree(mod->core_layout.base);
2268 void *__symbol_get(const char *symbol)
2270 struct module *owner;
2271 const struct kernel_symbol *sym;
2274 sym = find_symbol(symbol, &owner, NULL, NULL, true, true);
2275 if (sym && strong_try_module_get(owner))
2279 return sym ? (void *)kernel_symbol_value(sym) : NULL;
2281 EXPORT_SYMBOL_GPL(__symbol_get);
2284 * Ensure that an exported symbol [global namespace] does not already exist
2285 * in the kernel or in some other module's exported symbol table.
2287 * You must hold the module_mutex.
2289 static int verify_exported_symbols(struct module *mod)
2292 struct module *owner;
2293 const struct kernel_symbol *s;
2295 const struct kernel_symbol *sym;
2298 { mod->syms, mod->num_syms },
2299 { mod->gpl_syms, mod->num_gpl_syms },
2300 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2301 #ifdef CONFIG_UNUSED_SYMBOLS
2302 { mod->unused_syms, mod->num_unused_syms },
2303 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2307 for (i = 0; i < ARRAY_SIZE(arr); i++) {
2308 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2309 if (find_symbol(kernel_symbol_name(s), &owner, NULL,
2310 NULL, true, false)) {
2311 pr_err("%s: exports duplicate symbol %s"
2313 mod->name, kernel_symbol_name(s),
2314 module_name(owner));
2322 static bool ignore_undef_symbol(Elf_Half emachine, const char *name)
2325 * On x86, PIC code and Clang non-PIC code may have call foo@PLT. GNU as
2326 * before 2.37 produces an unreferenced _GLOBAL_OFFSET_TABLE_ on x86-64.
2327 * i386 has a similar problem but may not deserve a fix.
2329 * If we ever have to ignore many symbols, consider refactoring the code to
2330 * only warn if referenced by a relocation.
2332 if (emachine == EM_386 || emachine == EM_X86_64)
2333 return !strcmp(name, "_GLOBAL_OFFSET_TABLE_");
2337 /* Change all symbols so that st_value encodes the pointer directly. */
2338 static int simplify_symbols(struct module *mod, const struct load_info *info)
2340 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2341 Elf_Sym *sym = (void *)symsec->sh_addr;
2342 unsigned long secbase;
2345 const struct kernel_symbol *ksym;
2347 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2348 const char *name = info->strtab + sym[i].st_name;
2350 switch (sym[i].st_shndx) {
2352 /* Ignore common symbols */
2353 if (!strncmp(name, "__gnu_lto", 9))
2356 /* We compiled with -fno-common. These are not
2357 supposed to happen. */
2358 pr_debug("Common symbol: %s\n", name);
2359 pr_warn("%s: please compile with -fno-common\n",
2365 /* Don't need to do anything */
2366 pr_debug("Absolute symbol: 0x%08lx\n",
2367 (long)sym[i].st_value);
2371 /* Livepatch symbols are resolved by livepatch */
2375 ksym = resolve_symbol_wait(mod, info, name);
2376 /* Ok if resolved. */
2377 if (ksym && !IS_ERR(ksym)) {
2378 sym[i].st_value = kernel_symbol_value(ksym);
2382 /* Ok if weak or ignored. */
2384 (ELF_ST_BIND(sym[i].st_info) == STB_WEAK ||
2385 ignore_undef_symbol(info->hdr->e_machine, name)))
2388 ret = PTR_ERR(ksym) ?: -ENOENT;
2389 pr_warn("%s: Unknown symbol %s (err %d)\n",
2390 mod->name, name, ret);
2394 /* Divert to percpu allocation if a percpu var. */
2395 if (sym[i].st_shndx == info->index.pcpu)
2396 secbase = (unsigned long)mod_percpu(mod);
2398 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2399 sym[i].st_value += secbase;
2407 static int apply_relocations(struct module *mod, const struct load_info *info)
2412 /* Now do relocations. */
2413 for (i = 1; i < info->hdr->e_shnum; i++) {
2414 unsigned int infosec = info->sechdrs[i].sh_info;
2416 /* Not a valid relocation section? */
2417 if (infosec >= info->hdr->e_shnum)
2420 /* Don't bother with non-allocated sections */
2421 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2424 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
2425 err = klp_apply_section_relocs(mod, info->sechdrs,
2430 else if (info->sechdrs[i].sh_type == SHT_REL)
2431 err = apply_relocate(info->sechdrs, info->strtab,
2432 info->index.sym, i, mod);
2433 else if (info->sechdrs[i].sh_type == SHT_RELA)
2434 err = apply_relocate_add(info->sechdrs, info->strtab,
2435 info->index.sym, i, mod);
2442 /* Additional bytes needed by arch in front of individual sections */
2443 unsigned int __weak arch_mod_section_prepend(struct module *mod,
2444 unsigned int section)
2446 /* default implementation just returns zero */
2450 /* Update size with this section: return offset. */
2451 static long get_offset(struct module *mod, unsigned int *size,
2452 Elf_Shdr *sechdr, unsigned int section)
2456 *size += arch_mod_section_prepend(mod, section);
2457 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2458 *size = ret + sechdr->sh_size;
2462 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2463 might -- code, read-only data, read-write data, small data. Tally
2464 sizes, and place the offsets into sh_entsize fields: high bit means it
2466 static void layout_sections(struct module *mod, struct load_info *info)
2468 static unsigned long const masks[][2] = {
2469 /* NOTE: all executable code must be the first section
2470 * in this array; otherwise modify the text_size
2471 * finder in the two loops below */
2472 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2473 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2474 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
2475 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2476 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2480 for (i = 0; i < info->hdr->e_shnum; i++)
2481 info->sechdrs[i].sh_entsize = ~0UL;
2483 pr_debug("Core section allocation order:\n");
2484 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2485 for (i = 0; i < info->hdr->e_shnum; ++i) {
2486 Elf_Shdr *s = &info->sechdrs[i];
2487 const char *sname = info->secstrings + s->sh_name;
2489 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2490 || (s->sh_flags & masks[m][1])
2491 || s->sh_entsize != ~0UL
2492 || module_init_section(sname))
2494 s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2495 pr_debug("\t%s\n", sname);
2498 case 0: /* executable */
2499 mod->core_layout.size = debug_align(mod->core_layout.size);
2500 mod->core_layout.text_size = mod->core_layout.size;
2502 case 1: /* RO: text and ro-data */
2503 mod->core_layout.size = debug_align(mod->core_layout.size);
2504 mod->core_layout.ro_size = mod->core_layout.size;
2506 case 2: /* RO after init */
2507 mod->core_layout.size = debug_align(mod->core_layout.size);
2508 mod->core_layout.ro_after_init_size = mod->core_layout.size;
2510 case 4: /* whole core */
2511 mod->core_layout.size = debug_align(mod->core_layout.size);
2516 pr_debug("Init section allocation order:\n");
2517 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2518 for (i = 0; i < info->hdr->e_shnum; ++i) {
2519 Elf_Shdr *s = &info->sechdrs[i];
2520 const char *sname = info->secstrings + s->sh_name;
2522 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2523 || (s->sh_flags & masks[m][1])
2524 || s->sh_entsize != ~0UL
2525 || !module_init_section(sname))
2527 s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
2528 | INIT_OFFSET_MASK);
2529 pr_debug("\t%s\n", sname);
2532 case 0: /* executable */
2533 mod->init_layout.size = debug_align(mod->init_layout.size);
2534 mod->init_layout.text_size = mod->init_layout.size;
2536 case 1: /* RO: text and ro-data */
2537 mod->init_layout.size = debug_align(mod->init_layout.size);
2538 mod->init_layout.ro_size = mod->init_layout.size;
2542 * RO after init doesn't apply to init_layout (only
2543 * core_layout), so it just takes the value of ro_size.
2545 mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
2547 case 4: /* whole init */
2548 mod->init_layout.size = debug_align(mod->init_layout.size);
2554 static void set_license(struct module *mod, const char *license)
2557 license = "unspecified";
2559 if (!license_is_gpl_compatible(license)) {
2560 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2561 pr_warn("%s: module license '%s' taints kernel.\n",
2562 mod->name, license);
2563 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2564 LOCKDEP_NOW_UNRELIABLE);
2568 /* Parse tag=value strings from .modinfo section */
2569 static char *next_string(char *string, unsigned long *secsize)
2571 /* Skip non-zero chars */
2574 if ((*secsize)-- <= 1)
2578 /* Skip any zero padding. */
2579 while (!string[0]) {
2581 if ((*secsize)-- <= 1)
2587 static char *get_next_modinfo(const struct load_info *info, const char *tag,
2591 unsigned int taglen = strlen(tag);
2592 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2593 unsigned long size = infosec->sh_size;
2596 * get_modinfo() calls made before rewrite_section_headers()
2597 * must use sh_offset, as sh_addr isn't set!
2599 char *modinfo = (char *)info->hdr + infosec->sh_offset;
2602 size -= prev - modinfo;
2603 modinfo = next_string(prev, &size);
2606 for (p = modinfo; p; p = next_string(p, &size)) {
2607 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2608 return p + taglen + 1;
2613 static char *get_modinfo(const struct load_info *info, const char *tag)
2615 return get_next_modinfo(info, tag, NULL);
2618 static void setup_modinfo(struct module *mod, struct load_info *info)
2620 struct module_attribute *attr;
2623 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2625 attr->setup(mod, get_modinfo(info, attr->attr.name));
2629 static void free_modinfo(struct module *mod)
2631 struct module_attribute *attr;
2634 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2640 #ifdef CONFIG_KALLSYMS
2642 /* Lookup exported symbol in given range of kernel_symbols */
2643 static const struct kernel_symbol *lookup_exported_symbol(const char *name,
2644 const struct kernel_symbol *start,
2645 const struct kernel_symbol *stop)
2647 return bsearch(name, start, stop - start,
2648 sizeof(struct kernel_symbol), cmp_name);
2651 static int is_exported(const char *name, unsigned long value,
2652 const struct module *mod)
2654 const struct kernel_symbol *ks;
2656 ks = lookup_exported_symbol(name, __start___ksymtab, __stop___ksymtab);
2658 ks = lookup_exported_symbol(name, mod->syms, mod->syms + mod->num_syms);
2660 return ks != NULL && kernel_symbol_value(ks) == value;
2664 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2666 const Elf_Shdr *sechdrs = info->sechdrs;
2668 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2669 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2674 if (sym->st_shndx == SHN_UNDEF)
2676 if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
2678 if (sym->st_shndx >= SHN_LORESERVE)
2680 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2682 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2683 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2684 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2686 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2691 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2692 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2697 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2704 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2705 unsigned int shnum, unsigned int pcpundx)
2707 const Elf_Shdr *sec;
2709 if (src->st_shndx == SHN_UNDEF
2710 || src->st_shndx >= shnum
2714 #ifdef CONFIG_KALLSYMS_ALL
2715 if (src->st_shndx == pcpundx)
2719 sec = sechdrs + src->st_shndx;
2720 if (!(sec->sh_flags & SHF_ALLOC)
2721 #ifndef CONFIG_KALLSYMS_ALL
2722 || !(sec->sh_flags & SHF_EXECINSTR)
2724 || (sec->sh_entsize & INIT_OFFSET_MASK))
2731 * We only allocate and copy the strings needed by the parts of symtab
2732 * we keep. This is simple, but has the effect of making multiple
2733 * copies of duplicates. We could be more sophisticated, see
2734 * linux-kernel thread starting with
2735 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2737 static void layout_symtab(struct module *mod, struct load_info *info)
2739 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2740 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2742 unsigned int i, nsrc, ndst, strtab_size = 0;
2744 /* Put symbol section at end of init part of module. */
2745 symsect->sh_flags |= SHF_ALLOC;
2746 symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2747 info->index.sym) | INIT_OFFSET_MASK;
2748 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2750 src = (void *)info->hdr + symsect->sh_offset;
2751 nsrc = symsect->sh_size / sizeof(*src);
2753 /* Compute total space required for the core symbols' strtab. */
2754 for (ndst = i = 0; i < nsrc; i++) {
2755 if (i == 0 || is_livepatch_module(mod) ||
2756 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2757 info->index.pcpu)) {
2758 strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2763 /* Append room for core symbols at end of core part. */
2764 info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
2765 info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
2766 mod->core_layout.size += strtab_size;
2767 info->core_typeoffs = mod->core_layout.size;
2768 mod->core_layout.size += ndst * sizeof(char);
2769 mod->core_layout.size = debug_align(mod->core_layout.size);
2771 /* Put string table section at end of init part of module. */
2772 strsect->sh_flags |= SHF_ALLOC;
2773 strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2774 info->index.str) | INIT_OFFSET_MASK;
2775 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2777 /* We'll tack temporary mod_kallsyms on the end. */
2778 mod->init_layout.size = ALIGN(mod->init_layout.size,
2779 __alignof__(struct mod_kallsyms));
2780 info->mod_kallsyms_init_off = mod->init_layout.size;
2781 mod->init_layout.size += sizeof(struct mod_kallsyms);
2782 info->init_typeoffs = mod->init_layout.size;
2783 mod->init_layout.size += nsrc * sizeof(char);
2784 mod->init_layout.size = debug_align(mod->init_layout.size);
2788 * We use the full symtab and strtab which layout_symtab arranged to
2789 * be appended to the init section. Later we switch to the cut-down
2792 static void add_kallsyms(struct module *mod, const struct load_info *info)
2794 unsigned int i, ndst;
2798 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2800 /* Set up to point into init section. */
2801 mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
2803 mod->kallsyms->symtab = (void *)symsec->sh_addr;
2804 mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2805 /* Make sure we get permanent strtab: don't use info->strtab. */
2806 mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2807 mod->kallsyms->typetab = mod->init_layout.base + info->init_typeoffs;
2810 * Now populate the cut down core kallsyms for after init
2811 * and set types up while we still have access to sections.
2813 mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
2814 mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
2815 mod->core_kallsyms.typetab = mod->core_layout.base + info->core_typeoffs;
2816 src = mod->kallsyms->symtab;
2817 for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2818 mod->kallsyms->typetab[i] = elf_type(src + i, info);
2819 if (i == 0 || is_livepatch_module(mod) ||
2820 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2821 info->index.pcpu)) {
2822 mod->core_kallsyms.typetab[ndst] =
2823 mod->kallsyms->typetab[i];
2825 dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
2826 s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2830 mod->core_kallsyms.num_symtab = ndst;
2833 static inline void layout_symtab(struct module *mod, struct load_info *info)
2837 static void add_kallsyms(struct module *mod, const struct load_info *info)
2840 #endif /* CONFIG_KALLSYMS */
2842 static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num)
2846 ddebug_add_module(debug, num, mod->name);
2849 static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug)
2852 ddebug_remove_module(mod->name);
2855 void * __weak module_alloc(unsigned long size)
2857 return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
2858 GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS,
2859 NUMA_NO_NODE, __builtin_return_address(0));
2862 bool __weak module_init_section(const char *name)
2864 return strstarts(name, ".init");
2867 bool __weak module_exit_section(const char *name)
2869 return strstarts(name, ".exit");
2872 #ifdef CONFIG_DEBUG_KMEMLEAK
2873 static void kmemleak_load_module(const struct module *mod,
2874 const struct load_info *info)
2878 /* only scan the sections containing data */
2879 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2881 for (i = 1; i < info->hdr->e_shnum; i++) {
2882 /* Scan all writable sections that's not executable */
2883 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2884 !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2885 (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2888 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2889 info->sechdrs[i].sh_size, GFP_KERNEL);
2893 static inline void kmemleak_load_module(const struct module *mod,
2894 const struct load_info *info)
2899 #ifdef CONFIG_MODULE_SIG
2900 static int module_sig_check(struct load_info *info, int flags)
2903 const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2905 const void *mod = info->hdr;
2908 * Require flags == 0, as a module with version information
2909 * removed is no longer the module that was signed
2912 info->len > markerlen &&
2913 memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2914 /* We truncate the module to discard the signature */
2915 info->len -= markerlen;
2916 err = mod_verify_sig(mod, info);
2921 info->sig_ok = true;
2924 /* We don't permit modules to be loaded into trusted kernels
2925 * without a valid signature on them, but if we're not
2926 * enforcing, certain errors are non-fatal.
2929 reason = "unsigned module";
2932 reason = "module with unsupported crypto";
2935 reason = "module with unavailable key";
2938 /* All other errors are fatal, including nomem, unparseable
2939 * signatures and signature check failures - even if signatures
2946 if (is_module_sig_enforced()) {
2947 pr_notice("Loading of %s is rejected\n", reason);
2948 return -EKEYREJECTED;
2951 return security_locked_down(LOCKDOWN_MODULE_SIGNATURE);
2953 #else /* !CONFIG_MODULE_SIG */
2954 static int module_sig_check(struct load_info *info, int flags)
2958 #endif /* !CONFIG_MODULE_SIG */
2960 static int validate_section_offset(struct load_info *info, Elf_Shdr *shdr)
2962 unsigned long secend;
2965 * Check for both overflow and offset/size being
2968 secend = shdr->sh_offset + shdr->sh_size;
2969 if (secend < shdr->sh_offset || secend > info->len)
2976 * Sanity checks against invalid binaries, wrong arch, weird elf version.
2978 * Also do basic validity checks against section offsets and sizes, the
2979 * section name string table, and the indices used for it (sh_name).
2981 static int elf_validity_check(struct load_info *info)
2984 Elf_Shdr *shdr, *strhdr;
2987 if (info->len < sizeof(*(info->hdr)))
2990 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2991 || info->hdr->e_type != ET_REL
2992 || !elf_check_arch(info->hdr)
2993 || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2997 * e_shnum is 16 bits, and sizeof(Elf_Shdr) is
2998 * known and small. So e_shnum * sizeof(Elf_Shdr)
2999 * will not overflow unsigned long on any platform.
3001 if (info->hdr->e_shoff >= info->len
3002 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
3003 info->len - info->hdr->e_shoff))
3006 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
3009 * Verify if the section name table index is valid.
3011 if (info->hdr->e_shstrndx == SHN_UNDEF
3012 || info->hdr->e_shstrndx >= info->hdr->e_shnum)
3015 strhdr = &info->sechdrs[info->hdr->e_shstrndx];
3016 err = validate_section_offset(info, strhdr);
3021 * The section name table must be NUL-terminated, as required
3022 * by the spec. This makes strcmp and pr_* calls that access
3023 * strings in the section safe.
3025 info->secstrings = (void *)info->hdr + strhdr->sh_offset;
3026 if (info->secstrings[strhdr->sh_size - 1] != '\0')
3030 * The code assumes that section 0 has a length of zero and
3031 * an addr of zero, so check for it.
3033 if (info->sechdrs[0].sh_type != SHT_NULL
3034 || info->sechdrs[0].sh_size != 0
3035 || info->sechdrs[0].sh_addr != 0)
3038 for (i = 1; i < info->hdr->e_shnum; i++) {
3039 shdr = &info->sechdrs[i];
3040 switch (shdr->sh_type) {
3045 if (shdr->sh_link == SHN_UNDEF
3046 || shdr->sh_link >= info->hdr->e_shnum)
3050 err = validate_section_offset(info, shdr);
3052 pr_err("Invalid ELF section in module (section %u type %u)\n",
3057 if (shdr->sh_flags & SHF_ALLOC) {
3058 if (shdr->sh_name >= strhdr->sh_size) {
3059 pr_err("Invalid ELF section name in module (section %u type %u)\n",
3071 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
3073 static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
3076 unsigned long n = min(len, COPY_CHUNK_SIZE);
3078 if (copy_from_user(dst, usrc, n) != 0)
3088 #ifdef CONFIG_LIVEPATCH
3089 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
3091 if (get_modinfo(info, "livepatch")) {
3093 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
3094 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
3100 #else /* !CONFIG_LIVEPATCH */
3101 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
3103 if (get_modinfo(info, "livepatch")) {
3104 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
3111 #endif /* CONFIG_LIVEPATCH */
3113 static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
3115 if (retpoline_module_ok(get_modinfo(info, "retpoline")))
3118 pr_warn("%s: loading module not compiled with retpoline compiler.\n",
3122 /* Sets info->hdr and info->len. */
3123 static int copy_module_from_user(const void __user *umod, unsigned long len,
3124 struct load_info *info)
3129 if (info->len < sizeof(*(info->hdr)))
3132 err = security_kernel_load_data(LOADING_MODULE, true);
3136 /* Suck in entire file: we'll want most of it. */
3137 info->hdr = __vmalloc(info->len, GFP_KERNEL | __GFP_NOWARN);
3141 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
3146 err = security_kernel_post_load_data((char *)info->hdr, info->len,
3147 LOADING_MODULE, "init_module");
3155 static void free_copy(struct load_info *info)
3160 static int rewrite_section_headers(struct load_info *info, int flags)
3164 /* This should always be true, but let's be sure. */
3165 info->sechdrs[0].sh_addr = 0;
3167 for (i = 1; i < info->hdr->e_shnum; i++) {
3168 Elf_Shdr *shdr = &info->sechdrs[i];
3170 /* Mark all sections sh_addr with their address in the
3172 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
3174 #ifndef CONFIG_MODULE_UNLOAD
3175 /* Don't load .exit sections */
3176 if (module_exit_section(info->secstrings+shdr->sh_name))
3177 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
3181 /* Track but don't keep modinfo and version sections. */
3182 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
3183 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
3189 * Set up our basic convenience variables (pointers to section headers,
3190 * search for module section index etc), and do some basic section
3193 * Set info->mod to the temporary copy of the module in info->hdr. The final one
3194 * will be allocated in move_module().
3196 static int setup_load_info(struct load_info *info, int flags)
3200 /* Try to find a name early so we can log errors with a module name */
3201 info->index.info = find_sec(info, ".modinfo");
3202 if (info->index.info)
3203 info->name = get_modinfo(info, "name");
3205 /* Find internal symbols and strings. */
3206 for (i = 1; i < info->hdr->e_shnum; i++) {
3207 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
3208 info->index.sym = i;
3209 info->index.str = info->sechdrs[i].sh_link;
3210 info->strtab = (char *)info->hdr
3211 + info->sechdrs[info->index.str].sh_offset;
3216 if (info->index.sym == 0) {
3217 pr_warn("%s: module has no symbols (stripped?)\n",
3218 info->name ?: "(missing .modinfo section or name field)");
3222 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
3223 if (!info->index.mod) {
3224 pr_warn("%s: No module found in object\n",
3225 info->name ?: "(missing .modinfo section or name field)");
3228 /* This is temporary: point mod into copy of data. */
3229 info->mod = (void *)info->hdr + info->sechdrs[info->index.mod].sh_offset;
3232 * If we didn't load the .modinfo 'name' field earlier, fall back to
3233 * on-disk struct mod 'name' field.
3236 info->name = info->mod->name;
3238 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
3239 info->index.vers = 0; /* Pretend no __versions section! */
3241 info->index.vers = find_sec(info, "__versions");
3243 info->index.pcpu = find_pcpusec(info);
3248 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
3250 const char *modmagic = get_modinfo(info, "vermagic");
3253 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
3256 /* This is allowed: modprobe --force will invalidate it. */
3258 err = try_to_force_load(mod, "bad vermagic");
3261 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
3262 pr_err("%s: version magic '%s' should be '%s'\n",
3263 info->name, modmagic, vermagic);
3267 if (!get_modinfo(info, "intree")) {
3268 if (!test_taint(TAINT_OOT_MODULE))
3269 pr_warn("%s: loading out-of-tree module taints kernel.\n",
3271 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
3274 check_modinfo_retpoline(mod, info);
3276 if (get_modinfo(info, "staging")) {
3277 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
3278 pr_warn("%s: module is from the staging directory, the quality "
3279 "is unknown, you have been warned.\n", mod->name);
3282 err = check_modinfo_livepatch(mod, info);
3286 /* Set up license info based on the info section */
3287 set_license(mod, get_modinfo(info, "license"));
3292 static int find_module_sections(struct module *mod, struct load_info *info)
3294 mod->kp = section_objs(info, "__param",
3295 sizeof(*mod->kp), &mod->num_kp);
3296 mod->syms = section_objs(info, "__ksymtab",
3297 sizeof(*mod->syms), &mod->num_syms);
3298 mod->crcs = section_addr(info, "__kcrctab");
3299 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
3300 sizeof(*mod->gpl_syms),
3301 &mod->num_gpl_syms);
3302 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
3303 mod->gpl_future_syms = section_objs(info,
3304 "__ksymtab_gpl_future",
3305 sizeof(*mod->gpl_future_syms),
3306 &mod->num_gpl_future_syms);
3307 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
3309 #ifdef CONFIG_UNUSED_SYMBOLS
3310 mod->unused_syms = section_objs(info, "__ksymtab_unused",
3311 sizeof(*mod->unused_syms),
3312 &mod->num_unused_syms);
3313 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
3314 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
3315 sizeof(*mod->unused_gpl_syms),
3316 &mod->num_unused_gpl_syms);
3317 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
3319 #ifdef CONFIG_CONSTRUCTORS
3320 mod->ctors = section_objs(info, ".ctors",
3321 sizeof(*mod->ctors), &mod->num_ctors);
3323 mod->ctors = section_objs(info, ".init_array",
3324 sizeof(*mod->ctors), &mod->num_ctors);
3325 else if (find_sec(info, ".init_array")) {
3327 * This shouldn't happen with same compiler and binutils
3328 * building all parts of the module.
3330 pr_warn("%s: has both .ctors and .init_array.\n",
3336 mod->noinstr_text_start = section_objs(info, ".noinstr.text", 1,
3337 &mod->noinstr_text_size);
3339 #ifdef CONFIG_TRACEPOINTS
3340 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
3341 sizeof(*mod->tracepoints_ptrs),
3342 &mod->num_tracepoints);
3344 #ifdef CONFIG_TREE_SRCU
3345 mod->srcu_struct_ptrs = section_objs(info, "___srcu_struct_ptrs",
3346 sizeof(*mod->srcu_struct_ptrs),
3347 &mod->num_srcu_structs);
3349 #ifdef CONFIG_BPF_EVENTS
3350 mod->bpf_raw_events = section_objs(info, "__bpf_raw_tp_map",
3351 sizeof(*mod->bpf_raw_events),
3352 &mod->num_bpf_raw_events);
3354 #ifdef CONFIG_JUMP_LABEL
3355 mod->jump_entries = section_objs(info, "__jump_table",
3356 sizeof(*mod->jump_entries),
3357 &mod->num_jump_entries);
3359 #ifdef CONFIG_EVENT_TRACING
3360 mod->trace_events = section_objs(info, "_ftrace_events",
3361 sizeof(*mod->trace_events),
3362 &mod->num_trace_events);
3363 mod->trace_evals = section_objs(info, "_ftrace_eval_map",
3364 sizeof(*mod->trace_evals),
3365 &mod->num_trace_evals);
3367 #ifdef CONFIG_TRACING
3368 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
3369 sizeof(*mod->trace_bprintk_fmt_start),
3370 &mod->num_trace_bprintk_fmt);
3372 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
3373 /* sechdrs[0].sh_size is always zero */
3374 mod->ftrace_callsites = section_objs(info, FTRACE_CALLSITE_SECTION,
3375 sizeof(*mod->ftrace_callsites),
3376 &mod->num_ftrace_callsites);
3378 #ifdef CONFIG_FUNCTION_ERROR_INJECTION
3379 mod->ei_funcs = section_objs(info, "_error_injection_whitelist",
3380 sizeof(*mod->ei_funcs),
3381 &mod->num_ei_funcs);
3383 #ifdef CONFIG_KPROBES
3384 mod->kprobes_text_start = section_objs(info, ".kprobes.text", 1,
3385 &mod->kprobes_text_size);
3386 mod->kprobe_blacklist = section_objs(info, "_kprobe_blacklist",
3387 sizeof(unsigned long),
3388 &mod->num_kprobe_blacklist);
3390 #ifdef CONFIG_HAVE_STATIC_CALL_INLINE
3391 mod->static_call_sites = section_objs(info, ".static_call_sites",
3392 sizeof(*mod->static_call_sites),
3393 &mod->num_static_call_sites);
3395 mod->extable = section_objs(info, "__ex_table",
3396 sizeof(*mod->extable), &mod->num_exentries);
3398 if (section_addr(info, "__obsparm"))
3399 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
3401 info->debug = section_objs(info, "__dyndbg",
3402 sizeof(*info->debug), &info->num_debug);
3407 static int move_module(struct module *mod, struct load_info *info)
3412 /* Do the allocs. */
3413 ptr = module_alloc(mod->core_layout.size);
3415 * The pointer to this block is stored in the module structure
3416 * which is inside the block. Just mark it as not being a
3419 kmemleak_not_leak(ptr);
3423 memset(ptr, 0, mod->core_layout.size);
3424 mod->core_layout.base = ptr;
3426 if (mod->init_layout.size) {
3427 ptr = module_alloc(mod->init_layout.size);
3429 * The pointer to this block is stored in the module structure
3430 * which is inside the block. This block doesn't need to be
3431 * scanned as it contains data and code that will be freed
3432 * after the module is initialized.
3434 kmemleak_ignore(ptr);
3436 module_memfree(mod->core_layout.base);
3439 memset(ptr, 0, mod->init_layout.size);
3440 mod->init_layout.base = ptr;
3442 mod->init_layout.base = NULL;
3444 /* Transfer each section which specifies SHF_ALLOC */
3445 pr_debug("final section addresses:\n");
3446 for (i = 0; i < info->hdr->e_shnum; i++) {
3448 Elf_Shdr *shdr = &info->sechdrs[i];
3450 if (!(shdr->sh_flags & SHF_ALLOC))
3453 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3454 dest = mod->init_layout.base
3455 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3457 dest = mod->core_layout.base + shdr->sh_entsize;
3459 if (shdr->sh_type != SHT_NOBITS)
3460 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3461 /* Update sh_addr to point to copy in image. */
3462 shdr->sh_addr = (unsigned long)dest;
3463 pr_debug("\t0x%lx %s\n",
3464 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3470 static int check_module_license_and_versions(struct module *mod)
3472 int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
3475 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3476 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3477 * using GPL-only symbols it needs.
3479 if (strcmp(mod->name, "ndiswrapper") == 0)
3480 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3482 /* driverloader was caught wrongly pretending to be under GPL */
3483 if (strcmp(mod->name, "driverloader") == 0)
3484 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3485 LOCKDEP_NOW_UNRELIABLE);
3487 /* lve claims to be GPL but upstream won't provide source */
3488 if (strcmp(mod->name, "lve") == 0)
3489 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3490 LOCKDEP_NOW_UNRELIABLE);
3492 if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
3493 pr_warn("%s: module license taints kernel.\n", mod->name);
3495 #ifdef CONFIG_MODVERSIONS
3496 if ((mod->num_syms && !mod->crcs)
3497 || (mod->num_gpl_syms && !mod->gpl_crcs)
3498 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3499 #ifdef CONFIG_UNUSED_SYMBOLS
3500 || (mod->num_unused_syms && !mod->unused_crcs)
3501 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3504 return try_to_force_load(mod,
3505 "no versions for exported symbols");
3511 static void flush_module_icache(const struct module *mod)
3514 * Flush the instruction cache, since we've played with text.
3515 * Do it before processing of module parameters, so the module
3516 * can provide parameter accessor functions of its own.
3518 if (mod->init_layout.base)
3519 flush_icache_range((unsigned long)mod->init_layout.base,
3520 (unsigned long)mod->init_layout.base
3521 + mod->init_layout.size);
3522 flush_icache_range((unsigned long)mod->core_layout.base,
3523 (unsigned long)mod->core_layout.base + mod->core_layout.size);
3526 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3534 /* module_blacklist is a comma-separated list of module names */
3535 static char *module_blacklist;
3536 static bool blacklisted(const char *module_name)
3541 if (!module_blacklist)
3544 for (p = module_blacklist; *p; p += len) {
3545 len = strcspn(p, ",");
3546 if (strlen(module_name) == len && !memcmp(module_name, p, len))
3553 core_param(module_blacklist, module_blacklist, charp, 0400);
3555 static struct module *layout_and_allocate(struct load_info *info, int flags)
3561 err = check_modinfo(info->mod, info, flags);
3563 return ERR_PTR(err);
3565 /* Allow arches to frob section contents and sizes. */
3566 err = module_frob_arch_sections(info->hdr, info->sechdrs,
3567 info->secstrings, info->mod);
3569 return ERR_PTR(err);
3571 err = module_enforce_rwx_sections(info->hdr, info->sechdrs,
3572 info->secstrings, info->mod);
3574 return ERR_PTR(err);
3576 /* We will do a special allocation for per-cpu sections later. */
3577 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3580 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3581 * layout_sections() can put it in the right place.
3582 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3584 ndx = find_sec(info, ".data..ro_after_init");
3586 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3588 * Mark the __jump_table section as ro_after_init as well: these data
3589 * structures are never modified, with the exception of entries that
3590 * refer to code in the __init section, which are annotated as such
3591 * at module load time.
3593 ndx = find_sec(info, "__jump_table");
3595 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3597 /* Determine total sizes, and put offsets in sh_entsize. For now
3598 this is done generically; there doesn't appear to be any
3599 special cases for the architectures. */
3600 layout_sections(info->mod, info);
3601 layout_symtab(info->mod, info);
3603 /* Allocate and move to the final place */
3604 err = move_module(info->mod, info);
3606 return ERR_PTR(err);
3608 /* Module has been copied to its final place now: return it. */
3609 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3610 kmemleak_load_module(mod, info);
3614 /* mod is no longer valid after this! */
3615 static void module_deallocate(struct module *mod, struct load_info *info)
3617 percpu_modfree(mod);
3618 module_arch_freeing_init(mod);
3619 module_memfree(mod->init_layout.base);
3620 module_memfree(mod->core_layout.base);
3623 int __weak module_finalize(const Elf_Ehdr *hdr,
3624 const Elf_Shdr *sechdrs,
3630 static int post_relocation(struct module *mod, const struct load_info *info)
3632 /* Sort exception table now relocations are done. */
3633 sort_extable(mod->extable, mod->extable + mod->num_exentries);
3635 /* Copy relocated percpu area over. */
3636 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3637 info->sechdrs[info->index.pcpu].sh_size);
3639 /* Setup kallsyms-specific fields. */
3640 add_kallsyms(mod, info);
3642 /* Arch-specific module finalizing. */
3643 return module_finalize(info->hdr, info->sechdrs, mod);
3646 /* Is this module of this name done loading? No locks held. */
3647 static bool finished_loading(const char *name)
3653 * The module_mutex should not be a heavily contended lock;
3654 * if we get the occasional sleep here, we'll go an extra iteration
3655 * in the wait_event_interruptible(), which is harmless.
3657 sched_annotate_sleep();
3658 mutex_lock(&module_mutex);
3659 mod = find_module_all(name, strlen(name), true);
3660 ret = !mod || mod->state == MODULE_STATE_LIVE;
3661 mutex_unlock(&module_mutex);
3666 /* Call module constructors. */
3667 static void do_mod_ctors(struct module *mod)
3669 #ifdef CONFIG_CONSTRUCTORS
3672 for (i = 0; i < mod->num_ctors; i++)
3677 /* For freeing module_init on success, in case kallsyms traversing */
3678 struct mod_initfree {
3679 struct llist_node node;
3683 static void do_free_init(struct work_struct *w)
3685 struct llist_node *pos, *n, *list;
3686 struct mod_initfree *initfree;
3688 list = llist_del_all(&init_free_list);
3692 llist_for_each_safe(pos, n, list) {
3693 initfree = container_of(pos, struct mod_initfree, node);
3694 module_memfree(initfree->module_init);
3700 * This is where the real work happens.
3702 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3703 * helper command 'lx-symbols'.
3705 static noinline int do_init_module(struct module *mod)
3708 struct mod_initfree *freeinit;
3710 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3715 freeinit->module_init = mod->init_layout.base;
3718 * We want to find out whether @mod uses async during init. Clear
3719 * PF_USED_ASYNC. async_schedule*() will set it.
3721 current->flags &= ~PF_USED_ASYNC;
3724 /* Start the module */
3725 if (mod->init != NULL)
3726 ret = do_one_initcall(mod->init);
3728 goto fail_free_freeinit;
3731 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3732 "follow 0/-E convention\n"
3733 "%s: loading module anyway...\n",
3734 __func__, mod->name, ret, __func__);
3738 /* Now it's a first class citizen! */
3739 mod->state = MODULE_STATE_LIVE;
3740 blocking_notifier_call_chain(&module_notify_list,
3741 MODULE_STATE_LIVE, mod);
3743 /* Delay uevent until module has finished its init routine */
3744 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
3747 * We need to finish all async code before the module init sequence
3748 * is done. This has potential to deadlock. For example, a newly
3749 * detected block device can trigger request_module() of the
3750 * default iosched from async probing task. Once userland helper
3751 * reaches here, async_synchronize_full() will wait on the async
3752 * task waiting on request_module() and deadlock.
3754 * This deadlock is avoided by perfomring async_synchronize_full()
3755 * iff module init queued any async jobs. This isn't a full
3756 * solution as it will deadlock the same if module loading from
3757 * async jobs nests more than once; however, due to the various
3758 * constraints, this hack seems to be the best option for now.
3759 * Please refer to the following thread for details.
3761 * http://thread.gmane.org/gmane.linux.kernel/1420814
3763 if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3764 async_synchronize_full();
3766 ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base +
3767 mod->init_layout.size);
3768 mutex_lock(&module_mutex);
3769 /* Drop initial reference. */
3771 trim_init_extable(mod);
3772 #ifdef CONFIG_KALLSYMS
3773 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3774 rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3776 module_enable_ro(mod, true);
3777 mod_tree_remove_init(mod);
3778 module_arch_freeing_init(mod);
3779 mod->init_layout.base = NULL;
3780 mod->init_layout.size = 0;
3781 mod->init_layout.ro_size = 0;
3782 mod->init_layout.ro_after_init_size = 0;
3783 mod->init_layout.text_size = 0;
3785 * We want to free module_init, but be aware that kallsyms may be
3786 * walking this with preempt disabled. In all the failure paths, we
3787 * call synchronize_rcu(), but we don't want to slow down the success
3788 * path. module_memfree() cannot be called in an interrupt, so do the
3789 * work and call synchronize_rcu() in a work queue.
3791 * Note that module_alloc() on most architectures creates W+X page
3792 * mappings which won't be cleaned up until do_free_init() runs. Any
3793 * code such as mark_rodata_ro() which depends on those mappings to
3794 * be cleaned up needs to sync with the queued work - ie
3797 if (llist_add(&freeinit->node, &init_free_list))
3798 schedule_work(&init_free_wq);
3800 mutex_unlock(&module_mutex);
3801 wake_up_all(&module_wq);
3808 /* Try to protect us from buggy refcounters. */
3809 mod->state = MODULE_STATE_GOING;
3812 blocking_notifier_call_chain(&module_notify_list,
3813 MODULE_STATE_GOING, mod);
3814 klp_module_going(mod);
3815 ftrace_release_mod(mod);
3817 wake_up_all(&module_wq);
3821 static int may_init_module(void)
3823 if (!capable(CAP_SYS_MODULE) || modules_disabled)
3830 * We try to place it in the list now to make sure it's unique before
3831 * we dedicate too many resources. In particular, temporary percpu
3832 * memory exhaustion.
3834 static int add_unformed_module(struct module *mod)
3839 mod->state = MODULE_STATE_UNFORMED;
3842 mutex_lock(&module_mutex);
3843 old = find_module_all(mod->name, strlen(mod->name), true);
3845 if (old->state != MODULE_STATE_LIVE) {
3846 /* Wait in case it fails to load. */
3847 mutex_unlock(&module_mutex);
3848 err = wait_event_interruptible(module_wq,
3849 finished_loading(mod->name));
3857 mod_update_bounds(mod);
3858 list_add_rcu(&mod->list, &modules);
3859 mod_tree_insert(mod);
3863 mutex_unlock(&module_mutex);
3868 static int complete_formation(struct module *mod, struct load_info *info)
3872 mutex_lock(&module_mutex);
3874 /* Find duplicate symbols (must be called under lock). */
3875 err = verify_exported_symbols(mod);
3879 /* This relies on module_mutex for list integrity. */
3880 module_bug_finalize(info->hdr, info->sechdrs, mod);
3882 module_enable_ro(mod, false);
3883 module_enable_nx(mod);
3884 module_enable_x(mod);
3886 /* Mark state as coming so strong_try_module_get() ignores us,
3887 * but kallsyms etc. can see us. */
3888 mod->state = MODULE_STATE_COMING;
3889 mutex_unlock(&module_mutex);
3894 mutex_unlock(&module_mutex);
3898 static int prepare_coming_module(struct module *mod)
3902 ftrace_module_enable(mod);
3903 err = klp_module_coming(mod);
3907 err = blocking_notifier_call_chain_robust(&module_notify_list,
3908 MODULE_STATE_COMING, MODULE_STATE_GOING, mod);
3909 err = notifier_to_errno(err);
3911 klp_module_going(mod);
3916 static int unknown_module_param_cb(char *param, char *val, const char *modname,
3919 struct module *mod = arg;
3922 if (strcmp(param, "async_probe") == 0) {
3923 mod->async_probe_requested = true;
3927 /* Check for magic 'dyndbg' arg */
3928 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3930 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3934 /* Allocate and load the module: note that size of section 0 is always
3935 zero, and we rely on this for optional sections. */
3936 static int load_module(struct load_info *info, const char __user *uargs,
3944 * Do the signature check (if any) first. All that
3945 * the signature check needs is info->len, it does
3946 * not need any of the section info. That can be
3947 * set up later. This will minimize the chances
3948 * of a corrupt module causing problems before
3949 * we even get to the signature check.
3951 * The check will also adjust info->len by stripping
3952 * off the sig length at the end of the module, making
3953 * checks against info->len more correct.
3955 err = module_sig_check(info, flags);
3960 * Do basic sanity checks against the ELF header and
3963 err = elf_validity_check(info);
3965 pr_err("Module has invalid ELF structures\n");
3970 * Everything checks out, so set up the section info
3971 * in the info structure.
3973 err = setup_load_info(info, flags);
3978 * Now that we know we have the correct module name, check
3979 * if it's blacklisted.
3981 if (blacklisted(info->name)) {
3983 pr_err("Module %s is blacklisted\n", info->name);
3987 err = rewrite_section_headers(info, flags);
3991 /* Check module struct version now, before we try to use module. */
3992 if (!check_modstruct_version(info, info->mod)) {
3997 /* Figure out module layout, and allocate all the memory. */
3998 mod = layout_and_allocate(info, flags);
4004 audit_log_kern_module(mod->name);
4006 /* Reserve our place in the list. */
4007 err = add_unformed_module(mod);
4011 #ifdef CONFIG_MODULE_SIG
4012 mod->sig_ok = info->sig_ok;
4014 pr_notice_once("%s: module verification failed: signature "
4015 "and/or required key missing - tainting "
4016 "kernel\n", mod->name);
4017 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
4021 /* To avoid stressing percpu allocator, do this once we're unique. */
4022 err = percpu_modalloc(mod, info);
4026 /* Now module is in final location, initialize linked lists, etc. */
4027 err = module_unload_init(mod);
4031 init_param_lock(mod);
4033 /* Now we've got everything in the final locations, we can
4034 * find optional sections. */
4035 err = find_module_sections(mod, info);
4039 err = check_module_license_and_versions(mod);
4043 /* Set up MODINFO_ATTR fields */
4044 setup_modinfo(mod, info);
4046 /* Fix up syms, so that st_value is a pointer to location. */
4047 err = simplify_symbols(mod, info);
4051 err = apply_relocations(mod, info);
4055 err = post_relocation(mod, info);
4059 flush_module_icache(mod);
4061 /* Now copy in args */
4062 mod->args = strndup_user(uargs, ~0UL >> 1);
4063 if (IS_ERR(mod->args)) {
4064 err = PTR_ERR(mod->args);
4065 goto free_arch_cleanup;
4068 dynamic_debug_setup(mod, info->debug, info->num_debug);
4070 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
4071 ftrace_module_init(mod);
4073 /* Finally it's fully formed, ready to start executing. */
4074 err = complete_formation(mod, info);
4076 goto ddebug_cleanup;
4078 err = prepare_coming_module(mod);
4082 /* Module is ready to execute: parsing args may do that. */
4083 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
4085 unknown_module_param_cb);
4086 if (IS_ERR(after_dashes)) {
4087 err = PTR_ERR(after_dashes);
4088 goto coming_cleanup;
4089 } else if (after_dashes) {
4090 pr_warn("%s: parameters '%s' after `--' ignored\n",
4091 mod->name, after_dashes);
4094 /* Link in to sysfs. */
4095 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
4097 goto coming_cleanup;
4099 if (is_livepatch_module(mod)) {
4100 err = copy_module_elf(mod, info);
4105 /* Get rid of temporary copy. */
4109 trace_module_load(mod);
4111 return do_init_module(mod);
4114 mod_sysfs_teardown(mod);
4116 mod->state = MODULE_STATE_GOING;
4117 destroy_params(mod->kp, mod->num_kp);
4118 blocking_notifier_call_chain(&module_notify_list,
4119 MODULE_STATE_GOING, mod);
4120 klp_module_going(mod);
4122 mod->state = MODULE_STATE_GOING;
4123 /* module_bug_cleanup needs module_mutex protection */
4124 mutex_lock(&module_mutex);
4125 module_bug_cleanup(mod);
4126 mutex_unlock(&module_mutex);
4129 ftrace_release_mod(mod);
4130 dynamic_debug_remove(mod, info->debug);
4134 module_arch_cleanup(mod);
4138 module_unload_free(mod);
4140 mutex_lock(&module_mutex);
4141 /* Unlink carefully: kallsyms could be walking list. */
4142 list_del_rcu(&mod->list);
4143 mod_tree_remove(mod);
4144 wake_up_all(&module_wq);
4145 /* Wait for RCU-sched synchronizing before releasing mod->list. */
4147 mutex_unlock(&module_mutex);
4149 /* Free lock-classes; relies on the preceding sync_rcu() */
4150 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
4152 module_deallocate(mod, info);
4158 SYSCALL_DEFINE3(init_module, void __user *, umod,
4159 unsigned long, len, const char __user *, uargs)
4162 struct load_info info = { };
4164 err = may_init_module();
4168 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
4171 err = copy_module_from_user(umod, len, &info);
4175 return load_module(&info, uargs, 0);
4178 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
4180 struct load_info info = { };
4184 err = may_init_module();
4188 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
4190 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
4191 |MODULE_INIT_IGNORE_VERMAGIC))
4194 err = kernel_read_file_from_fd(fd, 0, &hdr, INT_MAX, NULL,
4201 return load_module(&info, uargs, flags);
4204 static inline int within(unsigned long addr, void *start, unsigned long size)
4206 return ((void *)addr >= start && (void *)addr < start + size);
4209 #ifdef CONFIG_KALLSYMS
4211 * This ignores the intensely annoying "mapping symbols" found
4212 * in ARM ELF files: $a, $t and $d.
4214 static inline int is_arm_mapping_symbol(const char *str)
4216 if (str[0] == '.' && str[1] == 'L')
4218 return str[0] == '$' && strchr("axtd", str[1])
4219 && (str[2] == '\0' || str[2] == '.');
4222 static const char *kallsyms_symbol_name(struct mod_kallsyms *kallsyms, unsigned int symnum)
4224 return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
4228 * Given a module and address, find the corresponding symbol and return its name
4229 * while providing its size and offset if needed.
4231 static const char *find_kallsyms_symbol(struct module *mod,
4233 unsigned long *size,
4234 unsigned long *offset)
4236 unsigned int i, best = 0;
4237 unsigned long nextval, bestval;
4238 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4240 /* At worse, next value is at end of module */
4241 if (within_module_init(addr, mod))
4242 nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
4244 nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
4246 bestval = kallsyms_symbol_value(&kallsyms->symtab[best]);
4248 /* Scan for closest preceding symbol, and next symbol. (ELF
4249 starts real symbols at 1). */
4250 for (i = 1; i < kallsyms->num_symtab; i++) {
4251 const Elf_Sym *sym = &kallsyms->symtab[i];
4252 unsigned long thisval = kallsyms_symbol_value(sym);
4254 if (sym->st_shndx == SHN_UNDEF)
4257 /* We ignore unnamed symbols: they're uninformative
4258 * and inserted at a whim. */
4259 if (*kallsyms_symbol_name(kallsyms, i) == '\0'
4260 || is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms, i)))
4263 if (thisval <= addr && thisval > bestval) {
4267 if (thisval > addr && thisval < nextval)
4275 *size = nextval - bestval;
4277 *offset = addr - bestval;
4279 return kallsyms_symbol_name(kallsyms, best);
4282 void * __weak dereference_module_function_descriptor(struct module *mod,
4288 /* For kallsyms to ask for address resolution. NULL means not found. Careful
4289 * not to lock to avoid deadlock on oopses, simply disable preemption. */
4290 const char *module_address_lookup(unsigned long addr,
4291 unsigned long *size,
4292 unsigned long *offset,
4296 const char *ret = NULL;
4300 mod = __module_address(addr);
4303 *modname = mod->name;
4305 ret = find_kallsyms_symbol(mod, addr, size, offset);
4307 /* Make a copy in here where it's safe */
4309 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
4317 int lookup_module_symbol_name(unsigned long addr, char *symname)
4322 list_for_each_entry_rcu(mod, &modules, list) {
4323 if (mod->state == MODULE_STATE_UNFORMED)
4325 if (within_module(addr, mod)) {
4328 sym = find_kallsyms_symbol(mod, addr, NULL, NULL);
4332 strlcpy(symname, sym, KSYM_NAME_LEN);
4342 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
4343 unsigned long *offset, char *modname, char *name)
4348 list_for_each_entry_rcu(mod, &modules, list) {
4349 if (mod->state == MODULE_STATE_UNFORMED)
4351 if (within_module(addr, mod)) {
4354 sym = find_kallsyms_symbol(mod, addr, size, offset);
4358 strlcpy(modname, mod->name, MODULE_NAME_LEN);
4360 strlcpy(name, sym, KSYM_NAME_LEN);
4370 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
4371 char *name, char *module_name, int *exported)
4376 list_for_each_entry_rcu(mod, &modules, list) {
4377 struct mod_kallsyms *kallsyms;
4379 if (mod->state == MODULE_STATE_UNFORMED)
4381 kallsyms = rcu_dereference_sched(mod->kallsyms);
4382 if (symnum < kallsyms->num_symtab) {
4383 const Elf_Sym *sym = &kallsyms->symtab[symnum];
4385 *value = kallsyms_symbol_value(sym);
4386 *type = kallsyms->typetab[symnum];
4387 strlcpy(name, kallsyms_symbol_name(kallsyms, symnum), KSYM_NAME_LEN);
4388 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
4389 *exported = is_exported(name, *value, mod);
4393 symnum -= kallsyms->num_symtab;
4399 /* Given a module and name of symbol, find and return the symbol's value */
4400 static unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name)
4403 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4405 for (i = 0; i < kallsyms->num_symtab; i++) {
4406 const Elf_Sym *sym = &kallsyms->symtab[i];
4408 if (strcmp(name, kallsyms_symbol_name(kallsyms, i)) == 0 &&
4409 sym->st_shndx != SHN_UNDEF)
4410 return kallsyms_symbol_value(sym);
4415 /* Look for this name: can be of form module:name. */
4416 unsigned long module_kallsyms_lookup_name(const char *name)
4420 unsigned long ret = 0;
4422 /* Don't lock: we're in enough trouble already. */
4424 if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
4425 if ((mod = find_module_all(name, colon - name, false)) != NULL)
4426 ret = find_kallsyms_symbol_value(mod, colon+1);
4428 list_for_each_entry_rcu(mod, &modules, list) {
4429 if (mod->state == MODULE_STATE_UNFORMED)
4431 if ((ret = find_kallsyms_symbol_value(mod, name)) != 0)
4439 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
4440 struct module *, unsigned long),
4447 module_assert_mutex();
4449 list_for_each_entry(mod, &modules, list) {
4450 /* We hold module_mutex: no need for rcu_dereference_sched */
4451 struct mod_kallsyms *kallsyms = mod->kallsyms;
4453 if (mod->state == MODULE_STATE_UNFORMED)
4455 for (i = 0; i < kallsyms->num_symtab; i++) {
4456 const Elf_Sym *sym = &kallsyms->symtab[i];
4458 if (sym->st_shndx == SHN_UNDEF)
4461 ret = fn(data, kallsyms_symbol_name(kallsyms, i),
4462 mod, kallsyms_symbol_value(sym));
4469 #endif /* CONFIG_KALLSYMS */
4471 /* Maximum number of characters written by module_flags() */
4472 #define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
4474 /* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
4475 static char *module_flags(struct module *mod, char *buf)
4479 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
4481 mod->state == MODULE_STATE_GOING ||
4482 mod->state == MODULE_STATE_COMING) {
4484 bx += module_flags_taint(mod, buf + bx);
4485 /* Show a - for module-is-being-unloaded */
4486 if (mod->state == MODULE_STATE_GOING)
4488 /* Show a + for module-is-being-loaded */
4489 if (mod->state == MODULE_STATE_COMING)
4498 #ifdef CONFIG_PROC_FS
4499 /* Called by the /proc file system to return a list of modules. */
4500 static void *m_start(struct seq_file *m, loff_t *pos)
4502 mutex_lock(&module_mutex);
4503 return seq_list_start(&modules, *pos);
4506 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
4508 return seq_list_next(p, &modules, pos);
4511 static void m_stop(struct seq_file *m, void *p)
4513 mutex_unlock(&module_mutex);
4516 static int m_show(struct seq_file *m, void *p)
4518 struct module *mod = list_entry(p, struct module, list);
4519 char buf[MODULE_FLAGS_BUF_SIZE];
4522 /* We always ignore unformed modules. */
4523 if (mod->state == MODULE_STATE_UNFORMED)
4526 seq_printf(m, "%s %u",
4527 mod->name, mod->init_layout.size + mod->core_layout.size);
4528 print_unload_info(m, mod);
4530 /* Informative for users. */
4531 seq_printf(m, " %s",
4532 mod->state == MODULE_STATE_GOING ? "Unloading" :
4533 mod->state == MODULE_STATE_COMING ? "Loading" :
4535 /* Used by oprofile and other similar tools. */
4536 value = m->private ? NULL : mod->core_layout.base;
4537 seq_printf(m, " 0x%px", value);
4541 seq_printf(m, " %s", module_flags(mod, buf));
4547 /* Format: modulename size refcount deps address
4549 Where refcount is a number or -, and deps is a comma-separated list
4552 static const struct seq_operations modules_op = {
4560 * This also sets the "private" pointer to non-NULL if the
4561 * kernel pointers should be hidden (so you can just test
4562 * "m->private" to see if you should keep the values private).
4564 * We use the same logic as for /proc/kallsyms.
4566 static int modules_open(struct inode *inode, struct file *file)
4568 int err = seq_open(file, &modules_op);
4571 struct seq_file *m = file->private_data;
4572 m->private = kallsyms_show_value(file->f_cred) ? NULL : (void *)8ul;
4578 static const struct proc_ops modules_proc_ops = {
4579 .proc_flags = PROC_ENTRY_PERMANENT,
4580 .proc_open = modules_open,
4581 .proc_read = seq_read,
4582 .proc_lseek = seq_lseek,
4583 .proc_release = seq_release,
4586 static int __init proc_modules_init(void)
4588 proc_create("modules", 0, NULL, &modules_proc_ops);
4591 module_init(proc_modules_init);
4594 /* Given an address, look for it in the module exception tables. */
4595 const struct exception_table_entry *search_module_extables(unsigned long addr)
4597 const struct exception_table_entry *e = NULL;
4601 mod = __module_address(addr);
4605 if (!mod->num_exentries)
4608 e = search_extable(mod->extable,
4615 * Now, if we found one, we are running inside it now, hence
4616 * we cannot unload the module, hence no refcnt needed.
4622 * is_module_address - is this address inside a module?
4623 * @addr: the address to check.
4625 * See is_module_text_address() if you simply want to see if the address
4626 * is code (not data).
4628 bool is_module_address(unsigned long addr)
4633 ret = __module_address(addr) != NULL;
4640 * __module_address - get the module which contains an address.
4641 * @addr: the address.
4643 * Must be called with preempt disabled or module mutex held so that
4644 * module doesn't get freed during this.
4646 struct module *__module_address(unsigned long addr)
4650 if (addr < module_addr_min || addr > module_addr_max)
4653 module_assert_mutex_or_preempt();
4655 mod = mod_find(addr);
4657 BUG_ON(!within_module(addr, mod));
4658 if (mod->state == MODULE_STATE_UNFORMED)
4665 * is_module_text_address - is this address inside module code?
4666 * @addr: the address to check.
4668 * See is_module_address() if you simply want to see if the address is
4669 * anywhere in a module. See kernel_text_address() for testing if an
4670 * address corresponds to kernel or module code.
4672 bool is_module_text_address(unsigned long addr)
4677 ret = __module_text_address(addr) != NULL;
4684 * __module_text_address - get the module whose code contains an address.
4685 * @addr: the address.
4687 * Must be called with preempt disabled or module mutex held so that
4688 * module doesn't get freed during this.
4690 struct module *__module_text_address(unsigned long addr)
4692 struct module *mod = __module_address(addr);
4694 /* Make sure it's within the text section. */
4695 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
4696 && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
4702 /* Don't grab lock, we're oopsing. */
4703 void print_modules(void)
4706 char buf[MODULE_FLAGS_BUF_SIZE];
4708 printk(KERN_DEFAULT "Modules linked in:");
4709 /* Most callers should already have preempt disabled, but make sure */
4711 list_for_each_entry_rcu(mod, &modules, list) {
4712 if (mod->state == MODULE_STATE_UNFORMED)
4714 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4717 if (last_unloaded_module[0])
4718 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4722 #ifdef CONFIG_MODVERSIONS
4723 /* Generate the signature for all relevant module structures here.
4724 * If these change, we don't want to try to parse the module. */
4725 void module_layout(struct module *mod,
4726 struct modversion_info *ver,
4727 struct kernel_param *kp,
4728 struct kernel_symbol *ks,
4729 struct tracepoint * const *tp)
4732 EXPORT_SYMBOL(module_layout);