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/slab.h>
22 #include <linux/vmalloc.h>
23 #include <linux/elf.h>
24 #include <linux/proc_fs.h>
25 #include <linux/security.h>
26 #include <linux/seq_file.h>
27 #include <linux/syscalls.h>
28 #include <linux/fcntl.h>
29 #include <linux/rcupdate.h>
30 #include <linux/capability.h>
31 #include <linux/cpu.h>
32 #include <linux/moduleparam.h>
33 #include <linux/errno.h>
34 #include <linux/err.h>
35 #include <linux/vermagic.h>
36 #include <linux/notifier.h>
37 #include <linux/sched.h>
38 #include <linux/device.h>
39 #include <linux/string.h>
40 #include <linux/mutex.h>
41 #include <linux/rculist.h>
42 #include <linux/uaccess.h>
43 #include <asm/cacheflush.h>
44 #include <linux/set_memory.h>
45 #include <asm/mmu_context.h>
46 #include <linux/license.h>
47 #include <asm/sections.h>
48 #include <linux/tracepoint.h>
49 #include <linux/ftrace.h>
50 #include <linux/livepatch.h>
51 #include <linux/async.h>
52 #include <linux/percpu.h>
53 #include <linux/kmemleak.h>
54 #include <linux/jump_label.h>
55 #include <linux/pfn.h>
56 #include <linux/bsearch.h>
57 #include <linux/dynamic_debug.h>
58 #include <linux/audit.h>
59 #include <uapi/linux/module.h>
60 #include "module-internal.h"
62 #define CREATE_TRACE_POINTS
63 #include <trace/events/module.h>
65 #ifndef ARCH_SHF_SMALL
66 #define ARCH_SHF_SMALL 0
70 * Modules' sections will be aligned on page boundaries
71 * to ensure complete separation of code and data, but
72 * only when CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y
74 #ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
75 # define debug_align(X) ALIGN(X, PAGE_SIZE)
77 # define debug_align(X) (X)
80 /* If this is set, the section belongs in the init part of the module */
81 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
85 * 1) List of modules (also safely readable with preempt_disable),
86 * 2) module_use links,
87 * 3) module_addr_min/module_addr_max.
88 * (delete and add uses RCU list operations). */
89 DEFINE_MUTEX(module_mutex);
90 EXPORT_SYMBOL_GPL(module_mutex);
91 static LIST_HEAD(modules);
93 /* Work queue for freeing init sections in success case */
94 static struct work_struct init_free_wq;
95 static struct llist_head init_free_list;
97 #ifdef CONFIG_MODULES_TREE_LOOKUP
100 * Use a latched RB-tree for __module_address(); this allows us to use
101 * RCU-sched lookups of the address from any context.
103 * This is conditional on PERF_EVENTS || TRACING because those can really hit
104 * __module_address() hard by doing a lot of stack unwinding; potentially from
108 static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
110 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
112 return (unsigned long)layout->base;
115 static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
117 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
119 return (unsigned long)layout->size;
122 static __always_inline bool
123 mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
125 return __mod_tree_val(a) < __mod_tree_val(b);
128 static __always_inline int
129 mod_tree_comp(void *key, struct latch_tree_node *n)
131 unsigned long val = (unsigned long)key;
132 unsigned long start, end;
134 start = __mod_tree_val(n);
138 end = start + __mod_tree_size(n);
145 static const struct latch_tree_ops mod_tree_ops = {
146 .less = mod_tree_less,
147 .comp = mod_tree_comp,
150 static struct mod_tree_root {
151 struct latch_tree_root root;
152 unsigned long addr_min;
153 unsigned long addr_max;
154 } mod_tree __cacheline_aligned = {
158 #define module_addr_min mod_tree.addr_min
159 #define module_addr_max mod_tree.addr_max
161 static noinline void __mod_tree_insert(struct mod_tree_node *node)
163 latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
166 static void __mod_tree_remove(struct mod_tree_node *node)
168 latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
172 * These modifications: insert, remove_init and remove; are serialized by the
175 static void mod_tree_insert(struct module *mod)
177 mod->core_layout.mtn.mod = mod;
178 mod->init_layout.mtn.mod = mod;
180 __mod_tree_insert(&mod->core_layout.mtn);
181 if (mod->init_layout.size)
182 __mod_tree_insert(&mod->init_layout.mtn);
185 static void mod_tree_remove_init(struct module *mod)
187 if (mod->init_layout.size)
188 __mod_tree_remove(&mod->init_layout.mtn);
191 static void mod_tree_remove(struct module *mod)
193 __mod_tree_remove(&mod->core_layout.mtn);
194 mod_tree_remove_init(mod);
197 static struct module *mod_find(unsigned long addr)
199 struct latch_tree_node *ltn;
201 ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
205 return container_of(ltn, struct mod_tree_node, node)->mod;
208 #else /* MODULES_TREE_LOOKUP */
210 static unsigned long module_addr_min = -1UL, module_addr_max = 0;
212 static void mod_tree_insert(struct module *mod) { }
213 static void mod_tree_remove_init(struct module *mod) { }
214 static void mod_tree_remove(struct module *mod) { }
216 static struct module *mod_find(unsigned long addr)
220 list_for_each_entry_rcu(mod, &modules, list,
221 lockdep_is_held(&module_mutex)) {
222 if (within_module(addr, mod))
229 #endif /* MODULES_TREE_LOOKUP */
232 * Bounds of module text, for speeding up __module_address.
233 * Protected by module_mutex.
235 static void __mod_update_bounds(void *base, unsigned int size)
237 unsigned long min = (unsigned long)base;
238 unsigned long max = min + size;
240 if (min < module_addr_min)
241 module_addr_min = min;
242 if (max > module_addr_max)
243 module_addr_max = max;
246 static void mod_update_bounds(struct module *mod)
248 __mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
249 if (mod->init_layout.size)
250 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
253 #ifdef CONFIG_KGDB_KDB
254 struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
255 #endif /* CONFIG_KGDB_KDB */
257 static void module_assert_mutex(void)
259 lockdep_assert_held(&module_mutex);
262 static void module_assert_mutex_or_preempt(void)
264 #ifdef CONFIG_LOCKDEP
265 if (unlikely(!debug_locks))
268 WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
269 !lockdep_is_held(&module_mutex));
273 static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
274 module_param(sig_enforce, bool_enable_only, 0644);
277 * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
278 * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
280 bool is_module_sig_enforced(void)
284 EXPORT_SYMBOL(is_module_sig_enforced);
286 void set_module_sig_enforced(void)
291 /* Block module loading/unloading? */
292 int modules_disabled = 0;
293 core_param(nomodule, modules_disabled, bint, 0);
295 /* Waiting for a module to finish initializing? */
296 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
298 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
300 int register_module_notifier(struct notifier_block *nb)
302 return blocking_notifier_chain_register(&module_notify_list, nb);
304 EXPORT_SYMBOL(register_module_notifier);
306 int unregister_module_notifier(struct notifier_block *nb)
308 return blocking_notifier_chain_unregister(&module_notify_list, nb);
310 EXPORT_SYMBOL(unregister_module_notifier);
313 * We require a truly strong try_module_get(): 0 means success.
314 * Otherwise an error is returned due to ongoing or failed
315 * initialization etc.
317 static inline int strong_try_module_get(struct module *mod)
319 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
320 if (mod && mod->state == MODULE_STATE_COMING)
322 if (try_module_get(mod))
328 static inline void add_taint_module(struct module *mod, unsigned flag,
329 enum lockdep_ok lockdep_ok)
331 add_taint(flag, lockdep_ok);
332 set_bit(flag, &mod->taints);
336 * A thread that wants to hold a reference to a module only while it
337 * is running can call this to safely exit. nfsd and lockd use this.
339 void __noreturn __module_put_and_exit(struct module *mod, long code)
344 EXPORT_SYMBOL(__module_put_and_exit);
346 /* Find a module section: 0 means not found. */
347 static unsigned int find_sec(const struct load_info *info, const char *name)
351 for (i = 1; i < info->hdr->e_shnum; i++) {
352 Elf_Shdr *shdr = &info->sechdrs[i];
353 /* Alloc bit cleared means "ignore it." */
354 if ((shdr->sh_flags & SHF_ALLOC)
355 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
361 /* Find a module section, or NULL. */
362 static void *section_addr(const struct load_info *info, const char *name)
364 /* Section 0 has sh_addr 0. */
365 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
368 /* Find a module section, or NULL. Fill in number of "objects" in section. */
369 static void *section_objs(const struct load_info *info,
374 unsigned int sec = find_sec(info, name);
376 /* Section 0 has sh_addr 0 and sh_size 0. */
377 *num = info->sechdrs[sec].sh_size / object_size;
378 return (void *)info->sechdrs[sec].sh_addr;
381 /* Provided by the linker */
382 extern const struct kernel_symbol __start___ksymtab[];
383 extern const struct kernel_symbol __stop___ksymtab[];
384 extern const struct kernel_symbol __start___ksymtab_gpl[];
385 extern const struct kernel_symbol __stop___ksymtab_gpl[];
386 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
387 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
388 extern const s32 __start___kcrctab[];
389 extern const s32 __start___kcrctab_gpl[];
390 extern const s32 __start___kcrctab_gpl_future[];
391 #ifdef CONFIG_UNUSED_SYMBOLS
392 extern const struct kernel_symbol __start___ksymtab_unused[];
393 extern const struct kernel_symbol __stop___ksymtab_unused[];
394 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
395 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
396 extern const s32 __start___kcrctab_unused[];
397 extern const s32 __start___kcrctab_unused_gpl[];
400 #ifndef CONFIG_MODVERSIONS
401 #define symversion(base, idx) NULL
403 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
406 static bool each_symbol_in_section(const struct symsearch *arr,
407 unsigned int arrsize,
408 struct module *owner,
409 bool (*fn)(const struct symsearch *syms,
410 struct module *owner,
416 for (j = 0; j < arrsize; j++) {
417 if (fn(&arr[j], owner, data))
424 /* Returns true as soon as fn returns true, otherwise false. */
425 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
426 struct module *owner,
431 static const struct symsearch arr[] = {
432 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
433 NOT_GPL_ONLY, false },
434 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
435 __start___kcrctab_gpl,
437 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
438 __start___kcrctab_gpl_future,
439 WILL_BE_GPL_ONLY, false },
440 #ifdef CONFIG_UNUSED_SYMBOLS
441 { __start___ksymtab_unused, __stop___ksymtab_unused,
442 __start___kcrctab_unused,
443 NOT_GPL_ONLY, true },
444 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
445 __start___kcrctab_unused_gpl,
450 module_assert_mutex_or_preempt();
452 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
455 list_for_each_entry_rcu(mod, &modules, list,
456 lockdep_is_held(&module_mutex)) {
457 struct symsearch arr[] = {
458 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
459 NOT_GPL_ONLY, false },
460 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
463 { mod->gpl_future_syms,
464 mod->gpl_future_syms + mod->num_gpl_future_syms,
465 mod->gpl_future_crcs,
466 WILL_BE_GPL_ONLY, false },
467 #ifdef CONFIG_UNUSED_SYMBOLS
469 mod->unused_syms + mod->num_unused_syms,
471 NOT_GPL_ONLY, true },
472 { mod->unused_gpl_syms,
473 mod->unused_gpl_syms + mod->num_unused_gpl_syms,
474 mod->unused_gpl_crcs,
479 if (mod->state == MODULE_STATE_UNFORMED)
482 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
487 EXPORT_SYMBOL_GPL(each_symbol_section);
489 struct find_symbol_arg {
496 struct module *owner;
498 const struct kernel_symbol *sym;
501 static bool check_exported_symbol(const struct symsearch *syms,
502 struct module *owner,
503 unsigned int symnum, void *data)
505 struct find_symbol_arg *fsa = data;
508 if (syms->licence == GPL_ONLY)
510 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
511 pr_warn("Symbol %s is being used by a non-GPL module, "
512 "which will not be allowed in the future\n",
517 #ifdef CONFIG_UNUSED_SYMBOLS
518 if (syms->unused && fsa->warn) {
519 pr_warn("Symbol %s is marked as UNUSED, however this module is "
520 "using it.\n", fsa->name);
521 pr_warn("This symbol will go away in the future.\n");
522 pr_warn("Please evaluate if this is the right api to use and "
523 "if it really is, submit a report to the linux kernel "
524 "mailing list together with submitting your code for "
530 fsa->crc = symversion(syms->crcs, symnum);
531 fsa->sym = &syms->start[symnum];
535 static unsigned long kernel_symbol_value(const struct kernel_symbol *sym)
537 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
538 return (unsigned long)offset_to_ptr(&sym->value_offset);
544 static const char *kernel_symbol_name(const struct kernel_symbol *sym)
546 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
547 return offset_to_ptr(&sym->name_offset);
553 static const char *kernel_symbol_namespace(const struct kernel_symbol *sym)
555 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
556 if (!sym->namespace_offset)
558 return offset_to_ptr(&sym->namespace_offset);
560 return sym->namespace;
564 static int cmp_name(const void *name, const void *sym)
566 return strcmp(name, kernel_symbol_name(sym));
569 static bool find_exported_symbol_in_section(const struct symsearch *syms,
570 struct module *owner,
573 struct find_symbol_arg *fsa = data;
574 struct kernel_symbol *sym;
576 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
577 sizeof(struct kernel_symbol), cmp_name);
579 if (sym != NULL && check_exported_symbol(syms, owner,
580 sym - syms->start, data))
586 /* Find an exported symbol and return it, along with, (optional) crc and
587 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
588 const struct kernel_symbol *find_symbol(const char *name,
589 struct module **owner,
594 struct find_symbol_arg fsa;
600 if (each_symbol_section(find_exported_symbol_in_section, &fsa)) {
608 pr_debug("Failed to find symbol %s\n", name);
611 EXPORT_SYMBOL_GPL(find_symbol);
614 * Search for module by name: must hold module_mutex (or preempt disabled
615 * for read-only access).
617 static struct module *find_module_all(const char *name, size_t len,
622 module_assert_mutex_or_preempt();
624 list_for_each_entry_rcu(mod, &modules, list,
625 lockdep_is_held(&module_mutex)) {
626 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
628 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
634 struct module *find_module(const char *name)
636 module_assert_mutex();
637 return find_module_all(name, strlen(name), false);
639 EXPORT_SYMBOL_GPL(find_module);
643 static inline void __percpu *mod_percpu(struct module *mod)
648 static int percpu_modalloc(struct module *mod, struct load_info *info)
650 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
651 unsigned long align = pcpusec->sh_addralign;
653 if (!pcpusec->sh_size)
656 if (align > PAGE_SIZE) {
657 pr_warn("%s: per-cpu alignment %li > %li\n",
658 mod->name, align, PAGE_SIZE);
662 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
664 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
665 mod->name, (unsigned long)pcpusec->sh_size);
668 mod->percpu_size = pcpusec->sh_size;
672 static void percpu_modfree(struct module *mod)
674 free_percpu(mod->percpu);
677 static unsigned int find_pcpusec(struct load_info *info)
679 return find_sec(info, ".data..percpu");
682 static void percpu_modcopy(struct module *mod,
683 const void *from, unsigned long size)
687 for_each_possible_cpu(cpu)
688 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
691 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
698 list_for_each_entry_rcu(mod, &modules, list) {
699 if (mod->state == MODULE_STATE_UNFORMED)
701 if (!mod->percpu_size)
703 for_each_possible_cpu(cpu) {
704 void *start = per_cpu_ptr(mod->percpu, cpu);
705 void *va = (void *)addr;
707 if (va >= start && va < start + mod->percpu_size) {
709 *can_addr = (unsigned long) (va - start);
710 *can_addr += (unsigned long)
711 per_cpu_ptr(mod->percpu,
725 * is_module_percpu_address - test whether address is from module static percpu
726 * @addr: address to test
728 * Test whether @addr belongs to module static percpu area.
731 * %true if @addr is from module static percpu area
733 bool is_module_percpu_address(unsigned long addr)
735 return __is_module_percpu_address(addr, NULL);
738 #else /* ... !CONFIG_SMP */
740 static inline void __percpu *mod_percpu(struct module *mod)
744 static int percpu_modalloc(struct module *mod, struct load_info *info)
746 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
747 if (info->sechdrs[info->index.pcpu].sh_size != 0)
751 static inline void percpu_modfree(struct module *mod)
754 static unsigned int find_pcpusec(struct load_info *info)
758 static inline void percpu_modcopy(struct module *mod,
759 const void *from, unsigned long size)
761 /* pcpusec should be 0, and size of that section should be 0. */
764 bool is_module_percpu_address(unsigned long addr)
769 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
774 #endif /* CONFIG_SMP */
776 #define MODINFO_ATTR(field) \
777 static void setup_modinfo_##field(struct module *mod, const char *s) \
779 mod->field = kstrdup(s, GFP_KERNEL); \
781 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
782 struct module_kobject *mk, char *buffer) \
784 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
786 static int modinfo_##field##_exists(struct module *mod) \
788 return mod->field != NULL; \
790 static void free_modinfo_##field(struct module *mod) \
795 static struct module_attribute modinfo_##field = { \
796 .attr = { .name = __stringify(field), .mode = 0444 }, \
797 .show = show_modinfo_##field, \
798 .setup = setup_modinfo_##field, \
799 .test = modinfo_##field##_exists, \
800 .free = free_modinfo_##field, \
803 MODINFO_ATTR(version);
804 MODINFO_ATTR(srcversion);
806 static char last_unloaded_module[MODULE_NAME_LEN+1];
808 #ifdef CONFIG_MODULE_UNLOAD
810 EXPORT_TRACEPOINT_SYMBOL(module_get);
812 /* MODULE_REF_BASE is the base reference count by kmodule loader. */
813 #define MODULE_REF_BASE 1
815 /* Init the unload section of the module. */
816 static int module_unload_init(struct module *mod)
819 * Initialize reference counter to MODULE_REF_BASE.
820 * refcnt == 0 means module is going.
822 atomic_set(&mod->refcnt, MODULE_REF_BASE);
824 INIT_LIST_HEAD(&mod->source_list);
825 INIT_LIST_HEAD(&mod->target_list);
827 /* Hold reference count during initialization. */
828 atomic_inc(&mod->refcnt);
833 /* Does a already use b? */
834 static int already_uses(struct module *a, struct module *b)
836 struct module_use *use;
838 list_for_each_entry(use, &b->source_list, source_list) {
839 if (use->source == a) {
840 pr_debug("%s uses %s!\n", a->name, b->name);
844 pr_debug("%s does not use %s!\n", a->name, b->name);
850 * - we add 'a' as a "source", 'b' as a "target" of module use
851 * - the module_use is added to the list of 'b' sources (so
852 * 'b' can walk the list to see who sourced them), and of 'a'
853 * targets (so 'a' can see what modules it targets).
855 static int add_module_usage(struct module *a, struct module *b)
857 struct module_use *use;
859 pr_debug("Allocating new usage for %s.\n", a->name);
860 use = kmalloc(sizeof(*use), GFP_ATOMIC);
866 list_add(&use->source_list, &b->source_list);
867 list_add(&use->target_list, &a->target_list);
871 /* Module a uses b: caller needs module_mutex() */
872 int ref_module(struct module *a, struct module *b)
876 if (b == NULL || already_uses(a, b))
879 /* If module isn't available, we fail. */
880 err = strong_try_module_get(b);
884 err = add_module_usage(a, b);
891 EXPORT_SYMBOL_GPL(ref_module);
893 /* Clear the unload stuff of the module. */
894 static void module_unload_free(struct module *mod)
896 struct module_use *use, *tmp;
898 mutex_lock(&module_mutex);
899 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
900 struct module *i = use->target;
901 pr_debug("%s unusing %s\n", mod->name, i->name);
903 list_del(&use->source_list);
904 list_del(&use->target_list);
907 mutex_unlock(&module_mutex);
910 #ifdef CONFIG_MODULE_FORCE_UNLOAD
911 static inline int try_force_unload(unsigned int flags)
913 int ret = (flags & O_TRUNC);
915 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
919 static inline int try_force_unload(unsigned int flags)
923 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
925 /* Try to release refcount of module, 0 means success. */
926 static int try_release_module_ref(struct module *mod)
930 /* Try to decrement refcnt which we set at loading */
931 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
934 /* Someone can put this right now, recover with checking */
935 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
940 static int try_stop_module(struct module *mod, int flags, int *forced)
942 /* If it's not unused, quit unless we're forcing. */
943 if (try_release_module_ref(mod) != 0) {
944 *forced = try_force_unload(flags);
949 /* Mark it as dying. */
950 mod->state = MODULE_STATE_GOING;
956 * module_refcount - return the refcount or -1 if unloading
958 * @mod: the module we're checking
961 * -1 if the module is in the process of unloading
962 * otherwise the number of references in the kernel to the module
964 int module_refcount(struct module *mod)
966 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
968 EXPORT_SYMBOL(module_refcount);
970 /* This exists whether we can unload or not */
971 static void free_module(struct module *mod);
973 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
977 char name[MODULE_NAME_LEN];
980 if (!capable(CAP_SYS_MODULE) || modules_disabled)
983 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
985 name[MODULE_NAME_LEN-1] = '\0';
987 audit_log_kern_module(name);
989 if (mutex_lock_interruptible(&module_mutex) != 0)
992 mod = find_module(name);
998 if (!list_empty(&mod->source_list)) {
999 /* Other modules depend on us: get rid of them first. */
1004 /* Doing init or already dying? */
1005 if (mod->state != MODULE_STATE_LIVE) {
1006 /* FIXME: if (force), slam module count damn the torpedoes */
1007 pr_debug("%s already dying\n", mod->name);
1012 /* If it has an init func, it must have an exit func to unload */
1013 if (mod->init && !mod->exit) {
1014 forced = try_force_unload(flags);
1016 /* This module can't be removed */
1022 /* Stop the machine so refcounts can't move and disable module. */
1023 ret = try_stop_module(mod, flags, &forced);
1027 mutex_unlock(&module_mutex);
1028 /* Final destruction now no one is using it. */
1029 if (mod->exit != NULL)
1031 blocking_notifier_call_chain(&module_notify_list,
1032 MODULE_STATE_GOING, mod);
1033 klp_module_going(mod);
1034 ftrace_release_mod(mod);
1036 async_synchronize_full();
1038 /* Store the name of the last unloaded module for diagnostic purposes */
1039 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
1042 /* someone could wait for the module in add_unformed_module() */
1043 wake_up_all(&module_wq);
1046 mutex_unlock(&module_mutex);
1050 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1052 struct module_use *use;
1053 int printed_something = 0;
1055 seq_printf(m, " %i ", module_refcount(mod));
1058 * Always include a trailing , so userspace can differentiate
1059 * between this and the old multi-field proc format.
1061 list_for_each_entry(use, &mod->source_list, source_list) {
1062 printed_something = 1;
1063 seq_printf(m, "%s,", use->source->name);
1066 if (mod->init != NULL && mod->exit == NULL) {
1067 printed_something = 1;
1068 seq_puts(m, "[permanent],");
1071 if (!printed_something)
1075 void __symbol_put(const char *symbol)
1077 struct module *owner;
1080 if (!find_symbol(symbol, &owner, NULL, true, false))
1085 EXPORT_SYMBOL(__symbol_put);
1087 /* Note this assumes addr is a function, which it currently always is. */
1088 void symbol_put_addr(void *addr)
1090 struct module *modaddr;
1091 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1093 if (core_kernel_text(a))
1097 * Even though we hold a reference on the module; we still need to
1098 * disable preemption in order to safely traverse the data structure.
1101 modaddr = __module_text_address(a);
1103 module_put(modaddr);
1106 EXPORT_SYMBOL_GPL(symbol_put_addr);
1108 static ssize_t show_refcnt(struct module_attribute *mattr,
1109 struct module_kobject *mk, char *buffer)
1111 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1114 static struct module_attribute modinfo_refcnt =
1115 __ATTR(refcnt, 0444, show_refcnt, NULL);
1117 void __module_get(struct module *module)
1121 atomic_inc(&module->refcnt);
1122 trace_module_get(module, _RET_IP_);
1126 EXPORT_SYMBOL(__module_get);
1128 bool try_module_get(struct module *module)
1134 /* Note: here, we can fail to get a reference */
1135 if (likely(module_is_live(module) &&
1136 atomic_inc_not_zero(&module->refcnt) != 0))
1137 trace_module_get(module, _RET_IP_);
1145 EXPORT_SYMBOL(try_module_get);
1147 void module_put(struct module *module)
1153 ret = atomic_dec_if_positive(&module->refcnt);
1154 WARN_ON(ret < 0); /* Failed to put refcount */
1155 trace_module_put(module, _RET_IP_);
1159 EXPORT_SYMBOL(module_put);
1161 #else /* !CONFIG_MODULE_UNLOAD */
1162 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1164 /* We don't know the usage count, or what modules are using. */
1165 seq_puts(m, " - -");
1168 static inline void module_unload_free(struct module *mod)
1172 int ref_module(struct module *a, struct module *b)
1174 return strong_try_module_get(b);
1176 EXPORT_SYMBOL_GPL(ref_module);
1178 static inline int module_unload_init(struct module *mod)
1182 #endif /* CONFIG_MODULE_UNLOAD */
1184 static size_t module_flags_taint(struct module *mod, char *buf)
1189 for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
1190 if (taint_flags[i].module && test_bit(i, &mod->taints))
1191 buf[l++] = taint_flags[i].c_true;
1197 static ssize_t show_initstate(struct module_attribute *mattr,
1198 struct module_kobject *mk, char *buffer)
1200 const char *state = "unknown";
1202 switch (mk->mod->state) {
1203 case MODULE_STATE_LIVE:
1206 case MODULE_STATE_COMING:
1209 case MODULE_STATE_GOING:
1215 return sprintf(buffer, "%s\n", state);
1218 static struct module_attribute modinfo_initstate =
1219 __ATTR(initstate, 0444, show_initstate, NULL);
1221 static ssize_t store_uevent(struct module_attribute *mattr,
1222 struct module_kobject *mk,
1223 const char *buffer, size_t count)
1227 rc = kobject_synth_uevent(&mk->kobj, buffer, count);
1228 return rc ? rc : count;
1231 struct module_attribute module_uevent =
1232 __ATTR(uevent, 0200, NULL, store_uevent);
1234 static ssize_t show_coresize(struct module_attribute *mattr,
1235 struct module_kobject *mk, char *buffer)
1237 return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1240 static struct module_attribute modinfo_coresize =
1241 __ATTR(coresize, 0444, show_coresize, NULL);
1243 static ssize_t show_initsize(struct module_attribute *mattr,
1244 struct module_kobject *mk, char *buffer)
1246 return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1249 static struct module_attribute modinfo_initsize =
1250 __ATTR(initsize, 0444, show_initsize, NULL);
1252 static ssize_t show_taint(struct module_attribute *mattr,
1253 struct module_kobject *mk, char *buffer)
1257 l = module_flags_taint(mk->mod, buffer);
1262 static struct module_attribute modinfo_taint =
1263 __ATTR(taint, 0444, show_taint, NULL);
1265 static struct module_attribute *modinfo_attrs[] = {
1268 &modinfo_srcversion,
1273 #ifdef CONFIG_MODULE_UNLOAD
1279 static const char vermagic[] = VERMAGIC_STRING;
1281 static int try_to_force_load(struct module *mod, const char *reason)
1283 #ifdef CONFIG_MODULE_FORCE_LOAD
1284 if (!test_taint(TAINT_FORCED_MODULE))
1285 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1286 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1293 #ifdef CONFIG_MODVERSIONS
1295 static u32 resolve_rel_crc(const s32 *crc)
1297 return *(u32 *)((void *)crc + *crc);
1300 static int check_version(const struct load_info *info,
1301 const char *symname,
1305 Elf_Shdr *sechdrs = info->sechdrs;
1306 unsigned int versindex = info->index.vers;
1307 unsigned int i, num_versions;
1308 struct modversion_info *versions;
1310 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1314 /* No versions at all? modprobe --force does this. */
1316 return try_to_force_load(mod, symname) == 0;
1318 versions = (void *) sechdrs[versindex].sh_addr;
1319 num_versions = sechdrs[versindex].sh_size
1320 / sizeof(struct modversion_info);
1322 for (i = 0; i < num_versions; i++) {
1325 if (strcmp(versions[i].name, symname) != 0)
1328 if (IS_ENABLED(CONFIG_MODULE_REL_CRCS))
1329 crcval = resolve_rel_crc(crc);
1332 if (versions[i].crc == crcval)
1334 pr_debug("Found checksum %X vs module %lX\n",
1335 crcval, versions[i].crc);
1339 /* Broken toolchain. Warn once, then let it go.. */
1340 pr_warn_once("%s: no symbol version for %s\n", info->name, symname);
1344 pr_warn("%s: disagrees about version of symbol %s\n",
1345 info->name, symname);
1349 static inline int check_modstruct_version(const struct load_info *info,
1355 * Since this should be found in kernel (which can't be removed), no
1356 * locking is necessary -- use preempt_disable() to placate lockdep.
1359 if (!find_symbol("module_layout", NULL, &crc, true, false)) {
1364 return check_version(info, "module_layout", mod, crc);
1367 /* First part is kernel version, which we ignore if module has crcs. */
1368 static inline int same_magic(const char *amagic, const char *bmagic,
1372 amagic += strcspn(amagic, " ");
1373 bmagic += strcspn(bmagic, " ");
1375 return strcmp(amagic, bmagic) == 0;
1378 static inline int check_version(const struct load_info *info,
1379 const char *symname,
1386 static inline int check_modstruct_version(const struct load_info *info,
1392 static inline int same_magic(const char *amagic, const char *bmagic,
1395 return strcmp(amagic, bmagic) == 0;
1397 #endif /* CONFIG_MODVERSIONS */
1399 static char *get_modinfo(const struct load_info *info, const char *tag);
1400 static char *get_next_modinfo(const struct load_info *info, const char *tag,
1403 static int verify_namespace_is_imported(const struct load_info *info,
1404 const struct kernel_symbol *sym,
1407 const char *namespace;
1408 char *imported_namespace;
1410 namespace = kernel_symbol_namespace(sym);
1411 if (namespace && namespace[0]) {
1412 imported_namespace = get_modinfo(info, "import_ns");
1413 while (imported_namespace) {
1414 if (strcmp(namespace, imported_namespace) == 0)
1416 imported_namespace = get_next_modinfo(
1417 info, "import_ns", imported_namespace);
1419 #ifdef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1424 "%s: module uses symbol (%s) from namespace %s, but does not import it.\n",
1425 mod->name, kernel_symbol_name(sym), namespace);
1426 #ifndef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1434 /* Resolve a symbol for this module. I.e. if we find one, record usage. */
1435 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1436 const struct load_info *info,
1440 struct module *owner;
1441 const struct kernel_symbol *sym;
1446 * The module_mutex should not be a heavily contended lock;
1447 * if we get the occasional sleep here, we'll go an extra iteration
1448 * in the wait_event_interruptible(), which is harmless.
1450 sched_annotate_sleep();
1451 mutex_lock(&module_mutex);
1452 sym = find_symbol(name, &owner, &crc,
1453 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1457 if (!check_version(info, name, mod, crc)) {
1458 sym = ERR_PTR(-EINVAL);
1462 err = verify_namespace_is_imported(info, sym, mod);
1468 err = ref_module(mod, owner);
1475 /* We must make copy under the lock if we failed to get ref. */
1476 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1478 mutex_unlock(&module_mutex);
1482 static const struct kernel_symbol *
1483 resolve_symbol_wait(struct module *mod,
1484 const struct load_info *info,
1487 const struct kernel_symbol *ksym;
1488 char owner[MODULE_NAME_LEN];
1490 if (wait_event_interruptible_timeout(module_wq,
1491 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1492 || PTR_ERR(ksym) != -EBUSY,
1494 pr_warn("%s: gave up waiting for init of module %s.\n",
1501 * /sys/module/foo/sections stuff
1502 * J. Corbet <corbet@lwn.net>
1506 #ifdef CONFIG_KALLSYMS
1507 static inline bool sect_empty(const Elf_Shdr *sect)
1509 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1512 struct module_sect_attr {
1513 struct bin_attribute battr;
1514 unsigned long address;
1517 struct module_sect_attrs {
1518 struct attribute_group grp;
1519 unsigned int nsections;
1520 struct module_sect_attr attrs[];
1523 #define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4))
1524 static ssize_t module_sect_read(struct file *file, struct kobject *kobj,
1525 struct bin_attribute *battr,
1526 char *buf, loff_t pos, size_t count)
1528 struct module_sect_attr *sattr =
1529 container_of(battr, struct module_sect_attr, battr);
1530 char bounce[MODULE_SECT_READ_SIZE + 1];
1537 * Since we're a binary read handler, we must account for the
1538 * trailing NUL byte that sprintf will write: if "buf" is
1539 * too small to hold the NUL, or the NUL is exactly the last
1540 * byte, the read will look like it got truncated by one byte.
1541 * Since there is no way to ask sprintf nicely to not write
1542 * the NUL, we have to use a bounce buffer.
1544 wrote = scnprintf(bounce, sizeof(bounce), "0x%px\n",
1545 kallsyms_show_value(file->f_cred)
1546 ? (void *)sattr->address : NULL);
1547 count = min(count, wrote);
1548 memcpy(buf, bounce, count);
1553 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1555 unsigned int section;
1557 for (section = 0; section < sect_attrs->nsections; section++)
1558 kfree(sect_attrs->attrs[section].battr.attr.name);
1562 static void add_sect_attrs(struct module *mod, const struct load_info *info)
1564 unsigned int nloaded = 0, i, size[2];
1565 struct module_sect_attrs *sect_attrs;
1566 struct module_sect_attr *sattr;
1567 struct bin_attribute **gattr;
1569 /* Count loaded sections and allocate structures */
1570 for (i = 0; i < info->hdr->e_shnum; i++)
1571 if (!sect_empty(&info->sechdrs[i]))
1573 size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded),
1574 sizeof(sect_attrs->grp.bin_attrs[0]));
1575 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.bin_attrs[0]);
1576 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1577 if (sect_attrs == NULL)
1580 /* Setup section attributes. */
1581 sect_attrs->grp.name = "sections";
1582 sect_attrs->grp.bin_attrs = (void *)sect_attrs + size[0];
1584 sect_attrs->nsections = 0;
1585 sattr = §_attrs->attrs[0];
1586 gattr = §_attrs->grp.bin_attrs[0];
1587 for (i = 0; i < info->hdr->e_shnum; i++) {
1588 Elf_Shdr *sec = &info->sechdrs[i];
1589 if (sect_empty(sec))
1591 sysfs_bin_attr_init(&sattr->battr);
1592 sattr->address = sec->sh_addr;
1593 sattr->battr.attr.name =
1594 kstrdup(info->secstrings + sec->sh_name, GFP_KERNEL);
1595 if (sattr->battr.attr.name == NULL)
1597 sect_attrs->nsections++;
1598 sattr->battr.read = module_sect_read;
1599 sattr->battr.size = MODULE_SECT_READ_SIZE;
1600 sattr->battr.attr.mode = 0400;
1601 *(gattr++) = &(sattr++)->battr;
1605 if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp))
1608 mod->sect_attrs = sect_attrs;
1611 free_sect_attrs(sect_attrs);
1614 static void remove_sect_attrs(struct module *mod)
1616 if (mod->sect_attrs) {
1617 sysfs_remove_group(&mod->mkobj.kobj,
1618 &mod->sect_attrs->grp);
1619 /* We are positive that no one is using any sect attrs
1620 * at this point. Deallocate immediately. */
1621 free_sect_attrs(mod->sect_attrs);
1622 mod->sect_attrs = NULL;
1627 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1630 struct module_notes_attrs {
1631 struct kobject *dir;
1633 struct bin_attribute attrs[];
1636 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1637 struct bin_attribute *bin_attr,
1638 char *buf, loff_t pos, size_t count)
1641 * The caller checked the pos and count against our size.
1643 memcpy(buf, bin_attr->private + pos, count);
1647 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1650 if (notes_attrs->dir) {
1652 sysfs_remove_bin_file(notes_attrs->dir,
1653 ¬es_attrs->attrs[i]);
1654 kobject_put(notes_attrs->dir);
1659 static void add_notes_attrs(struct module *mod, const struct load_info *info)
1661 unsigned int notes, loaded, i;
1662 struct module_notes_attrs *notes_attrs;
1663 struct bin_attribute *nattr;
1665 /* failed to create section attributes, so can't create notes */
1666 if (!mod->sect_attrs)
1669 /* Count notes sections and allocate structures. */
1671 for (i = 0; i < info->hdr->e_shnum; i++)
1672 if (!sect_empty(&info->sechdrs[i]) &&
1673 (info->sechdrs[i].sh_type == SHT_NOTE))
1679 notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes),
1681 if (notes_attrs == NULL)
1684 notes_attrs->notes = notes;
1685 nattr = ¬es_attrs->attrs[0];
1686 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1687 if (sect_empty(&info->sechdrs[i]))
1689 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1690 sysfs_bin_attr_init(nattr);
1691 nattr->attr.name = mod->sect_attrs->attrs[loaded].battr.attr.name;
1692 nattr->attr.mode = S_IRUGO;
1693 nattr->size = info->sechdrs[i].sh_size;
1694 nattr->private = (void *) info->sechdrs[i].sh_addr;
1695 nattr->read = module_notes_read;
1701 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1702 if (!notes_attrs->dir)
1705 for (i = 0; i < notes; ++i)
1706 if (sysfs_create_bin_file(notes_attrs->dir,
1707 ¬es_attrs->attrs[i]))
1710 mod->notes_attrs = notes_attrs;
1714 free_notes_attrs(notes_attrs, i);
1717 static void remove_notes_attrs(struct module *mod)
1719 if (mod->notes_attrs)
1720 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1725 static inline void add_sect_attrs(struct module *mod,
1726 const struct load_info *info)
1730 static inline void remove_sect_attrs(struct module *mod)
1734 static inline void add_notes_attrs(struct module *mod,
1735 const struct load_info *info)
1739 static inline void remove_notes_attrs(struct module *mod)
1742 #endif /* CONFIG_KALLSYMS */
1744 static void del_usage_links(struct module *mod)
1746 #ifdef CONFIG_MODULE_UNLOAD
1747 struct module_use *use;
1749 mutex_lock(&module_mutex);
1750 list_for_each_entry(use, &mod->target_list, target_list)
1751 sysfs_remove_link(use->target->holders_dir, mod->name);
1752 mutex_unlock(&module_mutex);
1756 static int add_usage_links(struct module *mod)
1759 #ifdef CONFIG_MODULE_UNLOAD
1760 struct module_use *use;
1762 mutex_lock(&module_mutex);
1763 list_for_each_entry(use, &mod->target_list, target_list) {
1764 ret = sysfs_create_link(use->target->holders_dir,
1765 &mod->mkobj.kobj, mod->name);
1769 mutex_unlock(&module_mutex);
1771 del_usage_links(mod);
1776 static void module_remove_modinfo_attrs(struct module *mod, int end);
1778 static int module_add_modinfo_attrs(struct module *mod)
1780 struct module_attribute *attr;
1781 struct module_attribute *temp_attr;
1785 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1786 (ARRAY_SIZE(modinfo_attrs) + 1)),
1788 if (!mod->modinfo_attrs)
1791 temp_attr = mod->modinfo_attrs;
1792 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1793 if (!attr->test || attr->test(mod)) {
1794 memcpy(temp_attr, attr, sizeof(*temp_attr));
1795 sysfs_attr_init(&temp_attr->attr);
1796 error = sysfs_create_file(&mod->mkobj.kobj,
1808 module_remove_modinfo_attrs(mod, --i);
1810 kfree(mod->modinfo_attrs);
1814 static void module_remove_modinfo_attrs(struct module *mod, int end)
1816 struct module_attribute *attr;
1819 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1820 if (end >= 0 && i > end)
1822 /* pick a field to test for end of list */
1823 if (!attr->attr.name)
1825 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1829 kfree(mod->modinfo_attrs);
1832 static void mod_kobject_put(struct module *mod)
1834 DECLARE_COMPLETION_ONSTACK(c);
1835 mod->mkobj.kobj_completion = &c;
1836 kobject_put(&mod->mkobj.kobj);
1837 wait_for_completion(&c);
1840 static int mod_sysfs_init(struct module *mod)
1843 struct kobject *kobj;
1845 if (!module_sysfs_initialized) {
1846 pr_err("%s: module sysfs not initialized\n", mod->name);
1851 kobj = kset_find_obj(module_kset, mod->name);
1853 pr_err("%s: module is already loaded\n", mod->name);
1859 mod->mkobj.mod = mod;
1861 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1862 mod->mkobj.kobj.kset = module_kset;
1863 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1866 mod_kobject_put(mod);
1868 /* delay uevent until full sysfs population */
1873 static int mod_sysfs_setup(struct module *mod,
1874 const struct load_info *info,
1875 struct kernel_param *kparam,
1876 unsigned int num_params)
1880 err = mod_sysfs_init(mod);
1884 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1885 if (!mod->holders_dir) {
1890 err = module_param_sysfs_setup(mod, kparam, num_params);
1892 goto out_unreg_holders;
1894 err = module_add_modinfo_attrs(mod);
1896 goto out_unreg_param;
1898 err = add_usage_links(mod);
1900 goto out_unreg_modinfo_attrs;
1902 add_sect_attrs(mod, info);
1903 add_notes_attrs(mod, info);
1905 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1908 out_unreg_modinfo_attrs:
1909 module_remove_modinfo_attrs(mod, -1);
1911 module_param_sysfs_remove(mod);
1913 kobject_put(mod->holders_dir);
1915 mod_kobject_put(mod);
1920 static void mod_sysfs_fini(struct module *mod)
1922 remove_notes_attrs(mod);
1923 remove_sect_attrs(mod);
1924 mod_kobject_put(mod);
1927 static void init_param_lock(struct module *mod)
1929 mutex_init(&mod->param_lock);
1931 #else /* !CONFIG_SYSFS */
1933 static int mod_sysfs_setup(struct module *mod,
1934 const struct load_info *info,
1935 struct kernel_param *kparam,
1936 unsigned int num_params)
1941 static void mod_sysfs_fini(struct module *mod)
1945 static void module_remove_modinfo_attrs(struct module *mod, int end)
1949 static void del_usage_links(struct module *mod)
1953 static void init_param_lock(struct module *mod)
1956 #endif /* CONFIG_SYSFS */
1958 static void mod_sysfs_teardown(struct module *mod)
1960 del_usage_links(mod);
1961 module_remove_modinfo_attrs(mod, -1);
1962 module_param_sysfs_remove(mod);
1963 kobject_put(mod->mkobj.drivers_dir);
1964 kobject_put(mod->holders_dir);
1965 mod_sysfs_fini(mod);
1969 * LKM RO/NX protection: protect module's text/ro-data
1970 * from modification and any data from execution.
1972 * General layout of module is:
1973 * [text] [read-only-data] [ro-after-init] [writable data]
1974 * text_size -----^ ^ ^ ^
1975 * ro_size ------------------------| | |
1976 * ro_after_init_size -----------------------------| |
1977 * size -----------------------------------------------------------|
1979 * These values are always page-aligned (as is base)
1983 * Since some arches are moving towards PAGE_KERNEL module allocations instead
1984 * of PAGE_KERNEL_EXEC, keep frob_text() and module_enable_x() outside of the
1985 * CONFIG_STRICT_MODULE_RWX block below because they are needed regardless of
1986 * whether we are strict.
1988 #ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
1989 static void frob_text(const struct module_layout *layout,
1990 int (*set_memory)(unsigned long start, int num_pages))
1992 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1993 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1994 set_memory((unsigned long)layout->base,
1995 layout->text_size >> PAGE_SHIFT);
1998 static void module_enable_x(const struct module *mod)
2000 frob_text(&mod->core_layout, set_memory_x);
2001 frob_text(&mod->init_layout, set_memory_x);
2003 #else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
2004 static void module_enable_x(const struct module *mod) { }
2005 #endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
2007 #ifdef CONFIG_STRICT_MODULE_RWX
2008 static void frob_rodata(const struct module_layout *layout,
2009 int (*set_memory)(unsigned long start, int num_pages))
2011 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
2012 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
2013 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
2014 set_memory((unsigned long)layout->base + layout->text_size,
2015 (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
2018 static void frob_ro_after_init(const struct module_layout *layout,
2019 int (*set_memory)(unsigned long start, int num_pages))
2021 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
2022 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
2023 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
2024 set_memory((unsigned long)layout->base + layout->ro_size,
2025 (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
2028 static void frob_writable_data(const struct module_layout *layout,
2029 int (*set_memory)(unsigned long start, int num_pages))
2031 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
2032 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
2033 BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
2034 set_memory((unsigned long)layout->base + layout->ro_after_init_size,
2035 (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
2038 static void module_enable_ro(const struct module *mod, bool after_init)
2040 if (!rodata_enabled)
2043 set_vm_flush_reset_perms(mod->core_layout.base);
2044 set_vm_flush_reset_perms(mod->init_layout.base);
2045 frob_text(&mod->core_layout, set_memory_ro);
2047 frob_rodata(&mod->core_layout, set_memory_ro);
2048 frob_text(&mod->init_layout, set_memory_ro);
2049 frob_rodata(&mod->init_layout, set_memory_ro);
2052 frob_ro_after_init(&mod->core_layout, set_memory_ro);
2055 static void module_enable_nx(const struct module *mod)
2057 frob_rodata(&mod->core_layout, set_memory_nx);
2058 frob_ro_after_init(&mod->core_layout, set_memory_nx);
2059 frob_writable_data(&mod->core_layout, set_memory_nx);
2060 frob_rodata(&mod->init_layout, set_memory_nx);
2061 frob_writable_data(&mod->init_layout, set_memory_nx);
2064 static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
2065 char *secstrings, struct module *mod)
2067 const unsigned long shf_wx = SHF_WRITE|SHF_EXECINSTR;
2070 for (i = 0; i < hdr->e_shnum; i++) {
2071 if ((sechdrs[i].sh_flags & shf_wx) == shf_wx)
2078 #else /* !CONFIG_STRICT_MODULE_RWX */
2079 static void module_enable_nx(const struct module *mod) { }
2080 static void module_enable_ro(const struct module *mod, bool after_init) {}
2081 static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
2082 char *secstrings, struct module *mod)
2086 #endif /* CONFIG_STRICT_MODULE_RWX */
2088 #ifdef CONFIG_LIVEPATCH
2090 * Persist Elf information about a module. Copy the Elf header,
2091 * section header table, section string table, and symtab section
2092 * index from info to mod->klp_info.
2094 static int copy_module_elf(struct module *mod, struct load_info *info)
2096 unsigned int size, symndx;
2099 size = sizeof(*mod->klp_info);
2100 mod->klp_info = kmalloc(size, GFP_KERNEL);
2101 if (mod->klp_info == NULL)
2105 size = sizeof(mod->klp_info->hdr);
2106 memcpy(&mod->klp_info->hdr, info->hdr, size);
2108 /* Elf section header table */
2109 size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
2110 mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL);
2111 if (mod->klp_info->sechdrs == NULL) {
2116 /* Elf section name string table */
2117 size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
2118 mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL);
2119 if (mod->klp_info->secstrings == NULL) {
2124 /* Elf symbol section index */
2125 symndx = info->index.sym;
2126 mod->klp_info->symndx = symndx;
2129 * For livepatch modules, core_kallsyms.symtab is a complete
2130 * copy of the original symbol table. Adjust sh_addr to point
2131 * to core_kallsyms.symtab since the copy of the symtab in module
2132 * init memory is freed at the end of do_init_module().
2134 mod->klp_info->sechdrs[symndx].sh_addr = \
2135 (unsigned long) mod->core_kallsyms.symtab;
2140 kfree(mod->klp_info->sechdrs);
2142 kfree(mod->klp_info);
2146 static void free_module_elf(struct module *mod)
2148 kfree(mod->klp_info->sechdrs);
2149 kfree(mod->klp_info->secstrings);
2150 kfree(mod->klp_info);
2152 #else /* !CONFIG_LIVEPATCH */
2153 static int copy_module_elf(struct module *mod, struct load_info *info)
2158 static void free_module_elf(struct module *mod)
2161 #endif /* CONFIG_LIVEPATCH */
2163 void __weak module_memfree(void *module_region)
2166 * This memory may be RO, and freeing RO memory in an interrupt is not
2167 * supported by vmalloc.
2169 WARN_ON(in_interrupt());
2170 vfree(module_region);
2173 void __weak module_arch_cleanup(struct module *mod)
2177 void __weak module_arch_freeing_init(struct module *mod)
2181 /* Free a module, remove from lists, etc. */
2182 static void free_module(struct module *mod)
2184 trace_module_free(mod);
2186 mod_sysfs_teardown(mod);
2188 /* We leave it in list to prevent duplicate loads, but make sure
2189 * that noone uses it while it's being deconstructed. */
2190 mutex_lock(&module_mutex);
2191 mod->state = MODULE_STATE_UNFORMED;
2192 mutex_unlock(&module_mutex);
2194 /* Remove dynamic debug info */
2195 ddebug_remove_module(mod->name);
2197 /* Arch-specific cleanup. */
2198 module_arch_cleanup(mod);
2200 /* Module unload stuff */
2201 module_unload_free(mod);
2203 /* Free any allocated parameters. */
2204 destroy_params(mod->kp, mod->num_kp);
2206 if (is_livepatch_module(mod))
2207 free_module_elf(mod);
2209 /* Now we can delete it from the lists */
2210 mutex_lock(&module_mutex);
2211 /* Unlink carefully: kallsyms could be walking list. */
2212 list_del_rcu(&mod->list);
2213 mod_tree_remove(mod);
2214 /* Remove this module from bug list, this uses list_del_rcu */
2215 module_bug_cleanup(mod);
2216 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2218 mutex_unlock(&module_mutex);
2220 /* This may be empty, but that's OK */
2221 module_arch_freeing_init(mod);
2222 module_memfree(mod->init_layout.base);
2224 percpu_modfree(mod);
2226 /* Free lock-classes; relies on the preceding sync_rcu(). */
2227 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
2229 /* Finally, free the core (containing the module structure) */
2230 module_memfree(mod->core_layout.base);
2233 void *__symbol_get(const char *symbol)
2235 struct module *owner;
2236 const struct kernel_symbol *sym;
2239 sym = find_symbol(symbol, &owner, NULL, true, true);
2240 if (sym && strong_try_module_get(owner))
2244 return sym ? (void *)kernel_symbol_value(sym) : NULL;
2246 EXPORT_SYMBOL_GPL(__symbol_get);
2249 * Ensure that an exported symbol [global namespace] does not already exist
2250 * in the kernel or in some other module's exported symbol table.
2252 * You must hold the module_mutex.
2254 static int verify_exported_symbols(struct module *mod)
2257 struct module *owner;
2258 const struct kernel_symbol *s;
2260 const struct kernel_symbol *sym;
2263 { mod->syms, mod->num_syms },
2264 { mod->gpl_syms, mod->num_gpl_syms },
2265 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2266 #ifdef CONFIG_UNUSED_SYMBOLS
2267 { mod->unused_syms, mod->num_unused_syms },
2268 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2272 for (i = 0; i < ARRAY_SIZE(arr); i++) {
2273 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2274 if (find_symbol(kernel_symbol_name(s), &owner, NULL,
2276 pr_err("%s: exports duplicate symbol %s"
2278 mod->name, kernel_symbol_name(s),
2279 module_name(owner));
2287 /* Change all symbols so that st_value encodes the pointer directly. */
2288 static int simplify_symbols(struct module *mod, const struct load_info *info)
2290 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2291 Elf_Sym *sym = (void *)symsec->sh_addr;
2292 unsigned long secbase;
2295 const struct kernel_symbol *ksym;
2297 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2298 const char *name = info->strtab + sym[i].st_name;
2300 switch (sym[i].st_shndx) {
2302 /* Ignore common symbols */
2303 if (!strncmp(name, "__gnu_lto", 9))
2306 /* We compiled with -fno-common. These are not
2307 supposed to happen. */
2308 pr_debug("Common symbol: %s\n", name);
2309 pr_warn("%s: please compile with -fno-common\n",
2315 /* Don't need to do anything */
2316 pr_debug("Absolute symbol: 0x%08lx\n",
2317 (long)sym[i].st_value);
2321 /* Livepatch symbols are resolved by livepatch */
2325 ksym = resolve_symbol_wait(mod, info, name);
2326 /* Ok if resolved. */
2327 if (ksym && !IS_ERR(ksym)) {
2328 sym[i].st_value = kernel_symbol_value(ksym);
2333 if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
2336 ret = PTR_ERR(ksym) ?: -ENOENT;
2337 pr_warn("%s: Unknown symbol %s (err %d)\n",
2338 mod->name, name, ret);
2342 /* Divert to percpu allocation if a percpu var. */
2343 if (sym[i].st_shndx == info->index.pcpu)
2344 secbase = (unsigned long)mod_percpu(mod);
2346 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2347 sym[i].st_value += secbase;
2355 static int apply_relocations(struct module *mod, const struct load_info *info)
2360 /* Now do relocations. */
2361 for (i = 1; i < info->hdr->e_shnum; i++) {
2362 unsigned int infosec = info->sechdrs[i].sh_info;
2364 /* Not a valid relocation section? */
2365 if (infosec >= info->hdr->e_shnum)
2368 /* Don't bother with non-allocated sections */
2369 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2372 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
2373 err = klp_apply_section_relocs(mod, info->sechdrs,
2378 else if (info->sechdrs[i].sh_type == SHT_REL)
2379 err = apply_relocate(info->sechdrs, info->strtab,
2380 info->index.sym, i, mod);
2381 else if (info->sechdrs[i].sh_type == SHT_RELA)
2382 err = apply_relocate_add(info->sechdrs, info->strtab,
2383 info->index.sym, i, mod);
2390 /* Additional bytes needed by arch in front of individual sections */
2391 unsigned int __weak arch_mod_section_prepend(struct module *mod,
2392 unsigned int section)
2394 /* default implementation just returns zero */
2398 /* Update size with this section: return offset. */
2399 static long get_offset(struct module *mod, unsigned int *size,
2400 Elf_Shdr *sechdr, unsigned int section)
2404 *size += arch_mod_section_prepend(mod, section);
2405 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2406 *size = ret + sechdr->sh_size;
2410 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2411 might -- code, read-only data, read-write data, small data. Tally
2412 sizes, and place the offsets into sh_entsize fields: high bit means it
2414 static void layout_sections(struct module *mod, struct load_info *info)
2416 static unsigned long const masks[][2] = {
2417 /* NOTE: all executable code must be the first section
2418 * in this array; otherwise modify the text_size
2419 * finder in the two loops below */
2420 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2421 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2422 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
2423 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2424 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2428 for (i = 0; i < info->hdr->e_shnum; i++)
2429 info->sechdrs[i].sh_entsize = ~0UL;
2431 pr_debug("Core section allocation order:\n");
2432 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2433 for (i = 0; i < info->hdr->e_shnum; ++i) {
2434 Elf_Shdr *s = &info->sechdrs[i];
2435 const char *sname = info->secstrings + s->sh_name;
2437 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2438 || (s->sh_flags & masks[m][1])
2439 || s->sh_entsize != ~0UL
2440 || module_init_section(sname))
2442 s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2443 pr_debug("\t%s\n", sname);
2446 case 0: /* executable */
2447 mod->core_layout.size = debug_align(mod->core_layout.size);
2448 mod->core_layout.text_size = mod->core_layout.size;
2450 case 1: /* RO: text and ro-data */
2451 mod->core_layout.size = debug_align(mod->core_layout.size);
2452 mod->core_layout.ro_size = mod->core_layout.size;
2454 case 2: /* RO after init */
2455 mod->core_layout.size = debug_align(mod->core_layout.size);
2456 mod->core_layout.ro_after_init_size = mod->core_layout.size;
2458 case 4: /* whole core */
2459 mod->core_layout.size = debug_align(mod->core_layout.size);
2464 pr_debug("Init section allocation order:\n");
2465 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2466 for (i = 0; i < info->hdr->e_shnum; ++i) {
2467 Elf_Shdr *s = &info->sechdrs[i];
2468 const char *sname = info->secstrings + s->sh_name;
2470 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2471 || (s->sh_flags & masks[m][1])
2472 || s->sh_entsize != ~0UL
2473 || !module_init_section(sname))
2475 s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
2476 | INIT_OFFSET_MASK);
2477 pr_debug("\t%s\n", sname);
2480 case 0: /* executable */
2481 mod->init_layout.size = debug_align(mod->init_layout.size);
2482 mod->init_layout.text_size = mod->init_layout.size;
2484 case 1: /* RO: text and ro-data */
2485 mod->init_layout.size = debug_align(mod->init_layout.size);
2486 mod->init_layout.ro_size = mod->init_layout.size;
2490 * RO after init doesn't apply to init_layout (only
2491 * core_layout), so it just takes the value of ro_size.
2493 mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
2495 case 4: /* whole init */
2496 mod->init_layout.size = debug_align(mod->init_layout.size);
2502 static void set_license(struct module *mod, const char *license)
2505 license = "unspecified";
2507 if (!license_is_gpl_compatible(license)) {
2508 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2509 pr_warn("%s: module license '%s' taints kernel.\n",
2510 mod->name, license);
2511 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2512 LOCKDEP_NOW_UNRELIABLE);
2516 /* Parse tag=value strings from .modinfo section */
2517 static char *next_string(char *string, unsigned long *secsize)
2519 /* Skip non-zero chars */
2522 if ((*secsize)-- <= 1)
2526 /* Skip any zero padding. */
2527 while (!string[0]) {
2529 if ((*secsize)-- <= 1)
2535 static char *get_next_modinfo(const struct load_info *info, const char *tag,
2539 unsigned int taglen = strlen(tag);
2540 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2541 unsigned long size = infosec->sh_size;
2544 * get_modinfo() calls made before rewrite_section_headers()
2545 * must use sh_offset, as sh_addr isn't set!
2547 char *modinfo = (char *)info->hdr + infosec->sh_offset;
2550 size -= prev - modinfo;
2551 modinfo = next_string(prev, &size);
2554 for (p = modinfo; p; p = next_string(p, &size)) {
2555 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2556 return p + taglen + 1;
2561 static char *get_modinfo(const struct load_info *info, const char *tag)
2563 return get_next_modinfo(info, tag, NULL);
2566 static void setup_modinfo(struct module *mod, struct load_info *info)
2568 struct module_attribute *attr;
2571 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2573 attr->setup(mod, get_modinfo(info, attr->attr.name));
2577 static void free_modinfo(struct module *mod)
2579 struct module_attribute *attr;
2582 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2588 #ifdef CONFIG_KALLSYMS
2590 /* Lookup exported symbol in given range of kernel_symbols */
2591 static const struct kernel_symbol *lookup_exported_symbol(const char *name,
2592 const struct kernel_symbol *start,
2593 const struct kernel_symbol *stop)
2595 return bsearch(name, start, stop - start,
2596 sizeof(struct kernel_symbol), cmp_name);
2599 static int is_exported(const char *name, unsigned long value,
2600 const struct module *mod)
2602 const struct kernel_symbol *ks;
2604 ks = lookup_exported_symbol(name, __start___ksymtab, __stop___ksymtab);
2606 ks = lookup_exported_symbol(name, mod->syms, mod->syms + mod->num_syms);
2608 return ks != NULL && kernel_symbol_value(ks) == value;
2612 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2614 const Elf_Shdr *sechdrs = info->sechdrs;
2616 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2617 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2622 if (sym->st_shndx == SHN_UNDEF)
2624 if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
2626 if (sym->st_shndx >= SHN_LORESERVE)
2628 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2630 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2631 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2632 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2634 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2639 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2640 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2645 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2652 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2653 unsigned int shnum, unsigned int pcpundx)
2655 const Elf_Shdr *sec;
2657 if (src->st_shndx == SHN_UNDEF
2658 || src->st_shndx >= shnum
2662 #ifdef CONFIG_KALLSYMS_ALL
2663 if (src->st_shndx == pcpundx)
2667 sec = sechdrs + src->st_shndx;
2668 if (!(sec->sh_flags & SHF_ALLOC)
2669 #ifndef CONFIG_KALLSYMS_ALL
2670 || !(sec->sh_flags & SHF_EXECINSTR)
2672 || (sec->sh_entsize & INIT_OFFSET_MASK))
2679 * We only allocate and copy the strings needed by the parts of symtab
2680 * we keep. This is simple, but has the effect of making multiple
2681 * copies of duplicates. We could be more sophisticated, see
2682 * linux-kernel thread starting with
2683 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2685 static void layout_symtab(struct module *mod, struct load_info *info)
2687 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2688 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2690 unsigned int i, nsrc, ndst, strtab_size = 0;
2692 /* Put symbol section at end of init part of module. */
2693 symsect->sh_flags |= SHF_ALLOC;
2694 symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2695 info->index.sym) | INIT_OFFSET_MASK;
2696 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2698 src = (void *)info->hdr + symsect->sh_offset;
2699 nsrc = symsect->sh_size / sizeof(*src);
2701 /* Compute total space required for the core symbols' strtab. */
2702 for (ndst = i = 0; i < nsrc; i++) {
2703 if (i == 0 || is_livepatch_module(mod) ||
2704 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2705 info->index.pcpu)) {
2706 strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2711 /* Append room for core symbols at end of core part. */
2712 info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
2713 info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
2714 mod->core_layout.size += strtab_size;
2715 info->core_typeoffs = mod->core_layout.size;
2716 mod->core_layout.size += ndst * sizeof(char);
2717 mod->core_layout.size = debug_align(mod->core_layout.size);
2719 /* Put string table section at end of init part of module. */
2720 strsect->sh_flags |= SHF_ALLOC;
2721 strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2722 info->index.str) | INIT_OFFSET_MASK;
2723 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2725 /* We'll tack temporary mod_kallsyms on the end. */
2726 mod->init_layout.size = ALIGN(mod->init_layout.size,
2727 __alignof__(struct mod_kallsyms));
2728 info->mod_kallsyms_init_off = mod->init_layout.size;
2729 mod->init_layout.size += sizeof(struct mod_kallsyms);
2730 info->init_typeoffs = mod->init_layout.size;
2731 mod->init_layout.size += nsrc * sizeof(char);
2732 mod->init_layout.size = debug_align(mod->init_layout.size);
2736 * We use the full symtab and strtab which layout_symtab arranged to
2737 * be appended to the init section. Later we switch to the cut-down
2740 static void add_kallsyms(struct module *mod, const struct load_info *info)
2742 unsigned int i, ndst;
2746 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2748 /* Set up to point into init section. */
2749 mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
2751 mod->kallsyms->symtab = (void *)symsec->sh_addr;
2752 mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2753 /* Make sure we get permanent strtab: don't use info->strtab. */
2754 mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2755 mod->kallsyms->typetab = mod->init_layout.base + info->init_typeoffs;
2758 * Now populate the cut down core kallsyms for after init
2759 * and set types up while we still have access to sections.
2761 mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
2762 mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
2763 mod->core_kallsyms.typetab = mod->core_layout.base + info->core_typeoffs;
2764 src = mod->kallsyms->symtab;
2765 for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2766 mod->kallsyms->typetab[i] = elf_type(src + i, info);
2767 if (i == 0 || is_livepatch_module(mod) ||
2768 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2769 info->index.pcpu)) {
2770 mod->core_kallsyms.typetab[ndst] =
2771 mod->kallsyms->typetab[i];
2773 dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
2774 s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2778 mod->core_kallsyms.num_symtab = ndst;
2781 static inline void layout_symtab(struct module *mod, struct load_info *info)
2785 static void add_kallsyms(struct module *mod, const struct load_info *info)
2788 #endif /* CONFIG_KALLSYMS */
2790 static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num)
2794 ddebug_add_module(debug, num, mod->name);
2797 static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug)
2800 ddebug_remove_module(mod->name);
2803 void * __weak module_alloc(unsigned long size)
2805 return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
2806 GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS,
2807 NUMA_NO_NODE, __builtin_return_address(0));
2810 bool __weak module_init_section(const char *name)
2812 return strstarts(name, ".init");
2815 bool __weak module_exit_section(const char *name)
2817 return strstarts(name, ".exit");
2820 #ifdef CONFIG_DEBUG_KMEMLEAK
2821 static void kmemleak_load_module(const struct module *mod,
2822 const struct load_info *info)
2826 /* only scan the sections containing data */
2827 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2829 for (i = 1; i < info->hdr->e_shnum; i++) {
2830 /* Scan all writable sections that's not executable */
2831 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2832 !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2833 (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2836 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2837 info->sechdrs[i].sh_size, GFP_KERNEL);
2841 static inline void kmemleak_load_module(const struct module *mod,
2842 const struct load_info *info)
2847 #ifdef CONFIG_MODULE_SIG
2848 static int module_sig_check(struct load_info *info, int flags)
2851 const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2853 const void *mod = info->hdr;
2856 * Require flags == 0, as a module with version information
2857 * removed is no longer the module that was signed
2860 info->len > markerlen &&
2861 memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2862 /* We truncate the module to discard the signature */
2863 info->len -= markerlen;
2864 err = mod_verify_sig(mod, info);
2869 info->sig_ok = true;
2872 /* We don't permit modules to be loaded into trusted kernels
2873 * without a valid signature on them, but if we're not
2874 * enforcing, certain errors are non-fatal.
2877 reason = "Loading of unsigned module";
2880 reason = "Loading of module with unsupported crypto";
2883 reason = "Loading of module with unavailable key";
2885 if (is_module_sig_enforced()) {
2886 pr_notice("%s: %s is rejected\n", info->name, reason);
2887 return -EKEYREJECTED;
2890 return security_locked_down(LOCKDOWN_MODULE_SIGNATURE);
2892 /* All other errors are fatal, including nomem, unparseable
2893 * signatures and signature check failures - even if signatures
2900 #else /* !CONFIG_MODULE_SIG */
2901 static int module_sig_check(struct load_info *info, int flags)
2905 #endif /* !CONFIG_MODULE_SIG */
2907 /* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2908 static int elf_header_check(struct load_info *info)
2910 if (info->len < sizeof(*(info->hdr)))
2913 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2914 || info->hdr->e_type != ET_REL
2915 || !elf_check_arch(info->hdr)
2916 || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2919 if (info->hdr->e_shoff >= info->len
2920 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2921 info->len - info->hdr->e_shoff))
2927 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2929 static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
2932 unsigned long n = min(len, COPY_CHUNK_SIZE);
2934 if (copy_from_user(dst, usrc, n) != 0)
2944 #ifdef CONFIG_LIVEPATCH
2945 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2947 if (get_modinfo(info, "livepatch")) {
2949 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
2950 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
2956 #else /* !CONFIG_LIVEPATCH */
2957 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2959 if (get_modinfo(info, "livepatch")) {
2960 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
2967 #endif /* CONFIG_LIVEPATCH */
2969 static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
2971 if (retpoline_module_ok(get_modinfo(info, "retpoline")))
2974 pr_warn("%s: loading module not compiled with retpoline compiler.\n",
2978 /* Sets info->hdr and info->len. */
2979 static int copy_module_from_user(const void __user *umod, unsigned long len,
2980 struct load_info *info)
2985 if (info->len < sizeof(*(info->hdr)))
2988 err = security_kernel_load_data(LOADING_MODULE);
2992 /* Suck in entire file: we'll want most of it. */
2993 info->hdr = __vmalloc(info->len, GFP_KERNEL | __GFP_NOWARN);
2997 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
3005 static void free_copy(struct load_info *info)
3010 static int rewrite_section_headers(struct load_info *info, int flags)
3014 /* This should always be true, but let's be sure. */
3015 info->sechdrs[0].sh_addr = 0;
3017 for (i = 1; i < info->hdr->e_shnum; i++) {
3018 Elf_Shdr *shdr = &info->sechdrs[i];
3019 if (shdr->sh_type != SHT_NOBITS
3020 && info->len < shdr->sh_offset + shdr->sh_size) {
3021 pr_err("Module len %lu truncated\n", info->len);
3025 /* Mark all sections sh_addr with their address in the
3027 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
3029 #ifndef CONFIG_MODULE_UNLOAD
3030 /* Don't load .exit sections */
3031 if (module_exit_section(info->secstrings+shdr->sh_name))
3032 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
3036 /* Track but don't keep modinfo and version sections. */
3037 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
3038 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
3044 * Set up our basic convenience variables (pointers to section headers,
3045 * search for module section index etc), and do some basic section
3048 * Set info->mod to the temporary copy of the module in info->hdr. The final one
3049 * will be allocated in move_module().
3051 static int setup_load_info(struct load_info *info, int flags)
3055 /* Set up the convenience variables */
3056 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
3057 info->secstrings = (void *)info->hdr
3058 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
3060 /* Try to find a name early so we can log errors with a module name */
3061 info->index.info = find_sec(info, ".modinfo");
3062 if (info->index.info)
3063 info->name = get_modinfo(info, "name");
3065 /* Find internal symbols and strings. */
3066 for (i = 1; i < info->hdr->e_shnum; i++) {
3067 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
3068 info->index.sym = i;
3069 info->index.str = info->sechdrs[i].sh_link;
3070 info->strtab = (char *)info->hdr
3071 + info->sechdrs[info->index.str].sh_offset;
3076 if (info->index.sym == 0) {
3077 pr_warn("%s: module has no symbols (stripped?)\n",
3078 info->name ?: "(missing .modinfo section or name field)");
3082 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
3083 if (!info->index.mod) {
3084 pr_warn("%s: No module found in object\n",
3085 info->name ?: "(missing .modinfo section or name field)");
3088 /* This is temporary: point mod into copy of data. */
3089 info->mod = (void *)info->hdr + info->sechdrs[info->index.mod].sh_offset;
3092 * If we didn't load the .modinfo 'name' field earlier, fall back to
3093 * on-disk struct mod 'name' field.
3096 info->name = info->mod->name;
3098 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
3099 info->index.vers = 0; /* Pretend no __versions section! */
3101 info->index.vers = find_sec(info, "__versions");
3103 info->index.pcpu = find_pcpusec(info);
3108 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
3110 const char *modmagic = get_modinfo(info, "vermagic");
3113 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
3116 /* This is allowed: modprobe --force will invalidate it. */
3118 err = try_to_force_load(mod, "bad vermagic");
3121 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
3122 pr_err("%s: version magic '%s' should be '%s'\n",
3123 info->name, modmagic, vermagic);
3127 if (!get_modinfo(info, "intree")) {
3128 if (!test_taint(TAINT_OOT_MODULE))
3129 pr_warn("%s: loading out-of-tree module taints kernel.\n",
3131 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
3134 check_modinfo_retpoline(mod, info);
3136 if (get_modinfo(info, "staging")) {
3137 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
3138 pr_warn("%s: module is from the staging directory, the quality "
3139 "is unknown, you have been warned.\n", mod->name);
3142 err = check_modinfo_livepatch(mod, info);
3146 /* Set up license info based on the info section */
3147 set_license(mod, get_modinfo(info, "license"));
3152 static int find_module_sections(struct module *mod, struct load_info *info)
3154 mod->kp = section_objs(info, "__param",
3155 sizeof(*mod->kp), &mod->num_kp);
3156 mod->syms = section_objs(info, "__ksymtab",
3157 sizeof(*mod->syms), &mod->num_syms);
3158 mod->crcs = section_addr(info, "__kcrctab");
3159 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
3160 sizeof(*mod->gpl_syms),
3161 &mod->num_gpl_syms);
3162 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
3163 mod->gpl_future_syms = section_objs(info,
3164 "__ksymtab_gpl_future",
3165 sizeof(*mod->gpl_future_syms),
3166 &mod->num_gpl_future_syms);
3167 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
3169 #ifdef CONFIG_UNUSED_SYMBOLS
3170 mod->unused_syms = section_objs(info, "__ksymtab_unused",
3171 sizeof(*mod->unused_syms),
3172 &mod->num_unused_syms);
3173 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
3174 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
3175 sizeof(*mod->unused_gpl_syms),
3176 &mod->num_unused_gpl_syms);
3177 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
3179 #ifdef CONFIG_CONSTRUCTORS
3180 mod->ctors = section_objs(info, ".ctors",
3181 sizeof(*mod->ctors), &mod->num_ctors);
3183 mod->ctors = section_objs(info, ".init_array",
3184 sizeof(*mod->ctors), &mod->num_ctors);
3185 else if (find_sec(info, ".init_array")) {
3187 * This shouldn't happen with same compiler and binutils
3188 * building all parts of the module.
3190 pr_warn("%s: has both .ctors and .init_array.\n",
3196 mod->noinstr_text_start = section_objs(info, ".noinstr.text", 1,
3197 &mod->noinstr_text_size);
3199 #ifdef CONFIG_TRACEPOINTS
3200 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
3201 sizeof(*mod->tracepoints_ptrs),
3202 &mod->num_tracepoints);
3204 #ifdef CONFIG_TREE_SRCU
3205 mod->srcu_struct_ptrs = section_objs(info, "___srcu_struct_ptrs",
3206 sizeof(*mod->srcu_struct_ptrs),
3207 &mod->num_srcu_structs);
3209 #ifdef CONFIG_BPF_EVENTS
3210 mod->bpf_raw_events = section_objs(info, "__bpf_raw_tp_map",
3211 sizeof(*mod->bpf_raw_events),
3212 &mod->num_bpf_raw_events);
3214 #ifdef CONFIG_JUMP_LABEL
3215 mod->jump_entries = section_objs(info, "__jump_table",
3216 sizeof(*mod->jump_entries),
3217 &mod->num_jump_entries);
3219 #ifdef CONFIG_EVENT_TRACING
3220 mod->trace_events = section_objs(info, "_ftrace_events",
3221 sizeof(*mod->trace_events),
3222 &mod->num_trace_events);
3223 mod->trace_evals = section_objs(info, "_ftrace_eval_map",
3224 sizeof(*mod->trace_evals),
3225 &mod->num_trace_evals);
3227 #ifdef CONFIG_TRACING
3228 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
3229 sizeof(*mod->trace_bprintk_fmt_start),
3230 &mod->num_trace_bprintk_fmt);
3232 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
3233 /* sechdrs[0].sh_size is always zero */
3234 mod->ftrace_callsites = section_objs(info, FTRACE_CALLSITE_SECTION,
3235 sizeof(*mod->ftrace_callsites),
3236 &mod->num_ftrace_callsites);
3238 #ifdef CONFIG_FUNCTION_ERROR_INJECTION
3239 mod->ei_funcs = section_objs(info, "_error_injection_whitelist",
3240 sizeof(*mod->ei_funcs),
3241 &mod->num_ei_funcs);
3243 #ifdef CONFIG_KPROBES
3244 mod->kprobes_text_start = section_objs(info, ".kprobes.text", 1,
3245 &mod->kprobes_text_size);
3246 mod->kprobe_blacklist = section_objs(info, "_kprobe_blacklist",
3247 sizeof(unsigned long),
3248 &mod->num_kprobe_blacklist);
3250 mod->extable = section_objs(info, "__ex_table",
3251 sizeof(*mod->extable), &mod->num_exentries);
3253 if (section_addr(info, "__obsparm"))
3254 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
3256 info->debug = section_objs(info, "__dyndbg",
3257 sizeof(*info->debug), &info->num_debug);
3262 static int move_module(struct module *mod, struct load_info *info)
3267 /* Do the allocs. */
3268 ptr = module_alloc(mod->core_layout.size);
3270 * The pointer to this block is stored in the module structure
3271 * which is inside the block. Just mark it as not being a
3274 kmemleak_not_leak(ptr);
3278 memset(ptr, 0, mod->core_layout.size);
3279 mod->core_layout.base = ptr;
3281 if (mod->init_layout.size) {
3282 ptr = module_alloc(mod->init_layout.size);
3284 * The pointer to this block is stored in the module structure
3285 * which is inside the block. This block doesn't need to be
3286 * scanned as it contains data and code that will be freed
3287 * after the module is initialized.
3289 kmemleak_ignore(ptr);
3291 module_memfree(mod->core_layout.base);
3294 memset(ptr, 0, mod->init_layout.size);
3295 mod->init_layout.base = ptr;
3297 mod->init_layout.base = NULL;
3299 /* Transfer each section which specifies SHF_ALLOC */
3300 pr_debug("final section addresses:\n");
3301 for (i = 0; i < info->hdr->e_shnum; i++) {
3303 Elf_Shdr *shdr = &info->sechdrs[i];
3305 if (!(shdr->sh_flags & SHF_ALLOC))
3308 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3309 dest = mod->init_layout.base
3310 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3312 dest = mod->core_layout.base + shdr->sh_entsize;
3314 if (shdr->sh_type != SHT_NOBITS)
3315 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3316 /* Update sh_addr to point to copy in image. */
3317 shdr->sh_addr = (unsigned long)dest;
3318 pr_debug("\t0x%lx %s\n",
3319 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3325 static int check_module_license_and_versions(struct module *mod)
3327 int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
3330 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3331 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3332 * using GPL-only symbols it needs.
3334 if (strcmp(mod->name, "ndiswrapper") == 0)
3335 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3337 /* driverloader was caught wrongly pretending to be under GPL */
3338 if (strcmp(mod->name, "driverloader") == 0)
3339 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3340 LOCKDEP_NOW_UNRELIABLE);
3342 /* lve claims to be GPL but upstream won't provide source */
3343 if (strcmp(mod->name, "lve") == 0)
3344 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3345 LOCKDEP_NOW_UNRELIABLE);
3347 if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
3348 pr_warn("%s: module license taints kernel.\n", mod->name);
3350 #ifdef CONFIG_MODVERSIONS
3351 if ((mod->num_syms && !mod->crcs)
3352 || (mod->num_gpl_syms && !mod->gpl_crcs)
3353 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3354 #ifdef CONFIG_UNUSED_SYMBOLS
3355 || (mod->num_unused_syms && !mod->unused_crcs)
3356 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3359 return try_to_force_load(mod,
3360 "no versions for exported symbols");
3366 static void flush_module_icache(const struct module *mod)
3369 * Flush the instruction cache, since we've played with text.
3370 * Do it before processing of module parameters, so the module
3371 * can provide parameter accessor functions of its own.
3373 if (mod->init_layout.base)
3374 flush_icache_range((unsigned long)mod->init_layout.base,
3375 (unsigned long)mod->init_layout.base
3376 + mod->init_layout.size);
3377 flush_icache_range((unsigned long)mod->core_layout.base,
3378 (unsigned long)mod->core_layout.base + mod->core_layout.size);
3381 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3389 /* module_blacklist is a comma-separated list of module names */
3390 static char *module_blacklist;
3391 static bool blacklisted(const char *module_name)
3396 if (!module_blacklist)
3399 for (p = module_blacklist; *p; p += len) {
3400 len = strcspn(p, ",");
3401 if (strlen(module_name) == len && !memcmp(module_name, p, len))
3408 core_param(module_blacklist, module_blacklist, charp, 0400);
3410 static struct module *layout_and_allocate(struct load_info *info, int flags)
3416 err = check_modinfo(info->mod, info, flags);
3418 return ERR_PTR(err);
3420 /* Allow arches to frob section contents and sizes. */
3421 err = module_frob_arch_sections(info->hdr, info->sechdrs,
3422 info->secstrings, info->mod);
3424 return ERR_PTR(err);
3426 err = module_enforce_rwx_sections(info->hdr, info->sechdrs,
3427 info->secstrings, info->mod);
3429 return ERR_PTR(err);
3431 /* We will do a special allocation for per-cpu sections later. */
3432 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3435 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3436 * layout_sections() can put it in the right place.
3437 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3439 ndx = find_sec(info, ".data..ro_after_init");
3441 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3443 * Mark the __jump_table section as ro_after_init as well: these data
3444 * structures are never modified, with the exception of entries that
3445 * refer to code in the __init section, which are annotated as such
3446 * at module load time.
3448 ndx = find_sec(info, "__jump_table");
3450 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3452 /* Determine total sizes, and put offsets in sh_entsize. For now
3453 this is done generically; there doesn't appear to be any
3454 special cases for the architectures. */
3455 layout_sections(info->mod, info);
3456 layout_symtab(info->mod, info);
3458 /* Allocate and move to the final place */
3459 err = move_module(info->mod, info);
3461 return ERR_PTR(err);
3463 /* Module has been copied to its final place now: return it. */
3464 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3465 kmemleak_load_module(mod, info);
3469 /* mod is no longer valid after this! */
3470 static void module_deallocate(struct module *mod, struct load_info *info)
3472 percpu_modfree(mod);
3473 module_arch_freeing_init(mod);
3474 module_memfree(mod->init_layout.base);
3475 module_memfree(mod->core_layout.base);
3478 int __weak module_finalize(const Elf_Ehdr *hdr,
3479 const Elf_Shdr *sechdrs,
3485 static int post_relocation(struct module *mod, const struct load_info *info)
3487 /* Sort exception table now relocations are done. */
3488 sort_extable(mod->extable, mod->extable + mod->num_exentries);
3490 /* Copy relocated percpu area over. */
3491 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3492 info->sechdrs[info->index.pcpu].sh_size);
3494 /* Setup kallsyms-specific fields. */
3495 add_kallsyms(mod, info);
3497 /* Arch-specific module finalizing. */
3498 return module_finalize(info->hdr, info->sechdrs, mod);
3501 /* Is this module of this name done loading? No locks held. */
3502 static bool finished_loading(const char *name)
3508 * The module_mutex should not be a heavily contended lock;
3509 * if we get the occasional sleep here, we'll go an extra iteration
3510 * in the wait_event_interruptible(), which is harmless.
3512 sched_annotate_sleep();
3513 mutex_lock(&module_mutex);
3514 mod = find_module_all(name, strlen(name), true);
3515 ret = !mod || mod->state == MODULE_STATE_LIVE;
3516 mutex_unlock(&module_mutex);
3521 /* Call module constructors. */
3522 static void do_mod_ctors(struct module *mod)
3524 #ifdef CONFIG_CONSTRUCTORS
3527 for (i = 0; i < mod->num_ctors; i++)
3532 /* For freeing module_init on success, in case kallsyms traversing */
3533 struct mod_initfree {
3534 struct llist_node node;
3538 static void do_free_init(struct work_struct *w)
3540 struct llist_node *pos, *n, *list;
3541 struct mod_initfree *initfree;
3543 list = llist_del_all(&init_free_list);
3547 llist_for_each_safe(pos, n, list) {
3548 initfree = container_of(pos, struct mod_initfree, node);
3549 module_memfree(initfree->module_init);
3554 static int __init modules_wq_init(void)
3556 INIT_WORK(&init_free_wq, do_free_init);
3557 init_llist_head(&init_free_list);
3560 module_init(modules_wq_init);
3563 * This is where the real work happens.
3565 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3566 * helper command 'lx-symbols'.
3568 static noinline int do_init_module(struct module *mod)
3571 struct mod_initfree *freeinit;
3573 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3578 freeinit->module_init = mod->init_layout.base;
3581 * We want to find out whether @mod uses async during init. Clear
3582 * PF_USED_ASYNC. async_schedule*() will set it.
3584 current->flags &= ~PF_USED_ASYNC;
3587 /* Start the module */
3588 if (mod->init != NULL)
3589 ret = do_one_initcall(mod->init);
3591 goto fail_free_freeinit;
3594 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3595 "follow 0/-E convention\n"
3596 "%s: loading module anyway...\n",
3597 __func__, mod->name, ret, __func__);
3601 /* Now it's a first class citizen! */
3602 mod->state = MODULE_STATE_LIVE;
3603 blocking_notifier_call_chain(&module_notify_list,
3604 MODULE_STATE_LIVE, mod);
3607 * We need to finish all async code before the module init sequence
3608 * is done. This has potential to deadlock. For example, a newly
3609 * detected block device can trigger request_module() of the
3610 * default iosched from async probing task. Once userland helper
3611 * reaches here, async_synchronize_full() will wait on the async
3612 * task waiting on request_module() and deadlock.
3614 * This deadlock is avoided by perfomring async_synchronize_full()
3615 * iff module init queued any async jobs. This isn't a full
3616 * solution as it will deadlock the same if module loading from
3617 * async jobs nests more than once; however, due to the various
3618 * constraints, this hack seems to be the best option for now.
3619 * Please refer to the following thread for details.
3621 * http://thread.gmane.org/gmane.linux.kernel/1420814
3623 if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3624 async_synchronize_full();
3626 ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base +
3627 mod->init_layout.size);
3628 mutex_lock(&module_mutex);
3629 /* Drop initial reference. */
3631 trim_init_extable(mod);
3632 #ifdef CONFIG_KALLSYMS
3633 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3634 rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3636 module_enable_ro(mod, true);
3637 mod_tree_remove_init(mod);
3638 module_arch_freeing_init(mod);
3639 mod->init_layout.base = NULL;
3640 mod->init_layout.size = 0;
3641 mod->init_layout.ro_size = 0;
3642 mod->init_layout.ro_after_init_size = 0;
3643 mod->init_layout.text_size = 0;
3645 * We want to free module_init, but be aware that kallsyms may be
3646 * walking this with preempt disabled. In all the failure paths, we
3647 * call synchronize_rcu(), but we don't want to slow down the success
3648 * path. module_memfree() cannot be called in an interrupt, so do the
3649 * work and call synchronize_rcu() in a work queue.
3651 * Note that module_alloc() on most architectures creates W+X page
3652 * mappings which won't be cleaned up until do_free_init() runs. Any
3653 * code such as mark_rodata_ro() which depends on those mappings to
3654 * be cleaned up needs to sync with the queued work - ie
3657 if (llist_add(&freeinit->node, &init_free_list))
3658 schedule_work(&init_free_wq);
3660 mutex_unlock(&module_mutex);
3661 wake_up_all(&module_wq);
3668 /* Try to protect us from buggy refcounters. */
3669 mod->state = MODULE_STATE_GOING;
3672 blocking_notifier_call_chain(&module_notify_list,
3673 MODULE_STATE_GOING, mod);
3674 klp_module_going(mod);
3675 ftrace_release_mod(mod);
3677 wake_up_all(&module_wq);
3681 static int may_init_module(void)
3683 if (!capable(CAP_SYS_MODULE) || modules_disabled)
3690 * We try to place it in the list now to make sure it's unique before
3691 * we dedicate too many resources. In particular, temporary percpu
3692 * memory exhaustion.
3694 static int add_unformed_module(struct module *mod)
3699 mod->state = MODULE_STATE_UNFORMED;
3702 mutex_lock(&module_mutex);
3703 old = find_module_all(mod->name, strlen(mod->name), true);
3705 if (old->state != MODULE_STATE_LIVE) {
3706 /* Wait in case it fails to load. */
3707 mutex_unlock(&module_mutex);
3708 err = wait_event_interruptible(module_wq,
3709 finished_loading(mod->name));
3717 mod_update_bounds(mod);
3718 list_add_rcu(&mod->list, &modules);
3719 mod_tree_insert(mod);
3723 mutex_unlock(&module_mutex);
3728 static int complete_formation(struct module *mod, struct load_info *info)
3732 mutex_lock(&module_mutex);
3734 /* Find duplicate symbols (must be called under lock). */
3735 err = verify_exported_symbols(mod);
3739 /* This relies on module_mutex for list integrity. */
3740 module_bug_finalize(info->hdr, info->sechdrs, mod);
3742 module_enable_ro(mod, false);
3743 module_enable_nx(mod);
3744 module_enable_x(mod);
3746 /* Mark state as coming so strong_try_module_get() ignores us,
3747 * but kallsyms etc. can see us. */
3748 mod->state = MODULE_STATE_COMING;
3749 mutex_unlock(&module_mutex);
3754 mutex_unlock(&module_mutex);
3758 static int prepare_coming_module(struct module *mod)
3762 ftrace_module_enable(mod);
3763 err = klp_module_coming(mod);
3767 blocking_notifier_call_chain(&module_notify_list,
3768 MODULE_STATE_COMING, mod);
3772 static int unknown_module_param_cb(char *param, char *val, const char *modname,
3775 struct module *mod = arg;
3778 if (strcmp(param, "async_probe") == 0) {
3779 mod->async_probe_requested = true;
3783 /* Check for magic 'dyndbg' arg */
3784 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3786 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3790 /* Allocate and load the module: note that size of section 0 is always
3791 zero, and we rely on this for optional sections. */
3792 static int load_module(struct load_info *info, const char __user *uargs,
3799 err = elf_header_check(info);
3803 err = setup_load_info(info, flags);
3807 if (blacklisted(info->name)) {
3812 err = module_sig_check(info, flags);
3816 err = rewrite_section_headers(info, flags);
3820 /* Check module struct version now, before we try to use module. */
3821 if (!check_modstruct_version(info, info->mod)) {
3826 /* Figure out module layout, and allocate all the memory. */
3827 mod = layout_and_allocate(info, flags);
3833 audit_log_kern_module(mod->name);
3835 /* Reserve our place in the list. */
3836 err = add_unformed_module(mod);
3840 #ifdef CONFIG_MODULE_SIG
3841 mod->sig_ok = info->sig_ok;
3843 pr_notice_once("%s: module verification failed: signature "
3844 "and/or required key missing - tainting "
3845 "kernel\n", mod->name);
3846 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3850 /* To avoid stressing percpu allocator, do this once we're unique. */
3851 err = percpu_modalloc(mod, info);
3855 /* Now module is in final location, initialize linked lists, etc. */
3856 err = module_unload_init(mod);
3860 init_param_lock(mod);
3862 /* Now we've got everything in the final locations, we can
3863 * find optional sections. */
3864 err = find_module_sections(mod, info);
3868 err = check_module_license_and_versions(mod);
3872 /* Set up MODINFO_ATTR fields */
3873 setup_modinfo(mod, info);
3875 /* Fix up syms, so that st_value is a pointer to location. */
3876 err = simplify_symbols(mod, info);
3880 err = apply_relocations(mod, info);
3884 err = post_relocation(mod, info);
3888 flush_module_icache(mod);
3890 /* Now copy in args */
3891 mod->args = strndup_user(uargs, ~0UL >> 1);
3892 if (IS_ERR(mod->args)) {
3893 err = PTR_ERR(mod->args);
3894 goto free_arch_cleanup;
3897 dynamic_debug_setup(mod, info->debug, info->num_debug);
3899 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3900 ftrace_module_init(mod);
3902 /* Finally it's fully formed, ready to start executing. */
3903 err = complete_formation(mod, info);
3905 goto ddebug_cleanup;
3907 err = prepare_coming_module(mod);
3911 /* Module is ready to execute: parsing args may do that. */
3912 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3914 unknown_module_param_cb);
3915 if (IS_ERR(after_dashes)) {
3916 err = PTR_ERR(after_dashes);
3917 goto coming_cleanup;
3918 } else if (after_dashes) {
3919 pr_warn("%s: parameters '%s' after `--' ignored\n",
3920 mod->name, after_dashes);
3923 /* Link in to sysfs. */
3924 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3926 goto coming_cleanup;
3928 if (is_livepatch_module(mod)) {
3929 err = copy_module_elf(mod, info);
3934 /* Get rid of temporary copy. */
3938 trace_module_load(mod);
3940 return do_init_module(mod);
3943 mod_sysfs_teardown(mod);
3945 mod->state = MODULE_STATE_GOING;
3946 destroy_params(mod->kp, mod->num_kp);
3947 blocking_notifier_call_chain(&module_notify_list,
3948 MODULE_STATE_GOING, mod);
3949 klp_module_going(mod);
3951 /* module_bug_cleanup needs module_mutex protection */
3952 mutex_lock(&module_mutex);
3953 module_bug_cleanup(mod);
3954 mutex_unlock(&module_mutex);
3957 ftrace_release_mod(mod);
3958 dynamic_debug_remove(mod, info->debug);
3962 module_arch_cleanup(mod);
3966 module_unload_free(mod);
3968 mutex_lock(&module_mutex);
3969 /* Unlink carefully: kallsyms could be walking list. */
3970 list_del_rcu(&mod->list);
3971 mod_tree_remove(mod);
3972 wake_up_all(&module_wq);
3973 /* Wait for RCU-sched synchronizing before releasing mod->list. */
3975 mutex_unlock(&module_mutex);
3977 /* Free lock-classes; relies on the preceding sync_rcu() */
3978 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
3980 module_deallocate(mod, info);
3986 SYSCALL_DEFINE3(init_module, void __user *, umod,
3987 unsigned long, len, const char __user *, uargs)
3990 struct load_info info = { };
3992 err = may_init_module();
3996 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3999 err = copy_module_from_user(umod, len, &info);
4003 return load_module(&info, uargs, 0);
4006 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
4008 struct load_info info = { };
4013 err = may_init_module();
4017 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
4019 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
4020 |MODULE_INIT_IGNORE_VERMAGIC))
4023 err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX,
4030 return load_module(&info, uargs, flags);
4033 static inline int within(unsigned long addr, void *start, unsigned long size)
4035 return ((void *)addr >= start && (void *)addr < start + size);
4038 #ifdef CONFIG_KALLSYMS
4040 * This ignores the intensely annoying "mapping symbols" found
4041 * in ARM ELF files: $a, $t and $d.
4043 static inline int is_arm_mapping_symbol(const char *str)
4045 if (str[0] == '.' && str[1] == 'L')
4047 return str[0] == '$' && strchr("axtd", str[1])
4048 && (str[2] == '\0' || str[2] == '.');
4051 static const char *kallsyms_symbol_name(struct mod_kallsyms *kallsyms, unsigned int symnum)
4053 return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
4057 * Given a module and address, find the corresponding symbol and return its name
4058 * while providing its size and offset if needed.
4060 static const char *find_kallsyms_symbol(struct module *mod,
4062 unsigned long *size,
4063 unsigned long *offset)
4065 unsigned int i, best = 0;
4066 unsigned long nextval, bestval;
4067 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4069 /* At worse, next value is at end of module */
4070 if (within_module_init(addr, mod))
4071 nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
4073 nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
4075 bestval = kallsyms_symbol_value(&kallsyms->symtab[best]);
4077 /* Scan for closest preceding symbol, and next symbol. (ELF
4078 starts real symbols at 1). */
4079 for (i = 1; i < kallsyms->num_symtab; i++) {
4080 const Elf_Sym *sym = &kallsyms->symtab[i];
4081 unsigned long thisval = kallsyms_symbol_value(sym);
4083 if (sym->st_shndx == SHN_UNDEF)
4086 /* We ignore unnamed symbols: they're uninformative
4087 * and inserted at a whim. */
4088 if (*kallsyms_symbol_name(kallsyms, i) == '\0'
4089 || is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms, i)))
4092 if (thisval <= addr && thisval > bestval) {
4096 if (thisval > addr && thisval < nextval)
4104 *size = nextval - bestval;
4106 *offset = addr - bestval;
4108 return kallsyms_symbol_name(kallsyms, best);
4111 void * __weak dereference_module_function_descriptor(struct module *mod,
4117 /* For kallsyms to ask for address resolution. NULL means not found. Careful
4118 * not to lock to avoid deadlock on oopses, simply disable preemption. */
4119 const char *module_address_lookup(unsigned long addr,
4120 unsigned long *size,
4121 unsigned long *offset,
4125 const char *ret = NULL;
4129 mod = __module_address(addr);
4132 *modname = mod->name;
4134 ret = find_kallsyms_symbol(mod, addr, size, offset);
4136 /* Make a copy in here where it's safe */
4138 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
4146 int lookup_module_symbol_name(unsigned long addr, char *symname)
4151 list_for_each_entry_rcu(mod, &modules, list) {
4152 if (mod->state == MODULE_STATE_UNFORMED)
4154 if (within_module(addr, mod)) {
4157 sym = find_kallsyms_symbol(mod, addr, NULL, NULL);
4161 strlcpy(symname, sym, KSYM_NAME_LEN);
4171 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
4172 unsigned long *offset, char *modname, char *name)
4177 list_for_each_entry_rcu(mod, &modules, list) {
4178 if (mod->state == MODULE_STATE_UNFORMED)
4180 if (within_module(addr, mod)) {
4183 sym = find_kallsyms_symbol(mod, addr, size, offset);
4187 strlcpy(modname, mod->name, MODULE_NAME_LEN);
4189 strlcpy(name, sym, KSYM_NAME_LEN);
4199 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
4200 char *name, char *module_name, int *exported)
4205 list_for_each_entry_rcu(mod, &modules, list) {
4206 struct mod_kallsyms *kallsyms;
4208 if (mod->state == MODULE_STATE_UNFORMED)
4210 kallsyms = rcu_dereference_sched(mod->kallsyms);
4211 if (symnum < kallsyms->num_symtab) {
4212 const Elf_Sym *sym = &kallsyms->symtab[symnum];
4214 *value = kallsyms_symbol_value(sym);
4215 *type = kallsyms->typetab[symnum];
4216 strlcpy(name, kallsyms_symbol_name(kallsyms, symnum), KSYM_NAME_LEN);
4217 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
4218 *exported = is_exported(name, *value, mod);
4222 symnum -= kallsyms->num_symtab;
4228 /* Given a module and name of symbol, find and return the symbol's value */
4229 static unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name)
4232 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4234 for (i = 0; i < kallsyms->num_symtab; i++) {
4235 const Elf_Sym *sym = &kallsyms->symtab[i];
4237 if (strcmp(name, kallsyms_symbol_name(kallsyms, i)) == 0 &&
4238 sym->st_shndx != SHN_UNDEF)
4239 return kallsyms_symbol_value(sym);
4244 /* Look for this name: can be of form module:name. */
4245 unsigned long module_kallsyms_lookup_name(const char *name)
4249 unsigned long ret = 0;
4251 /* Don't lock: we're in enough trouble already. */
4253 if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
4254 if ((mod = find_module_all(name, colon - name, false)) != NULL)
4255 ret = find_kallsyms_symbol_value(mod, colon+1);
4257 list_for_each_entry_rcu(mod, &modules, list) {
4258 if (mod->state == MODULE_STATE_UNFORMED)
4260 if ((ret = find_kallsyms_symbol_value(mod, name)) != 0)
4268 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
4269 struct module *, unsigned long),
4276 module_assert_mutex();
4278 list_for_each_entry(mod, &modules, list) {
4279 /* We hold module_mutex: no need for rcu_dereference_sched */
4280 struct mod_kallsyms *kallsyms = mod->kallsyms;
4282 if (mod->state == MODULE_STATE_UNFORMED)
4284 for (i = 0; i < kallsyms->num_symtab; i++) {
4285 const Elf_Sym *sym = &kallsyms->symtab[i];
4287 if (sym->st_shndx == SHN_UNDEF)
4290 ret = fn(data, kallsyms_symbol_name(kallsyms, i),
4291 mod, kallsyms_symbol_value(sym));
4298 #endif /* CONFIG_KALLSYMS */
4300 /* Maximum number of characters written by module_flags() */
4301 #define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
4303 /* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
4304 static char *module_flags(struct module *mod, char *buf)
4308 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
4310 mod->state == MODULE_STATE_GOING ||
4311 mod->state == MODULE_STATE_COMING) {
4313 bx += module_flags_taint(mod, buf + bx);
4314 /* Show a - for module-is-being-unloaded */
4315 if (mod->state == MODULE_STATE_GOING)
4317 /* Show a + for module-is-being-loaded */
4318 if (mod->state == MODULE_STATE_COMING)
4327 #ifdef CONFIG_PROC_FS
4328 /* Called by the /proc file system to return a list of modules. */
4329 static void *m_start(struct seq_file *m, loff_t *pos)
4331 mutex_lock(&module_mutex);
4332 return seq_list_start(&modules, *pos);
4335 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
4337 return seq_list_next(p, &modules, pos);
4340 static void m_stop(struct seq_file *m, void *p)
4342 mutex_unlock(&module_mutex);
4345 static int m_show(struct seq_file *m, void *p)
4347 struct module *mod = list_entry(p, struct module, list);
4348 char buf[MODULE_FLAGS_BUF_SIZE];
4351 /* We always ignore unformed modules. */
4352 if (mod->state == MODULE_STATE_UNFORMED)
4355 seq_printf(m, "%s %u",
4356 mod->name, mod->init_layout.size + mod->core_layout.size);
4357 print_unload_info(m, mod);
4359 /* Informative for users. */
4360 seq_printf(m, " %s",
4361 mod->state == MODULE_STATE_GOING ? "Unloading" :
4362 mod->state == MODULE_STATE_COMING ? "Loading" :
4364 /* Used by oprofile and other similar tools. */
4365 value = m->private ? NULL : mod->core_layout.base;
4366 seq_printf(m, " 0x%px", value);
4370 seq_printf(m, " %s", module_flags(mod, buf));
4376 /* Format: modulename size refcount deps address
4378 Where refcount is a number or -, and deps is a comma-separated list
4381 static const struct seq_operations modules_op = {
4389 * This also sets the "private" pointer to non-NULL if the
4390 * kernel pointers should be hidden (so you can just test
4391 * "m->private" to see if you should keep the values private).
4393 * We use the same logic as for /proc/kallsyms.
4395 static int modules_open(struct inode *inode, struct file *file)
4397 int err = seq_open(file, &modules_op);
4400 struct seq_file *m = file->private_data;
4401 m->private = kallsyms_show_value(file->f_cred) ? NULL : (void *)8ul;
4407 static const struct proc_ops modules_proc_ops = {
4408 .proc_flags = PROC_ENTRY_PERMANENT,
4409 .proc_open = modules_open,
4410 .proc_read = seq_read,
4411 .proc_lseek = seq_lseek,
4412 .proc_release = seq_release,
4415 static int __init proc_modules_init(void)
4417 proc_create("modules", 0, NULL, &modules_proc_ops);
4420 module_init(proc_modules_init);
4423 /* Given an address, look for it in the module exception tables. */
4424 const struct exception_table_entry *search_module_extables(unsigned long addr)
4426 const struct exception_table_entry *e = NULL;
4430 mod = __module_address(addr);
4434 if (!mod->num_exentries)
4437 e = search_extable(mod->extable,
4444 * Now, if we found one, we are running inside it now, hence
4445 * we cannot unload the module, hence no refcnt needed.
4451 * is_module_address - is this address inside a module?
4452 * @addr: the address to check.
4454 * See is_module_text_address() if you simply want to see if the address
4455 * is code (not data).
4457 bool is_module_address(unsigned long addr)
4462 ret = __module_address(addr) != NULL;
4469 * __module_address - get the module which contains an address.
4470 * @addr: the address.
4472 * Must be called with preempt disabled or module mutex held so that
4473 * module doesn't get freed during this.
4475 struct module *__module_address(unsigned long addr)
4479 if (addr < module_addr_min || addr > module_addr_max)
4482 module_assert_mutex_or_preempt();
4484 mod = mod_find(addr);
4486 BUG_ON(!within_module(addr, mod));
4487 if (mod->state == MODULE_STATE_UNFORMED)
4492 EXPORT_SYMBOL_GPL(__module_address);
4495 * is_module_text_address - is this address inside module code?
4496 * @addr: the address to check.
4498 * See is_module_address() if you simply want to see if the address is
4499 * anywhere in a module. See kernel_text_address() for testing if an
4500 * address corresponds to kernel or module code.
4502 bool is_module_text_address(unsigned long addr)
4507 ret = __module_text_address(addr) != NULL;
4514 * __module_text_address - get the module whose code contains an address.
4515 * @addr: the address.
4517 * Must be called with preempt disabled or module mutex held so that
4518 * module doesn't get freed during this.
4520 struct module *__module_text_address(unsigned long addr)
4522 struct module *mod = __module_address(addr);
4524 /* Make sure it's within the text section. */
4525 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
4526 && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
4531 EXPORT_SYMBOL_GPL(__module_text_address);
4533 /* Don't grab lock, we're oopsing. */
4534 void print_modules(void)
4537 char buf[MODULE_FLAGS_BUF_SIZE];
4539 printk(KERN_DEFAULT "Modules linked in:");
4540 /* Most callers should already have preempt disabled, but make sure */
4542 list_for_each_entry_rcu(mod, &modules, list) {
4543 if (mod->state == MODULE_STATE_UNFORMED)
4545 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4548 if (last_unloaded_module[0])
4549 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4553 #ifdef CONFIG_MODVERSIONS
4554 /* Generate the signature for all relevant module structures here.
4555 * If these change, we don't want to try to parse the module. */
4556 void module_layout(struct module *mod,
4557 struct modversion_info *ver,
4558 struct kernel_param *kp,
4559 struct kernel_symbol *ks,
4560 struct tracepoint * const *tp)
4563 EXPORT_SYMBOL(module_layout);