2 Copyright (C) 2002 Richard Henderson
3 Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 #include <linux/export.h>
20 #include <linux/extable.h>
21 #include <linux/moduleloader.h>
22 #include <linux/trace_events.h>
23 #include <linux/init.h>
24 #include <linux/kallsyms.h>
25 #include <linux/file.h>
27 #include <linux/sysfs.h>
28 #include <linux/kernel.h>
29 #include <linux/slab.h>
30 #include <linux/vmalloc.h>
31 #include <linux/elf.h>
32 #include <linux/proc_fs.h>
33 #include <linux/security.h>
34 #include <linux/seq_file.h>
35 #include <linux/syscalls.h>
36 #include <linux/fcntl.h>
37 #include <linux/rcupdate.h>
38 #include <linux/capability.h>
39 #include <linux/cpu.h>
40 #include <linux/moduleparam.h>
41 #include <linux/errno.h>
42 #include <linux/err.h>
43 #include <linux/vermagic.h>
44 #include <linux/notifier.h>
45 #include <linux/sched.h>
46 #include <linux/device.h>
47 #include <linux/string.h>
48 #include <linux/mutex.h>
49 #include <linux/rculist.h>
50 #include <linux/uaccess.h>
51 #include <asm/cacheflush.h>
52 #include <linux/set_memory.h>
53 #include <asm/mmu_context.h>
54 #include <linux/license.h>
55 #include <asm/sections.h>
56 #include <linux/tracepoint.h>
57 #include <linux/ftrace.h>
58 #include <linux/livepatch.h>
59 #include <linux/async.h>
60 #include <linux/percpu.h>
61 #include <linux/kmemleak.h>
62 #include <linux/jump_label.h>
63 #include <linux/pfn.h>
64 #include <linux/bsearch.h>
65 #include <linux/dynamic_debug.h>
66 #include <linux/audit.h>
67 #include <uapi/linux/module.h>
68 #include "module-internal.h"
70 #define CREATE_TRACE_POINTS
71 #include <trace/events/module.h>
73 #ifndef ARCH_SHF_SMALL
74 #define ARCH_SHF_SMALL 0
78 * Modules' sections will be aligned on page boundaries
79 * to ensure complete separation of code and data
81 # define debug_align(X) ALIGN(X, PAGE_SIZE)
83 /* If this is set, the section belongs in the init part of the module */
84 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
88 * 1) List of modules (also safely readable with preempt_disable),
89 * 2) module_use links,
90 * 3) module_addr_min/module_addr_max.
91 * (delete and add uses RCU list operations). */
92 DEFINE_MUTEX(module_mutex);
93 EXPORT_SYMBOL_GPL(module_mutex);
94 static LIST_HEAD(modules);
96 #ifdef CONFIG_MODULES_TREE_LOOKUP
99 * Use a latched RB-tree for __module_address(); this allows us to use
100 * RCU-sched lookups of the address from any context.
102 * This is conditional on PERF_EVENTS || TRACING because those can really hit
103 * __module_address() hard by doing a lot of stack unwinding; potentially from
107 static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
109 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
111 return (unsigned long)layout->base;
114 static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
116 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
118 return (unsigned long)layout->size;
121 static __always_inline bool
122 mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
124 return __mod_tree_val(a) < __mod_tree_val(b);
127 static __always_inline int
128 mod_tree_comp(void *key, struct latch_tree_node *n)
130 unsigned long val = (unsigned long)key;
131 unsigned long start, end;
133 start = __mod_tree_val(n);
137 end = start + __mod_tree_size(n);
144 static const struct latch_tree_ops mod_tree_ops = {
145 .less = mod_tree_less,
146 .comp = mod_tree_comp,
149 static struct mod_tree_root {
150 struct latch_tree_root root;
151 unsigned long addr_min;
152 unsigned long addr_max;
153 } mod_tree __cacheline_aligned = {
157 #define module_addr_min mod_tree.addr_min
158 #define module_addr_max mod_tree.addr_max
160 static noinline void __mod_tree_insert(struct mod_tree_node *node)
162 latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
165 static void __mod_tree_remove(struct mod_tree_node *node)
167 latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
171 * These modifications: insert, remove_init and remove; are serialized by the
174 static void mod_tree_insert(struct module *mod)
176 mod->core_layout.mtn.mod = mod;
177 mod->init_layout.mtn.mod = mod;
179 __mod_tree_insert(&mod->core_layout.mtn);
180 if (mod->init_layout.size)
181 __mod_tree_insert(&mod->init_layout.mtn);
184 static void mod_tree_remove_init(struct module *mod)
186 if (mod->init_layout.size)
187 __mod_tree_remove(&mod->init_layout.mtn);
190 static void mod_tree_remove(struct module *mod)
192 __mod_tree_remove(&mod->core_layout.mtn);
193 mod_tree_remove_init(mod);
196 static struct module *mod_find(unsigned long addr)
198 struct latch_tree_node *ltn;
200 ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
204 return container_of(ltn, struct mod_tree_node, node)->mod;
207 #else /* MODULES_TREE_LOOKUP */
209 static unsigned long module_addr_min = -1UL, module_addr_max = 0;
211 static void mod_tree_insert(struct module *mod) { }
212 static void mod_tree_remove_init(struct module *mod) { }
213 static void mod_tree_remove(struct module *mod) { }
215 static struct module *mod_find(unsigned long addr)
219 list_for_each_entry_rcu(mod, &modules, list) {
220 if (within_module(addr, mod))
227 #endif /* MODULES_TREE_LOOKUP */
230 * Bounds of module text, for speeding up __module_address.
231 * Protected by module_mutex.
233 static void __mod_update_bounds(void *base, unsigned int size)
235 unsigned long min = (unsigned long)base;
236 unsigned long max = min + size;
238 if (min < module_addr_min)
239 module_addr_min = min;
240 if (max > module_addr_max)
241 module_addr_max = max;
244 static void mod_update_bounds(struct module *mod)
246 __mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
247 if (mod->init_layout.size)
248 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
251 #ifdef CONFIG_KGDB_KDB
252 struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
253 #endif /* CONFIG_KGDB_KDB */
255 static void module_assert_mutex(void)
257 lockdep_assert_held(&module_mutex);
260 static void module_assert_mutex_or_preempt(void)
262 #ifdef CONFIG_LOCKDEP
263 if (unlikely(!debug_locks))
266 WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
267 !lockdep_is_held(&module_mutex));
271 static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
272 module_param(sig_enforce, bool_enable_only, 0644);
275 * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
276 * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
278 bool is_module_sig_enforced(void)
282 EXPORT_SYMBOL(is_module_sig_enforced);
284 /* Block module loading/unloading? */
285 int modules_disabled = 0;
286 core_param(nomodule, modules_disabled, bint, 0);
288 /* Waiting for a module to finish initializing? */
289 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
291 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
293 int register_module_notifier(struct notifier_block *nb)
295 return blocking_notifier_chain_register(&module_notify_list, nb);
297 EXPORT_SYMBOL(register_module_notifier);
299 int unregister_module_notifier(struct notifier_block *nb)
301 return blocking_notifier_chain_unregister(&module_notify_list, nb);
303 EXPORT_SYMBOL(unregister_module_notifier);
306 * We require a truly strong try_module_get(): 0 means success.
307 * Otherwise an error is returned due to ongoing or failed
308 * initialization etc.
310 static inline int strong_try_module_get(struct module *mod)
312 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
313 if (mod && mod->state == MODULE_STATE_COMING)
315 if (try_module_get(mod))
321 static inline void add_taint_module(struct module *mod, unsigned flag,
322 enum lockdep_ok lockdep_ok)
324 add_taint(flag, lockdep_ok);
325 set_bit(flag, &mod->taints);
329 * A thread that wants to hold a reference to a module only while it
330 * is running can call this to safely exit. nfsd and lockd use this.
332 void __noreturn __module_put_and_exit(struct module *mod, long code)
337 EXPORT_SYMBOL(__module_put_and_exit);
339 /* Find a module section: 0 means not found. */
340 static unsigned int find_sec(const struct load_info *info, const char *name)
344 for (i = 1; i < info->hdr->e_shnum; i++) {
345 Elf_Shdr *shdr = &info->sechdrs[i];
346 /* Alloc bit cleared means "ignore it." */
347 if ((shdr->sh_flags & SHF_ALLOC)
348 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
354 /* Find a module section, or NULL. */
355 static void *section_addr(const struct load_info *info, const char *name)
357 /* Section 0 has sh_addr 0. */
358 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
361 /* Find a module section, or NULL. Fill in number of "objects" in section. */
362 static void *section_objs(const struct load_info *info,
367 unsigned int sec = find_sec(info, name);
369 /* Section 0 has sh_addr 0 and sh_size 0. */
370 *num = info->sechdrs[sec].sh_size / object_size;
371 return (void *)info->sechdrs[sec].sh_addr;
374 /* Provided by the linker */
375 extern const struct kernel_symbol __start___ksymtab[];
376 extern const struct kernel_symbol __stop___ksymtab[];
377 extern const struct kernel_symbol __start___ksymtab_gpl[];
378 extern const struct kernel_symbol __stop___ksymtab_gpl[];
379 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
380 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
381 extern const s32 __start___kcrctab[];
382 extern const s32 __start___kcrctab_gpl[];
383 extern const s32 __start___kcrctab_gpl_future[];
384 #ifdef CONFIG_UNUSED_SYMBOLS
385 extern const struct kernel_symbol __start___ksymtab_unused[];
386 extern const struct kernel_symbol __stop___ksymtab_unused[];
387 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
388 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
389 extern const s32 __start___kcrctab_unused[];
390 extern const s32 __start___kcrctab_unused_gpl[];
393 #ifndef CONFIG_MODVERSIONS
394 #define symversion(base, idx) NULL
396 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
399 static bool each_symbol_in_section(const struct symsearch *arr,
400 unsigned int arrsize,
401 struct module *owner,
402 bool (*fn)(const struct symsearch *syms,
403 struct module *owner,
409 for (j = 0; j < arrsize; j++) {
410 if (fn(&arr[j], owner, data))
417 /* Returns true as soon as fn returns true, otherwise false. */
418 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
419 struct module *owner,
424 static const struct symsearch arr[] = {
425 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
426 NOT_GPL_ONLY, false },
427 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
428 __start___kcrctab_gpl,
430 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
431 __start___kcrctab_gpl_future,
432 WILL_BE_GPL_ONLY, false },
433 #ifdef CONFIG_UNUSED_SYMBOLS
434 { __start___ksymtab_unused, __stop___ksymtab_unused,
435 __start___kcrctab_unused,
436 NOT_GPL_ONLY, true },
437 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
438 __start___kcrctab_unused_gpl,
443 module_assert_mutex_or_preempt();
445 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
448 list_for_each_entry_rcu(mod, &modules, list) {
449 struct symsearch arr[] = {
450 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
451 NOT_GPL_ONLY, false },
452 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
455 { mod->gpl_future_syms,
456 mod->gpl_future_syms + mod->num_gpl_future_syms,
457 mod->gpl_future_crcs,
458 WILL_BE_GPL_ONLY, false },
459 #ifdef CONFIG_UNUSED_SYMBOLS
461 mod->unused_syms + mod->num_unused_syms,
463 NOT_GPL_ONLY, true },
464 { mod->unused_gpl_syms,
465 mod->unused_gpl_syms + mod->num_unused_gpl_syms,
466 mod->unused_gpl_crcs,
471 if (mod->state == MODULE_STATE_UNFORMED)
474 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
479 EXPORT_SYMBOL_GPL(each_symbol_section);
481 struct find_symbol_arg {
488 struct module *owner;
490 const struct kernel_symbol *sym;
493 static bool check_symbol(const struct symsearch *syms,
494 struct module *owner,
495 unsigned int symnum, void *data)
497 struct find_symbol_arg *fsa = data;
500 if (syms->licence == GPL_ONLY)
502 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
503 pr_warn("Symbol %s is being used by a non-GPL module, "
504 "which will not be allowed in the future\n",
509 #ifdef CONFIG_UNUSED_SYMBOLS
510 if (syms->unused && fsa->warn) {
511 pr_warn("Symbol %s is marked as UNUSED, however this module is "
512 "using it.\n", fsa->name);
513 pr_warn("This symbol will go away in the future.\n");
514 pr_warn("Please evaluate if this is the right api to use and "
515 "if it really is, submit a report to the linux kernel "
516 "mailing list together with submitting your code for "
522 fsa->crc = symversion(syms->crcs, symnum);
523 fsa->sym = &syms->start[symnum];
527 static unsigned long kernel_symbol_value(const struct kernel_symbol *sym)
529 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
530 return (unsigned long)offset_to_ptr(&sym->value_offset);
536 static const char *kernel_symbol_name(const struct kernel_symbol *sym)
538 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
539 return offset_to_ptr(&sym->name_offset);
545 static int cmp_name(const void *va, const void *vb)
548 const struct kernel_symbol *b;
550 return strcmp(a, kernel_symbol_name(b));
553 static bool find_symbol_in_section(const struct symsearch *syms,
554 struct module *owner,
557 struct find_symbol_arg *fsa = data;
558 struct kernel_symbol *sym;
560 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
561 sizeof(struct kernel_symbol), cmp_name);
563 if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
569 /* Find a symbol and return it, along with, (optional) crc and
570 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
571 const struct kernel_symbol *find_symbol(const char *name,
572 struct module **owner,
577 struct find_symbol_arg fsa;
583 if (each_symbol_section(find_symbol_in_section, &fsa)) {
591 pr_debug("Failed to find symbol %s\n", name);
594 EXPORT_SYMBOL_GPL(find_symbol);
597 * Search for module by name: must hold module_mutex (or preempt disabled
598 * for read-only access).
600 static struct module *find_module_all(const char *name, size_t len,
605 module_assert_mutex_or_preempt();
607 list_for_each_entry_rcu(mod, &modules, list) {
608 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
610 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
616 struct module *find_module(const char *name)
618 module_assert_mutex();
619 return find_module_all(name, strlen(name), false);
621 EXPORT_SYMBOL_GPL(find_module);
625 static inline void __percpu *mod_percpu(struct module *mod)
630 static int percpu_modalloc(struct module *mod, struct load_info *info)
632 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
633 unsigned long align = pcpusec->sh_addralign;
635 if (!pcpusec->sh_size)
638 if (align > PAGE_SIZE) {
639 pr_warn("%s: per-cpu alignment %li > %li\n",
640 mod->name, align, PAGE_SIZE);
644 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
646 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
647 mod->name, (unsigned long)pcpusec->sh_size);
650 mod->percpu_size = pcpusec->sh_size;
654 static void percpu_modfree(struct module *mod)
656 free_percpu(mod->percpu);
659 static unsigned int find_pcpusec(struct load_info *info)
661 return find_sec(info, ".data..percpu");
664 static void percpu_modcopy(struct module *mod,
665 const void *from, unsigned long size)
669 for_each_possible_cpu(cpu)
670 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
673 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
680 list_for_each_entry_rcu(mod, &modules, list) {
681 if (mod->state == MODULE_STATE_UNFORMED)
683 if (!mod->percpu_size)
685 for_each_possible_cpu(cpu) {
686 void *start = per_cpu_ptr(mod->percpu, cpu);
687 void *va = (void *)addr;
689 if (va >= start && va < start + mod->percpu_size) {
691 *can_addr = (unsigned long) (va - start);
692 *can_addr += (unsigned long)
693 per_cpu_ptr(mod->percpu,
707 * is_module_percpu_address - test whether address is from module static percpu
708 * @addr: address to test
710 * Test whether @addr belongs to module static percpu area.
713 * %true if @addr is from module static percpu area
715 bool is_module_percpu_address(unsigned long addr)
717 return __is_module_percpu_address(addr, NULL);
720 #else /* ... !CONFIG_SMP */
722 static inline void __percpu *mod_percpu(struct module *mod)
726 static int percpu_modalloc(struct module *mod, struct load_info *info)
728 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
729 if (info->sechdrs[info->index.pcpu].sh_size != 0)
733 static inline void percpu_modfree(struct module *mod)
736 static unsigned int find_pcpusec(struct load_info *info)
740 static inline void percpu_modcopy(struct module *mod,
741 const void *from, unsigned long size)
743 /* pcpusec should be 0, and size of that section should be 0. */
746 bool is_module_percpu_address(unsigned long addr)
751 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
756 #endif /* CONFIG_SMP */
758 #define MODINFO_ATTR(field) \
759 static void setup_modinfo_##field(struct module *mod, const char *s) \
761 mod->field = kstrdup(s, GFP_KERNEL); \
763 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
764 struct module_kobject *mk, char *buffer) \
766 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
768 static int modinfo_##field##_exists(struct module *mod) \
770 return mod->field != NULL; \
772 static void free_modinfo_##field(struct module *mod) \
777 static struct module_attribute modinfo_##field = { \
778 .attr = { .name = __stringify(field), .mode = 0444 }, \
779 .show = show_modinfo_##field, \
780 .setup = setup_modinfo_##field, \
781 .test = modinfo_##field##_exists, \
782 .free = free_modinfo_##field, \
785 MODINFO_ATTR(version);
786 MODINFO_ATTR(srcversion);
788 static char last_unloaded_module[MODULE_NAME_LEN+1];
790 #ifdef CONFIG_MODULE_UNLOAD
792 EXPORT_TRACEPOINT_SYMBOL(module_get);
794 /* MODULE_REF_BASE is the base reference count by kmodule loader. */
795 #define MODULE_REF_BASE 1
797 /* Init the unload section of the module. */
798 static int module_unload_init(struct module *mod)
801 * Initialize reference counter to MODULE_REF_BASE.
802 * refcnt == 0 means module is going.
804 atomic_set(&mod->refcnt, MODULE_REF_BASE);
806 INIT_LIST_HEAD(&mod->source_list);
807 INIT_LIST_HEAD(&mod->target_list);
809 /* Hold reference count during initialization. */
810 atomic_inc(&mod->refcnt);
815 /* Does a already use b? */
816 static int already_uses(struct module *a, struct module *b)
818 struct module_use *use;
820 list_for_each_entry(use, &b->source_list, source_list) {
821 if (use->source == a) {
822 pr_debug("%s uses %s!\n", a->name, b->name);
826 pr_debug("%s does not use %s!\n", a->name, b->name);
832 * - we add 'a' as a "source", 'b' as a "target" of module use
833 * - the module_use is added to the list of 'b' sources (so
834 * 'b' can walk the list to see who sourced them), and of 'a'
835 * targets (so 'a' can see what modules it targets).
837 static int add_module_usage(struct module *a, struct module *b)
839 struct module_use *use;
841 pr_debug("Allocating new usage for %s.\n", a->name);
842 use = kmalloc(sizeof(*use), GFP_ATOMIC);
848 list_add(&use->source_list, &b->source_list);
849 list_add(&use->target_list, &a->target_list);
853 /* Module a uses b: caller needs module_mutex() */
854 int ref_module(struct module *a, struct module *b)
858 if (b == NULL || already_uses(a, b))
861 /* If module isn't available, we fail. */
862 err = strong_try_module_get(b);
866 err = add_module_usage(a, b);
873 EXPORT_SYMBOL_GPL(ref_module);
875 /* Clear the unload stuff of the module. */
876 static void module_unload_free(struct module *mod)
878 struct module_use *use, *tmp;
880 mutex_lock(&module_mutex);
881 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
882 struct module *i = use->target;
883 pr_debug("%s unusing %s\n", mod->name, i->name);
885 list_del(&use->source_list);
886 list_del(&use->target_list);
889 mutex_unlock(&module_mutex);
892 #ifdef CONFIG_MODULE_FORCE_UNLOAD
893 static inline int try_force_unload(unsigned int flags)
895 int ret = (flags & O_TRUNC);
897 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
901 static inline int try_force_unload(unsigned int flags)
905 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
907 /* Try to release refcount of module, 0 means success. */
908 static int try_release_module_ref(struct module *mod)
912 /* Try to decrement refcnt which we set at loading */
913 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
916 /* Someone can put this right now, recover with checking */
917 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
922 static int try_stop_module(struct module *mod, int flags, int *forced)
924 /* If it's not unused, quit unless we're forcing. */
925 if (try_release_module_ref(mod) != 0) {
926 *forced = try_force_unload(flags);
931 /* Mark it as dying. */
932 mod->state = MODULE_STATE_GOING;
938 * module_refcount - return the refcount or -1 if unloading
940 * @mod: the module we're checking
943 * -1 if the module is in the process of unloading
944 * otherwise the number of references in the kernel to the module
946 int module_refcount(struct module *mod)
948 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
950 EXPORT_SYMBOL(module_refcount);
952 /* This exists whether we can unload or not */
953 static void free_module(struct module *mod);
955 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
959 char name[MODULE_NAME_LEN];
962 if (!capable(CAP_SYS_MODULE) || modules_disabled)
965 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
967 name[MODULE_NAME_LEN-1] = '\0';
969 audit_log_kern_module(name);
971 if (mutex_lock_interruptible(&module_mutex) != 0)
974 mod = find_module(name);
980 if (!list_empty(&mod->source_list)) {
981 /* Other modules depend on us: get rid of them first. */
986 /* Doing init or already dying? */
987 if (mod->state != MODULE_STATE_LIVE) {
988 /* FIXME: if (force), slam module count damn the torpedoes */
989 pr_debug("%s already dying\n", mod->name);
994 /* If it has an init func, it must have an exit func to unload */
995 if (mod->init && !mod->exit) {
996 forced = try_force_unload(flags);
998 /* This module can't be removed */
1004 /* Stop the machine so refcounts can't move and disable module. */
1005 ret = try_stop_module(mod, flags, &forced);
1009 mutex_unlock(&module_mutex);
1010 /* Final destruction now no one is using it. */
1011 if (mod->exit != NULL)
1013 blocking_notifier_call_chain(&module_notify_list,
1014 MODULE_STATE_GOING, mod);
1015 klp_module_going(mod);
1016 ftrace_release_mod(mod);
1018 async_synchronize_full();
1020 /* Store the name of the last unloaded module for diagnostic purposes */
1021 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
1026 mutex_unlock(&module_mutex);
1030 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1032 struct module_use *use;
1033 int printed_something = 0;
1035 seq_printf(m, " %i ", module_refcount(mod));
1038 * Always include a trailing , so userspace can differentiate
1039 * between this and the old multi-field proc format.
1041 list_for_each_entry(use, &mod->source_list, source_list) {
1042 printed_something = 1;
1043 seq_printf(m, "%s,", use->source->name);
1046 if (mod->init != NULL && mod->exit == NULL) {
1047 printed_something = 1;
1048 seq_puts(m, "[permanent],");
1051 if (!printed_something)
1055 void __symbol_put(const char *symbol)
1057 struct module *owner;
1060 if (!find_symbol(symbol, &owner, NULL, true, false))
1065 EXPORT_SYMBOL(__symbol_put);
1067 /* Note this assumes addr is a function, which it currently always is. */
1068 void symbol_put_addr(void *addr)
1070 struct module *modaddr;
1071 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1073 if (core_kernel_text(a))
1077 * Even though we hold a reference on the module; we still need to
1078 * disable preemption in order to safely traverse the data structure.
1081 modaddr = __module_text_address(a);
1083 module_put(modaddr);
1086 EXPORT_SYMBOL_GPL(symbol_put_addr);
1088 static ssize_t show_refcnt(struct module_attribute *mattr,
1089 struct module_kobject *mk, char *buffer)
1091 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1094 static struct module_attribute modinfo_refcnt =
1095 __ATTR(refcnt, 0444, show_refcnt, NULL);
1097 void __module_get(struct module *module)
1101 atomic_inc(&module->refcnt);
1102 trace_module_get(module, _RET_IP_);
1106 EXPORT_SYMBOL(__module_get);
1108 bool try_module_get(struct module *module)
1114 /* Note: here, we can fail to get a reference */
1115 if (likely(module_is_live(module) &&
1116 atomic_inc_not_zero(&module->refcnt) != 0))
1117 trace_module_get(module, _RET_IP_);
1125 EXPORT_SYMBOL(try_module_get);
1127 void module_put(struct module *module)
1133 ret = atomic_dec_if_positive(&module->refcnt);
1134 WARN_ON(ret < 0); /* Failed to put refcount */
1135 trace_module_put(module, _RET_IP_);
1139 EXPORT_SYMBOL(module_put);
1141 #else /* !CONFIG_MODULE_UNLOAD */
1142 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1144 /* We don't know the usage count, or what modules are using. */
1145 seq_puts(m, " - -");
1148 static inline void module_unload_free(struct module *mod)
1152 int ref_module(struct module *a, struct module *b)
1154 return strong_try_module_get(b);
1156 EXPORT_SYMBOL_GPL(ref_module);
1158 static inline int module_unload_init(struct module *mod)
1162 #endif /* CONFIG_MODULE_UNLOAD */
1164 static size_t module_flags_taint(struct module *mod, char *buf)
1169 for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
1170 if (taint_flags[i].module && test_bit(i, &mod->taints))
1171 buf[l++] = taint_flags[i].c_true;
1177 static ssize_t show_initstate(struct module_attribute *mattr,
1178 struct module_kobject *mk, char *buffer)
1180 const char *state = "unknown";
1182 switch (mk->mod->state) {
1183 case MODULE_STATE_LIVE:
1186 case MODULE_STATE_COMING:
1189 case MODULE_STATE_GOING:
1195 return sprintf(buffer, "%s\n", state);
1198 static struct module_attribute modinfo_initstate =
1199 __ATTR(initstate, 0444, show_initstate, NULL);
1201 static ssize_t store_uevent(struct module_attribute *mattr,
1202 struct module_kobject *mk,
1203 const char *buffer, size_t count)
1207 rc = kobject_synth_uevent(&mk->kobj, buffer, count);
1208 return rc ? rc : count;
1211 struct module_attribute module_uevent =
1212 __ATTR(uevent, 0200, NULL, store_uevent);
1214 static ssize_t show_coresize(struct module_attribute *mattr,
1215 struct module_kobject *mk, char *buffer)
1217 return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1220 static struct module_attribute modinfo_coresize =
1221 __ATTR(coresize, 0444, show_coresize, NULL);
1223 static ssize_t show_initsize(struct module_attribute *mattr,
1224 struct module_kobject *mk, char *buffer)
1226 return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1229 static struct module_attribute modinfo_initsize =
1230 __ATTR(initsize, 0444, show_initsize, NULL);
1232 static ssize_t show_taint(struct module_attribute *mattr,
1233 struct module_kobject *mk, char *buffer)
1237 l = module_flags_taint(mk->mod, buffer);
1242 static struct module_attribute modinfo_taint =
1243 __ATTR(taint, 0444, show_taint, NULL);
1245 static struct module_attribute *modinfo_attrs[] = {
1248 &modinfo_srcversion,
1253 #ifdef CONFIG_MODULE_UNLOAD
1259 static const char vermagic[] = VERMAGIC_STRING;
1261 static int try_to_force_load(struct module *mod, const char *reason)
1263 #ifdef CONFIG_MODULE_FORCE_LOAD
1264 if (!test_taint(TAINT_FORCED_MODULE))
1265 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1266 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1273 #ifdef CONFIG_MODVERSIONS
1275 static u32 resolve_rel_crc(const s32 *crc)
1277 return *(u32 *)((void *)crc + *crc);
1280 static int check_version(const struct load_info *info,
1281 const char *symname,
1285 Elf_Shdr *sechdrs = info->sechdrs;
1286 unsigned int versindex = info->index.vers;
1287 unsigned int i, num_versions;
1288 struct modversion_info *versions;
1290 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1294 /* No versions at all? modprobe --force does this. */
1296 return try_to_force_load(mod, symname) == 0;
1298 versions = (void *) sechdrs[versindex].sh_addr;
1299 num_versions = sechdrs[versindex].sh_size
1300 / sizeof(struct modversion_info);
1302 for (i = 0; i < num_versions; i++) {
1305 if (strcmp(versions[i].name, symname) != 0)
1308 if (IS_ENABLED(CONFIG_MODULE_REL_CRCS))
1309 crcval = resolve_rel_crc(crc);
1312 if (versions[i].crc == crcval)
1314 pr_debug("Found checksum %X vs module %lX\n",
1315 crcval, versions[i].crc);
1319 /* Broken toolchain. Warn once, then let it go.. */
1320 pr_warn_once("%s: no symbol version for %s\n", info->name, symname);
1324 pr_warn("%s: disagrees about version of symbol %s\n",
1325 info->name, symname);
1329 static inline int check_modstruct_version(const struct load_info *info,
1335 * Since this should be found in kernel (which can't be removed), no
1336 * locking is necessary -- use preempt_disable() to placate lockdep.
1339 if (!find_symbol("module_layout", NULL, &crc, true, false)) {
1344 return check_version(info, "module_layout", mod, crc);
1347 /* First part is kernel version, which we ignore if module has crcs. */
1348 static inline int same_magic(const char *amagic, const char *bmagic,
1352 amagic += strcspn(amagic, " ");
1353 bmagic += strcspn(bmagic, " ");
1355 return strcmp(amagic, bmagic) == 0;
1358 static inline int check_version(const struct load_info *info,
1359 const char *symname,
1366 static inline int check_modstruct_version(const struct load_info *info,
1372 static inline int same_magic(const char *amagic, const char *bmagic,
1375 return strcmp(amagic, bmagic) == 0;
1377 #endif /* CONFIG_MODVERSIONS */
1379 /* Resolve a symbol for this module. I.e. if we find one, record usage. */
1380 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1381 const struct load_info *info,
1385 struct module *owner;
1386 const struct kernel_symbol *sym;
1391 * The module_mutex should not be a heavily contended lock;
1392 * if we get the occasional sleep here, we'll go an extra iteration
1393 * in the wait_event_interruptible(), which is harmless.
1395 sched_annotate_sleep();
1396 mutex_lock(&module_mutex);
1397 sym = find_symbol(name, &owner, &crc,
1398 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1402 if (!check_version(info, name, mod, crc)) {
1403 sym = ERR_PTR(-EINVAL);
1407 err = ref_module(mod, owner);
1414 /* We must make copy under the lock if we failed to get ref. */
1415 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1417 mutex_unlock(&module_mutex);
1421 static const struct kernel_symbol *
1422 resolve_symbol_wait(struct module *mod,
1423 const struct load_info *info,
1426 const struct kernel_symbol *ksym;
1427 char owner[MODULE_NAME_LEN];
1429 if (wait_event_interruptible_timeout(module_wq,
1430 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1431 || PTR_ERR(ksym) != -EBUSY,
1433 pr_warn("%s: gave up waiting for init of module %s.\n",
1440 * /sys/module/foo/sections stuff
1441 * J. Corbet <corbet@lwn.net>
1445 #ifdef CONFIG_KALLSYMS
1446 static inline bool sect_empty(const Elf_Shdr *sect)
1448 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1451 struct module_sect_attr {
1452 struct module_attribute mattr;
1454 unsigned long address;
1457 struct module_sect_attrs {
1458 struct attribute_group grp;
1459 unsigned int nsections;
1460 struct module_sect_attr attrs[0];
1463 static ssize_t module_sect_show(struct module_attribute *mattr,
1464 struct module_kobject *mk, char *buf)
1466 struct module_sect_attr *sattr =
1467 container_of(mattr, struct module_sect_attr, mattr);
1468 return sprintf(buf, "0x%px\n", kptr_restrict < 2 ?
1469 (void *)sattr->address : NULL);
1472 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1474 unsigned int section;
1476 for (section = 0; section < sect_attrs->nsections; section++)
1477 kfree(sect_attrs->attrs[section].name);
1481 static void add_sect_attrs(struct module *mod, const struct load_info *info)
1483 unsigned int nloaded = 0, i, size[2];
1484 struct module_sect_attrs *sect_attrs;
1485 struct module_sect_attr *sattr;
1486 struct attribute **gattr;
1488 /* Count loaded sections and allocate structures */
1489 for (i = 0; i < info->hdr->e_shnum; i++)
1490 if (!sect_empty(&info->sechdrs[i]))
1492 size[0] = ALIGN(sizeof(*sect_attrs)
1493 + nloaded * sizeof(sect_attrs->attrs[0]),
1494 sizeof(sect_attrs->grp.attrs[0]));
1495 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1496 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1497 if (sect_attrs == NULL)
1500 /* Setup section attributes. */
1501 sect_attrs->grp.name = "sections";
1502 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1504 sect_attrs->nsections = 0;
1505 sattr = §_attrs->attrs[0];
1506 gattr = §_attrs->grp.attrs[0];
1507 for (i = 0; i < info->hdr->e_shnum; i++) {
1508 Elf_Shdr *sec = &info->sechdrs[i];
1509 if (sect_empty(sec))
1511 sattr->address = sec->sh_addr;
1512 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1514 if (sattr->name == NULL)
1516 sect_attrs->nsections++;
1517 sysfs_attr_init(&sattr->mattr.attr);
1518 sattr->mattr.show = module_sect_show;
1519 sattr->mattr.store = NULL;
1520 sattr->mattr.attr.name = sattr->name;
1521 sattr->mattr.attr.mode = S_IRUSR;
1522 *(gattr++) = &(sattr++)->mattr.attr;
1526 if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp))
1529 mod->sect_attrs = sect_attrs;
1532 free_sect_attrs(sect_attrs);
1535 static void remove_sect_attrs(struct module *mod)
1537 if (mod->sect_attrs) {
1538 sysfs_remove_group(&mod->mkobj.kobj,
1539 &mod->sect_attrs->grp);
1540 /* We are positive that no one is using any sect attrs
1541 * at this point. Deallocate immediately. */
1542 free_sect_attrs(mod->sect_attrs);
1543 mod->sect_attrs = NULL;
1548 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1551 struct module_notes_attrs {
1552 struct kobject *dir;
1554 struct bin_attribute attrs[0];
1557 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1558 struct bin_attribute *bin_attr,
1559 char *buf, loff_t pos, size_t count)
1562 * The caller checked the pos and count against our size.
1564 memcpy(buf, bin_attr->private + pos, count);
1568 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1571 if (notes_attrs->dir) {
1573 sysfs_remove_bin_file(notes_attrs->dir,
1574 ¬es_attrs->attrs[i]);
1575 kobject_put(notes_attrs->dir);
1580 static void add_notes_attrs(struct module *mod, const struct load_info *info)
1582 unsigned int notes, loaded, i;
1583 struct module_notes_attrs *notes_attrs;
1584 struct bin_attribute *nattr;
1586 /* failed to create section attributes, so can't create notes */
1587 if (!mod->sect_attrs)
1590 /* Count notes sections and allocate structures. */
1592 for (i = 0; i < info->hdr->e_shnum; i++)
1593 if (!sect_empty(&info->sechdrs[i]) &&
1594 (info->sechdrs[i].sh_type == SHT_NOTE))
1600 notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes),
1602 if (notes_attrs == NULL)
1605 notes_attrs->notes = notes;
1606 nattr = ¬es_attrs->attrs[0];
1607 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1608 if (sect_empty(&info->sechdrs[i]))
1610 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1611 sysfs_bin_attr_init(nattr);
1612 nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1613 nattr->attr.mode = S_IRUGO;
1614 nattr->size = info->sechdrs[i].sh_size;
1615 nattr->private = (void *) info->sechdrs[i].sh_addr;
1616 nattr->read = module_notes_read;
1622 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1623 if (!notes_attrs->dir)
1626 for (i = 0; i < notes; ++i)
1627 if (sysfs_create_bin_file(notes_attrs->dir,
1628 ¬es_attrs->attrs[i]))
1631 mod->notes_attrs = notes_attrs;
1635 free_notes_attrs(notes_attrs, i);
1638 static void remove_notes_attrs(struct module *mod)
1640 if (mod->notes_attrs)
1641 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1646 static inline void add_sect_attrs(struct module *mod,
1647 const struct load_info *info)
1651 static inline void remove_sect_attrs(struct module *mod)
1655 static inline void add_notes_attrs(struct module *mod,
1656 const struct load_info *info)
1660 static inline void remove_notes_attrs(struct module *mod)
1663 #endif /* CONFIG_KALLSYMS */
1665 static void del_usage_links(struct module *mod)
1667 #ifdef CONFIG_MODULE_UNLOAD
1668 struct module_use *use;
1670 mutex_lock(&module_mutex);
1671 list_for_each_entry(use, &mod->target_list, target_list)
1672 sysfs_remove_link(use->target->holders_dir, mod->name);
1673 mutex_unlock(&module_mutex);
1677 static int add_usage_links(struct module *mod)
1680 #ifdef CONFIG_MODULE_UNLOAD
1681 struct module_use *use;
1683 mutex_lock(&module_mutex);
1684 list_for_each_entry(use, &mod->target_list, target_list) {
1685 ret = sysfs_create_link(use->target->holders_dir,
1686 &mod->mkobj.kobj, mod->name);
1690 mutex_unlock(&module_mutex);
1692 del_usage_links(mod);
1697 static void module_remove_modinfo_attrs(struct module *mod, int end);
1699 static int module_add_modinfo_attrs(struct module *mod)
1701 struct module_attribute *attr;
1702 struct module_attribute *temp_attr;
1706 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1707 (ARRAY_SIZE(modinfo_attrs) + 1)),
1709 if (!mod->modinfo_attrs)
1712 temp_attr = mod->modinfo_attrs;
1713 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1714 if (!attr->test || attr->test(mod)) {
1715 memcpy(temp_attr, attr, sizeof(*temp_attr));
1716 sysfs_attr_init(&temp_attr->attr);
1717 error = sysfs_create_file(&mod->mkobj.kobj,
1729 module_remove_modinfo_attrs(mod, --i);
1733 static void module_remove_modinfo_attrs(struct module *mod, int end)
1735 struct module_attribute *attr;
1738 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1739 if (end >= 0 && i > end)
1741 /* pick a field to test for end of list */
1742 if (!attr->attr.name)
1744 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1748 kfree(mod->modinfo_attrs);
1751 static void mod_kobject_put(struct module *mod)
1753 DECLARE_COMPLETION_ONSTACK(c);
1754 mod->mkobj.kobj_completion = &c;
1755 kobject_put(&mod->mkobj.kobj);
1756 wait_for_completion(&c);
1759 static int mod_sysfs_init(struct module *mod)
1762 struct kobject *kobj;
1764 if (!module_sysfs_initialized) {
1765 pr_err("%s: module sysfs not initialized\n", mod->name);
1770 kobj = kset_find_obj(module_kset, mod->name);
1772 pr_err("%s: module is already loaded\n", mod->name);
1778 mod->mkobj.mod = mod;
1780 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1781 mod->mkobj.kobj.kset = module_kset;
1782 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1785 mod_kobject_put(mod);
1787 /* delay uevent until full sysfs population */
1792 static int mod_sysfs_setup(struct module *mod,
1793 const struct load_info *info,
1794 struct kernel_param *kparam,
1795 unsigned int num_params)
1799 err = mod_sysfs_init(mod);
1803 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1804 if (!mod->holders_dir) {
1809 err = module_param_sysfs_setup(mod, kparam, num_params);
1811 goto out_unreg_holders;
1813 err = module_add_modinfo_attrs(mod);
1815 goto out_unreg_param;
1817 err = add_usage_links(mod);
1819 goto out_unreg_modinfo_attrs;
1821 add_sect_attrs(mod, info);
1822 add_notes_attrs(mod, info);
1824 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1827 out_unreg_modinfo_attrs:
1828 module_remove_modinfo_attrs(mod, -1);
1830 module_param_sysfs_remove(mod);
1832 kobject_put(mod->holders_dir);
1834 mod_kobject_put(mod);
1839 static void mod_sysfs_fini(struct module *mod)
1841 remove_notes_attrs(mod);
1842 remove_sect_attrs(mod);
1843 mod_kobject_put(mod);
1846 static void init_param_lock(struct module *mod)
1848 mutex_init(&mod->param_lock);
1850 #else /* !CONFIG_SYSFS */
1852 static int mod_sysfs_setup(struct module *mod,
1853 const struct load_info *info,
1854 struct kernel_param *kparam,
1855 unsigned int num_params)
1860 static void mod_sysfs_fini(struct module *mod)
1864 static void module_remove_modinfo_attrs(struct module *mod, int end)
1868 static void del_usage_links(struct module *mod)
1872 static void init_param_lock(struct module *mod)
1875 #endif /* CONFIG_SYSFS */
1877 static void mod_sysfs_teardown(struct module *mod)
1879 del_usage_links(mod);
1880 module_remove_modinfo_attrs(mod, -1);
1881 module_param_sysfs_remove(mod);
1882 kobject_put(mod->mkobj.drivers_dir);
1883 kobject_put(mod->holders_dir);
1884 mod_sysfs_fini(mod);
1887 #ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
1889 * LKM RO/NX protection: protect module's text/ro-data
1890 * from modification and any data from execution.
1892 * General layout of module is:
1893 * [text] [read-only-data] [ro-after-init] [writable data]
1894 * text_size -----^ ^ ^ ^
1895 * ro_size ------------------------| | |
1896 * ro_after_init_size -----------------------------| |
1897 * size -----------------------------------------------------------|
1899 * These values are always page-aligned (as is base)
1901 static void frob_text(const struct module_layout *layout,
1902 int (*set_memory)(unsigned long start, int num_pages))
1904 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1905 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1906 set_memory((unsigned long)layout->base,
1907 layout->text_size >> PAGE_SHIFT);
1910 #ifdef CONFIG_STRICT_MODULE_RWX
1911 static void frob_rodata(const struct module_layout *layout,
1912 int (*set_memory)(unsigned long start, int num_pages))
1914 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1915 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1916 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1917 set_memory((unsigned long)layout->base + layout->text_size,
1918 (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
1921 static void frob_ro_after_init(const struct module_layout *layout,
1922 int (*set_memory)(unsigned long start, int num_pages))
1924 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1925 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1926 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1927 set_memory((unsigned long)layout->base + layout->ro_size,
1928 (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
1931 static void frob_writable_data(const struct module_layout *layout,
1932 int (*set_memory)(unsigned long start, int num_pages))
1934 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1935 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1936 BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
1937 set_memory((unsigned long)layout->base + layout->ro_after_init_size,
1938 (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
1941 /* livepatching wants to disable read-only so it can frob module. */
1942 void module_disable_ro(const struct module *mod)
1944 if (!rodata_enabled)
1947 frob_text(&mod->core_layout, set_memory_rw);
1948 frob_rodata(&mod->core_layout, set_memory_rw);
1949 frob_ro_after_init(&mod->core_layout, set_memory_rw);
1950 frob_text(&mod->init_layout, set_memory_rw);
1951 frob_rodata(&mod->init_layout, set_memory_rw);
1954 void module_enable_ro(const struct module *mod, bool after_init)
1956 if (!rodata_enabled)
1959 frob_text(&mod->core_layout, set_memory_ro);
1961 frob_rodata(&mod->core_layout, set_memory_ro);
1962 frob_text(&mod->init_layout, set_memory_ro);
1963 frob_rodata(&mod->init_layout, set_memory_ro);
1966 frob_ro_after_init(&mod->core_layout, set_memory_ro);
1969 static void module_enable_nx(const struct module *mod)
1971 frob_rodata(&mod->core_layout, set_memory_nx);
1972 frob_ro_after_init(&mod->core_layout, set_memory_nx);
1973 frob_writable_data(&mod->core_layout, set_memory_nx);
1974 frob_rodata(&mod->init_layout, set_memory_nx);
1975 frob_writable_data(&mod->init_layout, set_memory_nx);
1978 static void module_disable_nx(const struct module *mod)
1980 frob_rodata(&mod->core_layout, set_memory_x);
1981 frob_ro_after_init(&mod->core_layout, set_memory_x);
1982 frob_writable_data(&mod->core_layout, set_memory_x);
1983 frob_rodata(&mod->init_layout, set_memory_x);
1984 frob_writable_data(&mod->init_layout, set_memory_x);
1987 /* Iterate through all modules and set each module's text as RW */
1988 void set_all_modules_text_rw(void)
1992 if (!rodata_enabled)
1995 mutex_lock(&module_mutex);
1996 list_for_each_entry_rcu(mod, &modules, list) {
1997 if (mod->state == MODULE_STATE_UNFORMED)
2000 frob_text(&mod->core_layout, set_memory_rw);
2001 frob_text(&mod->init_layout, set_memory_rw);
2003 mutex_unlock(&module_mutex);
2006 /* Iterate through all modules and set each module's text as RO */
2007 void set_all_modules_text_ro(void)
2011 if (!rodata_enabled)
2014 mutex_lock(&module_mutex);
2015 list_for_each_entry_rcu(mod, &modules, list) {
2017 * Ignore going modules since it's possible that ro
2018 * protection has already been disabled, otherwise we'll
2019 * run into protection faults at module deallocation.
2021 if (mod->state == MODULE_STATE_UNFORMED ||
2022 mod->state == MODULE_STATE_GOING)
2025 frob_text(&mod->core_layout, set_memory_ro);
2026 frob_text(&mod->init_layout, set_memory_ro);
2028 mutex_unlock(&module_mutex);
2031 static void disable_ro_nx(const struct module_layout *layout)
2033 if (rodata_enabled) {
2034 frob_text(layout, set_memory_rw);
2035 frob_rodata(layout, set_memory_rw);
2036 frob_ro_after_init(layout, set_memory_rw);
2038 frob_rodata(layout, set_memory_x);
2039 frob_ro_after_init(layout, set_memory_x);
2040 frob_writable_data(layout, set_memory_x);
2043 #else /* !CONFIG_STRICT_MODULE_RWX */
2044 static void disable_ro_nx(const struct module_layout *layout) { }
2045 static void module_enable_nx(const struct module *mod) { }
2046 static void module_disable_nx(const struct module *mod) { }
2047 #endif /* CONFIG_STRICT_MODULE_RWX */
2049 static void module_enable_x(const struct module *mod)
2051 frob_text(&mod->core_layout, set_memory_x);
2052 frob_text(&mod->init_layout, set_memory_x);
2054 #else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
2055 static void disable_ro_nx(const struct module_layout *layout) { }
2056 static void module_enable_nx(const struct module *mod) { }
2057 static void module_disable_nx(const struct module *mod) { }
2058 static void module_enable_x(const struct module *mod) { }
2059 #endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
2061 #ifdef CONFIG_LIVEPATCH
2063 * Persist Elf information about a module. Copy the Elf header,
2064 * section header table, section string table, and symtab section
2065 * index from info to mod->klp_info.
2067 static int copy_module_elf(struct module *mod, struct load_info *info)
2069 unsigned int size, symndx;
2072 size = sizeof(*mod->klp_info);
2073 mod->klp_info = kmalloc(size, GFP_KERNEL);
2074 if (mod->klp_info == NULL)
2078 size = sizeof(mod->klp_info->hdr);
2079 memcpy(&mod->klp_info->hdr, info->hdr, size);
2081 /* Elf section header table */
2082 size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
2083 mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL);
2084 if (mod->klp_info->sechdrs == NULL) {
2089 /* Elf section name string table */
2090 size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
2091 mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL);
2092 if (mod->klp_info->secstrings == NULL) {
2097 /* Elf symbol section index */
2098 symndx = info->index.sym;
2099 mod->klp_info->symndx = symndx;
2102 * For livepatch modules, core_kallsyms.symtab is a complete
2103 * copy of the original symbol table. Adjust sh_addr to point
2104 * to core_kallsyms.symtab since the copy of the symtab in module
2105 * init memory is freed at the end of do_init_module().
2107 mod->klp_info->sechdrs[symndx].sh_addr = \
2108 (unsigned long) mod->core_kallsyms.symtab;
2113 kfree(mod->klp_info->sechdrs);
2115 kfree(mod->klp_info);
2119 static void free_module_elf(struct module *mod)
2121 kfree(mod->klp_info->sechdrs);
2122 kfree(mod->klp_info->secstrings);
2123 kfree(mod->klp_info);
2125 #else /* !CONFIG_LIVEPATCH */
2126 static int copy_module_elf(struct module *mod, struct load_info *info)
2131 static void free_module_elf(struct module *mod)
2134 #endif /* CONFIG_LIVEPATCH */
2136 void __weak module_memfree(void *module_region)
2138 vfree(module_region);
2141 void __weak module_arch_cleanup(struct module *mod)
2145 void __weak module_arch_freeing_init(struct module *mod)
2149 /* Free a module, remove from lists, etc. */
2150 static void free_module(struct module *mod)
2152 trace_module_free(mod);
2154 mod_sysfs_teardown(mod);
2156 /* We leave it in list to prevent duplicate loads, but make sure
2157 * that noone uses it while it's being deconstructed. */
2158 mutex_lock(&module_mutex);
2159 mod->state = MODULE_STATE_UNFORMED;
2160 mutex_unlock(&module_mutex);
2162 /* Remove dynamic debug info */
2163 ddebug_remove_module(mod->name);
2165 /* Arch-specific cleanup. */
2166 module_arch_cleanup(mod);
2168 /* Module unload stuff */
2169 module_unload_free(mod);
2171 /* Free any allocated parameters. */
2172 destroy_params(mod->kp, mod->num_kp);
2174 if (is_livepatch_module(mod))
2175 free_module_elf(mod);
2177 /* Now we can delete it from the lists */
2178 mutex_lock(&module_mutex);
2179 /* Unlink carefully: kallsyms could be walking list. */
2180 list_del_rcu(&mod->list);
2181 mod_tree_remove(mod);
2182 /* Remove this module from bug list, this uses list_del_rcu */
2183 module_bug_cleanup(mod);
2184 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2185 synchronize_sched();
2186 mutex_unlock(&module_mutex);
2188 /* This may be empty, but that's OK */
2189 disable_ro_nx(&mod->init_layout);
2190 module_arch_freeing_init(mod);
2191 module_memfree(mod->init_layout.base);
2193 percpu_modfree(mod);
2195 /* Free lock-classes; relies on the preceding sync_rcu(). */
2196 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
2198 /* Finally, free the core (containing the module structure) */
2199 disable_ro_nx(&mod->core_layout);
2200 module_memfree(mod->core_layout.base);
2203 void *__symbol_get(const char *symbol)
2205 struct module *owner;
2206 const struct kernel_symbol *sym;
2209 sym = find_symbol(symbol, &owner, NULL, true, true);
2210 if (sym && strong_try_module_get(owner))
2214 return sym ? (void *)kernel_symbol_value(sym) : NULL;
2216 EXPORT_SYMBOL_GPL(__symbol_get);
2219 * Ensure that an exported symbol [global namespace] does not already exist
2220 * in the kernel or in some other module's exported symbol table.
2222 * You must hold the module_mutex.
2224 static int verify_export_symbols(struct module *mod)
2227 struct module *owner;
2228 const struct kernel_symbol *s;
2230 const struct kernel_symbol *sym;
2233 { mod->syms, mod->num_syms },
2234 { mod->gpl_syms, mod->num_gpl_syms },
2235 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2236 #ifdef CONFIG_UNUSED_SYMBOLS
2237 { mod->unused_syms, mod->num_unused_syms },
2238 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2242 for (i = 0; i < ARRAY_SIZE(arr); i++) {
2243 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2244 if (find_symbol(kernel_symbol_name(s), &owner, NULL,
2246 pr_err("%s: exports duplicate symbol %s"
2248 mod->name, kernel_symbol_name(s),
2249 module_name(owner));
2257 /* Change all symbols so that st_value encodes the pointer directly. */
2258 static int simplify_symbols(struct module *mod, const struct load_info *info)
2260 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2261 Elf_Sym *sym = (void *)symsec->sh_addr;
2262 unsigned long secbase;
2265 const struct kernel_symbol *ksym;
2267 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2268 const char *name = info->strtab + sym[i].st_name;
2270 switch (sym[i].st_shndx) {
2272 /* Ignore common symbols */
2273 if (!strncmp(name, "__gnu_lto", 9))
2276 /* We compiled with -fno-common. These are not
2277 supposed to happen. */
2278 pr_debug("Common symbol: %s\n", name);
2279 pr_warn("%s: please compile with -fno-common\n",
2285 /* Don't need to do anything */
2286 pr_debug("Absolute symbol: 0x%08lx\n",
2287 (long)sym[i].st_value);
2291 /* Livepatch symbols are resolved by livepatch */
2295 ksym = resolve_symbol_wait(mod, info, name);
2296 /* Ok if resolved. */
2297 if (ksym && !IS_ERR(ksym)) {
2298 sym[i].st_value = kernel_symbol_value(ksym);
2303 if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
2306 ret = PTR_ERR(ksym) ?: -ENOENT;
2307 pr_warn("%s: Unknown symbol %s (err %d)\n",
2308 mod->name, name, ret);
2312 /* Divert to percpu allocation if a percpu var. */
2313 if (sym[i].st_shndx == info->index.pcpu)
2314 secbase = (unsigned long)mod_percpu(mod);
2316 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2317 sym[i].st_value += secbase;
2325 static int apply_relocations(struct module *mod, const struct load_info *info)
2330 /* Now do relocations. */
2331 for (i = 1; i < info->hdr->e_shnum; i++) {
2332 unsigned int infosec = info->sechdrs[i].sh_info;
2334 /* Not a valid relocation section? */
2335 if (infosec >= info->hdr->e_shnum)
2338 /* Don't bother with non-allocated sections */
2339 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2342 /* Livepatch relocation sections are applied by livepatch */
2343 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
2346 if (info->sechdrs[i].sh_type == SHT_REL)
2347 err = apply_relocate(info->sechdrs, info->strtab,
2348 info->index.sym, i, mod);
2349 else if (info->sechdrs[i].sh_type == SHT_RELA)
2350 err = apply_relocate_add(info->sechdrs, info->strtab,
2351 info->index.sym, i, mod);
2358 /* Additional bytes needed by arch in front of individual sections */
2359 unsigned int __weak arch_mod_section_prepend(struct module *mod,
2360 unsigned int section)
2362 /* default implementation just returns zero */
2366 /* Update size with this section: return offset. */
2367 static long get_offset(struct module *mod, unsigned int *size,
2368 Elf_Shdr *sechdr, unsigned int section)
2372 *size += arch_mod_section_prepend(mod, section);
2373 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2374 *size = ret + sechdr->sh_size;
2378 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2379 might -- code, read-only data, read-write data, small data. Tally
2380 sizes, and place the offsets into sh_entsize fields: high bit means it
2382 static void layout_sections(struct module *mod, struct load_info *info)
2384 static unsigned long const masks[][2] = {
2385 /* NOTE: all executable code must be the first section
2386 * in this array; otherwise modify the text_size
2387 * finder in the two loops below */
2388 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2389 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2390 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
2391 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2392 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2396 for (i = 0; i < info->hdr->e_shnum; i++)
2397 info->sechdrs[i].sh_entsize = ~0UL;
2399 pr_debug("Core section allocation order:\n");
2400 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2401 for (i = 0; i < info->hdr->e_shnum; ++i) {
2402 Elf_Shdr *s = &info->sechdrs[i];
2403 const char *sname = info->secstrings + s->sh_name;
2405 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2406 || (s->sh_flags & masks[m][1])
2407 || s->sh_entsize != ~0UL
2408 || strstarts(sname, ".init"))
2410 s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2411 pr_debug("\t%s\n", sname);
2414 case 0: /* executable */
2415 mod->core_layout.size = debug_align(mod->core_layout.size);
2416 mod->core_layout.text_size = mod->core_layout.size;
2418 case 1: /* RO: text and ro-data */
2419 mod->core_layout.size = debug_align(mod->core_layout.size);
2420 mod->core_layout.ro_size = mod->core_layout.size;
2422 case 2: /* RO after init */
2423 mod->core_layout.size = debug_align(mod->core_layout.size);
2424 mod->core_layout.ro_after_init_size = mod->core_layout.size;
2426 case 4: /* whole core */
2427 mod->core_layout.size = debug_align(mod->core_layout.size);
2432 pr_debug("Init section allocation order:\n");
2433 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2434 for (i = 0; i < info->hdr->e_shnum; ++i) {
2435 Elf_Shdr *s = &info->sechdrs[i];
2436 const char *sname = info->secstrings + s->sh_name;
2438 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2439 || (s->sh_flags & masks[m][1])
2440 || s->sh_entsize != ~0UL
2441 || !strstarts(sname, ".init"))
2443 s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
2444 | INIT_OFFSET_MASK);
2445 pr_debug("\t%s\n", sname);
2448 case 0: /* executable */
2449 mod->init_layout.size = debug_align(mod->init_layout.size);
2450 mod->init_layout.text_size = mod->init_layout.size;
2452 case 1: /* RO: text and ro-data */
2453 mod->init_layout.size = debug_align(mod->init_layout.size);
2454 mod->init_layout.ro_size = mod->init_layout.size;
2458 * RO after init doesn't apply to init_layout (only
2459 * core_layout), so it just takes the value of ro_size.
2461 mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
2463 case 4: /* whole init */
2464 mod->init_layout.size = debug_align(mod->init_layout.size);
2470 static void set_license(struct module *mod, const char *license)
2473 license = "unspecified";
2475 if (!license_is_gpl_compatible(license)) {
2476 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2477 pr_warn("%s: module license '%s' taints kernel.\n",
2478 mod->name, license);
2479 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2480 LOCKDEP_NOW_UNRELIABLE);
2484 /* Parse tag=value strings from .modinfo section */
2485 static char *next_string(char *string, unsigned long *secsize)
2487 /* Skip non-zero chars */
2490 if ((*secsize)-- <= 1)
2494 /* Skip any zero padding. */
2495 while (!string[0]) {
2497 if ((*secsize)-- <= 1)
2503 static char *get_modinfo(struct load_info *info, const char *tag)
2506 unsigned int taglen = strlen(tag);
2507 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2508 unsigned long size = infosec->sh_size;
2511 * get_modinfo() calls made before rewrite_section_headers()
2512 * must use sh_offset, as sh_addr isn't set!
2514 for (p = (char *)info->hdr + infosec->sh_offset; p; p = next_string(p, &size)) {
2515 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2516 return p + taglen + 1;
2521 static void setup_modinfo(struct module *mod, struct load_info *info)
2523 struct module_attribute *attr;
2526 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2528 attr->setup(mod, get_modinfo(info, attr->attr.name));
2532 static void free_modinfo(struct module *mod)
2534 struct module_attribute *attr;
2537 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2543 #ifdef CONFIG_KALLSYMS
2545 /* lookup symbol in given range of kernel_symbols */
2546 static const struct kernel_symbol *lookup_symbol(const char *name,
2547 const struct kernel_symbol *start,
2548 const struct kernel_symbol *stop)
2550 return bsearch(name, start, stop - start,
2551 sizeof(struct kernel_symbol), cmp_name);
2554 static int is_exported(const char *name, unsigned long value,
2555 const struct module *mod)
2557 const struct kernel_symbol *ks;
2559 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2561 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2562 return ks != NULL && kernel_symbol_value(ks) == value;
2566 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2568 const Elf_Shdr *sechdrs = info->sechdrs;
2570 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2571 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2576 if (sym->st_shndx == SHN_UNDEF)
2578 if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
2580 if (sym->st_shndx >= SHN_LORESERVE)
2582 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2584 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2585 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2586 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2588 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2593 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2594 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2599 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2606 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2607 unsigned int shnum, unsigned int pcpundx)
2609 const Elf_Shdr *sec;
2611 if (src->st_shndx == SHN_UNDEF
2612 || src->st_shndx >= shnum
2616 #ifdef CONFIG_KALLSYMS_ALL
2617 if (src->st_shndx == pcpundx)
2621 sec = sechdrs + src->st_shndx;
2622 if (!(sec->sh_flags & SHF_ALLOC)
2623 #ifndef CONFIG_KALLSYMS_ALL
2624 || !(sec->sh_flags & SHF_EXECINSTR)
2626 || (sec->sh_entsize & INIT_OFFSET_MASK))
2633 * We only allocate and copy the strings needed by the parts of symtab
2634 * we keep. This is simple, but has the effect of making multiple
2635 * copies of duplicates. We could be more sophisticated, see
2636 * linux-kernel thread starting with
2637 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2639 static void layout_symtab(struct module *mod, struct load_info *info)
2641 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2642 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2644 unsigned int i, nsrc, ndst, strtab_size = 0;
2646 /* Put symbol section at end of init part of module. */
2647 symsect->sh_flags |= SHF_ALLOC;
2648 symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2649 info->index.sym) | INIT_OFFSET_MASK;
2650 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2652 src = (void *)info->hdr + symsect->sh_offset;
2653 nsrc = symsect->sh_size / sizeof(*src);
2655 /* Compute total space required for the core symbols' strtab. */
2656 for (ndst = i = 0; i < nsrc; i++) {
2657 if (i == 0 || is_livepatch_module(mod) ||
2658 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2659 info->index.pcpu)) {
2660 strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2665 /* Append room for core symbols at end of core part. */
2666 info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
2667 info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
2668 mod->core_layout.size += strtab_size;
2669 mod->core_layout.size = debug_align(mod->core_layout.size);
2671 /* Put string table section at end of init part of module. */
2672 strsect->sh_flags |= SHF_ALLOC;
2673 strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2674 info->index.str) | INIT_OFFSET_MASK;
2675 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2677 /* We'll tack temporary mod_kallsyms on the end. */
2678 mod->init_layout.size = ALIGN(mod->init_layout.size,
2679 __alignof__(struct mod_kallsyms));
2680 info->mod_kallsyms_init_off = mod->init_layout.size;
2681 mod->init_layout.size += sizeof(struct mod_kallsyms);
2682 mod->init_layout.size = debug_align(mod->init_layout.size);
2686 * We use the full symtab and strtab which layout_symtab arranged to
2687 * be appended to the init section. Later we switch to the cut-down
2690 static void add_kallsyms(struct module *mod, const struct load_info *info)
2692 unsigned int i, ndst;
2696 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2698 /* Set up to point into init section. */
2699 mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
2701 mod->kallsyms->symtab = (void *)symsec->sh_addr;
2702 mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2703 /* Make sure we get permanent strtab: don't use info->strtab. */
2704 mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2706 /* Set types up while we still have access to sections. */
2707 for (i = 0; i < mod->kallsyms->num_symtab; i++)
2708 mod->kallsyms->symtab[i].st_info
2709 = elf_type(&mod->kallsyms->symtab[i], info);
2711 /* Now populate the cut down core kallsyms for after init. */
2712 mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
2713 mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
2714 src = mod->kallsyms->symtab;
2715 for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2716 if (i == 0 || is_livepatch_module(mod) ||
2717 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2718 info->index.pcpu)) {
2720 dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
2721 s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2725 mod->core_kallsyms.num_symtab = ndst;
2728 static inline void layout_symtab(struct module *mod, struct load_info *info)
2732 static void add_kallsyms(struct module *mod, const struct load_info *info)
2735 #endif /* CONFIG_KALLSYMS */
2737 static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num)
2741 #ifdef CONFIG_DYNAMIC_DEBUG
2742 if (ddebug_add_module(debug, num, mod->name))
2743 pr_err("dynamic debug error adding module: %s\n",
2748 static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug)
2751 ddebug_remove_module(mod->name);
2754 void * __weak module_alloc(unsigned long size)
2756 return vmalloc_exec(size);
2759 #ifdef CONFIG_DEBUG_KMEMLEAK
2760 static void kmemleak_load_module(const struct module *mod,
2761 const struct load_info *info)
2765 /* only scan the sections containing data */
2766 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2768 for (i = 1; i < info->hdr->e_shnum; i++) {
2769 /* Scan all writable sections that's not executable */
2770 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2771 !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2772 (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2775 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2776 info->sechdrs[i].sh_size, GFP_KERNEL);
2780 static inline void kmemleak_load_module(const struct module *mod,
2781 const struct load_info *info)
2786 #ifdef CONFIG_MODULE_SIG
2787 static int module_sig_check(struct load_info *info, int flags)
2790 const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2791 const void *mod = info->hdr;
2794 * Require flags == 0, as a module with version information
2795 * removed is no longer the module that was signed
2798 info->len > markerlen &&
2799 memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2800 /* We truncate the module to discard the signature */
2801 info->len -= markerlen;
2802 err = mod_verify_sig(mod, info);
2806 info->sig_ok = true;
2810 /* Not having a signature is only an error if we're strict. */
2811 if (err == -ENOKEY && !is_module_sig_enforced())
2816 #else /* !CONFIG_MODULE_SIG */
2817 static int module_sig_check(struct load_info *info, int flags)
2821 #endif /* !CONFIG_MODULE_SIG */
2823 /* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2824 static int elf_header_check(struct load_info *info)
2826 if (info->len < sizeof(*(info->hdr)))
2829 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2830 || info->hdr->e_type != ET_REL
2831 || !elf_check_arch(info->hdr)
2832 || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2835 if (info->hdr->e_shoff >= info->len
2836 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2837 info->len - info->hdr->e_shoff))
2843 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2845 static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
2848 unsigned long n = min(len, COPY_CHUNK_SIZE);
2850 if (copy_from_user(dst, usrc, n) != 0)
2860 #ifdef CONFIG_LIVEPATCH
2861 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2863 if (get_modinfo(info, "livepatch")) {
2865 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
2866 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
2872 #else /* !CONFIG_LIVEPATCH */
2873 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2875 if (get_modinfo(info, "livepatch")) {
2876 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
2883 #endif /* CONFIG_LIVEPATCH */
2885 static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
2887 if (retpoline_module_ok(get_modinfo(info, "retpoline")))
2890 pr_warn("%s: loading module not compiled with retpoline compiler.\n",
2894 /* Sets info->hdr and info->len. */
2895 static int copy_module_from_user(const void __user *umod, unsigned long len,
2896 struct load_info *info)
2901 if (info->len < sizeof(*(info->hdr)))
2904 err = security_kernel_load_data(LOADING_MODULE);
2908 /* Suck in entire file: we'll want most of it. */
2909 info->hdr = __vmalloc(info->len,
2910 GFP_KERNEL | __GFP_NOWARN, PAGE_KERNEL);
2914 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2922 static void free_copy(struct load_info *info)
2927 static int rewrite_section_headers(struct load_info *info, int flags)
2931 /* This should always be true, but let's be sure. */
2932 info->sechdrs[0].sh_addr = 0;
2934 for (i = 1; i < info->hdr->e_shnum; i++) {
2935 Elf_Shdr *shdr = &info->sechdrs[i];
2936 if (shdr->sh_type != SHT_NOBITS
2937 && info->len < shdr->sh_offset + shdr->sh_size) {
2938 pr_err("Module len %lu truncated\n", info->len);
2942 /* Mark all sections sh_addr with their address in the
2944 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2946 #ifndef CONFIG_MODULE_UNLOAD
2947 /* Don't load .exit sections */
2948 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2949 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2953 /* Track but don't keep modinfo and version sections. */
2954 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2955 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2961 * Set up our basic convenience variables (pointers to section headers,
2962 * search for module section index etc), and do some basic section
2965 * Set info->mod to the temporary copy of the module in info->hdr. The final one
2966 * will be allocated in move_module().
2968 static int setup_load_info(struct load_info *info, int flags)
2972 /* Set up the convenience variables */
2973 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2974 info->secstrings = (void *)info->hdr
2975 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2977 /* Try to find a name early so we can log errors with a module name */
2978 info->index.info = find_sec(info, ".modinfo");
2979 if (!info->index.info)
2980 info->name = "(missing .modinfo section)";
2982 info->name = get_modinfo(info, "name");
2984 /* Find internal symbols and strings. */
2985 for (i = 1; i < info->hdr->e_shnum; i++) {
2986 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2987 info->index.sym = i;
2988 info->index.str = info->sechdrs[i].sh_link;
2989 info->strtab = (char *)info->hdr
2990 + info->sechdrs[info->index.str].sh_offset;
2995 if (info->index.sym == 0) {
2996 pr_warn("%s: module has no symbols (stripped?)\n", info->name);
3000 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
3001 if (!info->index.mod) {
3002 pr_warn("%s: No module found in object\n",
3003 info->name ?: "(missing .modinfo name field)");
3006 /* This is temporary: point mod into copy of data. */
3007 info->mod = (void *)info->hdr + info->sechdrs[info->index.mod].sh_offset;
3010 * If we didn't load the .modinfo 'name' field earlier, fall back to
3011 * on-disk struct mod 'name' field.
3014 info->name = info->mod->name;
3016 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
3017 info->index.vers = 0; /* Pretend no __versions section! */
3019 info->index.vers = find_sec(info, "__versions");
3021 info->index.pcpu = find_pcpusec(info);
3026 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
3028 const char *modmagic = get_modinfo(info, "vermagic");
3031 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
3034 /* This is allowed: modprobe --force will invalidate it. */
3036 err = try_to_force_load(mod, "bad vermagic");
3039 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
3040 pr_err("%s: version magic '%s' should be '%s'\n",
3041 info->name, modmagic, vermagic);
3045 if (!get_modinfo(info, "intree")) {
3046 if (!test_taint(TAINT_OOT_MODULE))
3047 pr_warn("%s: loading out-of-tree module taints kernel.\n",
3049 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
3052 check_modinfo_retpoline(mod, info);
3054 if (get_modinfo(info, "staging")) {
3055 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
3056 pr_warn("%s: module is from the staging directory, the quality "
3057 "is unknown, you have been warned.\n", mod->name);
3060 err = check_modinfo_livepatch(mod, info);
3064 /* Set up license info based on the info section */
3065 set_license(mod, get_modinfo(info, "license"));
3070 static int find_module_sections(struct module *mod, struct load_info *info)
3072 mod->kp = section_objs(info, "__param",
3073 sizeof(*mod->kp), &mod->num_kp);
3074 mod->syms = section_objs(info, "__ksymtab",
3075 sizeof(*mod->syms), &mod->num_syms);
3076 mod->crcs = section_addr(info, "__kcrctab");
3077 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
3078 sizeof(*mod->gpl_syms),
3079 &mod->num_gpl_syms);
3080 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
3081 mod->gpl_future_syms = section_objs(info,
3082 "__ksymtab_gpl_future",
3083 sizeof(*mod->gpl_future_syms),
3084 &mod->num_gpl_future_syms);
3085 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
3087 #ifdef CONFIG_UNUSED_SYMBOLS
3088 mod->unused_syms = section_objs(info, "__ksymtab_unused",
3089 sizeof(*mod->unused_syms),
3090 &mod->num_unused_syms);
3091 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
3092 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
3093 sizeof(*mod->unused_gpl_syms),
3094 &mod->num_unused_gpl_syms);
3095 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
3097 #ifdef CONFIG_CONSTRUCTORS
3098 mod->ctors = section_objs(info, ".ctors",
3099 sizeof(*mod->ctors), &mod->num_ctors);
3101 mod->ctors = section_objs(info, ".init_array",
3102 sizeof(*mod->ctors), &mod->num_ctors);
3103 else if (find_sec(info, ".init_array")) {
3105 * This shouldn't happen with same compiler and binutils
3106 * building all parts of the module.
3108 pr_warn("%s: has both .ctors and .init_array.\n",
3114 #ifdef CONFIG_TRACEPOINTS
3115 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
3116 sizeof(*mod->tracepoints_ptrs),
3117 &mod->num_tracepoints);
3119 #ifdef CONFIG_JUMP_LABEL
3120 mod->jump_entries = section_objs(info, "__jump_table",
3121 sizeof(*mod->jump_entries),
3122 &mod->num_jump_entries);
3124 #ifdef CONFIG_EVENT_TRACING
3125 mod->trace_events = section_objs(info, "_ftrace_events",
3126 sizeof(*mod->trace_events),
3127 &mod->num_trace_events);
3128 mod->trace_evals = section_objs(info, "_ftrace_eval_map",
3129 sizeof(*mod->trace_evals),
3130 &mod->num_trace_evals);
3132 #ifdef CONFIG_TRACING
3133 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
3134 sizeof(*mod->trace_bprintk_fmt_start),
3135 &mod->num_trace_bprintk_fmt);
3137 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
3138 /* sechdrs[0].sh_size is always zero */
3139 mod->ftrace_callsites = section_objs(info, "__mcount_loc",
3140 sizeof(*mod->ftrace_callsites),
3141 &mod->num_ftrace_callsites);
3143 #ifdef CONFIG_FUNCTION_ERROR_INJECTION
3144 mod->ei_funcs = section_objs(info, "_error_injection_whitelist",
3145 sizeof(*mod->ei_funcs),
3146 &mod->num_ei_funcs);
3148 mod->extable = section_objs(info, "__ex_table",
3149 sizeof(*mod->extable), &mod->num_exentries);
3151 if (section_addr(info, "__obsparm"))
3152 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
3154 info->debug = section_objs(info, "__verbose",
3155 sizeof(*info->debug), &info->num_debug);
3160 static int move_module(struct module *mod, struct load_info *info)
3165 /* Do the allocs. */
3166 ptr = module_alloc(mod->core_layout.size);
3168 * The pointer to this block is stored in the module structure
3169 * which is inside the block. Just mark it as not being a
3172 kmemleak_not_leak(ptr);
3176 memset(ptr, 0, mod->core_layout.size);
3177 mod->core_layout.base = ptr;
3179 if (mod->init_layout.size) {
3180 ptr = module_alloc(mod->init_layout.size);
3182 * The pointer to this block is stored in the module structure
3183 * which is inside the block. This block doesn't need to be
3184 * scanned as it contains data and code that will be freed
3185 * after the module is initialized.
3187 kmemleak_ignore(ptr);
3189 module_memfree(mod->core_layout.base);
3192 memset(ptr, 0, mod->init_layout.size);
3193 mod->init_layout.base = ptr;
3195 mod->init_layout.base = NULL;
3197 /* Transfer each section which specifies SHF_ALLOC */
3198 pr_debug("final section addresses:\n");
3199 for (i = 0; i < info->hdr->e_shnum; i++) {
3201 Elf_Shdr *shdr = &info->sechdrs[i];
3203 if (!(shdr->sh_flags & SHF_ALLOC))
3206 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3207 dest = mod->init_layout.base
3208 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3210 dest = mod->core_layout.base + shdr->sh_entsize;
3212 if (shdr->sh_type != SHT_NOBITS)
3213 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3214 /* Update sh_addr to point to copy in image. */
3215 shdr->sh_addr = (unsigned long)dest;
3216 pr_debug("\t0x%lx %s\n",
3217 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3223 static int check_module_license_and_versions(struct module *mod)
3225 int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
3228 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3229 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3230 * using GPL-only symbols it needs.
3232 if (strcmp(mod->name, "ndiswrapper") == 0)
3233 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3235 /* driverloader was caught wrongly pretending to be under GPL */
3236 if (strcmp(mod->name, "driverloader") == 0)
3237 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3238 LOCKDEP_NOW_UNRELIABLE);
3240 /* lve claims to be GPL but upstream won't provide source */
3241 if (strcmp(mod->name, "lve") == 0)
3242 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3243 LOCKDEP_NOW_UNRELIABLE);
3245 if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
3246 pr_warn("%s: module license taints kernel.\n", mod->name);
3248 #ifdef CONFIG_MODVERSIONS
3249 if ((mod->num_syms && !mod->crcs)
3250 || (mod->num_gpl_syms && !mod->gpl_crcs)
3251 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3252 #ifdef CONFIG_UNUSED_SYMBOLS
3253 || (mod->num_unused_syms && !mod->unused_crcs)
3254 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3257 return try_to_force_load(mod,
3258 "no versions for exported symbols");
3264 static void flush_module_icache(const struct module *mod)
3266 mm_segment_t old_fs;
3268 /* flush the icache in correct context */
3273 * Flush the instruction cache, since we've played with text.
3274 * Do it before processing of module parameters, so the module
3275 * can provide parameter accessor functions of its own.
3277 if (mod->init_layout.base)
3278 flush_icache_range((unsigned long)mod->init_layout.base,
3279 (unsigned long)mod->init_layout.base
3280 + mod->init_layout.size);
3281 flush_icache_range((unsigned long)mod->core_layout.base,
3282 (unsigned long)mod->core_layout.base + mod->core_layout.size);
3287 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3295 /* module_blacklist is a comma-separated list of module names */
3296 static char *module_blacklist;
3297 static bool blacklisted(const char *module_name)
3302 if (!module_blacklist)
3305 for (p = module_blacklist; *p; p += len) {
3306 len = strcspn(p, ",");
3307 if (strlen(module_name) == len && !memcmp(module_name, p, len))
3314 core_param(module_blacklist, module_blacklist, charp, 0400);
3316 static struct module *layout_and_allocate(struct load_info *info, int flags)
3322 err = check_modinfo(info->mod, info, flags);
3324 return ERR_PTR(err);
3326 /* Allow arches to frob section contents and sizes. */
3327 err = module_frob_arch_sections(info->hdr, info->sechdrs,
3328 info->secstrings, info->mod);
3330 return ERR_PTR(err);
3332 /* We will do a special allocation for per-cpu sections later. */
3333 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3336 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3337 * layout_sections() can put it in the right place.
3338 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3340 ndx = find_sec(info, ".data..ro_after_init");
3342 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3344 /* Determine total sizes, and put offsets in sh_entsize. For now
3345 this is done generically; there doesn't appear to be any
3346 special cases for the architectures. */
3347 layout_sections(info->mod, info);
3348 layout_symtab(info->mod, info);
3350 /* Allocate and move to the final place */
3351 err = move_module(info->mod, info);
3353 return ERR_PTR(err);
3355 /* Module has been copied to its final place now: return it. */
3356 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3357 kmemleak_load_module(mod, info);
3361 /* mod is no longer valid after this! */
3362 static void module_deallocate(struct module *mod, struct load_info *info)
3364 percpu_modfree(mod);
3365 module_arch_freeing_init(mod);
3366 module_memfree(mod->init_layout.base);
3367 module_memfree(mod->core_layout.base);
3370 int __weak module_finalize(const Elf_Ehdr *hdr,
3371 const Elf_Shdr *sechdrs,
3377 static int post_relocation(struct module *mod, const struct load_info *info)
3379 /* Sort exception table now relocations are done. */
3380 sort_extable(mod->extable, mod->extable + mod->num_exentries);
3382 /* Copy relocated percpu area over. */
3383 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3384 info->sechdrs[info->index.pcpu].sh_size);
3386 /* Setup kallsyms-specific fields. */
3387 add_kallsyms(mod, info);
3389 /* Arch-specific module finalizing. */
3390 return module_finalize(info->hdr, info->sechdrs, mod);
3393 /* Is this module of this name done loading? No locks held. */
3394 static bool finished_loading(const char *name)
3400 * The module_mutex should not be a heavily contended lock;
3401 * if we get the occasional sleep here, we'll go an extra iteration
3402 * in the wait_event_interruptible(), which is harmless.
3404 sched_annotate_sleep();
3405 mutex_lock(&module_mutex);
3406 mod = find_module_all(name, strlen(name), true);
3407 ret = !mod || mod->state == MODULE_STATE_LIVE;
3408 mutex_unlock(&module_mutex);
3413 /* Call module constructors. */
3414 static void do_mod_ctors(struct module *mod)
3416 #ifdef CONFIG_CONSTRUCTORS
3419 for (i = 0; i < mod->num_ctors; i++)
3424 /* For freeing module_init on success, in case kallsyms traversing */
3425 struct mod_initfree {
3426 struct rcu_head rcu;
3430 static void do_free_init(struct rcu_head *head)
3432 struct mod_initfree *m = container_of(head, struct mod_initfree, rcu);
3433 module_memfree(m->module_init);
3438 * This is where the real work happens.
3440 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3441 * helper command 'lx-symbols'.
3443 static noinline int do_init_module(struct module *mod)
3446 struct mod_initfree *freeinit;
3448 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3453 freeinit->module_init = mod->init_layout.base;
3456 * We want to find out whether @mod uses async during init. Clear
3457 * PF_USED_ASYNC. async_schedule*() will set it.
3459 current->flags &= ~PF_USED_ASYNC;
3462 /* Start the module */
3463 if (mod->init != NULL)
3464 ret = do_one_initcall(mod->init);
3466 goto fail_free_freeinit;
3469 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3470 "follow 0/-E convention\n"
3471 "%s: loading module anyway...\n",
3472 __func__, mod->name, ret, __func__);
3476 /* Now it's a first class citizen! */
3477 mod->state = MODULE_STATE_LIVE;
3478 blocking_notifier_call_chain(&module_notify_list,
3479 MODULE_STATE_LIVE, mod);
3482 * We need to finish all async code before the module init sequence
3483 * is done. This has potential to deadlock. For example, a newly
3484 * detected block device can trigger request_module() of the
3485 * default iosched from async probing task. Once userland helper
3486 * reaches here, async_synchronize_full() will wait on the async
3487 * task waiting on request_module() and deadlock.
3489 * This deadlock is avoided by perfomring async_synchronize_full()
3490 * iff module init queued any async jobs. This isn't a full
3491 * solution as it will deadlock the same if module loading from
3492 * async jobs nests more than once; however, due to the various
3493 * constraints, this hack seems to be the best option for now.
3494 * Please refer to the following thread for details.
3496 * http://thread.gmane.org/gmane.linux.kernel/1420814
3498 if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3499 async_synchronize_full();
3501 ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base +
3502 mod->init_layout.size);
3503 mutex_lock(&module_mutex);
3504 /* Drop initial reference. */
3506 trim_init_extable(mod);
3507 #ifdef CONFIG_KALLSYMS
3508 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3509 rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3511 module_enable_ro(mod, true);
3512 mod_tree_remove_init(mod);
3513 disable_ro_nx(&mod->init_layout);
3514 module_arch_freeing_init(mod);
3515 mod->init_layout.base = NULL;
3516 mod->init_layout.size = 0;
3517 mod->init_layout.ro_size = 0;
3518 mod->init_layout.ro_after_init_size = 0;
3519 mod->init_layout.text_size = 0;
3521 * We want to free module_init, but be aware that kallsyms may be
3522 * walking this with preempt disabled. In all the failure paths, we
3523 * call synchronize_sched(), but we don't want to slow down the success
3524 * path, so use actual RCU here.
3525 * Note that module_alloc() on most architectures creates W+X page
3526 * mappings which won't be cleaned up until do_free_init() runs. Any
3527 * code such as mark_rodata_ro() which depends on those mappings to
3528 * be cleaned up needs to sync with the queued work - ie
3529 * rcu_barrier_sched()
3531 call_rcu_sched(&freeinit->rcu, do_free_init);
3532 mutex_unlock(&module_mutex);
3533 wake_up_all(&module_wq);
3540 /* Try to protect us from buggy refcounters. */
3541 mod->state = MODULE_STATE_GOING;
3542 synchronize_sched();
3544 blocking_notifier_call_chain(&module_notify_list,
3545 MODULE_STATE_GOING, mod);
3546 klp_module_going(mod);
3547 ftrace_release_mod(mod);
3549 wake_up_all(&module_wq);
3553 static int may_init_module(void)
3555 if (!capable(CAP_SYS_MODULE) || modules_disabled)
3562 * We try to place it in the list now to make sure it's unique before
3563 * we dedicate too many resources. In particular, temporary percpu
3564 * memory exhaustion.
3566 static int add_unformed_module(struct module *mod)
3571 mod->state = MODULE_STATE_UNFORMED;
3574 mutex_lock(&module_mutex);
3575 old = find_module_all(mod->name, strlen(mod->name), true);
3577 if (old->state != MODULE_STATE_LIVE) {
3578 /* Wait in case it fails to load. */
3579 mutex_unlock(&module_mutex);
3580 err = wait_event_interruptible(module_wq,
3581 finished_loading(mod->name));
3589 mod_update_bounds(mod);
3590 list_add_rcu(&mod->list, &modules);
3591 mod_tree_insert(mod);
3595 mutex_unlock(&module_mutex);
3600 static int complete_formation(struct module *mod, struct load_info *info)
3604 mutex_lock(&module_mutex);
3606 /* Find duplicate symbols (must be called under lock). */
3607 err = verify_export_symbols(mod);
3611 /* This relies on module_mutex for list integrity. */
3612 module_bug_finalize(info->hdr, info->sechdrs, mod);
3614 module_enable_ro(mod, false);
3615 module_enable_nx(mod);
3616 module_enable_x(mod);
3618 /* Mark state as coming so strong_try_module_get() ignores us,
3619 * but kallsyms etc. can see us. */
3620 mod->state = MODULE_STATE_COMING;
3621 mutex_unlock(&module_mutex);
3626 mutex_unlock(&module_mutex);
3630 static int prepare_coming_module(struct module *mod)
3634 ftrace_module_enable(mod);
3635 err = klp_module_coming(mod);
3639 blocking_notifier_call_chain(&module_notify_list,
3640 MODULE_STATE_COMING, mod);
3644 static int unknown_module_param_cb(char *param, char *val, const char *modname,
3647 struct module *mod = arg;
3650 if (strcmp(param, "async_probe") == 0) {
3651 mod->async_probe_requested = true;
3655 /* Check for magic 'dyndbg' arg */
3656 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3658 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3662 /* Allocate and load the module: note that size of section 0 is always
3663 zero, and we rely on this for optional sections. */
3664 static int load_module(struct load_info *info, const char __user *uargs,
3671 err = elf_header_check(info);
3675 err = setup_load_info(info, flags);
3679 if (blacklisted(info->name)) {
3684 err = module_sig_check(info, flags);
3688 err = rewrite_section_headers(info, flags);
3692 /* Check module struct version now, before we try to use module. */
3693 if (!check_modstruct_version(info, info->mod)) {
3698 /* Figure out module layout, and allocate all the memory. */
3699 mod = layout_and_allocate(info, flags);
3705 audit_log_kern_module(mod->name);
3707 /* Reserve our place in the list. */
3708 err = add_unformed_module(mod);
3712 #ifdef CONFIG_MODULE_SIG
3713 mod->sig_ok = info->sig_ok;
3715 pr_notice_once("%s: module verification failed: signature "
3716 "and/or required key missing - tainting "
3717 "kernel\n", mod->name);
3718 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3722 /* To avoid stressing percpu allocator, do this once we're unique. */
3723 err = percpu_modalloc(mod, info);
3727 /* Now module is in final location, initialize linked lists, etc. */
3728 err = module_unload_init(mod);
3732 init_param_lock(mod);
3734 /* Now we've got everything in the final locations, we can
3735 * find optional sections. */
3736 err = find_module_sections(mod, info);
3740 err = check_module_license_and_versions(mod);
3744 /* Set up MODINFO_ATTR fields */
3745 setup_modinfo(mod, info);
3747 /* Fix up syms, so that st_value is a pointer to location. */
3748 err = simplify_symbols(mod, info);
3752 err = apply_relocations(mod, info);
3756 err = post_relocation(mod, info);
3760 flush_module_icache(mod);
3762 /* Now copy in args */
3763 mod->args = strndup_user(uargs, ~0UL >> 1);
3764 if (IS_ERR(mod->args)) {
3765 err = PTR_ERR(mod->args);
3766 goto free_arch_cleanup;
3769 dynamic_debug_setup(mod, info->debug, info->num_debug);
3771 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3772 ftrace_module_init(mod);
3774 /* Finally it's fully formed, ready to start executing. */
3775 err = complete_formation(mod, info);
3777 goto ddebug_cleanup;
3779 err = prepare_coming_module(mod);
3783 /* Module is ready to execute: parsing args may do that. */
3784 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3786 unknown_module_param_cb);
3787 if (IS_ERR(after_dashes)) {
3788 err = PTR_ERR(after_dashes);
3789 goto coming_cleanup;
3790 } else if (after_dashes) {
3791 pr_warn("%s: parameters '%s' after `--' ignored\n",
3792 mod->name, after_dashes);
3795 /* Link in to sysfs. */
3796 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3798 goto coming_cleanup;
3800 if (is_livepatch_module(mod)) {
3801 err = copy_module_elf(mod, info);
3806 /* Get rid of temporary copy. */
3810 trace_module_load(mod);
3812 return do_init_module(mod);
3815 mod_sysfs_teardown(mod);
3817 mod->state = MODULE_STATE_GOING;
3818 destroy_params(mod->kp, mod->num_kp);
3819 blocking_notifier_call_chain(&module_notify_list,
3820 MODULE_STATE_GOING, mod);
3821 klp_module_going(mod);
3823 /* module_bug_cleanup needs module_mutex protection */
3824 mutex_lock(&module_mutex);
3825 module_bug_cleanup(mod);
3826 mutex_unlock(&module_mutex);
3828 /* we can't deallocate the module until we clear memory protection */
3829 module_disable_ro(mod);
3830 module_disable_nx(mod);
3833 ftrace_release_mod(mod);
3834 dynamic_debug_remove(mod, info->debug);
3835 synchronize_sched();
3838 module_arch_cleanup(mod);
3842 module_unload_free(mod);
3844 mutex_lock(&module_mutex);
3845 /* Unlink carefully: kallsyms could be walking list. */
3846 list_del_rcu(&mod->list);
3847 mod_tree_remove(mod);
3848 wake_up_all(&module_wq);
3849 /* Wait for RCU-sched synchronizing before releasing mod->list. */
3850 synchronize_sched();
3851 mutex_unlock(&module_mutex);
3853 /* Free lock-classes; relies on the preceding sync_rcu() */
3854 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
3856 module_deallocate(mod, info);
3862 SYSCALL_DEFINE3(init_module, void __user *, umod,
3863 unsigned long, len, const char __user *, uargs)
3866 struct load_info info = { };
3868 err = may_init_module();
3872 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3875 err = copy_module_from_user(umod, len, &info);
3879 return load_module(&info, uargs, 0);
3882 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3884 struct load_info info = { };
3889 err = may_init_module();
3893 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3895 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3896 |MODULE_INIT_IGNORE_VERMAGIC))
3899 err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX,
3906 return load_module(&info, uargs, flags);
3909 static inline int within(unsigned long addr, void *start, unsigned long size)
3911 return ((void *)addr >= start && (void *)addr < start + size);
3914 #ifdef CONFIG_KALLSYMS
3916 * This ignores the intensely annoying "mapping symbols" found
3917 * in ARM ELF files: $a, $t and $d.
3919 static inline int is_arm_mapping_symbol(const char *str)
3921 if (str[0] == '.' && str[1] == 'L')
3923 return str[0] == '$' && strchr("axtd", str[1])
3924 && (str[2] == '\0' || str[2] == '.');
3927 static const char *symname(struct mod_kallsyms *kallsyms, unsigned int symnum)
3929 return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
3932 static const char *get_ksymbol(struct module *mod,
3934 unsigned long *size,
3935 unsigned long *offset)
3937 unsigned int i, best = 0;
3938 unsigned long nextval;
3939 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
3941 /* At worse, next value is at end of module */
3942 if (within_module_init(addr, mod))
3943 nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
3945 nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
3947 /* Scan for closest preceding symbol, and next symbol. (ELF
3948 starts real symbols at 1). */
3949 for (i = 1; i < kallsyms->num_symtab; i++) {
3950 if (kallsyms->symtab[i].st_shndx == SHN_UNDEF)
3953 /* We ignore unnamed symbols: they're uninformative
3954 * and inserted at a whim. */
3955 if (*symname(kallsyms, i) == '\0'
3956 || is_arm_mapping_symbol(symname(kallsyms, i)))
3959 if (kallsyms->symtab[i].st_value <= addr
3960 && kallsyms->symtab[i].st_value > kallsyms->symtab[best].st_value)
3962 if (kallsyms->symtab[i].st_value > addr
3963 && kallsyms->symtab[i].st_value < nextval)
3964 nextval = kallsyms->symtab[i].st_value;
3971 *size = nextval - kallsyms->symtab[best].st_value;
3973 *offset = addr - kallsyms->symtab[best].st_value;
3974 return symname(kallsyms, best);
3977 void * __weak dereference_module_function_descriptor(struct module *mod,
3983 /* For kallsyms to ask for address resolution. NULL means not found. Careful
3984 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3985 const char *module_address_lookup(unsigned long addr,
3986 unsigned long *size,
3987 unsigned long *offset,
3991 const char *ret = NULL;
3995 mod = __module_address(addr);
3998 *modname = mod->name;
3999 ret = get_ksymbol(mod, addr, size, offset);
4001 /* Make a copy in here where it's safe */
4003 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
4011 int lookup_module_symbol_name(unsigned long addr, char *symname)
4016 list_for_each_entry_rcu(mod, &modules, list) {
4017 if (mod->state == MODULE_STATE_UNFORMED)
4019 if (within_module(addr, mod)) {
4022 sym = get_ksymbol(mod, addr, NULL, NULL);
4025 strlcpy(symname, sym, KSYM_NAME_LEN);
4035 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
4036 unsigned long *offset, char *modname, char *name)
4041 list_for_each_entry_rcu(mod, &modules, list) {
4042 if (mod->state == MODULE_STATE_UNFORMED)
4044 if (within_module(addr, mod)) {
4047 sym = get_ksymbol(mod, addr, size, offset);
4051 strlcpy(modname, mod->name, MODULE_NAME_LEN);
4053 strlcpy(name, sym, KSYM_NAME_LEN);
4063 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
4064 char *name, char *module_name, int *exported)
4069 list_for_each_entry_rcu(mod, &modules, list) {
4070 struct mod_kallsyms *kallsyms;
4072 if (mod->state == MODULE_STATE_UNFORMED)
4074 kallsyms = rcu_dereference_sched(mod->kallsyms);
4075 if (symnum < kallsyms->num_symtab) {
4076 *value = kallsyms->symtab[symnum].st_value;
4077 *type = kallsyms->symtab[symnum].st_info;
4078 strlcpy(name, symname(kallsyms, symnum), KSYM_NAME_LEN);
4079 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
4080 *exported = is_exported(name, *value, mod);
4084 symnum -= kallsyms->num_symtab;
4090 static unsigned long mod_find_symname(struct module *mod, const char *name)
4093 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4095 for (i = 0; i < kallsyms->num_symtab; i++)
4096 if (strcmp(name, symname(kallsyms, i)) == 0 &&
4097 kallsyms->symtab[i].st_shndx != SHN_UNDEF)
4098 return kallsyms->symtab[i].st_value;
4102 /* Look for this name: can be of form module:name. */
4103 unsigned long module_kallsyms_lookup_name(const char *name)
4107 unsigned long ret = 0;
4109 /* Don't lock: we're in enough trouble already. */
4111 if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
4112 if ((mod = find_module_all(name, colon - name, false)) != NULL)
4113 ret = mod_find_symname(mod, colon+1);
4115 list_for_each_entry_rcu(mod, &modules, list) {
4116 if (mod->state == MODULE_STATE_UNFORMED)
4118 if ((ret = mod_find_symname(mod, name)) != 0)
4126 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
4127 struct module *, unsigned long),
4134 module_assert_mutex();
4136 list_for_each_entry(mod, &modules, list) {
4137 /* We hold module_mutex: no need for rcu_dereference_sched */
4138 struct mod_kallsyms *kallsyms = mod->kallsyms;
4140 if (mod->state == MODULE_STATE_UNFORMED)
4142 for (i = 0; i < kallsyms->num_symtab; i++) {
4144 if (kallsyms->symtab[i].st_shndx == SHN_UNDEF)
4147 ret = fn(data, symname(kallsyms, i),
4148 mod, kallsyms->symtab[i].st_value);
4155 #endif /* CONFIG_KALLSYMS */
4157 /* Maximum number of characters written by module_flags() */
4158 #define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
4160 /* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
4161 static char *module_flags(struct module *mod, char *buf)
4165 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
4167 mod->state == MODULE_STATE_GOING ||
4168 mod->state == MODULE_STATE_COMING) {
4170 bx += module_flags_taint(mod, buf + bx);
4171 /* Show a - for module-is-being-unloaded */
4172 if (mod->state == MODULE_STATE_GOING)
4174 /* Show a + for module-is-being-loaded */
4175 if (mod->state == MODULE_STATE_COMING)
4184 #ifdef CONFIG_PROC_FS
4185 /* Called by the /proc file system to return a list of modules. */
4186 static void *m_start(struct seq_file *m, loff_t *pos)
4188 mutex_lock(&module_mutex);
4189 return seq_list_start(&modules, *pos);
4192 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
4194 return seq_list_next(p, &modules, pos);
4197 static void m_stop(struct seq_file *m, void *p)
4199 mutex_unlock(&module_mutex);
4202 static int m_show(struct seq_file *m, void *p)
4204 struct module *mod = list_entry(p, struct module, list);
4205 char buf[MODULE_FLAGS_BUF_SIZE];
4208 /* We always ignore unformed modules. */
4209 if (mod->state == MODULE_STATE_UNFORMED)
4212 seq_printf(m, "%s %u",
4213 mod->name, mod->init_layout.size + mod->core_layout.size);
4214 print_unload_info(m, mod);
4216 /* Informative for users. */
4217 seq_printf(m, " %s",
4218 mod->state == MODULE_STATE_GOING ? "Unloading" :
4219 mod->state == MODULE_STATE_COMING ? "Loading" :
4221 /* Used by oprofile and other similar tools. */
4222 value = m->private ? NULL : mod->core_layout.base;
4223 seq_printf(m, " 0x%px", value);
4227 seq_printf(m, " %s", module_flags(mod, buf));
4233 /* Format: modulename size refcount deps address
4235 Where refcount is a number or -, and deps is a comma-separated list
4238 static const struct seq_operations modules_op = {
4246 * This also sets the "private" pointer to non-NULL if the
4247 * kernel pointers should be hidden (so you can just test
4248 * "m->private" to see if you should keep the values private).
4250 * We use the same logic as for /proc/kallsyms.
4252 static int modules_open(struct inode *inode, struct file *file)
4254 int err = seq_open(file, &modules_op);
4257 struct seq_file *m = file->private_data;
4258 m->private = kallsyms_show_value() ? NULL : (void *)8ul;
4264 static const struct file_operations proc_modules_operations = {
4265 .open = modules_open,
4267 .llseek = seq_lseek,
4268 .release = seq_release,
4271 static int __init proc_modules_init(void)
4273 proc_create("modules", 0, NULL, &proc_modules_operations);
4276 module_init(proc_modules_init);
4279 /* Given an address, look for it in the module exception tables. */
4280 const struct exception_table_entry *search_module_extables(unsigned long addr)
4282 const struct exception_table_entry *e = NULL;
4286 mod = __module_address(addr);
4290 if (!mod->num_exentries)
4293 e = search_extable(mod->extable,
4300 * Now, if we found one, we are running inside it now, hence
4301 * we cannot unload the module, hence no refcnt needed.
4307 * is_module_address - is this address inside a module?
4308 * @addr: the address to check.
4310 * See is_module_text_address() if you simply want to see if the address
4311 * is code (not data).
4313 bool is_module_address(unsigned long addr)
4318 ret = __module_address(addr) != NULL;
4325 * __module_address - get the module which contains an address.
4326 * @addr: the address.
4328 * Must be called with preempt disabled or module mutex held so that
4329 * module doesn't get freed during this.
4331 struct module *__module_address(unsigned long addr)
4335 if (addr < module_addr_min || addr > module_addr_max)
4338 module_assert_mutex_or_preempt();
4340 mod = mod_find(addr);
4342 BUG_ON(!within_module(addr, mod));
4343 if (mod->state == MODULE_STATE_UNFORMED)
4348 EXPORT_SYMBOL_GPL(__module_address);
4351 * is_module_text_address - is this address inside module code?
4352 * @addr: the address to check.
4354 * See is_module_address() if you simply want to see if the address is
4355 * anywhere in a module. See kernel_text_address() for testing if an
4356 * address corresponds to kernel or module code.
4358 bool is_module_text_address(unsigned long addr)
4363 ret = __module_text_address(addr) != NULL;
4370 * __module_text_address - get the module whose code contains an address.
4371 * @addr: the address.
4373 * Must be called with preempt disabled or module mutex held so that
4374 * module doesn't get freed during this.
4376 struct module *__module_text_address(unsigned long addr)
4378 struct module *mod = __module_address(addr);
4380 /* Make sure it's within the text section. */
4381 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
4382 && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
4387 EXPORT_SYMBOL_GPL(__module_text_address);
4389 /* Don't grab lock, we're oopsing. */
4390 void print_modules(void)
4393 char buf[MODULE_FLAGS_BUF_SIZE];
4395 printk(KERN_DEFAULT "Modules linked in:");
4396 /* Most callers should already have preempt disabled, but make sure */
4398 list_for_each_entry_rcu(mod, &modules, list) {
4399 if (mod->state == MODULE_STATE_UNFORMED)
4401 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4404 if (last_unloaded_module[0])
4405 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4409 #ifdef CONFIG_MODVERSIONS
4410 /* Generate the signature for all relevant module structures here.
4411 * If these change, we don't want to try to parse the module. */
4412 void module_layout(struct module *mod,
4413 struct modversion_info *ver,
4414 struct kernel_param *kp,
4415 struct kernel_symbol *ks,
4416 struct tracepoint * const *tp)
4419 EXPORT_SYMBOL(module_layout);