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));
1024 /* someone could wait for the module in add_unformed_module() */
1025 wake_up_all(&module_wq);
1028 mutex_unlock(&module_mutex);
1032 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1034 struct module_use *use;
1035 int printed_something = 0;
1037 seq_printf(m, " %i ", module_refcount(mod));
1040 * Always include a trailing , so userspace can differentiate
1041 * between this and the old multi-field proc format.
1043 list_for_each_entry(use, &mod->source_list, source_list) {
1044 printed_something = 1;
1045 seq_printf(m, "%s,", use->source->name);
1048 if (mod->init != NULL && mod->exit == NULL) {
1049 printed_something = 1;
1050 seq_puts(m, "[permanent],");
1053 if (!printed_something)
1057 void __symbol_put(const char *symbol)
1059 struct module *owner;
1062 if (!find_symbol(symbol, &owner, NULL, true, false))
1067 EXPORT_SYMBOL(__symbol_put);
1069 /* Note this assumes addr is a function, which it currently always is. */
1070 void symbol_put_addr(void *addr)
1072 struct module *modaddr;
1073 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1075 if (core_kernel_text(a))
1079 * Even though we hold a reference on the module; we still need to
1080 * disable preemption in order to safely traverse the data structure.
1083 modaddr = __module_text_address(a);
1085 module_put(modaddr);
1088 EXPORT_SYMBOL_GPL(symbol_put_addr);
1090 static ssize_t show_refcnt(struct module_attribute *mattr,
1091 struct module_kobject *mk, char *buffer)
1093 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1096 static struct module_attribute modinfo_refcnt =
1097 __ATTR(refcnt, 0444, show_refcnt, NULL);
1099 void __module_get(struct module *module)
1103 atomic_inc(&module->refcnt);
1104 trace_module_get(module, _RET_IP_);
1108 EXPORT_SYMBOL(__module_get);
1110 bool try_module_get(struct module *module)
1116 /* Note: here, we can fail to get a reference */
1117 if (likely(module_is_live(module) &&
1118 atomic_inc_not_zero(&module->refcnt) != 0))
1119 trace_module_get(module, _RET_IP_);
1127 EXPORT_SYMBOL(try_module_get);
1129 void module_put(struct module *module)
1135 ret = atomic_dec_if_positive(&module->refcnt);
1136 WARN_ON(ret < 0); /* Failed to put refcount */
1137 trace_module_put(module, _RET_IP_);
1141 EXPORT_SYMBOL(module_put);
1143 #else /* !CONFIG_MODULE_UNLOAD */
1144 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1146 /* We don't know the usage count, or what modules are using. */
1147 seq_puts(m, " - -");
1150 static inline void module_unload_free(struct module *mod)
1154 int ref_module(struct module *a, struct module *b)
1156 return strong_try_module_get(b);
1158 EXPORT_SYMBOL_GPL(ref_module);
1160 static inline int module_unload_init(struct module *mod)
1164 #endif /* CONFIG_MODULE_UNLOAD */
1166 static size_t module_flags_taint(struct module *mod, char *buf)
1171 for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
1172 if (taint_flags[i].module && test_bit(i, &mod->taints))
1173 buf[l++] = taint_flags[i].c_true;
1179 static ssize_t show_initstate(struct module_attribute *mattr,
1180 struct module_kobject *mk, char *buffer)
1182 const char *state = "unknown";
1184 switch (mk->mod->state) {
1185 case MODULE_STATE_LIVE:
1188 case MODULE_STATE_COMING:
1191 case MODULE_STATE_GOING:
1197 return sprintf(buffer, "%s\n", state);
1200 static struct module_attribute modinfo_initstate =
1201 __ATTR(initstate, 0444, show_initstate, NULL);
1203 static ssize_t store_uevent(struct module_attribute *mattr,
1204 struct module_kobject *mk,
1205 const char *buffer, size_t count)
1209 rc = kobject_synth_uevent(&mk->kobj, buffer, count);
1210 return rc ? rc : count;
1213 struct module_attribute module_uevent =
1214 __ATTR(uevent, 0200, NULL, store_uevent);
1216 static ssize_t show_coresize(struct module_attribute *mattr,
1217 struct module_kobject *mk, char *buffer)
1219 return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1222 static struct module_attribute modinfo_coresize =
1223 __ATTR(coresize, 0444, show_coresize, NULL);
1225 static ssize_t show_initsize(struct module_attribute *mattr,
1226 struct module_kobject *mk, char *buffer)
1228 return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1231 static struct module_attribute modinfo_initsize =
1232 __ATTR(initsize, 0444, show_initsize, NULL);
1234 static ssize_t show_taint(struct module_attribute *mattr,
1235 struct module_kobject *mk, char *buffer)
1239 l = module_flags_taint(mk->mod, buffer);
1244 static struct module_attribute modinfo_taint =
1245 __ATTR(taint, 0444, show_taint, NULL);
1247 static struct module_attribute *modinfo_attrs[] = {
1250 &modinfo_srcversion,
1255 #ifdef CONFIG_MODULE_UNLOAD
1261 static const char vermagic[] = VERMAGIC_STRING;
1263 static int try_to_force_load(struct module *mod, const char *reason)
1265 #ifdef CONFIG_MODULE_FORCE_LOAD
1266 if (!test_taint(TAINT_FORCED_MODULE))
1267 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1268 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1275 #ifdef CONFIG_MODVERSIONS
1277 static u32 resolve_rel_crc(const s32 *crc)
1279 return *(u32 *)((void *)crc + *crc);
1282 static int check_version(const struct load_info *info,
1283 const char *symname,
1287 Elf_Shdr *sechdrs = info->sechdrs;
1288 unsigned int versindex = info->index.vers;
1289 unsigned int i, num_versions;
1290 struct modversion_info *versions;
1292 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1296 /* No versions at all? modprobe --force does this. */
1298 return try_to_force_load(mod, symname) == 0;
1300 versions = (void *) sechdrs[versindex].sh_addr;
1301 num_versions = sechdrs[versindex].sh_size
1302 / sizeof(struct modversion_info);
1304 for (i = 0; i < num_versions; i++) {
1307 if (strcmp(versions[i].name, symname) != 0)
1310 if (IS_ENABLED(CONFIG_MODULE_REL_CRCS))
1311 crcval = resolve_rel_crc(crc);
1314 if (versions[i].crc == crcval)
1316 pr_debug("Found checksum %X vs module %lX\n",
1317 crcval, versions[i].crc);
1321 /* Broken toolchain. Warn once, then let it go.. */
1322 pr_warn_once("%s: no symbol version for %s\n", info->name, symname);
1326 pr_warn("%s: disagrees about version of symbol %s\n",
1327 info->name, symname);
1331 static inline int check_modstruct_version(const struct load_info *info,
1337 * Since this should be found in kernel (which can't be removed), no
1338 * locking is necessary -- use preempt_disable() to placate lockdep.
1341 if (!find_symbol("module_layout", NULL, &crc, true, false)) {
1346 return check_version(info, "module_layout", mod, crc);
1349 /* First part is kernel version, which we ignore if module has crcs. */
1350 static inline int same_magic(const char *amagic, const char *bmagic,
1354 amagic += strcspn(amagic, " ");
1355 bmagic += strcspn(bmagic, " ");
1357 return strcmp(amagic, bmagic) == 0;
1360 static inline int check_version(const struct load_info *info,
1361 const char *symname,
1368 static inline int check_modstruct_version(const struct load_info *info,
1374 static inline int same_magic(const char *amagic, const char *bmagic,
1377 return strcmp(amagic, bmagic) == 0;
1379 #endif /* CONFIG_MODVERSIONS */
1381 /* Resolve a symbol for this module. I.e. if we find one, record usage. */
1382 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1383 const struct load_info *info,
1387 struct module *owner;
1388 const struct kernel_symbol *sym;
1393 * The module_mutex should not be a heavily contended lock;
1394 * if we get the occasional sleep here, we'll go an extra iteration
1395 * in the wait_event_interruptible(), which is harmless.
1397 sched_annotate_sleep();
1398 mutex_lock(&module_mutex);
1399 sym = find_symbol(name, &owner, &crc,
1400 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1404 if (!check_version(info, name, mod, crc)) {
1405 sym = ERR_PTR(-EINVAL);
1409 err = ref_module(mod, owner);
1416 /* We must make copy under the lock if we failed to get ref. */
1417 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1419 mutex_unlock(&module_mutex);
1423 static const struct kernel_symbol *
1424 resolve_symbol_wait(struct module *mod,
1425 const struct load_info *info,
1428 const struct kernel_symbol *ksym;
1429 char owner[MODULE_NAME_LEN];
1431 if (wait_event_interruptible_timeout(module_wq,
1432 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1433 || PTR_ERR(ksym) != -EBUSY,
1435 pr_warn("%s: gave up waiting for init of module %s.\n",
1442 * /sys/module/foo/sections stuff
1443 * J. Corbet <corbet@lwn.net>
1447 #ifdef CONFIG_KALLSYMS
1448 static inline bool sect_empty(const Elf_Shdr *sect)
1450 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1453 struct module_sect_attr {
1454 struct module_attribute mattr;
1456 unsigned long address;
1459 struct module_sect_attrs {
1460 struct attribute_group grp;
1461 unsigned int nsections;
1462 struct module_sect_attr attrs[0];
1465 static ssize_t module_sect_show(struct module_attribute *mattr,
1466 struct module_kobject *mk, char *buf)
1468 struct module_sect_attr *sattr =
1469 container_of(mattr, struct module_sect_attr, mattr);
1470 return sprintf(buf, "0x%px\n", kptr_restrict < 2 ?
1471 (void *)sattr->address : NULL);
1474 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1476 unsigned int section;
1478 for (section = 0; section < sect_attrs->nsections; section++)
1479 kfree(sect_attrs->attrs[section].name);
1483 static void add_sect_attrs(struct module *mod, const struct load_info *info)
1485 unsigned int nloaded = 0, i, size[2];
1486 struct module_sect_attrs *sect_attrs;
1487 struct module_sect_attr *sattr;
1488 struct attribute **gattr;
1490 /* Count loaded sections and allocate structures */
1491 for (i = 0; i < info->hdr->e_shnum; i++)
1492 if (!sect_empty(&info->sechdrs[i]))
1494 size[0] = ALIGN(sizeof(*sect_attrs)
1495 + nloaded * sizeof(sect_attrs->attrs[0]),
1496 sizeof(sect_attrs->grp.attrs[0]));
1497 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1498 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1499 if (sect_attrs == NULL)
1502 /* Setup section attributes. */
1503 sect_attrs->grp.name = "sections";
1504 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1506 sect_attrs->nsections = 0;
1507 sattr = §_attrs->attrs[0];
1508 gattr = §_attrs->grp.attrs[0];
1509 for (i = 0; i < info->hdr->e_shnum; i++) {
1510 Elf_Shdr *sec = &info->sechdrs[i];
1511 if (sect_empty(sec))
1513 sattr->address = sec->sh_addr;
1514 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1516 if (sattr->name == NULL)
1518 sect_attrs->nsections++;
1519 sysfs_attr_init(&sattr->mattr.attr);
1520 sattr->mattr.show = module_sect_show;
1521 sattr->mattr.store = NULL;
1522 sattr->mattr.attr.name = sattr->name;
1523 sattr->mattr.attr.mode = S_IRUSR;
1524 *(gattr++) = &(sattr++)->mattr.attr;
1528 if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp))
1531 mod->sect_attrs = sect_attrs;
1534 free_sect_attrs(sect_attrs);
1537 static void remove_sect_attrs(struct module *mod)
1539 if (mod->sect_attrs) {
1540 sysfs_remove_group(&mod->mkobj.kobj,
1541 &mod->sect_attrs->grp);
1542 /* We are positive that no one is using any sect attrs
1543 * at this point. Deallocate immediately. */
1544 free_sect_attrs(mod->sect_attrs);
1545 mod->sect_attrs = NULL;
1550 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1553 struct module_notes_attrs {
1554 struct kobject *dir;
1556 struct bin_attribute attrs[0];
1559 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1560 struct bin_attribute *bin_attr,
1561 char *buf, loff_t pos, size_t count)
1564 * The caller checked the pos and count against our size.
1566 memcpy(buf, bin_attr->private + pos, count);
1570 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1573 if (notes_attrs->dir) {
1575 sysfs_remove_bin_file(notes_attrs->dir,
1576 ¬es_attrs->attrs[i]);
1577 kobject_put(notes_attrs->dir);
1582 static void add_notes_attrs(struct module *mod, const struct load_info *info)
1584 unsigned int notes, loaded, i;
1585 struct module_notes_attrs *notes_attrs;
1586 struct bin_attribute *nattr;
1588 /* failed to create section attributes, so can't create notes */
1589 if (!mod->sect_attrs)
1592 /* Count notes sections and allocate structures. */
1594 for (i = 0; i < info->hdr->e_shnum; i++)
1595 if (!sect_empty(&info->sechdrs[i]) &&
1596 (info->sechdrs[i].sh_type == SHT_NOTE))
1602 notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes),
1604 if (notes_attrs == NULL)
1607 notes_attrs->notes = notes;
1608 nattr = ¬es_attrs->attrs[0];
1609 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1610 if (sect_empty(&info->sechdrs[i]))
1612 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1613 sysfs_bin_attr_init(nattr);
1614 nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1615 nattr->attr.mode = S_IRUGO;
1616 nattr->size = info->sechdrs[i].sh_size;
1617 nattr->private = (void *) info->sechdrs[i].sh_addr;
1618 nattr->read = module_notes_read;
1624 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1625 if (!notes_attrs->dir)
1628 for (i = 0; i < notes; ++i)
1629 if (sysfs_create_bin_file(notes_attrs->dir,
1630 ¬es_attrs->attrs[i]))
1633 mod->notes_attrs = notes_attrs;
1637 free_notes_attrs(notes_attrs, i);
1640 static void remove_notes_attrs(struct module *mod)
1642 if (mod->notes_attrs)
1643 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1648 static inline void add_sect_attrs(struct module *mod,
1649 const struct load_info *info)
1653 static inline void remove_sect_attrs(struct module *mod)
1657 static inline void add_notes_attrs(struct module *mod,
1658 const struct load_info *info)
1662 static inline void remove_notes_attrs(struct module *mod)
1665 #endif /* CONFIG_KALLSYMS */
1667 static void del_usage_links(struct module *mod)
1669 #ifdef CONFIG_MODULE_UNLOAD
1670 struct module_use *use;
1672 mutex_lock(&module_mutex);
1673 list_for_each_entry(use, &mod->target_list, target_list)
1674 sysfs_remove_link(use->target->holders_dir, mod->name);
1675 mutex_unlock(&module_mutex);
1679 static int add_usage_links(struct module *mod)
1682 #ifdef CONFIG_MODULE_UNLOAD
1683 struct module_use *use;
1685 mutex_lock(&module_mutex);
1686 list_for_each_entry(use, &mod->target_list, target_list) {
1687 ret = sysfs_create_link(use->target->holders_dir,
1688 &mod->mkobj.kobj, mod->name);
1692 mutex_unlock(&module_mutex);
1694 del_usage_links(mod);
1699 static void module_remove_modinfo_attrs(struct module *mod, int end);
1701 static int module_add_modinfo_attrs(struct module *mod)
1703 struct module_attribute *attr;
1704 struct module_attribute *temp_attr;
1708 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1709 (ARRAY_SIZE(modinfo_attrs) + 1)),
1711 if (!mod->modinfo_attrs)
1714 temp_attr = mod->modinfo_attrs;
1715 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1716 if (!attr->test || attr->test(mod)) {
1717 memcpy(temp_attr, attr, sizeof(*temp_attr));
1718 sysfs_attr_init(&temp_attr->attr);
1719 error = sysfs_create_file(&mod->mkobj.kobj,
1731 module_remove_modinfo_attrs(mod, --i);
1735 static void module_remove_modinfo_attrs(struct module *mod, int end)
1737 struct module_attribute *attr;
1740 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1741 if (end >= 0 && i > end)
1743 /* pick a field to test for end of list */
1744 if (!attr->attr.name)
1746 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1750 kfree(mod->modinfo_attrs);
1753 static void mod_kobject_put(struct module *mod)
1755 DECLARE_COMPLETION_ONSTACK(c);
1756 mod->mkobj.kobj_completion = &c;
1757 kobject_put(&mod->mkobj.kobj);
1758 wait_for_completion(&c);
1761 static int mod_sysfs_init(struct module *mod)
1764 struct kobject *kobj;
1766 if (!module_sysfs_initialized) {
1767 pr_err("%s: module sysfs not initialized\n", mod->name);
1772 kobj = kset_find_obj(module_kset, mod->name);
1774 pr_err("%s: module is already loaded\n", mod->name);
1780 mod->mkobj.mod = mod;
1782 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1783 mod->mkobj.kobj.kset = module_kset;
1784 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1787 mod_kobject_put(mod);
1789 /* delay uevent until full sysfs population */
1794 static int mod_sysfs_setup(struct module *mod,
1795 const struct load_info *info,
1796 struct kernel_param *kparam,
1797 unsigned int num_params)
1801 err = mod_sysfs_init(mod);
1805 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1806 if (!mod->holders_dir) {
1811 err = module_param_sysfs_setup(mod, kparam, num_params);
1813 goto out_unreg_holders;
1815 err = module_add_modinfo_attrs(mod);
1817 goto out_unreg_param;
1819 err = add_usage_links(mod);
1821 goto out_unreg_modinfo_attrs;
1823 add_sect_attrs(mod, info);
1824 add_notes_attrs(mod, info);
1826 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1829 out_unreg_modinfo_attrs:
1830 module_remove_modinfo_attrs(mod, -1);
1832 module_param_sysfs_remove(mod);
1834 kobject_put(mod->holders_dir);
1836 mod_kobject_put(mod);
1841 static void mod_sysfs_fini(struct module *mod)
1843 remove_notes_attrs(mod);
1844 remove_sect_attrs(mod);
1845 mod_kobject_put(mod);
1848 static void init_param_lock(struct module *mod)
1850 mutex_init(&mod->param_lock);
1852 #else /* !CONFIG_SYSFS */
1854 static int mod_sysfs_setup(struct module *mod,
1855 const struct load_info *info,
1856 struct kernel_param *kparam,
1857 unsigned int num_params)
1862 static void mod_sysfs_fini(struct module *mod)
1866 static void module_remove_modinfo_attrs(struct module *mod, int end)
1870 static void del_usage_links(struct module *mod)
1874 static void init_param_lock(struct module *mod)
1877 #endif /* CONFIG_SYSFS */
1879 static void mod_sysfs_teardown(struct module *mod)
1881 del_usage_links(mod);
1882 module_remove_modinfo_attrs(mod, -1);
1883 module_param_sysfs_remove(mod);
1884 kobject_put(mod->mkobj.drivers_dir);
1885 kobject_put(mod->holders_dir);
1886 mod_sysfs_fini(mod);
1889 #ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
1891 * LKM RO/NX protection: protect module's text/ro-data
1892 * from modification and any data from execution.
1894 * General layout of module is:
1895 * [text] [read-only-data] [ro-after-init] [writable data]
1896 * text_size -----^ ^ ^ ^
1897 * ro_size ------------------------| | |
1898 * ro_after_init_size -----------------------------| |
1899 * size -----------------------------------------------------------|
1901 * These values are always page-aligned (as is base)
1903 static void frob_text(const struct module_layout *layout,
1904 int (*set_memory)(unsigned long start, int num_pages))
1906 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1907 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1908 set_memory((unsigned long)layout->base,
1909 layout->text_size >> PAGE_SHIFT);
1912 #ifdef CONFIG_STRICT_MODULE_RWX
1913 static void frob_rodata(const struct module_layout *layout,
1914 int (*set_memory)(unsigned long start, int num_pages))
1916 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1917 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1918 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1919 set_memory((unsigned long)layout->base + layout->text_size,
1920 (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
1923 static void frob_ro_after_init(const struct module_layout *layout,
1924 int (*set_memory)(unsigned long start, int num_pages))
1926 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1927 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1928 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1929 set_memory((unsigned long)layout->base + layout->ro_size,
1930 (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
1933 static void frob_writable_data(const struct module_layout *layout,
1934 int (*set_memory)(unsigned long start, int num_pages))
1936 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1937 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1938 BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
1939 set_memory((unsigned long)layout->base + layout->ro_after_init_size,
1940 (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
1943 /* livepatching wants to disable read-only so it can frob module. */
1944 void module_disable_ro(const struct module *mod)
1946 if (!rodata_enabled)
1949 frob_text(&mod->core_layout, set_memory_rw);
1950 frob_rodata(&mod->core_layout, set_memory_rw);
1951 frob_ro_after_init(&mod->core_layout, set_memory_rw);
1952 frob_text(&mod->init_layout, set_memory_rw);
1953 frob_rodata(&mod->init_layout, set_memory_rw);
1956 void module_enable_ro(const struct module *mod, bool after_init)
1958 if (!rodata_enabled)
1961 frob_text(&mod->core_layout, set_memory_ro);
1963 frob_rodata(&mod->core_layout, set_memory_ro);
1964 frob_text(&mod->init_layout, set_memory_ro);
1965 frob_rodata(&mod->init_layout, set_memory_ro);
1968 frob_ro_after_init(&mod->core_layout, set_memory_ro);
1971 static void module_enable_nx(const struct module *mod)
1973 frob_rodata(&mod->core_layout, set_memory_nx);
1974 frob_ro_after_init(&mod->core_layout, set_memory_nx);
1975 frob_writable_data(&mod->core_layout, set_memory_nx);
1976 frob_rodata(&mod->init_layout, set_memory_nx);
1977 frob_writable_data(&mod->init_layout, set_memory_nx);
1980 static void module_disable_nx(const struct module *mod)
1982 frob_rodata(&mod->core_layout, set_memory_x);
1983 frob_ro_after_init(&mod->core_layout, set_memory_x);
1984 frob_writable_data(&mod->core_layout, set_memory_x);
1985 frob_rodata(&mod->init_layout, set_memory_x);
1986 frob_writable_data(&mod->init_layout, set_memory_x);
1989 /* Iterate through all modules and set each module's text as RW */
1990 void set_all_modules_text_rw(void)
1994 if (!rodata_enabled)
1997 mutex_lock(&module_mutex);
1998 list_for_each_entry_rcu(mod, &modules, list) {
1999 if (mod->state == MODULE_STATE_UNFORMED)
2002 frob_text(&mod->core_layout, set_memory_rw);
2003 frob_text(&mod->init_layout, set_memory_rw);
2005 mutex_unlock(&module_mutex);
2008 /* Iterate through all modules and set each module's text as RO */
2009 void set_all_modules_text_ro(void)
2013 if (!rodata_enabled)
2016 mutex_lock(&module_mutex);
2017 list_for_each_entry_rcu(mod, &modules, list) {
2019 * Ignore going modules since it's possible that ro
2020 * protection has already been disabled, otherwise we'll
2021 * run into protection faults at module deallocation.
2023 if (mod->state == MODULE_STATE_UNFORMED ||
2024 mod->state == MODULE_STATE_GOING)
2027 frob_text(&mod->core_layout, set_memory_ro);
2028 frob_text(&mod->init_layout, set_memory_ro);
2030 mutex_unlock(&module_mutex);
2033 static void disable_ro_nx(const struct module_layout *layout)
2035 if (rodata_enabled) {
2036 frob_text(layout, set_memory_rw);
2037 frob_rodata(layout, set_memory_rw);
2038 frob_ro_after_init(layout, set_memory_rw);
2040 frob_rodata(layout, set_memory_x);
2041 frob_ro_after_init(layout, set_memory_x);
2042 frob_writable_data(layout, set_memory_x);
2045 #else /* !CONFIG_STRICT_MODULE_RWX */
2046 static void disable_ro_nx(const struct module_layout *layout) { }
2047 static void module_enable_nx(const struct module *mod) { }
2048 static void module_disable_nx(const struct module *mod) { }
2049 #endif /* CONFIG_STRICT_MODULE_RWX */
2051 static void module_enable_x(const struct module *mod)
2053 frob_text(&mod->core_layout, set_memory_x);
2054 frob_text(&mod->init_layout, set_memory_x);
2056 #else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
2057 static void disable_ro_nx(const struct module_layout *layout) { }
2058 static void module_enable_nx(const struct module *mod) { }
2059 static void module_disable_nx(const struct module *mod) { }
2060 static void module_enable_x(const struct module *mod) { }
2061 #endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
2063 #ifdef CONFIG_LIVEPATCH
2065 * Persist Elf information about a module. Copy the Elf header,
2066 * section header table, section string table, and symtab section
2067 * index from info to mod->klp_info.
2069 static int copy_module_elf(struct module *mod, struct load_info *info)
2071 unsigned int size, symndx;
2074 size = sizeof(*mod->klp_info);
2075 mod->klp_info = kmalloc(size, GFP_KERNEL);
2076 if (mod->klp_info == NULL)
2080 size = sizeof(mod->klp_info->hdr);
2081 memcpy(&mod->klp_info->hdr, info->hdr, size);
2083 /* Elf section header table */
2084 size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
2085 mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL);
2086 if (mod->klp_info->sechdrs == NULL) {
2091 /* Elf section name string table */
2092 size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
2093 mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL);
2094 if (mod->klp_info->secstrings == NULL) {
2099 /* Elf symbol section index */
2100 symndx = info->index.sym;
2101 mod->klp_info->symndx = symndx;
2104 * For livepatch modules, core_kallsyms.symtab is a complete
2105 * copy of the original symbol table. Adjust sh_addr to point
2106 * to core_kallsyms.symtab since the copy of the symtab in module
2107 * init memory is freed at the end of do_init_module().
2109 mod->klp_info->sechdrs[symndx].sh_addr = \
2110 (unsigned long) mod->core_kallsyms.symtab;
2115 kfree(mod->klp_info->sechdrs);
2117 kfree(mod->klp_info);
2121 static void free_module_elf(struct module *mod)
2123 kfree(mod->klp_info->sechdrs);
2124 kfree(mod->klp_info->secstrings);
2125 kfree(mod->klp_info);
2127 #else /* !CONFIG_LIVEPATCH */
2128 static int copy_module_elf(struct module *mod, struct load_info *info)
2133 static void free_module_elf(struct module *mod)
2136 #endif /* CONFIG_LIVEPATCH */
2138 void __weak module_memfree(void *module_region)
2140 vfree(module_region);
2143 void __weak module_arch_cleanup(struct module *mod)
2147 void __weak module_arch_freeing_init(struct module *mod)
2151 /* Free a module, remove from lists, etc. */
2152 static void free_module(struct module *mod)
2154 trace_module_free(mod);
2156 mod_sysfs_teardown(mod);
2158 /* We leave it in list to prevent duplicate loads, but make sure
2159 * that noone uses it while it's being deconstructed. */
2160 mutex_lock(&module_mutex);
2161 mod->state = MODULE_STATE_UNFORMED;
2162 mutex_unlock(&module_mutex);
2164 /* Remove dynamic debug info */
2165 ddebug_remove_module(mod->name);
2167 /* Arch-specific cleanup. */
2168 module_arch_cleanup(mod);
2170 /* Module unload stuff */
2171 module_unload_free(mod);
2173 /* Free any allocated parameters. */
2174 destroy_params(mod->kp, mod->num_kp);
2176 if (is_livepatch_module(mod))
2177 free_module_elf(mod);
2179 /* Now we can delete it from the lists */
2180 mutex_lock(&module_mutex);
2181 /* Unlink carefully: kallsyms could be walking list. */
2182 list_del_rcu(&mod->list);
2183 mod_tree_remove(mod);
2184 /* Remove this module from bug list, this uses list_del_rcu */
2185 module_bug_cleanup(mod);
2186 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2187 synchronize_sched();
2188 mutex_unlock(&module_mutex);
2190 /* This may be empty, but that's OK */
2191 disable_ro_nx(&mod->init_layout);
2192 module_arch_freeing_init(mod);
2193 module_memfree(mod->init_layout.base);
2195 percpu_modfree(mod);
2197 /* Free lock-classes; relies on the preceding sync_rcu(). */
2198 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
2200 /* Finally, free the core (containing the module structure) */
2201 disable_ro_nx(&mod->core_layout);
2202 module_memfree(mod->core_layout.base);
2205 void *__symbol_get(const char *symbol)
2207 struct module *owner;
2208 const struct kernel_symbol *sym;
2211 sym = find_symbol(symbol, &owner, NULL, true, true);
2212 if (sym && strong_try_module_get(owner))
2216 return sym ? (void *)kernel_symbol_value(sym) : NULL;
2218 EXPORT_SYMBOL_GPL(__symbol_get);
2221 * Ensure that an exported symbol [global namespace] does not already exist
2222 * in the kernel or in some other module's exported symbol table.
2224 * You must hold the module_mutex.
2226 static int verify_export_symbols(struct module *mod)
2229 struct module *owner;
2230 const struct kernel_symbol *s;
2232 const struct kernel_symbol *sym;
2235 { mod->syms, mod->num_syms },
2236 { mod->gpl_syms, mod->num_gpl_syms },
2237 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2238 #ifdef CONFIG_UNUSED_SYMBOLS
2239 { mod->unused_syms, mod->num_unused_syms },
2240 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2244 for (i = 0; i < ARRAY_SIZE(arr); i++) {
2245 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2246 if (find_symbol(kernel_symbol_name(s), &owner, NULL,
2248 pr_err("%s: exports duplicate symbol %s"
2250 mod->name, kernel_symbol_name(s),
2251 module_name(owner));
2259 /* Change all symbols so that st_value encodes the pointer directly. */
2260 static int simplify_symbols(struct module *mod, const struct load_info *info)
2262 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2263 Elf_Sym *sym = (void *)symsec->sh_addr;
2264 unsigned long secbase;
2267 const struct kernel_symbol *ksym;
2269 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2270 const char *name = info->strtab + sym[i].st_name;
2272 switch (sym[i].st_shndx) {
2274 /* Ignore common symbols */
2275 if (!strncmp(name, "__gnu_lto", 9))
2278 /* We compiled with -fno-common. These are not
2279 supposed to happen. */
2280 pr_debug("Common symbol: %s\n", name);
2281 pr_warn("%s: please compile with -fno-common\n",
2287 /* Don't need to do anything */
2288 pr_debug("Absolute symbol: 0x%08lx\n",
2289 (long)sym[i].st_value);
2293 /* Livepatch symbols are resolved by livepatch */
2297 ksym = resolve_symbol_wait(mod, info, name);
2298 /* Ok if resolved. */
2299 if (ksym && !IS_ERR(ksym)) {
2300 sym[i].st_value = kernel_symbol_value(ksym);
2305 if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
2308 ret = PTR_ERR(ksym) ?: -ENOENT;
2309 pr_warn("%s: Unknown symbol %s (err %d)\n",
2310 mod->name, name, ret);
2314 /* Divert to percpu allocation if a percpu var. */
2315 if (sym[i].st_shndx == info->index.pcpu)
2316 secbase = (unsigned long)mod_percpu(mod);
2318 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2319 sym[i].st_value += secbase;
2327 static int apply_relocations(struct module *mod, const struct load_info *info)
2332 /* Now do relocations. */
2333 for (i = 1; i < info->hdr->e_shnum; i++) {
2334 unsigned int infosec = info->sechdrs[i].sh_info;
2336 /* Not a valid relocation section? */
2337 if (infosec >= info->hdr->e_shnum)
2340 /* Don't bother with non-allocated sections */
2341 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2344 /* Livepatch relocation sections are applied by livepatch */
2345 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
2348 if (info->sechdrs[i].sh_type == SHT_REL)
2349 err = apply_relocate(info->sechdrs, info->strtab,
2350 info->index.sym, i, mod);
2351 else if (info->sechdrs[i].sh_type == SHT_RELA)
2352 err = apply_relocate_add(info->sechdrs, info->strtab,
2353 info->index.sym, i, mod);
2360 /* Additional bytes needed by arch in front of individual sections */
2361 unsigned int __weak arch_mod_section_prepend(struct module *mod,
2362 unsigned int section)
2364 /* default implementation just returns zero */
2368 /* Update size with this section: return offset. */
2369 static long get_offset(struct module *mod, unsigned int *size,
2370 Elf_Shdr *sechdr, unsigned int section)
2374 *size += arch_mod_section_prepend(mod, section);
2375 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2376 *size = ret + sechdr->sh_size;
2380 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2381 might -- code, read-only data, read-write data, small data. Tally
2382 sizes, and place the offsets into sh_entsize fields: high bit means it
2384 static void layout_sections(struct module *mod, struct load_info *info)
2386 static unsigned long const masks[][2] = {
2387 /* NOTE: all executable code must be the first section
2388 * in this array; otherwise modify the text_size
2389 * finder in the two loops below */
2390 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2391 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2392 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
2393 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2394 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2398 for (i = 0; i < info->hdr->e_shnum; i++)
2399 info->sechdrs[i].sh_entsize = ~0UL;
2401 pr_debug("Core section allocation order:\n");
2402 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2403 for (i = 0; i < info->hdr->e_shnum; ++i) {
2404 Elf_Shdr *s = &info->sechdrs[i];
2405 const char *sname = info->secstrings + s->sh_name;
2407 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2408 || (s->sh_flags & masks[m][1])
2409 || s->sh_entsize != ~0UL
2410 || strstarts(sname, ".init"))
2412 s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2413 pr_debug("\t%s\n", sname);
2416 case 0: /* executable */
2417 mod->core_layout.size = debug_align(mod->core_layout.size);
2418 mod->core_layout.text_size = mod->core_layout.size;
2420 case 1: /* RO: text and ro-data */
2421 mod->core_layout.size = debug_align(mod->core_layout.size);
2422 mod->core_layout.ro_size = mod->core_layout.size;
2424 case 2: /* RO after init */
2425 mod->core_layout.size = debug_align(mod->core_layout.size);
2426 mod->core_layout.ro_after_init_size = mod->core_layout.size;
2428 case 4: /* whole core */
2429 mod->core_layout.size = debug_align(mod->core_layout.size);
2434 pr_debug("Init section allocation order:\n");
2435 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2436 for (i = 0; i < info->hdr->e_shnum; ++i) {
2437 Elf_Shdr *s = &info->sechdrs[i];
2438 const char *sname = info->secstrings + s->sh_name;
2440 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2441 || (s->sh_flags & masks[m][1])
2442 || s->sh_entsize != ~0UL
2443 || !strstarts(sname, ".init"))
2445 s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
2446 | INIT_OFFSET_MASK);
2447 pr_debug("\t%s\n", sname);
2450 case 0: /* executable */
2451 mod->init_layout.size = debug_align(mod->init_layout.size);
2452 mod->init_layout.text_size = mod->init_layout.size;
2454 case 1: /* RO: text and ro-data */
2455 mod->init_layout.size = debug_align(mod->init_layout.size);
2456 mod->init_layout.ro_size = mod->init_layout.size;
2460 * RO after init doesn't apply to init_layout (only
2461 * core_layout), so it just takes the value of ro_size.
2463 mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
2465 case 4: /* whole init */
2466 mod->init_layout.size = debug_align(mod->init_layout.size);
2472 static void set_license(struct module *mod, const char *license)
2475 license = "unspecified";
2477 if (!license_is_gpl_compatible(license)) {
2478 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2479 pr_warn("%s: module license '%s' taints kernel.\n",
2480 mod->name, license);
2481 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2482 LOCKDEP_NOW_UNRELIABLE);
2486 /* Parse tag=value strings from .modinfo section */
2487 static char *next_string(char *string, unsigned long *secsize)
2489 /* Skip non-zero chars */
2492 if ((*secsize)-- <= 1)
2496 /* Skip any zero padding. */
2497 while (!string[0]) {
2499 if ((*secsize)-- <= 1)
2505 static char *get_modinfo(struct load_info *info, const char *tag)
2508 unsigned int taglen = strlen(tag);
2509 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2510 unsigned long size = infosec->sh_size;
2513 * get_modinfo() calls made before rewrite_section_headers()
2514 * must use sh_offset, as sh_addr isn't set!
2516 for (p = (char *)info->hdr + infosec->sh_offset; p; p = next_string(p, &size)) {
2517 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2518 return p + taglen + 1;
2523 static void setup_modinfo(struct module *mod, struct load_info *info)
2525 struct module_attribute *attr;
2528 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2530 attr->setup(mod, get_modinfo(info, attr->attr.name));
2534 static void free_modinfo(struct module *mod)
2536 struct module_attribute *attr;
2539 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2545 #ifdef CONFIG_KALLSYMS
2547 /* lookup symbol in given range of kernel_symbols */
2548 static const struct kernel_symbol *lookup_symbol(const char *name,
2549 const struct kernel_symbol *start,
2550 const struct kernel_symbol *stop)
2552 return bsearch(name, start, stop - start,
2553 sizeof(struct kernel_symbol), cmp_name);
2556 static int is_exported(const char *name, unsigned long value,
2557 const struct module *mod)
2559 const struct kernel_symbol *ks;
2561 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2563 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2564 return ks != NULL && kernel_symbol_value(ks) == value;
2568 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2570 const Elf_Shdr *sechdrs = info->sechdrs;
2572 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2573 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2578 if (sym->st_shndx == SHN_UNDEF)
2580 if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
2582 if (sym->st_shndx >= SHN_LORESERVE)
2584 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2586 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2587 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2588 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2590 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2595 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2596 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2601 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2608 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2609 unsigned int shnum, unsigned int pcpundx)
2611 const Elf_Shdr *sec;
2613 if (src->st_shndx == SHN_UNDEF
2614 || src->st_shndx >= shnum
2618 #ifdef CONFIG_KALLSYMS_ALL
2619 if (src->st_shndx == pcpundx)
2623 sec = sechdrs + src->st_shndx;
2624 if (!(sec->sh_flags & SHF_ALLOC)
2625 #ifndef CONFIG_KALLSYMS_ALL
2626 || !(sec->sh_flags & SHF_EXECINSTR)
2628 || (sec->sh_entsize & INIT_OFFSET_MASK))
2635 * We only allocate and copy the strings needed by the parts of symtab
2636 * we keep. This is simple, but has the effect of making multiple
2637 * copies of duplicates. We could be more sophisticated, see
2638 * linux-kernel thread starting with
2639 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2641 static void layout_symtab(struct module *mod, struct load_info *info)
2643 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2644 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2646 unsigned int i, nsrc, ndst, strtab_size = 0;
2648 /* Put symbol section at end of init part of module. */
2649 symsect->sh_flags |= SHF_ALLOC;
2650 symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2651 info->index.sym) | INIT_OFFSET_MASK;
2652 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2654 src = (void *)info->hdr + symsect->sh_offset;
2655 nsrc = symsect->sh_size / sizeof(*src);
2657 /* Compute total space required for the core symbols' strtab. */
2658 for (ndst = i = 0; i < nsrc; i++) {
2659 if (i == 0 || is_livepatch_module(mod) ||
2660 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2661 info->index.pcpu)) {
2662 strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2667 /* Append room for core symbols at end of core part. */
2668 info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
2669 info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
2670 mod->core_layout.size += strtab_size;
2671 mod->core_layout.size = debug_align(mod->core_layout.size);
2673 /* Put string table section at end of init part of module. */
2674 strsect->sh_flags |= SHF_ALLOC;
2675 strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2676 info->index.str) | INIT_OFFSET_MASK;
2677 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2679 /* We'll tack temporary mod_kallsyms on the end. */
2680 mod->init_layout.size = ALIGN(mod->init_layout.size,
2681 __alignof__(struct mod_kallsyms));
2682 info->mod_kallsyms_init_off = mod->init_layout.size;
2683 mod->init_layout.size += sizeof(struct mod_kallsyms);
2684 mod->init_layout.size = debug_align(mod->init_layout.size);
2688 * We use the full symtab and strtab which layout_symtab arranged to
2689 * be appended to the init section. Later we switch to the cut-down
2692 static void add_kallsyms(struct module *mod, const struct load_info *info)
2694 unsigned int i, ndst;
2698 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2700 /* Set up to point into init section. */
2701 mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
2703 mod->kallsyms->symtab = (void *)symsec->sh_addr;
2704 mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2705 /* Make sure we get permanent strtab: don't use info->strtab. */
2706 mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2708 /* Set types up while we still have access to sections. */
2709 for (i = 0; i < mod->kallsyms->num_symtab; i++)
2710 mod->kallsyms->symtab[i].st_info
2711 = elf_type(&mod->kallsyms->symtab[i], info);
2713 /* Now populate the cut down core kallsyms for after init. */
2714 mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
2715 mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
2716 src = mod->kallsyms->symtab;
2717 for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2718 if (i == 0 || is_livepatch_module(mod) ||
2719 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2720 info->index.pcpu)) {
2722 dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
2723 s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2727 mod->core_kallsyms.num_symtab = ndst;
2730 static inline void layout_symtab(struct module *mod, struct load_info *info)
2734 static void add_kallsyms(struct module *mod, const struct load_info *info)
2737 #endif /* CONFIG_KALLSYMS */
2739 static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num)
2743 #ifdef CONFIG_DYNAMIC_DEBUG
2744 if (ddebug_add_module(debug, num, mod->name))
2745 pr_err("dynamic debug error adding module: %s\n",
2750 static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug)
2753 ddebug_remove_module(mod->name);
2756 void * __weak module_alloc(unsigned long size)
2758 return vmalloc_exec(size);
2761 #ifdef CONFIG_DEBUG_KMEMLEAK
2762 static void kmemleak_load_module(const struct module *mod,
2763 const struct load_info *info)
2767 /* only scan the sections containing data */
2768 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2770 for (i = 1; i < info->hdr->e_shnum; i++) {
2771 /* Scan all writable sections that's not executable */
2772 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2773 !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2774 (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2777 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2778 info->sechdrs[i].sh_size, GFP_KERNEL);
2782 static inline void kmemleak_load_module(const struct module *mod,
2783 const struct load_info *info)
2788 #ifdef CONFIG_MODULE_SIG
2789 static int module_sig_check(struct load_info *info, int flags)
2792 const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2793 const void *mod = info->hdr;
2796 * Require flags == 0, as a module with version information
2797 * removed is no longer the module that was signed
2800 info->len > markerlen &&
2801 memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2802 /* We truncate the module to discard the signature */
2803 info->len -= markerlen;
2804 err = mod_verify_sig(mod, info);
2808 info->sig_ok = true;
2812 /* Not having a signature is only an error if we're strict. */
2813 if (err == -ENOKEY && !is_module_sig_enforced())
2818 #else /* !CONFIG_MODULE_SIG */
2819 static int module_sig_check(struct load_info *info, int flags)
2823 #endif /* !CONFIG_MODULE_SIG */
2825 /* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2826 static int elf_header_check(struct load_info *info)
2828 if (info->len < sizeof(*(info->hdr)))
2831 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2832 || info->hdr->e_type != ET_REL
2833 || !elf_check_arch(info->hdr)
2834 || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2837 if (info->hdr->e_shoff >= info->len
2838 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2839 info->len - info->hdr->e_shoff))
2845 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2847 static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
2850 unsigned long n = min(len, COPY_CHUNK_SIZE);
2852 if (copy_from_user(dst, usrc, n) != 0)
2862 #ifdef CONFIG_LIVEPATCH
2863 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2865 if (get_modinfo(info, "livepatch")) {
2867 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
2868 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
2874 #else /* !CONFIG_LIVEPATCH */
2875 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2877 if (get_modinfo(info, "livepatch")) {
2878 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
2885 #endif /* CONFIG_LIVEPATCH */
2887 static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
2889 if (retpoline_module_ok(get_modinfo(info, "retpoline")))
2892 pr_warn("%s: loading module not compiled with retpoline compiler.\n",
2896 /* Sets info->hdr and info->len. */
2897 static int copy_module_from_user(const void __user *umod, unsigned long len,
2898 struct load_info *info)
2903 if (info->len < sizeof(*(info->hdr)))
2906 err = security_kernel_load_data(LOADING_MODULE);
2910 /* Suck in entire file: we'll want most of it. */
2911 info->hdr = __vmalloc(info->len,
2912 GFP_KERNEL | __GFP_NOWARN, PAGE_KERNEL);
2916 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2924 static void free_copy(struct load_info *info)
2929 static int rewrite_section_headers(struct load_info *info, int flags)
2933 /* This should always be true, but let's be sure. */
2934 info->sechdrs[0].sh_addr = 0;
2936 for (i = 1; i < info->hdr->e_shnum; i++) {
2937 Elf_Shdr *shdr = &info->sechdrs[i];
2938 if (shdr->sh_type != SHT_NOBITS
2939 && info->len < shdr->sh_offset + shdr->sh_size) {
2940 pr_err("Module len %lu truncated\n", info->len);
2944 /* Mark all sections sh_addr with their address in the
2946 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2948 #ifndef CONFIG_MODULE_UNLOAD
2949 /* Don't load .exit sections */
2950 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2951 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2955 /* Track but don't keep modinfo and version sections. */
2956 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2957 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2963 * Set up our basic convenience variables (pointers to section headers,
2964 * search for module section index etc), and do some basic section
2967 * Set info->mod to the temporary copy of the module in info->hdr. The final one
2968 * will be allocated in move_module().
2970 static int setup_load_info(struct load_info *info, int flags)
2974 /* Set up the convenience variables */
2975 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2976 info->secstrings = (void *)info->hdr
2977 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2979 /* Try to find a name early so we can log errors with a module name */
2980 info->index.info = find_sec(info, ".modinfo");
2981 if (!info->index.info)
2982 info->name = "(missing .modinfo section)";
2984 info->name = get_modinfo(info, "name");
2986 /* Find internal symbols and strings. */
2987 for (i = 1; i < info->hdr->e_shnum; i++) {
2988 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2989 info->index.sym = i;
2990 info->index.str = info->sechdrs[i].sh_link;
2991 info->strtab = (char *)info->hdr
2992 + info->sechdrs[info->index.str].sh_offset;
2997 if (info->index.sym == 0) {
2998 pr_warn("%s: module has no symbols (stripped?)\n", info->name);
3002 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
3003 if (!info->index.mod) {
3004 pr_warn("%s: No module found in object\n",
3005 info->name ?: "(missing .modinfo name field)");
3008 /* This is temporary: point mod into copy of data. */
3009 info->mod = (void *)info->hdr + info->sechdrs[info->index.mod].sh_offset;
3012 * If we didn't load the .modinfo 'name' field earlier, fall back to
3013 * on-disk struct mod 'name' field.
3016 info->name = info->mod->name;
3018 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
3019 info->index.vers = 0; /* Pretend no __versions section! */
3021 info->index.vers = find_sec(info, "__versions");
3023 info->index.pcpu = find_pcpusec(info);
3028 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
3030 const char *modmagic = get_modinfo(info, "vermagic");
3033 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
3036 /* This is allowed: modprobe --force will invalidate it. */
3038 err = try_to_force_load(mod, "bad vermagic");
3041 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
3042 pr_err("%s: version magic '%s' should be '%s'\n",
3043 info->name, modmagic, vermagic);
3047 if (!get_modinfo(info, "intree")) {
3048 if (!test_taint(TAINT_OOT_MODULE))
3049 pr_warn("%s: loading out-of-tree module taints kernel.\n",
3051 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
3054 check_modinfo_retpoline(mod, info);
3056 if (get_modinfo(info, "staging")) {
3057 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
3058 pr_warn("%s: module is from the staging directory, the quality "
3059 "is unknown, you have been warned.\n", mod->name);
3062 err = check_modinfo_livepatch(mod, info);
3066 /* Set up license info based on the info section */
3067 set_license(mod, get_modinfo(info, "license"));
3072 static int find_module_sections(struct module *mod, struct load_info *info)
3074 mod->kp = section_objs(info, "__param",
3075 sizeof(*mod->kp), &mod->num_kp);
3076 mod->syms = section_objs(info, "__ksymtab",
3077 sizeof(*mod->syms), &mod->num_syms);
3078 mod->crcs = section_addr(info, "__kcrctab");
3079 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
3080 sizeof(*mod->gpl_syms),
3081 &mod->num_gpl_syms);
3082 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
3083 mod->gpl_future_syms = section_objs(info,
3084 "__ksymtab_gpl_future",
3085 sizeof(*mod->gpl_future_syms),
3086 &mod->num_gpl_future_syms);
3087 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
3089 #ifdef CONFIG_UNUSED_SYMBOLS
3090 mod->unused_syms = section_objs(info, "__ksymtab_unused",
3091 sizeof(*mod->unused_syms),
3092 &mod->num_unused_syms);
3093 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
3094 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
3095 sizeof(*mod->unused_gpl_syms),
3096 &mod->num_unused_gpl_syms);
3097 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
3099 #ifdef CONFIG_CONSTRUCTORS
3100 mod->ctors = section_objs(info, ".ctors",
3101 sizeof(*mod->ctors), &mod->num_ctors);
3103 mod->ctors = section_objs(info, ".init_array",
3104 sizeof(*mod->ctors), &mod->num_ctors);
3105 else if (find_sec(info, ".init_array")) {
3107 * This shouldn't happen with same compiler and binutils
3108 * building all parts of the module.
3110 pr_warn("%s: has both .ctors and .init_array.\n",
3116 #ifdef CONFIG_TRACEPOINTS
3117 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
3118 sizeof(*mod->tracepoints_ptrs),
3119 &mod->num_tracepoints);
3121 #ifdef CONFIG_JUMP_LABEL
3122 mod->jump_entries = section_objs(info, "__jump_table",
3123 sizeof(*mod->jump_entries),
3124 &mod->num_jump_entries);
3126 #ifdef CONFIG_EVENT_TRACING
3127 mod->trace_events = section_objs(info, "_ftrace_events",
3128 sizeof(*mod->trace_events),
3129 &mod->num_trace_events);
3130 mod->trace_evals = section_objs(info, "_ftrace_eval_map",
3131 sizeof(*mod->trace_evals),
3132 &mod->num_trace_evals);
3134 #ifdef CONFIG_TRACING
3135 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
3136 sizeof(*mod->trace_bprintk_fmt_start),
3137 &mod->num_trace_bprintk_fmt);
3139 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
3140 /* sechdrs[0].sh_size is always zero */
3141 mod->ftrace_callsites = section_objs(info, "__mcount_loc",
3142 sizeof(*mod->ftrace_callsites),
3143 &mod->num_ftrace_callsites);
3145 #ifdef CONFIG_FUNCTION_ERROR_INJECTION
3146 mod->ei_funcs = section_objs(info, "_error_injection_whitelist",
3147 sizeof(*mod->ei_funcs),
3148 &mod->num_ei_funcs);
3150 mod->extable = section_objs(info, "__ex_table",
3151 sizeof(*mod->extable), &mod->num_exentries);
3153 if (section_addr(info, "__obsparm"))
3154 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
3156 info->debug = section_objs(info, "__verbose",
3157 sizeof(*info->debug), &info->num_debug);
3162 static int move_module(struct module *mod, struct load_info *info)
3167 /* Do the allocs. */
3168 ptr = module_alloc(mod->core_layout.size);
3170 * The pointer to this block is stored in the module structure
3171 * which is inside the block. Just mark it as not being a
3174 kmemleak_not_leak(ptr);
3178 memset(ptr, 0, mod->core_layout.size);
3179 mod->core_layout.base = ptr;
3181 if (mod->init_layout.size) {
3182 ptr = module_alloc(mod->init_layout.size);
3184 * The pointer to this block is stored in the module structure
3185 * which is inside the block. This block doesn't need to be
3186 * scanned as it contains data and code that will be freed
3187 * after the module is initialized.
3189 kmemleak_ignore(ptr);
3191 module_memfree(mod->core_layout.base);
3194 memset(ptr, 0, mod->init_layout.size);
3195 mod->init_layout.base = ptr;
3197 mod->init_layout.base = NULL;
3199 /* Transfer each section which specifies SHF_ALLOC */
3200 pr_debug("final section addresses:\n");
3201 for (i = 0; i < info->hdr->e_shnum; i++) {
3203 Elf_Shdr *shdr = &info->sechdrs[i];
3205 if (!(shdr->sh_flags & SHF_ALLOC))
3208 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3209 dest = mod->init_layout.base
3210 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3212 dest = mod->core_layout.base + shdr->sh_entsize;
3214 if (shdr->sh_type != SHT_NOBITS)
3215 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3216 /* Update sh_addr to point to copy in image. */
3217 shdr->sh_addr = (unsigned long)dest;
3218 pr_debug("\t0x%lx %s\n",
3219 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3225 static int check_module_license_and_versions(struct module *mod)
3227 int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
3230 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3231 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3232 * using GPL-only symbols it needs.
3234 if (strcmp(mod->name, "ndiswrapper") == 0)
3235 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3237 /* driverloader was caught wrongly pretending to be under GPL */
3238 if (strcmp(mod->name, "driverloader") == 0)
3239 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3240 LOCKDEP_NOW_UNRELIABLE);
3242 /* lve claims to be GPL but upstream won't provide source */
3243 if (strcmp(mod->name, "lve") == 0)
3244 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3245 LOCKDEP_NOW_UNRELIABLE);
3247 if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
3248 pr_warn("%s: module license taints kernel.\n", mod->name);
3250 #ifdef CONFIG_MODVERSIONS
3251 if ((mod->num_syms && !mod->crcs)
3252 || (mod->num_gpl_syms && !mod->gpl_crcs)
3253 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3254 #ifdef CONFIG_UNUSED_SYMBOLS
3255 || (mod->num_unused_syms && !mod->unused_crcs)
3256 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3259 return try_to_force_load(mod,
3260 "no versions for exported symbols");
3266 static void flush_module_icache(const struct module *mod)
3268 mm_segment_t old_fs;
3270 /* flush the icache in correct context */
3275 * Flush the instruction cache, since we've played with text.
3276 * Do it before processing of module parameters, so the module
3277 * can provide parameter accessor functions of its own.
3279 if (mod->init_layout.base)
3280 flush_icache_range((unsigned long)mod->init_layout.base,
3281 (unsigned long)mod->init_layout.base
3282 + mod->init_layout.size);
3283 flush_icache_range((unsigned long)mod->core_layout.base,
3284 (unsigned long)mod->core_layout.base + mod->core_layout.size);
3289 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3297 /* module_blacklist is a comma-separated list of module names */
3298 static char *module_blacklist;
3299 static bool blacklisted(const char *module_name)
3304 if (!module_blacklist)
3307 for (p = module_blacklist; *p; p += len) {
3308 len = strcspn(p, ",");
3309 if (strlen(module_name) == len && !memcmp(module_name, p, len))
3316 core_param(module_blacklist, module_blacklist, charp, 0400);
3318 static struct module *layout_and_allocate(struct load_info *info, int flags)
3324 err = check_modinfo(info->mod, info, flags);
3326 return ERR_PTR(err);
3328 /* Allow arches to frob section contents and sizes. */
3329 err = module_frob_arch_sections(info->hdr, info->sechdrs,
3330 info->secstrings, info->mod);
3332 return ERR_PTR(err);
3334 /* We will do a special allocation for per-cpu sections later. */
3335 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3338 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3339 * layout_sections() can put it in the right place.
3340 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3342 ndx = find_sec(info, ".data..ro_after_init");
3344 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3346 /* Determine total sizes, and put offsets in sh_entsize. For now
3347 this is done generically; there doesn't appear to be any
3348 special cases for the architectures. */
3349 layout_sections(info->mod, info);
3350 layout_symtab(info->mod, info);
3352 /* Allocate and move to the final place */
3353 err = move_module(info->mod, info);
3355 return ERR_PTR(err);
3357 /* Module has been copied to its final place now: return it. */
3358 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3359 kmemleak_load_module(mod, info);
3363 /* mod is no longer valid after this! */
3364 static void module_deallocate(struct module *mod, struct load_info *info)
3366 percpu_modfree(mod);
3367 module_arch_freeing_init(mod);
3368 module_memfree(mod->init_layout.base);
3369 module_memfree(mod->core_layout.base);
3372 int __weak module_finalize(const Elf_Ehdr *hdr,
3373 const Elf_Shdr *sechdrs,
3379 static int post_relocation(struct module *mod, const struct load_info *info)
3381 /* Sort exception table now relocations are done. */
3382 sort_extable(mod->extable, mod->extable + mod->num_exentries);
3384 /* Copy relocated percpu area over. */
3385 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3386 info->sechdrs[info->index.pcpu].sh_size);
3388 /* Setup kallsyms-specific fields. */
3389 add_kallsyms(mod, info);
3391 /* Arch-specific module finalizing. */
3392 return module_finalize(info->hdr, info->sechdrs, mod);
3395 /* Is this module of this name done loading? No locks held. */
3396 static bool finished_loading(const char *name)
3402 * The module_mutex should not be a heavily contended lock;
3403 * if we get the occasional sleep here, we'll go an extra iteration
3404 * in the wait_event_interruptible(), which is harmless.
3406 sched_annotate_sleep();
3407 mutex_lock(&module_mutex);
3408 mod = find_module_all(name, strlen(name), true);
3409 ret = !mod || mod->state == MODULE_STATE_LIVE;
3410 mutex_unlock(&module_mutex);
3415 /* Call module constructors. */
3416 static void do_mod_ctors(struct module *mod)
3418 #ifdef CONFIG_CONSTRUCTORS
3421 for (i = 0; i < mod->num_ctors; i++)
3426 /* For freeing module_init on success, in case kallsyms traversing */
3427 struct mod_initfree {
3428 struct rcu_head rcu;
3432 static void do_free_init(struct rcu_head *head)
3434 struct mod_initfree *m = container_of(head, struct mod_initfree, rcu);
3435 module_memfree(m->module_init);
3440 * This is where the real work happens.
3442 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3443 * helper command 'lx-symbols'.
3445 static noinline int do_init_module(struct module *mod)
3448 struct mod_initfree *freeinit;
3450 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3455 freeinit->module_init = mod->init_layout.base;
3458 * We want to find out whether @mod uses async during init. Clear
3459 * PF_USED_ASYNC. async_schedule*() will set it.
3461 current->flags &= ~PF_USED_ASYNC;
3464 /* Start the module */
3465 if (mod->init != NULL)
3466 ret = do_one_initcall(mod->init);
3468 goto fail_free_freeinit;
3471 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3472 "follow 0/-E convention\n"
3473 "%s: loading module anyway...\n",
3474 __func__, mod->name, ret, __func__);
3478 /* Now it's a first class citizen! */
3479 mod->state = MODULE_STATE_LIVE;
3480 blocking_notifier_call_chain(&module_notify_list,
3481 MODULE_STATE_LIVE, mod);
3484 * We need to finish all async code before the module init sequence
3485 * is done. This has potential to deadlock. For example, a newly
3486 * detected block device can trigger request_module() of the
3487 * default iosched from async probing task. Once userland helper
3488 * reaches here, async_synchronize_full() will wait on the async
3489 * task waiting on request_module() and deadlock.
3491 * This deadlock is avoided by perfomring async_synchronize_full()
3492 * iff module init queued any async jobs. This isn't a full
3493 * solution as it will deadlock the same if module loading from
3494 * async jobs nests more than once; however, due to the various
3495 * constraints, this hack seems to be the best option for now.
3496 * Please refer to the following thread for details.
3498 * http://thread.gmane.org/gmane.linux.kernel/1420814
3500 if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3501 async_synchronize_full();
3503 ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base +
3504 mod->init_layout.size);
3505 mutex_lock(&module_mutex);
3506 /* Drop initial reference. */
3508 trim_init_extable(mod);
3509 #ifdef CONFIG_KALLSYMS
3510 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3511 rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3513 module_enable_ro(mod, true);
3514 mod_tree_remove_init(mod);
3515 disable_ro_nx(&mod->init_layout);
3516 module_arch_freeing_init(mod);
3517 mod->init_layout.base = NULL;
3518 mod->init_layout.size = 0;
3519 mod->init_layout.ro_size = 0;
3520 mod->init_layout.ro_after_init_size = 0;
3521 mod->init_layout.text_size = 0;
3523 * We want to free module_init, but be aware that kallsyms may be
3524 * walking this with preempt disabled. In all the failure paths, we
3525 * call synchronize_sched(), but we don't want to slow down the success
3526 * path, so use actual RCU here.
3527 * Note that module_alloc() on most architectures creates W+X page
3528 * mappings which won't be cleaned up until do_free_init() runs. Any
3529 * code such as mark_rodata_ro() which depends on those mappings to
3530 * be cleaned up needs to sync with the queued work - ie
3531 * rcu_barrier_sched()
3533 call_rcu_sched(&freeinit->rcu, do_free_init);
3534 mutex_unlock(&module_mutex);
3535 wake_up_all(&module_wq);
3542 /* Try to protect us from buggy refcounters. */
3543 mod->state = MODULE_STATE_GOING;
3544 synchronize_sched();
3546 blocking_notifier_call_chain(&module_notify_list,
3547 MODULE_STATE_GOING, mod);
3548 klp_module_going(mod);
3549 ftrace_release_mod(mod);
3551 wake_up_all(&module_wq);
3555 static int may_init_module(void)
3557 if (!capable(CAP_SYS_MODULE) || modules_disabled)
3564 * We try to place it in the list now to make sure it's unique before
3565 * we dedicate too many resources. In particular, temporary percpu
3566 * memory exhaustion.
3568 static int add_unformed_module(struct module *mod)
3573 mod->state = MODULE_STATE_UNFORMED;
3576 mutex_lock(&module_mutex);
3577 old = find_module_all(mod->name, strlen(mod->name), true);
3579 if (old->state != MODULE_STATE_LIVE) {
3580 /* Wait in case it fails to load. */
3581 mutex_unlock(&module_mutex);
3582 err = wait_event_interruptible(module_wq,
3583 finished_loading(mod->name));
3591 mod_update_bounds(mod);
3592 list_add_rcu(&mod->list, &modules);
3593 mod_tree_insert(mod);
3597 mutex_unlock(&module_mutex);
3602 static int complete_formation(struct module *mod, struct load_info *info)
3606 mutex_lock(&module_mutex);
3608 /* Find duplicate symbols (must be called under lock). */
3609 err = verify_export_symbols(mod);
3613 /* This relies on module_mutex for list integrity. */
3614 module_bug_finalize(info->hdr, info->sechdrs, mod);
3616 module_enable_ro(mod, false);
3617 module_enable_nx(mod);
3618 module_enable_x(mod);
3620 /* Mark state as coming so strong_try_module_get() ignores us,
3621 * but kallsyms etc. can see us. */
3622 mod->state = MODULE_STATE_COMING;
3623 mutex_unlock(&module_mutex);
3628 mutex_unlock(&module_mutex);
3632 static int prepare_coming_module(struct module *mod)
3636 ftrace_module_enable(mod);
3637 err = klp_module_coming(mod);
3641 blocking_notifier_call_chain(&module_notify_list,
3642 MODULE_STATE_COMING, mod);
3646 static int unknown_module_param_cb(char *param, char *val, const char *modname,
3649 struct module *mod = arg;
3652 if (strcmp(param, "async_probe") == 0) {
3653 mod->async_probe_requested = true;
3657 /* Check for magic 'dyndbg' arg */
3658 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3660 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3664 /* Allocate and load the module: note that size of section 0 is always
3665 zero, and we rely on this for optional sections. */
3666 static int load_module(struct load_info *info, const char __user *uargs,
3673 err = elf_header_check(info);
3677 err = setup_load_info(info, flags);
3681 if (blacklisted(info->name)) {
3686 err = module_sig_check(info, flags);
3690 err = rewrite_section_headers(info, flags);
3694 /* Check module struct version now, before we try to use module. */
3695 if (!check_modstruct_version(info, info->mod)) {
3700 /* Figure out module layout, and allocate all the memory. */
3701 mod = layout_and_allocate(info, flags);
3707 audit_log_kern_module(mod->name);
3709 /* Reserve our place in the list. */
3710 err = add_unformed_module(mod);
3714 #ifdef CONFIG_MODULE_SIG
3715 mod->sig_ok = info->sig_ok;
3717 pr_notice_once("%s: module verification failed: signature "
3718 "and/or required key missing - tainting "
3719 "kernel\n", mod->name);
3720 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3724 /* To avoid stressing percpu allocator, do this once we're unique. */
3725 err = percpu_modalloc(mod, info);
3729 /* Now module is in final location, initialize linked lists, etc. */
3730 err = module_unload_init(mod);
3734 init_param_lock(mod);
3736 /* Now we've got everything in the final locations, we can
3737 * find optional sections. */
3738 err = find_module_sections(mod, info);
3742 err = check_module_license_and_versions(mod);
3746 /* Set up MODINFO_ATTR fields */
3747 setup_modinfo(mod, info);
3749 /* Fix up syms, so that st_value is a pointer to location. */
3750 err = simplify_symbols(mod, info);
3754 err = apply_relocations(mod, info);
3758 err = post_relocation(mod, info);
3762 flush_module_icache(mod);
3764 /* Now copy in args */
3765 mod->args = strndup_user(uargs, ~0UL >> 1);
3766 if (IS_ERR(mod->args)) {
3767 err = PTR_ERR(mod->args);
3768 goto free_arch_cleanup;
3771 dynamic_debug_setup(mod, info->debug, info->num_debug);
3773 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3774 ftrace_module_init(mod);
3776 /* Finally it's fully formed, ready to start executing. */
3777 err = complete_formation(mod, info);
3779 goto ddebug_cleanup;
3781 err = prepare_coming_module(mod);
3785 /* Module is ready to execute: parsing args may do that. */
3786 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3788 unknown_module_param_cb);
3789 if (IS_ERR(after_dashes)) {
3790 err = PTR_ERR(after_dashes);
3791 goto coming_cleanup;
3792 } else if (after_dashes) {
3793 pr_warn("%s: parameters '%s' after `--' ignored\n",
3794 mod->name, after_dashes);
3797 /* Link in to sysfs. */
3798 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3800 goto coming_cleanup;
3802 if (is_livepatch_module(mod)) {
3803 err = copy_module_elf(mod, info);
3808 /* Get rid of temporary copy. */
3812 trace_module_load(mod);
3814 return do_init_module(mod);
3817 mod_sysfs_teardown(mod);
3819 mod->state = MODULE_STATE_GOING;
3820 destroy_params(mod->kp, mod->num_kp);
3821 blocking_notifier_call_chain(&module_notify_list,
3822 MODULE_STATE_GOING, mod);
3823 klp_module_going(mod);
3825 /* module_bug_cleanup needs module_mutex protection */
3826 mutex_lock(&module_mutex);
3827 module_bug_cleanup(mod);
3828 mutex_unlock(&module_mutex);
3830 /* we can't deallocate the module until we clear memory protection */
3831 module_disable_ro(mod);
3832 module_disable_nx(mod);
3835 ftrace_release_mod(mod);
3836 dynamic_debug_remove(mod, info->debug);
3837 synchronize_sched();
3840 module_arch_cleanup(mod);
3844 module_unload_free(mod);
3846 mutex_lock(&module_mutex);
3847 /* Unlink carefully: kallsyms could be walking list. */
3848 list_del_rcu(&mod->list);
3849 mod_tree_remove(mod);
3850 wake_up_all(&module_wq);
3851 /* Wait for RCU-sched synchronizing before releasing mod->list. */
3852 synchronize_sched();
3853 mutex_unlock(&module_mutex);
3855 /* Free lock-classes; relies on the preceding sync_rcu() */
3856 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
3858 module_deallocate(mod, info);
3864 SYSCALL_DEFINE3(init_module, void __user *, umod,
3865 unsigned long, len, const char __user *, uargs)
3868 struct load_info info = { };
3870 err = may_init_module();
3874 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3877 err = copy_module_from_user(umod, len, &info);
3881 return load_module(&info, uargs, 0);
3884 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3886 struct load_info info = { };
3891 err = may_init_module();
3895 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3897 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3898 |MODULE_INIT_IGNORE_VERMAGIC))
3901 err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX,
3908 return load_module(&info, uargs, flags);
3911 static inline int within(unsigned long addr, void *start, unsigned long size)
3913 return ((void *)addr >= start && (void *)addr < start + size);
3916 #ifdef CONFIG_KALLSYMS
3918 * This ignores the intensely annoying "mapping symbols" found
3919 * in ARM ELF files: $a, $t and $d.
3921 static inline int is_arm_mapping_symbol(const char *str)
3923 if (str[0] == '.' && str[1] == 'L')
3925 return str[0] == '$' && strchr("axtd", str[1])
3926 && (str[2] == '\0' || str[2] == '.');
3929 static const char *symname(struct mod_kallsyms *kallsyms, unsigned int symnum)
3931 return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
3934 static const char *get_ksymbol(struct module *mod,
3936 unsigned long *size,
3937 unsigned long *offset)
3939 unsigned int i, best = 0;
3940 unsigned long nextval;
3941 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
3943 /* At worse, next value is at end of module */
3944 if (within_module_init(addr, mod))
3945 nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
3947 nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
3949 /* Scan for closest preceding symbol, and next symbol. (ELF
3950 starts real symbols at 1). */
3951 for (i = 1; i < kallsyms->num_symtab; i++) {
3952 if (kallsyms->symtab[i].st_shndx == SHN_UNDEF)
3955 /* We ignore unnamed symbols: they're uninformative
3956 * and inserted at a whim. */
3957 if (*symname(kallsyms, i) == '\0'
3958 || is_arm_mapping_symbol(symname(kallsyms, i)))
3961 if (kallsyms->symtab[i].st_value <= addr
3962 && kallsyms->symtab[i].st_value > kallsyms->symtab[best].st_value)
3964 if (kallsyms->symtab[i].st_value > addr
3965 && kallsyms->symtab[i].st_value < nextval)
3966 nextval = kallsyms->symtab[i].st_value;
3973 *size = nextval - kallsyms->symtab[best].st_value;
3975 *offset = addr - kallsyms->symtab[best].st_value;
3976 return symname(kallsyms, best);
3979 void * __weak dereference_module_function_descriptor(struct module *mod,
3985 /* For kallsyms to ask for address resolution. NULL means not found. Careful
3986 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3987 const char *module_address_lookup(unsigned long addr,
3988 unsigned long *size,
3989 unsigned long *offset,
3993 const char *ret = NULL;
3997 mod = __module_address(addr);
4000 *modname = mod->name;
4001 ret = get_ksymbol(mod, addr, size, offset);
4003 /* Make a copy in here where it's safe */
4005 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
4013 int lookup_module_symbol_name(unsigned long addr, char *symname)
4018 list_for_each_entry_rcu(mod, &modules, list) {
4019 if (mod->state == MODULE_STATE_UNFORMED)
4021 if (within_module(addr, mod)) {
4024 sym = get_ksymbol(mod, addr, NULL, NULL);
4027 strlcpy(symname, sym, KSYM_NAME_LEN);
4037 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
4038 unsigned long *offset, char *modname, char *name)
4043 list_for_each_entry_rcu(mod, &modules, list) {
4044 if (mod->state == MODULE_STATE_UNFORMED)
4046 if (within_module(addr, mod)) {
4049 sym = get_ksymbol(mod, addr, size, offset);
4053 strlcpy(modname, mod->name, MODULE_NAME_LEN);
4055 strlcpy(name, sym, KSYM_NAME_LEN);
4065 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
4066 char *name, char *module_name, int *exported)
4071 list_for_each_entry_rcu(mod, &modules, list) {
4072 struct mod_kallsyms *kallsyms;
4074 if (mod->state == MODULE_STATE_UNFORMED)
4076 kallsyms = rcu_dereference_sched(mod->kallsyms);
4077 if (symnum < kallsyms->num_symtab) {
4078 *value = kallsyms->symtab[symnum].st_value;
4079 *type = kallsyms->symtab[symnum].st_info;
4080 strlcpy(name, symname(kallsyms, symnum), KSYM_NAME_LEN);
4081 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
4082 *exported = is_exported(name, *value, mod);
4086 symnum -= kallsyms->num_symtab;
4092 static unsigned long mod_find_symname(struct module *mod, const char *name)
4095 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4097 for (i = 0; i < kallsyms->num_symtab; i++)
4098 if (strcmp(name, symname(kallsyms, i)) == 0 &&
4099 kallsyms->symtab[i].st_shndx != SHN_UNDEF)
4100 return kallsyms->symtab[i].st_value;
4104 /* Look for this name: can be of form module:name. */
4105 unsigned long module_kallsyms_lookup_name(const char *name)
4109 unsigned long ret = 0;
4111 /* Don't lock: we're in enough trouble already. */
4113 if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
4114 if ((mod = find_module_all(name, colon - name, false)) != NULL)
4115 ret = mod_find_symname(mod, colon+1);
4117 list_for_each_entry_rcu(mod, &modules, list) {
4118 if (mod->state == MODULE_STATE_UNFORMED)
4120 if ((ret = mod_find_symname(mod, name)) != 0)
4128 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
4129 struct module *, unsigned long),
4136 module_assert_mutex();
4138 list_for_each_entry(mod, &modules, list) {
4139 /* We hold module_mutex: no need for rcu_dereference_sched */
4140 struct mod_kallsyms *kallsyms = mod->kallsyms;
4142 if (mod->state == MODULE_STATE_UNFORMED)
4144 for (i = 0; i < kallsyms->num_symtab; i++) {
4146 if (kallsyms->symtab[i].st_shndx == SHN_UNDEF)
4149 ret = fn(data, symname(kallsyms, i),
4150 mod, kallsyms->symtab[i].st_value);
4157 #endif /* CONFIG_KALLSYMS */
4159 /* Maximum number of characters written by module_flags() */
4160 #define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
4162 /* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
4163 static char *module_flags(struct module *mod, char *buf)
4167 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
4169 mod->state == MODULE_STATE_GOING ||
4170 mod->state == MODULE_STATE_COMING) {
4172 bx += module_flags_taint(mod, buf + bx);
4173 /* Show a - for module-is-being-unloaded */
4174 if (mod->state == MODULE_STATE_GOING)
4176 /* Show a + for module-is-being-loaded */
4177 if (mod->state == MODULE_STATE_COMING)
4186 #ifdef CONFIG_PROC_FS
4187 /* Called by the /proc file system to return a list of modules. */
4188 static void *m_start(struct seq_file *m, loff_t *pos)
4190 mutex_lock(&module_mutex);
4191 return seq_list_start(&modules, *pos);
4194 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
4196 return seq_list_next(p, &modules, pos);
4199 static void m_stop(struct seq_file *m, void *p)
4201 mutex_unlock(&module_mutex);
4204 static int m_show(struct seq_file *m, void *p)
4206 struct module *mod = list_entry(p, struct module, list);
4207 char buf[MODULE_FLAGS_BUF_SIZE];
4210 /* We always ignore unformed modules. */
4211 if (mod->state == MODULE_STATE_UNFORMED)
4214 seq_printf(m, "%s %u",
4215 mod->name, mod->init_layout.size + mod->core_layout.size);
4216 print_unload_info(m, mod);
4218 /* Informative for users. */
4219 seq_printf(m, " %s",
4220 mod->state == MODULE_STATE_GOING ? "Unloading" :
4221 mod->state == MODULE_STATE_COMING ? "Loading" :
4223 /* Used by oprofile and other similar tools. */
4224 value = m->private ? NULL : mod->core_layout.base;
4225 seq_printf(m, " 0x%px", value);
4229 seq_printf(m, " %s", module_flags(mod, buf));
4235 /* Format: modulename size refcount deps address
4237 Where refcount is a number or -, and deps is a comma-separated list
4240 static const struct seq_operations modules_op = {
4248 * This also sets the "private" pointer to non-NULL if the
4249 * kernel pointers should be hidden (so you can just test
4250 * "m->private" to see if you should keep the values private).
4252 * We use the same logic as for /proc/kallsyms.
4254 static int modules_open(struct inode *inode, struct file *file)
4256 int err = seq_open(file, &modules_op);
4259 struct seq_file *m = file->private_data;
4260 m->private = kallsyms_show_value() ? NULL : (void *)8ul;
4266 static const struct file_operations proc_modules_operations = {
4267 .open = modules_open,
4269 .llseek = seq_lseek,
4270 .release = seq_release,
4273 static int __init proc_modules_init(void)
4275 proc_create("modules", 0, NULL, &proc_modules_operations);
4278 module_init(proc_modules_init);
4281 /* Given an address, look for it in the module exception tables. */
4282 const struct exception_table_entry *search_module_extables(unsigned long addr)
4284 const struct exception_table_entry *e = NULL;
4288 mod = __module_address(addr);
4292 if (!mod->num_exentries)
4295 e = search_extable(mod->extable,
4302 * Now, if we found one, we are running inside it now, hence
4303 * we cannot unload the module, hence no refcnt needed.
4309 * is_module_address - is this address inside a module?
4310 * @addr: the address to check.
4312 * See is_module_text_address() if you simply want to see if the address
4313 * is code (not data).
4315 bool is_module_address(unsigned long addr)
4320 ret = __module_address(addr) != NULL;
4327 * __module_address - get the module which contains an address.
4328 * @addr: the address.
4330 * Must be called with preempt disabled or module mutex held so that
4331 * module doesn't get freed during this.
4333 struct module *__module_address(unsigned long addr)
4337 if (addr < module_addr_min || addr > module_addr_max)
4340 module_assert_mutex_or_preempt();
4342 mod = mod_find(addr);
4344 BUG_ON(!within_module(addr, mod));
4345 if (mod->state == MODULE_STATE_UNFORMED)
4350 EXPORT_SYMBOL_GPL(__module_address);
4353 * is_module_text_address - is this address inside module code?
4354 * @addr: the address to check.
4356 * See is_module_address() if you simply want to see if the address is
4357 * anywhere in a module. See kernel_text_address() for testing if an
4358 * address corresponds to kernel or module code.
4360 bool is_module_text_address(unsigned long addr)
4365 ret = __module_text_address(addr) != NULL;
4372 * __module_text_address - get the module whose code contains an address.
4373 * @addr: the address.
4375 * Must be called with preempt disabled or module mutex held so that
4376 * module doesn't get freed during this.
4378 struct module *__module_text_address(unsigned long addr)
4380 struct module *mod = __module_address(addr);
4382 /* Make sure it's within the text section. */
4383 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
4384 && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
4389 EXPORT_SYMBOL_GPL(__module_text_address);
4391 /* Don't grab lock, we're oopsing. */
4392 void print_modules(void)
4395 char buf[MODULE_FLAGS_BUF_SIZE];
4397 printk(KERN_DEFAULT "Modules linked in:");
4398 /* Most callers should already have preempt disabled, but make sure */
4400 list_for_each_entry_rcu(mod, &modules, list) {
4401 if (mod->state == MODULE_STATE_UNFORMED)
4403 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4406 if (last_unloaded_module[0])
4407 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4411 #ifdef CONFIG_MODVERSIONS
4412 /* Generate the signature for all relevant module structures here.
4413 * If these change, we don't want to try to parse the module. */
4414 void module_layout(struct module *mod,
4415 struct modversion_info *ver,
4416 struct kernel_param *kp,
4417 struct kernel_symbol *ks,
4418 struct tracepoint * const *tp)
4421 EXPORT_SYMBOL(module_layout);