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, but
80 * only when CONFIG_STRICT_MODULE_RWX=y
82 #ifdef CONFIG_STRICT_MODULE_RWX
83 # define debug_align(X) ALIGN(X, PAGE_SIZE)
85 # define debug_align(X) (X)
88 /* If this is set, the section belongs in the init part of the module */
89 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
93 * 1) List of modules (also safely readable with preempt_disable),
94 * 2) module_use links,
95 * 3) module_addr_min/module_addr_max.
96 * (delete and add uses RCU list operations). */
97 DEFINE_MUTEX(module_mutex);
98 EXPORT_SYMBOL_GPL(module_mutex);
99 static LIST_HEAD(modules);
101 #ifdef CONFIG_MODULES_TREE_LOOKUP
104 * Use a latched RB-tree for __module_address(); this allows us to use
105 * RCU-sched lookups of the address from any context.
107 * This is conditional on PERF_EVENTS || TRACING because those can really hit
108 * __module_address() hard by doing a lot of stack unwinding; potentially from
112 static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
114 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
116 return (unsigned long)layout->base;
119 static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
121 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
123 return (unsigned long)layout->size;
126 static __always_inline bool
127 mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
129 return __mod_tree_val(a) < __mod_tree_val(b);
132 static __always_inline int
133 mod_tree_comp(void *key, struct latch_tree_node *n)
135 unsigned long val = (unsigned long)key;
136 unsigned long start, end;
138 start = __mod_tree_val(n);
142 end = start + __mod_tree_size(n);
149 static const struct latch_tree_ops mod_tree_ops = {
150 .less = mod_tree_less,
151 .comp = mod_tree_comp,
154 static struct mod_tree_root {
155 struct latch_tree_root root;
156 unsigned long addr_min;
157 unsigned long addr_max;
158 } mod_tree __cacheline_aligned = {
162 #define module_addr_min mod_tree.addr_min
163 #define module_addr_max mod_tree.addr_max
165 static noinline void __mod_tree_insert(struct mod_tree_node *node)
167 latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
170 static void __mod_tree_remove(struct mod_tree_node *node)
172 latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
176 * These modifications: insert, remove_init and remove; are serialized by the
179 static void mod_tree_insert(struct module *mod)
181 mod->core_layout.mtn.mod = mod;
182 mod->init_layout.mtn.mod = mod;
184 __mod_tree_insert(&mod->core_layout.mtn);
185 if (mod->init_layout.size)
186 __mod_tree_insert(&mod->init_layout.mtn);
189 static void mod_tree_remove_init(struct module *mod)
191 if (mod->init_layout.size)
192 __mod_tree_remove(&mod->init_layout.mtn);
195 static void mod_tree_remove(struct module *mod)
197 __mod_tree_remove(&mod->core_layout.mtn);
198 mod_tree_remove_init(mod);
201 static struct module *mod_find(unsigned long addr)
203 struct latch_tree_node *ltn;
205 ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
209 return container_of(ltn, struct mod_tree_node, node)->mod;
212 #else /* MODULES_TREE_LOOKUP */
214 static unsigned long module_addr_min = -1UL, module_addr_max = 0;
216 static void mod_tree_insert(struct module *mod) { }
217 static void mod_tree_remove_init(struct module *mod) { }
218 static void mod_tree_remove(struct module *mod) { }
220 static struct module *mod_find(unsigned long addr)
224 list_for_each_entry_rcu(mod, &modules, list) {
225 if (within_module(addr, mod))
232 #endif /* MODULES_TREE_LOOKUP */
235 * Bounds of module text, for speeding up __module_address.
236 * Protected by module_mutex.
238 static void __mod_update_bounds(void *base, unsigned int size)
240 unsigned long min = (unsigned long)base;
241 unsigned long max = min + size;
243 if (min < module_addr_min)
244 module_addr_min = min;
245 if (max > module_addr_max)
246 module_addr_max = max;
249 static void mod_update_bounds(struct module *mod)
251 __mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
252 if (mod->init_layout.size)
253 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
256 #ifdef CONFIG_KGDB_KDB
257 struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
258 #endif /* CONFIG_KGDB_KDB */
260 static void module_assert_mutex(void)
262 lockdep_assert_held(&module_mutex);
265 static void module_assert_mutex_or_preempt(void)
267 #ifdef CONFIG_LOCKDEP
268 if (unlikely(!debug_locks))
271 WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
272 !lockdep_is_held(&module_mutex));
276 static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
277 #ifndef CONFIG_MODULE_SIG_FORCE
278 module_param(sig_enforce, bool_enable_only, 0644);
279 #endif /* !CONFIG_MODULE_SIG_FORCE */
281 /* Block module loading/unloading? */
282 int modules_disabled = 0;
283 core_param(nomodule, modules_disabled, bint, 0);
285 /* Waiting for a module to finish initializing? */
286 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
288 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
290 int register_module_notifier(struct notifier_block *nb)
292 return blocking_notifier_chain_register(&module_notify_list, nb);
294 EXPORT_SYMBOL(register_module_notifier);
296 int unregister_module_notifier(struct notifier_block *nb)
298 return blocking_notifier_chain_unregister(&module_notify_list, nb);
300 EXPORT_SYMBOL(unregister_module_notifier);
307 char *secstrings, *strtab;
308 unsigned long symoffs, stroffs;
309 struct _ddebug *debug;
310 unsigned int num_debug;
312 #ifdef CONFIG_KALLSYMS
313 unsigned long mod_kallsyms_init_off;
316 unsigned int sym, str, mod, vers, info, pcpu;
321 * We require a truly strong try_module_get(): 0 means success.
322 * Otherwise an error is returned due to ongoing or failed
323 * initialization etc.
325 static inline int strong_try_module_get(struct module *mod)
327 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
328 if (mod && mod->state == MODULE_STATE_COMING)
330 if (try_module_get(mod))
336 static inline void add_taint_module(struct module *mod, unsigned flag,
337 enum lockdep_ok lockdep_ok)
339 add_taint(flag, lockdep_ok);
340 set_bit(flag, &mod->taints);
344 * A thread that wants to hold a reference to a module only while it
345 * is running can call this to safely exit. nfsd and lockd use this.
347 void __noreturn __module_put_and_exit(struct module *mod, long code)
352 EXPORT_SYMBOL(__module_put_and_exit);
354 /* Find a module section: 0 means not found. */
355 static unsigned int find_sec(const struct load_info *info, const char *name)
359 for (i = 1; i < info->hdr->e_shnum; i++) {
360 Elf_Shdr *shdr = &info->sechdrs[i];
361 /* Alloc bit cleared means "ignore it." */
362 if ((shdr->sh_flags & SHF_ALLOC)
363 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
369 /* Find a module section, or NULL. */
370 static void *section_addr(const struct load_info *info, const char *name)
372 /* Section 0 has sh_addr 0. */
373 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
376 /* Find a module section, or NULL. Fill in number of "objects" in section. */
377 static void *section_objs(const struct load_info *info,
382 unsigned int sec = find_sec(info, name);
384 /* Section 0 has sh_addr 0 and sh_size 0. */
385 *num = info->sechdrs[sec].sh_size / object_size;
386 return (void *)info->sechdrs[sec].sh_addr;
389 /* Provided by the linker */
390 extern const struct kernel_symbol __start___ksymtab[];
391 extern const struct kernel_symbol __stop___ksymtab[];
392 extern const struct kernel_symbol __start___ksymtab_gpl[];
393 extern const struct kernel_symbol __stop___ksymtab_gpl[];
394 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
395 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
396 extern const s32 __start___kcrctab[];
397 extern const s32 __start___kcrctab_gpl[];
398 extern const s32 __start___kcrctab_gpl_future[];
399 #ifdef CONFIG_UNUSED_SYMBOLS
400 extern const struct kernel_symbol __start___ksymtab_unused[];
401 extern const struct kernel_symbol __stop___ksymtab_unused[];
402 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
403 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
404 extern const s32 __start___kcrctab_unused[];
405 extern const s32 __start___kcrctab_unused_gpl[];
408 #ifndef CONFIG_MODVERSIONS
409 #define symversion(base, idx) NULL
411 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
414 static bool each_symbol_in_section(const struct symsearch *arr,
415 unsigned int arrsize,
416 struct module *owner,
417 bool (*fn)(const struct symsearch *syms,
418 struct module *owner,
424 for (j = 0; j < arrsize; j++) {
425 if (fn(&arr[j], owner, data))
432 /* Returns true as soon as fn returns true, otherwise false. */
433 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
434 struct module *owner,
439 static const struct symsearch arr[] = {
440 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
441 NOT_GPL_ONLY, false },
442 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
443 __start___kcrctab_gpl,
445 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
446 __start___kcrctab_gpl_future,
447 WILL_BE_GPL_ONLY, false },
448 #ifdef CONFIG_UNUSED_SYMBOLS
449 { __start___ksymtab_unused, __stop___ksymtab_unused,
450 __start___kcrctab_unused,
451 NOT_GPL_ONLY, true },
452 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
453 __start___kcrctab_unused_gpl,
458 module_assert_mutex_or_preempt();
460 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
463 list_for_each_entry_rcu(mod, &modules, list) {
464 struct symsearch arr[] = {
465 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
466 NOT_GPL_ONLY, false },
467 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
470 { mod->gpl_future_syms,
471 mod->gpl_future_syms + mod->num_gpl_future_syms,
472 mod->gpl_future_crcs,
473 WILL_BE_GPL_ONLY, false },
474 #ifdef CONFIG_UNUSED_SYMBOLS
476 mod->unused_syms + mod->num_unused_syms,
478 NOT_GPL_ONLY, true },
479 { mod->unused_gpl_syms,
480 mod->unused_gpl_syms + mod->num_unused_gpl_syms,
481 mod->unused_gpl_crcs,
486 if (mod->state == MODULE_STATE_UNFORMED)
489 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
494 EXPORT_SYMBOL_GPL(each_symbol_section);
496 struct find_symbol_arg {
503 struct module *owner;
505 const struct kernel_symbol *sym;
508 static bool check_symbol(const struct symsearch *syms,
509 struct module *owner,
510 unsigned int symnum, void *data)
512 struct find_symbol_arg *fsa = data;
515 if (syms->licence == GPL_ONLY)
517 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
518 pr_warn("Symbol %s is being used by a non-GPL module, "
519 "which will not be allowed in the future\n",
524 #ifdef CONFIG_UNUSED_SYMBOLS
525 if (syms->unused && fsa->warn) {
526 pr_warn("Symbol %s is marked as UNUSED, however this module is "
527 "using it.\n", fsa->name);
528 pr_warn("This symbol will go away in the future.\n");
529 pr_warn("Please evaluate if this is the right api to use and "
530 "if it really is, submit a report to the linux kernel "
531 "mailing list together with submitting your code for "
537 fsa->crc = symversion(syms->crcs, symnum);
538 fsa->sym = &syms->start[symnum];
542 static int cmp_name(const void *va, const void *vb)
545 const struct kernel_symbol *b;
547 return strcmp(a, b->name);
550 static bool find_symbol_in_section(const struct symsearch *syms,
551 struct module *owner,
554 struct find_symbol_arg *fsa = data;
555 struct kernel_symbol *sym;
557 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
558 sizeof(struct kernel_symbol), cmp_name);
560 if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
566 /* Find a symbol and return it, along with, (optional) crc and
567 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
568 const struct kernel_symbol *find_symbol(const char *name,
569 struct module **owner,
574 struct find_symbol_arg fsa;
580 if (each_symbol_section(find_symbol_in_section, &fsa)) {
588 pr_debug("Failed to find symbol %s\n", name);
591 EXPORT_SYMBOL_GPL(find_symbol);
594 * Search for module by name: must hold module_mutex (or preempt disabled
595 * for read-only access).
597 static struct module *find_module_all(const char *name, size_t len,
602 module_assert_mutex_or_preempt();
604 list_for_each_entry_rcu(mod, &modules, list) {
605 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
607 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
613 struct module *find_module(const char *name)
615 module_assert_mutex();
616 return find_module_all(name, strlen(name), false);
618 EXPORT_SYMBOL_GPL(find_module);
622 static inline void __percpu *mod_percpu(struct module *mod)
627 static int percpu_modalloc(struct module *mod, struct load_info *info)
629 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
630 unsigned long align = pcpusec->sh_addralign;
632 if (!pcpusec->sh_size)
635 if (align > PAGE_SIZE) {
636 pr_warn("%s: per-cpu alignment %li > %li\n",
637 mod->name, align, PAGE_SIZE);
641 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
643 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
644 mod->name, (unsigned long)pcpusec->sh_size);
647 mod->percpu_size = pcpusec->sh_size;
651 static void percpu_modfree(struct module *mod)
653 free_percpu(mod->percpu);
656 static unsigned int find_pcpusec(struct load_info *info)
658 return find_sec(info, ".data..percpu");
661 static void percpu_modcopy(struct module *mod,
662 const void *from, unsigned long size)
666 for_each_possible_cpu(cpu)
667 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
670 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
677 list_for_each_entry_rcu(mod, &modules, list) {
678 if (mod->state == MODULE_STATE_UNFORMED)
680 if (!mod->percpu_size)
682 for_each_possible_cpu(cpu) {
683 void *start = per_cpu_ptr(mod->percpu, cpu);
684 void *va = (void *)addr;
686 if (va >= start && va < start + mod->percpu_size) {
688 *can_addr = (unsigned long) (va - start);
689 *can_addr += (unsigned long)
690 per_cpu_ptr(mod->percpu,
704 * is_module_percpu_address - test whether address is from module static percpu
705 * @addr: address to test
707 * Test whether @addr belongs to module static percpu area.
710 * %true if @addr is from module static percpu area
712 bool is_module_percpu_address(unsigned long addr)
714 return __is_module_percpu_address(addr, NULL);
717 #else /* ... !CONFIG_SMP */
719 static inline void __percpu *mod_percpu(struct module *mod)
723 static int percpu_modalloc(struct module *mod, struct load_info *info)
725 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
726 if (info->sechdrs[info->index.pcpu].sh_size != 0)
730 static inline void percpu_modfree(struct module *mod)
733 static unsigned int find_pcpusec(struct load_info *info)
737 static inline void percpu_modcopy(struct module *mod,
738 const void *from, unsigned long size)
740 /* pcpusec should be 0, and size of that section should be 0. */
743 bool is_module_percpu_address(unsigned long addr)
748 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
753 #endif /* CONFIG_SMP */
755 #define MODINFO_ATTR(field) \
756 static void setup_modinfo_##field(struct module *mod, const char *s) \
758 mod->field = kstrdup(s, GFP_KERNEL); \
760 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
761 struct module_kobject *mk, char *buffer) \
763 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
765 static int modinfo_##field##_exists(struct module *mod) \
767 return mod->field != NULL; \
769 static void free_modinfo_##field(struct module *mod) \
774 static struct module_attribute modinfo_##field = { \
775 .attr = { .name = __stringify(field), .mode = 0444 }, \
776 .show = show_modinfo_##field, \
777 .setup = setup_modinfo_##field, \
778 .test = modinfo_##field##_exists, \
779 .free = free_modinfo_##field, \
782 MODINFO_ATTR(version);
783 MODINFO_ATTR(srcversion);
785 static char last_unloaded_module[MODULE_NAME_LEN+1];
787 #ifdef CONFIG_MODULE_UNLOAD
789 EXPORT_TRACEPOINT_SYMBOL(module_get);
791 /* MODULE_REF_BASE is the base reference count by kmodule loader. */
792 #define MODULE_REF_BASE 1
794 /* Init the unload section of the module. */
795 static int module_unload_init(struct module *mod)
798 * Initialize reference counter to MODULE_REF_BASE.
799 * refcnt == 0 means module is going.
801 atomic_set(&mod->refcnt, MODULE_REF_BASE);
803 INIT_LIST_HEAD(&mod->source_list);
804 INIT_LIST_HEAD(&mod->target_list);
806 /* Hold reference count during initialization. */
807 atomic_inc(&mod->refcnt);
812 /* Does a already use b? */
813 static int already_uses(struct module *a, struct module *b)
815 struct module_use *use;
817 list_for_each_entry(use, &b->source_list, source_list) {
818 if (use->source == a) {
819 pr_debug("%s uses %s!\n", a->name, b->name);
823 pr_debug("%s does not use %s!\n", a->name, b->name);
829 * - we add 'a' as a "source", 'b' as a "target" of module use
830 * - the module_use is added to the list of 'b' sources (so
831 * 'b' can walk the list to see who sourced them), and of 'a'
832 * targets (so 'a' can see what modules it targets).
834 static int add_module_usage(struct module *a, struct module *b)
836 struct module_use *use;
838 pr_debug("Allocating new usage for %s.\n", a->name);
839 use = kmalloc(sizeof(*use), GFP_ATOMIC);
845 list_add(&use->source_list, &b->source_list);
846 list_add(&use->target_list, &a->target_list);
850 /* Module a uses b: caller needs module_mutex() */
851 int ref_module(struct module *a, struct module *b)
855 if (b == NULL || already_uses(a, b))
858 /* If module isn't available, we fail. */
859 err = strong_try_module_get(b);
863 err = add_module_usage(a, b);
870 EXPORT_SYMBOL_GPL(ref_module);
872 /* Clear the unload stuff of the module. */
873 static void module_unload_free(struct module *mod)
875 struct module_use *use, *tmp;
877 mutex_lock(&module_mutex);
878 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
879 struct module *i = use->target;
880 pr_debug("%s unusing %s\n", mod->name, i->name);
882 list_del(&use->source_list);
883 list_del(&use->target_list);
886 mutex_unlock(&module_mutex);
889 #ifdef CONFIG_MODULE_FORCE_UNLOAD
890 static inline int try_force_unload(unsigned int flags)
892 int ret = (flags & O_TRUNC);
894 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
898 static inline int try_force_unload(unsigned int flags)
902 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
904 /* Try to release refcount of module, 0 means success. */
905 static int try_release_module_ref(struct module *mod)
909 /* Try to decrement refcnt which we set at loading */
910 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
913 /* Someone can put this right now, recover with checking */
914 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
919 static int try_stop_module(struct module *mod, int flags, int *forced)
921 /* If it's not unused, quit unless we're forcing. */
922 if (try_release_module_ref(mod) != 0) {
923 *forced = try_force_unload(flags);
928 /* Mark it as dying. */
929 mod->state = MODULE_STATE_GOING;
935 * module_refcount - return the refcount or -1 if unloading
937 * @mod: the module we're checking
940 * -1 if the module is in the process of unloading
941 * otherwise the number of references in the kernel to the module
943 int module_refcount(struct module *mod)
945 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
947 EXPORT_SYMBOL(module_refcount);
949 /* This exists whether we can unload or not */
950 static void free_module(struct module *mod);
952 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
956 char name[MODULE_NAME_LEN];
959 if (!capable(CAP_SYS_MODULE) || modules_disabled)
962 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
964 name[MODULE_NAME_LEN-1] = '\0';
966 audit_log_kern_module(name);
968 if (mutex_lock_interruptible(&module_mutex) != 0)
971 mod = find_module(name);
977 if (!list_empty(&mod->source_list)) {
978 /* Other modules depend on us: get rid of them first. */
983 /* Doing init or already dying? */
984 if (mod->state != MODULE_STATE_LIVE) {
985 /* FIXME: if (force), slam module count damn the torpedoes */
986 pr_debug("%s already dying\n", mod->name);
991 /* If it has an init func, it must have an exit func to unload */
992 if (mod->init && !mod->exit) {
993 forced = try_force_unload(flags);
995 /* This module can't be removed */
1001 /* Stop the machine so refcounts can't move and disable module. */
1002 ret = try_stop_module(mod, flags, &forced);
1006 mutex_unlock(&module_mutex);
1007 /* Final destruction now no one is using it. */
1008 if (mod->exit != NULL)
1010 blocking_notifier_call_chain(&module_notify_list,
1011 MODULE_STATE_GOING, mod);
1012 klp_module_going(mod);
1013 ftrace_release_mod(mod);
1015 async_synchronize_full();
1017 /* Store the name of the last unloaded module for diagnostic purposes */
1018 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
1023 mutex_unlock(&module_mutex);
1027 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1029 struct module_use *use;
1030 int printed_something = 0;
1032 seq_printf(m, " %i ", module_refcount(mod));
1035 * Always include a trailing , so userspace can differentiate
1036 * between this and the old multi-field proc format.
1038 list_for_each_entry(use, &mod->source_list, source_list) {
1039 printed_something = 1;
1040 seq_printf(m, "%s,", use->source->name);
1043 if (mod->init != NULL && mod->exit == NULL) {
1044 printed_something = 1;
1045 seq_puts(m, "[permanent],");
1048 if (!printed_something)
1052 void __symbol_put(const char *symbol)
1054 struct module *owner;
1057 if (!find_symbol(symbol, &owner, NULL, true, false))
1062 EXPORT_SYMBOL(__symbol_put);
1064 /* Note this assumes addr is a function, which it currently always is. */
1065 void symbol_put_addr(void *addr)
1067 struct module *modaddr;
1068 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1070 if (core_kernel_text(a))
1074 * Even though we hold a reference on the module; we still need to
1075 * disable preemption in order to safely traverse the data structure.
1078 modaddr = __module_text_address(a);
1080 module_put(modaddr);
1083 EXPORT_SYMBOL_GPL(symbol_put_addr);
1085 static ssize_t show_refcnt(struct module_attribute *mattr,
1086 struct module_kobject *mk, char *buffer)
1088 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1091 static struct module_attribute modinfo_refcnt =
1092 __ATTR(refcnt, 0444, show_refcnt, NULL);
1094 void __module_get(struct module *module)
1098 atomic_inc(&module->refcnt);
1099 trace_module_get(module, _RET_IP_);
1103 EXPORT_SYMBOL(__module_get);
1105 bool try_module_get(struct module *module)
1111 /* Note: here, we can fail to get a reference */
1112 if (likely(module_is_live(module) &&
1113 atomic_inc_not_zero(&module->refcnt) != 0))
1114 trace_module_get(module, _RET_IP_);
1122 EXPORT_SYMBOL(try_module_get);
1124 void module_put(struct module *module)
1130 ret = atomic_dec_if_positive(&module->refcnt);
1131 WARN_ON(ret < 0); /* Failed to put refcount */
1132 trace_module_put(module, _RET_IP_);
1136 EXPORT_SYMBOL(module_put);
1138 #else /* !CONFIG_MODULE_UNLOAD */
1139 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1141 /* We don't know the usage count, or what modules are using. */
1142 seq_puts(m, " - -");
1145 static inline void module_unload_free(struct module *mod)
1149 int ref_module(struct module *a, struct module *b)
1151 return strong_try_module_get(b);
1153 EXPORT_SYMBOL_GPL(ref_module);
1155 static inline int module_unload_init(struct module *mod)
1159 #endif /* CONFIG_MODULE_UNLOAD */
1161 static size_t module_flags_taint(struct module *mod, char *buf)
1166 for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
1167 if (taint_flags[i].module && test_bit(i, &mod->taints))
1168 buf[l++] = taint_flags[i].c_true;
1174 static ssize_t show_initstate(struct module_attribute *mattr,
1175 struct module_kobject *mk, char *buffer)
1177 const char *state = "unknown";
1179 switch (mk->mod->state) {
1180 case MODULE_STATE_LIVE:
1183 case MODULE_STATE_COMING:
1186 case MODULE_STATE_GOING:
1192 return sprintf(buffer, "%s\n", state);
1195 static struct module_attribute modinfo_initstate =
1196 __ATTR(initstate, 0444, show_initstate, NULL);
1198 static ssize_t store_uevent(struct module_attribute *mattr,
1199 struct module_kobject *mk,
1200 const char *buffer, size_t count)
1202 kobject_synth_uevent(&mk->kobj, buffer, count);
1206 struct module_attribute module_uevent =
1207 __ATTR(uevent, 0200, NULL, store_uevent);
1209 static ssize_t show_coresize(struct module_attribute *mattr,
1210 struct module_kobject *mk, char *buffer)
1212 return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1215 static struct module_attribute modinfo_coresize =
1216 __ATTR(coresize, 0444, show_coresize, NULL);
1218 static ssize_t show_initsize(struct module_attribute *mattr,
1219 struct module_kobject *mk, char *buffer)
1221 return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1224 static struct module_attribute modinfo_initsize =
1225 __ATTR(initsize, 0444, show_initsize, NULL);
1227 static ssize_t show_taint(struct module_attribute *mattr,
1228 struct module_kobject *mk, char *buffer)
1232 l = module_flags_taint(mk->mod, buffer);
1237 static struct module_attribute modinfo_taint =
1238 __ATTR(taint, 0444, show_taint, NULL);
1240 static struct module_attribute *modinfo_attrs[] = {
1243 &modinfo_srcversion,
1248 #ifdef CONFIG_MODULE_UNLOAD
1254 static const char vermagic[] = VERMAGIC_STRING;
1256 static int try_to_force_load(struct module *mod, const char *reason)
1258 #ifdef CONFIG_MODULE_FORCE_LOAD
1259 if (!test_taint(TAINT_FORCED_MODULE))
1260 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1261 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1268 #ifdef CONFIG_MODVERSIONS
1270 static u32 resolve_rel_crc(const s32 *crc)
1272 return *(u32 *)((void *)crc + *crc);
1275 static int check_version(const struct load_info *info,
1276 const char *symname,
1280 Elf_Shdr *sechdrs = info->sechdrs;
1281 unsigned int versindex = info->index.vers;
1282 unsigned int i, num_versions;
1283 struct modversion_info *versions;
1285 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1289 /* No versions at all? modprobe --force does this. */
1291 return try_to_force_load(mod, symname) == 0;
1293 versions = (void *) sechdrs[versindex].sh_addr;
1294 num_versions = sechdrs[versindex].sh_size
1295 / sizeof(struct modversion_info);
1297 for (i = 0; i < num_versions; i++) {
1300 if (strcmp(versions[i].name, symname) != 0)
1303 if (IS_ENABLED(CONFIG_MODULE_REL_CRCS))
1304 crcval = resolve_rel_crc(crc);
1307 if (versions[i].crc == crcval)
1309 pr_debug("Found checksum %X vs module %lX\n",
1310 crcval, versions[i].crc);
1314 /* Broken toolchain. Warn once, then let it go.. */
1315 pr_warn_once("%s: no symbol version for %s\n", info->name, symname);
1319 pr_warn("%s: disagrees about version of symbol %s\n",
1320 info->name, symname);
1324 static inline int check_modstruct_version(const struct load_info *info,
1330 * Since this should be found in kernel (which can't be removed), no
1331 * locking is necessary -- use preempt_disable() to placate lockdep.
1334 if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
1335 &crc, true, false)) {
1340 return check_version(info, VMLINUX_SYMBOL_STR(module_layout),
1344 /* First part is kernel version, which we ignore if module has crcs. */
1345 static inline int same_magic(const char *amagic, const char *bmagic,
1349 amagic += strcspn(amagic, " ");
1350 bmagic += strcspn(bmagic, " ");
1352 return strcmp(amagic, bmagic) == 0;
1355 static inline int check_version(const struct load_info *info,
1356 const char *symname,
1363 static inline int check_modstruct_version(const struct load_info *info,
1369 static inline int same_magic(const char *amagic, const char *bmagic,
1372 return strcmp(amagic, bmagic) == 0;
1374 #endif /* CONFIG_MODVERSIONS */
1376 /* Resolve a symbol for this module. I.e. if we find one, record usage. */
1377 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1378 const struct load_info *info,
1382 struct module *owner;
1383 const struct kernel_symbol *sym;
1388 * The module_mutex should not be a heavily contended lock;
1389 * if we get the occasional sleep here, we'll go an extra iteration
1390 * in the wait_event_interruptible(), which is harmless.
1392 sched_annotate_sleep();
1393 mutex_lock(&module_mutex);
1394 sym = find_symbol(name, &owner, &crc,
1395 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1399 if (!check_version(info, name, mod, crc)) {
1400 sym = ERR_PTR(-EINVAL);
1404 err = ref_module(mod, owner);
1411 /* We must make copy under the lock if we failed to get ref. */
1412 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1414 mutex_unlock(&module_mutex);
1418 static const struct kernel_symbol *
1419 resolve_symbol_wait(struct module *mod,
1420 const struct load_info *info,
1423 const struct kernel_symbol *ksym;
1424 char owner[MODULE_NAME_LEN];
1426 if (wait_event_interruptible_timeout(module_wq,
1427 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1428 || PTR_ERR(ksym) != -EBUSY,
1430 pr_warn("%s: gave up waiting for init of module %s.\n",
1437 * /sys/module/foo/sections stuff
1438 * J. Corbet <corbet@lwn.net>
1442 #ifdef CONFIG_KALLSYMS
1443 static inline bool sect_empty(const Elf_Shdr *sect)
1445 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1448 struct module_sect_attr {
1449 struct module_attribute mattr;
1451 unsigned long address;
1454 struct module_sect_attrs {
1455 struct attribute_group grp;
1456 unsigned int nsections;
1457 struct module_sect_attr attrs[0];
1460 static ssize_t module_sect_show(struct module_attribute *mattr,
1461 struct module_kobject *mk, char *buf)
1463 struct module_sect_attr *sattr =
1464 container_of(mattr, struct module_sect_attr, mattr);
1465 return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1468 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1470 unsigned int section;
1472 for (section = 0; section < sect_attrs->nsections; section++)
1473 kfree(sect_attrs->attrs[section].name);
1477 static void add_sect_attrs(struct module *mod, const struct load_info *info)
1479 unsigned int nloaded = 0, i, size[2];
1480 struct module_sect_attrs *sect_attrs;
1481 struct module_sect_attr *sattr;
1482 struct attribute **gattr;
1484 /* Count loaded sections and allocate structures */
1485 for (i = 0; i < info->hdr->e_shnum; i++)
1486 if (!sect_empty(&info->sechdrs[i]))
1488 size[0] = ALIGN(sizeof(*sect_attrs)
1489 + nloaded * sizeof(sect_attrs->attrs[0]),
1490 sizeof(sect_attrs->grp.attrs[0]));
1491 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1492 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1493 if (sect_attrs == NULL)
1496 /* Setup section attributes. */
1497 sect_attrs->grp.name = "sections";
1498 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1500 sect_attrs->nsections = 0;
1501 sattr = §_attrs->attrs[0];
1502 gattr = §_attrs->grp.attrs[0];
1503 for (i = 0; i < info->hdr->e_shnum; i++) {
1504 Elf_Shdr *sec = &info->sechdrs[i];
1505 if (sect_empty(sec))
1507 sattr->address = sec->sh_addr;
1508 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1510 if (sattr->name == NULL)
1512 sect_attrs->nsections++;
1513 sysfs_attr_init(&sattr->mattr.attr);
1514 sattr->mattr.show = module_sect_show;
1515 sattr->mattr.store = NULL;
1516 sattr->mattr.attr.name = sattr->name;
1517 sattr->mattr.attr.mode = S_IRUGO;
1518 *(gattr++) = &(sattr++)->mattr.attr;
1522 if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp))
1525 mod->sect_attrs = sect_attrs;
1528 free_sect_attrs(sect_attrs);
1531 static void remove_sect_attrs(struct module *mod)
1533 if (mod->sect_attrs) {
1534 sysfs_remove_group(&mod->mkobj.kobj,
1535 &mod->sect_attrs->grp);
1536 /* We are positive that no one is using any sect attrs
1537 * at this point. Deallocate immediately. */
1538 free_sect_attrs(mod->sect_attrs);
1539 mod->sect_attrs = NULL;
1544 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1547 struct module_notes_attrs {
1548 struct kobject *dir;
1550 struct bin_attribute attrs[0];
1553 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1554 struct bin_attribute *bin_attr,
1555 char *buf, loff_t pos, size_t count)
1558 * The caller checked the pos and count against our size.
1560 memcpy(buf, bin_attr->private + pos, count);
1564 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1567 if (notes_attrs->dir) {
1569 sysfs_remove_bin_file(notes_attrs->dir,
1570 ¬es_attrs->attrs[i]);
1571 kobject_put(notes_attrs->dir);
1576 static void add_notes_attrs(struct module *mod, const struct load_info *info)
1578 unsigned int notes, loaded, i;
1579 struct module_notes_attrs *notes_attrs;
1580 struct bin_attribute *nattr;
1582 /* failed to create section attributes, so can't create notes */
1583 if (!mod->sect_attrs)
1586 /* Count notes sections and allocate structures. */
1588 for (i = 0; i < info->hdr->e_shnum; i++)
1589 if (!sect_empty(&info->sechdrs[i]) &&
1590 (info->sechdrs[i].sh_type == SHT_NOTE))
1596 notes_attrs = kzalloc(sizeof(*notes_attrs)
1597 + notes * sizeof(notes_attrs->attrs[0]),
1599 if (notes_attrs == NULL)
1602 notes_attrs->notes = notes;
1603 nattr = ¬es_attrs->attrs[0];
1604 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1605 if (sect_empty(&info->sechdrs[i]))
1607 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1608 sysfs_bin_attr_init(nattr);
1609 nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1610 nattr->attr.mode = S_IRUGO;
1611 nattr->size = info->sechdrs[i].sh_size;
1612 nattr->private = (void *) info->sechdrs[i].sh_addr;
1613 nattr->read = module_notes_read;
1619 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1620 if (!notes_attrs->dir)
1623 for (i = 0; i < notes; ++i)
1624 if (sysfs_create_bin_file(notes_attrs->dir,
1625 ¬es_attrs->attrs[i]))
1628 mod->notes_attrs = notes_attrs;
1632 free_notes_attrs(notes_attrs, i);
1635 static void remove_notes_attrs(struct module *mod)
1637 if (mod->notes_attrs)
1638 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1643 static inline void add_sect_attrs(struct module *mod,
1644 const struct load_info *info)
1648 static inline void remove_sect_attrs(struct module *mod)
1652 static inline void add_notes_attrs(struct module *mod,
1653 const struct load_info *info)
1657 static inline void remove_notes_attrs(struct module *mod)
1660 #endif /* CONFIG_KALLSYMS */
1662 static void del_usage_links(struct module *mod)
1664 #ifdef CONFIG_MODULE_UNLOAD
1665 struct module_use *use;
1667 mutex_lock(&module_mutex);
1668 list_for_each_entry(use, &mod->target_list, target_list)
1669 sysfs_remove_link(use->target->holders_dir, mod->name);
1670 mutex_unlock(&module_mutex);
1674 static int add_usage_links(struct module *mod)
1677 #ifdef CONFIG_MODULE_UNLOAD
1678 struct module_use *use;
1680 mutex_lock(&module_mutex);
1681 list_for_each_entry(use, &mod->target_list, target_list) {
1682 ret = sysfs_create_link(use->target->holders_dir,
1683 &mod->mkobj.kobj, mod->name);
1687 mutex_unlock(&module_mutex);
1689 del_usage_links(mod);
1694 static int module_add_modinfo_attrs(struct module *mod)
1696 struct module_attribute *attr;
1697 struct module_attribute *temp_attr;
1701 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1702 (ARRAY_SIZE(modinfo_attrs) + 1)),
1704 if (!mod->modinfo_attrs)
1707 temp_attr = mod->modinfo_attrs;
1708 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1709 if (!attr->test || attr->test(mod)) {
1710 memcpy(temp_attr, attr, sizeof(*temp_attr));
1711 sysfs_attr_init(&temp_attr->attr);
1712 error = sysfs_create_file(&mod->mkobj.kobj,
1720 static void module_remove_modinfo_attrs(struct module *mod)
1722 struct module_attribute *attr;
1725 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1726 /* pick a field to test for end of list */
1727 if (!attr->attr.name)
1729 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1733 kfree(mod->modinfo_attrs);
1736 static void mod_kobject_put(struct module *mod)
1738 DECLARE_COMPLETION_ONSTACK(c);
1739 mod->mkobj.kobj_completion = &c;
1740 kobject_put(&mod->mkobj.kobj);
1741 wait_for_completion(&c);
1744 static int mod_sysfs_init(struct module *mod)
1747 struct kobject *kobj;
1749 if (!module_sysfs_initialized) {
1750 pr_err("%s: module sysfs not initialized\n", mod->name);
1755 kobj = kset_find_obj(module_kset, mod->name);
1757 pr_err("%s: module is already loaded\n", mod->name);
1763 mod->mkobj.mod = mod;
1765 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1766 mod->mkobj.kobj.kset = module_kset;
1767 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1770 mod_kobject_put(mod);
1772 /* delay uevent until full sysfs population */
1777 static int mod_sysfs_setup(struct module *mod,
1778 const struct load_info *info,
1779 struct kernel_param *kparam,
1780 unsigned int num_params)
1784 err = mod_sysfs_init(mod);
1788 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1789 if (!mod->holders_dir) {
1794 err = module_param_sysfs_setup(mod, kparam, num_params);
1796 goto out_unreg_holders;
1798 err = module_add_modinfo_attrs(mod);
1800 goto out_unreg_param;
1802 err = add_usage_links(mod);
1804 goto out_unreg_modinfo_attrs;
1806 add_sect_attrs(mod, info);
1807 add_notes_attrs(mod, info);
1809 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1812 out_unreg_modinfo_attrs:
1813 module_remove_modinfo_attrs(mod);
1815 module_param_sysfs_remove(mod);
1817 kobject_put(mod->holders_dir);
1819 mod_kobject_put(mod);
1824 static void mod_sysfs_fini(struct module *mod)
1826 remove_notes_attrs(mod);
1827 remove_sect_attrs(mod);
1828 mod_kobject_put(mod);
1831 static void init_param_lock(struct module *mod)
1833 mutex_init(&mod->param_lock);
1835 #else /* !CONFIG_SYSFS */
1837 static int mod_sysfs_setup(struct module *mod,
1838 const struct load_info *info,
1839 struct kernel_param *kparam,
1840 unsigned int num_params)
1845 static void mod_sysfs_fini(struct module *mod)
1849 static void module_remove_modinfo_attrs(struct module *mod)
1853 static void del_usage_links(struct module *mod)
1857 static void init_param_lock(struct module *mod)
1860 #endif /* CONFIG_SYSFS */
1862 static void mod_sysfs_teardown(struct module *mod)
1864 del_usage_links(mod);
1865 module_remove_modinfo_attrs(mod);
1866 module_param_sysfs_remove(mod);
1867 kobject_put(mod->mkobj.drivers_dir);
1868 kobject_put(mod->holders_dir);
1869 mod_sysfs_fini(mod);
1872 #ifdef CONFIG_STRICT_MODULE_RWX
1874 * LKM RO/NX protection: protect module's text/ro-data
1875 * from modification and any data from execution.
1877 * General layout of module is:
1878 * [text] [read-only-data] [ro-after-init] [writable data]
1879 * text_size -----^ ^ ^ ^
1880 * ro_size ------------------------| | |
1881 * ro_after_init_size -----------------------------| |
1882 * size -----------------------------------------------------------|
1884 * These values are always page-aligned (as is base)
1886 static void frob_text(const struct module_layout *layout,
1887 int (*set_memory)(unsigned long start, int num_pages))
1889 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1890 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1891 set_memory((unsigned long)layout->base,
1892 layout->text_size >> PAGE_SHIFT);
1895 static void frob_rodata(const struct module_layout *layout,
1896 int (*set_memory)(unsigned long start, int num_pages))
1898 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1899 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1900 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1901 set_memory((unsigned long)layout->base + layout->text_size,
1902 (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
1905 static void frob_ro_after_init(const struct module_layout *layout,
1906 int (*set_memory)(unsigned long start, int num_pages))
1908 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1909 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1910 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1911 set_memory((unsigned long)layout->base + layout->ro_size,
1912 (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
1915 static void frob_writable_data(const struct module_layout *layout,
1916 int (*set_memory)(unsigned long start, int num_pages))
1918 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1919 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1920 BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
1921 set_memory((unsigned long)layout->base + layout->ro_after_init_size,
1922 (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
1925 /* livepatching wants to disable read-only so it can frob module. */
1926 void module_disable_ro(const struct module *mod)
1928 if (!rodata_enabled)
1931 frob_text(&mod->core_layout, set_memory_rw);
1932 frob_rodata(&mod->core_layout, set_memory_rw);
1933 frob_ro_after_init(&mod->core_layout, set_memory_rw);
1934 frob_text(&mod->init_layout, set_memory_rw);
1935 frob_rodata(&mod->init_layout, set_memory_rw);
1938 void module_enable_ro(const struct module *mod, bool after_init)
1940 if (!rodata_enabled)
1943 frob_text(&mod->core_layout, set_memory_ro);
1944 frob_rodata(&mod->core_layout, set_memory_ro);
1945 frob_text(&mod->init_layout, set_memory_ro);
1946 frob_rodata(&mod->init_layout, set_memory_ro);
1949 frob_ro_after_init(&mod->core_layout, set_memory_ro);
1952 static void module_enable_nx(const struct module *mod)
1954 frob_rodata(&mod->core_layout, set_memory_nx);
1955 frob_ro_after_init(&mod->core_layout, set_memory_nx);
1956 frob_writable_data(&mod->core_layout, set_memory_nx);
1957 frob_rodata(&mod->init_layout, set_memory_nx);
1958 frob_writable_data(&mod->init_layout, set_memory_nx);
1961 static void module_disable_nx(const struct module *mod)
1963 frob_rodata(&mod->core_layout, set_memory_x);
1964 frob_ro_after_init(&mod->core_layout, set_memory_x);
1965 frob_writable_data(&mod->core_layout, set_memory_x);
1966 frob_rodata(&mod->init_layout, set_memory_x);
1967 frob_writable_data(&mod->init_layout, set_memory_x);
1970 /* Iterate through all modules and set each module's text as RW */
1971 void set_all_modules_text_rw(void)
1975 if (!rodata_enabled)
1978 mutex_lock(&module_mutex);
1979 list_for_each_entry_rcu(mod, &modules, list) {
1980 if (mod->state == MODULE_STATE_UNFORMED)
1983 frob_text(&mod->core_layout, set_memory_rw);
1984 frob_text(&mod->init_layout, set_memory_rw);
1986 mutex_unlock(&module_mutex);
1989 /* Iterate through all modules and set each module's text as RO */
1990 void set_all_modules_text_ro(void)
1994 if (!rodata_enabled)
1997 mutex_lock(&module_mutex);
1998 list_for_each_entry_rcu(mod, &modules, list) {
2000 * Ignore going modules since it's possible that ro
2001 * protection has already been disabled, otherwise we'll
2002 * run into protection faults at module deallocation.
2004 if (mod->state == MODULE_STATE_UNFORMED ||
2005 mod->state == MODULE_STATE_GOING)
2008 frob_text(&mod->core_layout, set_memory_ro);
2009 frob_text(&mod->init_layout, set_memory_ro);
2011 mutex_unlock(&module_mutex);
2014 static void disable_ro_nx(const struct module_layout *layout)
2016 if (rodata_enabled) {
2017 frob_text(layout, set_memory_rw);
2018 frob_rodata(layout, set_memory_rw);
2019 frob_ro_after_init(layout, set_memory_rw);
2021 frob_rodata(layout, set_memory_x);
2022 frob_ro_after_init(layout, set_memory_x);
2023 frob_writable_data(layout, set_memory_x);
2027 static void disable_ro_nx(const struct module_layout *layout) { }
2028 static void module_enable_nx(const struct module *mod) { }
2029 static void module_disable_nx(const struct module *mod) { }
2032 #ifdef CONFIG_LIVEPATCH
2034 * Persist Elf information about a module. Copy the Elf header,
2035 * section header table, section string table, and symtab section
2036 * index from info to mod->klp_info.
2038 static int copy_module_elf(struct module *mod, struct load_info *info)
2040 unsigned int size, symndx;
2043 size = sizeof(*mod->klp_info);
2044 mod->klp_info = kmalloc(size, GFP_KERNEL);
2045 if (mod->klp_info == NULL)
2049 size = sizeof(mod->klp_info->hdr);
2050 memcpy(&mod->klp_info->hdr, info->hdr, size);
2052 /* Elf section header table */
2053 size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
2054 mod->klp_info->sechdrs = kmalloc(size, GFP_KERNEL);
2055 if (mod->klp_info->sechdrs == NULL) {
2059 memcpy(mod->klp_info->sechdrs, info->sechdrs, size);
2061 /* Elf section name string table */
2062 size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
2063 mod->klp_info->secstrings = kmalloc(size, GFP_KERNEL);
2064 if (mod->klp_info->secstrings == NULL) {
2068 memcpy(mod->klp_info->secstrings, info->secstrings, size);
2070 /* Elf symbol section index */
2071 symndx = info->index.sym;
2072 mod->klp_info->symndx = symndx;
2075 * For livepatch modules, core_kallsyms.symtab is a complete
2076 * copy of the original symbol table. Adjust sh_addr to point
2077 * to core_kallsyms.symtab since the copy of the symtab in module
2078 * init memory is freed at the end of do_init_module().
2080 mod->klp_info->sechdrs[symndx].sh_addr = \
2081 (unsigned long) mod->core_kallsyms.symtab;
2086 kfree(mod->klp_info->sechdrs);
2088 kfree(mod->klp_info);
2092 static void free_module_elf(struct module *mod)
2094 kfree(mod->klp_info->sechdrs);
2095 kfree(mod->klp_info->secstrings);
2096 kfree(mod->klp_info);
2098 #else /* !CONFIG_LIVEPATCH */
2099 static int copy_module_elf(struct module *mod, struct load_info *info)
2104 static void free_module_elf(struct module *mod)
2107 #endif /* CONFIG_LIVEPATCH */
2109 void __weak module_memfree(void *module_region)
2111 vfree(module_region);
2114 void __weak module_arch_cleanup(struct module *mod)
2118 void __weak module_arch_freeing_init(struct module *mod)
2122 /* Free a module, remove from lists, etc. */
2123 static void free_module(struct module *mod)
2125 trace_module_free(mod);
2127 mod_sysfs_teardown(mod);
2129 /* We leave it in list to prevent duplicate loads, but make sure
2130 * that noone uses it while it's being deconstructed. */
2131 mutex_lock(&module_mutex);
2132 mod->state = MODULE_STATE_UNFORMED;
2133 mutex_unlock(&module_mutex);
2135 /* Remove dynamic debug info */
2136 ddebug_remove_module(mod->name);
2138 /* Arch-specific cleanup. */
2139 module_arch_cleanup(mod);
2141 /* Module unload stuff */
2142 module_unload_free(mod);
2144 /* Free any allocated parameters. */
2145 destroy_params(mod->kp, mod->num_kp);
2147 if (is_livepatch_module(mod))
2148 free_module_elf(mod);
2150 /* Now we can delete it from the lists */
2151 mutex_lock(&module_mutex);
2152 /* Unlink carefully: kallsyms could be walking list. */
2153 list_del_rcu(&mod->list);
2154 mod_tree_remove(mod);
2155 /* Remove this module from bug list, this uses list_del_rcu */
2156 module_bug_cleanup(mod);
2157 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2158 synchronize_sched();
2159 mutex_unlock(&module_mutex);
2161 /* This may be empty, but that's OK */
2162 disable_ro_nx(&mod->init_layout);
2163 module_arch_freeing_init(mod);
2164 module_memfree(mod->init_layout.base);
2166 percpu_modfree(mod);
2168 /* Free lock-classes; relies on the preceding sync_rcu(). */
2169 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
2171 /* Finally, free the core (containing the module structure) */
2172 disable_ro_nx(&mod->core_layout);
2173 module_memfree(mod->core_layout.base);
2176 update_protections(current->mm);
2180 void *__symbol_get(const char *symbol)
2182 struct module *owner;
2183 const struct kernel_symbol *sym;
2186 sym = find_symbol(symbol, &owner, NULL, true, true);
2187 if (sym && strong_try_module_get(owner))
2191 return sym ? (void *)sym->value : NULL;
2193 EXPORT_SYMBOL_GPL(__symbol_get);
2196 * Ensure that an exported symbol [global namespace] does not already exist
2197 * in the kernel or in some other module's exported symbol table.
2199 * You must hold the module_mutex.
2201 static int verify_export_symbols(struct module *mod)
2204 struct module *owner;
2205 const struct kernel_symbol *s;
2207 const struct kernel_symbol *sym;
2210 { mod->syms, mod->num_syms },
2211 { mod->gpl_syms, mod->num_gpl_syms },
2212 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2213 #ifdef CONFIG_UNUSED_SYMBOLS
2214 { mod->unused_syms, mod->num_unused_syms },
2215 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2219 for (i = 0; i < ARRAY_SIZE(arr); i++) {
2220 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2221 if (find_symbol(s->name, &owner, NULL, true, false)) {
2222 pr_err("%s: exports duplicate symbol %s"
2224 mod->name, s->name, module_name(owner));
2232 /* Change all symbols so that st_value encodes the pointer directly. */
2233 static int simplify_symbols(struct module *mod, const struct load_info *info)
2235 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2236 Elf_Sym *sym = (void *)symsec->sh_addr;
2237 unsigned long secbase;
2240 const struct kernel_symbol *ksym;
2242 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2243 const char *name = info->strtab + sym[i].st_name;
2245 switch (sym[i].st_shndx) {
2247 /* Ignore common symbols */
2248 if (!strncmp(name, "__gnu_lto", 9))
2251 /* We compiled with -fno-common. These are not
2252 supposed to happen. */
2253 pr_debug("Common symbol: %s\n", name);
2254 pr_warn("%s: please compile with -fno-common\n",
2260 /* Don't need to do anything */
2261 pr_debug("Absolute symbol: 0x%08lx\n",
2262 (long)sym[i].st_value);
2266 /* Livepatch symbols are resolved by livepatch */
2270 ksym = resolve_symbol_wait(mod, info, name);
2271 /* Ok if resolved. */
2272 if (ksym && !IS_ERR(ksym)) {
2273 sym[i].st_value = ksym->value;
2278 if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
2281 pr_warn("%s: Unknown symbol %s (err %li)\n",
2282 mod->name, name, PTR_ERR(ksym));
2283 ret = PTR_ERR(ksym) ?: -ENOENT;
2287 /* Divert to percpu allocation if a percpu var. */
2288 if (sym[i].st_shndx == info->index.pcpu)
2289 secbase = (unsigned long)mod_percpu(mod);
2291 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2292 sym[i].st_value += secbase;
2300 static int apply_relocations(struct module *mod, const struct load_info *info)
2305 /* Now do relocations. */
2306 for (i = 1; i < info->hdr->e_shnum; i++) {
2307 unsigned int infosec = info->sechdrs[i].sh_info;
2309 /* Not a valid relocation section? */
2310 if (infosec >= info->hdr->e_shnum)
2313 /* Don't bother with non-allocated sections */
2314 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2317 /* Livepatch relocation sections are applied by livepatch */
2318 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
2321 if (info->sechdrs[i].sh_type == SHT_REL)
2322 err = apply_relocate(info->sechdrs, info->strtab,
2323 info->index.sym, i, mod);
2324 else if (info->sechdrs[i].sh_type == SHT_RELA)
2325 err = apply_relocate_add(info->sechdrs, info->strtab,
2326 info->index.sym, i, mod);
2333 /* Additional bytes needed by arch in front of individual sections */
2334 unsigned int __weak arch_mod_section_prepend(struct module *mod,
2335 unsigned int section)
2337 /* default implementation just returns zero */
2341 /* Update size with this section: return offset. */
2342 static long get_offset(struct module *mod, unsigned int *size,
2343 Elf_Shdr *sechdr, unsigned int section)
2347 *size += arch_mod_section_prepend(mod, section);
2348 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2349 *size = ret + sechdr->sh_size;
2353 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2354 might -- code, read-only data, read-write data, small data. Tally
2355 sizes, and place the offsets into sh_entsize fields: high bit means it
2357 static void layout_sections(struct module *mod, struct load_info *info)
2359 static unsigned long const masks[][2] = {
2360 /* NOTE: all executable code must be the first section
2361 * in this array; otherwise modify the text_size
2362 * finder in the two loops below */
2363 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2364 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2365 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
2366 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2367 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2371 for (i = 0; i < info->hdr->e_shnum; i++)
2372 info->sechdrs[i].sh_entsize = ~0UL;
2374 pr_debug("Core section allocation order:\n");
2375 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2376 for (i = 0; i < info->hdr->e_shnum; ++i) {
2377 Elf_Shdr *s = &info->sechdrs[i];
2378 const char *sname = info->secstrings + s->sh_name;
2380 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2381 || (s->sh_flags & masks[m][1])
2382 || s->sh_entsize != ~0UL
2383 || strstarts(sname, ".init"))
2385 s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2386 pr_debug("\t%s\n", sname);
2389 case 0: /* executable */
2390 mod->core_layout.size = debug_align(mod->core_layout.size);
2391 mod->core_layout.text_size = mod->core_layout.size;
2393 case 1: /* RO: text and ro-data */
2394 mod->core_layout.size = debug_align(mod->core_layout.size);
2395 mod->core_layout.ro_size = mod->core_layout.size;
2397 case 2: /* RO after init */
2398 mod->core_layout.size = debug_align(mod->core_layout.size);
2399 mod->core_layout.ro_after_init_size = mod->core_layout.size;
2401 case 4: /* whole core */
2402 mod->core_layout.size = debug_align(mod->core_layout.size);
2407 pr_debug("Init section allocation order:\n");
2408 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2409 for (i = 0; i < info->hdr->e_shnum; ++i) {
2410 Elf_Shdr *s = &info->sechdrs[i];
2411 const char *sname = info->secstrings + s->sh_name;
2413 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2414 || (s->sh_flags & masks[m][1])
2415 || s->sh_entsize != ~0UL
2416 || !strstarts(sname, ".init"))
2418 s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
2419 | INIT_OFFSET_MASK);
2420 pr_debug("\t%s\n", sname);
2423 case 0: /* executable */
2424 mod->init_layout.size = debug_align(mod->init_layout.size);
2425 mod->init_layout.text_size = mod->init_layout.size;
2427 case 1: /* RO: text and ro-data */
2428 mod->init_layout.size = debug_align(mod->init_layout.size);
2429 mod->init_layout.ro_size = mod->init_layout.size;
2433 * RO after init doesn't apply to init_layout (only
2434 * core_layout), so it just takes the value of ro_size.
2436 mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
2438 case 4: /* whole init */
2439 mod->init_layout.size = debug_align(mod->init_layout.size);
2445 static void set_license(struct module *mod, const char *license)
2448 license = "unspecified";
2450 if (!license_is_gpl_compatible(license)) {
2451 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2452 pr_warn("%s: module license '%s' taints kernel.\n",
2453 mod->name, license);
2454 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2455 LOCKDEP_NOW_UNRELIABLE);
2459 /* Parse tag=value strings from .modinfo section */
2460 static char *next_string(char *string, unsigned long *secsize)
2462 /* Skip non-zero chars */
2465 if ((*secsize)-- <= 1)
2469 /* Skip any zero padding. */
2470 while (!string[0]) {
2472 if ((*secsize)-- <= 1)
2478 static char *get_modinfo(struct load_info *info, const char *tag)
2481 unsigned int taglen = strlen(tag);
2482 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2483 unsigned long size = infosec->sh_size;
2485 for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2486 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2487 return p + taglen + 1;
2492 static void setup_modinfo(struct module *mod, struct load_info *info)
2494 struct module_attribute *attr;
2497 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2499 attr->setup(mod, get_modinfo(info, attr->attr.name));
2503 static void free_modinfo(struct module *mod)
2505 struct module_attribute *attr;
2508 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2514 #ifdef CONFIG_KALLSYMS
2516 /* lookup symbol in given range of kernel_symbols */
2517 static const struct kernel_symbol *lookup_symbol(const char *name,
2518 const struct kernel_symbol *start,
2519 const struct kernel_symbol *stop)
2521 return bsearch(name, start, stop - start,
2522 sizeof(struct kernel_symbol), cmp_name);
2525 static int is_exported(const char *name, unsigned long value,
2526 const struct module *mod)
2528 const struct kernel_symbol *ks;
2530 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2532 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2533 return ks != NULL && ks->value == value;
2537 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2539 const Elf_Shdr *sechdrs = info->sechdrs;
2541 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2542 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2547 if (sym->st_shndx == SHN_UNDEF)
2549 if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
2551 if (sym->st_shndx >= SHN_LORESERVE)
2553 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2555 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2556 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2557 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2559 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2564 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2565 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2570 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2577 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2578 unsigned int shnum, unsigned int pcpundx)
2580 const Elf_Shdr *sec;
2582 if (src->st_shndx == SHN_UNDEF
2583 || src->st_shndx >= shnum
2587 #ifdef CONFIG_KALLSYMS_ALL
2588 if (src->st_shndx == pcpundx)
2592 sec = sechdrs + src->st_shndx;
2593 if (!(sec->sh_flags & SHF_ALLOC)
2594 #ifndef CONFIG_KALLSYMS_ALL
2595 || !(sec->sh_flags & SHF_EXECINSTR)
2597 || (sec->sh_entsize & INIT_OFFSET_MASK))
2604 * We only allocate and copy the strings needed by the parts of symtab
2605 * we keep. This is simple, but has the effect of making multiple
2606 * copies of duplicates. We could be more sophisticated, see
2607 * linux-kernel thread starting with
2608 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2610 static void layout_symtab(struct module *mod, struct load_info *info)
2612 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2613 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2615 unsigned int i, nsrc, ndst, strtab_size = 0;
2617 /* Put symbol section at end of init part of module. */
2618 symsect->sh_flags |= SHF_ALLOC;
2619 symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2620 info->index.sym) | INIT_OFFSET_MASK;
2621 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2623 src = (void *)info->hdr + symsect->sh_offset;
2624 nsrc = symsect->sh_size / sizeof(*src);
2626 /* Compute total space required for the core symbols' strtab. */
2627 for (ndst = i = 0; i < nsrc; i++) {
2628 if (i == 0 || is_livepatch_module(mod) ||
2629 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2630 info->index.pcpu)) {
2631 strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2636 /* Append room for core symbols at end of core part. */
2637 info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
2638 info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
2639 mod->core_layout.size += strtab_size;
2640 mod->core_layout.size = debug_align(mod->core_layout.size);
2642 /* Put string table section at end of init part of module. */
2643 strsect->sh_flags |= SHF_ALLOC;
2644 strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2645 info->index.str) | INIT_OFFSET_MASK;
2646 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2648 /* We'll tack temporary mod_kallsyms on the end. */
2649 mod->init_layout.size = ALIGN(mod->init_layout.size,
2650 __alignof__(struct mod_kallsyms));
2651 info->mod_kallsyms_init_off = mod->init_layout.size;
2652 mod->init_layout.size += sizeof(struct mod_kallsyms);
2653 mod->init_layout.size = debug_align(mod->init_layout.size);
2657 * We use the full symtab and strtab which layout_symtab arranged to
2658 * be appended to the init section. Later we switch to the cut-down
2661 static void add_kallsyms(struct module *mod, const struct load_info *info)
2663 unsigned int i, ndst;
2667 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2669 /* Set up to point into init section. */
2670 mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
2672 mod->kallsyms->symtab = (void *)symsec->sh_addr;
2673 mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2674 /* Make sure we get permanent strtab: don't use info->strtab. */
2675 mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2677 /* Set types up while we still have access to sections. */
2678 for (i = 0; i < mod->kallsyms->num_symtab; i++)
2679 mod->kallsyms->symtab[i].st_info
2680 = elf_type(&mod->kallsyms->symtab[i], info);
2682 /* Now populate the cut down core kallsyms for after init. */
2683 mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
2684 mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
2685 src = mod->kallsyms->symtab;
2686 for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2687 if (i == 0 || is_livepatch_module(mod) ||
2688 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2689 info->index.pcpu)) {
2691 dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
2692 s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2696 mod->core_kallsyms.num_symtab = ndst;
2699 static inline void layout_symtab(struct module *mod, struct load_info *info)
2703 static void add_kallsyms(struct module *mod, const struct load_info *info)
2706 #endif /* CONFIG_KALLSYMS */
2708 static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num)
2712 #ifdef CONFIG_DYNAMIC_DEBUG
2713 if (ddebug_add_module(debug, num, mod->name))
2714 pr_err("dynamic debug error adding module: %s\n",
2719 static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug)
2722 ddebug_remove_module(mod->name);
2725 void * __weak module_alloc(unsigned long size)
2727 return vmalloc_exec(size);
2730 #ifdef CONFIG_DEBUG_KMEMLEAK
2731 static void kmemleak_load_module(const struct module *mod,
2732 const struct load_info *info)
2736 /* only scan the sections containing data */
2737 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2739 for (i = 1; i < info->hdr->e_shnum; i++) {
2740 /* Scan all writable sections that's not executable */
2741 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2742 !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2743 (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2746 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2747 info->sechdrs[i].sh_size, GFP_KERNEL);
2751 static inline void kmemleak_load_module(const struct module *mod,
2752 const struct load_info *info)
2757 #ifdef CONFIG_MODULE_SIG
2758 static int module_sig_check(struct load_info *info, int flags)
2761 const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2762 const void *mod = info->hdr;
2765 * Require flags == 0, as a module with version information
2766 * removed is no longer the module that was signed
2769 info->len > markerlen &&
2770 memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2771 /* We truncate the module to discard the signature */
2772 info->len -= markerlen;
2773 err = mod_verify_sig(mod, &info->len);
2777 info->sig_ok = true;
2781 /* Not having a signature is only an error if we're strict. */
2782 if (err == -ENOKEY && !sig_enforce)
2787 #else /* !CONFIG_MODULE_SIG */
2788 static int module_sig_check(struct load_info *info, int flags)
2792 #endif /* !CONFIG_MODULE_SIG */
2794 /* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2795 static int elf_header_check(struct load_info *info)
2797 if (info->len < sizeof(*(info->hdr)))
2800 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2801 || info->hdr->e_type != ET_REL
2802 || !elf_check_arch(info->hdr)
2803 || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2806 if (info->hdr->e_shoff >= info->len
2807 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2808 info->len - info->hdr->e_shoff))
2814 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2816 static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
2819 unsigned long n = min(len, COPY_CHUNK_SIZE);
2821 if (copy_from_user(dst, usrc, n) != 0)
2831 #ifdef CONFIG_LIVEPATCH
2832 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2834 if (get_modinfo(info, "livepatch")) {
2836 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
2837 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
2843 #else /* !CONFIG_LIVEPATCH */
2844 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2846 if (get_modinfo(info, "livepatch")) {
2847 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
2854 #endif /* CONFIG_LIVEPATCH */
2856 /* Sets info->hdr and info->len. */
2857 static int copy_module_from_user(const void __user *umod, unsigned long len,
2858 struct load_info *info)
2863 if (info->len < sizeof(*(info->hdr)))
2866 err = security_kernel_read_file(NULL, READING_MODULE);
2870 /* Suck in entire file: we'll want most of it. */
2871 info->hdr = __vmalloc(info->len,
2872 GFP_KERNEL | __GFP_NOWARN, PAGE_KERNEL);
2876 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2884 static void free_copy(struct load_info *info)
2889 static int rewrite_section_headers(struct load_info *info, int flags)
2893 /* This should always be true, but let's be sure. */
2894 info->sechdrs[0].sh_addr = 0;
2896 for (i = 1; i < info->hdr->e_shnum; i++) {
2897 Elf_Shdr *shdr = &info->sechdrs[i];
2898 if (shdr->sh_type != SHT_NOBITS
2899 && info->len < shdr->sh_offset + shdr->sh_size) {
2900 pr_err("Module len %lu truncated\n", info->len);
2904 /* Mark all sections sh_addr with their address in the
2906 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2908 #ifndef CONFIG_MODULE_UNLOAD
2909 /* Don't load .exit sections */
2910 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2911 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2915 /* Track but don't keep modinfo and version sections. */
2916 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
2917 info->index.vers = 0; /* Pretend no __versions section! */
2919 info->index.vers = find_sec(info, "__versions");
2920 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2922 info->index.info = find_sec(info, ".modinfo");
2923 if (!info->index.info)
2924 info->name = "(missing .modinfo section)";
2926 info->name = get_modinfo(info, "name");
2927 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2933 * Set up our basic convenience variables (pointers to section headers,
2934 * search for module section index etc), and do some basic section
2937 * Return the temporary module pointer (we'll replace it with the final
2938 * one when we move the module sections around).
2940 static struct module *setup_load_info(struct load_info *info, int flags)
2946 /* Set up the convenience variables */
2947 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2948 info->secstrings = (void *)info->hdr
2949 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2951 err = rewrite_section_headers(info, flags);
2953 return ERR_PTR(err);
2955 /* Find internal symbols and strings. */
2956 for (i = 1; i < info->hdr->e_shnum; i++) {
2957 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2958 info->index.sym = i;
2959 info->index.str = info->sechdrs[i].sh_link;
2960 info->strtab = (char *)info->hdr
2961 + info->sechdrs[info->index.str].sh_offset;
2966 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2967 if (!info->index.mod) {
2968 pr_warn("%s: No module found in object\n",
2969 info->name ?: "(missing .modinfo name field)");
2970 return ERR_PTR(-ENOEXEC);
2972 /* This is temporary: point mod into copy of data. */
2973 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2976 * If we didn't load the .modinfo 'name' field, fall back to
2977 * on-disk struct mod 'name' field.
2980 info->name = mod->name;
2982 if (info->index.sym == 0) {
2983 pr_warn("%s: module has no symbols (stripped?)\n", info->name);
2984 return ERR_PTR(-ENOEXEC);
2987 info->index.pcpu = find_pcpusec(info);
2989 /* Check module struct version now, before we try to use module. */
2990 if (!check_modstruct_version(info, mod))
2991 return ERR_PTR(-ENOEXEC);
2996 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2998 const char *modmagic = get_modinfo(info, "vermagic");
3001 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
3004 /* This is allowed: modprobe --force will invalidate it. */
3006 err = try_to_force_load(mod, "bad vermagic");
3009 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
3010 pr_err("%s: version magic '%s' should be '%s'\n",
3011 info->name, modmagic, vermagic);
3015 if (!get_modinfo(info, "intree")) {
3016 if (!test_taint(TAINT_OOT_MODULE))
3017 pr_warn("%s: loading out-of-tree module taints kernel.\n",
3019 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
3022 if (get_modinfo(info, "staging")) {
3023 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
3024 pr_warn("%s: module is from the staging directory, the quality "
3025 "is unknown, you have been warned.\n", mod->name);
3028 err = check_modinfo_livepatch(mod, info);
3032 /* Set up license info based on the info section */
3033 set_license(mod, get_modinfo(info, "license"));
3038 static int find_module_sections(struct module *mod, struct load_info *info)
3040 mod->kp = section_objs(info, "__param",
3041 sizeof(*mod->kp), &mod->num_kp);
3042 mod->syms = section_objs(info, "__ksymtab",
3043 sizeof(*mod->syms), &mod->num_syms);
3044 mod->crcs = section_addr(info, "__kcrctab");
3045 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
3046 sizeof(*mod->gpl_syms),
3047 &mod->num_gpl_syms);
3048 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
3049 mod->gpl_future_syms = section_objs(info,
3050 "__ksymtab_gpl_future",
3051 sizeof(*mod->gpl_future_syms),
3052 &mod->num_gpl_future_syms);
3053 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
3055 #ifdef CONFIG_UNUSED_SYMBOLS
3056 mod->unused_syms = section_objs(info, "__ksymtab_unused",
3057 sizeof(*mod->unused_syms),
3058 &mod->num_unused_syms);
3059 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
3060 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
3061 sizeof(*mod->unused_gpl_syms),
3062 &mod->num_unused_gpl_syms);
3063 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
3065 #ifdef CONFIG_CONSTRUCTORS
3066 mod->ctors = section_objs(info, ".ctors",
3067 sizeof(*mod->ctors), &mod->num_ctors);
3069 mod->ctors = section_objs(info, ".init_array",
3070 sizeof(*mod->ctors), &mod->num_ctors);
3071 else if (find_sec(info, ".init_array")) {
3073 * This shouldn't happen with same compiler and binutils
3074 * building all parts of the module.
3076 pr_warn("%s: has both .ctors and .init_array.\n",
3082 #ifdef CONFIG_TRACEPOINTS
3083 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
3084 sizeof(*mod->tracepoints_ptrs),
3085 &mod->num_tracepoints);
3087 #ifdef HAVE_JUMP_LABEL
3088 mod->jump_entries = section_objs(info, "__jump_table",
3089 sizeof(*mod->jump_entries),
3090 &mod->num_jump_entries);
3092 #ifdef CONFIG_EVENT_TRACING
3093 mod->trace_events = section_objs(info, "_ftrace_events",
3094 sizeof(*mod->trace_events),
3095 &mod->num_trace_events);
3096 mod->trace_evals = section_objs(info, "_ftrace_eval_map",
3097 sizeof(*mod->trace_evals),
3098 &mod->num_trace_evals);
3100 #ifdef CONFIG_TRACING
3101 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
3102 sizeof(*mod->trace_bprintk_fmt_start),
3103 &mod->num_trace_bprintk_fmt);
3105 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
3106 /* sechdrs[0].sh_size is always zero */
3107 mod->ftrace_callsites = section_objs(info, "__mcount_loc",
3108 sizeof(*mod->ftrace_callsites),
3109 &mod->num_ftrace_callsites);
3112 mod->extable = section_objs(info, "__ex_table",
3113 sizeof(*mod->extable), &mod->num_exentries);
3115 if (section_addr(info, "__obsparm"))
3116 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
3118 info->debug = section_objs(info, "__verbose",
3119 sizeof(*info->debug), &info->num_debug);
3124 static int move_module(struct module *mod, struct load_info *info)
3129 /* Do the allocs. */
3130 ptr = module_alloc(mod->core_layout.size);
3132 * The pointer to this block is stored in the module structure
3133 * which is inside the block. Just mark it as not being a
3136 kmemleak_not_leak(ptr);
3140 memset(ptr, 0, mod->core_layout.size);
3141 mod->core_layout.base = ptr;
3143 if (mod->init_layout.size) {
3144 ptr = module_alloc(mod->init_layout.size);
3146 * The pointer to this block is stored in the module structure
3147 * which is inside the block. This block doesn't need to be
3148 * scanned as it contains data and code that will be freed
3149 * after the module is initialized.
3151 kmemleak_ignore(ptr);
3153 module_memfree(mod->core_layout.base);
3156 memset(ptr, 0, mod->init_layout.size);
3157 mod->init_layout.base = ptr;
3159 mod->init_layout.base = NULL;
3161 /* Transfer each section which specifies SHF_ALLOC */
3162 pr_debug("final section addresses:\n");
3163 for (i = 0; i < info->hdr->e_shnum; i++) {
3165 Elf_Shdr *shdr = &info->sechdrs[i];
3167 if (!(shdr->sh_flags & SHF_ALLOC))
3170 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3171 dest = mod->init_layout.base
3172 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3174 dest = mod->core_layout.base + shdr->sh_entsize;
3176 if (shdr->sh_type != SHT_NOBITS)
3177 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3178 /* Update sh_addr to point to copy in image. */
3179 shdr->sh_addr = (unsigned long)dest;
3180 pr_debug("\t0x%lx %s\n",
3181 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3187 static int check_module_license_and_versions(struct module *mod)
3189 int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
3192 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3193 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3194 * using GPL-only symbols it needs.
3196 if (strcmp(mod->name, "ndiswrapper") == 0)
3197 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3199 /* driverloader was caught wrongly pretending to be under GPL */
3200 if (strcmp(mod->name, "driverloader") == 0)
3201 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3202 LOCKDEP_NOW_UNRELIABLE);
3204 /* lve claims to be GPL but upstream won't provide source */
3205 if (strcmp(mod->name, "lve") == 0)
3206 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3207 LOCKDEP_NOW_UNRELIABLE);
3209 if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
3210 pr_warn("%s: module license taints kernel.\n", mod->name);
3212 #ifdef CONFIG_MODVERSIONS
3213 if ((mod->num_syms && !mod->crcs)
3214 || (mod->num_gpl_syms && !mod->gpl_crcs)
3215 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3216 #ifdef CONFIG_UNUSED_SYMBOLS
3217 || (mod->num_unused_syms && !mod->unused_crcs)
3218 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3221 return try_to_force_load(mod,
3222 "no versions for exported symbols");
3228 static void flush_module_icache(const struct module *mod)
3230 mm_segment_t old_fs;
3232 /* flush the icache in correct context */
3237 * Flush the instruction cache, since we've played with text.
3238 * Do it before processing of module parameters, so the module
3239 * can provide parameter accessor functions of its own.
3241 if (mod->init_layout.base)
3242 flush_icache_range((unsigned long)mod->init_layout.base,
3243 (unsigned long)mod->init_layout.base
3244 + mod->init_layout.size);
3245 flush_icache_range((unsigned long)mod->core_layout.base,
3246 (unsigned long)mod->core_layout.base + mod->core_layout.size);
3251 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3259 /* module_blacklist is a comma-separated list of module names */
3260 static char *module_blacklist;
3261 static bool blacklisted(const char *module_name)
3266 if (!module_blacklist)
3269 for (p = module_blacklist; *p; p += len) {
3270 len = strcspn(p, ",");
3271 if (strlen(module_name) == len && !memcmp(module_name, p, len))
3278 core_param(module_blacklist, module_blacklist, charp, 0400);
3280 static struct module *layout_and_allocate(struct load_info *info, int flags)
3282 /* Module within temporary copy. */
3287 mod = setup_load_info(info, flags);
3291 if (blacklisted(info->name))
3292 return ERR_PTR(-EPERM);
3294 err = check_modinfo(mod, info, flags);
3296 return ERR_PTR(err);
3298 /* Allow arches to frob section contents and sizes. */
3299 err = module_frob_arch_sections(info->hdr, info->sechdrs,
3300 info->secstrings, mod);
3302 return ERR_PTR(err);
3304 /* We will do a special allocation for per-cpu sections later. */
3305 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3308 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3309 * layout_sections() can put it in the right place.
3310 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3312 ndx = find_sec(info, ".data..ro_after_init");
3314 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3316 /* Determine total sizes, and put offsets in sh_entsize. For now
3317 this is done generically; there doesn't appear to be any
3318 special cases for the architectures. */
3319 layout_sections(mod, info);
3320 layout_symtab(mod, info);
3322 /* Allocate and move to the final place */
3323 err = move_module(mod, info);
3325 return ERR_PTR(err);
3327 /* Module has been copied to its final place now: return it. */
3328 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3329 kmemleak_load_module(mod, info);
3333 /* mod is no longer valid after this! */
3334 static void module_deallocate(struct module *mod, struct load_info *info)
3336 percpu_modfree(mod);
3337 module_arch_freeing_init(mod);
3338 module_memfree(mod->init_layout.base);
3339 module_memfree(mod->core_layout.base);
3342 int __weak module_finalize(const Elf_Ehdr *hdr,
3343 const Elf_Shdr *sechdrs,
3349 static int post_relocation(struct module *mod, const struct load_info *info)
3351 /* Sort exception table now relocations are done. */
3352 sort_extable(mod->extable, mod->extable + mod->num_exentries);
3354 /* Copy relocated percpu area over. */
3355 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3356 info->sechdrs[info->index.pcpu].sh_size);
3358 /* Setup kallsyms-specific fields. */
3359 add_kallsyms(mod, info);
3361 /* Arch-specific module finalizing. */
3362 return module_finalize(info->hdr, info->sechdrs, mod);
3365 /* Is this module of this name done loading? No locks held. */
3366 static bool finished_loading(const char *name)
3372 * The module_mutex should not be a heavily contended lock;
3373 * if we get the occasional sleep here, we'll go an extra iteration
3374 * in the wait_event_interruptible(), which is harmless.
3376 sched_annotate_sleep();
3377 mutex_lock(&module_mutex);
3378 mod = find_module_all(name, strlen(name), true);
3379 ret = !mod || mod->state == MODULE_STATE_LIVE
3380 || mod->state == MODULE_STATE_GOING;
3381 mutex_unlock(&module_mutex);
3386 /* Call module constructors. */
3387 static void do_mod_ctors(struct module *mod)
3389 #ifdef CONFIG_CONSTRUCTORS
3392 for (i = 0; i < mod->num_ctors; i++)
3397 /* For freeing module_init on success, in case kallsyms traversing */
3398 struct mod_initfree {
3399 struct rcu_head rcu;
3403 static void do_free_init(struct rcu_head *head)
3405 struct mod_initfree *m = container_of(head, struct mod_initfree, rcu);
3406 module_memfree(m->module_init);
3411 * This is where the real work happens.
3413 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3414 * helper command 'lx-symbols'.
3416 static noinline int do_init_module(struct module *mod)
3419 struct mod_initfree *freeinit;
3421 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3426 freeinit->module_init = mod->init_layout.base;
3429 * We want to find out whether @mod uses async during init. Clear
3430 * PF_USED_ASYNC. async_schedule*() will set it.
3432 current->flags &= ~PF_USED_ASYNC;
3435 /* Start the module */
3436 if (mod->init != NULL)
3437 ret = do_one_initcall(mod->init);
3439 goto fail_free_freeinit;
3442 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3443 "follow 0/-E convention\n"
3444 "%s: loading module anyway...\n",
3445 __func__, mod->name, ret, __func__);
3449 /* Now it's a first class citizen! */
3450 mod->state = MODULE_STATE_LIVE;
3451 blocking_notifier_call_chain(&module_notify_list,
3452 MODULE_STATE_LIVE, mod);
3455 * We need to finish all async code before the module init sequence
3456 * is done. This has potential to deadlock. For example, a newly
3457 * detected block device can trigger request_module() of the
3458 * default iosched from async probing task. Once userland helper
3459 * reaches here, async_synchronize_full() will wait on the async
3460 * task waiting on request_module() and deadlock.
3462 * This deadlock is avoided by perfomring async_synchronize_full()
3463 * iff module init queued any async jobs. This isn't a full
3464 * solution as it will deadlock the same if module loading from
3465 * async jobs nests more than once; however, due to the various
3466 * constraints, this hack seems to be the best option for now.
3467 * Please refer to the following thread for details.
3469 * http://thread.gmane.org/gmane.linux.kernel/1420814
3471 if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3472 async_synchronize_full();
3474 mutex_lock(&module_mutex);
3475 /* Drop initial reference. */
3477 trim_init_extable(mod);
3478 #ifdef CONFIG_KALLSYMS
3479 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3480 rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3482 module_enable_ro(mod, true);
3483 mod_tree_remove_init(mod);
3484 disable_ro_nx(&mod->init_layout);
3485 module_arch_freeing_init(mod);
3486 mod->init_layout.base = NULL;
3487 mod->init_layout.size = 0;
3488 mod->init_layout.ro_size = 0;
3489 mod->init_layout.ro_after_init_size = 0;
3490 mod->init_layout.text_size = 0;
3492 * We want to free module_init, but be aware that kallsyms may be
3493 * walking this with preempt disabled. In all the failure paths, we
3494 * call synchronize_sched(), but we don't want to slow down the success
3495 * path, so use actual RCU here.
3497 call_rcu_sched(&freeinit->rcu, do_free_init);
3498 mutex_unlock(&module_mutex);
3499 wake_up_all(&module_wq);
3506 /* Try to protect us from buggy refcounters. */
3507 mod->state = MODULE_STATE_GOING;
3508 synchronize_sched();
3510 blocking_notifier_call_chain(&module_notify_list,
3511 MODULE_STATE_GOING, mod);
3512 klp_module_going(mod);
3513 ftrace_release_mod(mod);
3515 wake_up_all(&module_wq);
3519 static int may_init_module(void)
3521 if (!capable(CAP_SYS_MODULE) || modules_disabled)
3528 * We try to place it in the list now to make sure it's unique before
3529 * we dedicate too many resources. In particular, temporary percpu
3530 * memory exhaustion.
3532 static int add_unformed_module(struct module *mod)
3537 mod->state = MODULE_STATE_UNFORMED;
3540 mutex_lock(&module_mutex);
3541 old = find_module_all(mod->name, strlen(mod->name), true);
3543 if (old->state == MODULE_STATE_COMING
3544 || old->state == MODULE_STATE_UNFORMED) {
3545 /* Wait in case it fails to load. */
3546 mutex_unlock(&module_mutex);
3547 err = wait_event_interruptible(module_wq,
3548 finished_loading(mod->name));
3556 mod_update_bounds(mod);
3557 list_add_rcu(&mod->list, &modules);
3558 mod_tree_insert(mod);
3562 mutex_unlock(&module_mutex);
3567 static int complete_formation(struct module *mod, struct load_info *info)
3571 mutex_lock(&module_mutex);
3573 /* Find duplicate symbols (must be called under lock). */
3574 err = verify_export_symbols(mod);
3578 /* This relies on module_mutex for list integrity. */
3579 module_bug_finalize(info->hdr, info->sechdrs, mod);
3581 module_enable_ro(mod, false);
3582 module_enable_nx(mod);
3584 /* Mark state as coming so strong_try_module_get() ignores us,
3585 * but kallsyms etc. can see us. */
3586 mod->state = MODULE_STATE_COMING;
3587 mutex_unlock(&module_mutex);
3592 mutex_unlock(&module_mutex);
3596 static int prepare_coming_module(struct module *mod)
3600 ftrace_module_enable(mod);
3601 err = klp_module_coming(mod);
3605 blocking_notifier_call_chain(&module_notify_list,
3606 MODULE_STATE_COMING, mod);
3610 static int unknown_module_param_cb(char *param, char *val, const char *modname,
3613 struct module *mod = arg;
3616 if (strcmp(param, "async_probe") == 0) {
3617 mod->async_probe_requested = true;
3621 /* Check for magic 'dyndbg' arg */
3622 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3624 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3628 /* Allocate and load the module: note that size of section 0 is always
3629 zero, and we rely on this for optional sections. */
3630 static int load_module(struct load_info *info, const char __user *uargs,
3637 err = module_sig_check(info, flags);
3641 err = elf_header_check(info);
3645 /* Figure out module layout, and allocate all the memory. */
3646 mod = layout_and_allocate(info, flags);
3652 audit_log_kern_module(mod->name);
3654 /* Reserve our place in the list. */
3655 err = add_unformed_module(mod);
3659 #ifdef CONFIG_MODULE_SIG
3660 mod->sig_ok = info->sig_ok;
3662 pr_notice_once("%s: module verification failed: signature "
3663 "and/or required key missing - tainting "
3664 "kernel\n", mod->name);
3665 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3669 /* To avoid stressing percpu allocator, do this once we're unique. */
3670 err = percpu_modalloc(mod, info);
3674 /* Now module is in final location, initialize linked lists, etc. */
3675 err = module_unload_init(mod);
3679 init_param_lock(mod);
3681 /* Now we've got everything in the final locations, we can
3682 * find optional sections. */
3683 err = find_module_sections(mod, info);
3687 err = check_module_license_and_versions(mod);
3691 /* Set up MODINFO_ATTR fields */
3692 setup_modinfo(mod, info);
3694 /* Fix up syms, so that st_value is a pointer to location. */
3695 err = simplify_symbols(mod, info);
3699 err = apply_relocations(mod, info);
3703 err = post_relocation(mod, info);
3707 flush_module_icache(mod);
3709 /* Now copy in args */
3710 mod->args = strndup_user(uargs, ~0UL >> 1);
3711 if (IS_ERR(mod->args)) {
3712 err = PTR_ERR(mod->args);
3713 goto free_arch_cleanup;
3716 dynamic_debug_setup(mod, info->debug, info->num_debug);
3718 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3719 ftrace_module_init(mod);
3721 /* Finally it's fully formed, ready to start executing. */
3722 err = complete_formation(mod, info);
3724 goto ddebug_cleanup;
3726 err = prepare_coming_module(mod);
3730 /* Module is ready to execute: parsing args may do that. */
3731 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3733 unknown_module_param_cb);
3734 if (IS_ERR(after_dashes)) {
3735 err = PTR_ERR(after_dashes);
3736 goto coming_cleanup;
3737 } else if (after_dashes) {
3738 pr_warn("%s: parameters '%s' after `--' ignored\n",
3739 mod->name, after_dashes);
3742 /* Link in to sysfs. */
3743 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3745 goto coming_cleanup;
3747 if (is_livepatch_module(mod)) {
3748 err = copy_module_elf(mod, info);
3753 /* Get rid of temporary copy. */
3757 trace_module_load(mod);
3759 return do_init_module(mod);
3762 mod_sysfs_teardown(mod);
3764 mod->state = MODULE_STATE_GOING;
3765 destroy_params(mod->kp, mod->num_kp);
3766 blocking_notifier_call_chain(&module_notify_list,
3767 MODULE_STATE_GOING, mod);
3768 klp_module_going(mod);
3770 /* module_bug_cleanup needs module_mutex protection */
3771 mutex_lock(&module_mutex);
3772 module_bug_cleanup(mod);
3773 mutex_unlock(&module_mutex);
3775 /* we can't deallocate the module until we clear memory protection */
3776 module_disable_ro(mod);
3777 module_disable_nx(mod);
3780 dynamic_debug_remove(mod, info->debug);
3781 synchronize_sched();
3784 module_arch_cleanup(mod);
3788 module_unload_free(mod);
3790 mutex_lock(&module_mutex);
3791 /* Unlink carefully: kallsyms could be walking list. */
3792 list_del_rcu(&mod->list);
3793 mod_tree_remove(mod);
3794 wake_up_all(&module_wq);
3795 /* Wait for RCU-sched synchronizing before releasing mod->list. */
3796 synchronize_sched();
3797 mutex_unlock(&module_mutex);
3800 * Ftrace needs to clean up what it initialized.
3801 * This does nothing if ftrace_module_init() wasn't called,
3802 * but it must be called outside of module_mutex.
3804 ftrace_release_mod(mod);
3805 /* Free lock-classes; relies on the preceding sync_rcu() */
3806 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
3808 module_deallocate(mod, info);
3814 SYSCALL_DEFINE3(init_module, void __user *, umod,
3815 unsigned long, len, const char __user *, uargs)
3818 struct load_info info = { };
3820 err = may_init_module();
3824 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3827 err = copy_module_from_user(umod, len, &info);
3831 return load_module(&info, uargs, 0);
3834 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3836 struct load_info info = { };
3841 err = may_init_module();
3845 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3847 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3848 |MODULE_INIT_IGNORE_VERMAGIC))
3851 err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX,
3858 return load_module(&info, uargs, flags);
3861 static inline int within(unsigned long addr, void *start, unsigned long size)
3863 return ((void *)addr >= start && (void *)addr < start + size);
3866 #ifdef CONFIG_KALLSYMS
3868 * This ignores the intensely annoying "mapping symbols" found
3869 * in ARM ELF files: $a, $t and $d.
3871 static inline int is_arm_mapping_symbol(const char *str)
3873 if (str[0] == '.' && str[1] == 'L')
3875 return str[0] == '$' && strchr("axtd", str[1])
3876 && (str[2] == '\0' || str[2] == '.');
3879 static const char *symname(struct mod_kallsyms *kallsyms, unsigned int symnum)
3881 return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
3884 static const char *get_ksymbol(struct module *mod,
3886 unsigned long *size,
3887 unsigned long *offset)
3889 unsigned int i, best = 0;
3890 unsigned long nextval;
3891 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
3893 /* At worse, next value is at end of module */
3894 if (within_module_init(addr, mod))
3895 nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
3897 nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
3899 /* Scan for closest preceding symbol, and next symbol. (ELF
3900 starts real symbols at 1). */
3901 for (i = 1; i < kallsyms->num_symtab; i++) {
3902 if (kallsyms->symtab[i].st_shndx == SHN_UNDEF)
3905 /* We ignore unnamed symbols: they're uninformative
3906 * and inserted at a whim. */
3907 if (*symname(kallsyms, i) == '\0'
3908 || is_arm_mapping_symbol(symname(kallsyms, i)))
3911 if (kallsyms->symtab[i].st_value <= addr
3912 && kallsyms->symtab[i].st_value > kallsyms->symtab[best].st_value)
3914 if (kallsyms->symtab[i].st_value > addr
3915 && kallsyms->symtab[i].st_value < nextval)
3916 nextval = kallsyms->symtab[i].st_value;
3923 *size = nextval - kallsyms->symtab[best].st_value;
3925 *offset = addr - kallsyms->symtab[best].st_value;
3926 return symname(kallsyms, best);
3929 /* For kallsyms to ask for address resolution. NULL means not found. Careful
3930 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3931 const char *module_address_lookup(unsigned long addr,
3932 unsigned long *size,
3933 unsigned long *offset,
3937 const char *ret = NULL;
3941 mod = __module_address(addr);
3944 *modname = mod->name;
3945 ret = get_ksymbol(mod, addr, size, offset);
3947 /* Make a copy in here where it's safe */
3949 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3957 int lookup_module_symbol_name(unsigned long addr, char *symname)
3962 list_for_each_entry_rcu(mod, &modules, list) {
3963 if (mod->state == MODULE_STATE_UNFORMED)
3965 if (within_module(addr, mod)) {
3968 sym = get_ksymbol(mod, addr, NULL, NULL);
3971 strlcpy(symname, sym, KSYM_NAME_LEN);
3981 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3982 unsigned long *offset, char *modname, char *name)
3987 list_for_each_entry_rcu(mod, &modules, list) {
3988 if (mod->state == MODULE_STATE_UNFORMED)
3990 if (within_module(addr, mod)) {
3993 sym = get_ksymbol(mod, addr, size, offset);
3997 strlcpy(modname, mod->name, MODULE_NAME_LEN);
3999 strlcpy(name, sym, KSYM_NAME_LEN);
4009 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
4010 char *name, char *module_name, int *exported)
4015 list_for_each_entry_rcu(mod, &modules, list) {
4016 struct mod_kallsyms *kallsyms;
4018 if (mod->state == MODULE_STATE_UNFORMED)
4020 kallsyms = rcu_dereference_sched(mod->kallsyms);
4021 if (symnum < kallsyms->num_symtab) {
4022 *value = kallsyms->symtab[symnum].st_value;
4023 *type = kallsyms->symtab[symnum].st_info;
4024 strlcpy(name, symname(kallsyms, symnum), KSYM_NAME_LEN);
4025 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
4026 *exported = is_exported(name, *value, mod);
4030 symnum -= kallsyms->num_symtab;
4036 static unsigned long mod_find_symname(struct module *mod, const char *name)
4039 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4041 for (i = 0; i < kallsyms->num_symtab; i++)
4042 if (strcmp(name, symname(kallsyms, i)) == 0 &&
4043 kallsyms->symtab[i].st_info != 'U')
4044 return kallsyms->symtab[i].st_value;
4048 /* Look for this name: can be of form module:name. */
4049 unsigned long module_kallsyms_lookup_name(const char *name)
4053 unsigned long ret = 0;
4055 /* Don't lock: we're in enough trouble already. */
4057 if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
4058 if ((mod = find_module_all(name, colon - name, false)) != NULL)
4059 ret = mod_find_symname(mod, colon+1);
4061 list_for_each_entry_rcu(mod, &modules, list) {
4062 if (mod->state == MODULE_STATE_UNFORMED)
4064 if ((ret = mod_find_symname(mod, name)) != 0)
4072 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
4073 struct module *, unsigned long),
4080 module_assert_mutex();
4082 list_for_each_entry(mod, &modules, list) {
4083 /* We hold module_mutex: no need for rcu_dereference_sched */
4084 struct mod_kallsyms *kallsyms = mod->kallsyms;
4086 if (mod->state == MODULE_STATE_UNFORMED)
4088 for (i = 0; i < kallsyms->num_symtab; i++) {
4089 ret = fn(data, symname(kallsyms, i),
4090 mod, kallsyms->symtab[i].st_value);
4097 #endif /* CONFIG_KALLSYMS */
4099 /* Maximum number of characters written by module_flags() */
4100 #define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
4102 /* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
4103 static char *module_flags(struct module *mod, char *buf)
4107 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
4109 mod->state == MODULE_STATE_GOING ||
4110 mod->state == MODULE_STATE_COMING) {
4112 bx += module_flags_taint(mod, buf + bx);
4113 /* Show a - for module-is-being-unloaded */
4114 if (mod->state == MODULE_STATE_GOING)
4116 /* Show a + for module-is-being-loaded */
4117 if (mod->state == MODULE_STATE_COMING)
4126 #ifdef CONFIG_PROC_FS
4127 /* Called by the /proc file system to return a list of modules. */
4128 static void *m_start(struct seq_file *m, loff_t *pos)
4130 mutex_lock(&module_mutex);
4131 return seq_list_start(&modules, *pos);
4134 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
4136 return seq_list_next(p, &modules, pos);
4139 static void m_stop(struct seq_file *m, void *p)
4141 mutex_unlock(&module_mutex);
4144 static int m_show(struct seq_file *m, void *p)
4146 struct module *mod = list_entry(p, struct module, list);
4147 char buf[MODULE_FLAGS_BUF_SIZE];
4149 /* We always ignore unformed modules. */
4150 if (mod->state == MODULE_STATE_UNFORMED)
4153 seq_printf(m, "%s %u",
4154 mod->name, mod->init_layout.size + mod->core_layout.size);
4155 print_unload_info(m, mod);
4157 /* Informative for users. */
4158 seq_printf(m, " %s",
4159 mod->state == MODULE_STATE_GOING ? "Unloading" :
4160 mod->state == MODULE_STATE_COMING ? "Loading" :
4162 /* Used by oprofile and other similar tools. */
4163 seq_printf(m, " 0x%pK", mod->core_layout.base);
4167 seq_printf(m, " %s", module_flags(mod, buf));
4173 /* Format: modulename size refcount deps address
4175 Where refcount is a number or -, and deps is a comma-separated list
4178 static const struct seq_operations modules_op = {
4185 static int modules_open(struct inode *inode, struct file *file)
4187 return seq_open(file, &modules_op);
4190 static const struct file_operations proc_modules_operations = {
4191 .open = modules_open,
4193 .llseek = seq_lseek,
4194 .release = seq_release,
4197 static int __init proc_modules_init(void)
4199 proc_create("modules", 0, NULL, &proc_modules_operations);
4202 module_init(proc_modules_init);
4205 /* Given an address, look for it in the module exception tables. */
4206 const struct exception_table_entry *search_module_extables(unsigned long addr)
4208 const struct exception_table_entry *e = NULL;
4212 mod = __module_address(addr);
4216 if (!mod->num_exentries)
4219 e = search_extable(mod->extable,
4226 * Now, if we found one, we are running inside it now, hence
4227 * we cannot unload the module, hence no refcnt needed.
4233 * is_module_address - is this address inside a module?
4234 * @addr: the address to check.
4236 * See is_module_text_address() if you simply want to see if the address
4237 * is code (not data).
4239 bool is_module_address(unsigned long addr)
4244 ret = __module_address(addr) != NULL;
4251 * __module_address - get the module which contains an address.
4252 * @addr: the address.
4254 * Must be called with preempt disabled or module mutex held so that
4255 * module doesn't get freed during this.
4257 struct module *__module_address(unsigned long addr)
4261 if (addr < module_addr_min || addr > module_addr_max)
4264 module_assert_mutex_or_preempt();
4266 mod = mod_find(addr);
4268 BUG_ON(!within_module(addr, mod));
4269 if (mod->state == MODULE_STATE_UNFORMED)
4274 EXPORT_SYMBOL_GPL(__module_address);
4277 * is_module_text_address - is this address inside module code?
4278 * @addr: the address to check.
4280 * See is_module_address() if you simply want to see if the address is
4281 * anywhere in a module. See kernel_text_address() for testing if an
4282 * address corresponds to kernel or module code.
4284 bool is_module_text_address(unsigned long addr)
4289 ret = __module_text_address(addr) != NULL;
4296 * __module_text_address - get the module whose code contains an address.
4297 * @addr: the address.
4299 * Must be called with preempt disabled or module mutex held so that
4300 * module doesn't get freed during this.
4302 struct module *__module_text_address(unsigned long addr)
4304 struct module *mod = __module_address(addr);
4306 /* Make sure it's within the text section. */
4307 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
4308 && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
4313 EXPORT_SYMBOL_GPL(__module_text_address);
4315 /* Don't grab lock, we're oopsing. */
4316 void print_modules(void)
4319 char buf[MODULE_FLAGS_BUF_SIZE];
4321 printk(KERN_DEFAULT "Modules linked in:");
4322 /* Most callers should already have preempt disabled, but make sure */
4324 list_for_each_entry_rcu(mod, &modules, list) {
4325 if (mod->state == MODULE_STATE_UNFORMED)
4327 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4330 if (last_unloaded_module[0])
4331 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4335 #ifdef CONFIG_MODVERSIONS
4336 /* Generate the signature for all relevant module structures here.
4337 * If these change, we don't want to try to parse the module. */
4338 void module_layout(struct module *mod,
4339 struct modversion_info *ver,
4340 struct kernel_param *kp,
4341 struct kernel_symbol *ks,
4342 struct tracepoint * const *tp)
4345 EXPORT_SYMBOL(module_layout);