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/moduleloader.h>
21 #include <linux/trace_events.h>
22 #include <linux/init.h>
23 #include <linux/kallsyms.h>
24 #include <linux/file.h>
26 #include <linux/sysfs.h>
27 #include <linux/kernel.h>
28 #include <linux/slab.h>
29 #include <linux/vmalloc.h>
30 #include <linux/elf.h>
31 #include <linux/proc_fs.h>
32 #include <linux/security.h>
33 #include <linux/seq_file.h>
34 #include <linux/syscalls.h>
35 #include <linux/fcntl.h>
36 #include <linux/rcupdate.h>
37 #include <linux/capability.h>
38 #include <linux/cpu.h>
39 #include <linux/moduleparam.h>
40 #include <linux/errno.h>
41 #include <linux/err.h>
42 #include <linux/vermagic.h>
43 #include <linux/notifier.h>
44 #include <linux/sched.h>
45 #include <linux/device.h>
46 #include <linux/string.h>
47 #include <linux/mutex.h>
48 #include <linux/rculist.h>
49 #include <asm/uaccess.h>
50 #include <asm/cacheflush.h>
51 #include <asm/mmu_context.h>
52 #include <linux/license.h>
53 #include <asm/sections.h>
54 #include <linux/tracepoint.h>
55 #include <linux/ftrace.h>
56 #include <linux/livepatch.h>
57 #include <linux/async.h>
58 #include <linux/percpu.h>
59 #include <linux/kmemleak.h>
60 #include <linux/jump_label.h>
61 #include <linux/pfn.h>
62 #include <linux/bsearch.h>
63 #include <uapi/linux/module.h>
64 #include "module-internal.h"
66 #define CREATE_TRACE_POINTS
67 #include <trace/events/module.h>
69 #ifndef ARCH_SHF_SMALL
70 #define ARCH_SHF_SMALL 0
74 * Modules' sections will be aligned on page boundaries
75 * to ensure complete separation of code and data, but
76 * only when CONFIG_DEBUG_SET_MODULE_RONX=y
78 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
79 # define debug_align(X) ALIGN(X, PAGE_SIZE)
81 # define debug_align(X) (X)
84 /* If this is set, the section belongs in the init part of the module */
85 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
89 * 1) List of modules (also safely readable with preempt_disable),
90 * 2) module_use links,
91 * 3) module_addr_min/module_addr_max.
92 * (delete and add uses RCU list operations). */
93 DEFINE_MUTEX(module_mutex);
94 EXPORT_SYMBOL_GPL(module_mutex);
95 static LIST_HEAD(modules);
97 #ifdef CONFIG_MODULES_TREE_LOOKUP
100 * Use a latched RB-tree for __module_address(); this allows us to use
101 * RCU-sched lookups of the address from any context.
103 * This is conditional on PERF_EVENTS || TRACING because those can really hit
104 * __module_address() hard by doing a lot of stack unwinding; potentially from
108 static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
110 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
112 return (unsigned long)layout->base;
115 static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
117 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
119 return (unsigned long)layout->size;
122 static __always_inline bool
123 mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
125 return __mod_tree_val(a) < __mod_tree_val(b);
128 static __always_inline int
129 mod_tree_comp(void *key, struct latch_tree_node *n)
131 unsigned long val = (unsigned long)key;
132 unsigned long start, end;
134 start = __mod_tree_val(n);
138 end = start + __mod_tree_size(n);
145 static const struct latch_tree_ops mod_tree_ops = {
146 .less = mod_tree_less,
147 .comp = mod_tree_comp,
150 static struct mod_tree_root {
151 struct latch_tree_root root;
152 unsigned long addr_min;
153 unsigned long addr_max;
154 } mod_tree __cacheline_aligned = {
158 #define module_addr_min mod_tree.addr_min
159 #define module_addr_max mod_tree.addr_max
161 static noinline void __mod_tree_insert(struct mod_tree_node *node)
163 latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
166 static void __mod_tree_remove(struct mod_tree_node *node)
168 latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
172 * These modifications: insert, remove_init and remove; are serialized by the
175 static void mod_tree_insert(struct module *mod)
177 mod->core_layout.mtn.mod = mod;
178 mod->init_layout.mtn.mod = mod;
180 __mod_tree_insert(&mod->core_layout.mtn);
181 if (mod->init_layout.size)
182 __mod_tree_insert(&mod->init_layout.mtn);
185 static void mod_tree_remove_init(struct module *mod)
187 if (mod->init_layout.size)
188 __mod_tree_remove(&mod->init_layout.mtn);
191 static void mod_tree_remove(struct module *mod)
193 __mod_tree_remove(&mod->core_layout.mtn);
194 mod_tree_remove_init(mod);
197 static struct module *mod_find(unsigned long addr)
199 struct latch_tree_node *ltn;
201 ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
205 return container_of(ltn, struct mod_tree_node, node)->mod;
208 #else /* MODULES_TREE_LOOKUP */
210 static unsigned long module_addr_min = -1UL, module_addr_max = 0;
212 static void mod_tree_insert(struct module *mod) { }
213 static void mod_tree_remove_init(struct module *mod) { }
214 static void mod_tree_remove(struct module *mod) { }
216 static struct module *mod_find(unsigned long addr)
220 list_for_each_entry_rcu(mod, &modules, list) {
221 if (within_module(addr, mod))
228 #endif /* MODULES_TREE_LOOKUP */
231 * Bounds of module text, for speeding up __module_address.
232 * Protected by module_mutex.
234 static void __mod_update_bounds(void *base, unsigned int size)
236 unsigned long min = (unsigned long)base;
237 unsigned long max = min + size;
239 if (min < module_addr_min)
240 module_addr_min = min;
241 if (max > module_addr_max)
242 module_addr_max = max;
245 static void mod_update_bounds(struct module *mod)
247 __mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
248 if (mod->init_layout.size)
249 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
252 #ifdef CONFIG_KGDB_KDB
253 struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
254 #endif /* CONFIG_KGDB_KDB */
256 static void module_assert_mutex(void)
258 lockdep_assert_held(&module_mutex);
261 static void module_assert_mutex_or_preempt(void)
263 #ifdef CONFIG_LOCKDEP
264 if (unlikely(!debug_locks))
267 WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
268 !lockdep_is_held(&module_mutex));
272 static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
273 #ifndef CONFIG_MODULE_SIG_FORCE
274 module_param(sig_enforce, bool_enable_only, 0644);
275 #endif /* !CONFIG_MODULE_SIG_FORCE */
277 /* Block module loading/unloading? */
278 int modules_disabled = 0;
279 core_param(nomodule, modules_disabled, bint, 0);
281 /* Waiting for a module to finish initializing? */
282 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
284 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
286 int register_module_notifier(struct notifier_block *nb)
288 return blocking_notifier_chain_register(&module_notify_list, nb);
290 EXPORT_SYMBOL(register_module_notifier);
292 int unregister_module_notifier(struct notifier_block *nb)
294 return blocking_notifier_chain_unregister(&module_notify_list, nb);
296 EXPORT_SYMBOL(unregister_module_notifier);
302 char *secstrings, *strtab;
303 unsigned long symoffs, stroffs;
304 struct _ddebug *debug;
305 unsigned int num_debug;
307 #ifdef CONFIG_KALLSYMS
308 unsigned long mod_kallsyms_init_off;
311 unsigned int sym, str, mod, vers, info, pcpu;
315 /* We require a truly strong try_module_get(): 0 means failure due to
316 ongoing or failed initialization etc. */
317 static inline int strong_try_module_get(struct module *mod)
319 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
320 if (mod && mod->state == MODULE_STATE_COMING)
322 if (try_module_get(mod))
328 static inline void add_taint_module(struct module *mod, unsigned flag,
329 enum lockdep_ok lockdep_ok)
331 add_taint(flag, lockdep_ok);
332 mod->taints |= (1U << flag);
336 * A thread that wants to hold a reference to a module only while it
337 * is running can call this to safely exit. nfsd and lockd use this.
339 void __noreturn __module_put_and_exit(struct module *mod, long code)
344 EXPORT_SYMBOL(__module_put_and_exit);
346 /* Find a module section: 0 means not found. */
347 static unsigned int find_sec(const struct load_info *info, const char *name)
351 for (i = 1; i < info->hdr->e_shnum; i++) {
352 Elf_Shdr *shdr = &info->sechdrs[i];
353 /* Alloc bit cleared means "ignore it." */
354 if ((shdr->sh_flags & SHF_ALLOC)
355 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
361 /* Find a module section, or NULL. */
362 static void *section_addr(const struct load_info *info, const char *name)
364 /* Section 0 has sh_addr 0. */
365 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
368 /* Find a module section, or NULL. Fill in number of "objects" in section. */
369 static void *section_objs(const struct load_info *info,
374 unsigned int sec = find_sec(info, name);
376 /* Section 0 has sh_addr 0 and sh_size 0. */
377 *num = info->sechdrs[sec].sh_size / object_size;
378 return (void *)info->sechdrs[sec].sh_addr;
381 /* Provided by the linker */
382 extern const struct kernel_symbol __start___ksymtab[];
383 extern const struct kernel_symbol __stop___ksymtab[];
384 extern const struct kernel_symbol __start___ksymtab_gpl[];
385 extern const struct kernel_symbol __stop___ksymtab_gpl[];
386 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
387 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
388 extern const unsigned long __start___kcrctab[];
389 extern const unsigned long __start___kcrctab_gpl[];
390 extern const unsigned long __start___kcrctab_gpl_future[];
391 #ifdef CONFIG_UNUSED_SYMBOLS
392 extern const struct kernel_symbol __start___ksymtab_unused[];
393 extern const struct kernel_symbol __stop___ksymtab_unused[];
394 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
395 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
396 extern const unsigned long __start___kcrctab_unused[];
397 extern const unsigned long __start___kcrctab_unused_gpl[];
400 #ifndef CONFIG_MODVERSIONS
401 #define symversion(base, idx) NULL
403 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
406 static bool each_symbol_in_section(const struct symsearch *arr,
407 unsigned int arrsize,
408 struct module *owner,
409 bool (*fn)(const struct symsearch *syms,
410 struct module *owner,
416 for (j = 0; j < arrsize; j++) {
417 if (fn(&arr[j], owner, data))
424 /* Returns true as soon as fn returns true, otherwise false. */
425 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
426 struct module *owner,
431 static const struct symsearch arr[] = {
432 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
433 NOT_GPL_ONLY, false },
434 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
435 __start___kcrctab_gpl,
437 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
438 __start___kcrctab_gpl_future,
439 WILL_BE_GPL_ONLY, false },
440 #ifdef CONFIG_UNUSED_SYMBOLS
441 { __start___ksymtab_unused, __stop___ksymtab_unused,
442 __start___kcrctab_unused,
443 NOT_GPL_ONLY, true },
444 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
445 __start___kcrctab_unused_gpl,
450 module_assert_mutex_or_preempt();
452 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
455 list_for_each_entry_rcu(mod, &modules, list) {
456 struct symsearch arr[] = {
457 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
458 NOT_GPL_ONLY, false },
459 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
462 { mod->gpl_future_syms,
463 mod->gpl_future_syms + mod->num_gpl_future_syms,
464 mod->gpl_future_crcs,
465 WILL_BE_GPL_ONLY, false },
466 #ifdef CONFIG_UNUSED_SYMBOLS
468 mod->unused_syms + mod->num_unused_syms,
470 NOT_GPL_ONLY, true },
471 { mod->unused_gpl_syms,
472 mod->unused_gpl_syms + mod->num_unused_gpl_syms,
473 mod->unused_gpl_crcs,
478 if (mod->state == MODULE_STATE_UNFORMED)
481 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
486 EXPORT_SYMBOL_GPL(each_symbol_section);
488 struct find_symbol_arg {
495 struct module *owner;
496 const unsigned long *crc;
497 const struct kernel_symbol *sym;
500 static bool check_symbol(const struct symsearch *syms,
501 struct module *owner,
502 unsigned int symnum, void *data)
504 struct find_symbol_arg *fsa = data;
507 if (syms->licence == GPL_ONLY)
509 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
510 pr_warn("Symbol %s is being used by a non-GPL module, "
511 "which will not be allowed in the future\n",
516 #ifdef CONFIG_UNUSED_SYMBOLS
517 if (syms->unused && fsa->warn) {
518 pr_warn("Symbol %s is marked as UNUSED, however this module is "
519 "using it.\n", fsa->name);
520 pr_warn("This symbol will go away in the future.\n");
521 pr_warn("Please evaluate if this is the right api to use and "
522 "if it really is, submit a report to the linux kernel "
523 "mailing list together with submitting your code for "
529 fsa->crc = symversion(syms->crcs, symnum);
530 fsa->sym = &syms->start[symnum];
534 static int cmp_name(const void *va, const void *vb)
537 const struct kernel_symbol *b;
539 return strcmp(a, b->name);
542 static bool find_symbol_in_section(const struct symsearch *syms,
543 struct module *owner,
546 struct find_symbol_arg *fsa = data;
547 struct kernel_symbol *sym;
549 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
550 sizeof(struct kernel_symbol), cmp_name);
552 if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
558 /* Find a symbol and return it, along with, (optional) crc and
559 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
560 const struct kernel_symbol *find_symbol(const char *name,
561 struct module **owner,
562 const unsigned long **crc,
566 struct find_symbol_arg fsa;
572 if (each_symbol_section(find_symbol_in_section, &fsa)) {
580 pr_debug("Failed to find symbol %s\n", name);
583 EXPORT_SYMBOL_GPL(find_symbol);
586 * Search for module by name: must hold module_mutex (or preempt disabled
587 * for read-only access).
589 static struct module *find_module_all(const char *name, size_t len,
594 module_assert_mutex_or_preempt();
596 list_for_each_entry(mod, &modules, list) {
597 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
599 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
605 struct module *find_module(const char *name)
607 module_assert_mutex();
608 return find_module_all(name, strlen(name), false);
610 EXPORT_SYMBOL_GPL(find_module);
614 static inline void __percpu *mod_percpu(struct module *mod)
619 static int percpu_modalloc(struct module *mod, struct load_info *info)
621 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
622 unsigned long align = pcpusec->sh_addralign;
624 if (!pcpusec->sh_size)
627 if (align > PAGE_SIZE) {
628 pr_warn("%s: per-cpu alignment %li > %li\n",
629 mod->name, align, PAGE_SIZE);
633 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
635 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
636 mod->name, (unsigned long)pcpusec->sh_size);
639 mod->percpu_size = pcpusec->sh_size;
643 static void percpu_modfree(struct module *mod)
645 free_percpu(mod->percpu);
648 static unsigned int find_pcpusec(struct load_info *info)
650 return find_sec(info, ".data..percpu");
653 static void percpu_modcopy(struct module *mod,
654 const void *from, unsigned long size)
658 for_each_possible_cpu(cpu)
659 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
663 * is_module_percpu_address - test whether address is from module static percpu
664 * @addr: address to test
666 * Test whether @addr belongs to module static percpu area.
669 * %true if @addr is from module static percpu area
671 bool is_module_percpu_address(unsigned long addr)
678 list_for_each_entry_rcu(mod, &modules, list) {
679 if (mod->state == MODULE_STATE_UNFORMED)
681 if (!mod->percpu_size)
683 for_each_possible_cpu(cpu) {
684 void *start = per_cpu_ptr(mod->percpu, cpu);
686 if ((void *)addr >= start &&
687 (void *)addr < start + mod->percpu_size) {
698 #else /* ... !CONFIG_SMP */
700 static inline void __percpu *mod_percpu(struct module *mod)
704 static int percpu_modalloc(struct module *mod, struct load_info *info)
706 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
707 if (info->sechdrs[info->index.pcpu].sh_size != 0)
711 static inline void percpu_modfree(struct module *mod)
714 static unsigned int find_pcpusec(struct load_info *info)
718 static inline void percpu_modcopy(struct module *mod,
719 const void *from, unsigned long size)
721 /* pcpusec should be 0, and size of that section should be 0. */
724 bool is_module_percpu_address(unsigned long addr)
729 #endif /* CONFIG_SMP */
731 #define MODINFO_ATTR(field) \
732 static void setup_modinfo_##field(struct module *mod, const char *s) \
734 mod->field = kstrdup(s, GFP_KERNEL); \
736 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
737 struct module_kobject *mk, char *buffer) \
739 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
741 static int modinfo_##field##_exists(struct module *mod) \
743 return mod->field != NULL; \
745 static void free_modinfo_##field(struct module *mod) \
750 static struct module_attribute modinfo_##field = { \
751 .attr = { .name = __stringify(field), .mode = 0444 }, \
752 .show = show_modinfo_##field, \
753 .setup = setup_modinfo_##field, \
754 .test = modinfo_##field##_exists, \
755 .free = free_modinfo_##field, \
758 MODINFO_ATTR(version);
759 MODINFO_ATTR(srcversion);
761 static char last_unloaded_module[MODULE_NAME_LEN+1];
763 #ifdef CONFIG_MODULE_UNLOAD
765 EXPORT_TRACEPOINT_SYMBOL(module_get);
767 /* MODULE_REF_BASE is the base reference count by kmodule loader. */
768 #define MODULE_REF_BASE 1
770 /* Init the unload section of the module. */
771 static int module_unload_init(struct module *mod)
774 * Initialize reference counter to MODULE_REF_BASE.
775 * refcnt == 0 means module is going.
777 atomic_set(&mod->refcnt, MODULE_REF_BASE);
779 INIT_LIST_HEAD(&mod->source_list);
780 INIT_LIST_HEAD(&mod->target_list);
782 /* Hold reference count during initialization. */
783 atomic_inc(&mod->refcnt);
788 /* Does a already use b? */
789 static int already_uses(struct module *a, struct module *b)
791 struct module_use *use;
793 list_for_each_entry(use, &b->source_list, source_list) {
794 if (use->source == a) {
795 pr_debug("%s uses %s!\n", a->name, b->name);
799 pr_debug("%s does not use %s!\n", a->name, b->name);
805 * - we add 'a' as a "source", 'b' as a "target" of module use
806 * - the module_use is added to the list of 'b' sources (so
807 * 'b' can walk the list to see who sourced them), and of 'a'
808 * targets (so 'a' can see what modules it targets).
810 static int add_module_usage(struct module *a, struct module *b)
812 struct module_use *use;
814 pr_debug("Allocating new usage for %s.\n", a->name);
815 use = kmalloc(sizeof(*use), GFP_ATOMIC);
817 pr_warn("%s: out of memory loading\n", a->name);
823 list_add(&use->source_list, &b->source_list);
824 list_add(&use->target_list, &a->target_list);
828 /* Module a uses b: caller needs module_mutex() */
829 int ref_module(struct module *a, struct module *b)
833 if (b == NULL || already_uses(a, b))
836 /* If module isn't available, we fail. */
837 err = strong_try_module_get(b);
841 err = add_module_usage(a, b);
848 EXPORT_SYMBOL_GPL(ref_module);
850 /* Clear the unload stuff of the module. */
851 static void module_unload_free(struct module *mod)
853 struct module_use *use, *tmp;
855 mutex_lock(&module_mutex);
856 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
857 struct module *i = use->target;
858 pr_debug("%s unusing %s\n", mod->name, i->name);
860 list_del(&use->source_list);
861 list_del(&use->target_list);
864 mutex_unlock(&module_mutex);
867 #ifdef CONFIG_MODULE_FORCE_UNLOAD
868 static inline int try_force_unload(unsigned int flags)
870 int ret = (flags & O_TRUNC);
872 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
876 static inline int try_force_unload(unsigned int flags)
880 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
882 /* Try to release refcount of module, 0 means success. */
883 static int try_release_module_ref(struct module *mod)
887 /* Try to decrement refcnt which we set at loading */
888 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
891 /* Someone can put this right now, recover with checking */
892 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
897 static int try_stop_module(struct module *mod, int flags, int *forced)
899 /* If it's not unused, quit unless we're forcing. */
900 if (try_release_module_ref(mod) != 0) {
901 *forced = try_force_unload(flags);
906 /* Mark it as dying. */
907 mod->state = MODULE_STATE_GOING;
913 * module_refcount - return the refcount or -1 if unloading
915 * @mod: the module we're checking
918 * -1 if the module is in the process of unloading
919 * otherwise the number of references in the kernel to the module
921 int module_refcount(struct module *mod)
923 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
925 EXPORT_SYMBOL(module_refcount);
927 /* This exists whether we can unload or not */
928 static void free_module(struct module *mod);
930 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
934 char name[MODULE_NAME_LEN];
937 if (!capable(CAP_SYS_MODULE) || modules_disabled)
940 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
942 name[MODULE_NAME_LEN-1] = '\0';
944 if (mutex_lock_interruptible(&module_mutex) != 0)
947 mod = find_module(name);
953 if (!list_empty(&mod->source_list)) {
954 /* Other modules depend on us: get rid of them first. */
959 /* Doing init or already dying? */
960 if (mod->state != MODULE_STATE_LIVE) {
961 /* FIXME: if (force), slam module count damn the torpedoes */
962 pr_debug("%s already dying\n", mod->name);
967 /* If it has an init func, it must have an exit func to unload */
968 if (mod->init && !mod->exit) {
969 forced = try_force_unload(flags);
971 /* This module can't be removed */
977 /* Stop the machine so refcounts can't move and disable module. */
978 ret = try_stop_module(mod, flags, &forced);
982 mutex_unlock(&module_mutex);
983 /* Final destruction now no one is using it. */
984 if (mod->exit != NULL)
986 blocking_notifier_call_chain(&module_notify_list,
987 MODULE_STATE_GOING, mod);
988 klp_module_going(mod);
989 ftrace_release_mod(mod);
991 async_synchronize_full();
993 /* Store the name of the last unloaded module for diagnostic purposes */
994 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
999 mutex_unlock(&module_mutex);
1003 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1005 struct module_use *use;
1006 int printed_something = 0;
1008 seq_printf(m, " %i ", module_refcount(mod));
1011 * Always include a trailing , so userspace can differentiate
1012 * between this and the old multi-field proc format.
1014 list_for_each_entry(use, &mod->source_list, source_list) {
1015 printed_something = 1;
1016 seq_printf(m, "%s,", use->source->name);
1019 if (mod->init != NULL && mod->exit == NULL) {
1020 printed_something = 1;
1021 seq_puts(m, "[permanent],");
1024 if (!printed_something)
1028 void __symbol_put(const char *symbol)
1030 struct module *owner;
1033 if (!find_symbol(symbol, &owner, NULL, true, false))
1038 EXPORT_SYMBOL(__symbol_put);
1040 /* Note this assumes addr is a function, which it currently always is. */
1041 void symbol_put_addr(void *addr)
1043 struct module *modaddr;
1044 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1046 if (core_kernel_text(a))
1050 * Even though we hold a reference on the module; we still need to
1051 * disable preemption in order to safely traverse the data structure.
1054 modaddr = __module_text_address(a);
1056 module_put(modaddr);
1059 EXPORT_SYMBOL_GPL(symbol_put_addr);
1061 static ssize_t show_refcnt(struct module_attribute *mattr,
1062 struct module_kobject *mk, char *buffer)
1064 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1067 static struct module_attribute modinfo_refcnt =
1068 __ATTR(refcnt, 0444, show_refcnt, NULL);
1070 void __module_get(struct module *module)
1074 atomic_inc(&module->refcnt);
1075 trace_module_get(module, _RET_IP_);
1079 EXPORT_SYMBOL(__module_get);
1081 bool try_module_get(struct module *module)
1087 /* Note: here, we can fail to get a reference */
1088 if (likely(module_is_live(module) &&
1089 atomic_inc_not_zero(&module->refcnt) != 0))
1090 trace_module_get(module, _RET_IP_);
1098 EXPORT_SYMBOL(try_module_get);
1100 void module_put(struct module *module)
1106 ret = atomic_dec_if_positive(&module->refcnt);
1107 WARN_ON(ret < 0); /* Failed to put refcount */
1108 trace_module_put(module, _RET_IP_);
1112 EXPORT_SYMBOL(module_put);
1114 #else /* !CONFIG_MODULE_UNLOAD */
1115 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1117 /* We don't know the usage count, or what modules are using. */
1118 seq_puts(m, " - -");
1121 static inline void module_unload_free(struct module *mod)
1125 int ref_module(struct module *a, struct module *b)
1127 return strong_try_module_get(b);
1129 EXPORT_SYMBOL_GPL(ref_module);
1131 static inline int module_unload_init(struct module *mod)
1135 #endif /* CONFIG_MODULE_UNLOAD */
1137 static size_t module_flags_taint(struct module *mod, char *buf)
1141 if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
1143 if (mod->taints & (1 << TAINT_OOT_MODULE))
1145 if (mod->taints & (1 << TAINT_FORCED_MODULE))
1147 if (mod->taints & (1 << TAINT_CRAP))
1149 if (mod->taints & (1 << TAINT_UNSIGNED_MODULE))
1152 * TAINT_FORCED_RMMOD: could be added.
1153 * TAINT_CPU_OUT_OF_SPEC, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
1159 static ssize_t show_initstate(struct module_attribute *mattr,
1160 struct module_kobject *mk, char *buffer)
1162 const char *state = "unknown";
1164 switch (mk->mod->state) {
1165 case MODULE_STATE_LIVE:
1168 case MODULE_STATE_COMING:
1171 case MODULE_STATE_GOING:
1177 return sprintf(buffer, "%s\n", state);
1180 static struct module_attribute modinfo_initstate =
1181 __ATTR(initstate, 0444, show_initstate, NULL);
1183 static ssize_t store_uevent(struct module_attribute *mattr,
1184 struct module_kobject *mk,
1185 const char *buffer, size_t count)
1187 enum kobject_action action;
1189 if (kobject_action_type(buffer, count, &action) == 0)
1190 kobject_uevent(&mk->kobj, action);
1194 struct module_attribute module_uevent =
1195 __ATTR(uevent, 0200, NULL, store_uevent);
1197 static ssize_t show_coresize(struct module_attribute *mattr,
1198 struct module_kobject *mk, char *buffer)
1200 return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1203 static struct module_attribute modinfo_coresize =
1204 __ATTR(coresize, 0444, show_coresize, NULL);
1206 static ssize_t show_initsize(struct module_attribute *mattr,
1207 struct module_kobject *mk, char *buffer)
1209 return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1212 static struct module_attribute modinfo_initsize =
1213 __ATTR(initsize, 0444, show_initsize, NULL);
1215 static ssize_t show_taint(struct module_attribute *mattr,
1216 struct module_kobject *mk, char *buffer)
1220 l = module_flags_taint(mk->mod, buffer);
1225 static struct module_attribute modinfo_taint =
1226 __ATTR(taint, 0444, show_taint, NULL);
1228 static struct module_attribute *modinfo_attrs[] = {
1231 &modinfo_srcversion,
1236 #ifdef CONFIG_MODULE_UNLOAD
1242 static const char vermagic[] = VERMAGIC_STRING;
1244 static int try_to_force_load(struct module *mod, const char *reason)
1246 #ifdef CONFIG_MODULE_FORCE_LOAD
1247 if (!test_taint(TAINT_FORCED_MODULE))
1248 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1249 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1256 #ifdef CONFIG_MODVERSIONS
1257 /* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
1258 static unsigned long maybe_relocated(unsigned long crc,
1259 const struct module *crc_owner)
1261 #ifdef ARCH_RELOCATES_KCRCTAB
1262 if (crc_owner == NULL)
1263 return crc - (unsigned long)reloc_start;
1268 static int check_version(Elf_Shdr *sechdrs,
1269 unsigned int versindex,
1270 const char *symname,
1272 const unsigned long *crc,
1273 const struct module *crc_owner)
1275 unsigned int i, num_versions;
1276 struct modversion_info *versions;
1278 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1282 /* No versions at all? modprobe --force does this. */
1284 return try_to_force_load(mod, symname) == 0;
1286 versions = (void *) sechdrs[versindex].sh_addr;
1287 num_versions = sechdrs[versindex].sh_size
1288 / sizeof(struct modversion_info);
1290 for (i = 0; i < num_versions; i++) {
1291 if (strcmp(versions[i].name, symname) != 0)
1294 if (versions[i].crc == maybe_relocated(*crc, crc_owner))
1296 pr_debug("Found checksum %lX vs module %lX\n",
1297 maybe_relocated(*crc, crc_owner), versions[i].crc);
1301 pr_warn("%s: no symbol version for %s\n", mod->name, symname);
1305 pr_warn("%s: disagrees about version of symbol %s\n",
1306 mod->name, symname);
1310 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1311 unsigned int versindex,
1314 const unsigned long *crc;
1317 * Since this should be found in kernel (which can't be removed), no
1318 * locking is necessary -- use preempt_disable() to placate lockdep.
1321 if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
1322 &crc, true, false)) {
1327 return check_version(sechdrs, versindex,
1328 VMLINUX_SYMBOL_STR(module_layout), mod, crc,
1332 /* First part is kernel version, which we ignore if module has crcs. */
1333 static inline int same_magic(const char *amagic, const char *bmagic,
1337 amagic += strcspn(amagic, " ");
1338 bmagic += strcspn(bmagic, " ");
1340 return strcmp(amagic, bmagic) == 0;
1343 static inline int check_version(Elf_Shdr *sechdrs,
1344 unsigned int versindex,
1345 const char *symname,
1347 const unsigned long *crc,
1348 const struct module *crc_owner)
1353 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1354 unsigned int versindex,
1360 static inline int same_magic(const char *amagic, const char *bmagic,
1363 return strcmp(amagic, bmagic) == 0;
1365 #endif /* CONFIG_MODVERSIONS */
1367 /* Resolve a symbol for this module. I.e. if we find one, record usage. */
1368 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1369 const struct load_info *info,
1373 struct module *owner;
1374 const struct kernel_symbol *sym;
1375 const unsigned long *crc;
1379 * The module_mutex should not be a heavily contended lock;
1380 * if we get the occasional sleep here, we'll go an extra iteration
1381 * in the wait_event_interruptible(), which is harmless.
1383 sched_annotate_sleep();
1384 mutex_lock(&module_mutex);
1385 sym = find_symbol(name, &owner, &crc,
1386 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1390 if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
1392 sym = ERR_PTR(-EINVAL);
1396 err = ref_module(mod, owner);
1403 /* We must make copy under the lock if we failed to get ref. */
1404 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1406 mutex_unlock(&module_mutex);
1410 static const struct kernel_symbol *
1411 resolve_symbol_wait(struct module *mod,
1412 const struct load_info *info,
1415 const struct kernel_symbol *ksym;
1416 char owner[MODULE_NAME_LEN];
1418 if (wait_event_interruptible_timeout(module_wq,
1419 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1420 || PTR_ERR(ksym) != -EBUSY,
1422 pr_warn("%s: gave up waiting for init of module %s.\n",
1429 * /sys/module/foo/sections stuff
1430 * J. Corbet <corbet@lwn.net>
1434 #ifdef CONFIG_KALLSYMS
1435 static inline bool sect_empty(const Elf_Shdr *sect)
1437 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1440 struct module_sect_attr {
1441 struct module_attribute mattr;
1443 unsigned long address;
1446 struct module_sect_attrs {
1447 struct attribute_group grp;
1448 unsigned int nsections;
1449 struct module_sect_attr attrs[0];
1452 static ssize_t module_sect_show(struct module_attribute *mattr,
1453 struct module_kobject *mk, char *buf)
1455 struct module_sect_attr *sattr =
1456 container_of(mattr, struct module_sect_attr, mattr);
1457 return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1460 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1462 unsigned int section;
1464 for (section = 0; section < sect_attrs->nsections; section++)
1465 kfree(sect_attrs->attrs[section].name);
1469 static void add_sect_attrs(struct module *mod, const struct load_info *info)
1471 unsigned int nloaded = 0, i, size[2];
1472 struct module_sect_attrs *sect_attrs;
1473 struct module_sect_attr *sattr;
1474 struct attribute **gattr;
1476 /* Count loaded sections and allocate structures */
1477 for (i = 0; i < info->hdr->e_shnum; i++)
1478 if (!sect_empty(&info->sechdrs[i]))
1480 size[0] = ALIGN(sizeof(*sect_attrs)
1481 + nloaded * sizeof(sect_attrs->attrs[0]),
1482 sizeof(sect_attrs->grp.attrs[0]));
1483 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1484 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1485 if (sect_attrs == NULL)
1488 /* Setup section attributes. */
1489 sect_attrs->grp.name = "sections";
1490 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1492 sect_attrs->nsections = 0;
1493 sattr = §_attrs->attrs[0];
1494 gattr = §_attrs->grp.attrs[0];
1495 for (i = 0; i < info->hdr->e_shnum; i++) {
1496 Elf_Shdr *sec = &info->sechdrs[i];
1497 if (sect_empty(sec))
1499 sattr->address = sec->sh_addr;
1500 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1502 if (sattr->name == NULL)
1504 sect_attrs->nsections++;
1505 sysfs_attr_init(&sattr->mattr.attr);
1506 sattr->mattr.show = module_sect_show;
1507 sattr->mattr.store = NULL;
1508 sattr->mattr.attr.name = sattr->name;
1509 sattr->mattr.attr.mode = S_IRUGO;
1510 *(gattr++) = &(sattr++)->mattr.attr;
1514 if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp))
1517 mod->sect_attrs = sect_attrs;
1520 free_sect_attrs(sect_attrs);
1523 static void remove_sect_attrs(struct module *mod)
1525 if (mod->sect_attrs) {
1526 sysfs_remove_group(&mod->mkobj.kobj,
1527 &mod->sect_attrs->grp);
1528 /* We are positive that no one is using any sect attrs
1529 * at this point. Deallocate immediately. */
1530 free_sect_attrs(mod->sect_attrs);
1531 mod->sect_attrs = NULL;
1536 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1539 struct module_notes_attrs {
1540 struct kobject *dir;
1542 struct bin_attribute attrs[0];
1545 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1546 struct bin_attribute *bin_attr,
1547 char *buf, loff_t pos, size_t count)
1550 * The caller checked the pos and count against our size.
1552 memcpy(buf, bin_attr->private + pos, count);
1556 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1559 if (notes_attrs->dir) {
1561 sysfs_remove_bin_file(notes_attrs->dir,
1562 ¬es_attrs->attrs[i]);
1563 kobject_put(notes_attrs->dir);
1568 static void add_notes_attrs(struct module *mod, const struct load_info *info)
1570 unsigned int notes, loaded, i;
1571 struct module_notes_attrs *notes_attrs;
1572 struct bin_attribute *nattr;
1574 /* failed to create section attributes, so can't create notes */
1575 if (!mod->sect_attrs)
1578 /* Count notes sections and allocate structures. */
1580 for (i = 0; i < info->hdr->e_shnum; i++)
1581 if (!sect_empty(&info->sechdrs[i]) &&
1582 (info->sechdrs[i].sh_type == SHT_NOTE))
1588 notes_attrs = kzalloc(sizeof(*notes_attrs)
1589 + notes * sizeof(notes_attrs->attrs[0]),
1591 if (notes_attrs == NULL)
1594 notes_attrs->notes = notes;
1595 nattr = ¬es_attrs->attrs[0];
1596 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1597 if (sect_empty(&info->sechdrs[i]))
1599 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1600 sysfs_bin_attr_init(nattr);
1601 nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1602 nattr->attr.mode = S_IRUGO;
1603 nattr->size = info->sechdrs[i].sh_size;
1604 nattr->private = (void *) info->sechdrs[i].sh_addr;
1605 nattr->read = module_notes_read;
1611 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1612 if (!notes_attrs->dir)
1615 for (i = 0; i < notes; ++i)
1616 if (sysfs_create_bin_file(notes_attrs->dir,
1617 ¬es_attrs->attrs[i]))
1620 mod->notes_attrs = notes_attrs;
1624 free_notes_attrs(notes_attrs, i);
1627 static void remove_notes_attrs(struct module *mod)
1629 if (mod->notes_attrs)
1630 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1635 static inline void add_sect_attrs(struct module *mod,
1636 const struct load_info *info)
1640 static inline void remove_sect_attrs(struct module *mod)
1644 static inline void add_notes_attrs(struct module *mod,
1645 const struct load_info *info)
1649 static inline void remove_notes_attrs(struct module *mod)
1652 #endif /* CONFIG_KALLSYMS */
1654 static void add_usage_links(struct module *mod)
1656 #ifdef CONFIG_MODULE_UNLOAD
1657 struct module_use *use;
1660 mutex_lock(&module_mutex);
1661 list_for_each_entry(use, &mod->target_list, target_list) {
1662 nowarn = sysfs_create_link(use->target->holders_dir,
1663 &mod->mkobj.kobj, mod->name);
1665 mutex_unlock(&module_mutex);
1669 static void del_usage_links(struct module *mod)
1671 #ifdef CONFIG_MODULE_UNLOAD
1672 struct module_use *use;
1674 mutex_lock(&module_mutex);
1675 list_for_each_entry(use, &mod->target_list, target_list)
1676 sysfs_remove_link(use->target->holders_dir, mod->name);
1677 mutex_unlock(&module_mutex);
1681 static int module_add_modinfo_attrs(struct module *mod)
1683 struct module_attribute *attr;
1684 struct module_attribute *temp_attr;
1688 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1689 (ARRAY_SIZE(modinfo_attrs) + 1)),
1691 if (!mod->modinfo_attrs)
1694 temp_attr = mod->modinfo_attrs;
1695 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1696 if (!attr->test || attr->test(mod)) {
1697 memcpy(temp_attr, attr, sizeof(*temp_attr));
1698 sysfs_attr_init(&temp_attr->attr);
1699 error = sysfs_create_file(&mod->mkobj.kobj,
1707 static void module_remove_modinfo_attrs(struct module *mod)
1709 struct module_attribute *attr;
1712 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1713 /* pick a field to test for end of list */
1714 if (!attr->attr.name)
1716 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1720 kfree(mod->modinfo_attrs);
1723 static void mod_kobject_put(struct module *mod)
1725 DECLARE_COMPLETION_ONSTACK(c);
1726 mod->mkobj.kobj_completion = &c;
1727 kobject_put(&mod->mkobj.kobj);
1728 wait_for_completion(&c);
1731 static int mod_sysfs_init(struct module *mod)
1734 struct kobject *kobj;
1736 if (!module_sysfs_initialized) {
1737 pr_err("%s: module sysfs not initialized\n", mod->name);
1742 kobj = kset_find_obj(module_kset, mod->name);
1744 pr_err("%s: module is already loaded\n", mod->name);
1750 mod->mkobj.mod = mod;
1752 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1753 mod->mkobj.kobj.kset = module_kset;
1754 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1757 mod_kobject_put(mod);
1759 /* delay uevent until full sysfs population */
1764 static int mod_sysfs_setup(struct module *mod,
1765 const struct load_info *info,
1766 struct kernel_param *kparam,
1767 unsigned int num_params)
1771 err = mod_sysfs_init(mod);
1775 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1776 if (!mod->holders_dir) {
1781 err = module_param_sysfs_setup(mod, kparam, num_params);
1783 goto out_unreg_holders;
1785 err = module_add_modinfo_attrs(mod);
1787 goto out_unreg_param;
1789 add_usage_links(mod);
1790 add_sect_attrs(mod, info);
1791 add_notes_attrs(mod, info);
1793 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1797 module_param_sysfs_remove(mod);
1799 kobject_put(mod->holders_dir);
1801 mod_kobject_put(mod);
1806 static void mod_sysfs_fini(struct module *mod)
1808 remove_notes_attrs(mod);
1809 remove_sect_attrs(mod);
1810 mod_kobject_put(mod);
1813 static void init_param_lock(struct module *mod)
1815 mutex_init(&mod->param_lock);
1817 #else /* !CONFIG_SYSFS */
1819 static int mod_sysfs_setup(struct module *mod,
1820 const struct load_info *info,
1821 struct kernel_param *kparam,
1822 unsigned int num_params)
1827 static void mod_sysfs_fini(struct module *mod)
1831 static void module_remove_modinfo_attrs(struct module *mod)
1835 static void del_usage_links(struct module *mod)
1839 static void init_param_lock(struct module *mod)
1842 #endif /* CONFIG_SYSFS */
1844 static void mod_sysfs_teardown(struct module *mod)
1846 del_usage_links(mod);
1847 module_remove_modinfo_attrs(mod);
1848 module_param_sysfs_remove(mod);
1849 kobject_put(mod->mkobj.drivers_dir);
1850 kobject_put(mod->holders_dir);
1851 mod_sysfs_fini(mod);
1854 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
1856 * LKM RO/NX protection: protect module's text/ro-data
1857 * from modification and any data from execution.
1859 * General layout of module is:
1860 * [text] [read-only-data] [ro-after-init] [writable data]
1861 * text_size -----^ ^ ^ ^
1862 * ro_size ------------------------| | |
1863 * ro_after_init_size -----------------------------| |
1864 * size -----------------------------------------------------------|
1866 * These values are always page-aligned (as is base)
1868 static void frob_text(const struct module_layout *layout,
1869 int (*set_memory)(unsigned long start, int num_pages))
1871 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1872 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1873 set_memory((unsigned long)layout->base,
1874 layout->text_size >> PAGE_SHIFT);
1877 static void frob_rodata(const struct module_layout *layout,
1878 int (*set_memory)(unsigned long start, int num_pages))
1880 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1881 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1882 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1883 set_memory((unsigned long)layout->base + layout->text_size,
1884 (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
1887 static void frob_ro_after_init(const struct module_layout *layout,
1888 int (*set_memory)(unsigned long start, int num_pages))
1890 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1891 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1892 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1893 set_memory((unsigned long)layout->base + layout->ro_size,
1894 (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
1897 static void frob_writable_data(const struct module_layout *layout,
1898 int (*set_memory)(unsigned long start, int num_pages))
1900 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1901 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1902 BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
1903 set_memory((unsigned long)layout->base + layout->ro_after_init_size,
1904 (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
1907 /* livepatching wants to disable read-only so it can frob module. */
1908 void module_disable_ro(const struct module *mod)
1910 frob_text(&mod->core_layout, set_memory_rw);
1911 frob_rodata(&mod->core_layout, set_memory_rw);
1912 frob_ro_after_init(&mod->core_layout, set_memory_rw);
1913 frob_text(&mod->init_layout, set_memory_rw);
1914 frob_rodata(&mod->init_layout, set_memory_rw);
1917 void module_enable_ro(const struct module *mod, bool after_init)
1919 frob_text(&mod->core_layout, set_memory_ro);
1920 frob_rodata(&mod->core_layout, set_memory_ro);
1921 frob_text(&mod->init_layout, set_memory_ro);
1922 frob_rodata(&mod->init_layout, set_memory_ro);
1925 frob_ro_after_init(&mod->core_layout, set_memory_ro);
1928 static void module_enable_nx(const struct module *mod)
1930 frob_rodata(&mod->core_layout, set_memory_nx);
1931 frob_ro_after_init(&mod->core_layout, set_memory_nx);
1932 frob_writable_data(&mod->core_layout, set_memory_nx);
1933 frob_rodata(&mod->init_layout, set_memory_nx);
1934 frob_writable_data(&mod->init_layout, set_memory_nx);
1937 static void module_disable_nx(const struct module *mod)
1939 frob_rodata(&mod->core_layout, set_memory_x);
1940 frob_ro_after_init(&mod->core_layout, set_memory_x);
1941 frob_writable_data(&mod->core_layout, set_memory_x);
1942 frob_rodata(&mod->init_layout, set_memory_x);
1943 frob_writable_data(&mod->init_layout, set_memory_x);
1946 /* Iterate through all modules and set each module's text as RW */
1947 void set_all_modules_text_rw(void)
1951 mutex_lock(&module_mutex);
1952 list_for_each_entry_rcu(mod, &modules, list) {
1953 if (mod->state == MODULE_STATE_UNFORMED)
1956 frob_text(&mod->core_layout, set_memory_rw);
1957 frob_text(&mod->init_layout, set_memory_rw);
1959 mutex_unlock(&module_mutex);
1962 /* Iterate through all modules and set each module's text as RO */
1963 void set_all_modules_text_ro(void)
1967 mutex_lock(&module_mutex);
1968 list_for_each_entry_rcu(mod, &modules, list) {
1969 if (mod->state == MODULE_STATE_UNFORMED)
1972 frob_text(&mod->core_layout, set_memory_ro);
1973 frob_text(&mod->init_layout, set_memory_ro);
1975 mutex_unlock(&module_mutex);
1978 static void disable_ro_nx(const struct module_layout *layout)
1980 frob_text(layout, set_memory_rw);
1981 frob_rodata(layout, set_memory_rw);
1982 frob_rodata(layout, set_memory_x);
1983 frob_ro_after_init(layout, set_memory_rw);
1984 frob_ro_after_init(layout, set_memory_x);
1985 frob_writable_data(layout, set_memory_x);
1989 static void disable_ro_nx(const struct module_layout *layout) { }
1990 static void module_enable_nx(const struct module *mod) { }
1991 static void module_disable_nx(const struct module *mod) { }
1994 #ifdef CONFIG_LIVEPATCH
1996 * Persist Elf information about a module. Copy the Elf header,
1997 * section header table, section string table, and symtab section
1998 * index from info to mod->klp_info.
2000 static int copy_module_elf(struct module *mod, struct load_info *info)
2002 unsigned int size, symndx;
2005 size = sizeof(*mod->klp_info);
2006 mod->klp_info = kmalloc(size, GFP_KERNEL);
2007 if (mod->klp_info == NULL)
2011 size = sizeof(mod->klp_info->hdr);
2012 memcpy(&mod->klp_info->hdr, info->hdr, size);
2014 /* Elf section header table */
2015 size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
2016 mod->klp_info->sechdrs = kmalloc(size, GFP_KERNEL);
2017 if (mod->klp_info->sechdrs == NULL) {
2021 memcpy(mod->klp_info->sechdrs, info->sechdrs, size);
2023 /* Elf section name string table */
2024 size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
2025 mod->klp_info->secstrings = kmalloc(size, GFP_KERNEL);
2026 if (mod->klp_info->secstrings == NULL) {
2030 memcpy(mod->klp_info->secstrings, info->secstrings, size);
2032 /* Elf symbol section index */
2033 symndx = info->index.sym;
2034 mod->klp_info->symndx = symndx;
2037 * For livepatch modules, core_kallsyms.symtab is a complete
2038 * copy of the original symbol table. Adjust sh_addr to point
2039 * to core_kallsyms.symtab since the copy of the symtab in module
2040 * init memory is freed at the end of do_init_module().
2042 mod->klp_info->sechdrs[symndx].sh_addr = \
2043 (unsigned long) mod->core_kallsyms.symtab;
2048 kfree(mod->klp_info->sechdrs);
2050 kfree(mod->klp_info);
2054 static void free_module_elf(struct module *mod)
2056 kfree(mod->klp_info->sechdrs);
2057 kfree(mod->klp_info->secstrings);
2058 kfree(mod->klp_info);
2060 #else /* !CONFIG_LIVEPATCH */
2061 static int copy_module_elf(struct module *mod, struct load_info *info)
2066 static void free_module_elf(struct module *mod)
2069 #endif /* CONFIG_LIVEPATCH */
2071 void __weak module_memfree(void *module_region)
2073 vfree(module_region);
2076 void __weak module_arch_cleanup(struct module *mod)
2080 void __weak module_arch_freeing_init(struct module *mod)
2084 /* Free a module, remove from lists, etc. */
2085 static void free_module(struct module *mod)
2087 trace_module_free(mod);
2089 mod_sysfs_teardown(mod);
2091 /* We leave it in list to prevent duplicate loads, but make sure
2092 * that noone uses it while it's being deconstructed. */
2093 mutex_lock(&module_mutex);
2094 mod->state = MODULE_STATE_UNFORMED;
2095 mutex_unlock(&module_mutex);
2097 /* Remove dynamic debug info */
2098 ddebug_remove_module(mod->name);
2100 /* Arch-specific cleanup. */
2101 module_arch_cleanup(mod);
2103 /* Module unload stuff */
2104 module_unload_free(mod);
2106 /* Free any allocated parameters. */
2107 destroy_params(mod->kp, mod->num_kp);
2109 if (is_livepatch_module(mod))
2110 free_module_elf(mod);
2112 /* Now we can delete it from the lists */
2113 mutex_lock(&module_mutex);
2114 /* Unlink carefully: kallsyms could be walking list. */
2115 list_del_rcu(&mod->list);
2116 mod_tree_remove(mod);
2117 /* Remove this module from bug list, this uses list_del_rcu */
2118 module_bug_cleanup(mod);
2119 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2120 synchronize_sched();
2121 mutex_unlock(&module_mutex);
2123 /* This may be empty, but that's OK */
2124 disable_ro_nx(&mod->init_layout);
2125 module_arch_freeing_init(mod);
2126 module_memfree(mod->init_layout.base);
2128 percpu_modfree(mod);
2130 /* Free lock-classes; relies on the preceding sync_rcu(). */
2131 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
2133 /* Finally, free the core (containing the module structure) */
2134 disable_ro_nx(&mod->core_layout);
2135 module_memfree(mod->core_layout.base);
2138 update_protections(current->mm);
2142 void *__symbol_get(const char *symbol)
2144 struct module *owner;
2145 const struct kernel_symbol *sym;
2148 sym = find_symbol(symbol, &owner, NULL, true, true);
2149 if (sym && strong_try_module_get(owner))
2153 return sym ? (void *)sym->value : NULL;
2155 EXPORT_SYMBOL_GPL(__symbol_get);
2158 * Ensure that an exported symbol [global namespace] does not already exist
2159 * in the kernel or in some other module's exported symbol table.
2161 * You must hold the module_mutex.
2163 static int verify_export_symbols(struct module *mod)
2166 struct module *owner;
2167 const struct kernel_symbol *s;
2169 const struct kernel_symbol *sym;
2172 { mod->syms, mod->num_syms },
2173 { mod->gpl_syms, mod->num_gpl_syms },
2174 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2175 #ifdef CONFIG_UNUSED_SYMBOLS
2176 { mod->unused_syms, mod->num_unused_syms },
2177 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2181 for (i = 0; i < ARRAY_SIZE(arr); i++) {
2182 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2183 if (find_symbol(s->name, &owner, NULL, true, false)) {
2184 pr_err("%s: exports duplicate symbol %s"
2186 mod->name, s->name, module_name(owner));
2194 /* Change all symbols so that st_value encodes the pointer directly. */
2195 static int simplify_symbols(struct module *mod, const struct load_info *info)
2197 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2198 Elf_Sym *sym = (void *)symsec->sh_addr;
2199 unsigned long secbase;
2202 const struct kernel_symbol *ksym;
2204 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2205 const char *name = info->strtab + sym[i].st_name;
2207 switch (sym[i].st_shndx) {
2209 /* Ignore common symbols */
2210 if (!strncmp(name, "__gnu_lto", 9))
2213 /* We compiled with -fno-common. These are not
2214 supposed to happen. */
2215 pr_debug("Common symbol: %s\n", name);
2216 pr_warn("%s: please compile with -fno-common\n",
2222 /* Don't need to do anything */
2223 pr_debug("Absolute symbol: 0x%08lx\n",
2224 (long)sym[i].st_value);
2228 /* Livepatch symbols are resolved by livepatch */
2232 ksym = resolve_symbol_wait(mod, info, name);
2233 /* Ok if resolved. */
2234 if (ksym && !IS_ERR(ksym)) {
2235 sym[i].st_value = ksym->value;
2240 if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
2243 pr_warn("%s: Unknown symbol %s (err %li)\n",
2244 mod->name, name, PTR_ERR(ksym));
2245 ret = PTR_ERR(ksym) ?: -ENOENT;
2249 /* Divert to percpu allocation if a percpu var. */
2250 if (sym[i].st_shndx == info->index.pcpu)
2251 secbase = (unsigned long)mod_percpu(mod);
2253 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2254 sym[i].st_value += secbase;
2262 static int apply_relocations(struct module *mod, const struct load_info *info)
2267 /* Now do relocations. */
2268 for (i = 1; i < info->hdr->e_shnum; i++) {
2269 unsigned int infosec = info->sechdrs[i].sh_info;
2271 /* Not a valid relocation section? */
2272 if (infosec >= info->hdr->e_shnum)
2275 /* Don't bother with non-allocated sections */
2276 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2279 /* Livepatch relocation sections are applied by livepatch */
2280 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
2283 if (info->sechdrs[i].sh_type == SHT_REL)
2284 err = apply_relocate(info->sechdrs, info->strtab,
2285 info->index.sym, i, mod);
2286 else if (info->sechdrs[i].sh_type == SHT_RELA)
2287 err = apply_relocate_add(info->sechdrs, info->strtab,
2288 info->index.sym, i, mod);
2295 /* Additional bytes needed by arch in front of individual sections */
2296 unsigned int __weak arch_mod_section_prepend(struct module *mod,
2297 unsigned int section)
2299 /* default implementation just returns zero */
2303 /* Update size with this section: return offset. */
2304 static long get_offset(struct module *mod, unsigned int *size,
2305 Elf_Shdr *sechdr, unsigned int section)
2309 *size += arch_mod_section_prepend(mod, section);
2310 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2311 *size = ret + sechdr->sh_size;
2315 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2316 might -- code, read-only data, read-write data, small data. Tally
2317 sizes, and place the offsets into sh_entsize fields: high bit means it
2319 static void layout_sections(struct module *mod, struct load_info *info)
2321 static unsigned long const masks[][2] = {
2322 /* NOTE: all executable code must be the first section
2323 * in this array; otherwise modify the text_size
2324 * finder in the two loops below */
2325 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2326 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2327 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
2328 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2329 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2333 for (i = 0; i < info->hdr->e_shnum; i++)
2334 info->sechdrs[i].sh_entsize = ~0UL;
2336 pr_debug("Core section allocation order:\n");
2337 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2338 for (i = 0; i < info->hdr->e_shnum; ++i) {
2339 Elf_Shdr *s = &info->sechdrs[i];
2340 const char *sname = info->secstrings + s->sh_name;
2342 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2343 || (s->sh_flags & masks[m][1])
2344 || s->sh_entsize != ~0UL
2345 || strstarts(sname, ".init"))
2347 s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2348 pr_debug("\t%s\n", sname);
2351 case 0: /* executable */
2352 mod->core_layout.size = debug_align(mod->core_layout.size);
2353 mod->core_layout.text_size = mod->core_layout.size;
2355 case 1: /* RO: text and ro-data */
2356 mod->core_layout.size = debug_align(mod->core_layout.size);
2357 mod->core_layout.ro_size = mod->core_layout.size;
2359 case 2: /* RO after init */
2360 mod->core_layout.size = debug_align(mod->core_layout.size);
2361 mod->core_layout.ro_after_init_size = mod->core_layout.size;
2363 case 4: /* whole core */
2364 mod->core_layout.size = debug_align(mod->core_layout.size);
2369 pr_debug("Init section allocation order:\n");
2370 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2371 for (i = 0; i < info->hdr->e_shnum; ++i) {
2372 Elf_Shdr *s = &info->sechdrs[i];
2373 const char *sname = info->secstrings + s->sh_name;
2375 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2376 || (s->sh_flags & masks[m][1])
2377 || s->sh_entsize != ~0UL
2378 || !strstarts(sname, ".init"))
2380 s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
2381 | INIT_OFFSET_MASK);
2382 pr_debug("\t%s\n", sname);
2385 case 0: /* executable */
2386 mod->init_layout.size = debug_align(mod->init_layout.size);
2387 mod->init_layout.text_size = mod->init_layout.size;
2389 case 1: /* RO: text and ro-data */
2390 mod->init_layout.size = debug_align(mod->init_layout.size);
2391 mod->init_layout.ro_size = mod->init_layout.size;
2395 * RO after init doesn't apply to init_layout (only
2396 * core_layout), so it just takes the value of ro_size.
2398 mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
2400 case 4: /* whole init */
2401 mod->init_layout.size = debug_align(mod->init_layout.size);
2407 static void set_license(struct module *mod, const char *license)
2410 license = "unspecified";
2412 if (!license_is_gpl_compatible(license)) {
2413 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2414 pr_warn("%s: module license '%s' taints kernel.\n",
2415 mod->name, license);
2416 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2417 LOCKDEP_NOW_UNRELIABLE);
2421 /* Parse tag=value strings from .modinfo section */
2422 static char *next_string(char *string, unsigned long *secsize)
2424 /* Skip non-zero chars */
2427 if ((*secsize)-- <= 1)
2431 /* Skip any zero padding. */
2432 while (!string[0]) {
2434 if ((*secsize)-- <= 1)
2440 static char *get_modinfo(struct load_info *info, const char *tag)
2443 unsigned int taglen = strlen(tag);
2444 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2445 unsigned long size = infosec->sh_size;
2447 for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2448 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2449 return p + taglen + 1;
2454 static void setup_modinfo(struct module *mod, struct load_info *info)
2456 struct module_attribute *attr;
2459 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2461 attr->setup(mod, get_modinfo(info, attr->attr.name));
2465 static void free_modinfo(struct module *mod)
2467 struct module_attribute *attr;
2470 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2476 #ifdef CONFIG_KALLSYMS
2478 /* lookup symbol in given range of kernel_symbols */
2479 static const struct kernel_symbol *lookup_symbol(const char *name,
2480 const struct kernel_symbol *start,
2481 const struct kernel_symbol *stop)
2483 return bsearch(name, start, stop - start,
2484 sizeof(struct kernel_symbol), cmp_name);
2487 static int is_exported(const char *name, unsigned long value,
2488 const struct module *mod)
2490 const struct kernel_symbol *ks;
2492 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2494 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2495 return ks != NULL && ks->value == value;
2499 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2501 const Elf_Shdr *sechdrs = info->sechdrs;
2503 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2504 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2509 if (sym->st_shndx == SHN_UNDEF)
2511 if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
2513 if (sym->st_shndx >= SHN_LORESERVE)
2515 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2517 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2518 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2519 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2521 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2526 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2527 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2532 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2539 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2540 unsigned int shnum, unsigned int pcpundx)
2542 const Elf_Shdr *sec;
2544 if (src->st_shndx == SHN_UNDEF
2545 || src->st_shndx >= shnum
2549 #ifdef CONFIG_KALLSYMS_ALL
2550 if (src->st_shndx == pcpundx)
2554 sec = sechdrs + src->st_shndx;
2555 if (!(sec->sh_flags & SHF_ALLOC)
2556 #ifndef CONFIG_KALLSYMS_ALL
2557 || !(sec->sh_flags & SHF_EXECINSTR)
2559 || (sec->sh_entsize & INIT_OFFSET_MASK))
2566 * We only allocate and copy the strings needed by the parts of symtab
2567 * we keep. This is simple, but has the effect of making multiple
2568 * copies of duplicates. We could be more sophisticated, see
2569 * linux-kernel thread starting with
2570 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2572 static void layout_symtab(struct module *mod, struct load_info *info)
2574 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2575 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2577 unsigned int i, nsrc, ndst, strtab_size = 0;
2579 /* Put symbol section at end of init part of module. */
2580 symsect->sh_flags |= SHF_ALLOC;
2581 symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2582 info->index.sym) | INIT_OFFSET_MASK;
2583 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2585 src = (void *)info->hdr + symsect->sh_offset;
2586 nsrc = symsect->sh_size / sizeof(*src);
2588 /* Compute total space required for the core symbols' strtab. */
2589 for (ndst = i = 0; i < nsrc; i++) {
2590 if (i == 0 || is_livepatch_module(mod) ||
2591 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2592 info->index.pcpu)) {
2593 strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2598 /* Append room for core symbols at end of core part. */
2599 info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
2600 info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
2601 mod->core_layout.size += strtab_size;
2602 mod->core_layout.size = debug_align(mod->core_layout.size);
2604 /* Put string table section at end of init part of module. */
2605 strsect->sh_flags |= SHF_ALLOC;
2606 strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2607 info->index.str) | INIT_OFFSET_MASK;
2608 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2610 /* We'll tack temporary mod_kallsyms on the end. */
2611 mod->init_layout.size = ALIGN(mod->init_layout.size,
2612 __alignof__(struct mod_kallsyms));
2613 info->mod_kallsyms_init_off = mod->init_layout.size;
2614 mod->init_layout.size += sizeof(struct mod_kallsyms);
2615 mod->init_layout.size = debug_align(mod->init_layout.size);
2619 * We use the full symtab and strtab which layout_symtab arranged to
2620 * be appended to the init section. Later we switch to the cut-down
2623 static void add_kallsyms(struct module *mod, const struct load_info *info)
2625 unsigned int i, ndst;
2629 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2631 /* Set up to point into init section. */
2632 mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
2634 mod->kallsyms->symtab = (void *)symsec->sh_addr;
2635 mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2636 /* Make sure we get permanent strtab: don't use info->strtab. */
2637 mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2639 /* Set types up while we still have access to sections. */
2640 for (i = 0; i < mod->kallsyms->num_symtab; i++)
2641 mod->kallsyms->symtab[i].st_info
2642 = elf_type(&mod->kallsyms->symtab[i], info);
2644 /* Now populate the cut down core kallsyms for after init. */
2645 mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
2646 mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
2647 src = mod->kallsyms->symtab;
2648 for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2649 if (i == 0 || is_livepatch_module(mod) ||
2650 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2651 info->index.pcpu)) {
2653 dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
2654 s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2658 mod->core_kallsyms.num_symtab = ndst;
2661 static inline void layout_symtab(struct module *mod, struct load_info *info)
2665 static void add_kallsyms(struct module *mod, const struct load_info *info)
2668 #endif /* CONFIG_KALLSYMS */
2670 static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2674 #ifdef CONFIG_DYNAMIC_DEBUG
2675 if (ddebug_add_module(debug, num, debug->modname))
2676 pr_err("dynamic debug error adding module: %s\n",
2681 static void dynamic_debug_remove(struct _ddebug *debug)
2684 ddebug_remove_module(debug->modname);
2687 void * __weak module_alloc(unsigned long size)
2689 return vmalloc_exec(size);
2692 #ifdef CONFIG_DEBUG_KMEMLEAK
2693 static void kmemleak_load_module(const struct module *mod,
2694 const struct load_info *info)
2698 /* only scan the sections containing data */
2699 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2701 for (i = 1; i < info->hdr->e_shnum; i++) {
2702 /* Scan all writable sections that's not executable */
2703 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2704 !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2705 (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2708 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2709 info->sechdrs[i].sh_size, GFP_KERNEL);
2713 static inline void kmemleak_load_module(const struct module *mod,
2714 const struct load_info *info)
2719 #ifdef CONFIG_MODULE_SIG
2720 static int module_sig_check(struct load_info *info, int flags)
2723 const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2724 const void *mod = info->hdr;
2727 * Require flags == 0, as a module with version information
2728 * removed is no longer the module that was signed
2731 info->len > markerlen &&
2732 memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2733 /* We truncate the module to discard the signature */
2734 info->len -= markerlen;
2735 err = mod_verify_sig(mod, &info->len);
2739 info->sig_ok = true;
2743 /* Not having a signature is only an error if we're strict. */
2744 if (err == -ENOKEY && !sig_enforce)
2749 #else /* !CONFIG_MODULE_SIG */
2750 static int module_sig_check(struct load_info *info, int flags)
2754 #endif /* !CONFIG_MODULE_SIG */
2756 /* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2757 static int elf_header_check(struct load_info *info)
2759 if (info->len < sizeof(*(info->hdr)))
2762 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2763 || info->hdr->e_type != ET_REL
2764 || !elf_check_arch(info->hdr)
2765 || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2768 if (info->hdr->e_shoff >= info->len
2769 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2770 info->len - info->hdr->e_shoff))
2776 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2778 static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
2781 unsigned long n = min(len, COPY_CHUNK_SIZE);
2783 if (copy_from_user(dst, usrc, n) != 0)
2793 #ifdef CONFIG_LIVEPATCH
2794 static int find_livepatch_modinfo(struct module *mod, struct load_info *info)
2796 mod->klp = get_modinfo(info, "livepatch") ? true : false;
2800 #else /* !CONFIG_LIVEPATCH */
2801 static int find_livepatch_modinfo(struct module *mod, struct load_info *info)
2803 if (get_modinfo(info, "livepatch")) {
2804 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
2811 #endif /* CONFIG_LIVEPATCH */
2813 /* Sets info->hdr and info->len. */
2814 static int copy_module_from_user(const void __user *umod, unsigned long len,
2815 struct load_info *info)
2820 if (info->len < sizeof(*(info->hdr)))
2823 err = security_kernel_read_file(NULL, READING_MODULE);
2827 /* Suck in entire file: we'll want most of it. */
2828 info->hdr = __vmalloc(info->len,
2829 GFP_KERNEL | __GFP_HIGHMEM | __GFP_NOWARN, PAGE_KERNEL);
2833 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2841 static void free_copy(struct load_info *info)
2846 static int rewrite_section_headers(struct load_info *info, int flags)
2850 /* This should always be true, but let's be sure. */
2851 info->sechdrs[0].sh_addr = 0;
2853 for (i = 1; i < info->hdr->e_shnum; i++) {
2854 Elf_Shdr *shdr = &info->sechdrs[i];
2855 if (shdr->sh_type != SHT_NOBITS
2856 && info->len < shdr->sh_offset + shdr->sh_size) {
2857 pr_err("Module len %lu truncated\n", info->len);
2861 /* Mark all sections sh_addr with their address in the
2863 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2865 #ifndef CONFIG_MODULE_UNLOAD
2866 /* Don't load .exit sections */
2867 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2868 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2872 /* Track but don't keep modinfo and version sections. */
2873 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
2874 info->index.vers = 0; /* Pretend no __versions section! */
2876 info->index.vers = find_sec(info, "__versions");
2877 info->index.info = find_sec(info, ".modinfo");
2878 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2879 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2884 * Set up our basic convenience variables (pointers to section headers,
2885 * search for module section index etc), and do some basic section
2888 * Return the temporary module pointer (we'll replace it with the final
2889 * one when we move the module sections around).
2891 static struct module *setup_load_info(struct load_info *info, int flags)
2897 /* Set up the convenience variables */
2898 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2899 info->secstrings = (void *)info->hdr
2900 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2902 err = rewrite_section_headers(info, flags);
2904 return ERR_PTR(err);
2906 /* Find internal symbols and strings. */
2907 for (i = 1; i < info->hdr->e_shnum; i++) {
2908 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2909 info->index.sym = i;
2910 info->index.str = info->sechdrs[i].sh_link;
2911 info->strtab = (char *)info->hdr
2912 + info->sechdrs[info->index.str].sh_offset;
2917 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2918 if (!info->index.mod) {
2919 pr_warn("No module found in object\n");
2920 return ERR_PTR(-ENOEXEC);
2922 /* This is temporary: point mod into copy of data. */
2923 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2925 if (info->index.sym == 0) {
2926 pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
2927 return ERR_PTR(-ENOEXEC);
2930 info->index.pcpu = find_pcpusec(info);
2932 /* Check module struct version now, before we try to use module. */
2933 if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2934 return ERR_PTR(-ENOEXEC);
2939 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2941 const char *modmagic = get_modinfo(info, "vermagic");
2944 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
2947 /* This is allowed: modprobe --force will invalidate it. */
2949 err = try_to_force_load(mod, "bad vermagic");
2952 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2953 pr_err("%s: version magic '%s' should be '%s'\n",
2954 mod->name, modmagic, vermagic);
2958 if (!get_modinfo(info, "intree")) {
2959 if (!test_taint(TAINT_OOT_MODULE))
2960 pr_warn("%s: loading out-of-tree module taints kernel.\n",
2962 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2965 if (get_modinfo(info, "staging")) {
2966 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
2967 pr_warn("%s: module is from the staging directory, the quality "
2968 "is unknown, you have been warned.\n", mod->name);
2971 err = find_livepatch_modinfo(mod, info);
2975 /* Set up license info based on the info section */
2976 set_license(mod, get_modinfo(info, "license"));
2981 static int find_module_sections(struct module *mod, struct load_info *info)
2983 mod->kp = section_objs(info, "__param",
2984 sizeof(*mod->kp), &mod->num_kp);
2985 mod->syms = section_objs(info, "__ksymtab",
2986 sizeof(*mod->syms), &mod->num_syms);
2987 mod->crcs = section_addr(info, "__kcrctab");
2988 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2989 sizeof(*mod->gpl_syms),
2990 &mod->num_gpl_syms);
2991 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2992 mod->gpl_future_syms = section_objs(info,
2993 "__ksymtab_gpl_future",
2994 sizeof(*mod->gpl_future_syms),
2995 &mod->num_gpl_future_syms);
2996 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2998 #ifdef CONFIG_UNUSED_SYMBOLS
2999 mod->unused_syms = section_objs(info, "__ksymtab_unused",
3000 sizeof(*mod->unused_syms),
3001 &mod->num_unused_syms);
3002 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
3003 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
3004 sizeof(*mod->unused_gpl_syms),
3005 &mod->num_unused_gpl_syms);
3006 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
3008 #ifdef CONFIG_CONSTRUCTORS
3009 mod->ctors = section_objs(info, ".ctors",
3010 sizeof(*mod->ctors), &mod->num_ctors);
3012 mod->ctors = section_objs(info, ".init_array",
3013 sizeof(*mod->ctors), &mod->num_ctors);
3014 else if (find_sec(info, ".init_array")) {
3016 * This shouldn't happen with same compiler and binutils
3017 * building all parts of the module.
3019 pr_warn("%s: has both .ctors and .init_array.\n",
3025 #ifdef CONFIG_TRACEPOINTS
3026 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
3027 sizeof(*mod->tracepoints_ptrs),
3028 &mod->num_tracepoints);
3030 #ifdef HAVE_JUMP_LABEL
3031 mod->jump_entries = section_objs(info, "__jump_table",
3032 sizeof(*mod->jump_entries),
3033 &mod->num_jump_entries);
3035 #ifdef CONFIG_EVENT_TRACING
3036 mod->trace_events = section_objs(info, "_ftrace_events",
3037 sizeof(*mod->trace_events),
3038 &mod->num_trace_events);
3039 mod->trace_enums = section_objs(info, "_ftrace_enum_map",
3040 sizeof(*mod->trace_enums),
3041 &mod->num_trace_enums);
3043 #ifdef CONFIG_TRACING
3044 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
3045 sizeof(*mod->trace_bprintk_fmt_start),
3046 &mod->num_trace_bprintk_fmt);
3048 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
3049 /* sechdrs[0].sh_size is always zero */
3050 mod->ftrace_callsites = section_objs(info, "__mcount_loc",
3051 sizeof(*mod->ftrace_callsites),
3052 &mod->num_ftrace_callsites);
3055 mod->extable = section_objs(info, "__ex_table",
3056 sizeof(*mod->extable), &mod->num_exentries);
3058 if (section_addr(info, "__obsparm"))
3059 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
3061 info->debug = section_objs(info, "__verbose",
3062 sizeof(*info->debug), &info->num_debug);
3067 static int move_module(struct module *mod, struct load_info *info)
3072 /* Do the allocs. */
3073 ptr = module_alloc(mod->core_layout.size);
3075 * The pointer to this block is stored in the module structure
3076 * which is inside the block. Just mark it as not being a
3079 kmemleak_not_leak(ptr);
3083 memset(ptr, 0, mod->core_layout.size);
3084 mod->core_layout.base = ptr;
3086 if (mod->init_layout.size) {
3087 ptr = module_alloc(mod->init_layout.size);
3089 * The pointer to this block is stored in the module structure
3090 * which is inside the block. This block doesn't need to be
3091 * scanned as it contains data and code that will be freed
3092 * after the module is initialized.
3094 kmemleak_ignore(ptr);
3096 module_memfree(mod->core_layout.base);
3099 memset(ptr, 0, mod->init_layout.size);
3100 mod->init_layout.base = ptr;
3102 mod->init_layout.base = NULL;
3104 /* Transfer each section which specifies SHF_ALLOC */
3105 pr_debug("final section addresses:\n");
3106 for (i = 0; i < info->hdr->e_shnum; i++) {
3108 Elf_Shdr *shdr = &info->sechdrs[i];
3110 if (!(shdr->sh_flags & SHF_ALLOC))
3113 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3114 dest = mod->init_layout.base
3115 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3117 dest = mod->core_layout.base + shdr->sh_entsize;
3119 if (shdr->sh_type != SHT_NOBITS)
3120 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3121 /* Update sh_addr to point to copy in image. */
3122 shdr->sh_addr = (unsigned long)dest;
3123 pr_debug("\t0x%lx %s\n",
3124 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3130 static int check_module_license_and_versions(struct module *mod)
3132 int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
3135 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3136 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3137 * using GPL-only symbols it needs.
3139 if (strcmp(mod->name, "ndiswrapper") == 0)
3140 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3142 /* driverloader was caught wrongly pretending to be under GPL */
3143 if (strcmp(mod->name, "driverloader") == 0)
3144 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3145 LOCKDEP_NOW_UNRELIABLE);
3147 /* lve claims to be GPL but upstream won't provide source */
3148 if (strcmp(mod->name, "lve") == 0)
3149 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3150 LOCKDEP_NOW_UNRELIABLE);
3152 if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
3153 pr_warn("%s: module license taints kernel.\n", mod->name);
3155 #ifdef CONFIG_MODVERSIONS
3156 if ((mod->num_syms && !mod->crcs)
3157 || (mod->num_gpl_syms && !mod->gpl_crcs)
3158 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3159 #ifdef CONFIG_UNUSED_SYMBOLS
3160 || (mod->num_unused_syms && !mod->unused_crcs)
3161 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3164 return try_to_force_load(mod,
3165 "no versions for exported symbols");
3171 static void flush_module_icache(const struct module *mod)
3173 mm_segment_t old_fs;
3175 /* flush the icache in correct context */
3180 * Flush the instruction cache, since we've played with text.
3181 * Do it before processing of module parameters, so the module
3182 * can provide parameter accessor functions of its own.
3184 if (mod->init_layout.base)
3185 flush_icache_range((unsigned long)mod->init_layout.base,
3186 (unsigned long)mod->init_layout.base
3187 + mod->init_layout.size);
3188 flush_icache_range((unsigned long)mod->core_layout.base,
3189 (unsigned long)mod->core_layout.base + mod->core_layout.size);
3194 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3202 /* module_blacklist is a comma-separated list of module names */
3203 static char *module_blacklist;
3204 static bool blacklisted(char *module_name)
3209 if (!module_blacklist)
3212 for (p = module_blacklist; *p; p += len) {
3213 len = strcspn(p, ",");
3214 if (strlen(module_name) == len && !memcmp(module_name, p, len))
3221 core_param(module_blacklist, module_blacklist, charp, 0400);
3223 static struct module *layout_and_allocate(struct load_info *info, int flags)
3225 /* Module within temporary copy. */
3230 mod = setup_load_info(info, flags);
3234 if (blacklisted(mod->name))
3235 return ERR_PTR(-EPERM);
3237 err = check_modinfo(mod, info, flags);
3239 return ERR_PTR(err);
3241 /* Allow arches to frob section contents and sizes. */
3242 err = module_frob_arch_sections(info->hdr, info->sechdrs,
3243 info->secstrings, mod);
3245 return ERR_PTR(err);
3247 /* We will do a special allocation for per-cpu sections later. */
3248 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3251 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3252 * layout_sections() can put it in the right place.
3253 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3255 ndx = find_sec(info, ".data..ro_after_init");
3257 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3259 /* Determine total sizes, and put offsets in sh_entsize. For now
3260 this is done generically; there doesn't appear to be any
3261 special cases for the architectures. */
3262 layout_sections(mod, info);
3263 layout_symtab(mod, info);
3265 /* Allocate and move to the final place */
3266 err = move_module(mod, info);
3268 return ERR_PTR(err);
3270 /* Module has been copied to its final place now: return it. */
3271 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3272 kmemleak_load_module(mod, info);
3276 /* mod is no longer valid after this! */
3277 static void module_deallocate(struct module *mod, struct load_info *info)
3279 percpu_modfree(mod);
3280 module_arch_freeing_init(mod);
3281 module_memfree(mod->init_layout.base);
3282 module_memfree(mod->core_layout.base);
3285 int __weak module_finalize(const Elf_Ehdr *hdr,
3286 const Elf_Shdr *sechdrs,
3292 static int post_relocation(struct module *mod, const struct load_info *info)
3294 /* Sort exception table now relocations are done. */
3295 sort_extable(mod->extable, mod->extable + mod->num_exentries);
3297 /* Copy relocated percpu area over. */
3298 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3299 info->sechdrs[info->index.pcpu].sh_size);
3301 /* Setup kallsyms-specific fields. */
3302 add_kallsyms(mod, info);
3304 /* Arch-specific module finalizing. */
3305 return module_finalize(info->hdr, info->sechdrs, mod);
3308 /* Is this module of this name done loading? No locks held. */
3309 static bool finished_loading(const char *name)
3315 * The module_mutex should not be a heavily contended lock;
3316 * if we get the occasional sleep here, we'll go an extra iteration
3317 * in the wait_event_interruptible(), which is harmless.
3319 sched_annotate_sleep();
3320 mutex_lock(&module_mutex);
3321 mod = find_module_all(name, strlen(name), true);
3322 ret = !mod || mod->state == MODULE_STATE_LIVE
3323 || mod->state == MODULE_STATE_GOING;
3324 mutex_unlock(&module_mutex);
3329 /* Call module constructors. */
3330 static void do_mod_ctors(struct module *mod)
3332 #ifdef CONFIG_CONSTRUCTORS
3335 for (i = 0; i < mod->num_ctors; i++)
3340 /* For freeing module_init on success, in case kallsyms traversing */
3341 struct mod_initfree {
3342 struct rcu_head rcu;
3346 static void do_free_init(struct rcu_head *head)
3348 struct mod_initfree *m = container_of(head, struct mod_initfree, rcu);
3349 module_memfree(m->module_init);
3354 * This is where the real work happens.
3356 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3357 * helper command 'lx-symbols'.
3359 static noinline int do_init_module(struct module *mod)
3362 struct mod_initfree *freeinit;
3364 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3369 freeinit->module_init = mod->init_layout.base;
3372 * We want to find out whether @mod uses async during init. Clear
3373 * PF_USED_ASYNC. async_schedule*() will set it.
3375 current->flags &= ~PF_USED_ASYNC;
3378 /* Start the module */
3379 if (mod->init != NULL)
3380 ret = do_one_initcall(mod->init);
3382 goto fail_free_freeinit;
3385 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3386 "follow 0/-E convention\n"
3387 "%s: loading module anyway...\n",
3388 __func__, mod->name, ret, __func__);
3392 /* Now it's a first class citizen! */
3393 mod->state = MODULE_STATE_LIVE;
3394 blocking_notifier_call_chain(&module_notify_list,
3395 MODULE_STATE_LIVE, mod);
3398 * We need to finish all async code before the module init sequence
3399 * is done. This has potential to deadlock. For example, a newly
3400 * detected block device can trigger request_module() of the
3401 * default iosched from async probing task. Once userland helper
3402 * reaches here, async_synchronize_full() will wait on the async
3403 * task waiting on request_module() and deadlock.
3405 * This deadlock is avoided by perfomring async_synchronize_full()
3406 * iff module init queued any async jobs. This isn't a full
3407 * solution as it will deadlock the same if module loading from
3408 * async jobs nests more than once; however, due to the various
3409 * constraints, this hack seems to be the best option for now.
3410 * Please refer to the following thread for details.
3412 * http://thread.gmane.org/gmane.linux.kernel/1420814
3414 if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3415 async_synchronize_full();
3417 mutex_lock(&module_mutex);
3418 /* Drop initial reference. */
3420 trim_init_extable(mod);
3421 #ifdef CONFIG_KALLSYMS
3422 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3423 rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3425 module_enable_ro(mod, true);
3426 mod_tree_remove_init(mod);
3427 disable_ro_nx(&mod->init_layout);
3428 module_arch_freeing_init(mod);
3429 mod->init_layout.base = NULL;
3430 mod->init_layout.size = 0;
3431 mod->init_layout.ro_size = 0;
3432 mod->init_layout.ro_after_init_size = 0;
3433 mod->init_layout.text_size = 0;
3435 * We want to free module_init, but be aware that kallsyms may be
3436 * walking this with preempt disabled. In all the failure paths, we
3437 * call synchronize_sched(), but we don't want to slow down the success
3438 * path, so use actual RCU here.
3440 call_rcu_sched(&freeinit->rcu, do_free_init);
3441 mutex_unlock(&module_mutex);
3442 wake_up_all(&module_wq);
3449 /* Try to protect us from buggy refcounters. */
3450 mod->state = MODULE_STATE_GOING;
3451 synchronize_sched();
3453 blocking_notifier_call_chain(&module_notify_list,
3454 MODULE_STATE_GOING, mod);
3455 klp_module_going(mod);
3456 ftrace_release_mod(mod);
3458 wake_up_all(&module_wq);
3462 static int may_init_module(void)
3464 if (!capable(CAP_SYS_MODULE) || modules_disabled)
3471 * We try to place it in the list now to make sure it's unique before
3472 * we dedicate too many resources. In particular, temporary percpu
3473 * memory exhaustion.
3475 static int add_unformed_module(struct module *mod)
3480 mod->state = MODULE_STATE_UNFORMED;
3483 mutex_lock(&module_mutex);
3484 old = find_module_all(mod->name, strlen(mod->name), true);
3486 if (old->state == MODULE_STATE_COMING
3487 || old->state == MODULE_STATE_UNFORMED) {
3488 /* Wait in case it fails to load. */
3489 mutex_unlock(&module_mutex);
3490 err = wait_event_interruptible(module_wq,
3491 finished_loading(mod->name));
3499 mod_update_bounds(mod);
3500 list_add_rcu(&mod->list, &modules);
3501 mod_tree_insert(mod);
3505 mutex_unlock(&module_mutex);
3510 static int complete_formation(struct module *mod, struct load_info *info)
3514 mutex_lock(&module_mutex);
3516 /* Find duplicate symbols (must be called under lock). */
3517 err = verify_export_symbols(mod);
3521 /* This relies on module_mutex for list integrity. */
3522 module_bug_finalize(info->hdr, info->sechdrs, mod);
3524 module_enable_ro(mod, false);
3525 module_enable_nx(mod);
3527 /* Mark state as coming so strong_try_module_get() ignores us,
3528 * but kallsyms etc. can see us. */
3529 mod->state = MODULE_STATE_COMING;
3530 mutex_unlock(&module_mutex);
3535 mutex_unlock(&module_mutex);
3539 static int prepare_coming_module(struct module *mod)
3543 ftrace_module_enable(mod);
3544 err = klp_module_coming(mod);
3548 blocking_notifier_call_chain(&module_notify_list,
3549 MODULE_STATE_COMING, mod);
3553 static int unknown_module_param_cb(char *param, char *val, const char *modname,
3556 struct module *mod = arg;
3559 if (strcmp(param, "async_probe") == 0) {
3560 mod->async_probe_requested = true;
3564 /* Check for magic 'dyndbg' arg */
3565 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3567 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3571 /* Allocate and load the module: note that size of section 0 is always
3572 zero, and we rely on this for optional sections. */
3573 static int load_module(struct load_info *info, const char __user *uargs,
3580 err = module_sig_check(info, flags);
3584 err = elf_header_check(info);
3588 /* Figure out module layout, and allocate all the memory. */
3589 mod = layout_and_allocate(info, flags);
3595 /* Reserve our place in the list. */
3596 err = add_unformed_module(mod);
3600 #ifdef CONFIG_MODULE_SIG
3601 mod->sig_ok = info->sig_ok;
3603 pr_notice_once("%s: module verification failed: signature "
3604 "and/or required key missing - tainting "
3605 "kernel\n", mod->name);
3606 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3610 /* To avoid stressing percpu allocator, do this once we're unique. */
3611 err = percpu_modalloc(mod, info);
3615 /* Now module is in final location, initialize linked lists, etc. */
3616 err = module_unload_init(mod);
3620 init_param_lock(mod);
3622 /* Now we've got everything in the final locations, we can
3623 * find optional sections. */
3624 err = find_module_sections(mod, info);
3628 err = check_module_license_and_versions(mod);
3632 /* Set up MODINFO_ATTR fields */
3633 setup_modinfo(mod, info);
3635 /* Fix up syms, so that st_value is a pointer to location. */
3636 err = simplify_symbols(mod, info);
3640 err = apply_relocations(mod, info);
3644 err = post_relocation(mod, info);
3648 flush_module_icache(mod);
3650 /* Now copy in args */
3651 mod->args = strndup_user(uargs, ~0UL >> 1);
3652 if (IS_ERR(mod->args)) {
3653 err = PTR_ERR(mod->args);
3654 goto free_arch_cleanup;
3657 dynamic_debug_setup(info->debug, info->num_debug);
3659 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3660 ftrace_module_init(mod);
3662 /* Finally it's fully formed, ready to start executing. */
3663 err = complete_formation(mod, info);
3665 goto ddebug_cleanup;
3667 err = prepare_coming_module(mod);
3671 /* Module is ready to execute: parsing args may do that. */
3672 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3674 unknown_module_param_cb);
3675 if (IS_ERR(after_dashes)) {
3676 err = PTR_ERR(after_dashes);
3677 goto coming_cleanup;
3678 } else if (after_dashes) {
3679 pr_warn("%s: parameters '%s' after `--' ignored\n",
3680 mod->name, after_dashes);
3683 /* Link in to syfs. */
3684 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3686 goto coming_cleanup;
3688 if (is_livepatch_module(mod)) {
3689 err = copy_module_elf(mod, info);
3694 /* Get rid of temporary copy. */
3698 trace_module_load(mod);
3700 return do_init_module(mod);
3703 mod_sysfs_teardown(mod);
3705 blocking_notifier_call_chain(&module_notify_list,
3706 MODULE_STATE_GOING, mod);
3707 klp_module_going(mod);
3709 /* module_bug_cleanup needs module_mutex protection */
3710 mutex_lock(&module_mutex);
3711 module_bug_cleanup(mod);
3712 mutex_unlock(&module_mutex);
3714 /* we can't deallocate the module until we clear memory protection */
3715 module_disable_ro(mod);
3716 module_disable_nx(mod);
3719 dynamic_debug_remove(info->debug);
3720 synchronize_sched();
3723 module_arch_cleanup(mod);
3727 module_unload_free(mod);
3729 mutex_lock(&module_mutex);
3730 /* Unlink carefully: kallsyms could be walking list. */
3731 list_del_rcu(&mod->list);
3732 mod_tree_remove(mod);
3733 wake_up_all(&module_wq);
3734 /* Wait for RCU-sched synchronizing before releasing mod->list. */
3735 synchronize_sched();
3736 mutex_unlock(&module_mutex);
3739 * Ftrace needs to clean up what it initialized.
3740 * This does nothing if ftrace_module_init() wasn't called,
3741 * but it must be called outside of module_mutex.
3743 ftrace_release_mod(mod);
3744 /* Free lock-classes; relies on the preceding sync_rcu() */
3745 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
3747 module_deallocate(mod, info);
3753 SYSCALL_DEFINE3(init_module, void __user *, umod,
3754 unsigned long, len, const char __user *, uargs)
3757 struct load_info info = { };
3759 err = may_init_module();
3763 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3766 err = copy_module_from_user(umod, len, &info);
3770 return load_module(&info, uargs, 0);
3773 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3775 struct load_info info = { };
3780 err = may_init_module();
3784 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3786 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3787 |MODULE_INIT_IGNORE_VERMAGIC))
3790 err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX,
3797 return load_module(&info, uargs, flags);
3800 static inline int within(unsigned long addr, void *start, unsigned long size)
3802 return ((void *)addr >= start && (void *)addr < start + size);
3805 #ifdef CONFIG_KALLSYMS
3807 * This ignores the intensely annoying "mapping symbols" found
3808 * in ARM ELF files: $a, $t and $d.
3810 static inline int is_arm_mapping_symbol(const char *str)
3812 if (str[0] == '.' && str[1] == 'L')
3814 return str[0] == '$' && strchr("axtd", str[1])
3815 && (str[2] == '\0' || str[2] == '.');
3818 static const char *symname(struct mod_kallsyms *kallsyms, unsigned int symnum)
3820 return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
3823 static const char *get_ksymbol(struct module *mod,
3825 unsigned long *size,
3826 unsigned long *offset)
3828 unsigned int i, best = 0;
3829 unsigned long nextval;
3830 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
3832 /* At worse, next value is at end of module */
3833 if (within_module_init(addr, mod))
3834 nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
3836 nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
3838 /* Scan for closest preceding symbol, and next symbol. (ELF
3839 starts real symbols at 1). */
3840 for (i = 1; i < kallsyms->num_symtab; i++) {
3841 if (kallsyms->symtab[i].st_shndx == SHN_UNDEF)
3844 /* We ignore unnamed symbols: they're uninformative
3845 * and inserted at a whim. */
3846 if (*symname(kallsyms, i) == '\0'
3847 || is_arm_mapping_symbol(symname(kallsyms, i)))
3850 if (kallsyms->symtab[i].st_value <= addr
3851 && kallsyms->symtab[i].st_value > kallsyms->symtab[best].st_value)
3853 if (kallsyms->symtab[i].st_value > addr
3854 && kallsyms->symtab[i].st_value < nextval)
3855 nextval = kallsyms->symtab[i].st_value;
3862 *size = nextval - kallsyms->symtab[best].st_value;
3864 *offset = addr - kallsyms->symtab[best].st_value;
3865 return symname(kallsyms, best);
3868 /* For kallsyms to ask for address resolution. NULL means not found. Careful
3869 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3870 const char *module_address_lookup(unsigned long addr,
3871 unsigned long *size,
3872 unsigned long *offset,
3876 const char *ret = NULL;
3880 mod = __module_address(addr);
3883 *modname = mod->name;
3884 ret = get_ksymbol(mod, addr, size, offset);
3886 /* Make a copy in here where it's safe */
3888 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3896 int lookup_module_symbol_name(unsigned long addr, char *symname)
3901 list_for_each_entry_rcu(mod, &modules, list) {
3902 if (mod->state == MODULE_STATE_UNFORMED)
3904 if (within_module(addr, mod)) {
3907 sym = get_ksymbol(mod, addr, NULL, NULL);
3910 strlcpy(symname, sym, KSYM_NAME_LEN);
3920 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3921 unsigned long *offset, char *modname, char *name)
3926 list_for_each_entry_rcu(mod, &modules, list) {
3927 if (mod->state == MODULE_STATE_UNFORMED)
3929 if (within_module(addr, mod)) {
3932 sym = get_ksymbol(mod, addr, size, offset);
3936 strlcpy(modname, mod->name, MODULE_NAME_LEN);
3938 strlcpy(name, sym, KSYM_NAME_LEN);
3948 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3949 char *name, char *module_name, int *exported)
3954 list_for_each_entry_rcu(mod, &modules, list) {
3955 struct mod_kallsyms *kallsyms;
3957 if (mod->state == MODULE_STATE_UNFORMED)
3959 kallsyms = rcu_dereference_sched(mod->kallsyms);
3960 if (symnum < kallsyms->num_symtab) {
3961 *value = kallsyms->symtab[symnum].st_value;
3962 *type = kallsyms->symtab[symnum].st_info;
3963 strlcpy(name, symname(kallsyms, symnum), KSYM_NAME_LEN);
3964 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3965 *exported = is_exported(name, *value, mod);
3969 symnum -= kallsyms->num_symtab;
3975 static unsigned long mod_find_symname(struct module *mod, const char *name)
3978 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
3980 for (i = 0; i < kallsyms->num_symtab; i++)
3981 if (strcmp(name, symname(kallsyms, i)) == 0 &&
3982 kallsyms->symtab[i].st_info != 'U')
3983 return kallsyms->symtab[i].st_value;
3987 /* Look for this name: can be of form module:name. */
3988 unsigned long module_kallsyms_lookup_name(const char *name)
3992 unsigned long ret = 0;
3994 /* Don't lock: we're in enough trouble already. */
3996 if ((colon = strchr(name, ':')) != NULL) {
3997 if ((mod = find_module_all(name, colon - name, false)) != NULL)
3998 ret = mod_find_symname(mod, colon+1);
4000 list_for_each_entry_rcu(mod, &modules, list) {
4001 if (mod->state == MODULE_STATE_UNFORMED)
4003 if ((ret = mod_find_symname(mod, name)) != 0)
4011 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
4012 struct module *, unsigned long),
4019 module_assert_mutex();
4021 list_for_each_entry(mod, &modules, list) {
4022 /* We hold module_mutex: no need for rcu_dereference_sched */
4023 struct mod_kallsyms *kallsyms = mod->kallsyms;
4025 if (mod->state == MODULE_STATE_UNFORMED)
4027 for (i = 0; i < kallsyms->num_symtab; i++) {
4028 ret = fn(data, symname(kallsyms, i),
4029 mod, kallsyms->symtab[i].st_value);
4036 #endif /* CONFIG_KALLSYMS */
4038 static char *module_flags(struct module *mod, char *buf)
4042 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
4044 mod->state == MODULE_STATE_GOING ||
4045 mod->state == MODULE_STATE_COMING) {
4047 bx += module_flags_taint(mod, buf + bx);
4048 /* Show a - for module-is-being-unloaded */
4049 if (mod->state == MODULE_STATE_GOING)
4051 /* Show a + for module-is-being-loaded */
4052 if (mod->state == MODULE_STATE_COMING)
4061 #ifdef CONFIG_PROC_FS
4062 /* Called by the /proc file system to return a list of modules. */
4063 static void *m_start(struct seq_file *m, loff_t *pos)
4065 mutex_lock(&module_mutex);
4066 return seq_list_start(&modules, *pos);
4069 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
4071 return seq_list_next(p, &modules, pos);
4074 static void m_stop(struct seq_file *m, void *p)
4076 mutex_unlock(&module_mutex);
4079 static int m_show(struct seq_file *m, void *p)
4081 struct module *mod = list_entry(p, struct module, list);
4084 /* We always ignore unformed modules. */
4085 if (mod->state == MODULE_STATE_UNFORMED)
4088 seq_printf(m, "%s %u",
4089 mod->name, mod->init_layout.size + mod->core_layout.size);
4090 print_unload_info(m, mod);
4092 /* Informative for users. */
4093 seq_printf(m, " %s",
4094 mod->state == MODULE_STATE_GOING ? "Unloading" :
4095 mod->state == MODULE_STATE_COMING ? "Loading" :
4097 /* Used by oprofile and other similar tools. */
4098 seq_printf(m, " 0x%pK", mod->core_layout.base);
4102 seq_printf(m, " %s", module_flags(mod, buf));
4108 /* Format: modulename size refcount deps address
4110 Where refcount is a number or -, and deps is a comma-separated list
4113 static const struct seq_operations modules_op = {
4120 static int modules_open(struct inode *inode, struct file *file)
4122 return seq_open(file, &modules_op);
4125 static const struct file_operations proc_modules_operations = {
4126 .open = modules_open,
4128 .llseek = seq_lseek,
4129 .release = seq_release,
4132 static int __init proc_modules_init(void)
4134 proc_create("modules", 0, NULL, &proc_modules_operations);
4137 module_init(proc_modules_init);
4140 /* Given an address, look for it in the module exception tables. */
4141 const struct exception_table_entry *search_module_extables(unsigned long addr)
4143 const struct exception_table_entry *e = NULL;
4147 list_for_each_entry_rcu(mod, &modules, list) {
4148 if (mod->state == MODULE_STATE_UNFORMED)
4150 if (mod->num_exentries == 0)
4153 e = search_extable(mod->extable,
4154 mod->extable + mod->num_exentries - 1,
4161 /* Now, if we found one, we are running inside it now, hence
4162 we cannot unload the module, hence no refcnt needed. */
4167 * is_module_address - is this address inside a module?
4168 * @addr: the address to check.
4170 * See is_module_text_address() if you simply want to see if the address
4171 * is code (not data).
4173 bool is_module_address(unsigned long addr)
4178 ret = __module_address(addr) != NULL;
4185 * __module_address - get the module which contains an address.
4186 * @addr: the address.
4188 * Must be called with preempt disabled or module mutex held so that
4189 * module doesn't get freed during this.
4191 struct module *__module_address(unsigned long addr)
4195 if (addr < module_addr_min || addr > module_addr_max)
4198 module_assert_mutex_or_preempt();
4200 mod = mod_find(addr);
4202 BUG_ON(!within_module(addr, mod));
4203 if (mod->state == MODULE_STATE_UNFORMED)
4208 EXPORT_SYMBOL_GPL(__module_address);
4211 * is_module_text_address - is this address inside module code?
4212 * @addr: the address to check.
4214 * See is_module_address() if you simply want to see if the address is
4215 * anywhere in a module. See kernel_text_address() for testing if an
4216 * address corresponds to kernel or module code.
4218 bool is_module_text_address(unsigned long addr)
4223 ret = __module_text_address(addr) != NULL;
4230 * __module_text_address - get the module whose code contains an address.
4231 * @addr: the address.
4233 * Must be called with preempt disabled or module mutex held so that
4234 * module doesn't get freed during this.
4236 struct module *__module_text_address(unsigned long addr)
4238 struct module *mod = __module_address(addr);
4240 /* Make sure it's within the text section. */
4241 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
4242 && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
4247 EXPORT_SYMBOL_GPL(__module_text_address);
4249 /* Don't grab lock, we're oopsing. */
4250 void print_modules(void)
4255 printk(KERN_DEFAULT "Modules linked in:");
4256 /* Most callers should already have preempt disabled, but make sure */
4258 list_for_each_entry_rcu(mod, &modules, list) {
4259 if (mod->state == MODULE_STATE_UNFORMED)
4261 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4264 if (last_unloaded_module[0])
4265 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4269 #ifdef CONFIG_MODVERSIONS
4270 /* Generate the signature for all relevant module structures here.
4271 * If these change, we don't want to try to parse the module. */
4272 void module_layout(struct module *mod,
4273 struct modversion_info *ver,
4274 struct kernel_param *kp,
4275 struct kernel_symbol *ks,
4276 struct tracepoint * const *tp)
4279 EXPORT_SYMBOL(module_layout);