2 Copyright (C) 2002 Richard Henderson
3 Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 #include <linux/export.h>
20 #include <linux/extable.h>
21 #include <linux/moduleloader.h>
22 #include <linux/trace_events.h>
23 #include <linux/init.h>
24 #include <linux/kallsyms.h>
25 #include <linux/file.h>
27 #include <linux/sysfs.h>
28 #include <linux/kernel.h>
29 #include <linux/slab.h>
30 #include <linux/vmalloc.h>
31 #include <linux/elf.h>
32 #include <linux/proc_fs.h>
33 #include <linux/security.h>
34 #include <linux/seq_file.h>
35 #include <linux/syscalls.h>
36 #include <linux/fcntl.h>
37 #include <linux/rcupdate.h>
38 #include <linux/capability.h>
39 #include <linux/cpu.h>
40 #include <linux/moduleparam.h>
41 #include <linux/errno.h>
42 #include <linux/err.h>
43 #include <linux/vermagic.h>
44 #include <linux/notifier.h>
45 #include <linux/sched.h>
46 #include <linux/device.h>
47 #include <linux/string.h>
48 #include <linux/mutex.h>
49 #include <linux/rculist.h>
50 #include <linux/uaccess.h>
51 #include <asm/cacheflush.h>
52 #include <linux/set_memory.h>
53 #include <asm/mmu_context.h>
54 #include <linux/license.h>
55 #include <asm/sections.h>
56 #include <linux/tracepoint.h>
57 #include <linux/ftrace.h>
58 #include <linux/livepatch.h>
59 #include <linux/async.h>
60 #include <linux/percpu.h>
61 #include <linux/kmemleak.h>
62 #include <linux/jump_label.h>
63 #include <linux/pfn.h>
64 #include <linux/bsearch.h>
65 #include <linux/dynamic_debug.h>
66 #include <linux/audit.h>
67 #include <uapi/linux/module.h>
68 #include "module-internal.h"
70 #define CREATE_TRACE_POINTS
71 #include <trace/events/module.h>
73 #ifndef ARCH_SHF_SMALL
74 #define ARCH_SHF_SMALL 0
78 * Modules' sections will be aligned on page boundaries
79 * to ensure complete separation of code and data, but
80 * only when CONFIG_STRICT_MODULE_RWX=y
82 #ifdef CONFIG_STRICT_MODULE_RWX
83 # define debug_align(X) ALIGN(X, PAGE_SIZE)
85 # define debug_align(X) (X)
88 /* If this is set, the section belongs in the init part of the module */
89 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
93 * 1) List of modules (also safely readable with preempt_disable),
94 * 2) module_use links,
95 * 3) module_addr_min/module_addr_max.
96 * (delete and add uses RCU list operations). */
97 DEFINE_MUTEX(module_mutex);
98 EXPORT_SYMBOL_GPL(module_mutex);
99 static LIST_HEAD(modules);
101 #ifdef CONFIG_MODULES_TREE_LOOKUP
104 * Use a latched RB-tree for __module_address(); this allows us to use
105 * RCU-sched lookups of the address from any context.
107 * This is conditional on PERF_EVENTS || TRACING because those can really hit
108 * __module_address() hard by doing a lot of stack unwinding; potentially from
112 static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
114 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
116 return (unsigned long)layout->base;
119 static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
121 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
123 return (unsigned long)layout->size;
126 static __always_inline bool
127 mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
129 return __mod_tree_val(a) < __mod_tree_val(b);
132 static __always_inline int
133 mod_tree_comp(void *key, struct latch_tree_node *n)
135 unsigned long val = (unsigned long)key;
136 unsigned long start, end;
138 start = __mod_tree_val(n);
142 end = start + __mod_tree_size(n);
149 static const struct latch_tree_ops mod_tree_ops = {
150 .less = mod_tree_less,
151 .comp = mod_tree_comp,
154 static struct mod_tree_root {
155 struct latch_tree_root root;
156 unsigned long addr_min;
157 unsigned long addr_max;
158 } mod_tree __cacheline_aligned = {
162 #define module_addr_min mod_tree.addr_min
163 #define module_addr_max mod_tree.addr_max
165 static noinline void __mod_tree_insert(struct mod_tree_node *node)
167 latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
170 static void __mod_tree_remove(struct mod_tree_node *node)
172 latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
176 * These modifications: insert, remove_init and remove; are serialized by the
179 static void mod_tree_insert(struct module *mod)
181 mod->core_layout.mtn.mod = mod;
182 mod->init_layout.mtn.mod = mod;
184 __mod_tree_insert(&mod->core_layout.mtn);
185 if (mod->init_layout.size)
186 __mod_tree_insert(&mod->init_layout.mtn);
189 static void mod_tree_remove_init(struct module *mod)
191 if (mod->init_layout.size)
192 __mod_tree_remove(&mod->init_layout.mtn);
195 static void mod_tree_remove(struct module *mod)
197 __mod_tree_remove(&mod->core_layout.mtn);
198 mod_tree_remove_init(mod);
201 static struct module *mod_find(unsigned long addr)
203 struct latch_tree_node *ltn;
205 ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
209 return container_of(ltn, struct mod_tree_node, node)->mod;
212 #else /* MODULES_TREE_LOOKUP */
214 static unsigned long module_addr_min = -1UL, module_addr_max = 0;
216 static void mod_tree_insert(struct module *mod) { }
217 static void mod_tree_remove_init(struct module *mod) { }
218 static void mod_tree_remove(struct module *mod) { }
220 static struct module *mod_find(unsigned long addr)
224 list_for_each_entry_rcu(mod, &modules, list) {
225 if (within_module(addr, mod))
232 #endif /* MODULES_TREE_LOOKUP */
235 * Bounds of module text, for speeding up __module_address.
236 * Protected by module_mutex.
238 static void __mod_update_bounds(void *base, unsigned int size)
240 unsigned long min = (unsigned long)base;
241 unsigned long max = min + size;
243 if (min < module_addr_min)
244 module_addr_min = min;
245 if (max > module_addr_max)
246 module_addr_max = max;
249 static void mod_update_bounds(struct module *mod)
251 __mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
252 if (mod->init_layout.size)
253 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
256 #ifdef CONFIG_KGDB_KDB
257 struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
258 #endif /* CONFIG_KGDB_KDB */
260 static void module_assert_mutex(void)
262 lockdep_assert_held(&module_mutex);
265 static void module_assert_mutex_or_preempt(void)
267 #ifdef CONFIG_LOCKDEP
268 if (unlikely(!debug_locks))
271 WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
272 !lockdep_is_held(&module_mutex));
276 static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
277 module_param(sig_enforce, bool_enable_only, 0644);
280 * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
281 * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
283 bool is_module_sig_enforced(void)
287 EXPORT_SYMBOL(is_module_sig_enforced);
289 /* Block module loading/unloading? */
290 int modules_disabled = 0;
291 core_param(nomodule, modules_disabled, bint, 0);
293 /* Waiting for a module to finish initializing? */
294 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
296 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
298 int register_module_notifier(struct notifier_block *nb)
300 return blocking_notifier_chain_register(&module_notify_list, nb);
302 EXPORT_SYMBOL(register_module_notifier);
304 int unregister_module_notifier(struct notifier_block *nb)
306 return blocking_notifier_chain_unregister(&module_notify_list, nb);
308 EXPORT_SYMBOL(unregister_module_notifier);
311 * We require a truly strong try_module_get(): 0 means success.
312 * Otherwise an error is returned due to ongoing or failed
313 * initialization etc.
315 static inline int strong_try_module_get(struct module *mod)
317 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
318 if (mod && mod->state == MODULE_STATE_COMING)
320 if (try_module_get(mod))
326 static inline void add_taint_module(struct module *mod, unsigned flag,
327 enum lockdep_ok lockdep_ok)
329 add_taint(flag, lockdep_ok);
330 set_bit(flag, &mod->taints);
334 * A thread that wants to hold a reference to a module only while it
335 * is running can call this to safely exit. nfsd and lockd use this.
337 void __noreturn __module_put_and_exit(struct module *mod, long code)
342 EXPORT_SYMBOL(__module_put_and_exit);
344 /* Find a module section: 0 means not found. */
345 static unsigned int find_sec(const struct load_info *info, const char *name)
349 for (i = 1; i < info->hdr->e_shnum; i++) {
350 Elf_Shdr *shdr = &info->sechdrs[i];
351 /* Alloc bit cleared means "ignore it." */
352 if ((shdr->sh_flags & SHF_ALLOC)
353 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
359 /* Find a module section, or NULL. */
360 static void *section_addr(const struct load_info *info, const char *name)
362 /* Section 0 has sh_addr 0. */
363 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
366 /* Find a module section, or NULL. Fill in number of "objects" in section. */
367 static void *section_objs(const struct load_info *info,
372 unsigned int sec = find_sec(info, name);
374 /* Section 0 has sh_addr 0 and sh_size 0. */
375 *num = info->sechdrs[sec].sh_size / object_size;
376 return (void *)info->sechdrs[sec].sh_addr;
379 /* Provided by the linker */
380 extern const struct kernel_symbol __start___ksymtab[];
381 extern const struct kernel_symbol __stop___ksymtab[];
382 extern const struct kernel_symbol __start___ksymtab_gpl[];
383 extern const struct kernel_symbol __stop___ksymtab_gpl[];
384 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
385 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
386 extern const s32 __start___kcrctab[];
387 extern const s32 __start___kcrctab_gpl[];
388 extern const s32 __start___kcrctab_gpl_future[];
389 #ifdef CONFIG_UNUSED_SYMBOLS
390 extern const struct kernel_symbol __start___ksymtab_unused[];
391 extern const struct kernel_symbol __stop___ksymtab_unused[];
392 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
393 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
394 extern const s32 __start___kcrctab_unused[];
395 extern const s32 __start___kcrctab_unused_gpl[];
398 #ifndef CONFIG_MODVERSIONS
399 #define symversion(base, idx) NULL
401 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
404 static bool each_symbol_in_section(const struct symsearch *arr,
405 unsigned int arrsize,
406 struct module *owner,
407 bool (*fn)(const struct symsearch *syms,
408 struct module *owner,
414 for (j = 0; j < arrsize; j++) {
415 if (fn(&arr[j], owner, data))
422 /* Returns true as soon as fn returns true, otherwise false. */
423 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
424 struct module *owner,
429 static const struct symsearch arr[] = {
430 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
431 NOT_GPL_ONLY, false },
432 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
433 __start___kcrctab_gpl,
435 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
436 __start___kcrctab_gpl_future,
437 WILL_BE_GPL_ONLY, false },
438 #ifdef CONFIG_UNUSED_SYMBOLS
439 { __start___ksymtab_unused, __stop___ksymtab_unused,
440 __start___kcrctab_unused,
441 NOT_GPL_ONLY, true },
442 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
443 __start___kcrctab_unused_gpl,
448 module_assert_mutex_or_preempt();
450 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
453 list_for_each_entry_rcu(mod, &modules, list) {
454 struct symsearch arr[] = {
455 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
456 NOT_GPL_ONLY, false },
457 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
460 { mod->gpl_future_syms,
461 mod->gpl_future_syms + mod->num_gpl_future_syms,
462 mod->gpl_future_crcs,
463 WILL_BE_GPL_ONLY, false },
464 #ifdef CONFIG_UNUSED_SYMBOLS
466 mod->unused_syms + mod->num_unused_syms,
468 NOT_GPL_ONLY, true },
469 { mod->unused_gpl_syms,
470 mod->unused_gpl_syms + mod->num_unused_gpl_syms,
471 mod->unused_gpl_crcs,
476 if (mod->state == MODULE_STATE_UNFORMED)
479 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
484 EXPORT_SYMBOL_GPL(each_symbol_section);
486 struct find_symbol_arg {
493 struct module *owner;
495 const struct kernel_symbol *sym;
498 static bool check_symbol(const struct symsearch *syms,
499 struct module *owner,
500 unsigned int symnum, void *data)
502 struct find_symbol_arg *fsa = data;
505 if (syms->licence == GPL_ONLY)
507 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
508 pr_warn("Symbol %s is being used by a non-GPL module, "
509 "which will not be allowed in the future\n",
514 #ifdef CONFIG_UNUSED_SYMBOLS
515 if (syms->unused && fsa->warn) {
516 pr_warn("Symbol %s is marked as UNUSED, however this module is "
517 "using it.\n", fsa->name);
518 pr_warn("This symbol will go away in the future.\n");
519 pr_warn("Please evaluate if this is the right api to use and "
520 "if it really is, submit a report to the linux kernel "
521 "mailing list together with submitting your code for "
527 fsa->crc = symversion(syms->crcs, symnum);
528 fsa->sym = &syms->start[symnum];
532 static unsigned long kernel_symbol_value(const struct kernel_symbol *sym)
534 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
535 return (unsigned long)offset_to_ptr(&sym->value_offset);
541 static const char *kernel_symbol_name(const struct kernel_symbol *sym)
543 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
544 return offset_to_ptr(&sym->name_offset);
550 static int cmp_name(const void *va, const void *vb)
553 const struct kernel_symbol *b;
555 return strcmp(a, kernel_symbol_name(b));
558 static bool find_symbol_in_section(const struct symsearch *syms,
559 struct module *owner,
562 struct find_symbol_arg *fsa = data;
563 struct kernel_symbol *sym;
565 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
566 sizeof(struct kernel_symbol), cmp_name);
568 if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
574 /* Find a symbol and return it, along with, (optional) crc and
575 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
576 const struct kernel_symbol *find_symbol(const char *name,
577 struct module **owner,
582 struct find_symbol_arg fsa;
588 if (each_symbol_section(find_symbol_in_section, &fsa)) {
596 pr_debug("Failed to find symbol %s\n", name);
599 EXPORT_SYMBOL_GPL(find_symbol);
602 * Search for module by name: must hold module_mutex (or preempt disabled
603 * for read-only access).
605 static struct module *find_module_all(const char *name, size_t len,
610 module_assert_mutex_or_preempt();
612 list_for_each_entry_rcu(mod, &modules, list) {
613 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
615 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
621 struct module *find_module(const char *name)
623 module_assert_mutex();
624 return find_module_all(name, strlen(name), false);
626 EXPORT_SYMBOL_GPL(find_module);
630 static inline void __percpu *mod_percpu(struct module *mod)
635 static int percpu_modalloc(struct module *mod, struct load_info *info)
637 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
638 unsigned long align = pcpusec->sh_addralign;
640 if (!pcpusec->sh_size)
643 if (align > PAGE_SIZE) {
644 pr_warn("%s: per-cpu alignment %li > %li\n",
645 mod->name, align, PAGE_SIZE);
649 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
651 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
652 mod->name, (unsigned long)pcpusec->sh_size);
655 mod->percpu_size = pcpusec->sh_size;
659 static void percpu_modfree(struct module *mod)
661 free_percpu(mod->percpu);
664 static unsigned int find_pcpusec(struct load_info *info)
666 return find_sec(info, ".data..percpu");
669 static void percpu_modcopy(struct module *mod,
670 const void *from, unsigned long size)
674 for_each_possible_cpu(cpu)
675 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
678 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
685 list_for_each_entry_rcu(mod, &modules, list) {
686 if (mod->state == MODULE_STATE_UNFORMED)
688 if (!mod->percpu_size)
690 for_each_possible_cpu(cpu) {
691 void *start = per_cpu_ptr(mod->percpu, cpu);
692 void *va = (void *)addr;
694 if (va >= start && va < start + mod->percpu_size) {
696 *can_addr = (unsigned long) (va - start);
697 *can_addr += (unsigned long)
698 per_cpu_ptr(mod->percpu,
712 * is_module_percpu_address - test whether address is from module static percpu
713 * @addr: address to test
715 * Test whether @addr belongs to module static percpu area.
718 * %true if @addr is from module static percpu area
720 bool is_module_percpu_address(unsigned long addr)
722 return __is_module_percpu_address(addr, NULL);
725 #else /* ... !CONFIG_SMP */
727 static inline void __percpu *mod_percpu(struct module *mod)
731 static int percpu_modalloc(struct module *mod, struct load_info *info)
733 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
734 if (info->sechdrs[info->index.pcpu].sh_size != 0)
738 static inline void percpu_modfree(struct module *mod)
741 static unsigned int find_pcpusec(struct load_info *info)
745 static inline void percpu_modcopy(struct module *mod,
746 const void *from, unsigned long size)
748 /* pcpusec should be 0, and size of that section should be 0. */
751 bool is_module_percpu_address(unsigned long addr)
756 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
761 #endif /* CONFIG_SMP */
763 #define MODINFO_ATTR(field) \
764 static void setup_modinfo_##field(struct module *mod, const char *s) \
766 mod->field = kstrdup(s, GFP_KERNEL); \
768 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
769 struct module_kobject *mk, char *buffer) \
771 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
773 static int modinfo_##field##_exists(struct module *mod) \
775 return mod->field != NULL; \
777 static void free_modinfo_##field(struct module *mod) \
782 static struct module_attribute modinfo_##field = { \
783 .attr = { .name = __stringify(field), .mode = 0444 }, \
784 .show = show_modinfo_##field, \
785 .setup = setup_modinfo_##field, \
786 .test = modinfo_##field##_exists, \
787 .free = free_modinfo_##field, \
790 MODINFO_ATTR(version);
791 MODINFO_ATTR(srcversion);
793 static char last_unloaded_module[MODULE_NAME_LEN+1];
795 #ifdef CONFIG_MODULE_UNLOAD
797 EXPORT_TRACEPOINT_SYMBOL(module_get);
799 /* MODULE_REF_BASE is the base reference count by kmodule loader. */
800 #define MODULE_REF_BASE 1
802 /* Init the unload section of the module. */
803 static int module_unload_init(struct module *mod)
806 * Initialize reference counter to MODULE_REF_BASE.
807 * refcnt == 0 means module is going.
809 atomic_set(&mod->refcnt, MODULE_REF_BASE);
811 INIT_LIST_HEAD(&mod->source_list);
812 INIT_LIST_HEAD(&mod->target_list);
814 /* Hold reference count during initialization. */
815 atomic_inc(&mod->refcnt);
820 /* Does a already use b? */
821 static int already_uses(struct module *a, struct module *b)
823 struct module_use *use;
825 list_for_each_entry(use, &b->source_list, source_list) {
826 if (use->source == a) {
827 pr_debug("%s uses %s!\n", a->name, b->name);
831 pr_debug("%s does not use %s!\n", a->name, b->name);
837 * - we add 'a' as a "source", 'b' as a "target" of module use
838 * - the module_use is added to the list of 'b' sources (so
839 * 'b' can walk the list to see who sourced them), and of 'a'
840 * targets (so 'a' can see what modules it targets).
842 static int add_module_usage(struct module *a, struct module *b)
844 struct module_use *use;
846 pr_debug("Allocating new usage for %s.\n", a->name);
847 use = kmalloc(sizeof(*use), GFP_ATOMIC);
853 list_add(&use->source_list, &b->source_list);
854 list_add(&use->target_list, &a->target_list);
858 /* Module a uses b: caller needs module_mutex() */
859 int ref_module(struct module *a, struct module *b)
863 if (b == NULL || already_uses(a, b))
866 /* If module isn't available, we fail. */
867 err = strong_try_module_get(b);
871 err = add_module_usage(a, b);
878 EXPORT_SYMBOL_GPL(ref_module);
880 /* Clear the unload stuff of the module. */
881 static void module_unload_free(struct module *mod)
883 struct module_use *use, *tmp;
885 mutex_lock(&module_mutex);
886 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
887 struct module *i = use->target;
888 pr_debug("%s unusing %s\n", mod->name, i->name);
890 list_del(&use->source_list);
891 list_del(&use->target_list);
894 mutex_unlock(&module_mutex);
897 #ifdef CONFIG_MODULE_FORCE_UNLOAD
898 static inline int try_force_unload(unsigned int flags)
900 int ret = (flags & O_TRUNC);
902 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
906 static inline int try_force_unload(unsigned int flags)
910 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
912 /* Try to release refcount of module, 0 means success. */
913 static int try_release_module_ref(struct module *mod)
917 /* Try to decrement refcnt which we set at loading */
918 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
921 /* Someone can put this right now, recover with checking */
922 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
927 static int try_stop_module(struct module *mod, int flags, int *forced)
929 /* If it's not unused, quit unless we're forcing. */
930 if (try_release_module_ref(mod) != 0) {
931 *forced = try_force_unload(flags);
936 /* Mark it as dying. */
937 mod->state = MODULE_STATE_GOING;
943 * module_refcount - return the refcount or -1 if unloading
945 * @mod: the module we're checking
948 * -1 if the module is in the process of unloading
949 * otherwise the number of references in the kernel to the module
951 int module_refcount(struct module *mod)
953 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
955 EXPORT_SYMBOL(module_refcount);
957 /* This exists whether we can unload or not */
958 static void free_module(struct module *mod);
960 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
964 char name[MODULE_NAME_LEN];
967 if (!capable(CAP_SYS_MODULE) || modules_disabled)
970 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
972 name[MODULE_NAME_LEN-1] = '\0';
974 audit_log_kern_module(name);
976 if (mutex_lock_interruptible(&module_mutex) != 0)
979 mod = find_module(name);
985 if (!list_empty(&mod->source_list)) {
986 /* Other modules depend on us: get rid of them first. */
991 /* Doing init or already dying? */
992 if (mod->state != MODULE_STATE_LIVE) {
993 /* FIXME: if (force), slam module count damn the torpedoes */
994 pr_debug("%s already dying\n", mod->name);
999 /* If it has an init func, it must have an exit func to unload */
1000 if (mod->init && !mod->exit) {
1001 forced = try_force_unload(flags);
1003 /* This module can't be removed */
1009 /* Stop the machine so refcounts can't move and disable module. */
1010 ret = try_stop_module(mod, flags, &forced);
1014 mutex_unlock(&module_mutex);
1015 /* Final destruction now no one is using it. */
1016 if (mod->exit != NULL)
1018 blocking_notifier_call_chain(&module_notify_list,
1019 MODULE_STATE_GOING, mod);
1020 klp_module_going(mod);
1021 ftrace_release_mod(mod);
1023 async_synchronize_full();
1025 /* Store the name of the last unloaded module for diagnostic purposes */
1026 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
1031 mutex_unlock(&module_mutex);
1035 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1037 struct module_use *use;
1038 int printed_something = 0;
1040 seq_printf(m, " %i ", module_refcount(mod));
1043 * Always include a trailing , so userspace can differentiate
1044 * between this and the old multi-field proc format.
1046 list_for_each_entry(use, &mod->source_list, source_list) {
1047 printed_something = 1;
1048 seq_printf(m, "%s,", use->source->name);
1051 if (mod->init != NULL && mod->exit == NULL) {
1052 printed_something = 1;
1053 seq_puts(m, "[permanent],");
1056 if (!printed_something)
1060 void __symbol_put(const char *symbol)
1062 struct module *owner;
1065 if (!find_symbol(symbol, &owner, NULL, true, false))
1070 EXPORT_SYMBOL(__symbol_put);
1072 /* Note this assumes addr is a function, which it currently always is. */
1073 void symbol_put_addr(void *addr)
1075 struct module *modaddr;
1076 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1078 if (core_kernel_text(a))
1082 * Even though we hold a reference on the module; we still need to
1083 * disable preemption in order to safely traverse the data structure.
1086 modaddr = __module_text_address(a);
1088 module_put(modaddr);
1091 EXPORT_SYMBOL_GPL(symbol_put_addr);
1093 static ssize_t show_refcnt(struct module_attribute *mattr,
1094 struct module_kobject *mk, char *buffer)
1096 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1099 static struct module_attribute modinfo_refcnt =
1100 __ATTR(refcnt, 0444, show_refcnt, NULL);
1102 void __module_get(struct module *module)
1106 atomic_inc(&module->refcnt);
1107 trace_module_get(module, _RET_IP_);
1111 EXPORT_SYMBOL(__module_get);
1113 bool try_module_get(struct module *module)
1119 /* Note: here, we can fail to get a reference */
1120 if (likely(module_is_live(module) &&
1121 atomic_inc_not_zero(&module->refcnt) != 0))
1122 trace_module_get(module, _RET_IP_);
1130 EXPORT_SYMBOL(try_module_get);
1132 void module_put(struct module *module)
1138 ret = atomic_dec_if_positive(&module->refcnt);
1139 WARN_ON(ret < 0); /* Failed to put refcount */
1140 trace_module_put(module, _RET_IP_);
1144 EXPORT_SYMBOL(module_put);
1146 #else /* !CONFIG_MODULE_UNLOAD */
1147 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1149 /* We don't know the usage count, or what modules are using. */
1150 seq_puts(m, " - -");
1153 static inline void module_unload_free(struct module *mod)
1157 int ref_module(struct module *a, struct module *b)
1159 return strong_try_module_get(b);
1161 EXPORT_SYMBOL_GPL(ref_module);
1163 static inline int module_unload_init(struct module *mod)
1167 #endif /* CONFIG_MODULE_UNLOAD */
1169 static size_t module_flags_taint(struct module *mod, char *buf)
1174 for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
1175 if (taint_flags[i].module && test_bit(i, &mod->taints))
1176 buf[l++] = taint_flags[i].c_true;
1182 static ssize_t show_initstate(struct module_attribute *mattr,
1183 struct module_kobject *mk, char *buffer)
1185 const char *state = "unknown";
1187 switch (mk->mod->state) {
1188 case MODULE_STATE_LIVE:
1191 case MODULE_STATE_COMING:
1194 case MODULE_STATE_GOING:
1200 return sprintf(buffer, "%s\n", state);
1203 static struct module_attribute modinfo_initstate =
1204 __ATTR(initstate, 0444, show_initstate, NULL);
1206 static ssize_t store_uevent(struct module_attribute *mattr,
1207 struct module_kobject *mk,
1208 const char *buffer, size_t count)
1212 rc = kobject_synth_uevent(&mk->kobj, buffer, count);
1213 return rc ? rc : count;
1216 struct module_attribute module_uevent =
1217 __ATTR(uevent, 0200, NULL, store_uevent);
1219 static ssize_t show_coresize(struct module_attribute *mattr,
1220 struct module_kobject *mk, char *buffer)
1222 return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1225 static struct module_attribute modinfo_coresize =
1226 __ATTR(coresize, 0444, show_coresize, NULL);
1228 static ssize_t show_initsize(struct module_attribute *mattr,
1229 struct module_kobject *mk, char *buffer)
1231 return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1234 static struct module_attribute modinfo_initsize =
1235 __ATTR(initsize, 0444, show_initsize, NULL);
1237 static ssize_t show_taint(struct module_attribute *mattr,
1238 struct module_kobject *mk, char *buffer)
1242 l = module_flags_taint(mk->mod, buffer);
1247 static struct module_attribute modinfo_taint =
1248 __ATTR(taint, 0444, show_taint, NULL);
1250 static struct module_attribute *modinfo_attrs[] = {
1253 &modinfo_srcversion,
1258 #ifdef CONFIG_MODULE_UNLOAD
1264 static const char vermagic[] = VERMAGIC_STRING;
1266 static int try_to_force_load(struct module *mod, const char *reason)
1268 #ifdef CONFIG_MODULE_FORCE_LOAD
1269 if (!test_taint(TAINT_FORCED_MODULE))
1270 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1271 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1278 #ifdef CONFIG_MODVERSIONS
1280 static u32 resolve_rel_crc(const s32 *crc)
1282 return *(u32 *)((void *)crc + *crc);
1285 static int check_version(const struct load_info *info,
1286 const char *symname,
1290 Elf_Shdr *sechdrs = info->sechdrs;
1291 unsigned int versindex = info->index.vers;
1292 unsigned int i, num_versions;
1293 struct modversion_info *versions;
1295 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1299 /* No versions at all? modprobe --force does this. */
1301 return try_to_force_load(mod, symname) == 0;
1303 versions = (void *) sechdrs[versindex].sh_addr;
1304 num_versions = sechdrs[versindex].sh_size
1305 / sizeof(struct modversion_info);
1307 for (i = 0; i < num_versions; i++) {
1310 if (strcmp(versions[i].name, symname) != 0)
1313 if (IS_ENABLED(CONFIG_MODULE_REL_CRCS))
1314 crcval = resolve_rel_crc(crc);
1317 if (versions[i].crc == crcval)
1319 pr_debug("Found checksum %X vs module %lX\n",
1320 crcval, versions[i].crc);
1324 /* Broken toolchain. Warn once, then let it go.. */
1325 pr_warn_once("%s: no symbol version for %s\n", info->name, symname);
1329 pr_warn("%s: disagrees about version of symbol %s\n",
1330 info->name, symname);
1334 static inline int check_modstruct_version(const struct load_info *info,
1340 * Since this should be found in kernel (which can't be removed), no
1341 * locking is necessary -- use preempt_disable() to placate lockdep.
1344 if (!find_symbol("module_layout", NULL, &crc, true, false)) {
1349 return check_version(info, "module_layout", mod, crc);
1352 /* First part is kernel version, which we ignore if module has crcs. */
1353 static inline int same_magic(const char *amagic, const char *bmagic,
1357 amagic += strcspn(amagic, " ");
1358 bmagic += strcspn(bmagic, " ");
1360 return strcmp(amagic, bmagic) == 0;
1363 static inline int check_version(const struct load_info *info,
1364 const char *symname,
1371 static inline int check_modstruct_version(const struct load_info *info,
1377 static inline int same_magic(const char *amagic, const char *bmagic,
1380 return strcmp(amagic, bmagic) == 0;
1382 #endif /* CONFIG_MODVERSIONS */
1384 /* Resolve a symbol for this module. I.e. if we find one, record usage. */
1385 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1386 const struct load_info *info,
1390 struct module *owner;
1391 const struct kernel_symbol *sym;
1396 * The module_mutex should not be a heavily contended lock;
1397 * if we get the occasional sleep here, we'll go an extra iteration
1398 * in the wait_event_interruptible(), which is harmless.
1400 sched_annotate_sleep();
1401 mutex_lock(&module_mutex);
1402 sym = find_symbol(name, &owner, &crc,
1403 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1407 if (!check_version(info, name, mod, crc)) {
1408 sym = ERR_PTR(-EINVAL);
1412 err = ref_module(mod, owner);
1419 /* We must make copy under the lock if we failed to get ref. */
1420 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1422 mutex_unlock(&module_mutex);
1426 static const struct kernel_symbol *
1427 resolve_symbol_wait(struct module *mod,
1428 const struct load_info *info,
1431 const struct kernel_symbol *ksym;
1432 char owner[MODULE_NAME_LEN];
1434 if (wait_event_interruptible_timeout(module_wq,
1435 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1436 || PTR_ERR(ksym) != -EBUSY,
1438 pr_warn("%s: gave up waiting for init of module %s.\n",
1445 * /sys/module/foo/sections stuff
1446 * J. Corbet <corbet@lwn.net>
1450 #ifdef CONFIG_KALLSYMS
1451 static inline bool sect_empty(const Elf_Shdr *sect)
1453 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1456 struct module_sect_attr {
1457 struct module_attribute mattr;
1459 unsigned long address;
1462 struct module_sect_attrs {
1463 struct attribute_group grp;
1464 unsigned int nsections;
1465 struct module_sect_attr attrs[0];
1468 static ssize_t module_sect_show(struct module_attribute *mattr,
1469 struct module_kobject *mk, char *buf)
1471 struct module_sect_attr *sattr =
1472 container_of(mattr, struct module_sect_attr, mattr);
1473 return sprintf(buf, "0x%px\n", kptr_restrict < 2 ?
1474 (void *)sattr->address : NULL);
1477 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1479 unsigned int section;
1481 for (section = 0; section < sect_attrs->nsections; section++)
1482 kfree(sect_attrs->attrs[section].name);
1486 static void add_sect_attrs(struct module *mod, const struct load_info *info)
1488 unsigned int nloaded = 0, i, size[2];
1489 struct module_sect_attrs *sect_attrs;
1490 struct module_sect_attr *sattr;
1491 struct attribute **gattr;
1493 /* Count loaded sections and allocate structures */
1494 for (i = 0; i < info->hdr->e_shnum; i++)
1495 if (!sect_empty(&info->sechdrs[i]))
1497 size[0] = ALIGN(sizeof(*sect_attrs)
1498 + nloaded * sizeof(sect_attrs->attrs[0]),
1499 sizeof(sect_attrs->grp.attrs[0]));
1500 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1501 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1502 if (sect_attrs == NULL)
1505 /* Setup section attributes. */
1506 sect_attrs->grp.name = "sections";
1507 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1509 sect_attrs->nsections = 0;
1510 sattr = §_attrs->attrs[0];
1511 gattr = §_attrs->grp.attrs[0];
1512 for (i = 0; i < info->hdr->e_shnum; i++) {
1513 Elf_Shdr *sec = &info->sechdrs[i];
1514 if (sect_empty(sec))
1516 sattr->address = sec->sh_addr;
1517 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1519 if (sattr->name == NULL)
1521 sect_attrs->nsections++;
1522 sysfs_attr_init(&sattr->mattr.attr);
1523 sattr->mattr.show = module_sect_show;
1524 sattr->mattr.store = NULL;
1525 sattr->mattr.attr.name = sattr->name;
1526 sattr->mattr.attr.mode = S_IRUSR;
1527 *(gattr++) = &(sattr++)->mattr.attr;
1531 if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp))
1534 mod->sect_attrs = sect_attrs;
1537 free_sect_attrs(sect_attrs);
1540 static void remove_sect_attrs(struct module *mod)
1542 if (mod->sect_attrs) {
1543 sysfs_remove_group(&mod->mkobj.kobj,
1544 &mod->sect_attrs->grp);
1545 /* We are positive that no one is using any sect attrs
1546 * at this point. Deallocate immediately. */
1547 free_sect_attrs(mod->sect_attrs);
1548 mod->sect_attrs = NULL;
1553 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1556 struct module_notes_attrs {
1557 struct kobject *dir;
1559 struct bin_attribute attrs[0];
1562 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1563 struct bin_attribute *bin_attr,
1564 char *buf, loff_t pos, size_t count)
1567 * The caller checked the pos and count against our size.
1569 memcpy(buf, bin_attr->private + pos, count);
1573 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1576 if (notes_attrs->dir) {
1578 sysfs_remove_bin_file(notes_attrs->dir,
1579 ¬es_attrs->attrs[i]);
1580 kobject_put(notes_attrs->dir);
1585 static void add_notes_attrs(struct module *mod, const struct load_info *info)
1587 unsigned int notes, loaded, i;
1588 struct module_notes_attrs *notes_attrs;
1589 struct bin_attribute *nattr;
1591 /* failed to create section attributes, so can't create notes */
1592 if (!mod->sect_attrs)
1595 /* Count notes sections and allocate structures. */
1597 for (i = 0; i < info->hdr->e_shnum; i++)
1598 if (!sect_empty(&info->sechdrs[i]) &&
1599 (info->sechdrs[i].sh_type == SHT_NOTE))
1605 notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes),
1607 if (notes_attrs == NULL)
1610 notes_attrs->notes = notes;
1611 nattr = ¬es_attrs->attrs[0];
1612 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1613 if (sect_empty(&info->sechdrs[i]))
1615 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1616 sysfs_bin_attr_init(nattr);
1617 nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1618 nattr->attr.mode = S_IRUGO;
1619 nattr->size = info->sechdrs[i].sh_size;
1620 nattr->private = (void *) info->sechdrs[i].sh_addr;
1621 nattr->read = module_notes_read;
1627 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1628 if (!notes_attrs->dir)
1631 for (i = 0; i < notes; ++i)
1632 if (sysfs_create_bin_file(notes_attrs->dir,
1633 ¬es_attrs->attrs[i]))
1636 mod->notes_attrs = notes_attrs;
1640 free_notes_attrs(notes_attrs, i);
1643 static void remove_notes_attrs(struct module *mod)
1645 if (mod->notes_attrs)
1646 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1651 static inline void add_sect_attrs(struct module *mod,
1652 const struct load_info *info)
1656 static inline void remove_sect_attrs(struct module *mod)
1660 static inline void add_notes_attrs(struct module *mod,
1661 const struct load_info *info)
1665 static inline void remove_notes_attrs(struct module *mod)
1668 #endif /* CONFIG_KALLSYMS */
1670 static void del_usage_links(struct module *mod)
1672 #ifdef CONFIG_MODULE_UNLOAD
1673 struct module_use *use;
1675 mutex_lock(&module_mutex);
1676 list_for_each_entry(use, &mod->target_list, target_list)
1677 sysfs_remove_link(use->target->holders_dir, mod->name);
1678 mutex_unlock(&module_mutex);
1682 static int add_usage_links(struct module *mod)
1685 #ifdef CONFIG_MODULE_UNLOAD
1686 struct module_use *use;
1688 mutex_lock(&module_mutex);
1689 list_for_each_entry(use, &mod->target_list, target_list) {
1690 ret = sysfs_create_link(use->target->holders_dir,
1691 &mod->mkobj.kobj, mod->name);
1695 mutex_unlock(&module_mutex);
1697 del_usage_links(mod);
1702 static int module_add_modinfo_attrs(struct module *mod)
1704 struct module_attribute *attr;
1705 struct module_attribute *temp_attr;
1709 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1710 (ARRAY_SIZE(modinfo_attrs) + 1)),
1712 if (!mod->modinfo_attrs)
1715 temp_attr = mod->modinfo_attrs;
1716 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1717 if (!attr->test || attr->test(mod)) {
1718 memcpy(temp_attr, attr, sizeof(*temp_attr));
1719 sysfs_attr_init(&temp_attr->attr);
1720 error = sysfs_create_file(&mod->mkobj.kobj,
1728 static void module_remove_modinfo_attrs(struct module *mod)
1730 struct module_attribute *attr;
1733 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1734 /* pick a field to test for end of list */
1735 if (!attr->attr.name)
1737 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1741 kfree(mod->modinfo_attrs);
1744 static void mod_kobject_put(struct module *mod)
1746 DECLARE_COMPLETION_ONSTACK(c);
1747 mod->mkobj.kobj_completion = &c;
1748 kobject_put(&mod->mkobj.kobj);
1749 wait_for_completion(&c);
1752 static int mod_sysfs_init(struct module *mod)
1755 struct kobject *kobj;
1757 if (!module_sysfs_initialized) {
1758 pr_err("%s: module sysfs not initialized\n", mod->name);
1763 kobj = kset_find_obj(module_kset, mod->name);
1765 pr_err("%s: module is already loaded\n", mod->name);
1771 mod->mkobj.mod = mod;
1773 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1774 mod->mkobj.kobj.kset = module_kset;
1775 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1778 mod_kobject_put(mod);
1780 /* delay uevent until full sysfs population */
1785 static int mod_sysfs_setup(struct module *mod,
1786 const struct load_info *info,
1787 struct kernel_param *kparam,
1788 unsigned int num_params)
1792 err = mod_sysfs_init(mod);
1796 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1797 if (!mod->holders_dir) {
1802 err = module_param_sysfs_setup(mod, kparam, num_params);
1804 goto out_unreg_holders;
1806 err = module_add_modinfo_attrs(mod);
1808 goto out_unreg_param;
1810 err = add_usage_links(mod);
1812 goto out_unreg_modinfo_attrs;
1814 add_sect_attrs(mod, info);
1815 add_notes_attrs(mod, info);
1817 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1820 out_unreg_modinfo_attrs:
1821 module_remove_modinfo_attrs(mod);
1823 module_param_sysfs_remove(mod);
1825 kobject_put(mod->holders_dir);
1827 mod_kobject_put(mod);
1832 static void mod_sysfs_fini(struct module *mod)
1834 remove_notes_attrs(mod);
1835 remove_sect_attrs(mod);
1836 mod_kobject_put(mod);
1839 static void init_param_lock(struct module *mod)
1841 mutex_init(&mod->param_lock);
1843 #else /* !CONFIG_SYSFS */
1845 static int mod_sysfs_setup(struct module *mod,
1846 const struct load_info *info,
1847 struct kernel_param *kparam,
1848 unsigned int num_params)
1853 static void mod_sysfs_fini(struct module *mod)
1857 static void module_remove_modinfo_attrs(struct module *mod)
1861 static void del_usage_links(struct module *mod)
1865 static void init_param_lock(struct module *mod)
1868 #endif /* CONFIG_SYSFS */
1870 static void mod_sysfs_teardown(struct module *mod)
1872 del_usage_links(mod);
1873 module_remove_modinfo_attrs(mod);
1874 module_param_sysfs_remove(mod);
1875 kobject_put(mod->mkobj.drivers_dir);
1876 kobject_put(mod->holders_dir);
1877 mod_sysfs_fini(mod);
1880 #ifdef CONFIG_STRICT_MODULE_RWX
1882 * LKM RO/NX protection: protect module's text/ro-data
1883 * from modification and any data from execution.
1885 * General layout of module is:
1886 * [text] [read-only-data] [ro-after-init] [writable data]
1887 * text_size -----^ ^ ^ ^
1888 * ro_size ------------------------| | |
1889 * ro_after_init_size -----------------------------| |
1890 * size -----------------------------------------------------------|
1892 * These values are always page-aligned (as is base)
1894 static void frob_text(const struct module_layout *layout,
1895 int (*set_memory)(unsigned long start, int num_pages))
1897 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1898 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1899 set_memory((unsigned long)layout->base,
1900 layout->text_size >> PAGE_SHIFT);
1903 static void frob_rodata(const struct module_layout *layout,
1904 int (*set_memory)(unsigned long start, int num_pages))
1906 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1907 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1908 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1909 set_memory((unsigned long)layout->base + layout->text_size,
1910 (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
1913 static void frob_ro_after_init(const struct module_layout *layout,
1914 int (*set_memory)(unsigned long start, int num_pages))
1916 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1917 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1918 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1919 set_memory((unsigned long)layout->base + layout->ro_size,
1920 (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
1923 static void frob_writable_data(const struct module_layout *layout,
1924 int (*set_memory)(unsigned long start, int num_pages))
1926 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1927 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1928 BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
1929 set_memory((unsigned long)layout->base + layout->ro_after_init_size,
1930 (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
1933 /* livepatching wants to disable read-only so it can frob module. */
1934 void module_disable_ro(const struct module *mod)
1936 if (!rodata_enabled)
1939 frob_text(&mod->core_layout, set_memory_rw);
1940 frob_rodata(&mod->core_layout, set_memory_rw);
1941 frob_ro_after_init(&mod->core_layout, set_memory_rw);
1942 frob_text(&mod->init_layout, set_memory_rw);
1943 frob_rodata(&mod->init_layout, set_memory_rw);
1946 void module_enable_ro(const struct module *mod, bool after_init)
1948 if (!rodata_enabled)
1951 frob_text(&mod->core_layout, set_memory_ro);
1952 frob_rodata(&mod->core_layout, set_memory_ro);
1953 frob_text(&mod->init_layout, set_memory_ro);
1954 frob_rodata(&mod->init_layout, set_memory_ro);
1957 frob_ro_after_init(&mod->core_layout, set_memory_ro);
1960 static void module_enable_nx(const struct module *mod)
1962 frob_rodata(&mod->core_layout, set_memory_nx);
1963 frob_ro_after_init(&mod->core_layout, set_memory_nx);
1964 frob_writable_data(&mod->core_layout, set_memory_nx);
1965 frob_rodata(&mod->init_layout, set_memory_nx);
1966 frob_writable_data(&mod->init_layout, set_memory_nx);
1969 static void module_disable_nx(const struct module *mod)
1971 frob_rodata(&mod->core_layout, set_memory_x);
1972 frob_ro_after_init(&mod->core_layout, set_memory_x);
1973 frob_writable_data(&mod->core_layout, set_memory_x);
1974 frob_rodata(&mod->init_layout, set_memory_x);
1975 frob_writable_data(&mod->init_layout, set_memory_x);
1978 /* Iterate through all modules and set each module's text as RW */
1979 void set_all_modules_text_rw(void)
1983 if (!rodata_enabled)
1986 mutex_lock(&module_mutex);
1987 list_for_each_entry_rcu(mod, &modules, list) {
1988 if (mod->state == MODULE_STATE_UNFORMED)
1991 frob_text(&mod->core_layout, set_memory_rw);
1992 frob_text(&mod->init_layout, set_memory_rw);
1994 mutex_unlock(&module_mutex);
1997 /* Iterate through all modules and set each module's text as RO */
1998 void set_all_modules_text_ro(void)
2002 if (!rodata_enabled)
2005 mutex_lock(&module_mutex);
2006 list_for_each_entry_rcu(mod, &modules, list) {
2008 * Ignore going modules since it's possible that ro
2009 * protection has already been disabled, otherwise we'll
2010 * run into protection faults at module deallocation.
2012 if (mod->state == MODULE_STATE_UNFORMED ||
2013 mod->state == MODULE_STATE_GOING)
2016 frob_text(&mod->core_layout, set_memory_ro);
2017 frob_text(&mod->init_layout, set_memory_ro);
2019 mutex_unlock(&module_mutex);
2022 static void disable_ro_nx(const struct module_layout *layout)
2024 if (rodata_enabled) {
2025 frob_text(layout, set_memory_rw);
2026 frob_rodata(layout, set_memory_rw);
2027 frob_ro_after_init(layout, set_memory_rw);
2029 frob_rodata(layout, set_memory_x);
2030 frob_ro_after_init(layout, set_memory_x);
2031 frob_writable_data(layout, set_memory_x);
2035 static void disable_ro_nx(const struct module_layout *layout) { }
2036 static void module_enable_nx(const struct module *mod) { }
2037 static void module_disable_nx(const struct module *mod) { }
2040 #ifdef CONFIG_LIVEPATCH
2042 * Persist Elf information about a module. Copy the Elf header,
2043 * section header table, section string table, and symtab section
2044 * index from info to mod->klp_info.
2046 static int copy_module_elf(struct module *mod, struct load_info *info)
2048 unsigned int size, symndx;
2051 size = sizeof(*mod->klp_info);
2052 mod->klp_info = kmalloc(size, GFP_KERNEL);
2053 if (mod->klp_info == NULL)
2057 size = sizeof(mod->klp_info->hdr);
2058 memcpy(&mod->klp_info->hdr, info->hdr, size);
2060 /* Elf section header table */
2061 size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
2062 mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL);
2063 if (mod->klp_info->sechdrs == NULL) {
2068 /* Elf section name string table */
2069 size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
2070 mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL);
2071 if (mod->klp_info->secstrings == NULL) {
2076 /* Elf symbol section index */
2077 symndx = info->index.sym;
2078 mod->klp_info->symndx = symndx;
2081 * For livepatch modules, core_kallsyms.symtab is a complete
2082 * copy of the original symbol table. Adjust sh_addr to point
2083 * to core_kallsyms.symtab since the copy of the symtab in module
2084 * init memory is freed at the end of do_init_module().
2086 mod->klp_info->sechdrs[symndx].sh_addr = \
2087 (unsigned long) mod->core_kallsyms.symtab;
2092 kfree(mod->klp_info->sechdrs);
2094 kfree(mod->klp_info);
2098 static void free_module_elf(struct module *mod)
2100 kfree(mod->klp_info->sechdrs);
2101 kfree(mod->klp_info->secstrings);
2102 kfree(mod->klp_info);
2104 #else /* !CONFIG_LIVEPATCH */
2105 static int copy_module_elf(struct module *mod, struct load_info *info)
2110 static void free_module_elf(struct module *mod)
2113 #endif /* CONFIG_LIVEPATCH */
2115 void __weak module_memfree(void *module_region)
2117 vfree(module_region);
2120 void __weak module_arch_cleanup(struct module *mod)
2124 void __weak module_arch_freeing_init(struct module *mod)
2128 /* Free a module, remove from lists, etc. */
2129 static void free_module(struct module *mod)
2131 trace_module_free(mod);
2133 mod_sysfs_teardown(mod);
2135 /* We leave it in list to prevent duplicate loads, but make sure
2136 * that noone uses it while it's being deconstructed. */
2137 mutex_lock(&module_mutex);
2138 mod->state = MODULE_STATE_UNFORMED;
2139 mutex_unlock(&module_mutex);
2141 /* Remove dynamic debug info */
2142 ddebug_remove_module(mod->name);
2144 /* Arch-specific cleanup. */
2145 module_arch_cleanup(mod);
2147 /* Module unload stuff */
2148 module_unload_free(mod);
2150 /* Free any allocated parameters. */
2151 destroy_params(mod->kp, mod->num_kp);
2153 if (is_livepatch_module(mod))
2154 free_module_elf(mod);
2156 /* Now we can delete it from the lists */
2157 mutex_lock(&module_mutex);
2158 /* Unlink carefully: kallsyms could be walking list. */
2159 list_del_rcu(&mod->list);
2160 mod_tree_remove(mod);
2161 /* Remove this module from bug list, this uses list_del_rcu */
2162 module_bug_cleanup(mod);
2163 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2164 synchronize_sched();
2165 mutex_unlock(&module_mutex);
2167 /* This may be empty, but that's OK */
2168 disable_ro_nx(&mod->init_layout);
2169 module_arch_freeing_init(mod);
2170 module_memfree(mod->init_layout.base);
2172 percpu_modfree(mod);
2174 /* Free lock-classes; relies on the preceding sync_rcu(). */
2175 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
2177 /* Finally, free the core (containing the module structure) */
2178 disable_ro_nx(&mod->core_layout);
2179 module_memfree(mod->core_layout.base);
2182 void *__symbol_get(const char *symbol)
2184 struct module *owner;
2185 const struct kernel_symbol *sym;
2188 sym = find_symbol(symbol, &owner, NULL, true, true);
2189 if (sym && strong_try_module_get(owner))
2193 return sym ? (void *)kernel_symbol_value(sym) : NULL;
2195 EXPORT_SYMBOL_GPL(__symbol_get);
2198 * Ensure that an exported symbol [global namespace] does not already exist
2199 * in the kernel or in some other module's exported symbol table.
2201 * You must hold the module_mutex.
2203 static int verify_export_symbols(struct module *mod)
2206 struct module *owner;
2207 const struct kernel_symbol *s;
2209 const struct kernel_symbol *sym;
2212 { mod->syms, mod->num_syms },
2213 { mod->gpl_syms, mod->num_gpl_syms },
2214 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2215 #ifdef CONFIG_UNUSED_SYMBOLS
2216 { mod->unused_syms, mod->num_unused_syms },
2217 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2221 for (i = 0; i < ARRAY_SIZE(arr); i++) {
2222 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2223 if (find_symbol(kernel_symbol_name(s), &owner, NULL,
2225 pr_err("%s: exports duplicate symbol %s"
2227 mod->name, kernel_symbol_name(s),
2228 module_name(owner));
2236 /* Change all symbols so that st_value encodes the pointer directly. */
2237 static int simplify_symbols(struct module *mod, const struct load_info *info)
2239 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2240 Elf_Sym *sym = (void *)symsec->sh_addr;
2241 unsigned long secbase;
2244 const struct kernel_symbol *ksym;
2246 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2247 const char *name = info->strtab + sym[i].st_name;
2249 switch (sym[i].st_shndx) {
2251 /* Ignore common symbols */
2252 if (!strncmp(name, "__gnu_lto", 9))
2255 /* We compiled with -fno-common. These are not
2256 supposed to happen. */
2257 pr_debug("Common symbol: %s\n", name);
2258 pr_warn("%s: please compile with -fno-common\n",
2264 /* Don't need to do anything */
2265 pr_debug("Absolute symbol: 0x%08lx\n",
2266 (long)sym[i].st_value);
2270 /* Livepatch symbols are resolved by livepatch */
2274 ksym = resolve_symbol_wait(mod, info, name);
2275 /* Ok if resolved. */
2276 if (ksym && !IS_ERR(ksym)) {
2277 sym[i].st_value = kernel_symbol_value(ksym);
2282 if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
2285 ret = PTR_ERR(ksym) ?: -ENOENT;
2286 pr_warn("%s: Unknown symbol %s (err %d)\n",
2287 mod->name, name, ret);
2291 /* Divert to percpu allocation if a percpu var. */
2292 if (sym[i].st_shndx == info->index.pcpu)
2293 secbase = (unsigned long)mod_percpu(mod);
2295 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2296 sym[i].st_value += secbase;
2304 static int apply_relocations(struct module *mod, const struct load_info *info)
2309 /* Now do relocations. */
2310 for (i = 1; i < info->hdr->e_shnum; i++) {
2311 unsigned int infosec = info->sechdrs[i].sh_info;
2313 /* Not a valid relocation section? */
2314 if (infosec >= info->hdr->e_shnum)
2317 /* Don't bother with non-allocated sections */
2318 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2321 /* Livepatch relocation sections are applied by livepatch */
2322 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
2325 if (info->sechdrs[i].sh_type == SHT_REL)
2326 err = apply_relocate(info->sechdrs, info->strtab,
2327 info->index.sym, i, mod);
2328 else if (info->sechdrs[i].sh_type == SHT_RELA)
2329 err = apply_relocate_add(info->sechdrs, info->strtab,
2330 info->index.sym, i, mod);
2337 /* Additional bytes needed by arch in front of individual sections */
2338 unsigned int __weak arch_mod_section_prepend(struct module *mod,
2339 unsigned int section)
2341 /* default implementation just returns zero */
2345 /* Update size with this section: return offset. */
2346 static long get_offset(struct module *mod, unsigned int *size,
2347 Elf_Shdr *sechdr, unsigned int section)
2351 *size += arch_mod_section_prepend(mod, section);
2352 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2353 *size = ret + sechdr->sh_size;
2357 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2358 might -- code, read-only data, read-write data, small data. Tally
2359 sizes, and place the offsets into sh_entsize fields: high bit means it
2361 static void layout_sections(struct module *mod, struct load_info *info)
2363 static unsigned long const masks[][2] = {
2364 /* NOTE: all executable code must be the first section
2365 * in this array; otherwise modify the text_size
2366 * finder in the two loops below */
2367 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2368 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2369 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
2370 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2371 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2375 for (i = 0; i < info->hdr->e_shnum; i++)
2376 info->sechdrs[i].sh_entsize = ~0UL;
2378 pr_debug("Core section allocation order:\n");
2379 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2380 for (i = 0; i < info->hdr->e_shnum; ++i) {
2381 Elf_Shdr *s = &info->sechdrs[i];
2382 const char *sname = info->secstrings + s->sh_name;
2384 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2385 || (s->sh_flags & masks[m][1])
2386 || s->sh_entsize != ~0UL
2387 || strstarts(sname, ".init"))
2389 s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2390 pr_debug("\t%s\n", sname);
2393 case 0: /* executable */
2394 mod->core_layout.size = debug_align(mod->core_layout.size);
2395 mod->core_layout.text_size = mod->core_layout.size;
2397 case 1: /* RO: text and ro-data */
2398 mod->core_layout.size = debug_align(mod->core_layout.size);
2399 mod->core_layout.ro_size = mod->core_layout.size;
2401 case 2: /* RO after init */
2402 mod->core_layout.size = debug_align(mod->core_layout.size);
2403 mod->core_layout.ro_after_init_size = mod->core_layout.size;
2405 case 4: /* whole core */
2406 mod->core_layout.size = debug_align(mod->core_layout.size);
2411 pr_debug("Init section allocation order:\n");
2412 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2413 for (i = 0; i < info->hdr->e_shnum; ++i) {
2414 Elf_Shdr *s = &info->sechdrs[i];
2415 const char *sname = info->secstrings + s->sh_name;
2417 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2418 || (s->sh_flags & masks[m][1])
2419 || s->sh_entsize != ~0UL
2420 || !strstarts(sname, ".init"))
2422 s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
2423 | INIT_OFFSET_MASK);
2424 pr_debug("\t%s\n", sname);
2427 case 0: /* executable */
2428 mod->init_layout.size = debug_align(mod->init_layout.size);
2429 mod->init_layout.text_size = mod->init_layout.size;
2431 case 1: /* RO: text and ro-data */
2432 mod->init_layout.size = debug_align(mod->init_layout.size);
2433 mod->init_layout.ro_size = mod->init_layout.size;
2437 * RO after init doesn't apply to init_layout (only
2438 * core_layout), so it just takes the value of ro_size.
2440 mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
2442 case 4: /* whole init */
2443 mod->init_layout.size = debug_align(mod->init_layout.size);
2449 static void set_license(struct module *mod, const char *license)
2452 license = "unspecified";
2454 if (!license_is_gpl_compatible(license)) {
2455 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2456 pr_warn("%s: module license '%s' taints kernel.\n",
2457 mod->name, license);
2458 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2459 LOCKDEP_NOW_UNRELIABLE);
2463 /* Parse tag=value strings from .modinfo section */
2464 static char *next_string(char *string, unsigned long *secsize)
2466 /* Skip non-zero chars */
2469 if ((*secsize)-- <= 1)
2473 /* Skip any zero padding. */
2474 while (!string[0]) {
2476 if ((*secsize)-- <= 1)
2482 static char *get_modinfo(struct load_info *info, const char *tag)
2485 unsigned int taglen = strlen(tag);
2486 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2487 unsigned long size = infosec->sh_size;
2490 * get_modinfo() calls made before rewrite_section_headers()
2491 * must use sh_offset, as sh_addr isn't set!
2493 for (p = (char *)info->hdr + infosec->sh_offset; p; p = next_string(p, &size)) {
2494 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2495 return p + taglen + 1;
2500 static void setup_modinfo(struct module *mod, struct load_info *info)
2502 struct module_attribute *attr;
2505 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2507 attr->setup(mod, get_modinfo(info, attr->attr.name));
2511 static void free_modinfo(struct module *mod)
2513 struct module_attribute *attr;
2516 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2522 #ifdef CONFIG_KALLSYMS
2524 /* lookup symbol in given range of kernel_symbols */
2525 static const struct kernel_symbol *lookup_symbol(const char *name,
2526 const struct kernel_symbol *start,
2527 const struct kernel_symbol *stop)
2529 return bsearch(name, start, stop - start,
2530 sizeof(struct kernel_symbol), cmp_name);
2533 static int is_exported(const char *name, unsigned long value,
2534 const struct module *mod)
2536 const struct kernel_symbol *ks;
2538 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2540 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2541 return ks != NULL && kernel_symbol_value(ks) == value;
2545 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2547 const Elf_Shdr *sechdrs = info->sechdrs;
2549 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2550 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2555 if (sym->st_shndx == SHN_UNDEF)
2557 if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
2559 if (sym->st_shndx >= SHN_LORESERVE)
2561 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2563 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2564 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2565 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2567 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2572 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2573 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2578 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2585 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2586 unsigned int shnum, unsigned int pcpundx)
2588 const Elf_Shdr *sec;
2590 if (src->st_shndx == SHN_UNDEF
2591 || src->st_shndx >= shnum
2595 #ifdef CONFIG_KALLSYMS_ALL
2596 if (src->st_shndx == pcpundx)
2600 sec = sechdrs + src->st_shndx;
2601 if (!(sec->sh_flags & SHF_ALLOC)
2602 #ifndef CONFIG_KALLSYMS_ALL
2603 || !(sec->sh_flags & SHF_EXECINSTR)
2605 || (sec->sh_entsize & INIT_OFFSET_MASK))
2612 * We only allocate and copy the strings needed by the parts of symtab
2613 * we keep. This is simple, but has the effect of making multiple
2614 * copies of duplicates. We could be more sophisticated, see
2615 * linux-kernel thread starting with
2616 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2618 static void layout_symtab(struct module *mod, struct load_info *info)
2620 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2621 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2623 unsigned int i, nsrc, ndst, strtab_size = 0;
2625 /* Put symbol section at end of init part of module. */
2626 symsect->sh_flags |= SHF_ALLOC;
2627 symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2628 info->index.sym) | INIT_OFFSET_MASK;
2629 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2631 src = (void *)info->hdr + symsect->sh_offset;
2632 nsrc = symsect->sh_size / sizeof(*src);
2634 /* Compute total space required for the core symbols' strtab. */
2635 for (ndst = i = 0; i < nsrc; i++) {
2636 if (i == 0 || is_livepatch_module(mod) ||
2637 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2638 info->index.pcpu)) {
2639 strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2644 /* Append room for core symbols at end of core part. */
2645 info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
2646 info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
2647 mod->core_layout.size += strtab_size;
2648 mod->core_layout.size = debug_align(mod->core_layout.size);
2650 /* Put string table section at end of init part of module. */
2651 strsect->sh_flags |= SHF_ALLOC;
2652 strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2653 info->index.str) | INIT_OFFSET_MASK;
2654 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2656 /* We'll tack temporary mod_kallsyms on the end. */
2657 mod->init_layout.size = ALIGN(mod->init_layout.size,
2658 __alignof__(struct mod_kallsyms));
2659 info->mod_kallsyms_init_off = mod->init_layout.size;
2660 mod->init_layout.size += sizeof(struct mod_kallsyms);
2661 mod->init_layout.size = debug_align(mod->init_layout.size);
2665 * We use the full symtab and strtab which layout_symtab arranged to
2666 * be appended to the init section. Later we switch to the cut-down
2669 static void add_kallsyms(struct module *mod, const struct load_info *info)
2671 unsigned int i, ndst;
2675 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2677 /* Set up to point into init section. */
2678 mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
2680 mod->kallsyms->symtab = (void *)symsec->sh_addr;
2681 mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2682 /* Make sure we get permanent strtab: don't use info->strtab. */
2683 mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2685 /* Set types up while we still have access to sections. */
2686 for (i = 0; i < mod->kallsyms->num_symtab; i++)
2687 mod->kallsyms->symtab[i].st_info
2688 = elf_type(&mod->kallsyms->symtab[i], info);
2690 /* Now populate the cut down core kallsyms for after init. */
2691 mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
2692 mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
2693 src = mod->kallsyms->symtab;
2694 for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2695 if (i == 0 || is_livepatch_module(mod) ||
2696 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2697 info->index.pcpu)) {
2699 dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
2700 s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2704 mod->core_kallsyms.num_symtab = ndst;
2707 static inline void layout_symtab(struct module *mod, struct load_info *info)
2711 static void add_kallsyms(struct module *mod, const struct load_info *info)
2714 #endif /* CONFIG_KALLSYMS */
2716 static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num)
2720 #ifdef CONFIG_DYNAMIC_DEBUG
2721 if (ddebug_add_module(debug, num, mod->name))
2722 pr_err("dynamic debug error adding module: %s\n",
2727 static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug)
2730 ddebug_remove_module(mod->name);
2733 void * __weak module_alloc(unsigned long size)
2735 return vmalloc_exec(size);
2738 #ifdef CONFIG_DEBUG_KMEMLEAK
2739 static void kmemleak_load_module(const struct module *mod,
2740 const struct load_info *info)
2744 /* only scan the sections containing data */
2745 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2747 for (i = 1; i < info->hdr->e_shnum; i++) {
2748 /* Scan all writable sections that's not executable */
2749 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2750 !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2751 (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2754 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2755 info->sechdrs[i].sh_size, GFP_KERNEL);
2759 static inline void kmemleak_load_module(const struct module *mod,
2760 const struct load_info *info)
2765 #ifdef CONFIG_MODULE_SIG
2766 static int module_sig_check(struct load_info *info, int flags)
2769 const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2770 const void *mod = info->hdr;
2773 * Require flags == 0, as a module with version information
2774 * removed is no longer the module that was signed
2777 info->len > markerlen &&
2778 memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2779 /* We truncate the module to discard the signature */
2780 info->len -= markerlen;
2781 err = mod_verify_sig(mod, info);
2785 info->sig_ok = true;
2789 /* Not having a signature is only an error if we're strict. */
2790 if (err == -ENOKEY && !is_module_sig_enforced())
2795 #else /* !CONFIG_MODULE_SIG */
2796 static int module_sig_check(struct load_info *info, int flags)
2800 #endif /* !CONFIG_MODULE_SIG */
2802 /* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2803 static int elf_header_check(struct load_info *info)
2805 if (info->len < sizeof(*(info->hdr)))
2808 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2809 || info->hdr->e_type != ET_REL
2810 || !elf_check_arch(info->hdr)
2811 || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2814 if (info->hdr->e_shoff >= info->len
2815 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2816 info->len - info->hdr->e_shoff))
2822 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2824 static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
2827 unsigned long n = min(len, COPY_CHUNK_SIZE);
2829 if (copy_from_user(dst, usrc, n) != 0)
2839 #ifdef CONFIG_LIVEPATCH
2840 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2842 if (get_modinfo(info, "livepatch")) {
2844 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
2845 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
2851 #else /* !CONFIG_LIVEPATCH */
2852 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2854 if (get_modinfo(info, "livepatch")) {
2855 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
2862 #endif /* CONFIG_LIVEPATCH */
2864 static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
2866 if (retpoline_module_ok(get_modinfo(info, "retpoline")))
2869 pr_warn("%s: loading module not compiled with retpoline compiler.\n",
2873 /* Sets info->hdr and info->len. */
2874 static int copy_module_from_user(const void __user *umod, unsigned long len,
2875 struct load_info *info)
2880 if (info->len < sizeof(*(info->hdr)))
2883 err = security_kernel_load_data(LOADING_MODULE);
2887 /* Suck in entire file: we'll want most of it. */
2888 info->hdr = __vmalloc(info->len,
2889 GFP_KERNEL | __GFP_NOWARN, PAGE_KERNEL);
2893 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2901 static void free_copy(struct load_info *info)
2906 static int rewrite_section_headers(struct load_info *info, int flags)
2910 /* This should always be true, but let's be sure. */
2911 info->sechdrs[0].sh_addr = 0;
2913 for (i = 1; i < info->hdr->e_shnum; i++) {
2914 Elf_Shdr *shdr = &info->sechdrs[i];
2915 if (shdr->sh_type != SHT_NOBITS
2916 && info->len < shdr->sh_offset + shdr->sh_size) {
2917 pr_err("Module len %lu truncated\n", info->len);
2921 /* Mark all sections sh_addr with their address in the
2923 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2925 #ifndef CONFIG_MODULE_UNLOAD
2926 /* Don't load .exit sections */
2927 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2928 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2932 /* Track but don't keep modinfo and version sections. */
2933 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2934 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2940 * Set up our basic convenience variables (pointers to section headers,
2941 * search for module section index etc), and do some basic section
2944 * Set info->mod to the temporary copy of the module in info->hdr. The final one
2945 * will be allocated in move_module().
2947 static int setup_load_info(struct load_info *info, int flags)
2951 /* Set up the convenience variables */
2952 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2953 info->secstrings = (void *)info->hdr
2954 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2956 /* Try to find a name early so we can log errors with a module name */
2957 info->index.info = find_sec(info, ".modinfo");
2958 if (!info->index.info)
2959 info->name = "(missing .modinfo section)";
2961 info->name = get_modinfo(info, "name");
2963 /* Find internal symbols and strings. */
2964 for (i = 1; i < info->hdr->e_shnum; i++) {
2965 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2966 info->index.sym = i;
2967 info->index.str = info->sechdrs[i].sh_link;
2968 info->strtab = (char *)info->hdr
2969 + info->sechdrs[info->index.str].sh_offset;
2974 if (info->index.sym == 0) {
2975 pr_warn("%s: module has no symbols (stripped?)\n", info->name);
2979 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2980 if (!info->index.mod) {
2981 pr_warn("%s: No module found in object\n",
2982 info->name ?: "(missing .modinfo name field)");
2985 /* This is temporary: point mod into copy of data. */
2986 info->mod = (void *)info->hdr + info->sechdrs[info->index.mod].sh_offset;
2989 * If we didn't load the .modinfo 'name' field earlier, fall back to
2990 * on-disk struct mod 'name' field.
2993 info->name = info->mod->name;
2995 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
2996 info->index.vers = 0; /* Pretend no __versions section! */
2998 info->index.vers = find_sec(info, "__versions");
3000 info->index.pcpu = find_pcpusec(info);
3005 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
3007 const char *modmagic = get_modinfo(info, "vermagic");
3010 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
3013 /* This is allowed: modprobe --force will invalidate it. */
3015 err = try_to_force_load(mod, "bad vermagic");
3018 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
3019 pr_err("%s: version magic '%s' should be '%s'\n",
3020 info->name, modmagic, vermagic);
3024 if (!get_modinfo(info, "intree")) {
3025 if (!test_taint(TAINT_OOT_MODULE))
3026 pr_warn("%s: loading out-of-tree module taints kernel.\n",
3028 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
3031 check_modinfo_retpoline(mod, info);
3033 if (get_modinfo(info, "staging")) {
3034 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
3035 pr_warn("%s: module is from the staging directory, the quality "
3036 "is unknown, you have been warned.\n", mod->name);
3039 err = check_modinfo_livepatch(mod, info);
3043 /* Set up license info based on the info section */
3044 set_license(mod, get_modinfo(info, "license"));
3049 static int find_module_sections(struct module *mod, struct load_info *info)
3051 mod->kp = section_objs(info, "__param",
3052 sizeof(*mod->kp), &mod->num_kp);
3053 mod->syms = section_objs(info, "__ksymtab",
3054 sizeof(*mod->syms), &mod->num_syms);
3055 mod->crcs = section_addr(info, "__kcrctab");
3056 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
3057 sizeof(*mod->gpl_syms),
3058 &mod->num_gpl_syms);
3059 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
3060 mod->gpl_future_syms = section_objs(info,
3061 "__ksymtab_gpl_future",
3062 sizeof(*mod->gpl_future_syms),
3063 &mod->num_gpl_future_syms);
3064 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
3066 #ifdef CONFIG_UNUSED_SYMBOLS
3067 mod->unused_syms = section_objs(info, "__ksymtab_unused",
3068 sizeof(*mod->unused_syms),
3069 &mod->num_unused_syms);
3070 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
3071 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
3072 sizeof(*mod->unused_gpl_syms),
3073 &mod->num_unused_gpl_syms);
3074 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
3076 #ifdef CONFIG_CONSTRUCTORS
3077 mod->ctors = section_objs(info, ".ctors",
3078 sizeof(*mod->ctors), &mod->num_ctors);
3080 mod->ctors = section_objs(info, ".init_array",
3081 sizeof(*mod->ctors), &mod->num_ctors);
3082 else if (find_sec(info, ".init_array")) {
3084 * This shouldn't happen with same compiler and binutils
3085 * building all parts of the module.
3087 pr_warn("%s: has both .ctors and .init_array.\n",
3093 #ifdef CONFIG_TRACEPOINTS
3094 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
3095 sizeof(*mod->tracepoints_ptrs),
3096 &mod->num_tracepoints);
3098 #ifdef HAVE_JUMP_LABEL
3099 mod->jump_entries = section_objs(info, "__jump_table",
3100 sizeof(*mod->jump_entries),
3101 &mod->num_jump_entries);
3103 #ifdef CONFIG_EVENT_TRACING
3104 mod->trace_events = section_objs(info, "_ftrace_events",
3105 sizeof(*mod->trace_events),
3106 &mod->num_trace_events);
3107 mod->trace_evals = section_objs(info, "_ftrace_eval_map",
3108 sizeof(*mod->trace_evals),
3109 &mod->num_trace_evals);
3111 #ifdef CONFIG_TRACING
3112 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
3113 sizeof(*mod->trace_bprintk_fmt_start),
3114 &mod->num_trace_bprintk_fmt);
3116 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
3117 /* sechdrs[0].sh_size is always zero */
3118 mod->ftrace_callsites = section_objs(info, "__mcount_loc",
3119 sizeof(*mod->ftrace_callsites),
3120 &mod->num_ftrace_callsites);
3122 #ifdef CONFIG_FUNCTION_ERROR_INJECTION
3123 mod->ei_funcs = section_objs(info, "_error_injection_whitelist",
3124 sizeof(*mod->ei_funcs),
3125 &mod->num_ei_funcs);
3127 mod->extable = section_objs(info, "__ex_table",
3128 sizeof(*mod->extable), &mod->num_exentries);
3130 if (section_addr(info, "__obsparm"))
3131 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
3133 info->debug = section_objs(info, "__verbose",
3134 sizeof(*info->debug), &info->num_debug);
3139 static int move_module(struct module *mod, struct load_info *info)
3144 /* Do the allocs. */
3145 ptr = module_alloc(mod->core_layout.size);
3147 * The pointer to this block is stored in the module structure
3148 * which is inside the block. Just mark it as not being a
3151 kmemleak_not_leak(ptr);
3155 memset(ptr, 0, mod->core_layout.size);
3156 mod->core_layout.base = ptr;
3158 if (mod->init_layout.size) {
3159 ptr = module_alloc(mod->init_layout.size);
3161 * The pointer to this block is stored in the module structure
3162 * which is inside the block. This block doesn't need to be
3163 * scanned as it contains data and code that will be freed
3164 * after the module is initialized.
3166 kmemleak_ignore(ptr);
3168 module_memfree(mod->core_layout.base);
3171 memset(ptr, 0, mod->init_layout.size);
3172 mod->init_layout.base = ptr;
3174 mod->init_layout.base = NULL;
3176 /* Transfer each section which specifies SHF_ALLOC */
3177 pr_debug("final section addresses:\n");
3178 for (i = 0; i < info->hdr->e_shnum; i++) {
3180 Elf_Shdr *shdr = &info->sechdrs[i];
3182 if (!(shdr->sh_flags & SHF_ALLOC))
3185 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3186 dest = mod->init_layout.base
3187 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3189 dest = mod->core_layout.base + shdr->sh_entsize;
3191 if (shdr->sh_type != SHT_NOBITS)
3192 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3193 /* Update sh_addr to point to copy in image. */
3194 shdr->sh_addr = (unsigned long)dest;
3195 pr_debug("\t0x%lx %s\n",
3196 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3202 static int check_module_license_and_versions(struct module *mod)
3204 int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
3207 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3208 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3209 * using GPL-only symbols it needs.
3211 if (strcmp(mod->name, "ndiswrapper") == 0)
3212 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3214 /* driverloader was caught wrongly pretending to be under GPL */
3215 if (strcmp(mod->name, "driverloader") == 0)
3216 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3217 LOCKDEP_NOW_UNRELIABLE);
3219 /* lve claims to be GPL but upstream won't provide source */
3220 if (strcmp(mod->name, "lve") == 0)
3221 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3222 LOCKDEP_NOW_UNRELIABLE);
3224 if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
3225 pr_warn("%s: module license taints kernel.\n", mod->name);
3227 #ifdef CONFIG_MODVERSIONS
3228 if ((mod->num_syms && !mod->crcs)
3229 || (mod->num_gpl_syms && !mod->gpl_crcs)
3230 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3231 #ifdef CONFIG_UNUSED_SYMBOLS
3232 || (mod->num_unused_syms && !mod->unused_crcs)
3233 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3236 return try_to_force_load(mod,
3237 "no versions for exported symbols");
3243 static void flush_module_icache(const struct module *mod)
3245 mm_segment_t old_fs;
3247 /* flush the icache in correct context */
3252 * Flush the instruction cache, since we've played with text.
3253 * Do it before processing of module parameters, so the module
3254 * can provide parameter accessor functions of its own.
3256 if (mod->init_layout.base)
3257 flush_icache_range((unsigned long)mod->init_layout.base,
3258 (unsigned long)mod->init_layout.base
3259 + mod->init_layout.size);
3260 flush_icache_range((unsigned long)mod->core_layout.base,
3261 (unsigned long)mod->core_layout.base + mod->core_layout.size);
3266 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3274 /* module_blacklist is a comma-separated list of module names */
3275 static char *module_blacklist;
3276 static bool blacklisted(const char *module_name)
3281 if (!module_blacklist)
3284 for (p = module_blacklist; *p; p += len) {
3285 len = strcspn(p, ",");
3286 if (strlen(module_name) == len && !memcmp(module_name, p, len))
3293 core_param(module_blacklist, module_blacklist, charp, 0400);
3295 static struct module *layout_and_allocate(struct load_info *info, int flags)
3301 err = check_modinfo(info->mod, info, flags);
3303 return ERR_PTR(err);
3305 /* Allow arches to frob section contents and sizes. */
3306 err = module_frob_arch_sections(info->hdr, info->sechdrs,
3307 info->secstrings, info->mod);
3309 return ERR_PTR(err);
3311 /* We will do a special allocation for per-cpu sections later. */
3312 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3315 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3316 * layout_sections() can put it in the right place.
3317 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3319 ndx = find_sec(info, ".data..ro_after_init");
3321 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3323 /* Determine total sizes, and put offsets in sh_entsize. For now
3324 this is done generically; there doesn't appear to be any
3325 special cases for the architectures. */
3326 layout_sections(info->mod, info);
3327 layout_symtab(info->mod, info);
3329 /* Allocate and move to the final place */
3330 err = move_module(info->mod, info);
3332 return ERR_PTR(err);
3334 /* Module has been copied to its final place now: return it. */
3335 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3336 kmemleak_load_module(mod, info);
3340 /* mod is no longer valid after this! */
3341 static void module_deallocate(struct module *mod, struct load_info *info)
3343 percpu_modfree(mod);
3344 module_arch_freeing_init(mod);
3345 module_memfree(mod->init_layout.base);
3346 module_memfree(mod->core_layout.base);
3349 int __weak module_finalize(const Elf_Ehdr *hdr,
3350 const Elf_Shdr *sechdrs,
3356 static int post_relocation(struct module *mod, const struct load_info *info)
3358 /* Sort exception table now relocations are done. */
3359 sort_extable(mod->extable, mod->extable + mod->num_exentries);
3361 /* Copy relocated percpu area over. */
3362 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3363 info->sechdrs[info->index.pcpu].sh_size);
3365 /* Setup kallsyms-specific fields. */
3366 add_kallsyms(mod, info);
3368 /* Arch-specific module finalizing. */
3369 return module_finalize(info->hdr, info->sechdrs, mod);
3372 /* Is this module of this name done loading? No locks held. */
3373 static bool finished_loading(const char *name)
3379 * The module_mutex should not be a heavily contended lock;
3380 * if we get the occasional sleep here, we'll go an extra iteration
3381 * in the wait_event_interruptible(), which is harmless.
3383 sched_annotate_sleep();
3384 mutex_lock(&module_mutex);
3385 mod = find_module_all(name, strlen(name), true);
3386 ret = !mod || mod->state == MODULE_STATE_LIVE
3387 || mod->state == MODULE_STATE_GOING;
3388 mutex_unlock(&module_mutex);
3393 /* Call module constructors. */
3394 static void do_mod_ctors(struct module *mod)
3396 #ifdef CONFIG_CONSTRUCTORS
3399 for (i = 0; i < mod->num_ctors; i++)
3404 /* For freeing module_init on success, in case kallsyms traversing */
3405 struct mod_initfree {
3406 struct rcu_head rcu;
3410 static void do_free_init(struct rcu_head *head)
3412 struct mod_initfree *m = container_of(head, struct mod_initfree, rcu);
3413 module_memfree(m->module_init);
3418 * This is where the real work happens.
3420 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3421 * helper command 'lx-symbols'.
3423 static noinline int do_init_module(struct module *mod)
3426 struct mod_initfree *freeinit;
3428 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3433 freeinit->module_init = mod->init_layout.base;
3436 * We want to find out whether @mod uses async during init. Clear
3437 * PF_USED_ASYNC. async_schedule*() will set it.
3439 current->flags &= ~PF_USED_ASYNC;
3442 /* Start the module */
3443 if (mod->init != NULL)
3444 ret = do_one_initcall(mod->init);
3446 goto fail_free_freeinit;
3449 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3450 "follow 0/-E convention\n"
3451 "%s: loading module anyway...\n",
3452 __func__, mod->name, ret, __func__);
3456 /* Now it's a first class citizen! */
3457 mod->state = MODULE_STATE_LIVE;
3458 blocking_notifier_call_chain(&module_notify_list,
3459 MODULE_STATE_LIVE, mod);
3462 * We need to finish all async code before the module init sequence
3463 * is done. This has potential to deadlock. For example, a newly
3464 * detected block device can trigger request_module() of the
3465 * default iosched from async probing task. Once userland helper
3466 * reaches here, async_synchronize_full() will wait on the async
3467 * task waiting on request_module() and deadlock.
3469 * This deadlock is avoided by perfomring async_synchronize_full()
3470 * iff module init queued any async jobs. This isn't a full
3471 * solution as it will deadlock the same if module loading from
3472 * async jobs nests more than once; however, due to the various
3473 * constraints, this hack seems to be the best option for now.
3474 * Please refer to the following thread for details.
3476 * http://thread.gmane.org/gmane.linux.kernel/1420814
3478 if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3479 async_synchronize_full();
3481 ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base +
3482 mod->init_layout.size);
3483 mutex_lock(&module_mutex);
3484 /* Drop initial reference. */
3486 trim_init_extable(mod);
3487 #ifdef CONFIG_KALLSYMS
3488 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3489 rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3491 module_enable_ro(mod, true);
3492 mod_tree_remove_init(mod);
3493 disable_ro_nx(&mod->init_layout);
3494 module_arch_freeing_init(mod);
3495 mod->init_layout.base = NULL;
3496 mod->init_layout.size = 0;
3497 mod->init_layout.ro_size = 0;
3498 mod->init_layout.ro_after_init_size = 0;
3499 mod->init_layout.text_size = 0;
3501 * We want to free module_init, but be aware that kallsyms may be
3502 * walking this with preempt disabled. In all the failure paths, we
3503 * call synchronize_sched(), but we don't want to slow down the success
3504 * path, so use actual RCU here.
3505 * Note that module_alloc() on most architectures creates W+X page
3506 * mappings which won't be cleaned up until do_free_init() runs. Any
3507 * code such as mark_rodata_ro() which depends on those mappings to
3508 * be cleaned up needs to sync with the queued work - ie
3509 * rcu_barrier_sched()
3511 call_rcu_sched(&freeinit->rcu, do_free_init);
3512 mutex_unlock(&module_mutex);
3513 wake_up_all(&module_wq);
3520 /* Try to protect us from buggy refcounters. */
3521 mod->state = MODULE_STATE_GOING;
3522 synchronize_sched();
3524 blocking_notifier_call_chain(&module_notify_list,
3525 MODULE_STATE_GOING, mod);
3526 klp_module_going(mod);
3527 ftrace_release_mod(mod);
3529 wake_up_all(&module_wq);
3533 static int may_init_module(void)
3535 if (!capable(CAP_SYS_MODULE) || modules_disabled)
3542 * We try to place it in the list now to make sure it's unique before
3543 * we dedicate too many resources. In particular, temporary percpu
3544 * memory exhaustion.
3546 static int add_unformed_module(struct module *mod)
3551 mod->state = MODULE_STATE_UNFORMED;
3554 mutex_lock(&module_mutex);
3555 old = find_module_all(mod->name, strlen(mod->name), true);
3557 if (old->state == MODULE_STATE_COMING
3558 || old->state == MODULE_STATE_UNFORMED) {
3559 /* Wait in case it fails to load. */
3560 mutex_unlock(&module_mutex);
3561 err = wait_event_interruptible(module_wq,
3562 finished_loading(mod->name));
3570 mod_update_bounds(mod);
3571 list_add_rcu(&mod->list, &modules);
3572 mod_tree_insert(mod);
3576 mutex_unlock(&module_mutex);
3581 static int complete_formation(struct module *mod, struct load_info *info)
3585 mutex_lock(&module_mutex);
3587 /* Find duplicate symbols (must be called under lock). */
3588 err = verify_export_symbols(mod);
3592 /* This relies on module_mutex for list integrity. */
3593 module_bug_finalize(info->hdr, info->sechdrs, mod);
3595 module_enable_ro(mod, false);
3596 module_enable_nx(mod);
3598 /* Mark state as coming so strong_try_module_get() ignores us,
3599 * but kallsyms etc. can see us. */
3600 mod->state = MODULE_STATE_COMING;
3601 mutex_unlock(&module_mutex);
3606 mutex_unlock(&module_mutex);
3610 static int prepare_coming_module(struct module *mod)
3614 ftrace_module_enable(mod);
3615 err = klp_module_coming(mod);
3619 blocking_notifier_call_chain(&module_notify_list,
3620 MODULE_STATE_COMING, mod);
3624 static int unknown_module_param_cb(char *param, char *val, const char *modname,
3627 struct module *mod = arg;
3630 if (strcmp(param, "async_probe") == 0) {
3631 mod->async_probe_requested = true;
3635 /* Check for magic 'dyndbg' arg */
3636 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3638 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3642 /* Allocate and load the module: note that size of section 0 is always
3643 zero, and we rely on this for optional sections. */
3644 static int load_module(struct load_info *info, const char __user *uargs,
3651 err = elf_header_check(info);
3655 err = setup_load_info(info, flags);
3659 if (blacklisted(info->name)) {
3664 err = module_sig_check(info, flags);
3668 err = rewrite_section_headers(info, flags);
3672 /* Check module struct version now, before we try to use module. */
3673 if (!check_modstruct_version(info, info->mod)) {
3678 /* Figure out module layout, and allocate all the memory. */
3679 mod = layout_and_allocate(info, flags);
3685 audit_log_kern_module(mod->name);
3687 /* Reserve our place in the list. */
3688 err = add_unformed_module(mod);
3692 #ifdef CONFIG_MODULE_SIG
3693 mod->sig_ok = info->sig_ok;
3695 pr_notice_once("%s: module verification failed: signature "
3696 "and/or required key missing - tainting "
3697 "kernel\n", mod->name);
3698 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3702 /* To avoid stressing percpu allocator, do this once we're unique. */
3703 err = percpu_modalloc(mod, info);
3707 /* Now module is in final location, initialize linked lists, etc. */
3708 err = module_unload_init(mod);
3712 init_param_lock(mod);
3714 /* Now we've got everything in the final locations, we can
3715 * find optional sections. */
3716 err = find_module_sections(mod, info);
3720 err = check_module_license_and_versions(mod);
3724 /* Set up MODINFO_ATTR fields */
3725 setup_modinfo(mod, info);
3727 /* Fix up syms, so that st_value is a pointer to location. */
3728 err = simplify_symbols(mod, info);
3732 err = apply_relocations(mod, info);
3736 err = post_relocation(mod, info);
3740 flush_module_icache(mod);
3742 /* Now copy in args */
3743 mod->args = strndup_user(uargs, ~0UL >> 1);
3744 if (IS_ERR(mod->args)) {
3745 err = PTR_ERR(mod->args);
3746 goto free_arch_cleanup;
3749 dynamic_debug_setup(mod, info->debug, info->num_debug);
3751 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3752 ftrace_module_init(mod);
3754 /* Finally it's fully formed, ready to start executing. */
3755 err = complete_formation(mod, info);
3757 goto ddebug_cleanup;
3759 err = prepare_coming_module(mod);
3763 /* Module is ready to execute: parsing args may do that. */
3764 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3766 unknown_module_param_cb);
3767 if (IS_ERR(after_dashes)) {
3768 err = PTR_ERR(after_dashes);
3769 goto coming_cleanup;
3770 } else if (after_dashes) {
3771 pr_warn("%s: parameters '%s' after `--' ignored\n",
3772 mod->name, after_dashes);
3775 /* Link in to sysfs. */
3776 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3778 goto coming_cleanup;
3780 if (is_livepatch_module(mod)) {
3781 err = copy_module_elf(mod, info);
3786 /* Get rid of temporary copy. */
3790 trace_module_load(mod);
3792 return do_init_module(mod);
3795 mod_sysfs_teardown(mod);
3797 mod->state = MODULE_STATE_GOING;
3798 destroy_params(mod->kp, mod->num_kp);
3799 blocking_notifier_call_chain(&module_notify_list,
3800 MODULE_STATE_GOING, mod);
3801 klp_module_going(mod);
3803 /* module_bug_cleanup needs module_mutex protection */
3804 mutex_lock(&module_mutex);
3805 module_bug_cleanup(mod);
3806 mutex_unlock(&module_mutex);
3808 /* we can't deallocate the module until we clear memory protection */
3809 module_disable_ro(mod);
3810 module_disable_nx(mod);
3813 ftrace_release_mod(mod);
3814 dynamic_debug_remove(mod, info->debug);
3815 synchronize_sched();
3818 module_arch_cleanup(mod);
3822 module_unload_free(mod);
3824 mutex_lock(&module_mutex);
3825 /* Unlink carefully: kallsyms could be walking list. */
3826 list_del_rcu(&mod->list);
3827 mod_tree_remove(mod);
3828 wake_up_all(&module_wq);
3829 /* Wait for RCU-sched synchronizing before releasing mod->list. */
3830 synchronize_sched();
3831 mutex_unlock(&module_mutex);
3833 /* Free lock-classes; relies on the preceding sync_rcu() */
3834 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
3836 module_deallocate(mod, info);
3842 SYSCALL_DEFINE3(init_module, void __user *, umod,
3843 unsigned long, len, const char __user *, uargs)
3846 struct load_info info = { };
3848 err = may_init_module();
3852 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3855 err = copy_module_from_user(umod, len, &info);
3859 return load_module(&info, uargs, 0);
3862 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3864 struct load_info info = { };
3869 err = may_init_module();
3873 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3875 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3876 |MODULE_INIT_IGNORE_VERMAGIC))
3879 err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX,
3886 return load_module(&info, uargs, flags);
3889 static inline int within(unsigned long addr, void *start, unsigned long size)
3891 return ((void *)addr >= start && (void *)addr < start + size);
3894 #ifdef CONFIG_KALLSYMS
3896 * This ignores the intensely annoying "mapping symbols" found
3897 * in ARM ELF files: $a, $t and $d.
3899 static inline int is_arm_mapping_symbol(const char *str)
3901 if (str[0] == '.' && str[1] == 'L')
3903 return str[0] == '$' && strchr("axtd", str[1])
3904 && (str[2] == '\0' || str[2] == '.');
3907 static const char *symname(struct mod_kallsyms *kallsyms, unsigned int symnum)
3909 return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
3912 static const char *get_ksymbol(struct module *mod,
3914 unsigned long *size,
3915 unsigned long *offset)
3917 unsigned int i, best = 0;
3918 unsigned long nextval;
3919 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
3921 /* At worse, next value is at end of module */
3922 if (within_module_init(addr, mod))
3923 nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
3925 nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
3927 /* Scan for closest preceding symbol, and next symbol. (ELF
3928 starts real symbols at 1). */
3929 for (i = 1; i < kallsyms->num_symtab; i++) {
3930 if (kallsyms->symtab[i].st_shndx == SHN_UNDEF)
3933 /* We ignore unnamed symbols: they're uninformative
3934 * and inserted at a whim. */
3935 if (*symname(kallsyms, i) == '\0'
3936 || is_arm_mapping_symbol(symname(kallsyms, i)))
3939 if (kallsyms->symtab[i].st_value <= addr
3940 && kallsyms->symtab[i].st_value > kallsyms->symtab[best].st_value)
3942 if (kallsyms->symtab[i].st_value > addr
3943 && kallsyms->symtab[i].st_value < nextval)
3944 nextval = kallsyms->symtab[i].st_value;
3951 *size = nextval - kallsyms->symtab[best].st_value;
3953 *offset = addr - kallsyms->symtab[best].st_value;
3954 return symname(kallsyms, best);
3957 void * __weak dereference_module_function_descriptor(struct module *mod,
3963 /* For kallsyms to ask for address resolution. NULL means not found. Careful
3964 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3965 const char *module_address_lookup(unsigned long addr,
3966 unsigned long *size,
3967 unsigned long *offset,
3971 const char *ret = NULL;
3975 mod = __module_address(addr);
3978 *modname = mod->name;
3979 ret = get_ksymbol(mod, addr, size, offset);
3981 /* Make a copy in here where it's safe */
3983 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3991 int lookup_module_symbol_name(unsigned long addr, char *symname)
3996 list_for_each_entry_rcu(mod, &modules, list) {
3997 if (mod->state == MODULE_STATE_UNFORMED)
3999 if (within_module(addr, mod)) {
4002 sym = get_ksymbol(mod, addr, NULL, NULL);
4005 strlcpy(symname, sym, KSYM_NAME_LEN);
4015 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
4016 unsigned long *offset, char *modname, char *name)
4021 list_for_each_entry_rcu(mod, &modules, list) {
4022 if (mod->state == MODULE_STATE_UNFORMED)
4024 if (within_module(addr, mod)) {
4027 sym = get_ksymbol(mod, addr, size, offset);
4031 strlcpy(modname, mod->name, MODULE_NAME_LEN);
4033 strlcpy(name, sym, KSYM_NAME_LEN);
4043 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
4044 char *name, char *module_name, int *exported)
4049 list_for_each_entry_rcu(mod, &modules, list) {
4050 struct mod_kallsyms *kallsyms;
4052 if (mod->state == MODULE_STATE_UNFORMED)
4054 kallsyms = rcu_dereference_sched(mod->kallsyms);
4055 if (symnum < kallsyms->num_symtab) {
4056 *value = kallsyms->symtab[symnum].st_value;
4057 *type = kallsyms->symtab[symnum].st_info;
4058 strlcpy(name, symname(kallsyms, symnum), KSYM_NAME_LEN);
4059 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
4060 *exported = is_exported(name, *value, mod);
4064 symnum -= kallsyms->num_symtab;
4070 static unsigned long mod_find_symname(struct module *mod, const char *name)
4073 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4075 for (i = 0; i < kallsyms->num_symtab; i++)
4076 if (strcmp(name, symname(kallsyms, i)) == 0 &&
4077 kallsyms->symtab[i].st_shndx != SHN_UNDEF)
4078 return kallsyms->symtab[i].st_value;
4082 /* Look for this name: can be of form module:name. */
4083 unsigned long module_kallsyms_lookup_name(const char *name)
4087 unsigned long ret = 0;
4089 /* Don't lock: we're in enough trouble already. */
4091 if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
4092 if ((mod = find_module_all(name, colon - name, false)) != NULL)
4093 ret = mod_find_symname(mod, colon+1);
4095 list_for_each_entry_rcu(mod, &modules, list) {
4096 if (mod->state == MODULE_STATE_UNFORMED)
4098 if ((ret = mod_find_symname(mod, name)) != 0)
4106 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
4107 struct module *, unsigned long),
4114 module_assert_mutex();
4116 list_for_each_entry(mod, &modules, list) {
4117 /* We hold module_mutex: no need for rcu_dereference_sched */
4118 struct mod_kallsyms *kallsyms = mod->kallsyms;
4120 if (mod->state == MODULE_STATE_UNFORMED)
4122 for (i = 0; i < kallsyms->num_symtab; i++) {
4124 if (kallsyms->symtab[i].st_shndx == SHN_UNDEF)
4127 ret = fn(data, symname(kallsyms, i),
4128 mod, kallsyms->symtab[i].st_value);
4135 #endif /* CONFIG_KALLSYMS */
4137 /* Maximum number of characters written by module_flags() */
4138 #define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
4140 /* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
4141 static char *module_flags(struct module *mod, char *buf)
4145 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
4147 mod->state == MODULE_STATE_GOING ||
4148 mod->state == MODULE_STATE_COMING) {
4150 bx += module_flags_taint(mod, buf + bx);
4151 /* Show a - for module-is-being-unloaded */
4152 if (mod->state == MODULE_STATE_GOING)
4154 /* Show a + for module-is-being-loaded */
4155 if (mod->state == MODULE_STATE_COMING)
4164 #ifdef CONFIG_PROC_FS
4165 /* Called by the /proc file system to return a list of modules. */
4166 static void *m_start(struct seq_file *m, loff_t *pos)
4168 mutex_lock(&module_mutex);
4169 return seq_list_start(&modules, *pos);
4172 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
4174 return seq_list_next(p, &modules, pos);
4177 static void m_stop(struct seq_file *m, void *p)
4179 mutex_unlock(&module_mutex);
4182 static int m_show(struct seq_file *m, void *p)
4184 struct module *mod = list_entry(p, struct module, list);
4185 char buf[MODULE_FLAGS_BUF_SIZE];
4188 /* We always ignore unformed modules. */
4189 if (mod->state == MODULE_STATE_UNFORMED)
4192 seq_printf(m, "%s %u",
4193 mod->name, mod->init_layout.size + mod->core_layout.size);
4194 print_unload_info(m, mod);
4196 /* Informative for users. */
4197 seq_printf(m, " %s",
4198 mod->state == MODULE_STATE_GOING ? "Unloading" :
4199 mod->state == MODULE_STATE_COMING ? "Loading" :
4201 /* Used by oprofile and other similar tools. */
4202 value = m->private ? NULL : mod->core_layout.base;
4203 seq_printf(m, " 0x%px", value);
4207 seq_printf(m, " %s", module_flags(mod, buf));
4213 /* Format: modulename size refcount deps address
4215 Where refcount is a number or -, and deps is a comma-separated list
4218 static const struct seq_operations modules_op = {
4226 * This also sets the "private" pointer to non-NULL if the
4227 * kernel pointers should be hidden (so you can just test
4228 * "m->private" to see if you should keep the values private).
4230 * We use the same logic as for /proc/kallsyms.
4232 static int modules_open(struct inode *inode, struct file *file)
4234 int err = seq_open(file, &modules_op);
4237 struct seq_file *m = file->private_data;
4238 m->private = kallsyms_show_value() ? NULL : (void *)8ul;
4244 static const struct file_operations proc_modules_operations = {
4245 .open = modules_open,
4247 .llseek = seq_lseek,
4248 .release = seq_release,
4251 static int __init proc_modules_init(void)
4253 proc_create("modules", 0, NULL, &proc_modules_operations);
4256 module_init(proc_modules_init);
4259 /* Given an address, look for it in the module exception tables. */
4260 const struct exception_table_entry *search_module_extables(unsigned long addr)
4262 const struct exception_table_entry *e = NULL;
4266 mod = __module_address(addr);
4270 if (!mod->num_exentries)
4273 e = search_extable(mod->extable,
4280 * Now, if we found one, we are running inside it now, hence
4281 * we cannot unload the module, hence no refcnt needed.
4287 * is_module_address - is this address inside a module?
4288 * @addr: the address to check.
4290 * See is_module_text_address() if you simply want to see if the address
4291 * is code (not data).
4293 bool is_module_address(unsigned long addr)
4298 ret = __module_address(addr) != NULL;
4305 * __module_address - get the module which contains an address.
4306 * @addr: the address.
4308 * Must be called with preempt disabled or module mutex held so that
4309 * module doesn't get freed during this.
4311 struct module *__module_address(unsigned long addr)
4315 if (addr < module_addr_min || addr > module_addr_max)
4318 module_assert_mutex_or_preempt();
4320 mod = mod_find(addr);
4322 BUG_ON(!within_module(addr, mod));
4323 if (mod->state == MODULE_STATE_UNFORMED)
4328 EXPORT_SYMBOL_GPL(__module_address);
4331 * is_module_text_address - is this address inside module code?
4332 * @addr: the address to check.
4334 * See is_module_address() if you simply want to see if the address is
4335 * anywhere in a module. See kernel_text_address() for testing if an
4336 * address corresponds to kernel or module code.
4338 bool is_module_text_address(unsigned long addr)
4343 ret = __module_text_address(addr) != NULL;
4350 * __module_text_address - get the module whose code contains an address.
4351 * @addr: the address.
4353 * Must be called with preempt disabled or module mutex held so that
4354 * module doesn't get freed during this.
4356 struct module *__module_text_address(unsigned long addr)
4358 struct module *mod = __module_address(addr);
4360 /* Make sure it's within the text section. */
4361 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
4362 && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
4367 EXPORT_SYMBOL_GPL(__module_text_address);
4369 /* Don't grab lock, we're oopsing. */
4370 void print_modules(void)
4373 char buf[MODULE_FLAGS_BUF_SIZE];
4375 printk(KERN_DEFAULT "Modules linked in:");
4376 /* Most callers should already have preempt disabled, but make sure */
4378 list_for_each_entry_rcu(mod, &modules, list) {
4379 if (mod->state == MODULE_STATE_UNFORMED)
4381 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4384 if (last_unloaded_module[0])
4385 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4389 #ifdef CONFIG_MODVERSIONS
4390 /* Generate the signature for all relevant module structures here.
4391 * If these change, we don't want to try to parse the module. */
4392 void module_layout(struct module *mod,
4393 struct modversion_info *ver,
4394 struct kernel_param *kp,
4395 struct kernel_symbol *ks,
4396 struct tracepoint * const *tp)
4399 EXPORT_SYMBOL(module_layout);