2 Copyright (C) 2002 Richard Henderson
3 Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 #include <linux/export.h>
20 #include <linux/moduleloader.h>
21 #include <linux/trace_events.h>
22 #include <linux/init.h>
23 #include <linux/kallsyms.h>
24 #include <linux/file.h>
26 #include <linux/sysfs.h>
27 #include <linux/kernel.h>
28 #include <linux/slab.h>
29 #include <linux/vmalloc.h>
30 #include <linux/elf.h>
31 #include <linux/proc_fs.h>
32 #include <linux/security.h>
33 #include <linux/seq_file.h>
34 #include <linux/syscalls.h>
35 #include <linux/fcntl.h>
36 #include <linux/rcupdate.h>
37 #include <linux/capability.h>
38 #include <linux/cpu.h>
39 #include <linux/moduleparam.h>
40 #include <linux/errno.h>
41 #include <linux/err.h>
42 #include <linux/vermagic.h>
43 #include <linux/notifier.h>
44 #include <linux/sched.h>
45 #include <linux/device.h>
46 #include <linux/string.h>
47 #include <linux/mutex.h>
48 #include <linux/rculist.h>
49 #include <asm/uaccess.h>
50 #include <asm/cacheflush.h>
51 #include <asm/mmu_context.h>
52 #include <linux/license.h>
53 #include <asm/sections.h>
54 #include <linux/tracepoint.h>
55 #include <linux/ftrace.h>
56 #include <linux/livepatch.h>
57 #include <linux/async.h>
58 #include <linux/percpu.h>
59 #include <linux/kmemleak.h>
60 #include <linux/jump_label.h>
61 #include <linux/pfn.h>
62 #include <linux/bsearch.h>
63 #include <linux/dynamic_debug.h>
64 #include <uapi/linux/module.h>
65 #include "module-internal.h"
67 #define CREATE_TRACE_POINTS
68 #include <trace/events/module.h>
70 #ifndef ARCH_SHF_SMALL
71 #define ARCH_SHF_SMALL 0
75 * Modules' sections will be aligned on page boundaries
76 * to ensure complete separation of code and data, but
77 * only when CONFIG_DEBUG_SET_MODULE_RONX=y
79 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
80 # define debug_align(X) ALIGN(X, PAGE_SIZE)
82 # define debug_align(X) (X)
85 /* If this is set, the section belongs in the init part of the module */
86 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
90 * 1) List of modules (also safely readable with preempt_disable),
91 * 2) module_use links,
92 * 3) module_addr_min/module_addr_max.
93 * (delete and add uses RCU list operations). */
94 DEFINE_MUTEX(module_mutex);
95 EXPORT_SYMBOL_GPL(module_mutex);
96 static LIST_HEAD(modules);
98 #ifdef CONFIG_MODULES_TREE_LOOKUP
101 * Use a latched RB-tree for __module_address(); this allows us to use
102 * RCU-sched lookups of the address from any context.
104 * This is conditional on PERF_EVENTS || TRACING because those can really hit
105 * __module_address() hard by doing a lot of stack unwinding; potentially from
109 static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
111 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
113 return (unsigned long)layout->base;
116 static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
118 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
120 return (unsigned long)layout->size;
123 static __always_inline bool
124 mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
126 return __mod_tree_val(a) < __mod_tree_val(b);
129 static __always_inline int
130 mod_tree_comp(void *key, struct latch_tree_node *n)
132 unsigned long val = (unsigned long)key;
133 unsigned long start, end;
135 start = __mod_tree_val(n);
139 end = start + __mod_tree_size(n);
146 static const struct latch_tree_ops mod_tree_ops = {
147 .less = mod_tree_less,
148 .comp = mod_tree_comp,
151 static struct mod_tree_root {
152 struct latch_tree_root root;
153 unsigned long addr_min;
154 unsigned long addr_max;
155 } mod_tree __cacheline_aligned = {
159 #define module_addr_min mod_tree.addr_min
160 #define module_addr_max mod_tree.addr_max
162 static noinline void __mod_tree_insert(struct mod_tree_node *node)
164 latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
167 static void __mod_tree_remove(struct mod_tree_node *node)
169 latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
173 * These modifications: insert, remove_init and remove; are serialized by the
176 static void mod_tree_insert(struct module *mod)
178 mod->core_layout.mtn.mod = mod;
179 mod->init_layout.mtn.mod = mod;
181 __mod_tree_insert(&mod->core_layout.mtn);
182 if (mod->init_layout.size)
183 __mod_tree_insert(&mod->init_layout.mtn);
186 static void mod_tree_remove_init(struct module *mod)
188 if (mod->init_layout.size)
189 __mod_tree_remove(&mod->init_layout.mtn);
192 static void mod_tree_remove(struct module *mod)
194 __mod_tree_remove(&mod->core_layout.mtn);
195 mod_tree_remove_init(mod);
198 static struct module *mod_find(unsigned long addr)
200 struct latch_tree_node *ltn;
202 ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
206 return container_of(ltn, struct mod_tree_node, node)->mod;
209 #else /* MODULES_TREE_LOOKUP */
211 static unsigned long module_addr_min = -1UL, module_addr_max = 0;
213 static void mod_tree_insert(struct module *mod) { }
214 static void mod_tree_remove_init(struct module *mod) { }
215 static void mod_tree_remove(struct module *mod) { }
217 static struct module *mod_find(unsigned long addr)
221 list_for_each_entry_rcu(mod, &modules, list) {
222 if (within_module(addr, mod))
229 #endif /* MODULES_TREE_LOOKUP */
232 * Bounds of module text, for speeding up __module_address.
233 * Protected by module_mutex.
235 static void __mod_update_bounds(void *base, unsigned int size)
237 unsigned long min = (unsigned long)base;
238 unsigned long max = min + size;
240 if (min < module_addr_min)
241 module_addr_min = min;
242 if (max > module_addr_max)
243 module_addr_max = max;
246 static void mod_update_bounds(struct module *mod)
248 __mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
249 if (mod->init_layout.size)
250 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
253 #ifdef CONFIG_KGDB_KDB
254 struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
255 #endif /* CONFIG_KGDB_KDB */
257 static void module_assert_mutex(void)
259 lockdep_assert_held(&module_mutex);
262 static void module_assert_mutex_or_preempt(void)
264 #ifdef CONFIG_LOCKDEP
265 if (unlikely(!debug_locks))
268 WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
269 !lockdep_is_held(&module_mutex));
273 static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
274 #ifndef CONFIG_MODULE_SIG_FORCE
275 module_param(sig_enforce, bool_enable_only, 0644);
276 #endif /* !CONFIG_MODULE_SIG_FORCE */
278 /* Block module loading/unloading? */
279 int modules_disabled = 0;
280 core_param(nomodule, modules_disabled, bint, 0);
282 /* Waiting for a module to finish initializing? */
283 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
285 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
287 int register_module_notifier(struct notifier_block *nb)
289 return blocking_notifier_chain_register(&module_notify_list, nb);
291 EXPORT_SYMBOL(register_module_notifier);
293 int unregister_module_notifier(struct notifier_block *nb)
295 return blocking_notifier_chain_unregister(&module_notify_list, nb);
297 EXPORT_SYMBOL(unregister_module_notifier);
303 char *secstrings, *strtab;
304 unsigned long symoffs, stroffs;
305 struct _ddebug *debug;
306 unsigned int num_debug;
308 #ifdef CONFIG_KALLSYMS
309 unsigned long mod_kallsyms_init_off;
312 unsigned int sym, str, mod, vers, info, pcpu;
316 /* We require a truly strong try_module_get(): 0 means failure due to
317 ongoing or failed initialization etc. */
318 static inline int strong_try_module_get(struct module *mod)
320 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
321 if (mod && mod->state == MODULE_STATE_COMING)
323 if (try_module_get(mod))
329 static inline void add_taint_module(struct module *mod, unsigned flag,
330 enum lockdep_ok lockdep_ok)
332 add_taint(flag, lockdep_ok);
333 mod->taints |= (1U << flag);
337 * A thread that wants to hold a reference to a module only while it
338 * is running can call this to safely exit. nfsd and lockd use this.
340 void __noreturn __module_put_and_exit(struct module *mod, long code)
345 EXPORT_SYMBOL(__module_put_and_exit);
347 /* Find a module section: 0 means not found. */
348 static unsigned int find_sec(const struct load_info *info, const char *name)
352 for (i = 1; i < info->hdr->e_shnum; i++) {
353 Elf_Shdr *shdr = &info->sechdrs[i];
354 /* Alloc bit cleared means "ignore it." */
355 if ((shdr->sh_flags & SHF_ALLOC)
356 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
362 /* Find a module section, or NULL. */
363 static void *section_addr(const struct load_info *info, const char *name)
365 /* Section 0 has sh_addr 0. */
366 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
369 /* Find a module section, or NULL. Fill in number of "objects" in section. */
370 static void *section_objs(const struct load_info *info,
375 unsigned int sec = find_sec(info, name);
377 /* Section 0 has sh_addr 0 and sh_size 0. */
378 *num = info->sechdrs[sec].sh_size / object_size;
379 return (void *)info->sechdrs[sec].sh_addr;
382 /* Provided by the linker */
383 extern const struct kernel_symbol __start___ksymtab[];
384 extern const struct kernel_symbol __stop___ksymtab[];
385 extern const struct kernel_symbol __start___ksymtab_gpl[];
386 extern const struct kernel_symbol __stop___ksymtab_gpl[];
387 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
388 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
389 extern const unsigned long __start___kcrctab[];
390 extern const unsigned long __start___kcrctab_gpl[];
391 extern const unsigned long __start___kcrctab_gpl_future[];
392 #ifdef CONFIG_UNUSED_SYMBOLS
393 extern const struct kernel_symbol __start___ksymtab_unused[];
394 extern const struct kernel_symbol __stop___ksymtab_unused[];
395 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
396 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
397 extern const unsigned long __start___kcrctab_unused[];
398 extern const unsigned long __start___kcrctab_unused_gpl[];
401 #ifndef CONFIG_MODVERSIONS
402 #define symversion(base, idx) NULL
404 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
407 static bool each_symbol_in_section(const struct symsearch *arr,
408 unsigned int arrsize,
409 struct module *owner,
410 bool (*fn)(const struct symsearch *syms,
411 struct module *owner,
417 for (j = 0; j < arrsize; j++) {
418 if (fn(&arr[j], owner, data))
425 /* Returns true as soon as fn returns true, otherwise false. */
426 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
427 struct module *owner,
432 static const struct symsearch arr[] = {
433 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
434 NOT_GPL_ONLY, false },
435 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
436 __start___kcrctab_gpl,
438 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
439 __start___kcrctab_gpl_future,
440 WILL_BE_GPL_ONLY, false },
441 #ifdef CONFIG_UNUSED_SYMBOLS
442 { __start___ksymtab_unused, __stop___ksymtab_unused,
443 __start___kcrctab_unused,
444 NOT_GPL_ONLY, true },
445 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
446 __start___kcrctab_unused_gpl,
451 module_assert_mutex_or_preempt();
453 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
456 list_for_each_entry_rcu(mod, &modules, list) {
457 struct symsearch arr[] = {
458 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
459 NOT_GPL_ONLY, false },
460 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
463 { mod->gpl_future_syms,
464 mod->gpl_future_syms + mod->num_gpl_future_syms,
465 mod->gpl_future_crcs,
466 WILL_BE_GPL_ONLY, false },
467 #ifdef CONFIG_UNUSED_SYMBOLS
469 mod->unused_syms + mod->num_unused_syms,
471 NOT_GPL_ONLY, true },
472 { mod->unused_gpl_syms,
473 mod->unused_gpl_syms + mod->num_unused_gpl_syms,
474 mod->unused_gpl_crcs,
479 if (mod->state == MODULE_STATE_UNFORMED)
482 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
487 EXPORT_SYMBOL_GPL(each_symbol_section);
489 struct find_symbol_arg {
496 struct module *owner;
497 const unsigned long *crc;
498 const struct kernel_symbol *sym;
501 static bool check_symbol(const struct symsearch *syms,
502 struct module *owner,
503 unsigned int symnum, void *data)
505 struct find_symbol_arg *fsa = data;
508 if (syms->licence == GPL_ONLY)
510 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
511 pr_warn("Symbol %s is being used by a non-GPL module, "
512 "which will not be allowed in the future\n",
517 #ifdef CONFIG_UNUSED_SYMBOLS
518 if (syms->unused && fsa->warn) {
519 pr_warn("Symbol %s is marked as UNUSED, however this module is "
520 "using it.\n", fsa->name);
521 pr_warn("This symbol will go away in the future.\n");
522 pr_warn("Please evaluate if this is the right api to use and "
523 "if it really is, submit a report to the linux kernel "
524 "mailing list together with submitting your code for "
530 fsa->crc = symversion(syms->crcs, symnum);
531 fsa->sym = &syms->start[symnum];
535 static int cmp_name(const void *va, const void *vb)
538 const struct kernel_symbol *b;
540 return strcmp(a, b->name);
543 static bool find_symbol_in_section(const struct symsearch *syms,
544 struct module *owner,
547 struct find_symbol_arg *fsa = data;
548 struct kernel_symbol *sym;
550 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
551 sizeof(struct kernel_symbol), cmp_name);
553 if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
559 /* Find a symbol and return it, along with, (optional) crc and
560 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
561 const struct kernel_symbol *find_symbol(const char *name,
562 struct module **owner,
563 const unsigned long **crc,
567 struct find_symbol_arg fsa;
573 if (each_symbol_section(find_symbol_in_section, &fsa)) {
581 pr_debug("Failed to find symbol %s\n", name);
584 EXPORT_SYMBOL_GPL(find_symbol);
587 * Search for module by name: must hold module_mutex (or preempt disabled
588 * for read-only access).
590 static struct module *find_module_all(const char *name, size_t len,
595 module_assert_mutex_or_preempt();
597 list_for_each_entry(mod, &modules, list) {
598 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
600 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
606 struct module *find_module(const char *name)
608 module_assert_mutex();
609 return find_module_all(name, strlen(name), false);
611 EXPORT_SYMBOL_GPL(find_module);
615 static inline void __percpu *mod_percpu(struct module *mod)
620 static int percpu_modalloc(struct module *mod, struct load_info *info)
622 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
623 unsigned long align = pcpusec->sh_addralign;
625 if (!pcpusec->sh_size)
628 if (align > PAGE_SIZE) {
629 pr_warn("%s: per-cpu alignment %li > %li\n",
630 mod->name, align, PAGE_SIZE);
634 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
636 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
637 mod->name, (unsigned long)pcpusec->sh_size);
640 mod->percpu_size = pcpusec->sh_size;
644 static void percpu_modfree(struct module *mod)
646 free_percpu(mod->percpu);
649 static unsigned int find_pcpusec(struct load_info *info)
651 return find_sec(info, ".data..percpu");
654 static void percpu_modcopy(struct module *mod,
655 const void *from, unsigned long size)
659 for_each_possible_cpu(cpu)
660 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
664 * is_module_percpu_address - test whether address is from module static percpu
665 * @addr: address to test
667 * Test whether @addr belongs to module static percpu area.
670 * %true if @addr is from module static percpu area
672 bool is_module_percpu_address(unsigned long addr)
679 list_for_each_entry_rcu(mod, &modules, list) {
680 if (mod->state == MODULE_STATE_UNFORMED)
682 if (!mod->percpu_size)
684 for_each_possible_cpu(cpu) {
685 void *start = per_cpu_ptr(mod->percpu, cpu);
687 if ((void *)addr >= start &&
688 (void *)addr < start + mod->percpu_size) {
699 #else /* ... !CONFIG_SMP */
701 static inline void __percpu *mod_percpu(struct module *mod)
705 static int percpu_modalloc(struct module *mod, struct load_info *info)
707 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
708 if (info->sechdrs[info->index.pcpu].sh_size != 0)
712 static inline void percpu_modfree(struct module *mod)
715 static unsigned int find_pcpusec(struct load_info *info)
719 static inline void percpu_modcopy(struct module *mod,
720 const void *from, unsigned long size)
722 /* pcpusec should be 0, and size of that section should be 0. */
725 bool is_module_percpu_address(unsigned long addr)
730 #endif /* CONFIG_SMP */
732 #define MODINFO_ATTR(field) \
733 static void setup_modinfo_##field(struct module *mod, const char *s) \
735 mod->field = kstrdup(s, GFP_KERNEL); \
737 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
738 struct module_kobject *mk, char *buffer) \
740 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
742 static int modinfo_##field##_exists(struct module *mod) \
744 return mod->field != NULL; \
746 static void free_modinfo_##field(struct module *mod) \
751 static struct module_attribute modinfo_##field = { \
752 .attr = { .name = __stringify(field), .mode = 0444 }, \
753 .show = show_modinfo_##field, \
754 .setup = setup_modinfo_##field, \
755 .test = modinfo_##field##_exists, \
756 .free = free_modinfo_##field, \
759 MODINFO_ATTR(version);
760 MODINFO_ATTR(srcversion);
762 static char last_unloaded_module[MODULE_NAME_LEN+1];
764 #ifdef CONFIG_MODULE_UNLOAD
766 EXPORT_TRACEPOINT_SYMBOL(module_get);
768 /* MODULE_REF_BASE is the base reference count by kmodule loader. */
769 #define MODULE_REF_BASE 1
771 /* Init the unload section of the module. */
772 static int module_unload_init(struct module *mod)
775 * Initialize reference counter to MODULE_REF_BASE.
776 * refcnt == 0 means module is going.
778 atomic_set(&mod->refcnt, MODULE_REF_BASE);
780 INIT_LIST_HEAD(&mod->source_list);
781 INIT_LIST_HEAD(&mod->target_list);
783 /* Hold reference count during initialization. */
784 atomic_inc(&mod->refcnt);
789 /* Does a already use b? */
790 static int already_uses(struct module *a, struct module *b)
792 struct module_use *use;
794 list_for_each_entry(use, &b->source_list, source_list) {
795 if (use->source == a) {
796 pr_debug("%s uses %s!\n", a->name, b->name);
800 pr_debug("%s does not use %s!\n", a->name, b->name);
806 * - we add 'a' as a "source", 'b' as a "target" of module use
807 * - the module_use is added to the list of 'b' sources (so
808 * 'b' can walk the list to see who sourced them), and of 'a'
809 * targets (so 'a' can see what modules it targets).
811 static int add_module_usage(struct module *a, struct module *b)
813 struct module_use *use;
815 pr_debug("Allocating new usage for %s.\n", a->name);
816 use = kmalloc(sizeof(*use), GFP_ATOMIC);
818 pr_warn("%s: out of memory loading\n", a->name);
824 list_add(&use->source_list, &b->source_list);
825 list_add(&use->target_list, &a->target_list);
829 /* Module a uses b: caller needs module_mutex() */
830 int ref_module(struct module *a, struct module *b)
834 if (b == NULL || already_uses(a, b))
837 /* If module isn't available, we fail. */
838 err = strong_try_module_get(b);
842 err = add_module_usage(a, b);
849 EXPORT_SYMBOL_GPL(ref_module);
851 /* Clear the unload stuff of the module. */
852 static void module_unload_free(struct module *mod)
854 struct module_use *use, *tmp;
856 mutex_lock(&module_mutex);
857 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
858 struct module *i = use->target;
859 pr_debug("%s unusing %s\n", mod->name, i->name);
861 list_del(&use->source_list);
862 list_del(&use->target_list);
865 mutex_unlock(&module_mutex);
868 #ifdef CONFIG_MODULE_FORCE_UNLOAD
869 static inline int try_force_unload(unsigned int flags)
871 int ret = (flags & O_TRUNC);
873 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
877 static inline int try_force_unload(unsigned int flags)
881 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
883 /* Try to release refcount of module, 0 means success. */
884 static int try_release_module_ref(struct module *mod)
888 /* Try to decrement refcnt which we set at loading */
889 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
892 /* Someone can put this right now, recover with checking */
893 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
898 static int try_stop_module(struct module *mod, int flags, int *forced)
900 /* If it's not unused, quit unless we're forcing. */
901 if (try_release_module_ref(mod) != 0) {
902 *forced = try_force_unload(flags);
907 /* Mark it as dying. */
908 mod->state = MODULE_STATE_GOING;
914 * module_refcount - return the refcount or -1 if unloading
916 * @mod: the module we're checking
919 * -1 if the module is in the process of unloading
920 * otherwise the number of references in the kernel to the module
922 int module_refcount(struct module *mod)
924 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
926 EXPORT_SYMBOL(module_refcount);
928 /* This exists whether we can unload or not */
929 static void free_module(struct module *mod);
931 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
935 char name[MODULE_NAME_LEN];
938 if (!capable(CAP_SYS_MODULE) || modules_disabled)
941 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
943 name[MODULE_NAME_LEN-1] = '\0';
945 if (mutex_lock_interruptible(&module_mutex) != 0)
948 mod = find_module(name);
954 if (!list_empty(&mod->source_list)) {
955 /* Other modules depend on us: get rid of them first. */
960 /* Doing init or already dying? */
961 if (mod->state != MODULE_STATE_LIVE) {
962 /* FIXME: if (force), slam module count damn the torpedoes */
963 pr_debug("%s already dying\n", mod->name);
968 /* If it has an init func, it must have an exit func to unload */
969 if (mod->init && !mod->exit) {
970 forced = try_force_unload(flags);
972 /* This module can't be removed */
978 /* Stop the machine so refcounts can't move and disable module. */
979 ret = try_stop_module(mod, flags, &forced);
983 mutex_unlock(&module_mutex);
984 /* Final destruction now no one is using it. */
985 if (mod->exit != NULL)
987 blocking_notifier_call_chain(&module_notify_list,
988 MODULE_STATE_GOING, mod);
989 klp_module_going(mod);
990 ftrace_release_mod(mod);
992 async_synchronize_full();
994 /* Store the name of the last unloaded module for diagnostic purposes */
995 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
998 /* someone could wait for the module in add_unformed_module() */
999 wake_up_all(&module_wq);
1002 mutex_unlock(&module_mutex);
1006 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1008 struct module_use *use;
1009 int printed_something = 0;
1011 seq_printf(m, " %i ", module_refcount(mod));
1014 * Always include a trailing , so userspace can differentiate
1015 * between this and the old multi-field proc format.
1017 list_for_each_entry(use, &mod->source_list, source_list) {
1018 printed_something = 1;
1019 seq_printf(m, "%s,", use->source->name);
1022 if (mod->init != NULL && mod->exit == NULL) {
1023 printed_something = 1;
1024 seq_puts(m, "[permanent],");
1027 if (!printed_something)
1031 void __symbol_put(const char *symbol)
1033 struct module *owner;
1036 if (!find_symbol(symbol, &owner, NULL, true, false))
1041 EXPORT_SYMBOL(__symbol_put);
1043 /* Note this assumes addr is a function, which it currently always is. */
1044 void symbol_put_addr(void *addr)
1046 struct module *modaddr;
1047 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1049 if (core_kernel_text(a))
1053 * Even though we hold a reference on the module; we still need to
1054 * disable preemption in order to safely traverse the data structure.
1057 modaddr = __module_text_address(a);
1059 module_put(modaddr);
1062 EXPORT_SYMBOL_GPL(symbol_put_addr);
1064 static ssize_t show_refcnt(struct module_attribute *mattr,
1065 struct module_kobject *mk, char *buffer)
1067 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1070 static struct module_attribute modinfo_refcnt =
1071 __ATTR(refcnt, 0444, show_refcnt, NULL);
1073 void __module_get(struct module *module)
1077 atomic_inc(&module->refcnt);
1078 trace_module_get(module, _RET_IP_);
1082 EXPORT_SYMBOL(__module_get);
1084 bool try_module_get(struct module *module)
1090 /* Note: here, we can fail to get a reference */
1091 if (likely(module_is_live(module) &&
1092 atomic_inc_not_zero(&module->refcnt) != 0))
1093 trace_module_get(module, _RET_IP_);
1101 EXPORT_SYMBOL(try_module_get);
1103 void module_put(struct module *module)
1109 ret = atomic_dec_if_positive(&module->refcnt);
1110 WARN_ON(ret < 0); /* Failed to put refcount */
1111 trace_module_put(module, _RET_IP_);
1115 EXPORT_SYMBOL(module_put);
1117 #else /* !CONFIG_MODULE_UNLOAD */
1118 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1120 /* We don't know the usage count, or what modules are using. */
1121 seq_puts(m, " - -");
1124 static inline void module_unload_free(struct module *mod)
1128 int ref_module(struct module *a, struct module *b)
1130 return strong_try_module_get(b);
1132 EXPORT_SYMBOL_GPL(ref_module);
1134 static inline int module_unload_init(struct module *mod)
1138 #endif /* CONFIG_MODULE_UNLOAD */
1140 static size_t module_flags_taint(struct module *mod, char *buf)
1144 if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
1146 if (mod->taints & (1 << TAINT_OOT_MODULE))
1148 if (mod->taints & (1 << TAINT_FORCED_MODULE))
1150 if (mod->taints & (1 << TAINT_CRAP))
1152 if (mod->taints & (1 << TAINT_UNSIGNED_MODULE))
1154 if (mod->taints & (1 << TAINT_LIVEPATCH))
1157 * TAINT_FORCED_RMMOD: could be added.
1158 * TAINT_CPU_OUT_OF_SPEC, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
1164 static ssize_t show_initstate(struct module_attribute *mattr,
1165 struct module_kobject *mk, char *buffer)
1167 const char *state = "unknown";
1169 switch (mk->mod->state) {
1170 case MODULE_STATE_LIVE:
1173 case MODULE_STATE_COMING:
1176 case MODULE_STATE_GOING:
1182 return sprintf(buffer, "%s\n", state);
1185 static struct module_attribute modinfo_initstate =
1186 __ATTR(initstate, 0444, show_initstate, NULL);
1188 static ssize_t store_uevent(struct module_attribute *mattr,
1189 struct module_kobject *mk,
1190 const char *buffer, size_t count)
1192 enum kobject_action action;
1194 if (kobject_action_type(buffer, count, &action) == 0)
1195 kobject_uevent(&mk->kobj, action);
1199 struct module_attribute module_uevent =
1200 __ATTR(uevent, 0200, NULL, store_uevent);
1202 static ssize_t show_coresize(struct module_attribute *mattr,
1203 struct module_kobject *mk, char *buffer)
1205 return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1208 static struct module_attribute modinfo_coresize =
1209 __ATTR(coresize, 0444, show_coresize, NULL);
1211 static ssize_t show_initsize(struct module_attribute *mattr,
1212 struct module_kobject *mk, char *buffer)
1214 return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1217 static struct module_attribute modinfo_initsize =
1218 __ATTR(initsize, 0444, show_initsize, NULL);
1220 static ssize_t show_taint(struct module_attribute *mattr,
1221 struct module_kobject *mk, char *buffer)
1225 l = module_flags_taint(mk->mod, buffer);
1230 static struct module_attribute modinfo_taint =
1231 __ATTR(taint, 0444, show_taint, NULL);
1233 static struct module_attribute *modinfo_attrs[] = {
1236 &modinfo_srcversion,
1241 #ifdef CONFIG_MODULE_UNLOAD
1247 static const char vermagic[] = VERMAGIC_STRING;
1249 static int try_to_force_load(struct module *mod, const char *reason)
1251 #ifdef CONFIG_MODULE_FORCE_LOAD
1252 if (!test_taint(TAINT_FORCED_MODULE))
1253 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1254 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1261 #ifdef CONFIG_MODVERSIONS
1262 /* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
1263 static unsigned long maybe_relocated(unsigned long crc,
1264 const struct module *crc_owner)
1266 #ifdef ARCH_RELOCATES_KCRCTAB
1267 if (crc_owner == NULL)
1268 return crc - (unsigned long)reloc_start;
1273 static int check_version(Elf_Shdr *sechdrs,
1274 unsigned int versindex,
1275 const char *symname,
1277 const unsigned long *crc,
1278 const struct module *crc_owner)
1280 unsigned int i, num_versions;
1281 struct modversion_info *versions;
1283 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1287 /* No versions at all? modprobe --force does this. */
1289 return try_to_force_load(mod, symname) == 0;
1291 versions = (void *) sechdrs[versindex].sh_addr;
1292 num_versions = sechdrs[versindex].sh_size
1293 / sizeof(struct modversion_info);
1295 for (i = 0; i < num_versions; i++) {
1296 if (strcmp(versions[i].name, symname) != 0)
1299 if (versions[i].crc == maybe_relocated(*crc, crc_owner))
1301 pr_debug("Found checksum %lX vs module %lX\n",
1302 maybe_relocated(*crc, crc_owner), versions[i].crc);
1306 /* Broken toolchain. Warn once, then let it go.. */
1307 pr_warn_once("%s: no symbol version for %s\n", mod->name, symname);
1311 pr_warn("%s: disagrees about version of symbol %s\n",
1312 mod->name, symname);
1316 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1317 unsigned int versindex,
1320 const unsigned long *crc;
1323 * Since this should be found in kernel (which can't be removed), no
1324 * locking is necessary -- use preempt_disable() to placate lockdep.
1327 if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
1328 &crc, true, false)) {
1333 return check_version(sechdrs, versindex,
1334 VMLINUX_SYMBOL_STR(module_layout), mod, crc,
1338 /* First part is kernel version, which we ignore if module has crcs. */
1339 static inline int same_magic(const char *amagic, const char *bmagic,
1343 amagic += strcspn(amagic, " ");
1344 bmagic += strcspn(bmagic, " ");
1346 return strcmp(amagic, bmagic) == 0;
1349 static inline int check_version(Elf_Shdr *sechdrs,
1350 unsigned int versindex,
1351 const char *symname,
1353 const unsigned long *crc,
1354 const struct module *crc_owner)
1359 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1360 unsigned int versindex,
1366 static inline int same_magic(const char *amagic, const char *bmagic,
1369 return strcmp(amagic, bmagic) == 0;
1371 #endif /* CONFIG_MODVERSIONS */
1373 /* Resolve a symbol for this module. I.e. if we find one, record usage. */
1374 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1375 const struct load_info *info,
1379 struct module *owner;
1380 const struct kernel_symbol *sym;
1381 const unsigned long *crc;
1385 * The module_mutex should not be a heavily contended lock;
1386 * if we get the occasional sleep here, we'll go an extra iteration
1387 * in the wait_event_interruptible(), which is harmless.
1389 sched_annotate_sleep();
1390 mutex_lock(&module_mutex);
1391 sym = find_symbol(name, &owner, &crc,
1392 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1396 if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
1398 sym = ERR_PTR(-EINVAL);
1402 err = ref_module(mod, owner);
1409 /* We must make copy under the lock if we failed to get ref. */
1410 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1412 mutex_unlock(&module_mutex);
1416 static const struct kernel_symbol *
1417 resolve_symbol_wait(struct module *mod,
1418 const struct load_info *info,
1421 const struct kernel_symbol *ksym;
1422 char owner[MODULE_NAME_LEN];
1424 if (wait_event_interruptible_timeout(module_wq,
1425 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1426 || PTR_ERR(ksym) != -EBUSY,
1428 pr_warn("%s: gave up waiting for init of module %s.\n",
1435 * /sys/module/foo/sections stuff
1436 * J. Corbet <corbet@lwn.net>
1440 #ifdef CONFIG_KALLSYMS
1441 static inline bool sect_empty(const Elf_Shdr *sect)
1443 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1446 struct module_sect_attr {
1447 struct module_attribute mattr;
1449 unsigned long address;
1452 struct module_sect_attrs {
1453 struct attribute_group grp;
1454 unsigned int nsections;
1455 struct module_sect_attr attrs[0];
1458 static ssize_t module_sect_show(struct module_attribute *mattr,
1459 struct module_kobject *mk, char *buf)
1461 struct module_sect_attr *sattr =
1462 container_of(mattr, struct module_sect_attr, mattr);
1463 return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1466 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1468 unsigned int section;
1470 for (section = 0; section < sect_attrs->nsections; section++)
1471 kfree(sect_attrs->attrs[section].name);
1475 static void add_sect_attrs(struct module *mod, const struct load_info *info)
1477 unsigned int nloaded = 0, i, size[2];
1478 struct module_sect_attrs *sect_attrs;
1479 struct module_sect_attr *sattr;
1480 struct attribute **gattr;
1482 /* Count loaded sections and allocate structures */
1483 for (i = 0; i < info->hdr->e_shnum; i++)
1484 if (!sect_empty(&info->sechdrs[i]))
1486 size[0] = ALIGN(sizeof(*sect_attrs)
1487 + nloaded * sizeof(sect_attrs->attrs[0]),
1488 sizeof(sect_attrs->grp.attrs[0]));
1489 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1490 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1491 if (sect_attrs == NULL)
1494 /* Setup section attributes. */
1495 sect_attrs->grp.name = "sections";
1496 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1498 sect_attrs->nsections = 0;
1499 sattr = §_attrs->attrs[0];
1500 gattr = §_attrs->grp.attrs[0];
1501 for (i = 0; i < info->hdr->e_shnum; i++) {
1502 Elf_Shdr *sec = &info->sechdrs[i];
1503 if (sect_empty(sec))
1505 sattr->address = sec->sh_addr;
1506 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1508 if (sattr->name == NULL)
1510 sect_attrs->nsections++;
1511 sysfs_attr_init(&sattr->mattr.attr);
1512 sattr->mattr.show = module_sect_show;
1513 sattr->mattr.store = NULL;
1514 sattr->mattr.attr.name = sattr->name;
1515 sattr->mattr.attr.mode = S_IRUGO;
1516 *(gattr++) = &(sattr++)->mattr.attr;
1520 if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp))
1523 mod->sect_attrs = sect_attrs;
1526 free_sect_attrs(sect_attrs);
1529 static void remove_sect_attrs(struct module *mod)
1531 if (mod->sect_attrs) {
1532 sysfs_remove_group(&mod->mkobj.kobj,
1533 &mod->sect_attrs->grp);
1534 /* We are positive that no one is using any sect attrs
1535 * at this point. Deallocate immediately. */
1536 free_sect_attrs(mod->sect_attrs);
1537 mod->sect_attrs = NULL;
1542 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1545 struct module_notes_attrs {
1546 struct kobject *dir;
1548 struct bin_attribute attrs[0];
1551 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1552 struct bin_attribute *bin_attr,
1553 char *buf, loff_t pos, size_t count)
1556 * The caller checked the pos and count against our size.
1558 memcpy(buf, bin_attr->private + pos, count);
1562 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1565 if (notes_attrs->dir) {
1567 sysfs_remove_bin_file(notes_attrs->dir,
1568 ¬es_attrs->attrs[i]);
1569 kobject_put(notes_attrs->dir);
1574 static void add_notes_attrs(struct module *mod, const struct load_info *info)
1576 unsigned int notes, loaded, i;
1577 struct module_notes_attrs *notes_attrs;
1578 struct bin_attribute *nattr;
1580 /* failed to create section attributes, so can't create notes */
1581 if (!mod->sect_attrs)
1584 /* Count notes sections and allocate structures. */
1586 for (i = 0; i < info->hdr->e_shnum; i++)
1587 if (!sect_empty(&info->sechdrs[i]) &&
1588 (info->sechdrs[i].sh_type == SHT_NOTE))
1594 notes_attrs = kzalloc(sizeof(*notes_attrs)
1595 + notes * sizeof(notes_attrs->attrs[0]),
1597 if (notes_attrs == NULL)
1600 notes_attrs->notes = notes;
1601 nattr = ¬es_attrs->attrs[0];
1602 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1603 if (sect_empty(&info->sechdrs[i]))
1605 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1606 sysfs_bin_attr_init(nattr);
1607 nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1608 nattr->attr.mode = S_IRUGO;
1609 nattr->size = info->sechdrs[i].sh_size;
1610 nattr->private = (void *) info->sechdrs[i].sh_addr;
1611 nattr->read = module_notes_read;
1617 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1618 if (!notes_attrs->dir)
1621 for (i = 0; i < notes; ++i)
1622 if (sysfs_create_bin_file(notes_attrs->dir,
1623 ¬es_attrs->attrs[i]))
1626 mod->notes_attrs = notes_attrs;
1630 free_notes_attrs(notes_attrs, i);
1633 static void remove_notes_attrs(struct module *mod)
1635 if (mod->notes_attrs)
1636 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1641 static inline void add_sect_attrs(struct module *mod,
1642 const struct load_info *info)
1646 static inline void remove_sect_attrs(struct module *mod)
1650 static inline void add_notes_attrs(struct module *mod,
1651 const struct load_info *info)
1655 static inline void remove_notes_attrs(struct module *mod)
1658 #endif /* CONFIG_KALLSYMS */
1660 static void add_usage_links(struct module *mod)
1662 #ifdef CONFIG_MODULE_UNLOAD
1663 struct module_use *use;
1666 mutex_lock(&module_mutex);
1667 list_for_each_entry(use, &mod->target_list, target_list) {
1668 nowarn = sysfs_create_link(use->target->holders_dir,
1669 &mod->mkobj.kobj, mod->name);
1671 mutex_unlock(&module_mutex);
1675 static void del_usage_links(struct module *mod)
1677 #ifdef CONFIG_MODULE_UNLOAD
1678 struct module_use *use;
1680 mutex_lock(&module_mutex);
1681 list_for_each_entry(use, &mod->target_list, target_list)
1682 sysfs_remove_link(use->target->holders_dir, mod->name);
1683 mutex_unlock(&module_mutex);
1687 static int module_add_modinfo_attrs(struct module *mod)
1689 struct module_attribute *attr;
1690 struct module_attribute *temp_attr;
1694 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1695 (ARRAY_SIZE(modinfo_attrs) + 1)),
1697 if (!mod->modinfo_attrs)
1700 temp_attr = mod->modinfo_attrs;
1701 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1702 if (!attr->test || attr->test(mod)) {
1703 memcpy(temp_attr, attr, sizeof(*temp_attr));
1704 sysfs_attr_init(&temp_attr->attr);
1705 error = sysfs_create_file(&mod->mkobj.kobj,
1713 static void module_remove_modinfo_attrs(struct module *mod)
1715 struct module_attribute *attr;
1718 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1719 /* pick a field to test for end of list */
1720 if (!attr->attr.name)
1722 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1726 kfree(mod->modinfo_attrs);
1729 static void mod_kobject_put(struct module *mod)
1731 DECLARE_COMPLETION_ONSTACK(c);
1732 mod->mkobj.kobj_completion = &c;
1733 kobject_put(&mod->mkobj.kobj);
1734 wait_for_completion(&c);
1737 static int mod_sysfs_init(struct module *mod)
1740 struct kobject *kobj;
1742 if (!module_sysfs_initialized) {
1743 pr_err("%s: module sysfs not initialized\n", mod->name);
1748 kobj = kset_find_obj(module_kset, mod->name);
1750 pr_err("%s: module is already loaded\n", mod->name);
1756 mod->mkobj.mod = mod;
1758 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1759 mod->mkobj.kobj.kset = module_kset;
1760 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1763 mod_kobject_put(mod);
1769 static int mod_sysfs_setup(struct module *mod,
1770 const struct load_info *info,
1771 struct kernel_param *kparam,
1772 unsigned int num_params)
1776 err = mod_sysfs_init(mod);
1780 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1781 if (!mod->holders_dir) {
1786 err = module_param_sysfs_setup(mod, kparam, num_params);
1788 goto out_unreg_holders;
1790 err = module_add_modinfo_attrs(mod);
1792 goto out_unreg_param;
1794 add_usage_links(mod);
1795 add_sect_attrs(mod, info);
1796 add_notes_attrs(mod, info);
1801 module_param_sysfs_remove(mod);
1803 kobject_put(mod->holders_dir);
1805 mod_kobject_put(mod);
1810 static void mod_sysfs_fini(struct module *mod)
1812 remove_notes_attrs(mod);
1813 remove_sect_attrs(mod);
1814 mod_kobject_put(mod);
1817 static void init_param_lock(struct module *mod)
1819 mutex_init(&mod->param_lock);
1821 #else /* !CONFIG_SYSFS */
1823 static int mod_sysfs_setup(struct module *mod,
1824 const struct load_info *info,
1825 struct kernel_param *kparam,
1826 unsigned int num_params)
1831 static void mod_sysfs_fini(struct module *mod)
1835 static void module_remove_modinfo_attrs(struct module *mod)
1839 static void del_usage_links(struct module *mod)
1843 static void init_param_lock(struct module *mod)
1846 #endif /* CONFIG_SYSFS */
1848 static void mod_sysfs_teardown(struct module *mod)
1850 del_usage_links(mod);
1851 module_remove_modinfo_attrs(mod);
1852 module_param_sysfs_remove(mod);
1853 kobject_put(mod->mkobj.drivers_dir);
1854 kobject_put(mod->holders_dir);
1855 mod_sysfs_fini(mod);
1858 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
1860 * LKM RO/NX protection: protect module's text/ro-data
1861 * from modification and any data from execution.
1863 * General layout of module is:
1864 * [text] [read-only-data] [ro-after-init] [writable data]
1865 * text_size -----^ ^ ^ ^
1866 * ro_size ------------------------| | |
1867 * ro_after_init_size -----------------------------| |
1868 * size -----------------------------------------------------------|
1870 * These values are always page-aligned (as is base)
1872 static void frob_text(const struct module_layout *layout,
1873 int (*set_memory)(unsigned long start, int num_pages))
1875 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1876 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1877 set_memory((unsigned long)layout->base,
1878 layout->text_size >> PAGE_SHIFT);
1881 static void frob_rodata(const struct module_layout *layout,
1882 int (*set_memory)(unsigned long start, int num_pages))
1884 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1885 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1886 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1887 set_memory((unsigned long)layout->base + layout->text_size,
1888 (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
1891 static void frob_ro_after_init(const struct module_layout *layout,
1892 int (*set_memory)(unsigned long start, int num_pages))
1894 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1895 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1896 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1897 set_memory((unsigned long)layout->base + layout->ro_size,
1898 (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
1901 static void frob_writable_data(const struct module_layout *layout,
1902 int (*set_memory)(unsigned long start, int num_pages))
1904 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1905 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1906 BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
1907 set_memory((unsigned long)layout->base + layout->ro_after_init_size,
1908 (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
1911 /* livepatching wants to disable read-only so it can frob module. */
1912 void module_disable_ro(const struct module *mod)
1914 if (!rodata_enabled)
1917 frob_text(&mod->core_layout, set_memory_rw);
1918 frob_rodata(&mod->core_layout, set_memory_rw);
1919 frob_ro_after_init(&mod->core_layout, set_memory_rw);
1920 frob_text(&mod->init_layout, set_memory_rw);
1921 frob_rodata(&mod->init_layout, set_memory_rw);
1924 void module_enable_ro(const struct module *mod, bool after_init)
1926 if (!rodata_enabled)
1929 frob_text(&mod->core_layout, set_memory_ro);
1930 frob_rodata(&mod->core_layout, set_memory_ro);
1931 frob_text(&mod->init_layout, set_memory_ro);
1932 frob_rodata(&mod->init_layout, set_memory_ro);
1935 frob_ro_after_init(&mod->core_layout, set_memory_ro);
1938 static void module_enable_nx(const struct module *mod)
1940 frob_rodata(&mod->core_layout, set_memory_nx);
1941 frob_ro_after_init(&mod->core_layout, set_memory_nx);
1942 frob_writable_data(&mod->core_layout, set_memory_nx);
1943 frob_rodata(&mod->init_layout, set_memory_nx);
1944 frob_writable_data(&mod->init_layout, set_memory_nx);
1947 static void module_disable_nx(const struct module *mod)
1949 frob_rodata(&mod->core_layout, set_memory_x);
1950 frob_ro_after_init(&mod->core_layout, set_memory_x);
1951 frob_writable_data(&mod->core_layout, set_memory_x);
1952 frob_rodata(&mod->init_layout, set_memory_x);
1953 frob_writable_data(&mod->init_layout, set_memory_x);
1956 /* Iterate through all modules and set each module's text as RW */
1957 void set_all_modules_text_rw(void)
1961 if (!rodata_enabled)
1964 mutex_lock(&module_mutex);
1965 list_for_each_entry_rcu(mod, &modules, list) {
1966 if (mod->state == MODULE_STATE_UNFORMED)
1969 frob_text(&mod->core_layout, set_memory_rw);
1970 frob_text(&mod->init_layout, set_memory_rw);
1972 mutex_unlock(&module_mutex);
1975 /* Iterate through all modules and set each module's text as RO */
1976 void set_all_modules_text_ro(void)
1980 if (!rodata_enabled)
1983 mutex_lock(&module_mutex);
1984 list_for_each_entry_rcu(mod, &modules, list) {
1985 if (mod->state == MODULE_STATE_UNFORMED)
1988 frob_text(&mod->core_layout, set_memory_ro);
1989 frob_text(&mod->init_layout, set_memory_ro);
1991 mutex_unlock(&module_mutex);
1994 static void disable_ro_nx(const struct module_layout *layout)
1996 if (rodata_enabled) {
1997 frob_text(layout, set_memory_rw);
1998 frob_rodata(layout, set_memory_rw);
1999 frob_ro_after_init(layout, set_memory_rw);
2001 frob_rodata(layout, set_memory_x);
2002 frob_ro_after_init(layout, set_memory_x);
2003 frob_writable_data(layout, set_memory_x);
2007 static void disable_ro_nx(const struct module_layout *layout) { }
2008 static void module_enable_nx(const struct module *mod) { }
2009 static void module_disable_nx(const struct module *mod) { }
2012 #ifdef CONFIG_LIVEPATCH
2014 * Persist Elf information about a module. Copy the Elf header,
2015 * section header table, section string table, and symtab section
2016 * index from info to mod->klp_info.
2018 static int copy_module_elf(struct module *mod, struct load_info *info)
2020 unsigned int size, symndx;
2023 size = sizeof(*mod->klp_info);
2024 mod->klp_info = kmalloc(size, GFP_KERNEL);
2025 if (mod->klp_info == NULL)
2029 size = sizeof(mod->klp_info->hdr);
2030 memcpy(&mod->klp_info->hdr, info->hdr, size);
2032 /* Elf section header table */
2033 size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
2034 mod->klp_info->sechdrs = kmalloc(size, GFP_KERNEL);
2035 if (mod->klp_info->sechdrs == NULL) {
2039 memcpy(mod->klp_info->sechdrs, info->sechdrs, size);
2041 /* Elf section name string table */
2042 size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
2043 mod->klp_info->secstrings = kmalloc(size, GFP_KERNEL);
2044 if (mod->klp_info->secstrings == NULL) {
2048 memcpy(mod->klp_info->secstrings, info->secstrings, size);
2050 /* Elf symbol section index */
2051 symndx = info->index.sym;
2052 mod->klp_info->symndx = symndx;
2055 * For livepatch modules, core_kallsyms.symtab is a complete
2056 * copy of the original symbol table. Adjust sh_addr to point
2057 * to core_kallsyms.symtab since the copy of the symtab in module
2058 * init memory is freed at the end of do_init_module().
2060 mod->klp_info->sechdrs[symndx].sh_addr = \
2061 (unsigned long) mod->core_kallsyms.symtab;
2066 kfree(mod->klp_info->sechdrs);
2068 kfree(mod->klp_info);
2072 static void free_module_elf(struct module *mod)
2074 kfree(mod->klp_info->sechdrs);
2075 kfree(mod->klp_info->secstrings);
2076 kfree(mod->klp_info);
2078 #else /* !CONFIG_LIVEPATCH */
2079 static int copy_module_elf(struct module *mod, struct load_info *info)
2084 static void free_module_elf(struct module *mod)
2087 #endif /* CONFIG_LIVEPATCH */
2089 void __weak module_memfree(void *module_region)
2091 vfree(module_region);
2094 void __weak module_arch_cleanup(struct module *mod)
2098 void __weak module_arch_freeing_init(struct module *mod)
2102 /* Free a module, remove from lists, etc. */
2103 static void free_module(struct module *mod)
2105 trace_module_free(mod);
2107 mod_sysfs_teardown(mod);
2109 /* We leave it in list to prevent duplicate loads, but make sure
2110 * that noone uses it while it's being deconstructed. */
2111 mutex_lock(&module_mutex);
2112 mod->state = MODULE_STATE_UNFORMED;
2113 mutex_unlock(&module_mutex);
2115 /* Remove dynamic debug info */
2116 ddebug_remove_module(mod->name);
2118 /* Arch-specific cleanup. */
2119 module_arch_cleanup(mod);
2121 /* Module unload stuff */
2122 module_unload_free(mod);
2124 /* Free any allocated parameters. */
2125 destroy_params(mod->kp, mod->num_kp);
2127 if (is_livepatch_module(mod))
2128 free_module_elf(mod);
2130 /* Now we can delete it from the lists */
2131 mutex_lock(&module_mutex);
2132 /* Unlink carefully: kallsyms could be walking list. */
2133 list_del_rcu(&mod->list);
2134 mod_tree_remove(mod);
2135 /* Remove this module from bug list, this uses list_del_rcu */
2136 module_bug_cleanup(mod);
2137 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2138 synchronize_sched();
2139 mutex_unlock(&module_mutex);
2141 /* This may be empty, but that's OK */
2142 disable_ro_nx(&mod->init_layout);
2143 module_arch_freeing_init(mod);
2144 module_memfree(mod->init_layout.base);
2146 percpu_modfree(mod);
2148 /* Free lock-classes; relies on the preceding sync_rcu(). */
2149 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
2151 /* Finally, free the core (containing the module structure) */
2152 disable_ro_nx(&mod->core_layout);
2153 module_memfree(mod->core_layout.base);
2156 update_protections(current->mm);
2160 void *__symbol_get(const char *symbol)
2162 struct module *owner;
2163 const struct kernel_symbol *sym;
2166 sym = find_symbol(symbol, &owner, NULL, true, true);
2167 if (sym && strong_try_module_get(owner))
2171 return sym ? (void *)sym->value : NULL;
2173 EXPORT_SYMBOL_GPL(__symbol_get);
2176 * Ensure that an exported symbol [global namespace] does not already exist
2177 * in the kernel or in some other module's exported symbol table.
2179 * You must hold the module_mutex.
2181 static int verify_export_symbols(struct module *mod)
2184 struct module *owner;
2185 const struct kernel_symbol *s;
2187 const struct kernel_symbol *sym;
2190 { mod->syms, mod->num_syms },
2191 { mod->gpl_syms, mod->num_gpl_syms },
2192 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2193 #ifdef CONFIG_UNUSED_SYMBOLS
2194 { mod->unused_syms, mod->num_unused_syms },
2195 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2199 for (i = 0; i < ARRAY_SIZE(arr); i++) {
2200 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2201 if (find_symbol(s->name, &owner, NULL, true, false)) {
2202 pr_err("%s: exports duplicate symbol %s"
2204 mod->name, s->name, module_name(owner));
2212 static bool ignore_undef_symbol(Elf_Half emachine, const char *name)
2215 * On x86, PIC code and Clang non-PIC code may have call foo@PLT. GNU as
2216 * before 2.37 produces an unreferenced _GLOBAL_OFFSET_TABLE_ on x86-64.
2217 * i386 has a similar problem but may not deserve a fix.
2219 * If we ever have to ignore many symbols, consider refactoring the code to
2220 * only warn if referenced by a relocation.
2222 if (emachine == EM_386 || emachine == EM_X86_64)
2223 return !strcmp(name, "_GLOBAL_OFFSET_TABLE_");
2227 /* Change all symbols so that st_value encodes the pointer directly. */
2228 static int simplify_symbols(struct module *mod, const struct load_info *info)
2230 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2231 Elf_Sym *sym = (void *)symsec->sh_addr;
2232 unsigned long secbase;
2235 const struct kernel_symbol *ksym;
2237 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2238 const char *name = info->strtab + sym[i].st_name;
2240 switch (sym[i].st_shndx) {
2242 /* Ignore common symbols */
2243 if (!strncmp(name, "__gnu_lto", 9))
2246 /* We compiled with -fno-common. These are not
2247 supposed to happen. */
2248 pr_debug("Common symbol: %s\n", name);
2249 pr_warn("%s: please compile with -fno-common\n",
2255 /* Don't need to do anything */
2256 pr_debug("Absolute symbol: 0x%08lx\n",
2257 (long)sym[i].st_value);
2261 /* Livepatch symbols are resolved by livepatch */
2265 ksym = resolve_symbol_wait(mod, info, name);
2266 /* Ok if resolved. */
2267 if (ksym && !IS_ERR(ksym)) {
2268 sym[i].st_value = ksym->value;
2272 /* Ok if weak or ignored. */
2274 (ELF_ST_BIND(sym[i].st_info) == STB_WEAK ||
2275 ignore_undef_symbol(info->hdr->e_machine, name)))
2278 pr_warn("%s: Unknown symbol %s (err %li)\n",
2279 mod->name, name, PTR_ERR(ksym));
2280 ret = PTR_ERR(ksym) ?: -ENOENT;
2284 /* Divert to percpu allocation if a percpu var. */
2285 if (sym[i].st_shndx == info->index.pcpu)
2286 secbase = (unsigned long)mod_percpu(mod);
2288 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2289 sym[i].st_value += secbase;
2297 static int apply_relocations(struct module *mod, const struct load_info *info)
2302 /* Now do relocations. */
2303 for (i = 1; i < info->hdr->e_shnum; i++) {
2304 unsigned int infosec = info->sechdrs[i].sh_info;
2306 /* Not a valid relocation section? */
2307 if (infosec >= info->hdr->e_shnum)
2310 /* Don't bother with non-allocated sections */
2311 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2314 /* Livepatch relocation sections are applied by livepatch */
2315 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
2318 if (info->sechdrs[i].sh_type == SHT_REL)
2319 err = apply_relocate(info->sechdrs, info->strtab,
2320 info->index.sym, i, mod);
2321 else if (info->sechdrs[i].sh_type == SHT_RELA)
2322 err = apply_relocate_add(info->sechdrs, info->strtab,
2323 info->index.sym, i, mod);
2330 /* Additional bytes needed by arch in front of individual sections */
2331 unsigned int __weak arch_mod_section_prepend(struct module *mod,
2332 unsigned int section)
2334 /* default implementation just returns zero */
2338 /* Update size with this section: return offset. */
2339 static long get_offset(struct module *mod, unsigned int *size,
2340 Elf_Shdr *sechdr, unsigned int section)
2344 *size += arch_mod_section_prepend(mod, section);
2345 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2346 *size = ret + sechdr->sh_size;
2350 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2351 might -- code, read-only data, read-write data, small data. Tally
2352 sizes, and place the offsets into sh_entsize fields: high bit means it
2354 static void layout_sections(struct module *mod, struct load_info *info)
2356 static unsigned long const masks[][2] = {
2357 /* NOTE: all executable code must be the first section
2358 * in this array; otherwise modify the text_size
2359 * finder in the two loops below */
2360 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2361 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2362 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
2363 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2364 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2368 for (i = 0; i < info->hdr->e_shnum; i++)
2369 info->sechdrs[i].sh_entsize = ~0UL;
2371 pr_debug("Core section allocation order:\n");
2372 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2373 for (i = 0; i < info->hdr->e_shnum; ++i) {
2374 Elf_Shdr *s = &info->sechdrs[i];
2375 const char *sname = info->secstrings + s->sh_name;
2377 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2378 || (s->sh_flags & masks[m][1])
2379 || s->sh_entsize != ~0UL
2380 || strstarts(sname, ".init"))
2382 s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2383 pr_debug("\t%s\n", sname);
2386 case 0: /* executable */
2387 mod->core_layout.size = debug_align(mod->core_layout.size);
2388 mod->core_layout.text_size = mod->core_layout.size;
2390 case 1: /* RO: text and ro-data */
2391 mod->core_layout.size = debug_align(mod->core_layout.size);
2392 mod->core_layout.ro_size = mod->core_layout.size;
2394 case 2: /* RO after init */
2395 mod->core_layout.size = debug_align(mod->core_layout.size);
2396 mod->core_layout.ro_after_init_size = mod->core_layout.size;
2398 case 4: /* whole core */
2399 mod->core_layout.size = debug_align(mod->core_layout.size);
2404 pr_debug("Init section allocation order:\n");
2405 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2406 for (i = 0; i < info->hdr->e_shnum; ++i) {
2407 Elf_Shdr *s = &info->sechdrs[i];
2408 const char *sname = info->secstrings + s->sh_name;
2410 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2411 || (s->sh_flags & masks[m][1])
2412 || s->sh_entsize != ~0UL
2413 || !strstarts(sname, ".init"))
2415 s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
2416 | INIT_OFFSET_MASK);
2417 pr_debug("\t%s\n", sname);
2420 case 0: /* executable */
2421 mod->init_layout.size = debug_align(mod->init_layout.size);
2422 mod->init_layout.text_size = mod->init_layout.size;
2424 case 1: /* RO: text and ro-data */
2425 mod->init_layout.size = debug_align(mod->init_layout.size);
2426 mod->init_layout.ro_size = mod->init_layout.size;
2430 * RO after init doesn't apply to init_layout (only
2431 * core_layout), so it just takes the value of ro_size.
2433 mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
2435 case 4: /* whole init */
2436 mod->init_layout.size = debug_align(mod->init_layout.size);
2442 static void set_license(struct module *mod, const char *license)
2445 license = "unspecified";
2447 if (!license_is_gpl_compatible(license)) {
2448 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2449 pr_warn("%s: module license '%s' taints kernel.\n",
2450 mod->name, license);
2451 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2452 LOCKDEP_NOW_UNRELIABLE);
2456 /* Parse tag=value strings from .modinfo section */
2457 static char *next_string(char *string, unsigned long *secsize)
2459 /* Skip non-zero chars */
2462 if ((*secsize)-- <= 1)
2466 /* Skip any zero padding. */
2467 while (!string[0]) {
2469 if ((*secsize)-- <= 1)
2475 static char *get_modinfo(struct load_info *info, const char *tag)
2478 unsigned int taglen = strlen(tag);
2479 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2480 unsigned long size = infosec->sh_size;
2482 for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2483 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2484 return p + taglen + 1;
2489 static void setup_modinfo(struct module *mod, struct load_info *info)
2491 struct module_attribute *attr;
2494 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2496 attr->setup(mod, get_modinfo(info, attr->attr.name));
2500 static void free_modinfo(struct module *mod)
2502 struct module_attribute *attr;
2505 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2511 #ifdef CONFIG_KALLSYMS
2513 /* lookup symbol in given range of kernel_symbols */
2514 static const struct kernel_symbol *lookup_symbol(const char *name,
2515 const struct kernel_symbol *start,
2516 const struct kernel_symbol *stop)
2518 return bsearch(name, start, stop - start,
2519 sizeof(struct kernel_symbol), cmp_name);
2522 static int is_exported(const char *name, unsigned long value,
2523 const struct module *mod)
2525 const struct kernel_symbol *ks;
2527 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2529 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2530 return ks != NULL && ks->value == value;
2534 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2536 const Elf_Shdr *sechdrs = info->sechdrs;
2538 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2539 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2544 if (sym->st_shndx == SHN_UNDEF)
2546 if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
2548 if (sym->st_shndx >= SHN_LORESERVE)
2550 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2552 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2553 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2554 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2556 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2561 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2562 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2567 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2574 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2575 unsigned int shnum, unsigned int pcpundx)
2577 const Elf_Shdr *sec;
2579 if (src->st_shndx == SHN_UNDEF
2580 || src->st_shndx >= shnum
2584 #ifdef CONFIG_KALLSYMS_ALL
2585 if (src->st_shndx == pcpundx)
2589 sec = sechdrs + src->st_shndx;
2590 if (!(sec->sh_flags & SHF_ALLOC)
2591 #ifndef CONFIG_KALLSYMS_ALL
2592 || !(sec->sh_flags & SHF_EXECINSTR)
2594 || (sec->sh_entsize & INIT_OFFSET_MASK))
2601 * We only allocate and copy the strings needed by the parts of symtab
2602 * we keep. This is simple, but has the effect of making multiple
2603 * copies of duplicates. We could be more sophisticated, see
2604 * linux-kernel thread starting with
2605 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2607 static void layout_symtab(struct module *mod, struct load_info *info)
2609 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2610 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2612 unsigned int i, nsrc, ndst, strtab_size = 0;
2614 /* Put symbol section at end of init part of module. */
2615 symsect->sh_flags |= SHF_ALLOC;
2616 symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2617 info->index.sym) | INIT_OFFSET_MASK;
2618 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2620 src = (void *)info->hdr + symsect->sh_offset;
2621 nsrc = symsect->sh_size / sizeof(*src);
2623 /* Compute total space required for the core symbols' strtab. */
2624 for (ndst = i = 0; i < nsrc; i++) {
2625 if (i == 0 || is_livepatch_module(mod) ||
2626 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2627 info->index.pcpu)) {
2628 strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2633 /* Append room for core symbols at end of core part. */
2634 info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
2635 info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
2636 mod->core_layout.size += strtab_size;
2637 mod->core_layout.size = debug_align(mod->core_layout.size);
2639 /* Put string table section at end of init part of module. */
2640 strsect->sh_flags |= SHF_ALLOC;
2641 strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2642 info->index.str) | INIT_OFFSET_MASK;
2643 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2645 /* We'll tack temporary mod_kallsyms on the end. */
2646 mod->init_layout.size = ALIGN(mod->init_layout.size,
2647 __alignof__(struct mod_kallsyms));
2648 info->mod_kallsyms_init_off = mod->init_layout.size;
2649 mod->init_layout.size += sizeof(struct mod_kallsyms);
2650 mod->init_layout.size = debug_align(mod->init_layout.size);
2654 * We use the full symtab and strtab which layout_symtab arranged to
2655 * be appended to the init section. Later we switch to the cut-down
2658 static void add_kallsyms(struct module *mod, const struct load_info *info)
2660 unsigned int i, ndst;
2664 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2666 /* Set up to point into init section. */
2667 mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
2669 mod->kallsyms->symtab = (void *)symsec->sh_addr;
2670 mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2671 /* Make sure we get permanent strtab: don't use info->strtab. */
2672 mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2674 /* Set types up while we still have access to sections. */
2675 for (i = 0; i < mod->kallsyms->num_symtab; i++)
2676 mod->kallsyms->symtab[i].st_info
2677 = elf_type(&mod->kallsyms->symtab[i], info);
2679 /* Now populate the cut down core kallsyms for after init. */
2680 mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
2681 mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
2682 src = mod->kallsyms->symtab;
2683 for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2684 if (i == 0 || is_livepatch_module(mod) ||
2685 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2686 info->index.pcpu)) {
2688 dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
2689 s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2693 mod->core_kallsyms.num_symtab = ndst;
2696 static inline void layout_symtab(struct module *mod, struct load_info *info)
2700 static void add_kallsyms(struct module *mod, const struct load_info *info)
2703 #endif /* CONFIG_KALLSYMS */
2705 static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2709 #ifdef CONFIG_DYNAMIC_DEBUG
2710 if (ddebug_add_module(debug, num, debug->modname))
2711 pr_err("dynamic debug error adding module: %s\n",
2716 static void dynamic_debug_remove(struct _ddebug *debug)
2719 ddebug_remove_module(debug->modname);
2722 void * __weak module_alloc(unsigned long size)
2724 return vmalloc_exec(size);
2727 #ifdef CONFIG_DEBUG_KMEMLEAK
2728 static void kmemleak_load_module(const struct module *mod,
2729 const struct load_info *info)
2733 /* only scan the sections containing data */
2734 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2736 for (i = 1; i < info->hdr->e_shnum; i++) {
2737 /* Scan all writable sections that's not executable */
2738 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2739 !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2740 (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2743 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2744 info->sechdrs[i].sh_size, GFP_KERNEL);
2748 static inline void kmemleak_load_module(const struct module *mod,
2749 const struct load_info *info)
2754 #ifdef CONFIG_MODULE_SIG
2755 static int module_sig_check(struct load_info *info, int flags)
2758 const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2759 const void *mod = info->hdr;
2762 * Require flags == 0, as a module with version information
2763 * removed is no longer the module that was signed
2766 info->len > markerlen &&
2767 memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2768 /* We truncate the module to discard the signature */
2769 info->len -= markerlen;
2770 err = mod_verify_sig(mod, &info->len);
2774 info->sig_ok = true;
2778 /* Not having a signature is only an error if we're strict. */
2779 if (err == -ENOKEY && !sig_enforce)
2784 #else /* !CONFIG_MODULE_SIG */
2785 static int module_sig_check(struct load_info *info, int flags)
2789 #endif /* !CONFIG_MODULE_SIG */
2791 /* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2792 static int elf_header_check(struct load_info *info)
2794 if (info->len < sizeof(*(info->hdr)))
2797 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2798 || info->hdr->e_type != ET_REL
2799 || !elf_check_arch(info->hdr)
2800 || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2803 if (info->hdr->e_shoff >= info->len
2804 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2805 info->len - info->hdr->e_shoff))
2811 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2813 static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
2816 unsigned long n = min(len, COPY_CHUNK_SIZE);
2818 if (copy_from_user(dst, usrc, n) != 0)
2828 #ifdef CONFIG_LIVEPATCH
2829 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2831 if (get_modinfo(info, "livepatch")) {
2833 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
2838 #else /* !CONFIG_LIVEPATCH */
2839 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2841 if (get_modinfo(info, "livepatch")) {
2842 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
2849 #endif /* CONFIG_LIVEPATCH */
2851 static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
2853 if (retpoline_module_ok(get_modinfo(info, "retpoline")))
2856 pr_warn("%s: loading module not compiled with retpoline compiler.\n",
2860 /* Sets info->hdr and info->len. */
2861 static int copy_module_from_user(const void __user *umod, unsigned long len,
2862 struct load_info *info)
2867 if (info->len < sizeof(*(info->hdr)))
2870 err = security_kernel_read_file(NULL, READING_MODULE);
2874 /* Suck in entire file: we'll want most of it. */
2875 info->hdr = __vmalloc(info->len,
2876 GFP_KERNEL | __GFP_HIGHMEM | __GFP_NOWARN, PAGE_KERNEL);
2880 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2888 static void free_copy(struct load_info *info)
2893 static int rewrite_section_headers(struct load_info *info, int flags)
2897 /* This should always be true, but let's be sure. */
2898 info->sechdrs[0].sh_addr = 0;
2900 for (i = 1; i < info->hdr->e_shnum; i++) {
2901 Elf_Shdr *shdr = &info->sechdrs[i];
2902 if (shdr->sh_type != SHT_NOBITS
2903 && info->len < shdr->sh_offset + shdr->sh_size) {
2904 pr_err("Module len %lu truncated\n", info->len);
2908 /* Mark all sections sh_addr with their address in the
2910 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2912 #ifndef CONFIG_MODULE_UNLOAD
2913 /* Don't load .exit sections */
2914 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2915 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2919 /* Track but don't keep modinfo and version sections. */
2920 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
2921 info->index.vers = 0; /* Pretend no __versions section! */
2923 info->index.vers = find_sec(info, "__versions");
2924 info->index.info = find_sec(info, ".modinfo");
2925 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2926 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2931 * Set up our basic convenience variables (pointers to section headers,
2932 * search for module section index etc), and do some basic section
2935 * Return the temporary module pointer (we'll replace it with the final
2936 * one when we move the module sections around).
2938 static struct module *setup_load_info(struct load_info *info, int flags)
2944 /* Set up the convenience variables */
2945 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2946 info->secstrings = (void *)info->hdr
2947 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2949 err = rewrite_section_headers(info, flags);
2951 return ERR_PTR(err);
2953 /* Find internal symbols and strings. */
2954 for (i = 1; i < info->hdr->e_shnum; i++) {
2955 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2956 info->index.sym = i;
2957 info->index.str = info->sechdrs[i].sh_link;
2958 info->strtab = (char *)info->hdr
2959 + info->sechdrs[info->index.str].sh_offset;
2964 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2965 if (!info->index.mod) {
2966 pr_warn("No module found in object\n");
2967 return ERR_PTR(-ENOEXEC);
2969 /* This is temporary: point mod into copy of data. */
2970 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2972 if (info->index.sym == 0) {
2973 pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
2974 return ERR_PTR(-ENOEXEC);
2977 info->index.pcpu = find_pcpusec(info);
2979 /* Check module struct version now, before we try to use module. */
2980 if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2981 return ERR_PTR(-ENOEXEC);
2986 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2988 const char *modmagic = get_modinfo(info, "vermagic");
2991 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
2994 /* This is allowed: modprobe --force will invalidate it. */
2996 err = try_to_force_load(mod, "bad vermagic");
2999 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
3000 pr_err("%s: version magic '%s' should be '%s'\n",
3001 mod->name, modmagic, vermagic);
3005 if (!get_modinfo(info, "intree")) {
3006 if (!test_taint(TAINT_OOT_MODULE))
3007 pr_warn("%s: loading out-of-tree module taints kernel.\n",
3009 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
3012 check_modinfo_retpoline(mod, info);
3014 if (get_modinfo(info, "staging")) {
3015 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
3016 pr_warn("%s: module is from the staging directory, the quality "
3017 "is unknown, you have been warned.\n", mod->name);
3020 err = check_modinfo_livepatch(mod, info);
3024 /* Set up license info based on the info section */
3025 set_license(mod, get_modinfo(info, "license"));
3030 static int find_module_sections(struct module *mod, struct load_info *info)
3032 mod->kp = section_objs(info, "__param",
3033 sizeof(*mod->kp), &mod->num_kp);
3034 mod->syms = section_objs(info, "__ksymtab",
3035 sizeof(*mod->syms), &mod->num_syms);
3036 mod->crcs = section_addr(info, "__kcrctab");
3037 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
3038 sizeof(*mod->gpl_syms),
3039 &mod->num_gpl_syms);
3040 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
3041 mod->gpl_future_syms = section_objs(info,
3042 "__ksymtab_gpl_future",
3043 sizeof(*mod->gpl_future_syms),
3044 &mod->num_gpl_future_syms);
3045 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
3047 #ifdef CONFIG_UNUSED_SYMBOLS
3048 mod->unused_syms = section_objs(info, "__ksymtab_unused",
3049 sizeof(*mod->unused_syms),
3050 &mod->num_unused_syms);
3051 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
3052 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
3053 sizeof(*mod->unused_gpl_syms),
3054 &mod->num_unused_gpl_syms);
3055 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
3057 #ifdef CONFIG_CONSTRUCTORS
3058 mod->ctors = section_objs(info, ".ctors",
3059 sizeof(*mod->ctors), &mod->num_ctors);
3061 mod->ctors = section_objs(info, ".init_array",
3062 sizeof(*mod->ctors), &mod->num_ctors);
3063 else if (find_sec(info, ".init_array")) {
3065 * This shouldn't happen with same compiler and binutils
3066 * building all parts of the module.
3068 pr_warn("%s: has both .ctors and .init_array.\n",
3074 #ifdef CONFIG_TRACEPOINTS
3075 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
3076 sizeof(*mod->tracepoints_ptrs),
3077 &mod->num_tracepoints);
3079 #ifdef HAVE_JUMP_LABEL
3080 mod->jump_entries = section_objs(info, "__jump_table",
3081 sizeof(*mod->jump_entries),
3082 &mod->num_jump_entries);
3084 #ifdef CONFIG_EVENT_TRACING
3085 mod->trace_events = section_objs(info, "_ftrace_events",
3086 sizeof(*mod->trace_events),
3087 &mod->num_trace_events);
3088 mod->trace_enums = section_objs(info, "_ftrace_enum_map",
3089 sizeof(*mod->trace_enums),
3090 &mod->num_trace_enums);
3092 #ifdef CONFIG_TRACING
3093 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
3094 sizeof(*mod->trace_bprintk_fmt_start),
3095 &mod->num_trace_bprintk_fmt);
3097 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
3098 /* sechdrs[0].sh_size is always zero */
3099 mod->ftrace_callsites = section_objs(info, "__mcount_loc",
3100 sizeof(*mod->ftrace_callsites),
3101 &mod->num_ftrace_callsites);
3104 mod->extable = section_objs(info, "__ex_table",
3105 sizeof(*mod->extable), &mod->num_exentries);
3107 if (section_addr(info, "__obsparm"))
3108 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
3110 info->debug = section_objs(info, "__verbose",
3111 sizeof(*info->debug), &info->num_debug);
3116 static int move_module(struct module *mod, struct load_info *info)
3121 /* Do the allocs. */
3122 ptr = module_alloc(mod->core_layout.size);
3124 * The pointer to this block is stored in the module structure
3125 * which is inside the block. Just mark it as not being a
3128 kmemleak_not_leak(ptr);
3132 memset(ptr, 0, mod->core_layout.size);
3133 mod->core_layout.base = ptr;
3135 if (mod->init_layout.size) {
3136 ptr = module_alloc(mod->init_layout.size);
3138 * The pointer to this block is stored in the module structure
3139 * which is inside the block. This block doesn't need to be
3140 * scanned as it contains data and code that will be freed
3141 * after the module is initialized.
3143 kmemleak_ignore(ptr);
3145 module_memfree(mod->core_layout.base);
3148 memset(ptr, 0, mod->init_layout.size);
3149 mod->init_layout.base = ptr;
3151 mod->init_layout.base = NULL;
3153 /* Transfer each section which specifies SHF_ALLOC */
3154 pr_debug("final section addresses:\n");
3155 for (i = 0; i < info->hdr->e_shnum; i++) {
3157 Elf_Shdr *shdr = &info->sechdrs[i];
3159 if (!(shdr->sh_flags & SHF_ALLOC))
3162 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3163 dest = mod->init_layout.base
3164 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3166 dest = mod->core_layout.base + shdr->sh_entsize;
3168 if (shdr->sh_type != SHT_NOBITS)
3169 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3170 /* Update sh_addr to point to copy in image. */
3171 shdr->sh_addr = (unsigned long)dest;
3172 pr_debug("\t0x%lx %s\n",
3173 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3179 static int check_module_license_and_versions(struct module *mod)
3181 int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
3184 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3185 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3186 * using GPL-only symbols it needs.
3188 if (strcmp(mod->name, "ndiswrapper") == 0)
3189 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3191 /* driverloader was caught wrongly pretending to be under GPL */
3192 if (strcmp(mod->name, "driverloader") == 0)
3193 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3194 LOCKDEP_NOW_UNRELIABLE);
3196 /* lve claims to be GPL but upstream won't provide source */
3197 if (strcmp(mod->name, "lve") == 0)
3198 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3199 LOCKDEP_NOW_UNRELIABLE);
3201 if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
3202 pr_warn("%s: module license taints kernel.\n", mod->name);
3204 #ifdef CONFIG_MODVERSIONS
3205 if ((mod->num_syms && !mod->crcs)
3206 || (mod->num_gpl_syms && !mod->gpl_crcs)
3207 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3208 #ifdef CONFIG_UNUSED_SYMBOLS
3209 || (mod->num_unused_syms && !mod->unused_crcs)
3210 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3213 return try_to_force_load(mod,
3214 "no versions for exported symbols");
3220 static void flush_module_icache(const struct module *mod)
3222 mm_segment_t old_fs;
3224 /* flush the icache in correct context */
3229 * Flush the instruction cache, since we've played with text.
3230 * Do it before processing of module parameters, so the module
3231 * can provide parameter accessor functions of its own.
3233 if (mod->init_layout.base)
3234 flush_icache_range((unsigned long)mod->init_layout.base,
3235 (unsigned long)mod->init_layout.base
3236 + mod->init_layout.size);
3237 flush_icache_range((unsigned long)mod->core_layout.base,
3238 (unsigned long)mod->core_layout.base + mod->core_layout.size);
3243 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3251 /* module_blacklist is a comma-separated list of module names */
3252 static char *module_blacklist;
3253 static bool blacklisted(char *module_name)
3258 if (!module_blacklist)
3261 for (p = module_blacklist; *p; p += len) {
3262 len = strcspn(p, ",");
3263 if (strlen(module_name) == len && !memcmp(module_name, p, len))
3270 core_param(module_blacklist, module_blacklist, charp, 0400);
3272 static struct module *layout_and_allocate(struct load_info *info, int flags)
3274 /* Module within temporary copy. */
3279 mod = setup_load_info(info, flags);
3283 if (blacklisted(mod->name))
3284 return ERR_PTR(-EPERM);
3286 err = check_modinfo(mod, info, flags);
3288 return ERR_PTR(err);
3290 /* Allow arches to frob section contents and sizes. */
3291 err = module_frob_arch_sections(info->hdr, info->sechdrs,
3292 info->secstrings, mod);
3294 return ERR_PTR(err);
3296 /* We will do a special allocation for per-cpu sections later. */
3297 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3300 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3301 * layout_sections() can put it in the right place.
3302 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3304 ndx = find_sec(info, ".data..ro_after_init");
3306 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3308 /* Determine total sizes, and put offsets in sh_entsize. For now
3309 this is done generically; there doesn't appear to be any
3310 special cases for the architectures. */
3311 layout_sections(mod, info);
3312 layout_symtab(mod, info);
3314 /* Allocate and move to the final place */
3315 err = move_module(mod, info);
3317 return ERR_PTR(err);
3319 /* Module has been copied to its final place now: return it. */
3320 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3321 kmemleak_load_module(mod, info);
3325 /* mod is no longer valid after this! */
3326 static void module_deallocate(struct module *mod, struct load_info *info)
3328 percpu_modfree(mod);
3329 module_arch_freeing_init(mod);
3330 module_memfree(mod->init_layout.base);
3331 module_memfree(mod->core_layout.base);
3334 int __weak module_finalize(const Elf_Ehdr *hdr,
3335 const Elf_Shdr *sechdrs,
3341 static int post_relocation(struct module *mod, const struct load_info *info)
3343 /* Sort exception table now relocations are done. */
3344 sort_extable(mod->extable, mod->extable + mod->num_exentries);
3346 /* Copy relocated percpu area over. */
3347 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3348 info->sechdrs[info->index.pcpu].sh_size);
3350 /* Setup kallsyms-specific fields. */
3351 add_kallsyms(mod, info);
3353 /* Arch-specific module finalizing. */
3354 return module_finalize(info->hdr, info->sechdrs, mod);
3357 /* Is this module of this name done loading? No locks held. */
3358 static bool finished_loading(const char *name)
3364 * The module_mutex should not be a heavily contended lock;
3365 * if we get the occasional sleep here, we'll go an extra iteration
3366 * in the wait_event_interruptible(), which is harmless.
3368 sched_annotate_sleep();
3369 mutex_lock(&module_mutex);
3370 mod = find_module_all(name, strlen(name), true);
3371 ret = !mod || mod->state == MODULE_STATE_LIVE;
3372 mutex_unlock(&module_mutex);
3377 /* Call module constructors. */
3378 static void do_mod_ctors(struct module *mod)
3380 #ifdef CONFIG_CONSTRUCTORS
3383 for (i = 0; i < mod->num_ctors; i++)
3388 /* For freeing module_init on success, in case kallsyms traversing */
3389 struct mod_initfree {
3390 struct rcu_head rcu;
3394 static void do_free_init(struct rcu_head *head)
3396 struct mod_initfree *m = container_of(head, struct mod_initfree, rcu);
3397 module_memfree(m->module_init);
3402 * This is where the real work happens.
3404 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3405 * helper command 'lx-symbols'.
3407 static noinline int do_init_module(struct module *mod)
3410 struct mod_initfree *freeinit;
3412 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3417 freeinit->module_init = mod->init_layout.base;
3420 * We want to find out whether @mod uses async during init. Clear
3421 * PF_USED_ASYNC. async_schedule*() will set it.
3423 current->flags &= ~PF_USED_ASYNC;
3426 /* Start the module */
3427 if (mod->init != NULL)
3428 ret = do_one_initcall(mod->init);
3430 goto fail_free_freeinit;
3433 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3434 "follow 0/-E convention\n"
3435 "%s: loading module anyway...\n",
3436 __func__, mod->name, ret, __func__);
3440 /* Now it's a first class citizen! */
3441 mod->state = MODULE_STATE_LIVE;
3442 blocking_notifier_call_chain(&module_notify_list,
3443 MODULE_STATE_LIVE, mod);
3445 /* Delay uevent until module has finished its init routine */
3446 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
3449 * We need to finish all async code before the module init sequence
3450 * is done. This has potential to deadlock. For example, a newly
3451 * detected block device can trigger request_module() of the
3452 * default iosched from async probing task. Once userland helper
3453 * reaches here, async_synchronize_full() will wait on the async
3454 * task waiting on request_module() and deadlock.
3456 * This deadlock is avoided by perfomring async_synchronize_full()
3457 * iff module init queued any async jobs. This isn't a full
3458 * solution as it will deadlock the same if module loading from
3459 * async jobs nests more than once; however, due to the various
3460 * constraints, this hack seems to be the best option for now.
3461 * Please refer to the following thread for details.
3463 * http://thread.gmane.org/gmane.linux.kernel/1420814
3465 if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3466 async_synchronize_full();
3468 mutex_lock(&module_mutex);
3469 /* Drop initial reference. */
3471 trim_init_extable(mod);
3472 #ifdef CONFIG_KALLSYMS
3473 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3474 rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3476 module_enable_ro(mod, true);
3477 mod_tree_remove_init(mod);
3478 disable_ro_nx(&mod->init_layout);
3479 module_arch_freeing_init(mod);
3480 mod->init_layout.base = NULL;
3481 mod->init_layout.size = 0;
3482 mod->init_layout.ro_size = 0;
3483 mod->init_layout.ro_after_init_size = 0;
3484 mod->init_layout.text_size = 0;
3486 * We want to free module_init, but be aware that kallsyms may be
3487 * walking this with preempt disabled. In all the failure paths, we
3488 * call synchronize_sched(), but we don't want to slow down the success
3489 * path, so use actual RCU here.
3491 call_rcu_sched(&freeinit->rcu, do_free_init);
3492 mutex_unlock(&module_mutex);
3493 wake_up_all(&module_wq);
3500 /* Try to protect us from buggy refcounters. */
3501 mod->state = MODULE_STATE_GOING;
3502 synchronize_sched();
3504 blocking_notifier_call_chain(&module_notify_list,
3505 MODULE_STATE_GOING, mod);
3506 klp_module_going(mod);
3507 ftrace_release_mod(mod);
3509 wake_up_all(&module_wq);
3513 static int may_init_module(void)
3515 if (!capable(CAP_SYS_MODULE) || modules_disabled)
3522 * We try to place it in the list now to make sure it's unique before
3523 * we dedicate too many resources. In particular, temporary percpu
3524 * memory exhaustion.
3526 static int add_unformed_module(struct module *mod)
3531 mod->state = MODULE_STATE_UNFORMED;
3534 mutex_lock(&module_mutex);
3535 old = find_module_all(mod->name, strlen(mod->name), true);
3537 if (old->state != MODULE_STATE_LIVE) {
3538 /* Wait in case it fails to load. */
3539 mutex_unlock(&module_mutex);
3540 err = wait_event_interruptible(module_wq,
3541 finished_loading(mod->name));
3549 mod_update_bounds(mod);
3550 list_add_rcu(&mod->list, &modules);
3551 mod_tree_insert(mod);
3555 mutex_unlock(&module_mutex);
3560 static int complete_formation(struct module *mod, struct load_info *info)
3564 mutex_lock(&module_mutex);
3566 /* Find duplicate symbols (must be called under lock). */
3567 err = verify_export_symbols(mod);
3571 /* This relies on module_mutex for list integrity. */
3572 module_bug_finalize(info->hdr, info->sechdrs, mod);
3574 module_enable_ro(mod, false);
3575 module_enable_nx(mod);
3577 /* Mark state as coming so strong_try_module_get() ignores us,
3578 * but kallsyms etc. can see us. */
3579 mod->state = MODULE_STATE_COMING;
3580 mutex_unlock(&module_mutex);
3585 mutex_unlock(&module_mutex);
3589 static int prepare_coming_module(struct module *mod)
3593 ftrace_module_enable(mod);
3594 err = klp_module_coming(mod);
3598 blocking_notifier_call_chain(&module_notify_list,
3599 MODULE_STATE_COMING, mod);
3603 static int unknown_module_param_cb(char *param, char *val, const char *modname,
3606 struct module *mod = arg;
3609 if (strcmp(param, "async_probe") == 0) {
3610 mod->async_probe_requested = true;
3614 /* Check for magic 'dyndbg' arg */
3615 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3617 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3621 /* Allocate and load the module: note that size of section 0 is always
3622 zero, and we rely on this for optional sections. */
3623 static int load_module(struct load_info *info, const char __user *uargs,
3630 err = module_sig_check(info, flags);
3634 err = elf_header_check(info);
3638 /* Figure out module layout, and allocate all the memory. */
3639 mod = layout_and_allocate(info, flags);
3645 /* Reserve our place in the list. */
3646 err = add_unformed_module(mod);
3650 #ifdef CONFIG_MODULE_SIG
3651 mod->sig_ok = info->sig_ok;
3653 pr_notice_once("%s: module verification failed: signature "
3654 "and/or required key missing - tainting "
3655 "kernel\n", mod->name);
3656 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3660 /* To avoid stressing percpu allocator, do this once we're unique. */
3661 err = percpu_modalloc(mod, info);
3665 /* Now module is in final location, initialize linked lists, etc. */
3666 err = module_unload_init(mod);
3670 init_param_lock(mod);
3672 /* Now we've got everything in the final locations, we can
3673 * find optional sections. */
3674 err = find_module_sections(mod, info);
3678 err = check_module_license_and_versions(mod);
3682 /* Set up MODINFO_ATTR fields */
3683 setup_modinfo(mod, info);
3685 /* Fix up syms, so that st_value is a pointer to location. */
3686 err = simplify_symbols(mod, info);
3690 err = apply_relocations(mod, info);
3694 err = post_relocation(mod, info);
3698 flush_module_icache(mod);
3700 /* Now copy in args */
3701 mod->args = strndup_user(uargs, ~0UL >> 1);
3702 if (IS_ERR(mod->args)) {
3703 err = PTR_ERR(mod->args);
3704 goto free_arch_cleanup;
3707 dynamic_debug_setup(info->debug, info->num_debug);
3709 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3710 ftrace_module_init(mod);
3712 /* Finally it's fully formed, ready to start executing. */
3713 err = complete_formation(mod, info);
3715 goto ddebug_cleanup;
3717 err = prepare_coming_module(mod);
3721 /* Module is ready to execute: parsing args may do that. */
3722 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3724 unknown_module_param_cb);
3725 if (IS_ERR(after_dashes)) {
3726 err = PTR_ERR(after_dashes);
3727 goto coming_cleanup;
3728 } else if (after_dashes) {
3729 pr_warn("%s: parameters '%s' after `--' ignored\n",
3730 mod->name, after_dashes);
3733 /* Link in to syfs. */
3734 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3736 goto coming_cleanup;
3738 if (is_livepatch_module(mod)) {
3739 err = copy_module_elf(mod, info);
3744 /* Get rid of temporary copy. */
3748 trace_module_load(mod);
3750 return do_init_module(mod);
3753 mod_sysfs_teardown(mod);
3755 blocking_notifier_call_chain(&module_notify_list,
3756 MODULE_STATE_GOING, mod);
3757 klp_module_going(mod);
3759 mod->state = MODULE_STATE_GOING;
3760 /* module_bug_cleanup needs module_mutex protection */
3761 mutex_lock(&module_mutex);
3762 module_bug_cleanup(mod);
3763 mutex_unlock(&module_mutex);
3765 /* we can't deallocate the module until we clear memory protection */
3766 module_disable_ro(mod);
3767 module_disable_nx(mod);
3770 dynamic_debug_remove(info->debug);
3771 synchronize_sched();
3774 module_arch_cleanup(mod);
3778 module_unload_free(mod);
3780 mutex_lock(&module_mutex);
3781 /* Unlink carefully: kallsyms could be walking list. */
3782 list_del_rcu(&mod->list);
3783 mod_tree_remove(mod);
3784 wake_up_all(&module_wq);
3785 /* Wait for RCU-sched synchronizing before releasing mod->list. */
3786 synchronize_sched();
3787 mutex_unlock(&module_mutex);
3790 * Ftrace needs to clean up what it initialized.
3791 * This does nothing if ftrace_module_init() wasn't called,
3792 * but it must be called outside of module_mutex.
3794 ftrace_release_mod(mod);
3795 /* Free lock-classes; relies on the preceding sync_rcu() */
3796 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
3798 module_deallocate(mod, info);
3804 SYSCALL_DEFINE3(init_module, void __user *, umod,
3805 unsigned long, len, const char __user *, uargs)
3808 struct load_info info = { };
3810 err = may_init_module();
3814 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3817 err = copy_module_from_user(umod, len, &info);
3821 return load_module(&info, uargs, 0);
3824 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3826 struct load_info info = { };
3831 err = may_init_module();
3835 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3837 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3838 |MODULE_INIT_IGNORE_VERMAGIC))
3841 err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX,
3848 return load_module(&info, uargs, flags);
3851 static inline int within(unsigned long addr, void *start, unsigned long size)
3853 return ((void *)addr >= start && (void *)addr < start + size);
3856 #ifdef CONFIG_KALLSYMS
3858 * This ignores the intensely annoying "mapping symbols" found
3859 * in ARM ELF files: $a, $t and $d.
3861 static inline int is_arm_mapping_symbol(const char *str)
3863 if (str[0] == '.' && str[1] == 'L')
3865 return str[0] == '$' && strchr("axtd", str[1])
3866 && (str[2] == '\0' || str[2] == '.');
3869 static const char *symname(struct mod_kallsyms *kallsyms, unsigned int symnum)
3871 return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
3874 static const char *get_ksymbol(struct module *mod,
3876 unsigned long *size,
3877 unsigned long *offset)
3879 unsigned int i, best = 0;
3880 unsigned long nextval;
3881 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
3883 /* At worse, next value is at end of module */
3884 if (within_module_init(addr, mod))
3885 nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
3887 nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
3889 /* Scan for closest preceding symbol, and next symbol. (ELF
3890 starts real symbols at 1). */
3891 for (i = 1; i < kallsyms->num_symtab; i++) {
3892 if (kallsyms->symtab[i].st_shndx == SHN_UNDEF)
3895 /* We ignore unnamed symbols: they're uninformative
3896 * and inserted at a whim. */
3897 if (*symname(kallsyms, i) == '\0'
3898 || is_arm_mapping_symbol(symname(kallsyms, i)))
3901 if (kallsyms->symtab[i].st_value <= addr
3902 && kallsyms->symtab[i].st_value > kallsyms->symtab[best].st_value)
3904 if (kallsyms->symtab[i].st_value > addr
3905 && kallsyms->symtab[i].st_value < nextval)
3906 nextval = kallsyms->symtab[i].st_value;
3913 *size = nextval - kallsyms->symtab[best].st_value;
3915 *offset = addr - kallsyms->symtab[best].st_value;
3916 return symname(kallsyms, best);
3919 /* For kallsyms to ask for address resolution. NULL means not found. Careful
3920 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3921 const char *module_address_lookup(unsigned long addr,
3922 unsigned long *size,
3923 unsigned long *offset,
3927 const char *ret = NULL;
3931 mod = __module_address(addr);
3934 *modname = mod->name;
3935 ret = get_ksymbol(mod, addr, size, offset);
3937 /* Make a copy in here where it's safe */
3939 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3947 int lookup_module_symbol_name(unsigned long addr, char *symname)
3952 list_for_each_entry_rcu(mod, &modules, list) {
3953 if (mod->state == MODULE_STATE_UNFORMED)
3955 if (within_module(addr, mod)) {
3958 sym = get_ksymbol(mod, addr, NULL, NULL);
3961 strlcpy(symname, sym, KSYM_NAME_LEN);
3971 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3972 unsigned long *offset, char *modname, char *name)
3977 list_for_each_entry_rcu(mod, &modules, list) {
3978 if (mod->state == MODULE_STATE_UNFORMED)
3980 if (within_module(addr, mod)) {
3983 sym = get_ksymbol(mod, addr, size, offset);
3987 strlcpy(modname, mod->name, MODULE_NAME_LEN);
3989 strlcpy(name, sym, KSYM_NAME_LEN);
3999 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
4000 char *name, char *module_name, int *exported)
4005 list_for_each_entry_rcu(mod, &modules, list) {
4006 struct mod_kallsyms *kallsyms;
4008 if (mod->state == MODULE_STATE_UNFORMED)
4010 kallsyms = rcu_dereference_sched(mod->kallsyms);
4011 if (symnum < kallsyms->num_symtab) {
4012 *value = kallsyms->symtab[symnum].st_value;
4013 *type = kallsyms->symtab[symnum].st_info;
4014 strlcpy(name, symname(kallsyms, symnum), KSYM_NAME_LEN);
4015 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
4016 *exported = is_exported(name, *value, mod);
4020 symnum -= kallsyms->num_symtab;
4026 static unsigned long mod_find_symname(struct module *mod, const char *name)
4029 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4031 for (i = 0; i < kallsyms->num_symtab; i++)
4032 if (strcmp(name, symname(kallsyms, i)) == 0 &&
4033 kallsyms->symtab[i].st_shndx != SHN_UNDEF)
4034 return kallsyms->symtab[i].st_value;
4038 /* Look for this name: can be of form module:name. */
4039 unsigned long module_kallsyms_lookup_name(const char *name)
4043 unsigned long ret = 0;
4045 /* Don't lock: we're in enough trouble already. */
4047 if ((colon = strchr(name, ':')) != NULL) {
4048 if ((mod = find_module_all(name, colon - name, false)) != NULL)
4049 ret = mod_find_symname(mod, colon+1);
4051 list_for_each_entry_rcu(mod, &modules, list) {
4052 if (mod->state == MODULE_STATE_UNFORMED)
4054 if ((ret = mod_find_symname(mod, name)) != 0)
4062 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
4063 struct module *, unsigned long),
4070 module_assert_mutex();
4072 list_for_each_entry(mod, &modules, list) {
4073 /* We hold module_mutex: no need for rcu_dereference_sched */
4074 struct mod_kallsyms *kallsyms = mod->kallsyms;
4076 if (mod->state == MODULE_STATE_UNFORMED)
4078 for (i = 0; i < kallsyms->num_symtab; i++) {
4080 if (kallsyms->symtab[i].st_shndx == SHN_UNDEF)
4083 ret = fn(data, symname(kallsyms, i),
4084 mod, kallsyms->symtab[i].st_value);
4091 #endif /* CONFIG_KALLSYMS */
4093 static char *module_flags(struct module *mod, char *buf)
4097 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
4099 mod->state == MODULE_STATE_GOING ||
4100 mod->state == MODULE_STATE_COMING) {
4102 bx += module_flags_taint(mod, buf + bx);
4103 /* Show a - for module-is-being-unloaded */
4104 if (mod->state == MODULE_STATE_GOING)
4106 /* Show a + for module-is-being-loaded */
4107 if (mod->state == MODULE_STATE_COMING)
4116 #ifdef CONFIG_PROC_FS
4117 /* Called by the /proc file system to return a list of modules. */
4118 static void *m_start(struct seq_file *m, loff_t *pos)
4120 mutex_lock(&module_mutex);
4121 return seq_list_start(&modules, *pos);
4124 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
4126 return seq_list_next(p, &modules, pos);
4129 static void m_stop(struct seq_file *m, void *p)
4131 mutex_unlock(&module_mutex);
4134 static int m_show(struct seq_file *m, void *p)
4136 struct module *mod = list_entry(p, struct module, list);
4139 /* We always ignore unformed modules. */
4140 if (mod->state == MODULE_STATE_UNFORMED)
4143 seq_printf(m, "%s %u",
4144 mod->name, mod->init_layout.size + mod->core_layout.size);
4145 print_unload_info(m, mod);
4147 /* Informative for users. */
4148 seq_printf(m, " %s",
4149 mod->state == MODULE_STATE_GOING ? "Unloading" :
4150 mod->state == MODULE_STATE_COMING ? "Loading" :
4152 /* Used by oprofile and other similar tools. */
4153 seq_printf(m, " 0x%pK", mod->core_layout.base);
4157 seq_printf(m, " %s", module_flags(mod, buf));
4163 /* Format: modulename size refcount deps address
4165 Where refcount is a number or -, and deps is a comma-separated list
4168 static const struct seq_operations modules_op = {
4175 static int modules_open(struct inode *inode, struct file *file)
4177 return seq_open(file, &modules_op);
4180 static const struct file_operations proc_modules_operations = {
4181 .open = modules_open,
4183 .llseek = seq_lseek,
4184 .release = seq_release,
4187 static int __init proc_modules_init(void)
4189 proc_create("modules", 0, NULL, &proc_modules_operations);
4192 module_init(proc_modules_init);
4195 /* Given an address, look for it in the module exception tables. */
4196 const struct exception_table_entry *search_module_extables(unsigned long addr)
4198 const struct exception_table_entry *e = NULL;
4202 list_for_each_entry_rcu(mod, &modules, list) {
4203 if (mod->state == MODULE_STATE_UNFORMED)
4205 if (mod->num_exentries == 0)
4208 e = search_extable(mod->extable,
4209 mod->extable + mod->num_exentries - 1,
4216 /* Now, if we found one, we are running inside it now, hence
4217 we cannot unload the module, hence no refcnt needed. */
4222 * is_module_address - is this address inside a module?
4223 * @addr: the address to check.
4225 * See is_module_text_address() if you simply want to see if the address
4226 * is code (not data).
4228 bool is_module_address(unsigned long addr)
4233 ret = __module_address(addr) != NULL;
4240 * __module_address - get the module which contains an address.
4241 * @addr: the address.
4243 * Must be called with preempt disabled or module mutex held so that
4244 * module doesn't get freed during this.
4246 struct module *__module_address(unsigned long addr)
4250 if (addr < module_addr_min || addr > module_addr_max)
4253 module_assert_mutex_or_preempt();
4255 mod = mod_find(addr);
4257 BUG_ON(!within_module(addr, mod));
4258 if (mod->state == MODULE_STATE_UNFORMED)
4263 EXPORT_SYMBOL_GPL(__module_address);
4266 * is_module_text_address - is this address inside module code?
4267 * @addr: the address to check.
4269 * See is_module_address() if you simply want to see if the address is
4270 * anywhere in a module. See kernel_text_address() for testing if an
4271 * address corresponds to kernel or module code.
4273 bool is_module_text_address(unsigned long addr)
4278 ret = __module_text_address(addr) != NULL;
4285 * __module_text_address - get the module whose code contains an address.
4286 * @addr: the address.
4288 * Must be called with preempt disabled or module mutex held so that
4289 * module doesn't get freed during this.
4291 struct module *__module_text_address(unsigned long addr)
4293 struct module *mod = __module_address(addr);
4295 /* Make sure it's within the text section. */
4296 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
4297 && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
4302 EXPORT_SYMBOL_GPL(__module_text_address);
4304 /* Don't grab lock, we're oopsing. */
4305 void print_modules(void)
4310 printk(KERN_DEFAULT "Modules linked in:");
4311 /* Most callers should already have preempt disabled, but make sure */
4313 list_for_each_entry_rcu(mod, &modules, list) {
4314 if (mod->state == MODULE_STATE_UNFORMED)
4316 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4319 if (last_unloaded_module[0])
4320 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4324 #ifdef CONFIG_MODVERSIONS
4325 /* Generate the signature for all relevant module structures here.
4326 * If these change, we don't want to try to parse the module. */
4327 void module_layout(struct module *mod,
4328 struct modversion_info *ver,
4329 struct kernel_param *kp,
4330 struct kernel_symbol *ks,
4331 struct tracepoint * const *tp)
4334 EXPORT_SYMBOL(module_layout);