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/async.h>
57 #include <linux/percpu.h>
58 #include <linux/kmemleak.h>
59 #include <linux/jump_label.h>
60 #include <linux/pfn.h>
61 #include <linux/bsearch.h>
62 #include <uapi/linux/module.h>
63 #include "module-internal.h"
65 #define CREATE_TRACE_POINTS
66 #include <trace/events/module.h>
68 #ifndef ARCH_SHF_SMALL
69 #define ARCH_SHF_SMALL 0
73 * Modules' sections will be aligned on page boundaries
74 * to ensure complete separation of code and data, but
75 * only when CONFIG_DEBUG_SET_MODULE_RONX=y
77 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
78 # define debug_align(X) ALIGN(X, PAGE_SIZE)
80 # define debug_align(X) (X)
84 * Given BASE and SIZE this macro calculates the number of pages the
85 * memory regions occupies
87 #define MOD_NUMBER_OF_PAGES(BASE, SIZE) (((SIZE) > 0) ? \
88 (PFN_DOWN((unsigned long)(BASE) + (SIZE) - 1) - \
89 PFN_DOWN((unsigned long)BASE) + 1) \
92 /* If this is set, the section belongs in the init part of the module */
93 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
97 * 1) List of modules (also safely readable with preempt_disable),
98 * 2) module_use links,
99 * 3) module_addr_min/module_addr_max.
100 * (delete and add uses RCU list operations). */
101 DEFINE_MUTEX(module_mutex);
102 EXPORT_SYMBOL_GPL(module_mutex);
103 static LIST_HEAD(modules);
105 #ifdef CONFIG_MODULES_TREE_LOOKUP
108 * Use a latched RB-tree for __module_address(); this allows us to use
109 * RCU-sched lookups of the address from any context.
111 * Because modules have two address ranges: init and core, we need two
112 * latch_tree_nodes entries. Therefore we need the back-pointer from
115 * Because init ranges are short lived we mark them unlikely and have placed
116 * them outside the critical cacheline in struct module.
118 * This is conditional on PERF_EVENTS || TRACING because those can really hit
119 * __module_address() hard by doing a lot of stack unwinding; potentially from
123 static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
125 struct mod_tree_node *mtn = container_of(n, struct mod_tree_node, node);
126 struct module *mod = mtn->mod;
128 if (unlikely(mtn == &mod->mtn_init))
129 return (unsigned long)mod->module_init;
131 return (unsigned long)mod->module_core;
134 static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
136 struct mod_tree_node *mtn = container_of(n, struct mod_tree_node, node);
137 struct module *mod = mtn->mod;
139 if (unlikely(mtn == &mod->mtn_init))
140 return (unsigned long)mod->init_size;
142 return (unsigned long)mod->core_size;
145 static __always_inline bool
146 mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
148 return __mod_tree_val(a) < __mod_tree_val(b);
151 static __always_inline int
152 mod_tree_comp(void *key, struct latch_tree_node *n)
154 unsigned long val = (unsigned long)key;
155 unsigned long start, end;
157 start = __mod_tree_val(n);
161 end = start + __mod_tree_size(n);
168 static const struct latch_tree_ops mod_tree_ops = {
169 .less = mod_tree_less,
170 .comp = mod_tree_comp,
173 static struct mod_tree_root {
174 struct latch_tree_root root;
175 unsigned long addr_min;
176 unsigned long addr_max;
177 } mod_tree __cacheline_aligned = {
181 #define module_addr_min mod_tree.addr_min
182 #define module_addr_max mod_tree.addr_max
184 static noinline void __mod_tree_insert(struct mod_tree_node *node)
186 latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
189 static void __mod_tree_remove(struct mod_tree_node *node)
191 latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
195 * These modifications: insert, remove_init and remove; are serialized by the
198 static void mod_tree_insert(struct module *mod)
200 mod->mtn_core.mod = mod;
201 mod->mtn_init.mod = mod;
203 __mod_tree_insert(&mod->mtn_core);
205 __mod_tree_insert(&mod->mtn_init);
208 static void mod_tree_remove_init(struct module *mod)
211 __mod_tree_remove(&mod->mtn_init);
214 static void mod_tree_remove(struct module *mod)
216 __mod_tree_remove(&mod->mtn_core);
217 mod_tree_remove_init(mod);
220 static struct module *mod_find(unsigned long addr)
222 struct latch_tree_node *ltn;
224 ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
228 return container_of(ltn, struct mod_tree_node, node)->mod;
231 #else /* MODULES_TREE_LOOKUP */
233 static unsigned long module_addr_min = -1UL, module_addr_max = 0;
235 static void mod_tree_insert(struct module *mod) { }
236 static void mod_tree_remove_init(struct module *mod) { }
237 static void mod_tree_remove(struct module *mod) { }
239 static struct module *mod_find(unsigned long addr)
243 list_for_each_entry_rcu(mod, &modules, list) {
244 if (within_module(addr, mod))
251 #endif /* MODULES_TREE_LOOKUP */
254 * Bounds of module text, for speeding up __module_address.
255 * Protected by module_mutex.
257 static void __mod_update_bounds(void *base, unsigned int size)
259 unsigned long min = (unsigned long)base;
260 unsigned long max = min + size;
262 if (min < module_addr_min)
263 module_addr_min = min;
264 if (max > module_addr_max)
265 module_addr_max = max;
268 static void mod_update_bounds(struct module *mod)
270 __mod_update_bounds(mod->module_core, mod->core_size);
272 __mod_update_bounds(mod->module_init, mod->init_size);
275 #ifdef CONFIG_KGDB_KDB
276 struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
277 #endif /* CONFIG_KGDB_KDB */
279 static void module_assert_mutex(void)
281 lockdep_assert_held(&module_mutex);
284 static void module_assert_mutex_or_preempt(void)
286 #ifdef CONFIG_LOCKDEP
287 if (unlikely(!debug_locks))
290 WARN_ON(!rcu_read_lock_sched_held() &&
291 !lockdep_is_held(&module_mutex));
295 static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
296 #ifndef CONFIG_MODULE_SIG_FORCE
297 module_param(sig_enforce, bool_enable_only, 0644);
298 #endif /* !CONFIG_MODULE_SIG_FORCE */
300 /* Block module loading/unloading? */
301 int modules_disabled = 0;
302 core_param(nomodule, modules_disabled, bint, 0);
304 /* Waiting for a module to finish initializing? */
305 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
307 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
309 int register_module_notifier(struct notifier_block *nb)
311 return blocking_notifier_chain_register(&module_notify_list, nb);
313 EXPORT_SYMBOL(register_module_notifier);
315 int unregister_module_notifier(struct notifier_block *nb)
317 return blocking_notifier_chain_unregister(&module_notify_list, nb);
319 EXPORT_SYMBOL(unregister_module_notifier);
325 char *secstrings, *strtab;
326 unsigned long symoffs, stroffs;
327 struct _ddebug *debug;
328 unsigned int num_debug;
330 #ifdef CONFIG_KALLSYMS
331 unsigned long mod_kallsyms_init_off;
334 unsigned int sym, str, mod, vers, info, pcpu;
338 /* We require a truly strong try_module_get(): 0 means failure due to
339 ongoing or failed initialization etc. */
340 static inline int strong_try_module_get(struct module *mod)
342 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
343 if (mod && mod->state == MODULE_STATE_COMING)
345 if (try_module_get(mod))
351 static inline void add_taint_module(struct module *mod, unsigned flag,
352 enum lockdep_ok lockdep_ok)
354 add_taint(flag, lockdep_ok);
355 mod->taints |= (1U << flag);
359 * A thread that wants to hold a reference to a module only while it
360 * is running can call this to safely exit. nfsd and lockd use this.
362 void __module_put_and_exit(struct module *mod, long code)
367 EXPORT_SYMBOL(__module_put_and_exit);
369 /* Find a module section: 0 means not found. */
370 static unsigned int find_sec(const struct load_info *info, const char *name)
374 for (i = 1; i < info->hdr->e_shnum; i++) {
375 Elf_Shdr *shdr = &info->sechdrs[i];
376 /* Alloc bit cleared means "ignore it." */
377 if ((shdr->sh_flags & SHF_ALLOC)
378 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
384 /* Find a module section, or NULL. */
385 static void *section_addr(const struct load_info *info, const char *name)
387 /* Section 0 has sh_addr 0. */
388 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
391 /* Find a module section, or NULL. Fill in number of "objects" in section. */
392 static void *section_objs(const struct load_info *info,
397 unsigned int sec = find_sec(info, name);
399 /* Section 0 has sh_addr 0 and sh_size 0. */
400 *num = info->sechdrs[sec].sh_size / object_size;
401 return (void *)info->sechdrs[sec].sh_addr;
404 /* Provided by the linker */
405 extern const struct kernel_symbol __start___ksymtab[];
406 extern const struct kernel_symbol __stop___ksymtab[];
407 extern const struct kernel_symbol __start___ksymtab_gpl[];
408 extern const struct kernel_symbol __stop___ksymtab_gpl[];
409 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
410 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
411 extern const unsigned long __start___kcrctab[];
412 extern const unsigned long __start___kcrctab_gpl[];
413 extern const unsigned long __start___kcrctab_gpl_future[];
414 #ifdef CONFIG_UNUSED_SYMBOLS
415 extern const struct kernel_symbol __start___ksymtab_unused[];
416 extern const struct kernel_symbol __stop___ksymtab_unused[];
417 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
418 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
419 extern const unsigned long __start___kcrctab_unused[];
420 extern const unsigned long __start___kcrctab_unused_gpl[];
423 #ifndef CONFIG_MODVERSIONS
424 #define symversion(base, idx) NULL
426 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
429 static bool each_symbol_in_section(const struct symsearch *arr,
430 unsigned int arrsize,
431 struct module *owner,
432 bool (*fn)(const struct symsearch *syms,
433 struct module *owner,
439 for (j = 0; j < arrsize; j++) {
440 if (fn(&arr[j], owner, data))
447 /* Returns true as soon as fn returns true, otherwise false. */
448 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
449 struct module *owner,
454 static const struct symsearch arr[] = {
455 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
456 NOT_GPL_ONLY, false },
457 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
458 __start___kcrctab_gpl,
460 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
461 __start___kcrctab_gpl_future,
462 WILL_BE_GPL_ONLY, false },
463 #ifdef CONFIG_UNUSED_SYMBOLS
464 { __start___ksymtab_unused, __stop___ksymtab_unused,
465 __start___kcrctab_unused,
466 NOT_GPL_ONLY, true },
467 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
468 __start___kcrctab_unused_gpl,
473 module_assert_mutex_or_preempt();
475 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
478 list_for_each_entry_rcu(mod, &modules, list) {
479 struct symsearch arr[] = {
480 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
481 NOT_GPL_ONLY, false },
482 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
485 { mod->gpl_future_syms,
486 mod->gpl_future_syms + mod->num_gpl_future_syms,
487 mod->gpl_future_crcs,
488 WILL_BE_GPL_ONLY, false },
489 #ifdef CONFIG_UNUSED_SYMBOLS
491 mod->unused_syms + mod->num_unused_syms,
493 NOT_GPL_ONLY, true },
494 { mod->unused_gpl_syms,
495 mod->unused_gpl_syms + mod->num_unused_gpl_syms,
496 mod->unused_gpl_crcs,
501 if (mod->state == MODULE_STATE_UNFORMED)
504 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
509 EXPORT_SYMBOL_GPL(each_symbol_section);
511 struct find_symbol_arg {
518 struct module *owner;
519 const unsigned long *crc;
520 const struct kernel_symbol *sym;
523 static bool check_symbol(const struct symsearch *syms,
524 struct module *owner,
525 unsigned int symnum, void *data)
527 struct find_symbol_arg *fsa = data;
530 if (syms->licence == GPL_ONLY)
532 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
533 pr_warn("Symbol %s is being used by a non-GPL module, "
534 "which will not be allowed in the future\n",
539 #ifdef CONFIG_UNUSED_SYMBOLS
540 if (syms->unused && fsa->warn) {
541 pr_warn("Symbol %s is marked as UNUSED, however this module is "
542 "using it.\n", fsa->name);
543 pr_warn("This symbol will go away in the future.\n");
544 pr_warn("Please evaluate if this is the right api to use and "
545 "if it really is, submit a report to the linux kernel "
546 "mailing list together with submitting your code for "
552 fsa->crc = symversion(syms->crcs, symnum);
553 fsa->sym = &syms->start[symnum];
557 static int cmp_name(const void *va, const void *vb)
560 const struct kernel_symbol *b;
562 return strcmp(a, b->name);
565 static bool find_symbol_in_section(const struct symsearch *syms,
566 struct module *owner,
569 struct find_symbol_arg *fsa = data;
570 struct kernel_symbol *sym;
572 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
573 sizeof(struct kernel_symbol), cmp_name);
575 if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
581 /* Find a symbol and return it, along with, (optional) crc and
582 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
583 const struct kernel_symbol *find_symbol(const char *name,
584 struct module **owner,
585 const unsigned long **crc,
589 struct find_symbol_arg fsa;
595 if (each_symbol_section(find_symbol_in_section, &fsa)) {
603 pr_debug("Failed to find symbol %s\n", name);
606 EXPORT_SYMBOL_GPL(find_symbol);
609 * Search for module by name: must hold module_mutex (or preempt disabled
610 * for read-only access).
612 static struct module *find_module_all(const char *name, size_t len,
617 module_assert_mutex_or_preempt();
619 list_for_each_entry(mod, &modules, list) {
620 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
622 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
628 struct module *find_module(const char *name)
630 module_assert_mutex();
631 return find_module_all(name, strlen(name), false);
633 EXPORT_SYMBOL_GPL(find_module);
637 static inline void __percpu *mod_percpu(struct module *mod)
642 static int percpu_modalloc(struct module *mod, struct load_info *info)
644 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
645 unsigned long align = pcpusec->sh_addralign;
647 if (!pcpusec->sh_size)
650 if (align > PAGE_SIZE) {
651 pr_warn("%s: per-cpu alignment %li > %li\n",
652 mod->name, align, PAGE_SIZE);
656 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
658 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
659 mod->name, (unsigned long)pcpusec->sh_size);
662 mod->percpu_size = pcpusec->sh_size;
666 static void percpu_modfree(struct module *mod)
668 free_percpu(mod->percpu);
671 static unsigned int find_pcpusec(struct load_info *info)
673 return find_sec(info, ".data..percpu");
676 static void percpu_modcopy(struct module *mod,
677 const void *from, unsigned long size)
681 for_each_possible_cpu(cpu)
682 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
686 * is_module_percpu_address - test whether address is from module static percpu
687 * @addr: address to test
689 * Test whether @addr belongs to module static percpu area.
692 * %true if @addr is from module static percpu area
694 bool is_module_percpu_address(unsigned long addr)
701 list_for_each_entry_rcu(mod, &modules, list) {
702 if (mod->state == MODULE_STATE_UNFORMED)
704 if (!mod->percpu_size)
706 for_each_possible_cpu(cpu) {
707 void *start = per_cpu_ptr(mod->percpu, cpu);
709 if ((void *)addr >= start &&
710 (void *)addr < start + mod->percpu_size) {
721 #else /* ... !CONFIG_SMP */
723 static inline void __percpu *mod_percpu(struct module *mod)
727 static int percpu_modalloc(struct module *mod, struct load_info *info)
729 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
730 if (info->sechdrs[info->index.pcpu].sh_size != 0)
734 static inline void percpu_modfree(struct module *mod)
737 static unsigned int find_pcpusec(struct load_info *info)
741 static inline void percpu_modcopy(struct module *mod,
742 const void *from, unsigned long size)
744 /* pcpusec should be 0, and size of that section should be 0. */
747 bool is_module_percpu_address(unsigned long addr)
752 #endif /* CONFIG_SMP */
754 #define MODINFO_ATTR(field) \
755 static void setup_modinfo_##field(struct module *mod, const char *s) \
757 mod->field = kstrdup(s, GFP_KERNEL); \
759 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
760 struct module_kobject *mk, char *buffer) \
762 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
764 static int modinfo_##field##_exists(struct module *mod) \
766 return mod->field != NULL; \
768 static void free_modinfo_##field(struct module *mod) \
773 static struct module_attribute modinfo_##field = { \
774 .attr = { .name = __stringify(field), .mode = 0444 }, \
775 .show = show_modinfo_##field, \
776 .setup = setup_modinfo_##field, \
777 .test = modinfo_##field##_exists, \
778 .free = free_modinfo_##field, \
781 MODINFO_ATTR(version);
782 MODINFO_ATTR(srcversion);
784 static char last_unloaded_module[MODULE_NAME_LEN+1];
786 #ifdef CONFIG_MODULE_UNLOAD
788 EXPORT_TRACEPOINT_SYMBOL(module_get);
790 /* MODULE_REF_BASE is the base reference count by kmodule loader. */
791 #define MODULE_REF_BASE 1
793 /* Init the unload section of the module. */
794 static int module_unload_init(struct module *mod)
797 * Initialize reference counter to MODULE_REF_BASE.
798 * refcnt == 0 means module is going.
800 atomic_set(&mod->refcnt, MODULE_REF_BASE);
802 INIT_LIST_HEAD(&mod->source_list);
803 INIT_LIST_HEAD(&mod->target_list);
805 /* Hold reference count during initialization. */
806 atomic_inc(&mod->refcnt);
811 /* Does a already use b? */
812 static int already_uses(struct module *a, struct module *b)
814 struct module_use *use;
816 list_for_each_entry(use, &b->source_list, source_list) {
817 if (use->source == a) {
818 pr_debug("%s uses %s!\n", a->name, b->name);
822 pr_debug("%s does not use %s!\n", a->name, b->name);
828 * - we add 'a' as a "source", 'b' as a "target" of module use
829 * - the module_use is added to the list of 'b' sources (so
830 * 'b' can walk the list to see who sourced them), and of 'a'
831 * targets (so 'a' can see what modules it targets).
833 static int add_module_usage(struct module *a, struct module *b)
835 struct module_use *use;
837 pr_debug("Allocating new usage for %s.\n", a->name);
838 use = kmalloc(sizeof(*use), GFP_ATOMIC);
840 pr_warn("%s: out of memory loading\n", a->name);
846 list_add(&use->source_list, &b->source_list);
847 list_add(&use->target_list, &a->target_list);
851 /* Module a uses b: caller needs module_mutex() */
852 int ref_module(struct module *a, struct module *b)
856 if (b == NULL || already_uses(a, b))
859 /* If module isn't available, we fail. */
860 err = strong_try_module_get(b);
864 err = add_module_usage(a, b);
871 EXPORT_SYMBOL_GPL(ref_module);
873 /* Clear the unload stuff of the module. */
874 static void module_unload_free(struct module *mod)
876 struct module_use *use, *tmp;
878 mutex_lock(&module_mutex);
879 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
880 struct module *i = use->target;
881 pr_debug("%s unusing %s\n", mod->name, i->name);
883 list_del(&use->source_list);
884 list_del(&use->target_list);
887 mutex_unlock(&module_mutex);
890 #ifdef CONFIG_MODULE_FORCE_UNLOAD
891 static inline int try_force_unload(unsigned int flags)
893 int ret = (flags & O_TRUNC);
895 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
899 static inline int try_force_unload(unsigned int flags)
903 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
905 /* Try to release refcount of module, 0 means success. */
906 static int try_release_module_ref(struct module *mod)
910 /* Try to decrement refcnt which we set at loading */
911 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
914 /* Someone can put this right now, recover with checking */
915 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
920 static int try_stop_module(struct module *mod, int flags, int *forced)
922 /* If it's not unused, quit unless we're forcing. */
923 if (try_release_module_ref(mod) != 0) {
924 *forced = try_force_unload(flags);
929 /* Mark it as dying. */
930 mod->state = MODULE_STATE_GOING;
936 * module_refcount - return the refcount or -1 if unloading
938 * @mod: the module we're checking
941 * -1 if the module is in the process of unloading
942 * otherwise the number of references in the kernel to the module
944 int module_refcount(struct module *mod)
946 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
948 EXPORT_SYMBOL(module_refcount);
950 /* This exists whether we can unload or not */
951 static void free_module(struct module *mod);
953 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
957 char name[MODULE_NAME_LEN];
960 if (!capable(CAP_SYS_MODULE) || modules_disabled)
963 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
965 name[MODULE_NAME_LEN-1] = '\0';
967 if (mutex_lock_interruptible(&module_mutex) != 0)
970 mod = find_module(name);
976 if (!list_empty(&mod->source_list)) {
977 /* Other modules depend on us: get rid of them first. */
982 /* Doing init or already dying? */
983 if (mod->state != MODULE_STATE_LIVE) {
984 /* FIXME: if (force), slam module count damn the torpedoes */
985 pr_debug("%s already dying\n", mod->name);
990 /* If it has an init func, it must have an exit func to unload */
991 if (mod->init && !mod->exit) {
992 forced = try_force_unload(flags);
994 /* This module can't be removed */
1000 /* Stop the machine so refcounts can't move and disable module. */
1001 ret = try_stop_module(mod, flags, &forced);
1005 mutex_unlock(&module_mutex);
1006 /* Final destruction now no one is using it. */
1007 if (mod->exit != NULL)
1009 blocking_notifier_call_chain(&module_notify_list,
1010 MODULE_STATE_GOING, mod);
1011 async_synchronize_full();
1013 /* Store the name of the last unloaded module for diagnostic purposes */
1014 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
1019 mutex_unlock(&module_mutex);
1023 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1025 struct module_use *use;
1026 int printed_something = 0;
1028 seq_printf(m, " %i ", module_refcount(mod));
1031 * Always include a trailing , so userspace can differentiate
1032 * between this and the old multi-field proc format.
1034 list_for_each_entry(use, &mod->source_list, source_list) {
1035 printed_something = 1;
1036 seq_printf(m, "%s,", use->source->name);
1039 if (mod->init != NULL && mod->exit == NULL) {
1040 printed_something = 1;
1041 seq_puts(m, "[permanent],");
1044 if (!printed_something)
1048 void __symbol_put(const char *symbol)
1050 struct module *owner;
1053 if (!find_symbol(symbol, &owner, NULL, true, false))
1058 EXPORT_SYMBOL(__symbol_put);
1060 /* Note this assumes addr is a function, which it currently always is. */
1061 void symbol_put_addr(void *addr)
1063 struct module *modaddr;
1064 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1066 if (core_kernel_text(a))
1070 * Even though we hold a reference on the module; we still need to
1071 * disable preemption in order to safely traverse the data structure.
1074 modaddr = __module_text_address(a);
1076 module_put(modaddr);
1079 EXPORT_SYMBOL_GPL(symbol_put_addr);
1081 static ssize_t show_refcnt(struct module_attribute *mattr,
1082 struct module_kobject *mk, char *buffer)
1084 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1087 static struct module_attribute modinfo_refcnt =
1088 __ATTR(refcnt, 0444, show_refcnt, NULL);
1090 void __module_get(struct module *module)
1094 atomic_inc(&module->refcnt);
1095 trace_module_get(module, _RET_IP_);
1099 EXPORT_SYMBOL(__module_get);
1101 bool try_module_get(struct module *module)
1107 /* Note: here, we can fail to get a reference */
1108 if (likely(module_is_live(module) &&
1109 atomic_inc_not_zero(&module->refcnt) != 0))
1110 trace_module_get(module, _RET_IP_);
1118 EXPORT_SYMBOL(try_module_get);
1120 void module_put(struct module *module)
1126 ret = atomic_dec_if_positive(&module->refcnt);
1127 WARN_ON(ret < 0); /* Failed to put refcount */
1128 trace_module_put(module, _RET_IP_);
1132 EXPORT_SYMBOL(module_put);
1134 #else /* !CONFIG_MODULE_UNLOAD */
1135 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1137 /* We don't know the usage count, or what modules are using. */
1138 seq_puts(m, " - -");
1141 static inline void module_unload_free(struct module *mod)
1145 int ref_module(struct module *a, struct module *b)
1147 return strong_try_module_get(b);
1149 EXPORT_SYMBOL_GPL(ref_module);
1151 static inline int module_unload_init(struct module *mod)
1155 #endif /* CONFIG_MODULE_UNLOAD */
1157 static size_t module_flags_taint(struct module *mod, char *buf)
1161 if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
1163 if (mod->taints & (1 << TAINT_OOT_MODULE))
1165 if (mod->taints & (1 << TAINT_FORCED_MODULE))
1167 if (mod->taints & (1 << TAINT_CRAP))
1169 if (mod->taints & (1 << TAINT_UNSIGNED_MODULE))
1172 * TAINT_FORCED_RMMOD: could be added.
1173 * TAINT_CPU_OUT_OF_SPEC, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
1179 static ssize_t show_initstate(struct module_attribute *mattr,
1180 struct module_kobject *mk, char *buffer)
1182 const char *state = "unknown";
1184 switch (mk->mod->state) {
1185 case MODULE_STATE_LIVE:
1188 case MODULE_STATE_COMING:
1191 case MODULE_STATE_GOING:
1197 return sprintf(buffer, "%s\n", state);
1200 static struct module_attribute modinfo_initstate =
1201 __ATTR(initstate, 0444, show_initstate, NULL);
1203 static ssize_t store_uevent(struct module_attribute *mattr,
1204 struct module_kobject *mk,
1205 const char *buffer, size_t count)
1207 enum kobject_action action;
1209 if (kobject_action_type(buffer, count, &action) == 0)
1210 kobject_uevent(&mk->kobj, action);
1214 struct module_attribute module_uevent =
1215 __ATTR(uevent, 0200, NULL, store_uevent);
1217 static ssize_t show_coresize(struct module_attribute *mattr,
1218 struct module_kobject *mk, char *buffer)
1220 return sprintf(buffer, "%u\n", mk->mod->core_size);
1223 static struct module_attribute modinfo_coresize =
1224 __ATTR(coresize, 0444, show_coresize, NULL);
1226 static ssize_t show_initsize(struct module_attribute *mattr,
1227 struct module_kobject *mk, char *buffer)
1229 return sprintf(buffer, "%u\n", mk->mod->init_size);
1232 static struct module_attribute modinfo_initsize =
1233 __ATTR(initsize, 0444, show_initsize, NULL);
1235 static ssize_t show_taint(struct module_attribute *mattr,
1236 struct module_kobject *mk, char *buffer)
1240 l = module_flags_taint(mk->mod, buffer);
1245 static struct module_attribute modinfo_taint =
1246 __ATTR(taint, 0444, show_taint, NULL);
1248 static struct module_attribute *modinfo_attrs[] = {
1251 &modinfo_srcversion,
1256 #ifdef CONFIG_MODULE_UNLOAD
1262 static const char vermagic[] = VERMAGIC_STRING;
1264 static int try_to_force_load(struct module *mod, const char *reason)
1266 #ifdef CONFIG_MODULE_FORCE_LOAD
1267 if (!test_taint(TAINT_FORCED_MODULE))
1268 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1269 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1276 #ifdef CONFIG_MODVERSIONS
1277 /* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
1278 static unsigned long maybe_relocated(unsigned long crc,
1279 const struct module *crc_owner)
1281 #ifdef ARCH_RELOCATES_KCRCTAB
1282 if (crc_owner == NULL)
1283 return crc - (unsigned long)reloc_start;
1288 static int check_version(Elf_Shdr *sechdrs,
1289 unsigned int versindex,
1290 const char *symname,
1292 const unsigned long *crc,
1293 const struct module *crc_owner)
1295 unsigned int i, num_versions;
1296 struct modversion_info *versions;
1298 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1302 /* No versions at all? modprobe --force does this. */
1304 return try_to_force_load(mod, symname) == 0;
1306 versions = (void *) sechdrs[versindex].sh_addr;
1307 num_versions = sechdrs[versindex].sh_size
1308 / sizeof(struct modversion_info);
1310 for (i = 0; i < num_versions; i++) {
1311 if (strcmp(versions[i].name, symname) != 0)
1314 if (versions[i].crc == maybe_relocated(*crc, crc_owner))
1316 pr_debug("Found checksum %lX vs module %lX\n",
1317 maybe_relocated(*crc, crc_owner), versions[i].crc);
1321 pr_warn("%s: no symbol version for %s\n", mod->name, symname);
1325 pr_warn("%s: disagrees about version of symbol %s\n",
1326 mod->name, symname);
1330 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1331 unsigned int versindex,
1334 const unsigned long *crc;
1337 * Since this should be found in kernel (which can't be removed), no
1338 * locking is necessary -- use preempt_disable() to placate lockdep.
1341 if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
1342 &crc, true, false)) {
1347 return check_version(sechdrs, versindex,
1348 VMLINUX_SYMBOL_STR(module_layout), mod, crc,
1352 /* First part is kernel version, which we ignore if module has crcs. */
1353 static inline int same_magic(const char *amagic, const char *bmagic,
1357 amagic += strcspn(amagic, " ");
1358 bmagic += strcspn(bmagic, " ");
1360 return strcmp(amagic, bmagic) == 0;
1363 static inline int check_version(Elf_Shdr *sechdrs,
1364 unsigned int versindex,
1365 const char *symname,
1367 const unsigned long *crc,
1368 const struct module *crc_owner)
1373 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1374 unsigned int versindex,
1380 static inline int same_magic(const char *amagic, const char *bmagic,
1383 return strcmp(amagic, bmagic) == 0;
1385 #endif /* CONFIG_MODVERSIONS */
1387 /* Resolve a symbol for this module. I.e. if we find one, record usage. */
1388 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1389 const struct load_info *info,
1393 struct module *owner;
1394 const struct kernel_symbol *sym;
1395 const unsigned long *crc;
1399 * The module_mutex should not be a heavily contended lock;
1400 * if we get the occasional sleep here, we'll go an extra iteration
1401 * in the wait_event_interruptible(), which is harmless.
1403 sched_annotate_sleep();
1404 mutex_lock(&module_mutex);
1405 sym = find_symbol(name, &owner, &crc,
1406 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1410 if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
1412 sym = ERR_PTR(-EINVAL);
1416 err = ref_module(mod, owner);
1423 /* We must make copy under the lock if we failed to get ref. */
1424 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1426 mutex_unlock(&module_mutex);
1430 static const struct kernel_symbol *
1431 resolve_symbol_wait(struct module *mod,
1432 const struct load_info *info,
1435 const struct kernel_symbol *ksym;
1436 char owner[MODULE_NAME_LEN];
1438 if (wait_event_interruptible_timeout(module_wq,
1439 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1440 || PTR_ERR(ksym) != -EBUSY,
1442 pr_warn("%s: gave up waiting for init of module %s.\n",
1449 * /sys/module/foo/sections stuff
1450 * J. Corbet <corbet@lwn.net>
1454 #ifdef CONFIG_KALLSYMS
1455 static inline bool sect_empty(const Elf_Shdr *sect)
1457 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1460 struct module_sect_attr {
1461 struct module_attribute mattr;
1463 unsigned long address;
1466 struct module_sect_attrs {
1467 struct attribute_group grp;
1468 unsigned int nsections;
1469 struct module_sect_attr attrs[0];
1472 static ssize_t module_sect_show(struct module_attribute *mattr,
1473 struct module_kobject *mk, char *buf)
1475 struct module_sect_attr *sattr =
1476 container_of(mattr, struct module_sect_attr, mattr);
1477 return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1480 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1482 unsigned int section;
1484 for (section = 0; section < sect_attrs->nsections; section++)
1485 kfree(sect_attrs->attrs[section].name);
1489 static void add_sect_attrs(struct module *mod, const struct load_info *info)
1491 unsigned int nloaded = 0, i, size[2];
1492 struct module_sect_attrs *sect_attrs;
1493 struct module_sect_attr *sattr;
1494 struct attribute **gattr;
1496 /* Count loaded sections and allocate structures */
1497 for (i = 0; i < info->hdr->e_shnum; i++)
1498 if (!sect_empty(&info->sechdrs[i]))
1500 size[0] = ALIGN(sizeof(*sect_attrs)
1501 + nloaded * sizeof(sect_attrs->attrs[0]),
1502 sizeof(sect_attrs->grp.attrs[0]));
1503 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1504 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1505 if (sect_attrs == NULL)
1508 /* Setup section attributes. */
1509 sect_attrs->grp.name = "sections";
1510 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1512 sect_attrs->nsections = 0;
1513 sattr = §_attrs->attrs[0];
1514 gattr = §_attrs->grp.attrs[0];
1515 for (i = 0; i < info->hdr->e_shnum; i++) {
1516 Elf_Shdr *sec = &info->sechdrs[i];
1517 if (sect_empty(sec))
1519 sattr->address = sec->sh_addr;
1520 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1522 if (sattr->name == NULL)
1524 sect_attrs->nsections++;
1525 sysfs_attr_init(&sattr->mattr.attr);
1526 sattr->mattr.show = module_sect_show;
1527 sattr->mattr.store = NULL;
1528 sattr->mattr.attr.name = sattr->name;
1529 sattr->mattr.attr.mode = S_IRUGO;
1530 *(gattr++) = &(sattr++)->mattr.attr;
1534 if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp))
1537 mod->sect_attrs = sect_attrs;
1540 free_sect_attrs(sect_attrs);
1543 static void remove_sect_attrs(struct module *mod)
1545 if (mod->sect_attrs) {
1546 sysfs_remove_group(&mod->mkobj.kobj,
1547 &mod->sect_attrs->grp);
1548 /* We are positive that no one is using any sect attrs
1549 * at this point. Deallocate immediately. */
1550 free_sect_attrs(mod->sect_attrs);
1551 mod->sect_attrs = NULL;
1556 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1559 struct module_notes_attrs {
1560 struct kobject *dir;
1562 struct bin_attribute attrs[0];
1565 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1566 struct bin_attribute *bin_attr,
1567 char *buf, loff_t pos, size_t count)
1570 * The caller checked the pos and count against our size.
1572 memcpy(buf, bin_attr->private + pos, count);
1576 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1579 if (notes_attrs->dir) {
1581 sysfs_remove_bin_file(notes_attrs->dir,
1582 ¬es_attrs->attrs[i]);
1583 kobject_put(notes_attrs->dir);
1588 static void add_notes_attrs(struct module *mod, const struct load_info *info)
1590 unsigned int notes, loaded, i;
1591 struct module_notes_attrs *notes_attrs;
1592 struct bin_attribute *nattr;
1594 /* failed to create section attributes, so can't create notes */
1595 if (!mod->sect_attrs)
1598 /* Count notes sections and allocate structures. */
1600 for (i = 0; i < info->hdr->e_shnum; i++)
1601 if (!sect_empty(&info->sechdrs[i]) &&
1602 (info->sechdrs[i].sh_type == SHT_NOTE))
1608 notes_attrs = kzalloc(sizeof(*notes_attrs)
1609 + notes * sizeof(notes_attrs->attrs[0]),
1611 if (notes_attrs == NULL)
1614 notes_attrs->notes = notes;
1615 nattr = ¬es_attrs->attrs[0];
1616 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1617 if (sect_empty(&info->sechdrs[i]))
1619 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1620 sysfs_bin_attr_init(nattr);
1621 nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1622 nattr->attr.mode = S_IRUGO;
1623 nattr->size = info->sechdrs[i].sh_size;
1624 nattr->private = (void *) info->sechdrs[i].sh_addr;
1625 nattr->read = module_notes_read;
1631 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1632 if (!notes_attrs->dir)
1635 for (i = 0; i < notes; ++i)
1636 if (sysfs_create_bin_file(notes_attrs->dir,
1637 ¬es_attrs->attrs[i]))
1640 mod->notes_attrs = notes_attrs;
1644 free_notes_attrs(notes_attrs, i);
1647 static void remove_notes_attrs(struct module *mod)
1649 if (mod->notes_attrs)
1650 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1655 static inline void add_sect_attrs(struct module *mod,
1656 const struct load_info *info)
1660 static inline void remove_sect_attrs(struct module *mod)
1664 static inline void add_notes_attrs(struct module *mod,
1665 const struct load_info *info)
1669 static inline void remove_notes_attrs(struct module *mod)
1672 #endif /* CONFIG_KALLSYMS */
1674 static void add_usage_links(struct module *mod)
1676 #ifdef CONFIG_MODULE_UNLOAD
1677 struct module_use *use;
1680 mutex_lock(&module_mutex);
1681 list_for_each_entry(use, &mod->target_list, target_list) {
1682 nowarn = sysfs_create_link(use->target->holders_dir,
1683 &mod->mkobj.kobj, mod->name);
1685 mutex_unlock(&module_mutex);
1689 static void del_usage_links(struct module *mod)
1691 #ifdef CONFIG_MODULE_UNLOAD
1692 struct module_use *use;
1694 mutex_lock(&module_mutex);
1695 list_for_each_entry(use, &mod->target_list, target_list)
1696 sysfs_remove_link(use->target->holders_dir, mod->name);
1697 mutex_unlock(&module_mutex);
1701 static int module_add_modinfo_attrs(struct module *mod)
1703 struct module_attribute *attr;
1704 struct module_attribute *temp_attr;
1708 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1709 (ARRAY_SIZE(modinfo_attrs) + 1)),
1711 if (!mod->modinfo_attrs)
1714 temp_attr = mod->modinfo_attrs;
1715 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1717 (attr->test && attr->test(mod))) {
1718 memcpy(temp_attr, attr, sizeof(*temp_attr));
1719 sysfs_attr_init(&temp_attr->attr);
1720 error = sysfs_create_file(&mod->mkobj.kobj,
1728 static void module_remove_modinfo_attrs(struct module *mod)
1730 struct module_attribute *attr;
1733 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1734 /* pick a field to test for end of list */
1735 if (!attr->attr.name)
1737 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1741 kfree(mod->modinfo_attrs);
1744 static void mod_kobject_put(struct module *mod)
1746 DECLARE_COMPLETION_ONSTACK(c);
1747 mod->mkobj.kobj_completion = &c;
1748 kobject_put(&mod->mkobj.kobj);
1749 wait_for_completion(&c);
1752 static int mod_sysfs_init(struct module *mod)
1755 struct kobject *kobj;
1757 if (!module_sysfs_initialized) {
1758 pr_err("%s: module sysfs not initialized\n", mod->name);
1763 kobj = kset_find_obj(module_kset, mod->name);
1765 pr_err("%s: module is already loaded\n", mod->name);
1771 mod->mkobj.mod = mod;
1773 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1774 mod->mkobj.kobj.kset = module_kset;
1775 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1778 mod_kobject_put(mod);
1780 /* delay uevent until full sysfs population */
1785 static int mod_sysfs_setup(struct module *mod,
1786 const struct load_info *info,
1787 struct kernel_param *kparam,
1788 unsigned int num_params)
1792 err = mod_sysfs_init(mod);
1796 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1797 if (!mod->holders_dir) {
1802 err = module_param_sysfs_setup(mod, kparam, num_params);
1804 goto out_unreg_holders;
1806 err = module_add_modinfo_attrs(mod);
1808 goto out_unreg_param;
1810 add_usage_links(mod);
1811 add_sect_attrs(mod, info);
1812 add_notes_attrs(mod, info);
1814 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1818 module_param_sysfs_remove(mod);
1820 kobject_put(mod->holders_dir);
1822 mod_kobject_put(mod);
1827 static void mod_sysfs_fini(struct module *mod)
1829 remove_notes_attrs(mod);
1830 remove_sect_attrs(mod);
1831 mod_kobject_put(mod);
1834 static void init_param_lock(struct module *mod)
1836 mutex_init(&mod->param_lock);
1838 #else /* !CONFIG_SYSFS */
1840 static int mod_sysfs_setup(struct module *mod,
1841 const struct load_info *info,
1842 struct kernel_param *kparam,
1843 unsigned int num_params)
1848 static void mod_sysfs_fini(struct module *mod)
1852 static void module_remove_modinfo_attrs(struct module *mod)
1856 static void del_usage_links(struct module *mod)
1860 static void init_param_lock(struct module *mod)
1863 #endif /* CONFIG_SYSFS */
1865 static void mod_sysfs_teardown(struct module *mod)
1867 del_usage_links(mod);
1868 module_remove_modinfo_attrs(mod);
1869 module_param_sysfs_remove(mod);
1870 kobject_put(mod->mkobj.drivers_dir);
1871 kobject_put(mod->holders_dir);
1872 mod_sysfs_fini(mod);
1875 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
1877 * LKM RO/NX protection: protect module's text/ro-data
1878 * from modification and any data from execution.
1880 void set_page_attributes(void *start, void *end, int (*set)(unsigned long start, int num_pages))
1882 unsigned long begin_pfn = PFN_DOWN((unsigned long)start);
1883 unsigned long end_pfn = PFN_DOWN((unsigned long)end);
1885 if (end_pfn > begin_pfn)
1886 set(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1889 static void set_section_ro_nx(void *base,
1890 unsigned long text_size,
1891 unsigned long ro_size,
1892 unsigned long total_size)
1894 /* begin and end PFNs of the current subsection */
1895 unsigned long begin_pfn;
1896 unsigned long end_pfn;
1899 * Set RO for module text and RO-data:
1900 * - Always protect first page.
1901 * - Do not protect last partial page.
1904 set_page_attributes(base, base + ro_size, set_memory_ro);
1907 * Set NX permissions for module data:
1908 * - Do not protect first partial page.
1909 * - Always protect last page.
1911 if (total_size > text_size) {
1912 begin_pfn = PFN_UP((unsigned long)base + text_size);
1913 end_pfn = PFN_UP((unsigned long)base + total_size);
1914 if (end_pfn > begin_pfn)
1915 set_memory_nx(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1919 static void unset_module_core_ro_nx(struct module *mod)
1921 set_page_attributes(mod->module_core + mod->core_text_size,
1922 mod->module_core + mod->core_size,
1924 set_page_attributes(mod->module_core,
1925 mod->module_core + mod->core_ro_size,
1929 static void unset_module_init_ro_nx(struct module *mod)
1931 set_page_attributes(mod->module_init + mod->init_text_size,
1932 mod->module_init + mod->init_size,
1934 set_page_attributes(mod->module_init,
1935 mod->module_init + mod->init_ro_size,
1939 /* Iterate through all modules and set each module's text as RW */
1940 void set_all_modules_text_rw(void)
1944 mutex_lock(&module_mutex);
1945 list_for_each_entry_rcu(mod, &modules, list) {
1946 if (mod->state == MODULE_STATE_UNFORMED)
1948 if ((mod->module_core) && (mod->core_text_size)) {
1949 set_page_attributes(mod->module_core,
1950 mod->module_core + mod->core_text_size,
1953 if ((mod->module_init) && (mod->init_text_size)) {
1954 set_page_attributes(mod->module_init,
1955 mod->module_init + mod->init_text_size,
1959 mutex_unlock(&module_mutex);
1962 /* Iterate through all modules and set each module's text as RO */
1963 void set_all_modules_text_ro(void)
1967 mutex_lock(&module_mutex);
1968 list_for_each_entry_rcu(mod, &modules, list) {
1969 if (mod->state == MODULE_STATE_UNFORMED)
1971 if ((mod->module_core) && (mod->core_text_size)) {
1972 set_page_attributes(mod->module_core,
1973 mod->module_core + mod->core_text_size,
1976 if ((mod->module_init) && (mod->init_text_size)) {
1977 set_page_attributes(mod->module_init,
1978 mod->module_init + mod->init_text_size,
1982 mutex_unlock(&module_mutex);
1985 static inline void set_section_ro_nx(void *base, unsigned long text_size, unsigned long ro_size, unsigned long total_size) { }
1986 static void unset_module_core_ro_nx(struct module *mod) { }
1987 static void unset_module_init_ro_nx(struct module *mod) { }
1990 void __weak module_memfree(void *module_region)
1992 vfree(module_region);
1995 void __weak module_arch_cleanup(struct module *mod)
1999 void __weak module_arch_freeing_init(struct module *mod)
2003 /* Free a module, remove from lists, etc. */
2004 static void free_module(struct module *mod)
2006 trace_module_free(mod);
2008 mod_sysfs_teardown(mod);
2010 /* We leave it in list to prevent duplicate loads, but make sure
2011 * that noone uses it while it's being deconstructed. */
2012 mutex_lock(&module_mutex);
2013 mod->state = MODULE_STATE_UNFORMED;
2014 mutex_unlock(&module_mutex);
2016 /* Remove dynamic debug info */
2017 ddebug_remove_module(mod->name);
2019 /* Arch-specific cleanup. */
2020 module_arch_cleanup(mod);
2022 /* Module unload stuff */
2023 module_unload_free(mod);
2025 /* Free any allocated parameters. */
2026 destroy_params(mod->kp, mod->num_kp);
2028 /* Now we can delete it from the lists */
2029 mutex_lock(&module_mutex);
2030 /* Unlink carefully: kallsyms could be walking list. */
2031 list_del_rcu(&mod->list);
2032 mod_tree_remove(mod);
2033 /* Remove this module from bug list, this uses list_del_rcu */
2034 module_bug_cleanup(mod);
2035 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2036 synchronize_sched();
2037 mutex_unlock(&module_mutex);
2039 /* This may be NULL, but that's OK */
2040 unset_module_init_ro_nx(mod);
2041 module_arch_freeing_init(mod);
2042 module_memfree(mod->module_init);
2044 percpu_modfree(mod);
2046 /* Free lock-classes; relies on the preceding sync_rcu(). */
2047 lockdep_free_key_range(mod->module_core, mod->core_size);
2049 /* Finally, free the core (containing the module structure) */
2050 unset_module_core_ro_nx(mod);
2051 module_memfree(mod->module_core);
2054 update_protections(current->mm);
2058 void *__symbol_get(const char *symbol)
2060 struct module *owner;
2061 const struct kernel_symbol *sym;
2064 sym = find_symbol(symbol, &owner, NULL, true, true);
2065 if (sym && strong_try_module_get(owner))
2069 return sym ? (void *)sym->value : NULL;
2071 EXPORT_SYMBOL_GPL(__symbol_get);
2074 * Ensure that an exported symbol [global namespace] does not already exist
2075 * in the kernel or in some other module's exported symbol table.
2077 * You must hold the module_mutex.
2079 static int verify_export_symbols(struct module *mod)
2082 struct module *owner;
2083 const struct kernel_symbol *s;
2085 const struct kernel_symbol *sym;
2088 { mod->syms, mod->num_syms },
2089 { mod->gpl_syms, mod->num_gpl_syms },
2090 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2091 #ifdef CONFIG_UNUSED_SYMBOLS
2092 { mod->unused_syms, mod->num_unused_syms },
2093 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2097 for (i = 0; i < ARRAY_SIZE(arr); i++) {
2098 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2099 if (find_symbol(s->name, &owner, NULL, true, false)) {
2100 pr_err("%s: exports duplicate symbol %s"
2102 mod->name, s->name, module_name(owner));
2110 /* Change all symbols so that st_value encodes the pointer directly. */
2111 static int simplify_symbols(struct module *mod, const struct load_info *info)
2113 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2114 Elf_Sym *sym = (void *)symsec->sh_addr;
2115 unsigned long secbase;
2118 const struct kernel_symbol *ksym;
2120 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2121 const char *name = info->strtab + sym[i].st_name;
2123 switch (sym[i].st_shndx) {
2125 /* Ignore common symbols */
2126 if (!strncmp(name, "__gnu_lto", 9))
2129 /* We compiled with -fno-common. These are not
2130 supposed to happen. */
2131 pr_debug("Common symbol: %s\n", name);
2132 pr_warn("%s: please compile with -fno-common\n",
2138 /* Don't need to do anything */
2139 pr_debug("Absolute symbol: 0x%08lx\n",
2140 (long)sym[i].st_value);
2144 ksym = resolve_symbol_wait(mod, info, name);
2145 /* Ok if resolved. */
2146 if (ksym && !IS_ERR(ksym)) {
2147 sym[i].st_value = ksym->value;
2152 if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
2155 pr_warn("%s: Unknown symbol %s (err %li)\n",
2156 mod->name, name, PTR_ERR(ksym));
2157 ret = PTR_ERR(ksym) ?: -ENOENT;
2161 /* Divert to percpu allocation if a percpu var. */
2162 if (sym[i].st_shndx == info->index.pcpu)
2163 secbase = (unsigned long)mod_percpu(mod);
2165 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2166 sym[i].st_value += secbase;
2174 static int apply_relocations(struct module *mod, const struct load_info *info)
2179 /* Now do relocations. */
2180 for (i = 1; i < info->hdr->e_shnum; i++) {
2181 unsigned int infosec = info->sechdrs[i].sh_info;
2183 /* Not a valid relocation section? */
2184 if (infosec >= info->hdr->e_shnum)
2187 /* Don't bother with non-allocated sections */
2188 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2191 if (info->sechdrs[i].sh_type == SHT_REL)
2192 err = apply_relocate(info->sechdrs, info->strtab,
2193 info->index.sym, i, mod);
2194 else if (info->sechdrs[i].sh_type == SHT_RELA)
2195 err = apply_relocate_add(info->sechdrs, info->strtab,
2196 info->index.sym, i, mod);
2203 /* Additional bytes needed by arch in front of individual sections */
2204 unsigned int __weak arch_mod_section_prepend(struct module *mod,
2205 unsigned int section)
2207 /* default implementation just returns zero */
2211 /* Update size with this section: return offset. */
2212 static long get_offset(struct module *mod, unsigned int *size,
2213 Elf_Shdr *sechdr, unsigned int section)
2217 *size += arch_mod_section_prepend(mod, section);
2218 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2219 *size = ret + sechdr->sh_size;
2223 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2224 might -- code, read-only data, read-write data, small data. Tally
2225 sizes, and place the offsets into sh_entsize fields: high bit means it
2227 static void layout_sections(struct module *mod, struct load_info *info)
2229 static unsigned long const masks[][2] = {
2230 /* NOTE: all executable code must be the first section
2231 * in this array; otherwise modify the text_size
2232 * finder in the two loops below */
2233 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2234 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2235 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2236 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2240 for (i = 0; i < info->hdr->e_shnum; i++)
2241 info->sechdrs[i].sh_entsize = ~0UL;
2243 pr_debug("Core section allocation order:\n");
2244 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2245 for (i = 0; i < info->hdr->e_shnum; ++i) {
2246 Elf_Shdr *s = &info->sechdrs[i];
2247 const char *sname = info->secstrings + s->sh_name;
2249 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2250 || (s->sh_flags & masks[m][1])
2251 || s->sh_entsize != ~0UL
2252 || strstarts(sname, ".init"))
2254 s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
2255 pr_debug("\t%s\n", sname);
2258 case 0: /* executable */
2259 mod->core_size = debug_align(mod->core_size);
2260 mod->core_text_size = mod->core_size;
2262 case 1: /* RO: text and ro-data */
2263 mod->core_size = debug_align(mod->core_size);
2264 mod->core_ro_size = mod->core_size;
2266 case 3: /* whole core */
2267 mod->core_size = debug_align(mod->core_size);
2272 pr_debug("Init section allocation order:\n");
2273 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2274 for (i = 0; i < info->hdr->e_shnum; ++i) {
2275 Elf_Shdr *s = &info->sechdrs[i];
2276 const char *sname = info->secstrings + s->sh_name;
2278 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2279 || (s->sh_flags & masks[m][1])
2280 || s->sh_entsize != ~0UL
2281 || !strstarts(sname, ".init"))
2283 s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
2284 | INIT_OFFSET_MASK);
2285 pr_debug("\t%s\n", sname);
2288 case 0: /* executable */
2289 mod->init_size = debug_align(mod->init_size);
2290 mod->init_text_size = mod->init_size;
2292 case 1: /* RO: text and ro-data */
2293 mod->init_size = debug_align(mod->init_size);
2294 mod->init_ro_size = mod->init_size;
2296 case 3: /* whole init */
2297 mod->init_size = debug_align(mod->init_size);
2303 static void set_license(struct module *mod, const char *license)
2306 license = "unspecified";
2308 if (!license_is_gpl_compatible(license)) {
2309 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2310 pr_warn("%s: module license '%s' taints kernel.\n",
2311 mod->name, license);
2312 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2313 LOCKDEP_NOW_UNRELIABLE);
2317 /* Parse tag=value strings from .modinfo section */
2318 static char *next_string(char *string, unsigned long *secsize)
2320 /* Skip non-zero chars */
2323 if ((*secsize)-- <= 1)
2327 /* Skip any zero padding. */
2328 while (!string[0]) {
2330 if ((*secsize)-- <= 1)
2336 static char *get_modinfo(struct load_info *info, const char *tag)
2339 unsigned int taglen = strlen(tag);
2340 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2341 unsigned long size = infosec->sh_size;
2343 for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2344 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2345 return p + taglen + 1;
2350 static void setup_modinfo(struct module *mod, struct load_info *info)
2352 struct module_attribute *attr;
2355 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2357 attr->setup(mod, get_modinfo(info, attr->attr.name));
2361 static void free_modinfo(struct module *mod)
2363 struct module_attribute *attr;
2366 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2372 #ifdef CONFIG_KALLSYMS
2374 /* lookup symbol in given range of kernel_symbols */
2375 static const struct kernel_symbol *lookup_symbol(const char *name,
2376 const struct kernel_symbol *start,
2377 const struct kernel_symbol *stop)
2379 return bsearch(name, start, stop - start,
2380 sizeof(struct kernel_symbol), cmp_name);
2383 static int is_exported(const char *name, unsigned long value,
2384 const struct module *mod)
2386 const struct kernel_symbol *ks;
2388 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2390 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2391 return ks != NULL && ks->value == value;
2395 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2397 const Elf_Shdr *sechdrs = info->sechdrs;
2399 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2400 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2405 if (sym->st_shndx == SHN_UNDEF)
2407 if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
2409 if (sym->st_shndx >= SHN_LORESERVE)
2411 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2413 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2414 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2415 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2417 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2422 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2423 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2428 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2435 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2436 unsigned int shnum, unsigned int pcpundx)
2438 const Elf_Shdr *sec;
2440 if (src->st_shndx == SHN_UNDEF
2441 || src->st_shndx >= shnum
2445 #ifdef CONFIG_KALLSYMS_ALL
2446 if (src->st_shndx == pcpundx)
2450 sec = sechdrs + src->st_shndx;
2451 if (!(sec->sh_flags & SHF_ALLOC)
2452 #ifndef CONFIG_KALLSYMS_ALL
2453 || !(sec->sh_flags & SHF_EXECINSTR)
2455 || (sec->sh_entsize & INIT_OFFSET_MASK))
2462 * We only allocate and copy the strings needed by the parts of symtab
2463 * we keep. This is simple, but has the effect of making multiple
2464 * copies of duplicates. We could be more sophisticated, see
2465 * linux-kernel thread starting with
2466 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2468 static void layout_symtab(struct module *mod, struct load_info *info)
2470 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2471 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2473 unsigned int i, nsrc, ndst, strtab_size = 0;
2475 /* Put symbol section at end of init part of module. */
2476 symsect->sh_flags |= SHF_ALLOC;
2477 symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
2478 info->index.sym) | INIT_OFFSET_MASK;
2479 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2481 src = (void *)info->hdr + symsect->sh_offset;
2482 nsrc = symsect->sh_size / sizeof(*src);
2484 /* Compute total space required for the core symbols' strtab. */
2485 for (ndst = i = 0; i < nsrc; i++) {
2487 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2488 info->index.pcpu)) {
2489 strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2494 /* Append room for core symbols at end of core part. */
2495 info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
2496 info->stroffs = mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym);
2497 mod->core_size += strtab_size;
2498 mod->core_size = debug_align(mod->core_size);
2500 /* Put string table section at end of init part of module. */
2501 strsect->sh_flags |= SHF_ALLOC;
2502 strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
2503 info->index.str) | INIT_OFFSET_MASK;
2504 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2506 /* We'll tack temporary mod_kallsyms on the end. */
2507 mod->init_size = ALIGN(mod->init_size,
2508 __alignof__(struct mod_kallsyms));
2509 info->mod_kallsyms_init_off = mod->init_size;
2510 mod->init_size += sizeof(struct mod_kallsyms);
2511 mod->init_size = debug_align(mod->init_size);
2515 * We use the full symtab and strtab which layout_symtab arranged to
2516 * be appended to the init section. Later we switch to the cut-down
2519 static void add_kallsyms(struct module *mod, const struct load_info *info)
2521 unsigned int i, ndst;
2525 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2527 /* Set up to point into init section. */
2528 mod->kallsyms = mod->module_init + info->mod_kallsyms_init_off;
2530 mod->kallsyms->symtab = (void *)symsec->sh_addr;
2531 mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2532 /* Make sure we get permanent strtab: don't use info->strtab. */
2533 mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2535 /* Set types up while we still have access to sections. */
2536 for (i = 0; i < mod->kallsyms->num_symtab; i++)
2537 mod->kallsyms->symtab[i].st_info
2538 = elf_type(&mod->kallsyms->symtab[i], info);
2540 /* Now populate the cut down core kallsyms for after init. */
2541 mod->core_kallsyms.symtab = dst = mod->module_core + info->symoffs;
2542 mod->core_kallsyms.strtab = s = mod->module_core + info->stroffs;
2543 src = mod->kallsyms->symtab;
2544 for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2546 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2547 info->index.pcpu)) {
2549 dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
2550 s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2554 mod->core_kallsyms.num_symtab = ndst;
2557 static inline void layout_symtab(struct module *mod, struct load_info *info)
2561 static void add_kallsyms(struct module *mod, const struct load_info *info)
2564 #endif /* CONFIG_KALLSYMS */
2566 static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2570 #ifdef CONFIG_DYNAMIC_DEBUG
2571 if (ddebug_add_module(debug, num, debug->modname))
2572 pr_err("dynamic debug error adding module: %s\n",
2577 static void dynamic_debug_remove(struct _ddebug *debug)
2580 ddebug_remove_module(debug->modname);
2583 void * __weak module_alloc(unsigned long size)
2585 return vmalloc_exec(size);
2588 #ifdef CONFIG_DEBUG_KMEMLEAK
2589 static void kmemleak_load_module(const struct module *mod,
2590 const struct load_info *info)
2594 /* only scan the sections containing data */
2595 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2597 for (i = 1; i < info->hdr->e_shnum; i++) {
2598 /* Scan all writable sections that's not executable */
2599 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2600 !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2601 (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2604 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2605 info->sechdrs[i].sh_size, GFP_KERNEL);
2609 static inline void kmemleak_load_module(const struct module *mod,
2610 const struct load_info *info)
2615 #ifdef CONFIG_MODULE_SIG
2616 static int module_sig_check(struct load_info *info, int flags)
2619 const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2620 const void *mod = info->hdr;
2623 * Require flags == 0, as a module with version information
2624 * removed is no longer the module that was signed
2627 info->len > markerlen &&
2628 memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2629 /* We truncate the module to discard the signature */
2630 info->len -= markerlen;
2631 err = mod_verify_sig(mod, &info->len);
2635 info->sig_ok = true;
2639 /* Not having a signature is only an error if we're strict. */
2640 if (err == -ENOKEY && !sig_enforce)
2645 #else /* !CONFIG_MODULE_SIG */
2646 static int module_sig_check(struct load_info *info, int flags)
2650 #endif /* !CONFIG_MODULE_SIG */
2652 /* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2653 static int elf_header_check(struct load_info *info)
2655 if (info->len < sizeof(*(info->hdr)))
2658 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2659 || info->hdr->e_type != ET_REL
2660 || !elf_check_arch(info->hdr)
2661 || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2664 if (info->hdr->e_shoff >= info->len
2665 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2666 info->len - info->hdr->e_shoff))
2672 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2674 static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
2677 unsigned long n = min(len, COPY_CHUNK_SIZE);
2679 if (copy_from_user(dst, usrc, n) != 0)
2689 /* Sets info->hdr and info->len. */
2690 static int copy_module_from_user(const void __user *umod, unsigned long len,
2691 struct load_info *info)
2696 if (info->len < sizeof(*(info->hdr)))
2699 err = security_kernel_module_from_file(NULL);
2703 /* Suck in entire file: we'll want most of it. */
2704 info->hdr = __vmalloc(info->len,
2705 GFP_KERNEL | __GFP_HIGHMEM | __GFP_NOWARN, PAGE_KERNEL);
2709 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2717 /* Sets info->hdr and info->len. */
2718 static int copy_module_from_fd(int fd, struct load_info *info)
2720 struct fd f = fdget(fd);
2729 err = security_kernel_module_from_file(f.file);
2733 err = vfs_getattr(&f.file->f_path, &stat);
2737 if (stat.size > INT_MAX) {
2742 /* Don't hand 0 to vmalloc, it whines. */
2743 if (stat.size == 0) {
2748 info->hdr = vmalloc(stat.size);
2755 while (pos < stat.size) {
2756 bytes = kernel_read(f.file, pos, (char *)(info->hdr) + pos,
2774 static void free_copy(struct load_info *info)
2779 static int rewrite_section_headers(struct load_info *info, int flags)
2783 /* This should always be true, but let's be sure. */
2784 info->sechdrs[0].sh_addr = 0;
2786 for (i = 1; i < info->hdr->e_shnum; i++) {
2787 Elf_Shdr *shdr = &info->sechdrs[i];
2788 if (shdr->sh_type != SHT_NOBITS
2789 && info->len < shdr->sh_offset + shdr->sh_size) {
2790 pr_err("Module len %lu truncated\n", info->len);
2794 /* Mark all sections sh_addr with their address in the
2796 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2798 #ifndef CONFIG_MODULE_UNLOAD
2799 /* Don't load .exit sections */
2800 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2801 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2805 /* Track but don't keep modinfo and version sections. */
2806 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
2807 info->index.vers = 0; /* Pretend no __versions section! */
2809 info->index.vers = find_sec(info, "__versions");
2810 info->index.info = find_sec(info, ".modinfo");
2811 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2812 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2817 * Set up our basic convenience variables (pointers to section headers,
2818 * search for module section index etc), and do some basic section
2821 * Return the temporary module pointer (we'll replace it with the final
2822 * one when we move the module sections around).
2824 static struct module *setup_load_info(struct load_info *info, int flags)
2830 /* Set up the convenience variables */
2831 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2832 info->secstrings = (void *)info->hdr
2833 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2835 err = rewrite_section_headers(info, flags);
2837 return ERR_PTR(err);
2839 /* Find internal symbols and strings. */
2840 for (i = 1; i < info->hdr->e_shnum; i++) {
2841 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2842 info->index.sym = i;
2843 info->index.str = info->sechdrs[i].sh_link;
2844 info->strtab = (char *)info->hdr
2845 + info->sechdrs[info->index.str].sh_offset;
2850 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2851 if (!info->index.mod) {
2852 pr_warn("No module found in object\n");
2853 return ERR_PTR(-ENOEXEC);
2855 /* This is temporary: point mod into copy of data. */
2856 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2858 if (info->index.sym == 0) {
2859 pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
2860 return ERR_PTR(-ENOEXEC);
2863 info->index.pcpu = find_pcpusec(info);
2865 /* Check module struct version now, before we try to use module. */
2866 if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2867 return ERR_PTR(-ENOEXEC);
2872 static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
2874 if (retpoline_module_ok(get_modinfo(info, "retpoline")))
2877 pr_warn("%s: loading module not compiled with retpoline compiler.\n",
2881 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2883 const char *modmagic = get_modinfo(info, "vermagic");
2886 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
2889 /* This is allowed: modprobe --force will invalidate it. */
2891 err = try_to_force_load(mod, "bad vermagic");
2894 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2895 pr_err("%s: version magic '%s' should be '%s'\n",
2896 mod->name, modmagic, vermagic);
2900 if (!get_modinfo(info, "intree")) {
2901 if (!test_taint(TAINT_OOT_MODULE))
2902 pr_warn("%s: loading out-of-tree module taints kernel.\n",
2904 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2907 check_modinfo_retpoline(mod, info);
2909 if (get_modinfo(info, "staging")) {
2910 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
2911 pr_warn("%s: module is from the staging directory, the quality "
2912 "is unknown, you have been warned.\n", mod->name);
2915 /* Set up license info based on the info section */
2916 set_license(mod, get_modinfo(info, "license"));
2921 static int find_module_sections(struct module *mod, struct load_info *info)
2923 mod->kp = section_objs(info, "__param",
2924 sizeof(*mod->kp), &mod->num_kp);
2925 mod->syms = section_objs(info, "__ksymtab",
2926 sizeof(*mod->syms), &mod->num_syms);
2927 mod->crcs = section_addr(info, "__kcrctab");
2928 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2929 sizeof(*mod->gpl_syms),
2930 &mod->num_gpl_syms);
2931 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2932 mod->gpl_future_syms = section_objs(info,
2933 "__ksymtab_gpl_future",
2934 sizeof(*mod->gpl_future_syms),
2935 &mod->num_gpl_future_syms);
2936 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2938 #ifdef CONFIG_UNUSED_SYMBOLS
2939 mod->unused_syms = section_objs(info, "__ksymtab_unused",
2940 sizeof(*mod->unused_syms),
2941 &mod->num_unused_syms);
2942 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
2943 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2944 sizeof(*mod->unused_gpl_syms),
2945 &mod->num_unused_gpl_syms);
2946 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2948 #ifdef CONFIG_CONSTRUCTORS
2949 mod->ctors = section_objs(info, ".ctors",
2950 sizeof(*mod->ctors), &mod->num_ctors);
2952 mod->ctors = section_objs(info, ".init_array",
2953 sizeof(*mod->ctors), &mod->num_ctors);
2954 else if (find_sec(info, ".init_array")) {
2956 * This shouldn't happen with same compiler and binutils
2957 * building all parts of the module.
2959 pr_warn("%s: has both .ctors and .init_array.\n",
2965 #ifdef CONFIG_TRACEPOINTS
2966 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2967 sizeof(*mod->tracepoints_ptrs),
2968 &mod->num_tracepoints);
2970 #ifdef HAVE_JUMP_LABEL
2971 mod->jump_entries = section_objs(info, "__jump_table",
2972 sizeof(*mod->jump_entries),
2973 &mod->num_jump_entries);
2975 #ifdef CONFIG_EVENT_TRACING
2976 mod->trace_events = section_objs(info, "_ftrace_events",
2977 sizeof(*mod->trace_events),
2978 &mod->num_trace_events);
2979 mod->trace_enums = section_objs(info, "_ftrace_enum_map",
2980 sizeof(*mod->trace_enums),
2981 &mod->num_trace_enums);
2983 #ifdef CONFIG_TRACING
2984 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2985 sizeof(*mod->trace_bprintk_fmt_start),
2986 &mod->num_trace_bprintk_fmt);
2988 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
2989 /* sechdrs[0].sh_size is always zero */
2990 mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2991 sizeof(*mod->ftrace_callsites),
2992 &mod->num_ftrace_callsites);
2995 mod->extable = section_objs(info, "__ex_table",
2996 sizeof(*mod->extable), &mod->num_exentries);
2998 if (section_addr(info, "__obsparm"))
2999 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
3001 info->debug = section_objs(info, "__verbose",
3002 sizeof(*info->debug), &info->num_debug);
3007 static int move_module(struct module *mod, struct load_info *info)
3012 /* Do the allocs. */
3013 ptr = module_alloc(mod->core_size);
3015 * The pointer to this block is stored in the module structure
3016 * which is inside the block. Just mark it as not being a
3019 kmemleak_not_leak(ptr);
3023 memset(ptr, 0, mod->core_size);
3024 mod->module_core = ptr;
3026 if (mod->init_size) {
3027 ptr = module_alloc(mod->init_size);
3029 * The pointer to this block is stored in the module structure
3030 * which is inside the block. This block doesn't need to be
3031 * scanned as it contains data and code that will be freed
3032 * after the module is initialized.
3034 kmemleak_ignore(ptr);
3036 module_memfree(mod->module_core);
3039 memset(ptr, 0, mod->init_size);
3040 mod->module_init = ptr;
3042 mod->module_init = NULL;
3044 /* Transfer each section which specifies SHF_ALLOC */
3045 pr_debug("final section addresses:\n");
3046 for (i = 0; i < info->hdr->e_shnum; i++) {
3048 Elf_Shdr *shdr = &info->sechdrs[i];
3050 if (!(shdr->sh_flags & SHF_ALLOC))
3053 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3054 dest = mod->module_init
3055 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3057 dest = mod->module_core + shdr->sh_entsize;
3059 if (shdr->sh_type != SHT_NOBITS)
3060 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3061 /* Update sh_addr to point to copy in image. */
3062 shdr->sh_addr = (unsigned long)dest;
3063 pr_debug("\t0x%lx %s\n",
3064 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3070 static int check_module_license_and_versions(struct module *mod)
3072 int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
3075 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3076 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3077 * using GPL-only symbols it needs.
3079 if (strcmp(mod->name, "ndiswrapper") == 0)
3080 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3082 /* driverloader was caught wrongly pretending to be under GPL */
3083 if (strcmp(mod->name, "driverloader") == 0)
3084 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3085 LOCKDEP_NOW_UNRELIABLE);
3087 /* lve claims to be GPL but upstream won't provide source */
3088 if (strcmp(mod->name, "lve") == 0)
3089 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3090 LOCKDEP_NOW_UNRELIABLE);
3092 if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
3093 pr_warn("%s: module license taints kernel.\n", mod->name);
3095 #ifdef CONFIG_MODVERSIONS
3096 if ((mod->num_syms && !mod->crcs)
3097 || (mod->num_gpl_syms && !mod->gpl_crcs)
3098 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3099 #ifdef CONFIG_UNUSED_SYMBOLS
3100 || (mod->num_unused_syms && !mod->unused_crcs)
3101 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3104 return try_to_force_load(mod,
3105 "no versions for exported symbols");
3111 static void flush_module_icache(const struct module *mod)
3113 mm_segment_t old_fs;
3115 /* flush the icache in correct context */
3120 * Flush the instruction cache, since we've played with text.
3121 * Do it before processing of module parameters, so the module
3122 * can provide parameter accessor functions of its own.
3124 if (mod->module_init)
3125 flush_icache_range((unsigned long)mod->module_init,
3126 (unsigned long)mod->module_init
3128 flush_icache_range((unsigned long)mod->module_core,
3129 (unsigned long)mod->module_core + mod->core_size);
3134 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3142 static struct module *layout_and_allocate(struct load_info *info, int flags)
3144 /* Module within temporary copy. */
3148 mod = setup_load_info(info, flags);
3152 err = check_modinfo(mod, info, flags);
3154 return ERR_PTR(err);
3156 /* Allow arches to frob section contents and sizes. */
3157 err = module_frob_arch_sections(info->hdr, info->sechdrs,
3158 info->secstrings, mod);
3160 return ERR_PTR(err);
3162 /* We will do a special allocation for per-cpu sections later. */
3163 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3165 /* Determine total sizes, and put offsets in sh_entsize. For now
3166 this is done generically; there doesn't appear to be any
3167 special cases for the architectures. */
3168 layout_sections(mod, info);
3169 layout_symtab(mod, info);
3171 /* Allocate and move to the final place */
3172 err = move_module(mod, info);
3174 return ERR_PTR(err);
3176 /* Module has been copied to its final place now: return it. */
3177 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3178 kmemleak_load_module(mod, info);
3182 /* mod is no longer valid after this! */
3183 static void module_deallocate(struct module *mod, struct load_info *info)
3185 percpu_modfree(mod);
3186 module_arch_freeing_init(mod);
3187 module_memfree(mod->module_init);
3188 module_memfree(mod->module_core);
3191 int __weak module_finalize(const Elf_Ehdr *hdr,
3192 const Elf_Shdr *sechdrs,
3198 static int post_relocation(struct module *mod, const struct load_info *info)
3200 /* Sort exception table now relocations are done. */
3201 sort_extable(mod->extable, mod->extable + mod->num_exentries);
3203 /* Copy relocated percpu area over. */
3204 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3205 info->sechdrs[info->index.pcpu].sh_size);
3207 /* Setup kallsyms-specific fields. */
3208 add_kallsyms(mod, info);
3210 /* Arch-specific module finalizing. */
3211 return module_finalize(info->hdr, info->sechdrs, mod);
3214 /* Is this module of this name done loading? No locks held. */
3215 static bool finished_loading(const char *name)
3221 * The module_mutex should not be a heavily contended lock;
3222 * if we get the occasional sleep here, we'll go an extra iteration
3223 * in the wait_event_interruptible(), which is harmless.
3225 sched_annotate_sleep();
3226 mutex_lock(&module_mutex);
3227 mod = find_module_all(name, strlen(name), true);
3228 ret = !mod || mod->state == MODULE_STATE_LIVE;
3229 mutex_unlock(&module_mutex);
3234 /* Call module constructors. */
3235 static void do_mod_ctors(struct module *mod)
3237 #ifdef CONFIG_CONSTRUCTORS
3240 for (i = 0; i < mod->num_ctors; i++)
3245 /* For freeing module_init on success, in case kallsyms traversing */
3246 struct mod_initfree {
3247 struct rcu_head rcu;
3251 static void do_free_init(struct rcu_head *head)
3253 struct mod_initfree *m = container_of(head, struct mod_initfree, rcu);
3254 module_memfree(m->module_init);
3259 * This is where the real work happens.
3261 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3262 * helper command 'lx-symbols'.
3264 static noinline int do_init_module(struct module *mod)
3267 struct mod_initfree *freeinit;
3269 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3274 freeinit->module_init = mod->module_init;
3277 * We want to find out whether @mod uses async during init. Clear
3278 * PF_USED_ASYNC. async_schedule*() will set it.
3280 current->flags &= ~PF_USED_ASYNC;
3283 /* Start the module */
3284 if (mod->init != NULL)
3285 ret = do_one_initcall(mod->init);
3287 goto fail_free_freeinit;
3290 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3291 "follow 0/-E convention\n"
3292 "%s: loading module anyway...\n",
3293 __func__, mod->name, ret, __func__);
3297 /* Now it's a first class citizen! */
3298 mod->state = MODULE_STATE_LIVE;
3299 blocking_notifier_call_chain(&module_notify_list,
3300 MODULE_STATE_LIVE, mod);
3303 * We need to finish all async code before the module init sequence
3304 * is done. This has potential to deadlock. For example, a newly
3305 * detected block device can trigger request_module() of the
3306 * default iosched from async probing task. Once userland helper
3307 * reaches here, async_synchronize_full() will wait on the async
3308 * task waiting on request_module() and deadlock.
3310 * This deadlock is avoided by perfomring async_synchronize_full()
3311 * iff module init queued any async jobs. This isn't a full
3312 * solution as it will deadlock the same if module loading from
3313 * async jobs nests more than once; however, due to the various
3314 * constraints, this hack seems to be the best option for now.
3315 * Please refer to the following thread for details.
3317 * http://thread.gmane.org/gmane.linux.kernel/1420814
3319 if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3320 async_synchronize_full();
3322 mutex_lock(&module_mutex);
3323 /* Drop initial reference. */
3325 trim_init_extable(mod);
3326 #ifdef CONFIG_KALLSYMS
3327 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3328 rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3330 mod_tree_remove_init(mod);
3331 unset_module_init_ro_nx(mod);
3332 module_arch_freeing_init(mod);
3333 mod->module_init = NULL;
3335 mod->init_ro_size = 0;
3336 mod->init_text_size = 0;
3338 * We want to free module_init, but be aware that kallsyms may be
3339 * walking this with preempt disabled. In all the failure paths, we
3340 * call synchronize_sched(), but we don't want to slow down the success
3341 * path, so use actual RCU here.
3343 call_rcu_sched(&freeinit->rcu, do_free_init);
3344 mutex_unlock(&module_mutex);
3345 wake_up_all(&module_wq);
3352 /* Try to protect us from buggy refcounters. */
3353 mod->state = MODULE_STATE_GOING;
3354 synchronize_sched();
3356 blocking_notifier_call_chain(&module_notify_list,
3357 MODULE_STATE_GOING, mod);
3359 wake_up_all(&module_wq);
3363 static int may_init_module(void)
3365 if (!capable(CAP_SYS_MODULE) || modules_disabled)
3372 * We try to place it in the list now to make sure it's unique before
3373 * we dedicate too many resources. In particular, temporary percpu
3374 * memory exhaustion.
3376 static int add_unformed_module(struct module *mod)
3381 mod->state = MODULE_STATE_UNFORMED;
3384 mutex_lock(&module_mutex);
3385 old = find_module_all(mod->name, strlen(mod->name), true);
3387 if (old->state != MODULE_STATE_LIVE) {
3388 /* Wait in case it fails to load. */
3389 mutex_unlock(&module_mutex);
3390 err = wait_event_interruptible(module_wq,
3391 finished_loading(mod->name));
3399 mod_update_bounds(mod);
3400 list_add_rcu(&mod->list, &modules);
3401 mod_tree_insert(mod);
3405 mutex_unlock(&module_mutex);
3410 static int complete_formation(struct module *mod, struct load_info *info)
3414 mutex_lock(&module_mutex);
3416 /* Find duplicate symbols (must be called under lock). */
3417 err = verify_export_symbols(mod);
3421 /* This relies on module_mutex for list integrity. */
3422 module_bug_finalize(info->hdr, info->sechdrs, mod);
3424 /* Set RO and NX regions for core */
3425 set_section_ro_nx(mod->module_core,
3426 mod->core_text_size,
3430 /* Set RO and NX regions for init */
3431 set_section_ro_nx(mod->module_init,
3432 mod->init_text_size,
3436 /* Mark state as coming so strong_try_module_get() ignores us,
3437 * but kallsyms etc. can see us. */
3438 mod->state = MODULE_STATE_COMING;
3439 mutex_unlock(&module_mutex);
3441 blocking_notifier_call_chain(&module_notify_list,
3442 MODULE_STATE_COMING, mod);
3446 mutex_unlock(&module_mutex);
3450 static int unknown_module_param_cb(char *param, char *val, const char *modname,
3453 struct module *mod = arg;
3456 if (strcmp(param, "async_probe") == 0) {
3457 mod->async_probe_requested = true;
3461 /* Check for magic 'dyndbg' arg */
3462 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3464 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3468 /* Allocate and load the module: note that size of section 0 is always
3469 zero, and we rely on this for optional sections. */
3470 static int load_module(struct load_info *info, const char __user *uargs,
3477 err = module_sig_check(info, flags);
3481 err = elf_header_check(info);
3485 /* Figure out module layout, and allocate all the memory. */
3486 mod = layout_and_allocate(info, flags);
3492 /* Reserve our place in the list. */
3493 err = add_unformed_module(mod);
3497 #ifdef CONFIG_MODULE_SIG
3498 mod->sig_ok = info->sig_ok;
3500 pr_notice_once("%s: module verification failed: signature "
3501 "and/or required key missing - tainting "
3502 "kernel\n", mod->name);
3503 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3507 /* To avoid stressing percpu allocator, do this once we're unique. */
3508 err = percpu_modalloc(mod, info);
3512 /* Now module is in final location, initialize linked lists, etc. */
3513 err = module_unload_init(mod);
3517 init_param_lock(mod);
3519 /* Now we've got everything in the final locations, we can
3520 * find optional sections. */
3521 err = find_module_sections(mod, info);
3525 err = check_module_license_and_versions(mod);
3529 /* Set up MODINFO_ATTR fields */
3530 setup_modinfo(mod, info);
3532 /* Fix up syms, so that st_value is a pointer to location. */
3533 err = simplify_symbols(mod, info);
3537 err = apply_relocations(mod, info);
3541 err = post_relocation(mod, info);
3545 flush_module_icache(mod);
3547 /* Now copy in args */
3548 mod->args = strndup_user(uargs, ~0UL >> 1);
3549 if (IS_ERR(mod->args)) {
3550 err = PTR_ERR(mod->args);
3551 goto free_arch_cleanup;
3554 dynamic_debug_setup(info->debug, info->num_debug);
3556 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3557 ftrace_module_init(mod);
3559 /* Finally it's fully formed, ready to start executing. */
3560 err = complete_formation(mod, info);
3562 goto ddebug_cleanup;
3564 /* Module is ready to execute: parsing args may do that. */
3565 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3567 unknown_module_param_cb);
3568 if (IS_ERR(after_dashes)) {
3569 err = PTR_ERR(after_dashes);
3571 } else if (after_dashes) {
3572 pr_warn("%s: parameters '%s' after `--' ignored\n",
3573 mod->name, after_dashes);
3576 /* Link in to syfs. */
3577 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3581 /* Get rid of temporary copy. */
3585 trace_module_load(mod);
3587 return do_init_module(mod);
3590 /* module_bug_cleanup needs module_mutex protection */
3591 mutex_lock(&module_mutex);
3592 module_bug_cleanup(mod);
3593 mutex_unlock(&module_mutex);
3595 blocking_notifier_call_chain(&module_notify_list,
3596 MODULE_STATE_GOING, mod);
3598 /* we can't deallocate the module until we clear memory protection */
3599 unset_module_init_ro_nx(mod);
3600 unset_module_core_ro_nx(mod);
3603 dynamic_debug_remove(info->debug);
3604 synchronize_sched();
3607 module_arch_cleanup(mod);
3611 module_unload_free(mod);
3613 mutex_lock(&module_mutex);
3614 /* Unlink carefully: kallsyms could be walking list. */
3615 list_del_rcu(&mod->list);
3616 mod_tree_remove(mod);
3617 wake_up_all(&module_wq);
3618 /* Wait for RCU-sched synchronizing before releasing mod->list. */
3619 synchronize_sched();
3620 mutex_unlock(&module_mutex);
3623 * Ftrace needs to clean up what it initialized.
3624 * This does nothing if ftrace_module_init() wasn't called,
3625 * but it must be called outside of module_mutex.
3627 ftrace_release_mod(mod);
3628 /* Free lock-classes; relies on the preceding sync_rcu() */
3629 lockdep_free_key_range(mod->module_core, mod->core_size);
3631 module_deallocate(mod, info);
3637 SYSCALL_DEFINE3(init_module, void __user *, umod,
3638 unsigned long, len, const char __user *, uargs)
3641 struct load_info info = { };
3643 err = may_init_module();
3647 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3650 err = copy_module_from_user(umod, len, &info);
3654 return load_module(&info, uargs, 0);
3657 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3660 struct load_info info = { };
3662 err = may_init_module();
3666 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3668 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3669 |MODULE_INIT_IGNORE_VERMAGIC))
3672 err = copy_module_from_fd(fd, &info);
3676 return load_module(&info, uargs, flags);
3679 static inline int within(unsigned long addr, void *start, unsigned long size)
3681 return ((void *)addr >= start && (void *)addr < start + size);
3684 #ifdef CONFIG_KALLSYMS
3686 * This ignores the intensely annoying "mapping symbols" found
3687 * in ARM ELF files: $a, $t and $d.
3689 static inline int is_arm_mapping_symbol(const char *str)
3691 if (str[0] == '.' && str[1] == 'L')
3693 return str[0] == '$' && strchr("axtd", str[1])
3694 && (str[2] == '\0' || str[2] == '.');
3697 static const char *symname(struct mod_kallsyms *kallsyms, unsigned int symnum)
3699 return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
3702 static const char *get_ksymbol(struct module *mod,
3704 unsigned long *size,
3705 unsigned long *offset)
3707 unsigned int i, best = 0;
3708 unsigned long nextval;
3709 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
3711 /* At worse, next value is at end of module */
3712 if (within_module_init(addr, mod))
3713 nextval = (unsigned long)mod->module_init+mod->init_text_size;
3715 nextval = (unsigned long)mod->module_core+mod->core_text_size;
3717 /* Scan for closest preceding symbol, and next symbol. (ELF
3718 starts real symbols at 1). */
3719 for (i = 1; i < kallsyms->num_symtab; i++) {
3720 if (kallsyms->symtab[i].st_shndx == SHN_UNDEF)
3723 /* We ignore unnamed symbols: they're uninformative
3724 * and inserted at a whim. */
3725 if (*symname(kallsyms, i) == '\0'
3726 || is_arm_mapping_symbol(symname(kallsyms, i)))
3729 if (kallsyms->symtab[i].st_value <= addr
3730 && kallsyms->symtab[i].st_value > kallsyms->symtab[best].st_value)
3732 if (kallsyms->symtab[i].st_value > addr
3733 && kallsyms->symtab[i].st_value < nextval)
3734 nextval = kallsyms->symtab[i].st_value;
3741 *size = nextval - kallsyms->symtab[best].st_value;
3743 *offset = addr - kallsyms->symtab[best].st_value;
3744 return symname(kallsyms, best);
3747 /* For kallsyms to ask for address resolution. NULL means not found. Careful
3748 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3749 const char *module_address_lookup(unsigned long addr,
3750 unsigned long *size,
3751 unsigned long *offset,
3755 const char *ret = NULL;
3759 mod = __module_address(addr);
3762 *modname = mod->name;
3763 ret = get_ksymbol(mod, addr, size, offset);
3765 /* Make a copy in here where it's safe */
3767 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3775 int lookup_module_symbol_name(unsigned long addr, char *symname)
3780 list_for_each_entry_rcu(mod, &modules, list) {
3781 if (mod->state == MODULE_STATE_UNFORMED)
3783 if (within_module(addr, mod)) {
3786 sym = get_ksymbol(mod, addr, NULL, NULL);
3789 strlcpy(symname, sym, KSYM_NAME_LEN);
3799 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3800 unsigned long *offset, char *modname, char *name)
3805 list_for_each_entry_rcu(mod, &modules, list) {
3806 if (mod->state == MODULE_STATE_UNFORMED)
3808 if (within_module(addr, mod)) {
3811 sym = get_ksymbol(mod, addr, size, offset);
3815 strlcpy(modname, mod->name, MODULE_NAME_LEN);
3817 strlcpy(name, sym, KSYM_NAME_LEN);
3827 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3828 char *name, char *module_name, int *exported)
3833 list_for_each_entry_rcu(mod, &modules, list) {
3834 struct mod_kallsyms *kallsyms;
3836 if (mod->state == MODULE_STATE_UNFORMED)
3838 kallsyms = rcu_dereference_sched(mod->kallsyms);
3839 if (symnum < kallsyms->num_symtab) {
3840 *value = kallsyms->symtab[symnum].st_value;
3841 *type = kallsyms->symtab[symnum].st_info;
3842 strlcpy(name, symname(kallsyms, symnum), KSYM_NAME_LEN);
3843 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3844 *exported = is_exported(name, *value, mod);
3848 symnum -= kallsyms->num_symtab;
3854 static unsigned long mod_find_symname(struct module *mod, const char *name)
3857 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
3859 for (i = 0; i < kallsyms->num_symtab; i++)
3860 if (strcmp(name, symname(kallsyms, i)) == 0 &&
3861 kallsyms->symtab[i].st_shndx != SHN_UNDEF)
3862 return kallsyms->symtab[i].st_value;
3866 /* Look for this name: can be of form module:name. */
3867 unsigned long module_kallsyms_lookup_name(const char *name)
3871 unsigned long ret = 0;
3873 /* Don't lock: we're in enough trouble already. */
3875 if ((colon = strchr(name, ':')) != NULL) {
3876 if ((mod = find_module_all(name, colon - name, false)) != NULL)
3877 ret = mod_find_symname(mod, colon+1);
3879 list_for_each_entry_rcu(mod, &modules, list) {
3880 if (mod->state == MODULE_STATE_UNFORMED)
3882 if ((ret = mod_find_symname(mod, name)) != 0)
3890 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
3891 struct module *, unsigned long),
3898 module_assert_mutex();
3900 list_for_each_entry(mod, &modules, list) {
3901 /* We hold module_mutex: no need for rcu_dereference_sched */
3902 struct mod_kallsyms *kallsyms = mod->kallsyms;
3904 if (mod->state == MODULE_STATE_UNFORMED)
3906 for (i = 0; i < kallsyms->num_symtab; i++) {
3908 if (kallsyms->symtab[i].st_shndx == SHN_UNDEF)
3911 ret = fn(data, symname(kallsyms, i),
3912 mod, kallsyms->symtab[i].st_value);
3919 #endif /* CONFIG_KALLSYMS */
3921 static char *module_flags(struct module *mod, char *buf)
3925 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
3927 mod->state == MODULE_STATE_GOING ||
3928 mod->state == MODULE_STATE_COMING) {
3930 bx += module_flags_taint(mod, buf + bx);
3931 /* Show a - for module-is-being-unloaded */
3932 if (mod->state == MODULE_STATE_GOING)
3934 /* Show a + for module-is-being-loaded */
3935 if (mod->state == MODULE_STATE_COMING)
3944 #ifdef CONFIG_PROC_FS
3945 /* Called by the /proc file system to return a list of modules. */
3946 static void *m_start(struct seq_file *m, loff_t *pos)
3948 mutex_lock(&module_mutex);
3949 return seq_list_start(&modules, *pos);
3952 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
3954 return seq_list_next(p, &modules, pos);
3957 static void m_stop(struct seq_file *m, void *p)
3959 mutex_unlock(&module_mutex);
3962 static int m_show(struct seq_file *m, void *p)
3964 struct module *mod = list_entry(p, struct module, list);
3967 /* We always ignore unformed modules. */
3968 if (mod->state == MODULE_STATE_UNFORMED)
3971 seq_printf(m, "%s %u",
3972 mod->name, mod->init_size + mod->core_size);
3973 print_unload_info(m, mod);
3975 /* Informative for users. */
3976 seq_printf(m, " %s",
3977 mod->state == MODULE_STATE_GOING ? "Unloading" :
3978 mod->state == MODULE_STATE_COMING ? "Loading" :
3980 /* Used by oprofile and other similar tools. */
3981 seq_printf(m, " 0x%pK", mod->module_core);
3985 seq_printf(m, " %s", module_flags(mod, buf));
3991 /* Format: modulename size refcount deps address
3993 Where refcount is a number or -, and deps is a comma-separated list
3996 static const struct seq_operations modules_op = {
4003 static int modules_open(struct inode *inode, struct file *file)
4005 return seq_open(file, &modules_op);
4008 static const struct file_operations proc_modules_operations = {
4009 .open = modules_open,
4011 .llseek = seq_lseek,
4012 .release = seq_release,
4015 static int __init proc_modules_init(void)
4017 proc_create("modules", 0, NULL, &proc_modules_operations);
4020 module_init(proc_modules_init);
4023 /* Given an address, look for it in the module exception tables. */
4024 const struct exception_table_entry *search_module_extables(unsigned long addr)
4026 const struct exception_table_entry *e = NULL;
4030 list_for_each_entry_rcu(mod, &modules, list) {
4031 if (mod->state == MODULE_STATE_UNFORMED)
4033 if (mod->num_exentries == 0)
4036 e = search_extable(mod->extable,
4037 mod->extable + mod->num_exentries - 1,
4044 /* Now, if we found one, we are running inside it now, hence
4045 we cannot unload the module, hence no refcnt needed. */
4050 * is_module_address - is this address inside a module?
4051 * @addr: the address to check.
4053 * See is_module_text_address() if you simply want to see if the address
4054 * is code (not data).
4056 bool is_module_address(unsigned long addr)
4061 ret = __module_address(addr) != NULL;
4068 * __module_address - get the module which contains an address.
4069 * @addr: the address.
4071 * Must be called with preempt disabled or module mutex held so that
4072 * module doesn't get freed during this.
4074 struct module *__module_address(unsigned long addr)
4078 if (addr < module_addr_min || addr > module_addr_max)
4081 module_assert_mutex_or_preempt();
4083 mod = mod_find(addr);
4085 BUG_ON(!within_module(addr, mod));
4086 if (mod->state == MODULE_STATE_UNFORMED)
4091 EXPORT_SYMBOL_GPL(__module_address);
4094 * is_module_text_address - is this address inside module code?
4095 * @addr: the address to check.
4097 * See is_module_address() if you simply want to see if the address is
4098 * anywhere in a module. See kernel_text_address() for testing if an
4099 * address corresponds to kernel or module code.
4101 bool is_module_text_address(unsigned long addr)
4106 ret = __module_text_address(addr) != NULL;
4113 * __module_text_address - get the module whose code contains an address.
4114 * @addr: the address.
4116 * Must be called with preempt disabled or module mutex held so that
4117 * module doesn't get freed during this.
4119 struct module *__module_text_address(unsigned long addr)
4121 struct module *mod = __module_address(addr);
4123 /* Make sure it's within the text section. */
4124 if (!within(addr, mod->module_init, mod->init_text_size)
4125 && !within(addr, mod->module_core, mod->core_text_size))
4130 EXPORT_SYMBOL_GPL(__module_text_address);
4132 /* Don't grab lock, we're oopsing. */
4133 void print_modules(void)
4138 printk(KERN_DEFAULT "Modules linked in:");
4139 /* Most callers should already have preempt disabled, but make sure */
4141 list_for_each_entry_rcu(mod, &modules, list) {
4142 if (mod->state == MODULE_STATE_UNFORMED)
4144 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4147 if (last_unloaded_module[0])
4148 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4152 #ifdef CONFIG_MODVERSIONS
4153 /* Generate the signature for all relevant module structures here.
4154 * If these change, we don't want to try to parse the module. */
4155 void module_layout(struct module *mod,
4156 struct modversion_info *ver,
4157 struct kernel_param *kp,
4158 struct kernel_symbol *ks,
4159 struct tracepoint * const *tp)
4162 EXPORT_SYMBOL(module_layout);