2 Copyright (C) 2002 Richard Henderson
3 Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 #include <linux/export.h>
20 #include <linux/extable.h>
21 #include <linux/moduleloader.h>
22 #include <linux/trace_events.h>
23 #include <linux/init.h>
24 #include <linux/kallsyms.h>
25 #include <linux/file.h>
27 #include <linux/sysfs.h>
28 #include <linux/kernel.h>
29 #include <linux/slab.h>
30 #include <linux/vmalloc.h>
31 #include <linux/elf.h>
32 #include <linux/proc_fs.h>
33 #include <linux/security.h>
34 #include <linux/seq_file.h>
35 #include <linux/syscalls.h>
36 #include <linux/fcntl.h>
37 #include <linux/rcupdate.h>
38 #include <linux/capability.h>
39 #include <linux/cpu.h>
40 #include <linux/moduleparam.h>
41 #include <linux/errno.h>
42 #include <linux/err.h>
43 #include <linux/vermagic.h>
44 #include <linux/notifier.h>
45 #include <linux/sched.h>
46 #include <linux/device.h>
47 #include <linux/string.h>
48 #include <linux/mutex.h>
49 #include <linux/rculist.h>
50 #include <linux/uaccess.h>
51 #include <asm/cacheflush.h>
52 #include <linux/set_memory.h>
53 #include <asm/mmu_context.h>
54 #include <linux/license.h>
55 #include <asm/sections.h>
56 #include <linux/tracepoint.h>
57 #include <linux/ftrace.h>
58 #include <linux/livepatch.h>
59 #include <linux/async.h>
60 #include <linux/percpu.h>
61 #include <linux/kmemleak.h>
62 #include <linux/jump_label.h>
63 #include <linux/pfn.h>
64 #include <linux/bsearch.h>
65 #include <linux/dynamic_debug.h>
66 #include <linux/audit.h>
67 #include <uapi/linux/module.h>
68 #include "module-internal.h"
70 #define CREATE_TRACE_POINTS
71 #include <trace/events/module.h>
73 #ifndef ARCH_SHF_SMALL
74 #define ARCH_SHF_SMALL 0
78 * Modules' sections will be aligned on page boundaries
79 * to ensure complete separation of code and data, but
80 * only when CONFIG_STRICT_MODULE_RWX=y
82 #ifdef CONFIG_STRICT_MODULE_RWX
83 # define debug_align(X) ALIGN(X, PAGE_SIZE)
85 # define debug_align(X) (X)
88 /* If this is set, the section belongs in the init part of the module */
89 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
93 * 1) List of modules (also safely readable with preempt_disable),
94 * 2) module_use links,
95 * 3) module_addr_min/module_addr_max.
96 * (delete and add uses RCU list operations). */
97 DEFINE_MUTEX(module_mutex);
98 EXPORT_SYMBOL_GPL(module_mutex);
99 static LIST_HEAD(modules);
101 #ifdef CONFIG_MODULES_TREE_LOOKUP
104 * Use a latched RB-tree for __module_address(); this allows us to use
105 * RCU-sched lookups of the address from any context.
107 * This is conditional on PERF_EVENTS || TRACING because those can really hit
108 * __module_address() hard by doing a lot of stack unwinding; potentially from
112 static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
114 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
116 return (unsigned long)layout->base;
119 static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
121 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
123 return (unsigned long)layout->size;
126 static __always_inline bool
127 mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
129 return __mod_tree_val(a) < __mod_tree_val(b);
132 static __always_inline int
133 mod_tree_comp(void *key, struct latch_tree_node *n)
135 unsigned long val = (unsigned long)key;
136 unsigned long start, end;
138 start = __mod_tree_val(n);
142 end = start + __mod_tree_size(n);
149 static const struct latch_tree_ops mod_tree_ops = {
150 .less = mod_tree_less,
151 .comp = mod_tree_comp,
154 static struct mod_tree_root {
155 struct latch_tree_root root;
156 unsigned long addr_min;
157 unsigned long addr_max;
158 } mod_tree __cacheline_aligned = {
162 #define module_addr_min mod_tree.addr_min
163 #define module_addr_max mod_tree.addr_max
165 static noinline void __mod_tree_insert(struct mod_tree_node *node)
167 latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
170 static void __mod_tree_remove(struct mod_tree_node *node)
172 latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
176 * These modifications: insert, remove_init and remove; are serialized by the
179 static void mod_tree_insert(struct module *mod)
181 mod->core_layout.mtn.mod = mod;
182 mod->init_layout.mtn.mod = mod;
184 __mod_tree_insert(&mod->core_layout.mtn);
185 if (mod->init_layout.size)
186 __mod_tree_insert(&mod->init_layout.mtn);
189 static void mod_tree_remove_init(struct module *mod)
191 if (mod->init_layout.size)
192 __mod_tree_remove(&mod->init_layout.mtn);
195 static void mod_tree_remove(struct module *mod)
197 __mod_tree_remove(&mod->core_layout.mtn);
198 mod_tree_remove_init(mod);
201 static struct module *mod_find(unsigned long addr)
203 struct latch_tree_node *ltn;
205 ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
209 return container_of(ltn, struct mod_tree_node, node)->mod;
212 #else /* MODULES_TREE_LOOKUP */
214 static unsigned long module_addr_min = -1UL, module_addr_max = 0;
216 static void mod_tree_insert(struct module *mod) { }
217 static void mod_tree_remove_init(struct module *mod) { }
218 static void mod_tree_remove(struct module *mod) { }
220 static struct module *mod_find(unsigned long addr)
224 list_for_each_entry_rcu(mod, &modules, list) {
225 if (within_module(addr, mod))
232 #endif /* MODULES_TREE_LOOKUP */
235 * Bounds of module text, for speeding up __module_address.
236 * Protected by module_mutex.
238 static void __mod_update_bounds(void *base, unsigned int size)
240 unsigned long min = (unsigned long)base;
241 unsigned long max = min + size;
243 if (min < module_addr_min)
244 module_addr_min = min;
245 if (max > module_addr_max)
246 module_addr_max = max;
249 static void mod_update_bounds(struct module *mod)
251 __mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
252 if (mod->init_layout.size)
253 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
256 #ifdef CONFIG_KGDB_KDB
257 struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
258 #endif /* CONFIG_KGDB_KDB */
260 static void module_assert_mutex(void)
262 lockdep_assert_held(&module_mutex);
265 static void module_assert_mutex_or_preempt(void)
267 #ifdef CONFIG_LOCKDEP
268 if (unlikely(!debug_locks))
271 WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
272 !lockdep_is_held(&module_mutex));
276 static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
277 module_param(sig_enforce, bool_enable_only, 0644);
280 * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
281 * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
283 bool is_module_sig_enforced(void)
287 EXPORT_SYMBOL(is_module_sig_enforced);
289 /* Block module loading/unloading? */
290 int modules_disabled = 0;
291 core_param(nomodule, modules_disabled, bint, 0);
293 /* Waiting for a module to finish initializing? */
294 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
296 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
298 int register_module_notifier(struct notifier_block *nb)
300 return blocking_notifier_chain_register(&module_notify_list, nb);
302 EXPORT_SYMBOL(register_module_notifier);
304 int unregister_module_notifier(struct notifier_block *nb)
306 return blocking_notifier_chain_unregister(&module_notify_list, nb);
308 EXPORT_SYMBOL(unregister_module_notifier);
311 * We require a truly strong try_module_get(): 0 means success.
312 * Otherwise an error is returned due to ongoing or failed
313 * initialization etc.
315 static inline int strong_try_module_get(struct module *mod)
317 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
318 if (mod && mod->state == MODULE_STATE_COMING)
320 if (try_module_get(mod))
326 static inline void add_taint_module(struct module *mod, unsigned flag,
327 enum lockdep_ok lockdep_ok)
329 add_taint(flag, lockdep_ok);
330 set_bit(flag, &mod->taints);
334 * A thread that wants to hold a reference to a module only while it
335 * is running can call this to safely exit. nfsd and lockd use this.
337 void __noreturn __module_put_and_exit(struct module *mod, long code)
342 EXPORT_SYMBOL(__module_put_and_exit);
344 /* Find a module section: 0 means not found. */
345 static unsigned int find_sec(const struct load_info *info, const char *name)
349 for (i = 1; i < info->hdr->e_shnum; i++) {
350 Elf_Shdr *shdr = &info->sechdrs[i];
351 /* Alloc bit cleared means "ignore it." */
352 if ((shdr->sh_flags & SHF_ALLOC)
353 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
359 /* Find a module section, or NULL. */
360 static void *section_addr(const struct load_info *info, const char *name)
362 /* Section 0 has sh_addr 0. */
363 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
366 /* Find a module section, or NULL. Fill in number of "objects" in section. */
367 static void *section_objs(const struct load_info *info,
372 unsigned int sec = find_sec(info, name);
374 /* Section 0 has sh_addr 0 and sh_size 0. */
375 *num = info->sechdrs[sec].sh_size / object_size;
376 return (void *)info->sechdrs[sec].sh_addr;
379 /* Provided by the linker */
380 extern const struct kernel_symbol __start___ksymtab[];
381 extern const struct kernel_symbol __stop___ksymtab[];
382 extern const struct kernel_symbol __start___ksymtab_gpl[];
383 extern const struct kernel_symbol __stop___ksymtab_gpl[];
384 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
385 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
386 extern const s32 __start___kcrctab[];
387 extern const s32 __start___kcrctab_gpl[];
388 extern const s32 __start___kcrctab_gpl_future[];
389 #ifdef CONFIG_UNUSED_SYMBOLS
390 extern const struct kernel_symbol __start___ksymtab_unused[];
391 extern const struct kernel_symbol __stop___ksymtab_unused[];
392 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
393 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
394 extern const s32 __start___kcrctab_unused[];
395 extern const s32 __start___kcrctab_unused_gpl[];
398 #ifndef CONFIG_MODVERSIONS
399 #define symversion(base, idx) NULL
401 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
404 static bool each_symbol_in_section(const struct symsearch *arr,
405 unsigned int arrsize,
406 struct module *owner,
407 bool (*fn)(const struct symsearch *syms,
408 struct module *owner,
414 for (j = 0; j < arrsize; j++) {
415 if (fn(&arr[j], owner, data))
422 /* Returns true as soon as fn returns true, otherwise false. */
423 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
424 struct module *owner,
429 static const struct symsearch arr[] = {
430 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
431 NOT_GPL_ONLY, false },
432 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
433 __start___kcrctab_gpl,
435 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
436 __start___kcrctab_gpl_future,
437 WILL_BE_GPL_ONLY, false },
438 #ifdef CONFIG_UNUSED_SYMBOLS
439 { __start___ksymtab_unused, __stop___ksymtab_unused,
440 __start___kcrctab_unused,
441 NOT_GPL_ONLY, true },
442 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
443 __start___kcrctab_unused_gpl,
448 module_assert_mutex_or_preempt();
450 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
453 list_for_each_entry_rcu(mod, &modules, list) {
454 struct symsearch arr[] = {
455 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
456 NOT_GPL_ONLY, false },
457 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
460 { mod->gpl_future_syms,
461 mod->gpl_future_syms + mod->num_gpl_future_syms,
462 mod->gpl_future_crcs,
463 WILL_BE_GPL_ONLY, false },
464 #ifdef CONFIG_UNUSED_SYMBOLS
466 mod->unused_syms + mod->num_unused_syms,
468 NOT_GPL_ONLY, true },
469 { mod->unused_gpl_syms,
470 mod->unused_gpl_syms + mod->num_unused_gpl_syms,
471 mod->unused_gpl_crcs,
476 if (mod->state == MODULE_STATE_UNFORMED)
479 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
484 EXPORT_SYMBOL_GPL(each_symbol_section);
486 struct find_symbol_arg {
493 struct module *owner;
495 const struct kernel_symbol *sym;
498 static bool check_symbol(const struct symsearch *syms,
499 struct module *owner,
500 unsigned int symnum, void *data)
502 struct find_symbol_arg *fsa = data;
505 if (syms->licence == GPL_ONLY)
507 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
508 pr_warn("Symbol %s is being used by a non-GPL module, "
509 "which will not be allowed in the future\n",
514 #ifdef CONFIG_UNUSED_SYMBOLS
515 if (syms->unused && fsa->warn) {
516 pr_warn("Symbol %s is marked as UNUSED, however this module is "
517 "using it.\n", fsa->name);
518 pr_warn("This symbol will go away in the future.\n");
519 pr_warn("Please evaluate if this is the right api to use and "
520 "if it really is, submit a report to the linux kernel "
521 "mailing list together with submitting your code for "
527 fsa->crc = symversion(syms->crcs, symnum);
528 fsa->sym = &syms->start[symnum];
532 static int cmp_name(const void *va, const void *vb)
535 const struct kernel_symbol *b;
537 return strcmp(a, b->name);
540 static bool find_symbol_in_section(const struct symsearch *syms,
541 struct module *owner,
544 struct find_symbol_arg *fsa = data;
545 struct kernel_symbol *sym;
547 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
548 sizeof(struct kernel_symbol), cmp_name);
550 if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
556 /* Find a symbol and return it, along with, (optional) crc and
557 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
558 const struct kernel_symbol *find_symbol(const char *name,
559 struct module **owner,
564 struct find_symbol_arg fsa;
570 if (each_symbol_section(find_symbol_in_section, &fsa)) {
578 pr_debug("Failed to find symbol %s\n", name);
581 EXPORT_SYMBOL_GPL(find_symbol);
584 * Search for module by name: must hold module_mutex (or preempt disabled
585 * for read-only access).
587 static struct module *find_module_all(const char *name, size_t len,
592 module_assert_mutex_or_preempt();
594 list_for_each_entry_rcu(mod, &modules, list) {
595 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
597 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
603 struct module *find_module(const char *name)
605 module_assert_mutex();
606 return find_module_all(name, strlen(name), false);
608 EXPORT_SYMBOL_GPL(find_module);
612 static inline void __percpu *mod_percpu(struct module *mod)
617 static int percpu_modalloc(struct module *mod, struct load_info *info)
619 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
620 unsigned long align = pcpusec->sh_addralign;
622 if (!pcpusec->sh_size)
625 if (align > PAGE_SIZE) {
626 pr_warn("%s: per-cpu alignment %li > %li\n",
627 mod->name, align, PAGE_SIZE);
631 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
633 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
634 mod->name, (unsigned long)pcpusec->sh_size);
637 mod->percpu_size = pcpusec->sh_size;
641 static void percpu_modfree(struct module *mod)
643 free_percpu(mod->percpu);
646 static unsigned int find_pcpusec(struct load_info *info)
648 return find_sec(info, ".data..percpu");
651 static void percpu_modcopy(struct module *mod,
652 const void *from, unsigned long size)
656 for_each_possible_cpu(cpu)
657 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
660 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
667 list_for_each_entry_rcu(mod, &modules, list) {
668 if (mod->state == MODULE_STATE_UNFORMED)
670 if (!mod->percpu_size)
672 for_each_possible_cpu(cpu) {
673 void *start = per_cpu_ptr(mod->percpu, cpu);
674 void *va = (void *)addr;
676 if (va >= start && va < start + mod->percpu_size) {
678 *can_addr = (unsigned long) (va - start);
679 *can_addr += (unsigned long)
680 per_cpu_ptr(mod->percpu,
694 * is_module_percpu_address - test whether address is from module static percpu
695 * @addr: address to test
697 * Test whether @addr belongs to module static percpu area.
700 * %true if @addr is from module static percpu area
702 bool is_module_percpu_address(unsigned long addr)
704 return __is_module_percpu_address(addr, NULL);
707 #else /* ... !CONFIG_SMP */
709 static inline void __percpu *mod_percpu(struct module *mod)
713 static int percpu_modalloc(struct module *mod, struct load_info *info)
715 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
716 if (info->sechdrs[info->index.pcpu].sh_size != 0)
720 static inline void percpu_modfree(struct module *mod)
723 static unsigned int find_pcpusec(struct load_info *info)
727 static inline void percpu_modcopy(struct module *mod,
728 const void *from, unsigned long size)
730 /* pcpusec should be 0, and size of that section should be 0. */
733 bool is_module_percpu_address(unsigned long addr)
738 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
743 #endif /* CONFIG_SMP */
745 #define MODINFO_ATTR(field) \
746 static void setup_modinfo_##field(struct module *mod, const char *s) \
748 mod->field = kstrdup(s, GFP_KERNEL); \
750 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
751 struct module_kobject *mk, char *buffer) \
753 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
755 static int modinfo_##field##_exists(struct module *mod) \
757 return mod->field != NULL; \
759 static void free_modinfo_##field(struct module *mod) \
764 static struct module_attribute modinfo_##field = { \
765 .attr = { .name = __stringify(field), .mode = 0444 }, \
766 .show = show_modinfo_##field, \
767 .setup = setup_modinfo_##field, \
768 .test = modinfo_##field##_exists, \
769 .free = free_modinfo_##field, \
772 MODINFO_ATTR(version);
773 MODINFO_ATTR(srcversion);
775 static char last_unloaded_module[MODULE_NAME_LEN+1];
777 #ifdef CONFIG_MODULE_UNLOAD
779 EXPORT_TRACEPOINT_SYMBOL(module_get);
781 /* MODULE_REF_BASE is the base reference count by kmodule loader. */
782 #define MODULE_REF_BASE 1
784 /* Init the unload section of the module. */
785 static int module_unload_init(struct module *mod)
788 * Initialize reference counter to MODULE_REF_BASE.
789 * refcnt == 0 means module is going.
791 atomic_set(&mod->refcnt, MODULE_REF_BASE);
793 INIT_LIST_HEAD(&mod->source_list);
794 INIT_LIST_HEAD(&mod->target_list);
796 /* Hold reference count during initialization. */
797 atomic_inc(&mod->refcnt);
802 /* Does a already use b? */
803 static int already_uses(struct module *a, struct module *b)
805 struct module_use *use;
807 list_for_each_entry(use, &b->source_list, source_list) {
808 if (use->source == a) {
809 pr_debug("%s uses %s!\n", a->name, b->name);
813 pr_debug("%s does not use %s!\n", a->name, b->name);
819 * - we add 'a' as a "source", 'b' as a "target" of module use
820 * - the module_use is added to the list of 'b' sources (so
821 * 'b' can walk the list to see who sourced them), and of 'a'
822 * targets (so 'a' can see what modules it targets).
824 static int add_module_usage(struct module *a, struct module *b)
826 struct module_use *use;
828 pr_debug("Allocating new usage for %s.\n", a->name);
829 use = kmalloc(sizeof(*use), GFP_ATOMIC);
835 list_add(&use->source_list, &b->source_list);
836 list_add(&use->target_list, &a->target_list);
840 /* Module a uses b: caller needs module_mutex() */
841 int ref_module(struct module *a, struct module *b)
845 if (b == NULL || already_uses(a, b))
848 /* If module isn't available, we fail. */
849 err = strong_try_module_get(b);
853 err = add_module_usage(a, b);
860 EXPORT_SYMBOL_GPL(ref_module);
862 /* Clear the unload stuff of the module. */
863 static void module_unload_free(struct module *mod)
865 struct module_use *use, *tmp;
867 mutex_lock(&module_mutex);
868 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
869 struct module *i = use->target;
870 pr_debug("%s unusing %s\n", mod->name, i->name);
872 list_del(&use->source_list);
873 list_del(&use->target_list);
876 mutex_unlock(&module_mutex);
879 #ifdef CONFIG_MODULE_FORCE_UNLOAD
880 static inline int try_force_unload(unsigned int flags)
882 int ret = (flags & O_TRUNC);
884 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
888 static inline int try_force_unload(unsigned int flags)
892 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
894 /* Try to release refcount of module, 0 means success. */
895 static int try_release_module_ref(struct module *mod)
899 /* Try to decrement refcnt which we set at loading */
900 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
903 /* Someone can put this right now, recover with checking */
904 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
909 static int try_stop_module(struct module *mod, int flags, int *forced)
911 /* If it's not unused, quit unless we're forcing. */
912 if (try_release_module_ref(mod) != 0) {
913 *forced = try_force_unload(flags);
918 /* Mark it as dying. */
919 mod->state = MODULE_STATE_GOING;
925 * module_refcount - return the refcount or -1 if unloading
927 * @mod: the module we're checking
930 * -1 if the module is in the process of unloading
931 * otherwise the number of references in the kernel to the module
933 int module_refcount(struct module *mod)
935 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
937 EXPORT_SYMBOL(module_refcount);
939 /* This exists whether we can unload or not */
940 static void free_module(struct module *mod);
942 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
946 char name[MODULE_NAME_LEN];
949 if (!capable(CAP_SYS_MODULE) || modules_disabled)
952 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
954 name[MODULE_NAME_LEN-1] = '\0';
956 audit_log_kern_module(name);
958 if (mutex_lock_interruptible(&module_mutex) != 0)
961 mod = find_module(name);
967 if (!list_empty(&mod->source_list)) {
968 /* Other modules depend on us: get rid of them first. */
973 /* Doing init or already dying? */
974 if (mod->state != MODULE_STATE_LIVE) {
975 /* FIXME: if (force), slam module count damn the torpedoes */
976 pr_debug("%s already dying\n", mod->name);
981 /* If it has an init func, it must have an exit func to unload */
982 if (mod->init && !mod->exit) {
983 forced = try_force_unload(flags);
985 /* This module can't be removed */
991 /* Stop the machine so refcounts can't move and disable module. */
992 ret = try_stop_module(mod, flags, &forced);
996 mutex_unlock(&module_mutex);
997 /* Final destruction now no one is using it. */
998 if (mod->exit != NULL)
1000 blocking_notifier_call_chain(&module_notify_list,
1001 MODULE_STATE_GOING, mod);
1002 klp_module_going(mod);
1003 ftrace_release_mod(mod);
1005 async_synchronize_full();
1007 /* Store the name of the last unloaded module for diagnostic purposes */
1008 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
1013 mutex_unlock(&module_mutex);
1017 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1019 struct module_use *use;
1020 int printed_something = 0;
1022 seq_printf(m, " %i ", module_refcount(mod));
1025 * Always include a trailing , so userspace can differentiate
1026 * between this and the old multi-field proc format.
1028 list_for_each_entry(use, &mod->source_list, source_list) {
1029 printed_something = 1;
1030 seq_printf(m, "%s,", use->source->name);
1033 if (mod->init != NULL && mod->exit == NULL) {
1034 printed_something = 1;
1035 seq_puts(m, "[permanent],");
1038 if (!printed_something)
1042 void __symbol_put(const char *symbol)
1044 struct module *owner;
1047 if (!find_symbol(symbol, &owner, NULL, true, false))
1052 EXPORT_SYMBOL(__symbol_put);
1054 /* Note this assumes addr is a function, which it currently always is. */
1055 void symbol_put_addr(void *addr)
1057 struct module *modaddr;
1058 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1060 if (core_kernel_text(a))
1064 * Even though we hold a reference on the module; we still need to
1065 * disable preemption in order to safely traverse the data structure.
1068 modaddr = __module_text_address(a);
1070 module_put(modaddr);
1073 EXPORT_SYMBOL_GPL(symbol_put_addr);
1075 static ssize_t show_refcnt(struct module_attribute *mattr,
1076 struct module_kobject *mk, char *buffer)
1078 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1081 static struct module_attribute modinfo_refcnt =
1082 __ATTR(refcnt, 0444, show_refcnt, NULL);
1084 void __module_get(struct module *module)
1088 atomic_inc(&module->refcnt);
1089 trace_module_get(module, _RET_IP_);
1093 EXPORT_SYMBOL(__module_get);
1095 bool try_module_get(struct module *module)
1101 /* Note: here, we can fail to get a reference */
1102 if (likely(module_is_live(module) &&
1103 atomic_inc_not_zero(&module->refcnt) != 0))
1104 trace_module_get(module, _RET_IP_);
1112 EXPORT_SYMBOL(try_module_get);
1114 void module_put(struct module *module)
1120 ret = atomic_dec_if_positive(&module->refcnt);
1121 WARN_ON(ret < 0); /* Failed to put refcount */
1122 trace_module_put(module, _RET_IP_);
1126 EXPORT_SYMBOL(module_put);
1128 #else /* !CONFIG_MODULE_UNLOAD */
1129 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1131 /* We don't know the usage count, or what modules are using. */
1132 seq_puts(m, " - -");
1135 static inline void module_unload_free(struct module *mod)
1139 int ref_module(struct module *a, struct module *b)
1141 return strong_try_module_get(b);
1143 EXPORT_SYMBOL_GPL(ref_module);
1145 static inline int module_unload_init(struct module *mod)
1149 #endif /* CONFIG_MODULE_UNLOAD */
1151 static size_t module_flags_taint(struct module *mod, char *buf)
1156 for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
1157 if (taint_flags[i].module && test_bit(i, &mod->taints))
1158 buf[l++] = taint_flags[i].c_true;
1164 static ssize_t show_initstate(struct module_attribute *mattr,
1165 struct module_kobject *mk, char *buffer)
1167 const char *state = "unknown";
1169 switch (mk->mod->state) {
1170 case MODULE_STATE_LIVE:
1173 case MODULE_STATE_COMING:
1176 case MODULE_STATE_GOING:
1182 return sprintf(buffer, "%s\n", state);
1185 static struct module_attribute modinfo_initstate =
1186 __ATTR(initstate, 0444, show_initstate, NULL);
1188 static ssize_t store_uevent(struct module_attribute *mattr,
1189 struct module_kobject *mk,
1190 const char *buffer, size_t count)
1192 kobject_synth_uevent(&mk->kobj, buffer, count);
1196 struct module_attribute module_uevent =
1197 __ATTR(uevent, 0200, NULL, store_uevent);
1199 static ssize_t show_coresize(struct module_attribute *mattr,
1200 struct module_kobject *mk, char *buffer)
1202 return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1205 static struct module_attribute modinfo_coresize =
1206 __ATTR(coresize, 0444, show_coresize, NULL);
1208 static ssize_t show_initsize(struct module_attribute *mattr,
1209 struct module_kobject *mk, char *buffer)
1211 return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1214 static struct module_attribute modinfo_initsize =
1215 __ATTR(initsize, 0444, show_initsize, NULL);
1217 static ssize_t show_taint(struct module_attribute *mattr,
1218 struct module_kobject *mk, char *buffer)
1222 l = module_flags_taint(mk->mod, buffer);
1227 static struct module_attribute modinfo_taint =
1228 __ATTR(taint, 0444, show_taint, NULL);
1230 static struct module_attribute *modinfo_attrs[] = {
1233 &modinfo_srcversion,
1238 #ifdef CONFIG_MODULE_UNLOAD
1244 static const char vermagic[] = VERMAGIC_STRING;
1246 static int try_to_force_load(struct module *mod, const char *reason)
1248 #ifdef CONFIG_MODULE_FORCE_LOAD
1249 if (!test_taint(TAINT_FORCED_MODULE))
1250 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1251 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1258 #ifdef CONFIG_MODVERSIONS
1260 static u32 resolve_rel_crc(const s32 *crc)
1262 return *(u32 *)((void *)crc + *crc);
1265 static int check_version(const struct load_info *info,
1266 const char *symname,
1270 Elf_Shdr *sechdrs = info->sechdrs;
1271 unsigned int versindex = info->index.vers;
1272 unsigned int i, num_versions;
1273 struct modversion_info *versions;
1275 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1279 /* No versions at all? modprobe --force does this. */
1281 return try_to_force_load(mod, symname) == 0;
1283 versions = (void *) sechdrs[versindex].sh_addr;
1284 num_versions = sechdrs[versindex].sh_size
1285 / sizeof(struct modversion_info);
1287 for (i = 0; i < num_versions; i++) {
1290 if (strcmp(versions[i].name, symname) != 0)
1293 if (IS_ENABLED(CONFIG_MODULE_REL_CRCS))
1294 crcval = resolve_rel_crc(crc);
1297 if (versions[i].crc == crcval)
1299 pr_debug("Found checksum %X vs module %lX\n",
1300 crcval, versions[i].crc);
1304 /* Broken toolchain. Warn once, then let it go.. */
1305 pr_warn_once("%s: no symbol version for %s\n", info->name, symname);
1309 pr_warn("%s: disagrees about version of symbol %s\n",
1310 info->name, symname);
1314 static inline int check_modstruct_version(const struct load_info *info,
1320 * Since this should be found in kernel (which can't be removed), no
1321 * locking is necessary -- use preempt_disable() to placate lockdep.
1324 if (!find_symbol("module_layout", NULL, &crc, true, false)) {
1329 return check_version(info, "module_layout", mod, crc);
1332 /* First part is kernel version, which we ignore if module has crcs. */
1333 static inline int same_magic(const char *amagic, const char *bmagic,
1337 amagic += strcspn(amagic, " ");
1338 bmagic += strcspn(bmagic, " ");
1340 return strcmp(amagic, bmagic) == 0;
1343 static inline int check_version(const struct load_info *info,
1344 const char *symname,
1351 static inline int check_modstruct_version(const struct load_info *info,
1357 static inline int same_magic(const char *amagic, const char *bmagic,
1360 return strcmp(amagic, bmagic) == 0;
1362 #endif /* CONFIG_MODVERSIONS */
1364 /* Resolve a symbol for this module. I.e. if we find one, record usage. */
1365 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1366 const struct load_info *info,
1370 struct module *owner;
1371 const struct kernel_symbol *sym;
1376 * The module_mutex should not be a heavily contended lock;
1377 * if we get the occasional sleep here, we'll go an extra iteration
1378 * in the wait_event_interruptible(), which is harmless.
1380 sched_annotate_sleep();
1381 mutex_lock(&module_mutex);
1382 sym = find_symbol(name, &owner, &crc,
1383 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1387 if (!check_version(info, name, mod, crc)) {
1388 sym = ERR_PTR(-EINVAL);
1392 err = ref_module(mod, owner);
1399 /* We must make copy under the lock if we failed to get ref. */
1400 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1402 mutex_unlock(&module_mutex);
1406 static const struct kernel_symbol *
1407 resolve_symbol_wait(struct module *mod,
1408 const struct load_info *info,
1411 const struct kernel_symbol *ksym;
1412 char owner[MODULE_NAME_LEN];
1414 if (wait_event_interruptible_timeout(module_wq,
1415 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1416 || PTR_ERR(ksym) != -EBUSY,
1418 pr_warn("%s: gave up waiting for init of module %s.\n",
1425 * /sys/module/foo/sections stuff
1426 * J. Corbet <corbet@lwn.net>
1430 #ifdef CONFIG_KALLSYMS
1431 static inline bool sect_empty(const Elf_Shdr *sect)
1433 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1436 struct module_sect_attr {
1437 struct module_attribute mattr;
1439 unsigned long address;
1442 struct module_sect_attrs {
1443 struct attribute_group grp;
1444 unsigned int nsections;
1445 struct module_sect_attr attrs[0];
1448 static ssize_t module_sect_show(struct module_attribute *mattr,
1449 struct module_kobject *mk, char *buf)
1451 struct module_sect_attr *sattr =
1452 container_of(mattr, struct module_sect_attr, mattr);
1453 return sprintf(buf, "0x%px\n", kptr_restrict < 2 ?
1454 (void *)sattr->address : NULL);
1457 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1459 unsigned int section;
1461 for (section = 0; section < sect_attrs->nsections; section++)
1462 kfree(sect_attrs->attrs[section].name);
1466 static void add_sect_attrs(struct module *mod, const struct load_info *info)
1468 unsigned int nloaded = 0, i, size[2];
1469 struct module_sect_attrs *sect_attrs;
1470 struct module_sect_attr *sattr;
1471 struct attribute **gattr;
1473 /* Count loaded sections and allocate structures */
1474 for (i = 0; i < info->hdr->e_shnum; i++)
1475 if (!sect_empty(&info->sechdrs[i]))
1477 size[0] = ALIGN(sizeof(*sect_attrs)
1478 + nloaded * sizeof(sect_attrs->attrs[0]),
1479 sizeof(sect_attrs->grp.attrs[0]));
1480 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1481 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1482 if (sect_attrs == NULL)
1485 /* Setup section attributes. */
1486 sect_attrs->grp.name = "sections";
1487 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1489 sect_attrs->nsections = 0;
1490 sattr = §_attrs->attrs[0];
1491 gattr = §_attrs->grp.attrs[0];
1492 for (i = 0; i < info->hdr->e_shnum; i++) {
1493 Elf_Shdr *sec = &info->sechdrs[i];
1494 if (sect_empty(sec))
1496 sattr->address = sec->sh_addr;
1497 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1499 if (sattr->name == NULL)
1501 sect_attrs->nsections++;
1502 sysfs_attr_init(&sattr->mattr.attr);
1503 sattr->mattr.show = module_sect_show;
1504 sattr->mattr.store = NULL;
1505 sattr->mattr.attr.name = sattr->name;
1506 sattr->mattr.attr.mode = S_IRUSR;
1507 *(gattr++) = &(sattr++)->mattr.attr;
1511 if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp))
1514 mod->sect_attrs = sect_attrs;
1517 free_sect_attrs(sect_attrs);
1520 static void remove_sect_attrs(struct module *mod)
1522 if (mod->sect_attrs) {
1523 sysfs_remove_group(&mod->mkobj.kobj,
1524 &mod->sect_attrs->grp);
1525 /* We are positive that no one is using any sect attrs
1526 * at this point. Deallocate immediately. */
1527 free_sect_attrs(mod->sect_attrs);
1528 mod->sect_attrs = NULL;
1533 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1536 struct module_notes_attrs {
1537 struct kobject *dir;
1539 struct bin_attribute attrs[0];
1542 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1543 struct bin_attribute *bin_attr,
1544 char *buf, loff_t pos, size_t count)
1547 * The caller checked the pos and count against our size.
1549 memcpy(buf, bin_attr->private + pos, count);
1553 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1556 if (notes_attrs->dir) {
1558 sysfs_remove_bin_file(notes_attrs->dir,
1559 ¬es_attrs->attrs[i]);
1560 kobject_put(notes_attrs->dir);
1565 static void add_notes_attrs(struct module *mod, const struct load_info *info)
1567 unsigned int notes, loaded, i;
1568 struct module_notes_attrs *notes_attrs;
1569 struct bin_attribute *nattr;
1571 /* failed to create section attributes, so can't create notes */
1572 if (!mod->sect_attrs)
1575 /* Count notes sections and allocate structures. */
1577 for (i = 0; i < info->hdr->e_shnum; i++)
1578 if (!sect_empty(&info->sechdrs[i]) &&
1579 (info->sechdrs[i].sh_type == SHT_NOTE))
1585 notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes),
1587 if (notes_attrs == NULL)
1590 notes_attrs->notes = notes;
1591 nattr = ¬es_attrs->attrs[0];
1592 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1593 if (sect_empty(&info->sechdrs[i]))
1595 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1596 sysfs_bin_attr_init(nattr);
1597 nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1598 nattr->attr.mode = S_IRUGO;
1599 nattr->size = info->sechdrs[i].sh_size;
1600 nattr->private = (void *) info->sechdrs[i].sh_addr;
1601 nattr->read = module_notes_read;
1607 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1608 if (!notes_attrs->dir)
1611 for (i = 0; i < notes; ++i)
1612 if (sysfs_create_bin_file(notes_attrs->dir,
1613 ¬es_attrs->attrs[i]))
1616 mod->notes_attrs = notes_attrs;
1620 free_notes_attrs(notes_attrs, i);
1623 static void remove_notes_attrs(struct module *mod)
1625 if (mod->notes_attrs)
1626 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1631 static inline void add_sect_attrs(struct module *mod,
1632 const struct load_info *info)
1636 static inline void remove_sect_attrs(struct module *mod)
1640 static inline void add_notes_attrs(struct module *mod,
1641 const struct load_info *info)
1645 static inline void remove_notes_attrs(struct module *mod)
1648 #endif /* CONFIG_KALLSYMS */
1650 static void del_usage_links(struct module *mod)
1652 #ifdef CONFIG_MODULE_UNLOAD
1653 struct module_use *use;
1655 mutex_lock(&module_mutex);
1656 list_for_each_entry(use, &mod->target_list, target_list)
1657 sysfs_remove_link(use->target->holders_dir, mod->name);
1658 mutex_unlock(&module_mutex);
1662 static int add_usage_links(struct module *mod)
1665 #ifdef CONFIG_MODULE_UNLOAD
1666 struct module_use *use;
1668 mutex_lock(&module_mutex);
1669 list_for_each_entry(use, &mod->target_list, target_list) {
1670 ret = sysfs_create_link(use->target->holders_dir,
1671 &mod->mkobj.kobj, mod->name);
1675 mutex_unlock(&module_mutex);
1677 del_usage_links(mod);
1682 static int module_add_modinfo_attrs(struct module *mod)
1684 struct module_attribute *attr;
1685 struct module_attribute *temp_attr;
1689 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1690 (ARRAY_SIZE(modinfo_attrs) + 1)),
1692 if (!mod->modinfo_attrs)
1695 temp_attr = mod->modinfo_attrs;
1696 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1697 if (!attr->test || attr->test(mod)) {
1698 memcpy(temp_attr, attr, sizeof(*temp_attr));
1699 sysfs_attr_init(&temp_attr->attr);
1700 error = sysfs_create_file(&mod->mkobj.kobj,
1708 static void module_remove_modinfo_attrs(struct module *mod)
1710 struct module_attribute *attr;
1713 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1714 /* pick a field to test for end of list */
1715 if (!attr->attr.name)
1717 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1721 kfree(mod->modinfo_attrs);
1724 static void mod_kobject_put(struct module *mod)
1726 DECLARE_COMPLETION_ONSTACK(c);
1727 mod->mkobj.kobj_completion = &c;
1728 kobject_put(&mod->mkobj.kobj);
1729 wait_for_completion(&c);
1732 static int mod_sysfs_init(struct module *mod)
1735 struct kobject *kobj;
1737 if (!module_sysfs_initialized) {
1738 pr_err("%s: module sysfs not initialized\n", mod->name);
1743 kobj = kset_find_obj(module_kset, mod->name);
1745 pr_err("%s: module is already loaded\n", mod->name);
1751 mod->mkobj.mod = mod;
1753 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1754 mod->mkobj.kobj.kset = module_kset;
1755 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1758 mod_kobject_put(mod);
1760 /* delay uevent until full sysfs population */
1765 static int mod_sysfs_setup(struct module *mod,
1766 const struct load_info *info,
1767 struct kernel_param *kparam,
1768 unsigned int num_params)
1772 err = mod_sysfs_init(mod);
1776 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1777 if (!mod->holders_dir) {
1782 err = module_param_sysfs_setup(mod, kparam, num_params);
1784 goto out_unreg_holders;
1786 err = module_add_modinfo_attrs(mod);
1788 goto out_unreg_param;
1790 err = add_usage_links(mod);
1792 goto out_unreg_modinfo_attrs;
1794 add_sect_attrs(mod, info);
1795 add_notes_attrs(mod, info);
1797 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1800 out_unreg_modinfo_attrs:
1801 module_remove_modinfo_attrs(mod);
1803 module_param_sysfs_remove(mod);
1805 kobject_put(mod->holders_dir);
1807 mod_kobject_put(mod);
1812 static void mod_sysfs_fini(struct module *mod)
1814 remove_notes_attrs(mod);
1815 remove_sect_attrs(mod);
1816 mod_kobject_put(mod);
1819 static void init_param_lock(struct module *mod)
1821 mutex_init(&mod->param_lock);
1823 #else /* !CONFIG_SYSFS */
1825 static int mod_sysfs_setup(struct module *mod,
1826 const struct load_info *info,
1827 struct kernel_param *kparam,
1828 unsigned int num_params)
1833 static void mod_sysfs_fini(struct module *mod)
1837 static void module_remove_modinfo_attrs(struct module *mod)
1841 static void del_usage_links(struct module *mod)
1845 static void init_param_lock(struct module *mod)
1848 #endif /* CONFIG_SYSFS */
1850 static void mod_sysfs_teardown(struct module *mod)
1852 del_usage_links(mod);
1853 module_remove_modinfo_attrs(mod);
1854 module_param_sysfs_remove(mod);
1855 kobject_put(mod->mkobj.drivers_dir);
1856 kobject_put(mod->holders_dir);
1857 mod_sysfs_fini(mod);
1860 #ifdef CONFIG_STRICT_MODULE_RWX
1862 * LKM RO/NX protection: protect module's text/ro-data
1863 * from modification and any data from execution.
1865 * General layout of module is:
1866 * [text] [read-only-data] [ro-after-init] [writable data]
1867 * text_size -----^ ^ ^ ^
1868 * ro_size ------------------------| | |
1869 * ro_after_init_size -----------------------------| |
1870 * size -----------------------------------------------------------|
1872 * These values are always page-aligned (as is base)
1874 static void frob_text(const struct module_layout *layout,
1875 int (*set_memory)(unsigned long start, int num_pages))
1877 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1878 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1879 set_memory((unsigned long)layout->base,
1880 layout->text_size >> PAGE_SHIFT);
1883 static void frob_rodata(const struct module_layout *layout,
1884 int (*set_memory)(unsigned long start, int num_pages))
1886 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1887 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1888 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1889 set_memory((unsigned long)layout->base + layout->text_size,
1890 (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
1893 static void frob_ro_after_init(const struct module_layout *layout,
1894 int (*set_memory)(unsigned long start, int num_pages))
1896 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1897 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1898 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1899 set_memory((unsigned long)layout->base + layout->ro_size,
1900 (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
1903 static void frob_writable_data(const struct module_layout *layout,
1904 int (*set_memory)(unsigned long start, int num_pages))
1906 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1907 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1908 BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
1909 set_memory((unsigned long)layout->base + layout->ro_after_init_size,
1910 (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
1913 /* livepatching wants to disable read-only so it can frob module. */
1914 void module_disable_ro(const struct module *mod)
1916 if (!rodata_enabled)
1919 frob_text(&mod->core_layout, set_memory_rw);
1920 frob_rodata(&mod->core_layout, set_memory_rw);
1921 frob_ro_after_init(&mod->core_layout, set_memory_rw);
1922 frob_text(&mod->init_layout, set_memory_rw);
1923 frob_rodata(&mod->init_layout, set_memory_rw);
1926 void module_enable_ro(const struct module *mod, bool after_init)
1928 if (!rodata_enabled)
1931 frob_text(&mod->core_layout, set_memory_ro);
1932 frob_rodata(&mod->core_layout, set_memory_ro);
1933 frob_text(&mod->init_layout, set_memory_ro);
1934 frob_rodata(&mod->init_layout, set_memory_ro);
1937 frob_ro_after_init(&mod->core_layout, set_memory_ro);
1940 static void module_enable_nx(const struct module *mod)
1942 frob_rodata(&mod->core_layout, set_memory_nx);
1943 frob_ro_after_init(&mod->core_layout, set_memory_nx);
1944 frob_writable_data(&mod->core_layout, set_memory_nx);
1945 frob_rodata(&mod->init_layout, set_memory_nx);
1946 frob_writable_data(&mod->init_layout, set_memory_nx);
1949 static void module_disable_nx(const struct module *mod)
1951 frob_rodata(&mod->core_layout, set_memory_x);
1952 frob_ro_after_init(&mod->core_layout, set_memory_x);
1953 frob_writable_data(&mod->core_layout, set_memory_x);
1954 frob_rodata(&mod->init_layout, set_memory_x);
1955 frob_writable_data(&mod->init_layout, set_memory_x);
1958 /* Iterate through all modules and set each module's text as RW */
1959 void set_all_modules_text_rw(void)
1963 if (!rodata_enabled)
1966 mutex_lock(&module_mutex);
1967 list_for_each_entry_rcu(mod, &modules, list) {
1968 if (mod->state == MODULE_STATE_UNFORMED)
1971 frob_text(&mod->core_layout, set_memory_rw);
1972 frob_text(&mod->init_layout, set_memory_rw);
1974 mutex_unlock(&module_mutex);
1977 /* Iterate through all modules and set each module's text as RO */
1978 void set_all_modules_text_ro(void)
1982 if (!rodata_enabled)
1985 mutex_lock(&module_mutex);
1986 list_for_each_entry_rcu(mod, &modules, list) {
1988 * Ignore going modules since it's possible that ro
1989 * protection has already been disabled, otherwise we'll
1990 * run into protection faults at module deallocation.
1992 if (mod->state == MODULE_STATE_UNFORMED ||
1993 mod->state == MODULE_STATE_GOING)
1996 frob_text(&mod->core_layout, set_memory_ro);
1997 frob_text(&mod->init_layout, set_memory_ro);
1999 mutex_unlock(&module_mutex);
2002 static void disable_ro_nx(const struct module_layout *layout)
2004 if (rodata_enabled) {
2005 frob_text(layout, set_memory_rw);
2006 frob_rodata(layout, set_memory_rw);
2007 frob_ro_after_init(layout, set_memory_rw);
2009 frob_rodata(layout, set_memory_x);
2010 frob_ro_after_init(layout, set_memory_x);
2011 frob_writable_data(layout, set_memory_x);
2015 static void disable_ro_nx(const struct module_layout *layout) { }
2016 static void module_enable_nx(const struct module *mod) { }
2017 static void module_disable_nx(const struct module *mod) { }
2020 #ifdef CONFIG_LIVEPATCH
2022 * Persist Elf information about a module. Copy the Elf header,
2023 * section header table, section string table, and symtab section
2024 * index from info to mod->klp_info.
2026 static int copy_module_elf(struct module *mod, struct load_info *info)
2028 unsigned int size, symndx;
2031 size = sizeof(*mod->klp_info);
2032 mod->klp_info = kmalloc(size, GFP_KERNEL);
2033 if (mod->klp_info == NULL)
2037 size = sizeof(mod->klp_info->hdr);
2038 memcpy(&mod->klp_info->hdr, info->hdr, size);
2040 /* Elf section header table */
2041 size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
2042 mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL);
2043 if (mod->klp_info->sechdrs == NULL) {
2048 /* Elf section name string table */
2049 size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
2050 mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL);
2051 if (mod->klp_info->secstrings == NULL) {
2056 /* Elf symbol section index */
2057 symndx = info->index.sym;
2058 mod->klp_info->symndx = symndx;
2061 * For livepatch modules, core_kallsyms.symtab is a complete
2062 * copy of the original symbol table. Adjust sh_addr to point
2063 * to core_kallsyms.symtab since the copy of the symtab in module
2064 * init memory is freed at the end of do_init_module().
2066 mod->klp_info->sechdrs[symndx].sh_addr = \
2067 (unsigned long) mod->core_kallsyms.symtab;
2072 kfree(mod->klp_info->sechdrs);
2074 kfree(mod->klp_info);
2078 static void free_module_elf(struct module *mod)
2080 kfree(mod->klp_info->sechdrs);
2081 kfree(mod->klp_info->secstrings);
2082 kfree(mod->klp_info);
2084 #else /* !CONFIG_LIVEPATCH */
2085 static int copy_module_elf(struct module *mod, struct load_info *info)
2090 static void free_module_elf(struct module *mod)
2093 #endif /* CONFIG_LIVEPATCH */
2095 void __weak module_memfree(void *module_region)
2097 vfree(module_region);
2100 void __weak module_arch_cleanup(struct module *mod)
2104 void __weak module_arch_freeing_init(struct module *mod)
2108 /* Free a module, remove from lists, etc. */
2109 static void free_module(struct module *mod)
2111 trace_module_free(mod);
2113 mod_sysfs_teardown(mod);
2115 /* We leave it in list to prevent duplicate loads, but make sure
2116 * that noone uses it while it's being deconstructed. */
2117 mutex_lock(&module_mutex);
2118 mod->state = MODULE_STATE_UNFORMED;
2119 mutex_unlock(&module_mutex);
2121 /* Remove dynamic debug info */
2122 ddebug_remove_module(mod->name);
2124 /* Arch-specific cleanup. */
2125 module_arch_cleanup(mod);
2127 /* Module unload stuff */
2128 module_unload_free(mod);
2130 /* Free any allocated parameters. */
2131 destroy_params(mod->kp, mod->num_kp);
2133 if (is_livepatch_module(mod))
2134 free_module_elf(mod);
2136 /* Now we can delete it from the lists */
2137 mutex_lock(&module_mutex);
2138 /* Unlink carefully: kallsyms could be walking list. */
2139 list_del_rcu(&mod->list);
2140 mod_tree_remove(mod);
2141 /* Remove this module from bug list, this uses list_del_rcu */
2142 module_bug_cleanup(mod);
2143 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2144 synchronize_sched();
2145 mutex_unlock(&module_mutex);
2147 /* This may be empty, but that's OK */
2148 disable_ro_nx(&mod->init_layout);
2149 module_arch_freeing_init(mod);
2150 module_memfree(mod->init_layout.base);
2152 percpu_modfree(mod);
2154 /* Free lock-classes; relies on the preceding sync_rcu(). */
2155 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
2157 /* Finally, free the core (containing the module structure) */
2158 disable_ro_nx(&mod->core_layout);
2159 module_memfree(mod->core_layout.base);
2162 void *__symbol_get(const char *symbol)
2164 struct module *owner;
2165 const struct kernel_symbol *sym;
2168 sym = find_symbol(symbol, &owner, NULL, true, true);
2169 if (sym && strong_try_module_get(owner))
2173 return sym ? (void *)sym->value : NULL;
2175 EXPORT_SYMBOL_GPL(__symbol_get);
2178 * Ensure that an exported symbol [global namespace] does not already exist
2179 * in the kernel or in some other module's exported symbol table.
2181 * You must hold the module_mutex.
2183 static int verify_export_symbols(struct module *mod)
2186 struct module *owner;
2187 const struct kernel_symbol *s;
2189 const struct kernel_symbol *sym;
2192 { mod->syms, mod->num_syms },
2193 { mod->gpl_syms, mod->num_gpl_syms },
2194 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2195 #ifdef CONFIG_UNUSED_SYMBOLS
2196 { mod->unused_syms, mod->num_unused_syms },
2197 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2201 for (i = 0; i < ARRAY_SIZE(arr); i++) {
2202 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2203 if (find_symbol(s->name, &owner, NULL, true, false)) {
2204 pr_err("%s: exports duplicate symbol %s"
2206 mod->name, s->name, module_name(owner));
2214 /* Change all symbols so that st_value encodes the pointer directly. */
2215 static int simplify_symbols(struct module *mod, const struct load_info *info)
2217 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2218 Elf_Sym *sym = (void *)symsec->sh_addr;
2219 unsigned long secbase;
2222 const struct kernel_symbol *ksym;
2224 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2225 const char *name = info->strtab + sym[i].st_name;
2227 switch (sym[i].st_shndx) {
2229 /* Ignore common symbols */
2230 if (!strncmp(name, "__gnu_lto", 9))
2233 /* We compiled with -fno-common. These are not
2234 supposed to happen. */
2235 pr_debug("Common symbol: %s\n", name);
2236 pr_warn("%s: please compile with -fno-common\n",
2242 /* Don't need to do anything */
2243 pr_debug("Absolute symbol: 0x%08lx\n",
2244 (long)sym[i].st_value);
2248 /* Livepatch symbols are resolved by livepatch */
2252 ksym = resolve_symbol_wait(mod, info, name);
2253 /* Ok if resolved. */
2254 if (ksym && !IS_ERR(ksym)) {
2255 sym[i].st_value = ksym->value;
2260 if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
2263 ret = PTR_ERR(ksym) ?: -ENOENT;
2264 pr_warn("%s: Unknown symbol %s (err %d)\n",
2265 mod->name, name, ret);
2269 /* Divert to percpu allocation if a percpu var. */
2270 if (sym[i].st_shndx == info->index.pcpu)
2271 secbase = (unsigned long)mod_percpu(mod);
2273 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2274 sym[i].st_value += secbase;
2282 static int apply_relocations(struct module *mod, const struct load_info *info)
2287 /* Now do relocations. */
2288 for (i = 1; i < info->hdr->e_shnum; i++) {
2289 unsigned int infosec = info->sechdrs[i].sh_info;
2291 /* Not a valid relocation section? */
2292 if (infosec >= info->hdr->e_shnum)
2295 /* Don't bother with non-allocated sections */
2296 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2299 /* Livepatch relocation sections are applied by livepatch */
2300 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
2303 if (info->sechdrs[i].sh_type == SHT_REL)
2304 err = apply_relocate(info->sechdrs, info->strtab,
2305 info->index.sym, i, mod);
2306 else if (info->sechdrs[i].sh_type == SHT_RELA)
2307 err = apply_relocate_add(info->sechdrs, info->strtab,
2308 info->index.sym, i, mod);
2315 /* Additional bytes needed by arch in front of individual sections */
2316 unsigned int __weak arch_mod_section_prepend(struct module *mod,
2317 unsigned int section)
2319 /* default implementation just returns zero */
2323 /* Update size with this section: return offset. */
2324 static long get_offset(struct module *mod, unsigned int *size,
2325 Elf_Shdr *sechdr, unsigned int section)
2329 *size += arch_mod_section_prepend(mod, section);
2330 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2331 *size = ret + sechdr->sh_size;
2335 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2336 might -- code, read-only data, read-write data, small data. Tally
2337 sizes, and place the offsets into sh_entsize fields: high bit means it
2339 static void layout_sections(struct module *mod, struct load_info *info)
2341 static unsigned long const masks[][2] = {
2342 /* NOTE: all executable code must be the first section
2343 * in this array; otherwise modify the text_size
2344 * finder in the two loops below */
2345 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2346 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2347 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
2348 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2349 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2353 for (i = 0; i < info->hdr->e_shnum; i++)
2354 info->sechdrs[i].sh_entsize = ~0UL;
2356 pr_debug("Core section allocation order:\n");
2357 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2358 for (i = 0; i < info->hdr->e_shnum; ++i) {
2359 Elf_Shdr *s = &info->sechdrs[i];
2360 const char *sname = info->secstrings + s->sh_name;
2362 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2363 || (s->sh_flags & masks[m][1])
2364 || s->sh_entsize != ~0UL
2365 || strstarts(sname, ".init"))
2367 s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2368 pr_debug("\t%s\n", sname);
2371 case 0: /* executable */
2372 mod->core_layout.size = debug_align(mod->core_layout.size);
2373 mod->core_layout.text_size = mod->core_layout.size;
2375 case 1: /* RO: text and ro-data */
2376 mod->core_layout.size = debug_align(mod->core_layout.size);
2377 mod->core_layout.ro_size = mod->core_layout.size;
2379 case 2: /* RO after init */
2380 mod->core_layout.size = debug_align(mod->core_layout.size);
2381 mod->core_layout.ro_after_init_size = mod->core_layout.size;
2383 case 4: /* whole core */
2384 mod->core_layout.size = debug_align(mod->core_layout.size);
2389 pr_debug("Init section allocation order:\n");
2390 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2391 for (i = 0; i < info->hdr->e_shnum; ++i) {
2392 Elf_Shdr *s = &info->sechdrs[i];
2393 const char *sname = info->secstrings + s->sh_name;
2395 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2396 || (s->sh_flags & masks[m][1])
2397 || s->sh_entsize != ~0UL
2398 || !strstarts(sname, ".init"))
2400 s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
2401 | INIT_OFFSET_MASK);
2402 pr_debug("\t%s\n", sname);
2405 case 0: /* executable */
2406 mod->init_layout.size = debug_align(mod->init_layout.size);
2407 mod->init_layout.text_size = mod->init_layout.size;
2409 case 1: /* RO: text and ro-data */
2410 mod->init_layout.size = debug_align(mod->init_layout.size);
2411 mod->init_layout.ro_size = mod->init_layout.size;
2415 * RO after init doesn't apply to init_layout (only
2416 * core_layout), so it just takes the value of ro_size.
2418 mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
2420 case 4: /* whole init */
2421 mod->init_layout.size = debug_align(mod->init_layout.size);
2427 static void set_license(struct module *mod, const char *license)
2430 license = "unspecified";
2432 if (!license_is_gpl_compatible(license)) {
2433 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2434 pr_warn("%s: module license '%s' taints kernel.\n",
2435 mod->name, license);
2436 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2437 LOCKDEP_NOW_UNRELIABLE);
2441 /* Parse tag=value strings from .modinfo section */
2442 static char *next_string(char *string, unsigned long *secsize)
2444 /* Skip non-zero chars */
2447 if ((*secsize)-- <= 1)
2451 /* Skip any zero padding. */
2452 while (!string[0]) {
2454 if ((*secsize)-- <= 1)
2460 static char *get_modinfo(struct load_info *info, const char *tag)
2463 unsigned int taglen = strlen(tag);
2464 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2465 unsigned long size = infosec->sh_size;
2468 * get_modinfo() calls made before rewrite_section_headers()
2469 * must use sh_offset, as sh_addr isn't set!
2471 for (p = (char *)info->hdr + infosec->sh_offset; p; p = next_string(p, &size)) {
2472 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2473 return p + taglen + 1;
2478 static void setup_modinfo(struct module *mod, struct load_info *info)
2480 struct module_attribute *attr;
2483 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2485 attr->setup(mod, get_modinfo(info, attr->attr.name));
2489 static void free_modinfo(struct module *mod)
2491 struct module_attribute *attr;
2494 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2500 #ifdef CONFIG_KALLSYMS
2502 /* lookup symbol in given range of kernel_symbols */
2503 static const struct kernel_symbol *lookup_symbol(const char *name,
2504 const struct kernel_symbol *start,
2505 const struct kernel_symbol *stop)
2507 return bsearch(name, start, stop - start,
2508 sizeof(struct kernel_symbol), cmp_name);
2511 static int is_exported(const char *name, unsigned long value,
2512 const struct module *mod)
2514 const struct kernel_symbol *ks;
2516 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2518 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2519 return ks != NULL && ks->value == value;
2523 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2525 const Elf_Shdr *sechdrs = info->sechdrs;
2527 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2528 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2533 if (sym->st_shndx == SHN_UNDEF)
2535 if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
2537 if (sym->st_shndx >= SHN_LORESERVE)
2539 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2541 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2542 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2543 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2545 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2550 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2551 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2556 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2563 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2564 unsigned int shnum, unsigned int pcpundx)
2566 const Elf_Shdr *sec;
2568 if (src->st_shndx == SHN_UNDEF
2569 || src->st_shndx >= shnum
2573 #ifdef CONFIG_KALLSYMS_ALL
2574 if (src->st_shndx == pcpundx)
2578 sec = sechdrs + src->st_shndx;
2579 if (!(sec->sh_flags & SHF_ALLOC)
2580 #ifndef CONFIG_KALLSYMS_ALL
2581 || !(sec->sh_flags & SHF_EXECINSTR)
2583 || (sec->sh_entsize & INIT_OFFSET_MASK))
2590 * We only allocate and copy the strings needed by the parts of symtab
2591 * we keep. This is simple, but has the effect of making multiple
2592 * copies of duplicates. We could be more sophisticated, see
2593 * linux-kernel thread starting with
2594 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2596 static void layout_symtab(struct module *mod, struct load_info *info)
2598 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2599 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2601 unsigned int i, nsrc, ndst, strtab_size = 0;
2603 /* Put symbol section at end of init part of module. */
2604 symsect->sh_flags |= SHF_ALLOC;
2605 symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2606 info->index.sym) | INIT_OFFSET_MASK;
2607 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2609 src = (void *)info->hdr + symsect->sh_offset;
2610 nsrc = symsect->sh_size / sizeof(*src);
2612 /* Compute total space required for the core symbols' strtab. */
2613 for (ndst = i = 0; i < nsrc; i++) {
2614 if (i == 0 || is_livepatch_module(mod) ||
2615 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2616 info->index.pcpu)) {
2617 strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2622 /* Append room for core symbols at end of core part. */
2623 info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
2624 info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
2625 mod->core_layout.size += strtab_size;
2626 mod->core_layout.size = debug_align(mod->core_layout.size);
2628 /* Put string table section at end of init part of module. */
2629 strsect->sh_flags |= SHF_ALLOC;
2630 strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2631 info->index.str) | INIT_OFFSET_MASK;
2632 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2634 /* We'll tack temporary mod_kallsyms on the end. */
2635 mod->init_layout.size = ALIGN(mod->init_layout.size,
2636 __alignof__(struct mod_kallsyms));
2637 info->mod_kallsyms_init_off = mod->init_layout.size;
2638 mod->init_layout.size += sizeof(struct mod_kallsyms);
2639 mod->init_layout.size = debug_align(mod->init_layout.size);
2643 * We use the full symtab and strtab which layout_symtab arranged to
2644 * be appended to the init section. Later we switch to the cut-down
2647 static void add_kallsyms(struct module *mod, const struct load_info *info)
2649 unsigned int i, ndst;
2653 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2655 /* Set up to point into init section. */
2656 mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
2658 mod->kallsyms->symtab = (void *)symsec->sh_addr;
2659 mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2660 /* Make sure we get permanent strtab: don't use info->strtab. */
2661 mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2663 /* Set types up while we still have access to sections. */
2664 for (i = 0; i < mod->kallsyms->num_symtab; i++)
2665 mod->kallsyms->symtab[i].st_info
2666 = elf_type(&mod->kallsyms->symtab[i], info);
2668 /* Now populate the cut down core kallsyms for after init. */
2669 mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
2670 mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
2671 src = mod->kallsyms->symtab;
2672 for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2673 if (i == 0 || is_livepatch_module(mod) ||
2674 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2675 info->index.pcpu)) {
2677 dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
2678 s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2682 mod->core_kallsyms.num_symtab = ndst;
2685 static inline void layout_symtab(struct module *mod, struct load_info *info)
2689 static void add_kallsyms(struct module *mod, const struct load_info *info)
2692 #endif /* CONFIG_KALLSYMS */
2694 static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num)
2698 #ifdef CONFIG_DYNAMIC_DEBUG
2699 if (ddebug_add_module(debug, num, mod->name))
2700 pr_err("dynamic debug error adding module: %s\n",
2705 static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug)
2708 ddebug_remove_module(mod->name);
2711 void * __weak module_alloc(unsigned long size)
2713 return vmalloc_exec(size);
2716 #ifdef CONFIG_DEBUG_KMEMLEAK
2717 static void kmemleak_load_module(const struct module *mod,
2718 const struct load_info *info)
2722 /* only scan the sections containing data */
2723 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2725 for (i = 1; i < info->hdr->e_shnum; i++) {
2726 /* Scan all writable sections that's not executable */
2727 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2728 !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2729 (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2732 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2733 info->sechdrs[i].sh_size, GFP_KERNEL);
2737 static inline void kmemleak_load_module(const struct module *mod,
2738 const struct load_info *info)
2743 #ifdef CONFIG_MODULE_SIG
2744 static int module_sig_check(struct load_info *info, int flags)
2747 const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2748 const void *mod = info->hdr;
2751 * Require flags == 0, as a module with version information
2752 * removed is no longer the module that was signed
2755 info->len > markerlen &&
2756 memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2757 /* We truncate the module to discard the signature */
2758 info->len -= markerlen;
2759 err = mod_verify_sig(mod, info);
2763 info->sig_ok = true;
2767 /* Not having a signature is only an error if we're strict. */
2768 if (err == -ENOKEY && !is_module_sig_enforced())
2773 #else /* !CONFIG_MODULE_SIG */
2774 static int module_sig_check(struct load_info *info, int flags)
2778 #endif /* !CONFIG_MODULE_SIG */
2780 /* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2781 static int elf_header_check(struct load_info *info)
2783 if (info->len < sizeof(*(info->hdr)))
2786 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2787 || info->hdr->e_type != ET_REL
2788 || !elf_check_arch(info->hdr)
2789 || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2792 if (info->hdr->e_shoff >= info->len
2793 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2794 info->len - info->hdr->e_shoff))
2800 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2802 static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
2805 unsigned long n = min(len, COPY_CHUNK_SIZE);
2807 if (copy_from_user(dst, usrc, n) != 0)
2817 #ifdef CONFIG_LIVEPATCH
2818 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2820 if (get_modinfo(info, "livepatch")) {
2822 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
2823 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
2829 #else /* !CONFIG_LIVEPATCH */
2830 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2832 if (get_modinfo(info, "livepatch")) {
2833 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
2840 #endif /* CONFIG_LIVEPATCH */
2842 static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
2844 if (retpoline_module_ok(get_modinfo(info, "retpoline")))
2847 pr_warn("%s: loading module not compiled with retpoline compiler.\n",
2851 /* Sets info->hdr and info->len. */
2852 static int copy_module_from_user(const void __user *umod, unsigned long len,
2853 struct load_info *info)
2858 if (info->len < sizeof(*(info->hdr)))
2861 err = security_kernel_load_data(LOADING_MODULE);
2865 /* Suck in entire file: we'll want most of it. */
2866 info->hdr = __vmalloc(info->len,
2867 GFP_KERNEL | __GFP_NOWARN, PAGE_KERNEL);
2871 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2879 static void free_copy(struct load_info *info)
2884 static int rewrite_section_headers(struct load_info *info, int flags)
2888 /* This should always be true, but let's be sure. */
2889 info->sechdrs[0].sh_addr = 0;
2891 for (i = 1; i < info->hdr->e_shnum; i++) {
2892 Elf_Shdr *shdr = &info->sechdrs[i];
2893 if (shdr->sh_type != SHT_NOBITS
2894 && info->len < shdr->sh_offset + shdr->sh_size) {
2895 pr_err("Module len %lu truncated\n", info->len);
2899 /* Mark all sections sh_addr with their address in the
2901 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2903 #ifndef CONFIG_MODULE_UNLOAD
2904 /* Don't load .exit sections */
2905 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2906 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2910 /* Track but don't keep modinfo and version sections. */
2911 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2912 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2918 * Set up our basic convenience variables (pointers to section headers,
2919 * search for module section index etc), and do some basic section
2922 * Set info->mod to the temporary copy of the module in info->hdr. The final one
2923 * will be allocated in move_module().
2925 static int setup_load_info(struct load_info *info, int flags)
2929 /* Set up the convenience variables */
2930 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2931 info->secstrings = (void *)info->hdr
2932 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2934 /* Try to find a name early so we can log errors with a module name */
2935 info->index.info = find_sec(info, ".modinfo");
2936 if (!info->index.info)
2937 info->name = "(missing .modinfo section)";
2939 info->name = get_modinfo(info, "name");
2941 /* Find internal symbols and strings. */
2942 for (i = 1; i < info->hdr->e_shnum; i++) {
2943 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2944 info->index.sym = i;
2945 info->index.str = info->sechdrs[i].sh_link;
2946 info->strtab = (char *)info->hdr
2947 + info->sechdrs[info->index.str].sh_offset;
2952 if (info->index.sym == 0) {
2953 pr_warn("%s: module has no symbols (stripped?)\n", info->name);
2957 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2958 if (!info->index.mod) {
2959 pr_warn("%s: No module found in object\n",
2960 info->name ?: "(missing .modinfo name field)");
2963 /* This is temporary: point mod into copy of data. */
2964 info->mod = (void *)info->hdr + info->sechdrs[info->index.mod].sh_offset;
2967 * If we didn't load the .modinfo 'name' field earlier, fall back to
2968 * on-disk struct mod 'name' field.
2971 info->name = info->mod->name;
2973 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
2974 info->index.vers = 0; /* Pretend no __versions section! */
2976 info->index.vers = find_sec(info, "__versions");
2978 info->index.pcpu = find_pcpusec(info);
2983 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2985 const char *modmagic = get_modinfo(info, "vermagic");
2988 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
2991 /* This is allowed: modprobe --force will invalidate it. */
2993 err = try_to_force_load(mod, "bad vermagic");
2996 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2997 pr_err("%s: version magic '%s' should be '%s'\n",
2998 info->name, modmagic, vermagic);
3002 if (!get_modinfo(info, "intree")) {
3003 if (!test_taint(TAINT_OOT_MODULE))
3004 pr_warn("%s: loading out-of-tree module taints kernel.\n",
3006 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
3009 check_modinfo_retpoline(mod, info);
3011 if (get_modinfo(info, "staging")) {
3012 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
3013 pr_warn("%s: module is from the staging directory, the quality "
3014 "is unknown, you have been warned.\n", mod->name);
3017 err = check_modinfo_livepatch(mod, info);
3021 /* Set up license info based on the info section */
3022 set_license(mod, get_modinfo(info, "license"));
3027 static int find_module_sections(struct module *mod, struct load_info *info)
3029 mod->kp = section_objs(info, "__param",
3030 sizeof(*mod->kp), &mod->num_kp);
3031 mod->syms = section_objs(info, "__ksymtab",
3032 sizeof(*mod->syms), &mod->num_syms);
3033 mod->crcs = section_addr(info, "__kcrctab");
3034 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
3035 sizeof(*mod->gpl_syms),
3036 &mod->num_gpl_syms);
3037 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
3038 mod->gpl_future_syms = section_objs(info,
3039 "__ksymtab_gpl_future",
3040 sizeof(*mod->gpl_future_syms),
3041 &mod->num_gpl_future_syms);
3042 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
3044 #ifdef CONFIG_UNUSED_SYMBOLS
3045 mod->unused_syms = section_objs(info, "__ksymtab_unused",
3046 sizeof(*mod->unused_syms),
3047 &mod->num_unused_syms);
3048 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
3049 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
3050 sizeof(*mod->unused_gpl_syms),
3051 &mod->num_unused_gpl_syms);
3052 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
3054 #ifdef CONFIG_CONSTRUCTORS
3055 mod->ctors = section_objs(info, ".ctors",
3056 sizeof(*mod->ctors), &mod->num_ctors);
3058 mod->ctors = section_objs(info, ".init_array",
3059 sizeof(*mod->ctors), &mod->num_ctors);
3060 else if (find_sec(info, ".init_array")) {
3062 * This shouldn't happen with same compiler and binutils
3063 * building all parts of the module.
3065 pr_warn("%s: has both .ctors and .init_array.\n",
3071 #ifdef CONFIG_TRACEPOINTS
3072 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
3073 sizeof(*mod->tracepoints_ptrs),
3074 &mod->num_tracepoints);
3076 #ifdef HAVE_JUMP_LABEL
3077 mod->jump_entries = section_objs(info, "__jump_table",
3078 sizeof(*mod->jump_entries),
3079 &mod->num_jump_entries);
3081 #ifdef CONFIG_EVENT_TRACING
3082 mod->trace_events = section_objs(info, "_ftrace_events",
3083 sizeof(*mod->trace_events),
3084 &mod->num_trace_events);
3085 mod->trace_evals = section_objs(info, "_ftrace_eval_map",
3086 sizeof(*mod->trace_evals),
3087 &mod->num_trace_evals);
3089 #ifdef CONFIG_TRACING
3090 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
3091 sizeof(*mod->trace_bprintk_fmt_start),
3092 &mod->num_trace_bprintk_fmt);
3094 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
3095 /* sechdrs[0].sh_size is always zero */
3096 mod->ftrace_callsites = section_objs(info, "__mcount_loc",
3097 sizeof(*mod->ftrace_callsites),
3098 &mod->num_ftrace_callsites);
3100 #ifdef CONFIG_FUNCTION_ERROR_INJECTION
3101 mod->ei_funcs = section_objs(info, "_error_injection_whitelist",
3102 sizeof(*mod->ei_funcs),
3103 &mod->num_ei_funcs);
3105 mod->extable = section_objs(info, "__ex_table",
3106 sizeof(*mod->extable), &mod->num_exentries);
3108 if (section_addr(info, "__obsparm"))
3109 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
3111 info->debug = section_objs(info, "__verbose",
3112 sizeof(*info->debug), &info->num_debug);
3117 static int move_module(struct module *mod, struct load_info *info)
3122 /* Do the allocs. */
3123 ptr = module_alloc(mod->core_layout.size);
3125 * The pointer to this block is stored in the module structure
3126 * which is inside the block. Just mark it as not being a
3129 kmemleak_not_leak(ptr);
3133 memset(ptr, 0, mod->core_layout.size);
3134 mod->core_layout.base = ptr;
3136 if (mod->init_layout.size) {
3137 ptr = module_alloc(mod->init_layout.size);
3139 * The pointer to this block is stored in the module structure
3140 * which is inside the block. This block doesn't need to be
3141 * scanned as it contains data and code that will be freed
3142 * after the module is initialized.
3144 kmemleak_ignore(ptr);
3146 module_memfree(mod->core_layout.base);
3149 memset(ptr, 0, mod->init_layout.size);
3150 mod->init_layout.base = ptr;
3152 mod->init_layout.base = NULL;
3154 /* Transfer each section which specifies SHF_ALLOC */
3155 pr_debug("final section addresses:\n");
3156 for (i = 0; i < info->hdr->e_shnum; i++) {
3158 Elf_Shdr *shdr = &info->sechdrs[i];
3160 if (!(shdr->sh_flags & SHF_ALLOC))
3163 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3164 dest = mod->init_layout.base
3165 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3167 dest = mod->core_layout.base + shdr->sh_entsize;
3169 if (shdr->sh_type != SHT_NOBITS)
3170 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3171 /* Update sh_addr to point to copy in image. */
3172 shdr->sh_addr = (unsigned long)dest;
3173 pr_debug("\t0x%lx %s\n",
3174 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3180 static int check_module_license_and_versions(struct module *mod)
3182 int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
3185 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3186 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3187 * using GPL-only symbols it needs.
3189 if (strcmp(mod->name, "ndiswrapper") == 0)
3190 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3192 /* driverloader was caught wrongly pretending to be under GPL */
3193 if (strcmp(mod->name, "driverloader") == 0)
3194 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3195 LOCKDEP_NOW_UNRELIABLE);
3197 /* lve claims to be GPL but upstream won't provide source */
3198 if (strcmp(mod->name, "lve") == 0)
3199 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3200 LOCKDEP_NOW_UNRELIABLE);
3202 if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
3203 pr_warn("%s: module license taints kernel.\n", mod->name);
3205 #ifdef CONFIG_MODVERSIONS
3206 if ((mod->num_syms && !mod->crcs)
3207 || (mod->num_gpl_syms && !mod->gpl_crcs)
3208 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3209 #ifdef CONFIG_UNUSED_SYMBOLS
3210 || (mod->num_unused_syms && !mod->unused_crcs)
3211 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3214 return try_to_force_load(mod,
3215 "no versions for exported symbols");
3221 static void flush_module_icache(const struct module *mod)
3223 mm_segment_t old_fs;
3225 /* flush the icache in correct context */
3230 * Flush the instruction cache, since we've played with text.
3231 * Do it before processing of module parameters, so the module
3232 * can provide parameter accessor functions of its own.
3234 if (mod->init_layout.base)
3235 flush_icache_range((unsigned long)mod->init_layout.base,
3236 (unsigned long)mod->init_layout.base
3237 + mod->init_layout.size);
3238 flush_icache_range((unsigned long)mod->core_layout.base,
3239 (unsigned long)mod->core_layout.base + mod->core_layout.size);
3244 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3252 /* module_blacklist is a comma-separated list of module names */
3253 static char *module_blacklist;
3254 static bool blacklisted(const char *module_name)
3259 if (!module_blacklist)
3262 for (p = module_blacklist; *p; p += len) {
3263 len = strcspn(p, ",");
3264 if (strlen(module_name) == len && !memcmp(module_name, p, len))
3271 core_param(module_blacklist, module_blacklist, charp, 0400);
3273 static struct module *layout_and_allocate(struct load_info *info, int flags)
3279 err = check_modinfo(info->mod, info, flags);
3281 return ERR_PTR(err);
3283 /* Allow arches to frob section contents and sizes. */
3284 err = module_frob_arch_sections(info->hdr, info->sechdrs,
3285 info->secstrings, info->mod);
3287 return ERR_PTR(err);
3289 /* We will do a special allocation for per-cpu sections later. */
3290 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3293 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3294 * layout_sections() can put it in the right place.
3295 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3297 ndx = find_sec(info, ".data..ro_after_init");
3299 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3301 /* Determine total sizes, and put offsets in sh_entsize. For now
3302 this is done generically; there doesn't appear to be any
3303 special cases for the architectures. */
3304 layout_sections(info->mod, info);
3305 layout_symtab(info->mod, info);
3307 /* Allocate and move to the final place */
3308 err = move_module(info->mod, info);
3310 return ERR_PTR(err);
3312 /* Module has been copied to its final place now: return it. */
3313 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3314 kmemleak_load_module(mod, info);
3318 /* mod is no longer valid after this! */
3319 static void module_deallocate(struct module *mod, struct load_info *info)
3321 percpu_modfree(mod);
3322 module_arch_freeing_init(mod);
3323 module_memfree(mod->init_layout.base);
3324 module_memfree(mod->core_layout.base);
3327 int __weak module_finalize(const Elf_Ehdr *hdr,
3328 const Elf_Shdr *sechdrs,
3334 static int post_relocation(struct module *mod, const struct load_info *info)
3336 /* Sort exception table now relocations are done. */
3337 sort_extable(mod->extable, mod->extable + mod->num_exentries);
3339 /* Copy relocated percpu area over. */
3340 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3341 info->sechdrs[info->index.pcpu].sh_size);
3343 /* Setup kallsyms-specific fields. */
3344 add_kallsyms(mod, info);
3346 /* Arch-specific module finalizing. */
3347 return module_finalize(info->hdr, info->sechdrs, mod);
3350 /* Is this module of this name done loading? No locks held. */
3351 static bool finished_loading(const char *name)
3357 * The module_mutex should not be a heavily contended lock;
3358 * if we get the occasional sleep here, we'll go an extra iteration
3359 * in the wait_event_interruptible(), which is harmless.
3361 sched_annotate_sleep();
3362 mutex_lock(&module_mutex);
3363 mod = find_module_all(name, strlen(name), true);
3364 ret = !mod || mod->state == MODULE_STATE_LIVE
3365 || mod->state == MODULE_STATE_GOING;
3366 mutex_unlock(&module_mutex);
3371 /* Call module constructors. */
3372 static void do_mod_ctors(struct module *mod)
3374 #ifdef CONFIG_CONSTRUCTORS
3377 for (i = 0; i < mod->num_ctors; i++)
3382 /* For freeing module_init on success, in case kallsyms traversing */
3383 struct mod_initfree {
3384 struct rcu_head rcu;
3388 static void do_free_init(struct rcu_head *head)
3390 struct mod_initfree *m = container_of(head, struct mod_initfree, rcu);
3391 module_memfree(m->module_init);
3396 * This is where the real work happens.
3398 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3399 * helper command 'lx-symbols'.
3401 static noinline int do_init_module(struct module *mod)
3404 struct mod_initfree *freeinit;
3406 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3411 freeinit->module_init = mod->init_layout.base;
3414 * We want to find out whether @mod uses async during init. Clear
3415 * PF_USED_ASYNC. async_schedule*() will set it.
3417 current->flags &= ~PF_USED_ASYNC;
3420 /* Start the module */
3421 if (mod->init != NULL)
3422 ret = do_one_initcall(mod->init);
3424 goto fail_free_freeinit;
3427 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3428 "follow 0/-E convention\n"
3429 "%s: loading module anyway...\n",
3430 __func__, mod->name, ret, __func__);
3434 /* Now it's a first class citizen! */
3435 mod->state = MODULE_STATE_LIVE;
3436 blocking_notifier_call_chain(&module_notify_list,
3437 MODULE_STATE_LIVE, mod);
3440 * We need to finish all async code before the module init sequence
3441 * is done. This has potential to deadlock. For example, a newly
3442 * detected block device can trigger request_module() of the
3443 * default iosched from async probing task. Once userland helper
3444 * reaches here, async_synchronize_full() will wait on the async
3445 * task waiting on request_module() and deadlock.
3447 * This deadlock is avoided by perfomring async_synchronize_full()
3448 * iff module init queued any async jobs. This isn't a full
3449 * solution as it will deadlock the same if module loading from
3450 * async jobs nests more than once; however, due to the various
3451 * constraints, this hack seems to be the best option for now.
3452 * Please refer to the following thread for details.
3454 * http://thread.gmane.org/gmane.linux.kernel/1420814
3456 if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3457 async_synchronize_full();
3459 ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base +
3460 mod->init_layout.size);
3461 mutex_lock(&module_mutex);
3462 /* Drop initial reference. */
3464 trim_init_extable(mod);
3465 #ifdef CONFIG_KALLSYMS
3466 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3467 rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3469 module_enable_ro(mod, true);
3470 mod_tree_remove_init(mod);
3471 disable_ro_nx(&mod->init_layout);
3472 module_arch_freeing_init(mod);
3473 mod->init_layout.base = NULL;
3474 mod->init_layout.size = 0;
3475 mod->init_layout.ro_size = 0;
3476 mod->init_layout.ro_after_init_size = 0;
3477 mod->init_layout.text_size = 0;
3479 * We want to free module_init, but be aware that kallsyms may be
3480 * walking this with preempt disabled. In all the failure paths, we
3481 * call synchronize_sched(), but we don't want to slow down the success
3482 * path, so use actual RCU here.
3483 * Note that module_alloc() on most architectures creates W+X page
3484 * mappings which won't be cleaned up until do_free_init() runs. Any
3485 * code such as mark_rodata_ro() which depends on those mappings to
3486 * be cleaned up needs to sync with the queued work - ie
3487 * rcu_barrier_sched()
3489 call_rcu_sched(&freeinit->rcu, do_free_init);
3490 mutex_unlock(&module_mutex);
3491 wake_up_all(&module_wq);
3498 /* Try to protect us from buggy refcounters. */
3499 mod->state = MODULE_STATE_GOING;
3500 synchronize_sched();
3502 blocking_notifier_call_chain(&module_notify_list,
3503 MODULE_STATE_GOING, mod);
3504 klp_module_going(mod);
3505 ftrace_release_mod(mod);
3507 wake_up_all(&module_wq);
3511 static int may_init_module(void)
3513 if (!capable(CAP_SYS_MODULE) || modules_disabled)
3520 * We try to place it in the list now to make sure it's unique before
3521 * we dedicate too many resources. In particular, temporary percpu
3522 * memory exhaustion.
3524 static int add_unformed_module(struct module *mod)
3529 mod->state = MODULE_STATE_UNFORMED;
3532 mutex_lock(&module_mutex);
3533 old = find_module_all(mod->name, strlen(mod->name), true);
3535 if (old->state == MODULE_STATE_COMING
3536 || old->state == MODULE_STATE_UNFORMED) {
3537 /* Wait in case it fails to load. */
3538 mutex_unlock(&module_mutex);
3539 err = wait_event_interruptible(module_wq,
3540 finished_loading(mod->name));
3548 mod_update_bounds(mod);
3549 list_add_rcu(&mod->list, &modules);
3550 mod_tree_insert(mod);
3554 mutex_unlock(&module_mutex);
3559 static int complete_formation(struct module *mod, struct load_info *info)
3563 mutex_lock(&module_mutex);
3565 /* Find duplicate symbols (must be called under lock). */
3566 err = verify_export_symbols(mod);
3570 /* This relies on module_mutex for list integrity. */
3571 module_bug_finalize(info->hdr, info->sechdrs, mod);
3573 module_enable_ro(mod, false);
3574 module_enable_nx(mod);
3576 /* Mark state as coming so strong_try_module_get() ignores us,
3577 * but kallsyms etc. can see us. */
3578 mod->state = MODULE_STATE_COMING;
3579 mutex_unlock(&module_mutex);
3584 mutex_unlock(&module_mutex);
3588 static int prepare_coming_module(struct module *mod)
3592 ftrace_module_enable(mod);
3593 err = klp_module_coming(mod);
3597 blocking_notifier_call_chain(&module_notify_list,
3598 MODULE_STATE_COMING, mod);
3602 static int unknown_module_param_cb(char *param, char *val, const char *modname,
3605 struct module *mod = arg;
3608 if (strcmp(param, "async_probe") == 0) {
3609 mod->async_probe_requested = true;
3613 /* Check for magic 'dyndbg' arg */
3614 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3616 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3620 /* Allocate and load the module: note that size of section 0 is always
3621 zero, and we rely on this for optional sections. */
3622 static int load_module(struct load_info *info, const char __user *uargs,
3629 err = elf_header_check(info);
3633 err = setup_load_info(info, flags);
3637 if (blacklisted(info->name)) {
3642 err = module_sig_check(info, flags);
3646 err = rewrite_section_headers(info, flags);
3650 /* Check module struct version now, before we try to use module. */
3651 if (!check_modstruct_version(info, info->mod)) {
3656 /* Figure out module layout, and allocate all the memory. */
3657 mod = layout_and_allocate(info, flags);
3663 audit_log_kern_module(mod->name);
3665 /* Reserve our place in the list. */
3666 err = add_unformed_module(mod);
3670 #ifdef CONFIG_MODULE_SIG
3671 mod->sig_ok = info->sig_ok;
3673 pr_notice_once("%s: module verification failed: signature "
3674 "and/or required key missing - tainting "
3675 "kernel\n", mod->name);
3676 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3680 /* To avoid stressing percpu allocator, do this once we're unique. */
3681 err = percpu_modalloc(mod, info);
3685 /* Now module is in final location, initialize linked lists, etc. */
3686 err = module_unload_init(mod);
3690 init_param_lock(mod);
3692 /* Now we've got everything in the final locations, we can
3693 * find optional sections. */
3694 err = find_module_sections(mod, info);
3698 err = check_module_license_and_versions(mod);
3702 /* Set up MODINFO_ATTR fields */
3703 setup_modinfo(mod, info);
3705 /* Fix up syms, so that st_value is a pointer to location. */
3706 err = simplify_symbols(mod, info);
3710 err = apply_relocations(mod, info);
3714 err = post_relocation(mod, info);
3718 flush_module_icache(mod);
3720 /* Now copy in args */
3721 mod->args = strndup_user(uargs, ~0UL >> 1);
3722 if (IS_ERR(mod->args)) {
3723 err = PTR_ERR(mod->args);
3724 goto free_arch_cleanup;
3727 dynamic_debug_setup(mod, info->debug, info->num_debug);
3729 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3730 ftrace_module_init(mod);
3732 /* Finally it's fully formed, ready to start executing. */
3733 err = complete_formation(mod, info);
3735 goto ddebug_cleanup;
3737 err = prepare_coming_module(mod);
3741 /* Module is ready to execute: parsing args may do that. */
3742 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3744 unknown_module_param_cb);
3745 if (IS_ERR(after_dashes)) {
3746 err = PTR_ERR(after_dashes);
3747 goto coming_cleanup;
3748 } else if (after_dashes) {
3749 pr_warn("%s: parameters '%s' after `--' ignored\n",
3750 mod->name, after_dashes);
3753 /* Link in to sysfs. */
3754 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3756 goto coming_cleanup;
3758 if (is_livepatch_module(mod)) {
3759 err = copy_module_elf(mod, info);
3764 /* Get rid of temporary copy. */
3768 trace_module_load(mod);
3770 return do_init_module(mod);
3773 mod_sysfs_teardown(mod);
3775 mod->state = MODULE_STATE_GOING;
3776 destroy_params(mod->kp, mod->num_kp);
3777 blocking_notifier_call_chain(&module_notify_list,
3778 MODULE_STATE_GOING, mod);
3779 klp_module_going(mod);
3781 /* module_bug_cleanup needs module_mutex protection */
3782 mutex_lock(&module_mutex);
3783 module_bug_cleanup(mod);
3784 mutex_unlock(&module_mutex);
3786 /* we can't deallocate the module until we clear memory protection */
3787 module_disable_ro(mod);
3788 module_disable_nx(mod);
3791 ftrace_release_mod(mod);
3792 dynamic_debug_remove(mod, info->debug);
3793 synchronize_sched();
3796 module_arch_cleanup(mod);
3800 module_unload_free(mod);
3802 mutex_lock(&module_mutex);
3803 /* Unlink carefully: kallsyms could be walking list. */
3804 list_del_rcu(&mod->list);
3805 mod_tree_remove(mod);
3806 wake_up_all(&module_wq);
3807 /* Wait for RCU-sched synchronizing before releasing mod->list. */
3808 synchronize_sched();
3809 mutex_unlock(&module_mutex);
3811 /* Free lock-classes; relies on the preceding sync_rcu() */
3812 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
3814 module_deallocate(mod, info);
3820 SYSCALL_DEFINE3(init_module, void __user *, umod,
3821 unsigned long, len, const char __user *, uargs)
3824 struct load_info info = { };
3826 err = may_init_module();
3830 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3833 err = copy_module_from_user(umod, len, &info);
3837 return load_module(&info, uargs, 0);
3840 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3842 struct load_info info = { };
3847 err = may_init_module();
3851 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3853 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3854 |MODULE_INIT_IGNORE_VERMAGIC))
3857 err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX,
3864 return load_module(&info, uargs, flags);
3867 static inline int within(unsigned long addr, void *start, unsigned long size)
3869 return ((void *)addr >= start && (void *)addr < start + size);
3872 #ifdef CONFIG_KALLSYMS
3874 * This ignores the intensely annoying "mapping symbols" found
3875 * in ARM ELF files: $a, $t and $d.
3877 static inline int is_arm_mapping_symbol(const char *str)
3879 if (str[0] == '.' && str[1] == 'L')
3881 return str[0] == '$' && strchr("axtd", str[1])
3882 && (str[2] == '\0' || str[2] == '.');
3885 static const char *symname(struct mod_kallsyms *kallsyms, unsigned int symnum)
3887 return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
3890 static const char *get_ksymbol(struct module *mod,
3892 unsigned long *size,
3893 unsigned long *offset)
3895 unsigned int i, best = 0;
3896 unsigned long nextval;
3897 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
3899 /* At worse, next value is at end of module */
3900 if (within_module_init(addr, mod))
3901 nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
3903 nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
3905 /* Scan for closest preceding symbol, and next symbol. (ELF
3906 starts real symbols at 1). */
3907 for (i = 1; i < kallsyms->num_symtab; i++) {
3908 if (kallsyms->symtab[i].st_shndx == SHN_UNDEF)
3911 /* We ignore unnamed symbols: they're uninformative
3912 * and inserted at a whim. */
3913 if (*symname(kallsyms, i) == '\0'
3914 || is_arm_mapping_symbol(symname(kallsyms, i)))
3917 if (kallsyms->symtab[i].st_value <= addr
3918 && kallsyms->symtab[i].st_value > kallsyms->symtab[best].st_value)
3920 if (kallsyms->symtab[i].st_value > addr
3921 && kallsyms->symtab[i].st_value < nextval)
3922 nextval = kallsyms->symtab[i].st_value;
3929 *size = nextval - kallsyms->symtab[best].st_value;
3931 *offset = addr - kallsyms->symtab[best].st_value;
3932 return symname(kallsyms, best);
3935 void * __weak dereference_module_function_descriptor(struct module *mod,
3941 /* For kallsyms to ask for address resolution. NULL means not found. Careful
3942 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3943 const char *module_address_lookup(unsigned long addr,
3944 unsigned long *size,
3945 unsigned long *offset,
3949 const char *ret = NULL;
3953 mod = __module_address(addr);
3956 *modname = mod->name;
3957 ret = get_ksymbol(mod, addr, size, offset);
3959 /* Make a copy in here where it's safe */
3961 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3969 int lookup_module_symbol_name(unsigned long addr, char *symname)
3974 list_for_each_entry_rcu(mod, &modules, list) {
3975 if (mod->state == MODULE_STATE_UNFORMED)
3977 if (within_module(addr, mod)) {
3980 sym = get_ksymbol(mod, addr, NULL, NULL);
3983 strlcpy(symname, sym, KSYM_NAME_LEN);
3993 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3994 unsigned long *offset, char *modname, char *name)
3999 list_for_each_entry_rcu(mod, &modules, list) {
4000 if (mod->state == MODULE_STATE_UNFORMED)
4002 if (within_module(addr, mod)) {
4005 sym = get_ksymbol(mod, addr, size, offset);
4009 strlcpy(modname, mod->name, MODULE_NAME_LEN);
4011 strlcpy(name, sym, KSYM_NAME_LEN);
4021 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
4022 char *name, char *module_name, int *exported)
4027 list_for_each_entry_rcu(mod, &modules, list) {
4028 struct mod_kallsyms *kallsyms;
4030 if (mod->state == MODULE_STATE_UNFORMED)
4032 kallsyms = rcu_dereference_sched(mod->kallsyms);
4033 if (symnum < kallsyms->num_symtab) {
4034 *value = kallsyms->symtab[symnum].st_value;
4035 *type = kallsyms->symtab[symnum].st_info;
4036 strlcpy(name, symname(kallsyms, symnum), KSYM_NAME_LEN);
4037 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
4038 *exported = is_exported(name, *value, mod);
4042 symnum -= kallsyms->num_symtab;
4048 static unsigned long mod_find_symname(struct module *mod, const char *name)
4051 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4053 for (i = 0; i < kallsyms->num_symtab; i++)
4054 if (strcmp(name, symname(kallsyms, i)) == 0 &&
4055 kallsyms->symtab[i].st_shndx != SHN_UNDEF)
4056 return kallsyms->symtab[i].st_value;
4060 /* Look for this name: can be of form module:name. */
4061 unsigned long module_kallsyms_lookup_name(const char *name)
4065 unsigned long ret = 0;
4067 /* Don't lock: we're in enough trouble already. */
4069 if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
4070 if ((mod = find_module_all(name, colon - name, false)) != NULL)
4071 ret = mod_find_symname(mod, colon+1);
4073 list_for_each_entry_rcu(mod, &modules, list) {
4074 if (mod->state == MODULE_STATE_UNFORMED)
4076 if ((ret = mod_find_symname(mod, name)) != 0)
4084 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
4085 struct module *, unsigned long),
4092 module_assert_mutex();
4094 list_for_each_entry(mod, &modules, list) {
4095 /* We hold module_mutex: no need for rcu_dereference_sched */
4096 struct mod_kallsyms *kallsyms = mod->kallsyms;
4098 if (mod->state == MODULE_STATE_UNFORMED)
4100 for (i = 0; i < kallsyms->num_symtab; i++) {
4102 if (kallsyms->symtab[i].st_shndx == SHN_UNDEF)
4105 ret = fn(data, symname(kallsyms, i),
4106 mod, kallsyms->symtab[i].st_value);
4113 #endif /* CONFIG_KALLSYMS */
4115 /* Maximum number of characters written by module_flags() */
4116 #define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
4118 /* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
4119 static char *module_flags(struct module *mod, char *buf)
4123 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
4125 mod->state == MODULE_STATE_GOING ||
4126 mod->state == MODULE_STATE_COMING) {
4128 bx += module_flags_taint(mod, buf + bx);
4129 /* Show a - for module-is-being-unloaded */
4130 if (mod->state == MODULE_STATE_GOING)
4132 /* Show a + for module-is-being-loaded */
4133 if (mod->state == MODULE_STATE_COMING)
4142 #ifdef CONFIG_PROC_FS
4143 /* Called by the /proc file system to return a list of modules. */
4144 static void *m_start(struct seq_file *m, loff_t *pos)
4146 mutex_lock(&module_mutex);
4147 return seq_list_start(&modules, *pos);
4150 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
4152 return seq_list_next(p, &modules, pos);
4155 static void m_stop(struct seq_file *m, void *p)
4157 mutex_unlock(&module_mutex);
4160 static int m_show(struct seq_file *m, void *p)
4162 struct module *mod = list_entry(p, struct module, list);
4163 char buf[MODULE_FLAGS_BUF_SIZE];
4166 /* We always ignore unformed modules. */
4167 if (mod->state == MODULE_STATE_UNFORMED)
4170 seq_printf(m, "%s %u",
4171 mod->name, mod->init_layout.size + mod->core_layout.size);
4172 print_unload_info(m, mod);
4174 /* Informative for users. */
4175 seq_printf(m, " %s",
4176 mod->state == MODULE_STATE_GOING ? "Unloading" :
4177 mod->state == MODULE_STATE_COMING ? "Loading" :
4179 /* Used by oprofile and other similar tools. */
4180 value = m->private ? NULL : mod->core_layout.base;
4181 seq_printf(m, " 0x%px", value);
4185 seq_printf(m, " %s", module_flags(mod, buf));
4191 /* Format: modulename size refcount deps address
4193 Where refcount is a number or -, and deps is a comma-separated list
4196 static const struct seq_operations modules_op = {
4204 * This also sets the "private" pointer to non-NULL if the
4205 * kernel pointers should be hidden (so you can just test
4206 * "m->private" to see if you should keep the values private).
4208 * We use the same logic as for /proc/kallsyms.
4210 static int modules_open(struct inode *inode, struct file *file)
4212 int err = seq_open(file, &modules_op);
4215 struct seq_file *m = file->private_data;
4216 m->private = kallsyms_show_value() ? NULL : (void *)8ul;
4222 static const struct file_operations proc_modules_operations = {
4223 .open = modules_open,
4225 .llseek = seq_lseek,
4226 .release = seq_release,
4229 static int __init proc_modules_init(void)
4231 proc_create("modules", 0, NULL, &proc_modules_operations);
4234 module_init(proc_modules_init);
4237 /* Given an address, look for it in the module exception tables. */
4238 const struct exception_table_entry *search_module_extables(unsigned long addr)
4240 const struct exception_table_entry *e = NULL;
4244 mod = __module_address(addr);
4248 if (!mod->num_exentries)
4251 e = search_extable(mod->extable,
4258 * Now, if we found one, we are running inside it now, hence
4259 * we cannot unload the module, hence no refcnt needed.
4265 * is_module_address - is this address inside a module?
4266 * @addr: the address to check.
4268 * See is_module_text_address() if you simply want to see if the address
4269 * is code (not data).
4271 bool is_module_address(unsigned long addr)
4276 ret = __module_address(addr) != NULL;
4283 * __module_address - get the module which contains an address.
4284 * @addr: the address.
4286 * Must be called with preempt disabled or module mutex held so that
4287 * module doesn't get freed during this.
4289 struct module *__module_address(unsigned long addr)
4293 if (addr < module_addr_min || addr > module_addr_max)
4296 module_assert_mutex_or_preempt();
4298 mod = mod_find(addr);
4300 BUG_ON(!within_module(addr, mod));
4301 if (mod->state == MODULE_STATE_UNFORMED)
4306 EXPORT_SYMBOL_GPL(__module_address);
4309 * is_module_text_address - is this address inside module code?
4310 * @addr: the address to check.
4312 * See is_module_address() if you simply want to see if the address is
4313 * anywhere in a module. See kernel_text_address() for testing if an
4314 * address corresponds to kernel or module code.
4316 bool is_module_text_address(unsigned long addr)
4321 ret = __module_text_address(addr) != NULL;
4328 * __module_text_address - get the module whose code contains an address.
4329 * @addr: the address.
4331 * Must be called with preempt disabled or module mutex held so that
4332 * module doesn't get freed during this.
4334 struct module *__module_text_address(unsigned long addr)
4336 struct module *mod = __module_address(addr);
4338 /* Make sure it's within the text section. */
4339 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
4340 && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
4345 EXPORT_SYMBOL_GPL(__module_text_address);
4347 /* Don't grab lock, we're oopsing. */
4348 void print_modules(void)
4351 char buf[MODULE_FLAGS_BUF_SIZE];
4353 printk(KERN_DEFAULT "Modules linked in:");
4354 /* Most callers should already have preempt disabled, but make sure */
4356 list_for_each_entry_rcu(mod, &modules, list) {
4357 if (mod->state == MODULE_STATE_UNFORMED)
4359 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4362 if (last_unloaded_module[0])
4363 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4367 #ifdef CONFIG_MODVERSIONS
4368 /* Generate the signature for all relevant module structures here.
4369 * If these change, we don't want to try to parse the module. */
4370 void module_layout(struct module *mod,
4371 struct modversion_info *ver,
4372 struct kernel_param *kp,
4373 struct kernel_symbol *ks,
4374 struct tracepoint * const *tp)
4377 EXPORT_SYMBOL(module_layout);