1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Copyright (C) 2002 Richard Henderson
4 * Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
7 #define INCLUDE_VERMAGIC
9 #include <linux/export.h>
10 #include <linux/extable.h>
11 #include <linux/moduleloader.h>
12 #include <linux/module_signature.h>
13 #include <linux/trace_events.h>
14 #include <linux/init.h>
15 #include <linux/kallsyms.h>
16 #include <linux/buildid.h>
17 #include <linux/file.h>
19 #include <linux/sysfs.h>
20 #include <linux/kernel.h>
21 #include <linux/kernel_read_file.h>
22 #include <linux/slab.h>
23 #include <linux/vmalloc.h>
24 #include <linux/elf.h>
25 #include <linux/proc_fs.h>
26 #include <linux/security.h>
27 #include <linux/seq_file.h>
28 #include <linux/syscalls.h>
29 #include <linux/fcntl.h>
30 #include <linux/rcupdate.h>
31 #include <linux/capability.h>
32 #include <linux/cpu.h>
33 #include <linux/moduleparam.h>
34 #include <linux/errno.h>
35 #include <linux/err.h>
36 #include <linux/vermagic.h>
37 #include <linux/notifier.h>
38 #include <linux/sched.h>
39 #include <linux/device.h>
40 #include <linux/string.h>
41 #include <linux/mutex.h>
42 #include <linux/rculist.h>
43 #include <linux/uaccess.h>
44 #include <asm/cacheflush.h>
45 #include <linux/set_memory.h>
46 #include <asm/mmu_context.h>
47 #include <linux/license.h>
48 #include <asm/sections.h>
49 #include <linux/tracepoint.h>
50 #include <linux/ftrace.h>
51 #include <linux/livepatch.h>
52 #include <linux/async.h>
53 #include <linux/percpu.h>
54 #include <linux/kmemleak.h>
55 #include <linux/jump_label.h>
56 #include <linux/pfn.h>
57 #include <linux/bsearch.h>
58 #include <linux/dynamic_debug.h>
59 #include <linux/audit.h>
60 #include <uapi/linux/module.h>
61 #include "module-internal.h"
63 #define CREATE_TRACE_POINTS
64 #include <trace/events/module.h>
66 #ifndef ARCH_SHF_SMALL
67 #define ARCH_SHF_SMALL 0
71 * Modules' sections will be aligned on page boundaries
72 * to ensure complete separation of code and data, but
73 * only when CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y
75 #ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
76 # define debug_align(X) ALIGN(X, PAGE_SIZE)
78 # define debug_align(X) (X)
81 /* If this is set, the section belongs in the init part of the module */
82 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
86 * 1) List of modules (also safely readable with preempt_disable),
87 * 2) module_use links,
88 * 3) module_addr_min/module_addr_max.
89 * (delete and add uses RCU list operations).
91 static DEFINE_MUTEX(module_mutex);
92 static LIST_HEAD(modules);
94 /* Work queue for freeing init sections in success case */
95 static void do_free_init(struct work_struct *w);
96 static DECLARE_WORK(init_free_wq, do_free_init);
97 static LLIST_HEAD(init_free_list);
99 #ifdef CONFIG_MODULES_TREE_LOOKUP
102 * Use a latched RB-tree for __module_address(); this allows us to use
103 * RCU-sched lookups of the address from any context.
105 * This is conditional on PERF_EVENTS || TRACING because those can really hit
106 * __module_address() hard by doing a lot of stack unwinding; potentially from
110 static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
112 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
114 return (unsigned long)layout->base;
117 static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
119 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
121 return (unsigned long)layout->size;
124 static __always_inline bool
125 mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
127 return __mod_tree_val(a) < __mod_tree_val(b);
130 static __always_inline int
131 mod_tree_comp(void *key, struct latch_tree_node *n)
133 unsigned long val = (unsigned long)key;
134 unsigned long start, end;
136 start = __mod_tree_val(n);
140 end = start + __mod_tree_size(n);
147 static const struct latch_tree_ops mod_tree_ops = {
148 .less = mod_tree_less,
149 .comp = mod_tree_comp,
152 static struct mod_tree_root {
153 struct latch_tree_root root;
154 unsigned long addr_min;
155 unsigned long addr_max;
156 } mod_tree __cacheline_aligned = {
160 #define module_addr_min mod_tree.addr_min
161 #define module_addr_max mod_tree.addr_max
163 static noinline void __mod_tree_insert(struct mod_tree_node *node)
165 latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
168 static void __mod_tree_remove(struct mod_tree_node *node)
170 latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
174 * These modifications: insert, remove_init and remove; are serialized by the
177 static void mod_tree_insert(struct module *mod)
179 mod->core_layout.mtn.mod = mod;
180 mod->init_layout.mtn.mod = mod;
182 __mod_tree_insert(&mod->core_layout.mtn);
183 if (mod->init_layout.size)
184 __mod_tree_insert(&mod->init_layout.mtn);
187 static void mod_tree_remove_init(struct module *mod)
189 if (mod->init_layout.size)
190 __mod_tree_remove(&mod->init_layout.mtn);
193 static void mod_tree_remove(struct module *mod)
195 __mod_tree_remove(&mod->core_layout.mtn);
196 mod_tree_remove_init(mod);
199 static struct module *mod_find(unsigned long addr)
201 struct latch_tree_node *ltn;
203 ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
207 return container_of(ltn, struct mod_tree_node, node)->mod;
210 #else /* MODULES_TREE_LOOKUP */
212 static unsigned long module_addr_min = -1UL, module_addr_max = 0;
214 static void mod_tree_insert(struct module *mod) { }
215 static void mod_tree_remove_init(struct module *mod) { }
216 static void mod_tree_remove(struct module *mod) { }
218 static struct module *mod_find(unsigned long addr)
222 list_for_each_entry_rcu(mod, &modules, list,
223 lockdep_is_held(&module_mutex)) {
224 if (within_module(addr, mod))
231 #endif /* MODULES_TREE_LOOKUP */
234 * Bounds of module text, for speeding up __module_address.
235 * Protected by module_mutex.
237 static void __mod_update_bounds(void *base, unsigned int size)
239 unsigned long min = (unsigned long)base;
240 unsigned long max = min + size;
242 if (min < module_addr_min)
243 module_addr_min = min;
244 if (max > module_addr_max)
245 module_addr_max = max;
248 static void mod_update_bounds(struct module *mod)
250 __mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
251 if (mod->init_layout.size)
252 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
255 #ifdef CONFIG_KGDB_KDB
256 struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
257 #endif /* CONFIG_KGDB_KDB */
259 static void module_assert_mutex_or_preempt(void)
261 #ifdef CONFIG_LOCKDEP
262 if (unlikely(!debug_locks))
265 WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
266 !lockdep_is_held(&module_mutex));
270 #ifdef CONFIG_MODULE_SIG
271 static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
272 module_param(sig_enforce, bool_enable_only, 0644);
274 void set_module_sig_enforced(void)
279 #define sig_enforce false
283 * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
284 * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
286 bool is_module_sig_enforced(void)
290 EXPORT_SYMBOL(is_module_sig_enforced);
292 /* Block module loading/unloading? */
293 int modules_disabled = 0;
294 core_param(nomodule, modules_disabled, bint, 0);
296 /* Waiting for a module to finish initializing? */
297 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
299 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
301 int register_module_notifier(struct notifier_block *nb)
303 return blocking_notifier_chain_register(&module_notify_list, nb);
305 EXPORT_SYMBOL(register_module_notifier);
307 int unregister_module_notifier(struct notifier_block *nb)
309 return blocking_notifier_chain_unregister(&module_notify_list, nb);
311 EXPORT_SYMBOL(unregister_module_notifier);
314 * We require a truly strong try_module_get(): 0 means success.
315 * Otherwise an error is returned due to ongoing or failed
316 * initialization etc.
318 static inline int strong_try_module_get(struct module *mod)
320 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
321 if (mod && mod->state == MODULE_STATE_COMING)
323 if (try_module_get(mod))
329 static inline void add_taint_module(struct module *mod, unsigned flag,
330 enum lockdep_ok lockdep_ok)
332 add_taint(flag, lockdep_ok);
333 set_bit(flag, &mod->taints);
337 * A thread that wants to hold a reference to a module only while it
338 * is running can call this to safely exit. nfsd and lockd use this.
340 void __noreturn __module_put_and_exit(struct module *mod, long code)
345 EXPORT_SYMBOL(__module_put_and_exit);
347 /* Find a module section: 0 means not found. */
348 static unsigned int find_sec(const struct load_info *info, const char *name)
352 for (i = 1; i < info->hdr->e_shnum; i++) {
353 Elf_Shdr *shdr = &info->sechdrs[i];
354 /* Alloc bit cleared means "ignore it." */
355 if ((shdr->sh_flags & SHF_ALLOC)
356 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
362 /* Find a module section, or NULL. */
363 static void *section_addr(const struct load_info *info, const char *name)
365 /* Section 0 has sh_addr 0. */
366 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
369 /* Find a module section, or NULL. Fill in number of "objects" in section. */
370 static void *section_objs(const struct load_info *info,
375 unsigned int sec = find_sec(info, name);
377 /* Section 0 has sh_addr 0 and sh_size 0. */
378 *num = info->sechdrs[sec].sh_size / object_size;
379 return (void *)info->sechdrs[sec].sh_addr;
382 /* Find a module section: 0 means not found. Ignores SHF_ALLOC flag. */
383 static unsigned int find_any_sec(const struct load_info *info, const char *name)
387 for (i = 1; i < info->hdr->e_shnum; i++) {
388 Elf_Shdr *shdr = &info->sechdrs[i];
389 if (strcmp(info->secstrings + shdr->sh_name, name) == 0)
396 * Find a module section, or NULL. Fill in number of "objects" in section.
397 * Ignores SHF_ALLOC flag.
399 static __maybe_unused void *any_section_objs(const struct load_info *info,
404 unsigned int sec = find_any_sec(info, name);
406 /* Section 0 has sh_addr 0 and sh_size 0. */
407 *num = info->sechdrs[sec].sh_size / object_size;
408 return (void *)info->sechdrs[sec].sh_addr;
411 /* Provided by the linker */
412 extern const struct kernel_symbol __start___ksymtab[];
413 extern const struct kernel_symbol __stop___ksymtab[];
414 extern const struct kernel_symbol __start___ksymtab_gpl[];
415 extern const struct kernel_symbol __stop___ksymtab_gpl[];
416 extern const s32 __start___kcrctab[];
417 extern const s32 __start___kcrctab_gpl[];
419 #ifndef CONFIG_MODVERSIONS
420 #define symversion(base, idx) NULL
422 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
426 const struct kernel_symbol *start, *stop;
434 struct find_symbol_arg {
441 struct module *owner;
443 const struct kernel_symbol *sym;
444 enum mod_license license;
447 static bool check_exported_symbol(const struct symsearch *syms,
448 struct module *owner,
449 unsigned int symnum, void *data)
451 struct find_symbol_arg *fsa = data;
453 if (!fsa->gplok && syms->license == GPL_ONLY)
456 fsa->crc = symversion(syms->crcs, symnum);
457 fsa->sym = &syms->start[symnum];
458 fsa->license = syms->license;
462 static unsigned long kernel_symbol_value(const struct kernel_symbol *sym)
464 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
465 return (unsigned long)offset_to_ptr(&sym->value_offset);
471 static const char *kernel_symbol_name(const struct kernel_symbol *sym)
473 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
474 return offset_to_ptr(&sym->name_offset);
480 static const char *kernel_symbol_namespace(const struct kernel_symbol *sym)
482 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
483 if (!sym->namespace_offset)
485 return offset_to_ptr(&sym->namespace_offset);
487 return sym->namespace;
491 static int cmp_name(const void *name, const void *sym)
493 return strcmp(name, kernel_symbol_name(sym));
496 static bool find_exported_symbol_in_section(const struct symsearch *syms,
497 struct module *owner,
500 struct find_symbol_arg *fsa = data;
501 struct kernel_symbol *sym;
503 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
504 sizeof(struct kernel_symbol), cmp_name);
506 if (sym != NULL && check_exported_symbol(syms, owner,
507 sym - syms->start, data))
514 * Find an exported symbol and return it, along with, (optional) crc and
515 * (optional) module which owns it. Needs preempt disabled or module_mutex.
517 static bool find_symbol(struct find_symbol_arg *fsa)
519 static const struct symsearch arr[] = {
520 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
522 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
523 __start___kcrctab_gpl,
529 module_assert_mutex_or_preempt();
531 for (i = 0; i < ARRAY_SIZE(arr); i++)
532 if (find_exported_symbol_in_section(&arr[i], NULL, fsa))
535 list_for_each_entry_rcu(mod, &modules, list,
536 lockdep_is_held(&module_mutex)) {
537 struct symsearch arr[] = {
538 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
540 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
545 if (mod->state == MODULE_STATE_UNFORMED)
548 for (i = 0; i < ARRAY_SIZE(arr); i++)
549 if (find_exported_symbol_in_section(&arr[i], mod, fsa))
553 pr_debug("Failed to find symbol %s\n", fsa->name);
558 * Search for module by name: must hold module_mutex (or preempt disabled
559 * for read-only access).
561 static struct module *find_module_all(const char *name, size_t len,
566 module_assert_mutex_or_preempt();
568 list_for_each_entry_rcu(mod, &modules, list,
569 lockdep_is_held(&module_mutex)) {
570 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
572 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
578 struct module *find_module(const char *name)
580 return find_module_all(name, strlen(name), false);
585 static inline void __percpu *mod_percpu(struct module *mod)
590 static int percpu_modalloc(struct module *mod, struct load_info *info)
592 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
593 unsigned long align = pcpusec->sh_addralign;
595 if (!pcpusec->sh_size)
598 if (align > PAGE_SIZE) {
599 pr_warn("%s: per-cpu alignment %li > %li\n",
600 mod->name, align, PAGE_SIZE);
604 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
606 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
607 mod->name, (unsigned long)pcpusec->sh_size);
610 mod->percpu_size = pcpusec->sh_size;
614 static void percpu_modfree(struct module *mod)
616 free_percpu(mod->percpu);
619 static unsigned int find_pcpusec(struct load_info *info)
621 return find_sec(info, ".data..percpu");
624 static void percpu_modcopy(struct module *mod,
625 const void *from, unsigned long size)
629 for_each_possible_cpu(cpu)
630 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
633 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
640 list_for_each_entry_rcu(mod, &modules, list) {
641 if (mod->state == MODULE_STATE_UNFORMED)
643 if (!mod->percpu_size)
645 for_each_possible_cpu(cpu) {
646 void *start = per_cpu_ptr(mod->percpu, cpu);
647 void *va = (void *)addr;
649 if (va >= start && va < start + mod->percpu_size) {
651 *can_addr = (unsigned long) (va - start);
652 *can_addr += (unsigned long)
653 per_cpu_ptr(mod->percpu,
667 * is_module_percpu_address() - test whether address is from module static percpu
668 * @addr: address to test
670 * Test whether @addr belongs to module static percpu area.
672 * Return: %true if @addr is from module static percpu area
674 bool is_module_percpu_address(unsigned long addr)
676 return __is_module_percpu_address(addr, NULL);
679 #else /* ... !CONFIG_SMP */
681 static inline void __percpu *mod_percpu(struct module *mod)
685 static int percpu_modalloc(struct module *mod, struct load_info *info)
687 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
688 if (info->sechdrs[info->index.pcpu].sh_size != 0)
692 static inline void percpu_modfree(struct module *mod)
695 static unsigned int find_pcpusec(struct load_info *info)
699 static inline void percpu_modcopy(struct module *mod,
700 const void *from, unsigned long size)
702 /* pcpusec should be 0, and size of that section should be 0. */
705 bool is_module_percpu_address(unsigned long addr)
710 bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
715 #endif /* CONFIG_SMP */
717 #define MODINFO_ATTR(field) \
718 static void setup_modinfo_##field(struct module *mod, const char *s) \
720 mod->field = kstrdup(s, GFP_KERNEL); \
722 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
723 struct module_kobject *mk, char *buffer) \
725 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
727 static int modinfo_##field##_exists(struct module *mod) \
729 return mod->field != NULL; \
731 static void free_modinfo_##field(struct module *mod) \
736 static struct module_attribute modinfo_##field = { \
737 .attr = { .name = __stringify(field), .mode = 0444 }, \
738 .show = show_modinfo_##field, \
739 .setup = setup_modinfo_##field, \
740 .test = modinfo_##field##_exists, \
741 .free = free_modinfo_##field, \
744 MODINFO_ATTR(version);
745 MODINFO_ATTR(srcversion);
747 static char last_unloaded_module[MODULE_NAME_LEN+1];
749 #ifdef CONFIG_MODULE_UNLOAD
751 EXPORT_TRACEPOINT_SYMBOL(module_get);
753 /* MODULE_REF_BASE is the base reference count by kmodule loader. */
754 #define MODULE_REF_BASE 1
756 /* Init the unload section of the module. */
757 static int module_unload_init(struct module *mod)
760 * Initialize reference counter to MODULE_REF_BASE.
761 * refcnt == 0 means module is going.
763 atomic_set(&mod->refcnt, MODULE_REF_BASE);
765 INIT_LIST_HEAD(&mod->source_list);
766 INIT_LIST_HEAD(&mod->target_list);
768 /* Hold reference count during initialization. */
769 atomic_inc(&mod->refcnt);
774 /* Does a already use b? */
775 static int already_uses(struct module *a, struct module *b)
777 struct module_use *use;
779 list_for_each_entry(use, &b->source_list, source_list) {
780 if (use->source == a) {
781 pr_debug("%s uses %s!\n", a->name, b->name);
785 pr_debug("%s does not use %s!\n", a->name, b->name);
791 * - we add 'a' as a "source", 'b' as a "target" of module use
792 * - the module_use is added to the list of 'b' sources (so
793 * 'b' can walk the list to see who sourced them), and of 'a'
794 * targets (so 'a' can see what modules it targets).
796 static int add_module_usage(struct module *a, struct module *b)
798 struct module_use *use;
800 pr_debug("Allocating new usage for %s.\n", a->name);
801 use = kmalloc(sizeof(*use), GFP_ATOMIC);
807 list_add(&use->source_list, &b->source_list);
808 list_add(&use->target_list, &a->target_list);
812 /* Module a uses b: caller needs module_mutex() */
813 static int ref_module(struct module *a, struct module *b)
817 if (b == NULL || already_uses(a, b))
820 /* If module isn't available, we fail. */
821 err = strong_try_module_get(b);
825 err = add_module_usage(a, b);
833 /* Clear the unload stuff of the module. */
834 static void module_unload_free(struct module *mod)
836 struct module_use *use, *tmp;
838 mutex_lock(&module_mutex);
839 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
840 struct module *i = use->target;
841 pr_debug("%s unusing %s\n", mod->name, i->name);
843 list_del(&use->source_list);
844 list_del(&use->target_list);
847 mutex_unlock(&module_mutex);
850 #ifdef CONFIG_MODULE_FORCE_UNLOAD
851 static inline int try_force_unload(unsigned int flags)
853 int ret = (flags & O_TRUNC);
855 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
859 static inline int try_force_unload(unsigned int flags)
863 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
865 /* Try to release refcount of module, 0 means success. */
866 static int try_release_module_ref(struct module *mod)
870 /* Try to decrement refcnt which we set at loading */
871 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
874 /* Someone can put this right now, recover with checking */
875 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
880 static int try_stop_module(struct module *mod, int flags, int *forced)
882 /* If it's not unused, quit unless we're forcing. */
883 if (try_release_module_ref(mod) != 0) {
884 *forced = try_force_unload(flags);
889 /* Mark it as dying. */
890 mod->state = MODULE_STATE_GOING;
896 * module_refcount() - return the refcount or -1 if unloading
897 * @mod: the module we're checking
900 * -1 if the module is in the process of unloading
901 * otherwise the number of references in the kernel to the module
903 int module_refcount(struct module *mod)
905 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
907 EXPORT_SYMBOL(module_refcount);
909 /* This exists whether we can unload or not */
910 static void free_module(struct module *mod);
912 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
916 char name[MODULE_NAME_LEN];
919 if (!capable(CAP_SYS_MODULE) || modules_disabled)
922 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
924 name[MODULE_NAME_LEN-1] = '\0';
926 audit_log_kern_module(name);
928 if (mutex_lock_interruptible(&module_mutex) != 0)
931 mod = find_module(name);
937 if (!list_empty(&mod->source_list)) {
938 /* Other modules depend on us: get rid of them first. */
943 /* Doing init or already dying? */
944 if (mod->state != MODULE_STATE_LIVE) {
945 /* FIXME: if (force), slam module count damn the torpedoes */
946 pr_debug("%s already dying\n", mod->name);
951 /* If it has an init func, it must have an exit func to unload */
952 if (mod->init && !mod->exit) {
953 forced = try_force_unload(flags);
955 /* This module can't be removed */
961 /* Stop the machine so refcounts can't move and disable module. */
962 ret = try_stop_module(mod, flags, &forced);
966 mutex_unlock(&module_mutex);
967 /* Final destruction now no one is using it. */
968 if (mod->exit != NULL)
970 blocking_notifier_call_chain(&module_notify_list,
971 MODULE_STATE_GOING, mod);
972 klp_module_going(mod);
973 ftrace_release_mod(mod);
975 async_synchronize_full();
977 /* Store the name of the last unloaded module for diagnostic purposes */
978 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
981 /* someone could wait for the module in add_unformed_module() */
982 wake_up_all(&module_wq);
985 mutex_unlock(&module_mutex);
989 static inline void print_unload_info(struct seq_file *m, struct module *mod)
991 struct module_use *use;
992 int printed_something = 0;
994 seq_printf(m, " %i ", module_refcount(mod));
997 * Always include a trailing , so userspace can differentiate
998 * between this and the old multi-field proc format.
1000 list_for_each_entry(use, &mod->source_list, source_list) {
1001 printed_something = 1;
1002 seq_printf(m, "%s,", use->source->name);
1005 if (mod->init != NULL && mod->exit == NULL) {
1006 printed_something = 1;
1007 seq_puts(m, "[permanent],");
1010 if (!printed_something)
1014 void __symbol_put(const char *symbol)
1016 struct find_symbol_arg fsa = {
1022 BUG_ON(!find_symbol(&fsa));
1023 module_put(fsa.owner);
1026 EXPORT_SYMBOL(__symbol_put);
1028 /* Note this assumes addr is a function, which it currently always is. */
1029 void symbol_put_addr(void *addr)
1031 struct module *modaddr;
1032 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1034 if (core_kernel_text(a))
1038 * Even though we hold a reference on the module; we still need to
1039 * disable preemption in order to safely traverse the data structure.
1042 modaddr = __module_text_address(a);
1044 module_put(modaddr);
1047 EXPORT_SYMBOL_GPL(symbol_put_addr);
1049 static ssize_t show_refcnt(struct module_attribute *mattr,
1050 struct module_kobject *mk, char *buffer)
1052 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1055 static struct module_attribute modinfo_refcnt =
1056 __ATTR(refcnt, 0444, show_refcnt, NULL);
1058 void __module_get(struct module *module)
1062 atomic_inc(&module->refcnt);
1063 trace_module_get(module, _RET_IP_);
1067 EXPORT_SYMBOL(__module_get);
1069 bool try_module_get(struct module *module)
1075 /* Note: here, we can fail to get a reference */
1076 if (likely(module_is_live(module) &&
1077 atomic_inc_not_zero(&module->refcnt) != 0))
1078 trace_module_get(module, _RET_IP_);
1086 EXPORT_SYMBOL(try_module_get);
1088 void module_put(struct module *module)
1094 ret = atomic_dec_if_positive(&module->refcnt);
1095 WARN_ON(ret < 0); /* Failed to put refcount */
1096 trace_module_put(module, _RET_IP_);
1100 EXPORT_SYMBOL(module_put);
1102 #else /* !CONFIG_MODULE_UNLOAD */
1103 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1105 /* We don't know the usage count, or what modules are using. */
1106 seq_puts(m, " - -");
1109 static inline void module_unload_free(struct module *mod)
1113 static int ref_module(struct module *a, struct module *b)
1115 return strong_try_module_get(b);
1118 static inline int module_unload_init(struct module *mod)
1122 #endif /* CONFIG_MODULE_UNLOAD */
1124 static size_t module_flags_taint(struct module *mod, char *buf)
1129 for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
1130 if (taint_flags[i].module && test_bit(i, &mod->taints))
1131 buf[l++] = taint_flags[i].c_true;
1137 static ssize_t show_initstate(struct module_attribute *mattr,
1138 struct module_kobject *mk, char *buffer)
1140 const char *state = "unknown";
1142 switch (mk->mod->state) {
1143 case MODULE_STATE_LIVE:
1146 case MODULE_STATE_COMING:
1149 case MODULE_STATE_GOING:
1155 return sprintf(buffer, "%s\n", state);
1158 static struct module_attribute modinfo_initstate =
1159 __ATTR(initstate, 0444, show_initstate, NULL);
1161 static ssize_t store_uevent(struct module_attribute *mattr,
1162 struct module_kobject *mk,
1163 const char *buffer, size_t count)
1167 rc = kobject_synth_uevent(&mk->kobj, buffer, count);
1168 return rc ? rc : count;
1171 struct module_attribute module_uevent =
1172 __ATTR(uevent, 0200, NULL, store_uevent);
1174 static ssize_t show_coresize(struct module_attribute *mattr,
1175 struct module_kobject *mk, char *buffer)
1177 return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1180 static struct module_attribute modinfo_coresize =
1181 __ATTR(coresize, 0444, show_coresize, NULL);
1183 static ssize_t show_initsize(struct module_attribute *mattr,
1184 struct module_kobject *mk, char *buffer)
1186 return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1189 static struct module_attribute modinfo_initsize =
1190 __ATTR(initsize, 0444, show_initsize, NULL);
1192 static ssize_t show_taint(struct module_attribute *mattr,
1193 struct module_kobject *mk, char *buffer)
1197 l = module_flags_taint(mk->mod, buffer);
1202 static struct module_attribute modinfo_taint =
1203 __ATTR(taint, 0444, show_taint, NULL);
1205 static struct module_attribute *modinfo_attrs[] = {
1208 &modinfo_srcversion,
1213 #ifdef CONFIG_MODULE_UNLOAD
1219 static const char vermagic[] = VERMAGIC_STRING;
1221 static int try_to_force_load(struct module *mod, const char *reason)
1223 #ifdef CONFIG_MODULE_FORCE_LOAD
1224 if (!test_taint(TAINT_FORCED_MODULE))
1225 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1226 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1233 #ifdef CONFIG_MODVERSIONS
1235 static u32 resolve_rel_crc(const s32 *crc)
1237 return *(u32 *)((void *)crc + *crc);
1240 static int check_version(const struct load_info *info,
1241 const char *symname,
1245 Elf_Shdr *sechdrs = info->sechdrs;
1246 unsigned int versindex = info->index.vers;
1247 unsigned int i, num_versions;
1248 struct modversion_info *versions;
1250 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1254 /* No versions at all? modprobe --force does this. */
1256 return try_to_force_load(mod, symname) == 0;
1258 versions = (void *) sechdrs[versindex].sh_addr;
1259 num_versions = sechdrs[versindex].sh_size
1260 / sizeof(struct modversion_info);
1262 for (i = 0; i < num_versions; i++) {
1265 if (strcmp(versions[i].name, symname) != 0)
1268 if (IS_ENABLED(CONFIG_MODULE_REL_CRCS))
1269 crcval = resolve_rel_crc(crc);
1272 if (versions[i].crc == crcval)
1274 pr_debug("Found checksum %X vs module %lX\n",
1275 crcval, versions[i].crc);
1279 /* Broken toolchain. Warn once, then let it go.. */
1280 pr_warn_once("%s: no symbol version for %s\n", info->name, symname);
1284 pr_warn("%s: disagrees about version of symbol %s\n",
1285 info->name, symname);
1289 static inline int check_modstruct_version(const struct load_info *info,
1292 struct find_symbol_arg fsa = {
1293 .name = "module_layout",
1298 * Since this should be found in kernel (which can't be removed), no
1299 * locking is necessary -- use preempt_disable() to placate lockdep.
1302 if (!find_symbol(&fsa)) {
1307 return check_version(info, "module_layout", mod, fsa.crc);
1310 /* First part is kernel version, which we ignore if module has crcs. */
1311 static inline int same_magic(const char *amagic, const char *bmagic,
1315 amagic += strcspn(amagic, " ");
1316 bmagic += strcspn(bmagic, " ");
1318 return strcmp(amagic, bmagic) == 0;
1321 static inline int check_version(const struct load_info *info,
1322 const char *symname,
1329 static inline int check_modstruct_version(const struct load_info *info,
1335 static inline int same_magic(const char *amagic, const char *bmagic,
1338 return strcmp(amagic, bmagic) == 0;
1340 #endif /* CONFIG_MODVERSIONS */
1342 static char *get_modinfo(const struct load_info *info, const char *tag);
1343 static char *get_next_modinfo(const struct load_info *info, const char *tag,
1346 static int verify_namespace_is_imported(const struct load_info *info,
1347 const struct kernel_symbol *sym,
1350 const char *namespace;
1351 char *imported_namespace;
1353 namespace = kernel_symbol_namespace(sym);
1354 if (namespace && namespace[0]) {
1355 imported_namespace = get_modinfo(info, "import_ns");
1356 while (imported_namespace) {
1357 if (strcmp(namespace, imported_namespace) == 0)
1359 imported_namespace = get_next_modinfo(
1360 info, "import_ns", imported_namespace);
1362 #ifdef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1367 "%s: module uses symbol (%s) from namespace %s, but does not import it.\n",
1368 mod->name, kernel_symbol_name(sym), namespace);
1369 #ifndef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1376 static bool inherit_taint(struct module *mod, struct module *owner)
1378 if (!owner || !test_bit(TAINT_PROPRIETARY_MODULE, &owner->taints))
1381 if (mod->using_gplonly_symbols) {
1382 pr_err("%s: module using GPL-only symbols uses symbols from proprietary module %s.\n",
1383 mod->name, owner->name);
1387 if (!test_bit(TAINT_PROPRIETARY_MODULE, &mod->taints)) {
1388 pr_warn("%s: module uses symbols from proprietary module %s, inheriting taint.\n",
1389 mod->name, owner->name);
1390 set_bit(TAINT_PROPRIETARY_MODULE, &mod->taints);
1395 /* Resolve a symbol for this module. I.e. if we find one, record usage. */
1396 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1397 const struct load_info *info,
1401 struct find_symbol_arg fsa = {
1403 .gplok = !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)),
1409 * The module_mutex should not be a heavily contended lock;
1410 * if we get the occasional sleep here, we'll go an extra iteration
1411 * in the wait_event_interruptible(), which is harmless.
1413 sched_annotate_sleep();
1414 mutex_lock(&module_mutex);
1415 if (!find_symbol(&fsa))
1418 if (fsa.license == GPL_ONLY)
1419 mod->using_gplonly_symbols = true;
1421 if (!inherit_taint(mod, fsa.owner)) {
1426 if (!check_version(info, name, mod, fsa.crc)) {
1427 fsa.sym = ERR_PTR(-EINVAL);
1431 err = verify_namespace_is_imported(info, fsa.sym, mod);
1433 fsa.sym = ERR_PTR(err);
1437 err = ref_module(mod, fsa.owner);
1439 fsa.sym = ERR_PTR(err);
1444 /* We must make copy under the lock if we failed to get ref. */
1445 strncpy(ownername, module_name(fsa.owner), MODULE_NAME_LEN);
1447 mutex_unlock(&module_mutex);
1451 static const struct kernel_symbol *
1452 resolve_symbol_wait(struct module *mod,
1453 const struct load_info *info,
1456 const struct kernel_symbol *ksym;
1457 char owner[MODULE_NAME_LEN];
1459 if (wait_event_interruptible_timeout(module_wq,
1460 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1461 || PTR_ERR(ksym) != -EBUSY,
1463 pr_warn("%s: gave up waiting for init of module %s.\n",
1469 #ifdef CONFIG_KALLSYMS
1470 static inline bool sect_empty(const Elf_Shdr *sect)
1472 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1477 * /sys/module/foo/sections stuff
1478 * J. Corbet <corbet@lwn.net>
1482 #ifdef CONFIG_KALLSYMS
1483 struct module_sect_attr {
1484 struct bin_attribute battr;
1485 unsigned long address;
1488 struct module_sect_attrs {
1489 struct attribute_group grp;
1490 unsigned int nsections;
1491 struct module_sect_attr attrs[];
1494 #define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4))
1495 static ssize_t module_sect_read(struct file *file, struct kobject *kobj,
1496 struct bin_attribute *battr,
1497 char *buf, loff_t pos, size_t count)
1499 struct module_sect_attr *sattr =
1500 container_of(battr, struct module_sect_attr, battr);
1501 char bounce[MODULE_SECT_READ_SIZE + 1];
1508 * Since we're a binary read handler, we must account for the
1509 * trailing NUL byte that sprintf will write: if "buf" is
1510 * too small to hold the NUL, or the NUL is exactly the last
1511 * byte, the read will look like it got truncated by one byte.
1512 * Since there is no way to ask sprintf nicely to not write
1513 * the NUL, we have to use a bounce buffer.
1515 wrote = scnprintf(bounce, sizeof(bounce), "0x%px\n",
1516 kallsyms_show_value(file->f_cred)
1517 ? (void *)sattr->address : NULL);
1518 count = min(count, wrote);
1519 memcpy(buf, bounce, count);
1524 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1526 unsigned int section;
1528 for (section = 0; section < sect_attrs->nsections; section++)
1529 kfree(sect_attrs->attrs[section].battr.attr.name);
1533 static void add_sect_attrs(struct module *mod, const struct load_info *info)
1535 unsigned int nloaded = 0, i, size[2];
1536 struct module_sect_attrs *sect_attrs;
1537 struct module_sect_attr *sattr;
1538 struct bin_attribute **gattr;
1540 /* Count loaded sections and allocate structures */
1541 for (i = 0; i < info->hdr->e_shnum; i++)
1542 if (!sect_empty(&info->sechdrs[i]))
1544 size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded),
1545 sizeof(sect_attrs->grp.bin_attrs[0]));
1546 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.bin_attrs[0]);
1547 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1548 if (sect_attrs == NULL)
1551 /* Setup section attributes. */
1552 sect_attrs->grp.name = "sections";
1553 sect_attrs->grp.bin_attrs = (void *)sect_attrs + size[0];
1555 sect_attrs->nsections = 0;
1556 sattr = §_attrs->attrs[0];
1557 gattr = §_attrs->grp.bin_attrs[0];
1558 for (i = 0; i < info->hdr->e_shnum; i++) {
1559 Elf_Shdr *sec = &info->sechdrs[i];
1560 if (sect_empty(sec))
1562 sysfs_bin_attr_init(&sattr->battr);
1563 sattr->address = sec->sh_addr;
1564 sattr->battr.attr.name =
1565 kstrdup(info->secstrings + sec->sh_name, GFP_KERNEL);
1566 if (sattr->battr.attr.name == NULL)
1568 sect_attrs->nsections++;
1569 sattr->battr.read = module_sect_read;
1570 sattr->battr.size = MODULE_SECT_READ_SIZE;
1571 sattr->battr.attr.mode = 0400;
1572 *(gattr++) = &(sattr++)->battr;
1576 if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp))
1579 mod->sect_attrs = sect_attrs;
1582 free_sect_attrs(sect_attrs);
1585 static void remove_sect_attrs(struct module *mod)
1587 if (mod->sect_attrs) {
1588 sysfs_remove_group(&mod->mkobj.kobj,
1589 &mod->sect_attrs->grp);
1591 * We are positive that no one is using any sect attrs
1592 * at this point. Deallocate immediately.
1594 free_sect_attrs(mod->sect_attrs);
1595 mod->sect_attrs = NULL;
1600 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1603 struct module_notes_attrs {
1604 struct kobject *dir;
1606 struct bin_attribute attrs[];
1609 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1610 struct bin_attribute *bin_attr,
1611 char *buf, loff_t pos, size_t count)
1614 * The caller checked the pos and count against our size.
1616 memcpy(buf, bin_attr->private + pos, count);
1620 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1623 if (notes_attrs->dir) {
1625 sysfs_remove_bin_file(notes_attrs->dir,
1626 ¬es_attrs->attrs[i]);
1627 kobject_put(notes_attrs->dir);
1632 static void add_notes_attrs(struct module *mod, const struct load_info *info)
1634 unsigned int notes, loaded, i;
1635 struct module_notes_attrs *notes_attrs;
1636 struct bin_attribute *nattr;
1638 /* failed to create section attributes, so can't create notes */
1639 if (!mod->sect_attrs)
1642 /* Count notes sections and allocate structures. */
1644 for (i = 0; i < info->hdr->e_shnum; i++)
1645 if (!sect_empty(&info->sechdrs[i]) &&
1646 (info->sechdrs[i].sh_type == SHT_NOTE))
1652 notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes),
1654 if (notes_attrs == NULL)
1657 notes_attrs->notes = notes;
1658 nattr = ¬es_attrs->attrs[0];
1659 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1660 if (sect_empty(&info->sechdrs[i]))
1662 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1663 sysfs_bin_attr_init(nattr);
1664 nattr->attr.name = mod->sect_attrs->attrs[loaded].battr.attr.name;
1665 nattr->attr.mode = S_IRUGO;
1666 nattr->size = info->sechdrs[i].sh_size;
1667 nattr->private = (void *) info->sechdrs[i].sh_addr;
1668 nattr->read = module_notes_read;
1674 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1675 if (!notes_attrs->dir)
1678 for (i = 0; i < notes; ++i)
1679 if (sysfs_create_bin_file(notes_attrs->dir,
1680 ¬es_attrs->attrs[i]))
1683 mod->notes_attrs = notes_attrs;
1687 free_notes_attrs(notes_attrs, i);
1690 static void remove_notes_attrs(struct module *mod)
1692 if (mod->notes_attrs)
1693 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1698 static inline void add_sect_attrs(struct module *mod,
1699 const struct load_info *info)
1703 static inline void remove_sect_attrs(struct module *mod)
1707 static inline void add_notes_attrs(struct module *mod,
1708 const struct load_info *info)
1712 static inline void remove_notes_attrs(struct module *mod)
1715 #endif /* CONFIG_KALLSYMS */
1717 static void del_usage_links(struct module *mod)
1719 #ifdef CONFIG_MODULE_UNLOAD
1720 struct module_use *use;
1722 mutex_lock(&module_mutex);
1723 list_for_each_entry(use, &mod->target_list, target_list)
1724 sysfs_remove_link(use->target->holders_dir, mod->name);
1725 mutex_unlock(&module_mutex);
1729 static int add_usage_links(struct module *mod)
1732 #ifdef CONFIG_MODULE_UNLOAD
1733 struct module_use *use;
1735 mutex_lock(&module_mutex);
1736 list_for_each_entry(use, &mod->target_list, target_list) {
1737 ret = sysfs_create_link(use->target->holders_dir,
1738 &mod->mkobj.kobj, mod->name);
1742 mutex_unlock(&module_mutex);
1744 del_usage_links(mod);
1749 static void module_remove_modinfo_attrs(struct module *mod, int end);
1751 static int module_add_modinfo_attrs(struct module *mod)
1753 struct module_attribute *attr;
1754 struct module_attribute *temp_attr;
1758 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1759 (ARRAY_SIZE(modinfo_attrs) + 1)),
1761 if (!mod->modinfo_attrs)
1764 temp_attr = mod->modinfo_attrs;
1765 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1766 if (!attr->test || attr->test(mod)) {
1767 memcpy(temp_attr, attr, sizeof(*temp_attr));
1768 sysfs_attr_init(&temp_attr->attr);
1769 error = sysfs_create_file(&mod->mkobj.kobj,
1781 module_remove_modinfo_attrs(mod, --i);
1783 kfree(mod->modinfo_attrs);
1787 static void module_remove_modinfo_attrs(struct module *mod, int end)
1789 struct module_attribute *attr;
1792 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1793 if (end >= 0 && i > end)
1795 /* pick a field to test for end of list */
1796 if (!attr->attr.name)
1798 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1802 kfree(mod->modinfo_attrs);
1805 static void mod_kobject_put(struct module *mod)
1807 DECLARE_COMPLETION_ONSTACK(c);
1808 mod->mkobj.kobj_completion = &c;
1809 kobject_put(&mod->mkobj.kobj);
1810 wait_for_completion(&c);
1813 static int mod_sysfs_init(struct module *mod)
1816 struct kobject *kobj;
1818 if (!module_sysfs_initialized) {
1819 pr_err("%s: module sysfs not initialized\n", mod->name);
1824 kobj = kset_find_obj(module_kset, mod->name);
1826 pr_err("%s: module is already loaded\n", mod->name);
1832 mod->mkobj.mod = mod;
1834 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1835 mod->mkobj.kobj.kset = module_kset;
1836 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1839 mod_kobject_put(mod);
1845 static int mod_sysfs_setup(struct module *mod,
1846 const struct load_info *info,
1847 struct kernel_param *kparam,
1848 unsigned int num_params)
1852 err = mod_sysfs_init(mod);
1856 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1857 if (!mod->holders_dir) {
1862 err = module_param_sysfs_setup(mod, kparam, num_params);
1864 goto out_unreg_holders;
1866 err = module_add_modinfo_attrs(mod);
1868 goto out_unreg_param;
1870 err = add_usage_links(mod);
1872 goto out_unreg_modinfo_attrs;
1874 add_sect_attrs(mod, info);
1875 add_notes_attrs(mod, info);
1879 out_unreg_modinfo_attrs:
1880 module_remove_modinfo_attrs(mod, -1);
1882 module_param_sysfs_remove(mod);
1884 kobject_put(mod->holders_dir);
1886 mod_kobject_put(mod);
1891 static void mod_sysfs_fini(struct module *mod)
1893 remove_notes_attrs(mod);
1894 remove_sect_attrs(mod);
1895 mod_kobject_put(mod);
1898 static void init_param_lock(struct module *mod)
1900 mutex_init(&mod->param_lock);
1902 #else /* !CONFIG_SYSFS */
1904 static int mod_sysfs_setup(struct module *mod,
1905 const struct load_info *info,
1906 struct kernel_param *kparam,
1907 unsigned int num_params)
1912 static void mod_sysfs_fini(struct module *mod)
1916 static void module_remove_modinfo_attrs(struct module *mod, int end)
1920 static void del_usage_links(struct module *mod)
1924 static void init_param_lock(struct module *mod)
1927 #endif /* CONFIG_SYSFS */
1929 static void mod_sysfs_teardown(struct module *mod)
1931 del_usage_links(mod);
1932 module_remove_modinfo_attrs(mod, -1);
1933 module_param_sysfs_remove(mod);
1934 kobject_put(mod->mkobj.drivers_dir);
1935 kobject_put(mod->holders_dir);
1936 mod_sysfs_fini(mod);
1940 * LKM RO/NX protection: protect module's text/ro-data
1941 * from modification and any data from execution.
1943 * General layout of module is:
1944 * [text] [read-only-data] [ro-after-init] [writable data]
1945 * text_size -----^ ^ ^ ^
1946 * ro_size ------------------------| | |
1947 * ro_after_init_size -----------------------------| |
1948 * size -----------------------------------------------------------|
1950 * These values are always page-aligned (as is base)
1954 * Since some arches are moving towards PAGE_KERNEL module allocations instead
1955 * of PAGE_KERNEL_EXEC, keep frob_text() and module_enable_x() outside of the
1956 * CONFIG_STRICT_MODULE_RWX block below because they are needed regardless of
1957 * whether we are strict.
1959 #ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
1960 static void frob_text(const struct module_layout *layout,
1961 int (*set_memory)(unsigned long start, int num_pages))
1963 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1964 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1965 set_memory((unsigned long)layout->base,
1966 layout->text_size >> PAGE_SHIFT);
1969 static void module_enable_x(const struct module *mod)
1971 frob_text(&mod->core_layout, set_memory_x);
1972 frob_text(&mod->init_layout, set_memory_x);
1974 #else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
1975 static void module_enable_x(const struct module *mod) { }
1976 #endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
1978 #ifdef CONFIG_STRICT_MODULE_RWX
1979 static void frob_rodata(const struct module_layout *layout,
1980 int (*set_memory)(unsigned long start, int num_pages))
1982 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1983 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1984 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1985 set_memory((unsigned long)layout->base + layout->text_size,
1986 (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
1989 static void frob_ro_after_init(const struct module_layout *layout,
1990 int (*set_memory)(unsigned long start, int num_pages))
1992 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1993 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1994 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1995 set_memory((unsigned long)layout->base + layout->ro_size,
1996 (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
1999 static void frob_writable_data(const struct module_layout *layout,
2000 int (*set_memory)(unsigned long start, int num_pages))
2002 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
2003 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
2004 BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
2005 set_memory((unsigned long)layout->base + layout->ro_after_init_size,
2006 (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
2009 static void module_enable_ro(const struct module *mod, bool after_init)
2011 if (!rodata_enabled)
2014 set_vm_flush_reset_perms(mod->core_layout.base);
2015 set_vm_flush_reset_perms(mod->init_layout.base);
2016 frob_text(&mod->core_layout, set_memory_ro);
2018 frob_rodata(&mod->core_layout, set_memory_ro);
2019 frob_text(&mod->init_layout, set_memory_ro);
2020 frob_rodata(&mod->init_layout, set_memory_ro);
2023 frob_ro_after_init(&mod->core_layout, set_memory_ro);
2026 static void module_enable_nx(const struct module *mod)
2028 frob_rodata(&mod->core_layout, set_memory_nx);
2029 frob_ro_after_init(&mod->core_layout, set_memory_nx);
2030 frob_writable_data(&mod->core_layout, set_memory_nx);
2031 frob_rodata(&mod->init_layout, set_memory_nx);
2032 frob_writable_data(&mod->init_layout, set_memory_nx);
2035 static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
2036 char *secstrings, struct module *mod)
2038 const unsigned long shf_wx = SHF_WRITE|SHF_EXECINSTR;
2041 for (i = 0; i < hdr->e_shnum; i++) {
2042 if ((sechdrs[i].sh_flags & shf_wx) == shf_wx) {
2043 pr_err("%s: section %s (index %d) has invalid WRITE|EXEC flags\n",
2044 mod->name, secstrings + sechdrs[i].sh_name, i);
2052 #else /* !CONFIG_STRICT_MODULE_RWX */
2053 static void module_enable_nx(const struct module *mod) { }
2054 static void module_enable_ro(const struct module *mod, bool after_init) {}
2055 static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
2056 char *secstrings, struct module *mod)
2060 #endif /* CONFIG_STRICT_MODULE_RWX */
2062 #ifdef CONFIG_LIVEPATCH
2064 * Persist Elf information about a module. Copy the Elf header,
2065 * section header table, section string table, and symtab section
2066 * index from info to mod->klp_info.
2068 static int copy_module_elf(struct module *mod, struct load_info *info)
2070 unsigned int size, symndx;
2073 size = sizeof(*mod->klp_info);
2074 mod->klp_info = kmalloc(size, GFP_KERNEL);
2075 if (mod->klp_info == NULL)
2079 size = sizeof(mod->klp_info->hdr);
2080 memcpy(&mod->klp_info->hdr, info->hdr, size);
2082 /* Elf section header table */
2083 size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
2084 mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL);
2085 if (mod->klp_info->sechdrs == NULL) {
2090 /* Elf section name string table */
2091 size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
2092 mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL);
2093 if (mod->klp_info->secstrings == NULL) {
2098 /* Elf symbol section index */
2099 symndx = info->index.sym;
2100 mod->klp_info->symndx = symndx;
2103 * For livepatch modules, core_kallsyms.symtab is a complete
2104 * copy of the original symbol table. Adjust sh_addr to point
2105 * to core_kallsyms.symtab since the copy of the symtab in module
2106 * init memory is freed at the end of do_init_module().
2108 mod->klp_info->sechdrs[symndx].sh_addr = \
2109 (unsigned long) mod->core_kallsyms.symtab;
2114 kfree(mod->klp_info->sechdrs);
2116 kfree(mod->klp_info);
2120 static void free_module_elf(struct module *mod)
2122 kfree(mod->klp_info->sechdrs);
2123 kfree(mod->klp_info->secstrings);
2124 kfree(mod->klp_info);
2126 #else /* !CONFIG_LIVEPATCH */
2127 static int copy_module_elf(struct module *mod, struct load_info *info)
2132 static void free_module_elf(struct module *mod)
2135 #endif /* CONFIG_LIVEPATCH */
2137 void __weak module_memfree(void *module_region)
2140 * This memory may be RO, and freeing RO memory in an interrupt is not
2141 * supported by vmalloc.
2143 WARN_ON(in_interrupt());
2144 vfree(module_region);
2147 void __weak module_arch_cleanup(struct module *mod)
2151 void __weak module_arch_freeing_init(struct module *mod)
2155 static void cfi_cleanup(struct module *mod);
2157 /* Free a module, remove from lists, etc. */
2158 static void free_module(struct module *mod)
2160 trace_module_free(mod);
2162 mod_sysfs_teardown(mod);
2165 * We leave it in list to prevent duplicate loads, but make sure
2166 * that noone uses it while it's being deconstructed.
2168 mutex_lock(&module_mutex);
2169 mod->state = MODULE_STATE_UNFORMED;
2170 mutex_unlock(&module_mutex);
2172 /* Remove dynamic debug info */
2173 ddebug_remove_module(mod->name);
2175 /* Arch-specific cleanup. */
2176 module_arch_cleanup(mod);
2178 /* Module unload stuff */
2179 module_unload_free(mod);
2181 /* Free any allocated parameters. */
2182 destroy_params(mod->kp, mod->num_kp);
2184 if (is_livepatch_module(mod))
2185 free_module_elf(mod);
2187 /* Now we can delete it from the lists */
2188 mutex_lock(&module_mutex);
2189 /* Unlink carefully: kallsyms could be walking list. */
2190 list_del_rcu(&mod->list);
2191 mod_tree_remove(mod);
2192 /* Remove this module from bug list, this uses list_del_rcu */
2193 module_bug_cleanup(mod);
2194 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2196 mutex_unlock(&module_mutex);
2198 /* Clean up CFI for the module. */
2201 /* This may be empty, but that's OK */
2202 module_arch_freeing_init(mod);
2203 module_memfree(mod->init_layout.base);
2205 percpu_modfree(mod);
2207 /* Free lock-classes; relies on the preceding sync_rcu(). */
2208 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
2210 /* Finally, free the core (containing the module structure) */
2211 module_memfree(mod->core_layout.base);
2214 void *__symbol_get(const char *symbol)
2216 struct find_symbol_arg fsa = {
2223 if (!find_symbol(&fsa))
2225 if (fsa.license != GPL_ONLY) {
2226 pr_warn("failing symbol_get of non-GPLONLY symbol %s.\n",
2230 if (strong_try_module_get(fsa.owner))
2233 return (void *)kernel_symbol_value(fsa.sym);
2238 EXPORT_SYMBOL_GPL(__symbol_get);
2241 * Ensure that an exported symbol [global namespace] does not already exist
2242 * in the kernel or in some other module's exported symbol table.
2244 * You must hold the module_mutex.
2246 static int verify_exported_symbols(struct module *mod)
2249 const struct kernel_symbol *s;
2251 const struct kernel_symbol *sym;
2254 { mod->syms, mod->num_syms },
2255 { mod->gpl_syms, mod->num_gpl_syms },
2258 for (i = 0; i < ARRAY_SIZE(arr); i++) {
2259 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2260 struct find_symbol_arg fsa = {
2261 .name = kernel_symbol_name(s),
2264 if (find_symbol(&fsa)) {
2265 pr_err("%s: exports duplicate symbol %s"
2267 mod->name, kernel_symbol_name(s),
2268 module_name(fsa.owner));
2276 static bool ignore_undef_symbol(Elf_Half emachine, const char *name)
2279 * On x86, PIC code and Clang non-PIC code may have call foo@PLT. GNU as
2280 * before 2.37 produces an unreferenced _GLOBAL_OFFSET_TABLE_ on x86-64.
2281 * i386 has a similar problem but may not deserve a fix.
2283 * If we ever have to ignore many symbols, consider refactoring the code to
2284 * only warn if referenced by a relocation.
2286 if (emachine == EM_386 || emachine == EM_X86_64)
2287 return !strcmp(name, "_GLOBAL_OFFSET_TABLE_");
2291 /* Change all symbols so that st_value encodes the pointer directly. */
2292 static int simplify_symbols(struct module *mod, const struct load_info *info)
2294 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2295 Elf_Sym *sym = (void *)symsec->sh_addr;
2296 unsigned long secbase;
2299 const struct kernel_symbol *ksym;
2301 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2302 const char *name = info->strtab + sym[i].st_name;
2304 switch (sym[i].st_shndx) {
2306 /* Ignore common symbols */
2307 if (!strncmp(name, "__gnu_lto", 9))
2311 * We compiled with -fno-common. These are not
2312 * supposed to happen.
2314 pr_debug("Common symbol: %s\n", name);
2315 pr_warn("%s: please compile with -fno-common\n",
2321 /* Don't need to do anything */
2322 pr_debug("Absolute symbol: 0x%08lx\n",
2323 (long)sym[i].st_value);
2327 /* Livepatch symbols are resolved by livepatch */
2331 ksym = resolve_symbol_wait(mod, info, name);
2332 /* Ok if resolved. */
2333 if (ksym && !IS_ERR(ksym)) {
2334 sym[i].st_value = kernel_symbol_value(ksym);
2338 /* Ok if weak or ignored. */
2340 (ELF_ST_BIND(sym[i].st_info) == STB_WEAK ||
2341 ignore_undef_symbol(info->hdr->e_machine, name)))
2344 ret = PTR_ERR(ksym) ?: -ENOENT;
2345 pr_warn("%s: Unknown symbol %s (err %d)\n",
2346 mod->name, name, ret);
2350 /* Divert to percpu allocation if a percpu var. */
2351 if (sym[i].st_shndx == info->index.pcpu)
2352 secbase = (unsigned long)mod_percpu(mod);
2354 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2355 sym[i].st_value += secbase;
2363 static int apply_relocations(struct module *mod, const struct load_info *info)
2368 /* Now do relocations. */
2369 for (i = 1; i < info->hdr->e_shnum; i++) {
2370 unsigned int infosec = info->sechdrs[i].sh_info;
2372 /* Not a valid relocation section? */
2373 if (infosec >= info->hdr->e_shnum)
2376 /* Don't bother with non-allocated sections */
2377 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2380 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
2381 err = klp_apply_section_relocs(mod, info->sechdrs,
2386 else if (info->sechdrs[i].sh_type == SHT_REL)
2387 err = apply_relocate(info->sechdrs, info->strtab,
2388 info->index.sym, i, mod);
2389 else if (info->sechdrs[i].sh_type == SHT_RELA)
2390 err = apply_relocate_add(info->sechdrs, info->strtab,
2391 info->index.sym, i, mod);
2398 /* Additional bytes needed by arch in front of individual sections */
2399 unsigned int __weak arch_mod_section_prepend(struct module *mod,
2400 unsigned int section)
2402 /* default implementation just returns zero */
2406 /* Update size with this section: return offset. */
2407 static long get_offset(struct module *mod, unsigned int *size,
2408 Elf_Shdr *sechdr, unsigned int section)
2412 *size += arch_mod_section_prepend(mod, section);
2413 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2414 *size = ret + sechdr->sh_size;
2418 bool module_init_layout_section(const char *sname)
2420 #ifndef CONFIG_MODULE_UNLOAD
2421 if (module_exit_section(sname))
2424 return module_init_section(sname);
2428 * Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2429 * might -- code, read-only data, read-write data, small data. Tally
2430 * sizes, and place the offsets into sh_entsize fields: high bit means it
2433 static void layout_sections(struct module *mod, struct load_info *info)
2435 static unsigned long const masks[][2] = {
2437 * NOTE: all executable code must be the first section
2438 * in this array; otherwise modify the text_size
2439 * finder in the two loops below
2441 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2442 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2443 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
2444 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2445 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2449 for (i = 0; i < info->hdr->e_shnum; i++)
2450 info->sechdrs[i].sh_entsize = ~0UL;
2452 pr_debug("Core section allocation order:\n");
2453 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2454 for (i = 0; i < info->hdr->e_shnum; ++i) {
2455 Elf_Shdr *s = &info->sechdrs[i];
2456 const char *sname = info->secstrings + s->sh_name;
2458 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2459 || (s->sh_flags & masks[m][1])
2460 || s->sh_entsize != ~0UL
2461 || module_init_layout_section(sname))
2463 s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2464 pr_debug("\t%s\n", sname);
2467 case 0: /* executable */
2468 mod->core_layout.size = debug_align(mod->core_layout.size);
2469 mod->core_layout.text_size = mod->core_layout.size;
2471 case 1: /* RO: text and ro-data */
2472 mod->core_layout.size = debug_align(mod->core_layout.size);
2473 mod->core_layout.ro_size = mod->core_layout.size;
2475 case 2: /* RO after init */
2476 mod->core_layout.size = debug_align(mod->core_layout.size);
2477 mod->core_layout.ro_after_init_size = mod->core_layout.size;
2479 case 4: /* whole core */
2480 mod->core_layout.size = debug_align(mod->core_layout.size);
2485 pr_debug("Init section allocation order:\n");
2486 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2487 for (i = 0; i < info->hdr->e_shnum; ++i) {
2488 Elf_Shdr *s = &info->sechdrs[i];
2489 const char *sname = info->secstrings + s->sh_name;
2491 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2492 || (s->sh_flags & masks[m][1])
2493 || s->sh_entsize != ~0UL
2494 || !module_init_layout_section(sname))
2496 s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
2497 | INIT_OFFSET_MASK);
2498 pr_debug("\t%s\n", sname);
2501 case 0: /* executable */
2502 mod->init_layout.size = debug_align(mod->init_layout.size);
2503 mod->init_layout.text_size = mod->init_layout.size;
2505 case 1: /* RO: text and ro-data */
2506 mod->init_layout.size = debug_align(mod->init_layout.size);
2507 mod->init_layout.ro_size = mod->init_layout.size;
2511 * RO after init doesn't apply to init_layout (only
2512 * core_layout), so it just takes the value of ro_size.
2514 mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
2516 case 4: /* whole init */
2517 mod->init_layout.size = debug_align(mod->init_layout.size);
2523 static void set_license(struct module *mod, const char *license)
2526 license = "unspecified";
2528 if (!license_is_gpl_compatible(license)) {
2529 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2530 pr_warn("%s: module license '%s' taints kernel.\n",
2531 mod->name, license);
2532 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2533 LOCKDEP_NOW_UNRELIABLE);
2537 /* Parse tag=value strings from .modinfo section */
2538 static char *next_string(char *string, unsigned long *secsize)
2540 /* Skip non-zero chars */
2543 if ((*secsize)-- <= 1)
2547 /* Skip any zero padding. */
2548 while (!string[0]) {
2550 if ((*secsize)-- <= 1)
2556 static char *get_next_modinfo(const struct load_info *info, const char *tag,
2560 unsigned int taglen = strlen(tag);
2561 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2562 unsigned long size = infosec->sh_size;
2565 * get_modinfo() calls made before rewrite_section_headers()
2566 * must use sh_offset, as sh_addr isn't set!
2568 char *modinfo = (char *)info->hdr + infosec->sh_offset;
2571 size -= prev - modinfo;
2572 modinfo = next_string(prev, &size);
2575 for (p = modinfo; p; p = next_string(p, &size)) {
2576 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2577 return p + taglen + 1;
2582 static char *get_modinfo(const struct load_info *info, const char *tag)
2584 return get_next_modinfo(info, tag, NULL);
2587 static void setup_modinfo(struct module *mod, struct load_info *info)
2589 struct module_attribute *attr;
2592 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2594 attr->setup(mod, get_modinfo(info, attr->attr.name));
2598 static void free_modinfo(struct module *mod)
2600 struct module_attribute *attr;
2603 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2609 #ifdef CONFIG_KALLSYMS
2611 /* Lookup exported symbol in given range of kernel_symbols */
2612 static const struct kernel_symbol *lookup_exported_symbol(const char *name,
2613 const struct kernel_symbol *start,
2614 const struct kernel_symbol *stop)
2616 return bsearch(name, start, stop - start,
2617 sizeof(struct kernel_symbol), cmp_name);
2620 static int is_exported(const char *name, unsigned long value,
2621 const struct module *mod)
2623 const struct kernel_symbol *ks;
2625 ks = lookup_exported_symbol(name, __start___ksymtab, __stop___ksymtab);
2627 ks = lookup_exported_symbol(name, mod->syms, mod->syms + mod->num_syms);
2629 return ks != NULL && kernel_symbol_value(ks) == value;
2633 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2635 const Elf_Shdr *sechdrs = info->sechdrs;
2637 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2638 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2643 if (sym->st_shndx == SHN_UNDEF)
2645 if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
2647 if (sym->st_shndx >= SHN_LORESERVE)
2649 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2651 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2652 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2653 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2655 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2660 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2661 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2666 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2673 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2674 unsigned int shnum, unsigned int pcpundx)
2676 const Elf_Shdr *sec;
2678 if (src->st_shndx == SHN_UNDEF
2679 || src->st_shndx >= shnum
2683 #ifdef CONFIG_KALLSYMS_ALL
2684 if (src->st_shndx == pcpundx)
2688 sec = sechdrs + src->st_shndx;
2689 if (!(sec->sh_flags & SHF_ALLOC)
2690 #ifndef CONFIG_KALLSYMS_ALL
2691 || !(sec->sh_flags & SHF_EXECINSTR)
2693 || (sec->sh_entsize & INIT_OFFSET_MASK))
2700 * We only allocate and copy the strings needed by the parts of symtab
2701 * we keep. This is simple, but has the effect of making multiple
2702 * copies of duplicates. We could be more sophisticated, see
2703 * linux-kernel thread starting with
2704 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2706 static void layout_symtab(struct module *mod, struct load_info *info)
2708 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2709 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2711 unsigned int i, nsrc, ndst, strtab_size = 0;
2713 /* Put symbol section at end of init part of module. */
2714 symsect->sh_flags |= SHF_ALLOC;
2715 symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2716 info->index.sym) | INIT_OFFSET_MASK;
2717 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2719 src = (void *)info->hdr + symsect->sh_offset;
2720 nsrc = symsect->sh_size / sizeof(*src);
2722 /* Compute total space required for the core symbols' strtab. */
2723 for (ndst = i = 0; i < nsrc; i++) {
2724 if (i == 0 || is_livepatch_module(mod) ||
2725 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2726 info->index.pcpu)) {
2727 strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2732 /* Append room for core symbols at end of core part. */
2733 info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
2734 info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
2735 mod->core_layout.size += strtab_size;
2736 info->core_typeoffs = mod->core_layout.size;
2737 mod->core_layout.size += ndst * sizeof(char);
2738 mod->core_layout.size = debug_align(mod->core_layout.size);
2740 /* Put string table section at end of init part of module. */
2741 strsect->sh_flags |= SHF_ALLOC;
2742 strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2743 info->index.str) | INIT_OFFSET_MASK;
2744 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2746 /* We'll tack temporary mod_kallsyms on the end. */
2747 mod->init_layout.size = ALIGN(mod->init_layout.size,
2748 __alignof__(struct mod_kallsyms));
2749 info->mod_kallsyms_init_off = mod->init_layout.size;
2750 mod->init_layout.size += sizeof(struct mod_kallsyms);
2751 info->init_typeoffs = mod->init_layout.size;
2752 mod->init_layout.size += nsrc * sizeof(char);
2753 mod->init_layout.size = debug_align(mod->init_layout.size);
2757 * We use the full symtab and strtab which layout_symtab arranged to
2758 * be appended to the init section. Later we switch to the cut-down
2761 static void add_kallsyms(struct module *mod, const struct load_info *info)
2763 unsigned int i, ndst;
2767 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2769 /* Set up to point into init section. */
2770 mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
2772 mod->kallsyms->symtab = (void *)symsec->sh_addr;
2773 mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2774 /* Make sure we get permanent strtab: don't use info->strtab. */
2775 mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2776 mod->kallsyms->typetab = mod->init_layout.base + info->init_typeoffs;
2779 * Now populate the cut down core kallsyms for after init
2780 * and set types up while we still have access to sections.
2782 mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
2783 mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
2784 mod->core_kallsyms.typetab = mod->core_layout.base + info->core_typeoffs;
2785 src = mod->kallsyms->symtab;
2786 for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2787 mod->kallsyms->typetab[i] = elf_type(src + i, info);
2788 if (i == 0 || is_livepatch_module(mod) ||
2789 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2790 info->index.pcpu)) {
2791 mod->core_kallsyms.typetab[ndst] =
2792 mod->kallsyms->typetab[i];
2794 dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
2795 s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2799 mod->core_kallsyms.num_symtab = ndst;
2802 static inline void layout_symtab(struct module *mod, struct load_info *info)
2806 static void add_kallsyms(struct module *mod, const struct load_info *info)
2809 #endif /* CONFIG_KALLSYMS */
2811 #if IS_ENABLED(CONFIG_KALLSYMS) && IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
2812 static void init_build_id(struct module *mod, const struct load_info *info)
2814 const Elf_Shdr *sechdr;
2817 for (i = 0; i < info->hdr->e_shnum; i++) {
2818 sechdr = &info->sechdrs[i];
2819 if (!sect_empty(sechdr) && sechdr->sh_type == SHT_NOTE &&
2820 !build_id_parse_buf((void *)sechdr->sh_addr, mod->build_id,
2826 static void init_build_id(struct module *mod, const struct load_info *info)
2831 static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num)
2835 ddebug_add_module(debug, num, mod->name);
2838 static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug)
2841 ddebug_remove_module(mod->name);
2844 void * __weak module_alloc(unsigned long size)
2846 return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
2847 GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS,
2848 NUMA_NO_NODE, __builtin_return_address(0));
2851 bool __weak module_init_section(const char *name)
2853 return strstarts(name, ".init");
2856 bool __weak module_exit_section(const char *name)
2858 return strstarts(name, ".exit");
2861 #ifdef CONFIG_DEBUG_KMEMLEAK
2862 static void kmemleak_load_module(const struct module *mod,
2863 const struct load_info *info)
2867 /* only scan the sections containing data */
2868 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2870 for (i = 1; i < info->hdr->e_shnum; i++) {
2871 /* Scan all writable sections that's not executable */
2872 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2873 !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2874 (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2877 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2878 info->sechdrs[i].sh_size, GFP_KERNEL);
2882 static inline void kmemleak_load_module(const struct module *mod,
2883 const struct load_info *info)
2888 #ifdef CONFIG_MODULE_SIG
2889 static int module_sig_check(struct load_info *info, int flags)
2892 const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2894 const void *mod = info->hdr;
2897 * Require flags == 0, as a module with version information
2898 * removed is no longer the module that was signed
2901 info->len > markerlen &&
2902 memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2903 /* We truncate the module to discard the signature */
2904 info->len -= markerlen;
2905 err = mod_verify_sig(mod, info);
2907 info->sig_ok = true;
2913 * We don't permit modules to be loaded into the trusted kernels
2914 * without a valid signature on them, but if we're not enforcing,
2915 * certain errors are non-fatal.
2919 reason = "unsigned module";
2922 reason = "module with unsupported crypto";
2925 reason = "module with unavailable key";
2930 * All other errors are fatal, including lack of memory,
2931 * unparseable signatures, and signature check failures --
2932 * even if signatures aren't required.
2937 if (is_module_sig_enforced()) {
2938 pr_notice("Loading of %s is rejected\n", reason);
2939 return -EKEYREJECTED;
2942 return security_locked_down(LOCKDOWN_MODULE_SIGNATURE);
2944 #else /* !CONFIG_MODULE_SIG */
2945 static int module_sig_check(struct load_info *info, int flags)
2949 #endif /* !CONFIG_MODULE_SIG */
2951 static int validate_section_offset(struct load_info *info, Elf_Shdr *shdr)
2953 unsigned long secend;
2956 * Check for both overflow and offset/size being
2959 secend = shdr->sh_offset + shdr->sh_size;
2960 if (secend < shdr->sh_offset || secend > info->len)
2967 * Sanity checks against invalid binaries, wrong arch, weird elf version.
2969 * Also do basic validity checks against section offsets and sizes, the
2970 * section name string table, and the indices used for it (sh_name).
2972 static int elf_validity_check(struct load_info *info)
2975 Elf_Shdr *shdr, *strhdr;
2978 if (info->len < sizeof(*(info->hdr))) {
2979 pr_err("Invalid ELF header len %lu\n", info->len);
2983 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0) {
2984 pr_err("Invalid ELF header magic: != %s\n", ELFMAG);
2987 if (info->hdr->e_type != ET_REL) {
2988 pr_err("Invalid ELF header type: %u != %u\n",
2989 info->hdr->e_type, ET_REL);
2992 if (!elf_check_arch(info->hdr)) {
2993 pr_err("Invalid architecture in ELF header: %u\n",
2994 info->hdr->e_machine);
2997 if (info->hdr->e_shentsize != sizeof(Elf_Shdr)) {
2998 pr_err("Invalid ELF section header size\n");
3003 * e_shnum is 16 bits, and sizeof(Elf_Shdr) is
3004 * known and small. So e_shnum * sizeof(Elf_Shdr)
3005 * will not overflow unsigned long on any platform.
3007 if (info->hdr->e_shoff >= info->len
3008 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
3009 info->len - info->hdr->e_shoff)) {
3010 pr_err("Invalid ELF section header overflow\n");
3014 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
3017 * Verify if the section name table index is valid.
3019 if (info->hdr->e_shstrndx == SHN_UNDEF
3020 || info->hdr->e_shstrndx >= info->hdr->e_shnum) {
3021 pr_err("Invalid ELF section name index: %d || e_shstrndx (%d) >= e_shnum (%d)\n",
3022 info->hdr->e_shstrndx, info->hdr->e_shstrndx,
3023 info->hdr->e_shnum);
3027 strhdr = &info->sechdrs[info->hdr->e_shstrndx];
3028 err = validate_section_offset(info, strhdr);
3030 pr_err("Invalid ELF section hdr(type %u)\n", strhdr->sh_type);
3035 * The section name table must be NUL-terminated, as required
3036 * by the spec. This makes strcmp and pr_* calls that access
3037 * strings in the section safe.
3039 info->secstrings = (void *)info->hdr + strhdr->sh_offset;
3040 if (strhdr->sh_size == 0) {
3041 pr_err("empty section name table\n");
3044 if (info->secstrings[strhdr->sh_size - 1] != '\0') {
3045 pr_err("ELF Spec violation: section name table isn't null terminated\n");
3050 * The code assumes that section 0 has a length of zero and
3051 * an addr of zero, so check for it.
3053 if (info->sechdrs[0].sh_type != SHT_NULL
3054 || info->sechdrs[0].sh_size != 0
3055 || info->sechdrs[0].sh_addr != 0) {
3056 pr_err("ELF Spec violation: section 0 type(%d)!=SH_NULL or non-zero len or addr\n",
3057 info->sechdrs[0].sh_type);
3061 for (i = 1; i < info->hdr->e_shnum; i++) {
3062 shdr = &info->sechdrs[i];
3063 switch (shdr->sh_type) {
3068 if (shdr->sh_link == SHN_UNDEF
3069 || shdr->sh_link >= info->hdr->e_shnum) {
3070 pr_err("Invalid ELF sh_link!=SHN_UNDEF(%d) or (sh_link(%d) >= hdr->e_shnum(%d)\n",
3071 shdr->sh_link, shdr->sh_link,
3072 info->hdr->e_shnum);
3077 err = validate_section_offset(info, shdr);
3079 pr_err("Invalid ELF section in module (section %u type %u)\n",
3084 if (shdr->sh_flags & SHF_ALLOC) {
3085 if (shdr->sh_name >= strhdr->sh_size) {
3086 pr_err("Invalid ELF section name in module (section %u type %u)\n",
3101 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
3103 static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
3106 unsigned long n = min(len, COPY_CHUNK_SIZE);
3108 if (copy_from_user(dst, usrc, n) != 0)
3118 #ifdef CONFIG_LIVEPATCH
3119 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
3121 if (get_modinfo(info, "livepatch")) {
3123 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
3124 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
3130 #else /* !CONFIG_LIVEPATCH */
3131 static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
3133 if (get_modinfo(info, "livepatch")) {
3134 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
3141 #endif /* CONFIG_LIVEPATCH */
3143 static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
3145 if (retpoline_module_ok(get_modinfo(info, "retpoline")))
3148 pr_warn("%s: loading module not compiled with retpoline compiler.\n",
3152 /* Sets info->hdr and info->len. */
3153 static int copy_module_from_user(const void __user *umod, unsigned long len,
3154 struct load_info *info)
3159 if (info->len < sizeof(*(info->hdr)))
3162 err = security_kernel_load_data(LOADING_MODULE, true);
3166 /* Suck in entire file: we'll want most of it. */
3167 info->hdr = __vmalloc(info->len, GFP_KERNEL | __GFP_NOWARN);
3171 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
3176 err = security_kernel_post_load_data((char *)info->hdr, info->len,
3177 LOADING_MODULE, "init_module");
3185 static void free_copy(struct load_info *info)
3190 static int rewrite_section_headers(struct load_info *info, int flags)
3194 /* This should always be true, but let's be sure. */
3195 info->sechdrs[0].sh_addr = 0;
3197 for (i = 1; i < info->hdr->e_shnum; i++) {
3198 Elf_Shdr *shdr = &info->sechdrs[i];
3201 * Mark all sections sh_addr with their address in the
3204 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
3208 /* Track but don't keep modinfo and version sections. */
3209 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
3210 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
3216 * Set up our basic convenience variables (pointers to section headers,
3217 * search for module section index etc), and do some basic section
3220 * Set info->mod to the temporary copy of the module in info->hdr. The final one
3221 * will be allocated in move_module().
3223 static int setup_load_info(struct load_info *info, int flags)
3227 /* Try to find a name early so we can log errors with a module name */
3228 info->index.info = find_sec(info, ".modinfo");
3229 if (info->index.info)
3230 info->name = get_modinfo(info, "name");
3232 /* Find internal symbols and strings. */
3233 for (i = 1; i < info->hdr->e_shnum; i++) {
3234 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
3235 info->index.sym = i;
3236 info->index.str = info->sechdrs[i].sh_link;
3237 info->strtab = (char *)info->hdr
3238 + info->sechdrs[info->index.str].sh_offset;
3243 if (info->index.sym == 0) {
3244 pr_warn("%s: module has no symbols (stripped?)\n",
3245 info->name ?: "(missing .modinfo section or name field)");
3249 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
3250 if (!info->index.mod) {
3251 pr_warn("%s: No module found in object\n",
3252 info->name ?: "(missing .modinfo section or name field)");
3255 /* This is temporary: point mod into copy of data. */
3256 info->mod = (void *)info->hdr + info->sechdrs[info->index.mod].sh_offset;
3259 * If we didn't load the .modinfo 'name' field earlier, fall back to
3260 * on-disk struct mod 'name' field.
3263 info->name = info->mod->name;
3265 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
3266 info->index.vers = 0; /* Pretend no __versions section! */
3268 info->index.vers = find_sec(info, "__versions");
3270 info->index.pcpu = find_pcpusec(info);
3275 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
3277 const char *modmagic = get_modinfo(info, "vermagic");
3280 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
3283 /* This is allowed: modprobe --force will invalidate it. */
3285 err = try_to_force_load(mod, "bad vermagic");
3288 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
3289 pr_err("%s: version magic '%s' should be '%s'\n",
3290 info->name, modmagic, vermagic);
3294 if (!get_modinfo(info, "intree")) {
3295 if (!test_taint(TAINT_OOT_MODULE))
3296 pr_warn("%s: loading out-of-tree module taints kernel.\n",
3298 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
3301 check_modinfo_retpoline(mod, info);
3303 if (get_modinfo(info, "staging")) {
3304 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
3305 pr_warn("%s: module is from the staging directory, the quality "
3306 "is unknown, you have been warned.\n", mod->name);
3309 err = check_modinfo_livepatch(mod, info);
3313 /* Set up license info based on the info section */
3314 set_license(mod, get_modinfo(info, "license"));
3319 static int find_module_sections(struct module *mod, struct load_info *info)
3321 mod->kp = section_objs(info, "__param",
3322 sizeof(*mod->kp), &mod->num_kp);
3323 mod->syms = section_objs(info, "__ksymtab",
3324 sizeof(*mod->syms), &mod->num_syms);
3325 mod->crcs = section_addr(info, "__kcrctab");
3326 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
3327 sizeof(*mod->gpl_syms),
3328 &mod->num_gpl_syms);
3329 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
3331 #ifdef CONFIG_CONSTRUCTORS
3332 mod->ctors = section_objs(info, ".ctors",
3333 sizeof(*mod->ctors), &mod->num_ctors);
3335 mod->ctors = section_objs(info, ".init_array",
3336 sizeof(*mod->ctors), &mod->num_ctors);
3337 else if (find_sec(info, ".init_array")) {
3339 * This shouldn't happen with same compiler and binutils
3340 * building all parts of the module.
3342 pr_warn("%s: has both .ctors and .init_array.\n",
3348 mod->noinstr_text_start = section_objs(info, ".noinstr.text", 1,
3349 &mod->noinstr_text_size);
3351 #ifdef CONFIG_TRACEPOINTS
3352 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
3353 sizeof(*mod->tracepoints_ptrs),
3354 &mod->num_tracepoints);
3356 #ifdef CONFIG_TREE_SRCU
3357 mod->srcu_struct_ptrs = section_objs(info, "___srcu_struct_ptrs",
3358 sizeof(*mod->srcu_struct_ptrs),
3359 &mod->num_srcu_structs);
3361 #ifdef CONFIG_BPF_EVENTS
3362 mod->bpf_raw_events = section_objs(info, "__bpf_raw_tp_map",
3363 sizeof(*mod->bpf_raw_events),
3364 &mod->num_bpf_raw_events);
3366 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
3367 mod->btf_data = any_section_objs(info, ".BTF", 1, &mod->btf_data_size);
3369 #ifdef CONFIG_JUMP_LABEL
3370 mod->jump_entries = section_objs(info, "__jump_table",
3371 sizeof(*mod->jump_entries),
3372 &mod->num_jump_entries);
3374 #ifdef CONFIG_EVENT_TRACING
3375 mod->trace_events = section_objs(info, "_ftrace_events",
3376 sizeof(*mod->trace_events),
3377 &mod->num_trace_events);
3378 mod->trace_evals = section_objs(info, "_ftrace_eval_map",
3379 sizeof(*mod->trace_evals),
3380 &mod->num_trace_evals);
3382 #ifdef CONFIG_TRACING
3383 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
3384 sizeof(*mod->trace_bprintk_fmt_start),
3385 &mod->num_trace_bprintk_fmt);
3387 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
3388 /* sechdrs[0].sh_size is always zero */
3389 mod->ftrace_callsites = section_objs(info, FTRACE_CALLSITE_SECTION,
3390 sizeof(*mod->ftrace_callsites),
3391 &mod->num_ftrace_callsites);
3393 #ifdef CONFIG_FUNCTION_ERROR_INJECTION
3394 mod->ei_funcs = section_objs(info, "_error_injection_whitelist",
3395 sizeof(*mod->ei_funcs),
3396 &mod->num_ei_funcs);
3398 #ifdef CONFIG_KPROBES
3399 mod->kprobes_text_start = section_objs(info, ".kprobes.text", 1,
3400 &mod->kprobes_text_size);
3401 mod->kprobe_blacklist = section_objs(info, "_kprobe_blacklist",
3402 sizeof(unsigned long),
3403 &mod->num_kprobe_blacklist);
3405 #ifdef CONFIG_PRINTK_INDEX
3406 mod->printk_index_start = section_objs(info, ".printk_index",
3407 sizeof(*mod->printk_index_start),
3408 &mod->printk_index_size);
3410 #ifdef CONFIG_HAVE_STATIC_CALL_INLINE
3411 mod->static_call_sites = section_objs(info, ".static_call_sites",
3412 sizeof(*mod->static_call_sites),
3413 &mod->num_static_call_sites);
3415 mod->extable = section_objs(info, "__ex_table",
3416 sizeof(*mod->extable), &mod->num_exentries);
3418 if (section_addr(info, "__obsparm"))
3419 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
3421 info->debug = section_objs(info, "__dyndbg",
3422 sizeof(*info->debug), &info->num_debug);
3427 static int move_module(struct module *mod, struct load_info *info)
3432 /* Do the allocs. */
3433 ptr = module_alloc(mod->core_layout.size);
3435 * The pointer to this block is stored in the module structure
3436 * which is inside the block. Just mark it as not being a
3439 kmemleak_not_leak(ptr);
3443 memset(ptr, 0, mod->core_layout.size);
3444 mod->core_layout.base = ptr;
3446 if (mod->init_layout.size) {
3447 ptr = module_alloc(mod->init_layout.size);
3449 * The pointer to this block is stored in the module structure
3450 * which is inside the block. This block doesn't need to be
3451 * scanned as it contains data and code that will be freed
3452 * after the module is initialized.
3454 kmemleak_ignore(ptr);
3456 module_memfree(mod->core_layout.base);
3459 memset(ptr, 0, mod->init_layout.size);
3460 mod->init_layout.base = ptr;
3462 mod->init_layout.base = NULL;
3464 /* Transfer each section which specifies SHF_ALLOC */
3465 pr_debug("final section addresses:\n");
3466 for (i = 0; i < info->hdr->e_shnum; i++) {
3468 Elf_Shdr *shdr = &info->sechdrs[i];
3470 if (!(shdr->sh_flags & SHF_ALLOC))
3473 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3474 dest = mod->init_layout.base
3475 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3477 dest = mod->core_layout.base + shdr->sh_entsize;
3479 if (shdr->sh_type != SHT_NOBITS)
3480 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3481 /* Update sh_addr to point to copy in image. */
3482 shdr->sh_addr = (unsigned long)dest;
3483 pr_debug("\t0x%lx %s\n",
3484 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3490 static int check_module_license_and_versions(struct module *mod)
3492 int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
3495 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3496 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3497 * using GPL-only symbols it needs.
3499 if (strcmp(mod->name, "ndiswrapper") == 0)
3500 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3502 /* driverloader was caught wrongly pretending to be under GPL */
3503 if (strcmp(mod->name, "driverloader") == 0)
3504 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3505 LOCKDEP_NOW_UNRELIABLE);
3507 /* lve claims to be GPL but upstream won't provide source */
3508 if (strcmp(mod->name, "lve") == 0)
3509 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3510 LOCKDEP_NOW_UNRELIABLE);
3512 if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
3513 pr_warn("%s: module license taints kernel.\n", mod->name);
3515 #ifdef CONFIG_MODVERSIONS
3516 if ((mod->num_syms && !mod->crcs) ||
3517 (mod->num_gpl_syms && !mod->gpl_crcs)) {
3518 return try_to_force_load(mod,
3519 "no versions for exported symbols");
3525 static void flush_module_icache(const struct module *mod)
3528 * Flush the instruction cache, since we've played with text.
3529 * Do it before processing of module parameters, so the module
3530 * can provide parameter accessor functions of its own.
3532 if (mod->init_layout.base)
3533 flush_icache_range((unsigned long)mod->init_layout.base,
3534 (unsigned long)mod->init_layout.base
3535 + mod->init_layout.size);
3536 flush_icache_range((unsigned long)mod->core_layout.base,
3537 (unsigned long)mod->core_layout.base + mod->core_layout.size);
3540 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3548 /* module_blacklist is a comma-separated list of module names */
3549 static char *module_blacklist;
3550 static bool blacklisted(const char *module_name)
3555 if (!module_blacklist)
3558 for (p = module_blacklist; *p; p += len) {
3559 len = strcspn(p, ",");
3560 if (strlen(module_name) == len && !memcmp(module_name, p, len))
3567 core_param(module_blacklist, module_blacklist, charp, 0400);
3569 static struct module *layout_and_allocate(struct load_info *info, int flags)
3575 err = check_modinfo(info->mod, info, flags);
3577 return ERR_PTR(err);
3579 /* Allow arches to frob section contents and sizes. */
3580 err = module_frob_arch_sections(info->hdr, info->sechdrs,
3581 info->secstrings, info->mod);
3583 return ERR_PTR(err);
3585 err = module_enforce_rwx_sections(info->hdr, info->sechdrs,
3586 info->secstrings, info->mod);
3588 return ERR_PTR(err);
3590 /* We will do a special allocation for per-cpu sections later. */
3591 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3594 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3595 * layout_sections() can put it in the right place.
3596 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3598 ndx = find_sec(info, ".data..ro_after_init");
3600 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3602 * Mark the __jump_table section as ro_after_init as well: these data
3603 * structures are never modified, with the exception of entries that
3604 * refer to code in the __init section, which are annotated as such
3605 * at module load time.
3607 ndx = find_sec(info, "__jump_table");
3609 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3612 * Determine total sizes, and put offsets in sh_entsize. For now
3613 * this is done generically; there doesn't appear to be any
3614 * special cases for the architectures.
3616 layout_sections(info->mod, info);
3617 layout_symtab(info->mod, info);
3619 /* Allocate and move to the final place */
3620 err = move_module(info->mod, info);
3622 return ERR_PTR(err);
3624 /* Module has been copied to its final place now: return it. */
3625 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3626 kmemleak_load_module(mod, info);
3630 /* mod is no longer valid after this! */
3631 static void module_deallocate(struct module *mod, struct load_info *info)
3633 percpu_modfree(mod);
3634 module_arch_freeing_init(mod);
3635 module_memfree(mod->init_layout.base);
3636 module_memfree(mod->core_layout.base);
3639 int __weak module_finalize(const Elf_Ehdr *hdr,
3640 const Elf_Shdr *sechdrs,
3646 static int post_relocation(struct module *mod, const struct load_info *info)
3648 /* Sort exception table now relocations are done. */
3649 sort_extable(mod->extable, mod->extable + mod->num_exentries);
3651 /* Copy relocated percpu area over. */
3652 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3653 info->sechdrs[info->index.pcpu].sh_size);
3655 /* Setup kallsyms-specific fields. */
3656 add_kallsyms(mod, info);
3658 /* Arch-specific module finalizing. */
3659 return module_finalize(info->hdr, info->sechdrs, mod);
3662 /* Is this module of this name done loading? No locks held. */
3663 static bool finished_loading(const char *name)
3669 * The module_mutex should not be a heavily contended lock;
3670 * if we get the occasional sleep here, we'll go an extra iteration
3671 * in the wait_event_interruptible(), which is harmless.
3673 sched_annotate_sleep();
3674 mutex_lock(&module_mutex);
3675 mod = find_module_all(name, strlen(name), true);
3676 ret = !mod || mod->state == MODULE_STATE_LIVE
3677 || mod->state == MODULE_STATE_GOING;
3678 mutex_unlock(&module_mutex);
3683 /* Call module constructors. */
3684 static void do_mod_ctors(struct module *mod)
3686 #ifdef CONFIG_CONSTRUCTORS
3689 for (i = 0; i < mod->num_ctors; i++)
3694 /* For freeing module_init on success, in case kallsyms traversing */
3695 struct mod_initfree {
3696 struct llist_node node;
3700 static void do_free_init(struct work_struct *w)
3702 struct llist_node *pos, *n, *list;
3703 struct mod_initfree *initfree;
3705 list = llist_del_all(&init_free_list);
3709 llist_for_each_safe(pos, n, list) {
3710 initfree = container_of(pos, struct mod_initfree, node);
3711 module_memfree(initfree->module_init);
3717 * This is where the real work happens.
3719 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3720 * helper command 'lx-symbols'.
3722 static noinline int do_init_module(struct module *mod)
3725 struct mod_initfree *freeinit;
3727 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3732 freeinit->module_init = mod->init_layout.base;
3735 /* Start the module */
3736 if (mod->init != NULL)
3737 ret = do_one_initcall(mod->init);
3739 goto fail_free_freeinit;
3742 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3743 "follow 0/-E convention\n"
3744 "%s: loading module anyway...\n",
3745 __func__, mod->name, ret, __func__);
3749 /* Now it's a first class citizen! */
3750 mod->state = MODULE_STATE_LIVE;
3751 blocking_notifier_call_chain(&module_notify_list,
3752 MODULE_STATE_LIVE, mod);
3754 /* Delay uevent until module has finished its init routine */
3755 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
3758 * We need to finish all async code before the module init sequence
3759 * is done. This has potential to deadlock if synchronous module
3760 * loading is requested from async (which is not allowed!).
3762 * See commit 0fdff3ec6d87 ("async, kmod: warn on synchronous
3763 * request_module() from async workers") for more details.
3765 if (!mod->async_probe_requested)
3766 async_synchronize_full();
3768 ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base +
3769 mod->init_layout.size);
3770 mutex_lock(&module_mutex);
3771 /* Drop initial reference. */
3773 trim_init_extable(mod);
3774 #ifdef CONFIG_KALLSYMS
3775 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3776 rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3778 module_enable_ro(mod, true);
3779 mod_tree_remove_init(mod);
3780 module_arch_freeing_init(mod);
3781 mod->init_layout.base = NULL;
3782 mod->init_layout.size = 0;
3783 mod->init_layout.ro_size = 0;
3784 mod->init_layout.ro_after_init_size = 0;
3785 mod->init_layout.text_size = 0;
3786 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
3787 /* .BTF is not SHF_ALLOC and will get removed, so sanitize pointer */
3788 mod->btf_data = NULL;
3791 * We want to free module_init, but be aware that kallsyms may be
3792 * walking this with preempt disabled. In all the failure paths, we
3793 * call synchronize_rcu(), but we don't want to slow down the success
3794 * path. module_memfree() cannot be called in an interrupt, so do the
3795 * work and call synchronize_rcu() in a work queue.
3797 * Note that module_alloc() on most architectures creates W+X page
3798 * mappings which won't be cleaned up until do_free_init() runs. Any
3799 * code such as mark_rodata_ro() which depends on those mappings to
3800 * be cleaned up needs to sync with the queued work - ie
3803 if (llist_add(&freeinit->node, &init_free_list))
3804 schedule_work(&init_free_wq);
3806 mutex_unlock(&module_mutex);
3807 wake_up_all(&module_wq);
3814 /* Try to protect us from buggy refcounters. */
3815 mod->state = MODULE_STATE_GOING;
3818 blocking_notifier_call_chain(&module_notify_list,
3819 MODULE_STATE_GOING, mod);
3820 klp_module_going(mod);
3821 ftrace_release_mod(mod);
3823 wake_up_all(&module_wq);
3827 static int may_init_module(void)
3829 if (!capable(CAP_SYS_MODULE) || modules_disabled)
3836 * We try to place it in the list now to make sure it's unique before
3837 * we dedicate too many resources. In particular, temporary percpu
3838 * memory exhaustion.
3840 static int add_unformed_module(struct module *mod)
3845 mod->state = MODULE_STATE_UNFORMED;
3847 mutex_lock(&module_mutex);
3848 old = find_module_all(mod->name, strlen(mod->name), true);
3850 if (old->state == MODULE_STATE_COMING
3851 || old->state == MODULE_STATE_UNFORMED) {
3852 /* Wait in case it fails to load. */
3853 mutex_unlock(&module_mutex);
3854 err = wait_event_interruptible(module_wq,
3855 finished_loading(mod->name));
3859 /* The module might have gone in the meantime. */
3860 mutex_lock(&module_mutex);
3861 old = find_module_all(mod->name, strlen(mod->name),
3866 * We are here only when the same module was being loaded. Do
3867 * not try to load it again right now. It prevents long delays
3868 * caused by serialized module load failures. It might happen
3869 * when more devices of the same type trigger load of
3870 * a particular module.
3872 if (old && old->state == MODULE_STATE_LIVE)
3878 mod_update_bounds(mod);
3879 list_add_rcu(&mod->list, &modules);
3880 mod_tree_insert(mod);
3884 mutex_unlock(&module_mutex);
3889 static int complete_formation(struct module *mod, struct load_info *info)
3893 mutex_lock(&module_mutex);
3895 /* Find duplicate symbols (must be called under lock). */
3896 err = verify_exported_symbols(mod);
3900 /* This relies on module_mutex for list integrity. */
3901 module_bug_finalize(info->hdr, info->sechdrs, mod);
3903 module_enable_ro(mod, false);
3904 module_enable_nx(mod);
3905 module_enable_x(mod);
3908 * Mark state as coming so strong_try_module_get() ignores us,
3909 * but kallsyms etc. can see us.
3911 mod->state = MODULE_STATE_COMING;
3912 mutex_unlock(&module_mutex);
3917 mutex_unlock(&module_mutex);
3921 static int prepare_coming_module(struct module *mod)
3925 ftrace_module_enable(mod);
3926 err = klp_module_coming(mod);
3930 err = blocking_notifier_call_chain_robust(&module_notify_list,
3931 MODULE_STATE_COMING, MODULE_STATE_GOING, mod);
3932 err = notifier_to_errno(err);
3934 klp_module_going(mod);
3939 static int unknown_module_param_cb(char *param, char *val, const char *modname,
3942 struct module *mod = arg;
3945 if (strcmp(param, "async_probe") == 0) {
3946 mod->async_probe_requested = true;
3950 /* Check for magic 'dyndbg' arg */
3951 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3953 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3957 static void cfi_init(struct module *mod);
3960 * Allocate and load the module: note that size of section 0 is always
3961 * zero, and we rely on this for optional sections.
3963 static int load_module(struct load_info *info, const char __user *uargs,
3971 * Do the signature check (if any) first. All that
3972 * the signature check needs is info->len, it does
3973 * not need any of the section info. That can be
3974 * set up later. This will minimize the chances
3975 * of a corrupt module causing problems before
3976 * we even get to the signature check.
3978 * The check will also adjust info->len by stripping
3979 * off the sig length at the end of the module, making
3980 * checks against info->len more correct.
3982 err = module_sig_check(info, flags);
3987 * Do basic sanity checks against the ELF header and
3990 err = elf_validity_check(info);
3995 * Everything checks out, so set up the section info
3996 * in the info structure.
3998 err = setup_load_info(info, flags);
4003 * Now that we know we have the correct module name, check
4004 * if it's blacklisted.
4006 if (blacklisted(info->name)) {
4008 pr_err("Module %s is blacklisted\n", info->name);
4012 err = rewrite_section_headers(info, flags);
4016 /* Check module struct version now, before we try to use module. */
4017 if (!check_modstruct_version(info, info->mod)) {
4022 /* Figure out module layout, and allocate all the memory. */
4023 mod = layout_and_allocate(info, flags);
4029 audit_log_kern_module(mod->name);
4031 /* Reserve our place in the list. */
4032 err = add_unformed_module(mod);
4036 #ifdef CONFIG_MODULE_SIG
4037 mod->sig_ok = info->sig_ok;
4039 pr_notice_once("%s: module verification failed: signature "
4040 "and/or required key missing - tainting "
4041 "kernel\n", mod->name);
4042 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
4046 /* To avoid stressing percpu allocator, do this once we're unique. */
4047 err = percpu_modalloc(mod, info);
4051 /* Now module is in final location, initialize linked lists, etc. */
4052 err = module_unload_init(mod);
4056 init_param_lock(mod);
4059 * Now we've got everything in the final locations, we can
4060 * find optional sections.
4062 err = find_module_sections(mod, info);
4066 err = check_module_license_and_versions(mod);
4070 /* Set up MODINFO_ATTR fields */
4071 setup_modinfo(mod, info);
4073 /* Fix up syms, so that st_value is a pointer to location. */
4074 err = simplify_symbols(mod, info);
4078 err = apply_relocations(mod, info);
4082 err = post_relocation(mod, info);
4086 flush_module_icache(mod);
4088 /* Setup CFI for the module. */
4091 /* Now copy in args */
4092 mod->args = strndup_user(uargs, ~0UL >> 1);
4093 if (IS_ERR(mod->args)) {
4094 err = PTR_ERR(mod->args);
4095 goto free_arch_cleanup;
4098 init_build_id(mod, info);
4099 dynamic_debug_setup(mod, info->debug, info->num_debug);
4101 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
4102 ftrace_module_init(mod);
4104 /* Finally it's fully formed, ready to start executing. */
4105 err = complete_formation(mod, info);
4107 goto ddebug_cleanup;
4109 err = prepare_coming_module(mod);
4113 /* Module is ready to execute: parsing args may do that. */
4114 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
4116 unknown_module_param_cb);
4117 if (IS_ERR(after_dashes)) {
4118 err = PTR_ERR(after_dashes);
4119 goto coming_cleanup;
4120 } else if (after_dashes) {
4121 pr_warn("%s: parameters '%s' after `--' ignored\n",
4122 mod->name, after_dashes);
4125 /* Link in to sysfs. */
4126 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
4128 goto coming_cleanup;
4130 if (is_livepatch_module(mod)) {
4131 err = copy_module_elf(mod, info);
4136 /* Get rid of temporary copy. */
4140 trace_module_load(mod);
4142 return do_init_module(mod);
4145 mod_sysfs_teardown(mod);
4147 mod->state = MODULE_STATE_GOING;
4148 destroy_params(mod->kp, mod->num_kp);
4149 blocking_notifier_call_chain(&module_notify_list,
4150 MODULE_STATE_GOING, mod);
4151 klp_module_going(mod);
4153 mod->state = MODULE_STATE_GOING;
4154 /* module_bug_cleanup needs module_mutex protection */
4155 mutex_lock(&module_mutex);
4156 module_bug_cleanup(mod);
4157 mutex_unlock(&module_mutex);
4160 ftrace_release_mod(mod);
4161 dynamic_debug_remove(mod, info->debug);
4166 module_arch_cleanup(mod);
4170 module_unload_free(mod);
4172 mutex_lock(&module_mutex);
4173 /* Unlink carefully: kallsyms could be walking list. */
4174 list_del_rcu(&mod->list);
4175 mod_tree_remove(mod);
4176 wake_up_all(&module_wq);
4177 /* Wait for RCU-sched synchronizing before releasing mod->list. */
4179 mutex_unlock(&module_mutex);
4181 /* Free lock-classes; relies on the preceding sync_rcu() */
4182 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
4184 module_deallocate(mod, info);
4190 SYSCALL_DEFINE3(init_module, void __user *, umod,
4191 unsigned long, len, const char __user *, uargs)
4194 struct load_info info = { };
4196 err = may_init_module();
4200 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
4203 err = copy_module_from_user(umod, len, &info);
4207 return load_module(&info, uargs, 0);
4210 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
4212 struct load_info info = { };
4216 err = may_init_module();
4220 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
4222 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
4223 |MODULE_INIT_IGNORE_VERMAGIC))
4226 err = kernel_read_file_from_fd(fd, 0, &hdr, INT_MAX, NULL,
4233 return load_module(&info, uargs, flags);
4236 static inline int within(unsigned long addr, void *start, unsigned long size)
4238 return ((void *)addr >= start && (void *)addr < start + size);
4241 #ifdef CONFIG_KALLSYMS
4243 * This ignores the intensely annoying "mapping symbols" found
4244 * in ARM ELF files: $a, $t and $d.
4246 static inline int is_arm_mapping_symbol(const char *str)
4248 if (str[0] == '.' && str[1] == 'L')
4250 return str[0] == '$' && strchr("axtd", str[1])
4251 && (str[2] == '\0' || str[2] == '.');
4254 static const char *kallsyms_symbol_name(struct mod_kallsyms *kallsyms, unsigned int symnum)
4256 return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
4260 * Given a module and address, find the corresponding symbol and return its name
4261 * while providing its size and offset if needed.
4263 static const char *find_kallsyms_symbol(struct module *mod,
4265 unsigned long *size,
4266 unsigned long *offset)
4268 unsigned int i, best = 0;
4269 unsigned long nextval, bestval;
4270 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4272 /* At worse, next value is at end of module */
4273 if (within_module_init(addr, mod))
4274 nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
4276 nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
4278 bestval = kallsyms_symbol_value(&kallsyms->symtab[best]);
4281 * Scan for closest preceding symbol, and next symbol. (ELF
4282 * starts real symbols at 1).
4284 for (i = 1; i < kallsyms->num_symtab; i++) {
4285 const Elf_Sym *sym = &kallsyms->symtab[i];
4286 unsigned long thisval = kallsyms_symbol_value(sym);
4288 if (sym->st_shndx == SHN_UNDEF)
4292 * We ignore unnamed symbols: they're uninformative
4293 * and inserted at a whim.
4295 if (*kallsyms_symbol_name(kallsyms, i) == '\0'
4296 || is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms, i)))
4299 if (thisval <= addr && thisval > bestval) {
4303 if (thisval > addr && thisval < nextval)
4311 *size = nextval - bestval;
4313 *offset = addr - bestval;
4315 return kallsyms_symbol_name(kallsyms, best);
4318 void * __weak dereference_module_function_descriptor(struct module *mod,
4325 * For kallsyms to ask for address resolution. NULL means not found. Careful
4326 * not to lock to avoid deadlock on oopses, simply disable preemption.
4328 const char *module_address_lookup(unsigned long addr,
4329 unsigned long *size,
4330 unsigned long *offset,
4332 const unsigned char **modbuildid,
4335 const char *ret = NULL;
4339 mod = __module_address(addr);
4342 *modname = mod->name;
4344 #if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
4345 *modbuildid = mod->build_id;
4351 ret = find_kallsyms_symbol(mod, addr, size, offset);
4353 /* Make a copy in here where it's safe */
4355 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
4363 int lookup_module_symbol_name(unsigned long addr, char *symname)
4368 list_for_each_entry_rcu(mod, &modules, list) {
4369 if (mod->state == MODULE_STATE_UNFORMED)
4371 if (within_module(addr, mod)) {
4374 sym = find_kallsyms_symbol(mod, addr, NULL, NULL);
4378 strlcpy(symname, sym, KSYM_NAME_LEN);
4388 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
4389 unsigned long *offset, char *modname, char *name)
4394 list_for_each_entry_rcu(mod, &modules, list) {
4395 if (mod->state == MODULE_STATE_UNFORMED)
4397 if (within_module(addr, mod)) {
4400 sym = find_kallsyms_symbol(mod, addr, size, offset);
4404 strlcpy(modname, mod->name, MODULE_NAME_LEN);
4406 strlcpy(name, sym, KSYM_NAME_LEN);
4416 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
4417 char *name, char *module_name, int *exported)
4422 list_for_each_entry_rcu(mod, &modules, list) {
4423 struct mod_kallsyms *kallsyms;
4425 if (mod->state == MODULE_STATE_UNFORMED)
4427 kallsyms = rcu_dereference_sched(mod->kallsyms);
4428 if (symnum < kallsyms->num_symtab) {
4429 const Elf_Sym *sym = &kallsyms->symtab[symnum];
4431 *value = kallsyms_symbol_value(sym);
4432 *type = kallsyms->typetab[symnum];
4433 strlcpy(name, kallsyms_symbol_name(kallsyms, symnum), KSYM_NAME_LEN);
4434 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
4435 *exported = is_exported(name, *value, mod);
4439 symnum -= kallsyms->num_symtab;
4445 /* Given a module and name of symbol, find and return the symbol's value */
4446 static unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name)
4449 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4451 for (i = 0; i < kallsyms->num_symtab; i++) {
4452 const Elf_Sym *sym = &kallsyms->symtab[i];
4454 if (strcmp(name, kallsyms_symbol_name(kallsyms, i)) == 0 &&
4455 sym->st_shndx != SHN_UNDEF)
4456 return kallsyms_symbol_value(sym);
4461 /* Look for this name: can be of form module:name. */
4462 unsigned long module_kallsyms_lookup_name(const char *name)
4466 unsigned long ret = 0;
4468 /* Don't lock: we're in enough trouble already. */
4470 if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
4471 if ((mod = find_module_all(name, colon - name, false)) != NULL)
4472 ret = find_kallsyms_symbol_value(mod, colon+1);
4474 list_for_each_entry_rcu(mod, &modules, list) {
4475 if (mod->state == MODULE_STATE_UNFORMED)
4477 if ((ret = find_kallsyms_symbol_value(mod, name)) != 0)
4485 #ifdef CONFIG_LIVEPATCH
4486 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
4487 struct module *, unsigned long),
4494 mutex_lock(&module_mutex);
4495 list_for_each_entry(mod, &modules, list) {
4496 /* We hold module_mutex: no need for rcu_dereference_sched */
4497 struct mod_kallsyms *kallsyms = mod->kallsyms;
4499 if (mod->state == MODULE_STATE_UNFORMED)
4501 for (i = 0; i < kallsyms->num_symtab; i++) {
4502 const Elf_Sym *sym = &kallsyms->symtab[i];
4504 if (sym->st_shndx == SHN_UNDEF)
4507 ret = fn(data, kallsyms_symbol_name(kallsyms, i),
4508 mod, kallsyms_symbol_value(sym));
4514 mutex_unlock(&module_mutex);
4517 #endif /* CONFIG_LIVEPATCH */
4518 #endif /* CONFIG_KALLSYMS */
4520 static void cfi_init(struct module *mod)
4522 #ifdef CONFIG_CFI_CLANG
4526 rcu_read_lock_sched();
4527 mod->cfi_check = (cfi_check_fn)
4528 find_kallsyms_symbol_value(mod, "__cfi_check");
4529 init = (initcall_t *)
4530 find_kallsyms_symbol_value(mod, "__cfi_jt_init_module");
4531 exit = (exitcall_t *)
4532 find_kallsyms_symbol_value(mod, "__cfi_jt_cleanup_module");
4533 rcu_read_unlock_sched();
4535 /* Fix init/exit functions to point to the CFI jump table */
4538 #ifdef CONFIG_MODULE_UNLOAD
4543 cfi_module_add(mod, module_addr_min);
4547 static void cfi_cleanup(struct module *mod)
4549 #ifdef CONFIG_CFI_CLANG
4550 cfi_module_remove(mod, module_addr_min);
4554 /* Maximum number of characters written by module_flags() */
4555 #define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
4557 /* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
4558 static char *module_flags(struct module *mod, char *buf)
4562 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
4564 mod->state == MODULE_STATE_GOING ||
4565 mod->state == MODULE_STATE_COMING) {
4567 bx += module_flags_taint(mod, buf + bx);
4568 /* Show a - for module-is-being-unloaded */
4569 if (mod->state == MODULE_STATE_GOING)
4571 /* Show a + for module-is-being-loaded */
4572 if (mod->state == MODULE_STATE_COMING)
4581 #ifdef CONFIG_PROC_FS
4582 /* Called by the /proc file system to return a list of modules. */
4583 static void *m_start(struct seq_file *m, loff_t *pos)
4585 mutex_lock(&module_mutex);
4586 return seq_list_start(&modules, *pos);
4589 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
4591 return seq_list_next(p, &modules, pos);
4594 static void m_stop(struct seq_file *m, void *p)
4596 mutex_unlock(&module_mutex);
4599 static int m_show(struct seq_file *m, void *p)
4601 struct module *mod = list_entry(p, struct module, list);
4602 char buf[MODULE_FLAGS_BUF_SIZE];
4605 /* We always ignore unformed modules. */
4606 if (mod->state == MODULE_STATE_UNFORMED)
4609 seq_printf(m, "%s %u",
4610 mod->name, mod->init_layout.size + mod->core_layout.size);
4611 print_unload_info(m, mod);
4613 /* Informative for users. */
4614 seq_printf(m, " %s",
4615 mod->state == MODULE_STATE_GOING ? "Unloading" :
4616 mod->state == MODULE_STATE_COMING ? "Loading" :
4618 /* Used by oprofile and other similar tools. */
4619 value = m->private ? NULL : mod->core_layout.base;
4620 seq_printf(m, " 0x%px", value);
4624 seq_printf(m, " %s", module_flags(mod, buf));
4631 * Format: modulename size refcount deps address
4633 * Where refcount is a number or -, and deps is a comma-separated list
4636 static const struct seq_operations modules_op = {
4644 * This also sets the "private" pointer to non-NULL if the
4645 * kernel pointers should be hidden (so you can just test
4646 * "m->private" to see if you should keep the values private).
4648 * We use the same logic as for /proc/kallsyms.
4650 static int modules_open(struct inode *inode, struct file *file)
4652 int err = seq_open(file, &modules_op);
4655 struct seq_file *m = file->private_data;
4656 m->private = kallsyms_show_value(file->f_cred) ? NULL : (void *)8ul;
4662 static const struct proc_ops modules_proc_ops = {
4663 .proc_flags = PROC_ENTRY_PERMANENT,
4664 .proc_open = modules_open,
4665 .proc_read = seq_read,
4666 .proc_lseek = seq_lseek,
4667 .proc_release = seq_release,
4670 static int __init proc_modules_init(void)
4672 proc_create("modules", 0, NULL, &modules_proc_ops);
4675 module_init(proc_modules_init);
4678 /* Given an address, look for it in the module exception tables. */
4679 const struct exception_table_entry *search_module_extables(unsigned long addr)
4681 const struct exception_table_entry *e = NULL;
4685 mod = __module_address(addr);
4689 if (!mod->num_exentries)
4692 e = search_extable(mod->extable,
4699 * Now, if we found one, we are running inside it now, hence
4700 * we cannot unload the module, hence no refcnt needed.
4706 * is_module_address() - is this address inside a module?
4707 * @addr: the address to check.
4709 * See is_module_text_address() if you simply want to see if the address
4710 * is code (not data).
4712 bool is_module_address(unsigned long addr)
4717 ret = __module_address(addr) != NULL;
4724 * __module_address() - get the module which contains an address.
4725 * @addr: the address.
4727 * Must be called with preempt disabled or module mutex held so that
4728 * module doesn't get freed during this.
4730 struct module *__module_address(unsigned long addr)
4734 if (addr < module_addr_min || addr > module_addr_max)
4737 module_assert_mutex_or_preempt();
4739 mod = mod_find(addr);
4741 BUG_ON(!within_module(addr, mod));
4742 if (mod->state == MODULE_STATE_UNFORMED)
4749 * is_module_text_address() - is this address inside module code?
4750 * @addr: the address to check.
4752 * See is_module_address() if you simply want to see if the address is
4753 * anywhere in a module. See kernel_text_address() for testing if an
4754 * address corresponds to kernel or module code.
4756 bool is_module_text_address(unsigned long addr)
4761 ret = __module_text_address(addr) != NULL;
4768 * __module_text_address() - get the module whose code contains an address.
4769 * @addr: the address.
4771 * Must be called with preempt disabled or module mutex held so that
4772 * module doesn't get freed during this.
4774 struct module *__module_text_address(unsigned long addr)
4776 struct module *mod = __module_address(addr);
4778 /* Make sure it's within the text section. */
4779 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
4780 && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
4786 /* Don't grab lock, we're oopsing. */
4787 void print_modules(void)
4790 char buf[MODULE_FLAGS_BUF_SIZE];
4792 printk(KERN_DEFAULT "Modules linked in:");
4793 /* Most callers should already have preempt disabled, but make sure */
4795 list_for_each_entry_rcu(mod, &modules, list) {
4796 if (mod->state == MODULE_STATE_UNFORMED)
4798 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4801 if (last_unloaded_module[0])
4802 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4806 #ifdef CONFIG_MODVERSIONS
4808 * Generate the signature for all relevant module structures here.
4809 * If these change, we don't want to try to parse the module.
4811 void module_layout(struct module *mod,
4812 struct modversion_info *ver,
4813 struct kernel_param *kp,
4814 struct kernel_symbol *ks,
4815 struct tracepoint * const *tp)
4818 EXPORT_SYMBOL(module_layout);