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/file.h>
18 #include <linux/sysfs.h>
19 #include <linux/kernel.h>
20 #include <linux/kernel_read_file.h>
21 #include <linux/slab.h>
22 #include <linux/vmalloc.h>
23 #include <linux/elf.h>
24 #include <linux/proc_fs.h>
25 #include <linux/security.h>
26 #include <linux/seq_file.h>
27 #include <linux/syscalls.h>
28 #include <linux/fcntl.h>
29 #include <linux/rcupdate.h>
30 #include <linux/capability.h>
31 #include <linux/cpu.h>
32 #include <linux/moduleparam.h>
33 #include <linux/errno.h>
34 #include <linux/err.h>
35 #include <linux/vermagic.h>
36 #include <linux/notifier.h>
37 #include <linux/sched.h>
38 #include <linux/device.h>
39 #include <linux/string.h>
40 #include <linux/mutex.h>
41 #include <linux/rculist.h>
42 #include <linux/uaccess.h>
43 #include <asm/cacheflush.h>
44 #include <linux/set_memory.h>
45 #include <asm/mmu_context.h>
46 #include <linux/license.h>
47 #include <asm/sections.h>
48 #include <linux/tracepoint.h>
49 #include <linux/ftrace.h>
50 #include <linux/livepatch.h>
51 #include <linux/async.h>
52 #include <linux/percpu.h>
53 #include <linux/kmemleak.h>
54 #include <linux/jump_label.h>
55 #include <linux/pfn.h>
56 #include <linux/bsearch.h>
57 #include <linux/dynamic_debug.h>
58 #include <linux/audit.h>
59 #include <uapi/linux/module.h>
60 #include "module-internal.h"
62 #define CREATE_TRACE_POINTS
63 #include <trace/events/module.h>
65 #ifndef ARCH_SHF_SMALL
66 #define ARCH_SHF_SMALL 0
70 * Modules' sections will be aligned on page boundaries
71 * to ensure complete separation of code and data, but
72 * only when CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y
74 #ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
75 # define debug_align(X) ALIGN(X, PAGE_SIZE)
77 # define debug_align(X) (X)
80 /* If this is set, the section belongs in the init part of the module */
81 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
85 * 1) List of modules (also safely readable with preempt_disable),
86 * 2) module_use links,
87 * 3) module_addr_min/module_addr_max.
88 * (delete and add uses RCU list operations).
90 static DEFINE_MUTEX(module_mutex
);
91 static LIST_HEAD(modules
);
93 /* Work queue for freeing init sections in success case */
94 static void do_free_init(struct work_struct
*w
);
95 static DECLARE_WORK(init_free_wq
, do_free_init
);
96 static LLIST_HEAD(init_free_list
);
98 #ifdef CONFIG_MODULES_TREE_LOOKUP
101 * Use a latched RB-tree for __module_address(); this allows us to use
102 * RCU-sched lookups of the address from any context.
104 * This is conditional on PERF_EVENTS || TRACING because those can really hit
105 * __module_address() hard by doing a lot of stack unwinding; potentially from
109 static __always_inline
unsigned long __mod_tree_val(struct latch_tree_node
*n
)
111 struct module_layout
*layout
= container_of(n
, struct module_layout
, mtn
.node
);
113 return (unsigned long)layout
->base
;
116 static __always_inline
unsigned long __mod_tree_size(struct latch_tree_node
*n
)
118 struct module_layout
*layout
= container_of(n
, struct module_layout
, mtn
.node
);
120 return (unsigned long)layout
->size
;
123 static __always_inline
bool
124 mod_tree_less(struct latch_tree_node
*a
, struct latch_tree_node
*b
)
126 return __mod_tree_val(a
) < __mod_tree_val(b
);
129 static __always_inline
int
130 mod_tree_comp(void *key
, struct latch_tree_node
*n
)
132 unsigned long val
= (unsigned long)key
;
133 unsigned long start
, end
;
135 start
= __mod_tree_val(n
);
139 end
= start
+ __mod_tree_size(n
);
146 static const struct latch_tree_ops mod_tree_ops
= {
147 .less
= mod_tree_less
,
148 .comp
= mod_tree_comp
,
151 static struct mod_tree_root
{
152 struct latch_tree_root root
;
153 unsigned long addr_min
;
154 unsigned long addr_max
;
155 } mod_tree __cacheline_aligned
= {
159 #define module_addr_min mod_tree.addr_min
160 #define module_addr_max mod_tree.addr_max
162 static noinline
void __mod_tree_insert(struct mod_tree_node
*node
)
164 latch_tree_insert(&node
->node
, &mod_tree
.root
, &mod_tree_ops
);
167 static void __mod_tree_remove(struct mod_tree_node
*node
)
169 latch_tree_erase(&node
->node
, &mod_tree
.root
, &mod_tree_ops
);
173 * These modifications: insert, remove_init and remove; are serialized by the
176 static void mod_tree_insert(struct module
*mod
)
178 mod
->core_layout
.mtn
.mod
= mod
;
179 mod
->init_layout
.mtn
.mod
= mod
;
181 __mod_tree_insert(&mod
->core_layout
.mtn
);
182 if (mod
->init_layout
.size
)
183 __mod_tree_insert(&mod
->init_layout
.mtn
);
186 static void mod_tree_remove_init(struct module
*mod
)
188 if (mod
->init_layout
.size
)
189 __mod_tree_remove(&mod
->init_layout
.mtn
);
192 static void mod_tree_remove(struct module
*mod
)
194 __mod_tree_remove(&mod
->core_layout
.mtn
);
195 mod_tree_remove_init(mod
);
198 static struct module
*mod_find(unsigned long addr
)
200 struct latch_tree_node
*ltn
;
202 ltn
= latch_tree_find((void *)addr
, &mod_tree
.root
, &mod_tree_ops
);
206 return container_of(ltn
, struct mod_tree_node
, node
)->mod
;
209 #else /* MODULES_TREE_LOOKUP */
211 static unsigned long module_addr_min
= -1UL, module_addr_max
= 0;
213 static void mod_tree_insert(struct module
*mod
) { }
214 static void mod_tree_remove_init(struct module
*mod
) { }
215 static void mod_tree_remove(struct module
*mod
) { }
217 static struct module
*mod_find(unsigned long addr
)
221 list_for_each_entry_rcu(mod
, &modules
, list
,
222 lockdep_is_held(&module_mutex
)) {
223 if (within_module(addr
, mod
))
230 #endif /* MODULES_TREE_LOOKUP */
233 * Bounds of module text, for speeding up __module_address.
234 * Protected by module_mutex.
236 static void __mod_update_bounds(void *base
, unsigned int size
)
238 unsigned long min
= (unsigned long)base
;
239 unsigned long max
= min
+ size
;
241 if (min
< module_addr_min
)
242 module_addr_min
= min
;
243 if (max
> module_addr_max
)
244 module_addr_max
= max
;
247 static void mod_update_bounds(struct module
*mod
)
249 __mod_update_bounds(mod
->core_layout
.base
, mod
->core_layout
.size
);
250 if (mod
->init_layout
.size
)
251 __mod_update_bounds(mod
->init_layout
.base
, mod
->init_layout
.size
);
254 #ifdef CONFIG_KGDB_KDB
255 struct list_head
*kdb_modules
= &modules
; /* kdb needs the list of modules */
256 #endif /* CONFIG_KGDB_KDB */
258 static void module_assert_mutex_or_preempt(void)
260 #ifdef CONFIG_LOCKDEP
261 if (unlikely(!debug_locks
))
264 WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
265 !lockdep_is_held(&module_mutex
));
269 #ifdef CONFIG_MODULE_SIG
270 static bool sig_enforce
= IS_ENABLED(CONFIG_MODULE_SIG_FORCE
);
271 module_param(sig_enforce
, bool_enable_only
, 0644);
273 void set_module_sig_enforced(void)
278 #define sig_enforce false
282 * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
283 * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
285 bool is_module_sig_enforced(void)
289 EXPORT_SYMBOL(is_module_sig_enforced
);
291 /* Block module loading/unloading? */
292 int modules_disabled
= 0;
293 core_param(nomodule
, modules_disabled
, bint
, 0);
295 /* Waiting for a module to finish initializing? */
296 static DECLARE_WAIT_QUEUE_HEAD(module_wq
);
298 static BLOCKING_NOTIFIER_HEAD(module_notify_list
);
300 int register_module_notifier(struct notifier_block
*nb
)
302 return blocking_notifier_chain_register(&module_notify_list
, nb
);
304 EXPORT_SYMBOL(register_module_notifier
);
306 int unregister_module_notifier(struct notifier_block
*nb
)
308 return blocking_notifier_chain_unregister(&module_notify_list
, nb
);
310 EXPORT_SYMBOL(unregister_module_notifier
);
313 * We require a truly strong try_module_get(): 0 means success.
314 * Otherwise an error is returned due to ongoing or failed
315 * initialization etc.
317 static inline int strong_try_module_get(struct module
*mod
)
319 BUG_ON(mod
&& mod
->state
== MODULE_STATE_UNFORMED
);
320 if (mod
&& mod
->state
== MODULE_STATE_COMING
)
322 if (try_module_get(mod
))
328 static inline void add_taint_module(struct module
*mod
, unsigned flag
,
329 enum lockdep_ok lockdep_ok
)
331 add_taint(flag
, lockdep_ok
);
332 set_bit(flag
, &mod
->taints
);
336 * A thread that wants to hold a reference to a module only while it
337 * is running can call this to safely exit. nfsd and lockd use this.
339 void __noreturn
__module_put_and_exit(struct module
*mod
, long code
)
344 EXPORT_SYMBOL(__module_put_and_exit
);
346 /* Find a module section: 0 means not found. */
347 static unsigned int find_sec(const struct load_info
*info
, const char *name
)
351 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
352 Elf_Shdr
*shdr
= &info
->sechdrs
[i
];
353 /* Alloc bit cleared means "ignore it." */
354 if ((shdr
->sh_flags
& SHF_ALLOC
)
355 && strcmp(info
->secstrings
+ shdr
->sh_name
, name
) == 0)
361 /* Find a module section, or NULL. */
362 static void *section_addr(const struct load_info
*info
, const char *name
)
364 /* Section 0 has sh_addr 0. */
365 return (void *)info
->sechdrs
[find_sec(info
, name
)].sh_addr
;
368 /* Find a module section, or NULL. Fill in number of "objects" in section. */
369 static void *section_objs(const struct load_info
*info
,
374 unsigned int sec
= find_sec(info
, name
);
376 /* Section 0 has sh_addr 0 and sh_size 0. */
377 *num
= info
->sechdrs
[sec
].sh_size
/ object_size
;
378 return (void *)info
->sechdrs
[sec
].sh_addr
;
381 /* Find a module section: 0 means not found. Ignores SHF_ALLOC flag. */
382 static unsigned int find_any_sec(const struct load_info
*info
, const char *name
)
386 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
387 Elf_Shdr
*shdr
= &info
->sechdrs
[i
];
388 if (strcmp(info
->secstrings
+ shdr
->sh_name
, name
) == 0)
395 * Find a module section, or NULL. Fill in number of "objects" in section.
396 * Ignores SHF_ALLOC flag.
398 static __maybe_unused
void *any_section_objs(const struct load_info
*info
,
403 unsigned int sec
= find_any_sec(info
, name
);
405 /* Section 0 has sh_addr 0 and sh_size 0. */
406 *num
= info
->sechdrs
[sec
].sh_size
/ object_size
;
407 return (void *)info
->sechdrs
[sec
].sh_addr
;
410 /* Provided by the linker */
411 extern const struct kernel_symbol __start___ksymtab
[];
412 extern const struct kernel_symbol __stop___ksymtab
[];
413 extern const struct kernel_symbol __start___ksymtab_gpl
[];
414 extern const struct kernel_symbol __stop___ksymtab_gpl
[];
415 extern const s32 __start___kcrctab
[];
416 extern const s32 __start___kcrctab_gpl
[];
418 #ifndef CONFIG_MODVERSIONS
419 #define symversion(base, idx) NULL
421 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
425 const struct kernel_symbol
*start
, *stop
;
433 struct find_symbol_arg
{
440 struct module
*owner
;
442 const struct kernel_symbol
*sym
;
443 enum mod_license license
;
446 static bool check_exported_symbol(const struct symsearch
*syms
,
447 struct module
*owner
,
448 unsigned int symnum
, void *data
)
450 struct find_symbol_arg
*fsa
= data
;
452 if (!fsa
->gplok
&& syms
->license
== GPL_ONLY
)
455 fsa
->crc
= symversion(syms
->crcs
, symnum
);
456 fsa
->sym
= &syms
->start
[symnum
];
457 fsa
->license
= syms
->license
;
461 static unsigned long kernel_symbol_value(const struct kernel_symbol
*sym
)
463 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
464 return (unsigned long)offset_to_ptr(&sym
->value_offset
);
470 static const char *kernel_symbol_name(const struct kernel_symbol
*sym
)
472 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
473 return offset_to_ptr(&sym
->name_offset
);
479 static const char *kernel_symbol_namespace(const struct kernel_symbol
*sym
)
481 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
482 if (!sym
->namespace_offset
)
484 return offset_to_ptr(&sym
->namespace_offset
);
486 return sym
->namespace;
490 static int cmp_name(const void *name
, const void *sym
)
492 return strcmp(name
, kernel_symbol_name(sym
));
495 static bool find_exported_symbol_in_section(const struct symsearch
*syms
,
496 struct module
*owner
,
499 struct find_symbol_arg
*fsa
= data
;
500 struct kernel_symbol
*sym
;
502 sym
= bsearch(fsa
->name
, syms
->start
, syms
->stop
- syms
->start
,
503 sizeof(struct kernel_symbol
), cmp_name
);
505 if (sym
!= NULL
&& check_exported_symbol(syms
, owner
,
506 sym
- syms
->start
, data
))
513 * Find an exported symbol and return it, along with, (optional) crc and
514 * (optional) module which owns it. Needs preempt disabled or module_mutex.
516 static bool find_symbol(struct find_symbol_arg
*fsa
)
518 static const struct symsearch arr
[] = {
519 { __start___ksymtab
, __stop___ksymtab
, __start___kcrctab
,
521 { __start___ksymtab_gpl
, __stop___ksymtab_gpl
,
522 __start___kcrctab_gpl
,
528 module_assert_mutex_or_preempt();
530 for (i
= 0; i
< ARRAY_SIZE(arr
); i
++)
531 if (find_exported_symbol_in_section(&arr
[i
], NULL
, fsa
))
534 list_for_each_entry_rcu(mod
, &modules
, list
,
535 lockdep_is_held(&module_mutex
)) {
536 struct symsearch arr
[] = {
537 { mod
->syms
, mod
->syms
+ mod
->num_syms
, mod
->crcs
,
539 { mod
->gpl_syms
, mod
->gpl_syms
+ mod
->num_gpl_syms
,
544 if (mod
->state
== MODULE_STATE_UNFORMED
)
547 for (i
= 0; i
< ARRAY_SIZE(arr
); i
++)
548 if (find_exported_symbol_in_section(&arr
[i
], mod
, fsa
))
552 pr_debug("Failed to find symbol %s\n", fsa
->name
);
557 * Search for module by name: must hold module_mutex (or preempt disabled
558 * for read-only access).
560 static struct module
*find_module_all(const char *name
, size_t len
,
565 module_assert_mutex_or_preempt();
567 list_for_each_entry_rcu(mod
, &modules
, list
,
568 lockdep_is_held(&module_mutex
)) {
569 if (!even_unformed
&& mod
->state
== MODULE_STATE_UNFORMED
)
571 if (strlen(mod
->name
) == len
&& !memcmp(mod
->name
, name
, len
))
577 struct module
*find_module(const char *name
)
579 return find_module_all(name
, strlen(name
), false);
584 static inline void __percpu
*mod_percpu(struct module
*mod
)
589 static int percpu_modalloc(struct module
*mod
, struct load_info
*info
)
591 Elf_Shdr
*pcpusec
= &info
->sechdrs
[info
->index
.pcpu
];
592 unsigned long align
= pcpusec
->sh_addralign
;
594 if (!pcpusec
->sh_size
)
597 if (align
> PAGE_SIZE
) {
598 pr_warn("%s: per-cpu alignment %li > %li\n",
599 mod
->name
, align
, PAGE_SIZE
);
603 mod
->percpu
= __alloc_reserved_percpu(pcpusec
->sh_size
, align
);
605 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
606 mod
->name
, (unsigned long)pcpusec
->sh_size
);
609 mod
->percpu_size
= pcpusec
->sh_size
;
613 static void percpu_modfree(struct module
*mod
)
615 free_percpu(mod
->percpu
);
618 static unsigned int find_pcpusec(struct load_info
*info
)
620 return find_sec(info
, ".data..percpu");
623 static void percpu_modcopy(struct module
*mod
,
624 const void *from
, unsigned long size
)
628 for_each_possible_cpu(cpu
)
629 memcpy(per_cpu_ptr(mod
->percpu
, cpu
), from
, size
);
632 bool __is_module_percpu_address(unsigned long addr
, unsigned long *can_addr
)
639 list_for_each_entry_rcu(mod
, &modules
, list
) {
640 if (mod
->state
== MODULE_STATE_UNFORMED
)
642 if (!mod
->percpu_size
)
644 for_each_possible_cpu(cpu
) {
645 void *start
= per_cpu_ptr(mod
->percpu
, cpu
);
646 void *va
= (void *)addr
;
648 if (va
>= start
&& va
< start
+ mod
->percpu_size
) {
650 *can_addr
= (unsigned long) (va
- start
);
651 *can_addr
+= (unsigned long)
652 per_cpu_ptr(mod
->percpu
,
666 * is_module_percpu_address() - test whether address is from module static percpu
667 * @addr: address to test
669 * Test whether @addr belongs to module static percpu area.
671 * Return: %true if @addr is from module static percpu area
673 bool is_module_percpu_address(unsigned long addr
)
675 return __is_module_percpu_address(addr
, NULL
);
678 #else /* ... !CONFIG_SMP */
680 static inline void __percpu
*mod_percpu(struct module
*mod
)
684 static int percpu_modalloc(struct module
*mod
, struct load_info
*info
)
686 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
687 if (info
->sechdrs
[info
->index
.pcpu
].sh_size
!= 0)
691 static inline void percpu_modfree(struct module
*mod
)
694 static unsigned int find_pcpusec(struct load_info
*info
)
698 static inline void percpu_modcopy(struct module
*mod
,
699 const void *from
, unsigned long size
)
701 /* pcpusec should be 0, and size of that section should be 0. */
704 bool is_module_percpu_address(unsigned long addr
)
709 bool __is_module_percpu_address(unsigned long addr
, unsigned long *can_addr
)
714 #endif /* CONFIG_SMP */
716 #define MODINFO_ATTR(field) \
717 static void setup_modinfo_##field(struct module *mod, const char *s) \
719 mod->field = kstrdup(s, GFP_KERNEL); \
721 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
722 struct module_kobject *mk, char *buffer) \
724 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
726 static int modinfo_##field##_exists(struct module *mod) \
728 return mod->field != NULL; \
730 static void free_modinfo_##field(struct module *mod) \
735 static struct module_attribute modinfo_##field = { \
736 .attr = { .name = __stringify(field), .mode = 0444 }, \
737 .show = show_modinfo_##field, \
738 .setup = setup_modinfo_##field, \
739 .test = modinfo_##field##_exists, \
740 .free = free_modinfo_##field, \
743 MODINFO_ATTR(version
);
744 MODINFO_ATTR(srcversion
);
746 static char last_unloaded_module
[MODULE_NAME_LEN
+1];
748 #ifdef CONFIG_MODULE_UNLOAD
750 EXPORT_TRACEPOINT_SYMBOL(module_get
);
752 /* MODULE_REF_BASE is the base reference count by kmodule loader. */
753 #define MODULE_REF_BASE 1
755 /* Init the unload section of the module. */
756 static int module_unload_init(struct module
*mod
)
759 * Initialize reference counter to MODULE_REF_BASE.
760 * refcnt == 0 means module is going.
762 atomic_set(&mod
->refcnt
, MODULE_REF_BASE
);
764 INIT_LIST_HEAD(&mod
->source_list
);
765 INIT_LIST_HEAD(&mod
->target_list
);
767 /* Hold reference count during initialization. */
768 atomic_inc(&mod
->refcnt
);
773 /* Does a already use b? */
774 static int already_uses(struct module
*a
, struct module
*b
)
776 struct module_use
*use
;
778 list_for_each_entry(use
, &b
->source_list
, source_list
) {
779 if (use
->source
== a
) {
780 pr_debug("%s uses %s!\n", a
->name
, b
->name
);
784 pr_debug("%s does not use %s!\n", a
->name
, b
->name
);
790 * - we add 'a' as a "source", 'b' as a "target" of module use
791 * - the module_use is added to the list of 'b' sources (so
792 * 'b' can walk the list to see who sourced them), and of 'a'
793 * targets (so 'a' can see what modules it targets).
795 static int add_module_usage(struct module
*a
, struct module
*b
)
797 struct module_use
*use
;
799 pr_debug("Allocating new usage for %s.\n", a
->name
);
800 use
= kmalloc(sizeof(*use
), GFP_ATOMIC
);
806 list_add(&use
->source_list
, &b
->source_list
);
807 list_add(&use
->target_list
, &a
->target_list
);
811 /* Module a uses b: caller needs module_mutex() */
812 static int ref_module(struct module
*a
, struct module
*b
)
816 if (b
== NULL
|| already_uses(a
, b
))
819 /* If module isn't available, we fail. */
820 err
= strong_try_module_get(b
);
824 err
= add_module_usage(a
, b
);
832 /* Clear the unload stuff of the module. */
833 static void module_unload_free(struct module
*mod
)
835 struct module_use
*use
, *tmp
;
837 mutex_lock(&module_mutex
);
838 list_for_each_entry_safe(use
, tmp
, &mod
->target_list
, target_list
) {
839 struct module
*i
= use
->target
;
840 pr_debug("%s unusing %s\n", mod
->name
, i
->name
);
842 list_del(&use
->source_list
);
843 list_del(&use
->target_list
);
846 mutex_unlock(&module_mutex
);
849 #ifdef CONFIG_MODULE_FORCE_UNLOAD
850 static inline int try_force_unload(unsigned int flags
)
852 int ret
= (flags
& O_TRUNC
);
854 add_taint(TAINT_FORCED_RMMOD
, LOCKDEP_NOW_UNRELIABLE
);
858 static inline int try_force_unload(unsigned int flags
)
862 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
864 /* Try to release refcount of module, 0 means success. */
865 static int try_release_module_ref(struct module
*mod
)
869 /* Try to decrement refcnt which we set at loading */
870 ret
= atomic_sub_return(MODULE_REF_BASE
, &mod
->refcnt
);
873 /* Someone can put this right now, recover with checking */
874 ret
= atomic_add_unless(&mod
->refcnt
, MODULE_REF_BASE
, 0);
879 static int try_stop_module(struct module
*mod
, int flags
, int *forced
)
881 /* If it's not unused, quit unless we're forcing. */
882 if (try_release_module_ref(mod
) != 0) {
883 *forced
= try_force_unload(flags
);
888 /* Mark it as dying. */
889 mod
->state
= MODULE_STATE_GOING
;
895 * module_refcount() - return the refcount or -1 if unloading
896 * @mod: the module we're checking
899 * -1 if the module is in the process of unloading
900 * otherwise the number of references in the kernel to the module
902 int module_refcount(struct module
*mod
)
904 return atomic_read(&mod
->refcnt
) - MODULE_REF_BASE
;
906 EXPORT_SYMBOL(module_refcount
);
908 /* This exists whether we can unload or not */
909 static void free_module(struct module
*mod
);
911 SYSCALL_DEFINE2(delete_module
, const char __user
*, name_user
,
915 char name
[MODULE_NAME_LEN
];
918 if (!capable(CAP_SYS_MODULE
) || modules_disabled
)
921 if (strncpy_from_user(name
, name_user
, MODULE_NAME_LEN
-1) < 0)
923 name
[MODULE_NAME_LEN
-1] = '\0';
925 audit_log_kern_module(name
);
927 if (mutex_lock_interruptible(&module_mutex
) != 0)
930 mod
= find_module(name
);
936 if (!list_empty(&mod
->source_list
)) {
937 /* Other modules depend on us: get rid of them first. */
942 /* Doing init or already dying? */
943 if (mod
->state
!= MODULE_STATE_LIVE
) {
944 /* FIXME: if (force), slam module count damn the torpedoes */
945 pr_debug("%s already dying\n", mod
->name
);
950 /* If it has an init func, it must have an exit func to unload */
951 if (mod
->init
&& !mod
->exit
) {
952 forced
= try_force_unload(flags
);
954 /* This module can't be removed */
960 /* Stop the machine so refcounts can't move and disable module. */
961 ret
= try_stop_module(mod
, flags
, &forced
);
965 mutex_unlock(&module_mutex
);
966 /* Final destruction now no one is using it. */
967 if (mod
->exit
!= NULL
)
969 blocking_notifier_call_chain(&module_notify_list
,
970 MODULE_STATE_GOING
, mod
);
971 klp_module_going(mod
);
972 ftrace_release_mod(mod
);
974 async_synchronize_full();
976 /* Store the name of the last unloaded module for diagnostic purposes */
977 strlcpy(last_unloaded_module
, mod
->name
, sizeof(last_unloaded_module
));
980 /* someone could wait for the module in add_unformed_module() */
981 wake_up_all(&module_wq
);
984 mutex_unlock(&module_mutex
);
988 static inline void print_unload_info(struct seq_file
*m
, struct module
*mod
)
990 struct module_use
*use
;
991 int printed_something
= 0;
993 seq_printf(m
, " %i ", module_refcount(mod
));
996 * Always include a trailing , so userspace can differentiate
997 * between this and the old multi-field proc format.
999 list_for_each_entry(use
, &mod
->source_list
, source_list
) {
1000 printed_something
= 1;
1001 seq_printf(m
, "%s,", use
->source
->name
);
1004 if (mod
->init
!= NULL
&& mod
->exit
== NULL
) {
1005 printed_something
= 1;
1006 seq_puts(m
, "[permanent],");
1009 if (!printed_something
)
1013 void __symbol_put(const char *symbol
)
1015 struct find_symbol_arg fsa
= {
1021 if (!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",
1470 * /sys/module/foo/sections stuff
1471 * J. Corbet <corbet@lwn.net>
1475 #ifdef CONFIG_KALLSYMS
1476 static inline bool sect_empty(const Elf_Shdr
*sect
)
1478 return !(sect
->sh_flags
& SHF_ALLOC
) || sect
->sh_size
== 0;
1481 struct module_sect_attr
{
1482 struct bin_attribute battr
;
1483 unsigned long address
;
1486 struct module_sect_attrs
{
1487 struct attribute_group grp
;
1488 unsigned int nsections
;
1489 struct module_sect_attr attrs
[];
1492 #define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4))
1493 static ssize_t
module_sect_read(struct file
*file
, struct kobject
*kobj
,
1494 struct bin_attribute
*battr
,
1495 char *buf
, loff_t pos
, size_t count
)
1497 struct module_sect_attr
*sattr
=
1498 container_of(battr
, struct module_sect_attr
, battr
);
1499 char bounce
[MODULE_SECT_READ_SIZE
+ 1];
1506 * Since we're a binary read handler, we must account for the
1507 * trailing NUL byte that sprintf will write: if "buf" is
1508 * too small to hold the NUL, or the NUL is exactly the last
1509 * byte, the read will look like it got truncated by one byte.
1510 * Since there is no way to ask sprintf nicely to not write
1511 * the NUL, we have to use a bounce buffer.
1513 wrote
= scnprintf(bounce
, sizeof(bounce
), "0x%px\n",
1514 kallsyms_show_value(file
->f_cred
)
1515 ? (void *)sattr
->address
: NULL
);
1516 count
= min(count
, wrote
);
1517 memcpy(buf
, bounce
, count
);
1522 static void free_sect_attrs(struct module_sect_attrs
*sect_attrs
)
1524 unsigned int section
;
1526 for (section
= 0; section
< sect_attrs
->nsections
; section
++)
1527 kfree(sect_attrs
->attrs
[section
].battr
.attr
.name
);
1531 static void add_sect_attrs(struct module
*mod
, const struct load_info
*info
)
1533 unsigned int nloaded
= 0, i
, size
[2];
1534 struct module_sect_attrs
*sect_attrs
;
1535 struct module_sect_attr
*sattr
;
1536 struct bin_attribute
**gattr
;
1538 /* Count loaded sections and allocate structures */
1539 for (i
= 0; i
< info
->hdr
->e_shnum
; i
++)
1540 if (!sect_empty(&info
->sechdrs
[i
]))
1542 size
[0] = ALIGN(struct_size(sect_attrs
, attrs
, nloaded
),
1543 sizeof(sect_attrs
->grp
.bin_attrs
[0]));
1544 size
[1] = (nloaded
+ 1) * sizeof(sect_attrs
->grp
.bin_attrs
[0]);
1545 sect_attrs
= kzalloc(size
[0] + size
[1], GFP_KERNEL
);
1546 if (sect_attrs
== NULL
)
1549 /* Setup section attributes. */
1550 sect_attrs
->grp
.name
= "sections";
1551 sect_attrs
->grp
.bin_attrs
= (void *)sect_attrs
+ size
[0];
1553 sect_attrs
->nsections
= 0;
1554 sattr
= §_attrs
->attrs
[0];
1555 gattr
= §_attrs
->grp
.bin_attrs
[0];
1556 for (i
= 0; i
< info
->hdr
->e_shnum
; i
++) {
1557 Elf_Shdr
*sec
= &info
->sechdrs
[i
];
1558 if (sect_empty(sec
))
1560 sysfs_bin_attr_init(&sattr
->battr
);
1561 sattr
->address
= sec
->sh_addr
;
1562 sattr
->battr
.attr
.name
=
1563 kstrdup(info
->secstrings
+ sec
->sh_name
, GFP_KERNEL
);
1564 if (sattr
->battr
.attr
.name
== NULL
)
1566 sect_attrs
->nsections
++;
1567 sattr
->battr
.read
= module_sect_read
;
1568 sattr
->battr
.size
= MODULE_SECT_READ_SIZE
;
1569 sattr
->battr
.attr
.mode
= 0400;
1570 *(gattr
++) = &(sattr
++)->battr
;
1574 if (sysfs_create_group(&mod
->mkobj
.kobj
, §_attrs
->grp
))
1577 mod
->sect_attrs
= sect_attrs
;
1580 free_sect_attrs(sect_attrs
);
1583 static void remove_sect_attrs(struct module
*mod
)
1585 if (mod
->sect_attrs
) {
1586 sysfs_remove_group(&mod
->mkobj
.kobj
,
1587 &mod
->sect_attrs
->grp
);
1589 * We are positive that no one is using any sect attrs
1590 * at this point. Deallocate immediately.
1592 free_sect_attrs(mod
->sect_attrs
);
1593 mod
->sect_attrs
= NULL
;
1598 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1601 struct module_notes_attrs
{
1602 struct kobject
*dir
;
1604 struct bin_attribute attrs
[];
1607 static ssize_t
module_notes_read(struct file
*filp
, struct kobject
*kobj
,
1608 struct bin_attribute
*bin_attr
,
1609 char *buf
, loff_t pos
, size_t count
)
1612 * The caller checked the pos and count against our size.
1614 memcpy(buf
, bin_attr
->private + pos
, count
);
1618 static void free_notes_attrs(struct module_notes_attrs
*notes_attrs
,
1621 if (notes_attrs
->dir
) {
1623 sysfs_remove_bin_file(notes_attrs
->dir
,
1624 ¬es_attrs
->attrs
[i
]);
1625 kobject_put(notes_attrs
->dir
);
1630 static void add_notes_attrs(struct module
*mod
, const struct load_info
*info
)
1632 unsigned int notes
, loaded
, i
;
1633 struct module_notes_attrs
*notes_attrs
;
1634 struct bin_attribute
*nattr
;
1636 /* failed to create section attributes, so can't create notes */
1637 if (!mod
->sect_attrs
)
1640 /* Count notes sections and allocate structures. */
1642 for (i
= 0; i
< info
->hdr
->e_shnum
; i
++)
1643 if (!sect_empty(&info
->sechdrs
[i
]) &&
1644 (info
->sechdrs
[i
].sh_type
== SHT_NOTE
))
1650 notes_attrs
= kzalloc(struct_size(notes_attrs
, attrs
, notes
),
1652 if (notes_attrs
== NULL
)
1655 notes_attrs
->notes
= notes
;
1656 nattr
= ¬es_attrs
->attrs
[0];
1657 for (loaded
= i
= 0; i
< info
->hdr
->e_shnum
; ++i
) {
1658 if (sect_empty(&info
->sechdrs
[i
]))
1660 if (info
->sechdrs
[i
].sh_type
== SHT_NOTE
) {
1661 sysfs_bin_attr_init(nattr
);
1662 nattr
->attr
.name
= mod
->sect_attrs
->attrs
[loaded
].battr
.attr
.name
;
1663 nattr
->attr
.mode
= S_IRUGO
;
1664 nattr
->size
= info
->sechdrs
[i
].sh_size
;
1665 nattr
->private = (void *) info
->sechdrs
[i
].sh_addr
;
1666 nattr
->read
= module_notes_read
;
1672 notes_attrs
->dir
= kobject_create_and_add("notes", &mod
->mkobj
.kobj
);
1673 if (!notes_attrs
->dir
)
1676 for (i
= 0; i
< notes
; ++i
)
1677 if (sysfs_create_bin_file(notes_attrs
->dir
,
1678 ¬es_attrs
->attrs
[i
]))
1681 mod
->notes_attrs
= notes_attrs
;
1685 free_notes_attrs(notes_attrs
, i
);
1688 static void remove_notes_attrs(struct module
*mod
)
1690 if (mod
->notes_attrs
)
1691 free_notes_attrs(mod
->notes_attrs
, mod
->notes_attrs
->notes
);
1696 static inline void add_sect_attrs(struct module
*mod
,
1697 const struct load_info
*info
)
1701 static inline void remove_sect_attrs(struct module
*mod
)
1705 static inline void add_notes_attrs(struct module
*mod
,
1706 const struct load_info
*info
)
1710 static inline void remove_notes_attrs(struct module
*mod
)
1713 #endif /* CONFIG_KALLSYMS */
1715 static void del_usage_links(struct module
*mod
)
1717 #ifdef CONFIG_MODULE_UNLOAD
1718 struct module_use
*use
;
1720 mutex_lock(&module_mutex
);
1721 list_for_each_entry(use
, &mod
->target_list
, target_list
)
1722 sysfs_remove_link(use
->target
->holders_dir
, mod
->name
);
1723 mutex_unlock(&module_mutex
);
1727 static int add_usage_links(struct module
*mod
)
1730 #ifdef CONFIG_MODULE_UNLOAD
1731 struct module_use
*use
;
1733 mutex_lock(&module_mutex
);
1734 list_for_each_entry(use
, &mod
->target_list
, target_list
) {
1735 ret
= sysfs_create_link(use
->target
->holders_dir
,
1736 &mod
->mkobj
.kobj
, mod
->name
);
1740 mutex_unlock(&module_mutex
);
1742 del_usage_links(mod
);
1747 static void module_remove_modinfo_attrs(struct module
*mod
, int end
);
1749 static int module_add_modinfo_attrs(struct module
*mod
)
1751 struct module_attribute
*attr
;
1752 struct module_attribute
*temp_attr
;
1756 mod
->modinfo_attrs
= kzalloc((sizeof(struct module_attribute
) *
1757 (ARRAY_SIZE(modinfo_attrs
) + 1)),
1759 if (!mod
->modinfo_attrs
)
1762 temp_attr
= mod
->modinfo_attrs
;
1763 for (i
= 0; (attr
= modinfo_attrs
[i
]); i
++) {
1764 if (!attr
->test
|| attr
->test(mod
)) {
1765 memcpy(temp_attr
, attr
, sizeof(*temp_attr
));
1766 sysfs_attr_init(&temp_attr
->attr
);
1767 error
= sysfs_create_file(&mod
->mkobj
.kobj
,
1779 module_remove_modinfo_attrs(mod
, --i
);
1781 kfree(mod
->modinfo_attrs
);
1785 static void module_remove_modinfo_attrs(struct module
*mod
, int end
)
1787 struct module_attribute
*attr
;
1790 for (i
= 0; (attr
= &mod
->modinfo_attrs
[i
]); i
++) {
1791 if (end
>= 0 && i
> end
)
1793 /* pick a field to test for end of list */
1794 if (!attr
->attr
.name
)
1796 sysfs_remove_file(&mod
->mkobj
.kobj
, &attr
->attr
);
1800 kfree(mod
->modinfo_attrs
);
1803 static void mod_kobject_put(struct module
*mod
)
1805 DECLARE_COMPLETION_ONSTACK(c
);
1806 mod
->mkobj
.kobj_completion
= &c
;
1807 kobject_put(&mod
->mkobj
.kobj
);
1808 wait_for_completion(&c
);
1811 static int mod_sysfs_init(struct module
*mod
)
1814 struct kobject
*kobj
;
1816 if (!module_sysfs_initialized
) {
1817 pr_err("%s: module sysfs not initialized\n", mod
->name
);
1822 kobj
= kset_find_obj(module_kset
, mod
->name
);
1824 pr_err("%s: module is already loaded\n", mod
->name
);
1830 mod
->mkobj
.mod
= mod
;
1832 memset(&mod
->mkobj
.kobj
, 0, sizeof(mod
->mkobj
.kobj
));
1833 mod
->mkobj
.kobj
.kset
= module_kset
;
1834 err
= kobject_init_and_add(&mod
->mkobj
.kobj
, &module_ktype
, NULL
,
1837 mod_kobject_put(mod
);
1843 static int mod_sysfs_setup(struct module
*mod
,
1844 const struct load_info
*info
,
1845 struct kernel_param
*kparam
,
1846 unsigned int num_params
)
1850 err
= mod_sysfs_init(mod
);
1854 mod
->holders_dir
= kobject_create_and_add("holders", &mod
->mkobj
.kobj
);
1855 if (!mod
->holders_dir
) {
1860 err
= module_param_sysfs_setup(mod
, kparam
, num_params
);
1862 goto out_unreg_holders
;
1864 err
= module_add_modinfo_attrs(mod
);
1866 goto out_unreg_param
;
1868 err
= add_usage_links(mod
);
1870 goto out_unreg_modinfo_attrs
;
1872 add_sect_attrs(mod
, info
);
1873 add_notes_attrs(mod
, info
);
1877 out_unreg_modinfo_attrs
:
1878 module_remove_modinfo_attrs(mod
, -1);
1880 module_param_sysfs_remove(mod
);
1882 kobject_put(mod
->holders_dir
);
1884 mod_kobject_put(mod
);
1889 static void mod_sysfs_fini(struct module
*mod
)
1891 remove_notes_attrs(mod
);
1892 remove_sect_attrs(mod
);
1893 mod_kobject_put(mod
);
1896 static void init_param_lock(struct module
*mod
)
1898 mutex_init(&mod
->param_lock
);
1900 #else /* !CONFIG_SYSFS */
1902 static int mod_sysfs_setup(struct module
*mod
,
1903 const struct load_info
*info
,
1904 struct kernel_param
*kparam
,
1905 unsigned int num_params
)
1910 static void mod_sysfs_fini(struct module
*mod
)
1914 static void module_remove_modinfo_attrs(struct module
*mod
, int end
)
1918 static void del_usage_links(struct module
*mod
)
1922 static void init_param_lock(struct module
*mod
)
1925 #endif /* CONFIG_SYSFS */
1927 static void mod_sysfs_teardown(struct module
*mod
)
1929 del_usage_links(mod
);
1930 module_remove_modinfo_attrs(mod
, -1);
1931 module_param_sysfs_remove(mod
);
1932 kobject_put(mod
->mkobj
.drivers_dir
);
1933 kobject_put(mod
->holders_dir
);
1934 mod_sysfs_fini(mod
);
1938 * LKM RO/NX protection: protect module's text/ro-data
1939 * from modification and any data from execution.
1941 * General layout of module is:
1942 * [text] [read-only-data] [ro-after-init] [writable data]
1943 * text_size -----^ ^ ^ ^
1944 * ro_size ------------------------| | |
1945 * ro_after_init_size -----------------------------| |
1946 * size -----------------------------------------------------------|
1948 * These values are always page-aligned (as is base)
1952 * Since some arches are moving towards PAGE_KERNEL module allocations instead
1953 * of PAGE_KERNEL_EXEC, keep frob_text() and module_enable_x() outside of the
1954 * CONFIG_STRICT_MODULE_RWX block below because they are needed regardless of
1955 * whether we are strict.
1957 #ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
1958 static void frob_text(const struct module_layout
*layout
,
1959 int (*set_memory
)(unsigned long start
, int num_pages
))
1961 BUG_ON((unsigned long)layout
->base
& (PAGE_SIZE
-1));
1962 BUG_ON((unsigned long)layout
->text_size
& (PAGE_SIZE
-1));
1963 set_memory((unsigned long)layout
->base
,
1964 layout
->text_size
>> PAGE_SHIFT
);
1967 static void module_enable_x(const struct module
*mod
)
1969 frob_text(&mod
->core_layout
, set_memory_x
);
1970 frob_text(&mod
->init_layout
, set_memory_x
);
1972 #else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
1973 static void module_enable_x(const struct module
*mod
) { }
1974 #endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
1976 #ifdef CONFIG_STRICT_MODULE_RWX
1977 static void frob_rodata(const struct module_layout
*layout
,
1978 int (*set_memory
)(unsigned long start
, int num_pages
))
1980 BUG_ON((unsigned long)layout
->base
& (PAGE_SIZE
-1));
1981 BUG_ON((unsigned long)layout
->text_size
& (PAGE_SIZE
-1));
1982 BUG_ON((unsigned long)layout
->ro_size
& (PAGE_SIZE
-1));
1983 set_memory((unsigned long)layout
->base
+ layout
->text_size
,
1984 (layout
->ro_size
- layout
->text_size
) >> PAGE_SHIFT
);
1987 static void frob_ro_after_init(const struct module_layout
*layout
,
1988 int (*set_memory
)(unsigned long start
, int num_pages
))
1990 BUG_ON((unsigned long)layout
->base
& (PAGE_SIZE
-1));
1991 BUG_ON((unsigned long)layout
->ro_size
& (PAGE_SIZE
-1));
1992 BUG_ON((unsigned long)layout
->ro_after_init_size
& (PAGE_SIZE
-1));
1993 set_memory((unsigned long)layout
->base
+ layout
->ro_size
,
1994 (layout
->ro_after_init_size
- layout
->ro_size
) >> PAGE_SHIFT
);
1997 static void frob_writable_data(const struct module_layout
*layout
,
1998 int (*set_memory
)(unsigned long start
, int num_pages
))
2000 BUG_ON((unsigned long)layout
->base
& (PAGE_SIZE
-1));
2001 BUG_ON((unsigned long)layout
->ro_after_init_size
& (PAGE_SIZE
-1));
2002 BUG_ON((unsigned long)layout
->size
& (PAGE_SIZE
-1));
2003 set_memory((unsigned long)layout
->base
+ layout
->ro_after_init_size
,
2004 (layout
->size
- layout
->ro_after_init_size
) >> PAGE_SHIFT
);
2007 static void module_enable_ro(const struct module
*mod
, bool after_init
)
2009 if (!rodata_enabled
)
2012 set_vm_flush_reset_perms(mod
->core_layout
.base
);
2013 set_vm_flush_reset_perms(mod
->init_layout
.base
);
2014 frob_text(&mod
->core_layout
, set_memory_ro
);
2016 frob_rodata(&mod
->core_layout
, set_memory_ro
);
2017 frob_text(&mod
->init_layout
, set_memory_ro
);
2018 frob_rodata(&mod
->init_layout
, set_memory_ro
);
2021 frob_ro_after_init(&mod
->core_layout
, set_memory_ro
);
2024 static void module_enable_nx(const struct module
*mod
)
2026 frob_rodata(&mod
->core_layout
, set_memory_nx
);
2027 frob_ro_after_init(&mod
->core_layout
, set_memory_nx
);
2028 frob_writable_data(&mod
->core_layout
, set_memory_nx
);
2029 frob_rodata(&mod
->init_layout
, set_memory_nx
);
2030 frob_writable_data(&mod
->init_layout
, set_memory_nx
);
2033 static int module_enforce_rwx_sections(Elf_Ehdr
*hdr
, Elf_Shdr
*sechdrs
,
2034 char *secstrings
, struct module
*mod
)
2036 const unsigned long shf_wx
= SHF_WRITE
|SHF_EXECINSTR
;
2039 for (i
= 0; i
< hdr
->e_shnum
; i
++) {
2040 if ((sechdrs
[i
].sh_flags
& shf_wx
) == shf_wx
) {
2041 pr_err("%s: section %s (index %d) has invalid WRITE|EXEC flags\n",
2042 mod
->name
, secstrings
+ sechdrs
[i
].sh_name
, i
);
2050 #else /* !CONFIG_STRICT_MODULE_RWX */
2051 static void module_enable_nx(const struct module
*mod
) { }
2052 static void module_enable_ro(const struct module
*mod
, bool after_init
) {}
2053 static int module_enforce_rwx_sections(Elf_Ehdr
*hdr
, Elf_Shdr
*sechdrs
,
2054 char *secstrings
, struct module
*mod
)
2058 #endif /* CONFIG_STRICT_MODULE_RWX */
2060 #ifdef CONFIG_LIVEPATCH
2062 * Persist Elf information about a module. Copy the Elf header,
2063 * section header table, section string table, and symtab section
2064 * index from info to mod->klp_info.
2066 static int copy_module_elf(struct module
*mod
, struct load_info
*info
)
2068 unsigned int size
, symndx
;
2071 size
= sizeof(*mod
->klp_info
);
2072 mod
->klp_info
= kmalloc(size
, GFP_KERNEL
);
2073 if (mod
->klp_info
== NULL
)
2077 size
= sizeof(mod
->klp_info
->hdr
);
2078 memcpy(&mod
->klp_info
->hdr
, info
->hdr
, size
);
2080 /* Elf section header table */
2081 size
= sizeof(*info
->sechdrs
) * info
->hdr
->e_shnum
;
2082 mod
->klp_info
->sechdrs
= kmemdup(info
->sechdrs
, size
, GFP_KERNEL
);
2083 if (mod
->klp_info
->sechdrs
== NULL
) {
2088 /* Elf section name string table */
2089 size
= info
->sechdrs
[info
->hdr
->e_shstrndx
].sh_size
;
2090 mod
->klp_info
->secstrings
= kmemdup(info
->secstrings
, size
, GFP_KERNEL
);
2091 if (mod
->klp_info
->secstrings
== NULL
) {
2096 /* Elf symbol section index */
2097 symndx
= info
->index
.sym
;
2098 mod
->klp_info
->symndx
= symndx
;
2101 * For livepatch modules, core_kallsyms.symtab is a complete
2102 * copy of the original symbol table. Adjust sh_addr to point
2103 * to core_kallsyms.symtab since the copy of the symtab in module
2104 * init memory is freed at the end of do_init_module().
2106 mod
->klp_info
->sechdrs
[symndx
].sh_addr
= \
2107 (unsigned long) mod
->core_kallsyms
.symtab
;
2112 kfree(mod
->klp_info
->sechdrs
);
2114 kfree(mod
->klp_info
);
2118 static void free_module_elf(struct module
*mod
)
2120 kfree(mod
->klp_info
->sechdrs
);
2121 kfree(mod
->klp_info
->secstrings
);
2122 kfree(mod
->klp_info
);
2124 #else /* !CONFIG_LIVEPATCH */
2125 static int copy_module_elf(struct module
*mod
, struct load_info
*info
)
2130 static void free_module_elf(struct module
*mod
)
2133 #endif /* CONFIG_LIVEPATCH */
2135 void __weak
module_memfree(void *module_region
)
2138 * This memory may be RO, and freeing RO memory in an interrupt is not
2139 * supported by vmalloc.
2141 WARN_ON(in_interrupt());
2142 vfree(module_region
);
2145 void __weak
module_arch_cleanup(struct module
*mod
)
2149 void __weak
module_arch_freeing_init(struct module
*mod
)
2153 static void cfi_cleanup(struct module
*mod
);
2155 /* Free a module, remove from lists, etc. */
2156 static void free_module(struct module
*mod
)
2158 trace_module_free(mod
);
2160 mod_sysfs_teardown(mod
);
2163 * We leave it in list to prevent duplicate loads, but make sure
2164 * that noone uses it while it's being deconstructed.
2166 mutex_lock(&module_mutex
);
2167 mod
->state
= MODULE_STATE_UNFORMED
;
2168 mutex_unlock(&module_mutex
);
2170 /* Remove dynamic debug info */
2171 ddebug_remove_module(mod
->name
);
2173 /* Arch-specific cleanup. */
2174 module_arch_cleanup(mod
);
2176 /* Module unload stuff */
2177 module_unload_free(mod
);
2179 /* Free any allocated parameters. */
2180 destroy_params(mod
->kp
, mod
->num_kp
);
2182 if (is_livepatch_module(mod
))
2183 free_module_elf(mod
);
2185 /* Now we can delete it from the lists */
2186 mutex_lock(&module_mutex
);
2187 /* Unlink carefully: kallsyms could be walking list. */
2188 list_del_rcu(&mod
->list
);
2189 mod_tree_remove(mod
);
2190 /* Remove this module from bug list, this uses list_del_rcu */
2191 module_bug_cleanup(mod
);
2192 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2194 mutex_unlock(&module_mutex
);
2196 /* Clean up CFI for the module. */
2199 /* This may be empty, but that's OK */
2200 module_arch_freeing_init(mod
);
2201 module_memfree(mod
->init_layout
.base
);
2203 percpu_modfree(mod
);
2205 /* Free lock-classes; relies on the preceding sync_rcu(). */
2206 lockdep_free_key_range(mod
->core_layout
.base
, mod
->core_layout
.size
);
2208 /* Finally, free the core (containing the module structure) */
2209 module_memfree(mod
->core_layout
.base
);
2212 void *__symbol_get(const char *symbol
)
2214 struct find_symbol_arg fsa
= {
2221 if (!find_symbol(&fsa
) || strong_try_module_get(fsa
.owner
)) {
2226 return (void *)kernel_symbol_value(fsa
.sym
);
2228 EXPORT_SYMBOL_GPL(__symbol_get
);
2231 * Ensure that an exported symbol [global namespace] does not already exist
2232 * in the kernel or in some other module's exported symbol table.
2234 * You must hold the module_mutex.
2236 static int verify_exported_symbols(struct module
*mod
)
2239 const struct kernel_symbol
*s
;
2241 const struct kernel_symbol
*sym
;
2244 { mod
->syms
, mod
->num_syms
},
2245 { mod
->gpl_syms
, mod
->num_gpl_syms
},
2248 for (i
= 0; i
< ARRAY_SIZE(arr
); i
++) {
2249 for (s
= arr
[i
].sym
; s
< arr
[i
].sym
+ arr
[i
].num
; s
++) {
2250 struct find_symbol_arg fsa
= {
2251 .name
= kernel_symbol_name(s
),
2254 if (find_symbol(&fsa
)) {
2255 pr_err("%s: exports duplicate symbol %s"
2257 mod
->name
, kernel_symbol_name(s
),
2258 module_name(fsa
.owner
));
2266 static bool ignore_undef_symbol(Elf_Half emachine
, const char *name
)
2269 * On x86, PIC code and Clang non-PIC code may have call foo@PLT. GNU as
2270 * before 2.37 produces an unreferenced _GLOBAL_OFFSET_TABLE_ on x86-64.
2271 * i386 has a similar problem but may not deserve a fix.
2273 * If we ever have to ignore many symbols, consider refactoring the code to
2274 * only warn if referenced by a relocation.
2276 if (emachine
== EM_386
|| emachine
== EM_X86_64
)
2277 return !strcmp(name
, "_GLOBAL_OFFSET_TABLE_");
2281 /* Change all symbols so that st_value encodes the pointer directly. */
2282 static int simplify_symbols(struct module
*mod
, const struct load_info
*info
)
2284 Elf_Shdr
*symsec
= &info
->sechdrs
[info
->index
.sym
];
2285 Elf_Sym
*sym
= (void *)symsec
->sh_addr
;
2286 unsigned long secbase
;
2289 const struct kernel_symbol
*ksym
;
2291 for (i
= 1; i
< symsec
->sh_size
/ sizeof(Elf_Sym
); i
++) {
2292 const char *name
= info
->strtab
+ sym
[i
].st_name
;
2294 switch (sym
[i
].st_shndx
) {
2296 /* Ignore common symbols */
2297 if (!strncmp(name
, "__gnu_lto", 9))
2301 * We compiled with -fno-common. These are not
2302 * supposed to happen.
2304 pr_debug("Common symbol: %s\n", name
);
2305 pr_warn("%s: please compile with -fno-common\n",
2311 /* Don't need to do anything */
2312 pr_debug("Absolute symbol: 0x%08lx\n",
2313 (long)sym
[i
].st_value
);
2317 /* Livepatch symbols are resolved by livepatch */
2321 ksym
= resolve_symbol_wait(mod
, info
, name
);
2322 /* Ok if resolved. */
2323 if (ksym
&& !IS_ERR(ksym
)) {
2324 sym
[i
].st_value
= kernel_symbol_value(ksym
);
2328 /* Ok if weak or ignored. */
2330 (ELF_ST_BIND(sym
[i
].st_info
) == STB_WEAK
||
2331 ignore_undef_symbol(info
->hdr
->e_machine
, name
)))
2334 ret
= PTR_ERR(ksym
) ?: -ENOENT
;
2335 pr_warn("%s: Unknown symbol %s (err %d)\n",
2336 mod
->name
, name
, ret
);
2340 /* Divert to percpu allocation if a percpu var. */
2341 if (sym
[i
].st_shndx
== info
->index
.pcpu
)
2342 secbase
= (unsigned long)mod_percpu(mod
);
2344 secbase
= info
->sechdrs
[sym
[i
].st_shndx
].sh_addr
;
2345 sym
[i
].st_value
+= secbase
;
2353 static int apply_relocations(struct module
*mod
, const struct load_info
*info
)
2358 /* Now do relocations. */
2359 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
2360 unsigned int infosec
= info
->sechdrs
[i
].sh_info
;
2362 /* Not a valid relocation section? */
2363 if (infosec
>= info
->hdr
->e_shnum
)
2366 /* Don't bother with non-allocated sections */
2367 if (!(info
->sechdrs
[infosec
].sh_flags
& SHF_ALLOC
))
2370 if (info
->sechdrs
[i
].sh_flags
& SHF_RELA_LIVEPATCH
)
2371 err
= klp_apply_section_relocs(mod
, info
->sechdrs
,
2376 else if (info
->sechdrs
[i
].sh_type
== SHT_REL
)
2377 err
= apply_relocate(info
->sechdrs
, info
->strtab
,
2378 info
->index
.sym
, i
, mod
);
2379 else if (info
->sechdrs
[i
].sh_type
== SHT_RELA
)
2380 err
= apply_relocate_add(info
->sechdrs
, info
->strtab
,
2381 info
->index
.sym
, i
, mod
);
2388 /* Additional bytes needed by arch in front of individual sections */
2389 unsigned int __weak
arch_mod_section_prepend(struct module
*mod
,
2390 unsigned int section
)
2392 /* default implementation just returns zero */
2396 /* Update size with this section: return offset. */
2397 static long get_offset(struct module
*mod
, unsigned int *size
,
2398 Elf_Shdr
*sechdr
, unsigned int section
)
2402 *size
+= arch_mod_section_prepend(mod
, section
);
2403 ret
= ALIGN(*size
, sechdr
->sh_addralign
?: 1);
2404 *size
= ret
+ sechdr
->sh_size
;
2408 static bool module_init_layout_section(const char *sname
)
2410 #ifndef CONFIG_MODULE_UNLOAD
2411 if (module_exit_section(sname
))
2414 return module_init_section(sname
);
2418 * Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2419 * might -- code, read-only data, read-write data, small data. Tally
2420 * sizes, and place the offsets into sh_entsize fields: high bit means it
2423 static void layout_sections(struct module
*mod
, struct load_info
*info
)
2425 static unsigned long const masks
[][2] = {
2427 * NOTE: all executable code must be the first section
2428 * in this array; otherwise modify the text_size
2429 * finder in the two loops below
2431 { SHF_EXECINSTR
| SHF_ALLOC
, ARCH_SHF_SMALL
},
2432 { SHF_ALLOC
, SHF_WRITE
| ARCH_SHF_SMALL
},
2433 { SHF_RO_AFTER_INIT
| SHF_ALLOC
, ARCH_SHF_SMALL
},
2434 { SHF_WRITE
| SHF_ALLOC
, ARCH_SHF_SMALL
},
2435 { ARCH_SHF_SMALL
| SHF_ALLOC
, 0 }
2439 for (i
= 0; i
< info
->hdr
->e_shnum
; i
++)
2440 info
->sechdrs
[i
].sh_entsize
= ~0UL;
2442 pr_debug("Core section allocation order:\n");
2443 for (m
= 0; m
< ARRAY_SIZE(masks
); ++m
) {
2444 for (i
= 0; i
< info
->hdr
->e_shnum
; ++i
) {
2445 Elf_Shdr
*s
= &info
->sechdrs
[i
];
2446 const char *sname
= info
->secstrings
+ s
->sh_name
;
2448 if ((s
->sh_flags
& masks
[m
][0]) != masks
[m
][0]
2449 || (s
->sh_flags
& masks
[m
][1])
2450 || s
->sh_entsize
!= ~0UL
2451 || module_init_layout_section(sname
))
2453 s
->sh_entsize
= get_offset(mod
, &mod
->core_layout
.size
, s
, i
);
2454 pr_debug("\t%s\n", sname
);
2457 case 0: /* executable */
2458 mod
->core_layout
.size
= debug_align(mod
->core_layout
.size
);
2459 mod
->core_layout
.text_size
= mod
->core_layout
.size
;
2461 case 1: /* RO: text and ro-data */
2462 mod
->core_layout
.size
= debug_align(mod
->core_layout
.size
);
2463 mod
->core_layout
.ro_size
= mod
->core_layout
.size
;
2465 case 2: /* RO after init */
2466 mod
->core_layout
.size
= debug_align(mod
->core_layout
.size
);
2467 mod
->core_layout
.ro_after_init_size
= mod
->core_layout
.size
;
2469 case 4: /* whole core */
2470 mod
->core_layout
.size
= debug_align(mod
->core_layout
.size
);
2475 pr_debug("Init section allocation order:\n");
2476 for (m
= 0; m
< ARRAY_SIZE(masks
); ++m
) {
2477 for (i
= 0; i
< info
->hdr
->e_shnum
; ++i
) {
2478 Elf_Shdr
*s
= &info
->sechdrs
[i
];
2479 const char *sname
= info
->secstrings
+ s
->sh_name
;
2481 if ((s
->sh_flags
& masks
[m
][0]) != masks
[m
][0]
2482 || (s
->sh_flags
& masks
[m
][1])
2483 || s
->sh_entsize
!= ~0UL
2484 || !module_init_layout_section(sname
))
2486 s
->sh_entsize
= (get_offset(mod
, &mod
->init_layout
.size
, s
, i
)
2487 | INIT_OFFSET_MASK
);
2488 pr_debug("\t%s\n", sname
);
2491 case 0: /* executable */
2492 mod
->init_layout
.size
= debug_align(mod
->init_layout
.size
);
2493 mod
->init_layout
.text_size
= mod
->init_layout
.size
;
2495 case 1: /* RO: text and ro-data */
2496 mod
->init_layout
.size
= debug_align(mod
->init_layout
.size
);
2497 mod
->init_layout
.ro_size
= mod
->init_layout
.size
;
2501 * RO after init doesn't apply to init_layout (only
2502 * core_layout), so it just takes the value of ro_size.
2504 mod
->init_layout
.ro_after_init_size
= mod
->init_layout
.ro_size
;
2506 case 4: /* whole init */
2507 mod
->init_layout
.size
= debug_align(mod
->init_layout
.size
);
2513 static void set_license(struct module
*mod
, const char *license
)
2516 license
= "unspecified";
2518 if (!license_is_gpl_compatible(license
)) {
2519 if (!test_taint(TAINT_PROPRIETARY_MODULE
))
2520 pr_warn("%s: module license '%s' taints kernel.\n",
2521 mod
->name
, license
);
2522 add_taint_module(mod
, TAINT_PROPRIETARY_MODULE
,
2523 LOCKDEP_NOW_UNRELIABLE
);
2527 /* Parse tag=value strings from .modinfo section */
2528 static char *next_string(char *string
, unsigned long *secsize
)
2530 /* Skip non-zero chars */
2533 if ((*secsize
)-- <= 1)
2537 /* Skip any zero padding. */
2538 while (!string
[0]) {
2540 if ((*secsize
)-- <= 1)
2546 static char *get_next_modinfo(const struct load_info
*info
, const char *tag
,
2550 unsigned int taglen
= strlen(tag
);
2551 Elf_Shdr
*infosec
= &info
->sechdrs
[info
->index
.info
];
2552 unsigned long size
= infosec
->sh_size
;
2555 * get_modinfo() calls made before rewrite_section_headers()
2556 * must use sh_offset, as sh_addr isn't set!
2558 char *modinfo
= (char *)info
->hdr
+ infosec
->sh_offset
;
2561 size
-= prev
- modinfo
;
2562 modinfo
= next_string(prev
, &size
);
2565 for (p
= modinfo
; p
; p
= next_string(p
, &size
)) {
2566 if (strncmp(p
, tag
, taglen
) == 0 && p
[taglen
] == '=')
2567 return p
+ taglen
+ 1;
2572 static char *get_modinfo(const struct load_info
*info
, const char *tag
)
2574 return get_next_modinfo(info
, tag
, NULL
);
2577 static void setup_modinfo(struct module
*mod
, struct load_info
*info
)
2579 struct module_attribute
*attr
;
2582 for (i
= 0; (attr
= modinfo_attrs
[i
]); i
++) {
2584 attr
->setup(mod
, get_modinfo(info
, attr
->attr
.name
));
2588 static void free_modinfo(struct module
*mod
)
2590 struct module_attribute
*attr
;
2593 for (i
= 0; (attr
= modinfo_attrs
[i
]); i
++) {
2599 #ifdef CONFIG_KALLSYMS
2601 /* Lookup exported symbol in given range of kernel_symbols */
2602 static const struct kernel_symbol
*lookup_exported_symbol(const char *name
,
2603 const struct kernel_symbol
*start
,
2604 const struct kernel_symbol
*stop
)
2606 return bsearch(name
, start
, stop
- start
,
2607 sizeof(struct kernel_symbol
), cmp_name
);
2610 static int is_exported(const char *name
, unsigned long value
,
2611 const struct module
*mod
)
2613 const struct kernel_symbol
*ks
;
2615 ks
= lookup_exported_symbol(name
, __start___ksymtab
, __stop___ksymtab
);
2617 ks
= lookup_exported_symbol(name
, mod
->syms
, mod
->syms
+ mod
->num_syms
);
2619 return ks
!= NULL
&& kernel_symbol_value(ks
) == value
;
2623 static char elf_type(const Elf_Sym
*sym
, const struct load_info
*info
)
2625 const Elf_Shdr
*sechdrs
= info
->sechdrs
;
2627 if (ELF_ST_BIND(sym
->st_info
) == STB_WEAK
) {
2628 if (ELF_ST_TYPE(sym
->st_info
) == STT_OBJECT
)
2633 if (sym
->st_shndx
== SHN_UNDEF
)
2635 if (sym
->st_shndx
== SHN_ABS
|| sym
->st_shndx
== info
->index
.pcpu
)
2637 if (sym
->st_shndx
>= SHN_LORESERVE
)
2639 if (sechdrs
[sym
->st_shndx
].sh_flags
& SHF_EXECINSTR
)
2641 if (sechdrs
[sym
->st_shndx
].sh_flags
& SHF_ALLOC
2642 && sechdrs
[sym
->st_shndx
].sh_type
!= SHT_NOBITS
) {
2643 if (!(sechdrs
[sym
->st_shndx
].sh_flags
& SHF_WRITE
))
2645 else if (sechdrs
[sym
->st_shndx
].sh_flags
& ARCH_SHF_SMALL
)
2650 if (sechdrs
[sym
->st_shndx
].sh_type
== SHT_NOBITS
) {
2651 if (sechdrs
[sym
->st_shndx
].sh_flags
& ARCH_SHF_SMALL
)
2656 if (strstarts(info
->secstrings
+ sechdrs
[sym
->st_shndx
].sh_name
,
2663 static bool is_core_symbol(const Elf_Sym
*src
, const Elf_Shdr
*sechdrs
,
2664 unsigned int shnum
, unsigned int pcpundx
)
2666 const Elf_Shdr
*sec
;
2668 if (src
->st_shndx
== SHN_UNDEF
2669 || src
->st_shndx
>= shnum
2673 #ifdef CONFIG_KALLSYMS_ALL
2674 if (src
->st_shndx
== pcpundx
)
2678 sec
= sechdrs
+ src
->st_shndx
;
2679 if (!(sec
->sh_flags
& SHF_ALLOC
)
2680 #ifndef CONFIG_KALLSYMS_ALL
2681 || !(sec
->sh_flags
& SHF_EXECINSTR
)
2683 || (sec
->sh_entsize
& INIT_OFFSET_MASK
))
2690 * We only allocate and copy the strings needed by the parts of symtab
2691 * we keep. This is simple, but has the effect of making multiple
2692 * copies of duplicates. We could be more sophisticated, see
2693 * linux-kernel thread starting with
2694 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2696 static void layout_symtab(struct module
*mod
, struct load_info
*info
)
2698 Elf_Shdr
*symsect
= info
->sechdrs
+ info
->index
.sym
;
2699 Elf_Shdr
*strsect
= info
->sechdrs
+ info
->index
.str
;
2701 unsigned int i
, nsrc
, ndst
, strtab_size
= 0;
2703 /* Put symbol section at end of init part of module. */
2704 symsect
->sh_flags
|= SHF_ALLOC
;
2705 symsect
->sh_entsize
= get_offset(mod
, &mod
->init_layout
.size
, symsect
,
2706 info
->index
.sym
) | INIT_OFFSET_MASK
;
2707 pr_debug("\t%s\n", info
->secstrings
+ symsect
->sh_name
);
2709 src
= (void *)info
->hdr
+ symsect
->sh_offset
;
2710 nsrc
= symsect
->sh_size
/ sizeof(*src
);
2712 /* Compute total space required for the core symbols' strtab. */
2713 for (ndst
= i
= 0; i
< nsrc
; i
++) {
2714 if (i
== 0 || is_livepatch_module(mod
) ||
2715 is_core_symbol(src
+i
, info
->sechdrs
, info
->hdr
->e_shnum
,
2716 info
->index
.pcpu
)) {
2717 strtab_size
+= strlen(&info
->strtab
[src
[i
].st_name
])+1;
2722 /* Append room for core symbols at end of core part. */
2723 info
->symoffs
= ALIGN(mod
->core_layout
.size
, symsect
->sh_addralign
?: 1);
2724 info
->stroffs
= mod
->core_layout
.size
= info
->symoffs
+ ndst
* sizeof(Elf_Sym
);
2725 mod
->core_layout
.size
+= strtab_size
;
2726 info
->core_typeoffs
= mod
->core_layout
.size
;
2727 mod
->core_layout
.size
+= ndst
* sizeof(char);
2728 mod
->core_layout
.size
= debug_align(mod
->core_layout
.size
);
2730 /* Put string table section at end of init part of module. */
2731 strsect
->sh_flags
|= SHF_ALLOC
;
2732 strsect
->sh_entsize
= get_offset(mod
, &mod
->init_layout
.size
, strsect
,
2733 info
->index
.str
) | INIT_OFFSET_MASK
;
2734 pr_debug("\t%s\n", info
->secstrings
+ strsect
->sh_name
);
2736 /* We'll tack temporary mod_kallsyms on the end. */
2737 mod
->init_layout
.size
= ALIGN(mod
->init_layout
.size
,
2738 __alignof__(struct mod_kallsyms
));
2739 info
->mod_kallsyms_init_off
= mod
->init_layout
.size
;
2740 mod
->init_layout
.size
+= sizeof(struct mod_kallsyms
);
2741 info
->init_typeoffs
= mod
->init_layout
.size
;
2742 mod
->init_layout
.size
+= nsrc
* sizeof(char);
2743 mod
->init_layout
.size
= debug_align(mod
->init_layout
.size
);
2747 * We use the full symtab and strtab which layout_symtab arranged to
2748 * be appended to the init section. Later we switch to the cut-down
2751 static void add_kallsyms(struct module
*mod
, const struct load_info
*info
)
2753 unsigned int i
, ndst
;
2757 Elf_Shdr
*symsec
= &info
->sechdrs
[info
->index
.sym
];
2759 /* Set up to point into init section. */
2760 mod
->kallsyms
= mod
->init_layout
.base
+ info
->mod_kallsyms_init_off
;
2762 mod
->kallsyms
->symtab
= (void *)symsec
->sh_addr
;
2763 mod
->kallsyms
->num_symtab
= symsec
->sh_size
/ sizeof(Elf_Sym
);
2764 /* Make sure we get permanent strtab: don't use info->strtab. */
2765 mod
->kallsyms
->strtab
= (void *)info
->sechdrs
[info
->index
.str
].sh_addr
;
2766 mod
->kallsyms
->typetab
= mod
->init_layout
.base
+ info
->init_typeoffs
;
2769 * Now populate the cut down core kallsyms for after init
2770 * and set types up while we still have access to sections.
2772 mod
->core_kallsyms
.symtab
= dst
= mod
->core_layout
.base
+ info
->symoffs
;
2773 mod
->core_kallsyms
.strtab
= s
= mod
->core_layout
.base
+ info
->stroffs
;
2774 mod
->core_kallsyms
.typetab
= mod
->core_layout
.base
+ info
->core_typeoffs
;
2775 src
= mod
->kallsyms
->symtab
;
2776 for (ndst
= i
= 0; i
< mod
->kallsyms
->num_symtab
; i
++) {
2777 mod
->kallsyms
->typetab
[i
] = elf_type(src
+ i
, info
);
2778 if (i
== 0 || is_livepatch_module(mod
) ||
2779 is_core_symbol(src
+i
, info
->sechdrs
, info
->hdr
->e_shnum
,
2780 info
->index
.pcpu
)) {
2781 mod
->core_kallsyms
.typetab
[ndst
] =
2782 mod
->kallsyms
->typetab
[i
];
2784 dst
[ndst
++].st_name
= s
- mod
->core_kallsyms
.strtab
;
2785 s
+= strlcpy(s
, &mod
->kallsyms
->strtab
[src
[i
].st_name
],
2789 mod
->core_kallsyms
.num_symtab
= ndst
;
2792 static inline void layout_symtab(struct module
*mod
, struct load_info
*info
)
2796 static void add_kallsyms(struct module
*mod
, const struct load_info
*info
)
2799 #endif /* CONFIG_KALLSYMS */
2801 static void dynamic_debug_setup(struct module
*mod
, struct _ddebug
*debug
, unsigned int num
)
2805 ddebug_add_module(debug
, num
, mod
->name
);
2808 static void dynamic_debug_remove(struct module
*mod
, struct _ddebug
*debug
)
2811 ddebug_remove_module(mod
->name
);
2814 void * __weak
module_alloc(unsigned long size
)
2816 return __vmalloc_node_range(size
, 1, VMALLOC_START
, VMALLOC_END
,
2817 GFP_KERNEL
, PAGE_KERNEL_EXEC
, VM_FLUSH_RESET_PERMS
,
2818 NUMA_NO_NODE
, __builtin_return_address(0));
2821 bool __weak
module_init_section(const char *name
)
2823 return strstarts(name
, ".init");
2826 bool __weak
module_exit_section(const char *name
)
2828 return strstarts(name
, ".exit");
2831 #ifdef CONFIG_DEBUG_KMEMLEAK
2832 static void kmemleak_load_module(const struct module
*mod
,
2833 const struct load_info
*info
)
2837 /* only scan the sections containing data */
2838 kmemleak_scan_area(mod
, sizeof(struct module
), GFP_KERNEL
);
2840 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
2841 /* Scan all writable sections that's not executable */
2842 if (!(info
->sechdrs
[i
].sh_flags
& SHF_ALLOC
) ||
2843 !(info
->sechdrs
[i
].sh_flags
& SHF_WRITE
) ||
2844 (info
->sechdrs
[i
].sh_flags
& SHF_EXECINSTR
))
2847 kmemleak_scan_area((void *)info
->sechdrs
[i
].sh_addr
,
2848 info
->sechdrs
[i
].sh_size
, GFP_KERNEL
);
2852 static inline void kmemleak_load_module(const struct module
*mod
,
2853 const struct load_info
*info
)
2858 #ifdef CONFIG_MODULE_SIG
2859 static int module_sig_check(struct load_info
*info
, int flags
)
2862 const unsigned long markerlen
= sizeof(MODULE_SIG_STRING
) - 1;
2864 const void *mod
= info
->hdr
;
2867 * Require flags == 0, as a module with version information
2868 * removed is no longer the module that was signed
2871 info
->len
> markerlen
&&
2872 memcmp(mod
+ info
->len
- markerlen
, MODULE_SIG_STRING
, markerlen
) == 0) {
2873 /* We truncate the module to discard the signature */
2874 info
->len
-= markerlen
;
2875 err
= mod_verify_sig(mod
, info
);
2877 info
->sig_ok
= true;
2883 * We don't permit modules to be loaded into the trusted kernels
2884 * without a valid signature on them, but if we're not enforcing,
2885 * certain errors are non-fatal.
2889 reason
= "unsigned module";
2892 reason
= "module with unsupported crypto";
2895 reason
= "module with unavailable key";
2900 * All other errors are fatal, including lack of memory,
2901 * unparseable signatures, and signature check failures --
2902 * even if signatures aren't required.
2907 if (is_module_sig_enforced()) {
2908 pr_notice("Loading of %s is rejected\n", reason
);
2909 return -EKEYREJECTED
;
2912 return security_locked_down(LOCKDOWN_MODULE_SIGNATURE
);
2914 #else /* !CONFIG_MODULE_SIG */
2915 static int module_sig_check(struct load_info
*info
, int flags
)
2919 #endif /* !CONFIG_MODULE_SIG */
2921 static int validate_section_offset(struct load_info
*info
, Elf_Shdr
*shdr
)
2923 unsigned long secend
;
2926 * Check for both overflow and offset/size being
2929 secend
= shdr
->sh_offset
+ shdr
->sh_size
;
2930 if (secend
< shdr
->sh_offset
|| secend
> info
->len
)
2937 * Sanity checks against invalid binaries, wrong arch, weird elf version.
2939 * Also do basic validity checks against section offsets and sizes, the
2940 * section name string table, and the indices used for it (sh_name).
2942 static int elf_validity_check(struct load_info
*info
)
2945 Elf_Shdr
*shdr
, *strhdr
;
2948 if (info
->len
< sizeof(*(info
->hdr
)))
2951 if (memcmp(info
->hdr
->e_ident
, ELFMAG
, SELFMAG
) != 0
2952 || info
->hdr
->e_type
!= ET_REL
2953 || !elf_check_arch(info
->hdr
)
2954 || info
->hdr
->e_shentsize
!= sizeof(Elf_Shdr
))
2958 * e_shnum is 16 bits, and sizeof(Elf_Shdr) is
2959 * known and small. So e_shnum * sizeof(Elf_Shdr)
2960 * will not overflow unsigned long on any platform.
2962 if (info
->hdr
->e_shoff
>= info
->len
2963 || (info
->hdr
->e_shnum
* sizeof(Elf_Shdr
) >
2964 info
->len
- info
->hdr
->e_shoff
))
2967 info
->sechdrs
= (void *)info
->hdr
+ info
->hdr
->e_shoff
;
2970 * Verify if the section name table index is valid.
2972 if (info
->hdr
->e_shstrndx
== SHN_UNDEF
2973 || info
->hdr
->e_shstrndx
>= info
->hdr
->e_shnum
)
2976 strhdr
= &info
->sechdrs
[info
->hdr
->e_shstrndx
];
2977 err
= validate_section_offset(info
, strhdr
);
2982 * The section name table must be NUL-terminated, as required
2983 * by the spec. This makes strcmp and pr_* calls that access
2984 * strings in the section safe.
2986 info
->secstrings
= (void *)info
->hdr
+ strhdr
->sh_offset
;
2987 if (info
->secstrings
[strhdr
->sh_size
- 1] != '\0')
2991 * The code assumes that section 0 has a length of zero and
2992 * an addr of zero, so check for it.
2994 if (info
->sechdrs
[0].sh_type
!= SHT_NULL
2995 || info
->sechdrs
[0].sh_size
!= 0
2996 || info
->sechdrs
[0].sh_addr
!= 0)
2999 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
3000 shdr
= &info
->sechdrs
[i
];
3001 switch (shdr
->sh_type
) {
3006 if (shdr
->sh_link
== SHN_UNDEF
3007 || shdr
->sh_link
>= info
->hdr
->e_shnum
)
3011 err
= validate_section_offset(info
, shdr
);
3013 pr_err("Invalid ELF section in module (section %u type %u)\n",
3018 if (shdr
->sh_flags
& SHF_ALLOC
) {
3019 if (shdr
->sh_name
>= strhdr
->sh_size
) {
3020 pr_err("Invalid ELF section name in module (section %u type %u)\n",
3032 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
3034 static int copy_chunked_from_user(void *dst
, const void __user
*usrc
, unsigned long len
)
3037 unsigned long n
= min(len
, COPY_CHUNK_SIZE
);
3039 if (copy_from_user(dst
, usrc
, n
) != 0)
3049 #ifdef CONFIG_LIVEPATCH
3050 static int check_modinfo_livepatch(struct module
*mod
, struct load_info
*info
)
3052 if (get_modinfo(info
, "livepatch")) {
3054 add_taint_module(mod
, TAINT_LIVEPATCH
, LOCKDEP_STILL_OK
);
3055 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
3061 #else /* !CONFIG_LIVEPATCH */
3062 static int check_modinfo_livepatch(struct module
*mod
, struct load_info
*info
)
3064 if (get_modinfo(info
, "livepatch")) {
3065 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
3072 #endif /* CONFIG_LIVEPATCH */
3074 static void check_modinfo_retpoline(struct module
*mod
, struct load_info
*info
)
3076 if (retpoline_module_ok(get_modinfo(info
, "retpoline")))
3079 pr_warn("%s: loading module not compiled with retpoline compiler.\n",
3083 /* Sets info->hdr and info->len. */
3084 static int copy_module_from_user(const void __user
*umod
, unsigned long len
,
3085 struct load_info
*info
)
3090 if (info
->len
< sizeof(*(info
->hdr
)))
3093 err
= security_kernel_load_data(LOADING_MODULE
, true);
3097 /* Suck in entire file: we'll want most of it. */
3098 info
->hdr
= __vmalloc(info
->len
, GFP_KERNEL
| __GFP_NOWARN
);
3102 if (copy_chunked_from_user(info
->hdr
, umod
, info
->len
) != 0) {
3107 err
= security_kernel_post_load_data((char *)info
->hdr
, info
->len
,
3108 LOADING_MODULE
, "init_module");
3116 static void free_copy(struct load_info
*info
)
3121 static int rewrite_section_headers(struct load_info
*info
, int flags
)
3125 /* This should always be true, but let's be sure. */
3126 info
->sechdrs
[0].sh_addr
= 0;
3128 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
3129 Elf_Shdr
*shdr
= &info
->sechdrs
[i
];
3132 * Mark all sections sh_addr with their address in the
3135 shdr
->sh_addr
= (size_t)info
->hdr
+ shdr
->sh_offset
;
3139 /* Track but don't keep modinfo and version sections. */
3140 info
->sechdrs
[info
->index
.vers
].sh_flags
&= ~(unsigned long)SHF_ALLOC
;
3141 info
->sechdrs
[info
->index
.info
].sh_flags
&= ~(unsigned long)SHF_ALLOC
;
3147 * Set up our basic convenience variables (pointers to section headers,
3148 * search for module section index etc), and do some basic section
3151 * Set info->mod to the temporary copy of the module in info->hdr. The final one
3152 * will be allocated in move_module().
3154 static int setup_load_info(struct load_info
*info
, int flags
)
3158 /* Try to find a name early so we can log errors with a module name */
3159 info
->index
.info
= find_sec(info
, ".modinfo");
3160 if (info
->index
.info
)
3161 info
->name
= get_modinfo(info
, "name");
3163 /* Find internal symbols and strings. */
3164 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
3165 if (info
->sechdrs
[i
].sh_type
== SHT_SYMTAB
) {
3166 info
->index
.sym
= i
;
3167 info
->index
.str
= info
->sechdrs
[i
].sh_link
;
3168 info
->strtab
= (char *)info
->hdr
3169 + info
->sechdrs
[info
->index
.str
].sh_offset
;
3174 if (info
->index
.sym
== 0) {
3175 pr_warn("%s: module has no symbols (stripped?)\n",
3176 info
->name
?: "(missing .modinfo section or name field)");
3180 info
->index
.mod
= find_sec(info
, ".gnu.linkonce.this_module");
3181 if (!info
->index
.mod
) {
3182 pr_warn("%s: No module found in object\n",
3183 info
->name
?: "(missing .modinfo section or name field)");
3186 /* This is temporary: point mod into copy of data. */
3187 info
->mod
= (void *)info
->hdr
+ info
->sechdrs
[info
->index
.mod
].sh_offset
;
3190 * If we didn't load the .modinfo 'name' field earlier, fall back to
3191 * on-disk struct mod 'name' field.
3194 info
->name
= info
->mod
->name
;
3196 if (flags
& MODULE_INIT_IGNORE_MODVERSIONS
)
3197 info
->index
.vers
= 0; /* Pretend no __versions section! */
3199 info
->index
.vers
= find_sec(info
, "__versions");
3201 info
->index
.pcpu
= find_pcpusec(info
);
3206 static int check_modinfo(struct module
*mod
, struct load_info
*info
, int flags
)
3208 const char *modmagic
= get_modinfo(info
, "vermagic");
3211 if (flags
& MODULE_INIT_IGNORE_VERMAGIC
)
3214 /* This is allowed: modprobe --force will invalidate it. */
3216 err
= try_to_force_load(mod
, "bad vermagic");
3219 } else if (!same_magic(modmagic
, vermagic
, info
->index
.vers
)) {
3220 pr_err("%s: version magic '%s' should be '%s'\n",
3221 info
->name
, modmagic
, vermagic
);
3225 if (!get_modinfo(info
, "intree")) {
3226 if (!test_taint(TAINT_OOT_MODULE
))
3227 pr_warn("%s: loading out-of-tree module taints kernel.\n",
3229 add_taint_module(mod
, TAINT_OOT_MODULE
, LOCKDEP_STILL_OK
);
3232 check_modinfo_retpoline(mod
, info
);
3234 if (get_modinfo(info
, "staging")) {
3235 add_taint_module(mod
, TAINT_CRAP
, LOCKDEP_STILL_OK
);
3236 pr_warn("%s: module is from the staging directory, the quality "
3237 "is unknown, you have been warned.\n", mod
->name
);
3240 err
= check_modinfo_livepatch(mod
, info
);
3244 /* Set up license info based on the info section */
3245 set_license(mod
, get_modinfo(info
, "license"));
3250 static int find_module_sections(struct module
*mod
, struct load_info
*info
)
3252 mod
->kp
= section_objs(info
, "__param",
3253 sizeof(*mod
->kp
), &mod
->num_kp
);
3254 mod
->syms
= section_objs(info
, "__ksymtab",
3255 sizeof(*mod
->syms
), &mod
->num_syms
);
3256 mod
->crcs
= section_addr(info
, "__kcrctab");
3257 mod
->gpl_syms
= section_objs(info
, "__ksymtab_gpl",
3258 sizeof(*mod
->gpl_syms
),
3259 &mod
->num_gpl_syms
);
3260 mod
->gpl_crcs
= section_addr(info
, "__kcrctab_gpl");
3262 #ifdef CONFIG_CONSTRUCTORS
3263 mod
->ctors
= section_objs(info
, ".ctors",
3264 sizeof(*mod
->ctors
), &mod
->num_ctors
);
3266 mod
->ctors
= section_objs(info
, ".init_array",
3267 sizeof(*mod
->ctors
), &mod
->num_ctors
);
3268 else if (find_sec(info
, ".init_array")) {
3270 * This shouldn't happen with same compiler and binutils
3271 * building all parts of the module.
3273 pr_warn("%s: has both .ctors and .init_array.\n",
3279 mod
->noinstr_text_start
= section_objs(info
, ".noinstr.text", 1,
3280 &mod
->noinstr_text_size
);
3282 #ifdef CONFIG_TRACEPOINTS
3283 mod
->tracepoints_ptrs
= section_objs(info
, "__tracepoints_ptrs",
3284 sizeof(*mod
->tracepoints_ptrs
),
3285 &mod
->num_tracepoints
);
3287 #ifdef CONFIG_TREE_SRCU
3288 mod
->srcu_struct_ptrs
= section_objs(info
, "___srcu_struct_ptrs",
3289 sizeof(*mod
->srcu_struct_ptrs
),
3290 &mod
->num_srcu_structs
);
3292 #ifdef CONFIG_BPF_EVENTS
3293 mod
->bpf_raw_events
= section_objs(info
, "__bpf_raw_tp_map",
3294 sizeof(*mod
->bpf_raw_events
),
3295 &mod
->num_bpf_raw_events
);
3297 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
3298 mod
->btf_data
= any_section_objs(info
, ".BTF", 1, &mod
->btf_data_size
);
3300 #ifdef CONFIG_JUMP_LABEL
3301 mod
->jump_entries
= section_objs(info
, "__jump_table",
3302 sizeof(*mod
->jump_entries
),
3303 &mod
->num_jump_entries
);
3305 #ifdef CONFIG_EVENT_TRACING
3306 mod
->trace_events
= section_objs(info
, "_ftrace_events",
3307 sizeof(*mod
->trace_events
),
3308 &mod
->num_trace_events
);
3309 mod
->trace_evals
= section_objs(info
, "_ftrace_eval_map",
3310 sizeof(*mod
->trace_evals
),
3311 &mod
->num_trace_evals
);
3313 #ifdef CONFIG_TRACING
3314 mod
->trace_bprintk_fmt_start
= section_objs(info
, "__trace_printk_fmt",
3315 sizeof(*mod
->trace_bprintk_fmt_start
),
3316 &mod
->num_trace_bprintk_fmt
);
3318 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
3319 /* sechdrs[0].sh_size is always zero */
3320 mod
->ftrace_callsites
= section_objs(info
, FTRACE_CALLSITE_SECTION
,
3321 sizeof(*mod
->ftrace_callsites
),
3322 &mod
->num_ftrace_callsites
);
3324 #ifdef CONFIG_FUNCTION_ERROR_INJECTION
3325 mod
->ei_funcs
= section_objs(info
, "_error_injection_whitelist",
3326 sizeof(*mod
->ei_funcs
),
3327 &mod
->num_ei_funcs
);
3329 #ifdef CONFIG_KPROBES
3330 mod
->kprobes_text_start
= section_objs(info
, ".kprobes.text", 1,
3331 &mod
->kprobes_text_size
);
3332 mod
->kprobe_blacklist
= section_objs(info
, "_kprobe_blacklist",
3333 sizeof(unsigned long),
3334 &mod
->num_kprobe_blacklist
);
3336 #ifdef CONFIG_HAVE_STATIC_CALL_INLINE
3337 mod
->static_call_sites
= section_objs(info
, ".static_call_sites",
3338 sizeof(*mod
->static_call_sites
),
3339 &mod
->num_static_call_sites
);
3341 mod
->extable
= section_objs(info
, "__ex_table",
3342 sizeof(*mod
->extable
), &mod
->num_exentries
);
3344 if (section_addr(info
, "__obsparm"))
3345 pr_warn("%s: Ignoring obsolete parameters\n", mod
->name
);
3347 info
->debug
= section_objs(info
, "__dyndbg",
3348 sizeof(*info
->debug
), &info
->num_debug
);
3353 static int move_module(struct module
*mod
, struct load_info
*info
)
3358 /* Do the allocs. */
3359 ptr
= module_alloc(mod
->core_layout
.size
);
3361 * The pointer to this block is stored in the module structure
3362 * which is inside the block. Just mark it as not being a
3365 kmemleak_not_leak(ptr
);
3369 memset(ptr
, 0, mod
->core_layout
.size
);
3370 mod
->core_layout
.base
= ptr
;
3372 if (mod
->init_layout
.size
) {
3373 ptr
= module_alloc(mod
->init_layout
.size
);
3375 * The pointer to this block is stored in the module structure
3376 * which is inside the block. This block doesn't need to be
3377 * scanned as it contains data and code that will be freed
3378 * after the module is initialized.
3380 kmemleak_ignore(ptr
);
3382 module_memfree(mod
->core_layout
.base
);
3385 memset(ptr
, 0, mod
->init_layout
.size
);
3386 mod
->init_layout
.base
= ptr
;
3388 mod
->init_layout
.base
= NULL
;
3390 /* Transfer each section which specifies SHF_ALLOC */
3391 pr_debug("final section addresses:\n");
3392 for (i
= 0; i
< info
->hdr
->e_shnum
; i
++) {
3394 Elf_Shdr
*shdr
= &info
->sechdrs
[i
];
3396 if (!(shdr
->sh_flags
& SHF_ALLOC
))
3399 if (shdr
->sh_entsize
& INIT_OFFSET_MASK
)
3400 dest
= mod
->init_layout
.base
3401 + (shdr
->sh_entsize
& ~INIT_OFFSET_MASK
);
3403 dest
= mod
->core_layout
.base
+ shdr
->sh_entsize
;
3405 if (shdr
->sh_type
!= SHT_NOBITS
)
3406 memcpy(dest
, (void *)shdr
->sh_addr
, shdr
->sh_size
);
3407 /* Update sh_addr to point to copy in image. */
3408 shdr
->sh_addr
= (unsigned long)dest
;
3409 pr_debug("\t0x%lx %s\n",
3410 (long)shdr
->sh_addr
, info
->secstrings
+ shdr
->sh_name
);
3416 static int check_module_license_and_versions(struct module
*mod
)
3418 int prev_taint
= test_taint(TAINT_PROPRIETARY_MODULE
);
3421 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3422 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3423 * using GPL-only symbols it needs.
3425 if (strcmp(mod
->name
, "ndiswrapper") == 0)
3426 add_taint(TAINT_PROPRIETARY_MODULE
, LOCKDEP_NOW_UNRELIABLE
);
3428 /* driverloader was caught wrongly pretending to be under GPL */
3429 if (strcmp(mod
->name
, "driverloader") == 0)
3430 add_taint_module(mod
, TAINT_PROPRIETARY_MODULE
,
3431 LOCKDEP_NOW_UNRELIABLE
);
3433 /* lve claims to be GPL but upstream won't provide source */
3434 if (strcmp(mod
->name
, "lve") == 0)
3435 add_taint_module(mod
, TAINT_PROPRIETARY_MODULE
,
3436 LOCKDEP_NOW_UNRELIABLE
);
3438 if (!prev_taint
&& test_taint(TAINT_PROPRIETARY_MODULE
))
3439 pr_warn("%s: module license taints kernel.\n", mod
->name
);
3441 #ifdef CONFIG_MODVERSIONS
3442 if ((mod
->num_syms
&& !mod
->crcs
) ||
3443 (mod
->num_gpl_syms
&& !mod
->gpl_crcs
)) {
3444 return try_to_force_load(mod
,
3445 "no versions for exported symbols");
3451 static void flush_module_icache(const struct module
*mod
)
3454 * Flush the instruction cache, since we've played with text.
3455 * Do it before processing of module parameters, so the module
3456 * can provide parameter accessor functions of its own.
3458 if (mod
->init_layout
.base
)
3459 flush_icache_range((unsigned long)mod
->init_layout
.base
,
3460 (unsigned long)mod
->init_layout
.base
3461 + mod
->init_layout
.size
);
3462 flush_icache_range((unsigned long)mod
->core_layout
.base
,
3463 (unsigned long)mod
->core_layout
.base
+ mod
->core_layout
.size
);
3466 int __weak
module_frob_arch_sections(Elf_Ehdr
*hdr
,
3474 /* module_blacklist is a comma-separated list of module names */
3475 static char *module_blacklist
;
3476 static bool blacklisted(const char *module_name
)
3481 if (!module_blacklist
)
3484 for (p
= module_blacklist
; *p
; p
+= len
) {
3485 len
= strcspn(p
, ",");
3486 if (strlen(module_name
) == len
&& !memcmp(module_name
, p
, len
))
3493 core_param(module_blacklist
, module_blacklist
, charp
, 0400);
3495 static struct module
*layout_and_allocate(struct load_info
*info
, int flags
)
3501 err
= check_modinfo(info
->mod
, info
, flags
);
3503 return ERR_PTR(err
);
3505 /* Allow arches to frob section contents and sizes. */
3506 err
= module_frob_arch_sections(info
->hdr
, info
->sechdrs
,
3507 info
->secstrings
, info
->mod
);
3509 return ERR_PTR(err
);
3511 err
= module_enforce_rwx_sections(info
->hdr
, info
->sechdrs
,
3512 info
->secstrings
, info
->mod
);
3514 return ERR_PTR(err
);
3516 /* We will do a special allocation for per-cpu sections later. */
3517 info
->sechdrs
[info
->index
.pcpu
].sh_flags
&= ~(unsigned long)SHF_ALLOC
;
3520 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3521 * layout_sections() can put it in the right place.
3522 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3524 ndx
= find_sec(info
, ".data..ro_after_init");
3526 info
->sechdrs
[ndx
].sh_flags
|= SHF_RO_AFTER_INIT
;
3528 * Mark the __jump_table section as ro_after_init as well: these data
3529 * structures are never modified, with the exception of entries that
3530 * refer to code in the __init section, which are annotated as such
3531 * at module load time.
3533 ndx
= find_sec(info
, "__jump_table");
3535 info
->sechdrs
[ndx
].sh_flags
|= SHF_RO_AFTER_INIT
;
3538 * Determine total sizes, and put offsets in sh_entsize. For now
3539 * this is done generically; there doesn't appear to be any
3540 * special cases for the architectures.
3542 layout_sections(info
->mod
, info
);
3543 layout_symtab(info
->mod
, info
);
3545 /* Allocate and move to the final place */
3546 err
= move_module(info
->mod
, info
);
3548 return ERR_PTR(err
);
3550 /* Module has been copied to its final place now: return it. */
3551 mod
= (void *)info
->sechdrs
[info
->index
.mod
].sh_addr
;
3552 kmemleak_load_module(mod
, info
);
3556 /* mod is no longer valid after this! */
3557 static void module_deallocate(struct module
*mod
, struct load_info
*info
)
3559 percpu_modfree(mod
);
3560 module_arch_freeing_init(mod
);
3561 module_memfree(mod
->init_layout
.base
);
3562 module_memfree(mod
->core_layout
.base
);
3565 int __weak
module_finalize(const Elf_Ehdr
*hdr
,
3566 const Elf_Shdr
*sechdrs
,
3572 static int post_relocation(struct module
*mod
, const struct load_info
*info
)
3574 /* Sort exception table now relocations are done. */
3575 sort_extable(mod
->extable
, mod
->extable
+ mod
->num_exentries
);
3577 /* Copy relocated percpu area over. */
3578 percpu_modcopy(mod
, (void *)info
->sechdrs
[info
->index
.pcpu
].sh_addr
,
3579 info
->sechdrs
[info
->index
.pcpu
].sh_size
);
3581 /* Setup kallsyms-specific fields. */
3582 add_kallsyms(mod
, info
);
3584 /* Arch-specific module finalizing. */
3585 return module_finalize(info
->hdr
, info
->sechdrs
, mod
);
3588 /* Is this module of this name done loading? No locks held. */
3589 static bool finished_loading(const char *name
)
3595 * The module_mutex should not be a heavily contended lock;
3596 * if we get the occasional sleep here, we'll go an extra iteration
3597 * in the wait_event_interruptible(), which is harmless.
3599 sched_annotate_sleep();
3600 mutex_lock(&module_mutex
);
3601 mod
= find_module_all(name
, strlen(name
), true);
3602 ret
= !mod
|| mod
->state
== MODULE_STATE_LIVE
;
3603 mutex_unlock(&module_mutex
);
3608 /* Call module constructors. */
3609 static void do_mod_ctors(struct module
*mod
)
3611 #ifdef CONFIG_CONSTRUCTORS
3614 for (i
= 0; i
< mod
->num_ctors
; i
++)
3619 /* For freeing module_init on success, in case kallsyms traversing */
3620 struct mod_initfree
{
3621 struct llist_node node
;
3625 static void do_free_init(struct work_struct
*w
)
3627 struct llist_node
*pos
, *n
, *list
;
3628 struct mod_initfree
*initfree
;
3630 list
= llist_del_all(&init_free_list
);
3634 llist_for_each_safe(pos
, n
, list
) {
3635 initfree
= container_of(pos
, struct mod_initfree
, node
);
3636 module_memfree(initfree
->module_init
);
3642 * This is where the real work happens.
3644 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3645 * helper command 'lx-symbols'.
3647 static noinline
int do_init_module(struct module
*mod
)
3650 struct mod_initfree
*freeinit
;
3652 freeinit
= kmalloc(sizeof(*freeinit
), GFP_KERNEL
);
3657 freeinit
->module_init
= mod
->init_layout
.base
;
3660 * We want to find out whether @mod uses async during init. Clear
3661 * PF_USED_ASYNC. async_schedule*() will set it.
3663 current
->flags
&= ~PF_USED_ASYNC
;
3666 /* Start the module */
3667 if (mod
->init
!= NULL
)
3668 ret
= do_one_initcall(mod
->init
);
3670 goto fail_free_freeinit
;
3673 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3674 "follow 0/-E convention\n"
3675 "%s: loading module anyway...\n",
3676 __func__
, mod
->name
, ret
, __func__
);
3680 /* Now it's a first class citizen! */
3681 mod
->state
= MODULE_STATE_LIVE
;
3682 blocking_notifier_call_chain(&module_notify_list
,
3683 MODULE_STATE_LIVE
, mod
);
3685 /* Delay uevent until module has finished its init routine */
3686 kobject_uevent(&mod
->mkobj
.kobj
, KOBJ_ADD
);
3689 * We need to finish all async code before the module init sequence
3690 * is done. This has potential to deadlock. For example, a newly
3691 * detected block device can trigger request_module() of the
3692 * default iosched from async probing task. Once userland helper
3693 * reaches here, async_synchronize_full() will wait on the async
3694 * task waiting on request_module() and deadlock.
3696 * This deadlock is avoided by perfomring async_synchronize_full()
3697 * iff module init queued any async jobs. This isn't a full
3698 * solution as it will deadlock the same if module loading from
3699 * async jobs nests more than once; however, due to the various
3700 * constraints, this hack seems to be the best option for now.
3701 * Please refer to the following thread for details.
3703 * http://thread.gmane.org/gmane.linux.kernel/1420814
3705 if (!mod
->async_probe_requested
&& (current
->flags
& PF_USED_ASYNC
))
3706 async_synchronize_full();
3708 ftrace_free_mem(mod
, mod
->init_layout
.base
, mod
->init_layout
.base
+
3709 mod
->init_layout
.size
);
3710 mutex_lock(&module_mutex
);
3711 /* Drop initial reference. */
3713 trim_init_extable(mod
);
3714 #ifdef CONFIG_KALLSYMS
3715 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3716 rcu_assign_pointer(mod
->kallsyms
, &mod
->core_kallsyms
);
3718 module_enable_ro(mod
, true);
3719 mod_tree_remove_init(mod
);
3720 module_arch_freeing_init(mod
);
3721 mod
->init_layout
.base
= NULL
;
3722 mod
->init_layout
.size
= 0;
3723 mod
->init_layout
.ro_size
= 0;
3724 mod
->init_layout
.ro_after_init_size
= 0;
3725 mod
->init_layout
.text_size
= 0;
3726 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
3727 /* .BTF is not SHF_ALLOC and will get removed, so sanitize pointer */
3728 mod
->btf_data
= NULL
;
3731 * We want to free module_init, but be aware that kallsyms may be
3732 * walking this with preempt disabled. In all the failure paths, we
3733 * call synchronize_rcu(), but we don't want to slow down the success
3734 * path. module_memfree() cannot be called in an interrupt, so do the
3735 * work and call synchronize_rcu() in a work queue.
3737 * Note that module_alloc() on most architectures creates W+X page
3738 * mappings which won't be cleaned up until do_free_init() runs. Any
3739 * code such as mark_rodata_ro() which depends on those mappings to
3740 * be cleaned up needs to sync with the queued work - ie
3743 if (llist_add(&freeinit
->node
, &init_free_list
))
3744 schedule_work(&init_free_wq
);
3746 mutex_unlock(&module_mutex
);
3747 wake_up_all(&module_wq
);
3754 /* Try to protect us from buggy refcounters. */
3755 mod
->state
= MODULE_STATE_GOING
;
3758 blocking_notifier_call_chain(&module_notify_list
,
3759 MODULE_STATE_GOING
, mod
);
3760 klp_module_going(mod
);
3761 ftrace_release_mod(mod
);
3763 wake_up_all(&module_wq
);
3767 static int may_init_module(void)
3769 if (!capable(CAP_SYS_MODULE
) || modules_disabled
)
3776 * We try to place it in the list now to make sure it's unique before
3777 * we dedicate too many resources. In particular, temporary percpu
3778 * memory exhaustion.
3780 static int add_unformed_module(struct module
*mod
)
3785 mod
->state
= MODULE_STATE_UNFORMED
;
3788 mutex_lock(&module_mutex
);
3789 old
= find_module_all(mod
->name
, strlen(mod
->name
), true);
3791 if (old
->state
!= MODULE_STATE_LIVE
) {
3792 /* Wait in case it fails to load. */
3793 mutex_unlock(&module_mutex
);
3794 err
= wait_event_interruptible(module_wq
,
3795 finished_loading(mod
->name
));
3803 mod_update_bounds(mod
);
3804 list_add_rcu(&mod
->list
, &modules
);
3805 mod_tree_insert(mod
);
3809 mutex_unlock(&module_mutex
);
3814 static int complete_formation(struct module
*mod
, struct load_info
*info
)
3818 mutex_lock(&module_mutex
);
3820 /* Find duplicate symbols (must be called under lock). */
3821 err
= verify_exported_symbols(mod
);
3825 /* This relies on module_mutex for list integrity. */
3826 module_bug_finalize(info
->hdr
, info
->sechdrs
, mod
);
3828 module_enable_ro(mod
, false);
3829 module_enable_nx(mod
);
3830 module_enable_x(mod
);
3833 * Mark state as coming so strong_try_module_get() ignores us,
3834 * but kallsyms etc. can see us.
3836 mod
->state
= MODULE_STATE_COMING
;
3837 mutex_unlock(&module_mutex
);
3842 mutex_unlock(&module_mutex
);
3846 static int prepare_coming_module(struct module
*mod
)
3850 ftrace_module_enable(mod
);
3851 err
= klp_module_coming(mod
);
3855 err
= blocking_notifier_call_chain_robust(&module_notify_list
,
3856 MODULE_STATE_COMING
, MODULE_STATE_GOING
, mod
);
3857 err
= notifier_to_errno(err
);
3859 klp_module_going(mod
);
3864 static int unknown_module_param_cb(char *param
, char *val
, const char *modname
,
3867 struct module
*mod
= arg
;
3870 if (strcmp(param
, "async_probe") == 0) {
3871 mod
->async_probe_requested
= true;
3875 /* Check for magic 'dyndbg' arg */
3876 ret
= ddebug_dyndbg_module_param_cb(param
, val
, modname
);
3878 pr_warn("%s: unknown parameter '%s' ignored\n", modname
, param
);
3882 static void cfi_init(struct module
*mod
);
3885 * Allocate and load the module: note that size of section 0 is always
3886 * zero, and we rely on this for optional sections.
3888 static int load_module(struct load_info
*info
, const char __user
*uargs
,
3896 * Do the signature check (if any) first. All that
3897 * the signature check needs is info->len, it does
3898 * not need any of the section info. That can be
3899 * set up later. This will minimize the chances
3900 * of a corrupt module causing problems before
3901 * we even get to the signature check.
3903 * The check will also adjust info->len by stripping
3904 * off the sig length at the end of the module, making
3905 * checks against info->len more correct.
3907 err
= module_sig_check(info
, flags
);
3912 * Do basic sanity checks against the ELF header and
3915 err
= elf_validity_check(info
);
3917 pr_err("Module has invalid ELF structures\n");
3922 * Everything checks out, so set up the section info
3923 * in the info structure.
3925 err
= setup_load_info(info
, flags
);
3930 * Now that we know we have the correct module name, check
3931 * if it's blacklisted.
3933 if (blacklisted(info
->name
)) {
3935 pr_err("Module %s is blacklisted\n", info
->name
);
3939 err
= rewrite_section_headers(info
, flags
);
3943 /* Check module struct version now, before we try to use module. */
3944 if (!check_modstruct_version(info
, info
->mod
)) {
3949 /* Figure out module layout, and allocate all the memory. */
3950 mod
= layout_and_allocate(info
, flags
);
3956 audit_log_kern_module(mod
->name
);
3958 /* Reserve our place in the list. */
3959 err
= add_unformed_module(mod
);
3963 #ifdef CONFIG_MODULE_SIG
3964 mod
->sig_ok
= info
->sig_ok
;
3966 pr_notice_once("%s: module verification failed: signature "
3967 "and/or required key missing - tainting "
3968 "kernel\n", mod
->name
);
3969 add_taint_module(mod
, TAINT_UNSIGNED_MODULE
, LOCKDEP_STILL_OK
);
3973 /* To avoid stressing percpu allocator, do this once we're unique. */
3974 err
= percpu_modalloc(mod
, info
);
3978 /* Now module is in final location, initialize linked lists, etc. */
3979 err
= module_unload_init(mod
);
3983 init_param_lock(mod
);
3986 * Now we've got everything in the final locations, we can
3987 * find optional sections.
3989 err
= find_module_sections(mod
, info
);
3993 err
= check_module_license_and_versions(mod
);
3997 /* Set up MODINFO_ATTR fields */
3998 setup_modinfo(mod
, info
);
4000 /* Fix up syms, so that st_value is a pointer to location. */
4001 err
= simplify_symbols(mod
, info
);
4005 err
= apply_relocations(mod
, info
);
4009 err
= post_relocation(mod
, info
);
4013 flush_module_icache(mod
);
4015 /* Setup CFI for the module. */
4018 /* Now copy in args */
4019 mod
->args
= strndup_user(uargs
, ~0UL >> 1);
4020 if (IS_ERR(mod
->args
)) {
4021 err
= PTR_ERR(mod
->args
);
4022 goto free_arch_cleanup
;
4025 dynamic_debug_setup(mod
, info
->debug
, info
->num_debug
);
4027 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
4028 ftrace_module_init(mod
);
4030 /* Finally it's fully formed, ready to start executing. */
4031 err
= complete_formation(mod
, info
);
4033 goto ddebug_cleanup
;
4035 err
= prepare_coming_module(mod
);
4039 /* Module is ready to execute: parsing args may do that. */
4040 after_dashes
= parse_args(mod
->name
, mod
->args
, mod
->kp
, mod
->num_kp
,
4042 unknown_module_param_cb
);
4043 if (IS_ERR(after_dashes
)) {
4044 err
= PTR_ERR(after_dashes
);
4045 goto coming_cleanup
;
4046 } else if (after_dashes
) {
4047 pr_warn("%s: parameters '%s' after `--' ignored\n",
4048 mod
->name
, after_dashes
);
4051 /* Link in to sysfs. */
4052 err
= mod_sysfs_setup(mod
, info
, mod
->kp
, mod
->num_kp
);
4054 goto coming_cleanup
;
4056 if (is_livepatch_module(mod
)) {
4057 err
= copy_module_elf(mod
, info
);
4062 /* Get rid of temporary copy. */
4066 trace_module_load(mod
);
4068 return do_init_module(mod
);
4071 mod_sysfs_teardown(mod
);
4073 mod
->state
= MODULE_STATE_GOING
;
4074 destroy_params(mod
->kp
, mod
->num_kp
);
4075 blocking_notifier_call_chain(&module_notify_list
,
4076 MODULE_STATE_GOING
, mod
);
4077 klp_module_going(mod
);
4079 mod
->state
= MODULE_STATE_GOING
;
4080 /* module_bug_cleanup needs module_mutex protection */
4081 mutex_lock(&module_mutex
);
4082 module_bug_cleanup(mod
);
4083 mutex_unlock(&module_mutex
);
4086 ftrace_release_mod(mod
);
4087 dynamic_debug_remove(mod
, info
->debug
);
4092 module_arch_cleanup(mod
);
4096 module_unload_free(mod
);
4098 mutex_lock(&module_mutex
);
4099 /* Unlink carefully: kallsyms could be walking list. */
4100 list_del_rcu(&mod
->list
);
4101 mod_tree_remove(mod
);
4102 wake_up_all(&module_wq
);
4103 /* Wait for RCU-sched synchronizing before releasing mod->list. */
4105 mutex_unlock(&module_mutex
);
4107 /* Free lock-classes; relies on the preceding sync_rcu() */
4108 lockdep_free_key_range(mod
->core_layout
.base
, mod
->core_layout
.size
);
4110 module_deallocate(mod
, info
);
4116 SYSCALL_DEFINE3(init_module
, void __user
*, umod
,
4117 unsigned long, len
, const char __user
*, uargs
)
4120 struct load_info info
= { };
4122 err
= may_init_module();
4126 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
4129 err
= copy_module_from_user(umod
, len
, &info
);
4133 return load_module(&info
, uargs
, 0);
4136 SYSCALL_DEFINE3(finit_module
, int, fd
, const char __user
*, uargs
, int, flags
)
4138 struct load_info info
= { };
4142 err
= may_init_module();
4146 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd
, uargs
, flags
);
4148 if (flags
& ~(MODULE_INIT_IGNORE_MODVERSIONS
4149 |MODULE_INIT_IGNORE_VERMAGIC
))
4152 err
= kernel_read_file_from_fd(fd
, 0, &hdr
, INT_MAX
, NULL
,
4159 return load_module(&info
, uargs
, flags
);
4162 static inline int within(unsigned long addr
, void *start
, unsigned long size
)
4164 return ((void *)addr
>= start
&& (void *)addr
< start
+ size
);
4167 #ifdef CONFIG_KALLSYMS
4169 * This ignores the intensely annoying "mapping symbols" found
4170 * in ARM ELF files: $a, $t and $d.
4172 static inline int is_arm_mapping_symbol(const char *str
)
4174 if (str
[0] == '.' && str
[1] == 'L')
4176 return str
[0] == '$' && strchr("axtd", str
[1])
4177 && (str
[2] == '\0' || str
[2] == '.');
4180 static const char *kallsyms_symbol_name(struct mod_kallsyms
*kallsyms
, unsigned int symnum
)
4182 return kallsyms
->strtab
+ kallsyms
->symtab
[symnum
].st_name
;
4186 * Given a module and address, find the corresponding symbol and return its name
4187 * while providing its size and offset if needed.
4189 static const char *find_kallsyms_symbol(struct module
*mod
,
4191 unsigned long *size
,
4192 unsigned long *offset
)
4194 unsigned int i
, best
= 0;
4195 unsigned long nextval
, bestval
;
4196 struct mod_kallsyms
*kallsyms
= rcu_dereference_sched(mod
->kallsyms
);
4198 /* At worse, next value is at end of module */
4199 if (within_module_init(addr
, mod
))
4200 nextval
= (unsigned long)mod
->init_layout
.base
+mod
->init_layout
.text_size
;
4202 nextval
= (unsigned long)mod
->core_layout
.base
+mod
->core_layout
.text_size
;
4204 bestval
= kallsyms_symbol_value(&kallsyms
->symtab
[best
]);
4207 * Scan for closest preceding symbol, and next symbol. (ELF
4208 * starts real symbols at 1).
4210 for (i
= 1; i
< kallsyms
->num_symtab
; i
++) {
4211 const Elf_Sym
*sym
= &kallsyms
->symtab
[i
];
4212 unsigned long thisval
= kallsyms_symbol_value(sym
);
4214 if (sym
->st_shndx
== SHN_UNDEF
)
4218 * We ignore unnamed symbols: they're uninformative
4219 * and inserted at a whim.
4221 if (*kallsyms_symbol_name(kallsyms
, i
) == '\0'
4222 || is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms
, i
)))
4225 if (thisval
<= addr
&& thisval
> bestval
) {
4229 if (thisval
> addr
&& thisval
< nextval
)
4237 *size
= nextval
- bestval
;
4239 *offset
= addr
- bestval
;
4241 return kallsyms_symbol_name(kallsyms
, best
);
4244 void * __weak
dereference_module_function_descriptor(struct module
*mod
,
4251 * For kallsyms to ask for address resolution. NULL means not found. Careful
4252 * not to lock to avoid deadlock on oopses, simply disable preemption.
4254 const char *module_address_lookup(unsigned long addr
,
4255 unsigned long *size
,
4256 unsigned long *offset
,
4260 const char *ret
= NULL
;
4264 mod
= __module_address(addr
);
4267 *modname
= mod
->name
;
4269 ret
= find_kallsyms_symbol(mod
, addr
, size
, offset
);
4271 /* Make a copy in here where it's safe */
4273 strncpy(namebuf
, ret
, KSYM_NAME_LEN
- 1);
4281 int lookup_module_symbol_name(unsigned long addr
, char *symname
)
4286 list_for_each_entry_rcu(mod
, &modules
, list
) {
4287 if (mod
->state
== MODULE_STATE_UNFORMED
)
4289 if (within_module(addr
, mod
)) {
4292 sym
= find_kallsyms_symbol(mod
, addr
, NULL
, NULL
);
4296 strlcpy(symname
, sym
, KSYM_NAME_LEN
);
4306 int lookup_module_symbol_attrs(unsigned long addr
, unsigned long *size
,
4307 unsigned long *offset
, char *modname
, char *name
)
4312 list_for_each_entry_rcu(mod
, &modules
, list
) {
4313 if (mod
->state
== MODULE_STATE_UNFORMED
)
4315 if (within_module(addr
, mod
)) {
4318 sym
= find_kallsyms_symbol(mod
, addr
, size
, offset
);
4322 strlcpy(modname
, mod
->name
, MODULE_NAME_LEN
);
4324 strlcpy(name
, sym
, KSYM_NAME_LEN
);
4334 int module_get_kallsym(unsigned int symnum
, unsigned long *value
, char *type
,
4335 char *name
, char *module_name
, int *exported
)
4340 list_for_each_entry_rcu(mod
, &modules
, list
) {
4341 struct mod_kallsyms
*kallsyms
;
4343 if (mod
->state
== MODULE_STATE_UNFORMED
)
4345 kallsyms
= rcu_dereference_sched(mod
->kallsyms
);
4346 if (symnum
< kallsyms
->num_symtab
) {
4347 const Elf_Sym
*sym
= &kallsyms
->symtab
[symnum
];
4349 *value
= kallsyms_symbol_value(sym
);
4350 *type
= kallsyms
->typetab
[symnum
];
4351 strlcpy(name
, kallsyms_symbol_name(kallsyms
, symnum
), KSYM_NAME_LEN
);
4352 strlcpy(module_name
, mod
->name
, MODULE_NAME_LEN
);
4353 *exported
= is_exported(name
, *value
, mod
);
4357 symnum
-= kallsyms
->num_symtab
;
4363 /* Given a module and name of symbol, find and return the symbol's value */
4364 static unsigned long find_kallsyms_symbol_value(struct module
*mod
, const char *name
)
4367 struct mod_kallsyms
*kallsyms
= rcu_dereference_sched(mod
->kallsyms
);
4369 for (i
= 0; i
< kallsyms
->num_symtab
; i
++) {
4370 const Elf_Sym
*sym
= &kallsyms
->symtab
[i
];
4372 if (strcmp(name
, kallsyms_symbol_name(kallsyms
, i
)) == 0 &&
4373 sym
->st_shndx
!= SHN_UNDEF
)
4374 return kallsyms_symbol_value(sym
);
4379 /* Look for this name: can be of form module:name. */
4380 unsigned long module_kallsyms_lookup_name(const char *name
)
4384 unsigned long ret
= 0;
4386 /* Don't lock: we're in enough trouble already. */
4388 if ((colon
= strnchr(name
, MODULE_NAME_LEN
, ':')) != NULL
) {
4389 if ((mod
= find_module_all(name
, colon
- name
, false)) != NULL
)
4390 ret
= find_kallsyms_symbol_value(mod
, colon
+1);
4392 list_for_each_entry_rcu(mod
, &modules
, list
) {
4393 if (mod
->state
== MODULE_STATE_UNFORMED
)
4395 if ((ret
= find_kallsyms_symbol_value(mod
, name
)) != 0)
4403 #ifdef CONFIG_LIVEPATCH
4404 int module_kallsyms_on_each_symbol(int (*fn
)(void *, const char *,
4405 struct module
*, unsigned long),
4412 mutex_lock(&module_mutex
);
4413 list_for_each_entry(mod
, &modules
, list
) {
4414 /* We hold module_mutex: no need for rcu_dereference_sched */
4415 struct mod_kallsyms
*kallsyms
= mod
->kallsyms
;
4417 if (mod
->state
== MODULE_STATE_UNFORMED
)
4419 for (i
= 0; i
< kallsyms
->num_symtab
; i
++) {
4420 const Elf_Sym
*sym
= &kallsyms
->symtab
[i
];
4422 if (sym
->st_shndx
== SHN_UNDEF
)
4425 ret
= fn(data
, kallsyms_symbol_name(kallsyms
, i
),
4426 mod
, kallsyms_symbol_value(sym
));
4431 mutex_unlock(&module_mutex
);
4434 #endif /* CONFIG_LIVEPATCH */
4435 #endif /* CONFIG_KALLSYMS */
4437 static void cfi_init(struct module
*mod
)
4439 #ifdef CONFIG_CFI_CLANG
4443 rcu_read_lock_sched();
4444 mod
->cfi_check
= (cfi_check_fn
)
4445 find_kallsyms_symbol_value(mod
, "__cfi_check");
4446 init
= (initcall_t
*)
4447 find_kallsyms_symbol_value(mod
, "__cfi_jt_init_module");
4448 exit
= (exitcall_t
*)
4449 find_kallsyms_symbol_value(mod
, "__cfi_jt_cleanup_module");
4450 rcu_read_unlock_sched();
4452 /* Fix init/exit functions to point to the CFI jump table */
4458 cfi_module_add(mod
, module_addr_min
);
4462 static void cfi_cleanup(struct module
*mod
)
4464 #ifdef CONFIG_CFI_CLANG
4465 cfi_module_remove(mod
, module_addr_min
);
4469 /* Maximum number of characters written by module_flags() */
4470 #define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
4472 /* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
4473 static char *module_flags(struct module
*mod
, char *buf
)
4477 BUG_ON(mod
->state
== MODULE_STATE_UNFORMED
);
4479 mod
->state
== MODULE_STATE_GOING
||
4480 mod
->state
== MODULE_STATE_COMING
) {
4482 bx
+= module_flags_taint(mod
, buf
+ bx
);
4483 /* Show a - for module-is-being-unloaded */
4484 if (mod
->state
== MODULE_STATE_GOING
)
4486 /* Show a + for module-is-being-loaded */
4487 if (mod
->state
== MODULE_STATE_COMING
)
4496 #ifdef CONFIG_PROC_FS
4497 /* Called by the /proc file system to return a list of modules. */
4498 static void *m_start(struct seq_file
*m
, loff_t
*pos
)
4500 mutex_lock(&module_mutex
);
4501 return seq_list_start(&modules
, *pos
);
4504 static void *m_next(struct seq_file
*m
, void *p
, loff_t
*pos
)
4506 return seq_list_next(p
, &modules
, pos
);
4509 static void m_stop(struct seq_file
*m
, void *p
)
4511 mutex_unlock(&module_mutex
);
4514 static int m_show(struct seq_file
*m
, void *p
)
4516 struct module
*mod
= list_entry(p
, struct module
, list
);
4517 char buf
[MODULE_FLAGS_BUF_SIZE
];
4520 /* We always ignore unformed modules. */
4521 if (mod
->state
== MODULE_STATE_UNFORMED
)
4524 seq_printf(m
, "%s %u",
4525 mod
->name
, mod
->init_layout
.size
+ mod
->core_layout
.size
);
4526 print_unload_info(m
, mod
);
4528 /* Informative for users. */
4529 seq_printf(m
, " %s",
4530 mod
->state
== MODULE_STATE_GOING
? "Unloading" :
4531 mod
->state
== MODULE_STATE_COMING
? "Loading" :
4533 /* Used by oprofile and other similar tools. */
4534 value
= m
->private ? NULL
: mod
->core_layout
.base
;
4535 seq_printf(m
, " 0x%px", value
);
4539 seq_printf(m
, " %s", module_flags(mod
, buf
));
4546 * Format: modulename size refcount deps address
4548 * Where refcount is a number or -, and deps is a comma-separated list
4551 static const struct seq_operations modules_op
= {
4559 * This also sets the "private" pointer to non-NULL if the
4560 * kernel pointers should be hidden (so you can just test
4561 * "m->private" to see if you should keep the values private).
4563 * We use the same logic as for /proc/kallsyms.
4565 static int modules_open(struct inode
*inode
, struct file
*file
)
4567 int err
= seq_open(file
, &modules_op
);
4570 struct seq_file
*m
= file
->private_data
;
4571 m
->private = kallsyms_show_value(file
->f_cred
) ? NULL
: (void *)8ul;
4577 static const struct proc_ops modules_proc_ops
= {
4578 .proc_flags
= PROC_ENTRY_PERMANENT
,
4579 .proc_open
= modules_open
,
4580 .proc_read
= seq_read
,
4581 .proc_lseek
= seq_lseek
,
4582 .proc_release
= seq_release
,
4585 static int __init
proc_modules_init(void)
4587 proc_create("modules", 0, NULL
, &modules_proc_ops
);
4590 module_init(proc_modules_init
);
4593 /* Given an address, look for it in the module exception tables. */
4594 const struct exception_table_entry
*search_module_extables(unsigned long addr
)
4596 const struct exception_table_entry
*e
= NULL
;
4600 mod
= __module_address(addr
);
4604 if (!mod
->num_exentries
)
4607 e
= search_extable(mod
->extable
,
4614 * Now, if we found one, we are running inside it now, hence
4615 * we cannot unload the module, hence no refcnt needed.
4621 * is_module_address() - is this address inside a module?
4622 * @addr: the address to check.
4624 * See is_module_text_address() if you simply want to see if the address
4625 * is code (not data).
4627 bool is_module_address(unsigned long addr
)
4632 ret
= __module_address(addr
) != NULL
;
4639 * __module_address() - get the module which contains an address.
4640 * @addr: the address.
4642 * Must be called with preempt disabled or module mutex held so that
4643 * module doesn't get freed during this.
4645 struct module
*__module_address(unsigned long addr
)
4649 if (addr
< module_addr_min
|| addr
> module_addr_max
)
4652 module_assert_mutex_or_preempt();
4654 mod
= mod_find(addr
);
4656 BUG_ON(!within_module(addr
, mod
));
4657 if (mod
->state
== MODULE_STATE_UNFORMED
)
4664 * is_module_text_address() - is this address inside module code?
4665 * @addr: the address to check.
4667 * See is_module_address() if you simply want to see if the address is
4668 * anywhere in a module. See kernel_text_address() for testing if an
4669 * address corresponds to kernel or module code.
4671 bool is_module_text_address(unsigned long addr
)
4676 ret
= __module_text_address(addr
) != NULL
;
4683 * __module_text_address() - get the module whose code contains an address.
4684 * @addr: the address.
4686 * Must be called with preempt disabled or module mutex held so that
4687 * module doesn't get freed during this.
4689 struct module
*__module_text_address(unsigned long addr
)
4691 struct module
*mod
= __module_address(addr
);
4693 /* Make sure it's within the text section. */
4694 if (!within(addr
, mod
->init_layout
.base
, mod
->init_layout
.text_size
)
4695 && !within(addr
, mod
->core_layout
.base
, mod
->core_layout
.text_size
))
4701 /* Don't grab lock, we're oopsing. */
4702 void print_modules(void)
4705 char buf
[MODULE_FLAGS_BUF_SIZE
];
4707 printk(KERN_DEFAULT
"Modules linked in:");
4708 /* Most callers should already have preempt disabled, but make sure */
4710 list_for_each_entry_rcu(mod
, &modules
, list
) {
4711 if (mod
->state
== MODULE_STATE_UNFORMED
)
4713 pr_cont(" %s%s", mod
->name
, module_flags(mod
, buf
));
4716 if (last_unloaded_module
[0])
4717 pr_cont(" [last unloaded: %s]", last_unloaded_module
);
4721 #ifdef CONFIG_MODVERSIONS
4723 * Generate the signature for all relevant module structures here.
4724 * If these change, we don't want to try to parse the module.
4726 void module_layout(struct module
*mod
,
4727 struct modversion_info
*ver
,
4728 struct kernel_param
*kp
,
4729 struct kernel_symbol
*ks
,
4730 struct tracepoint
* const *tp
)
4733 EXPORT_SYMBOL(module_layout
);