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 static bool sig_enforce
= IS_ENABLED(CONFIG_MODULE_SIG_FORCE
);
270 module_param(sig_enforce
, bool_enable_only
, 0644);
273 * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
274 * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
276 bool is_module_sig_enforced(void)
280 EXPORT_SYMBOL(is_module_sig_enforced
);
282 void set_module_sig_enforced(void)
287 /* Block module loading/unloading? */
288 int modules_disabled
= 0;
289 core_param(nomodule
, modules_disabled
, bint
, 0);
291 /* Waiting for a module to finish initializing? */
292 static DECLARE_WAIT_QUEUE_HEAD(module_wq
);
294 static BLOCKING_NOTIFIER_HEAD(module_notify_list
);
296 int register_module_notifier(struct notifier_block
*nb
)
298 return blocking_notifier_chain_register(&module_notify_list
, nb
);
300 EXPORT_SYMBOL(register_module_notifier
);
302 int unregister_module_notifier(struct notifier_block
*nb
)
304 return blocking_notifier_chain_unregister(&module_notify_list
, nb
);
306 EXPORT_SYMBOL(unregister_module_notifier
);
309 * We require a truly strong try_module_get(): 0 means success.
310 * Otherwise an error is returned due to ongoing or failed
311 * initialization etc.
313 static inline int strong_try_module_get(struct module
*mod
)
315 BUG_ON(mod
&& mod
->state
== MODULE_STATE_UNFORMED
);
316 if (mod
&& mod
->state
== MODULE_STATE_COMING
)
318 if (try_module_get(mod
))
324 static inline void add_taint_module(struct module
*mod
, unsigned flag
,
325 enum lockdep_ok lockdep_ok
)
327 add_taint(flag
, lockdep_ok
);
328 set_bit(flag
, &mod
->taints
);
332 * A thread that wants to hold a reference to a module only while it
333 * is running can call this to safely exit. nfsd and lockd use this.
335 void __noreturn
__module_put_and_exit(struct module
*mod
, long code
)
340 EXPORT_SYMBOL(__module_put_and_exit
);
342 /* Find a module section: 0 means not found. */
343 static unsigned int find_sec(const struct load_info
*info
, const char *name
)
347 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
348 Elf_Shdr
*shdr
= &info
->sechdrs
[i
];
349 /* Alloc bit cleared means "ignore it." */
350 if ((shdr
->sh_flags
& SHF_ALLOC
)
351 && strcmp(info
->secstrings
+ shdr
->sh_name
, name
) == 0)
357 /* Find a module section, or NULL. */
358 static void *section_addr(const struct load_info
*info
, const char *name
)
360 /* Section 0 has sh_addr 0. */
361 return (void *)info
->sechdrs
[find_sec(info
, name
)].sh_addr
;
364 /* Find a module section, or NULL. Fill in number of "objects" in section. */
365 static void *section_objs(const struct load_info
*info
,
370 unsigned int sec
= find_sec(info
, name
);
372 /* Section 0 has sh_addr 0 and sh_size 0. */
373 *num
= info
->sechdrs
[sec
].sh_size
/ object_size
;
374 return (void *)info
->sechdrs
[sec
].sh_addr
;
377 /* Find a module section: 0 means not found. Ignores SHF_ALLOC flag. */
378 static unsigned int find_any_sec(const struct load_info
*info
, const char *name
)
382 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
383 Elf_Shdr
*shdr
= &info
->sechdrs
[i
];
384 if (strcmp(info
->secstrings
+ shdr
->sh_name
, name
) == 0)
391 * Find a module section, or NULL. Fill in number of "objects" in section.
392 * Ignores SHF_ALLOC flag.
394 static __maybe_unused
void *any_section_objs(const struct load_info
*info
,
399 unsigned int sec
= find_any_sec(info
, name
);
401 /* Section 0 has sh_addr 0 and sh_size 0. */
402 *num
= info
->sechdrs
[sec
].sh_size
/ object_size
;
403 return (void *)info
->sechdrs
[sec
].sh_addr
;
406 /* Provided by the linker */
407 extern const struct kernel_symbol __start___ksymtab
[];
408 extern const struct kernel_symbol __stop___ksymtab
[];
409 extern const struct kernel_symbol __start___ksymtab_gpl
[];
410 extern const struct kernel_symbol __stop___ksymtab_gpl
[];
411 extern const s32 __start___kcrctab
[];
412 extern const s32 __start___kcrctab_gpl
[];
414 #ifndef CONFIG_MODVERSIONS
415 #define symversion(base, idx) NULL
417 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
421 const struct kernel_symbol
*start
, *stop
;
429 struct find_symbol_arg
{
436 struct module
*owner
;
438 const struct kernel_symbol
*sym
;
439 enum mod_license license
;
442 static bool check_exported_symbol(const struct symsearch
*syms
,
443 struct module
*owner
,
444 unsigned int symnum
, void *data
)
446 struct find_symbol_arg
*fsa
= data
;
448 if (!fsa
->gplok
&& syms
->license
== GPL_ONLY
)
451 fsa
->crc
= symversion(syms
->crcs
, symnum
);
452 fsa
->sym
= &syms
->start
[symnum
];
453 fsa
->license
= syms
->license
;
457 static unsigned long kernel_symbol_value(const struct kernel_symbol
*sym
)
459 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
460 return (unsigned long)offset_to_ptr(&sym
->value_offset
);
466 static const char *kernel_symbol_name(const struct kernel_symbol
*sym
)
468 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
469 return offset_to_ptr(&sym
->name_offset
);
475 static const char *kernel_symbol_namespace(const struct kernel_symbol
*sym
)
477 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
478 if (!sym
->namespace_offset
)
480 return offset_to_ptr(&sym
->namespace_offset
);
482 return sym
->namespace;
486 static int cmp_name(const void *name
, const void *sym
)
488 return strcmp(name
, kernel_symbol_name(sym
));
491 static bool find_exported_symbol_in_section(const struct symsearch
*syms
,
492 struct module
*owner
,
495 struct find_symbol_arg
*fsa
= data
;
496 struct kernel_symbol
*sym
;
498 sym
= bsearch(fsa
->name
, syms
->start
, syms
->stop
- syms
->start
,
499 sizeof(struct kernel_symbol
), cmp_name
);
501 if (sym
!= NULL
&& check_exported_symbol(syms
, owner
,
502 sym
- syms
->start
, data
))
509 * Find an exported symbol and return it, along with, (optional) crc and
510 * (optional) module which owns it. Needs preempt disabled or module_mutex.
512 static bool find_symbol(struct find_symbol_arg
*fsa
)
514 static const struct symsearch arr
[] = {
515 { __start___ksymtab
, __stop___ksymtab
, __start___kcrctab
,
517 { __start___ksymtab_gpl
, __stop___ksymtab_gpl
,
518 __start___kcrctab_gpl
,
524 module_assert_mutex_or_preempt();
526 for (i
= 0; i
< ARRAY_SIZE(arr
); i
++)
527 if (find_exported_symbol_in_section(&arr
[i
], NULL
, fsa
))
530 list_for_each_entry_rcu(mod
, &modules
, list
,
531 lockdep_is_held(&module_mutex
)) {
532 struct symsearch arr
[] = {
533 { mod
->syms
, mod
->syms
+ mod
->num_syms
, mod
->crcs
,
535 { mod
->gpl_syms
, mod
->gpl_syms
+ mod
->num_gpl_syms
,
540 if (mod
->state
== MODULE_STATE_UNFORMED
)
543 for (i
= 0; i
< ARRAY_SIZE(arr
); i
++)
544 if (find_exported_symbol_in_section(&arr
[i
], mod
, fsa
))
548 pr_debug("Failed to find symbol %s\n", fsa
->name
);
553 * Search for module by name: must hold module_mutex (or preempt disabled
554 * for read-only access).
556 static struct module
*find_module_all(const char *name
, size_t len
,
561 module_assert_mutex_or_preempt();
563 list_for_each_entry_rcu(mod
, &modules
, list
,
564 lockdep_is_held(&module_mutex
)) {
565 if (!even_unformed
&& mod
->state
== MODULE_STATE_UNFORMED
)
567 if (strlen(mod
->name
) == len
&& !memcmp(mod
->name
, name
, len
))
573 struct module
*find_module(const char *name
)
575 return find_module_all(name
, strlen(name
), false);
580 static inline void __percpu
*mod_percpu(struct module
*mod
)
585 static int percpu_modalloc(struct module
*mod
, struct load_info
*info
)
587 Elf_Shdr
*pcpusec
= &info
->sechdrs
[info
->index
.pcpu
];
588 unsigned long align
= pcpusec
->sh_addralign
;
590 if (!pcpusec
->sh_size
)
593 if (align
> PAGE_SIZE
) {
594 pr_warn("%s: per-cpu alignment %li > %li\n",
595 mod
->name
, align
, PAGE_SIZE
);
599 mod
->percpu
= __alloc_reserved_percpu(pcpusec
->sh_size
, align
);
601 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
602 mod
->name
, (unsigned long)pcpusec
->sh_size
);
605 mod
->percpu_size
= pcpusec
->sh_size
;
609 static void percpu_modfree(struct module
*mod
)
611 free_percpu(mod
->percpu
);
614 static unsigned int find_pcpusec(struct load_info
*info
)
616 return find_sec(info
, ".data..percpu");
619 static void percpu_modcopy(struct module
*mod
,
620 const void *from
, unsigned long size
)
624 for_each_possible_cpu(cpu
)
625 memcpy(per_cpu_ptr(mod
->percpu
, cpu
), from
, size
);
628 bool __is_module_percpu_address(unsigned long addr
, unsigned long *can_addr
)
635 list_for_each_entry_rcu(mod
, &modules
, list
) {
636 if (mod
->state
== MODULE_STATE_UNFORMED
)
638 if (!mod
->percpu_size
)
640 for_each_possible_cpu(cpu
) {
641 void *start
= per_cpu_ptr(mod
->percpu
, cpu
);
642 void *va
= (void *)addr
;
644 if (va
>= start
&& va
< start
+ mod
->percpu_size
) {
646 *can_addr
= (unsigned long) (va
- start
);
647 *can_addr
+= (unsigned long)
648 per_cpu_ptr(mod
->percpu
,
662 * is_module_percpu_address() - test whether address is from module static percpu
663 * @addr: address to test
665 * Test whether @addr belongs to module static percpu area.
667 * Return: %true if @addr is from module static percpu area
669 bool is_module_percpu_address(unsigned long addr
)
671 return __is_module_percpu_address(addr
, NULL
);
674 #else /* ... !CONFIG_SMP */
676 static inline void __percpu
*mod_percpu(struct module
*mod
)
680 static int percpu_modalloc(struct module
*mod
, struct load_info
*info
)
682 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
683 if (info
->sechdrs
[info
->index
.pcpu
].sh_size
!= 0)
687 static inline void percpu_modfree(struct module
*mod
)
690 static unsigned int find_pcpusec(struct load_info
*info
)
694 static inline void percpu_modcopy(struct module
*mod
,
695 const void *from
, unsigned long size
)
697 /* pcpusec should be 0, and size of that section should be 0. */
700 bool is_module_percpu_address(unsigned long addr
)
705 bool __is_module_percpu_address(unsigned long addr
, unsigned long *can_addr
)
710 #endif /* CONFIG_SMP */
712 #define MODINFO_ATTR(field) \
713 static void setup_modinfo_##field(struct module *mod, const char *s) \
715 mod->field = kstrdup(s, GFP_KERNEL); \
717 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
718 struct module_kobject *mk, char *buffer) \
720 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
722 static int modinfo_##field##_exists(struct module *mod) \
724 return mod->field != NULL; \
726 static void free_modinfo_##field(struct module *mod) \
731 static struct module_attribute modinfo_##field = { \
732 .attr = { .name = __stringify(field), .mode = 0444 }, \
733 .show = show_modinfo_##field, \
734 .setup = setup_modinfo_##field, \
735 .test = modinfo_##field##_exists, \
736 .free = free_modinfo_##field, \
739 MODINFO_ATTR(version
);
740 MODINFO_ATTR(srcversion
);
742 static char last_unloaded_module
[MODULE_NAME_LEN
+1];
744 #ifdef CONFIG_MODULE_UNLOAD
746 EXPORT_TRACEPOINT_SYMBOL(module_get
);
748 /* MODULE_REF_BASE is the base reference count by kmodule loader. */
749 #define MODULE_REF_BASE 1
751 /* Init the unload section of the module. */
752 static int module_unload_init(struct module
*mod
)
755 * Initialize reference counter to MODULE_REF_BASE.
756 * refcnt == 0 means module is going.
758 atomic_set(&mod
->refcnt
, MODULE_REF_BASE
);
760 INIT_LIST_HEAD(&mod
->source_list
);
761 INIT_LIST_HEAD(&mod
->target_list
);
763 /* Hold reference count during initialization. */
764 atomic_inc(&mod
->refcnt
);
769 /* Does a already use b? */
770 static int already_uses(struct module
*a
, struct module
*b
)
772 struct module_use
*use
;
774 list_for_each_entry(use
, &b
->source_list
, source_list
) {
775 if (use
->source
== a
) {
776 pr_debug("%s uses %s!\n", a
->name
, b
->name
);
780 pr_debug("%s does not use %s!\n", a
->name
, b
->name
);
786 * - we add 'a' as a "source", 'b' as a "target" of module use
787 * - the module_use is added to the list of 'b' sources (so
788 * 'b' can walk the list to see who sourced them), and of 'a'
789 * targets (so 'a' can see what modules it targets).
791 static int add_module_usage(struct module
*a
, struct module
*b
)
793 struct module_use
*use
;
795 pr_debug("Allocating new usage for %s.\n", a
->name
);
796 use
= kmalloc(sizeof(*use
), GFP_ATOMIC
);
802 list_add(&use
->source_list
, &b
->source_list
);
803 list_add(&use
->target_list
, &a
->target_list
);
807 /* Module a uses b: caller needs module_mutex() */
808 static int ref_module(struct module
*a
, struct module
*b
)
812 if (b
== NULL
|| already_uses(a
, b
))
815 /* If module isn't available, we fail. */
816 err
= strong_try_module_get(b
);
820 err
= add_module_usage(a
, b
);
828 /* Clear the unload stuff of the module. */
829 static void module_unload_free(struct module
*mod
)
831 struct module_use
*use
, *tmp
;
833 mutex_lock(&module_mutex
);
834 list_for_each_entry_safe(use
, tmp
, &mod
->target_list
, target_list
) {
835 struct module
*i
= use
->target
;
836 pr_debug("%s unusing %s\n", mod
->name
, i
->name
);
838 list_del(&use
->source_list
);
839 list_del(&use
->target_list
);
842 mutex_unlock(&module_mutex
);
845 #ifdef CONFIG_MODULE_FORCE_UNLOAD
846 static inline int try_force_unload(unsigned int flags
)
848 int ret
= (flags
& O_TRUNC
);
850 add_taint(TAINT_FORCED_RMMOD
, LOCKDEP_NOW_UNRELIABLE
);
854 static inline int try_force_unload(unsigned int flags
)
858 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
860 /* Try to release refcount of module, 0 means success. */
861 static int try_release_module_ref(struct module
*mod
)
865 /* Try to decrement refcnt which we set at loading */
866 ret
= atomic_sub_return(MODULE_REF_BASE
, &mod
->refcnt
);
869 /* Someone can put this right now, recover with checking */
870 ret
= atomic_add_unless(&mod
->refcnt
, MODULE_REF_BASE
, 0);
875 static int try_stop_module(struct module
*mod
, int flags
, int *forced
)
877 /* If it's not unused, quit unless we're forcing. */
878 if (try_release_module_ref(mod
) != 0) {
879 *forced
= try_force_unload(flags
);
884 /* Mark it as dying. */
885 mod
->state
= MODULE_STATE_GOING
;
891 * module_refcount() - return the refcount or -1 if unloading
892 * @mod: the module we're checking
895 * -1 if the module is in the process of unloading
896 * otherwise the number of references in the kernel to the module
898 int module_refcount(struct module
*mod
)
900 return atomic_read(&mod
->refcnt
) - MODULE_REF_BASE
;
902 EXPORT_SYMBOL(module_refcount
);
904 /* This exists whether we can unload or not */
905 static void free_module(struct module
*mod
);
907 SYSCALL_DEFINE2(delete_module
, const char __user
*, name_user
,
911 char name
[MODULE_NAME_LEN
];
914 if (!capable(CAP_SYS_MODULE
) || modules_disabled
)
917 if (strncpy_from_user(name
, name_user
, MODULE_NAME_LEN
-1) < 0)
919 name
[MODULE_NAME_LEN
-1] = '\0';
921 audit_log_kern_module(name
);
923 if (mutex_lock_interruptible(&module_mutex
) != 0)
926 mod
= find_module(name
);
932 if (!list_empty(&mod
->source_list
)) {
933 /* Other modules depend on us: get rid of them first. */
938 /* Doing init or already dying? */
939 if (mod
->state
!= MODULE_STATE_LIVE
) {
940 /* FIXME: if (force), slam module count damn the torpedoes */
941 pr_debug("%s already dying\n", mod
->name
);
946 /* If it has an init func, it must have an exit func to unload */
947 if (mod
->init
&& !mod
->exit
) {
948 forced
= try_force_unload(flags
);
950 /* This module can't be removed */
956 /* Stop the machine so refcounts can't move and disable module. */
957 ret
= try_stop_module(mod
, flags
, &forced
);
961 mutex_unlock(&module_mutex
);
962 /* Final destruction now no one is using it. */
963 if (mod
->exit
!= NULL
)
965 blocking_notifier_call_chain(&module_notify_list
,
966 MODULE_STATE_GOING
, mod
);
967 klp_module_going(mod
);
968 ftrace_release_mod(mod
);
970 async_synchronize_full();
972 /* Store the name of the last unloaded module for diagnostic purposes */
973 strlcpy(last_unloaded_module
, mod
->name
, sizeof(last_unloaded_module
));
976 /* someone could wait for the module in add_unformed_module() */
977 wake_up_all(&module_wq
);
980 mutex_unlock(&module_mutex
);
984 static inline void print_unload_info(struct seq_file
*m
, struct module
*mod
)
986 struct module_use
*use
;
987 int printed_something
= 0;
989 seq_printf(m
, " %i ", module_refcount(mod
));
992 * Always include a trailing , so userspace can differentiate
993 * between this and the old multi-field proc format.
995 list_for_each_entry(use
, &mod
->source_list
, source_list
) {
996 printed_something
= 1;
997 seq_printf(m
, "%s,", use
->source
->name
);
1000 if (mod
->init
!= NULL
&& mod
->exit
== NULL
) {
1001 printed_something
= 1;
1002 seq_puts(m
, "[permanent],");
1005 if (!printed_something
)
1009 void __symbol_put(const char *symbol
)
1011 struct find_symbol_arg fsa
= {
1017 if (!find_symbol(&fsa
))
1019 module_put(fsa
.owner
);
1022 EXPORT_SYMBOL(__symbol_put
);
1024 /* Note this assumes addr is a function, which it currently always is. */
1025 void symbol_put_addr(void *addr
)
1027 struct module
*modaddr
;
1028 unsigned long a
= (unsigned long)dereference_function_descriptor(addr
);
1030 if (core_kernel_text(a
))
1034 * Even though we hold a reference on the module; we still need to
1035 * disable preemption in order to safely traverse the data structure.
1038 modaddr
= __module_text_address(a
);
1040 module_put(modaddr
);
1043 EXPORT_SYMBOL_GPL(symbol_put_addr
);
1045 static ssize_t
show_refcnt(struct module_attribute
*mattr
,
1046 struct module_kobject
*mk
, char *buffer
)
1048 return sprintf(buffer
, "%i\n", module_refcount(mk
->mod
));
1051 static struct module_attribute modinfo_refcnt
=
1052 __ATTR(refcnt
, 0444, show_refcnt
, NULL
);
1054 void __module_get(struct module
*module
)
1058 atomic_inc(&module
->refcnt
);
1059 trace_module_get(module
, _RET_IP_
);
1063 EXPORT_SYMBOL(__module_get
);
1065 bool try_module_get(struct module
*module
)
1071 /* Note: here, we can fail to get a reference */
1072 if (likely(module_is_live(module
) &&
1073 atomic_inc_not_zero(&module
->refcnt
) != 0))
1074 trace_module_get(module
, _RET_IP_
);
1082 EXPORT_SYMBOL(try_module_get
);
1084 void module_put(struct module
*module
)
1090 ret
= atomic_dec_if_positive(&module
->refcnt
);
1091 WARN_ON(ret
< 0); /* Failed to put refcount */
1092 trace_module_put(module
, _RET_IP_
);
1096 EXPORT_SYMBOL(module_put
);
1098 #else /* !CONFIG_MODULE_UNLOAD */
1099 static inline void print_unload_info(struct seq_file
*m
, struct module
*mod
)
1101 /* We don't know the usage count, or what modules are using. */
1102 seq_puts(m
, " - -");
1105 static inline void module_unload_free(struct module
*mod
)
1109 static int ref_module(struct module
*a
, struct module
*b
)
1111 return strong_try_module_get(b
);
1114 static inline int module_unload_init(struct module
*mod
)
1118 #endif /* CONFIG_MODULE_UNLOAD */
1120 static size_t module_flags_taint(struct module
*mod
, char *buf
)
1125 for (i
= 0; i
< TAINT_FLAGS_COUNT
; i
++) {
1126 if (taint_flags
[i
].module
&& test_bit(i
, &mod
->taints
))
1127 buf
[l
++] = taint_flags
[i
].c_true
;
1133 static ssize_t
show_initstate(struct module_attribute
*mattr
,
1134 struct module_kobject
*mk
, char *buffer
)
1136 const char *state
= "unknown";
1138 switch (mk
->mod
->state
) {
1139 case MODULE_STATE_LIVE
:
1142 case MODULE_STATE_COMING
:
1145 case MODULE_STATE_GOING
:
1151 return sprintf(buffer
, "%s\n", state
);
1154 static struct module_attribute modinfo_initstate
=
1155 __ATTR(initstate
, 0444, show_initstate
, NULL
);
1157 static ssize_t
store_uevent(struct module_attribute
*mattr
,
1158 struct module_kobject
*mk
,
1159 const char *buffer
, size_t count
)
1163 rc
= kobject_synth_uevent(&mk
->kobj
, buffer
, count
);
1164 return rc
? rc
: count
;
1167 struct module_attribute module_uevent
=
1168 __ATTR(uevent
, 0200, NULL
, store_uevent
);
1170 static ssize_t
show_coresize(struct module_attribute
*mattr
,
1171 struct module_kobject
*mk
, char *buffer
)
1173 return sprintf(buffer
, "%u\n", mk
->mod
->core_layout
.size
);
1176 static struct module_attribute modinfo_coresize
=
1177 __ATTR(coresize
, 0444, show_coresize
, NULL
);
1179 static ssize_t
show_initsize(struct module_attribute
*mattr
,
1180 struct module_kobject
*mk
, char *buffer
)
1182 return sprintf(buffer
, "%u\n", mk
->mod
->init_layout
.size
);
1185 static struct module_attribute modinfo_initsize
=
1186 __ATTR(initsize
, 0444, show_initsize
, NULL
);
1188 static ssize_t
show_taint(struct module_attribute
*mattr
,
1189 struct module_kobject
*mk
, char *buffer
)
1193 l
= module_flags_taint(mk
->mod
, buffer
);
1198 static struct module_attribute modinfo_taint
=
1199 __ATTR(taint
, 0444, show_taint
, NULL
);
1201 static struct module_attribute
*modinfo_attrs
[] = {
1204 &modinfo_srcversion
,
1209 #ifdef CONFIG_MODULE_UNLOAD
1215 static const char vermagic
[] = VERMAGIC_STRING
;
1217 static int try_to_force_load(struct module
*mod
, const char *reason
)
1219 #ifdef CONFIG_MODULE_FORCE_LOAD
1220 if (!test_taint(TAINT_FORCED_MODULE
))
1221 pr_warn("%s: %s: kernel tainted.\n", mod
->name
, reason
);
1222 add_taint_module(mod
, TAINT_FORCED_MODULE
, LOCKDEP_NOW_UNRELIABLE
);
1229 #ifdef CONFIG_MODVERSIONS
1231 static u32
resolve_rel_crc(const s32
*crc
)
1233 return *(u32
*)((void *)crc
+ *crc
);
1236 static int check_version(const struct load_info
*info
,
1237 const char *symname
,
1241 Elf_Shdr
*sechdrs
= info
->sechdrs
;
1242 unsigned int versindex
= info
->index
.vers
;
1243 unsigned int i
, num_versions
;
1244 struct modversion_info
*versions
;
1246 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1250 /* No versions at all? modprobe --force does this. */
1252 return try_to_force_load(mod
, symname
) == 0;
1254 versions
= (void *) sechdrs
[versindex
].sh_addr
;
1255 num_versions
= sechdrs
[versindex
].sh_size
1256 / sizeof(struct modversion_info
);
1258 for (i
= 0; i
< num_versions
; i
++) {
1261 if (strcmp(versions
[i
].name
, symname
) != 0)
1264 if (IS_ENABLED(CONFIG_MODULE_REL_CRCS
))
1265 crcval
= resolve_rel_crc(crc
);
1268 if (versions
[i
].crc
== crcval
)
1270 pr_debug("Found checksum %X vs module %lX\n",
1271 crcval
, versions
[i
].crc
);
1275 /* Broken toolchain. Warn once, then let it go.. */
1276 pr_warn_once("%s: no symbol version for %s\n", info
->name
, symname
);
1280 pr_warn("%s: disagrees about version of symbol %s\n",
1281 info
->name
, symname
);
1285 static inline int check_modstruct_version(const struct load_info
*info
,
1288 struct find_symbol_arg fsa
= {
1289 .name
= "module_layout",
1294 * Since this should be found in kernel (which can't be removed), no
1295 * locking is necessary -- use preempt_disable() to placate lockdep.
1298 if (!find_symbol(&fsa
)) {
1303 return check_version(info
, "module_layout", mod
, fsa
.crc
);
1306 /* First part is kernel version, which we ignore if module has crcs. */
1307 static inline int same_magic(const char *amagic
, const char *bmagic
,
1311 amagic
+= strcspn(amagic
, " ");
1312 bmagic
+= strcspn(bmagic
, " ");
1314 return strcmp(amagic
, bmagic
) == 0;
1317 static inline int check_version(const struct load_info
*info
,
1318 const char *symname
,
1325 static inline int check_modstruct_version(const struct load_info
*info
,
1331 static inline int same_magic(const char *amagic
, const char *bmagic
,
1334 return strcmp(amagic
, bmagic
) == 0;
1336 #endif /* CONFIG_MODVERSIONS */
1338 static char *get_modinfo(const struct load_info
*info
, const char *tag
);
1339 static char *get_next_modinfo(const struct load_info
*info
, const char *tag
,
1342 static int verify_namespace_is_imported(const struct load_info
*info
,
1343 const struct kernel_symbol
*sym
,
1346 const char *namespace;
1347 char *imported_namespace
;
1349 namespace = kernel_symbol_namespace(sym
);
1350 if (namespace && namespace[0]) {
1351 imported_namespace
= get_modinfo(info
, "import_ns");
1352 while (imported_namespace
) {
1353 if (strcmp(namespace, imported_namespace
) == 0)
1355 imported_namespace
= get_next_modinfo(
1356 info
, "import_ns", imported_namespace
);
1358 #ifdef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1363 "%s: module uses symbol (%s) from namespace %s, but does not import it.\n",
1364 mod
->name
, kernel_symbol_name(sym
), namespace);
1365 #ifndef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1372 static bool inherit_taint(struct module
*mod
, struct module
*owner
)
1374 if (!owner
|| !test_bit(TAINT_PROPRIETARY_MODULE
, &owner
->taints
))
1377 if (mod
->using_gplonly_symbols
) {
1378 pr_err("%s: module using GPL-only symbols uses symbols from proprietary module %s.\n",
1379 mod
->name
, owner
->name
);
1383 if (!test_bit(TAINT_PROPRIETARY_MODULE
, &mod
->taints
)) {
1384 pr_warn("%s: module uses symbols from proprietary module %s, inheriting taint.\n",
1385 mod
->name
, owner
->name
);
1386 set_bit(TAINT_PROPRIETARY_MODULE
, &mod
->taints
);
1391 /* Resolve a symbol for this module. I.e. if we find one, record usage. */
1392 static const struct kernel_symbol
*resolve_symbol(struct module
*mod
,
1393 const struct load_info
*info
,
1397 struct find_symbol_arg fsa
= {
1399 .gplok
= !(mod
->taints
& (1 << TAINT_PROPRIETARY_MODULE
)),
1405 * The module_mutex should not be a heavily contended lock;
1406 * if we get the occasional sleep here, we'll go an extra iteration
1407 * in the wait_event_interruptible(), which is harmless.
1409 sched_annotate_sleep();
1410 mutex_lock(&module_mutex
);
1411 if (!find_symbol(&fsa
))
1414 if (fsa
.license
== GPL_ONLY
)
1415 mod
->using_gplonly_symbols
= true;
1417 if (!inherit_taint(mod
, fsa
.owner
)) {
1422 if (!check_version(info
, name
, mod
, fsa
.crc
)) {
1423 fsa
.sym
= ERR_PTR(-EINVAL
);
1427 err
= verify_namespace_is_imported(info
, fsa
.sym
, mod
);
1429 fsa
.sym
= ERR_PTR(err
);
1433 err
= ref_module(mod
, fsa
.owner
);
1435 fsa
.sym
= ERR_PTR(err
);
1440 /* We must make copy under the lock if we failed to get ref. */
1441 strncpy(ownername
, module_name(fsa
.owner
), MODULE_NAME_LEN
);
1443 mutex_unlock(&module_mutex
);
1447 static const struct kernel_symbol
*
1448 resolve_symbol_wait(struct module
*mod
,
1449 const struct load_info
*info
,
1452 const struct kernel_symbol
*ksym
;
1453 char owner
[MODULE_NAME_LEN
];
1455 if (wait_event_interruptible_timeout(module_wq
,
1456 !IS_ERR(ksym
= resolve_symbol(mod
, info
, name
, owner
))
1457 || PTR_ERR(ksym
) != -EBUSY
,
1459 pr_warn("%s: gave up waiting for init of module %s.\n",
1466 * /sys/module/foo/sections stuff
1467 * J. Corbet <corbet@lwn.net>
1471 #ifdef CONFIG_KALLSYMS
1472 static inline bool sect_empty(const Elf_Shdr
*sect
)
1474 return !(sect
->sh_flags
& SHF_ALLOC
) || sect
->sh_size
== 0;
1477 struct module_sect_attr
{
1478 struct bin_attribute battr
;
1479 unsigned long address
;
1482 struct module_sect_attrs
{
1483 struct attribute_group grp
;
1484 unsigned int nsections
;
1485 struct module_sect_attr attrs
[];
1488 #define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4))
1489 static ssize_t
module_sect_read(struct file
*file
, struct kobject
*kobj
,
1490 struct bin_attribute
*battr
,
1491 char *buf
, loff_t pos
, size_t count
)
1493 struct module_sect_attr
*sattr
=
1494 container_of(battr
, struct module_sect_attr
, battr
);
1495 char bounce
[MODULE_SECT_READ_SIZE
+ 1];
1502 * Since we're a binary read handler, we must account for the
1503 * trailing NUL byte that sprintf will write: if "buf" is
1504 * too small to hold the NUL, or the NUL is exactly the last
1505 * byte, the read will look like it got truncated by one byte.
1506 * Since there is no way to ask sprintf nicely to not write
1507 * the NUL, we have to use a bounce buffer.
1509 wrote
= scnprintf(bounce
, sizeof(bounce
), "0x%px\n",
1510 kallsyms_show_value(file
->f_cred
)
1511 ? (void *)sattr
->address
: NULL
);
1512 count
= min(count
, wrote
);
1513 memcpy(buf
, bounce
, count
);
1518 static void free_sect_attrs(struct module_sect_attrs
*sect_attrs
)
1520 unsigned int section
;
1522 for (section
= 0; section
< sect_attrs
->nsections
; section
++)
1523 kfree(sect_attrs
->attrs
[section
].battr
.attr
.name
);
1527 static void add_sect_attrs(struct module
*mod
, const struct load_info
*info
)
1529 unsigned int nloaded
= 0, i
, size
[2];
1530 struct module_sect_attrs
*sect_attrs
;
1531 struct module_sect_attr
*sattr
;
1532 struct bin_attribute
**gattr
;
1534 /* Count loaded sections and allocate structures */
1535 for (i
= 0; i
< info
->hdr
->e_shnum
; i
++)
1536 if (!sect_empty(&info
->sechdrs
[i
]))
1538 size
[0] = ALIGN(struct_size(sect_attrs
, attrs
, nloaded
),
1539 sizeof(sect_attrs
->grp
.bin_attrs
[0]));
1540 size
[1] = (nloaded
+ 1) * sizeof(sect_attrs
->grp
.bin_attrs
[0]);
1541 sect_attrs
= kzalloc(size
[0] + size
[1], GFP_KERNEL
);
1542 if (sect_attrs
== NULL
)
1545 /* Setup section attributes. */
1546 sect_attrs
->grp
.name
= "sections";
1547 sect_attrs
->grp
.bin_attrs
= (void *)sect_attrs
+ size
[0];
1549 sect_attrs
->nsections
= 0;
1550 sattr
= §_attrs
->attrs
[0];
1551 gattr
= §_attrs
->grp
.bin_attrs
[0];
1552 for (i
= 0; i
< info
->hdr
->e_shnum
; i
++) {
1553 Elf_Shdr
*sec
= &info
->sechdrs
[i
];
1554 if (sect_empty(sec
))
1556 sysfs_bin_attr_init(&sattr
->battr
);
1557 sattr
->address
= sec
->sh_addr
;
1558 sattr
->battr
.attr
.name
=
1559 kstrdup(info
->secstrings
+ sec
->sh_name
, GFP_KERNEL
);
1560 if (sattr
->battr
.attr
.name
== NULL
)
1562 sect_attrs
->nsections
++;
1563 sattr
->battr
.read
= module_sect_read
;
1564 sattr
->battr
.size
= MODULE_SECT_READ_SIZE
;
1565 sattr
->battr
.attr
.mode
= 0400;
1566 *(gattr
++) = &(sattr
++)->battr
;
1570 if (sysfs_create_group(&mod
->mkobj
.kobj
, §_attrs
->grp
))
1573 mod
->sect_attrs
= sect_attrs
;
1576 free_sect_attrs(sect_attrs
);
1579 static void remove_sect_attrs(struct module
*mod
)
1581 if (mod
->sect_attrs
) {
1582 sysfs_remove_group(&mod
->mkobj
.kobj
,
1583 &mod
->sect_attrs
->grp
);
1585 * We are positive that no one is using any sect attrs
1586 * at this point. Deallocate immediately.
1588 free_sect_attrs(mod
->sect_attrs
);
1589 mod
->sect_attrs
= NULL
;
1594 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1597 struct module_notes_attrs
{
1598 struct kobject
*dir
;
1600 struct bin_attribute attrs
[];
1603 static ssize_t
module_notes_read(struct file
*filp
, struct kobject
*kobj
,
1604 struct bin_attribute
*bin_attr
,
1605 char *buf
, loff_t pos
, size_t count
)
1608 * The caller checked the pos and count against our size.
1610 memcpy(buf
, bin_attr
->private + pos
, count
);
1614 static void free_notes_attrs(struct module_notes_attrs
*notes_attrs
,
1617 if (notes_attrs
->dir
) {
1619 sysfs_remove_bin_file(notes_attrs
->dir
,
1620 ¬es_attrs
->attrs
[i
]);
1621 kobject_put(notes_attrs
->dir
);
1626 static void add_notes_attrs(struct module
*mod
, const struct load_info
*info
)
1628 unsigned int notes
, loaded
, i
;
1629 struct module_notes_attrs
*notes_attrs
;
1630 struct bin_attribute
*nattr
;
1632 /* failed to create section attributes, so can't create notes */
1633 if (!mod
->sect_attrs
)
1636 /* Count notes sections and allocate structures. */
1638 for (i
= 0; i
< info
->hdr
->e_shnum
; i
++)
1639 if (!sect_empty(&info
->sechdrs
[i
]) &&
1640 (info
->sechdrs
[i
].sh_type
== SHT_NOTE
))
1646 notes_attrs
= kzalloc(struct_size(notes_attrs
, attrs
, notes
),
1648 if (notes_attrs
== NULL
)
1651 notes_attrs
->notes
= notes
;
1652 nattr
= ¬es_attrs
->attrs
[0];
1653 for (loaded
= i
= 0; i
< info
->hdr
->e_shnum
; ++i
) {
1654 if (sect_empty(&info
->sechdrs
[i
]))
1656 if (info
->sechdrs
[i
].sh_type
== SHT_NOTE
) {
1657 sysfs_bin_attr_init(nattr
);
1658 nattr
->attr
.name
= mod
->sect_attrs
->attrs
[loaded
].battr
.attr
.name
;
1659 nattr
->attr
.mode
= S_IRUGO
;
1660 nattr
->size
= info
->sechdrs
[i
].sh_size
;
1661 nattr
->private = (void *) info
->sechdrs
[i
].sh_addr
;
1662 nattr
->read
= module_notes_read
;
1668 notes_attrs
->dir
= kobject_create_and_add("notes", &mod
->mkobj
.kobj
);
1669 if (!notes_attrs
->dir
)
1672 for (i
= 0; i
< notes
; ++i
)
1673 if (sysfs_create_bin_file(notes_attrs
->dir
,
1674 ¬es_attrs
->attrs
[i
]))
1677 mod
->notes_attrs
= notes_attrs
;
1681 free_notes_attrs(notes_attrs
, i
);
1684 static void remove_notes_attrs(struct module
*mod
)
1686 if (mod
->notes_attrs
)
1687 free_notes_attrs(mod
->notes_attrs
, mod
->notes_attrs
->notes
);
1692 static inline void add_sect_attrs(struct module
*mod
,
1693 const struct load_info
*info
)
1697 static inline void remove_sect_attrs(struct module
*mod
)
1701 static inline void add_notes_attrs(struct module
*mod
,
1702 const struct load_info
*info
)
1706 static inline void remove_notes_attrs(struct module
*mod
)
1709 #endif /* CONFIG_KALLSYMS */
1711 static void del_usage_links(struct module
*mod
)
1713 #ifdef CONFIG_MODULE_UNLOAD
1714 struct module_use
*use
;
1716 mutex_lock(&module_mutex
);
1717 list_for_each_entry(use
, &mod
->target_list
, target_list
)
1718 sysfs_remove_link(use
->target
->holders_dir
, mod
->name
);
1719 mutex_unlock(&module_mutex
);
1723 static int add_usage_links(struct module
*mod
)
1726 #ifdef CONFIG_MODULE_UNLOAD
1727 struct module_use
*use
;
1729 mutex_lock(&module_mutex
);
1730 list_for_each_entry(use
, &mod
->target_list
, target_list
) {
1731 ret
= sysfs_create_link(use
->target
->holders_dir
,
1732 &mod
->mkobj
.kobj
, mod
->name
);
1736 mutex_unlock(&module_mutex
);
1738 del_usage_links(mod
);
1743 static void module_remove_modinfo_attrs(struct module
*mod
, int end
);
1745 static int module_add_modinfo_attrs(struct module
*mod
)
1747 struct module_attribute
*attr
;
1748 struct module_attribute
*temp_attr
;
1752 mod
->modinfo_attrs
= kzalloc((sizeof(struct module_attribute
) *
1753 (ARRAY_SIZE(modinfo_attrs
) + 1)),
1755 if (!mod
->modinfo_attrs
)
1758 temp_attr
= mod
->modinfo_attrs
;
1759 for (i
= 0; (attr
= modinfo_attrs
[i
]); i
++) {
1760 if (!attr
->test
|| attr
->test(mod
)) {
1761 memcpy(temp_attr
, attr
, sizeof(*temp_attr
));
1762 sysfs_attr_init(&temp_attr
->attr
);
1763 error
= sysfs_create_file(&mod
->mkobj
.kobj
,
1775 module_remove_modinfo_attrs(mod
, --i
);
1777 kfree(mod
->modinfo_attrs
);
1781 static void module_remove_modinfo_attrs(struct module
*mod
, int end
)
1783 struct module_attribute
*attr
;
1786 for (i
= 0; (attr
= &mod
->modinfo_attrs
[i
]); i
++) {
1787 if (end
>= 0 && i
> end
)
1789 /* pick a field to test for end of list */
1790 if (!attr
->attr
.name
)
1792 sysfs_remove_file(&mod
->mkobj
.kobj
, &attr
->attr
);
1796 kfree(mod
->modinfo_attrs
);
1799 static void mod_kobject_put(struct module
*mod
)
1801 DECLARE_COMPLETION_ONSTACK(c
);
1802 mod
->mkobj
.kobj_completion
= &c
;
1803 kobject_put(&mod
->mkobj
.kobj
);
1804 wait_for_completion(&c
);
1807 static int mod_sysfs_init(struct module
*mod
)
1810 struct kobject
*kobj
;
1812 if (!module_sysfs_initialized
) {
1813 pr_err("%s: module sysfs not initialized\n", mod
->name
);
1818 kobj
= kset_find_obj(module_kset
, mod
->name
);
1820 pr_err("%s: module is already loaded\n", mod
->name
);
1826 mod
->mkobj
.mod
= mod
;
1828 memset(&mod
->mkobj
.kobj
, 0, sizeof(mod
->mkobj
.kobj
));
1829 mod
->mkobj
.kobj
.kset
= module_kset
;
1830 err
= kobject_init_and_add(&mod
->mkobj
.kobj
, &module_ktype
, NULL
,
1833 mod_kobject_put(mod
);
1839 static int mod_sysfs_setup(struct module
*mod
,
1840 const struct load_info
*info
,
1841 struct kernel_param
*kparam
,
1842 unsigned int num_params
)
1846 err
= mod_sysfs_init(mod
);
1850 mod
->holders_dir
= kobject_create_and_add("holders", &mod
->mkobj
.kobj
);
1851 if (!mod
->holders_dir
) {
1856 err
= module_param_sysfs_setup(mod
, kparam
, num_params
);
1858 goto out_unreg_holders
;
1860 err
= module_add_modinfo_attrs(mod
);
1862 goto out_unreg_param
;
1864 err
= add_usage_links(mod
);
1866 goto out_unreg_modinfo_attrs
;
1868 add_sect_attrs(mod
, info
);
1869 add_notes_attrs(mod
, info
);
1873 out_unreg_modinfo_attrs
:
1874 module_remove_modinfo_attrs(mod
, -1);
1876 module_param_sysfs_remove(mod
);
1878 kobject_put(mod
->holders_dir
);
1880 mod_kobject_put(mod
);
1885 static void mod_sysfs_fini(struct module
*mod
)
1887 remove_notes_attrs(mod
);
1888 remove_sect_attrs(mod
);
1889 mod_kobject_put(mod
);
1892 static void init_param_lock(struct module
*mod
)
1894 mutex_init(&mod
->param_lock
);
1896 #else /* !CONFIG_SYSFS */
1898 static int mod_sysfs_setup(struct module
*mod
,
1899 const struct load_info
*info
,
1900 struct kernel_param
*kparam
,
1901 unsigned int num_params
)
1906 static void mod_sysfs_fini(struct module
*mod
)
1910 static void module_remove_modinfo_attrs(struct module
*mod
, int end
)
1914 static void del_usage_links(struct module
*mod
)
1918 static void init_param_lock(struct module
*mod
)
1921 #endif /* CONFIG_SYSFS */
1923 static void mod_sysfs_teardown(struct module
*mod
)
1925 del_usage_links(mod
);
1926 module_remove_modinfo_attrs(mod
, -1);
1927 module_param_sysfs_remove(mod
);
1928 kobject_put(mod
->mkobj
.drivers_dir
);
1929 kobject_put(mod
->holders_dir
);
1930 mod_sysfs_fini(mod
);
1934 * LKM RO/NX protection: protect module's text/ro-data
1935 * from modification and any data from execution.
1937 * General layout of module is:
1938 * [text] [read-only-data] [ro-after-init] [writable data]
1939 * text_size -----^ ^ ^ ^
1940 * ro_size ------------------------| | |
1941 * ro_after_init_size -----------------------------| |
1942 * size -----------------------------------------------------------|
1944 * These values are always page-aligned (as is base)
1948 * Since some arches are moving towards PAGE_KERNEL module allocations instead
1949 * of PAGE_KERNEL_EXEC, keep frob_text() and module_enable_x() outside of the
1950 * CONFIG_STRICT_MODULE_RWX block below because they are needed regardless of
1951 * whether we are strict.
1953 #ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
1954 static void frob_text(const struct module_layout
*layout
,
1955 int (*set_memory
)(unsigned long start
, int num_pages
))
1957 BUG_ON((unsigned long)layout
->base
& (PAGE_SIZE
-1));
1958 BUG_ON((unsigned long)layout
->text_size
& (PAGE_SIZE
-1));
1959 set_memory((unsigned long)layout
->base
,
1960 layout
->text_size
>> PAGE_SHIFT
);
1963 static void module_enable_x(const struct module
*mod
)
1965 frob_text(&mod
->core_layout
, set_memory_x
);
1966 frob_text(&mod
->init_layout
, set_memory_x
);
1968 #else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
1969 static void module_enable_x(const struct module
*mod
) { }
1970 #endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
1972 #ifdef CONFIG_STRICT_MODULE_RWX
1973 static void frob_rodata(const struct module_layout
*layout
,
1974 int (*set_memory
)(unsigned long start
, int num_pages
))
1976 BUG_ON((unsigned long)layout
->base
& (PAGE_SIZE
-1));
1977 BUG_ON((unsigned long)layout
->text_size
& (PAGE_SIZE
-1));
1978 BUG_ON((unsigned long)layout
->ro_size
& (PAGE_SIZE
-1));
1979 set_memory((unsigned long)layout
->base
+ layout
->text_size
,
1980 (layout
->ro_size
- layout
->text_size
) >> PAGE_SHIFT
);
1983 static void frob_ro_after_init(const struct module_layout
*layout
,
1984 int (*set_memory
)(unsigned long start
, int num_pages
))
1986 BUG_ON((unsigned long)layout
->base
& (PAGE_SIZE
-1));
1987 BUG_ON((unsigned long)layout
->ro_size
& (PAGE_SIZE
-1));
1988 BUG_ON((unsigned long)layout
->ro_after_init_size
& (PAGE_SIZE
-1));
1989 set_memory((unsigned long)layout
->base
+ layout
->ro_size
,
1990 (layout
->ro_after_init_size
- layout
->ro_size
) >> PAGE_SHIFT
);
1993 static void frob_writable_data(const struct module_layout
*layout
,
1994 int (*set_memory
)(unsigned long start
, int num_pages
))
1996 BUG_ON((unsigned long)layout
->base
& (PAGE_SIZE
-1));
1997 BUG_ON((unsigned long)layout
->ro_after_init_size
& (PAGE_SIZE
-1));
1998 BUG_ON((unsigned long)layout
->size
& (PAGE_SIZE
-1));
1999 set_memory((unsigned long)layout
->base
+ layout
->ro_after_init_size
,
2000 (layout
->size
- layout
->ro_after_init_size
) >> PAGE_SHIFT
);
2003 static void module_enable_ro(const struct module
*mod
, bool after_init
)
2005 if (!rodata_enabled
)
2008 set_vm_flush_reset_perms(mod
->core_layout
.base
);
2009 set_vm_flush_reset_perms(mod
->init_layout
.base
);
2010 frob_text(&mod
->core_layout
, set_memory_ro
);
2012 frob_rodata(&mod
->core_layout
, set_memory_ro
);
2013 frob_text(&mod
->init_layout
, set_memory_ro
);
2014 frob_rodata(&mod
->init_layout
, set_memory_ro
);
2017 frob_ro_after_init(&mod
->core_layout
, set_memory_ro
);
2020 static void module_enable_nx(const struct module
*mod
)
2022 frob_rodata(&mod
->core_layout
, set_memory_nx
);
2023 frob_ro_after_init(&mod
->core_layout
, set_memory_nx
);
2024 frob_writable_data(&mod
->core_layout
, set_memory_nx
);
2025 frob_rodata(&mod
->init_layout
, set_memory_nx
);
2026 frob_writable_data(&mod
->init_layout
, set_memory_nx
);
2029 static int module_enforce_rwx_sections(Elf_Ehdr
*hdr
, Elf_Shdr
*sechdrs
,
2030 char *secstrings
, struct module
*mod
)
2032 const unsigned long shf_wx
= SHF_WRITE
|SHF_EXECINSTR
;
2035 for (i
= 0; i
< hdr
->e_shnum
; i
++) {
2036 if ((sechdrs
[i
].sh_flags
& shf_wx
) == shf_wx
) {
2037 pr_err("%s: section %s (index %d) has invalid WRITE|EXEC flags\n",
2038 mod
->name
, secstrings
+ sechdrs
[i
].sh_name
, i
);
2046 #else /* !CONFIG_STRICT_MODULE_RWX */
2047 static void module_enable_nx(const struct module
*mod
) { }
2048 static void module_enable_ro(const struct module
*mod
, bool after_init
) {}
2049 static int module_enforce_rwx_sections(Elf_Ehdr
*hdr
, Elf_Shdr
*sechdrs
,
2050 char *secstrings
, struct module
*mod
)
2054 #endif /* CONFIG_STRICT_MODULE_RWX */
2056 #ifdef CONFIG_LIVEPATCH
2058 * Persist Elf information about a module. Copy the Elf header,
2059 * section header table, section string table, and symtab section
2060 * index from info to mod->klp_info.
2062 static int copy_module_elf(struct module
*mod
, struct load_info
*info
)
2064 unsigned int size
, symndx
;
2067 size
= sizeof(*mod
->klp_info
);
2068 mod
->klp_info
= kmalloc(size
, GFP_KERNEL
);
2069 if (mod
->klp_info
== NULL
)
2073 size
= sizeof(mod
->klp_info
->hdr
);
2074 memcpy(&mod
->klp_info
->hdr
, info
->hdr
, size
);
2076 /* Elf section header table */
2077 size
= sizeof(*info
->sechdrs
) * info
->hdr
->e_shnum
;
2078 mod
->klp_info
->sechdrs
= kmemdup(info
->sechdrs
, size
, GFP_KERNEL
);
2079 if (mod
->klp_info
->sechdrs
== NULL
) {
2084 /* Elf section name string table */
2085 size
= info
->sechdrs
[info
->hdr
->e_shstrndx
].sh_size
;
2086 mod
->klp_info
->secstrings
= kmemdup(info
->secstrings
, size
, GFP_KERNEL
);
2087 if (mod
->klp_info
->secstrings
== NULL
) {
2092 /* Elf symbol section index */
2093 symndx
= info
->index
.sym
;
2094 mod
->klp_info
->symndx
= symndx
;
2097 * For livepatch modules, core_kallsyms.symtab is a complete
2098 * copy of the original symbol table. Adjust sh_addr to point
2099 * to core_kallsyms.symtab since the copy of the symtab in module
2100 * init memory is freed at the end of do_init_module().
2102 mod
->klp_info
->sechdrs
[symndx
].sh_addr
= \
2103 (unsigned long) mod
->core_kallsyms
.symtab
;
2108 kfree(mod
->klp_info
->sechdrs
);
2110 kfree(mod
->klp_info
);
2114 static void free_module_elf(struct module
*mod
)
2116 kfree(mod
->klp_info
->sechdrs
);
2117 kfree(mod
->klp_info
->secstrings
);
2118 kfree(mod
->klp_info
);
2120 #else /* !CONFIG_LIVEPATCH */
2121 static int copy_module_elf(struct module
*mod
, struct load_info
*info
)
2126 static void free_module_elf(struct module
*mod
)
2129 #endif /* CONFIG_LIVEPATCH */
2131 void __weak
module_memfree(void *module_region
)
2134 * This memory may be RO, and freeing RO memory in an interrupt is not
2135 * supported by vmalloc.
2137 WARN_ON(in_interrupt());
2138 vfree(module_region
);
2141 void __weak
module_arch_cleanup(struct module
*mod
)
2145 void __weak
module_arch_freeing_init(struct module
*mod
)
2149 static void cfi_cleanup(struct module
*mod
);
2151 /* Free a module, remove from lists, etc. */
2152 static void free_module(struct module
*mod
)
2154 trace_module_free(mod
);
2156 mod_sysfs_teardown(mod
);
2159 * We leave it in list to prevent duplicate loads, but make sure
2160 * that noone uses it while it's being deconstructed.
2162 mutex_lock(&module_mutex
);
2163 mod
->state
= MODULE_STATE_UNFORMED
;
2164 mutex_unlock(&module_mutex
);
2166 /* Remove dynamic debug info */
2167 ddebug_remove_module(mod
->name
);
2169 /* Arch-specific cleanup. */
2170 module_arch_cleanup(mod
);
2172 /* Module unload stuff */
2173 module_unload_free(mod
);
2175 /* Free any allocated parameters. */
2176 destroy_params(mod
->kp
, mod
->num_kp
);
2178 if (is_livepatch_module(mod
))
2179 free_module_elf(mod
);
2181 /* Now we can delete it from the lists */
2182 mutex_lock(&module_mutex
);
2183 /* Unlink carefully: kallsyms could be walking list. */
2184 list_del_rcu(&mod
->list
);
2185 mod_tree_remove(mod
);
2186 /* Remove this module from bug list, this uses list_del_rcu */
2187 module_bug_cleanup(mod
);
2188 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2190 mutex_unlock(&module_mutex
);
2192 /* Clean up CFI for the module. */
2195 /* This may be empty, but that's OK */
2196 module_arch_freeing_init(mod
);
2197 module_memfree(mod
->init_layout
.base
);
2199 percpu_modfree(mod
);
2201 /* Free lock-classes; relies on the preceding sync_rcu(). */
2202 lockdep_free_key_range(mod
->core_layout
.base
, mod
->core_layout
.size
);
2204 /* Finally, free the core (containing the module structure) */
2205 module_memfree(mod
->core_layout
.base
);
2208 void *__symbol_get(const char *symbol
)
2210 struct find_symbol_arg fsa
= {
2217 if (!find_symbol(&fsa
) || strong_try_module_get(fsa
.owner
)) {
2222 return (void *)kernel_symbol_value(fsa
.sym
);
2224 EXPORT_SYMBOL_GPL(__symbol_get
);
2227 * Ensure that an exported symbol [global namespace] does not already exist
2228 * in the kernel or in some other module's exported symbol table.
2230 * You must hold the module_mutex.
2232 static int verify_exported_symbols(struct module
*mod
)
2235 const struct kernel_symbol
*s
;
2237 const struct kernel_symbol
*sym
;
2240 { mod
->syms
, mod
->num_syms
},
2241 { mod
->gpl_syms
, mod
->num_gpl_syms
},
2244 for (i
= 0; i
< ARRAY_SIZE(arr
); i
++) {
2245 for (s
= arr
[i
].sym
; s
< arr
[i
].sym
+ arr
[i
].num
; s
++) {
2246 struct find_symbol_arg fsa
= {
2247 .name
= kernel_symbol_name(s
),
2250 if (find_symbol(&fsa
)) {
2251 pr_err("%s: exports duplicate symbol %s"
2253 mod
->name
, kernel_symbol_name(s
),
2254 module_name(fsa
.owner
));
2262 static bool ignore_undef_symbol(Elf_Half emachine
, const char *name
)
2265 * On x86, PIC code and Clang non-PIC code may have call foo@PLT. GNU as
2266 * before 2.37 produces an unreferenced _GLOBAL_OFFSET_TABLE_ on x86-64.
2267 * i386 has a similar problem but may not deserve a fix.
2269 * If we ever have to ignore many symbols, consider refactoring the code to
2270 * only warn if referenced by a relocation.
2272 if (emachine
== EM_386
|| emachine
== EM_X86_64
)
2273 return !strcmp(name
, "_GLOBAL_OFFSET_TABLE_");
2277 /* Change all symbols so that st_value encodes the pointer directly. */
2278 static int simplify_symbols(struct module
*mod
, const struct load_info
*info
)
2280 Elf_Shdr
*symsec
= &info
->sechdrs
[info
->index
.sym
];
2281 Elf_Sym
*sym
= (void *)symsec
->sh_addr
;
2282 unsigned long secbase
;
2285 const struct kernel_symbol
*ksym
;
2287 for (i
= 1; i
< symsec
->sh_size
/ sizeof(Elf_Sym
); i
++) {
2288 const char *name
= info
->strtab
+ sym
[i
].st_name
;
2290 switch (sym
[i
].st_shndx
) {
2292 /* Ignore common symbols */
2293 if (!strncmp(name
, "__gnu_lto", 9))
2297 * We compiled with -fno-common. These are not
2298 * supposed to happen.
2300 pr_debug("Common symbol: %s\n", name
);
2301 pr_warn("%s: please compile with -fno-common\n",
2307 /* Don't need to do anything */
2308 pr_debug("Absolute symbol: 0x%08lx\n",
2309 (long)sym
[i
].st_value
);
2313 /* Livepatch symbols are resolved by livepatch */
2317 ksym
= resolve_symbol_wait(mod
, info
, name
);
2318 /* Ok if resolved. */
2319 if (ksym
&& !IS_ERR(ksym
)) {
2320 sym
[i
].st_value
= kernel_symbol_value(ksym
);
2324 /* Ok if weak or ignored. */
2326 (ELF_ST_BIND(sym
[i
].st_info
) == STB_WEAK
||
2327 ignore_undef_symbol(info
->hdr
->e_machine
, name
)))
2330 ret
= PTR_ERR(ksym
) ?: -ENOENT
;
2331 pr_warn("%s: Unknown symbol %s (err %d)\n",
2332 mod
->name
, name
, ret
);
2336 /* Divert to percpu allocation if a percpu var. */
2337 if (sym
[i
].st_shndx
== info
->index
.pcpu
)
2338 secbase
= (unsigned long)mod_percpu(mod
);
2340 secbase
= info
->sechdrs
[sym
[i
].st_shndx
].sh_addr
;
2341 sym
[i
].st_value
+= secbase
;
2349 static int apply_relocations(struct module
*mod
, const struct load_info
*info
)
2354 /* Now do relocations. */
2355 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
2356 unsigned int infosec
= info
->sechdrs
[i
].sh_info
;
2358 /* Not a valid relocation section? */
2359 if (infosec
>= info
->hdr
->e_shnum
)
2362 /* Don't bother with non-allocated sections */
2363 if (!(info
->sechdrs
[infosec
].sh_flags
& SHF_ALLOC
))
2366 if (info
->sechdrs
[i
].sh_flags
& SHF_RELA_LIVEPATCH
)
2367 err
= klp_apply_section_relocs(mod
, info
->sechdrs
,
2372 else if (info
->sechdrs
[i
].sh_type
== SHT_REL
)
2373 err
= apply_relocate(info
->sechdrs
, info
->strtab
,
2374 info
->index
.sym
, i
, mod
);
2375 else if (info
->sechdrs
[i
].sh_type
== SHT_RELA
)
2376 err
= apply_relocate_add(info
->sechdrs
, info
->strtab
,
2377 info
->index
.sym
, i
, mod
);
2384 /* Additional bytes needed by arch in front of individual sections */
2385 unsigned int __weak
arch_mod_section_prepend(struct module
*mod
,
2386 unsigned int section
)
2388 /* default implementation just returns zero */
2392 /* Update size with this section: return offset. */
2393 static long get_offset(struct module
*mod
, unsigned int *size
,
2394 Elf_Shdr
*sechdr
, unsigned int section
)
2398 *size
+= arch_mod_section_prepend(mod
, section
);
2399 ret
= ALIGN(*size
, sechdr
->sh_addralign
?: 1);
2400 *size
= ret
+ sechdr
->sh_size
;
2405 * Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2406 * might -- code, read-only data, read-write data, small data. Tally
2407 * sizes, and place the offsets into sh_entsize fields: high bit means it
2410 static void layout_sections(struct module
*mod
, struct load_info
*info
)
2412 static unsigned long const masks
[][2] = {
2414 * NOTE: all executable code must be the first section
2415 * in this array; otherwise modify the text_size
2416 * finder in the two loops below
2418 { SHF_EXECINSTR
| SHF_ALLOC
, ARCH_SHF_SMALL
},
2419 { SHF_ALLOC
, SHF_WRITE
| ARCH_SHF_SMALL
},
2420 { SHF_RO_AFTER_INIT
| SHF_ALLOC
, ARCH_SHF_SMALL
},
2421 { SHF_WRITE
| SHF_ALLOC
, ARCH_SHF_SMALL
},
2422 { ARCH_SHF_SMALL
| SHF_ALLOC
, 0 }
2426 for (i
= 0; i
< info
->hdr
->e_shnum
; i
++)
2427 info
->sechdrs
[i
].sh_entsize
= ~0UL;
2429 pr_debug("Core section allocation order:\n");
2430 for (m
= 0; m
< ARRAY_SIZE(masks
); ++m
) {
2431 for (i
= 0; i
< info
->hdr
->e_shnum
; ++i
) {
2432 Elf_Shdr
*s
= &info
->sechdrs
[i
];
2433 const char *sname
= info
->secstrings
+ s
->sh_name
;
2435 if ((s
->sh_flags
& masks
[m
][0]) != masks
[m
][0]
2436 || (s
->sh_flags
& masks
[m
][1])
2437 || s
->sh_entsize
!= ~0UL
2438 || module_init_section(sname
))
2440 s
->sh_entsize
= get_offset(mod
, &mod
->core_layout
.size
, s
, i
);
2441 pr_debug("\t%s\n", sname
);
2444 case 0: /* executable */
2445 mod
->core_layout
.size
= debug_align(mod
->core_layout
.size
);
2446 mod
->core_layout
.text_size
= mod
->core_layout
.size
;
2448 case 1: /* RO: text and ro-data */
2449 mod
->core_layout
.size
= debug_align(mod
->core_layout
.size
);
2450 mod
->core_layout
.ro_size
= mod
->core_layout
.size
;
2452 case 2: /* RO after init */
2453 mod
->core_layout
.size
= debug_align(mod
->core_layout
.size
);
2454 mod
->core_layout
.ro_after_init_size
= mod
->core_layout
.size
;
2456 case 4: /* whole core */
2457 mod
->core_layout
.size
= debug_align(mod
->core_layout
.size
);
2462 pr_debug("Init section allocation order:\n");
2463 for (m
= 0; m
< ARRAY_SIZE(masks
); ++m
) {
2464 for (i
= 0; i
< info
->hdr
->e_shnum
; ++i
) {
2465 Elf_Shdr
*s
= &info
->sechdrs
[i
];
2466 const char *sname
= info
->secstrings
+ s
->sh_name
;
2468 if ((s
->sh_flags
& masks
[m
][0]) != masks
[m
][0]
2469 || (s
->sh_flags
& masks
[m
][1])
2470 || s
->sh_entsize
!= ~0UL
2471 || !module_init_section(sname
))
2473 s
->sh_entsize
= (get_offset(mod
, &mod
->init_layout
.size
, s
, i
)
2474 | INIT_OFFSET_MASK
);
2475 pr_debug("\t%s\n", sname
);
2478 case 0: /* executable */
2479 mod
->init_layout
.size
= debug_align(mod
->init_layout
.size
);
2480 mod
->init_layout
.text_size
= mod
->init_layout
.size
;
2482 case 1: /* RO: text and ro-data */
2483 mod
->init_layout
.size
= debug_align(mod
->init_layout
.size
);
2484 mod
->init_layout
.ro_size
= mod
->init_layout
.size
;
2488 * RO after init doesn't apply to init_layout (only
2489 * core_layout), so it just takes the value of ro_size.
2491 mod
->init_layout
.ro_after_init_size
= mod
->init_layout
.ro_size
;
2493 case 4: /* whole init */
2494 mod
->init_layout
.size
= debug_align(mod
->init_layout
.size
);
2500 static void set_license(struct module
*mod
, const char *license
)
2503 license
= "unspecified";
2505 if (!license_is_gpl_compatible(license
)) {
2506 if (!test_taint(TAINT_PROPRIETARY_MODULE
))
2507 pr_warn("%s: module license '%s' taints kernel.\n",
2508 mod
->name
, license
);
2509 add_taint_module(mod
, TAINT_PROPRIETARY_MODULE
,
2510 LOCKDEP_NOW_UNRELIABLE
);
2514 /* Parse tag=value strings from .modinfo section */
2515 static char *next_string(char *string
, unsigned long *secsize
)
2517 /* Skip non-zero chars */
2520 if ((*secsize
)-- <= 1)
2524 /* Skip any zero padding. */
2525 while (!string
[0]) {
2527 if ((*secsize
)-- <= 1)
2533 static char *get_next_modinfo(const struct load_info
*info
, const char *tag
,
2537 unsigned int taglen
= strlen(tag
);
2538 Elf_Shdr
*infosec
= &info
->sechdrs
[info
->index
.info
];
2539 unsigned long size
= infosec
->sh_size
;
2542 * get_modinfo() calls made before rewrite_section_headers()
2543 * must use sh_offset, as sh_addr isn't set!
2545 char *modinfo
= (char *)info
->hdr
+ infosec
->sh_offset
;
2548 size
-= prev
- modinfo
;
2549 modinfo
= next_string(prev
, &size
);
2552 for (p
= modinfo
; p
; p
= next_string(p
, &size
)) {
2553 if (strncmp(p
, tag
, taglen
) == 0 && p
[taglen
] == '=')
2554 return p
+ taglen
+ 1;
2559 static char *get_modinfo(const struct load_info
*info
, const char *tag
)
2561 return get_next_modinfo(info
, tag
, NULL
);
2564 static void setup_modinfo(struct module
*mod
, struct load_info
*info
)
2566 struct module_attribute
*attr
;
2569 for (i
= 0; (attr
= modinfo_attrs
[i
]); i
++) {
2571 attr
->setup(mod
, get_modinfo(info
, attr
->attr
.name
));
2575 static void free_modinfo(struct module
*mod
)
2577 struct module_attribute
*attr
;
2580 for (i
= 0; (attr
= modinfo_attrs
[i
]); i
++) {
2586 #ifdef CONFIG_KALLSYMS
2588 /* Lookup exported symbol in given range of kernel_symbols */
2589 static const struct kernel_symbol
*lookup_exported_symbol(const char *name
,
2590 const struct kernel_symbol
*start
,
2591 const struct kernel_symbol
*stop
)
2593 return bsearch(name
, start
, stop
- start
,
2594 sizeof(struct kernel_symbol
), cmp_name
);
2597 static int is_exported(const char *name
, unsigned long value
,
2598 const struct module
*mod
)
2600 const struct kernel_symbol
*ks
;
2602 ks
= lookup_exported_symbol(name
, __start___ksymtab
, __stop___ksymtab
);
2604 ks
= lookup_exported_symbol(name
, mod
->syms
, mod
->syms
+ mod
->num_syms
);
2606 return ks
!= NULL
&& kernel_symbol_value(ks
) == value
;
2610 static char elf_type(const Elf_Sym
*sym
, const struct load_info
*info
)
2612 const Elf_Shdr
*sechdrs
= info
->sechdrs
;
2614 if (ELF_ST_BIND(sym
->st_info
) == STB_WEAK
) {
2615 if (ELF_ST_TYPE(sym
->st_info
) == STT_OBJECT
)
2620 if (sym
->st_shndx
== SHN_UNDEF
)
2622 if (sym
->st_shndx
== SHN_ABS
|| sym
->st_shndx
== info
->index
.pcpu
)
2624 if (sym
->st_shndx
>= SHN_LORESERVE
)
2626 if (sechdrs
[sym
->st_shndx
].sh_flags
& SHF_EXECINSTR
)
2628 if (sechdrs
[sym
->st_shndx
].sh_flags
& SHF_ALLOC
2629 && sechdrs
[sym
->st_shndx
].sh_type
!= SHT_NOBITS
) {
2630 if (!(sechdrs
[sym
->st_shndx
].sh_flags
& SHF_WRITE
))
2632 else if (sechdrs
[sym
->st_shndx
].sh_flags
& ARCH_SHF_SMALL
)
2637 if (sechdrs
[sym
->st_shndx
].sh_type
== SHT_NOBITS
) {
2638 if (sechdrs
[sym
->st_shndx
].sh_flags
& ARCH_SHF_SMALL
)
2643 if (strstarts(info
->secstrings
+ sechdrs
[sym
->st_shndx
].sh_name
,
2650 static bool is_core_symbol(const Elf_Sym
*src
, const Elf_Shdr
*sechdrs
,
2651 unsigned int shnum
, unsigned int pcpundx
)
2653 const Elf_Shdr
*sec
;
2655 if (src
->st_shndx
== SHN_UNDEF
2656 || src
->st_shndx
>= shnum
2660 #ifdef CONFIG_KALLSYMS_ALL
2661 if (src
->st_shndx
== pcpundx
)
2665 sec
= sechdrs
+ src
->st_shndx
;
2666 if (!(sec
->sh_flags
& SHF_ALLOC
)
2667 #ifndef CONFIG_KALLSYMS_ALL
2668 || !(sec
->sh_flags
& SHF_EXECINSTR
)
2670 || (sec
->sh_entsize
& INIT_OFFSET_MASK
))
2677 * We only allocate and copy the strings needed by the parts of symtab
2678 * we keep. This is simple, but has the effect of making multiple
2679 * copies of duplicates. We could be more sophisticated, see
2680 * linux-kernel thread starting with
2681 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2683 static void layout_symtab(struct module
*mod
, struct load_info
*info
)
2685 Elf_Shdr
*symsect
= info
->sechdrs
+ info
->index
.sym
;
2686 Elf_Shdr
*strsect
= info
->sechdrs
+ info
->index
.str
;
2688 unsigned int i
, nsrc
, ndst
, strtab_size
= 0;
2690 /* Put symbol section at end of init part of module. */
2691 symsect
->sh_flags
|= SHF_ALLOC
;
2692 symsect
->sh_entsize
= get_offset(mod
, &mod
->init_layout
.size
, symsect
,
2693 info
->index
.sym
) | INIT_OFFSET_MASK
;
2694 pr_debug("\t%s\n", info
->secstrings
+ symsect
->sh_name
);
2696 src
= (void *)info
->hdr
+ symsect
->sh_offset
;
2697 nsrc
= symsect
->sh_size
/ sizeof(*src
);
2699 /* Compute total space required for the core symbols' strtab. */
2700 for (ndst
= i
= 0; i
< nsrc
; i
++) {
2701 if (i
== 0 || is_livepatch_module(mod
) ||
2702 is_core_symbol(src
+i
, info
->sechdrs
, info
->hdr
->e_shnum
,
2703 info
->index
.pcpu
)) {
2704 strtab_size
+= strlen(&info
->strtab
[src
[i
].st_name
])+1;
2709 /* Append room for core symbols at end of core part. */
2710 info
->symoffs
= ALIGN(mod
->core_layout
.size
, symsect
->sh_addralign
?: 1);
2711 info
->stroffs
= mod
->core_layout
.size
= info
->symoffs
+ ndst
* sizeof(Elf_Sym
);
2712 mod
->core_layout
.size
+= strtab_size
;
2713 info
->core_typeoffs
= mod
->core_layout
.size
;
2714 mod
->core_layout
.size
+= ndst
* sizeof(char);
2715 mod
->core_layout
.size
= debug_align(mod
->core_layout
.size
);
2717 /* Put string table section at end of init part of module. */
2718 strsect
->sh_flags
|= SHF_ALLOC
;
2719 strsect
->sh_entsize
= get_offset(mod
, &mod
->init_layout
.size
, strsect
,
2720 info
->index
.str
) | INIT_OFFSET_MASK
;
2721 pr_debug("\t%s\n", info
->secstrings
+ strsect
->sh_name
);
2723 /* We'll tack temporary mod_kallsyms on the end. */
2724 mod
->init_layout
.size
= ALIGN(mod
->init_layout
.size
,
2725 __alignof__(struct mod_kallsyms
));
2726 info
->mod_kallsyms_init_off
= mod
->init_layout
.size
;
2727 mod
->init_layout
.size
+= sizeof(struct mod_kallsyms
);
2728 info
->init_typeoffs
= mod
->init_layout
.size
;
2729 mod
->init_layout
.size
+= nsrc
* sizeof(char);
2730 mod
->init_layout
.size
= debug_align(mod
->init_layout
.size
);
2734 * We use the full symtab and strtab which layout_symtab arranged to
2735 * be appended to the init section. Later we switch to the cut-down
2738 static void add_kallsyms(struct module
*mod
, const struct load_info
*info
)
2740 unsigned int i
, ndst
;
2744 Elf_Shdr
*symsec
= &info
->sechdrs
[info
->index
.sym
];
2746 /* Set up to point into init section. */
2747 mod
->kallsyms
= mod
->init_layout
.base
+ info
->mod_kallsyms_init_off
;
2749 mod
->kallsyms
->symtab
= (void *)symsec
->sh_addr
;
2750 mod
->kallsyms
->num_symtab
= symsec
->sh_size
/ sizeof(Elf_Sym
);
2751 /* Make sure we get permanent strtab: don't use info->strtab. */
2752 mod
->kallsyms
->strtab
= (void *)info
->sechdrs
[info
->index
.str
].sh_addr
;
2753 mod
->kallsyms
->typetab
= mod
->init_layout
.base
+ info
->init_typeoffs
;
2756 * Now populate the cut down core kallsyms for after init
2757 * and set types up while we still have access to sections.
2759 mod
->core_kallsyms
.symtab
= dst
= mod
->core_layout
.base
+ info
->symoffs
;
2760 mod
->core_kallsyms
.strtab
= s
= mod
->core_layout
.base
+ info
->stroffs
;
2761 mod
->core_kallsyms
.typetab
= mod
->core_layout
.base
+ info
->core_typeoffs
;
2762 src
= mod
->kallsyms
->symtab
;
2763 for (ndst
= i
= 0; i
< mod
->kallsyms
->num_symtab
; i
++) {
2764 mod
->kallsyms
->typetab
[i
] = elf_type(src
+ i
, info
);
2765 if (i
== 0 || is_livepatch_module(mod
) ||
2766 is_core_symbol(src
+i
, info
->sechdrs
, info
->hdr
->e_shnum
,
2767 info
->index
.pcpu
)) {
2768 mod
->core_kallsyms
.typetab
[ndst
] =
2769 mod
->kallsyms
->typetab
[i
];
2771 dst
[ndst
++].st_name
= s
- mod
->core_kallsyms
.strtab
;
2772 s
+= strlcpy(s
, &mod
->kallsyms
->strtab
[src
[i
].st_name
],
2776 mod
->core_kallsyms
.num_symtab
= ndst
;
2779 static inline void layout_symtab(struct module
*mod
, struct load_info
*info
)
2783 static void add_kallsyms(struct module
*mod
, const struct load_info
*info
)
2786 #endif /* CONFIG_KALLSYMS */
2788 static void dynamic_debug_setup(struct module
*mod
, struct _ddebug
*debug
, unsigned int num
)
2792 ddebug_add_module(debug
, num
, mod
->name
);
2795 static void dynamic_debug_remove(struct module
*mod
, struct _ddebug
*debug
)
2798 ddebug_remove_module(mod
->name
);
2801 void * __weak
module_alloc(unsigned long size
)
2803 return __vmalloc_node_range(size
, 1, VMALLOC_START
, VMALLOC_END
,
2804 GFP_KERNEL
, PAGE_KERNEL_EXEC
, VM_FLUSH_RESET_PERMS
,
2805 NUMA_NO_NODE
, __builtin_return_address(0));
2808 bool __weak
module_init_section(const char *name
)
2810 #ifndef CONFIG_MODULE_UNLOAD
2811 return strstarts(name
, ".init") || module_exit_section(name
);
2813 return strstarts(name
, ".init");
2817 bool __weak
module_exit_section(const char *name
)
2819 return strstarts(name
, ".exit");
2822 #ifdef CONFIG_DEBUG_KMEMLEAK
2823 static void kmemleak_load_module(const struct module
*mod
,
2824 const struct load_info
*info
)
2828 /* only scan the sections containing data */
2829 kmemleak_scan_area(mod
, sizeof(struct module
), GFP_KERNEL
);
2831 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
2832 /* Scan all writable sections that's not executable */
2833 if (!(info
->sechdrs
[i
].sh_flags
& SHF_ALLOC
) ||
2834 !(info
->sechdrs
[i
].sh_flags
& SHF_WRITE
) ||
2835 (info
->sechdrs
[i
].sh_flags
& SHF_EXECINSTR
))
2838 kmemleak_scan_area((void *)info
->sechdrs
[i
].sh_addr
,
2839 info
->sechdrs
[i
].sh_size
, GFP_KERNEL
);
2843 static inline void kmemleak_load_module(const struct module
*mod
,
2844 const struct load_info
*info
)
2849 #ifdef CONFIG_MODULE_SIG
2850 static int module_sig_check(struct load_info
*info
, int flags
)
2853 const unsigned long markerlen
= sizeof(MODULE_SIG_STRING
) - 1;
2855 const void *mod
= info
->hdr
;
2858 * Require flags == 0, as a module with version information
2859 * removed is no longer the module that was signed
2862 info
->len
> markerlen
&&
2863 memcmp(mod
+ info
->len
- markerlen
, MODULE_SIG_STRING
, markerlen
) == 0) {
2864 /* We truncate the module to discard the signature */
2865 info
->len
-= markerlen
;
2866 err
= mod_verify_sig(mod
, info
);
2868 info
->sig_ok
= true;
2874 * We don't permit modules to be loaded into the trusted kernels
2875 * without a valid signature on them, but if we're not enforcing,
2876 * certain errors are non-fatal.
2880 reason
= "unsigned module";
2883 reason
= "module with unsupported crypto";
2886 reason
= "module with unavailable key";
2891 * All other errors are fatal, including lack of memory,
2892 * unparseable signatures, and signature check failures --
2893 * even if signatures aren't required.
2898 if (is_module_sig_enforced()) {
2899 pr_notice("Loading of %s is rejected\n", reason
);
2900 return -EKEYREJECTED
;
2903 return security_locked_down(LOCKDOWN_MODULE_SIGNATURE
);
2905 #else /* !CONFIG_MODULE_SIG */
2906 static int module_sig_check(struct load_info
*info
, int flags
)
2910 #endif /* !CONFIG_MODULE_SIG */
2912 static int validate_section_offset(struct load_info
*info
, Elf_Shdr
*shdr
)
2914 unsigned long secend
;
2917 * Check for both overflow and offset/size being
2920 secend
= shdr
->sh_offset
+ shdr
->sh_size
;
2921 if (secend
< shdr
->sh_offset
|| secend
> info
->len
)
2928 * Sanity checks against invalid binaries, wrong arch, weird elf version.
2930 * Also do basic validity checks against section offsets and sizes, the
2931 * section name string table, and the indices used for it (sh_name).
2933 static int elf_validity_check(struct load_info
*info
)
2936 Elf_Shdr
*shdr
, *strhdr
;
2939 if (info
->len
< sizeof(*(info
->hdr
)))
2942 if (memcmp(info
->hdr
->e_ident
, ELFMAG
, SELFMAG
) != 0
2943 || info
->hdr
->e_type
!= ET_REL
2944 || !elf_check_arch(info
->hdr
)
2945 || info
->hdr
->e_shentsize
!= sizeof(Elf_Shdr
))
2949 * e_shnum is 16 bits, and sizeof(Elf_Shdr) is
2950 * known and small. So e_shnum * sizeof(Elf_Shdr)
2951 * will not overflow unsigned long on any platform.
2953 if (info
->hdr
->e_shoff
>= info
->len
2954 || (info
->hdr
->e_shnum
* sizeof(Elf_Shdr
) >
2955 info
->len
- info
->hdr
->e_shoff
))
2958 info
->sechdrs
= (void *)info
->hdr
+ info
->hdr
->e_shoff
;
2961 * Verify if the section name table index is valid.
2963 if (info
->hdr
->e_shstrndx
== SHN_UNDEF
2964 || info
->hdr
->e_shstrndx
>= info
->hdr
->e_shnum
)
2967 strhdr
= &info
->sechdrs
[info
->hdr
->e_shstrndx
];
2968 err
= validate_section_offset(info
, strhdr
);
2973 * The section name table must be NUL-terminated, as required
2974 * by the spec. This makes strcmp and pr_* calls that access
2975 * strings in the section safe.
2977 info
->secstrings
= (void *)info
->hdr
+ strhdr
->sh_offset
;
2978 if (info
->secstrings
[strhdr
->sh_size
- 1] != '\0')
2982 * The code assumes that section 0 has a length of zero and
2983 * an addr of zero, so check for it.
2985 if (info
->sechdrs
[0].sh_type
!= SHT_NULL
2986 || info
->sechdrs
[0].sh_size
!= 0
2987 || info
->sechdrs
[0].sh_addr
!= 0)
2990 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
2991 shdr
= &info
->sechdrs
[i
];
2992 switch (shdr
->sh_type
) {
2997 if (shdr
->sh_link
== SHN_UNDEF
2998 || shdr
->sh_link
>= info
->hdr
->e_shnum
)
3002 err
= validate_section_offset(info
, shdr
);
3004 pr_err("Invalid ELF section in module (section %u type %u)\n",
3009 if (shdr
->sh_flags
& SHF_ALLOC
) {
3010 if (shdr
->sh_name
>= strhdr
->sh_size
) {
3011 pr_err("Invalid ELF section name in module (section %u type %u)\n",
3023 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
3025 static int copy_chunked_from_user(void *dst
, const void __user
*usrc
, unsigned long len
)
3028 unsigned long n
= min(len
, COPY_CHUNK_SIZE
);
3030 if (copy_from_user(dst
, usrc
, n
) != 0)
3040 #ifdef CONFIG_LIVEPATCH
3041 static int check_modinfo_livepatch(struct module
*mod
, struct load_info
*info
)
3043 if (get_modinfo(info
, "livepatch")) {
3045 add_taint_module(mod
, TAINT_LIVEPATCH
, LOCKDEP_STILL_OK
);
3046 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
3052 #else /* !CONFIG_LIVEPATCH */
3053 static int check_modinfo_livepatch(struct module
*mod
, struct load_info
*info
)
3055 if (get_modinfo(info
, "livepatch")) {
3056 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
3063 #endif /* CONFIG_LIVEPATCH */
3065 static void check_modinfo_retpoline(struct module
*mod
, struct load_info
*info
)
3067 if (retpoline_module_ok(get_modinfo(info
, "retpoline")))
3070 pr_warn("%s: loading module not compiled with retpoline compiler.\n",
3074 /* Sets info->hdr and info->len. */
3075 static int copy_module_from_user(const void __user
*umod
, unsigned long len
,
3076 struct load_info
*info
)
3081 if (info
->len
< sizeof(*(info
->hdr
)))
3084 err
= security_kernel_load_data(LOADING_MODULE
, true);
3088 /* Suck in entire file: we'll want most of it. */
3089 info
->hdr
= __vmalloc(info
->len
, GFP_KERNEL
| __GFP_NOWARN
);
3093 if (copy_chunked_from_user(info
->hdr
, umod
, info
->len
) != 0) {
3098 err
= security_kernel_post_load_data((char *)info
->hdr
, info
->len
,
3099 LOADING_MODULE
, "init_module");
3107 static void free_copy(struct load_info
*info
)
3112 static int rewrite_section_headers(struct load_info
*info
, int flags
)
3116 /* This should always be true, but let's be sure. */
3117 info
->sechdrs
[0].sh_addr
= 0;
3119 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
3120 Elf_Shdr
*shdr
= &info
->sechdrs
[i
];
3123 * Mark all sections sh_addr with their address in the
3126 shdr
->sh_addr
= (size_t)info
->hdr
+ shdr
->sh_offset
;
3130 /* Track but don't keep modinfo and version sections. */
3131 info
->sechdrs
[info
->index
.vers
].sh_flags
&= ~(unsigned long)SHF_ALLOC
;
3132 info
->sechdrs
[info
->index
.info
].sh_flags
&= ~(unsigned long)SHF_ALLOC
;
3138 * Set up our basic convenience variables (pointers to section headers,
3139 * search for module section index etc), and do some basic section
3142 * Set info->mod to the temporary copy of the module in info->hdr. The final one
3143 * will be allocated in move_module().
3145 static int setup_load_info(struct load_info
*info
, int flags
)
3149 /* Try to find a name early so we can log errors with a module name */
3150 info
->index
.info
= find_sec(info
, ".modinfo");
3151 if (info
->index
.info
)
3152 info
->name
= get_modinfo(info
, "name");
3154 /* Find internal symbols and strings. */
3155 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
3156 if (info
->sechdrs
[i
].sh_type
== SHT_SYMTAB
) {
3157 info
->index
.sym
= i
;
3158 info
->index
.str
= info
->sechdrs
[i
].sh_link
;
3159 info
->strtab
= (char *)info
->hdr
3160 + info
->sechdrs
[info
->index
.str
].sh_offset
;
3165 if (info
->index
.sym
== 0) {
3166 pr_warn("%s: module has no symbols (stripped?)\n",
3167 info
->name
?: "(missing .modinfo section or name field)");
3171 info
->index
.mod
= find_sec(info
, ".gnu.linkonce.this_module");
3172 if (!info
->index
.mod
) {
3173 pr_warn("%s: No module found in object\n",
3174 info
->name
?: "(missing .modinfo section or name field)");
3177 /* This is temporary: point mod into copy of data. */
3178 info
->mod
= (void *)info
->hdr
+ info
->sechdrs
[info
->index
.mod
].sh_offset
;
3181 * If we didn't load the .modinfo 'name' field earlier, fall back to
3182 * on-disk struct mod 'name' field.
3185 info
->name
= info
->mod
->name
;
3187 if (flags
& MODULE_INIT_IGNORE_MODVERSIONS
)
3188 info
->index
.vers
= 0; /* Pretend no __versions section! */
3190 info
->index
.vers
= find_sec(info
, "__versions");
3192 info
->index
.pcpu
= find_pcpusec(info
);
3197 static int check_modinfo(struct module
*mod
, struct load_info
*info
, int flags
)
3199 const char *modmagic
= get_modinfo(info
, "vermagic");
3202 if (flags
& MODULE_INIT_IGNORE_VERMAGIC
)
3205 /* This is allowed: modprobe --force will invalidate it. */
3207 err
= try_to_force_load(mod
, "bad vermagic");
3210 } else if (!same_magic(modmagic
, vermagic
, info
->index
.vers
)) {
3211 pr_err("%s: version magic '%s' should be '%s'\n",
3212 info
->name
, modmagic
, vermagic
);
3216 if (!get_modinfo(info
, "intree")) {
3217 if (!test_taint(TAINT_OOT_MODULE
))
3218 pr_warn("%s: loading out-of-tree module taints kernel.\n",
3220 add_taint_module(mod
, TAINT_OOT_MODULE
, LOCKDEP_STILL_OK
);
3223 check_modinfo_retpoline(mod
, info
);
3225 if (get_modinfo(info
, "staging")) {
3226 add_taint_module(mod
, TAINT_CRAP
, LOCKDEP_STILL_OK
);
3227 pr_warn("%s: module is from the staging directory, the quality "
3228 "is unknown, you have been warned.\n", mod
->name
);
3231 err
= check_modinfo_livepatch(mod
, info
);
3235 /* Set up license info based on the info section */
3236 set_license(mod
, get_modinfo(info
, "license"));
3241 static int find_module_sections(struct module
*mod
, struct load_info
*info
)
3243 mod
->kp
= section_objs(info
, "__param",
3244 sizeof(*mod
->kp
), &mod
->num_kp
);
3245 mod
->syms
= section_objs(info
, "__ksymtab",
3246 sizeof(*mod
->syms
), &mod
->num_syms
);
3247 mod
->crcs
= section_addr(info
, "__kcrctab");
3248 mod
->gpl_syms
= section_objs(info
, "__ksymtab_gpl",
3249 sizeof(*mod
->gpl_syms
),
3250 &mod
->num_gpl_syms
);
3251 mod
->gpl_crcs
= section_addr(info
, "__kcrctab_gpl");
3253 #ifdef CONFIG_CONSTRUCTORS
3254 mod
->ctors
= section_objs(info
, ".ctors",
3255 sizeof(*mod
->ctors
), &mod
->num_ctors
);
3257 mod
->ctors
= section_objs(info
, ".init_array",
3258 sizeof(*mod
->ctors
), &mod
->num_ctors
);
3259 else if (find_sec(info
, ".init_array")) {
3261 * This shouldn't happen with same compiler and binutils
3262 * building all parts of the module.
3264 pr_warn("%s: has both .ctors and .init_array.\n",
3270 mod
->noinstr_text_start
= section_objs(info
, ".noinstr.text", 1,
3271 &mod
->noinstr_text_size
);
3273 #ifdef CONFIG_TRACEPOINTS
3274 mod
->tracepoints_ptrs
= section_objs(info
, "__tracepoints_ptrs",
3275 sizeof(*mod
->tracepoints_ptrs
),
3276 &mod
->num_tracepoints
);
3278 #ifdef CONFIG_TREE_SRCU
3279 mod
->srcu_struct_ptrs
= section_objs(info
, "___srcu_struct_ptrs",
3280 sizeof(*mod
->srcu_struct_ptrs
),
3281 &mod
->num_srcu_structs
);
3283 #ifdef CONFIG_BPF_EVENTS
3284 mod
->bpf_raw_events
= section_objs(info
, "__bpf_raw_tp_map",
3285 sizeof(*mod
->bpf_raw_events
),
3286 &mod
->num_bpf_raw_events
);
3288 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
3289 mod
->btf_data
= any_section_objs(info
, ".BTF", 1, &mod
->btf_data_size
);
3291 #ifdef CONFIG_JUMP_LABEL
3292 mod
->jump_entries
= section_objs(info
, "__jump_table",
3293 sizeof(*mod
->jump_entries
),
3294 &mod
->num_jump_entries
);
3296 #ifdef CONFIG_EVENT_TRACING
3297 mod
->trace_events
= section_objs(info
, "_ftrace_events",
3298 sizeof(*mod
->trace_events
),
3299 &mod
->num_trace_events
);
3300 mod
->trace_evals
= section_objs(info
, "_ftrace_eval_map",
3301 sizeof(*mod
->trace_evals
),
3302 &mod
->num_trace_evals
);
3304 #ifdef CONFIG_TRACING
3305 mod
->trace_bprintk_fmt_start
= section_objs(info
, "__trace_printk_fmt",
3306 sizeof(*mod
->trace_bprintk_fmt_start
),
3307 &mod
->num_trace_bprintk_fmt
);
3309 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
3310 /* sechdrs[0].sh_size is always zero */
3311 mod
->ftrace_callsites
= section_objs(info
, FTRACE_CALLSITE_SECTION
,
3312 sizeof(*mod
->ftrace_callsites
),
3313 &mod
->num_ftrace_callsites
);
3315 #ifdef CONFIG_FUNCTION_ERROR_INJECTION
3316 mod
->ei_funcs
= section_objs(info
, "_error_injection_whitelist",
3317 sizeof(*mod
->ei_funcs
),
3318 &mod
->num_ei_funcs
);
3320 #ifdef CONFIG_KPROBES
3321 mod
->kprobes_text_start
= section_objs(info
, ".kprobes.text", 1,
3322 &mod
->kprobes_text_size
);
3323 mod
->kprobe_blacklist
= section_objs(info
, "_kprobe_blacklist",
3324 sizeof(unsigned long),
3325 &mod
->num_kprobe_blacklist
);
3327 #ifdef CONFIG_HAVE_STATIC_CALL_INLINE
3328 mod
->static_call_sites
= section_objs(info
, ".static_call_sites",
3329 sizeof(*mod
->static_call_sites
),
3330 &mod
->num_static_call_sites
);
3332 mod
->extable
= section_objs(info
, "__ex_table",
3333 sizeof(*mod
->extable
), &mod
->num_exentries
);
3335 if (section_addr(info
, "__obsparm"))
3336 pr_warn("%s: Ignoring obsolete parameters\n", mod
->name
);
3338 info
->debug
= section_objs(info
, "__dyndbg",
3339 sizeof(*info
->debug
), &info
->num_debug
);
3344 static int move_module(struct module
*mod
, struct load_info
*info
)
3349 /* Do the allocs. */
3350 ptr
= module_alloc(mod
->core_layout
.size
);
3352 * The pointer to this block is stored in the module structure
3353 * which is inside the block. Just mark it as not being a
3356 kmemleak_not_leak(ptr
);
3360 memset(ptr
, 0, mod
->core_layout
.size
);
3361 mod
->core_layout
.base
= ptr
;
3363 if (mod
->init_layout
.size
) {
3364 ptr
= module_alloc(mod
->init_layout
.size
);
3366 * The pointer to this block is stored in the module structure
3367 * which is inside the block. This block doesn't need to be
3368 * scanned as it contains data and code that will be freed
3369 * after the module is initialized.
3371 kmemleak_ignore(ptr
);
3373 module_memfree(mod
->core_layout
.base
);
3376 memset(ptr
, 0, mod
->init_layout
.size
);
3377 mod
->init_layout
.base
= ptr
;
3379 mod
->init_layout
.base
= NULL
;
3381 /* Transfer each section which specifies SHF_ALLOC */
3382 pr_debug("final section addresses:\n");
3383 for (i
= 0; i
< info
->hdr
->e_shnum
; i
++) {
3385 Elf_Shdr
*shdr
= &info
->sechdrs
[i
];
3387 if (!(shdr
->sh_flags
& SHF_ALLOC
))
3390 if (shdr
->sh_entsize
& INIT_OFFSET_MASK
)
3391 dest
= mod
->init_layout
.base
3392 + (shdr
->sh_entsize
& ~INIT_OFFSET_MASK
);
3394 dest
= mod
->core_layout
.base
+ shdr
->sh_entsize
;
3396 if (shdr
->sh_type
!= SHT_NOBITS
)
3397 memcpy(dest
, (void *)shdr
->sh_addr
, shdr
->sh_size
);
3398 /* Update sh_addr to point to copy in image. */
3399 shdr
->sh_addr
= (unsigned long)dest
;
3400 pr_debug("\t0x%lx %s\n",
3401 (long)shdr
->sh_addr
, info
->secstrings
+ shdr
->sh_name
);
3407 static int check_module_license_and_versions(struct module
*mod
)
3409 int prev_taint
= test_taint(TAINT_PROPRIETARY_MODULE
);
3412 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3413 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3414 * using GPL-only symbols it needs.
3416 if (strcmp(mod
->name
, "ndiswrapper") == 0)
3417 add_taint(TAINT_PROPRIETARY_MODULE
, LOCKDEP_NOW_UNRELIABLE
);
3419 /* driverloader was caught wrongly pretending to be under GPL */
3420 if (strcmp(mod
->name
, "driverloader") == 0)
3421 add_taint_module(mod
, TAINT_PROPRIETARY_MODULE
,
3422 LOCKDEP_NOW_UNRELIABLE
);
3424 /* lve claims to be GPL but upstream won't provide source */
3425 if (strcmp(mod
->name
, "lve") == 0)
3426 add_taint_module(mod
, TAINT_PROPRIETARY_MODULE
,
3427 LOCKDEP_NOW_UNRELIABLE
);
3429 if (!prev_taint
&& test_taint(TAINT_PROPRIETARY_MODULE
))
3430 pr_warn("%s: module license taints kernel.\n", mod
->name
);
3432 #ifdef CONFIG_MODVERSIONS
3433 if ((mod
->num_syms
&& !mod
->crcs
) ||
3434 (mod
->num_gpl_syms
&& !mod
->gpl_crcs
)) {
3435 return try_to_force_load(mod
,
3436 "no versions for exported symbols");
3442 static void flush_module_icache(const struct module
*mod
)
3445 * Flush the instruction cache, since we've played with text.
3446 * Do it before processing of module parameters, so the module
3447 * can provide parameter accessor functions of its own.
3449 if (mod
->init_layout
.base
)
3450 flush_icache_range((unsigned long)mod
->init_layout
.base
,
3451 (unsigned long)mod
->init_layout
.base
3452 + mod
->init_layout
.size
);
3453 flush_icache_range((unsigned long)mod
->core_layout
.base
,
3454 (unsigned long)mod
->core_layout
.base
+ mod
->core_layout
.size
);
3457 int __weak
module_frob_arch_sections(Elf_Ehdr
*hdr
,
3465 /* module_blacklist is a comma-separated list of module names */
3466 static char *module_blacklist
;
3467 static bool blacklisted(const char *module_name
)
3472 if (!module_blacklist
)
3475 for (p
= module_blacklist
; *p
; p
+= len
) {
3476 len
= strcspn(p
, ",");
3477 if (strlen(module_name
) == len
&& !memcmp(module_name
, p
, len
))
3484 core_param(module_blacklist
, module_blacklist
, charp
, 0400);
3486 static struct module
*layout_and_allocate(struct load_info
*info
, int flags
)
3492 err
= check_modinfo(info
->mod
, info
, flags
);
3494 return ERR_PTR(err
);
3496 /* Allow arches to frob section contents and sizes. */
3497 err
= module_frob_arch_sections(info
->hdr
, info
->sechdrs
,
3498 info
->secstrings
, info
->mod
);
3500 return ERR_PTR(err
);
3502 err
= module_enforce_rwx_sections(info
->hdr
, info
->sechdrs
,
3503 info
->secstrings
, info
->mod
);
3505 return ERR_PTR(err
);
3507 /* We will do a special allocation for per-cpu sections later. */
3508 info
->sechdrs
[info
->index
.pcpu
].sh_flags
&= ~(unsigned long)SHF_ALLOC
;
3511 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3512 * layout_sections() can put it in the right place.
3513 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3515 ndx
= find_sec(info
, ".data..ro_after_init");
3517 info
->sechdrs
[ndx
].sh_flags
|= SHF_RO_AFTER_INIT
;
3519 * Mark the __jump_table section as ro_after_init as well: these data
3520 * structures are never modified, with the exception of entries that
3521 * refer to code in the __init section, which are annotated as such
3522 * at module load time.
3524 ndx
= find_sec(info
, "__jump_table");
3526 info
->sechdrs
[ndx
].sh_flags
|= SHF_RO_AFTER_INIT
;
3529 * Determine total sizes, and put offsets in sh_entsize. For now
3530 * this is done generically; there doesn't appear to be any
3531 * special cases for the architectures.
3533 layout_sections(info
->mod
, info
);
3534 layout_symtab(info
->mod
, info
);
3536 /* Allocate and move to the final place */
3537 err
= move_module(info
->mod
, info
);
3539 return ERR_PTR(err
);
3541 /* Module has been copied to its final place now: return it. */
3542 mod
= (void *)info
->sechdrs
[info
->index
.mod
].sh_addr
;
3543 kmemleak_load_module(mod
, info
);
3547 /* mod is no longer valid after this! */
3548 static void module_deallocate(struct module
*mod
, struct load_info
*info
)
3550 percpu_modfree(mod
);
3551 module_arch_freeing_init(mod
);
3552 module_memfree(mod
->init_layout
.base
);
3553 module_memfree(mod
->core_layout
.base
);
3556 int __weak
module_finalize(const Elf_Ehdr
*hdr
,
3557 const Elf_Shdr
*sechdrs
,
3563 static int post_relocation(struct module
*mod
, const struct load_info
*info
)
3565 /* Sort exception table now relocations are done. */
3566 sort_extable(mod
->extable
, mod
->extable
+ mod
->num_exentries
);
3568 /* Copy relocated percpu area over. */
3569 percpu_modcopy(mod
, (void *)info
->sechdrs
[info
->index
.pcpu
].sh_addr
,
3570 info
->sechdrs
[info
->index
.pcpu
].sh_size
);
3572 /* Setup kallsyms-specific fields. */
3573 add_kallsyms(mod
, info
);
3575 /* Arch-specific module finalizing. */
3576 return module_finalize(info
->hdr
, info
->sechdrs
, mod
);
3579 /* Is this module of this name done loading? No locks held. */
3580 static bool finished_loading(const char *name
)
3586 * The module_mutex should not be a heavily contended lock;
3587 * if we get the occasional sleep here, we'll go an extra iteration
3588 * in the wait_event_interruptible(), which is harmless.
3590 sched_annotate_sleep();
3591 mutex_lock(&module_mutex
);
3592 mod
= find_module_all(name
, strlen(name
), true);
3593 ret
= !mod
|| mod
->state
== MODULE_STATE_LIVE
;
3594 mutex_unlock(&module_mutex
);
3599 /* Call module constructors. */
3600 static void do_mod_ctors(struct module
*mod
)
3602 #ifdef CONFIG_CONSTRUCTORS
3605 for (i
= 0; i
< mod
->num_ctors
; i
++)
3610 /* For freeing module_init on success, in case kallsyms traversing */
3611 struct mod_initfree
{
3612 struct llist_node node
;
3616 static void do_free_init(struct work_struct
*w
)
3618 struct llist_node
*pos
, *n
, *list
;
3619 struct mod_initfree
*initfree
;
3621 list
= llist_del_all(&init_free_list
);
3625 llist_for_each_safe(pos
, n
, list
) {
3626 initfree
= container_of(pos
, struct mod_initfree
, node
);
3627 module_memfree(initfree
->module_init
);
3633 * This is where the real work happens.
3635 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3636 * helper command 'lx-symbols'.
3638 static noinline
int do_init_module(struct module
*mod
)
3641 struct mod_initfree
*freeinit
;
3643 freeinit
= kmalloc(sizeof(*freeinit
), GFP_KERNEL
);
3648 freeinit
->module_init
= mod
->init_layout
.base
;
3651 * We want to find out whether @mod uses async during init. Clear
3652 * PF_USED_ASYNC. async_schedule*() will set it.
3654 current
->flags
&= ~PF_USED_ASYNC
;
3657 /* Start the module */
3658 if (mod
->init
!= NULL
)
3659 ret
= do_one_initcall(mod
->init
);
3661 goto fail_free_freeinit
;
3664 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3665 "follow 0/-E convention\n"
3666 "%s: loading module anyway...\n",
3667 __func__
, mod
->name
, ret
, __func__
);
3671 /* Now it's a first class citizen! */
3672 mod
->state
= MODULE_STATE_LIVE
;
3673 blocking_notifier_call_chain(&module_notify_list
,
3674 MODULE_STATE_LIVE
, mod
);
3676 /* Delay uevent until module has finished its init routine */
3677 kobject_uevent(&mod
->mkobj
.kobj
, KOBJ_ADD
);
3680 * We need to finish all async code before the module init sequence
3681 * is done. This has potential to deadlock. For example, a newly
3682 * detected block device can trigger request_module() of the
3683 * default iosched from async probing task. Once userland helper
3684 * reaches here, async_synchronize_full() will wait on the async
3685 * task waiting on request_module() and deadlock.
3687 * This deadlock is avoided by perfomring async_synchronize_full()
3688 * iff module init queued any async jobs. This isn't a full
3689 * solution as it will deadlock the same if module loading from
3690 * async jobs nests more than once; however, due to the various
3691 * constraints, this hack seems to be the best option for now.
3692 * Please refer to the following thread for details.
3694 * http://thread.gmane.org/gmane.linux.kernel/1420814
3696 if (!mod
->async_probe_requested
&& (current
->flags
& PF_USED_ASYNC
))
3697 async_synchronize_full();
3699 ftrace_free_mem(mod
, mod
->init_layout
.base
, mod
->init_layout
.base
+
3700 mod
->init_layout
.size
);
3701 mutex_lock(&module_mutex
);
3702 /* Drop initial reference. */
3704 trim_init_extable(mod
);
3705 #ifdef CONFIG_KALLSYMS
3706 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3707 rcu_assign_pointer(mod
->kallsyms
, &mod
->core_kallsyms
);
3709 module_enable_ro(mod
, true);
3710 mod_tree_remove_init(mod
);
3711 module_arch_freeing_init(mod
);
3712 mod
->init_layout
.base
= NULL
;
3713 mod
->init_layout
.size
= 0;
3714 mod
->init_layout
.ro_size
= 0;
3715 mod
->init_layout
.ro_after_init_size
= 0;
3716 mod
->init_layout
.text_size
= 0;
3717 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
3718 /* .BTF is not SHF_ALLOC and will get removed, so sanitize pointer */
3719 mod
->btf_data
= NULL
;
3722 * We want to free module_init, but be aware that kallsyms may be
3723 * walking this with preempt disabled. In all the failure paths, we
3724 * call synchronize_rcu(), but we don't want to slow down the success
3725 * path. module_memfree() cannot be called in an interrupt, so do the
3726 * work and call synchronize_rcu() in a work queue.
3728 * Note that module_alloc() on most architectures creates W+X page
3729 * mappings which won't be cleaned up until do_free_init() runs. Any
3730 * code such as mark_rodata_ro() which depends on those mappings to
3731 * be cleaned up needs to sync with the queued work - ie
3734 if (llist_add(&freeinit
->node
, &init_free_list
))
3735 schedule_work(&init_free_wq
);
3737 mutex_unlock(&module_mutex
);
3738 wake_up_all(&module_wq
);
3745 /* Try to protect us from buggy refcounters. */
3746 mod
->state
= MODULE_STATE_GOING
;
3749 blocking_notifier_call_chain(&module_notify_list
,
3750 MODULE_STATE_GOING
, mod
);
3751 klp_module_going(mod
);
3752 ftrace_release_mod(mod
);
3754 wake_up_all(&module_wq
);
3758 static int may_init_module(void)
3760 if (!capable(CAP_SYS_MODULE
) || modules_disabled
)
3767 * We try to place it in the list now to make sure it's unique before
3768 * we dedicate too many resources. In particular, temporary percpu
3769 * memory exhaustion.
3771 static int add_unformed_module(struct module
*mod
)
3776 mod
->state
= MODULE_STATE_UNFORMED
;
3779 mutex_lock(&module_mutex
);
3780 old
= find_module_all(mod
->name
, strlen(mod
->name
), true);
3782 if (old
->state
!= MODULE_STATE_LIVE
) {
3783 /* Wait in case it fails to load. */
3784 mutex_unlock(&module_mutex
);
3785 err
= wait_event_interruptible(module_wq
,
3786 finished_loading(mod
->name
));
3794 mod_update_bounds(mod
);
3795 list_add_rcu(&mod
->list
, &modules
);
3796 mod_tree_insert(mod
);
3800 mutex_unlock(&module_mutex
);
3805 static int complete_formation(struct module
*mod
, struct load_info
*info
)
3809 mutex_lock(&module_mutex
);
3811 /* Find duplicate symbols (must be called under lock). */
3812 err
= verify_exported_symbols(mod
);
3816 /* This relies on module_mutex for list integrity. */
3817 module_bug_finalize(info
->hdr
, info
->sechdrs
, mod
);
3819 module_enable_ro(mod
, false);
3820 module_enable_nx(mod
);
3821 module_enable_x(mod
);
3824 * Mark state as coming so strong_try_module_get() ignores us,
3825 * but kallsyms etc. can see us.
3827 mod
->state
= MODULE_STATE_COMING
;
3828 mutex_unlock(&module_mutex
);
3833 mutex_unlock(&module_mutex
);
3837 static int prepare_coming_module(struct module
*mod
)
3841 ftrace_module_enable(mod
);
3842 err
= klp_module_coming(mod
);
3846 err
= blocking_notifier_call_chain_robust(&module_notify_list
,
3847 MODULE_STATE_COMING
, MODULE_STATE_GOING
, mod
);
3848 err
= notifier_to_errno(err
);
3850 klp_module_going(mod
);
3855 static int unknown_module_param_cb(char *param
, char *val
, const char *modname
,
3858 struct module
*mod
= arg
;
3861 if (strcmp(param
, "async_probe") == 0) {
3862 mod
->async_probe_requested
= true;
3866 /* Check for magic 'dyndbg' arg */
3867 ret
= ddebug_dyndbg_module_param_cb(param
, val
, modname
);
3869 pr_warn("%s: unknown parameter '%s' ignored\n", modname
, param
);
3873 static void cfi_init(struct module
*mod
);
3876 * Allocate and load the module: note that size of section 0 is always
3877 * zero, and we rely on this for optional sections.
3879 static int load_module(struct load_info
*info
, const char __user
*uargs
,
3887 * Do the signature check (if any) first. All that
3888 * the signature check needs is info->len, it does
3889 * not need any of the section info. That can be
3890 * set up later. This will minimize the chances
3891 * of a corrupt module causing problems before
3892 * we even get to the signature check.
3894 * The check will also adjust info->len by stripping
3895 * off the sig length at the end of the module, making
3896 * checks against info->len more correct.
3898 err
= module_sig_check(info
, flags
);
3903 * Do basic sanity checks against the ELF header and
3906 err
= elf_validity_check(info
);
3908 pr_err("Module has invalid ELF structures\n");
3913 * Everything checks out, so set up the section info
3914 * in the info structure.
3916 err
= setup_load_info(info
, flags
);
3921 * Now that we know we have the correct module name, check
3922 * if it's blacklisted.
3924 if (blacklisted(info
->name
)) {
3926 pr_err("Module %s is blacklisted\n", info
->name
);
3930 err
= rewrite_section_headers(info
, flags
);
3934 /* Check module struct version now, before we try to use module. */
3935 if (!check_modstruct_version(info
, info
->mod
)) {
3940 /* Figure out module layout, and allocate all the memory. */
3941 mod
= layout_and_allocate(info
, flags
);
3947 audit_log_kern_module(mod
->name
);
3949 /* Reserve our place in the list. */
3950 err
= add_unformed_module(mod
);
3954 #ifdef CONFIG_MODULE_SIG
3955 mod
->sig_ok
= info
->sig_ok
;
3957 pr_notice_once("%s: module verification failed: signature "
3958 "and/or required key missing - tainting "
3959 "kernel\n", mod
->name
);
3960 add_taint_module(mod
, TAINT_UNSIGNED_MODULE
, LOCKDEP_STILL_OK
);
3964 /* To avoid stressing percpu allocator, do this once we're unique. */
3965 err
= percpu_modalloc(mod
, info
);
3969 /* Now module is in final location, initialize linked lists, etc. */
3970 err
= module_unload_init(mod
);
3974 init_param_lock(mod
);
3977 * Now we've got everything in the final locations, we can
3978 * find optional sections.
3980 err
= find_module_sections(mod
, info
);
3984 err
= check_module_license_and_versions(mod
);
3988 /* Set up MODINFO_ATTR fields */
3989 setup_modinfo(mod
, info
);
3991 /* Fix up syms, so that st_value is a pointer to location. */
3992 err
= simplify_symbols(mod
, info
);
3996 err
= apply_relocations(mod
, info
);
4000 err
= post_relocation(mod
, info
);
4004 flush_module_icache(mod
);
4006 /* Setup CFI for the module. */
4009 /* Now copy in args */
4010 mod
->args
= strndup_user(uargs
, ~0UL >> 1);
4011 if (IS_ERR(mod
->args
)) {
4012 err
= PTR_ERR(mod
->args
);
4013 goto free_arch_cleanup
;
4016 dynamic_debug_setup(mod
, info
->debug
, info
->num_debug
);
4018 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
4019 ftrace_module_init(mod
);
4021 /* Finally it's fully formed, ready to start executing. */
4022 err
= complete_formation(mod
, info
);
4024 goto ddebug_cleanup
;
4026 err
= prepare_coming_module(mod
);
4030 /* Module is ready to execute: parsing args may do that. */
4031 after_dashes
= parse_args(mod
->name
, mod
->args
, mod
->kp
, mod
->num_kp
,
4033 unknown_module_param_cb
);
4034 if (IS_ERR(after_dashes
)) {
4035 err
= PTR_ERR(after_dashes
);
4036 goto coming_cleanup
;
4037 } else if (after_dashes
) {
4038 pr_warn("%s: parameters '%s' after `--' ignored\n",
4039 mod
->name
, after_dashes
);
4042 /* Link in to sysfs. */
4043 err
= mod_sysfs_setup(mod
, info
, mod
->kp
, mod
->num_kp
);
4045 goto coming_cleanup
;
4047 if (is_livepatch_module(mod
)) {
4048 err
= copy_module_elf(mod
, info
);
4053 /* Get rid of temporary copy. */
4057 trace_module_load(mod
);
4059 return do_init_module(mod
);
4062 mod_sysfs_teardown(mod
);
4064 mod
->state
= MODULE_STATE_GOING
;
4065 destroy_params(mod
->kp
, mod
->num_kp
);
4066 blocking_notifier_call_chain(&module_notify_list
,
4067 MODULE_STATE_GOING
, mod
);
4068 klp_module_going(mod
);
4070 mod
->state
= MODULE_STATE_GOING
;
4071 /* module_bug_cleanup needs module_mutex protection */
4072 mutex_lock(&module_mutex
);
4073 module_bug_cleanup(mod
);
4074 mutex_unlock(&module_mutex
);
4077 ftrace_release_mod(mod
);
4078 dynamic_debug_remove(mod
, info
->debug
);
4083 module_arch_cleanup(mod
);
4087 module_unload_free(mod
);
4089 mutex_lock(&module_mutex
);
4090 /* Unlink carefully: kallsyms could be walking list. */
4091 list_del_rcu(&mod
->list
);
4092 mod_tree_remove(mod
);
4093 wake_up_all(&module_wq
);
4094 /* Wait for RCU-sched synchronizing before releasing mod->list. */
4096 mutex_unlock(&module_mutex
);
4098 /* Free lock-classes; relies on the preceding sync_rcu() */
4099 lockdep_free_key_range(mod
->core_layout
.base
, mod
->core_layout
.size
);
4101 module_deallocate(mod
, info
);
4107 SYSCALL_DEFINE3(init_module
, void __user
*, umod
,
4108 unsigned long, len
, const char __user
*, uargs
)
4111 struct load_info info
= { };
4113 err
= may_init_module();
4117 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
4120 err
= copy_module_from_user(umod
, len
, &info
);
4124 return load_module(&info
, uargs
, 0);
4127 SYSCALL_DEFINE3(finit_module
, int, fd
, const char __user
*, uargs
, int, flags
)
4129 struct load_info info
= { };
4133 err
= may_init_module();
4137 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd
, uargs
, flags
);
4139 if (flags
& ~(MODULE_INIT_IGNORE_MODVERSIONS
4140 |MODULE_INIT_IGNORE_VERMAGIC
))
4143 err
= kernel_read_file_from_fd(fd
, 0, &hdr
, INT_MAX
, NULL
,
4150 return load_module(&info
, uargs
, flags
);
4153 static inline int within(unsigned long addr
, void *start
, unsigned long size
)
4155 return ((void *)addr
>= start
&& (void *)addr
< start
+ size
);
4158 #ifdef CONFIG_KALLSYMS
4160 * This ignores the intensely annoying "mapping symbols" found
4161 * in ARM ELF files: $a, $t and $d.
4163 static inline int is_arm_mapping_symbol(const char *str
)
4165 if (str
[0] == '.' && str
[1] == 'L')
4167 return str
[0] == '$' && strchr("axtd", str
[1])
4168 && (str
[2] == '\0' || str
[2] == '.');
4171 static const char *kallsyms_symbol_name(struct mod_kallsyms
*kallsyms
, unsigned int symnum
)
4173 return kallsyms
->strtab
+ kallsyms
->symtab
[symnum
].st_name
;
4177 * Given a module and address, find the corresponding symbol and return its name
4178 * while providing its size and offset if needed.
4180 static const char *find_kallsyms_symbol(struct module
*mod
,
4182 unsigned long *size
,
4183 unsigned long *offset
)
4185 unsigned int i
, best
= 0;
4186 unsigned long nextval
, bestval
;
4187 struct mod_kallsyms
*kallsyms
= rcu_dereference_sched(mod
->kallsyms
);
4189 /* At worse, next value is at end of module */
4190 if (within_module_init(addr
, mod
))
4191 nextval
= (unsigned long)mod
->init_layout
.base
+mod
->init_layout
.text_size
;
4193 nextval
= (unsigned long)mod
->core_layout
.base
+mod
->core_layout
.text_size
;
4195 bestval
= kallsyms_symbol_value(&kallsyms
->symtab
[best
]);
4198 * Scan for closest preceding symbol, and next symbol. (ELF
4199 * starts real symbols at 1).
4201 for (i
= 1; i
< kallsyms
->num_symtab
; i
++) {
4202 const Elf_Sym
*sym
= &kallsyms
->symtab
[i
];
4203 unsigned long thisval
= kallsyms_symbol_value(sym
);
4205 if (sym
->st_shndx
== SHN_UNDEF
)
4209 * We ignore unnamed symbols: they're uninformative
4210 * and inserted at a whim.
4212 if (*kallsyms_symbol_name(kallsyms
, i
) == '\0'
4213 || is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms
, i
)))
4216 if (thisval
<= addr
&& thisval
> bestval
) {
4220 if (thisval
> addr
&& thisval
< nextval
)
4228 *size
= nextval
- bestval
;
4230 *offset
= addr
- bestval
;
4232 return kallsyms_symbol_name(kallsyms
, best
);
4235 void * __weak
dereference_module_function_descriptor(struct module
*mod
,
4242 * For kallsyms to ask for address resolution. NULL means not found. Careful
4243 * not to lock to avoid deadlock on oopses, simply disable preemption.
4245 const char *module_address_lookup(unsigned long addr
,
4246 unsigned long *size
,
4247 unsigned long *offset
,
4251 const char *ret
= NULL
;
4255 mod
= __module_address(addr
);
4258 *modname
= mod
->name
;
4260 ret
= find_kallsyms_symbol(mod
, addr
, size
, offset
);
4262 /* Make a copy in here where it's safe */
4264 strncpy(namebuf
, ret
, KSYM_NAME_LEN
- 1);
4272 int lookup_module_symbol_name(unsigned long addr
, char *symname
)
4277 list_for_each_entry_rcu(mod
, &modules
, list
) {
4278 if (mod
->state
== MODULE_STATE_UNFORMED
)
4280 if (within_module(addr
, mod
)) {
4283 sym
= find_kallsyms_symbol(mod
, addr
, NULL
, NULL
);
4287 strlcpy(symname
, sym
, KSYM_NAME_LEN
);
4297 int lookup_module_symbol_attrs(unsigned long addr
, unsigned long *size
,
4298 unsigned long *offset
, char *modname
, char *name
)
4303 list_for_each_entry_rcu(mod
, &modules
, list
) {
4304 if (mod
->state
== MODULE_STATE_UNFORMED
)
4306 if (within_module(addr
, mod
)) {
4309 sym
= find_kallsyms_symbol(mod
, addr
, size
, offset
);
4313 strlcpy(modname
, mod
->name
, MODULE_NAME_LEN
);
4315 strlcpy(name
, sym
, KSYM_NAME_LEN
);
4325 int module_get_kallsym(unsigned int symnum
, unsigned long *value
, char *type
,
4326 char *name
, char *module_name
, int *exported
)
4331 list_for_each_entry_rcu(mod
, &modules
, list
) {
4332 struct mod_kallsyms
*kallsyms
;
4334 if (mod
->state
== MODULE_STATE_UNFORMED
)
4336 kallsyms
= rcu_dereference_sched(mod
->kallsyms
);
4337 if (symnum
< kallsyms
->num_symtab
) {
4338 const Elf_Sym
*sym
= &kallsyms
->symtab
[symnum
];
4340 *value
= kallsyms_symbol_value(sym
);
4341 *type
= kallsyms
->typetab
[symnum
];
4342 strlcpy(name
, kallsyms_symbol_name(kallsyms
, symnum
), KSYM_NAME_LEN
);
4343 strlcpy(module_name
, mod
->name
, MODULE_NAME_LEN
);
4344 *exported
= is_exported(name
, *value
, mod
);
4348 symnum
-= kallsyms
->num_symtab
;
4354 /* Given a module and name of symbol, find and return the symbol's value */
4355 static unsigned long find_kallsyms_symbol_value(struct module
*mod
, const char *name
)
4358 struct mod_kallsyms
*kallsyms
= rcu_dereference_sched(mod
->kallsyms
);
4360 for (i
= 0; i
< kallsyms
->num_symtab
; i
++) {
4361 const Elf_Sym
*sym
= &kallsyms
->symtab
[i
];
4363 if (strcmp(name
, kallsyms_symbol_name(kallsyms
, i
)) == 0 &&
4364 sym
->st_shndx
!= SHN_UNDEF
)
4365 return kallsyms_symbol_value(sym
);
4370 /* Look for this name: can be of form module:name. */
4371 unsigned long module_kallsyms_lookup_name(const char *name
)
4375 unsigned long ret
= 0;
4377 /* Don't lock: we're in enough trouble already. */
4379 if ((colon
= strnchr(name
, MODULE_NAME_LEN
, ':')) != NULL
) {
4380 if ((mod
= find_module_all(name
, colon
- name
, false)) != NULL
)
4381 ret
= find_kallsyms_symbol_value(mod
, colon
+1);
4383 list_for_each_entry_rcu(mod
, &modules
, list
) {
4384 if (mod
->state
== MODULE_STATE_UNFORMED
)
4386 if ((ret
= find_kallsyms_symbol_value(mod
, name
)) != 0)
4394 #ifdef CONFIG_LIVEPATCH
4395 int module_kallsyms_on_each_symbol(int (*fn
)(void *, const char *,
4396 struct module
*, unsigned long),
4403 mutex_lock(&module_mutex
);
4404 list_for_each_entry(mod
, &modules
, list
) {
4405 /* We hold module_mutex: no need for rcu_dereference_sched */
4406 struct mod_kallsyms
*kallsyms
= mod
->kallsyms
;
4408 if (mod
->state
== MODULE_STATE_UNFORMED
)
4410 for (i
= 0; i
< kallsyms
->num_symtab
; i
++) {
4411 const Elf_Sym
*sym
= &kallsyms
->symtab
[i
];
4413 if (sym
->st_shndx
== SHN_UNDEF
)
4416 ret
= fn(data
, kallsyms_symbol_name(kallsyms
, i
),
4417 mod
, kallsyms_symbol_value(sym
));
4422 mutex_unlock(&module_mutex
);
4425 #endif /* CONFIG_LIVEPATCH */
4426 #endif /* CONFIG_KALLSYMS */
4428 static void cfi_init(struct module
*mod
)
4430 #ifdef CONFIG_CFI_CLANG
4434 rcu_read_lock_sched();
4435 mod
->cfi_check
= (cfi_check_fn
)
4436 find_kallsyms_symbol_value(mod
, "__cfi_check");
4437 init
= (initcall_t
*)
4438 find_kallsyms_symbol_value(mod
, "__cfi_jt_init_module");
4439 exit
= (exitcall_t
*)
4440 find_kallsyms_symbol_value(mod
, "__cfi_jt_cleanup_module");
4441 rcu_read_unlock_sched();
4443 /* Fix init/exit functions to point to the CFI jump table */
4449 cfi_module_add(mod
, module_addr_min
);
4453 static void cfi_cleanup(struct module
*mod
)
4455 #ifdef CONFIG_CFI_CLANG
4456 cfi_module_remove(mod
, module_addr_min
);
4460 /* Maximum number of characters written by module_flags() */
4461 #define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
4463 /* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
4464 static char *module_flags(struct module
*mod
, char *buf
)
4468 BUG_ON(mod
->state
== MODULE_STATE_UNFORMED
);
4470 mod
->state
== MODULE_STATE_GOING
||
4471 mod
->state
== MODULE_STATE_COMING
) {
4473 bx
+= module_flags_taint(mod
, buf
+ bx
);
4474 /* Show a - for module-is-being-unloaded */
4475 if (mod
->state
== MODULE_STATE_GOING
)
4477 /* Show a + for module-is-being-loaded */
4478 if (mod
->state
== MODULE_STATE_COMING
)
4487 #ifdef CONFIG_PROC_FS
4488 /* Called by the /proc file system to return a list of modules. */
4489 static void *m_start(struct seq_file
*m
, loff_t
*pos
)
4491 mutex_lock(&module_mutex
);
4492 return seq_list_start(&modules
, *pos
);
4495 static void *m_next(struct seq_file
*m
, void *p
, loff_t
*pos
)
4497 return seq_list_next(p
, &modules
, pos
);
4500 static void m_stop(struct seq_file
*m
, void *p
)
4502 mutex_unlock(&module_mutex
);
4505 static int m_show(struct seq_file
*m
, void *p
)
4507 struct module
*mod
= list_entry(p
, struct module
, list
);
4508 char buf
[MODULE_FLAGS_BUF_SIZE
];
4511 /* We always ignore unformed modules. */
4512 if (mod
->state
== MODULE_STATE_UNFORMED
)
4515 seq_printf(m
, "%s %u",
4516 mod
->name
, mod
->init_layout
.size
+ mod
->core_layout
.size
);
4517 print_unload_info(m
, mod
);
4519 /* Informative for users. */
4520 seq_printf(m
, " %s",
4521 mod
->state
== MODULE_STATE_GOING
? "Unloading" :
4522 mod
->state
== MODULE_STATE_COMING
? "Loading" :
4524 /* Used by oprofile and other similar tools. */
4525 value
= m
->private ? NULL
: mod
->core_layout
.base
;
4526 seq_printf(m
, " 0x%px", value
);
4530 seq_printf(m
, " %s", module_flags(mod
, buf
));
4537 * Format: modulename size refcount deps address
4539 * Where refcount is a number or -, and deps is a comma-separated list
4542 static const struct seq_operations modules_op
= {
4550 * This also sets the "private" pointer to non-NULL if the
4551 * kernel pointers should be hidden (so you can just test
4552 * "m->private" to see if you should keep the values private).
4554 * We use the same logic as for /proc/kallsyms.
4556 static int modules_open(struct inode
*inode
, struct file
*file
)
4558 int err
= seq_open(file
, &modules_op
);
4561 struct seq_file
*m
= file
->private_data
;
4562 m
->private = kallsyms_show_value(file
->f_cred
) ? NULL
: (void *)8ul;
4568 static const struct proc_ops modules_proc_ops
= {
4569 .proc_flags
= PROC_ENTRY_PERMANENT
,
4570 .proc_open
= modules_open
,
4571 .proc_read
= seq_read
,
4572 .proc_lseek
= seq_lseek
,
4573 .proc_release
= seq_release
,
4576 static int __init
proc_modules_init(void)
4578 proc_create("modules", 0, NULL
, &modules_proc_ops
);
4581 module_init(proc_modules_init
);
4584 /* Given an address, look for it in the module exception tables. */
4585 const struct exception_table_entry
*search_module_extables(unsigned long addr
)
4587 const struct exception_table_entry
*e
= NULL
;
4591 mod
= __module_address(addr
);
4595 if (!mod
->num_exentries
)
4598 e
= search_extable(mod
->extable
,
4605 * Now, if we found one, we are running inside it now, hence
4606 * we cannot unload the module, hence no refcnt needed.
4612 * is_module_address() - is this address inside a module?
4613 * @addr: the address to check.
4615 * See is_module_text_address() if you simply want to see if the address
4616 * is code (not data).
4618 bool is_module_address(unsigned long addr
)
4623 ret
= __module_address(addr
) != NULL
;
4630 * __module_address() - get the module which contains an address.
4631 * @addr: the address.
4633 * Must be called with preempt disabled or module mutex held so that
4634 * module doesn't get freed during this.
4636 struct module
*__module_address(unsigned long addr
)
4640 if (addr
< module_addr_min
|| addr
> module_addr_max
)
4643 module_assert_mutex_or_preempt();
4645 mod
= mod_find(addr
);
4647 BUG_ON(!within_module(addr
, mod
));
4648 if (mod
->state
== MODULE_STATE_UNFORMED
)
4655 * is_module_text_address() - is this address inside module code?
4656 * @addr: the address to check.
4658 * See is_module_address() if you simply want to see if the address is
4659 * anywhere in a module. See kernel_text_address() for testing if an
4660 * address corresponds to kernel or module code.
4662 bool is_module_text_address(unsigned long addr
)
4667 ret
= __module_text_address(addr
) != NULL
;
4674 * __module_text_address() - get the module whose code contains an address.
4675 * @addr: the address.
4677 * Must be called with preempt disabled or module mutex held so that
4678 * module doesn't get freed during this.
4680 struct module
*__module_text_address(unsigned long addr
)
4682 struct module
*mod
= __module_address(addr
);
4684 /* Make sure it's within the text section. */
4685 if (!within(addr
, mod
->init_layout
.base
, mod
->init_layout
.text_size
)
4686 && !within(addr
, mod
->core_layout
.base
, mod
->core_layout
.text_size
))
4692 /* Don't grab lock, we're oopsing. */
4693 void print_modules(void)
4696 char buf
[MODULE_FLAGS_BUF_SIZE
];
4698 printk(KERN_DEFAULT
"Modules linked in:");
4699 /* Most callers should already have preempt disabled, but make sure */
4701 list_for_each_entry_rcu(mod
, &modules
, list
) {
4702 if (mod
->state
== MODULE_STATE_UNFORMED
)
4704 pr_cont(" %s%s", mod
->name
, module_flags(mod
, buf
));
4707 if (last_unloaded_module
[0])
4708 pr_cont(" [last unloaded: %s]", last_unloaded_module
);
4712 #ifdef CONFIG_MODVERSIONS
4714 * Generate the signature for all relevant module structures here.
4715 * If these change, we don't want to try to parse the module.
4717 void module_layout(struct module
*mod
,
4718 struct modversion_info
*ver
,
4719 struct kernel_param
*kp
,
4720 struct kernel_symbol
*ks
,
4721 struct tracepoint
* const *tp
)
4724 EXPORT_SYMBOL(module_layout
);