1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Copyright (C) 2002 Richard Henderson
4 * Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
7 #define INCLUDE_VERMAGIC
9 #include <linux/export.h>
10 #include <linux/extable.h>
11 #include <linux/moduleloader.h>
12 #include <linux/module_signature.h>
13 #include <linux/trace_events.h>
14 #include <linux/init.h>
15 #include <linux/kallsyms.h>
16 #include <linux/buildid.h>
17 #include <linux/file.h>
19 #include <linux/sysfs.h>
20 #include <linux/kernel.h>
21 #include <linux/kernel_read_file.h>
22 #include <linux/slab.h>
23 #include <linux/vmalloc.h>
24 #include <linux/elf.h>
25 #include <linux/proc_fs.h>
26 #include <linux/security.h>
27 #include <linux/seq_file.h>
28 #include <linux/syscalls.h>
29 #include <linux/fcntl.h>
30 #include <linux/rcupdate.h>
31 #include <linux/capability.h>
32 #include <linux/cpu.h>
33 #include <linux/moduleparam.h>
34 #include <linux/errno.h>
35 #include <linux/err.h>
36 #include <linux/vermagic.h>
37 #include <linux/notifier.h>
38 #include <linux/sched.h>
39 #include <linux/device.h>
40 #include <linux/string.h>
41 #include <linux/mutex.h>
42 #include <linux/rculist.h>
43 #include <linux/uaccess.h>
44 #include <asm/cacheflush.h>
45 #include <linux/set_memory.h>
46 #include <asm/mmu_context.h>
47 #include <linux/license.h>
48 #include <asm/sections.h>
49 #include <linux/tracepoint.h>
50 #include <linux/ftrace.h>
51 #include <linux/livepatch.h>
52 #include <linux/async.h>
53 #include <linux/percpu.h>
54 #include <linux/kmemleak.h>
55 #include <linux/jump_label.h>
56 #include <linux/pfn.h>
57 #include <linux/bsearch.h>
58 #include <linux/dynamic_debug.h>
59 #include <linux/audit.h>
60 #include <uapi/linux/module.h>
61 #include "module-internal.h"
63 #define CREATE_TRACE_POINTS
64 #include <trace/events/module.h>
66 #ifndef ARCH_SHF_SMALL
67 #define ARCH_SHF_SMALL 0
71 * Modules' sections will be aligned on page boundaries
72 * to ensure complete separation of code and data, but
73 * only when CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y
75 #ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
76 # define debug_align(X) ALIGN(X, PAGE_SIZE)
78 # define debug_align(X) (X)
81 /* If this is set, the section belongs in the init part of the module */
82 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
86 * 1) List of modules (also safely readable with preempt_disable),
87 * 2) module_use links,
88 * 3) module_addr_min/module_addr_max.
89 * (delete and add uses RCU list operations).
91 static DEFINE_MUTEX(module_mutex
);
92 static LIST_HEAD(modules
);
94 /* Work queue for freeing init sections in success case */
95 static void do_free_init(struct work_struct
*w
);
96 static DECLARE_WORK(init_free_wq
, do_free_init
);
97 static LLIST_HEAD(init_free_list
);
99 #ifdef CONFIG_MODULES_TREE_LOOKUP
102 * Use a latched RB-tree for __module_address(); this allows us to use
103 * RCU-sched lookups of the address from any context.
105 * This is conditional on PERF_EVENTS || TRACING because those can really hit
106 * __module_address() hard by doing a lot of stack unwinding; potentially from
110 static __always_inline
unsigned long __mod_tree_val(struct latch_tree_node
*n
)
112 struct module_layout
*layout
= container_of(n
, struct module_layout
, mtn
.node
);
114 return (unsigned long)layout
->base
;
117 static __always_inline
unsigned long __mod_tree_size(struct latch_tree_node
*n
)
119 struct module_layout
*layout
= container_of(n
, struct module_layout
, mtn
.node
);
121 return (unsigned long)layout
->size
;
124 static __always_inline
bool
125 mod_tree_less(struct latch_tree_node
*a
, struct latch_tree_node
*b
)
127 return __mod_tree_val(a
) < __mod_tree_val(b
);
130 static __always_inline
int
131 mod_tree_comp(void *key
, struct latch_tree_node
*n
)
133 unsigned long val
= (unsigned long)key
;
134 unsigned long start
, end
;
136 start
= __mod_tree_val(n
);
140 end
= start
+ __mod_tree_size(n
);
147 static const struct latch_tree_ops mod_tree_ops
= {
148 .less
= mod_tree_less
,
149 .comp
= mod_tree_comp
,
152 static struct mod_tree_root
{
153 struct latch_tree_root root
;
154 unsigned long addr_min
;
155 unsigned long addr_max
;
156 } mod_tree __cacheline_aligned
= {
160 #define module_addr_min mod_tree.addr_min
161 #define module_addr_max mod_tree.addr_max
163 static noinline
void __mod_tree_insert(struct mod_tree_node
*node
)
165 latch_tree_insert(&node
->node
, &mod_tree
.root
, &mod_tree_ops
);
168 static void __mod_tree_remove(struct mod_tree_node
*node
)
170 latch_tree_erase(&node
->node
, &mod_tree
.root
, &mod_tree_ops
);
174 * These modifications: insert, remove_init and remove; are serialized by the
177 static void mod_tree_insert(struct module
*mod
)
179 mod
->core_layout
.mtn
.mod
= mod
;
180 mod
->init_layout
.mtn
.mod
= mod
;
182 __mod_tree_insert(&mod
->core_layout
.mtn
);
183 if (mod
->init_layout
.size
)
184 __mod_tree_insert(&mod
->init_layout
.mtn
);
187 static void mod_tree_remove_init(struct module
*mod
)
189 if (mod
->init_layout
.size
)
190 __mod_tree_remove(&mod
->init_layout
.mtn
);
193 static void mod_tree_remove(struct module
*mod
)
195 __mod_tree_remove(&mod
->core_layout
.mtn
);
196 mod_tree_remove_init(mod
);
199 static struct module
*mod_find(unsigned long addr
)
201 struct latch_tree_node
*ltn
;
203 ltn
= latch_tree_find((void *)addr
, &mod_tree
.root
, &mod_tree_ops
);
207 return container_of(ltn
, struct mod_tree_node
, node
)->mod
;
210 #else /* MODULES_TREE_LOOKUP */
212 static unsigned long module_addr_min
= -1UL, module_addr_max
= 0;
214 static void mod_tree_insert(struct module
*mod
) { }
215 static void mod_tree_remove_init(struct module
*mod
) { }
216 static void mod_tree_remove(struct module
*mod
) { }
218 static struct module
*mod_find(unsigned long addr
)
222 list_for_each_entry_rcu(mod
, &modules
, list
,
223 lockdep_is_held(&module_mutex
)) {
224 if (within_module(addr
, mod
))
231 #endif /* MODULES_TREE_LOOKUP */
234 * Bounds of module text, for speeding up __module_address.
235 * Protected by module_mutex.
237 static void __mod_update_bounds(void *base
, unsigned int size
)
239 unsigned long min
= (unsigned long)base
;
240 unsigned long max
= min
+ size
;
242 if (min
< module_addr_min
)
243 module_addr_min
= min
;
244 if (max
> module_addr_max
)
245 module_addr_max
= max
;
248 static void mod_update_bounds(struct module
*mod
)
250 __mod_update_bounds(mod
->core_layout
.base
, mod
->core_layout
.size
);
251 if (mod
->init_layout
.size
)
252 __mod_update_bounds(mod
->init_layout
.base
, mod
->init_layout
.size
);
255 #ifdef CONFIG_KGDB_KDB
256 struct list_head
*kdb_modules
= &modules
; /* kdb needs the list of modules */
257 #endif /* CONFIG_KGDB_KDB */
259 static void module_assert_mutex_or_preempt(void)
261 #ifdef CONFIG_LOCKDEP
262 if (unlikely(!debug_locks
))
265 WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
266 !lockdep_is_held(&module_mutex
));
270 #ifdef CONFIG_MODULE_SIG
271 static bool sig_enforce
= IS_ENABLED(CONFIG_MODULE_SIG_FORCE
);
272 module_param(sig_enforce
, bool_enable_only
, 0644);
274 void set_module_sig_enforced(void)
279 #define sig_enforce false
283 * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
284 * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
286 bool is_module_sig_enforced(void)
290 EXPORT_SYMBOL(is_module_sig_enforced
);
292 /* Block module loading/unloading? */
293 int modules_disabled
= 0;
294 core_param(nomodule
, modules_disabled
, bint
, 0);
296 /* Waiting for a module to finish initializing? */
297 static DECLARE_WAIT_QUEUE_HEAD(module_wq
);
299 static BLOCKING_NOTIFIER_HEAD(module_notify_list
);
301 int register_module_notifier(struct notifier_block
*nb
)
303 return blocking_notifier_chain_register(&module_notify_list
, nb
);
305 EXPORT_SYMBOL(register_module_notifier
);
307 int unregister_module_notifier(struct notifier_block
*nb
)
309 return blocking_notifier_chain_unregister(&module_notify_list
, nb
);
311 EXPORT_SYMBOL(unregister_module_notifier
);
314 * We require a truly strong try_module_get(): 0 means success.
315 * Otherwise an error is returned due to ongoing or failed
316 * initialization etc.
318 static inline int strong_try_module_get(struct module
*mod
)
320 BUG_ON(mod
&& mod
->state
== MODULE_STATE_UNFORMED
);
321 if (mod
&& mod
->state
== MODULE_STATE_COMING
)
323 if (try_module_get(mod
))
329 static inline void add_taint_module(struct module
*mod
, unsigned flag
,
330 enum lockdep_ok lockdep_ok
)
332 add_taint(flag
, lockdep_ok
);
333 set_bit(flag
, &mod
->taints
);
337 * A thread that wants to hold a reference to a module only while it
338 * is running can call this to safely exit. nfsd and lockd use this.
340 void __noreturn
__module_put_and_exit(struct module
*mod
, long code
)
345 EXPORT_SYMBOL(__module_put_and_exit
);
347 /* Find a module section: 0 means not found. */
348 static unsigned int find_sec(const struct load_info
*info
, const char *name
)
352 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
353 Elf_Shdr
*shdr
= &info
->sechdrs
[i
];
354 /* Alloc bit cleared means "ignore it." */
355 if ((shdr
->sh_flags
& SHF_ALLOC
)
356 && strcmp(info
->secstrings
+ shdr
->sh_name
, name
) == 0)
362 /* Find a module section, or NULL. */
363 static void *section_addr(const struct load_info
*info
, const char *name
)
365 /* Section 0 has sh_addr 0. */
366 return (void *)info
->sechdrs
[find_sec(info
, name
)].sh_addr
;
369 /* Find a module section, or NULL. Fill in number of "objects" in section. */
370 static void *section_objs(const struct load_info
*info
,
375 unsigned int sec
= find_sec(info
, name
);
377 /* Section 0 has sh_addr 0 and sh_size 0. */
378 *num
= info
->sechdrs
[sec
].sh_size
/ object_size
;
379 return (void *)info
->sechdrs
[sec
].sh_addr
;
382 /* Find a module section: 0 means not found. Ignores SHF_ALLOC flag. */
383 static unsigned int find_any_sec(const struct load_info
*info
, const char *name
)
387 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
388 Elf_Shdr
*shdr
= &info
->sechdrs
[i
];
389 if (strcmp(info
->secstrings
+ shdr
->sh_name
, name
) == 0)
396 * Find a module section, or NULL. Fill in number of "objects" in section.
397 * Ignores SHF_ALLOC flag.
399 static __maybe_unused
void *any_section_objs(const struct load_info
*info
,
404 unsigned int sec
= find_any_sec(info
, name
);
406 /* Section 0 has sh_addr 0 and sh_size 0. */
407 *num
= info
->sechdrs
[sec
].sh_size
/ object_size
;
408 return (void *)info
->sechdrs
[sec
].sh_addr
;
411 /* Provided by the linker */
412 extern const struct kernel_symbol __start___ksymtab
[];
413 extern const struct kernel_symbol __stop___ksymtab
[];
414 extern const struct kernel_symbol __start___ksymtab_gpl
[];
415 extern const struct kernel_symbol __stop___ksymtab_gpl
[];
416 extern const s32 __start___kcrctab
[];
417 extern const s32 __start___kcrctab_gpl
[];
419 #ifndef CONFIG_MODVERSIONS
420 #define symversion(base, idx) NULL
422 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
426 const struct kernel_symbol
*start
, *stop
;
434 struct find_symbol_arg
{
441 struct module
*owner
;
443 const struct kernel_symbol
*sym
;
444 enum mod_license license
;
447 static bool check_exported_symbol(const struct symsearch
*syms
,
448 struct module
*owner
,
449 unsigned int symnum
, void *data
)
451 struct find_symbol_arg
*fsa
= data
;
453 if (!fsa
->gplok
&& syms
->license
== GPL_ONLY
)
456 fsa
->crc
= symversion(syms
->crcs
, symnum
);
457 fsa
->sym
= &syms
->start
[symnum
];
458 fsa
->license
= syms
->license
;
462 static unsigned long kernel_symbol_value(const struct kernel_symbol
*sym
)
464 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
465 return (unsigned long)offset_to_ptr(&sym
->value_offset
);
471 static const char *kernel_symbol_name(const struct kernel_symbol
*sym
)
473 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
474 return offset_to_ptr(&sym
->name_offset
);
480 static const char *kernel_symbol_namespace(const struct kernel_symbol
*sym
)
482 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
483 if (!sym
->namespace_offset
)
485 return offset_to_ptr(&sym
->namespace_offset
);
487 return sym
->namespace;
491 static int cmp_name(const void *name
, const void *sym
)
493 return strcmp(name
, kernel_symbol_name(sym
));
496 static bool find_exported_symbol_in_section(const struct symsearch
*syms
,
497 struct module
*owner
,
500 struct find_symbol_arg
*fsa
= data
;
501 struct kernel_symbol
*sym
;
503 sym
= bsearch(fsa
->name
, syms
->start
, syms
->stop
- syms
->start
,
504 sizeof(struct kernel_symbol
), cmp_name
);
506 if (sym
!= NULL
&& check_exported_symbol(syms
, owner
,
507 sym
- syms
->start
, data
))
514 * Find an exported symbol and return it, along with, (optional) crc and
515 * (optional) module which owns it. Needs preempt disabled or module_mutex.
517 static bool find_symbol(struct find_symbol_arg
*fsa
)
519 static const struct symsearch arr
[] = {
520 { __start___ksymtab
, __stop___ksymtab
, __start___kcrctab
,
522 { __start___ksymtab_gpl
, __stop___ksymtab_gpl
,
523 __start___kcrctab_gpl
,
529 module_assert_mutex_or_preempt();
531 for (i
= 0; i
< ARRAY_SIZE(arr
); i
++)
532 if (find_exported_symbol_in_section(&arr
[i
], NULL
, fsa
))
535 list_for_each_entry_rcu(mod
, &modules
, list
,
536 lockdep_is_held(&module_mutex
)) {
537 struct symsearch arr
[] = {
538 { mod
->syms
, mod
->syms
+ mod
->num_syms
, mod
->crcs
,
540 { mod
->gpl_syms
, mod
->gpl_syms
+ mod
->num_gpl_syms
,
545 if (mod
->state
== MODULE_STATE_UNFORMED
)
548 for (i
= 0; i
< ARRAY_SIZE(arr
); i
++)
549 if (find_exported_symbol_in_section(&arr
[i
], mod
, fsa
))
553 pr_debug("Failed to find symbol %s\n", fsa
->name
);
558 * Search for module by name: must hold module_mutex (or preempt disabled
559 * for read-only access).
561 static struct module
*find_module_all(const char *name
, size_t len
,
566 module_assert_mutex_or_preempt();
568 list_for_each_entry_rcu(mod
, &modules
, list
,
569 lockdep_is_held(&module_mutex
)) {
570 if (!even_unformed
&& mod
->state
== MODULE_STATE_UNFORMED
)
572 if (strlen(mod
->name
) == len
&& !memcmp(mod
->name
, name
, len
))
578 struct module
*find_module(const char *name
)
580 return find_module_all(name
, strlen(name
), false);
585 static inline void __percpu
*mod_percpu(struct module
*mod
)
590 static int percpu_modalloc(struct module
*mod
, struct load_info
*info
)
592 Elf_Shdr
*pcpusec
= &info
->sechdrs
[info
->index
.pcpu
];
593 unsigned long align
= pcpusec
->sh_addralign
;
595 if (!pcpusec
->sh_size
)
598 if (align
> PAGE_SIZE
) {
599 pr_warn("%s: per-cpu alignment %li > %li\n",
600 mod
->name
, align
, PAGE_SIZE
);
604 mod
->percpu
= __alloc_reserved_percpu(pcpusec
->sh_size
, align
);
606 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
607 mod
->name
, (unsigned long)pcpusec
->sh_size
);
610 mod
->percpu_size
= pcpusec
->sh_size
;
614 static void percpu_modfree(struct module
*mod
)
616 free_percpu(mod
->percpu
);
619 static unsigned int find_pcpusec(struct load_info
*info
)
621 return find_sec(info
, ".data..percpu");
624 static void percpu_modcopy(struct module
*mod
,
625 const void *from
, unsigned long size
)
629 for_each_possible_cpu(cpu
)
630 memcpy(per_cpu_ptr(mod
->percpu
, cpu
), from
, size
);
633 bool __is_module_percpu_address(unsigned long addr
, unsigned long *can_addr
)
640 list_for_each_entry_rcu(mod
, &modules
, list
) {
641 if (mod
->state
== MODULE_STATE_UNFORMED
)
643 if (!mod
->percpu_size
)
645 for_each_possible_cpu(cpu
) {
646 void *start
= per_cpu_ptr(mod
->percpu
, cpu
);
647 void *va
= (void *)addr
;
649 if (va
>= start
&& va
< start
+ mod
->percpu_size
) {
651 *can_addr
= (unsigned long) (va
- start
);
652 *can_addr
+= (unsigned long)
653 per_cpu_ptr(mod
->percpu
,
667 * is_module_percpu_address() - test whether address is from module static percpu
668 * @addr: address to test
670 * Test whether @addr belongs to module static percpu area.
672 * Return: %true if @addr is from module static percpu area
674 bool is_module_percpu_address(unsigned long addr
)
676 return __is_module_percpu_address(addr
, NULL
);
679 #else /* ... !CONFIG_SMP */
681 static inline void __percpu
*mod_percpu(struct module
*mod
)
685 static int percpu_modalloc(struct module
*mod
, struct load_info
*info
)
687 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
688 if (info
->sechdrs
[info
->index
.pcpu
].sh_size
!= 0)
692 static inline void percpu_modfree(struct module
*mod
)
695 static unsigned int find_pcpusec(struct load_info
*info
)
699 static inline void percpu_modcopy(struct module
*mod
,
700 const void *from
, unsigned long size
)
702 /* pcpusec should be 0, and size of that section should be 0. */
705 bool is_module_percpu_address(unsigned long addr
)
710 bool __is_module_percpu_address(unsigned long addr
, unsigned long *can_addr
)
715 #endif /* CONFIG_SMP */
717 #define MODINFO_ATTR(field) \
718 static void setup_modinfo_##field(struct module *mod, const char *s) \
720 mod->field = kstrdup(s, GFP_KERNEL); \
722 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
723 struct module_kobject *mk, char *buffer) \
725 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
727 static int modinfo_##field##_exists(struct module *mod) \
729 return mod->field != NULL; \
731 static void free_modinfo_##field(struct module *mod) \
736 static struct module_attribute modinfo_##field = { \
737 .attr = { .name = __stringify(field), .mode = 0444 }, \
738 .show = show_modinfo_##field, \
739 .setup = setup_modinfo_##field, \
740 .test = modinfo_##field##_exists, \
741 .free = free_modinfo_##field, \
744 MODINFO_ATTR(version
);
745 MODINFO_ATTR(srcversion
);
747 static char last_unloaded_module
[MODULE_NAME_LEN
+1];
749 #ifdef CONFIG_MODULE_UNLOAD
751 EXPORT_TRACEPOINT_SYMBOL(module_get
);
753 /* MODULE_REF_BASE is the base reference count by kmodule loader. */
754 #define MODULE_REF_BASE 1
756 /* Init the unload section of the module. */
757 static int module_unload_init(struct module
*mod
)
760 * Initialize reference counter to MODULE_REF_BASE.
761 * refcnt == 0 means module is going.
763 atomic_set(&mod
->refcnt
, MODULE_REF_BASE
);
765 INIT_LIST_HEAD(&mod
->source_list
);
766 INIT_LIST_HEAD(&mod
->target_list
);
768 /* Hold reference count during initialization. */
769 atomic_inc(&mod
->refcnt
);
774 /* Does a already use b? */
775 static int already_uses(struct module
*a
, struct module
*b
)
777 struct module_use
*use
;
779 list_for_each_entry(use
, &b
->source_list
, source_list
) {
780 if (use
->source
== a
) {
781 pr_debug("%s uses %s!\n", a
->name
, b
->name
);
785 pr_debug("%s does not use %s!\n", a
->name
, b
->name
);
791 * - we add 'a' as a "source", 'b' as a "target" of module use
792 * - the module_use is added to the list of 'b' sources (so
793 * 'b' can walk the list to see who sourced them), and of 'a'
794 * targets (so 'a' can see what modules it targets).
796 static int add_module_usage(struct module
*a
, struct module
*b
)
798 struct module_use
*use
;
800 pr_debug("Allocating new usage for %s.\n", a
->name
);
801 use
= kmalloc(sizeof(*use
), GFP_ATOMIC
);
807 list_add(&use
->source_list
, &b
->source_list
);
808 list_add(&use
->target_list
, &a
->target_list
);
812 /* Module a uses b: caller needs module_mutex() */
813 static int ref_module(struct module
*a
, struct module
*b
)
817 if (b
== NULL
|| already_uses(a
, b
))
820 /* If module isn't available, we fail. */
821 err
= strong_try_module_get(b
);
825 err
= add_module_usage(a
, b
);
833 /* Clear the unload stuff of the module. */
834 static void module_unload_free(struct module
*mod
)
836 struct module_use
*use
, *tmp
;
838 mutex_lock(&module_mutex
);
839 list_for_each_entry_safe(use
, tmp
, &mod
->target_list
, target_list
) {
840 struct module
*i
= use
->target
;
841 pr_debug("%s unusing %s\n", mod
->name
, i
->name
);
843 list_del(&use
->source_list
);
844 list_del(&use
->target_list
);
847 mutex_unlock(&module_mutex
);
850 #ifdef CONFIG_MODULE_FORCE_UNLOAD
851 static inline int try_force_unload(unsigned int flags
)
853 int ret
= (flags
& O_TRUNC
);
855 add_taint(TAINT_FORCED_RMMOD
, LOCKDEP_NOW_UNRELIABLE
);
859 static inline int try_force_unload(unsigned int flags
)
863 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
865 /* Try to release refcount of module, 0 means success. */
866 static int try_release_module_ref(struct module
*mod
)
870 /* Try to decrement refcnt which we set at loading */
871 ret
= atomic_sub_return(MODULE_REF_BASE
, &mod
->refcnt
);
874 /* Someone can put this right now, recover with checking */
875 ret
= atomic_add_unless(&mod
->refcnt
, MODULE_REF_BASE
, 0);
880 static int try_stop_module(struct module
*mod
, int flags
, int *forced
)
882 /* If it's not unused, quit unless we're forcing. */
883 if (try_release_module_ref(mod
) != 0) {
884 *forced
= try_force_unload(flags
);
889 /* Mark it as dying. */
890 mod
->state
= MODULE_STATE_GOING
;
896 * module_refcount() - return the refcount or -1 if unloading
897 * @mod: the module we're checking
900 * -1 if the module is in the process of unloading
901 * otherwise the number of references in the kernel to the module
903 int module_refcount(struct module
*mod
)
905 return atomic_read(&mod
->refcnt
) - MODULE_REF_BASE
;
907 EXPORT_SYMBOL(module_refcount
);
909 /* This exists whether we can unload or not */
910 static void free_module(struct module
*mod
);
912 SYSCALL_DEFINE2(delete_module
, const char __user
*, name_user
,
916 char name
[MODULE_NAME_LEN
];
919 if (!capable(CAP_SYS_MODULE
) || modules_disabled
)
922 if (strncpy_from_user(name
, name_user
, MODULE_NAME_LEN
-1) < 0)
924 name
[MODULE_NAME_LEN
-1] = '\0';
926 audit_log_kern_module(name
);
928 if (mutex_lock_interruptible(&module_mutex
) != 0)
931 mod
= find_module(name
);
937 if (!list_empty(&mod
->source_list
)) {
938 /* Other modules depend on us: get rid of them first. */
943 /* Doing init or already dying? */
944 if (mod
->state
!= MODULE_STATE_LIVE
) {
945 /* FIXME: if (force), slam module count damn the torpedoes */
946 pr_debug("%s already dying\n", mod
->name
);
951 /* If it has an init func, it must have an exit func to unload */
952 if (mod
->init
&& !mod
->exit
) {
953 forced
= try_force_unload(flags
);
955 /* This module can't be removed */
961 /* Stop the machine so refcounts can't move and disable module. */
962 ret
= try_stop_module(mod
, flags
, &forced
);
966 mutex_unlock(&module_mutex
);
967 /* Final destruction now no one is using it. */
968 if (mod
->exit
!= NULL
)
970 blocking_notifier_call_chain(&module_notify_list
,
971 MODULE_STATE_GOING
, mod
);
972 klp_module_going(mod
);
973 ftrace_release_mod(mod
);
975 async_synchronize_full();
977 /* Store the name of the last unloaded module for diagnostic purposes */
978 strlcpy(last_unloaded_module
, mod
->name
, sizeof(last_unloaded_module
));
981 /* someone could wait for the module in add_unformed_module() */
982 wake_up_all(&module_wq
);
985 mutex_unlock(&module_mutex
);
989 static inline void print_unload_info(struct seq_file
*m
, struct module
*mod
)
991 struct module_use
*use
;
992 int printed_something
= 0;
994 seq_printf(m
, " %i ", module_refcount(mod
));
997 * Always include a trailing , so userspace can differentiate
998 * between this and the old multi-field proc format.
1000 list_for_each_entry(use
, &mod
->source_list
, source_list
) {
1001 printed_something
= 1;
1002 seq_printf(m
, "%s,", use
->source
->name
);
1005 if (mod
->init
!= NULL
&& mod
->exit
== NULL
) {
1006 printed_something
= 1;
1007 seq_puts(m
, "[permanent],");
1010 if (!printed_something
)
1014 void __symbol_put(const char *symbol
)
1016 struct find_symbol_arg fsa
= {
1022 BUG_ON(!find_symbol(&fsa
));
1023 module_put(fsa
.owner
);
1026 EXPORT_SYMBOL(__symbol_put
);
1028 /* Note this assumes addr is a function, which it currently always is. */
1029 void symbol_put_addr(void *addr
)
1031 struct module
*modaddr
;
1032 unsigned long a
= (unsigned long)dereference_function_descriptor(addr
);
1034 if (core_kernel_text(a
))
1038 * Even though we hold a reference on the module; we still need to
1039 * disable preemption in order to safely traverse the data structure.
1042 modaddr
= __module_text_address(a
);
1044 module_put(modaddr
);
1047 EXPORT_SYMBOL_GPL(symbol_put_addr
);
1049 static ssize_t
show_refcnt(struct module_attribute
*mattr
,
1050 struct module_kobject
*mk
, char *buffer
)
1052 return sprintf(buffer
, "%i\n", module_refcount(mk
->mod
));
1055 static struct module_attribute modinfo_refcnt
=
1056 __ATTR(refcnt
, 0444, show_refcnt
, NULL
);
1058 void __module_get(struct module
*module
)
1062 atomic_inc(&module
->refcnt
);
1063 trace_module_get(module
, _RET_IP_
);
1067 EXPORT_SYMBOL(__module_get
);
1069 bool try_module_get(struct module
*module
)
1075 /* Note: here, we can fail to get a reference */
1076 if (likely(module_is_live(module
) &&
1077 atomic_inc_not_zero(&module
->refcnt
) != 0))
1078 trace_module_get(module
, _RET_IP_
);
1086 EXPORT_SYMBOL(try_module_get
);
1088 void module_put(struct module
*module
)
1094 ret
= atomic_dec_if_positive(&module
->refcnt
);
1095 WARN_ON(ret
< 0); /* Failed to put refcount */
1096 trace_module_put(module
, _RET_IP_
);
1100 EXPORT_SYMBOL(module_put
);
1102 #else /* !CONFIG_MODULE_UNLOAD */
1103 static inline void print_unload_info(struct seq_file
*m
, struct module
*mod
)
1105 /* We don't know the usage count, or what modules are using. */
1106 seq_puts(m
, " - -");
1109 static inline void module_unload_free(struct module
*mod
)
1113 static int ref_module(struct module
*a
, struct module
*b
)
1115 return strong_try_module_get(b
);
1118 static inline int module_unload_init(struct module
*mod
)
1122 #endif /* CONFIG_MODULE_UNLOAD */
1124 static size_t module_flags_taint(struct module
*mod
, char *buf
)
1129 for (i
= 0; i
< TAINT_FLAGS_COUNT
; i
++) {
1130 if (taint_flags
[i
].module
&& test_bit(i
, &mod
->taints
))
1131 buf
[l
++] = taint_flags
[i
].c_true
;
1137 static ssize_t
show_initstate(struct module_attribute
*mattr
,
1138 struct module_kobject
*mk
, char *buffer
)
1140 const char *state
= "unknown";
1142 switch (mk
->mod
->state
) {
1143 case MODULE_STATE_LIVE
:
1146 case MODULE_STATE_COMING
:
1149 case MODULE_STATE_GOING
:
1155 return sprintf(buffer
, "%s\n", state
);
1158 static struct module_attribute modinfo_initstate
=
1159 __ATTR(initstate
, 0444, show_initstate
, NULL
);
1161 static ssize_t
store_uevent(struct module_attribute
*mattr
,
1162 struct module_kobject
*mk
,
1163 const char *buffer
, size_t count
)
1167 rc
= kobject_synth_uevent(&mk
->kobj
, buffer
, count
);
1168 return rc
? rc
: count
;
1171 struct module_attribute module_uevent
=
1172 __ATTR(uevent
, 0200, NULL
, store_uevent
);
1174 static ssize_t
show_coresize(struct module_attribute
*mattr
,
1175 struct module_kobject
*mk
, char *buffer
)
1177 return sprintf(buffer
, "%u\n", mk
->mod
->core_layout
.size
);
1180 static struct module_attribute modinfo_coresize
=
1181 __ATTR(coresize
, 0444, show_coresize
, NULL
);
1183 static ssize_t
show_initsize(struct module_attribute
*mattr
,
1184 struct module_kobject
*mk
, char *buffer
)
1186 return sprintf(buffer
, "%u\n", mk
->mod
->init_layout
.size
);
1189 static struct module_attribute modinfo_initsize
=
1190 __ATTR(initsize
, 0444, show_initsize
, NULL
);
1192 static ssize_t
show_taint(struct module_attribute
*mattr
,
1193 struct module_kobject
*mk
, char *buffer
)
1197 l
= module_flags_taint(mk
->mod
, buffer
);
1202 static struct module_attribute modinfo_taint
=
1203 __ATTR(taint
, 0444, show_taint
, NULL
);
1205 static struct module_attribute
*modinfo_attrs
[] = {
1208 &modinfo_srcversion
,
1213 #ifdef CONFIG_MODULE_UNLOAD
1219 static const char vermagic
[] = VERMAGIC_STRING
;
1221 static int try_to_force_load(struct module
*mod
, const char *reason
)
1223 #ifdef CONFIG_MODULE_FORCE_LOAD
1224 if (!test_taint(TAINT_FORCED_MODULE
))
1225 pr_warn("%s: %s: kernel tainted.\n", mod
->name
, reason
);
1226 add_taint_module(mod
, TAINT_FORCED_MODULE
, LOCKDEP_NOW_UNRELIABLE
);
1233 #ifdef CONFIG_MODVERSIONS
1235 static u32
resolve_rel_crc(const s32
*crc
)
1237 return *(u32
*)((void *)crc
+ *crc
);
1240 static int check_version(const struct load_info
*info
,
1241 const char *symname
,
1245 Elf_Shdr
*sechdrs
= info
->sechdrs
;
1246 unsigned int versindex
= info
->index
.vers
;
1247 unsigned int i
, num_versions
;
1248 struct modversion_info
*versions
;
1250 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1254 /* No versions at all? modprobe --force does this. */
1256 return try_to_force_load(mod
, symname
) == 0;
1258 versions
= (void *) sechdrs
[versindex
].sh_addr
;
1259 num_versions
= sechdrs
[versindex
].sh_size
1260 / sizeof(struct modversion_info
);
1262 for (i
= 0; i
< num_versions
; i
++) {
1265 if (strcmp(versions
[i
].name
, symname
) != 0)
1268 if (IS_ENABLED(CONFIG_MODULE_REL_CRCS
))
1269 crcval
= resolve_rel_crc(crc
);
1272 if (versions
[i
].crc
== crcval
)
1274 pr_debug("Found checksum %X vs module %lX\n",
1275 crcval
, versions
[i
].crc
);
1279 /* Broken toolchain. Warn once, then let it go.. */
1280 pr_warn_once("%s: no symbol version for %s\n", info
->name
, symname
);
1284 pr_warn("%s: disagrees about version of symbol %s\n",
1285 info
->name
, symname
);
1289 static inline int check_modstruct_version(const struct load_info
*info
,
1292 struct find_symbol_arg fsa
= {
1293 .name
= "module_layout",
1298 * Since this should be found in kernel (which can't be removed), no
1299 * locking is necessary -- use preempt_disable() to placate lockdep.
1302 if (!find_symbol(&fsa
)) {
1307 return check_version(info
, "module_layout", mod
, fsa
.crc
);
1310 /* First part is kernel version, which we ignore if module has crcs. */
1311 static inline int same_magic(const char *amagic
, const char *bmagic
,
1315 amagic
+= strcspn(amagic
, " ");
1316 bmagic
+= strcspn(bmagic
, " ");
1318 return strcmp(amagic
, bmagic
) == 0;
1321 static inline int check_version(const struct load_info
*info
,
1322 const char *symname
,
1329 static inline int check_modstruct_version(const struct load_info
*info
,
1335 static inline int same_magic(const char *amagic
, const char *bmagic
,
1338 return strcmp(amagic
, bmagic
) == 0;
1340 #endif /* CONFIG_MODVERSIONS */
1342 static char *get_modinfo(const struct load_info
*info
, const char *tag
);
1343 static char *get_next_modinfo(const struct load_info
*info
, const char *tag
,
1346 static int verify_namespace_is_imported(const struct load_info
*info
,
1347 const struct kernel_symbol
*sym
,
1350 const char *namespace;
1351 char *imported_namespace
;
1353 namespace = kernel_symbol_namespace(sym
);
1354 if (namespace && namespace[0]) {
1355 imported_namespace
= get_modinfo(info
, "import_ns");
1356 while (imported_namespace
) {
1357 if (strcmp(namespace, imported_namespace
) == 0)
1359 imported_namespace
= get_next_modinfo(
1360 info
, "import_ns", imported_namespace
);
1362 #ifdef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1367 "%s: module uses symbol (%s) from namespace %s, but does not import it.\n",
1368 mod
->name
, kernel_symbol_name(sym
), namespace);
1369 #ifndef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1376 static bool inherit_taint(struct module
*mod
, struct module
*owner
)
1378 if (!owner
|| !test_bit(TAINT_PROPRIETARY_MODULE
, &owner
->taints
))
1381 if (mod
->using_gplonly_symbols
) {
1382 pr_err("%s: module using GPL-only symbols uses symbols from proprietary module %s.\n",
1383 mod
->name
, owner
->name
);
1387 if (!test_bit(TAINT_PROPRIETARY_MODULE
, &mod
->taints
)) {
1388 pr_warn("%s: module uses symbols from proprietary module %s, inheriting taint.\n",
1389 mod
->name
, owner
->name
);
1390 set_bit(TAINT_PROPRIETARY_MODULE
, &mod
->taints
);
1395 /* Resolve a symbol for this module. I.e. if we find one, record usage. */
1396 static const struct kernel_symbol
*resolve_symbol(struct module
*mod
,
1397 const struct load_info
*info
,
1401 struct find_symbol_arg fsa
= {
1403 .gplok
= !(mod
->taints
& (1 << TAINT_PROPRIETARY_MODULE
)),
1409 * The module_mutex should not be a heavily contended lock;
1410 * if we get the occasional sleep here, we'll go an extra iteration
1411 * in the wait_event_interruptible(), which is harmless.
1413 sched_annotate_sleep();
1414 mutex_lock(&module_mutex
);
1415 if (!find_symbol(&fsa
))
1418 if (fsa
.license
== GPL_ONLY
)
1419 mod
->using_gplonly_symbols
= true;
1421 if (!inherit_taint(mod
, fsa
.owner
)) {
1426 if (!check_version(info
, name
, mod
, fsa
.crc
)) {
1427 fsa
.sym
= ERR_PTR(-EINVAL
);
1431 err
= verify_namespace_is_imported(info
, fsa
.sym
, mod
);
1433 fsa
.sym
= ERR_PTR(err
);
1437 err
= ref_module(mod
, fsa
.owner
);
1439 fsa
.sym
= ERR_PTR(err
);
1444 /* We must make copy under the lock if we failed to get ref. */
1445 strncpy(ownername
, module_name(fsa
.owner
), MODULE_NAME_LEN
);
1447 mutex_unlock(&module_mutex
);
1451 static const struct kernel_symbol
*
1452 resolve_symbol_wait(struct module
*mod
,
1453 const struct load_info
*info
,
1456 const struct kernel_symbol
*ksym
;
1457 char owner
[MODULE_NAME_LEN
];
1459 if (wait_event_interruptible_timeout(module_wq
,
1460 !IS_ERR(ksym
= resolve_symbol(mod
, info
, name
, owner
))
1461 || PTR_ERR(ksym
) != -EBUSY
,
1463 pr_warn("%s: gave up waiting for init of module %s.\n",
1469 #ifdef CONFIG_KALLSYMS
1470 static inline bool sect_empty(const Elf_Shdr
*sect
)
1472 return !(sect
->sh_flags
& SHF_ALLOC
) || sect
->sh_size
== 0;
1477 * /sys/module/foo/sections stuff
1478 * J. Corbet <corbet@lwn.net>
1482 #ifdef CONFIG_KALLSYMS
1483 struct module_sect_attr
{
1484 struct bin_attribute battr
;
1485 unsigned long address
;
1488 struct module_sect_attrs
{
1489 struct attribute_group grp
;
1490 unsigned int nsections
;
1491 struct module_sect_attr attrs
[];
1494 #define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4))
1495 static ssize_t
module_sect_read(struct file
*file
, struct kobject
*kobj
,
1496 struct bin_attribute
*battr
,
1497 char *buf
, loff_t pos
, size_t count
)
1499 struct module_sect_attr
*sattr
=
1500 container_of(battr
, struct module_sect_attr
, battr
);
1501 char bounce
[MODULE_SECT_READ_SIZE
+ 1];
1508 * Since we're a binary read handler, we must account for the
1509 * trailing NUL byte that sprintf will write: if "buf" is
1510 * too small to hold the NUL, or the NUL is exactly the last
1511 * byte, the read will look like it got truncated by one byte.
1512 * Since there is no way to ask sprintf nicely to not write
1513 * the NUL, we have to use a bounce buffer.
1515 wrote
= scnprintf(bounce
, sizeof(bounce
), "0x%px\n",
1516 kallsyms_show_value(file
->f_cred
)
1517 ? (void *)sattr
->address
: NULL
);
1518 count
= min(count
, wrote
);
1519 memcpy(buf
, bounce
, count
);
1524 static void free_sect_attrs(struct module_sect_attrs
*sect_attrs
)
1526 unsigned int section
;
1528 for (section
= 0; section
< sect_attrs
->nsections
; section
++)
1529 kfree(sect_attrs
->attrs
[section
].battr
.attr
.name
);
1533 static void add_sect_attrs(struct module
*mod
, const struct load_info
*info
)
1535 unsigned int nloaded
= 0, i
, size
[2];
1536 struct module_sect_attrs
*sect_attrs
;
1537 struct module_sect_attr
*sattr
;
1538 struct bin_attribute
**gattr
;
1540 /* Count loaded sections and allocate structures */
1541 for (i
= 0; i
< info
->hdr
->e_shnum
; i
++)
1542 if (!sect_empty(&info
->sechdrs
[i
]))
1544 size
[0] = ALIGN(struct_size(sect_attrs
, attrs
, nloaded
),
1545 sizeof(sect_attrs
->grp
.bin_attrs
[0]));
1546 size
[1] = (nloaded
+ 1) * sizeof(sect_attrs
->grp
.bin_attrs
[0]);
1547 sect_attrs
= kzalloc(size
[0] + size
[1], GFP_KERNEL
);
1548 if (sect_attrs
== NULL
)
1551 /* Setup section attributes. */
1552 sect_attrs
->grp
.name
= "sections";
1553 sect_attrs
->grp
.bin_attrs
= (void *)sect_attrs
+ size
[0];
1555 sect_attrs
->nsections
= 0;
1556 sattr
= §_attrs
->attrs
[0];
1557 gattr
= §_attrs
->grp
.bin_attrs
[0];
1558 for (i
= 0; i
< info
->hdr
->e_shnum
; i
++) {
1559 Elf_Shdr
*sec
= &info
->sechdrs
[i
];
1560 if (sect_empty(sec
))
1562 sysfs_bin_attr_init(&sattr
->battr
);
1563 sattr
->address
= sec
->sh_addr
;
1564 sattr
->battr
.attr
.name
=
1565 kstrdup(info
->secstrings
+ sec
->sh_name
, GFP_KERNEL
);
1566 if (sattr
->battr
.attr
.name
== NULL
)
1568 sect_attrs
->nsections
++;
1569 sattr
->battr
.read
= module_sect_read
;
1570 sattr
->battr
.size
= MODULE_SECT_READ_SIZE
;
1571 sattr
->battr
.attr
.mode
= 0400;
1572 *(gattr
++) = &(sattr
++)->battr
;
1576 if (sysfs_create_group(&mod
->mkobj
.kobj
, §_attrs
->grp
))
1579 mod
->sect_attrs
= sect_attrs
;
1582 free_sect_attrs(sect_attrs
);
1585 static void remove_sect_attrs(struct module
*mod
)
1587 if (mod
->sect_attrs
) {
1588 sysfs_remove_group(&mod
->mkobj
.kobj
,
1589 &mod
->sect_attrs
->grp
);
1591 * We are positive that no one is using any sect attrs
1592 * at this point. Deallocate immediately.
1594 free_sect_attrs(mod
->sect_attrs
);
1595 mod
->sect_attrs
= NULL
;
1600 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1603 struct module_notes_attrs
{
1604 struct kobject
*dir
;
1606 struct bin_attribute attrs
[];
1609 static ssize_t
module_notes_read(struct file
*filp
, struct kobject
*kobj
,
1610 struct bin_attribute
*bin_attr
,
1611 char *buf
, loff_t pos
, size_t count
)
1614 * The caller checked the pos and count against our size.
1616 memcpy(buf
, bin_attr
->private + pos
, count
);
1620 static void free_notes_attrs(struct module_notes_attrs
*notes_attrs
,
1623 if (notes_attrs
->dir
) {
1625 sysfs_remove_bin_file(notes_attrs
->dir
,
1626 ¬es_attrs
->attrs
[i
]);
1627 kobject_put(notes_attrs
->dir
);
1632 static void add_notes_attrs(struct module
*mod
, const struct load_info
*info
)
1634 unsigned int notes
, loaded
, i
;
1635 struct module_notes_attrs
*notes_attrs
;
1636 struct bin_attribute
*nattr
;
1638 /* failed to create section attributes, so can't create notes */
1639 if (!mod
->sect_attrs
)
1642 /* Count notes sections and allocate structures. */
1644 for (i
= 0; i
< info
->hdr
->e_shnum
; i
++)
1645 if (!sect_empty(&info
->sechdrs
[i
]) &&
1646 (info
->sechdrs
[i
].sh_type
== SHT_NOTE
))
1652 notes_attrs
= kzalloc(struct_size(notes_attrs
, attrs
, notes
),
1654 if (notes_attrs
== NULL
)
1657 notes_attrs
->notes
= notes
;
1658 nattr
= ¬es_attrs
->attrs
[0];
1659 for (loaded
= i
= 0; i
< info
->hdr
->e_shnum
; ++i
) {
1660 if (sect_empty(&info
->sechdrs
[i
]))
1662 if (info
->sechdrs
[i
].sh_type
== SHT_NOTE
) {
1663 sysfs_bin_attr_init(nattr
);
1664 nattr
->attr
.name
= mod
->sect_attrs
->attrs
[loaded
].battr
.attr
.name
;
1665 nattr
->attr
.mode
= S_IRUGO
;
1666 nattr
->size
= info
->sechdrs
[i
].sh_size
;
1667 nattr
->private = (void *) info
->sechdrs
[i
].sh_addr
;
1668 nattr
->read
= module_notes_read
;
1674 notes_attrs
->dir
= kobject_create_and_add("notes", &mod
->mkobj
.kobj
);
1675 if (!notes_attrs
->dir
)
1678 for (i
= 0; i
< notes
; ++i
)
1679 if (sysfs_create_bin_file(notes_attrs
->dir
,
1680 ¬es_attrs
->attrs
[i
]))
1683 mod
->notes_attrs
= notes_attrs
;
1687 free_notes_attrs(notes_attrs
, i
);
1690 static void remove_notes_attrs(struct module
*mod
)
1692 if (mod
->notes_attrs
)
1693 free_notes_attrs(mod
->notes_attrs
, mod
->notes_attrs
->notes
);
1698 static inline void add_sect_attrs(struct module
*mod
,
1699 const struct load_info
*info
)
1703 static inline void remove_sect_attrs(struct module
*mod
)
1707 static inline void add_notes_attrs(struct module
*mod
,
1708 const struct load_info
*info
)
1712 static inline void remove_notes_attrs(struct module
*mod
)
1715 #endif /* CONFIG_KALLSYMS */
1717 static void del_usage_links(struct module
*mod
)
1719 #ifdef CONFIG_MODULE_UNLOAD
1720 struct module_use
*use
;
1722 mutex_lock(&module_mutex
);
1723 list_for_each_entry(use
, &mod
->target_list
, target_list
)
1724 sysfs_remove_link(use
->target
->holders_dir
, mod
->name
);
1725 mutex_unlock(&module_mutex
);
1729 static int add_usage_links(struct module
*mod
)
1732 #ifdef CONFIG_MODULE_UNLOAD
1733 struct module_use
*use
;
1735 mutex_lock(&module_mutex
);
1736 list_for_each_entry(use
, &mod
->target_list
, target_list
) {
1737 ret
= sysfs_create_link(use
->target
->holders_dir
,
1738 &mod
->mkobj
.kobj
, mod
->name
);
1742 mutex_unlock(&module_mutex
);
1744 del_usage_links(mod
);
1749 static void module_remove_modinfo_attrs(struct module
*mod
, int end
);
1751 static int module_add_modinfo_attrs(struct module
*mod
)
1753 struct module_attribute
*attr
;
1754 struct module_attribute
*temp_attr
;
1758 mod
->modinfo_attrs
= kzalloc((sizeof(struct module_attribute
) *
1759 (ARRAY_SIZE(modinfo_attrs
) + 1)),
1761 if (!mod
->modinfo_attrs
)
1764 temp_attr
= mod
->modinfo_attrs
;
1765 for (i
= 0; (attr
= modinfo_attrs
[i
]); i
++) {
1766 if (!attr
->test
|| attr
->test(mod
)) {
1767 memcpy(temp_attr
, attr
, sizeof(*temp_attr
));
1768 sysfs_attr_init(&temp_attr
->attr
);
1769 error
= sysfs_create_file(&mod
->mkobj
.kobj
,
1781 module_remove_modinfo_attrs(mod
, --i
);
1783 kfree(mod
->modinfo_attrs
);
1787 static void module_remove_modinfo_attrs(struct module
*mod
, int end
)
1789 struct module_attribute
*attr
;
1792 for (i
= 0; (attr
= &mod
->modinfo_attrs
[i
]); i
++) {
1793 if (end
>= 0 && i
> end
)
1795 /* pick a field to test for end of list */
1796 if (!attr
->attr
.name
)
1798 sysfs_remove_file(&mod
->mkobj
.kobj
, &attr
->attr
);
1802 kfree(mod
->modinfo_attrs
);
1805 static void mod_kobject_put(struct module
*mod
)
1807 DECLARE_COMPLETION_ONSTACK(c
);
1808 mod
->mkobj
.kobj_completion
= &c
;
1809 kobject_put(&mod
->mkobj
.kobj
);
1810 wait_for_completion(&c
);
1813 static int mod_sysfs_init(struct module
*mod
)
1816 struct kobject
*kobj
;
1818 if (!module_sysfs_initialized
) {
1819 pr_err("%s: module sysfs not initialized\n", mod
->name
);
1824 kobj
= kset_find_obj(module_kset
, mod
->name
);
1826 pr_err("%s: module is already loaded\n", mod
->name
);
1832 mod
->mkobj
.mod
= mod
;
1834 memset(&mod
->mkobj
.kobj
, 0, sizeof(mod
->mkobj
.kobj
));
1835 mod
->mkobj
.kobj
.kset
= module_kset
;
1836 err
= kobject_init_and_add(&mod
->mkobj
.kobj
, &module_ktype
, NULL
,
1839 mod_kobject_put(mod
);
1845 static int mod_sysfs_setup(struct module
*mod
,
1846 const struct load_info
*info
,
1847 struct kernel_param
*kparam
,
1848 unsigned int num_params
)
1852 err
= mod_sysfs_init(mod
);
1856 mod
->holders_dir
= kobject_create_and_add("holders", &mod
->mkobj
.kobj
);
1857 if (!mod
->holders_dir
) {
1862 err
= module_param_sysfs_setup(mod
, kparam
, num_params
);
1864 goto out_unreg_holders
;
1866 err
= module_add_modinfo_attrs(mod
);
1868 goto out_unreg_param
;
1870 err
= add_usage_links(mod
);
1872 goto out_unreg_modinfo_attrs
;
1874 add_sect_attrs(mod
, info
);
1875 add_notes_attrs(mod
, info
);
1879 out_unreg_modinfo_attrs
:
1880 module_remove_modinfo_attrs(mod
, -1);
1882 module_param_sysfs_remove(mod
);
1884 kobject_put(mod
->holders_dir
);
1886 mod_kobject_put(mod
);
1891 static void mod_sysfs_fini(struct module
*mod
)
1893 remove_notes_attrs(mod
);
1894 remove_sect_attrs(mod
);
1895 mod_kobject_put(mod
);
1898 static void init_param_lock(struct module
*mod
)
1900 mutex_init(&mod
->param_lock
);
1902 #else /* !CONFIG_SYSFS */
1904 static int mod_sysfs_setup(struct module
*mod
,
1905 const struct load_info
*info
,
1906 struct kernel_param
*kparam
,
1907 unsigned int num_params
)
1912 static void mod_sysfs_fini(struct module
*mod
)
1916 static void module_remove_modinfo_attrs(struct module
*mod
, int end
)
1920 static void del_usage_links(struct module
*mod
)
1924 static void init_param_lock(struct module
*mod
)
1927 #endif /* CONFIG_SYSFS */
1929 static void mod_sysfs_teardown(struct module
*mod
)
1931 del_usage_links(mod
);
1932 module_remove_modinfo_attrs(mod
, -1);
1933 module_param_sysfs_remove(mod
);
1934 kobject_put(mod
->mkobj
.drivers_dir
);
1935 kobject_put(mod
->holders_dir
);
1936 mod_sysfs_fini(mod
);
1940 * LKM RO/NX protection: protect module's text/ro-data
1941 * from modification and any data from execution.
1943 * General layout of module is:
1944 * [text] [read-only-data] [ro-after-init] [writable data]
1945 * text_size -----^ ^ ^ ^
1946 * ro_size ------------------------| | |
1947 * ro_after_init_size -----------------------------| |
1948 * size -----------------------------------------------------------|
1950 * These values are always page-aligned (as is base)
1954 * Since some arches are moving towards PAGE_KERNEL module allocations instead
1955 * of PAGE_KERNEL_EXEC, keep frob_text() and module_enable_x() outside of the
1956 * CONFIG_STRICT_MODULE_RWX block below because they are needed regardless of
1957 * whether we are strict.
1959 #ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
1960 static void frob_text(const struct module_layout
*layout
,
1961 int (*set_memory
)(unsigned long start
, int num_pages
))
1963 BUG_ON((unsigned long)layout
->base
& (PAGE_SIZE
-1));
1964 BUG_ON((unsigned long)layout
->text_size
& (PAGE_SIZE
-1));
1965 set_memory((unsigned long)layout
->base
,
1966 layout
->text_size
>> PAGE_SHIFT
);
1969 static void module_enable_x(const struct module
*mod
)
1971 frob_text(&mod
->core_layout
, set_memory_x
);
1972 frob_text(&mod
->init_layout
, set_memory_x
);
1974 #else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
1975 static void module_enable_x(const struct module
*mod
) { }
1976 #endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
1978 #ifdef CONFIG_STRICT_MODULE_RWX
1979 static void frob_rodata(const struct module_layout
*layout
,
1980 int (*set_memory
)(unsigned long start
, int num_pages
))
1982 BUG_ON((unsigned long)layout
->base
& (PAGE_SIZE
-1));
1983 BUG_ON((unsigned long)layout
->text_size
& (PAGE_SIZE
-1));
1984 BUG_ON((unsigned long)layout
->ro_size
& (PAGE_SIZE
-1));
1985 set_memory((unsigned long)layout
->base
+ layout
->text_size
,
1986 (layout
->ro_size
- layout
->text_size
) >> PAGE_SHIFT
);
1989 static void frob_ro_after_init(const struct module_layout
*layout
,
1990 int (*set_memory
)(unsigned long start
, int num_pages
))
1992 BUG_ON((unsigned long)layout
->base
& (PAGE_SIZE
-1));
1993 BUG_ON((unsigned long)layout
->ro_size
& (PAGE_SIZE
-1));
1994 BUG_ON((unsigned long)layout
->ro_after_init_size
& (PAGE_SIZE
-1));
1995 set_memory((unsigned long)layout
->base
+ layout
->ro_size
,
1996 (layout
->ro_after_init_size
- layout
->ro_size
) >> PAGE_SHIFT
);
1999 static void frob_writable_data(const struct module_layout
*layout
,
2000 int (*set_memory
)(unsigned long start
, int num_pages
))
2002 BUG_ON((unsigned long)layout
->base
& (PAGE_SIZE
-1));
2003 BUG_ON((unsigned long)layout
->ro_after_init_size
& (PAGE_SIZE
-1));
2004 BUG_ON((unsigned long)layout
->size
& (PAGE_SIZE
-1));
2005 set_memory((unsigned long)layout
->base
+ layout
->ro_after_init_size
,
2006 (layout
->size
- layout
->ro_after_init_size
) >> PAGE_SHIFT
);
2009 static void module_enable_ro(const struct module
*mod
, bool after_init
)
2011 if (!rodata_enabled
)
2014 set_vm_flush_reset_perms(mod
->core_layout
.base
);
2015 set_vm_flush_reset_perms(mod
->init_layout
.base
);
2016 frob_text(&mod
->core_layout
, set_memory_ro
);
2018 frob_rodata(&mod
->core_layout
, set_memory_ro
);
2019 frob_text(&mod
->init_layout
, set_memory_ro
);
2020 frob_rodata(&mod
->init_layout
, set_memory_ro
);
2023 frob_ro_after_init(&mod
->core_layout
, set_memory_ro
);
2026 static void module_enable_nx(const struct module
*mod
)
2028 frob_rodata(&mod
->core_layout
, set_memory_nx
);
2029 frob_ro_after_init(&mod
->core_layout
, set_memory_nx
);
2030 frob_writable_data(&mod
->core_layout
, set_memory_nx
);
2031 frob_rodata(&mod
->init_layout
, set_memory_nx
);
2032 frob_writable_data(&mod
->init_layout
, set_memory_nx
);
2035 static int module_enforce_rwx_sections(Elf_Ehdr
*hdr
, Elf_Shdr
*sechdrs
,
2036 char *secstrings
, struct module
*mod
)
2038 const unsigned long shf_wx
= SHF_WRITE
|SHF_EXECINSTR
;
2041 for (i
= 0; i
< hdr
->e_shnum
; i
++) {
2042 if ((sechdrs
[i
].sh_flags
& shf_wx
) == shf_wx
) {
2043 pr_err("%s: section %s (index %d) has invalid WRITE|EXEC flags\n",
2044 mod
->name
, secstrings
+ sechdrs
[i
].sh_name
, i
);
2052 #else /* !CONFIG_STRICT_MODULE_RWX */
2053 static void module_enable_nx(const struct module
*mod
) { }
2054 static void module_enable_ro(const struct module
*mod
, bool after_init
) {}
2055 static int module_enforce_rwx_sections(Elf_Ehdr
*hdr
, Elf_Shdr
*sechdrs
,
2056 char *secstrings
, struct module
*mod
)
2060 #endif /* CONFIG_STRICT_MODULE_RWX */
2062 #ifdef CONFIG_LIVEPATCH
2064 * Persist Elf information about a module. Copy the Elf header,
2065 * section header table, section string table, and symtab section
2066 * index from info to mod->klp_info.
2068 static int copy_module_elf(struct module
*mod
, struct load_info
*info
)
2070 unsigned int size
, symndx
;
2073 size
= sizeof(*mod
->klp_info
);
2074 mod
->klp_info
= kmalloc(size
, GFP_KERNEL
);
2075 if (mod
->klp_info
== NULL
)
2079 size
= sizeof(mod
->klp_info
->hdr
);
2080 memcpy(&mod
->klp_info
->hdr
, info
->hdr
, size
);
2082 /* Elf section header table */
2083 size
= sizeof(*info
->sechdrs
) * info
->hdr
->e_shnum
;
2084 mod
->klp_info
->sechdrs
= kmemdup(info
->sechdrs
, size
, GFP_KERNEL
);
2085 if (mod
->klp_info
->sechdrs
== NULL
) {
2090 /* Elf section name string table */
2091 size
= info
->sechdrs
[info
->hdr
->e_shstrndx
].sh_size
;
2092 mod
->klp_info
->secstrings
= kmemdup(info
->secstrings
, size
, GFP_KERNEL
);
2093 if (mod
->klp_info
->secstrings
== NULL
) {
2098 /* Elf symbol section index */
2099 symndx
= info
->index
.sym
;
2100 mod
->klp_info
->symndx
= symndx
;
2103 * For livepatch modules, core_kallsyms.symtab is a complete
2104 * copy of the original symbol table. Adjust sh_addr to point
2105 * to core_kallsyms.symtab since the copy of the symtab in module
2106 * init memory is freed at the end of do_init_module().
2108 mod
->klp_info
->sechdrs
[symndx
].sh_addr
= \
2109 (unsigned long) mod
->core_kallsyms
.symtab
;
2114 kfree(mod
->klp_info
->sechdrs
);
2116 kfree(mod
->klp_info
);
2120 static void free_module_elf(struct module
*mod
)
2122 kfree(mod
->klp_info
->sechdrs
);
2123 kfree(mod
->klp_info
->secstrings
);
2124 kfree(mod
->klp_info
);
2126 #else /* !CONFIG_LIVEPATCH */
2127 static int copy_module_elf(struct module
*mod
, struct load_info
*info
)
2132 static void free_module_elf(struct module
*mod
)
2135 #endif /* CONFIG_LIVEPATCH */
2137 void __weak
module_memfree(void *module_region
)
2140 * This memory may be RO, and freeing RO memory in an interrupt is not
2141 * supported by vmalloc.
2143 WARN_ON(in_interrupt());
2144 vfree(module_region
);
2147 void __weak
module_arch_cleanup(struct module
*mod
)
2151 void __weak
module_arch_freeing_init(struct module
*mod
)
2155 static void cfi_cleanup(struct module
*mod
);
2157 /* Free a module, remove from lists, etc. */
2158 static void free_module(struct module
*mod
)
2160 trace_module_free(mod
);
2162 mod_sysfs_teardown(mod
);
2165 * We leave it in list to prevent duplicate loads, but make sure
2166 * that noone uses it while it's being deconstructed.
2168 mutex_lock(&module_mutex
);
2169 mod
->state
= MODULE_STATE_UNFORMED
;
2170 mutex_unlock(&module_mutex
);
2172 /* Remove dynamic debug info */
2173 ddebug_remove_module(mod
->name
);
2175 /* Arch-specific cleanup. */
2176 module_arch_cleanup(mod
);
2178 /* Module unload stuff */
2179 module_unload_free(mod
);
2181 /* Free any allocated parameters. */
2182 destroy_params(mod
->kp
, mod
->num_kp
);
2184 if (is_livepatch_module(mod
))
2185 free_module_elf(mod
);
2187 /* Now we can delete it from the lists */
2188 mutex_lock(&module_mutex
);
2189 /* Unlink carefully: kallsyms could be walking list. */
2190 list_del_rcu(&mod
->list
);
2191 mod_tree_remove(mod
);
2192 /* Remove this module from bug list, this uses list_del_rcu */
2193 module_bug_cleanup(mod
);
2194 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2196 mutex_unlock(&module_mutex
);
2198 /* Clean up CFI for the module. */
2201 /* This may be empty, but that's OK */
2202 module_arch_freeing_init(mod
);
2203 module_memfree(mod
->init_layout
.base
);
2205 percpu_modfree(mod
);
2207 /* Free lock-classes; relies on the preceding sync_rcu(). */
2208 lockdep_free_key_range(mod
->core_layout
.base
, mod
->core_layout
.size
);
2210 /* Finally, free the core (containing the module structure) */
2211 module_memfree(mod
->core_layout
.base
);
2214 void *__symbol_get(const char *symbol
)
2216 struct find_symbol_arg fsa
= {
2223 if (!find_symbol(&fsa
) || strong_try_module_get(fsa
.owner
)) {
2228 return (void *)kernel_symbol_value(fsa
.sym
);
2230 EXPORT_SYMBOL_GPL(__symbol_get
);
2233 * Ensure that an exported symbol [global namespace] does not already exist
2234 * in the kernel or in some other module's exported symbol table.
2236 * You must hold the module_mutex.
2238 static int verify_exported_symbols(struct module
*mod
)
2241 const struct kernel_symbol
*s
;
2243 const struct kernel_symbol
*sym
;
2246 { mod
->syms
, mod
->num_syms
},
2247 { mod
->gpl_syms
, mod
->num_gpl_syms
},
2250 for (i
= 0; i
< ARRAY_SIZE(arr
); i
++) {
2251 for (s
= arr
[i
].sym
; s
< arr
[i
].sym
+ arr
[i
].num
; s
++) {
2252 struct find_symbol_arg fsa
= {
2253 .name
= kernel_symbol_name(s
),
2256 if (find_symbol(&fsa
)) {
2257 pr_err("%s: exports duplicate symbol %s"
2259 mod
->name
, kernel_symbol_name(s
),
2260 module_name(fsa
.owner
));
2268 static bool ignore_undef_symbol(Elf_Half emachine
, const char *name
)
2271 * On x86, PIC code and Clang non-PIC code may have call foo@PLT. GNU as
2272 * before 2.37 produces an unreferenced _GLOBAL_OFFSET_TABLE_ on x86-64.
2273 * i386 has a similar problem but may not deserve a fix.
2275 * If we ever have to ignore many symbols, consider refactoring the code to
2276 * only warn if referenced by a relocation.
2278 if (emachine
== EM_386
|| emachine
== EM_X86_64
)
2279 return !strcmp(name
, "_GLOBAL_OFFSET_TABLE_");
2283 /* Change all symbols so that st_value encodes the pointer directly. */
2284 static int simplify_symbols(struct module
*mod
, const struct load_info
*info
)
2286 Elf_Shdr
*symsec
= &info
->sechdrs
[info
->index
.sym
];
2287 Elf_Sym
*sym
= (void *)symsec
->sh_addr
;
2288 unsigned long secbase
;
2291 const struct kernel_symbol
*ksym
;
2293 for (i
= 1; i
< symsec
->sh_size
/ sizeof(Elf_Sym
); i
++) {
2294 const char *name
= info
->strtab
+ sym
[i
].st_name
;
2296 switch (sym
[i
].st_shndx
) {
2298 /* Ignore common symbols */
2299 if (!strncmp(name
, "__gnu_lto", 9))
2303 * We compiled with -fno-common. These are not
2304 * supposed to happen.
2306 pr_debug("Common symbol: %s\n", name
);
2307 pr_warn("%s: please compile with -fno-common\n",
2313 /* Don't need to do anything */
2314 pr_debug("Absolute symbol: 0x%08lx\n",
2315 (long)sym
[i
].st_value
);
2319 /* Livepatch symbols are resolved by livepatch */
2323 ksym
= resolve_symbol_wait(mod
, info
, name
);
2324 /* Ok if resolved. */
2325 if (ksym
&& !IS_ERR(ksym
)) {
2326 sym
[i
].st_value
= kernel_symbol_value(ksym
);
2330 /* Ok if weak or ignored. */
2332 (ELF_ST_BIND(sym
[i
].st_info
) == STB_WEAK
||
2333 ignore_undef_symbol(info
->hdr
->e_machine
, name
)))
2336 ret
= PTR_ERR(ksym
) ?: -ENOENT
;
2337 pr_warn("%s: Unknown symbol %s (err %d)\n",
2338 mod
->name
, name
, ret
);
2342 /* Divert to percpu allocation if a percpu var. */
2343 if (sym
[i
].st_shndx
== info
->index
.pcpu
)
2344 secbase
= (unsigned long)mod_percpu(mod
);
2346 secbase
= info
->sechdrs
[sym
[i
].st_shndx
].sh_addr
;
2347 sym
[i
].st_value
+= secbase
;
2355 static int apply_relocations(struct module
*mod
, const struct load_info
*info
)
2360 /* Now do relocations. */
2361 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
2362 unsigned int infosec
= info
->sechdrs
[i
].sh_info
;
2364 /* Not a valid relocation section? */
2365 if (infosec
>= info
->hdr
->e_shnum
)
2368 /* Don't bother with non-allocated sections */
2369 if (!(info
->sechdrs
[infosec
].sh_flags
& SHF_ALLOC
))
2372 if (info
->sechdrs
[i
].sh_flags
& SHF_RELA_LIVEPATCH
)
2373 err
= klp_apply_section_relocs(mod
, info
->sechdrs
,
2378 else if (info
->sechdrs
[i
].sh_type
== SHT_REL
)
2379 err
= apply_relocate(info
->sechdrs
, info
->strtab
,
2380 info
->index
.sym
, i
, mod
);
2381 else if (info
->sechdrs
[i
].sh_type
== SHT_RELA
)
2382 err
= apply_relocate_add(info
->sechdrs
, info
->strtab
,
2383 info
->index
.sym
, i
, mod
);
2390 /* Additional bytes needed by arch in front of individual sections */
2391 unsigned int __weak
arch_mod_section_prepend(struct module
*mod
,
2392 unsigned int section
)
2394 /* default implementation just returns zero */
2398 /* Update size with this section: return offset. */
2399 static long get_offset(struct module
*mod
, unsigned int *size
,
2400 Elf_Shdr
*sechdr
, unsigned int section
)
2404 *size
+= arch_mod_section_prepend(mod
, section
);
2405 ret
= ALIGN(*size
, sechdr
->sh_addralign
?: 1);
2406 *size
= ret
+ sechdr
->sh_size
;
2410 static bool module_init_layout_section(const char *sname
)
2412 #ifndef CONFIG_MODULE_UNLOAD
2413 if (module_exit_section(sname
))
2416 return module_init_section(sname
);
2420 * Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2421 * might -- code, read-only data, read-write data, small data. Tally
2422 * sizes, and place the offsets into sh_entsize fields: high bit means it
2425 static void layout_sections(struct module
*mod
, struct load_info
*info
)
2427 static unsigned long const masks
[][2] = {
2429 * NOTE: all executable code must be the first section
2430 * in this array; otherwise modify the text_size
2431 * finder in the two loops below
2433 { SHF_EXECINSTR
| SHF_ALLOC
, ARCH_SHF_SMALL
},
2434 { SHF_ALLOC
, SHF_WRITE
| ARCH_SHF_SMALL
},
2435 { SHF_RO_AFTER_INIT
| SHF_ALLOC
, ARCH_SHF_SMALL
},
2436 { SHF_WRITE
| SHF_ALLOC
, ARCH_SHF_SMALL
},
2437 { ARCH_SHF_SMALL
| SHF_ALLOC
, 0 }
2441 for (i
= 0; i
< info
->hdr
->e_shnum
; i
++)
2442 info
->sechdrs
[i
].sh_entsize
= ~0UL;
2444 pr_debug("Core section allocation order:\n");
2445 for (m
= 0; m
< ARRAY_SIZE(masks
); ++m
) {
2446 for (i
= 0; i
< info
->hdr
->e_shnum
; ++i
) {
2447 Elf_Shdr
*s
= &info
->sechdrs
[i
];
2448 const char *sname
= info
->secstrings
+ s
->sh_name
;
2450 if ((s
->sh_flags
& masks
[m
][0]) != masks
[m
][0]
2451 || (s
->sh_flags
& masks
[m
][1])
2452 || s
->sh_entsize
!= ~0UL
2453 || module_init_layout_section(sname
))
2455 s
->sh_entsize
= get_offset(mod
, &mod
->core_layout
.size
, s
, i
);
2456 pr_debug("\t%s\n", sname
);
2459 case 0: /* executable */
2460 mod
->core_layout
.size
= debug_align(mod
->core_layout
.size
);
2461 mod
->core_layout
.text_size
= mod
->core_layout
.size
;
2463 case 1: /* RO: text and ro-data */
2464 mod
->core_layout
.size
= debug_align(mod
->core_layout
.size
);
2465 mod
->core_layout
.ro_size
= mod
->core_layout
.size
;
2467 case 2: /* RO after init */
2468 mod
->core_layout
.size
= debug_align(mod
->core_layout
.size
);
2469 mod
->core_layout
.ro_after_init_size
= mod
->core_layout
.size
;
2471 case 4: /* whole core */
2472 mod
->core_layout
.size
= debug_align(mod
->core_layout
.size
);
2477 pr_debug("Init section allocation order:\n");
2478 for (m
= 0; m
< ARRAY_SIZE(masks
); ++m
) {
2479 for (i
= 0; i
< info
->hdr
->e_shnum
; ++i
) {
2480 Elf_Shdr
*s
= &info
->sechdrs
[i
];
2481 const char *sname
= info
->secstrings
+ s
->sh_name
;
2483 if ((s
->sh_flags
& masks
[m
][0]) != masks
[m
][0]
2484 || (s
->sh_flags
& masks
[m
][1])
2485 || s
->sh_entsize
!= ~0UL
2486 || !module_init_layout_section(sname
))
2488 s
->sh_entsize
= (get_offset(mod
, &mod
->init_layout
.size
, s
, i
)
2489 | INIT_OFFSET_MASK
);
2490 pr_debug("\t%s\n", sname
);
2493 case 0: /* executable */
2494 mod
->init_layout
.size
= debug_align(mod
->init_layout
.size
);
2495 mod
->init_layout
.text_size
= mod
->init_layout
.size
;
2497 case 1: /* RO: text and ro-data */
2498 mod
->init_layout
.size
= debug_align(mod
->init_layout
.size
);
2499 mod
->init_layout
.ro_size
= mod
->init_layout
.size
;
2503 * RO after init doesn't apply to init_layout (only
2504 * core_layout), so it just takes the value of ro_size.
2506 mod
->init_layout
.ro_after_init_size
= mod
->init_layout
.ro_size
;
2508 case 4: /* whole init */
2509 mod
->init_layout
.size
= debug_align(mod
->init_layout
.size
);
2515 static void set_license(struct module
*mod
, const char *license
)
2518 license
= "unspecified";
2520 if (!license_is_gpl_compatible(license
)) {
2521 if (!test_taint(TAINT_PROPRIETARY_MODULE
))
2522 pr_warn("%s: module license '%s' taints kernel.\n",
2523 mod
->name
, license
);
2524 add_taint_module(mod
, TAINT_PROPRIETARY_MODULE
,
2525 LOCKDEP_NOW_UNRELIABLE
);
2529 /* Parse tag=value strings from .modinfo section */
2530 static char *next_string(char *string
, unsigned long *secsize
)
2532 /* Skip non-zero chars */
2535 if ((*secsize
)-- <= 1)
2539 /* Skip any zero padding. */
2540 while (!string
[0]) {
2542 if ((*secsize
)-- <= 1)
2548 static char *get_next_modinfo(const struct load_info
*info
, const char *tag
,
2552 unsigned int taglen
= strlen(tag
);
2553 Elf_Shdr
*infosec
= &info
->sechdrs
[info
->index
.info
];
2554 unsigned long size
= infosec
->sh_size
;
2557 * get_modinfo() calls made before rewrite_section_headers()
2558 * must use sh_offset, as sh_addr isn't set!
2560 char *modinfo
= (char *)info
->hdr
+ infosec
->sh_offset
;
2563 size
-= prev
- modinfo
;
2564 modinfo
= next_string(prev
, &size
);
2567 for (p
= modinfo
; p
; p
= next_string(p
, &size
)) {
2568 if (strncmp(p
, tag
, taglen
) == 0 && p
[taglen
] == '=')
2569 return p
+ taglen
+ 1;
2574 static char *get_modinfo(const struct load_info
*info
, const char *tag
)
2576 return get_next_modinfo(info
, tag
, NULL
);
2579 static void setup_modinfo(struct module
*mod
, struct load_info
*info
)
2581 struct module_attribute
*attr
;
2584 for (i
= 0; (attr
= modinfo_attrs
[i
]); i
++) {
2586 attr
->setup(mod
, get_modinfo(info
, attr
->attr
.name
));
2590 static void free_modinfo(struct module
*mod
)
2592 struct module_attribute
*attr
;
2595 for (i
= 0; (attr
= modinfo_attrs
[i
]); i
++) {
2601 #ifdef CONFIG_KALLSYMS
2603 /* Lookup exported symbol in given range of kernel_symbols */
2604 static const struct kernel_symbol
*lookup_exported_symbol(const char *name
,
2605 const struct kernel_symbol
*start
,
2606 const struct kernel_symbol
*stop
)
2608 return bsearch(name
, start
, stop
- start
,
2609 sizeof(struct kernel_symbol
), cmp_name
);
2612 static int is_exported(const char *name
, unsigned long value
,
2613 const struct module
*mod
)
2615 const struct kernel_symbol
*ks
;
2617 ks
= lookup_exported_symbol(name
, __start___ksymtab
, __stop___ksymtab
);
2619 ks
= lookup_exported_symbol(name
, mod
->syms
, mod
->syms
+ mod
->num_syms
);
2621 return ks
!= NULL
&& kernel_symbol_value(ks
) == value
;
2625 static char elf_type(const Elf_Sym
*sym
, const struct load_info
*info
)
2627 const Elf_Shdr
*sechdrs
= info
->sechdrs
;
2629 if (ELF_ST_BIND(sym
->st_info
) == STB_WEAK
) {
2630 if (ELF_ST_TYPE(sym
->st_info
) == STT_OBJECT
)
2635 if (sym
->st_shndx
== SHN_UNDEF
)
2637 if (sym
->st_shndx
== SHN_ABS
|| sym
->st_shndx
== info
->index
.pcpu
)
2639 if (sym
->st_shndx
>= SHN_LORESERVE
)
2641 if (sechdrs
[sym
->st_shndx
].sh_flags
& SHF_EXECINSTR
)
2643 if (sechdrs
[sym
->st_shndx
].sh_flags
& SHF_ALLOC
2644 && sechdrs
[sym
->st_shndx
].sh_type
!= SHT_NOBITS
) {
2645 if (!(sechdrs
[sym
->st_shndx
].sh_flags
& SHF_WRITE
))
2647 else if (sechdrs
[sym
->st_shndx
].sh_flags
& ARCH_SHF_SMALL
)
2652 if (sechdrs
[sym
->st_shndx
].sh_type
== SHT_NOBITS
) {
2653 if (sechdrs
[sym
->st_shndx
].sh_flags
& ARCH_SHF_SMALL
)
2658 if (strstarts(info
->secstrings
+ sechdrs
[sym
->st_shndx
].sh_name
,
2665 static bool is_core_symbol(const Elf_Sym
*src
, const Elf_Shdr
*sechdrs
,
2666 unsigned int shnum
, unsigned int pcpundx
)
2668 const Elf_Shdr
*sec
;
2670 if (src
->st_shndx
== SHN_UNDEF
2671 || src
->st_shndx
>= shnum
2675 #ifdef CONFIG_KALLSYMS_ALL
2676 if (src
->st_shndx
== pcpundx
)
2680 sec
= sechdrs
+ src
->st_shndx
;
2681 if (!(sec
->sh_flags
& SHF_ALLOC
)
2682 #ifndef CONFIG_KALLSYMS_ALL
2683 || !(sec
->sh_flags
& SHF_EXECINSTR
)
2685 || (sec
->sh_entsize
& INIT_OFFSET_MASK
))
2692 * We only allocate and copy the strings needed by the parts of symtab
2693 * we keep. This is simple, but has the effect of making multiple
2694 * copies of duplicates. We could be more sophisticated, see
2695 * linux-kernel thread starting with
2696 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2698 static void layout_symtab(struct module
*mod
, struct load_info
*info
)
2700 Elf_Shdr
*symsect
= info
->sechdrs
+ info
->index
.sym
;
2701 Elf_Shdr
*strsect
= info
->sechdrs
+ info
->index
.str
;
2703 unsigned int i
, nsrc
, ndst
, strtab_size
= 0;
2705 /* Put symbol section at end of init part of module. */
2706 symsect
->sh_flags
|= SHF_ALLOC
;
2707 symsect
->sh_entsize
= get_offset(mod
, &mod
->init_layout
.size
, symsect
,
2708 info
->index
.sym
) | INIT_OFFSET_MASK
;
2709 pr_debug("\t%s\n", info
->secstrings
+ symsect
->sh_name
);
2711 src
= (void *)info
->hdr
+ symsect
->sh_offset
;
2712 nsrc
= symsect
->sh_size
/ sizeof(*src
);
2714 /* Compute total space required for the core symbols' strtab. */
2715 for (ndst
= i
= 0; i
< nsrc
; i
++) {
2716 if (i
== 0 || is_livepatch_module(mod
) ||
2717 is_core_symbol(src
+i
, info
->sechdrs
, info
->hdr
->e_shnum
,
2718 info
->index
.pcpu
)) {
2719 strtab_size
+= strlen(&info
->strtab
[src
[i
].st_name
])+1;
2724 /* Append room for core symbols at end of core part. */
2725 info
->symoffs
= ALIGN(mod
->core_layout
.size
, symsect
->sh_addralign
?: 1);
2726 info
->stroffs
= mod
->core_layout
.size
= info
->symoffs
+ ndst
* sizeof(Elf_Sym
);
2727 mod
->core_layout
.size
+= strtab_size
;
2728 info
->core_typeoffs
= mod
->core_layout
.size
;
2729 mod
->core_layout
.size
+= ndst
* sizeof(char);
2730 mod
->core_layout
.size
= debug_align(mod
->core_layout
.size
);
2732 /* Put string table section at end of init part of module. */
2733 strsect
->sh_flags
|= SHF_ALLOC
;
2734 strsect
->sh_entsize
= get_offset(mod
, &mod
->init_layout
.size
, strsect
,
2735 info
->index
.str
) | INIT_OFFSET_MASK
;
2736 pr_debug("\t%s\n", info
->secstrings
+ strsect
->sh_name
);
2738 /* We'll tack temporary mod_kallsyms on the end. */
2739 mod
->init_layout
.size
= ALIGN(mod
->init_layout
.size
,
2740 __alignof__(struct mod_kallsyms
));
2741 info
->mod_kallsyms_init_off
= mod
->init_layout
.size
;
2742 mod
->init_layout
.size
+= sizeof(struct mod_kallsyms
);
2743 info
->init_typeoffs
= mod
->init_layout
.size
;
2744 mod
->init_layout
.size
+= nsrc
* sizeof(char);
2745 mod
->init_layout
.size
= debug_align(mod
->init_layout
.size
);
2749 * We use the full symtab and strtab which layout_symtab arranged to
2750 * be appended to the init section. Later we switch to the cut-down
2753 static void add_kallsyms(struct module
*mod
, const struct load_info
*info
)
2755 unsigned int i
, ndst
;
2759 Elf_Shdr
*symsec
= &info
->sechdrs
[info
->index
.sym
];
2761 /* Set up to point into init section. */
2762 mod
->kallsyms
= mod
->init_layout
.base
+ info
->mod_kallsyms_init_off
;
2764 mod
->kallsyms
->symtab
= (void *)symsec
->sh_addr
;
2765 mod
->kallsyms
->num_symtab
= symsec
->sh_size
/ sizeof(Elf_Sym
);
2766 /* Make sure we get permanent strtab: don't use info->strtab. */
2767 mod
->kallsyms
->strtab
= (void *)info
->sechdrs
[info
->index
.str
].sh_addr
;
2768 mod
->kallsyms
->typetab
= mod
->init_layout
.base
+ info
->init_typeoffs
;
2771 * Now populate the cut down core kallsyms for after init
2772 * and set types up while we still have access to sections.
2774 mod
->core_kallsyms
.symtab
= dst
= mod
->core_layout
.base
+ info
->symoffs
;
2775 mod
->core_kallsyms
.strtab
= s
= mod
->core_layout
.base
+ info
->stroffs
;
2776 mod
->core_kallsyms
.typetab
= mod
->core_layout
.base
+ info
->core_typeoffs
;
2777 src
= mod
->kallsyms
->symtab
;
2778 for (ndst
= i
= 0; i
< mod
->kallsyms
->num_symtab
; i
++) {
2779 mod
->kallsyms
->typetab
[i
] = elf_type(src
+ i
, info
);
2780 if (i
== 0 || is_livepatch_module(mod
) ||
2781 is_core_symbol(src
+i
, info
->sechdrs
, info
->hdr
->e_shnum
,
2782 info
->index
.pcpu
)) {
2783 mod
->core_kallsyms
.typetab
[ndst
] =
2784 mod
->kallsyms
->typetab
[i
];
2786 dst
[ndst
++].st_name
= s
- mod
->core_kallsyms
.strtab
;
2787 s
+= strlcpy(s
, &mod
->kallsyms
->strtab
[src
[i
].st_name
],
2791 mod
->core_kallsyms
.num_symtab
= ndst
;
2794 static inline void layout_symtab(struct module
*mod
, struct load_info
*info
)
2798 static void add_kallsyms(struct module
*mod
, const struct load_info
*info
)
2801 #endif /* CONFIG_KALLSYMS */
2803 #if IS_ENABLED(CONFIG_KALLSYMS) && IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
2804 static void init_build_id(struct module
*mod
, const struct load_info
*info
)
2806 const Elf_Shdr
*sechdr
;
2809 for (i
= 0; i
< info
->hdr
->e_shnum
; i
++) {
2810 sechdr
= &info
->sechdrs
[i
];
2811 if (!sect_empty(sechdr
) && sechdr
->sh_type
== SHT_NOTE
&&
2812 !build_id_parse_buf((void *)sechdr
->sh_addr
, mod
->build_id
,
2818 static void init_build_id(struct module
*mod
, const struct load_info
*info
)
2823 static void dynamic_debug_setup(struct module
*mod
, struct _ddebug
*debug
, unsigned int num
)
2827 ddebug_add_module(debug
, num
, mod
->name
);
2830 static void dynamic_debug_remove(struct module
*mod
, struct _ddebug
*debug
)
2833 ddebug_remove_module(mod
->name
);
2836 void * __weak
module_alloc(unsigned long size
)
2838 return __vmalloc_node_range(size
, 1, VMALLOC_START
, VMALLOC_END
,
2839 GFP_KERNEL
, PAGE_KERNEL_EXEC
, VM_FLUSH_RESET_PERMS
,
2840 NUMA_NO_NODE
, __builtin_return_address(0));
2843 bool __weak
module_init_section(const char *name
)
2845 return strstarts(name
, ".init");
2848 bool __weak
module_exit_section(const char *name
)
2850 return strstarts(name
, ".exit");
2853 #ifdef CONFIG_DEBUG_KMEMLEAK
2854 static void kmemleak_load_module(const struct module
*mod
,
2855 const struct load_info
*info
)
2859 /* only scan the sections containing data */
2860 kmemleak_scan_area(mod
, sizeof(struct module
), GFP_KERNEL
);
2862 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
2863 /* Scan all writable sections that's not executable */
2864 if (!(info
->sechdrs
[i
].sh_flags
& SHF_ALLOC
) ||
2865 !(info
->sechdrs
[i
].sh_flags
& SHF_WRITE
) ||
2866 (info
->sechdrs
[i
].sh_flags
& SHF_EXECINSTR
))
2869 kmemleak_scan_area((void *)info
->sechdrs
[i
].sh_addr
,
2870 info
->sechdrs
[i
].sh_size
, GFP_KERNEL
);
2874 static inline void kmemleak_load_module(const struct module
*mod
,
2875 const struct load_info
*info
)
2880 #ifdef CONFIG_MODULE_SIG
2881 static int module_sig_check(struct load_info
*info
, int flags
)
2884 const unsigned long markerlen
= sizeof(MODULE_SIG_STRING
) - 1;
2886 const void *mod
= info
->hdr
;
2889 * Require flags == 0, as a module with version information
2890 * removed is no longer the module that was signed
2893 info
->len
> markerlen
&&
2894 memcmp(mod
+ info
->len
- markerlen
, MODULE_SIG_STRING
, markerlen
) == 0) {
2895 /* We truncate the module to discard the signature */
2896 info
->len
-= markerlen
;
2897 err
= mod_verify_sig(mod
, info
);
2899 info
->sig_ok
= true;
2905 * We don't permit modules to be loaded into the trusted kernels
2906 * without a valid signature on them, but if we're not enforcing,
2907 * certain errors are non-fatal.
2911 reason
= "unsigned module";
2914 reason
= "module with unsupported crypto";
2917 reason
= "module with unavailable key";
2922 * All other errors are fatal, including lack of memory,
2923 * unparseable signatures, and signature check failures --
2924 * even if signatures aren't required.
2929 if (is_module_sig_enforced()) {
2930 pr_notice("Loading of %s is rejected\n", reason
);
2931 return -EKEYREJECTED
;
2934 return security_locked_down(LOCKDOWN_MODULE_SIGNATURE
);
2936 #else /* !CONFIG_MODULE_SIG */
2937 static int module_sig_check(struct load_info
*info
, int flags
)
2941 #endif /* !CONFIG_MODULE_SIG */
2943 static int validate_section_offset(struct load_info
*info
, Elf_Shdr
*shdr
)
2945 #if defined(CONFIG_64BIT)
2946 unsigned long long secend
;
2948 unsigned long secend
;
2952 * Check for both overflow and offset/size being
2955 secend
= shdr
->sh_offset
+ shdr
->sh_size
;
2956 if (secend
< shdr
->sh_offset
|| secend
> info
->len
)
2963 * Sanity checks against invalid binaries, wrong arch, weird elf version.
2965 * Also do basic validity checks against section offsets and sizes, the
2966 * section name string table, and the indices used for it (sh_name).
2968 static int elf_validity_check(struct load_info
*info
)
2971 Elf_Shdr
*shdr
, *strhdr
;
2974 if (info
->len
< sizeof(*(info
->hdr
))) {
2975 pr_err("Invalid ELF header len %lu\n", info
->len
);
2979 if (memcmp(info
->hdr
->e_ident
, ELFMAG
, SELFMAG
) != 0) {
2980 pr_err("Invalid ELF header magic: != %s\n", ELFMAG
);
2983 if (info
->hdr
->e_type
!= ET_REL
) {
2984 pr_err("Invalid ELF header type: %u != %u\n",
2985 info
->hdr
->e_type
, ET_REL
);
2988 if (!elf_check_arch(info
->hdr
)) {
2989 pr_err("Invalid architecture in ELF header: %u\n",
2990 info
->hdr
->e_machine
);
2993 if (info
->hdr
->e_shentsize
!= sizeof(Elf_Shdr
)) {
2994 pr_err("Invalid ELF section header size\n");
2999 * e_shnum is 16 bits, and sizeof(Elf_Shdr) is
3000 * known and small. So e_shnum * sizeof(Elf_Shdr)
3001 * will not overflow unsigned long on any platform.
3003 if (info
->hdr
->e_shoff
>= info
->len
3004 || (info
->hdr
->e_shnum
* sizeof(Elf_Shdr
) >
3005 info
->len
- info
->hdr
->e_shoff
)) {
3006 pr_err("Invalid ELF section header overflow\n");
3010 info
->sechdrs
= (void *)info
->hdr
+ info
->hdr
->e_shoff
;
3013 * Verify if the section name table index is valid.
3015 if (info
->hdr
->e_shstrndx
== SHN_UNDEF
3016 || info
->hdr
->e_shstrndx
>= info
->hdr
->e_shnum
) {
3017 pr_err("Invalid ELF section name index: %d || e_shstrndx (%d) >= e_shnum (%d)\n",
3018 info
->hdr
->e_shstrndx
, info
->hdr
->e_shstrndx
,
3019 info
->hdr
->e_shnum
);
3023 strhdr
= &info
->sechdrs
[info
->hdr
->e_shstrndx
];
3024 err
= validate_section_offset(info
, strhdr
);
3026 pr_err("Invalid ELF section hdr(type %u)\n", strhdr
->sh_type
);
3031 * The section name table must be NUL-terminated, as required
3032 * by the spec. This makes strcmp and pr_* calls that access
3033 * strings in the section safe.
3035 info
->secstrings
= (void *)info
->hdr
+ strhdr
->sh_offset
;
3036 if (info
->secstrings
[strhdr
->sh_size
- 1] != '\0') {
3037 pr_err("ELF Spec violation: section name table isn't null terminated\n");
3042 * The code assumes that section 0 has a length of zero and
3043 * an addr of zero, so check for it.
3045 if (info
->sechdrs
[0].sh_type
!= SHT_NULL
3046 || info
->sechdrs
[0].sh_size
!= 0
3047 || info
->sechdrs
[0].sh_addr
!= 0) {
3048 pr_err("ELF Spec violation: section 0 type(%d)!=SH_NULL or non-zero len or addr\n",
3049 info
->sechdrs
[0].sh_type
);
3053 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
3054 shdr
= &info
->sechdrs
[i
];
3055 switch (shdr
->sh_type
) {
3060 if (shdr
->sh_link
== SHN_UNDEF
3061 || shdr
->sh_link
>= info
->hdr
->e_shnum
) {
3062 pr_err("Invalid ELF sh_link!=SHN_UNDEF(%d) or (sh_link(%d) >= hdr->e_shnum(%d)\n",
3063 shdr
->sh_link
, shdr
->sh_link
,
3064 info
->hdr
->e_shnum
);
3069 err
= validate_section_offset(info
, shdr
);
3071 pr_err("Invalid ELF section in module (section %u type %u)\n",
3076 if (shdr
->sh_flags
& SHF_ALLOC
) {
3077 if (shdr
->sh_name
>= strhdr
->sh_size
) {
3078 pr_err("Invalid ELF section name in module (section %u type %u)\n",
3093 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
3095 static int copy_chunked_from_user(void *dst
, const void __user
*usrc
, unsigned long len
)
3098 unsigned long n
= min(len
, COPY_CHUNK_SIZE
);
3100 if (copy_from_user(dst
, usrc
, n
) != 0)
3110 #ifdef CONFIG_LIVEPATCH
3111 static int check_modinfo_livepatch(struct module
*mod
, struct load_info
*info
)
3113 if (get_modinfo(info
, "livepatch")) {
3115 add_taint_module(mod
, TAINT_LIVEPATCH
, LOCKDEP_STILL_OK
);
3116 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
3122 #else /* !CONFIG_LIVEPATCH */
3123 static int check_modinfo_livepatch(struct module
*mod
, struct load_info
*info
)
3125 if (get_modinfo(info
, "livepatch")) {
3126 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
3133 #endif /* CONFIG_LIVEPATCH */
3135 static void check_modinfo_retpoline(struct module
*mod
, struct load_info
*info
)
3137 if (retpoline_module_ok(get_modinfo(info
, "retpoline")))
3140 pr_warn("%s: loading module not compiled with retpoline compiler.\n",
3144 /* Sets info->hdr and info->len. */
3145 static int copy_module_from_user(const void __user
*umod
, unsigned long len
,
3146 struct load_info
*info
)
3151 if (info
->len
< sizeof(*(info
->hdr
)))
3154 err
= security_kernel_load_data(LOADING_MODULE
, true);
3158 /* Suck in entire file: we'll want most of it. */
3159 info
->hdr
= __vmalloc(info
->len
, GFP_KERNEL
| __GFP_NOWARN
);
3163 if (copy_chunked_from_user(info
->hdr
, umod
, info
->len
) != 0) {
3168 err
= security_kernel_post_load_data((char *)info
->hdr
, info
->len
,
3169 LOADING_MODULE
, "init_module");
3177 static void free_copy(struct load_info
*info
)
3182 static int rewrite_section_headers(struct load_info
*info
, int flags
)
3186 /* This should always be true, but let's be sure. */
3187 info
->sechdrs
[0].sh_addr
= 0;
3189 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
3190 Elf_Shdr
*shdr
= &info
->sechdrs
[i
];
3193 * Mark all sections sh_addr with their address in the
3196 shdr
->sh_addr
= (size_t)info
->hdr
+ shdr
->sh_offset
;
3200 /* Track but don't keep modinfo and version sections. */
3201 info
->sechdrs
[info
->index
.vers
].sh_flags
&= ~(unsigned long)SHF_ALLOC
;
3202 info
->sechdrs
[info
->index
.info
].sh_flags
&= ~(unsigned long)SHF_ALLOC
;
3208 * Set up our basic convenience variables (pointers to section headers,
3209 * search for module section index etc), and do some basic section
3212 * Set info->mod to the temporary copy of the module in info->hdr. The final one
3213 * will be allocated in move_module().
3215 static int setup_load_info(struct load_info
*info
, int flags
)
3219 /* Try to find a name early so we can log errors with a module name */
3220 info
->index
.info
= find_sec(info
, ".modinfo");
3221 if (info
->index
.info
)
3222 info
->name
= get_modinfo(info
, "name");
3224 /* Find internal symbols and strings. */
3225 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
3226 if (info
->sechdrs
[i
].sh_type
== SHT_SYMTAB
) {
3227 info
->index
.sym
= i
;
3228 info
->index
.str
= info
->sechdrs
[i
].sh_link
;
3229 info
->strtab
= (char *)info
->hdr
3230 + info
->sechdrs
[info
->index
.str
].sh_offset
;
3235 if (info
->index
.sym
== 0) {
3236 pr_warn("%s: module has no symbols (stripped?)\n",
3237 info
->name
?: "(missing .modinfo section or name field)");
3241 info
->index
.mod
= find_sec(info
, ".gnu.linkonce.this_module");
3242 if (!info
->index
.mod
) {
3243 pr_warn("%s: No module found in object\n",
3244 info
->name
?: "(missing .modinfo section or name field)");
3247 /* This is temporary: point mod into copy of data. */
3248 info
->mod
= (void *)info
->hdr
+ info
->sechdrs
[info
->index
.mod
].sh_offset
;
3251 * If we didn't load the .modinfo 'name' field earlier, fall back to
3252 * on-disk struct mod 'name' field.
3255 info
->name
= info
->mod
->name
;
3257 if (flags
& MODULE_INIT_IGNORE_MODVERSIONS
)
3258 info
->index
.vers
= 0; /* Pretend no __versions section! */
3260 info
->index
.vers
= find_sec(info
, "__versions");
3262 info
->index
.pcpu
= find_pcpusec(info
);
3267 static int check_modinfo(struct module
*mod
, struct load_info
*info
, int flags
)
3269 const char *modmagic
= get_modinfo(info
, "vermagic");
3272 if (flags
& MODULE_INIT_IGNORE_VERMAGIC
)
3275 /* This is allowed: modprobe --force will invalidate it. */
3277 err
= try_to_force_load(mod
, "bad vermagic");
3280 } else if (!same_magic(modmagic
, vermagic
, info
->index
.vers
)) {
3281 pr_err("%s: version magic '%s' should be '%s'\n",
3282 info
->name
, modmagic
, vermagic
);
3286 if (!get_modinfo(info
, "intree")) {
3287 if (!test_taint(TAINT_OOT_MODULE
))
3288 pr_warn("%s: loading out-of-tree module taints kernel.\n",
3290 add_taint_module(mod
, TAINT_OOT_MODULE
, LOCKDEP_STILL_OK
);
3293 check_modinfo_retpoline(mod
, info
);
3295 if (get_modinfo(info
, "staging")) {
3296 add_taint_module(mod
, TAINT_CRAP
, LOCKDEP_STILL_OK
);
3297 pr_warn("%s: module is from the staging directory, the quality "
3298 "is unknown, you have been warned.\n", mod
->name
);
3301 err
= check_modinfo_livepatch(mod
, info
);
3305 /* Set up license info based on the info section */
3306 set_license(mod
, get_modinfo(info
, "license"));
3311 static int find_module_sections(struct module
*mod
, struct load_info
*info
)
3313 mod
->kp
= section_objs(info
, "__param",
3314 sizeof(*mod
->kp
), &mod
->num_kp
);
3315 mod
->syms
= section_objs(info
, "__ksymtab",
3316 sizeof(*mod
->syms
), &mod
->num_syms
);
3317 mod
->crcs
= section_addr(info
, "__kcrctab");
3318 mod
->gpl_syms
= section_objs(info
, "__ksymtab_gpl",
3319 sizeof(*mod
->gpl_syms
),
3320 &mod
->num_gpl_syms
);
3321 mod
->gpl_crcs
= section_addr(info
, "__kcrctab_gpl");
3323 #ifdef CONFIG_CONSTRUCTORS
3324 mod
->ctors
= section_objs(info
, ".ctors",
3325 sizeof(*mod
->ctors
), &mod
->num_ctors
);
3327 mod
->ctors
= section_objs(info
, ".init_array",
3328 sizeof(*mod
->ctors
), &mod
->num_ctors
);
3329 else if (find_sec(info
, ".init_array")) {
3331 * This shouldn't happen with same compiler and binutils
3332 * building all parts of the module.
3334 pr_warn("%s: has both .ctors and .init_array.\n",
3340 mod
->noinstr_text_start
= section_objs(info
, ".noinstr.text", 1,
3341 &mod
->noinstr_text_size
);
3343 #ifdef CONFIG_TRACEPOINTS
3344 mod
->tracepoints_ptrs
= section_objs(info
, "__tracepoints_ptrs",
3345 sizeof(*mod
->tracepoints_ptrs
),
3346 &mod
->num_tracepoints
);
3348 #ifdef CONFIG_TREE_SRCU
3349 mod
->srcu_struct_ptrs
= section_objs(info
, "___srcu_struct_ptrs",
3350 sizeof(*mod
->srcu_struct_ptrs
),
3351 &mod
->num_srcu_structs
);
3353 #ifdef CONFIG_BPF_EVENTS
3354 mod
->bpf_raw_events
= section_objs(info
, "__bpf_raw_tp_map",
3355 sizeof(*mod
->bpf_raw_events
),
3356 &mod
->num_bpf_raw_events
);
3358 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
3359 mod
->btf_data
= any_section_objs(info
, ".BTF", 1, &mod
->btf_data_size
);
3361 #ifdef CONFIG_JUMP_LABEL
3362 mod
->jump_entries
= section_objs(info
, "__jump_table",
3363 sizeof(*mod
->jump_entries
),
3364 &mod
->num_jump_entries
);
3366 #ifdef CONFIG_EVENT_TRACING
3367 mod
->trace_events
= section_objs(info
, "_ftrace_events",
3368 sizeof(*mod
->trace_events
),
3369 &mod
->num_trace_events
);
3370 mod
->trace_evals
= section_objs(info
, "_ftrace_eval_map",
3371 sizeof(*mod
->trace_evals
),
3372 &mod
->num_trace_evals
);
3374 #ifdef CONFIG_TRACING
3375 mod
->trace_bprintk_fmt_start
= section_objs(info
, "__trace_printk_fmt",
3376 sizeof(*mod
->trace_bprintk_fmt_start
),
3377 &mod
->num_trace_bprintk_fmt
);
3379 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
3380 /* sechdrs[0].sh_size is always zero */
3381 mod
->ftrace_callsites
= section_objs(info
, FTRACE_CALLSITE_SECTION
,
3382 sizeof(*mod
->ftrace_callsites
),
3383 &mod
->num_ftrace_callsites
);
3385 #ifdef CONFIG_FUNCTION_ERROR_INJECTION
3386 mod
->ei_funcs
= section_objs(info
, "_error_injection_whitelist",
3387 sizeof(*mod
->ei_funcs
),
3388 &mod
->num_ei_funcs
);
3390 #ifdef CONFIG_KPROBES
3391 mod
->kprobes_text_start
= section_objs(info
, ".kprobes.text", 1,
3392 &mod
->kprobes_text_size
);
3393 mod
->kprobe_blacklist
= section_objs(info
, "_kprobe_blacklist",
3394 sizeof(unsigned long),
3395 &mod
->num_kprobe_blacklist
);
3397 #ifdef CONFIG_PRINTK_INDEX
3398 mod
->printk_index_start
= section_objs(info
, ".printk_index",
3399 sizeof(*mod
->printk_index_start
),
3400 &mod
->printk_index_size
);
3402 #ifdef CONFIG_HAVE_STATIC_CALL_INLINE
3403 mod
->static_call_sites
= section_objs(info
, ".static_call_sites",
3404 sizeof(*mod
->static_call_sites
),
3405 &mod
->num_static_call_sites
);
3407 mod
->extable
= section_objs(info
, "__ex_table",
3408 sizeof(*mod
->extable
), &mod
->num_exentries
);
3410 if (section_addr(info
, "__obsparm"))
3411 pr_warn("%s: Ignoring obsolete parameters\n", mod
->name
);
3413 info
->debug
= section_objs(info
, "__dyndbg",
3414 sizeof(*info
->debug
), &info
->num_debug
);
3419 static int move_module(struct module
*mod
, struct load_info
*info
)
3424 /* Do the allocs. */
3425 ptr
= module_alloc(mod
->core_layout
.size
);
3427 * The pointer to this block is stored in the module structure
3428 * which is inside the block. Just mark it as not being a
3431 kmemleak_not_leak(ptr
);
3435 memset(ptr
, 0, mod
->core_layout
.size
);
3436 mod
->core_layout
.base
= ptr
;
3438 if (mod
->init_layout
.size
) {
3439 ptr
= module_alloc(mod
->init_layout
.size
);
3441 * The pointer to this block is stored in the module structure
3442 * which is inside the block. This block doesn't need to be
3443 * scanned as it contains data and code that will be freed
3444 * after the module is initialized.
3446 kmemleak_ignore(ptr
);
3448 module_memfree(mod
->core_layout
.base
);
3451 memset(ptr
, 0, mod
->init_layout
.size
);
3452 mod
->init_layout
.base
= ptr
;
3454 mod
->init_layout
.base
= NULL
;
3456 /* Transfer each section which specifies SHF_ALLOC */
3457 pr_debug("final section addresses:\n");
3458 for (i
= 0; i
< info
->hdr
->e_shnum
; i
++) {
3460 Elf_Shdr
*shdr
= &info
->sechdrs
[i
];
3462 if (!(shdr
->sh_flags
& SHF_ALLOC
))
3465 if (shdr
->sh_entsize
& INIT_OFFSET_MASK
)
3466 dest
= mod
->init_layout
.base
3467 + (shdr
->sh_entsize
& ~INIT_OFFSET_MASK
);
3469 dest
= mod
->core_layout
.base
+ shdr
->sh_entsize
;
3471 if (shdr
->sh_type
!= SHT_NOBITS
)
3472 memcpy(dest
, (void *)shdr
->sh_addr
, shdr
->sh_size
);
3473 /* Update sh_addr to point to copy in image. */
3474 shdr
->sh_addr
= (unsigned long)dest
;
3475 pr_debug("\t0x%lx %s\n",
3476 (long)shdr
->sh_addr
, info
->secstrings
+ shdr
->sh_name
);
3482 static int check_module_license_and_versions(struct module
*mod
)
3484 int prev_taint
= test_taint(TAINT_PROPRIETARY_MODULE
);
3487 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3488 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3489 * using GPL-only symbols it needs.
3491 if (strcmp(mod
->name
, "ndiswrapper") == 0)
3492 add_taint(TAINT_PROPRIETARY_MODULE
, LOCKDEP_NOW_UNRELIABLE
);
3494 /* driverloader was caught wrongly pretending to be under GPL */
3495 if (strcmp(mod
->name
, "driverloader") == 0)
3496 add_taint_module(mod
, TAINT_PROPRIETARY_MODULE
,
3497 LOCKDEP_NOW_UNRELIABLE
);
3499 /* lve claims to be GPL but upstream won't provide source */
3500 if (strcmp(mod
->name
, "lve") == 0)
3501 add_taint_module(mod
, TAINT_PROPRIETARY_MODULE
,
3502 LOCKDEP_NOW_UNRELIABLE
);
3504 if (!prev_taint
&& test_taint(TAINT_PROPRIETARY_MODULE
))
3505 pr_warn("%s: module license taints kernel.\n", mod
->name
);
3507 #ifdef CONFIG_MODVERSIONS
3508 if ((mod
->num_syms
&& !mod
->crcs
) ||
3509 (mod
->num_gpl_syms
&& !mod
->gpl_crcs
)) {
3510 return try_to_force_load(mod
,
3511 "no versions for exported symbols");
3517 static void flush_module_icache(const struct module
*mod
)
3520 * Flush the instruction cache, since we've played with text.
3521 * Do it before processing of module parameters, so the module
3522 * can provide parameter accessor functions of its own.
3524 if (mod
->init_layout
.base
)
3525 flush_icache_range((unsigned long)mod
->init_layout
.base
,
3526 (unsigned long)mod
->init_layout
.base
3527 + mod
->init_layout
.size
);
3528 flush_icache_range((unsigned long)mod
->core_layout
.base
,
3529 (unsigned long)mod
->core_layout
.base
+ mod
->core_layout
.size
);
3532 int __weak
module_frob_arch_sections(Elf_Ehdr
*hdr
,
3540 /* module_blacklist is a comma-separated list of module names */
3541 static char *module_blacklist
;
3542 static bool blacklisted(const char *module_name
)
3547 if (!module_blacklist
)
3550 for (p
= module_blacklist
; *p
; p
+= len
) {
3551 len
= strcspn(p
, ",");
3552 if (strlen(module_name
) == len
&& !memcmp(module_name
, p
, len
))
3559 core_param(module_blacklist
, module_blacklist
, charp
, 0400);
3561 static struct module
*layout_and_allocate(struct load_info
*info
, int flags
)
3567 err
= check_modinfo(info
->mod
, info
, flags
);
3569 return ERR_PTR(err
);
3571 /* Allow arches to frob section contents and sizes. */
3572 err
= module_frob_arch_sections(info
->hdr
, info
->sechdrs
,
3573 info
->secstrings
, info
->mod
);
3575 return ERR_PTR(err
);
3577 err
= module_enforce_rwx_sections(info
->hdr
, info
->sechdrs
,
3578 info
->secstrings
, info
->mod
);
3580 return ERR_PTR(err
);
3582 /* We will do a special allocation for per-cpu sections later. */
3583 info
->sechdrs
[info
->index
.pcpu
].sh_flags
&= ~(unsigned long)SHF_ALLOC
;
3586 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3587 * layout_sections() can put it in the right place.
3588 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3590 ndx
= find_sec(info
, ".data..ro_after_init");
3592 info
->sechdrs
[ndx
].sh_flags
|= SHF_RO_AFTER_INIT
;
3594 * Mark the __jump_table section as ro_after_init as well: these data
3595 * structures are never modified, with the exception of entries that
3596 * refer to code in the __init section, which are annotated as such
3597 * at module load time.
3599 ndx
= find_sec(info
, "__jump_table");
3601 info
->sechdrs
[ndx
].sh_flags
|= SHF_RO_AFTER_INIT
;
3604 * Determine total sizes, and put offsets in sh_entsize. For now
3605 * this is done generically; there doesn't appear to be any
3606 * special cases for the architectures.
3608 layout_sections(info
->mod
, info
);
3609 layout_symtab(info
->mod
, info
);
3611 /* Allocate and move to the final place */
3612 err
= move_module(info
->mod
, info
);
3614 return ERR_PTR(err
);
3616 /* Module has been copied to its final place now: return it. */
3617 mod
= (void *)info
->sechdrs
[info
->index
.mod
].sh_addr
;
3618 kmemleak_load_module(mod
, info
);
3622 /* mod is no longer valid after this! */
3623 static void module_deallocate(struct module
*mod
, struct load_info
*info
)
3625 percpu_modfree(mod
);
3626 module_arch_freeing_init(mod
);
3627 module_memfree(mod
->init_layout
.base
);
3628 module_memfree(mod
->core_layout
.base
);
3631 int __weak
module_finalize(const Elf_Ehdr
*hdr
,
3632 const Elf_Shdr
*sechdrs
,
3638 static int post_relocation(struct module
*mod
, const struct load_info
*info
)
3640 /* Sort exception table now relocations are done. */
3641 sort_extable(mod
->extable
, mod
->extable
+ mod
->num_exentries
);
3643 /* Copy relocated percpu area over. */
3644 percpu_modcopy(mod
, (void *)info
->sechdrs
[info
->index
.pcpu
].sh_addr
,
3645 info
->sechdrs
[info
->index
.pcpu
].sh_size
);
3647 /* Setup kallsyms-specific fields. */
3648 add_kallsyms(mod
, info
);
3650 /* Arch-specific module finalizing. */
3651 return module_finalize(info
->hdr
, info
->sechdrs
, mod
);
3654 /* Is this module of this name done loading? No locks held. */
3655 static bool finished_loading(const char *name
)
3661 * The module_mutex should not be a heavily contended lock;
3662 * if we get the occasional sleep here, we'll go an extra iteration
3663 * in the wait_event_interruptible(), which is harmless.
3665 sched_annotate_sleep();
3666 mutex_lock(&module_mutex
);
3667 mod
= find_module_all(name
, strlen(name
), true);
3668 ret
= !mod
|| mod
->state
== MODULE_STATE_LIVE
;
3669 mutex_unlock(&module_mutex
);
3674 /* Call module constructors. */
3675 static void do_mod_ctors(struct module
*mod
)
3677 #ifdef CONFIG_CONSTRUCTORS
3680 for (i
= 0; i
< mod
->num_ctors
; i
++)
3685 /* For freeing module_init on success, in case kallsyms traversing */
3686 struct mod_initfree
{
3687 struct llist_node node
;
3691 static void do_free_init(struct work_struct
*w
)
3693 struct llist_node
*pos
, *n
, *list
;
3694 struct mod_initfree
*initfree
;
3696 list
= llist_del_all(&init_free_list
);
3700 llist_for_each_safe(pos
, n
, list
) {
3701 initfree
= container_of(pos
, struct mod_initfree
, node
);
3702 module_memfree(initfree
->module_init
);
3708 * This is where the real work happens.
3710 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3711 * helper command 'lx-symbols'.
3713 static noinline
int do_init_module(struct module
*mod
)
3716 struct mod_initfree
*freeinit
;
3718 freeinit
= kmalloc(sizeof(*freeinit
), GFP_KERNEL
);
3723 freeinit
->module_init
= mod
->init_layout
.base
;
3726 * We want to find out whether @mod uses async during init. Clear
3727 * PF_USED_ASYNC. async_schedule*() will set it.
3729 current
->flags
&= ~PF_USED_ASYNC
;
3732 /* Start the module */
3733 if (mod
->init
!= NULL
)
3734 ret
= do_one_initcall(mod
->init
);
3736 goto fail_free_freeinit
;
3739 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3740 "follow 0/-E convention\n"
3741 "%s: loading module anyway...\n",
3742 __func__
, mod
->name
, ret
, __func__
);
3746 /* Now it's a first class citizen! */
3747 mod
->state
= MODULE_STATE_LIVE
;
3748 blocking_notifier_call_chain(&module_notify_list
,
3749 MODULE_STATE_LIVE
, mod
);
3751 /* Delay uevent until module has finished its init routine */
3752 kobject_uevent(&mod
->mkobj
.kobj
, KOBJ_ADD
);
3755 * We need to finish all async code before the module init sequence
3756 * is done. This has potential to deadlock. For example, a newly
3757 * detected block device can trigger request_module() of the
3758 * default iosched from async probing task. Once userland helper
3759 * reaches here, async_synchronize_full() will wait on the async
3760 * task waiting on request_module() and deadlock.
3762 * This deadlock is avoided by perfomring async_synchronize_full()
3763 * iff module init queued any async jobs. This isn't a full
3764 * solution as it will deadlock the same if module loading from
3765 * async jobs nests more than once; however, due to the various
3766 * constraints, this hack seems to be the best option for now.
3767 * Please refer to the following thread for details.
3769 * http://thread.gmane.org/gmane.linux.kernel/1420814
3771 if (!mod
->async_probe_requested
&& (current
->flags
& PF_USED_ASYNC
))
3772 async_synchronize_full();
3774 ftrace_free_mem(mod
, mod
->init_layout
.base
, mod
->init_layout
.base
+
3775 mod
->init_layout
.size
);
3776 mutex_lock(&module_mutex
);
3777 /* Drop initial reference. */
3779 trim_init_extable(mod
);
3780 #ifdef CONFIG_KALLSYMS
3781 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3782 rcu_assign_pointer(mod
->kallsyms
, &mod
->core_kallsyms
);
3784 module_enable_ro(mod
, true);
3785 mod_tree_remove_init(mod
);
3786 module_arch_freeing_init(mod
);
3787 mod
->init_layout
.base
= NULL
;
3788 mod
->init_layout
.size
= 0;
3789 mod
->init_layout
.ro_size
= 0;
3790 mod
->init_layout
.ro_after_init_size
= 0;
3791 mod
->init_layout
.text_size
= 0;
3792 #ifdef CONFIG_DEBUG_INFO_BTF_MODULES
3793 /* .BTF is not SHF_ALLOC and will get removed, so sanitize pointer */
3794 mod
->btf_data
= NULL
;
3797 * We want to free module_init, but be aware that kallsyms may be
3798 * walking this with preempt disabled. In all the failure paths, we
3799 * call synchronize_rcu(), but we don't want to slow down the success
3800 * path. module_memfree() cannot be called in an interrupt, so do the
3801 * work and call synchronize_rcu() in a work queue.
3803 * Note that module_alloc() on most architectures creates W+X page
3804 * mappings which won't be cleaned up until do_free_init() runs. Any
3805 * code such as mark_rodata_ro() which depends on those mappings to
3806 * be cleaned up needs to sync with the queued work - ie
3809 if (llist_add(&freeinit
->node
, &init_free_list
))
3810 schedule_work(&init_free_wq
);
3812 mutex_unlock(&module_mutex
);
3813 wake_up_all(&module_wq
);
3820 /* Try to protect us from buggy refcounters. */
3821 mod
->state
= MODULE_STATE_GOING
;
3824 blocking_notifier_call_chain(&module_notify_list
,
3825 MODULE_STATE_GOING
, mod
);
3826 klp_module_going(mod
);
3827 ftrace_release_mod(mod
);
3829 wake_up_all(&module_wq
);
3833 static int may_init_module(void)
3835 if (!capable(CAP_SYS_MODULE
) || modules_disabled
)
3842 * We try to place it in the list now to make sure it's unique before
3843 * we dedicate too many resources. In particular, temporary percpu
3844 * memory exhaustion.
3846 static int add_unformed_module(struct module
*mod
)
3851 mod
->state
= MODULE_STATE_UNFORMED
;
3854 mutex_lock(&module_mutex
);
3855 old
= find_module_all(mod
->name
, strlen(mod
->name
), true);
3857 if (old
->state
!= MODULE_STATE_LIVE
) {
3858 /* Wait in case it fails to load. */
3859 mutex_unlock(&module_mutex
);
3860 err
= wait_event_interruptible(module_wq
,
3861 finished_loading(mod
->name
));
3869 mod_update_bounds(mod
);
3870 list_add_rcu(&mod
->list
, &modules
);
3871 mod_tree_insert(mod
);
3875 mutex_unlock(&module_mutex
);
3880 static int complete_formation(struct module
*mod
, struct load_info
*info
)
3884 mutex_lock(&module_mutex
);
3886 /* Find duplicate symbols (must be called under lock). */
3887 err
= verify_exported_symbols(mod
);
3891 /* This relies on module_mutex for list integrity. */
3892 module_bug_finalize(info
->hdr
, info
->sechdrs
, mod
);
3894 module_enable_ro(mod
, false);
3895 module_enable_nx(mod
);
3896 module_enable_x(mod
);
3899 * Mark state as coming so strong_try_module_get() ignores us,
3900 * but kallsyms etc. can see us.
3902 mod
->state
= MODULE_STATE_COMING
;
3903 mutex_unlock(&module_mutex
);
3908 mutex_unlock(&module_mutex
);
3912 static int prepare_coming_module(struct module
*mod
)
3916 ftrace_module_enable(mod
);
3917 err
= klp_module_coming(mod
);
3921 err
= blocking_notifier_call_chain_robust(&module_notify_list
,
3922 MODULE_STATE_COMING
, MODULE_STATE_GOING
, mod
);
3923 err
= notifier_to_errno(err
);
3925 klp_module_going(mod
);
3930 static int unknown_module_param_cb(char *param
, char *val
, const char *modname
,
3933 struct module
*mod
= arg
;
3936 if (strcmp(param
, "async_probe") == 0) {
3937 mod
->async_probe_requested
= true;
3941 /* Check for magic 'dyndbg' arg */
3942 ret
= ddebug_dyndbg_module_param_cb(param
, val
, modname
);
3944 pr_warn("%s: unknown parameter '%s' ignored\n", modname
, param
);
3948 static void cfi_init(struct module
*mod
);
3951 * Allocate and load the module: note that size of section 0 is always
3952 * zero, and we rely on this for optional sections.
3954 static int load_module(struct load_info
*info
, const char __user
*uargs
,
3962 * Do the signature check (if any) first. All that
3963 * the signature check needs is info->len, it does
3964 * not need any of the section info. That can be
3965 * set up later. This will minimize the chances
3966 * of a corrupt module causing problems before
3967 * we even get to the signature check.
3969 * The check will also adjust info->len by stripping
3970 * off the sig length at the end of the module, making
3971 * checks against info->len more correct.
3973 err
= module_sig_check(info
, flags
);
3978 * Do basic sanity checks against the ELF header and
3981 err
= elf_validity_check(info
);
3986 * Everything checks out, so set up the section info
3987 * in the info structure.
3989 err
= setup_load_info(info
, flags
);
3994 * Now that we know we have the correct module name, check
3995 * if it's blacklisted.
3997 if (blacklisted(info
->name
)) {
3999 pr_err("Module %s is blacklisted\n", info
->name
);
4003 err
= rewrite_section_headers(info
, flags
);
4007 /* Check module struct version now, before we try to use module. */
4008 if (!check_modstruct_version(info
, info
->mod
)) {
4013 /* Figure out module layout, and allocate all the memory. */
4014 mod
= layout_and_allocate(info
, flags
);
4020 audit_log_kern_module(mod
->name
);
4022 /* Reserve our place in the list. */
4023 err
= add_unformed_module(mod
);
4027 #ifdef CONFIG_MODULE_SIG
4028 mod
->sig_ok
= info
->sig_ok
;
4030 pr_notice_once("%s: module verification failed: signature "
4031 "and/or required key missing - tainting "
4032 "kernel\n", mod
->name
);
4033 add_taint_module(mod
, TAINT_UNSIGNED_MODULE
, LOCKDEP_STILL_OK
);
4037 /* To avoid stressing percpu allocator, do this once we're unique. */
4038 err
= percpu_modalloc(mod
, info
);
4042 /* Now module is in final location, initialize linked lists, etc. */
4043 err
= module_unload_init(mod
);
4047 init_param_lock(mod
);
4050 * Now we've got everything in the final locations, we can
4051 * find optional sections.
4053 err
= find_module_sections(mod
, info
);
4057 err
= check_module_license_and_versions(mod
);
4061 /* Set up MODINFO_ATTR fields */
4062 setup_modinfo(mod
, info
);
4064 /* Fix up syms, so that st_value is a pointer to location. */
4065 err
= simplify_symbols(mod
, info
);
4069 err
= apply_relocations(mod
, info
);
4073 err
= post_relocation(mod
, info
);
4077 flush_module_icache(mod
);
4079 /* Setup CFI for the module. */
4082 /* Now copy in args */
4083 mod
->args
= strndup_user(uargs
, ~0UL >> 1);
4084 if (IS_ERR(mod
->args
)) {
4085 err
= PTR_ERR(mod
->args
);
4086 goto free_arch_cleanup
;
4089 init_build_id(mod
, info
);
4090 dynamic_debug_setup(mod
, info
->debug
, info
->num_debug
);
4092 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
4093 ftrace_module_init(mod
);
4095 /* Finally it's fully formed, ready to start executing. */
4096 err
= complete_formation(mod
, info
);
4098 goto ddebug_cleanup
;
4100 err
= prepare_coming_module(mod
);
4104 /* Module is ready to execute: parsing args may do that. */
4105 after_dashes
= parse_args(mod
->name
, mod
->args
, mod
->kp
, mod
->num_kp
,
4107 unknown_module_param_cb
);
4108 if (IS_ERR(after_dashes
)) {
4109 err
= PTR_ERR(after_dashes
);
4110 goto coming_cleanup
;
4111 } else if (after_dashes
) {
4112 pr_warn("%s: parameters '%s' after `--' ignored\n",
4113 mod
->name
, after_dashes
);
4116 /* Link in to sysfs. */
4117 err
= mod_sysfs_setup(mod
, info
, mod
->kp
, mod
->num_kp
);
4119 goto coming_cleanup
;
4121 if (is_livepatch_module(mod
)) {
4122 err
= copy_module_elf(mod
, info
);
4127 /* Get rid of temporary copy. */
4131 trace_module_load(mod
);
4133 return do_init_module(mod
);
4136 mod_sysfs_teardown(mod
);
4138 mod
->state
= MODULE_STATE_GOING
;
4139 destroy_params(mod
->kp
, mod
->num_kp
);
4140 blocking_notifier_call_chain(&module_notify_list
,
4141 MODULE_STATE_GOING
, mod
);
4142 klp_module_going(mod
);
4144 mod
->state
= MODULE_STATE_GOING
;
4145 /* module_bug_cleanup needs module_mutex protection */
4146 mutex_lock(&module_mutex
);
4147 module_bug_cleanup(mod
);
4148 mutex_unlock(&module_mutex
);
4151 ftrace_release_mod(mod
);
4152 dynamic_debug_remove(mod
, info
->debug
);
4157 module_arch_cleanup(mod
);
4161 module_unload_free(mod
);
4163 mutex_lock(&module_mutex
);
4164 /* Unlink carefully: kallsyms could be walking list. */
4165 list_del_rcu(&mod
->list
);
4166 mod_tree_remove(mod
);
4167 wake_up_all(&module_wq
);
4168 /* Wait for RCU-sched synchronizing before releasing mod->list. */
4170 mutex_unlock(&module_mutex
);
4172 /* Free lock-classes; relies on the preceding sync_rcu() */
4173 lockdep_free_key_range(mod
->core_layout
.base
, mod
->core_layout
.size
);
4175 module_deallocate(mod
, info
);
4181 SYSCALL_DEFINE3(init_module
, void __user
*, umod
,
4182 unsigned long, len
, const char __user
*, uargs
)
4185 struct load_info info
= { };
4187 err
= may_init_module();
4191 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
4194 err
= copy_module_from_user(umod
, len
, &info
);
4198 return load_module(&info
, uargs
, 0);
4201 SYSCALL_DEFINE3(finit_module
, int, fd
, const char __user
*, uargs
, int, flags
)
4203 struct load_info info
= { };
4207 err
= may_init_module();
4211 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd
, uargs
, flags
);
4213 if (flags
& ~(MODULE_INIT_IGNORE_MODVERSIONS
4214 |MODULE_INIT_IGNORE_VERMAGIC
))
4217 err
= kernel_read_file_from_fd(fd
, 0, &hdr
, INT_MAX
, NULL
,
4224 return load_module(&info
, uargs
, flags
);
4227 static inline int within(unsigned long addr
, void *start
, unsigned long size
)
4229 return ((void *)addr
>= start
&& (void *)addr
< start
+ size
);
4232 #ifdef CONFIG_KALLSYMS
4234 * This ignores the intensely annoying "mapping symbols" found
4235 * in ARM ELF files: $a, $t and $d.
4237 static inline int is_arm_mapping_symbol(const char *str
)
4239 if (str
[0] == '.' && str
[1] == 'L')
4241 return str
[0] == '$' && strchr("axtd", str
[1])
4242 && (str
[2] == '\0' || str
[2] == '.');
4245 static const char *kallsyms_symbol_name(struct mod_kallsyms
*kallsyms
, unsigned int symnum
)
4247 return kallsyms
->strtab
+ kallsyms
->symtab
[symnum
].st_name
;
4251 * Given a module and address, find the corresponding symbol and return its name
4252 * while providing its size and offset if needed.
4254 static const char *find_kallsyms_symbol(struct module
*mod
,
4256 unsigned long *size
,
4257 unsigned long *offset
)
4259 unsigned int i
, best
= 0;
4260 unsigned long nextval
, bestval
;
4261 struct mod_kallsyms
*kallsyms
= rcu_dereference_sched(mod
->kallsyms
);
4263 /* At worse, next value is at end of module */
4264 if (within_module_init(addr
, mod
))
4265 nextval
= (unsigned long)mod
->init_layout
.base
+mod
->init_layout
.text_size
;
4267 nextval
= (unsigned long)mod
->core_layout
.base
+mod
->core_layout
.text_size
;
4269 bestval
= kallsyms_symbol_value(&kallsyms
->symtab
[best
]);
4272 * Scan for closest preceding symbol, and next symbol. (ELF
4273 * starts real symbols at 1).
4275 for (i
= 1; i
< kallsyms
->num_symtab
; i
++) {
4276 const Elf_Sym
*sym
= &kallsyms
->symtab
[i
];
4277 unsigned long thisval
= kallsyms_symbol_value(sym
);
4279 if (sym
->st_shndx
== SHN_UNDEF
)
4283 * We ignore unnamed symbols: they're uninformative
4284 * and inserted at a whim.
4286 if (*kallsyms_symbol_name(kallsyms
, i
) == '\0'
4287 || is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms
, i
)))
4290 if (thisval
<= addr
&& thisval
> bestval
) {
4294 if (thisval
> addr
&& thisval
< nextval
)
4302 *size
= nextval
- bestval
;
4304 *offset
= addr
- bestval
;
4306 return kallsyms_symbol_name(kallsyms
, best
);
4309 void * __weak
dereference_module_function_descriptor(struct module
*mod
,
4316 * For kallsyms to ask for address resolution. NULL means not found. Careful
4317 * not to lock to avoid deadlock on oopses, simply disable preemption.
4319 const char *module_address_lookup(unsigned long addr
,
4320 unsigned long *size
,
4321 unsigned long *offset
,
4323 const unsigned char **modbuildid
,
4326 const char *ret
= NULL
;
4330 mod
= __module_address(addr
);
4333 *modname
= mod
->name
;
4335 #if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
4336 *modbuildid
= mod
->build_id
;
4342 ret
= find_kallsyms_symbol(mod
, addr
, size
, offset
);
4344 /* Make a copy in here where it's safe */
4346 strncpy(namebuf
, ret
, KSYM_NAME_LEN
- 1);
4354 int lookup_module_symbol_name(unsigned long addr
, char *symname
)
4359 list_for_each_entry_rcu(mod
, &modules
, list
) {
4360 if (mod
->state
== MODULE_STATE_UNFORMED
)
4362 if (within_module(addr
, mod
)) {
4365 sym
= find_kallsyms_symbol(mod
, addr
, NULL
, NULL
);
4369 strlcpy(symname
, sym
, KSYM_NAME_LEN
);
4379 int lookup_module_symbol_attrs(unsigned long addr
, unsigned long *size
,
4380 unsigned long *offset
, char *modname
, char *name
)
4385 list_for_each_entry_rcu(mod
, &modules
, list
) {
4386 if (mod
->state
== MODULE_STATE_UNFORMED
)
4388 if (within_module(addr
, mod
)) {
4391 sym
= find_kallsyms_symbol(mod
, addr
, size
, offset
);
4395 strlcpy(modname
, mod
->name
, MODULE_NAME_LEN
);
4397 strlcpy(name
, sym
, KSYM_NAME_LEN
);
4407 int module_get_kallsym(unsigned int symnum
, unsigned long *value
, char *type
,
4408 char *name
, char *module_name
, int *exported
)
4413 list_for_each_entry_rcu(mod
, &modules
, list
) {
4414 struct mod_kallsyms
*kallsyms
;
4416 if (mod
->state
== MODULE_STATE_UNFORMED
)
4418 kallsyms
= rcu_dereference_sched(mod
->kallsyms
);
4419 if (symnum
< kallsyms
->num_symtab
) {
4420 const Elf_Sym
*sym
= &kallsyms
->symtab
[symnum
];
4422 *value
= kallsyms_symbol_value(sym
);
4423 *type
= kallsyms
->typetab
[symnum
];
4424 strlcpy(name
, kallsyms_symbol_name(kallsyms
, symnum
), KSYM_NAME_LEN
);
4425 strlcpy(module_name
, mod
->name
, MODULE_NAME_LEN
);
4426 *exported
= is_exported(name
, *value
, mod
);
4430 symnum
-= kallsyms
->num_symtab
;
4436 /* Given a module and name of symbol, find and return the symbol's value */
4437 static unsigned long find_kallsyms_symbol_value(struct module
*mod
, const char *name
)
4440 struct mod_kallsyms
*kallsyms
= rcu_dereference_sched(mod
->kallsyms
);
4442 for (i
= 0; i
< kallsyms
->num_symtab
; i
++) {
4443 const Elf_Sym
*sym
= &kallsyms
->symtab
[i
];
4445 if (strcmp(name
, kallsyms_symbol_name(kallsyms
, i
)) == 0 &&
4446 sym
->st_shndx
!= SHN_UNDEF
)
4447 return kallsyms_symbol_value(sym
);
4452 /* Look for this name: can be of form module:name. */
4453 unsigned long module_kallsyms_lookup_name(const char *name
)
4457 unsigned long ret
= 0;
4459 /* Don't lock: we're in enough trouble already. */
4461 if ((colon
= strnchr(name
, MODULE_NAME_LEN
, ':')) != NULL
) {
4462 if ((mod
= find_module_all(name
, colon
- name
, false)) != NULL
)
4463 ret
= find_kallsyms_symbol_value(mod
, colon
+1);
4465 list_for_each_entry_rcu(mod
, &modules
, list
) {
4466 if (mod
->state
== MODULE_STATE_UNFORMED
)
4468 if ((ret
= find_kallsyms_symbol_value(mod
, name
)) != 0)
4476 #ifdef CONFIG_LIVEPATCH
4477 int module_kallsyms_on_each_symbol(int (*fn
)(void *, const char *,
4478 struct module
*, unsigned long),
4485 mutex_lock(&module_mutex
);
4486 list_for_each_entry(mod
, &modules
, list
) {
4487 /* We hold module_mutex: no need for rcu_dereference_sched */
4488 struct mod_kallsyms
*kallsyms
= mod
->kallsyms
;
4490 if (mod
->state
== MODULE_STATE_UNFORMED
)
4492 for (i
= 0; i
< kallsyms
->num_symtab
; i
++) {
4493 const Elf_Sym
*sym
= &kallsyms
->symtab
[i
];
4495 if (sym
->st_shndx
== SHN_UNDEF
)
4498 ret
= fn(data
, kallsyms_symbol_name(kallsyms
, i
),
4499 mod
, kallsyms_symbol_value(sym
));
4505 mutex_unlock(&module_mutex
);
4508 #endif /* CONFIG_LIVEPATCH */
4509 #endif /* CONFIG_KALLSYMS */
4511 static void cfi_init(struct module
*mod
)
4513 #ifdef CONFIG_CFI_CLANG
4517 rcu_read_lock_sched();
4518 mod
->cfi_check
= (cfi_check_fn
)
4519 find_kallsyms_symbol_value(mod
, "__cfi_check");
4520 init
= (initcall_t
*)
4521 find_kallsyms_symbol_value(mod
, "__cfi_jt_init_module");
4522 exit
= (exitcall_t
*)
4523 find_kallsyms_symbol_value(mod
, "__cfi_jt_cleanup_module");
4524 rcu_read_unlock_sched();
4526 /* Fix init/exit functions to point to the CFI jump table */
4529 #ifdef CONFIG_MODULE_UNLOAD
4534 cfi_module_add(mod
, module_addr_min
);
4538 static void cfi_cleanup(struct module
*mod
)
4540 #ifdef CONFIG_CFI_CLANG
4541 cfi_module_remove(mod
, module_addr_min
);
4545 /* Maximum number of characters written by module_flags() */
4546 #define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
4548 /* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
4549 static char *module_flags(struct module
*mod
, char *buf
)
4553 BUG_ON(mod
->state
== MODULE_STATE_UNFORMED
);
4555 mod
->state
== MODULE_STATE_GOING
||
4556 mod
->state
== MODULE_STATE_COMING
) {
4558 bx
+= module_flags_taint(mod
, buf
+ bx
);
4559 /* Show a - for module-is-being-unloaded */
4560 if (mod
->state
== MODULE_STATE_GOING
)
4562 /* Show a + for module-is-being-loaded */
4563 if (mod
->state
== MODULE_STATE_COMING
)
4572 #ifdef CONFIG_PROC_FS
4573 /* Called by the /proc file system to return a list of modules. */
4574 static void *m_start(struct seq_file
*m
, loff_t
*pos
)
4576 mutex_lock(&module_mutex
);
4577 return seq_list_start(&modules
, *pos
);
4580 static void *m_next(struct seq_file
*m
, void *p
, loff_t
*pos
)
4582 return seq_list_next(p
, &modules
, pos
);
4585 static void m_stop(struct seq_file
*m
, void *p
)
4587 mutex_unlock(&module_mutex
);
4590 static int m_show(struct seq_file
*m
, void *p
)
4592 struct module
*mod
= list_entry(p
, struct module
, list
);
4593 char buf
[MODULE_FLAGS_BUF_SIZE
];
4596 /* We always ignore unformed modules. */
4597 if (mod
->state
== MODULE_STATE_UNFORMED
)
4600 seq_printf(m
, "%s %u",
4601 mod
->name
, mod
->init_layout
.size
+ mod
->core_layout
.size
);
4602 print_unload_info(m
, mod
);
4604 /* Informative for users. */
4605 seq_printf(m
, " %s",
4606 mod
->state
== MODULE_STATE_GOING
? "Unloading" :
4607 mod
->state
== MODULE_STATE_COMING
? "Loading" :
4609 /* Used by oprofile and other similar tools. */
4610 value
= m
->private ? NULL
: mod
->core_layout
.base
;
4611 seq_printf(m
, " 0x%px", value
);
4615 seq_printf(m
, " %s", module_flags(mod
, buf
));
4622 * Format: modulename size refcount deps address
4624 * Where refcount is a number or -, and deps is a comma-separated list
4627 static const struct seq_operations modules_op
= {
4635 * This also sets the "private" pointer to non-NULL if the
4636 * kernel pointers should be hidden (so you can just test
4637 * "m->private" to see if you should keep the values private).
4639 * We use the same logic as for /proc/kallsyms.
4641 static int modules_open(struct inode
*inode
, struct file
*file
)
4643 int err
= seq_open(file
, &modules_op
);
4646 struct seq_file
*m
= file
->private_data
;
4647 m
->private = kallsyms_show_value(file
->f_cred
) ? NULL
: (void *)8ul;
4653 static const struct proc_ops modules_proc_ops
= {
4654 .proc_flags
= PROC_ENTRY_PERMANENT
,
4655 .proc_open
= modules_open
,
4656 .proc_read
= seq_read
,
4657 .proc_lseek
= seq_lseek
,
4658 .proc_release
= seq_release
,
4661 static int __init
proc_modules_init(void)
4663 proc_create("modules", 0, NULL
, &modules_proc_ops
);
4666 module_init(proc_modules_init
);
4669 /* Given an address, look for it in the module exception tables. */
4670 const struct exception_table_entry
*search_module_extables(unsigned long addr
)
4672 const struct exception_table_entry
*e
= NULL
;
4676 mod
= __module_address(addr
);
4680 if (!mod
->num_exentries
)
4683 e
= search_extable(mod
->extable
,
4690 * Now, if we found one, we are running inside it now, hence
4691 * we cannot unload the module, hence no refcnt needed.
4697 * is_module_address() - is this address inside a module?
4698 * @addr: the address to check.
4700 * See is_module_text_address() if you simply want to see if the address
4701 * is code (not data).
4703 bool is_module_address(unsigned long addr
)
4708 ret
= __module_address(addr
) != NULL
;
4715 * __module_address() - get the module which contains an address.
4716 * @addr: the address.
4718 * Must be called with preempt disabled or module mutex held so that
4719 * module doesn't get freed during this.
4721 struct module
*__module_address(unsigned long addr
)
4725 if (addr
< module_addr_min
|| addr
> module_addr_max
)
4728 module_assert_mutex_or_preempt();
4730 mod
= mod_find(addr
);
4732 BUG_ON(!within_module(addr
, mod
));
4733 if (mod
->state
== MODULE_STATE_UNFORMED
)
4740 * is_module_text_address() - is this address inside module code?
4741 * @addr: the address to check.
4743 * See is_module_address() if you simply want to see if the address is
4744 * anywhere in a module. See kernel_text_address() for testing if an
4745 * address corresponds to kernel or module code.
4747 bool is_module_text_address(unsigned long addr
)
4752 ret
= __module_text_address(addr
) != NULL
;
4759 * __module_text_address() - get the module whose code contains an address.
4760 * @addr: the address.
4762 * Must be called with preempt disabled or module mutex held so that
4763 * module doesn't get freed during this.
4765 struct module
*__module_text_address(unsigned long addr
)
4767 struct module
*mod
= __module_address(addr
);
4769 /* Make sure it's within the text section. */
4770 if (!within(addr
, mod
->init_layout
.base
, mod
->init_layout
.text_size
)
4771 && !within(addr
, mod
->core_layout
.base
, mod
->core_layout
.text_size
))
4777 /* Don't grab lock, we're oopsing. */
4778 void print_modules(void)
4781 char buf
[MODULE_FLAGS_BUF_SIZE
];
4783 printk(KERN_DEFAULT
"Modules linked in:");
4784 /* Most callers should already have preempt disabled, but make sure */
4786 list_for_each_entry_rcu(mod
, &modules
, list
) {
4787 if (mod
->state
== MODULE_STATE_UNFORMED
)
4789 pr_cont(" %s%s", mod
->name
, module_flags(mod
, buf
));
4792 if (last_unloaded_module
[0])
4793 pr_cont(" [last unloaded: %s]", last_unloaded_module
);
4797 #ifdef CONFIG_MODVERSIONS
4799 * Generate the signature for all relevant module structures here.
4800 * If these change, we don't want to try to parse the module.
4802 void module_layout(struct module
*mod
,
4803 struct modversion_info
*ver
,
4804 struct kernel_param
*kp
,
4805 struct kernel_symbol
*ks
,
4806 struct tracepoint
* const *tp
)
4809 EXPORT_SYMBOL(module_layout
);