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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2002 Richard Henderson
4 * Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
5 */
6
7#define INCLUDE_VERMAGIC
8
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/fs.h>
18#include <linux/kernel.h>
19#include <linux/kernel_read_file.h>
20#include <linux/slab.h>
21#include <linux/vmalloc.h>
22#include <linux/elf.h>
23#include <linux/seq_file.h>
24#include <linux/syscalls.h>
25#include <linux/fcntl.h>
26#include <linux/rcupdate.h>
27#include <linux/capability.h>
28#include <linux/cpu.h>
29#include <linux/moduleparam.h>
30#include <linux/errno.h>
31#include <linux/err.h>
32#include <linux/vermagic.h>
33#include <linux/notifier.h>
34#include <linux/sched.h>
35#include <linux/device.h>
36#include <linux/string.h>
37#include <linux/mutex.h>
38#include <linux/rculist.h>
39#include <linux/uaccess.h>
40#include <asm/cacheflush.h>
41#include <linux/set_memory.h>
42#include <asm/mmu_context.h>
43#include <linux/license.h>
44#include <asm/sections.h>
45#include <linux/tracepoint.h>
46#include <linux/ftrace.h>
47#include <linux/livepatch.h>
48#include <linux/async.h>
49#include <linux/percpu.h>
50#include <linux/kmemleak.h>
51#include <linux/jump_label.h>
52#include <linux/pfn.h>
53#include <linux/bsearch.h>
54#include <linux/dynamic_debug.h>
55#include <linux/audit.h>
56#include <linux/cfi.h>
57#include <uapi/linux/module.h>
58#include "internal.h"
59
60#define CREATE_TRACE_POINTS
61#include <trace/events/module.h>
62
63/*
64 * Mutex protects:
65 * 1) List of modules (also safely readable with preempt_disable),
66 * 2) module_use links,
67 * 3) mod_tree.addr_min/mod_tree.addr_max.
68 * (delete and add uses RCU list operations).
69 */
70DEFINE_MUTEX(module_mutex);
71LIST_HEAD(modules);
72
73/* Work queue for freeing init sections in success case */
74static void do_free_init(struct work_struct *w);
75static DECLARE_WORK(init_free_wq, do_free_init);
76static LLIST_HEAD(init_free_list);
77
78struct mod_tree_root mod_tree __cacheline_aligned = {
79 .addr_min = -1UL,
80};
81
82#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
83struct mod_tree_root mod_data_tree __cacheline_aligned = {
84 .addr_min = -1UL,
85};
86#endif
87
88struct symsearch {
89 const struct kernel_symbol *start, *stop;
90 const s32 *crcs;
91 enum mod_license license;
92};
93
94/*
95 * Bounds of module text, for speeding up __module_address.
96 * Protected by module_mutex.
97 */
98static void __mod_update_bounds(void *base, unsigned int size, struct mod_tree_root *tree)
99{
100 unsigned long min = (unsigned long)base;
101 unsigned long max = min + size;
102
103 if (min < tree->addr_min)
104 tree->addr_min = min;
105 if (max > tree->addr_max)
106 tree->addr_max = max;
107}
108
109static void mod_update_bounds(struct module *mod)
110{
111 __mod_update_bounds(mod->core_layout.base, mod->core_layout.size, &mod_tree);
112 if (mod->init_layout.size)
113 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size, &mod_tree);
114#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
115 __mod_update_bounds(mod->data_layout.base, mod->data_layout.size, &mod_data_tree);
116#endif
117}
118
119/* Block module loading/unloading? */
120int modules_disabled;
121core_param(nomodule, modules_disabled, bint, 0);
122
123/* Waiting for a module to finish initializing? */
124static DECLARE_WAIT_QUEUE_HEAD(module_wq);
125
126static BLOCKING_NOTIFIER_HEAD(module_notify_list);
127
128int register_module_notifier(struct notifier_block *nb)
129{
130 return blocking_notifier_chain_register(&module_notify_list, nb);
131}
132EXPORT_SYMBOL(register_module_notifier);
133
134int unregister_module_notifier(struct notifier_block *nb)
135{
136 return blocking_notifier_chain_unregister(&module_notify_list, nb);
137}
138EXPORT_SYMBOL(unregister_module_notifier);
139
140/*
141 * We require a truly strong try_module_get(): 0 means success.
142 * Otherwise an error is returned due to ongoing or failed
143 * initialization etc.
144 */
145static inline int strong_try_module_get(struct module *mod)
146{
147 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
148 if (mod && mod->state == MODULE_STATE_COMING)
149 return -EBUSY;
150 if (try_module_get(mod))
151 return 0;
152 else
153 return -ENOENT;
154}
155
156static inline void add_taint_module(struct module *mod, unsigned flag,
157 enum lockdep_ok lockdep_ok)
158{
159 add_taint(flag, lockdep_ok);
160 set_bit(flag, &mod->taints);
161}
162
163/*
164 * A thread that wants to hold a reference to a module only while it
165 * is running can call this to safely exit.
166 */
167void __noreturn __module_put_and_kthread_exit(struct module *mod, long code)
168{
169 module_put(mod);
170 kthread_exit(code);
171}
172EXPORT_SYMBOL(__module_put_and_kthread_exit);
173
174/* Find a module section: 0 means not found. */
175static unsigned int find_sec(const struct load_info *info, const char *name)
176{
177 unsigned int i;
178
179 for (i = 1; i < info->hdr->e_shnum; i++) {
180 Elf_Shdr *shdr = &info->sechdrs[i];
181 /* Alloc bit cleared means "ignore it." */
182 if ((shdr->sh_flags & SHF_ALLOC)
183 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
184 return i;
185 }
186 return 0;
187}
188
189/* Find a module section, or NULL. */
190static void *section_addr(const struct load_info *info, const char *name)
191{
192 /* Section 0 has sh_addr 0. */
193 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
194}
195
196/* Find a module section, or NULL. Fill in number of "objects" in section. */
197static void *section_objs(const struct load_info *info,
198 const char *name,
199 size_t object_size,
200 unsigned int *num)
201{
202 unsigned int sec = find_sec(info, name);
203
204 /* Section 0 has sh_addr 0 and sh_size 0. */
205 *num = info->sechdrs[sec].sh_size / object_size;
206 return (void *)info->sechdrs[sec].sh_addr;
207}
208
209/* Find a module section: 0 means not found. Ignores SHF_ALLOC flag. */
210static unsigned int find_any_sec(const struct load_info *info, const char *name)
211{
212 unsigned int i;
213
214 for (i = 1; i < info->hdr->e_shnum; i++) {
215 Elf_Shdr *shdr = &info->sechdrs[i];
216 if (strcmp(info->secstrings + shdr->sh_name, name) == 0)
217 return i;
218 }
219 return 0;
220}
221
222/*
223 * Find a module section, or NULL. Fill in number of "objects" in section.
224 * Ignores SHF_ALLOC flag.
225 */
226static __maybe_unused void *any_section_objs(const struct load_info *info,
227 const char *name,
228 size_t object_size,
229 unsigned int *num)
230{
231 unsigned int sec = find_any_sec(info, name);
232
233 /* Section 0 has sh_addr 0 and sh_size 0. */
234 *num = info->sechdrs[sec].sh_size / object_size;
235 return (void *)info->sechdrs[sec].sh_addr;
236}
237
238#ifndef CONFIG_MODVERSIONS
239#define symversion(base, idx) NULL
240#else
241#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
242#endif
243
244static const char *kernel_symbol_name(const struct kernel_symbol *sym)
245{
246#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
247 return offset_to_ptr(&sym->name_offset);
248#else
249 return sym->name;
250#endif
251}
252
253static const char *kernel_symbol_namespace(const struct kernel_symbol *sym)
254{
255#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
256 if (!sym->namespace_offset)
257 return NULL;
258 return offset_to_ptr(&sym->namespace_offset);
259#else
260 return sym->namespace;
261#endif
262}
263
264int cmp_name(const void *name, const void *sym)
265{
266 return strcmp(name, kernel_symbol_name(sym));
267}
268
269static bool find_exported_symbol_in_section(const struct symsearch *syms,
270 struct module *owner,
271 struct find_symbol_arg *fsa)
272{
273 struct kernel_symbol *sym;
274
275 if (!fsa->gplok && syms->license == GPL_ONLY)
276 return false;
277
278 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
279 sizeof(struct kernel_symbol), cmp_name);
280 if (!sym)
281 return false;
282
283 fsa->owner = owner;
284 fsa->crc = symversion(syms->crcs, sym - syms->start);
285 fsa->sym = sym;
286 fsa->license = syms->license;
287
288 return true;
289}
290
291/*
292 * Find an exported symbol and return it, along with, (optional) crc and
293 * (optional) module which owns it. Needs preempt disabled or module_mutex.
294 */
295bool find_symbol(struct find_symbol_arg *fsa)
296{
297 static const struct symsearch arr[] = {
298 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
299 NOT_GPL_ONLY },
300 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
301 __start___kcrctab_gpl,
302 GPL_ONLY },
303 };
304 struct module *mod;
305 unsigned int i;
306
307 module_assert_mutex_or_preempt();
308
309 for (i = 0; i < ARRAY_SIZE(arr); i++)
310 if (find_exported_symbol_in_section(&arr[i], NULL, fsa))
311 return true;
312
313 list_for_each_entry_rcu(mod, &modules, list,
314 lockdep_is_held(&module_mutex)) {
315 struct symsearch arr[] = {
316 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
317 NOT_GPL_ONLY },
318 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
319 mod->gpl_crcs,
320 GPL_ONLY },
321 };
322
323 if (mod->state == MODULE_STATE_UNFORMED)
324 continue;
325
326 for (i = 0; i < ARRAY_SIZE(arr); i++)
327 if (find_exported_symbol_in_section(&arr[i], mod, fsa))
328 return true;
329 }
330
331 pr_debug("Failed to find symbol %s\n", fsa->name);
332 return false;
333}
334
335/*
336 * Search for module by name: must hold module_mutex (or preempt disabled
337 * for read-only access).
338 */
339struct module *find_module_all(const char *name, size_t len,
340 bool even_unformed)
341{
342 struct module *mod;
343
344 module_assert_mutex_or_preempt();
345
346 list_for_each_entry_rcu(mod, &modules, list,
347 lockdep_is_held(&module_mutex)) {
348 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
349 continue;
350 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
351 return mod;
352 }
353 return NULL;
354}
355
356struct module *find_module(const char *name)
357{
358 return find_module_all(name, strlen(name), false);
359}
360
361#ifdef CONFIG_SMP
362
363static inline void __percpu *mod_percpu(struct module *mod)
364{
365 return mod->percpu;
366}
367
368static int percpu_modalloc(struct module *mod, struct load_info *info)
369{
370 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
371 unsigned long align = pcpusec->sh_addralign;
372
373 if (!pcpusec->sh_size)
374 return 0;
375
376 if (align > PAGE_SIZE) {
377 pr_warn("%s: per-cpu alignment %li > %li\n",
378 mod->name, align, PAGE_SIZE);
379 align = PAGE_SIZE;
380 }
381
382 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
383 if (!mod->percpu) {
384 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
385 mod->name, (unsigned long)pcpusec->sh_size);
386 return -ENOMEM;
387 }
388 mod->percpu_size = pcpusec->sh_size;
389 return 0;
390}
391
392static void percpu_modfree(struct module *mod)
393{
394 free_percpu(mod->percpu);
395}
396
397static unsigned int find_pcpusec(struct load_info *info)
398{
399 return find_sec(info, ".data..percpu");
400}
401
402static void percpu_modcopy(struct module *mod,
403 const void *from, unsigned long size)
404{
405 int cpu;
406
407 for_each_possible_cpu(cpu)
408 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
409}
410
411bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
412{
413 struct module *mod;
414 unsigned int cpu;
415
416 preempt_disable();
417
418 list_for_each_entry_rcu(mod, &modules, list) {
419 if (mod->state == MODULE_STATE_UNFORMED)
420 continue;
421 if (!mod->percpu_size)
422 continue;
423 for_each_possible_cpu(cpu) {
424 void *start = per_cpu_ptr(mod->percpu, cpu);
425 void *va = (void *)addr;
426
427 if (va >= start && va < start + mod->percpu_size) {
428 if (can_addr) {
429 *can_addr = (unsigned long) (va - start);
430 *can_addr += (unsigned long)
431 per_cpu_ptr(mod->percpu,
432 get_boot_cpu_id());
433 }
434 preempt_enable();
435 return true;
436 }
437 }
438 }
439
440 preempt_enable();
441 return false;
442}
443
444/**
445 * is_module_percpu_address() - test whether address is from module static percpu
446 * @addr: address to test
447 *
448 * Test whether @addr belongs to module static percpu area.
449 *
450 * Return: %true if @addr is from module static percpu area
451 */
452bool is_module_percpu_address(unsigned long addr)
453{
454 return __is_module_percpu_address(addr, NULL);
455}
456
457#else /* ... !CONFIG_SMP */
458
459static inline void __percpu *mod_percpu(struct module *mod)
460{
461 return NULL;
462}
463static int percpu_modalloc(struct module *mod, struct load_info *info)
464{
465 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
466 if (info->sechdrs[info->index.pcpu].sh_size != 0)
467 return -ENOMEM;
468 return 0;
469}
470static inline void percpu_modfree(struct module *mod)
471{
472}
473static unsigned int find_pcpusec(struct load_info *info)
474{
475 return 0;
476}
477static inline void percpu_modcopy(struct module *mod,
478 const void *from, unsigned long size)
479{
480 /* pcpusec should be 0, and size of that section should be 0. */
481 BUG_ON(size != 0);
482}
483bool is_module_percpu_address(unsigned long addr)
484{
485 return false;
486}
487
488bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
489{
490 return false;
491}
492
493#endif /* CONFIG_SMP */
494
495#define MODINFO_ATTR(field) \
496static void setup_modinfo_##field(struct module *mod, const char *s) \
497{ \
498 mod->field = kstrdup(s, GFP_KERNEL); \
499} \
500static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
501 struct module_kobject *mk, char *buffer) \
502{ \
503 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
504} \
505static int modinfo_##field##_exists(struct module *mod) \
506{ \
507 return mod->field != NULL; \
508} \
509static void free_modinfo_##field(struct module *mod) \
510{ \
511 kfree(mod->field); \
512 mod->field = NULL; \
513} \
514static struct module_attribute modinfo_##field = { \
515 .attr = { .name = __stringify(field), .mode = 0444 }, \
516 .show = show_modinfo_##field, \
517 .setup = setup_modinfo_##field, \
518 .test = modinfo_##field##_exists, \
519 .free = free_modinfo_##field, \
520};
521
522MODINFO_ATTR(version);
523MODINFO_ATTR(srcversion);
524
525static struct {
526 char name[MODULE_NAME_LEN + 1];
527 char taints[MODULE_FLAGS_BUF_SIZE];
528} last_unloaded_module;
529
530#ifdef CONFIG_MODULE_UNLOAD
531
532EXPORT_TRACEPOINT_SYMBOL(module_get);
533
534/* MODULE_REF_BASE is the base reference count by kmodule loader. */
535#define MODULE_REF_BASE 1
536
537/* Init the unload section of the module. */
538static int module_unload_init(struct module *mod)
539{
540 /*
541 * Initialize reference counter to MODULE_REF_BASE.
542 * refcnt == 0 means module is going.
543 */
544 atomic_set(&mod->refcnt, MODULE_REF_BASE);
545
546 INIT_LIST_HEAD(&mod->source_list);
547 INIT_LIST_HEAD(&mod->target_list);
548
549 /* Hold reference count during initialization. */
550 atomic_inc(&mod->refcnt);
551
552 return 0;
553}
554
555/* Does a already use b? */
556static int already_uses(struct module *a, struct module *b)
557{
558 struct module_use *use;
559
560 list_for_each_entry(use, &b->source_list, source_list) {
561 if (use->source == a) {
562 pr_debug("%s uses %s!\n", a->name, b->name);
563 return 1;
564 }
565 }
566 pr_debug("%s does not use %s!\n", a->name, b->name);
567 return 0;
568}
569
570/*
571 * Module a uses b
572 * - we add 'a' as a "source", 'b' as a "target" of module use
573 * - the module_use is added to the list of 'b' sources (so
574 * 'b' can walk the list to see who sourced them), and of 'a'
575 * targets (so 'a' can see what modules it targets).
576 */
577static int add_module_usage(struct module *a, struct module *b)
578{
579 struct module_use *use;
580
581 pr_debug("Allocating new usage for %s.\n", a->name);
582 use = kmalloc(sizeof(*use), GFP_ATOMIC);
583 if (!use)
584 return -ENOMEM;
585
586 use->source = a;
587 use->target = b;
588 list_add(&use->source_list, &b->source_list);
589 list_add(&use->target_list, &a->target_list);
590 return 0;
591}
592
593/* Module a uses b: caller needs module_mutex() */
594static int ref_module(struct module *a, struct module *b)
595{
596 int err;
597
598 if (b == NULL || already_uses(a, b))
599 return 0;
600
601 /* If module isn't available, we fail. */
602 err = strong_try_module_get(b);
603 if (err)
604 return err;
605
606 err = add_module_usage(a, b);
607 if (err) {
608 module_put(b);
609 return err;
610 }
611 return 0;
612}
613
614/* Clear the unload stuff of the module. */
615static void module_unload_free(struct module *mod)
616{
617 struct module_use *use, *tmp;
618
619 mutex_lock(&module_mutex);
620 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
621 struct module *i = use->target;
622 pr_debug("%s unusing %s\n", mod->name, i->name);
623 module_put(i);
624 list_del(&use->source_list);
625 list_del(&use->target_list);
626 kfree(use);
627 }
628 mutex_unlock(&module_mutex);
629}
630
631#ifdef CONFIG_MODULE_FORCE_UNLOAD
632static inline int try_force_unload(unsigned int flags)
633{
634 int ret = (flags & O_TRUNC);
635 if (ret)
636 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
637 return ret;
638}
639#else
640static inline int try_force_unload(unsigned int flags)
641{
642 return 0;
643}
644#endif /* CONFIG_MODULE_FORCE_UNLOAD */
645
646/* Try to release refcount of module, 0 means success. */
647static int try_release_module_ref(struct module *mod)
648{
649 int ret;
650
651 /* Try to decrement refcnt which we set at loading */
652 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
653 BUG_ON(ret < 0);
654 if (ret)
655 /* Someone can put this right now, recover with checking */
656 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
657
658 return ret;
659}
660
661static int try_stop_module(struct module *mod, int flags, int *forced)
662{
663 /* If it's not unused, quit unless we're forcing. */
664 if (try_release_module_ref(mod) != 0) {
665 *forced = try_force_unload(flags);
666 if (!(*forced))
667 return -EWOULDBLOCK;
668 }
669
670 /* Mark it as dying. */
671 mod->state = MODULE_STATE_GOING;
672
673 return 0;
674}
675
676/**
677 * module_refcount() - return the refcount or -1 if unloading
678 * @mod: the module we're checking
679 *
680 * Return:
681 * -1 if the module is in the process of unloading
682 * otherwise the number of references in the kernel to the module
683 */
684int module_refcount(struct module *mod)
685{
686 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
687}
688EXPORT_SYMBOL(module_refcount);
689
690/* This exists whether we can unload or not */
691static void free_module(struct module *mod);
692
693SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
694 unsigned int, flags)
695{
696 struct module *mod;
697 char name[MODULE_NAME_LEN];
698 char buf[MODULE_FLAGS_BUF_SIZE];
699 int ret, forced = 0;
700
701 if (!capable(CAP_SYS_MODULE) || modules_disabled)
702 return -EPERM;
703
704 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
705 return -EFAULT;
706 name[MODULE_NAME_LEN-1] = '\0';
707
708 audit_log_kern_module(name);
709
710 if (mutex_lock_interruptible(&module_mutex) != 0)
711 return -EINTR;
712
713 mod = find_module(name);
714 if (!mod) {
715 ret = -ENOENT;
716 goto out;
717 }
718
719 if (!list_empty(&mod->source_list)) {
720 /* Other modules depend on us: get rid of them first. */
721 ret = -EWOULDBLOCK;
722 goto out;
723 }
724
725 /* Doing init or already dying? */
726 if (mod->state != MODULE_STATE_LIVE) {
727 /* FIXME: if (force), slam module count damn the torpedoes */
728 pr_debug("%s already dying\n", mod->name);
729 ret = -EBUSY;
730 goto out;
731 }
732
733 /* If it has an init func, it must have an exit func to unload */
734 if (mod->init && !mod->exit) {
735 forced = try_force_unload(flags);
736 if (!forced) {
737 /* This module can't be removed */
738 ret = -EBUSY;
739 goto out;
740 }
741 }
742
743 ret = try_stop_module(mod, flags, &forced);
744 if (ret != 0)
745 goto out;
746
747 mutex_unlock(&module_mutex);
748 /* Final destruction now no one is using it. */
749 if (mod->exit != NULL)
750 mod->exit();
751 blocking_notifier_call_chain(&module_notify_list,
752 MODULE_STATE_GOING, mod);
753 klp_module_going(mod);
754 ftrace_release_mod(mod);
755
756 async_synchronize_full();
757
758 /* Store the name and taints of the last unloaded module for diagnostic purposes */
759 strscpy(last_unloaded_module.name, mod->name, sizeof(last_unloaded_module.name));
760 strscpy(last_unloaded_module.taints, module_flags(mod, buf, false), sizeof(last_unloaded_module.taints));
761
762 free_module(mod);
763 /* someone could wait for the module in add_unformed_module() */
764 wake_up_all(&module_wq);
765 return 0;
766out:
767 mutex_unlock(&module_mutex);
768 return ret;
769}
770
771void __symbol_put(const char *symbol)
772{
773 struct find_symbol_arg fsa = {
774 .name = symbol,
775 .gplok = true,
776 };
777
778 preempt_disable();
779 BUG_ON(!find_symbol(&fsa));
780 module_put(fsa.owner);
781 preempt_enable();
782}
783EXPORT_SYMBOL(__symbol_put);
784
785/* Note this assumes addr is a function, which it currently always is. */
786void symbol_put_addr(void *addr)
787{
788 struct module *modaddr;
789 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
790
791 if (core_kernel_text(a))
792 return;
793
794 /*
795 * Even though we hold a reference on the module; we still need to
796 * disable preemption in order to safely traverse the data structure.
797 */
798 preempt_disable();
799 modaddr = __module_text_address(a);
800 BUG_ON(!modaddr);
801 module_put(modaddr);
802 preempt_enable();
803}
804EXPORT_SYMBOL_GPL(symbol_put_addr);
805
806static ssize_t show_refcnt(struct module_attribute *mattr,
807 struct module_kobject *mk, char *buffer)
808{
809 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
810}
811
812static struct module_attribute modinfo_refcnt =
813 __ATTR(refcnt, 0444, show_refcnt, NULL);
814
815void __module_get(struct module *module)
816{
817 if (module) {
818 preempt_disable();
819 atomic_inc(&module->refcnt);
820 trace_module_get(module, _RET_IP_);
821 preempt_enable();
822 }
823}
824EXPORT_SYMBOL(__module_get);
825
826bool try_module_get(struct module *module)
827{
828 bool ret = true;
829
830 if (module) {
831 preempt_disable();
832 /* Note: here, we can fail to get a reference */
833 if (likely(module_is_live(module) &&
834 atomic_inc_not_zero(&module->refcnt) != 0))
835 trace_module_get(module, _RET_IP_);
836 else
837 ret = false;
838
839 preempt_enable();
840 }
841 return ret;
842}
843EXPORT_SYMBOL(try_module_get);
844
845void module_put(struct module *module)
846{
847 int ret;
848
849 if (module) {
850 preempt_disable();
851 ret = atomic_dec_if_positive(&module->refcnt);
852 WARN_ON(ret < 0); /* Failed to put refcount */
853 trace_module_put(module, _RET_IP_);
854 preempt_enable();
855 }
856}
857EXPORT_SYMBOL(module_put);
858
859#else /* !CONFIG_MODULE_UNLOAD */
860static inline void module_unload_free(struct module *mod)
861{
862}
863
864static int ref_module(struct module *a, struct module *b)
865{
866 return strong_try_module_get(b);
867}
868
869static inline int module_unload_init(struct module *mod)
870{
871 return 0;
872}
873#endif /* CONFIG_MODULE_UNLOAD */
874
875size_t module_flags_taint(unsigned long taints, char *buf)
876{
877 size_t l = 0;
878 int i;
879
880 for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
881 if (taint_flags[i].module && test_bit(i, &taints))
882 buf[l++] = taint_flags[i].c_true;
883 }
884
885 return l;
886}
887
888static ssize_t show_initstate(struct module_attribute *mattr,
889 struct module_kobject *mk, char *buffer)
890{
891 const char *state = "unknown";
892
893 switch (mk->mod->state) {
894 case MODULE_STATE_LIVE:
895 state = "live";
896 break;
897 case MODULE_STATE_COMING:
898 state = "coming";
899 break;
900 case MODULE_STATE_GOING:
901 state = "going";
902 break;
903 default:
904 BUG();
905 }
906 return sprintf(buffer, "%s\n", state);
907}
908
909static struct module_attribute modinfo_initstate =
910 __ATTR(initstate, 0444, show_initstate, NULL);
911
912static ssize_t store_uevent(struct module_attribute *mattr,
913 struct module_kobject *mk,
914 const char *buffer, size_t count)
915{
916 int rc;
917
918 rc = kobject_synth_uevent(&mk->kobj, buffer, count);
919 return rc ? rc : count;
920}
921
922struct module_attribute module_uevent =
923 __ATTR(uevent, 0200, NULL, store_uevent);
924
925static ssize_t show_coresize(struct module_attribute *mattr,
926 struct module_kobject *mk, char *buffer)
927{
928 return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
929}
930
931static struct module_attribute modinfo_coresize =
932 __ATTR(coresize, 0444, show_coresize, NULL);
933
934#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
935static ssize_t show_datasize(struct module_attribute *mattr,
936 struct module_kobject *mk, char *buffer)
937{
938 return sprintf(buffer, "%u\n", mk->mod->data_layout.size);
939}
940
941static struct module_attribute modinfo_datasize =
942 __ATTR(datasize, 0444, show_datasize, NULL);
943#endif
944
945static ssize_t show_initsize(struct module_attribute *mattr,
946 struct module_kobject *mk, char *buffer)
947{
948 return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
949}
950
951static struct module_attribute modinfo_initsize =
952 __ATTR(initsize, 0444, show_initsize, NULL);
953
954static ssize_t show_taint(struct module_attribute *mattr,
955 struct module_kobject *mk, char *buffer)
956{
957 size_t l;
958
959 l = module_flags_taint(mk->mod->taints, buffer);
960 buffer[l++] = '\n';
961 return l;
962}
963
964static struct module_attribute modinfo_taint =
965 __ATTR(taint, 0444, show_taint, NULL);
966
967struct module_attribute *modinfo_attrs[] = {
968 &module_uevent,
969 &modinfo_version,
970 &modinfo_srcversion,
971 &modinfo_initstate,
972 &modinfo_coresize,
973#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
974 &modinfo_datasize,
975#endif
976 &modinfo_initsize,
977 &modinfo_taint,
978#ifdef CONFIG_MODULE_UNLOAD
979 &modinfo_refcnt,
980#endif
981 NULL,
982};
983
984size_t modinfo_attrs_count = ARRAY_SIZE(modinfo_attrs);
985
986static const char vermagic[] = VERMAGIC_STRING;
987
988int try_to_force_load(struct module *mod, const char *reason)
989{
990#ifdef CONFIG_MODULE_FORCE_LOAD
991 if (!test_taint(TAINT_FORCED_MODULE))
992 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
993 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
994 return 0;
995#else
996 return -ENOEXEC;
997#endif
998}
999
1000static char *get_modinfo(const struct load_info *info, const char *tag);
1001static char *get_next_modinfo(const struct load_info *info, const char *tag,
1002 char *prev);
1003
1004static int verify_namespace_is_imported(const struct load_info *info,
1005 const struct kernel_symbol *sym,
1006 struct module *mod)
1007{
1008 const char *namespace;
1009 char *imported_namespace;
1010
1011 namespace = kernel_symbol_namespace(sym);
1012 if (namespace && namespace[0]) {
1013 imported_namespace = get_modinfo(info, "import_ns");
1014 while (imported_namespace) {
1015 if (strcmp(namespace, imported_namespace) == 0)
1016 return 0;
1017 imported_namespace = get_next_modinfo(
1018 info, "import_ns", imported_namespace);
1019 }
1020#ifdef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1021 pr_warn(
1022#else
1023 pr_err(
1024#endif
1025 "%s: module uses symbol (%s) from namespace %s, but does not import it.\n",
1026 mod->name, kernel_symbol_name(sym), namespace);
1027#ifndef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1028 return -EINVAL;
1029#endif
1030 }
1031 return 0;
1032}
1033
1034static bool inherit_taint(struct module *mod, struct module *owner, const char *name)
1035{
1036 if (!owner || !test_bit(TAINT_PROPRIETARY_MODULE, &owner->taints))
1037 return true;
1038
1039 if (mod->using_gplonly_symbols) {
1040 pr_err("%s: module using GPL-only symbols uses symbols %s from proprietary module %s.\n",
1041 mod->name, name, owner->name);
1042 return false;
1043 }
1044
1045 if (!test_bit(TAINT_PROPRIETARY_MODULE, &mod->taints)) {
1046 pr_warn("%s: module uses symbols %s from proprietary module %s, inheriting taint.\n",
1047 mod->name, name, owner->name);
1048 set_bit(TAINT_PROPRIETARY_MODULE, &mod->taints);
1049 }
1050 return true;
1051}
1052
1053/* Resolve a symbol for this module. I.e. if we find one, record usage. */
1054static const struct kernel_symbol *resolve_symbol(struct module *mod,
1055 const struct load_info *info,
1056 const char *name,
1057 char ownername[])
1058{
1059 struct find_symbol_arg fsa = {
1060 .name = name,
1061 .gplok = !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)),
1062 .warn = true,
1063 };
1064 int err;
1065
1066 /*
1067 * The module_mutex should not be a heavily contended lock;
1068 * if we get the occasional sleep here, we'll go an extra iteration
1069 * in the wait_event_interruptible(), which is harmless.
1070 */
1071 sched_annotate_sleep();
1072 mutex_lock(&module_mutex);
1073 if (!find_symbol(&fsa))
1074 goto unlock;
1075
1076 if (fsa.license == GPL_ONLY)
1077 mod->using_gplonly_symbols = true;
1078
1079 if (!inherit_taint(mod, fsa.owner, name)) {
1080 fsa.sym = NULL;
1081 goto getname;
1082 }
1083
1084 if (!check_version(info, name, mod, fsa.crc)) {
1085 fsa.sym = ERR_PTR(-EINVAL);
1086 goto getname;
1087 }
1088
1089 err = verify_namespace_is_imported(info, fsa.sym, mod);
1090 if (err) {
1091 fsa.sym = ERR_PTR(err);
1092 goto getname;
1093 }
1094
1095 err = ref_module(mod, fsa.owner);
1096 if (err) {
1097 fsa.sym = ERR_PTR(err);
1098 goto getname;
1099 }
1100
1101getname:
1102 /* We must make copy under the lock if we failed to get ref. */
1103 strncpy(ownername, module_name(fsa.owner), MODULE_NAME_LEN);
1104unlock:
1105 mutex_unlock(&module_mutex);
1106 return fsa.sym;
1107}
1108
1109static const struct kernel_symbol *
1110resolve_symbol_wait(struct module *mod,
1111 const struct load_info *info,
1112 const char *name)
1113{
1114 const struct kernel_symbol *ksym;
1115 char owner[MODULE_NAME_LEN];
1116
1117 if (wait_event_interruptible_timeout(module_wq,
1118 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1119 || PTR_ERR(ksym) != -EBUSY,
1120 30 * HZ) <= 0) {
1121 pr_warn("%s: gave up waiting for init of module %s.\n",
1122 mod->name, owner);
1123 }
1124 return ksym;
1125}
1126
1127void __weak module_memfree(void *module_region)
1128{
1129 /*
1130 * This memory may be RO, and freeing RO memory in an interrupt is not
1131 * supported by vmalloc.
1132 */
1133 WARN_ON(in_interrupt());
1134 vfree(module_region);
1135}
1136
1137void __weak module_arch_cleanup(struct module *mod)
1138{
1139}
1140
1141void __weak module_arch_freeing_init(struct module *mod)
1142{
1143}
1144
1145/* Free a module, remove from lists, etc. */
1146static void free_module(struct module *mod)
1147{
1148 trace_module_free(mod);
1149
1150 mod_sysfs_teardown(mod);
1151
1152 /*
1153 * We leave it in list to prevent duplicate loads, but make sure
1154 * that noone uses it while it's being deconstructed.
1155 */
1156 mutex_lock(&module_mutex);
1157 mod->state = MODULE_STATE_UNFORMED;
1158 mutex_unlock(&module_mutex);
1159
1160 /* Remove dynamic debug info */
1161 ddebug_remove_module(mod->name);
1162
1163 /* Arch-specific cleanup. */
1164 module_arch_cleanup(mod);
1165
1166 /* Module unload stuff */
1167 module_unload_free(mod);
1168
1169 /* Free any allocated parameters. */
1170 destroy_params(mod->kp, mod->num_kp);
1171
1172 if (is_livepatch_module(mod))
1173 free_module_elf(mod);
1174
1175 /* Now we can delete it from the lists */
1176 mutex_lock(&module_mutex);
1177 /* Unlink carefully: kallsyms could be walking list. */
1178 list_del_rcu(&mod->list);
1179 mod_tree_remove(mod);
1180 /* Remove this module from bug list, this uses list_del_rcu */
1181 module_bug_cleanup(mod);
1182 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
1183 synchronize_rcu();
1184 if (try_add_tainted_module(mod))
1185 pr_err("%s: adding tainted module to the unloaded tainted modules list failed.\n",
1186 mod->name);
1187 mutex_unlock(&module_mutex);
1188
1189 /* This may be empty, but that's OK */
1190 module_arch_freeing_init(mod);
1191 module_memfree(mod->init_layout.base);
1192 kfree(mod->args);
1193 percpu_modfree(mod);
1194
1195 /* Free lock-classes; relies on the preceding sync_rcu(). */
1196 lockdep_free_key_range(mod->data_layout.base, mod->data_layout.size);
1197
1198 /* Finally, free the core (containing the module structure) */
1199 module_memfree(mod->core_layout.base);
1200#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
1201 vfree(mod->data_layout.base);
1202#endif
1203}
1204
1205void *__symbol_get(const char *symbol)
1206{
1207 struct find_symbol_arg fsa = {
1208 .name = symbol,
1209 .gplok = true,
1210 .warn = true,
1211 };
1212
1213 preempt_disable();
1214 if (!find_symbol(&fsa) || strong_try_module_get(fsa.owner)) {
1215 preempt_enable();
1216 return NULL;
1217 }
1218 preempt_enable();
1219 return (void *)kernel_symbol_value(fsa.sym);
1220}
1221EXPORT_SYMBOL_GPL(__symbol_get);
1222
1223/*
1224 * Ensure that an exported symbol [global namespace] does not already exist
1225 * in the kernel or in some other module's exported symbol table.
1226 *
1227 * You must hold the module_mutex.
1228 */
1229static int verify_exported_symbols(struct module *mod)
1230{
1231 unsigned int i;
1232 const struct kernel_symbol *s;
1233 struct {
1234 const struct kernel_symbol *sym;
1235 unsigned int num;
1236 } arr[] = {
1237 { mod->syms, mod->num_syms },
1238 { mod->gpl_syms, mod->num_gpl_syms },
1239 };
1240
1241 for (i = 0; i < ARRAY_SIZE(arr); i++) {
1242 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1243 struct find_symbol_arg fsa = {
1244 .name = kernel_symbol_name(s),
1245 .gplok = true,
1246 };
1247 if (find_symbol(&fsa)) {
1248 pr_err("%s: exports duplicate symbol %s"
1249 " (owned by %s)\n",
1250 mod->name, kernel_symbol_name(s),
1251 module_name(fsa.owner));
1252 return -ENOEXEC;
1253 }
1254 }
1255 }
1256 return 0;
1257}
1258
1259static bool ignore_undef_symbol(Elf_Half emachine, const char *name)
1260{
1261 /*
1262 * On x86, PIC code and Clang non-PIC code may have call foo@PLT. GNU as
1263 * before 2.37 produces an unreferenced _GLOBAL_OFFSET_TABLE_ on x86-64.
1264 * i386 has a similar problem but may not deserve a fix.
1265 *
1266 * If we ever have to ignore many symbols, consider refactoring the code to
1267 * only warn if referenced by a relocation.
1268 */
1269 if (emachine == EM_386 || emachine == EM_X86_64)
1270 return !strcmp(name, "_GLOBAL_OFFSET_TABLE_");
1271 return false;
1272}
1273
1274/* Change all symbols so that st_value encodes the pointer directly. */
1275static int simplify_symbols(struct module *mod, const struct load_info *info)
1276{
1277 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
1278 Elf_Sym *sym = (void *)symsec->sh_addr;
1279 unsigned long secbase;
1280 unsigned int i;
1281 int ret = 0;
1282 const struct kernel_symbol *ksym;
1283
1284 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
1285 const char *name = info->strtab + sym[i].st_name;
1286
1287 switch (sym[i].st_shndx) {
1288 case SHN_COMMON:
1289 /* Ignore common symbols */
1290 if (!strncmp(name, "__gnu_lto", 9))
1291 break;
1292
1293 /*
1294 * We compiled with -fno-common. These are not
1295 * supposed to happen.
1296 */
1297 pr_debug("Common symbol: %s\n", name);
1298 pr_warn("%s: please compile with -fno-common\n",
1299 mod->name);
1300 ret = -ENOEXEC;
1301 break;
1302
1303 case SHN_ABS:
1304 /* Don't need to do anything */
1305 pr_debug("Absolute symbol: 0x%08lx\n",
1306 (long)sym[i].st_value);
1307 break;
1308
1309 case SHN_LIVEPATCH:
1310 /* Livepatch symbols are resolved by livepatch */
1311 break;
1312
1313 case SHN_UNDEF:
1314 ksym = resolve_symbol_wait(mod, info, name);
1315 /* Ok if resolved. */
1316 if (ksym && !IS_ERR(ksym)) {
1317 sym[i].st_value = kernel_symbol_value(ksym);
1318 break;
1319 }
1320
1321 /* Ok if weak or ignored. */
1322 if (!ksym &&
1323 (ELF_ST_BIND(sym[i].st_info) == STB_WEAK ||
1324 ignore_undef_symbol(info->hdr->e_machine, name)))
1325 break;
1326
1327 ret = PTR_ERR(ksym) ?: -ENOENT;
1328 pr_warn("%s: Unknown symbol %s (err %d)\n",
1329 mod->name, name, ret);
1330 break;
1331
1332 default:
1333 /* Divert to percpu allocation if a percpu var. */
1334 if (sym[i].st_shndx == info->index.pcpu)
1335 secbase = (unsigned long)mod_percpu(mod);
1336 else
1337 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
1338 sym[i].st_value += secbase;
1339 break;
1340 }
1341 }
1342
1343 return ret;
1344}
1345
1346static int apply_relocations(struct module *mod, const struct load_info *info)
1347{
1348 unsigned int i;
1349 int err = 0;
1350
1351 /* Now do relocations. */
1352 for (i = 1; i < info->hdr->e_shnum; i++) {
1353 unsigned int infosec = info->sechdrs[i].sh_info;
1354
1355 /* Not a valid relocation section? */
1356 if (infosec >= info->hdr->e_shnum)
1357 continue;
1358
1359 /* Don't bother with non-allocated sections */
1360 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
1361 continue;
1362
1363 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
1364 err = klp_apply_section_relocs(mod, info->sechdrs,
1365 info->secstrings,
1366 info->strtab,
1367 info->index.sym, i,
1368 NULL);
1369 else if (info->sechdrs[i].sh_type == SHT_REL)
1370 err = apply_relocate(info->sechdrs, info->strtab,
1371 info->index.sym, i, mod);
1372 else if (info->sechdrs[i].sh_type == SHT_RELA)
1373 err = apply_relocate_add(info->sechdrs, info->strtab,
1374 info->index.sym, i, mod);
1375 if (err < 0)
1376 break;
1377 }
1378 return err;
1379}
1380
1381/* Additional bytes needed by arch in front of individual sections */
1382unsigned int __weak arch_mod_section_prepend(struct module *mod,
1383 unsigned int section)
1384{
1385 /* default implementation just returns zero */
1386 return 0;
1387}
1388
1389/* Update size with this section: return offset. */
1390long module_get_offset(struct module *mod, unsigned int *size,
1391 Elf_Shdr *sechdr, unsigned int section)
1392{
1393 long ret;
1394
1395 *size += arch_mod_section_prepend(mod, section);
1396 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
1397 *size = ret + sechdr->sh_size;
1398 return ret;
1399}
1400
1401static bool module_init_layout_section(const char *sname)
1402{
1403#ifndef CONFIG_MODULE_UNLOAD
1404 if (module_exit_section(sname))
1405 return true;
1406#endif
1407 return module_init_section(sname);
1408}
1409
1410/*
1411 * Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
1412 * might -- code, read-only data, read-write data, small data. Tally
1413 * sizes, and place the offsets into sh_entsize fields: high bit means it
1414 * belongs in init.
1415 */
1416static void layout_sections(struct module *mod, struct load_info *info)
1417{
1418 static unsigned long const masks[][2] = {
1419 /*
1420 * NOTE: all executable code must be the first section
1421 * in this array; otherwise modify the text_size
1422 * finder in the two loops below
1423 */
1424 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
1425 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
1426 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
1427 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
1428 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
1429 };
1430 unsigned int m, i;
1431
1432 for (i = 0; i < info->hdr->e_shnum; i++)
1433 info->sechdrs[i].sh_entsize = ~0UL;
1434
1435 pr_debug("Core section allocation order:\n");
1436 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1437 for (i = 0; i < info->hdr->e_shnum; ++i) {
1438 Elf_Shdr *s = &info->sechdrs[i];
1439 const char *sname = info->secstrings + s->sh_name;
1440 unsigned int *sizep;
1441
1442 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1443 || (s->sh_flags & masks[m][1])
1444 || s->sh_entsize != ~0UL
1445 || module_init_layout_section(sname))
1446 continue;
1447 sizep = m ? &mod->data_layout.size : &mod->core_layout.size;
1448 s->sh_entsize = module_get_offset(mod, sizep, s, i);
1449 pr_debug("\t%s\n", sname);
1450 }
1451 switch (m) {
1452 case 0: /* executable */
1453 mod->core_layout.size = strict_align(mod->core_layout.size);
1454 mod->core_layout.text_size = mod->core_layout.size;
1455 break;
1456 case 1: /* RO: text and ro-data */
1457 mod->data_layout.size = strict_align(mod->data_layout.size);
1458 mod->data_layout.ro_size = mod->data_layout.size;
1459 break;
1460 case 2: /* RO after init */
1461 mod->data_layout.size = strict_align(mod->data_layout.size);
1462 mod->data_layout.ro_after_init_size = mod->data_layout.size;
1463 break;
1464 case 4: /* whole core */
1465 mod->data_layout.size = strict_align(mod->data_layout.size);
1466 break;
1467 }
1468 }
1469
1470 pr_debug("Init section allocation order:\n");
1471 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1472 for (i = 0; i < info->hdr->e_shnum; ++i) {
1473 Elf_Shdr *s = &info->sechdrs[i];
1474 const char *sname = info->secstrings + s->sh_name;
1475
1476 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1477 || (s->sh_flags & masks[m][1])
1478 || s->sh_entsize != ~0UL
1479 || !module_init_layout_section(sname))
1480 continue;
1481 s->sh_entsize = (module_get_offset(mod, &mod->init_layout.size, s, i)
1482 | INIT_OFFSET_MASK);
1483 pr_debug("\t%s\n", sname);
1484 }
1485 switch (m) {
1486 case 0: /* executable */
1487 mod->init_layout.size = strict_align(mod->init_layout.size);
1488 mod->init_layout.text_size = mod->init_layout.size;
1489 break;
1490 case 1: /* RO: text and ro-data */
1491 mod->init_layout.size = strict_align(mod->init_layout.size);
1492 mod->init_layout.ro_size = mod->init_layout.size;
1493 break;
1494 case 2:
1495 /*
1496 * RO after init doesn't apply to init_layout (only
1497 * core_layout), so it just takes the value of ro_size.
1498 */
1499 mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
1500 break;
1501 case 4: /* whole init */
1502 mod->init_layout.size = strict_align(mod->init_layout.size);
1503 break;
1504 }
1505 }
1506}
1507
1508static void set_license(struct module *mod, const char *license)
1509{
1510 if (!license)
1511 license = "unspecified";
1512
1513 if (!license_is_gpl_compatible(license)) {
1514 if (!test_taint(TAINT_PROPRIETARY_MODULE))
1515 pr_warn("%s: module license '%s' taints kernel.\n",
1516 mod->name, license);
1517 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
1518 LOCKDEP_NOW_UNRELIABLE);
1519 }
1520}
1521
1522/* Parse tag=value strings from .modinfo section */
1523static char *next_string(char *string, unsigned long *secsize)
1524{
1525 /* Skip non-zero chars */
1526 while (string[0]) {
1527 string++;
1528 if ((*secsize)-- <= 1)
1529 return NULL;
1530 }
1531
1532 /* Skip any zero padding. */
1533 while (!string[0]) {
1534 string++;
1535 if ((*secsize)-- <= 1)
1536 return NULL;
1537 }
1538 return string;
1539}
1540
1541static char *get_next_modinfo(const struct load_info *info, const char *tag,
1542 char *prev)
1543{
1544 char *p;
1545 unsigned int taglen = strlen(tag);
1546 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
1547 unsigned long size = infosec->sh_size;
1548
1549 /*
1550 * get_modinfo() calls made before rewrite_section_headers()
1551 * must use sh_offset, as sh_addr isn't set!
1552 */
1553 char *modinfo = (char *)info->hdr + infosec->sh_offset;
1554
1555 if (prev) {
1556 size -= prev - modinfo;
1557 modinfo = next_string(prev, &size);
1558 }
1559
1560 for (p = modinfo; p; p = next_string(p, &size)) {
1561 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
1562 return p + taglen + 1;
1563 }
1564 return NULL;
1565}
1566
1567static char *get_modinfo(const struct load_info *info, const char *tag)
1568{
1569 return get_next_modinfo(info, tag, NULL);
1570}
1571
1572static void setup_modinfo(struct module *mod, struct load_info *info)
1573{
1574 struct module_attribute *attr;
1575 int i;
1576
1577 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1578 if (attr->setup)
1579 attr->setup(mod, get_modinfo(info, attr->attr.name));
1580 }
1581}
1582
1583static void free_modinfo(struct module *mod)
1584{
1585 struct module_attribute *attr;
1586 int i;
1587
1588 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1589 if (attr->free)
1590 attr->free(mod);
1591 }
1592}
1593
1594static void dynamic_debug_setup(struct module *mod, struct _ddebug_info *dyndbg)
1595{
1596 if (!dyndbg->num_descs)
1597 return;
1598 ddebug_add_module(dyndbg, mod->name);
1599}
1600
1601static void dynamic_debug_remove(struct module *mod, struct _ddebug_info *dyndbg)
1602{
1603 if (dyndbg->num_descs)
1604 ddebug_remove_module(mod->name);
1605}
1606
1607void * __weak module_alloc(unsigned long size)
1608{
1609 return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
1610 GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS,
1611 NUMA_NO_NODE, __builtin_return_address(0));
1612}
1613
1614bool __weak module_init_section(const char *name)
1615{
1616 return strstarts(name, ".init");
1617}
1618
1619bool __weak module_exit_section(const char *name)
1620{
1621 return strstarts(name, ".exit");
1622}
1623
1624static int validate_section_offset(struct load_info *info, Elf_Shdr *shdr)
1625{
1626#if defined(CONFIG_64BIT)
1627 unsigned long long secend;
1628#else
1629 unsigned long secend;
1630#endif
1631
1632 /*
1633 * Check for both overflow and offset/size being
1634 * too large.
1635 */
1636 secend = shdr->sh_offset + shdr->sh_size;
1637 if (secend < shdr->sh_offset || secend > info->len)
1638 return -ENOEXEC;
1639
1640 return 0;
1641}
1642
1643/*
1644 * Sanity checks against invalid binaries, wrong arch, weird elf version.
1645 *
1646 * Also do basic validity checks against section offsets and sizes, the
1647 * section name string table, and the indices used for it (sh_name).
1648 */
1649static int elf_validity_check(struct load_info *info)
1650{
1651 unsigned int i;
1652 Elf_Shdr *shdr, *strhdr;
1653 int err;
1654
1655 if (info->len < sizeof(*(info->hdr))) {
1656 pr_err("Invalid ELF header len %lu\n", info->len);
1657 goto no_exec;
1658 }
1659
1660 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0) {
1661 pr_err("Invalid ELF header magic: != %s\n", ELFMAG);
1662 goto no_exec;
1663 }
1664 if (info->hdr->e_type != ET_REL) {
1665 pr_err("Invalid ELF header type: %u != %u\n",
1666 info->hdr->e_type, ET_REL);
1667 goto no_exec;
1668 }
1669 if (!elf_check_arch(info->hdr)) {
1670 pr_err("Invalid architecture in ELF header: %u\n",
1671 info->hdr->e_machine);
1672 goto no_exec;
1673 }
1674 if (!module_elf_check_arch(info->hdr)) {
1675 pr_err("Invalid module architecture in ELF header: %u\n",
1676 info->hdr->e_machine);
1677 goto no_exec;
1678 }
1679 if (info->hdr->e_shentsize != sizeof(Elf_Shdr)) {
1680 pr_err("Invalid ELF section header size\n");
1681 goto no_exec;
1682 }
1683
1684 /*
1685 * e_shnum is 16 bits, and sizeof(Elf_Shdr) is
1686 * known and small. So e_shnum * sizeof(Elf_Shdr)
1687 * will not overflow unsigned long on any platform.
1688 */
1689 if (info->hdr->e_shoff >= info->len
1690 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
1691 info->len - info->hdr->e_shoff)) {
1692 pr_err("Invalid ELF section header overflow\n");
1693 goto no_exec;
1694 }
1695
1696 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
1697
1698 /*
1699 * Verify if the section name table index is valid.
1700 */
1701 if (info->hdr->e_shstrndx == SHN_UNDEF
1702 || info->hdr->e_shstrndx >= info->hdr->e_shnum) {
1703 pr_err("Invalid ELF section name index: %d || e_shstrndx (%d) >= e_shnum (%d)\n",
1704 info->hdr->e_shstrndx, info->hdr->e_shstrndx,
1705 info->hdr->e_shnum);
1706 goto no_exec;
1707 }
1708
1709 strhdr = &info->sechdrs[info->hdr->e_shstrndx];
1710 err = validate_section_offset(info, strhdr);
1711 if (err < 0) {
1712 pr_err("Invalid ELF section hdr(type %u)\n", strhdr->sh_type);
1713 return err;
1714 }
1715
1716 /*
1717 * The section name table must be NUL-terminated, as required
1718 * by the spec. This makes strcmp and pr_* calls that access
1719 * strings in the section safe.
1720 */
1721 info->secstrings = (void *)info->hdr + strhdr->sh_offset;
1722 if (strhdr->sh_size == 0) {
1723 pr_err("empty section name table\n");
1724 goto no_exec;
1725 }
1726 if (info->secstrings[strhdr->sh_size - 1] != '\0') {
1727 pr_err("ELF Spec violation: section name table isn't null terminated\n");
1728 goto no_exec;
1729 }
1730
1731 /*
1732 * The code assumes that section 0 has a length of zero and
1733 * an addr of zero, so check for it.
1734 */
1735 if (info->sechdrs[0].sh_type != SHT_NULL
1736 || info->sechdrs[0].sh_size != 0
1737 || info->sechdrs[0].sh_addr != 0) {
1738 pr_err("ELF Spec violation: section 0 type(%d)!=SH_NULL or non-zero len or addr\n",
1739 info->sechdrs[0].sh_type);
1740 goto no_exec;
1741 }
1742
1743 for (i = 1; i < info->hdr->e_shnum; i++) {
1744 shdr = &info->sechdrs[i];
1745 switch (shdr->sh_type) {
1746 case SHT_NULL:
1747 case SHT_NOBITS:
1748 continue;
1749 case SHT_SYMTAB:
1750 if (shdr->sh_link == SHN_UNDEF
1751 || shdr->sh_link >= info->hdr->e_shnum) {
1752 pr_err("Invalid ELF sh_link!=SHN_UNDEF(%d) or (sh_link(%d) >= hdr->e_shnum(%d)\n",
1753 shdr->sh_link, shdr->sh_link,
1754 info->hdr->e_shnum);
1755 goto no_exec;
1756 }
1757 fallthrough;
1758 default:
1759 err = validate_section_offset(info, shdr);
1760 if (err < 0) {
1761 pr_err("Invalid ELF section in module (section %u type %u)\n",
1762 i, shdr->sh_type);
1763 return err;
1764 }
1765
1766 if (shdr->sh_flags & SHF_ALLOC) {
1767 if (shdr->sh_name >= strhdr->sh_size) {
1768 pr_err("Invalid ELF section name in module (section %u type %u)\n",
1769 i, shdr->sh_type);
1770 return -ENOEXEC;
1771 }
1772 }
1773 break;
1774 }
1775 }
1776
1777 return 0;
1778
1779no_exec:
1780 return -ENOEXEC;
1781}
1782
1783#define COPY_CHUNK_SIZE (16*PAGE_SIZE)
1784
1785static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
1786{
1787 do {
1788 unsigned long n = min(len, COPY_CHUNK_SIZE);
1789
1790 if (copy_from_user(dst, usrc, n) != 0)
1791 return -EFAULT;
1792 cond_resched();
1793 dst += n;
1794 usrc += n;
1795 len -= n;
1796 } while (len);
1797 return 0;
1798}
1799
1800static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
1801{
1802 if (!get_modinfo(info, "livepatch"))
1803 /* Nothing more to do */
1804 return 0;
1805
1806 if (set_livepatch_module(mod)) {
1807 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
1808 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
1809 mod->name);
1810 return 0;
1811 }
1812
1813 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
1814 mod->name);
1815 return -ENOEXEC;
1816}
1817
1818static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
1819{
1820 if (retpoline_module_ok(get_modinfo(info, "retpoline")))
1821 return;
1822
1823 pr_warn("%s: loading module not compiled with retpoline compiler.\n",
1824 mod->name);
1825}
1826
1827/* Sets info->hdr and info->len. */
1828static int copy_module_from_user(const void __user *umod, unsigned long len,
1829 struct load_info *info)
1830{
1831 int err;
1832
1833 info->len = len;
1834 if (info->len < sizeof(*(info->hdr)))
1835 return -ENOEXEC;
1836
1837 err = security_kernel_load_data(LOADING_MODULE, true);
1838 if (err)
1839 return err;
1840
1841 /* Suck in entire file: we'll want most of it. */
1842 info->hdr = __vmalloc(info->len, GFP_KERNEL | __GFP_NOWARN);
1843 if (!info->hdr)
1844 return -ENOMEM;
1845
1846 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
1847 err = -EFAULT;
1848 goto out;
1849 }
1850
1851 err = security_kernel_post_load_data((char *)info->hdr, info->len,
1852 LOADING_MODULE, "init_module");
1853out:
1854 if (err)
1855 vfree(info->hdr);
1856
1857 return err;
1858}
1859
1860static void free_copy(struct load_info *info, int flags)
1861{
1862 if (flags & MODULE_INIT_COMPRESSED_FILE)
1863 module_decompress_cleanup(info);
1864 else
1865 vfree(info->hdr);
1866}
1867
1868static int rewrite_section_headers(struct load_info *info, int flags)
1869{
1870 unsigned int i;
1871
1872 /* This should always be true, but let's be sure. */
1873 info->sechdrs[0].sh_addr = 0;
1874
1875 for (i = 1; i < info->hdr->e_shnum; i++) {
1876 Elf_Shdr *shdr = &info->sechdrs[i];
1877
1878 /*
1879 * Mark all sections sh_addr with their address in the
1880 * temporary image.
1881 */
1882 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
1883
1884 }
1885
1886 /* Track but don't keep modinfo and version sections. */
1887 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
1888 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
1889
1890 return 0;
1891}
1892
1893/*
1894 * Set up our basic convenience variables (pointers to section headers,
1895 * search for module section index etc), and do some basic section
1896 * verification.
1897 *
1898 * Set info->mod to the temporary copy of the module in info->hdr. The final one
1899 * will be allocated in move_module().
1900 */
1901static int setup_load_info(struct load_info *info, int flags)
1902{
1903 unsigned int i;
1904
1905 /* Try to find a name early so we can log errors with a module name */
1906 info->index.info = find_sec(info, ".modinfo");
1907 if (info->index.info)
1908 info->name = get_modinfo(info, "name");
1909
1910 /* Find internal symbols and strings. */
1911 for (i = 1; i < info->hdr->e_shnum; i++) {
1912 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
1913 info->index.sym = i;
1914 info->index.str = info->sechdrs[i].sh_link;
1915 info->strtab = (char *)info->hdr
1916 + info->sechdrs[info->index.str].sh_offset;
1917 break;
1918 }
1919 }
1920
1921 if (info->index.sym == 0) {
1922 pr_warn("%s: module has no symbols (stripped?)\n",
1923 info->name ?: "(missing .modinfo section or name field)");
1924 return -ENOEXEC;
1925 }
1926
1927 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
1928 if (!info->index.mod) {
1929 pr_warn("%s: No module found in object\n",
1930 info->name ?: "(missing .modinfo section or name field)");
1931 return -ENOEXEC;
1932 }
1933 /* This is temporary: point mod into copy of data. */
1934 info->mod = (void *)info->hdr + info->sechdrs[info->index.mod].sh_offset;
1935
1936 /*
1937 * If we didn't load the .modinfo 'name' field earlier, fall back to
1938 * on-disk struct mod 'name' field.
1939 */
1940 if (!info->name)
1941 info->name = info->mod->name;
1942
1943 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
1944 info->index.vers = 0; /* Pretend no __versions section! */
1945 else
1946 info->index.vers = find_sec(info, "__versions");
1947
1948 info->index.pcpu = find_pcpusec(info);
1949
1950 return 0;
1951}
1952
1953static int check_modinfo(struct module *mod, struct load_info *info, int flags)
1954{
1955 const char *modmagic = get_modinfo(info, "vermagic");
1956 int err;
1957
1958 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
1959 modmagic = NULL;
1960
1961 /* This is allowed: modprobe --force will invalidate it. */
1962 if (!modmagic) {
1963 err = try_to_force_load(mod, "bad vermagic");
1964 if (err)
1965 return err;
1966 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
1967 pr_err("%s: version magic '%s' should be '%s'\n",
1968 info->name, modmagic, vermagic);
1969 return -ENOEXEC;
1970 }
1971
1972 if (!get_modinfo(info, "intree")) {
1973 if (!test_taint(TAINT_OOT_MODULE))
1974 pr_warn("%s: loading out-of-tree module taints kernel.\n",
1975 mod->name);
1976 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
1977 }
1978
1979 check_modinfo_retpoline(mod, info);
1980
1981 if (get_modinfo(info, "staging")) {
1982 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
1983 pr_warn("%s: module is from the staging directory, the quality "
1984 "is unknown, you have been warned.\n", mod->name);
1985 }
1986
1987 err = check_modinfo_livepatch(mod, info);
1988 if (err)
1989 return err;
1990
1991 /* Set up license info based on the info section */
1992 set_license(mod, get_modinfo(info, "license"));
1993
1994 if (get_modinfo(info, "test")) {
1995 if (!test_taint(TAINT_TEST))
1996 pr_warn("%s: loading test module taints kernel.\n",
1997 mod->name);
1998 add_taint_module(mod, TAINT_TEST, LOCKDEP_STILL_OK);
1999 }
2000
2001 return 0;
2002}
2003
2004static int find_module_sections(struct module *mod, struct load_info *info)
2005{
2006 mod->kp = section_objs(info, "__param",
2007 sizeof(*mod->kp), &mod->num_kp);
2008 mod->syms = section_objs(info, "__ksymtab",
2009 sizeof(*mod->syms), &mod->num_syms);
2010 mod->crcs = section_addr(info, "__kcrctab");
2011 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2012 sizeof(*mod->gpl_syms),
2013 &mod->num_gpl_syms);
2014 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2015
2016#ifdef CONFIG_CONSTRUCTORS
2017 mod->ctors = section_objs(info, ".ctors",
2018 sizeof(*mod->ctors), &mod->num_ctors);
2019 if (!mod->ctors)
2020 mod->ctors = section_objs(info, ".init_array",
2021 sizeof(*mod->ctors), &mod->num_ctors);
2022 else if (find_sec(info, ".init_array")) {
2023 /*
2024 * This shouldn't happen with same compiler and binutils
2025 * building all parts of the module.
2026 */
2027 pr_warn("%s: has both .ctors and .init_array.\n",
2028 mod->name);
2029 return -EINVAL;
2030 }
2031#endif
2032
2033 mod->noinstr_text_start = section_objs(info, ".noinstr.text", 1,
2034 &mod->noinstr_text_size);
2035
2036#ifdef CONFIG_TRACEPOINTS
2037 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2038 sizeof(*mod->tracepoints_ptrs),
2039 &mod->num_tracepoints);
2040#endif
2041#ifdef CONFIG_TREE_SRCU
2042 mod->srcu_struct_ptrs = section_objs(info, "___srcu_struct_ptrs",
2043 sizeof(*mod->srcu_struct_ptrs),
2044 &mod->num_srcu_structs);
2045#endif
2046#ifdef CONFIG_BPF_EVENTS
2047 mod->bpf_raw_events = section_objs(info, "__bpf_raw_tp_map",
2048 sizeof(*mod->bpf_raw_events),
2049 &mod->num_bpf_raw_events);
2050#endif
2051#ifdef CONFIG_DEBUG_INFO_BTF_MODULES
2052 mod->btf_data = any_section_objs(info, ".BTF", 1, &mod->btf_data_size);
2053#endif
2054#ifdef CONFIG_JUMP_LABEL
2055 mod->jump_entries = section_objs(info, "__jump_table",
2056 sizeof(*mod->jump_entries),
2057 &mod->num_jump_entries);
2058#endif
2059#ifdef CONFIG_EVENT_TRACING
2060 mod->trace_events = section_objs(info, "_ftrace_events",
2061 sizeof(*mod->trace_events),
2062 &mod->num_trace_events);
2063 mod->trace_evals = section_objs(info, "_ftrace_eval_map",
2064 sizeof(*mod->trace_evals),
2065 &mod->num_trace_evals);
2066#endif
2067#ifdef CONFIG_TRACING
2068 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2069 sizeof(*mod->trace_bprintk_fmt_start),
2070 &mod->num_trace_bprintk_fmt);
2071#endif
2072#ifdef CONFIG_FTRACE_MCOUNT_RECORD
2073 /* sechdrs[0].sh_size is always zero */
2074 mod->ftrace_callsites = section_objs(info, FTRACE_CALLSITE_SECTION,
2075 sizeof(*mod->ftrace_callsites),
2076 &mod->num_ftrace_callsites);
2077#endif
2078#ifdef CONFIG_FUNCTION_ERROR_INJECTION
2079 mod->ei_funcs = section_objs(info, "_error_injection_whitelist",
2080 sizeof(*mod->ei_funcs),
2081 &mod->num_ei_funcs);
2082#endif
2083#ifdef CONFIG_KPROBES
2084 mod->kprobes_text_start = section_objs(info, ".kprobes.text", 1,
2085 &mod->kprobes_text_size);
2086 mod->kprobe_blacklist = section_objs(info, "_kprobe_blacklist",
2087 sizeof(unsigned long),
2088 &mod->num_kprobe_blacklist);
2089#endif
2090#ifdef CONFIG_PRINTK_INDEX
2091 mod->printk_index_start = section_objs(info, ".printk_index",
2092 sizeof(*mod->printk_index_start),
2093 &mod->printk_index_size);
2094#endif
2095#ifdef CONFIG_HAVE_STATIC_CALL_INLINE
2096 mod->static_call_sites = section_objs(info, ".static_call_sites",
2097 sizeof(*mod->static_call_sites),
2098 &mod->num_static_call_sites);
2099#endif
2100#if IS_ENABLED(CONFIG_KUNIT)
2101 mod->kunit_suites = section_objs(info, ".kunit_test_suites",
2102 sizeof(*mod->kunit_suites),
2103 &mod->num_kunit_suites);
2104#endif
2105
2106 mod->extable = section_objs(info, "__ex_table",
2107 sizeof(*mod->extable), &mod->num_exentries);
2108
2109 if (section_addr(info, "__obsparm"))
2110 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
2111
2112 info->dyndbg.descs = section_objs(info, "__dyndbg",
2113 sizeof(*info->dyndbg.descs), &info->dyndbg.num_descs);
2114 info->dyndbg.classes = section_objs(info, "__dyndbg_classes",
2115 sizeof(*info->dyndbg.classes), &info->dyndbg.num_classes);
2116
2117 return 0;
2118}
2119
2120static int move_module(struct module *mod, struct load_info *info)
2121{
2122 int i;
2123 void *ptr;
2124
2125 /* Do the allocs. */
2126 ptr = module_alloc(mod->core_layout.size);
2127 /*
2128 * The pointer to this block is stored in the module structure
2129 * which is inside the block. Just mark it as not being a
2130 * leak.
2131 */
2132 kmemleak_not_leak(ptr);
2133 if (!ptr)
2134 return -ENOMEM;
2135
2136 memset(ptr, 0, mod->core_layout.size);
2137 mod->core_layout.base = ptr;
2138
2139 if (mod->init_layout.size) {
2140 ptr = module_alloc(mod->init_layout.size);
2141 /*
2142 * The pointer to this block is stored in the module structure
2143 * which is inside the block. This block doesn't need to be
2144 * scanned as it contains data and code that will be freed
2145 * after the module is initialized.
2146 */
2147 kmemleak_ignore(ptr);
2148 if (!ptr) {
2149 module_memfree(mod->core_layout.base);
2150 return -ENOMEM;
2151 }
2152 memset(ptr, 0, mod->init_layout.size);
2153 mod->init_layout.base = ptr;
2154 } else
2155 mod->init_layout.base = NULL;
2156
2157#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
2158 /* Do the allocs. */
2159 ptr = vzalloc(mod->data_layout.size);
2160 /*
2161 * The pointer to this block is stored in the module structure
2162 * which is inside the block. Just mark it as not being a
2163 * leak.
2164 */
2165 kmemleak_not_leak(ptr);
2166 if (!ptr) {
2167 module_memfree(mod->core_layout.base);
2168 module_memfree(mod->init_layout.base);
2169 return -ENOMEM;
2170 }
2171
2172 mod->data_layout.base = ptr;
2173#endif
2174 /* Transfer each section which specifies SHF_ALLOC */
2175 pr_debug("final section addresses:\n");
2176 for (i = 0; i < info->hdr->e_shnum; i++) {
2177 void *dest;
2178 Elf_Shdr *shdr = &info->sechdrs[i];
2179
2180 if (!(shdr->sh_flags & SHF_ALLOC))
2181 continue;
2182
2183 if (shdr->sh_entsize & INIT_OFFSET_MASK)
2184 dest = mod->init_layout.base
2185 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
2186 else if (!(shdr->sh_flags & SHF_EXECINSTR))
2187 dest = mod->data_layout.base + shdr->sh_entsize;
2188 else
2189 dest = mod->core_layout.base + shdr->sh_entsize;
2190
2191 if (shdr->sh_type != SHT_NOBITS)
2192 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2193 /* Update sh_addr to point to copy in image. */
2194 shdr->sh_addr = (unsigned long)dest;
2195 pr_debug("\t0x%lx %s\n",
2196 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
2197 }
2198
2199 return 0;
2200}
2201
2202static int check_module_license_and_versions(struct module *mod)
2203{
2204 int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
2205
2206 /*
2207 * ndiswrapper is under GPL by itself, but loads proprietary modules.
2208 * Don't use add_taint_module(), as it would prevent ndiswrapper from
2209 * using GPL-only symbols it needs.
2210 */
2211 if (strcmp(mod->name, "ndiswrapper") == 0)
2212 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
2213
2214 /* driverloader was caught wrongly pretending to be under GPL */
2215 if (strcmp(mod->name, "driverloader") == 0)
2216 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2217 LOCKDEP_NOW_UNRELIABLE);
2218
2219 /* lve claims to be GPL but upstream won't provide source */
2220 if (strcmp(mod->name, "lve") == 0)
2221 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2222 LOCKDEP_NOW_UNRELIABLE);
2223
2224 if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
2225 pr_warn("%s: module license taints kernel.\n", mod->name);
2226
2227#ifdef CONFIG_MODVERSIONS
2228 if ((mod->num_syms && !mod->crcs) ||
2229 (mod->num_gpl_syms && !mod->gpl_crcs)) {
2230 return try_to_force_load(mod,
2231 "no versions for exported symbols");
2232 }
2233#endif
2234 return 0;
2235}
2236
2237static void flush_module_icache(const struct module *mod)
2238{
2239 /*
2240 * Flush the instruction cache, since we've played with text.
2241 * Do it before processing of module parameters, so the module
2242 * can provide parameter accessor functions of its own.
2243 */
2244 if (mod->init_layout.base)
2245 flush_icache_range((unsigned long)mod->init_layout.base,
2246 (unsigned long)mod->init_layout.base
2247 + mod->init_layout.size);
2248 flush_icache_range((unsigned long)mod->core_layout.base,
2249 (unsigned long)mod->core_layout.base + mod->core_layout.size);
2250}
2251
2252bool __weak module_elf_check_arch(Elf_Ehdr *hdr)
2253{
2254 return true;
2255}
2256
2257int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
2258 Elf_Shdr *sechdrs,
2259 char *secstrings,
2260 struct module *mod)
2261{
2262 return 0;
2263}
2264
2265/* module_blacklist is a comma-separated list of module names */
2266static char *module_blacklist;
2267static bool blacklisted(const char *module_name)
2268{
2269 const char *p;
2270 size_t len;
2271
2272 if (!module_blacklist)
2273 return false;
2274
2275 for (p = module_blacklist; *p; p += len) {
2276 len = strcspn(p, ",");
2277 if (strlen(module_name) == len && !memcmp(module_name, p, len))
2278 return true;
2279 if (p[len] == ',')
2280 len++;
2281 }
2282 return false;
2283}
2284core_param(module_blacklist, module_blacklist, charp, 0400);
2285
2286static struct module *layout_and_allocate(struct load_info *info, int flags)
2287{
2288 struct module *mod;
2289 unsigned int ndx;
2290 int err;
2291
2292 err = check_modinfo(info->mod, info, flags);
2293 if (err)
2294 return ERR_PTR(err);
2295
2296 /* Allow arches to frob section contents and sizes. */
2297 err = module_frob_arch_sections(info->hdr, info->sechdrs,
2298 info->secstrings, info->mod);
2299 if (err < 0)
2300 return ERR_PTR(err);
2301
2302 err = module_enforce_rwx_sections(info->hdr, info->sechdrs,
2303 info->secstrings, info->mod);
2304 if (err < 0)
2305 return ERR_PTR(err);
2306
2307 /* We will do a special allocation for per-cpu sections later. */
2308 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
2309
2310 /*
2311 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
2312 * layout_sections() can put it in the right place.
2313 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
2314 */
2315 ndx = find_sec(info, ".data..ro_after_init");
2316 if (ndx)
2317 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
2318 /*
2319 * Mark the __jump_table section as ro_after_init as well: these data
2320 * structures are never modified, with the exception of entries that
2321 * refer to code in the __init section, which are annotated as such
2322 * at module load time.
2323 */
2324 ndx = find_sec(info, "__jump_table");
2325 if (ndx)
2326 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
2327
2328 /*
2329 * Determine total sizes, and put offsets in sh_entsize. For now
2330 * this is done generically; there doesn't appear to be any
2331 * special cases for the architectures.
2332 */
2333 layout_sections(info->mod, info);
2334 layout_symtab(info->mod, info);
2335
2336 /* Allocate and move to the final place */
2337 err = move_module(info->mod, info);
2338 if (err)
2339 return ERR_PTR(err);
2340
2341 /* Module has been copied to its final place now: return it. */
2342 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2343 kmemleak_load_module(mod, info);
2344 return mod;
2345}
2346
2347/* mod is no longer valid after this! */
2348static void module_deallocate(struct module *mod, struct load_info *info)
2349{
2350 percpu_modfree(mod);
2351 module_arch_freeing_init(mod);
2352 module_memfree(mod->init_layout.base);
2353 module_memfree(mod->core_layout.base);
2354#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
2355 vfree(mod->data_layout.base);
2356#endif
2357}
2358
2359int __weak module_finalize(const Elf_Ehdr *hdr,
2360 const Elf_Shdr *sechdrs,
2361 struct module *me)
2362{
2363 return 0;
2364}
2365
2366static int post_relocation(struct module *mod, const struct load_info *info)
2367{
2368 /* Sort exception table now relocations are done. */
2369 sort_extable(mod->extable, mod->extable + mod->num_exentries);
2370
2371 /* Copy relocated percpu area over. */
2372 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
2373 info->sechdrs[info->index.pcpu].sh_size);
2374
2375 /* Setup kallsyms-specific fields. */
2376 add_kallsyms(mod, info);
2377
2378 /* Arch-specific module finalizing. */
2379 return module_finalize(info->hdr, info->sechdrs, mod);
2380}
2381
2382/* Is this module of this name done loading? No locks held. */
2383static bool finished_loading(const char *name)
2384{
2385 struct module *mod;
2386 bool ret;
2387
2388 /*
2389 * The module_mutex should not be a heavily contended lock;
2390 * if we get the occasional sleep here, we'll go an extra iteration
2391 * in the wait_event_interruptible(), which is harmless.
2392 */
2393 sched_annotate_sleep();
2394 mutex_lock(&module_mutex);
2395 mod = find_module_all(name, strlen(name), true);
2396 ret = !mod || mod->state == MODULE_STATE_LIVE
2397 || mod->state == MODULE_STATE_GOING;
2398 mutex_unlock(&module_mutex);
2399
2400 return ret;
2401}
2402
2403/* Call module constructors. */
2404static void do_mod_ctors(struct module *mod)
2405{
2406#ifdef CONFIG_CONSTRUCTORS
2407 unsigned long i;
2408
2409 for (i = 0; i < mod->num_ctors; i++)
2410 mod->ctors[i]();
2411#endif
2412}
2413
2414/* For freeing module_init on success, in case kallsyms traversing */
2415struct mod_initfree {
2416 struct llist_node node;
2417 void *module_init;
2418};
2419
2420static void do_free_init(struct work_struct *w)
2421{
2422 struct llist_node *pos, *n, *list;
2423 struct mod_initfree *initfree;
2424
2425 list = llist_del_all(&init_free_list);
2426
2427 synchronize_rcu();
2428
2429 llist_for_each_safe(pos, n, list) {
2430 initfree = container_of(pos, struct mod_initfree, node);
2431 module_memfree(initfree->module_init);
2432 kfree(initfree);
2433 }
2434}
2435
2436#undef MODULE_PARAM_PREFIX
2437#define MODULE_PARAM_PREFIX "module."
2438/* Default value for module->async_probe_requested */
2439static bool async_probe;
2440module_param(async_probe, bool, 0644);
2441
2442/*
2443 * This is where the real work happens.
2444 *
2445 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
2446 * helper command 'lx-symbols'.
2447 */
2448static noinline int do_init_module(struct module *mod)
2449{
2450 int ret = 0;
2451 struct mod_initfree *freeinit;
2452
2453 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
2454 if (!freeinit) {
2455 ret = -ENOMEM;
2456 goto fail;
2457 }
2458 freeinit->module_init = mod->init_layout.base;
2459
2460 do_mod_ctors(mod);
2461 /* Start the module */
2462 if (mod->init != NULL)
2463 ret = do_one_initcall(mod->init);
2464 if (ret < 0) {
2465 goto fail_free_freeinit;
2466 }
2467 if (ret > 0) {
2468 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
2469 "follow 0/-E convention\n"
2470 "%s: loading module anyway...\n",
2471 __func__, mod->name, ret, __func__);
2472 dump_stack();
2473 }
2474
2475 /* Now it's a first class citizen! */
2476 mod->state = MODULE_STATE_LIVE;
2477 blocking_notifier_call_chain(&module_notify_list,
2478 MODULE_STATE_LIVE, mod);
2479
2480 /* Delay uevent until module has finished its init routine */
2481 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
2482
2483 /*
2484 * We need to finish all async code before the module init sequence
2485 * is done. This has potential to deadlock if synchronous module
2486 * loading is requested from async (which is not allowed!).
2487 *
2488 * See commit 0fdff3ec6d87 ("async, kmod: warn on synchronous
2489 * request_module() from async workers") for more details.
2490 */
2491 if (!mod->async_probe_requested)
2492 async_synchronize_full();
2493
2494 ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base +
2495 mod->init_layout.size);
2496 mutex_lock(&module_mutex);
2497 /* Drop initial reference. */
2498 module_put(mod);
2499 trim_init_extable(mod);
2500#ifdef CONFIG_KALLSYMS
2501 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
2502 rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
2503#endif
2504 module_enable_ro(mod, true);
2505 mod_tree_remove_init(mod);
2506 module_arch_freeing_init(mod);
2507 mod->init_layout.base = NULL;
2508 mod->init_layout.size = 0;
2509 mod->init_layout.ro_size = 0;
2510 mod->init_layout.ro_after_init_size = 0;
2511 mod->init_layout.text_size = 0;
2512#ifdef CONFIG_DEBUG_INFO_BTF_MODULES
2513 /* .BTF is not SHF_ALLOC and will get removed, so sanitize pointer */
2514 mod->btf_data = NULL;
2515#endif
2516 /*
2517 * We want to free module_init, but be aware that kallsyms may be
2518 * walking this with preempt disabled. In all the failure paths, we
2519 * call synchronize_rcu(), but we don't want to slow down the success
2520 * path. module_memfree() cannot be called in an interrupt, so do the
2521 * work and call synchronize_rcu() in a work queue.
2522 *
2523 * Note that module_alloc() on most architectures creates W+X page
2524 * mappings which won't be cleaned up until do_free_init() runs. Any
2525 * code such as mark_rodata_ro() which depends on those mappings to
2526 * be cleaned up needs to sync with the queued work - ie
2527 * rcu_barrier()
2528 */
2529 if (llist_add(&freeinit->node, &init_free_list))
2530 schedule_work(&init_free_wq);
2531
2532 mutex_unlock(&module_mutex);
2533 wake_up_all(&module_wq);
2534
2535 return 0;
2536
2537fail_free_freeinit:
2538 kfree(freeinit);
2539fail:
2540 /* Try to protect us from buggy refcounters. */
2541 mod->state = MODULE_STATE_GOING;
2542 synchronize_rcu();
2543 module_put(mod);
2544 blocking_notifier_call_chain(&module_notify_list,
2545 MODULE_STATE_GOING, mod);
2546 klp_module_going(mod);
2547 ftrace_release_mod(mod);
2548 free_module(mod);
2549 wake_up_all(&module_wq);
2550 return ret;
2551}
2552
2553static int may_init_module(void)
2554{
2555 if (!capable(CAP_SYS_MODULE) || modules_disabled)
2556 return -EPERM;
2557
2558 return 0;
2559}
2560
2561/*
2562 * We try to place it in the list now to make sure it's unique before
2563 * we dedicate too many resources. In particular, temporary percpu
2564 * memory exhaustion.
2565 */
2566static int add_unformed_module(struct module *mod)
2567{
2568 int err;
2569 struct module *old;
2570
2571 mod->state = MODULE_STATE_UNFORMED;
2572
2573 mutex_lock(&module_mutex);
2574 old = find_module_all(mod->name, strlen(mod->name), true);
2575 if (old != NULL) {
2576 if (old->state == MODULE_STATE_COMING
2577 || old->state == MODULE_STATE_UNFORMED) {
2578 /* Wait in case it fails to load. */
2579 mutex_unlock(&module_mutex);
2580 err = wait_event_interruptible(module_wq,
2581 finished_loading(mod->name));
2582 if (err)
2583 goto out_unlocked;
2584
2585 /* The module might have gone in the meantime. */
2586 mutex_lock(&module_mutex);
2587 old = find_module_all(mod->name, strlen(mod->name),
2588 true);
2589 }
2590
2591 /*
2592 * We are here only when the same module was being loaded. Do
2593 * not try to load it again right now. It prevents long delays
2594 * caused by serialized module load failures. It might happen
2595 * when more devices of the same type trigger load of
2596 * a particular module.
2597 */
2598 if (old && old->state == MODULE_STATE_LIVE)
2599 err = -EEXIST;
2600 else
2601 err = -EBUSY;
2602 goto out;
2603 }
2604 mod_update_bounds(mod);
2605 list_add_rcu(&mod->list, &modules);
2606 mod_tree_insert(mod);
2607 err = 0;
2608
2609out:
2610 mutex_unlock(&module_mutex);
2611out_unlocked:
2612 return err;
2613}
2614
2615static int complete_formation(struct module *mod, struct load_info *info)
2616{
2617 int err;
2618
2619 mutex_lock(&module_mutex);
2620
2621 /* Find duplicate symbols (must be called under lock). */
2622 err = verify_exported_symbols(mod);
2623 if (err < 0)
2624 goto out;
2625
2626 /* These rely on module_mutex for list integrity. */
2627 module_bug_finalize(info->hdr, info->sechdrs, mod);
2628 module_cfi_finalize(info->hdr, info->sechdrs, mod);
2629
2630 if (module_check_misalignment(mod))
2631 goto out_misaligned;
2632
2633 module_enable_ro(mod, false);
2634 module_enable_nx(mod);
2635 module_enable_x(mod);
2636
2637 /*
2638 * Mark state as coming so strong_try_module_get() ignores us,
2639 * but kallsyms etc. can see us.
2640 */
2641 mod->state = MODULE_STATE_COMING;
2642 mutex_unlock(&module_mutex);
2643
2644 return 0;
2645
2646out_misaligned:
2647 err = -EINVAL;
2648out:
2649 mutex_unlock(&module_mutex);
2650 return err;
2651}
2652
2653static int prepare_coming_module(struct module *mod)
2654{
2655 int err;
2656
2657 ftrace_module_enable(mod);
2658 err = klp_module_coming(mod);
2659 if (err)
2660 return err;
2661
2662 err = blocking_notifier_call_chain_robust(&module_notify_list,
2663 MODULE_STATE_COMING, MODULE_STATE_GOING, mod);
2664 err = notifier_to_errno(err);
2665 if (err)
2666 klp_module_going(mod);
2667
2668 return err;
2669}
2670
2671static int unknown_module_param_cb(char *param, char *val, const char *modname,
2672 void *arg)
2673{
2674 struct module *mod = arg;
2675 int ret;
2676
2677 if (strcmp(param, "async_probe") == 0) {
2678 if (strtobool(val, &mod->async_probe_requested))
2679 mod->async_probe_requested = true;
2680 return 0;
2681 }
2682
2683 /* Check for magic 'dyndbg' arg */
2684 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
2685 if (ret != 0)
2686 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
2687 return 0;
2688}
2689
2690/*
2691 * Allocate and load the module: note that size of section 0 is always
2692 * zero, and we rely on this for optional sections.
2693 */
2694static int load_module(struct load_info *info, const char __user *uargs,
2695 int flags)
2696{
2697 struct module *mod;
2698 long err = 0;
2699 char *after_dashes;
2700
2701 /*
2702 * Do the signature check (if any) first. All that
2703 * the signature check needs is info->len, it does
2704 * not need any of the section info. That can be
2705 * set up later. This will minimize the chances
2706 * of a corrupt module causing problems before
2707 * we even get to the signature check.
2708 *
2709 * The check will also adjust info->len by stripping
2710 * off the sig length at the end of the module, making
2711 * checks against info->len more correct.
2712 */
2713 err = module_sig_check(info, flags);
2714 if (err)
2715 goto free_copy;
2716
2717 /*
2718 * Do basic sanity checks against the ELF header and
2719 * sections.
2720 */
2721 err = elf_validity_check(info);
2722 if (err)
2723 goto free_copy;
2724
2725 /*
2726 * Everything checks out, so set up the section info
2727 * in the info structure.
2728 */
2729 err = setup_load_info(info, flags);
2730 if (err)
2731 goto free_copy;
2732
2733 /*
2734 * Now that we know we have the correct module name, check
2735 * if it's blacklisted.
2736 */
2737 if (blacklisted(info->name)) {
2738 err = -EPERM;
2739 pr_err("Module %s is blacklisted\n", info->name);
2740 goto free_copy;
2741 }
2742
2743 err = rewrite_section_headers(info, flags);
2744 if (err)
2745 goto free_copy;
2746
2747 /* Check module struct version now, before we try to use module. */
2748 if (!check_modstruct_version(info, info->mod)) {
2749 err = -ENOEXEC;
2750 goto free_copy;
2751 }
2752
2753 /* Figure out module layout, and allocate all the memory. */
2754 mod = layout_and_allocate(info, flags);
2755 if (IS_ERR(mod)) {
2756 err = PTR_ERR(mod);
2757 goto free_copy;
2758 }
2759
2760 audit_log_kern_module(mod->name);
2761
2762 /* Reserve our place in the list. */
2763 err = add_unformed_module(mod);
2764 if (err)
2765 goto free_module;
2766
2767#ifdef CONFIG_MODULE_SIG
2768 mod->sig_ok = info->sig_ok;
2769 if (!mod->sig_ok) {
2770 pr_notice_once("%s: module verification failed: signature "
2771 "and/or required key missing - tainting "
2772 "kernel\n", mod->name);
2773 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
2774 }
2775#endif
2776
2777 /* To avoid stressing percpu allocator, do this once we're unique. */
2778 err = percpu_modalloc(mod, info);
2779 if (err)
2780 goto unlink_mod;
2781
2782 /* Now module is in final location, initialize linked lists, etc. */
2783 err = module_unload_init(mod);
2784 if (err)
2785 goto unlink_mod;
2786
2787 init_param_lock(mod);
2788
2789 /*
2790 * Now we've got everything in the final locations, we can
2791 * find optional sections.
2792 */
2793 err = find_module_sections(mod, info);
2794 if (err)
2795 goto free_unload;
2796
2797 err = check_module_license_and_versions(mod);
2798 if (err)
2799 goto free_unload;
2800
2801 /* Set up MODINFO_ATTR fields */
2802 setup_modinfo(mod, info);
2803
2804 /* Fix up syms, so that st_value is a pointer to location. */
2805 err = simplify_symbols(mod, info);
2806 if (err < 0)
2807 goto free_modinfo;
2808
2809 err = apply_relocations(mod, info);
2810 if (err < 0)
2811 goto free_modinfo;
2812
2813 err = post_relocation(mod, info);
2814 if (err < 0)
2815 goto free_modinfo;
2816
2817 flush_module_icache(mod);
2818
2819 /* Now copy in args */
2820 mod->args = strndup_user(uargs, ~0UL >> 1);
2821 if (IS_ERR(mod->args)) {
2822 err = PTR_ERR(mod->args);
2823 goto free_arch_cleanup;
2824 }
2825
2826 init_build_id(mod, info);
2827 dynamic_debug_setup(mod, &info->dyndbg);
2828
2829 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
2830 ftrace_module_init(mod);
2831
2832 /* Finally it's fully formed, ready to start executing. */
2833 err = complete_formation(mod, info);
2834 if (err)
2835 goto ddebug_cleanup;
2836
2837 err = prepare_coming_module(mod);
2838 if (err)
2839 goto bug_cleanup;
2840
2841 mod->async_probe_requested = async_probe;
2842
2843 /* Module is ready to execute: parsing args may do that. */
2844 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
2845 -32768, 32767, mod,
2846 unknown_module_param_cb);
2847 if (IS_ERR(after_dashes)) {
2848 err = PTR_ERR(after_dashes);
2849 goto coming_cleanup;
2850 } else if (after_dashes) {
2851 pr_warn("%s: parameters '%s' after `--' ignored\n",
2852 mod->name, after_dashes);
2853 }
2854
2855 /* Link in to sysfs. */
2856 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
2857 if (err < 0)
2858 goto coming_cleanup;
2859
2860 if (is_livepatch_module(mod)) {
2861 err = copy_module_elf(mod, info);
2862 if (err < 0)
2863 goto sysfs_cleanup;
2864 }
2865
2866 /* Get rid of temporary copy. */
2867 free_copy(info, flags);
2868
2869 /* Done! */
2870 trace_module_load(mod);
2871
2872 return do_init_module(mod);
2873
2874 sysfs_cleanup:
2875 mod_sysfs_teardown(mod);
2876 coming_cleanup:
2877 mod->state = MODULE_STATE_GOING;
2878 destroy_params(mod->kp, mod->num_kp);
2879 blocking_notifier_call_chain(&module_notify_list,
2880 MODULE_STATE_GOING, mod);
2881 klp_module_going(mod);
2882 bug_cleanup:
2883 mod->state = MODULE_STATE_GOING;
2884 /* module_bug_cleanup needs module_mutex protection */
2885 mutex_lock(&module_mutex);
2886 module_bug_cleanup(mod);
2887 mutex_unlock(&module_mutex);
2888
2889 ddebug_cleanup:
2890 ftrace_release_mod(mod);
2891 dynamic_debug_remove(mod, &info->dyndbg);
2892 synchronize_rcu();
2893 kfree(mod->args);
2894 free_arch_cleanup:
2895 module_arch_cleanup(mod);
2896 free_modinfo:
2897 free_modinfo(mod);
2898 free_unload:
2899 module_unload_free(mod);
2900 unlink_mod:
2901 mutex_lock(&module_mutex);
2902 /* Unlink carefully: kallsyms could be walking list. */
2903 list_del_rcu(&mod->list);
2904 mod_tree_remove(mod);
2905 wake_up_all(&module_wq);
2906 /* Wait for RCU-sched synchronizing before releasing mod->list. */
2907 synchronize_rcu();
2908 mutex_unlock(&module_mutex);
2909 free_module:
2910 /* Free lock-classes; relies on the preceding sync_rcu() */
2911 lockdep_free_key_range(mod->data_layout.base, mod->data_layout.size);
2912
2913 module_deallocate(mod, info);
2914 free_copy:
2915 free_copy(info, flags);
2916 return err;
2917}
2918
2919SYSCALL_DEFINE3(init_module, void __user *, umod,
2920 unsigned long, len, const char __user *, uargs)
2921{
2922 int err;
2923 struct load_info info = { };
2924
2925 err = may_init_module();
2926 if (err)
2927 return err;
2928
2929 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
2930 umod, len, uargs);
2931
2932 err = copy_module_from_user(umod, len, &info);
2933 if (err)
2934 return err;
2935
2936 return load_module(&info, uargs, 0);
2937}
2938
2939SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
2940{
2941 struct load_info info = { };
2942 void *buf = NULL;
2943 int len;
2944 int err;
2945
2946 err = may_init_module();
2947 if (err)
2948 return err;
2949
2950 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
2951
2952 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
2953 |MODULE_INIT_IGNORE_VERMAGIC
2954 |MODULE_INIT_COMPRESSED_FILE))
2955 return -EINVAL;
2956
2957 len = kernel_read_file_from_fd(fd, 0, &buf, INT_MAX, NULL,
2958 READING_MODULE);
2959 if (len < 0)
2960 return len;
2961
2962 if (flags & MODULE_INIT_COMPRESSED_FILE) {
2963 err = module_decompress(&info, buf, len);
2964 vfree(buf); /* compressed data is no longer needed */
2965 if (err)
2966 return err;
2967 } else {
2968 info.hdr = buf;
2969 info.len = len;
2970 }
2971
2972 return load_module(&info, uargs, flags);
2973}
2974
2975static inline int within(unsigned long addr, void *start, unsigned long size)
2976{
2977 return ((void *)addr >= start && (void *)addr < start + size);
2978}
2979
2980/* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
2981char *module_flags(struct module *mod, char *buf, bool show_state)
2982{
2983 int bx = 0;
2984
2985 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
2986 if (!mod->taints && !show_state)
2987 goto out;
2988 if (mod->taints ||
2989 mod->state == MODULE_STATE_GOING ||
2990 mod->state == MODULE_STATE_COMING) {
2991 buf[bx++] = '(';
2992 bx += module_flags_taint(mod->taints, buf + bx);
2993 /* Show a - for module-is-being-unloaded */
2994 if (mod->state == MODULE_STATE_GOING && show_state)
2995 buf[bx++] = '-';
2996 /* Show a + for module-is-being-loaded */
2997 if (mod->state == MODULE_STATE_COMING && show_state)
2998 buf[bx++] = '+';
2999 buf[bx++] = ')';
3000 }
3001out:
3002 buf[bx] = '\0';
3003
3004 return buf;
3005}
3006
3007/* Given an address, look for it in the module exception tables. */
3008const struct exception_table_entry *search_module_extables(unsigned long addr)
3009{
3010 const struct exception_table_entry *e = NULL;
3011 struct module *mod;
3012
3013 preempt_disable();
3014 mod = __module_address(addr);
3015 if (!mod)
3016 goto out;
3017
3018 if (!mod->num_exentries)
3019 goto out;
3020
3021 e = search_extable(mod->extable,
3022 mod->num_exentries,
3023 addr);
3024out:
3025 preempt_enable();
3026
3027 /*
3028 * Now, if we found one, we are running inside it now, hence
3029 * we cannot unload the module, hence no refcnt needed.
3030 */
3031 return e;
3032}
3033
3034/**
3035 * is_module_address() - is this address inside a module?
3036 * @addr: the address to check.
3037 *
3038 * See is_module_text_address() if you simply want to see if the address
3039 * is code (not data).
3040 */
3041bool is_module_address(unsigned long addr)
3042{
3043 bool ret;
3044
3045 preempt_disable();
3046 ret = __module_address(addr) != NULL;
3047 preempt_enable();
3048
3049 return ret;
3050}
3051
3052/**
3053 * __module_address() - get the module which contains an address.
3054 * @addr: the address.
3055 *
3056 * Must be called with preempt disabled or module mutex held so that
3057 * module doesn't get freed during this.
3058 */
3059struct module *__module_address(unsigned long addr)
3060{
3061 struct module *mod;
3062 struct mod_tree_root *tree;
3063
3064 if (addr >= mod_tree.addr_min && addr <= mod_tree.addr_max)
3065 tree = &mod_tree;
3066#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
3067 else if (addr >= mod_data_tree.addr_min && addr <= mod_data_tree.addr_max)
3068 tree = &mod_data_tree;
3069#endif
3070 else
3071 return NULL;
3072
3073 module_assert_mutex_or_preempt();
3074
3075 mod = mod_find(addr, tree);
3076 if (mod) {
3077 BUG_ON(!within_module(addr, mod));
3078 if (mod->state == MODULE_STATE_UNFORMED)
3079 mod = NULL;
3080 }
3081 return mod;
3082}
3083
3084/**
3085 * is_module_text_address() - is this address inside module code?
3086 * @addr: the address to check.
3087 *
3088 * See is_module_address() if you simply want to see if the address is
3089 * anywhere in a module. See kernel_text_address() for testing if an
3090 * address corresponds to kernel or module code.
3091 */
3092bool is_module_text_address(unsigned long addr)
3093{
3094 bool ret;
3095
3096 preempt_disable();
3097 ret = __module_text_address(addr) != NULL;
3098 preempt_enable();
3099
3100 return ret;
3101}
3102
3103/**
3104 * __module_text_address() - get the module whose code contains an address.
3105 * @addr: the address.
3106 *
3107 * Must be called with preempt disabled or module mutex held so that
3108 * module doesn't get freed during this.
3109 */
3110struct module *__module_text_address(unsigned long addr)
3111{
3112 struct module *mod = __module_address(addr);
3113 if (mod) {
3114 /* Make sure it's within the text section. */
3115 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
3116 && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
3117 mod = NULL;
3118 }
3119 return mod;
3120}
3121
3122/* Don't grab lock, we're oopsing. */
3123void print_modules(void)
3124{
3125 struct module *mod;
3126 char buf[MODULE_FLAGS_BUF_SIZE];
3127
3128 printk(KERN_DEFAULT "Modules linked in:");
3129 /* Most callers should already have preempt disabled, but make sure */
3130 preempt_disable();
3131 list_for_each_entry_rcu(mod, &modules, list) {
3132 if (mod->state == MODULE_STATE_UNFORMED)
3133 continue;
3134 pr_cont(" %s%s", mod->name, module_flags(mod, buf, true));
3135 }
3136
3137 print_unloaded_tainted_modules();
3138 preempt_enable();
3139 if (last_unloaded_module.name[0])
3140 pr_cont(" [last unloaded: %s%s]", last_unloaded_module.name,
3141 last_unloaded_module.taints);
3142 pr_cont("\n");
3143}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2002 Richard Henderson
4 * Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
5 * Copyright (C) 2023 Luis Chamberlain <mcgrof@kernel.org>
6 */
7
8#define INCLUDE_VERMAGIC
9
10#include <linux/export.h>
11#include <linux/extable.h>
12#include <linux/moduleloader.h>
13#include <linux/module_signature.h>
14#include <linux/trace_events.h>
15#include <linux/init.h>
16#include <linux/kallsyms.h>
17#include <linux/buildid.h>
18#include <linux/fs.h>
19#include <linux/kernel.h>
20#include <linux/kernel_read_file.h>
21#include <linux/kstrtox.h>
22#include <linux/slab.h>
23#include <linux/vmalloc.h>
24#include <linux/elf.h>
25#include <linux/seq_file.h>
26#include <linux/syscalls.h>
27#include <linux/fcntl.h>
28#include <linux/rcupdate.h>
29#include <linux/capability.h>
30#include <linux/cpu.h>
31#include <linux/moduleparam.h>
32#include <linux/errno.h>
33#include <linux/err.h>
34#include <linux/vermagic.h>
35#include <linux/notifier.h>
36#include <linux/sched.h>
37#include <linux/device.h>
38#include <linux/string.h>
39#include <linux/mutex.h>
40#include <linux/rculist.h>
41#include <linux/uaccess.h>
42#include <asm/cacheflush.h>
43#include <linux/set_memory.h>
44#include <asm/mmu_context.h>
45#include <linux/license.h>
46#include <asm/sections.h>
47#include <linux/tracepoint.h>
48#include <linux/ftrace.h>
49#include <linux/livepatch.h>
50#include <linux/async.h>
51#include <linux/percpu.h>
52#include <linux/kmemleak.h>
53#include <linux/jump_label.h>
54#include <linux/pfn.h>
55#include <linux/bsearch.h>
56#include <linux/dynamic_debug.h>
57#include <linux/audit.h>
58#include <linux/cfi.h>
59#include <linux/debugfs.h>
60#include <uapi/linux/module.h>
61#include "internal.h"
62
63#define CREATE_TRACE_POINTS
64#include <trace/events/module.h>
65
66/*
67 * Mutex protects:
68 * 1) List of modules (also safely readable with preempt_disable),
69 * 2) module_use links,
70 * 3) mod_tree.addr_min/mod_tree.addr_max.
71 * (delete and add uses RCU list operations).
72 */
73DEFINE_MUTEX(module_mutex);
74LIST_HEAD(modules);
75
76/* Work queue for freeing init sections in success case */
77static void do_free_init(struct work_struct *w);
78static DECLARE_WORK(init_free_wq, do_free_init);
79static LLIST_HEAD(init_free_list);
80
81struct mod_tree_root mod_tree __cacheline_aligned = {
82 .addr_min = -1UL,
83};
84
85struct symsearch {
86 const struct kernel_symbol *start, *stop;
87 const s32 *crcs;
88 enum mod_license license;
89};
90
91/*
92 * Bounds of module memory, for speeding up __module_address.
93 * Protected by module_mutex.
94 */
95static void __mod_update_bounds(enum mod_mem_type type __maybe_unused, void *base,
96 unsigned int size, struct mod_tree_root *tree)
97{
98 unsigned long min = (unsigned long)base;
99 unsigned long max = min + size;
100
101#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
102 if (mod_mem_type_is_core_data(type)) {
103 if (min < tree->data_addr_min)
104 tree->data_addr_min = min;
105 if (max > tree->data_addr_max)
106 tree->data_addr_max = max;
107 return;
108 }
109#endif
110 if (min < tree->addr_min)
111 tree->addr_min = min;
112 if (max > tree->addr_max)
113 tree->addr_max = max;
114}
115
116static void mod_update_bounds(struct module *mod)
117{
118 for_each_mod_mem_type(type) {
119 struct module_memory *mod_mem = &mod->mem[type];
120
121 if (mod_mem->size)
122 __mod_update_bounds(type, mod_mem->base, mod_mem->size, &mod_tree);
123 }
124}
125
126/* Block module loading/unloading? */
127int modules_disabled;
128core_param(nomodule, modules_disabled, bint, 0);
129
130/* Waiting for a module to finish initializing? */
131static DECLARE_WAIT_QUEUE_HEAD(module_wq);
132
133static BLOCKING_NOTIFIER_HEAD(module_notify_list);
134
135int register_module_notifier(struct notifier_block *nb)
136{
137 return blocking_notifier_chain_register(&module_notify_list, nb);
138}
139EXPORT_SYMBOL(register_module_notifier);
140
141int unregister_module_notifier(struct notifier_block *nb)
142{
143 return blocking_notifier_chain_unregister(&module_notify_list, nb);
144}
145EXPORT_SYMBOL(unregister_module_notifier);
146
147/*
148 * We require a truly strong try_module_get(): 0 means success.
149 * Otherwise an error is returned due to ongoing or failed
150 * initialization etc.
151 */
152static inline int strong_try_module_get(struct module *mod)
153{
154 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
155 if (mod && mod->state == MODULE_STATE_COMING)
156 return -EBUSY;
157 if (try_module_get(mod))
158 return 0;
159 else
160 return -ENOENT;
161}
162
163static inline void add_taint_module(struct module *mod, unsigned flag,
164 enum lockdep_ok lockdep_ok)
165{
166 add_taint(flag, lockdep_ok);
167 set_bit(flag, &mod->taints);
168}
169
170/*
171 * A thread that wants to hold a reference to a module only while it
172 * is running can call this to safely exit.
173 */
174void __noreturn __module_put_and_kthread_exit(struct module *mod, long code)
175{
176 module_put(mod);
177 kthread_exit(code);
178}
179EXPORT_SYMBOL(__module_put_and_kthread_exit);
180
181/* Find a module section: 0 means not found. */
182static unsigned int find_sec(const struct load_info *info, const char *name)
183{
184 unsigned int i;
185
186 for (i = 1; i < info->hdr->e_shnum; i++) {
187 Elf_Shdr *shdr = &info->sechdrs[i];
188 /* Alloc bit cleared means "ignore it." */
189 if ((shdr->sh_flags & SHF_ALLOC)
190 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
191 return i;
192 }
193 return 0;
194}
195
196/* Find a module section, or NULL. */
197static void *section_addr(const struct load_info *info, const char *name)
198{
199 /* Section 0 has sh_addr 0. */
200 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
201}
202
203/* Find a module section, or NULL. Fill in number of "objects" in section. */
204static void *section_objs(const struct load_info *info,
205 const char *name,
206 size_t object_size,
207 unsigned int *num)
208{
209 unsigned int sec = find_sec(info, name);
210
211 /* Section 0 has sh_addr 0 and sh_size 0. */
212 *num = info->sechdrs[sec].sh_size / object_size;
213 return (void *)info->sechdrs[sec].sh_addr;
214}
215
216/* Find a module section: 0 means not found. Ignores SHF_ALLOC flag. */
217static unsigned int find_any_sec(const struct load_info *info, const char *name)
218{
219 unsigned int i;
220
221 for (i = 1; i < info->hdr->e_shnum; i++) {
222 Elf_Shdr *shdr = &info->sechdrs[i];
223 if (strcmp(info->secstrings + shdr->sh_name, name) == 0)
224 return i;
225 }
226 return 0;
227}
228
229/*
230 * Find a module section, or NULL. Fill in number of "objects" in section.
231 * Ignores SHF_ALLOC flag.
232 */
233static __maybe_unused void *any_section_objs(const struct load_info *info,
234 const char *name,
235 size_t object_size,
236 unsigned int *num)
237{
238 unsigned int sec = find_any_sec(info, name);
239
240 /* Section 0 has sh_addr 0 and sh_size 0. */
241 *num = info->sechdrs[sec].sh_size / object_size;
242 return (void *)info->sechdrs[sec].sh_addr;
243}
244
245#ifndef CONFIG_MODVERSIONS
246#define symversion(base, idx) NULL
247#else
248#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
249#endif
250
251static const char *kernel_symbol_name(const struct kernel_symbol *sym)
252{
253#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
254 return offset_to_ptr(&sym->name_offset);
255#else
256 return sym->name;
257#endif
258}
259
260static const char *kernel_symbol_namespace(const struct kernel_symbol *sym)
261{
262#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
263 if (!sym->namespace_offset)
264 return NULL;
265 return offset_to_ptr(&sym->namespace_offset);
266#else
267 return sym->namespace;
268#endif
269}
270
271int cmp_name(const void *name, const void *sym)
272{
273 return strcmp(name, kernel_symbol_name(sym));
274}
275
276static bool find_exported_symbol_in_section(const struct symsearch *syms,
277 struct module *owner,
278 struct find_symbol_arg *fsa)
279{
280 struct kernel_symbol *sym;
281
282 if (!fsa->gplok && syms->license == GPL_ONLY)
283 return false;
284
285 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
286 sizeof(struct kernel_symbol), cmp_name);
287 if (!sym)
288 return false;
289
290 fsa->owner = owner;
291 fsa->crc = symversion(syms->crcs, sym - syms->start);
292 fsa->sym = sym;
293 fsa->license = syms->license;
294
295 return true;
296}
297
298/*
299 * Find an exported symbol and return it, along with, (optional) crc and
300 * (optional) module which owns it. Needs preempt disabled or module_mutex.
301 */
302bool find_symbol(struct find_symbol_arg *fsa)
303{
304 static const struct symsearch arr[] = {
305 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
306 NOT_GPL_ONLY },
307 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
308 __start___kcrctab_gpl,
309 GPL_ONLY },
310 };
311 struct module *mod;
312 unsigned int i;
313
314 module_assert_mutex_or_preempt();
315
316 for (i = 0; i < ARRAY_SIZE(arr); i++)
317 if (find_exported_symbol_in_section(&arr[i], NULL, fsa))
318 return true;
319
320 list_for_each_entry_rcu(mod, &modules, list,
321 lockdep_is_held(&module_mutex)) {
322 struct symsearch arr[] = {
323 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
324 NOT_GPL_ONLY },
325 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
326 mod->gpl_crcs,
327 GPL_ONLY },
328 };
329
330 if (mod->state == MODULE_STATE_UNFORMED)
331 continue;
332
333 for (i = 0; i < ARRAY_SIZE(arr); i++)
334 if (find_exported_symbol_in_section(&arr[i], mod, fsa))
335 return true;
336 }
337
338 pr_debug("Failed to find symbol %s\n", fsa->name);
339 return false;
340}
341
342/*
343 * Search for module by name: must hold module_mutex (or preempt disabled
344 * for read-only access).
345 */
346struct module *find_module_all(const char *name, size_t len,
347 bool even_unformed)
348{
349 struct module *mod;
350
351 module_assert_mutex_or_preempt();
352
353 list_for_each_entry_rcu(mod, &modules, list,
354 lockdep_is_held(&module_mutex)) {
355 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
356 continue;
357 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
358 return mod;
359 }
360 return NULL;
361}
362
363struct module *find_module(const char *name)
364{
365 return find_module_all(name, strlen(name), false);
366}
367
368#ifdef CONFIG_SMP
369
370static inline void __percpu *mod_percpu(struct module *mod)
371{
372 return mod->percpu;
373}
374
375static int percpu_modalloc(struct module *mod, struct load_info *info)
376{
377 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
378 unsigned long align = pcpusec->sh_addralign;
379
380 if (!pcpusec->sh_size)
381 return 0;
382
383 if (align > PAGE_SIZE) {
384 pr_warn("%s: per-cpu alignment %li > %li\n",
385 mod->name, align, PAGE_SIZE);
386 align = PAGE_SIZE;
387 }
388
389 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
390 if (!mod->percpu) {
391 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
392 mod->name, (unsigned long)pcpusec->sh_size);
393 return -ENOMEM;
394 }
395 mod->percpu_size = pcpusec->sh_size;
396 return 0;
397}
398
399static void percpu_modfree(struct module *mod)
400{
401 free_percpu(mod->percpu);
402}
403
404static unsigned int find_pcpusec(struct load_info *info)
405{
406 return find_sec(info, ".data..percpu");
407}
408
409static void percpu_modcopy(struct module *mod,
410 const void *from, unsigned long size)
411{
412 int cpu;
413
414 for_each_possible_cpu(cpu)
415 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
416}
417
418bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
419{
420 struct module *mod;
421 unsigned int cpu;
422
423 preempt_disable();
424
425 list_for_each_entry_rcu(mod, &modules, list) {
426 if (mod->state == MODULE_STATE_UNFORMED)
427 continue;
428 if (!mod->percpu_size)
429 continue;
430 for_each_possible_cpu(cpu) {
431 void *start = per_cpu_ptr(mod->percpu, cpu);
432 void *va = (void *)addr;
433
434 if (va >= start && va < start + mod->percpu_size) {
435 if (can_addr) {
436 *can_addr = (unsigned long) (va - start);
437 *can_addr += (unsigned long)
438 per_cpu_ptr(mod->percpu,
439 get_boot_cpu_id());
440 }
441 preempt_enable();
442 return true;
443 }
444 }
445 }
446
447 preempt_enable();
448 return false;
449}
450
451/**
452 * is_module_percpu_address() - test whether address is from module static percpu
453 * @addr: address to test
454 *
455 * Test whether @addr belongs to module static percpu area.
456 *
457 * Return: %true if @addr is from module static percpu area
458 */
459bool is_module_percpu_address(unsigned long addr)
460{
461 return __is_module_percpu_address(addr, NULL);
462}
463
464#else /* ... !CONFIG_SMP */
465
466static inline void __percpu *mod_percpu(struct module *mod)
467{
468 return NULL;
469}
470static int percpu_modalloc(struct module *mod, struct load_info *info)
471{
472 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
473 if (info->sechdrs[info->index.pcpu].sh_size != 0)
474 return -ENOMEM;
475 return 0;
476}
477static inline void percpu_modfree(struct module *mod)
478{
479}
480static unsigned int find_pcpusec(struct load_info *info)
481{
482 return 0;
483}
484static inline void percpu_modcopy(struct module *mod,
485 const void *from, unsigned long size)
486{
487 /* pcpusec should be 0, and size of that section should be 0. */
488 BUG_ON(size != 0);
489}
490bool is_module_percpu_address(unsigned long addr)
491{
492 return false;
493}
494
495bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
496{
497 return false;
498}
499
500#endif /* CONFIG_SMP */
501
502#define MODINFO_ATTR(field) \
503static void setup_modinfo_##field(struct module *mod, const char *s) \
504{ \
505 mod->field = kstrdup(s, GFP_KERNEL); \
506} \
507static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
508 struct module_kobject *mk, char *buffer) \
509{ \
510 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
511} \
512static int modinfo_##field##_exists(struct module *mod) \
513{ \
514 return mod->field != NULL; \
515} \
516static void free_modinfo_##field(struct module *mod) \
517{ \
518 kfree(mod->field); \
519 mod->field = NULL; \
520} \
521static struct module_attribute modinfo_##field = { \
522 .attr = { .name = __stringify(field), .mode = 0444 }, \
523 .show = show_modinfo_##field, \
524 .setup = setup_modinfo_##field, \
525 .test = modinfo_##field##_exists, \
526 .free = free_modinfo_##field, \
527};
528
529MODINFO_ATTR(version);
530MODINFO_ATTR(srcversion);
531
532static struct {
533 char name[MODULE_NAME_LEN + 1];
534 char taints[MODULE_FLAGS_BUF_SIZE];
535} last_unloaded_module;
536
537#ifdef CONFIG_MODULE_UNLOAD
538
539EXPORT_TRACEPOINT_SYMBOL(module_get);
540
541/* MODULE_REF_BASE is the base reference count by kmodule loader. */
542#define MODULE_REF_BASE 1
543
544/* Init the unload section of the module. */
545static int module_unload_init(struct module *mod)
546{
547 /*
548 * Initialize reference counter to MODULE_REF_BASE.
549 * refcnt == 0 means module is going.
550 */
551 atomic_set(&mod->refcnt, MODULE_REF_BASE);
552
553 INIT_LIST_HEAD(&mod->source_list);
554 INIT_LIST_HEAD(&mod->target_list);
555
556 /* Hold reference count during initialization. */
557 atomic_inc(&mod->refcnt);
558
559 return 0;
560}
561
562/* Does a already use b? */
563static int already_uses(struct module *a, struct module *b)
564{
565 struct module_use *use;
566
567 list_for_each_entry(use, &b->source_list, source_list) {
568 if (use->source == a)
569 return 1;
570 }
571 pr_debug("%s does not use %s!\n", a->name, b->name);
572 return 0;
573}
574
575/*
576 * Module a uses b
577 * - we add 'a' as a "source", 'b' as a "target" of module use
578 * - the module_use is added to the list of 'b' sources (so
579 * 'b' can walk the list to see who sourced them), and of 'a'
580 * targets (so 'a' can see what modules it targets).
581 */
582static int add_module_usage(struct module *a, struct module *b)
583{
584 struct module_use *use;
585
586 pr_debug("Allocating new usage for %s.\n", a->name);
587 use = kmalloc(sizeof(*use), GFP_ATOMIC);
588 if (!use)
589 return -ENOMEM;
590
591 use->source = a;
592 use->target = b;
593 list_add(&use->source_list, &b->source_list);
594 list_add(&use->target_list, &a->target_list);
595 return 0;
596}
597
598/* Module a uses b: caller needs module_mutex() */
599static int ref_module(struct module *a, struct module *b)
600{
601 int err;
602
603 if (b == NULL || already_uses(a, b))
604 return 0;
605
606 /* If module isn't available, we fail. */
607 err = strong_try_module_get(b);
608 if (err)
609 return err;
610
611 err = add_module_usage(a, b);
612 if (err) {
613 module_put(b);
614 return err;
615 }
616 return 0;
617}
618
619/* Clear the unload stuff of the module. */
620static void module_unload_free(struct module *mod)
621{
622 struct module_use *use, *tmp;
623
624 mutex_lock(&module_mutex);
625 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
626 struct module *i = use->target;
627 pr_debug("%s unusing %s\n", mod->name, i->name);
628 module_put(i);
629 list_del(&use->source_list);
630 list_del(&use->target_list);
631 kfree(use);
632 }
633 mutex_unlock(&module_mutex);
634}
635
636#ifdef CONFIG_MODULE_FORCE_UNLOAD
637static inline int try_force_unload(unsigned int flags)
638{
639 int ret = (flags & O_TRUNC);
640 if (ret)
641 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
642 return ret;
643}
644#else
645static inline int try_force_unload(unsigned int flags)
646{
647 return 0;
648}
649#endif /* CONFIG_MODULE_FORCE_UNLOAD */
650
651/* Try to release refcount of module, 0 means success. */
652static int try_release_module_ref(struct module *mod)
653{
654 int ret;
655
656 /* Try to decrement refcnt which we set at loading */
657 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
658 BUG_ON(ret < 0);
659 if (ret)
660 /* Someone can put this right now, recover with checking */
661 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
662
663 return ret;
664}
665
666static int try_stop_module(struct module *mod, int flags, int *forced)
667{
668 /* If it's not unused, quit unless we're forcing. */
669 if (try_release_module_ref(mod) != 0) {
670 *forced = try_force_unload(flags);
671 if (!(*forced))
672 return -EWOULDBLOCK;
673 }
674
675 /* Mark it as dying. */
676 mod->state = MODULE_STATE_GOING;
677
678 return 0;
679}
680
681/**
682 * module_refcount() - return the refcount or -1 if unloading
683 * @mod: the module we're checking
684 *
685 * Return:
686 * -1 if the module is in the process of unloading
687 * otherwise the number of references in the kernel to the module
688 */
689int module_refcount(struct module *mod)
690{
691 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
692}
693EXPORT_SYMBOL(module_refcount);
694
695/* This exists whether we can unload or not */
696static void free_module(struct module *mod);
697
698SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
699 unsigned int, flags)
700{
701 struct module *mod;
702 char name[MODULE_NAME_LEN];
703 char buf[MODULE_FLAGS_BUF_SIZE];
704 int ret, forced = 0;
705
706 if (!capable(CAP_SYS_MODULE) || modules_disabled)
707 return -EPERM;
708
709 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
710 return -EFAULT;
711 name[MODULE_NAME_LEN-1] = '\0';
712
713 audit_log_kern_module(name);
714
715 if (mutex_lock_interruptible(&module_mutex) != 0)
716 return -EINTR;
717
718 mod = find_module(name);
719 if (!mod) {
720 ret = -ENOENT;
721 goto out;
722 }
723
724 if (!list_empty(&mod->source_list)) {
725 /* Other modules depend on us: get rid of them first. */
726 ret = -EWOULDBLOCK;
727 goto out;
728 }
729
730 /* Doing init or already dying? */
731 if (mod->state != MODULE_STATE_LIVE) {
732 /* FIXME: if (force), slam module count damn the torpedoes */
733 pr_debug("%s already dying\n", mod->name);
734 ret = -EBUSY;
735 goto out;
736 }
737
738 /* If it has an init func, it must have an exit func to unload */
739 if (mod->init && !mod->exit) {
740 forced = try_force_unload(flags);
741 if (!forced) {
742 /* This module can't be removed */
743 ret = -EBUSY;
744 goto out;
745 }
746 }
747
748 ret = try_stop_module(mod, flags, &forced);
749 if (ret != 0)
750 goto out;
751
752 mutex_unlock(&module_mutex);
753 /* Final destruction now no one is using it. */
754 if (mod->exit != NULL)
755 mod->exit();
756 blocking_notifier_call_chain(&module_notify_list,
757 MODULE_STATE_GOING, mod);
758 klp_module_going(mod);
759 ftrace_release_mod(mod);
760
761 async_synchronize_full();
762
763 /* Store the name and taints of the last unloaded module for diagnostic purposes */
764 strscpy(last_unloaded_module.name, mod->name, sizeof(last_unloaded_module.name));
765 strscpy(last_unloaded_module.taints, module_flags(mod, buf, false), sizeof(last_unloaded_module.taints));
766
767 free_module(mod);
768 /* someone could wait for the module in add_unformed_module() */
769 wake_up_all(&module_wq);
770 return 0;
771out:
772 mutex_unlock(&module_mutex);
773 return ret;
774}
775
776void __symbol_put(const char *symbol)
777{
778 struct find_symbol_arg fsa = {
779 .name = symbol,
780 .gplok = true,
781 };
782
783 preempt_disable();
784 BUG_ON(!find_symbol(&fsa));
785 module_put(fsa.owner);
786 preempt_enable();
787}
788EXPORT_SYMBOL(__symbol_put);
789
790/* Note this assumes addr is a function, which it currently always is. */
791void symbol_put_addr(void *addr)
792{
793 struct module *modaddr;
794 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
795
796 if (core_kernel_text(a))
797 return;
798
799 /*
800 * Even though we hold a reference on the module; we still need to
801 * disable preemption in order to safely traverse the data structure.
802 */
803 preempt_disable();
804 modaddr = __module_text_address(a);
805 BUG_ON(!modaddr);
806 module_put(modaddr);
807 preempt_enable();
808}
809EXPORT_SYMBOL_GPL(symbol_put_addr);
810
811static ssize_t show_refcnt(struct module_attribute *mattr,
812 struct module_kobject *mk, char *buffer)
813{
814 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
815}
816
817static struct module_attribute modinfo_refcnt =
818 __ATTR(refcnt, 0444, show_refcnt, NULL);
819
820void __module_get(struct module *module)
821{
822 if (module) {
823 atomic_inc(&module->refcnt);
824 trace_module_get(module, _RET_IP_);
825 }
826}
827EXPORT_SYMBOL(__module_get);
828
829bool try_module_get(struct module *module)
830{
831 bool ret = true;
832
833 if (module) {
834 /* Note: here, we can fail to get a reference */
835 if (likely(module_is_live(module) &&
836 atomic_inc_not_zero(&module->refcnt) != 0))
837 trace_module_get(module, _RET_IP_);
838 else
839 ret = false;
840 }
841 return ret;
842}
843EXPORT_SYMBOL(try_module_get);
844
845void module_put(struct module *module)
846{
847 int ret;
848
849 if (module) {
850 ret = atomic_dec_if_positive(&module->refcnt);
851 WARN_ON(ret < 0); /* Failed to put refcount */
852 trace_module_put(module, _RET_IP_);
853 }
854}
855EXPORT_SYMBOL(module_put);
856
857#else /* !CONFIG_MODULE_UNLOAD */
858static inline void module_unload_free(struct module *mod)
859{
860}
861
862static int ref_module(struct module *a, struct module *b)
863{
864 return strong_try_module_get(b);
865}
866
867static inline int module_unload_init(struct module *mod)
868{
869 return 0;
870}
871#endif /* CONFIG_MODULE_UNLOAD */
872
873size_t module_flags_taint(unsigned long taints, char *buf)
874{
875 size_t l = 0;
876 int i;
877
878 for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
879 if (taint_flags[i].module && test_bit(i, &taints))
880 buf[l++] = taint_flags[i].c_true;
881 }
882
883 return l;
884}
885
886static ssize_t show_initstate(struct module_attribute *mattr,
887 struct module_kobject *mk, char *buffer)
888{
889 const char *state = "unknown";
890
891 switch (mk->mod->state) {
892 case MODULE_STATE_LIVE:
893 state = "live";
894 break;
895 case MODULE_STATE_COMING:
896 state = "coming";
897 break;
898 case MODULE_STATE_GOING:
899 state = "going";
900 break;
901 default:
902 BUG();
903 }
904 return sprintf(buffer, "%s\n", state);
905}
906
907static struct module_attribute modinfo_initstate =
908 __ATTR(initstate, 0444, show_initstate, NULL);
909
910static ssize_t store_uevent(struct module_attribute *mattr,
911 struct module_kobject *mk,
912 const char *buffer, size_t count)
913{
914 int rc;
915
916 rc = kobject_synth_uevent(&mk->kobj, buffer, count);
917 return rc ? rc : count;
918}
919
920struct module_attribute module_uevent =
921 __ATTR(uevent, 0200, NULL, store_uevent);
922
923static ssize_t show_coresize(struct module_attribute *mattr,
924 struct module_kobject *mk, char *buffer)
925{
926 unsigned int size = mk->mod->mem[MOD_TEXT].size;
927
928 if (!IS_ENABLED(CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC)) {
929 for_class_mod_mem_type(type, core_data)
930 size += mk->mod->mem[type].size;
931 }
932 return sprintf(buffer, "%u\n", size);
933}
934
935static struct module_attribute modinfo_coresize =
936 __ATTR(coresize, 0444, show_coresize, NULL);
937
938#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
939static ssize_t show_datasize(struct module_attribute *mattr,
940 struct module_kobject *mk, char *buffer)
941{
942 unsigned int size = 0;
943
944 for_class_mod_mem_type(type, core_data)
945 size += mk->mod->mem[type].size;
946 return sprintf(buffer, "%u\n", size);
947}
948
949static struct module_attribute modinfo_datasize =
950 __ATTR(datasize, 0444, show_datasize, NULL);
951#endif
952
953static ssize_t show_initsize(struct module_attribute *mattr,
954 struct module_kobject *mk, char *buffer)
955{
956 unsigned int size = 0;
957
958 for_class_mod_mem_type(type, init)
959 size += mk->mod->mem[type].size;
960 return sprintf(buffer, "%u\n", size);
961}
962
963static struct module_attribute modinfo_initsize =
964 __ATTR(initsize, 0444, show_initsize, NULL);
965
966static ssize_t show_taint(struct module_attribute *mattr,
967 struct module_kobject *mk, char *buffer)
968{
969 size_t l;
970
971 l = module_flags_taint(mk->mod->taints, buffer);
972 buffer[l++] = '\n';
973 return l;
974}
975
976static struct module_attribute modinfo_taint =
977 __ATTR(taint, 0444, show_taint, NULL);
978
979struct module_attribute *modinfo_attrs[] = {
980 &module_uevent,
981 &modinfo_version,
982 &modinfo_srcversion,
983 &modinfo_initstate,
984 &modinfo_coresize,
985#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
986 &modinfo_datasize,
987#endif
988 &modinfo_initsize,
989 &modinfo_taint,
990#ifdef CONFIG_MODULE_UNLOAD
991 &modinfo_refcnt,
992#endif
993 NULL,
994};
995
996size_t modinfo_attrs_count = ARRAY_SIZE(modinfo_attrs);
997
998static const char vermagic[] = VERMAGIC_STRING;
999
1000int try_to_force_load(struct module *mod, const char *reason)
1001{
1002#ifdef CONFIG_MODULE_FORCE_LOAD
1003 if (!test_taint(TAINT_FORCED_MODULE))
1004 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1005 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1006 return 0;
1007#else
1008 return -ENOEXEC;
1009#endif
1010}
1011
1012/* Parse tag=value strings from .modinfo section */
1013char *module_next_tag_pair(char *string, unsigned long *secsize)
1014{
1015 /* Skip non-zero chars */
1016 while (string[0]) {
1017 string++;
1018 if ((*secsize)-- <= 1)
1019 return NULL;
1020 }
1021
1022 /* Skip any zero padding. */
1023 while (!string[0]) {
1024 string++;
1025 if ((*secsize)-- <= 1)
1026 return NULL;
1027 }
1028 return string;
1029}
1030
1031static char *get_next_modinfo(const struct load_info *info, const char *tag,
1032 char *prev)
1033{
1034 char *p;
1035 unsigned int taglen = strlen(tag);
1036 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
1037 unsigned long size = infosec->sh_size;
1038
1039 /*
1040 * get_modinfo() calls made before rewrite_section_headers()
1041 * must use sh_offset, as sh_addr isn't set!
1042 */
1043 char *modinfo = (char *)info->hdr + infosec->sh_offset;
1044
1045 if (prev) {
1046 size -= prev - modinfo;
1047 modinfo = module_next_tag_pair(prev, &size);
1048 }
1049
1050 for (p = modinfo; p; p = module_next_tag_pair(p, &size)) {
1051 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
1052 return p + taglen + 1;
1053 }
1054 return NULL;
1055}
1056
1057static char *get_modinfo(const struct load_info *info, const char *tag)
1058{
1059 return get_next_modinfo(info, tag, NULL);
1060}
1061
1062static int verify_namespace_is_imported(const struct load_info *info,
1063 const struct kernel_symbol *sym,
1064 struct module *mod)
1065{
1066 const char *namespace;
1067 char *imported_namespace;
1068
1069 namespace = kernel_symbol_namespace(sym);
1070 if (namespace && namespace[0]) {
1071 for_each_modinfo_entry(imported_namespace, info, "import_ns") {
1072 if (strcmp(namespace, imported_namespace) == 0)
1073 return 0;
1074 }
1075#ifdef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1076 pr_warn(
1077#else
1078 pr_err(
1079#endif
1080 "%s: module uses symbol (%s) from namespace %s, but does not import it.\n",
1081 mod->name, kernel_symbol_name(sym), namespace);
1082#ifndef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1083 return -EINVAL;
1084#endif
1085 }
1086 return 0;
1087}
1088
1089static bool inherit_taint(struct module *mod, struct module *owner, const char *name)
1090{
1091 if (!owner || !test_bit(TAINT_PROPRIETARY_MODULE, &owner->taints))
1092 return true;
1093
1094 if (mod->using_gplonly_symbols) {
1095 pr_err("%s: module using GPL-only symbols uses symbols %s from proprietary module %s.\n",
1096 mod->name, name, owner->name);
1097 return false;
1098 }
1099
1100 if (!test_bit(TAINT_PROPRIETARY_MODULE, &mod->taints)) {
1101 pr_warn("%s: module uses symbols %s from proprietary module %s, inheriting taint.\n",
1102 mod->name, name, owner->name);
1103 set_bit(TAINT_PROPRIETARY_MODULE, &mod->taints);
1104 }
1105 return true;
1106}
1107
1108/* Resolve a symbol for this module. I.e. if we find one, record usage. */
1109static const struct kernel_symbol *resolve_symbol(struct module *mod,
1110 const struct load_info *info,
1111 const char *name,
1112 char ownername[])
1113{
1114 struct find_symbol_arg fsa = {
1115 .name = name,
1116 .gplok = !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)),
1117 .warn = true,
1118 };
1119 int err;
1120
1121 /*
1122 * The module_mutex should not be a heavily contended lock;
1123 * if we get the occasional sleep here, we'll go an extra iteration
1124 * in the wait_event_interruptible(), which is harmless.
1125 */
1126 sched_annotate_sleep();
1127 mutex_lock(&module_mutex);
1128 if (!find_symbol(&fsa))
1129 goto unlock;
1130
1131 if (fsa.license == GPL_ONLY)
1132 mod->using_gplonly_symbols = true;
1133
1134 if (!inherit_taint(mod, fsa.owner, name)) {
1135 fsa.sym = NULL;
1136 goto getname;
1137 }
1138
1139 if (!check_version(info, name, mod, fsa.crc)) {
1140 fsa.sym = ERR_PTR(-EINVAL);
1141 goto getname;
1142 }
1143
1144 err = verify_namespace_is_imported(info, fsa.sym, mod);
1145 if (err) {
1146 fsa.sym = ERR_PTR(err);
1147 goto getname;
1148 }
1149
1150 err = ref_module(mod, fsa.owner);
1151 if (err) {
1152 fsa.sym = ERR_PTR(err);
1153 goto getname;
1154 }
1155
1156getname:
1157 /* We must make copy under the lock if we failed to get ref. */
1158 strncpy(ownername, module_name(fsa.owner), MODULE_NAME_LEN);
1159unlock:
1160 mutex_unlock(&module_mutex);
1161 return fsa.sym;
1162}
1163
1164static const struct kernel_symbol *
1165resolve_symbol_wait(struct module *mod,
1166 const struct load_info *info,
1167 const char *name)
1168{
1169 const struct kernel_symbol *ksym;
1170 char owner[MODULE_NAME_LEN];
1171
1172 if (wait_event_interruptible_timeout(module_wq,
1173 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1174 || PTR_ERR(ksym) != -EBUSY,
1175 30 * HZ) <= 0) {
1176 pr_warn("%s: gave up waiting for init of module %s.\n",
1177 mod->name, owner);
1178 }
1179 return ksym;
1180}
1181
1182void __weak module_memfree(void *module_region)
1183{
1184 /*
1185 * This memory may be RO, and freeing RO memory in an interrupt is not
1186 * supported by vmalloc.
1187 */
1188 WARN_ON(in_interrupt());
1189 vfree(module_region);
1190}
1191
1192void __weak module_arch_cleanup(struct module *mod)
1193{
1194}
1195
1196void __weak module_arch_freeing_init(struct module *mod)
1197{
1198}
1199
1200static bool mod_mem_use_vmalloc(enum mod_mem_type type)
1201{
1202 return IS_ENABLED(CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC) &&
1203 mod_mem_type_is_core_data(type);
1204}
1205
1206static void *module_memory_alloc(unsigned int size, enum mod_mem_type type)
1207{
1208 if (mod_mem_use_vmalloc(type))
1209 return vzalloc(size);
1210 return module_alloc(size);
1211}
1212
1213static void module_memory_free(void *ptr, enum mod_mem_type type)
1214{
1215 if (mod_mem_use_vmalloc(type))
1216 vfree(ptr);
1217 else
1218 module_memfree(ptr);
1219}
1220
1221static void free_mod_mem(struct module *mod)
1222{
1223 for_each_mod_mem_type(type) {
1224 struct module_memory *mod_mem = &mod->mem[type];
1225
1226 if (type == MOD_DATA)
1227 continue;
1228
1229 /* Free lock-classes; relies on the preceding sync_rcu(). */
1230 lockdep_free_key_range(mod_mem->base, mod_mem->size);
1231 if (mod_mem->size)
1232 module_memory_free(mod_mem->base, type);
1233 }
1234
1235 /* MOD_DATA hosts mod, so free it at last */
1236 lockdep_free_key_range(mod->mem[MOD_DATA].base, mod->mem[MOD_DATA].size);
1237 module_memory_free(mod->mem[MOD_DATA].base, MOD_DATA);
1238}
1239
1240/* Free a module, remove from lists, etc. */
1241static void free_module(struct module *mod)
1242{
1243 trace_module_free(mod);
1244
1245 mod_sysfs_teardown(mod);
1246
1247 /*
1248 * We leave it in list to prevent duplicate loads, but make sure
1249 * that noone uses it while it's being deconstructed.
1250 */
1251 mutex_lock(&module_mutex);
1252 mod->state = MODULE_STATE_UNFORMED;
1253 mutex_unlock(&module_mutex);
1254
1255 /* Arch-specific cleanup. */
1256 module_arch_cleanup(mod);
1257
1258 /* Module unload stuff */
1259 module_unload_free(mod);
1260
1261 /* Free any allocated parameters. */
1262 destroy_params(mod->kp, mod->num_kp);
1263
1264 if (is_livepatch_module(mod))
1265 free_module_elf(mod);
1266
1267 /* Now we can delete it from the lists */
1268 mutex_lock(&module_mutex);
1269 /* Unlink carefully: kallsyms could be walking list. */
1270 list_del_rcu(&mod->list);
1271 mod_tree_remove(mod);
1272 /* Remove this module from bug list, this uses list_del_rcu */
1273 module_bug_cleanup(mod);
1274 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
1275 synchronize_rcu();
1276 if (try_add_tainted_module(mod))
1277 pr_err("%s: adding tainted module to the unloaded tainted modules list failed.\n",
1278 mod->name);
1279 mutex_unlock(&module_mutex);
1280
1281 /* This may be empty, but that's OK */
1282 module_arch_freeing_init(mod);
1283 kfree(mod->args);
1284 percpu_modfree(mod);
1285
1286 free_mod_mem(mod);
1287}
1288
1289void *__symbol_get(const char *symbol)
1290{
1291 struct find_symbol_arg fsa = {
1292 .name = symbol,
1293 .gplok = true,
1294 .warn = true,
1295 };
1296
1297 preempt_disable();
1298 if (!find_symbol(&fsa))
1299 goto fail;
1300 if (fsa.license != GPL_ONLY) {
1301 pr_warn("failing symbol_get of non-GPLONLY symbol %s.\n",
1302 symbol);
1303 goto fail;
1304 }
1305 if (strong_try_module_get(fsa.owner))
1306 goto fail;
1307 preempt_enable();
1308 return (void *)kernel_symbol_value(fsa.sym);
1309fail:
1310 preempt_enable();
1311 return NULL;
1312}
1313EXPORT_SYMBOL_GPL(__symbol_get);
1314
1315/*
1316 * Ensure that an exported symbol [global namespace] does not already exist
1317 * in the kernel or in some other module's exported symbol table.
1318 *
1319 * You must hold the module_mutex.
1320 */
1321static int verify_exported_symbols(struct module *mod)
1322{
1323 unsigned int i;
1324 const struct kernel_symbol *s;
1325 struct {
1326 const struct kernel_symbol *sym;
1327 unsigned int num;
1328 } arr[] = {
1329 { mod->syms, mod->num_syms },
1330 { mod->gpl_syms, mod->num_gpl_syms },
1331 };
1332
1333 for (i = 0; i < ARRAY_SIZE(arr); i++) {
1334 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1335 struct find_symbol_arg fsa = {
1336 .name = kernel_symbol_name(s),
1337 .gplok = true,
1338 };
1339 if (find_symbol(&fsa)) {
1340 pr_err("%s: exports duplicate symbol %s"
1341 " (owned by %s)\n",
1342 mod->name, kernel_symbol_name(s),
1343 module_name(fsa.owner));
1344 return -ENOEXEC;
1345 }
1346 }
1347 }
1348 return 0;
1349}
1350
1351static bool ignore_undef_symbol(Elf_Half emachine, const char *name)
1352{
1353 /*
1354 * On x86, PIC code and Clang non-PIC code may have call foo@PLT. GNU as
1355 * before 2.37 produces an unreferenced _GLOBAL_OFFSET_TABLE_ on x86-64.
1356 * i386 has a similar problem but may not deserve a fix.
1357 *
1358 * If we ever have to ignore many symbols, consider refactoring the code to
1359 * only warn if referenced by a relocation.
1360 */
1361 if (emachine == EM_386 || emachine == EM_X86_64)
1362 return !strcmp(name, "_GLOBAL_OFFSET_TABLE_");
1363 return false;
1364}
1365
1366/* Change all symbols so that st_value encodes the pointer directly. */
1367static int simplify_symbols(struct module *mod, const struct load_info *info)
1368{
1369 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
1370 Elf_Sym *sym = (void *)symsec->sh_addr;
1371 unsigned long secbase;
1372 unsigned int i;
1373 int ret = 0;
1374 const struct kernel_symbol *ksym;
1375
1376 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
1377 const char *name = info->strtab + sym[i].st_name;
1378
1379 switch (sym[i].st_shndx) {
1380 case SHN_COMMON:
1381 /* Ignore common symbols */
1382 if (!strncmp(name, "__gnu_lto", 9))
1383 break;
1384
1385 /*
1386 * We compiled with -fno-common. These are not
1387 * supposed to happen.
1388 */
1389 pr_debug("Common symbol: %s\n", name);
1390 pr_warn("%s: please compile with -fno-common\n",
1391 mod->name);
1392 ret = -ENOEXEC;
1393 break;
1394
1395 case SHN_ABS:
1396 /* Don't need to do anything */
1397 pr_debug("Absolute symbol: 0x%08lx %s\n",
1398 (long)sym[i].st_value, name);
1399 break;
1400
1401 case SHN_LIVEPATCH:
1402 /* Livepatch symbols are resolved by livepatch */
1403 break;
1404
1405 case SHN_UNDEF:
1406 ksym = resolve_symbol_wait(mod, info, name);
1407 /* Ok if resolved. */
1408 if (ksym && !IS_ERR(ksym)) {
1409 sym[i].st_value = kernel_symbol_value(ksym);
1410 break;
1411 }
1412
1413 /* Ok if weak or ignored. */
1414 if (!ksym &&
1415 (ELF_ST_BIND(sym[i].st_info) == STB_WEAK ||
1416 ignore_undef_symbol(info->hdr->e_machine, name)))
1417 break;
1418
1419 ret = PTR_ERR(ksym) ?: -ENOENT;
1420 pr_warn("%s: Unknown symbol %s (err %d)\n",
1421 mod->name, name, ret);
1422 break;
1423
1424 default:
1425 /* Divert to percpu allocation if a percpu var. */
1426 if (sym[i].st_shndx == info->index.pcpu)
1427 secbase = (unsigned long)mod_percpu(mod);
1428 else
1429 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
1430 sym[i].st_value += secbase;
1431 break;
1432 }
1433 }
1434
1435 return ret;
1436}
1437
1438static int apply_relocations(struct module *mod, const struct load_info *info)
1439{
1440 unsigned int i;
1441 int err = 0;
1442
1443 /* Now do relocations. */
1444 for (i = 1; i < info->hdr->e_shnum; i++) {
1445 unsigned int infosec = info->sechdrs[i].sh_info;
1446
1447 /* Not a valid relocation section? */
1448 if (infosec >= info->hdr->e_shnum)
1449 continue;
1450
1451 /* Don't bother with non-allocated sections */
1452 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
1453 continue;
1454
1455 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
1456 err = klp_apply_section_relocs(mod, info->sechdrs,
1457 info->secstrings,
1458 info->strtab,
1459 info->index.sym, i,
1460 NULL);
1461 else if (info->sechdrs[i].sh_type == SHT_REL)
1462 err = apply_relocate(info->sechdrs, info->strtab,
1463 info->index.sym, i, mod);
1464 else if (info->sechdrs[i].sh_type == SHT_RELA)
1465 err = apply_relocate_add(info->sechdrs, info->strtab,
1466 info->index.sym, i, mod);
1467 if (err < 0)
1468 break;
1469 }
1470 return err;
1471}
1472
1473/* Additional bytes needed by arch in front of individual sections */
1474unsigned int __weak arch_mod_section_prepend(struct module *mod,
1475 unsigned int section)
1476{
1477 /* default implementation just returns zero */
1478 return 0;
1479}
1480
1481long module_get_offset_and_type(struct module *mod, enum mod_mem_type type,
1482 Elf_Shdr *sechdr, unsigned int section)
1483{
1484 long offset;
1485 long mask = ((unsigned long)(type) & SH_ENTSIZE_TYPE_MASK) << SH_ENTSIZE_TYPE_SHIFT;
1486
1487 mod->mem[type].size += arch_mod_section_prepend(mod, section);
1488 offset = ALIGN(mod->mem[type].size, sechdr->sh_addralign ?: 1);
1489 mod->mem[type].size = offset + sechdr->sh_size;
1490
1491 WARN_ON_ONCE(offset & mask);
1492 return offset | mask;
1493}
1494
1495bool module_init_layout_section(const char *sname)
1496{
1497#ifndef CONFIG_MODULE_UNLOAD
1498 if (module_exit_section(sname))
1499 return true;
1500#endif
1501 return module_init_section(sname);
1502}
1503
1504static void __layout_sections(struct module *mod, struct load_info *info, bool is_init)
1505{
1506 unsigned int m, i;
1507
1508 static const unsigned long masks[][2] = {
1509 /*
1510 * NOTE: all executable code must be the first section
1511 * in this array; otherwise modify the text_size
1512 * finder in the two loops below
1513 */
1514 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
1515 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
1516 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
1517 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
1518 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
1519 };
1520 static const int core_m_to_mem_type[] = {
1521 MOD_TEXT,
1522 MOD_RODATA,
1523 MOD_RO_AFTER_INIT,
1524 MOD_DATA,
1525 MOD_DATA,
1526 };
1527 static const int init_m_to_mem_type[] = {
1528 MOD_INIT_TEXT,
1529 MOD_INIT_RODATA,
1530 MOD_INVALID,
1531 MOD_INIT_DATA,
1532 MOD_INIT_DATA,
1533 };
1534
1535 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1536 enum mod_mem_type type = is_init ? init_m_to_mem_type[m] : core_m_to_mem_type[m];
1537
1538 for (i = 0; i < info->hdr->e_shnum; ++i) {
1539 Elf_Shdr *s = &info->sechdrs[i];
1540 const char *sname = info->secstrings + s->sh_name;
1541
1542 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1543 || (s->sh_flags & masks[m][1])
1544 || s->sh_entsize != ~0UL
1545 || is_init != module_init_layout_section(sname))
1546 continue;
1547
1548 if (WARN_ON_ONCE(type == MOD_INVALID))
1549 continue;
1550
1551 s->sh_entsize = module_get_offset_and_type(mod, type, s, i);
1552 pr_debug("\t%s\n", sname);
1553 }
1554 }
1555}
1556
1557/*
1558 * Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
1559 * might -- code, read-only data, read-write data, small data. Tally
1560 * sizes, and place the offsets into sh_entsize fields: high bit means it
1561 * belongs in init.
1562 */
1563static void layout_sections(struct module *mod, struct load_info *info)
1564{
1565 unsigned int i;
1566
1567 for (i = 0; i < info->hdr->e_shnum; i++)
1568 info->sechdrs[i].sh_entsize = ~0UL;
1569
1570 pr_debug("Core section allocation order for %s:\n", mod->name);
1571 __layout_sections(mod, info, false);
1572
1573 pr_debug("Init section allocation order for %s:\n", mod->name);
1574 __layout_sections(mod, info, true);
1575}
1576
1577static void module_license_taint_check(struct module *mod, const char *license)
1578{
1579 if (!license)
1580 license = "unspecified";
1581
1582 if (!license_is_gpl_compatible(license)) {
1583 if (!test_taint(TAINT_PROPRIETARY_MODULE))
1584 pr_warn("%s: module license '%s' taints kernel.\n",
1585 mod->name, license);
1586 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
1587 LOCKDEP_NOW_UNRELIABLE);
1588 }
1589}
1590
1591static void setup_modinfo(struct module *mod, struct load_info *info)
1592{
1593 struct module_attribute *attr;
1594 int i;
1595
1596 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1597 if (attr->setup)
1598 attr->setup(mod, get_modinfo(info, attr->attr.name));
1599 }
1600}
1601
1602static void free_modinfo(struct module *mod)
1603{
1604 struct module_attribute *attr;
1605 int i;
1606
1607 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1608 if (attr->free)
1609 attr->free(mod);
1610 }
1611}
1612
1613void * __weak module_alloc(unsigned long size)
1614{
1615 return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
1616 GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS,
1617 NUMA_NO_NODE, __builtin_return_address(0));
1618}
1619
1620bool __weak module_init_section(const char *name)
1621{
1622 return strstarts(name, ".init");
1623}
1624
1625bool __weak module_exit_section(const char *name)
1626{
1627 return strstarts(name, ".exit");
1628}
1629
1630static int validate_section_offset(struct load_info *info, Elf_Shdr *shdr)
1631{
1632#if defined(CONFIG_64BIT)
1633 unsigned long long secend;
1634#else
1635 unsigned long secend;
1636#endif
1637
1638 /*
1639 * Check for both overflow and offset/size being
1640 * too large.
1641 */
1642 secend = shdr->sh_offset + shdr->sh_size;
1643 if (secend < shdr->sh_offset || secend > info->len)
1644 return -ENOEXEC;
1645
1646 return 0;
1647}
1648
1649/*
1650 * Check userspace passed ELF module against our expectations, and cache
1651 * useful variables for further processing as we go.
1652 *
1653 * This does basic validity checks against section offsets and sizes, the
1654 * section name string table, and the indices used for it (sh_name).
1655 *
1656 * As a last step, since we're already checking the ELF sections we cache
1657 * useful variables which will be used later for our convenience:
1658 *
1659 * o pointers to section headers
1660 * o cache the modinfo symbol section
1661 * o cache the string symbol section
1662 * o cache the module section
1663 *
1664 * As a last step we set info->mod to the temporary copy of the module in
1665 * info->hdr. The final one will be allocated in move_module(). Any
1666 * modifications we make to our copy of the module will be carried over
1667 * to the final minted module.
1668 */
1669static int elf_validity_cache_copy(struct load_info *info, int flags)
1670{
1671 unsigned int i;
1672 Elf_Shdr *shdr, *strhdr;
1673 int err;
1674 unsigned int num_mod_secs = 0, mod_idx;
1675 unsigned int num_info_secs = 0, info_idx;
1676 unsigned int num_sym_secs = 0, sym_idx;
1677
1678 if (info->len < sizeof(*(info->hdr))) {
1679 pr_err("Invalid ELF header len %lu\n", info->len);
1680 goto no_exec;
1681 }
1682
1683 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0) {
1684 pr_err("Invalid ELF header magic: != %s\n", ELFMAG);
1685 goto no_exec;
1686 }
1687 if (info->hdr->e_type != ET_REL) {
1688 pr_err("Invalid ELF header type: %u != %u\n",
1689 info->hdr->e_type, ET_REL);
1690 goto no_exec;
1691 }
1692 if (!elf_check_arch(info->hdr)) {
1693 pr_err("Invalid architecture in ELF header: %u\n",
1694 info->hdr->e_machine);
1695 goto no_exec;
1696 }
1697 if (!module_elf_check_arch(info->hdr)) {
1698 pr_err("Invalid module architecture in ELF header: %u\n",
1699 info->hdr->e_machine);
1700 goto no_exec;
1701 }
1702 if (info->hdr->e_shentsize != sizeof(Elf_Shdr)) {
1703 pr_err("Invalid ELF section header size\n");
1704 goto no_exec;
1705 }
1706
1707 /*
1708 * e_shnum is 16 bits, and sizeof(Elf_Shdr) is
1709 * known and small. So e_shnum * sizeof(Elf_Shdr)
1710 * will not overflow unsigned long on any platform.
1711 */
1712 if (info->hdr->e_shoff >= info->len
1713 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
1714 info->len - info->hdr->e_shoff)) {
1715 pr_err("Invalid ELF section header overflow\n");
1716 goto no_exec;
1717 }
1718
1719 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
1720
1721 /*
1722 * Verify if the section name table index is valid.
1723 */
1724 if (info->hdr->e_shstrndx == SHN_UNDEF
1725 || info->hdr->e_shstrndx >= info->hdr->e_shnum) {
1726 pr_err("Invalid ELF section name index: %d || e_shstrndx (%d) >= e_shnum (%d)\n",
1727 info->hdr->e_shstrndx, info->hdr->e_shstrndx,
1728 info->hdr->e_shnum);
1729 goto no_exec;
1730 }
1731
1732 strhdr = &info->sechdrs[info->hdr->e_shstrndx];
1733 err = validate_section_offset(info, strhdr);
1734 if (err < 0) {
1735 pr_err("Invalid ELF section hdr(type %u)\n", strhdr->sh_type);
1736 return err;
1737 }
1738
1739 /*
1740 * The section name table must be NUL-terminated, as required
1741 * by the spec. This makes strcmp and pr_* calls that access
1742 * strings in the section safe.
1743 */
1744 info->secstrings = (void *)info->hdr + strhdr->sh_offset;
1745 if (strhdr->sh_size == 0) {
1746 pr_err("empty section name table\n");
1747 goto no_exec;
1748 }
1749 if (info->secstrings[strhdr->sh_size - 1] != '\0') {
1750 pr_err("ELF Spec violation: section name table isn't null terminated\n");
1751 goto no_exec;
1752 }
1753
1754 /*
1755 * The code assumes that section 0 has a length of zero and
1756 * an addr of zero, so check for it.
1757 */
1758 if (info->sechdrs[0].sh_type != SHT_NULL
1759 || info->sechdrs[0].sh_size != 0
1760 || info->sechdrs[0].sh_addr != 0) {
1761 pr_err("ELF Spec violation: section 0 type(%d)!=SH_NULL or non-zero len or addr\n",
1762 info->sechdrs[0].sh_type);
1763 goto no_exec;
1764 }
1765
1766 for (i = 1; i < info->hdr->e_shnum; i++) {
1767 shdr = &info->sechdrs[i];
1768 switch (shdr->sh_type) {
1769 case SHT_NULL:
1770 case SHT_NOBITS:
1771 continue;
1772 case SHT_SYMTAB:
1773 if (shdr->sh_link == SHN_UNDEF
1774 || shdr->sh_link >= info->hdr->e_shnum) {
1775 pr_err("Invalid ELF sh_link!=SHN_UNDEF(%d) or (sh_link(%d) >= hdr->e_shnum(%d)\n",
1776 shdr->sh_link, shdr->sh_link,
1777 info->hdr->e_shnum);
1778 goto no_exec;
1779 }
1780 num_sym_secs++;
1781 sym_idx = i;
1782 fallthrough;
1783 default:
1784 err = validate_section_offset(info, shdr);
1785 if (err < 0) {
1786 pr_err("Invalid ELF section in module (section %u type %u)\n",
1787 i, shdr->sh_type);
1788 return err;
1789 }
1790 if (strcmp(info->secstrings + shdr->sh_name,
1791 ".gnu.linkonce.this_module") == 0) {
1792 num_mod_secs++;
1793 mod_idx = i;
1794 } else if (strcmp(info->secstrings + shdr->sh_name,
1795 ".modinfo") == 0) {
1796 num_info_secs++;
1797 info_idx = i;
1798 }
1799
1800 if (shdr->sh_flags & SHF_ALLOC) {
1801 if (shdr->sh_name >= strhdr->sh_size) {
1802 pr_err("Invalid ELF section name in module (section %u type %u)\n",
1803 i, shdr->sh_type);
1804 return -ENOEXEC;
1805 }
1806 }
1807 break;
1808 }
1809 }
1810
1811 if (num_info_secs > 1) {
1812 pr_err("Only one .modinfo section must exist.\n");
1813 goto no_exec;
1814 } else if (num_info_secs == 1) {
1815 /* Try to find a name early so we can log errors with a module name */
1816 info->index.info = info_idx;
1817 info->name = get_modinfo(info, "name");
1818 }
1819
1820 if (num_sym_secs != 1) {
1821 pr_warn("%s: module has no symbols (stripped?)\n",
1822 info->name ?: "(missing .modinfo section or name field)");
1823 goto no_exec;
1824 }
1825
1826 /* Sets internal symbols and strings. */
1827 info->index.sym = sym_idx;
1828 shdr = &info->sechdrs[sym_idx];
1829 info->index.str = shdr->sh_link;
1830 info->strtab = (char *)info->hdr + info->sechdrs[info->index.str].sh_offset;
1831
1832 /*
1833 * The ".gnu.linkonce.this_module" ELF section is special. It is
1834 * what modpost uses to refer to __this_module and let's use rely
1835 * on THIS_MODULE to point to &__this_module properly. The kernel's
1836 * modpost declares it on each modules's *.mod.c file. If the struct
1837 * module of the kernel changes a full kernel rebuild is required.
1838 *
1839 * We have a few expectaions for this special section, the following
1840 * code validates all this for us:
1841 *
1842 * o Only one section must exist
1843 * o We expect the kernel to always have to allocate it: SHF_ALLOC
1844 * o The section size must match the kernel's run time's struct module
1845 * size
1846 */
1847 if (num_mod_secs != 1) {
1848 pr_err("module %s: Only one .gnu.linkonce.this_module section must exist.\n",
1849 info->name ?: "(missing .modinfo section or name field)");
1850 goto no_exec;
1851 }
1852
1853 shdr = &info->sechdrs[mod_idx];
1854
1855 /*
1856 * This is already implied on the switch above, however let's be
1857 * pedantic about it.
1858 */
1859 if (shdr->sh_type == SHT_NOBITS) {
1860 pr_err("module %s: .gnu.linkonce.this_module section must have a size set\n",
1861 info->name ?: "(missing .modinfo section or name field)");
1862 goto no_exec;
1863 }
1864
1865 if (!(shdr->sh_flags & SHF_ALLOC)) {
1866 pr_err("module %s: .gnu.linkonce.this_module must occupy memory during process execution\n",
1867 info->name ?: "(missing .modinfo section or name field)");
1868 goto no_exec;
1869 }
1870
1871 if (shdr->sh_size != sizeof(struct module)) {
1872 pr_err("module %s: .gnu.linkonce.this_module section size must match the kernel's built struct module size at run time\n",
1873 info->name ?: "(missing .modinfo section or name field)");
1874 goto no_exec;
1875 }
1876
1877 info->index.mod = mod_idx;
1878
1879 /* This is temporary: point mod into copy of data. */
1880 info->mod = (void *)info->hdr + shdr->sh_offset;
1881
1882 /*
1883 * If we didn't load the .modinfo 'name' field earlier, fall back to
1884 * on-disk struct mod 'name' field.
1885 */
1886 if (!info->name)
1887 info->name = info->mod->name;
1888
1889 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
1890 info->index.vers = 0; /* Pretend no __versions section! */
1891 else
1892 info->index.vers = find_sec(info, "__versions");
1893
1894 info->index.pcpu = find_pcpusec(info);
1895
1896 return 0;
1897
1898no_exec:
1899 return -ENOEXEC;
1900}
1901
1902#define COPY_CHUNK_SIZE (16*PAGE_SIZE)
1903
1904static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
1905{
1906 do {
1907 unsigned long n = min(len, COPY_CHUNK_SIZE);
1908
1909 if (copy_from_user(dst, usrc, n) != 0)
1910 return -EFAULT;
1911 cond_resched();
1912 dst += n;
1913 usrc += n;
1914 len -= n;
1915 } while (len);
1916 return 0;
1917}
1918
1919static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
1920{
1921 if (!get_modinfo(info, "livepatch"))
1922 /* Nothing more to do */
1923 return 0;
1924
1925 if (set_livepatch_module(mod))
1926 return 0;
1927
1928 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
1929 mod->name);
1930 return -ENOEXEC;
1931}
1932
1933static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
1934{
1935 if (retpoline_module_ok(get_modinfo(info, "retpoline")))
1936 return;
1937
1938 pr_warn("%s: loading module not compiled with retpoline compiler.\n",
1939 mod->name);
1940}
1941
1942/* Sets info->hdr and info->len. */
1943static int copy_module_from_user(const void __user *umod, unsigned long len,
1944 struct load_info *info)
1945{
1946 int err;
1947
1948 info->len = len;
1949 if (info->len < sizeof(*(info->hdr)))
1950 return -ENOEXEC;
1951
1952 err = security_kernel_load_data(LOADING_MODULE, true);
1953 if (err)
1954 return err;
1955
1956 /* Suck in entire file: we'll want most of it. */
1957 info->hdr = __vmalloc(info->len, GFP_KERNEL | __GFP_NOWARN);
1958 if (!info->hdr)
1959 return -ENOMEM;
1960
1961 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
1962 err = -EFAULT;
1963 goto out;
1964 }
1965
1966 err = security_kernel_post_load_data((char *)info->hdr, info->len,
1967 LOADING_MODULE, "init_module");
1968out:
1969 if (err)
1970 vfree(info->hdr);
1971
1972 return err;
1973}
1974
1975static void free_copy(struct load_info *info, int flags)
1976{
1977 if (flags & MODULE_INIT_COMPRESSED_FILE)
1978 module_decompress_cleanup(info);
1979 else
1980 vfree(info->hdr);
1981}
1982
1983static int rewrite_section_headers(struct load_info *info, int flags)
1984{
1985 unsigned int i;
1986
1987 /* This should always be true, but let's be sure. */
1988 info->sechdrs[0].sh_addr = 0;
1989
1990 for (i = 1; i < info->hdr->e_shnum; i++) {
1991 Elf_Shdr *shdr = &info->sechdrs[i];
1992
1993 /*
1994 * Mark all sections sh_addr with their address in the
1995 * temporary image.
1996 */
1997 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
1998
1999 }
2000
2001 /* Track but don't keep modinfo and version sections. */
2002 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2003 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2004
2005 return 0;
2006}
2007
2008/*
2009 * These calls taint the kernel depending certain module circumstances */
2010static void module_augment_kernel_taints(struct module *mod, struct load_info *info)
2011{
2012 int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
2013
2014 if (!get_modinfo(info, "intree")) {
2015 if (!test_taint(TAINT_OOT_MODULE))
2016 pr_warn("%s: loading out-of-tree module taints kernel.\n",
2017 mod->name);
2018 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2019 }
2020
2021 check_modinfo_retpoline(mod, info);
2022
2023 if (get_modinfo(info, "staging")) {
2024 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
2025 pr_warn("%s: module is from the staging directory, the quality "
2026 "is unknown, you have been warned.\n", mod->name);
2027 }
2028
2029 if (is_livepatch_module(mod)) {
2030 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
2031 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
2032 mod->name);
2033 }
2034
2035 module_license_taint_check(mod, get_modinfo(info, "license"));
2036
2037 if (get_modinfo(info, "test")) {
2038 if (!test_taint(TAINT_TEST))
2039 pr_warn("%s: loading test module taints kernel.\n",
2040 mod->name);
2041 add_taint_module(mod, TAINT_TEST, LOCKDEP_STILL_OK);
2042 }
2043#ifdef CONFIG_MODULE_SIG
2044 mod->sig_ok = info->sig_ok;
2045 if (!mod->sig_ok) {
2046 pr_notice_once("%s: module verification failed: signature "
2047 "and/or required key missing - tainting "
2048 "kernel\n", mod->name);
2049 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
2050 }
2051#endif
2052
2053 /*
2054 * ndiswrapper is under GPL by itself, but loads proprietary modules.
2055 * Don't use add_taint_module(), as it would prevent ndiswrapper from
2056 * using GPL-only symbols it needs.
2057 */
2058 if (strcmp(mod->name, "ndiswrapper") == 0)
2059 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
2060
2061 /* driverloader was caught wrongly pretending to be under GPL */
2062 if (strcmp(mod->name, "driverloader") == 0)
2063 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2064 LOCKDEP_NOW_UNRELIABLE);
2065
2066 /* lve claims to be GPL but upstream won't provide source */
2067 if (strcmp(mod->name, "lve") == 0)
2068 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2069 LOCKDEP_NOW_UNRELIABLE);
2070
2071 if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
2072 pr_warn("%s: module license taints kernel.\n", mod->name);
2073
2074}
2075
2076static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2077{
2078 const char *modmagic = get_modinfo(info, "vermagic");
2079 int err;
2080
2081 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
2082 modmagic = NULL;
2083
2084 /* This is allowed: modprobe --force will invalidate it. */
2085 if (!modmagic) {
2086 err = try_to_force_load(mod, "bad vermagic");
2087 if (err)
2088 return err;
2089 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2090 pr_err("%s: version magic '%s' should be '%s'\n",
2091 info->name, modmagic, vermagic);
2092 return -ENOEXEC;
2093 }
2094
2095 err = check_modinfo_livepatch(mod, info);
2096 if (err)
2097 return err;
2098
2099 return 0;
2100}
2101
2102static int find_module_sections(struct module *mod, struct load_info *info)
2103{
2104 mod->kp = section_objs(info, "__param",
2105 sizeof(*mod->kp), &mod->num_kp);
2106 mod->syms = section_objs(info, "__ksymtab",
2107 sizeof(*mod->syms), &mod->num_syms);
2108 mod->crcs = section_addr(info, "__kcrctab");
2109 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2110 sizeof(*mod->gpl_syms),
2111 &mod->num_gpl_syms);
2112 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2113
2114#ifdef CONFIG_CONSTRUCTORS
2115 mod->ctors = section_objs(info, ".ctors",
2116 sizeof(*mod->ctors), &mod->num_ctors);
2117 if (!mod->ctors)
2118 mod->ctors = section_objs(info, ".init_array",
2119 sizeof(*mod->ctors), &mod->num_ctors);
2120 else if (find_sec(info, ".init_array")) {
2121 /*
2122 * This shouldn't happen with same compiler and binutils
2123 * building all parts of the module.
2124 */
2125 pr_warn("%s: has both .ctors and .init_array.\n",
2126 mod->name);
2127 return -EINVAL;
2128 }
2129#endif
2130
2131 mod->noinstr_text_start = section_objs(info, ".noinstr.text", 1,
2132 &mod->noinstr_text_size);
2133
2134#ifdef CONFIG_TRACEPOINTS
2135 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2136 sizeof(*mod->tracepoints_ptrs),
2137 &mod->num_tracepoints);
2138#endif
2139#ifdef CONFIG_TREE_SRCU
2140 mod->srcu_struct_ptrs = section_objs(info, "___srcu_struct_ptrs",
2141 sizeof(*mod->srcu_struct_ptrs),
2142 &mod->num_srcu_structs);
2143#endif
2144#ifdef CONFIG_BPF_EVENTS
2145 mod->bpf_raw_events = section_objs(info, "__bpf_raw_tp_map",
2146 sizeof(*mod->bpf_raw_events),
2147 &mod->num_bpf_raw_events);
2148#endif
2149#ifdef CONFIG_DEBUG_INFO_BTF_MODULES
2150 mod->btf_data = any_section_objs(info, ".BTF", 1, &mod->btf_data_size);
2151#endif
2152#ifdef CONFIG_JUMP_LABEL
2153 mod->jump_entries = section_objs(info, "__jump_table",
2154 sizeof(*mod->jump_entries),
2155 &mod->num_jump_entries);
2156#endif
2157#ifdef CONFIG_EVENT_TRACING
2158 mod->trace_events = section_objs(info, "_ftrace_events",
2159 sizeof(*mod->trace_events),
2160 &mod->num_trace_events);
2161 mod->trace_evals = section_objs(info, "_ftrace_eval_map",
2162 sizeof(*mod->trace_evals),
2163 &mod->num_trace_evals);
2164#endif
2165#ifdef CONFIG_TRACING
2166 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2167 sizeof(*mod->trace_bprintk_fmt_start),
2168 &mod->num_trace_bprintk_fmt);
2169#endif
2170#ifdef CONFIG_FTRACE_MCOUNT_RECORD
2171 /* sechdrs[0].sh_size is always zero */
2172 mod->ftrace_callsites = section_objs(info, FTRACE_CALLSITE_SECTION,
2173 sizeof(*mod->ftrace_callsites),
2174 &mod->num_ftrace_callsites);
2175#endif
2176#ifdef CONFIG_FUNCTION_ERROR_INJECTION
2177 mod->ei_funcs = section_objs(info, "_error_injection_whitelist",
2178 sizeof(*mod->ei_funcs),
2179 &mod->num_ei_funcs);
2180#endif
2181#ifdef CONFIG_KPROBES
2182 mod->kprobes_text_start = section_objs(info, ".kprobes.text", 1,
2183 &mod->kprobes_text_size);
2184 mod->kprobe_blacklist = section_objs(info, "_kprobe_blacklist",
2185 sizeof(unsigned long),
2186 &mod->num_kprobe_blacklist);
2187#endif
2188#ifdef CONFIG_PRINTK_INDEX
2189 mod->printk_index_start = section_objs(info, ".printk_index",
2190 sizeof(*mod->printk_index_start),
2191 &mod->printk_index_size);
2192#endif
2193#ifdef CONFIG_HAVE_STATIC_CALL_INLINE
2194 mod->static_call_sites = section_objs(info, ".static_call_sites",
2195 sizeof(*mod->static_call_sites),
2196 &mod->num_static_call_sites);
2197#endif
2198#if IS_ENABLED(CONFIG_KUNIT)
2199 mod->kunit_suites = section_objs(info, ".kunit_test_suites",
2200 sizeof(*mod->kunit_suites),
2201 &mod->num_kunit_suites);
2202 mod->kunit_init_suites = section_objs(info, ".kunit_init_test_suites",
2203 sizeof(*mod->kunit_init_suites),
2204 &mod->num_kunit_init_suites);
2205#endif
2206
2207 mod->extable = section_objs(info, "__ex_table",
2208 sizeof(*mod->extable), &mod->num_exentries);
2209
2210 if (section_addr(info, "__obsparm"))
2211 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
2212
2213#ifdef CONFIG_DYNAMIC_DEBUG_CORE
2214 mod->dyndbg_info.descs = section_objs(info, "__dyndbg",
2215 sizeof(*mod->dyndbg_info.descs),
2216 &mod->dyndbg_info.num_descs);
2217 mod->dyndbg_info.classes = section_objs(info, "__dyndbg_classes",
2218 sizeof(*mod->dyndbg_info.classes),
2219 &mod->dyndbg_info.num_classes);
2220#endif
2221
2222 return 0;
2223}
2224
2225static int move_module(struct module *mod, struct load_info *info)
2226{
2227 int i;
2228 void *ptr;
2229 enum mod_mem_type t = 0;
2230 int ret = -ENOMEM;
2231
2232 for_each_mod_mem_type(type) {
2233 if (!mod->mem[type].size) {
2234 mod->mem[type].base = NULL;
2235 continue;
2236 }
2237 mod->mem[type].size = PAGE_ALIGN(mod->mem[type].size);
2238 ptr = module_memory_alloc(mod->mem[type].size, type);
2239 /*
2240 * The pointer to these blocks of memory are stored on the module
2241 * structure and we keep that around so long as the module is
2242 * around. We only free that memory when we unload the module.
2243 * Just mark them as not being a leak then. The .init* ELF
2244 * sections *do* get freed after boot so we *could* treat them
2245 * slightly differently with kmemleak_ignore() and only grey
2246 * them out as they work as typical memory allocations which
2247 * *do* eventually get freed, but let's just keep things simple
2248 * and avoid *any* false positives.
2249 */
2250 kmemleak_not_leak(ptr);
2251 if (!ptr) {
2252 t = type;
2253 goto out_enomem;
2254 }
2255 memset(ptr, 0, mod->mem[type].size);
2256 mod->mem[type].base = ptr;
2257 }
2258
2259 /* Transfer each section which specifies SHF_ALLOC */
2260 pr_debug("Final section addresses for %s:\n", mod->name);
2261 for (i = 0; i < info->hdr->e_shnum; i++) {
2262 void *dest;
2263 Elf_Shdr *shdr = &info->sechdrs[i];
2264 enum mod_mem_type type = shdr->sh_entsize >> SH_ENTSIZE_TYPE_SHIFT;
2265
2266 if (!(shdr->sh_flags & SHF_ALLOC))
2267 continue;
2268
2269 dest = mod->mem[type].base + (shdr->sh_entsize & SH_ENTSIZE_OFFSET_MASK);
2270
2271 if (shdr->sh_type != SHT_NOBITS) {
2272 /*
2273 * Our ELF checker already validated this, but let's
2274 * be pedantic and make the goal clearer. We actually
2275 * end up copying over all modifications made to the
2276 * userspace copy of the entire struct module.
2277 */
2278 if (i == info->index.mod &&
2279 (WARN_ON_ONCE(shdr->sh_size != sizeof(struct module)))) {
2280 ret = -ENOEXEC;
2281 goto out_enomem;
2282 }
2283 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2284 }
2285 /*
2286 * Update the userspace copy's ELF section address to point to
2287 * our newly allocated memory as a pure convenience so that
2288 * users of info can keep taking advantage and using the newly
2289 * minted official memory area.
2290 */
2291 shdr->sh_addr = (unsigned long)dest;
2292 pr_debug("\t0x%lx 0x%.8lx %s\n", (long)shdr->sh_addr,
2293 (long)shdr->sh_size, info->secstrings + shdr->sh_name);
2294 }
2295
2296 return 0;
2297out_enomem:
2298 for (t--; t >= 0; t--)
2299 module_memory_free(mod->mem[t].base, t);
2300 return ret;
2301}
2302
2303static int check_export_symbol_versions(struct module *mod)
2304{
2305#ifdef CONFIG_MODVERSIONS
2306 if ((mod->num_syms && !mod->crcs) ||
2307 (mod->num_gpl_syms && !mod->gpl_crcs)) {
2308 return try_to_force_load(mod,
2309 "no versions for exported symbols");
2310 }
2311#endif
2312 return 0;
2313}
2314
2315static void flush_module_icache(const struct module *mod)
2316{
2317 /*
2318 * Flush the instruction cache, since we've played with text.
2319 * Do it before processing of module parameters, so the module
2320 * can provide parameter accessor functions of its own.
2321 */
2322 for_each_mod_mem_type(type) {
2323 const struct module_memory *mod_mem = &mod->mem[type];
2324
2325 if (mod_mem->size) {
2326 flush_icache_range((unsigned long)mod_mem->base,
2327 (unsigned long)mod_mem->base + mod_mem->size);
2328 }
2329 }
2330}
2331
2332bool __weak module_elf_check_arch(Elf_Ehdr *hdr)
2333{
2334 return true;
2335}
2336
2337int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
2338 Elf_Shdr *sechdrs,
2339 char *secstrings,
2340 struct module *mod)
2341{
2342 return 0;
2343}
2344
2345/* module_blacklist is a comma-separated list of module names */
2346static char *module_blacklist;
2347static bool blacklisted(const char *module_name)
2348{
2349 const char *p;
2350 size_t len;
2351
2352 if (!module_blacklist)
2353 return false;
2354
2355 for (p = module_blacklist; *p; p += len) {
2356 len = strcspn(p, ",");
2357 if (strlen(module_name) == len && !memcmp(module_name, p, len))
2358 return true;
2359 if (p[len] == ',')
2360 len++;
2361 }
2362 return false;
2363}
2364core_param(module_blacklist, module_blacklist, charp, 0400);
2365
2366static struct module *layout_and_allocate(struct load_info *info, int flags)
2367{
2368 struct module *mod;
2369 unsigned int ndx;
2370 int err;
2371
2372 /* Allow arches to frob section contents and sizes. */
2373 err = module_frob_arch_sections(info->hdr, info->sechdrs,
2374 info->secstrings, info->mod);
2375 if (err < 0)
2376 return ERR_PTR(err);
2377
2378 err = module_enforce_rwx_sections(info->hdr, info->sechdrs,
2379 info->secstrings, info->mod);
2380 if (err < 0)
2381 return ERR_PTR(err);
2382
2383 /* We will do a special allocation for per-cpu sections later. */
2384 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
2385
2386 /*
2387 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
2388 * layout_sections() can put it in the right place.
2389 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
2390 */
2391 ndx = find_sec(info, ".data..ro_after_init");
2392 if (ndx)
2393 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
2394 /*
2395 * Mark the __jump_table section as ro_after_init as well: these data
2396 * structures are never modified, with the exception of entries that
2397 * refer to code in the __init section, which are annotated as such
2398 * at module load time.
2399 */
2400 ndx = find_sec(info, "__jump_table");
2401 if (ndx)
2402 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
2403
2404 /*
2405 * Determine total sizes, and put offsets in sh_entsize. For now
2406 * this is done generically; there doesn't appear to be any
2407 * special cases for the architectures.
2408 */
2409 layout_sections(info->mod, info);
2410 layout_symtab(info->mod, info);
2411
2412 /* Allocate and move to the final place */
2413 err = move_module(info->mod, info);
2414 if (err)
2415 return ERR_PTR(err);
2416
2417 /* Module has been copied to its final place now: return it. */
2418 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2419 kmemleak_load_module(mod, info);
2420 return mod;
2421}
2422
2423/* mod is no longer valid after this! */
2424static void module_deallocate(struct module *mod, struct load_info *info)
2425{
2426 percpu_modfree(mod);
2427 module_arch_freeing_init(mod);
2428
2429 free_mod_mem(mod);
2430}
2431
2432int __weak module_finalize(const Elf_Ehdr *hdr,
2433 const Elf_Shdr *sechdrs,
2434 struct module *me)
2435{
2436 return 0;
2437}
2438
2439static int post_relocation(struct module *mod, const struct load_info *info)
2440{
2441 /* Sort exception table now relocations are done. */
2442 sort_extable(mod->extable, mod->extable + mod->num_exentries);
2443
2444 /* Copy relocated percpu area over. */
2445 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
2446 info->sechdrs[info->index.pcpu].sh_size);
2447
2448 /* Setup kallsyms-specific fields. */
2449 add_kallsyms(mod, info);
2450
2451 /* Arch-specific module finalizing. */
2452 return module_finalize(info->hdr, info->sechdrs, mod);
2453}
2454
2455/* Call module constructors. */
2456static void do_mod_ctors(struct module *mod)
2457{
2458#ifdef CONFIG_CONSTRUCTORS
2459 unsigned long i;
2460
2461 for (i = 0; i < mod->num_ctors; i++)
2462 mod->ctors[i]();
2463#endif
2464}
2465
2466/* For freeing module_init on success, in case kallsyms traversing */
2467struct mod_initfree {
2468 struct llist_node node;
2469 void *init_text;
2470 void *init_data;
2471 void *init_rodata;
2472};
2473
2474static void do_free_init(struct work_struct *w)
2475{
2476 struct llist_node *pos, *n, *list;
2477 struct mod_initfree *initfree;
2478
2479 list = llist_del_all(&init_free_list);
2480
2481 synchronize_rcu();
2482
2483 llist_for_each_safe(pos, n, list) {
2484 initfree = container_of(pos, struct mod_initfree, node);
2485 module_memfree(initfree->init_text);
2486 module_memfree(initfree->init_data);
2487 module_memfree(initfree->init_rodata);
2488 kfree(initfree);
2489 }
2490}
2491
2492void flush_module_init_free_work(void)
2493{
2494 flush_work(&init_free_wq);
2495}
2496
2497#undef MODULE_PARAM_PREFIX
2498#define MODULE_PARAM_PREFIX "module."
2499/* Default value for module->async_probe_requested */
2500static bool async_probe;
2501module_param(async_probe, bool, 0644);
2502
2503/*
2504 * This is where the real work happens.
2505 *
2506 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
2507 * helper command 'lx-symbols'.
2508 */
2509static noinline int do_init_module(struct module *mod)
2510{
2511 int ret = 0;
2512 struct mod_initfree *freeinit;
2513#if defined(CONFIG_MODULE_STATS)
2514 unsigned int text_size = 0, total_size = 0;
2515
2516 for_each_mod_mem_type(type) {
2517 const struct module_memory *mod_mem = &mod->mem[type];
2518 if (mod_mem->size) {
2519 total_size += mod_mem->size;
2520 if (type == MOD_TEXT || type == MOD_INIT_TEXT)
2521 text_size += mod_mem->size;
2522 }
2523 }
2524#endif
2525
2526 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
2527 if (!freeinit) {
2528 ret = -ENOMEM;
2529 goto fail;
2530 }
2531 freeinit->init_text = mod->mem[MOD_INIT_TEXT].base;
2532 freeinit->init_data = mod->mem[MOD_INIT_DATA].base;
2533 freeinit->init_rodata = mod->mem[MOD_INIT_RODATA].base;
2534
2535 do_mod_ctors(mod);
2536 /* Start the module */
2537 if (mod->init != NULL)
2538 ret = do_one_initcall(mod->init);
2539 if (ret < 0) {
2540 goto fail_free_freeinit;
2541 }
2542 if (ret > 0) {
2543 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
2544 "follow 0/-E convention\n"
2545 "%s: loading module anyway...\n",
2546 __func__, mod->name, ret, __func__);
2547 dump_stack();
2548 }
2549
2550 /* Now it's a first class citizen! */
2551 mod->state = MODULE_STATE_LIVE;
2552 blocking_notifier_call_chain(&module_notify_list,
2553 MODULE_STATE_LIVE, mod);
2554
2555 /* Delay uevent until module has finished its init routine */
2556 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
2557
2558 /*
2559 * We need to finish all async code before the module init sequence
2560 * is done. This has potential to deadlock if synchronous module
2561 * loading is requested from async (which is not allowed!).
2562 *
2563 * See commit 0fdff3ec6d87 ("async, kmod: warn on synchronous
2564 * request_module() from async workers") for more details.
2565 */
2566 if (!mod->async_probe_requested)
2567 async_synchronize_full();
2568
2569 ftrace_free_mem(mod, mod->mem[MOD_INIT_TEXT].base,
2570 mod->mem[MOD_INIT_TEXT].base + mod->mem[MOD_INIT_TEXT].size);
2571 mutex_lock(&module_mutex);
2572 /* Drop initial reference. */
2573 module_put(mod);
2574 trim_init_extable(mod);
2575#ifdef CONFIG_KALLSYMS
2576 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
2577 rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
2578#endif
2579 ret = module_enable_rodata_ro(mod, true);
2580 if (ret)
2581 goto fail_mutex_unlock;
2582 mod_tree_remove_init(mod);
2583 module_arch_freeing_init(mod);
2584 for_class_mod_mem_type(type, init) {
2585 mod->mem[type].base = NULL;
2586 mod->mem[type].size = 0;
2587 }
2588
2589#ifdef CONFIG_DEBUG_INFO_BTF_MODULES
2590 /* .BTF is not SHF_ALLOC and will get removed, so sanitize pointer */
2591 mod->btf_data = NULL;
2592#endif
2593 /*
2594 * We want to free module_init, but be aware that kallsyms may be
2595 * walking this with preempt disabled. In all the failure paths, we
2596 * call synchronize_rcu(), but we don't want to slow down the success
2597 * path. module_memfree() cannot be called in an interrupt, so do the
2598 * work and call synchronize_rcu() in a work queue.
2599 *
2600 * Note that module_alloc() on most architectures creates W+X page
2601 * mappings which won't be cleaned up until do_free_init() runs. Any
2602 * code such as mark_rodata_ro() which depends on those mappings to
2603 * be cleaned up needs to sync with the queued work by invoking
2604 * flush_module_init_free_work().
2605 */
2606 if (llist_add(&freeinit->node, &init_free_list))
2607 schedule_work(&init_free_wq);
2608
2609 mutex_unlock(&module_mutex);
2610 wake_up_all(&module_wq);
2611
2612 mod_stat_add_long(text_size, &total_text_size);
2613 mod_stat_add_long(total_size, &total_mod_size);
2614
2615 mod_stat_inc(&modcount);
2616
2617 return 0;
2618
2619fail_mutex_unlock:
2620 mutex_unlock(&module_mutex);
2621fail_free_freeinit:
2622 kfree(freeinit);
2623fail:
2624 /* Try to protect us from buggy refcounters. */
2625 mod->state = MODULE_STATE_GOING;
2626 synchronize_rcu();
2627 module_put(mod);
2628 blocking_notifier_call_chain(&module_notify_list,
2629 MODULE_STATE_GOING, mod);
2630 klp_module_going(mod);
2631 ftrace_release_mod(mod);
2632 free_module(mod);
2633 wake_up_all(&module_wq);
2634
2635 return ret;
2636}
2637
2638static int may_init_module(void)
2639{
2640 if (!capable(CAP_SYS_MODULE) || modules_disabled)
2641 return -EPERM;
2642
2643 return 0;
2644}
2645
2646/* Is this module of this name done loading? No locks held. */
2647static bool finished_loading(const char *name)
2648{
2649 struct module *mod;
2650 bool ret;
2651
2652 /*
2653 * The module_mutex should not be a heavily contended lock;
2654 * if we get the occasional sleep here, we'll go an extra iteration
2655 * in the wait_event_interruptible(), which is harmless.
2656 */
2657 sched_annotate_sleep();
2658 mutex_lock(&module_mutex);
2659 mod = find_module_all(name, strlen(name), true);
2660 ret = !mod || mod->state == MODULE_STATE_LIVE
2661 || mod->state == MODULE_STATE_GOING;
2662 mutex_unlock(&module_mutex);
2663
2664 return ret;
2665}
2666
2667/* Must be called with module_mutex held */
2668static int module_patient_check_exists(const char *name,
2669 enum fail_dup_mod_reason reason)
2670{
2671 struct module *old;
2672 int err = 0;
2673
2674 old = find_module_all(name, strlen(name), true);
2675 if (old == NULL)
2676 return 0;
2677
2678 if (old->state == MODULE_STATE_COMING ||
2679 old->state == MODULE_STATE_UNFORMED) {
2680 /* Wait in case it fails to load. */
2681 mutex_unlock(&module_mutex);
2682 err = wait_event_interruptible(module_wq,
2683 finished_loading(name));
2684 mutex_lock(&module_mutex);
2685 if (err)
2686 return err;
2687
2688 /* The module might have gone in the meantime. */
2689 old = find_module_all(name, strlen(name), true);
2690 }
2691
2692 if (try_add_failed_module(name, reason))
2693 pr_warn("Could not add fail-tracking for module: %s\n", name);
2694
2695 /*
2696 * We are here only when the same module was being loaded. Do
2697 * not try to load it again right now. It prevents long delays
2698 * caused by serialized module load failures. It might happen
2699 * when more devices of the same type trigger load of
2700 * a particular module.
2701 */
2702 if (old && old->state == MODULE_STATE_LIVE)
2703 return -EEXIST;
2704 return -EBUSY;
2705}
2706
2707/*
2708 * We try to place it in the list now to make sure it's unique before
2709 * we dedicate too many resources. In particular, temporary percpu
2710 * memory exhaustion.
2711 */
2712static int add_unformed_module(struct module *mod)
2713{
2714 int err;
2715
2716 mod->state = MODULE_STATE_UNFORMED;
2717
2718 mutex_lock(&module_mutex);
2719 err = module_patient_check_exists(mod->name, FAIL_DUP_MOD_LOAD);
2720 if (err)
2721 goto out;
2722
2723 mod_update_bounds(mod);
2724 list_add_rcu(&mod->list, &modules);
2725 mod_tree_insert(mod);
2726 err = 0;
2727
2728out:
2729 mutex_unlock(&module_mutex);
2730 return err;
2731}
2732
2733static int complete_formation(struct module *mod, struct load_info *info)
2734{
2735 int err;
2736
2737 mutex_lock(&module_mutex);
2738
2739 /* Find duplicate symbols (must be called under lock). */
2740 err = verify_exported_symbols(mod);
2741 if (err < 0)
2742 goto out;
2743
2744 /* These rely on module_mutex for list integrity. */
2745 module_bug_finalize(info->hdr, info->sechdrs, mod);
2746 module_cfi_finalize(info->hdr, info->sechdrs, mod);
2747
2748 err = module_enable_rodata_ro(mod, false);
2749 if (err)
2750 goto out_strict_rwx;
2751 err = module_enable_data_nx(mod);
2752 if (err)
2753 goto out_strict_rwx;
2754 err = module_enable_text_rox(mod);
2755 if (err)
2756 goto out_strict_rwx;
2757
2758 /*
2759 * Mark state as coming so strong_try_module_get() ignores us,
2760 * but kallsyms etc. can see us.
2761 */
2762 mod->state = MODULE_STATE_COMING;
2763 mutex_unlock(&module_mutex);
2764
2765 return 0;
2766
2767out_strict_rwx:
2768 module_bug_cleanup(mod);
2769out:
2770 mutex_unlock(&module_mutex);
2771 return err;
2772}
2773
2774static int prepare_coming_module(struct module *mod)
2775{
2776 int err;
2777
2778 ftrace_module_enable(mod);
2779 err = klp_module_coming(mod);
2780 if (err)
2781 return err;
2782
2783 err = blocking_notifier_call_chain_robust(&module_notify_list,
2784 MODULE_STATE_COMING, MODULE_STATE_GOING, mod);
2785 err = notifier_to_errno(err);
2786 if (err)
2787 klp_module_going(mod);
2788
2789 return err;
2790}
2791
2792static int unknown_module_param_cb(char *param, char *val, const char *modname,
2793 void *arg)
2794{
2795 struct module *mod = arg;
2796 int ret;
2797
2798 if (strcmp(param, "async_probe") == 0) {
2799 if (kstrtobool(val, &mod->async_probe_requested))
2800 mod->async_probe_requested = true;
2801 return 0;
2802 }
2803
2804 /* Check for magic 'dyndbg' arg */
2805 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
2806 if (ret != 0)
2807 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
2808 return 0;
2809}
2810
2811/* Module within temporary copy, this doesn't do any allocation */
2812static int early_mod_check(struct load_info *info, int flags)
2813{
2814 int err;
2815
2816 /*
2817 * Now that we know we have the correct module name, check
2818 * if it's blacklisted.
2819 */
2820 if (blacklisted(info->name)) {
2821 pr_err("Module %s is blacklisted\n", info->name);
2822 return -EPERM;
2823 }
2824
2825 err = rewrite_section_headers(info, flags);
2826 if (err)
2827 return err;
2828
2829 /* Check module struct version now, before we try to use module. */
2830 if (!check_modstruct_version(info, info->mod))
2831 return -ENOEXEC;
2832
2833 err = check_modinfo(info->mod, info, flags);
2834 if (err)
2835 return err;
2836
2837 mutex_lock(&module_mutex);
2838 err = module_patient_check_exists(info->mod->name, FAIL_DUP_MOD_BECOMING);
2839 mutex_unlock(&module_mutex);
2840
2841 return err;
2842}
2843
2844/*
2845 * Allocate and load the module: note that size of section 0 is always
2846 * zero, and we rely on this for optional sections.
2847 */
2848static int load_module(struct load_info *info, const char __user *uargs,
2849 int flags)
2850{
2851 struct module *mod;
2852 bool module_allocated = false;
2853 long err = 0;
2854 char *after_dashes;
2855
2856 /*
2857 * Do the signature check (if any) first. All that
2858 * the signature check needs is info->len, it does
2859 * not need any of the section info. That can be
2860 * set up later. This will minimize the chances
2861 * of a corrupt module causing problems before
2862 * we even get to the signature check.
2863 *
2864 * The check will also adjust info->len by stripping
2865 * off the sig length at the end of the module, making
2866 * checks against info->len more correct.
2867 */
2868 err = module_sig_check(info, flags);
2869 if (err)
2870 goto free_copy;
2871
2872 /*
2873 * Do basic sanity checks against the ELF header and
2874 * sections. Cache useful sections and set the
2875 * info->mod to the userspace passed struct module.
2876 */
2877 err = elf_validity_cache_copy(info, flags);
2878 if (err)
2879 goto free_copy;
2880
2881 err = early_mod_check(info, flags);
2882 if (err)
2883 goto free_copy;
2884
2885 /* Figure out module layout, and allocate all the memory. */
2886 mod = layout_and_allocate(info, flags);
2887 if (IS_ERR(mod)) {
2888 err = PTR_ERR(mod);
2889 goto free_copy;
2890 }
2891
2892 module_allocated = true;
2893
2894 audit_log_kern_module(mod->name);
2895
2896 /* Reserve our place in the list. */
2897 err = add_unformed_module(mod);
2898 if (err)
2899 goto free_module;
2900
2901 /*
2902 * We are tainting your kernel if your module gets into
2903 * the modules linked list somehow.
2904 */
2905 module_augment_kernel_taints(mod, info);
2906
2907 /* To avoid stressing percpu allocator, do this once we're unique. */
2908 err = percpu_modalloc(mod, info);
2909 if (err)
2910 goto unlink_mod;
2911
2912 /* Now module is in final location, initialize linked lists, etc. */
2913 err = module_unload_init(mod);
2914 if (err)
2915 goto unlink_mod;
2916
2917 init_param_lock(mod);
2918
2919 /*
2920 * Now we've got everything in the final locations, we can
2921 * find optional sections.
2922 */
2923 err = find_module_sections(mod, info);
2924 if (err)
2925 goto free_unload;
2926
2927 err = check_export_symbol_versions(mod);
2928 if (err)
2929 goto free_unload;
2930
2931 /* Set up MODINFO_ATTR fields */
2932 setup_modinfo(mod, info);
2933
2934 /* Fix up syms, so that st_value is a pointer to location. */
2935 err = simplify_symbols(mod, info);
2936 if (err < 0)
2937 goto free_modinfo;
2938
2939 err = apply_relocations(mod, info);
2940 if (err < 0)
2941 goto free_modinfo;
2942
2943 err = post_relocation(mod, info);
2944 if (err < 0)
2945 goto free_modinfo;
2946
2947 flush_module_icache(mod);
2948
2949 /* Now copy in args */
2950 mod->args = strndup_user(uargs, ~0UL >> 1);
2951 if (IS_ERR(mod->args)) {
2952 err = PTR_ERR(mod->args);
2953 goto free_arch_cleanup;
2954 }
2955
2956 init_build_id(mod, info);
2957
2958 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
2959 ftrace_module_init(mod);
2960
2961 /* Finally it's fully formed, ready to start executing. */
2962 err = complete_formation(mod, info);
2963 if (err)
2964 goto ddebug_cleanup;
2965
2966 err = prepare_coming_module(mod);
2967 if (err)
2968 goto bug_cleanup;
2969
2970 mod->async_probe_requested = async_probe;
2971
2972 /* Module is ready to execute: parsing args may do that. */
2973 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
2974 -32768, 32767, mod,
2975 unknown_module_param_cb);
2976 if (IS_ERR(after_dashes)) {
2977 err = PTR_ERR(after_dashes);
2978 goto coming_cleanup;
2979 } else if (after_dashes) {
2980 pr_warn("%s: parameters '%s' after `--' ignored\n",
2981 mod->name, after_dashes);
2982 }
2983
2984 /* Link in to sysfs. */
2985 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
2986 if (err < 0)
2987 goto coming_cleanup;
2988
2989 if (is_livepatch_module(mod)) {
2990 err = copy_module_elf(mod, info);
2991 if (err < 0)
2992 goto sysfs_cleanup;
2993 }
2994
2995 /* Get rid of temporary copy. */
2996 free_copy(info, flags);
2997
2998 /* Done! */
2999 trace_module_load(mod);
3000
3001 return do_init_module(mod);
3002
3003 sysfs_cleanup:
3004 mod_sysfs_teardown(mod);
3005 coming_cleanup:
3006 mod->state = MODULE_STATE_GOING;
3007 destroy_params(mod->kp, mod->num_kp);
3008 blocking_notifier_call_chain(&module_notify_list,
3009 MODULE_STATE_GOING, mod);
3010 klp_module_going(mod);
3011 bug_cleanup:
3012 mod->state = MODULE_STATE_GOING;
3013 /* module_bug_cleanup needs module_mutex protection */
3014 mutex_lock(&module_mutex);
3015 module_bug_cleanup(mod);
3016 mutex_unlock(&module_mutex);
3017
3018 ddebug_cleanup:
3019 ftrace_release_mod(mod);
3020 synchronize_rcu();
3021 kfree(mod->args);
3022 free_arch_cleanup:
3023 module_arch_cleanup(mod);
3024 free_modinfo:
3025 free_modinfo(mod);
3026 free_unload:
3027 module_unload_free(mod);
3028 unlink_mod:
3029 mutex_lock(&module_mutex);
3030 /* Unlink carefully: kallsyms could be walking list. */
3031 list_del_rcu(&mod->list);
3032 mod_tree_remove(mod);
3033 wake_up_all(&module_wq);
3034 /* Wait for RCU-sched synchronizing before releasing mod->list. */
3035 synchronize_rcu();
3036 mutex_unlock(&module_mutex);
3037 free_module:
3038 mod_stat_bump_invalid(info, flags);
3039 /* Free lock-classes; relies on the preceding sync_rcu() */
3040 for_class_mod_mem_type(type, core_data) {
3041 lockdep_free_key_range(mod->mem[type].base,
3042 mod->mem[type].size);
3043 }
3044
3045 module_deallocate(mod, info);
3046 free_copy:
3047 /*
3048 * The info->len is always set. We distinguish between
3049 * failures once the proper module was allocated and
3050 * before that.
3051 */
3052 if (!module_allocated)
3053 mod_stat_bump_becoming(info, flags);
3054 free_copy(info, flags);
3055 return err;
3056}
3057
3058SYSCALL_DEFINE3(init_module, void __user *, umod,
3059 unsigned long, len, const char __user *, uargs)
3060{
3061 int err;
3062 struct load_info info = { };
3063
3064 err = may_init_module();
3065 if (err)
3066 return err;
3067
3068 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3069 umod, len, uargs);
3070
3071 err = copy_module_from_user(umod, len, &info);
3072 if (err) {
3073 mod_stat_inc(&failed_kreads);
3074 mod_stat_add_long(len, &invalid_kread_bytes);
3075 return err;
3076 }
3077
3078 return load_module(&info, uargs, 0);
3079}
3080
3081struct idempotent {
3082 const void *cookie;
3083 struct hlist_node entry;
3084 struct completion complete;
3085 int ret;
3086};
3087
3088#define IDEM_HASH_BITS 8
3089static struct hlist_head idem_hash[1 << IDEM_HASH_BITS];
3090static DEFINE_SPINLOCK(idem_lock);
3091
3092static bool idempotent(struct idempotent *u, const void *cookie)
3093{
3094 int hash = hash_ptr(cookie, IDEM_HASH_BITS);
3095 struct hlist_head *head = idem_hash + hash;
3096 struct idempotent *existing;
3097 bool first;
3098
3099 u->ret = 0;
3100 u->cookie = cookie;
3101 init_completion(&u->complete);
3102
3103 spin_lock(&idem_lock);
3104 first = true;
3105 hlist_for_each_entry(existing, head, entry) {
3106 if (existing->cookie != cookie)
3107 continue;
3108 first = false;
3109 break;
3110 }
3111 hlist_add_head(&u->entry, idem_hash + hash);
3112 spin_unlock(&idem_lock);
3113
3114 return !first;
3115}
3116
3117/*
3118 * We were the first one with 'cookie' on the list, and we ended
3119 * up completing the operation. We now need to walk the list,
3120 * remove everybody - which includes ourselves - fill in the return
3121 * value, and then complete the operation.
3122 */
3123static int idempotent_complete(struct idempotent *u, int ret)
3124{
3125 const void *cookie = u->cookie;
3126 int hash = hash_ptr(cookie, IDEM_HASH_BITS);
3127 struct hlist_head *head = idem_hash + hash;
3128 struct hlist_node *next;
3129 struct idempotent *pos;
3130
3131 spin_lock(&idem_lock);
3132 hlist_for_each_entry_safe(pos, next, head, entry) {
3133 if (pos->cookie != cookie)
3134 continue;
3135 hlist_del(&pos->entry);
3136 pos->ret = ret;
3137 complete(&pos->complete);
3138 }
3139 spin_unlock(&idem_lock);
3140 return ret;
3141}
3142
3143static int init_module_from_file(struct file *f, const char __user * uargs, int flags)
3144{
3145 struct load_info info = { };
3146 void *buf = NULL;
3147 int len;
3148
3149 len = kernel_read_file(f, 0, &buf, INT_MAX, NULL, READING_MODULE);
3150 if (len < 0) {
3151 mod_stat_inc(&failed_kreads);
3152 return len;
3153 }
3154
3155 if (flags & MODULE_INIT_COMPRESSED_FILE) {
3156 int err = module_decompress(&info, buf, len);
3157 vfree(buf); /* compressed data is no longer needed */
3158 if (err) {
3159 mod_stat_inc(&failed_decompress);
3160 mod_stat_add_long(len, &invalid_decompress_bytes);
3161 return err;
3162 }
3163 } else {
3164 info.hdr = buf;
3165 info.len = len;
3166 }
3167
3168 return load_module(&info, uargs, flags);
3169}
3170
3171static int idempotent_init_module(struct file *f, const char __user * uargs, int flags)
3172{
3173 struct idempotent idem;
3174
3175 if (!f || !(f->f_mode & FMODE_READ))
3176 return -EBADF;
3177
3178 /* See if somebody else is doing the operation? */
3179 if (idempotent(&idem, file_inode(f))) {
3180 wait_for_completion(&idem.complete);
3181 return idem.ret;
3182 }
3183
3184 /* Otherwise, we'll do it and complete others */
3185 return idempotent_complete(&idem,
3186 init_module_from_file(f, uargs, flags));
3187}
3188
3189SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3190{
3191 int err;
3192 struct fd f;
3193
3194 err = may_init_module();
3195 if (err)
3196 return err;
3197
3198 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3199
3200 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3201 |MODULE_INIT_IGNORE_VERMAGIC
3202 |MODULE_INIT_COMPRESSED_FILE))
3203 return -EINVAL;
3204
3205 f = fdget(fd);
3206 err = idempotent_init_module(f.file, uargs, flags);
3207 fdput(f);
3208 return err;
3209}
3210
3211/* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
3212char *module_flags(struct module *mod, char *buf, bool show_state)
3213{
3214 int bx = 0;
3215
3216 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
3217 if (!mod->taints && !show_state)
3218 goto out;
3219 if (mod->taints ||
3220 mod->state == MODULE_STATE_GOING ||
3221 mod->state == MODULE_STATE_COMING) {
3222 buf[bx++] = '(';
3223 bx += module_flags_taint(mod->taints, buf + bx);
3224 /* Show a - for module-is-being-unloaded */
3225 if (mod->state == MODULE_STATE_GOING && show_state)
3226 buf[bx++] = '-';
3227 /* Show a + for module-is-being-loaded */
3228 if (mod->state == MODULE_STATE_COMING && show_state)
3229 buf[bx++] = '+';
3230 buf[bx++] = ')';
3231 }
3232out:
3233 buf[bx] = '\0';
3234
3235 return buf;
3236}
3237
3238/* Given an address, look for it in the module exception tables. */
3239const struct exception_table_entry *search_module_extables(unsigned long addr)
3240{
3241 const struct exception_table_entry *e = NULL;
3242 struct module *mod;
3243
3244 preempt_disable();
3245 mod = __module_address(addr);
3246 if (!mod)
3247 goto out;
3248
3249 if (!mod->num_exentries)
3250 goto out;
3251
3252 e = search_extable(mod->extable,
3253 mod->num_exentries,
3254 addr);
3255out:
3256 preempt_enable();
3257
3258 /*
3259 * Now, if we found one, we are running inside it now, hence
3260 * we cannot unload the module, hence no refcnt needed.
3261 */
3262 return e;
3263}
3264
3265/**
3266 * is_module_address() - is this address inside a module?
3267 * @addr: the address to check.
3268 *
3269 * See is_module_text_address() if you simply want to see if the address
3270 * is code (not data).
3271 */
3272bool is_module_address(unsigned long addr)
3273{
3274 bool ret;
3275
3276 preempt_disable();
3277 ret = __module_address(addr) != NULL;
3278 preempt_enable();
3279
3280 return ret;
3281}
3282
3283/**
3284 * __module_address() - get the module which contains an address.
3285 * @addr: the address.
3286 *
3287 * Must be called with preempt disabled or module mutex held so that
3288 * module doesn't get freed during this.
3289 */
3290struct module *__module_address(unsigned long addr)
3291{
3292 struct module *mod;
3293
3294 if (addr >= mod_tree.addr_min && addr <= mod_tree.addr_max)
3295 goto lookup;
3296
3297#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
3298 if (addr >= mod_tree.data_addr_min && addr <= mod_tree.data_addr_max)
3299 goto lookup;
3300#endif
3301
3302 return NULL;
3303
3304lookup:
3305 module_assert_mutex_or_preempt();
3306
3307 mod = mod_find(addr, &mod_tree);
3308 if (mod) {
3309 BUG_ON(!within_module(addr, mod));
3310 if (mod->state == MODULE_STATE_UNFORMED)
3311 mod = NULL;
3312 }
3313 return mod;
3314}
3315
3316/**
3317 * is_module_text_address() - is this address inside module code?
3318 * @addr: the address to check.
3319 *
3320 * See is_module_address() if you simply want to see if the address is
3321 * anywhere in a module. See kernel_text_address() for testing if an
3322 * address corresponds to kernel or module code.
3323 */
3324bool is_module_text_address(unsigned long addr)
3325{
3326 bool ret;
3327
3328 preempt_disable();
3329 ret = __module_text_address(addr) != NULL;
3330 preempt_enable();
3331
3332 return ret;
3333}
3334
3335/**
3336 * __module_text_address() - get the module whose code contains an address.
3337 * @addr: the address.
3338 *
3339 * Must be called with preempt disabled or module mutex held so that
3340 * module doesn't get freed during this.
3341 */
3342struct module *__module_text_address(unsigned long addr)
3343{
3344 struct module *mod = __module_address(addr);
3345 if (mod) {
3346 /* Make sure it's within the text section. */
3347 if (!within_module_mem_type(addr, mod, MOD_TEXT) &&
3348 !within_module_mem_type(addr, mod, MOD_INIT_TEXT))
3349 mod = NULL;
3350 }
3351 return mod;
3352}
3353
3354/* Don't grab lock, we're oopsing. */
3355void print_modules(void)
3356{
3357 struct module *mod;
3358 char buf[MODULE_FLAGS_BUF_SIZE];
3359
3360 printk(KERN_DEFAULT "Modules linked in:");
3361 /* Most callers should already have preempt disabled, but make sure */
3362 preempt_disable();
3363 list_for_each_entry_rcu(mod, &modules, list) {
3364 if (mod->state == MODULE_STATE_UNFORMED)
3365 continue;
3366 pr_cont(" %s%s", mod->name, module_flags(mod, buf, true));
3367 }
3368
3369 print_unloaded_tainted_modules();
3370 preempt_enable();
3371 if (last_unloaded_module.name[0])
3372 pr_cont(" [last unloaded: %s%s]", last_unloaded_module.name,
3373 last_unloaded_module.taints);
3374 pr_cont("\n");
3375}
3376
3377#ifdef CONFIG_MODULE_DEBUGFS
3378struct dentry *mod_debugfs_root;
3379
3380static int module_debugfs_init(void)
3381{
3382 mod_debugfs_root = debugfs_create_dir("modules", NULL);
3383 return 0;
3384}
3385module_init(module_debugfs_init);
3386#endif