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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/codetag.h>
60#include <linux/debugfs.h>
61#include <linux/execmem.h>
62#include <uapi/linux/module.h>
63#include "internal.h"
64
65#define CREATE_TRACE_POINTS
66#include <trace/events/module.h>
67
68/*
69 * Mutex protects:
70 * 1) List of modules (also safely readable with preempt_disable),
71 * 2) module_use links,
72 * 3) mod_tree.addr_min/mod_tree.addr_max.
73 * (delete and add uses RCU list operations).
74 */
75DEFINE_MUTEX(module_mutex);
76LIST_HEAD(modules);
77
78/* Work queue for freeing init sections in success case */
79static void do_free_init(struct work_struct *w);
80static DECLARE_WORK(init_free_wq, do_free_init);
81static LLIST_HEAD(init_free_list);
82
83struct mod_tree_root mod_tree __cacheline_aligned = {
84 .addr_min = -1UL,
85};
86
87struct symsearch {
88 const struct kernel_symbol *start, *stop;
89 const s32 *crcs;
90 enum mod_license license;
91};
92
93/*
94 * Bounds of module memory, for speeding up __module_address.
95 * Protected by module_mutex.
96 */
97static void __mod_update_bounds(enum mod_mem_type type __maybe_unused, void *base,
98 unsigned int size, struct mod_tree_root *tree)
99{
100 unsigned long min = (unsigned long)base;
101 unsigned long max = min + size;
102
103#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
104 if (mod_mem_type_is_core_data(type)) {
105 if (min < tree->data_addr_min)
106 tree->data_addr_min = min;
107 if (max > tree->data_addr_max)
108 tree->data_addr_max = max;
109 return;
110 }
111#endif
112 if (min < tree->addr_min)
113 tree->addr_min = min;
114 if (max > tree->addr_max)
115 tree->addr_max = max;
116}
117
118static void mod_update_bounds(struct module *mod)
119{
120 for_each_mod_mem_type(type) {
121 struct module_memory *mod_mem = &mod->mem[type];
122
123 if (mod_mem->size)
124 __mod_update_bounds(type, mod_mem->base, mod_mem->size, &mod_tree);
125 }
126}
127
128/* Block module loading/unloading? */
129int modules_disabled;
130core_param(nomodule, modules_disabled, bint, 0);
131
132/* Waiting for a module to finish initializing? */
133static DECLARE_WAIT_QUEUE_HEAD(module_wq);
134
135static BLOCKING_NOTIFIER_HEAD(module_notify_list);
136
137int register_module_notifier(struct notifier_block *nb)
138{
139 return blocking_notifier_chain_register(&module_notify_list, nb);
140}
141EXPORT_SYMBOL(register_module_notifier);
142
143int unregister_module_notifier(struct notifier_block *nb)
144{
145 return blocking_notifier_chain_unregister(&module_notify_list, nb);
146}
147EXPORT_SYMBOL(unregister_module_notifier);
148
149/*
150 * We require a truly strong try_module_get(): 0 means success.
151 * Otherwise an error is returned due to ongoing or failed
152 * initialization etc.
153 */
154static inline int strong_try_module_get(struct module *mod)
155{
156 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
157 if (mod && mod->state == MODULE_STATE_COMING)
158 return -EBUSY;
159 if (try_module_get(mod))
160 return 0;
161 else
162 return -ENOENT;
163}
164
165static inline void add_taint_module(struct module *mod, unsigned flag,
166 enum lockdep_ok lockdep_ok)
167{
168 add_taint(flag, lockdep_ok);
169 set_bit(flag, &mod->taints);
170}
171
172/*
173 * A thread that wants to hold a reference to a module only while it
174 * is running can call this to safely exit.
175 */
176void __noreturn __module_put_and_kthread_exit(struct module *mod, long code)
177{
178 module_put(mod);
179 kthread_exit(code);
180}
181EXPORT_SYMBOL(__module_put_and_kthread_exit);
182
183/* Find a module section: 0 means not found. */
184static unsigned int find_sec(const struct load_info *info, const char *name)
185{
186 unsigned int i;
187
188 for (i = 1; i < info->hdr->e_shnum; i++) {
189 Elf_Shdr *shdr = &info->sechdrs[i];
190 /* Alloc bit cleared means "ignore it." */
191 if ((shdr->sh_flags & SHF_ALLOC)
192 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
193 return i;
194 }
195 return 0;
196}
197
198/**
199 * find_any_unique_sec() - Find a unique section index by name
200 * @info: Load info for the module to scan
201 * @name: Name of the section we're looking for
202 *
203 * Locates a unique section by name. Ignores SHF_ALLOC.
204 *
205 * Return: Section index if found uniquely, zero if absent, negative count
206 * of total instances if multiple were found.
207 */
208static int find_any_unique_sec(const struct load_info *info, const char *name)
209{
210 unsigned int idx;
211 unsigned int count = 0;
212 int i;
213
214 for (i = 1; i < info->hdr->e_shnum; i++) {
215 if (strcmp(info->secstrings + info->sechdrs[i].sh_name,
216 name) == 0) {
217 count++;
218 idx = i;
219 }
220 }
221 if (count == 1) {
222 return idx;
223 } else if (count == 0) {
224 return 0;
225 } else {
226 return -count;
227 }
228}
229
230/* Find a module section, or NULL. */
231static void *section_addr(const struct load_info *info, const char *name)
232{
233 /* Section 0 has sh_addr 0. */
234 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
235}
236
237/* Find a module section, or NULL. Fill in number of "objects" in section. */
238static void *section_objs(const struct load_info *info,
239 const char *name,
240 size_t object_size,
241 unsigned int *num)
242{
243 unsigned int sec = find_sec(info, name);
244
245 /* Section 0 has sh_addr 0 and sh_size 0. */
246 *num = info->sechdrs[sec].sh_size / object_size;
247 return (void *)info->sechdrs[sec].sh_addr;
248}
249
250/* Find a module section: 0 means not found. Ignores SHF_ALLOC flag. */
251static unsigned int find_any_sec(const struct load_info *info, const char *name)
252{
253 unsigned int i;
254
255 for (i = 1; i < info->hdr->e_shnum; i++) {
256 Elf_Shdr *shdr = &info->sechdrs[i];
257 if (strcmp(info->secstrings + shdr->sh_name, name) == 0)
258 return i;
259 }
260 return 0;
261}
262
263/*
264 * Find a module section, or NULL. Fill in number of "objects" in section.
265 * Ignores SHF_ALLOC flag.
266 */
267static __maybe_unused void *any_section_objs(const struct load_info *info,
268 const char *name,
269 size_t object_size,
270 unsigned int *num)
271{
272 unsigned int sec = find_any_sec(info, name);
273
274 /* Section 0 has sh_addr 0 and sh_size 0. */
275 *num = info->sechdrs[sec].sh_size / object_size;
276 return (void *)info->sechdrs[sec].sh_addr;
277}
278
279#ifndef CONFIG_MODVERSIONS
280#define symversion(base, idx) NULL
281#else
282#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
283#endif
284
285static const char *kernel_symbol_name(const struct kernel_symbol *sym)
286{
287#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
288 return offset_to_ptr(&sym->name_offset);
289#else
290 return sym->name;
291#endif
292}
293
294static const char *kernel_symbol_namespace(const struct kernel_symbol *sym)
295{
296#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
297 if (!sym->namespace_offset)
298 return NULL;
299 return offset_to_ptr(&sym->namespace_offset);
300#else
301 return sym->namespace;
302#endif
303}
304
305int cmp_name(const void *name, const void *sym)
306{
307 return strcmp(name, kernel_symbol_name(sym));
308}
309
310static bool find_exported_symbol_in_section(const struct symsearch *syms,
311 struct module *owner,
312 struct find_symbol_arg *fsa)
313{
314 struct kernel_symbol *sym;
315
316 if (!fsa->gplok && syms->license == GPL_ONLY)
317 return false;
318
319 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
320 sizeof(struct kernel_symbol), cmp_name);
321 if (!sym)
322 return false;
323
324 fsa->owner = owner;
325 fsa->crc = symversion(syms->crcs, sym - syms->start);
326 fsa->sym = sym;
327 fsa->license = syms->license;
328
329 return true;
330}
331
332/*
333 * Find an exported symbol and return it, along with, (optional) crc and
334 * (optional) module which owns it. Needs preempt disabled or module_mutex.
335 */
336bool find_symbol(struct find_symbol_arg *fsa)
337{
338 static const struct symsearch arr[] = {
339 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
340 NOT_GPL_ONLY },
341 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
342 __start___kcrctab_gpl,
343 GPL_ONLY },
344 };
345 struct module *mod;
346 unsigned int i;
347
348 module_assert_mutex_or_preempt();
349
350 for (i = 0; i < ARRAY_SIZE(arr); i++)
351 if (find_exported_symbol_in_section(&arr[i], NULL, fsa))
352 return true;
353
354 list_for_each_entry_rcu(mod, &modules, list,
355 lockdep_is_held(&module_mutex)) {
356 struct symsearch arr[] = {
357 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
358 NOT_GPL_ONLY },
359 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
360 mod->gpl_crcs,
361 GPL_ONLY },
362 };
363
364 if (mod->state == MODULE_STATE_UNFORMED)
365 continue;
366
367 for (i = 0; i < ARRAY_SIZE(arr); i++)
368 if (find_exported_symbol_in_section(&arr[i], mod, fsa))
369 return true;
370 }
371
372 pr_debug("Failed to find symbol %s\n", fsa->name);
373 return false;
374}
375
376/*
377 * Search for module by name: must hold module_mutex (or preempt disabled
378 * for read-only access).
379 */
380struct module *find_module_all(const char *name, size_t len,
381 bool even_unformed)
382{
383 struct module *mod;
384
385 module_assert_mutex_or_preempt();
386
387 list_for_each_entry_rcu(mod, &modules, list,
388 lockdep_is_held(&module_mutex)) {
389 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
390 continue;
391 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
392 return mod;
393 }
394 return NULL;
395}
396
397struct module *find_module(const char *name)
398{
399 return find_module_all(name, strlen(name), false);
400}
401
402#ifdef CONFIG_SMP
403
404static inline void __percpu *mod_percpu(struct module *mod)
405{
406 return mod->percpu;
407}
408
409static int percpu_modalloc(struct module *mod, struct load_info *info)
410{
411 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
412 unsigned long align = pcpusec->sh_addralign;
413
414 if (!pcpusec->sh_size)
415 return 0;
416
417 if (align > PAGE_SIZE) {
418 pr_warn("%s: per-cpu alignment %li > %li\n",
419 mod->name, align, PAGE_SIZE);
420 align = PAGE_SIZE;
421 }
422
423 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
424 if (!mod->percpu) {
425 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
426 mod->name, (unsigned long)pcpusec->sh_size);
427 return -ENOMEM;
428 }
429 mod->percpu_size = pcpusec->sh_size;
430 return 0;
431}
432
433static void percpu_modfree(struct module *mod)
434{
435 free_percpu(mod->percpu);
436}
437
438static unsigned int find_pcpusec(struct load_info *info)
439{
440 return find_sec(info, ".data..percpu");
441}
442
443static void percpu_modcopy(struct module *mod,
444 const void *from, unsigned long size)
445{
446 int cpu;
447
448 for_each_possible_cpu(cpu)
449 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
450}
451
452bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
453{
454 struct module *mod;
455 unsigned int cpu;
456
457 preempt_disable();
458
459 list_for_each_entry_rcu(mod, &modules, list) {
460 if (mod->state == MODULE_STATE_UNFORMED)
461 continue;
462 if (!mod->percpu_size)
463 continue;
464 for_each_possible_cpu(cpu) {
465 void *start = per_cpu_ptr(mod->percpu, cpu);
466 void *va = (void *)addr;
467
468 if (va >= start && va < start + mod->percpu_size) {
469 if (can_addr) {
470 *can_addr = (unsigned long) (va - start);
471 *can_addr += (unsigned long)
472 per_cpu_ptr(mod->percpu,
473 get_boot_cpu_id());
474 }
475 preempt_enable();
476 return true;
477 }
478 }
479 }
480
481 preempt_enable();
482 return false;
483}
484
485/**
486 * is_module_percpu_address() - test whether address is from module static percpu
487 * @addr: address to test
488 *
489 * Test whether @addr belongs to module static percpu area.
490 *
491 * Return: %true if @addr is from module static percpu area
492 */
493bool is_module_percpu_address(unsigned long addr)
494{
495 return __is_module_percpu_address(addr, NULL);
496}
497
498#else /* ... !CONFIG_SMP */
499
500static inline void __percpu *mod_percpu(struct module *mod)
501{
502 return NULL;
503}
504static int percpu_modalloc(struct module *mod, struct load_info *info)
505{
506 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
507 if (info->sechdrs[info->index.pcpu].sh_size != 0)
508 return -ENOMEM;
509 return 0;
510}
511static inline void percpu_modfree(struct module *mod)
512{
513}
514static unsigned int find_pcpusec(struct load_info *info)
515{
516 return 0;
517}
518static inline void percpu_modcopy(struct module *mod,
519 const void *from, unsigned long size)
520{
521 /* pcpusec should be 0, and size of that section should be 0. */
522 BUG_ON(size != 0);
523}
524bool is_module_percpu_address(unsigned long addr)
525{
526 return false;
527}
528
529bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
530{
531 return false;
532}
533
534#endif /* CONFIG_SMP */
535
536#define MODINFO_ATTR(field) \
537static void setup_modinfo_##field(struct module *mod, const char *s) \
538{ \
539 mod->field = kstrdup(s, GFP_KERNEL); \
540} \
541static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
542 struct module_kobject *mk, char *buffer) \
543{ \
544 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
545} \
546static int modinfo_##field##_exists(struct module *mod) \
547{ \
548 return mod->field != NULL; \
549} \
550static void free_modinfo_##field(struct module *mod) \
551{ \
552 kfree(mod->field); \
553 mod->field = NULL; \
554} \
555static struct module_attribute modinfo_##field = { \
556 .attr = { .name = __stringify(field), .mode = 0444 }, \
557 .show = show_modinfo_##field, \
558 .setup = setup_modinfo_##field, \
559 .test = modinfo_##field##_exists, \
560 .free = free_modinfo_##field, \
561};
562
563MODINFO_ATTR(version);
564MODINFO_ATTR(srcversion);
565
566static struct {
567 char name[MODULE_NAME_LEN + 1];
568 char taints[MODULE_FLAGS_BUF_SIZE];
569} last_unloaded_module;
570
571#ifdef CONFIG_MODULE_UNLOAD
572
573EXPORT_TRACEPOINT_SYMBOL(module_get);
574
575/* MODULE_REF_BASE is the base reference count by kmodule loader. */
576#define MODULE_REF_BASE 1
577
578/* Init the unload section of the module. */
579static int module_unload_init(struct module *mod)
580{
581 /*
582 * Initialize reference counter to MODULE_REF_BASE.
583 * refcnt == 0 means module is going.
584 */
585 atomic_set(&mod->refcnt, MODULE_REF_BASE);
586
587 INIT_LIST_HEAD(&mod->source_list);
588 INIT_LIST_HEAD(&mod->target_list);
589
590 /* Hold reference count during initialization. */
591 atomic_inc(&mod->refcnt);
592
593 return 0;
594}
595
596/* Does a already use b? */
597static int already_uses(struct module *a, struct module *b)
598{
599 struct module_use *use;
600
601 list_for_each_entry(use, &b->source_list, source_list) {
602 if (use->source == a)
603 return 1;
604 }
605 pr_debug("%s does not use %s!\n", a->name, b->name);
606 return 0;
607}
608
609/*
610 * Module a uses b
611 * - we add 'a' as a "source", 'b' as a "target" of module use
612 * - the module_use is added to the list of 'b' sources (so
613 * 'b' can walk the list to see who sourced them), and of 'a'
614 * targets (so 'a' can see what modules it targets).
615 */
616static int add_module_usage(struct module *a, struct module *b)
617{
618 struct module_use *use;
619
620 pr_debug("Allocating new usage for %s.\n", a->name);
621 use = kmalloc(sizeof(*use), GFP_ATOMIC);
622 if (!use)
623 return -ENOMEM;
624
625 use->source = a;
626 use->target = b;
627 list_add(&use->source_list, &b->source_list);
628 list_add(&use->target_list, &a->target_list);
629 return 0;
630}
631
632/* Module a uses b: caller needs module_mutex() */
633static int ref_module(struct module *a, struct module *b)
634{
635 int err;
636
637 if (b == NULL || already_uses(a, b))
638 return 0;
639
640 /* If module isn't available, we fail. */
641 err = strong_try_module_get(b);
642 if (err)
643 return err;
644
645 err = add_module_usage(a, b);
646 if (err) {
647 module_put(b);
648 return err;
649 }
650 return 0;
651}
652
653/* Clear the unload stuff of the module. */
654static void module_unload_free(struct module *mod)
655{
656 struct module_use *use, *tmp;
657
658 mutex_lock(&module_mutex);
659 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
660 struct module *i = use->target;
661 pr_debug("%s unusing %s\n", mod->name, i->name);
662 module_put(i);
663 list_del(&use->source_list);
664 list_del(&use->target_list);
665 kfree(use);
666 }
667 mutex_unlock(&module_mutex);
668}
669
670#ifdef CONFIG_MODULE_FORCE_UNLOAD
671static inline int try_force_unload(unsigned int flags)
672{
673 int ret = (flags & O_TRUNC);
674 if (ret)
675 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
676 return ret;
677}
678#else
679static inline int try_force_unload(unsigned int flags)
680{
681 return 0;
682}
683#endif /* CONFIG_MODULE_FORCE_UNLOAD */
684
685/* Try to release refcount of module, 0 means success. */
686static int try_release_module_ref(struct module *mod)
687{
688 int ret;
689
690 /* Try to decrement refcnt which we set at loading */
691 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
692 BUG_ON(ret < 0);
693 if (ret)
694 /* Someone can put this right now, recover with checking */
695 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
696
697 return ret;
698}
699
700static int try_stop_module(struct module *mod, int flags, int *forced)
701{
702 /* If it's not unused, quit unless we're forcing. */
703 if (try_release_module_ref(mod) != 0) {
704 *forced = try_force_unload(flags);
705 if (!(*forced))
706 return -EWOULDBLOCK;
707 }
708
709 /* Mark it as dying. */
710 mod->state = MODULE_STATE_GOING;
711
712 return 0;
713}
714
715/**
716 * module_refcount() - return the refcount or -1 if unloading
717 * @mod: the module we're checking
718 *
719 * Return:
720 * -1 if the module is in the process of unloading
721 * otherwise the number of references in the kernel to the module
722 */
723int module_refcount(struct module *mod)
724{
725 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
726}
727EXPORT_SYMBOL(module_refcount);
728
729/* This exists whether we can unload or not */
730static void free_module(struct module *mod);
731
732SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
733 unsigned int, flags)
734{
735 struct module *mod;
736 char name[MODULE_NAME_LEN];
737 char buf[MODULE_FLAGS_BUF_SIZE];
738 int ret, forced = 0;
739
740 if (!capable(CAP_SYS_MODULE) || modules_disabled)
741 return -EPERM;
742
743 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
744 return -EFAULT;
745 name[MODULE_NAME_LEN-1] = '\0';
746
747 audit_log_kern_module(name);
748
749 if (mutex_lock_interruptible(&module_mutex) != 0)
750 return -EINTR;
751
752 mod = find_module(name);
753 if (!mod) {
754 ret = -ENOENT;
755 goto out;
756 }
757
758 if (!list_empty(&mod->source_list)) {
759 /* Other modules depend on us: get rid of them first. */
760 ret = -EWOULDBLOCK;
761 goto out;
762 }
763
764 /* Doing init or already dying? */
765 if (mod->state != MODULE_STATE_LIVE) {
766 /* FIXME: if (force), slam module count damn the torpedoes */
767 pr_debug("%s already dying\n", mod->name);
768 ret = -EBUSY;
769 goto out;
770 }
771
772 /* If it has an init func, it must have an exit func to unload */
773 if (mod->init && !mod->exit) {
774 forced = try_force_unload(flags);
775 if (!forced) {
776 /* This module can't be removed */
777 ret = -EBUSY;
778 goto out;
779 }
780 }
781
782 ret = try_stop_module(mod, flags, &forced);
783 if (ret != 0)
784 goto out;
785
786 mutex_unlock(&module_mutex);
787 /* Final destruction now no one is using it. */
788 if (mod->exit != NULL)
789 mod->exit();
790 blocking_notifier_call_chain(&module_notify_list,
791 MODULE_STATE_GOING, mod);
792 klp_module_going(mod);
793 ftrace_release_mod(mod);
794
795 async_synchronize_full();
796
797 /* Store the name and taints of the last unloaded module for diagnostic purposes */
798 strscpy(last_unloaded_module.name, mod->name, sizeof(last_unloaded_module.name));
799 strscpy(last_unloaded_module.taints, module_flags(mod, buf, false), sizeof(last_unloaded_module.taints));
800
801 free_module(mod);
802 /* someone could wait for the module in add_unformed_module() */
803 wake_up_all(&module_wq);
804 return 0;
805out:
806 mutex_unlock(&module_mutex);
807 return ret;
808}
809
810void __symbol_put(const char *symbol)
811{
812 struct find_symbol_arg fsa = {
813 .name = symbol,
814 .gplok = true,
815 };
816
817 preempt_disable();
818 BUG_ON(!find_symbol(&fsa));
819 module_put(fsa.owner);
820 preempt_enable();
821}
822EXPORT_SYMBOL(__symbol_put);
823
824/* Note this assumes addr is a function, which it currently always is. */
825void symbol_put_addr(void *addr)
826{
827 struct module *modaddr;
828 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
829
830 if (core_kernel_text(a))
831 return;
832
833 /*
834 * Even though we hold a reference on the module; we still need to
835 * disable preemption in order to safely traverse the data structure.
836 */
837 preempt_disable();
838 modaddr = __module_text_address(a);
839 BUG_ON(!modaddr);
840 module_put(modaddr);
841 preempt_enable();
842}
843EXPORT_SYMBOL_GPL(symbol_put_addr);
844
845static ssize_t show_refcnt(struct module_attribute *mattr,
846 struct module_kobject *mk, char *buffer)
847{
848 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
849}
850
851static struct module_attribute modinfo_refcnt =
852 __ATTR(refcnt, 0444, show_refcnt, NULL);
853
854void __module_get(struct module *module)
855{
856 if (module) {
857 atomic_inc(&module->refcnt);
858 trace_module_get(module, _RET_IP_);
859 }
860}
861EXPORT_SYMBOL(__module_get);
862
863bool try_module_get(struct module *module)
864{
865 bool ret = true;
866
867 if (module) {
868 /* Note: here, we can fail to get a reference */
869 if (likely(module_is_live(module) &&
870 atomic_inc_not_zero(&module->refcnt) != 0))
871 trace_module_get(module, _RET_IP_);
872 else
873 ret = false;
874 }
875 return ret;
876}
877EXPORT_SYMBOL(try_module_get);
878
879void module_put(struct module *module)
880{
881 int ret;
882
883 if (module) {
884 ret = atomic_dec_if_positive(&module->refcnt);
885 WARN_ON(ret < 0); /* Failed to put refcount */
886 trace_module_put(module, _RET_IP_);
887 }
888}
889EXPORT_SYMBOL(module_put);
890
891#else /* !CONFIG_MODULE_UNLOAD */
892static inline void module_unload_free(struct module *mod)
893{
894}
895
896static int ref_module(struct module *a, struct module *b)
897{
898 return strong_try_module_get(b);
899}
900
901static inline int module_unload_init(struct module *mod)
902{
903 return 0;
904}
905#endif /* CONFIG_MODULE_UNLOAD */
906
907size_t module_flags_taint(unsigned long taints, char *buf)
908{
909 size_t l = 0;
910 int i;
911
912 for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
913 if (taint_flags[i].module && test_bit(i, &taints))
914 buf[l++] = taint_flags[i].c_true;
915 }
916
917 return l;
918}
919
920static ssize_t show_initstate(struct module_attribute *mattr,
921 struct module_kobject *mk, char *buffer)
922{
923 const char *state = "unknown";
924
925 switch (mk->mod->state) {
926 case MODULE_STATE_LIVE:
927 state = "live";
928 break;
929 case MODULE_STATE_COMING:
930 state = "coming";
931 break;
932 case MODULE_STATE_GOING:
933 state = "going";
934 break;
935 default:
936 BUG();
937 }
938 return sprintf(buffer, "%s\n", state);
939}
940
941static struct module_attribute modinfo_initstate =
942 __ATTR(initstate, 0444, show_initstate, NULL);
943
944static ssize_t store_uevent(struct module_attribute *mattr,
945 struct module_kobject *mk,
946 const char *buffer, size_t count)
947{
948 int rc;
949
950 rc = kobject_synth_uevent(&mk->kobj, buffer, count);
951 return rc ? rc : count;
952}
953
954struct module_attribute module_uevent =
955 __ATTR(uevent, 0200, NULL, store_uevent);
956
957static ssize_t show_coresize(struct module_attribute *mattr,
958 struct module_kobject *mk, char *buffer)
959{
960 unsigned int size = mk->mod->mem[MOD_TEXT].size;
961
962 if (!IS_ENABLED(CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC)) {
963 for_class_mod_mem_type(type, core_data)
964 size += mk->mod->mem[type].size;
965 }
966 return sprintf(buffer, "%u\n", size);
967}
968
969static struct module_attribute modinfo_coresize =
970 __ATTR(coresize, 0444, show_coresize, NULL);
971
972#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
973static ssize_t show_datasize(struct module_attribute *mattr,
974 struct module_kobject *mk, char *buffer)
975{
976 unsigned int size = 0;
977
978 for_class_mod_mem_type(type, core_data)
979 size += mk->mod->mem[type].size;
980 return sprintf(buffer, "%u\n", size);
981}
982
983static struct module_attribute modinfo_datasize =
984 __ATTR(datasize, 0444, show_datasize, NULL);
985#endif
986
987static ssize_t show_initsize(struct module_attribute *mattr,
988 struct module_kobject *mk, char *buffer)
989{
990 unsigned int size = 0;
991
992 for_class_mod_mem_type(type, init)
993 size += mk->mod->mem[type].size;
994 return sprintf(buffer, "%u\n", size);
995}
996
997static struct module_attribute modinfo_initsize =
998 __ATTR(initsize, 0444, show_initsize, NULL);
999
1000static ssize_t show_taint(struct module_attribute *mattr,
1001 struct module_kobject *mk, char *buffer)
1002{
1003 size_t l;
1004
1005 l = module_flags_taint(mk->mod->taints, buffer);
1006 buffer[l++] = '\n';
1007 return l;
1008}
1009
1010static struct module_attribute modinfo_taint =
1011 __ATTR(taint, 0444, show_taint, NULL);
1012
1013struct module_attribute *modinfo_attrs[] = {
1014 &module_uevent,
1015 &modinfo_version,
1016 &modinfo_srcversion,
1017 &modinfo_initstate,
1018 &modinfo_coresize,
1019#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
1020 &modinfo_datasize,
1021#endif
1022 &modinfo_initsize,
1023 &modinfo_taint,
1024#ifdef CONFIG_MODULE_UNLOAD
1025 &modinfo_refcnt,
1026#endif
1027 NULL,
1028};
1029
1030size_t modinfo_attrs_count = ARRAY_SIZE(modinfo_attrs);
1031
1032static const char vermagic[] = VERMAGIC_STRING;
1033
1034int try_to_force_load(struct module *mod, const char *reason)
1035{
1036#ifdef CONFIG_MODULE_FORCE_LOAD
1037 if (!test_taint(TAINT_FORCED_MODULE))
1038 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1039 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1040 return 0;
1041#else
1042 return -ENOEXEC;
1043#endif
1044}
1045
1046/* Parse tag=value strings from .modinfo section */
1047char *module_next_tag_pair(char *string, unsigned long *secsize)
1048{
1049 /* Skip non-zero chars */
1050 while (string[0]) {
1051 string++;
1052 if ((*secsize)-- <= 1)
1053 return NULL;
1054 }
1055
1056 /* Skip any zero padding. */
1057 while (!string[0]) {
1058 string++;
1059 if ((*secsize)-- <= 1)
1060 return NULL;
1061 }
1062 return string;
1063}
1064
1065static char *get_next_modinfo(const struct load_info *info, const char *tag,
1066 char *prev)
1067{
1068 char *p;
1069 unsigned int taglen = strlen(tag);
1070 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
1071 unsigned long size = infosec->sh_size;
1072
1073 /*
1074 * get_modinfo() calls made before rewrite_section_headers()
1075 * must use sh_offset, as sh_addr isn't set!
1076 */
1077 char *modinfo = (char *)info->hdr + infosec->sh_offset;
1078
1079 if (prev) {
1080 size -= prev - modinfo;
1081 modinfo = module_next_tag_pair(prev, &size);
1082 }
1083
1084 for (p = modinfo; p; p = module_next_tag_pair(p, &size)) {
1085 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
1086 return p + taglen + 1;
1087 }
1088 return NULL;
1089}
1090
1091static char *get_modinfo(const struct load_info *info, const char *tag)
1092{
1093 return get_next_modinfo(info, tag, NULL);
1094}
1095
1096static int verify_namespace_is_imported(const struct load_info *info,
1097 const struct kernel_symbol *sym,
1098 struct module *mod)
1099{
1100 const char *namespace;
1101 char *imported_namespace;
1102
1103 namespace = kernel_symbol_namespace(sym);
1104 if (namespace && namespace[0]) {
1105 for_each_modinfo_entry(imported_namespace, info, "import_ns") {
1106 if (strcmp(namespace, imported_namespace) == 0)
1107 return 0;
1108 }
1109#ifdef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1110 pr_warn(
1111#else
1112 pr_err(
1113#endif
1114 "%s: module uses symbol (%s) from namespace %s, but does not import it.\n",
1115 mod->name, kernel_symbol_name(sym), namespace);
1116#ifndef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1117 return -EINVAL;
1118#endif
1119 }
1120 return 0;
1121}
1122
1123static bool inherit_taint(struct module *mod, struct module *owner, const char *name)
1124{
1125 if (!owner || !test_bit(TAINT_PROPRIETARY_MODULE, &owner->taints))
1126 return true;
1127
1128 if (mod->using_gplonly_symbols) {
1129 pr_err("%s: module using GPL-only symbols uses symbols %s from proprietary module %s.\n",
1130 mod->name, name, owner->name);
1131 return false;
1132 }
1133
1134 if (!test_bit(TAINT_PROPRIETARY_MODULE, &mod->taints)) {
1135 pr_warn("%s: module uses symbols %s from proprietary module %s, inheriting taint.\n",
1136 mod->name, name, owner->name);
1137 set_bit(TAINT_PROPRIETARY_MODULE, &mod->taints);
1138 }
1139 return true;
1140}
1141
1142/* Resolve a symbol for this module. I.e. if we find one, record usage. */
1143static const struct kernel_symbol *resolve_symbol(struct module *mod,
1144 const struct load_info *info,
1145 const char *name,
1146 char ownername[])
1147{
1148 struct find_symbol_arg fsa = {
1149 .name = name,
1150 .gplok = !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)),
1151 .warn = true,
1152 };
1153 int err;
1154
1155 /*
1156 * The module_mutex should not be a heavily contended lock;
1157 * if we get the occasional sleep here, we'll go an extra iteration
1158 * in the wait_event_interruptible(), which is harmless.
1159 */
1160 sched_annotate_sleep();
1161 mutex_lock(&module_mutex);
1162 if (!find_symbol(&fsa))
1163 goto unlock;
1164
1165 if (fsa.license == GPL_ONLY)
1166 mod->using_gplonly_symbols = true;
1167
1168 if (!inherit_taint(mod, fsa.owner, name)) {
1169 fsa.sym = NULL;
1170 goto getname;
1171 }
1172
1173 if (!check_version(info, name, mod, fsa.crc)) {
1174 fsa.sym = ERR_PTR(-EINVAL);
1175 goto getname;
1176 }
1177
1178 err = verify_namespace_is_imported(info, fsa.sym, mod);
1179 if (err) {
1180 fsa.sym = ERR_PTR(err);
1181 goto getname;
1182 }
1183
1184 err = ref_module(mod, fsa.owner);
1185 if (err) {
1186 fsa.sym = ERR_PTR(err);
1187 goto getname;
1188 }
1189
1190getname:
1191 /* We must make copy under the lock if we failed to get ref. */
1192 strncpy(ownername, module_name(fsa.owner), MODULE_NAME_LEN);
1193unlock:
1194 mutex_unlock(&module_mutex);
1195 return fsa.sym;
1196}
1197
1198static const struct kernel_symbol *
1199resolve_symbol_wait(struct module *mod,
1200 const struct load_info *info,
1201 const char *name)
1202{
1203 const struct kernel_symbol *ksym;
1204 char owner[MODULE_NAME_LEN];
1205
1206 if (wait_event_interruptible_timeout(module_wq,
1207 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1208 || PTR_ERR(ksym) != -EBUSY,
1209 30 * HZ) <= 0) {
1210 pr_warn("%s: gave up waiting for init of module %s.\n",
1211 mod->name, owner);
1212 }
1213 return ksym;
1214}
1215
1216void __weak module_arch_cleanup(struct module *mod)
1217{
1218}
1219
1220void __weak module_arch_freeing_init(struct module *mod)
1221{
1222}
1223
1224void *__module_writable_address(struct module *mod, void *loc)
1225{
1226 for_class_mod_mem_type(type, text) {
1227 struct module_memory *mem = &mod->mem[type];
1228
1229 if (loc >= mem->base && loc < mem->base + mem->size)
1230 return loc + (mem->rw_copy - mem->base);
1231 }
1232
1233 return loc;
1234}
1235
1236static int module_memory_alloc(struct module *mod, enum mod_mem_type type)
1237{
1238 unsigned int size = PAGE_ALIGN(mod->mem[type].size);
1239 enum execmem_type execmem_type;
1240 void *ptr;
1241
1242 mod->mem[type].size = size;
1243
1244 if (mod_mem_type_is_data(type))
1245 execmem_type = EXECMEM_MODULE_DATA;
1246 else
1247 execmem_type = EXECMEM_MODULE_TEXT;
1248
1249 ptr = execmem_alloc(execmem_type, size);
1250 if (!ptr)
1251 return -ENOMEM;
1252
1253 mod->mem[type].base = ptr;
1254
1255 if (execmem_is_rox(execmem_type)) {
1256 ptr = vzalloc(size);
1257
1258 if (!ptr) {
1259 execmem_free(mod->mem[type].base);
1260 return -ENOMEM;
1261 }
1262
1263 mod->mem[type].rw_copy = ptr;
1264 mod->mem[type].is_rox = true;
1265 } else {
1266 mod->mem[type].rw_copy = mod->mem[type].base;
1267 memset(mod->mem[type].base, 0, size);
1268 }
1269
1270 /*
1271 * The pointer to these blocks of memory are stored on the module
1272 * structure and we keep that around so long as the module is
1273 * around. We only free that memory when we unload the module.
1274 * Just mark them as not being a leak then. The .init* ELF
1275 * sections *do* get freed after boot so we *could* treat them
1276 * slightly differently with kmemleak_ignore() and only grey
1277 * them out as they work as typical memory allocations which
1278 * *do* eventually get freed, but let's just keep things simple
1279 * and avoid *any* false positives.
1280 */
1281 kmemleak_not_leak(ptr);
1282
1283 return 0;
1284}
1285
1286static void module_memory_free(struct module *mod, enum mod_mem_type type)
1287{
1288 struct module_memory *mem = &mod->mem[type];
1289
1290 if (mem->is_rox)
1291 vfree(mem->rw_copy);
1292
1293 execmem_free(mem->base);
1294}
1295
1296static void free_mod_mem(struct module *mod)
1297{
1298 for_each_mod_mem_type(type) {
1299 struct module_memory *mod_mem = &mod->mem[type];
1300
1301 if (type == MOD_DATA)
1302 continue;
1303
1304 /* Free lock-classes; relies on the preceding sync_rcu(). */
1305 lockdep_free_key_range(mod_mem->base, mod_mem->size);
1306 if (mod_mem->size)
1307 module_memory_free(mod, type);
1308 }
1309
1310 /* MOD_DATA hosts mod, so free it at last */
1311 lockdep_free_key_range(mod->mem[MOD_DATA].base, mod->mem[MOD_DATA].size);
1312 module_memory_free(mod, MOD_DATA);
1313}
1314
1315/* Free a module, remove from lists, etc. */
1316static void free_module(struct module *mod)
1317{
1318 trace_module_free(mod);
1319
1320 codetag_unload_module(mod);
1321
1322 mod_sysfs_teardown(mod);
1323
1324 /*
1325 * We leave it in list to prevent duplicate loads, but make sure
1326 * that noone uses it while it's being deconstructed.
1327 */
1328 mutex_lock(&module_mutex);
1329 mod->state = MODULE_STATE_UNFORMED;
1330 mutex_unlock(&module_mutex);
1331
1332 /* Arch-specific cleanup. */
1333 module_arch_cleanup(mod);
1334
1335 /* Module unload stuff */
1336 module_unload_free(mod);
1337
1338 /* Free any allocated parameters. */
1339 destroy_params(mod->kp, mod->num_kp);
1340
1341 if (is_livepatch_module(mod))
1342 free_module_elf(mod);
1343
1344 /* Now we can delete it from the lists */
1345 mutex_lock(&module_mutex);
1346 /* Unlink carefully: kallsyms could be walking list. */
1347 list_del_rcu(&mod->list);
1348 mod_tree_remove(mod);
1349 /* Remove this module from bug list, this uses list_del_rcu */
1350 module_bug_cleanup(mod);
1351 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
1352 synchronize_rcu();
1353 if (try_add_tainted_module(mod))
1354 pr_err("%s: adding tainted module to the unloaded tainted modules list failed.\n",
1355 mod->name);
1356 mutex_unlock(&module_mutex);
1357
1358 /* This may be empty, but that's OK */
1359 module_arch_freeing_init(mod);
1360 kfree(mod->args);
1361 percpu_modfree(mod);
1362
1363 free_mod_mem(mod);
1364}
1365
1366void *__symbol_get(const char *symbol)
1367{
1368 struct find_symbol_arg fsa = {
1369 .name = symbol,
1370 .gplok = true,
1371 .warn = true,
1372 };
1373
1374 preempt_disable();
1375 if (!find_symbol(&fsa))
1376 goto fail;
1377 if (fsa.license != GPL_ONLY) {
1378 pr_warn("failing symbol_get of non-GPLONLY symbol %s.\n",
1379 symbol);
1380 goto fail;
1381 }
1382 if (strong_try_module_get(fsa.owner))
1383 goto fail;
1384 preempt_enable();
1385 return (void *)kernel_symbol_value(fsa.sym);
1386fail:
1387 preempt_enable();
1388 return NULL;
1389}
1390EXPORT_SYMBOL_GPL(__symbol_get);
1391
1392/*
1393 * Ensure that an exported symbol [global namespace] does not already exist
1394 * in the kernel or in some other module's exported symbol table.
1395 *
1396 * You must hold the module_mutex.
1397 */
1398static int verify_exported_symbols(struct module *mod)
1399{
1400 unsigned int i;
1401 const struct kernel_symbol *s;
1402 struct {
1403 const struct kernel_symbol *sym;
1404 unsigned int num;
1405 } arr[] = {
1406 { mod->syms, mod->num_syms },
1407 { mod->gpl_syms, mod->num_gpl_syms },
1408 };
1409
1410 for (i = 0; i < ARRAY_SIZE(arr); i++) {
1411 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1412 struct find_symbol_arg fsa = {
1413 .name = kernel_symbol_name(s),
1414 .gplok = true,
1415 };
1416 if (find_symbol(&fsa)) {
1417 pr_err("%s: exports duplicate symbol %s"
1418 " (owned by %s)\n",
1419 mod->name, kernel_symbol_name(s),
1420 module_name(fsa.owner));
1421 return -ENOEXEC;
1422 }
1423 }
1424 }
1425 return 0;
1426}
1427
1428static bool ignore_undef_symbol(Elf_Half emachine, const char *name)
1429{
1430 /*
1431 * On x86, PIC code and Clang non-PIC code may have call foo@PLT. GNU as
1432 * before 2.37 produces an unreferenced _GLOBAL_OFFSET_TABLE_ on x86-64.
1433 * i386 has a similar problem but may not deserve a fix.
1434 *
1435 * If we ever have to ignore many symbols, consider refactoring the code to
1436 * only warn if referenced by a relocation.
1437 */
1438 if (emachine == EM_386 || emachine == EM_X86_64)
1439 return !strcmp(name, "_GLOBAL_OFFSET_TABLE_");
1440 return false;
1441}
1442
1443/* Change all symbols so that st_value encodes the pointer directly. */
1444static int simplify_symbols(struct module *mod, const struct load_info *info)
1445{
1446 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
1447 Elf_Sym *sym = (void *)symsec->sh_addr;
1448 unsigned long secbase;
1449 unsigned int i;
1450 int ret = 0;
1451 const struct kernel_symbol *ksym;
1452
1453 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
1454 const char *name = info->strtab + sym[i].st_name;
1455
1456 switch (sym[i].st_shndx) {
1457 case SHN_COMMON:
1458 /* Ignore common symbols */
1459 if (!strncmp(name, "__gnu_lto", 9))
1460 break;
1461
1462 /*
1463 * We compiled with -fno-common. These are not
1464 * supposed to happen.
1465 */
1466 pr_debug("Common symbol: %s\n", name);
1467 pr_warn("%s: please compile with -fno-common\n",
1468 mod->name);
1469 ret = -ENOEXEC;
1470 break;
1471
1472 case SHN_ABS:
1473 /* Don't need to do anything */
1474 pr_debug("Absolute symbol: 0x%08lx %s\n",
1475 (long)sym[i].st_value, name);
1476 break;
1477
1478 case SHN_LIVEPATCH:
1479 /* Livepatch symbols are resolved by livepatch */
1480 break;
1481
1482 case SHN_UNDEF:
1483 ksym = resolve_symbol_wait(mod, info, name);
1484 /* Ok if resolved. */
1485 if (ksym && !IS_ERR(ksym)) {
1486 sym[i].st_value = kernel_symbol_value(ksym);
1487 break;
1488 }
1489
1490 /* Ok if weak or ignored. */
1491 if (!ksym &&
1492 (ELF_ST_BIND(sym[i].st_info) == STB_WEAK ||
1493 ignore_undef_symbol(info->hdr->e_machine, name)))
1494 break;
1495
1496 ret = PTR_ERR(ksym) ?: -ENOENT;
1497 pr_warn("%s: Unknown symbol %s (err %d)\n",
1498 mod->name, name, ret);
1499 break;
1500
1501 default:
1502 /* Divert to percpu allocation if a percpu var. */
1503 if (sym[i].st_shndx == info->index.pcpu)
1504 secbase = (unsigned long)mod_percpu(mod);
1505 else
1506 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
1507 sym[i].st_value += secbase;
1508 break;
1509 }
1510 }
1511
1512 return ret;
1513}
1514
1515static int apply_relocations(struct module *mod, const struct load_info *info)
1516{
1517 unsigned int i;
1518 int err = 0;
1519
1520 /* Now do relocations. */
1521 for (i = 1; i < info->hdr->e_shnum; i++) {
1522 unsigned int infosec = info->sechdrs[i].sh_info;
1523
1524 /* Not a valid relocation section? */
1525 if (infosec >= info->hdr->e_shnum)
1526 continue;
1527
1528 /* Don't bother with non-allocated sections */
1529 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
1530 continue;
1531
1532 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
1533 err = klp_apply_section_relocs(mod, info->sechdrs,
1534 info->secstrings,
1535 info->strtab,
1536 info->index.sym, i,
1537 NULL);
1538 else if (info->sechdrs[i].sh_type == SHT_REL)
1539 err = apply_relocate(info->sechdrs, info->strtab,
1540 info->index.sym, i, mod);
1541 else if (info->sechdrs[i].sh_type == SHT_RELA)
1542 err = apply_relocate_add(info->sechdrs, info->strtab,
1543 info->index.sym, i, mod);
1544 if (err < 0)
1545 break;
1546 }
1547 return err;
1548}
1549
1550/* Additional bytes needed by arch in front of individual sections */
1551unsigned int __weak arch_mod_section_prepend(struct module *mod,
1552 unsigned int section)
1553{
1554 /* default implementation just returns zero */
1555 return 0;
1556}
1557
1558long module_get_offset_and_type(struct module *mod, enum mod_mem_type type,
1559 Elf_Shdr *sechdr, unsigned int section)
1560{
1561 long offset;
1562 long mask = ((unsigned long)(type) & SH_ENTSIZE_TYPE_MASK) << SH_ENTSIZE_TYPE_SHIFT;
1563
1564 mod->mem[type].size += arch_mod_section_prepend(mod, section);
1565 offset = ALIGN(mod->mem[type].size, sechdr->sh_addralign ?: 1);
1566 mod->mem[type].size = offset + sechdr->sh_size;
1567
1568 WARN_ON_ONCE(offset & mask);
1569 return offset | mask;
1570}
1571
1572bool module_init_layout_section(const char *sname)
1573{
1574#ifndef CONFIG_MODULE_UNLOAD
1575 if (module_exit_section(sname))
1576 return true;
1577#endif
1578 return module_init_section(sname);
1579}
1580
1581static void __layout_sections(struct module *mod, struct load_info *info, bool is_init)
1582{
1583 unsigned int m, i;
1584
1585 static const unsigned long masks[][2] = {
1586 /*
1587 * NOTE: all executable code must be the first section
1588 * in this array; otherwise modify the text_size
1589 * finder in the two loops below
1590 */
1591 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
1592 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
1593 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
1594 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
1595 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
1596 };
1597 static const int core_m_to_mem_type[] = {
1598 MOD_TEXT,
1599 MOD_RODATA,
1600 MOD_RO_AFTER_INIT,
1601 MOD_DATA,
1602 MOD_DATA,
1603 };
1604 static const int init_m_to_mem_type[] = {
1605 MOD_INIT_TEXT,
1606 MOD_INIT_RODATA,
1607 MOD_INVALID,
1608 MOD_INIT_DATA,
1609 MOD_INIT_DATA,
1610 };
1611
1612 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1613 enum mod_mem_type type = is_init ? init_m_to_mem_type[m] : core_m_to_mem_type[m];
1614
1615 for (i = 0; i < info->hdr->e_shnum; ++i) {
1616 Elf_Shdr *s = &info->sechdrs[i];
1617 const char *sname = info->secstrings + s->sh_name;
1618
1619 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1620 || (s->sh_flags & masks[m][1])
1621 || s->sh_entsize != ~0UL
1622 || is_init != module_init_layout_section(sname))
1623 continue;
1624
1625 if (WARN_ON_ONCE(type == MOD_INVALID))
1626 continue;
1627
1628 /*
1629 * Do not allocate codetag memory as we load it into
1630 * preallocated contiguous memory.
1631 */
1632 if (codetag_needs_module_section(mod, sname, s->sh_size)) {
1633 /*
1634 * s->sh_entsize won't be used but populate the
1635 * type field to avoid confusion.
1636 */
1637 s->sh_entsize = ((unsigned long)(type) & SH_ENTSIZE_TYPE_MASK)
1638 << SH_ENTSIZE_TYPE_SHIFT;
1639 continue;
1640 }
1641
1642 s->sh_entsize = module_get_offset_and_type(mod, type, s, i);
1643 pr_debug("\t%s\n", sname);
1644 }
1645 }
1646}
1647
1648/*
1649 * Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
1650 * might -- code, read-only data, read-write data, small data. Tally
1651 * sizes, and place the offsets into sh_entsize fields: high bit means it
1652 * belongs in init.
1653 */
1654static void layout_sections(struct module *mod, struct load_info *info)
1655{
1656 unsigned int i;
1657
1658 for (i = 0; i < info->hdr->e_shnum; i++)
1659 info->sechdrs[i].sh_entsize = ~0UL;
1660
1661 pr_debug("Core section allocation order for %s:\n", mod->name);
1662 __layout_sections(mod, info, false);
1663
1664 pr_debug("Init section allocation order for %s:\n", mod->name);
1665 __layout_sections(mod, info, true);
1666}
1667
1668static void module_license_taint_check(struct module *mod, const char *license)
1669{
1670 if (!license)
1671 license = "unspecified";
1672
1673 if (!license_is_gpl_compatible(license)) {
1674 if (!test_taint(TAINT_PROPRIETARY_MODULE))
1675 pr_warn("%s: module license '%s' taints kernel.\n",
1676 mod->name, license);
1677 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
1678 LOCKDEP_NOW_UNRELIABLE);
1679 }
1680}
1681
1682static void setup_modinfo(struct module *mod, struct load_info *info)
1683{
1684 struct module_attribute *attr;
1685 int i;
1686
1687 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1688 if (attr->setup)
1689 attr->setup(mod, get_modinfo(info, attr->attr.name));
1690 }
1691}
1692
1693static void free_modinfo(struct module *mod)
1694{
1695 struct module_attribute *attr;
1696 int i;
1697
1698 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1699 if (attr->free)
1700 attr->free(mod);
1701 }
1702}
1703
1704bool __weak module_init_section(const char *name)
1705{
1706 return strstarts(name, ".init");
1707}
1708
1709bool __weak module_exit_section(const char *name)
1710{
1711 return strstarts(name, ".exit");
1712}
1713
1714static int validate_section_offset(const struct load_info *info, Elf_Shdr *shdr)
1715{
1716#if defined(CONFIG_64BIT)
1717 unsigned long long secend;
1718#else
1719 unsigned long secend;
1720#endif
1721
1722 /*
1723 * Check for both overflow and offset/size being
1724 * too large.
1725 */
1726 secend = shdr->sh_offset + shdr->sh_size;
1727 if (secend < shdr->sh_offset || secend > info->len)
1728 return -ENOEXEC;
1729
1730 return 0;
1731}
1732
1733/**
1734 * elf_validity_ehdr() - Checks an ELF header for module validity
1735 * @info: Load info containing the ELF header to check
1736 *
1737 * Checks whether an ELF header could belong to a valid module. Checks:
1738 *
1739 * * ELF header is within the data the user provided
1740 * * ELF magic is present
1741 * * It is relocatable (not final linked, not core file, etc.)
1742 * * The header's machine type matches what the architecture expects.
1743 * * Optional arch-specific hook for other properties
1744 * - module_elf_check_arch() is currently only used by PPC to check
1745 * ELF ABI version, but may be used by others in the future.
1746 *
1747 * Return: %0 if valid, %-ENOEXEC on failure.
1748 */
1749static int elf_validity_ehdr(const struct load_info *info)
1750{
1751 if (info->len < sizeof(*(info->hdr))) {
1752 pr_err("Invalid ELF header len %lu\n", info->len);
1753 return -ENOEXEC;
1754 }
1755 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0) {
1756 pr_err("Invalid ELF header magic: != %s\n", ELFMAG);
1757 return -ENOEXEC;
1758 }
1759 if (info->hdr->e_type != ET_REL) {
1760 pr_err("Invalid ELF header type: %u != %u\n",
1761 info->hdr->e_type, ET_REL);
1762 return -ENOEXEC;
1763 }
1764 if (!elf_check_arch(info->hdr)) {
1765 pr_err("Invalid architecture in ELF header: %u\n",
1766 info->hdr->e_machine);
1767 return -ENOEXEC;
1768 }
1769 if (!module_elf_check_arch(info->hdr)) {
1770 pr_err("Invalid module architecture in ELF header: %u\n",
1771 info->hdr->e_machine);
1772 return -ENOEXEC;
1773 }
1774 return 0;
1775}
1776
1777/**
1778 * elf_validity_cache_sechdrs() - Cache section headers if valid
1779 * @info: Load info to compute section headers from
1780 *
1781 * Checks:
1782 *
1783 * * ELF header is valid (see elf_validity_ehdr())
1784 * * Section headers are the size we expect
1785 * * Section array fits in the user provided data
1786 * * Section index 0 is NULL
1787 * * Section contents are inbounds
1788 *
1789 * Then updates @info with a &load_info->sechdrs pointer if valid.
1790 *
1791 * Return: %0 if valid, negative error code if validation failed.
1792 */
1793static int elf_validity_cache_sechdrs(struct load_info *info)
1794{
1795 Elf_Shdr *sechdrs;
1796 Elf_Shdr *shdr;
1797 int i;
1798 int err;
1799
1800 err = elf_validity_ehdr(info);
1801 if (err < 0)
1802 return err;
1803
1804 if (info->hdr->e_shentsize != sizeof(Elf_Shdr)) {
1805 pr_err("Invalid ELF section header size\n");
1806 return -ENOEXEC;
1807 }
1808
1809 /*
1810 * e_shnum is 16 bits, and sizeof(Elf_Shdr) is
1811 * known and small. So e_shnum * sizeof(Elf_Shdr)
1812 * will not overflow unsigned long on any platform.
1813 */
1814 if (info->hdr->e_shoff >= info->len
1815 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
1816 info->len - info->hdr->e_shoff)) {
1817 pr_err("Invalid ELF section header overflow\n");
1818 return -ENOEXEC;
1819 }
1820
1821 sechdrs = (void *)info->hdr + info->hdr->e_shoff;
1822
1823 /*
1824 * The code assumes that section 0 has a length of zero and
1825 * an addr of zero, so check for it.
1826 */
1827 if (sechdrs[0].sh_type != SHT_NULL
1828 || sechdrs[0].sh_size != 0
1829 || sechdrs[0].sh_addr != 0) {
1830 pr_err("ELF Spec violation: section 0 type(%d)!=SH_NULL or non-zero len or addr\n",
1831 sechdrs[0].sh_type);
1832 return -ENOEXEC;
1833 }
1834
1835 /* Validate contents are inbounds */
1836 for (i = 1; i < info->hdr->e_shnum; i++) {
1837 shdr = &sechdrs[i];
1838 switch (shdr->sh_type) {
1839 case SHT_NULL:
1840 case SHT_NOBITS:
1841 /* No contents, offset/size don't mean anything */
1842 continue;
1843 default:
1844 err = validate_section_offset(info, shdr);
1845 if (err < 0) {
1846 pr_err("Invalid ELF section in module (section %u type %u)\n",
1847 i, shdr->sh_type);
1848 return err;
1849 }
1850 }
1851 }
1852
1853 info->sechdrs = sechdrs;
1854
1855 return 0;
1856}
1857
1858/**
1859 * elf_validity_cache_secstrings() - Caches section names if valid
1860 * @info: Load info to cache section names from. Must have valid sechdrs.
1861 *
1862 * Specifically checks:
1863 *
1864 * * Section name table index is inbounds of section headers
1865 * * Section name table is not empty
1866 * * Section name table is NUL terminated
1867 * * All section name offsets are inbounds of the section
1868 *
1869 * Then updates @info with a &load_info->secstrings pointer if valid.
1870 *
1871 * Return: %0 if valid, negative error code if validation failed.
1872 */
1873static int elf_validity_cache_secstrings(struct load_info *info)
1874{
1875 Elf_Shdr *strhdr, *shdr;
1876 char *secstrings;
1877 int i;
1878
1879 /*
1880 * Verify if the section name table index is valid.
1881 */
1882 if (info->hdr->e_shstrndx == SHN_UNDEF
1883 || info->hdr->e_shstrndx >= info->hdr->e_shnum) {
1884 pr_err("Invalid ELF section name index: %d || e_shstrndx (%d) >= e_shnum (%d)\n",
1885 info->hdr->e_shstrndx, info->hdr->e_shstrndx,
1886 info->hdr->e_shnum);
1887 return -ENOEXEC;
1888 }
1889
1890 strhdr = &info->sechdrs[info->hdr->e_shstrndx];
1891
1892 /*
1893 * The section name table must be NUL-terminated, as required
1894 * by the spec. This makes strcmp and pr_* calls that access
1895 * strings in the section safe.
1896 */
1897 secstrings = (void *)info->hdr + strhdr->sh_offset;
1898 if (strhdr->sh_size == 0) {
1899 pr_err("empty section name table\n");
1900 return -ENOEXEC;
1901 }
1902 if (secstrings[strhdr->sh_size - 1] != '\0') {
1903 pr_err("ELF Spec violation: section name table isn't null terminated\n");
1904 return -ENOEXEC;
1905 }
1906
1907 for (i = 0; i < info->hdr->e_shnum; i++) {
1908 shdr = &info->sechdrs[i];
1909 /* SHT_NULL means sh_name has an undefined value */
1910 if (shdr->sh_type == SHT_NULL)
1911 continue;
1912 if (shdr->sh_name >= strhdr->sh_size) {
1913 pr_err("Invalid ELF section name in module (section %u type %u)\n",
1914 i, shdr->sh_type);
1915 return -ENOEXEC;
1916 }
1917 }
1918
1919 info->secstrings = secstrings;
1920 return 0;
1921}
1922
1923/**
1924 * elf_validity_cache_index_info() - Validate and cache modinfo section
1925 * @info: Load info to populate the modinfo index on.
1926 * Must have &load_info->sechdrs and &load_info->secstrings populated
1927 *
1928 * Checks that if there is a .modinfo section, it is unique.
1929 * Then, it caches its index in &load_info->index.info.
1930 * Finally, it tries to populate the name to improve error messages.
1931 *
1932 * Return: %0 if valid, %-ENOEXEC if multiple modinfo sections were found.
1933 */
1934static int elf_validity_cache_index_info(struct load_info *info)
1935{
1936 int info_idx;
1937
1938 info_idx = find_any_unique_sec(info, ".modinfo");
1939
1940 if (info_idx == 0)
1941 /* Early return, no .modinfo */
1942 return 0;
1943
1944 if (info_idx < 0) {
1945 pr_err("Only one .modinfo section must exist.\n");
1946 return -ENOEXEC;
1947 }
1948
1949 info->index.info = info_idx;
1950 /* Try to find a name early so we can log errors with a module name */
1951 info->name = get_modinfo(info, "name");
1952
1953 return 0;
1954}
1955
1956/**
1957 * elf_validity_cache_index_mod() - Validates and caches this_module section
1958 * @info: Load info to cache this_module on.
1959 * Must have &load_info->sechdrs and &load_info->secstrings populated
1960 *
1961 * The ".gnu.linkonce.this_module" ELF section is special. It is what modpost
1962 * uses to refer to __this_module and let's use rely on THIS_MODULE to point
1963 * to &__this_module properly. The kernel's modpost declares it on each
1964 * modules's *.mod.c file. If the struct module of the kernel changes a full
1965 * kernel rebuild is required.
1966 *
1967 * We have a few expectations for this special section, this function
1968 * validates all this for us:
1969 *
1970 * * The section has contents
1971 * * The section is unique
1972 * * We expect the kernel to always have to allocate it: SHF_ALLOC
1973 * * The section size must match the kernel's run time's struct module
1974 * size
1975 *
1976 * If all checks pass, the index will be cached in &load_info->index.mod
1977 *
1978 * Return: %0 on validation success, %-ENOEXEC on failure
1979 */
1980static int elf_validity_cache_index_mod(struct load_info *info)
1981{
1982 Elf_Shdr *shdr;
1983 int mod_idx;
1984
1985 mod_idx = find_any_unique_sec(info, ".gnu.linkonce.this_module");
1986 if (mod_idx <= 0) {
1987 pr_err("module %s: Exactly one .gnu.linkonce.this_module section must exist.\n",
1988 info->name ?: "(missing .modinfo section or name field)");
1989 return -ENOEXEC;
1990 }
1991
1992 shdr = &info->sechdrs[mod_idx];
1993
1994 if (shdr->sh_type == SHT_NOBITS) {
1995 pr_err("module %s: .gnu.linkonce.this_module section must have a size set\n",
1996 info->name ?: "(missing .modinfo section or name field)");
1997 return -ENOEXEC;
1998 }
1999
2000 if (!(shdr->sh_flags & SHF_ALLOC)) {
2001 pr_err("module %s: .gnu.linkonce.this_module must occupy memory during process execution\n",
2002 info->name ?: "(missing .modinfo section or name field)");
2003 return -ENOEXEC;
2004 }
2005
2006 if (shdr->sh_size != sizeof(struct module)) {
2007 pr_err("module %s: .gnu.linkonce.this_module section size must match the kernel's built struct module size at run time\n",
2008 info->name ?: "(missing .modinfo section or name field)");
2009 return -ENOEXEC;
2010 }
2011
2012 info->index.mod = mod_idx;
2013
2014 return 0;
2015}
2016
2017/**
2018 * elf_validity_cache_index_sym() - Validate and cache symtab index
2019 * @info: Load info to cache symtab index in.
2020 * Must have &load_info->sechdrs and &load_info->secstrings populated.
2021 *
2022 * Checks that there is exactly one symbol table, then caches its index in
2023 * &load_info->index.sym.
2024 *
2025 * Return: %0 if valid, %-ENOEXEC on failure.
2026 */
2027static int elf_validity_cache_index_sym(struct load_info *info)
2028{
2029 unsigned int sym_idx;
2030 unsigned int num_sym_secs = 0;
2031 int i;
2032
2033 for (i = 1; i < info->hdr->e_shnum; i++) {
2034 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2035 num_sym_secs++;
2036 sym_idx = i;
2037 }
2038 }
2039
2040 if (num_sym_secs != 1) {
2041 pr_warn("%s: module has no symbols (stripped?)\n",
2042 info->name ?: "(missing .modinfo section or name field)");
2043 return -ENOEXEC;
2044 }
2045
2046 info->index.sym = sym_idx;
2047
2048 return 0;
2049}
2050
2051/**
2052 * elf_validity_cache_index_str() - Validate and cache strtab index
2053 * @info: Load info to cache strtab index in.
2054 * Must have &load_info->sechdrs and &load_info->secstrings populated.
2055 * Must have &load_info->index.sym populated.
2056 *
2057 * Looks at the symbol table's associated string table, makes sure it is
2058 * in-bounds, and caches it.
2059 *
2060 * Return: %0 if valid, %-ENOEXEC on failure.
2061 */
2062static int elf_validity_cache_index_str(struct load_info *info)
2063{
2064 unsigned int str_idx = info->sechdrs[info->index.sym].sh_link;
2065
2066 if (str_idx == SHN_UNDEF || str_idx >= info->hdr->e_shnum) {
2067 pr_err("Invalid ELF sh_link!=SHN_UNDEF(%d) or (sh_link(%d) >= hdr->e_shnum(%d)\n",
2068 str_idx, str_idx, info->hdr->e_shnum);
2069 return -ENOEXEC;
2070 }
2071
2072 info->index.str = str_idx;
2073 return 0;
2074}
2075
2076/**
2077 * elf_validity_cache_index() - Resolve, validate, cache section indices
2078 * @info: Load info to read from and update.
2079 * &load_info->sechdrs and &load_info->secstrings must be populated.
2080 * @flags: Load flags, relevant to suppress version loading, see
2081 * uapi/linux/module.h
2082 *
2083 * Populates &load_info->index, validating as it goes.
2084 * See child functions for per-field validation:
2085 *
2086 * * elf_validity_cache_index_info()
2087 * * elf_validity_cache_index_mod()
2088 * * elf_validity_cache_index_sym()
2089 * * elf_validity_cache_index_str()
2090 *
2091 * If versioning is not suppressed via flags, load the version index from
2092 * a section called "__versions" with no validation.
2093 *
2094 * If CONFIG_SMP is enabled, load the percpu section by name with no
2095 * validation.
2096 *
2097 * Return: 0 on success, negative error code if an index failed validation.
2098 */
2099static int elf_validity_cache_index(struct load_info *info, int flags)
2100{
2101 int err;
2102
2103 err = elf_validity_cache_index_info(info);
2104 if (err < 0)
2105 return err;
2106 err = elf_validity_cache_index_mod(info);
2107 if (err < 0)
2108 return err;
2109 err = elf_validity_cache_index_sym(info);
2110 if (err < 0)
2111 return err;
2112 err = elf_validity_cache_index_str(info);
2113 if (err < 0)
2114 return err;
2115
2116 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
2117 info->index.vers = 0; /* Pretend no __versions section! */
2118 else
2119 info->index.vers = find_sec(info, "__versions");
2120
2121 info->index.pcpu = find_pcpusec(info);
2122
2123 return 0;
2124}
2125
2126/**
2127 * elf_validity_cache_strtab() - Validate and cache symbol string table
2128 * @info: Load info to read from and update.
2129 * Must have &load_info->sechdrs and &load_info->secstrings populated.
2130 * Must have &load_info->index populated.
2131 *
2132 * Checks:
2133 *
2134 * * The string table is not empty.
2135 * * The string table starts and ends with NUL (required by ELF spec).
2136 * * Every &Elf_Sym->st_name offset in the symbol table is inbounds of the
2137 * string table.
2138 *
2139 * And caches the pointer as &load_info->strtab in @info.
2140 *
2141 * Return: 0 on success, negative error code if a check failed.
2142 */
2143static int elf_validity_cache_strtab(struct load_info *info)
2144{
2145 Elf_Shdr *str_shdr = &info->sechdrs[info->index.str];
2146 Elf_Shdr *sym_shdr = &info->sechdrs[info->index.sym];
2147 char *strtab = (char *)info->hdr + str_shdr->sh_offset;
2148 Elf_Sym *syms = (void *)info->hdr + sym_shdr->sh_offset;
2149 int i;
2150
2151 if (str_shdr->sh_size == 0) {
2152 pr_err("empty symbol string table\n");
2153 return -ENOEXEC;
2154 }
2155 if (strtab[0] != '\0') {
2156 pr_err("symbol string table missing leading NUL\n");
2157 return -ENOEXEC;
2158 }
2159 if (strtab[str_shdr->sh_size - 1] != '\0') {
2160 pr_err("symbol string table isn't NUL terminated\n");
2161 return -ENOEXEC;
2162 }
2163
2164 /*
2165 * Now that we know strtab is correctly structured, check symbol
2166 * starts are inbounds before they're used later.
2167 */
2168 for (i = 0; i < sym_shdr->sh_size / sizeof(*syms); i++) {
2169 if (syms[i].st_name >= str_shdr->sh_size) {
2170 pr_err("symbol name out of bounds in string table");
2171 return -ENOEXEC;
2172 }
2173 }
2174
2175 info->strtab = strtab;
2176 return 0;
2177}
2178
2179/*
2180 * Check userspace passed ELF module against our expectations, and cache
2181 * useful variables for further processing as we go.
2182 *
2183 * This does basic validity checks against section offsets and sizes, the
2184 * section name string table, and the indices used for it (sh_name).
2185 *
2186 * As a last step, since we're already checking the ELF sections we cache
2187 * useful variables which will be used later for our convenience:
2188 *
2189 * o pointers to section headers
2190 * o cache the modinfo symbol section
2191 * o cache the string symbol section
2192 * o cache the module section
2193 *
2194 * As a last step we set info->mod to the temporary copy of the module in
2195 * info->hdr. The final one will be allocated in move_module(). Any
2196 * modifications we make to our copy of the module will be carried over
2197 * to the final minted module.
2198 */
2199static int elf_validity_cache_copy(struct load_info *info, int flags)
2200{
2201 int err;
2202
2203 err = elf_validity_cache_sechdrs(info);
2204 if (err < 0)
2205 return err;
2206 err = elf_validity_cache_secstrings(info);
2207 if (err < 0)
2208 return err;
2209 err = elf_validity_cache_index(info, flags);
2210 if (err < 0)
2211 return err;
2212 err = elf_validity_cache_strtab(info);
2213 if (err < 0)
2214 return err;
2215
2216 /* This is temporary: point mod into copy of data. */
2217 info->mod = (void *)info->hdr + info->sechdrs[info->index.mod].sh_offset;
2218
2219 /*
2220 * If we didn't load the .modinfo 'name' field earlier, fall back to
2221 * on-disk struct mod 'name' field.
2222 */
2223 if (!info->name)
2224 info->name = info->mod->name;
2225
2226 return 0;
2227}
2228
2229#define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2230
2231static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
2232{
2233 do {
2234 unsigned long n = min(len, COPY_CHUNK_SIZE);
2235
2236 if (copy_from_user(dst, usrc, n) != 0)
2237 return -EFAULT;
2238 cond_resched();
2239 dst += n;
2240 usrc += n;
2241 len -= n;
2242 } while (len);
2243 return 0;
2244}
2245
2246static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2247{
2248 if (!get_modinfo(info, "livepatch"))
2249 /* Nothing more to do */
2250 return 0;
2251
2252 if (set_livepatch_module(mod))
2253 return 0;
2254
2255 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
2256 mod->name);
2257 return -ENOEXEC;
2258}
2259
2260static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
2261{
2262 if (retpoline_module_ok(get_modinfo(info, "retpoline")))
2263 return;
2264
2265 pr_warn("%s: loading module not compiled with retpoline compiler.\n",
2266 mod->name);
2267}
2268
2269/* Sets info->hdr and info->len. */
2270static int copy_module_from_user(const void __user *umod, unsigned long len,
2271 struct load_info *info)
2272{
2273 int err;
2274
2275 info->len = len;
2276 if (info->len < sizeof(*(info->hdr)))
2277 return -ENOEXEC;
2278
2279 err = security_kernel_load_data(LOADING_MODULE, true);
2280 if (err)
2281 return err;
2282
2283 /* Suck in entire file: we'll want most of it. */
2284 info->hdr = __vmalloc(info->len, GFP_KERNEL | __GFP_NOWARN);
2285 if (!info->hdr)
2286 return -ENOMEM;
2287
2288 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2289 err = -EFAULT;
2290 goto out;
2291 }
2292
2293 err = security_kernel_post_load_data((char *)info->hdr, info->len,
2294 LOADING_MODULE, "init_module");
2295out:
2296 if (err)
2297 vfree(info->hdr);
2298
2299 return err;
2300}
2301
2302static void free_copy(struct load_info *info, int flags)
2303{
2304 if (flags & MODULE_INIT_COMPRESSED_FILE)
2305 module_decompress_cleanup(info);
2306 else
2307 vfree(info->hdr);
2308}
2309
2310static int rewrite_section_headers(struct load_info *info, int flags)
2311{
2312 unsigned int i;
2313
2314 /* This should always be true, but let's be sure. */
2315 info->sechdrs[0].sh_addr = 0;
2316
2317 for (i = 1; i < info->hdr->e_shnum; i++) {
2318 Elf_Shdr *shdr = &info->sechdrs[i];
2319
2320 /*
2321 * Mark all sections sh_addr with their address in the
2322 * temporary image.
2323 */
2324 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2325
2326 }
2327
2328 /* Track but don't keep modinfo and version sections. */
2329 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2330 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2331
2332 return 0;
2333}
2334
2335/*
2336 * These calls taint the kernel depending certain module circumstances */
2337static void module_augment_kernel_taints(struct module *mod, struct load_info *info)
2338{
2339 int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
2340
2341 if (!get_modinfo(info, "intree")) {
2342 if (!test_taint(TAINT_OOT_MODULE))
2343 pr_warn("%s: loading out-of-tree module taints kernel.\n",
2344 mod->name);
2345 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2346 }
2347
2348 check_modinfo_retpoline(mod, info);
2349
2350 if (get_modinfo(info, "staging")) {
2351 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
2352 pr_warn("%s: module is from the staging directory, the quality "
2353 "is unknown, you have been warned.\n", mod->name);
2354 }
2355
2356 if (is_livepatch_module(mod)) {
2357 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
2358 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
2359 mod->name);
2360 }
2361
2362 module_license_taint_check(mod, get_modinfo(info, "license"));
2363
2364 if (get_modinfo(info, "test")) {
2365 if (!test_taint(TAINT_TEST))
2366 pr_warn("%s: loading test module taints kernel.\n",
2367 mod->name);
2368 add_taint_module(mod, TAINT_TEST, LOCKDEP_STILL_OK);
2369 }
2370#ifdef CONFIG_MODULE_SIG
2371 mod->sig_ok = info->sig_ok;
2372 if (!mod->sig_ok) {
2373 pr_notice_once("%s: module verification failed: signature "
2374 "and/or required key missing - tainting "
2375 "kernel\n", mod->name);
2376 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
2377 }
2378#endif
2379
2380 /*
2381 * ndiswrapper is under GPL by itself, but loads proprietary modules.
2382 * Don't use add_taint_module(), as it would prevent ndiswrapper from
2383 * using GPL-only symbols it needs.
2384 */
2385 if (strcmp(mod->name, "ndiswrapper") == 0)
2386 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
2387
2388 /* driverloader was caught wrongly pretending to be under GPL */
2389 if (strcmp(mod->name, "driverloader") == 0)
2390 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2391 LOCKDEP_NOW_UNRELIABLE);
2392
2393 /* lve claims to be GPL but upstream won't provide source */
2394 if (strcmp(mod->name, "lve") == 0)
2395 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2396 LOCKDEP_NOW_UNRELIABLE);
2397
2398 if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
2399 pr_warn("%s: module license taints kernel.\n", mod->name);
2400
2401}
2402
2403static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2404{
2405 const char *modmagic = get_modinfo(info, "vermagic");
2406 int err;
2407
2408 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
2409 modmagic = NULL;
2410
2411 /* This is allowed: modprobe --force will invalidate it. */
2412 if (!modmagic) {
2413 err = try_to_force_load(mod, "bad vermagic");
2414 if (err)
2415 return err;
2416 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2417 pr_err("%s: version magic '%s' should be '%s'\n",
2418 info->name, modmagic, vermagic);
2419 return -ENOEXEC;
2420 }
2421
2422 err = check_modinfo_livepatch(mod, info);
2423 if (err)
2424 return err;
2425
2426 return 0;
2427}
2428
2429static int find_module_sections(struct module *mod, struct load_info *info)
2430{
2431 mod->kp = section_objs(info, "__param",
2432 sizeof(*mod->kp), &mod->num_kp);
2433 mod->syms = section_objs(info, "__ksymtab",
2434 sizeof(*mod->syms), &mod->num_syms);
2435 mod->crcs = section_addr(info, "__kcrctab");
2436 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2437 sizeof(*mod->gpl_syms),
2438 &mod->num_gpl_syms);
2439 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2440
2441#ifdef CONFIG_CONSTRUCTORS
2442 mod->ctors = section_objs(info, ".ctors",
2443 sizeof(*mod->ctors), &mod->num_ctors);
2444 if (!mod->ctors)
2445 mod->ctors = section_objs(info, ".init_array",
2446 sizeof(*mod->ctors), &mod->num_ctors);
2447 else if (find_sec(info, ".init_array")) {
2448 /*
2449 * This shouldn't happen with same compiler and binutils
2450 * building all parts of the module.
2451 */
2452 pr_warn("%s: has both .ctors and .init_array.\n",
2453 mod->name);
2454 return -EINVAL;
2455 }
2456#endif
2457
2458 mod->noinstr_text_start = section_objs(info, ".noinstr.text", 1,
2459 &mod->noinstr_text_size);
2460
2461#ifdef CONFIG_TRACEPOINTS
2462 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2463 sizeof(*mod->tracepoints_ptrs),
2464 &mod->num_tracepoints);
2465#endif
2466#ifdef CONFIG_TREE_SRCU
2467 mod->srcu_struct_ptrs = section_objs(info, "___srcu_struct_ptrs",
2468 sizeof(*mod->srcu_struct_ptrs),
2469 &mod->num_srcu_structs);
2470#endif
2471#ifdef CONFIG_BPF_EVENTS
2472 mod->bpf_raw_events = section_objs(info, "__bpf_raw_tp_map",
2473 sizeof(*mod->bpf_raw_events),
2474 &mod->num_bpf_raw_events);
2475#endif
2476#ifdef CONFIG_DEBUG_INFO_BTF_MODULES
2477 mod->btf_data = any_section_objs(info, ".BTF", 1, &mod->btf_data_size);
2478 mod->btf_base_data = any_section_objs(info, ".BTF.base", 1,
2479 &mod->btf_base_data_size);
2480#endif
2481#ifdef CONFIG_JUMP_LABEL
2482 mod->jump_entries = section_objs(info, "__jump_table",
2483 sizeof(*mod->jump_entries),
2484 &mod->num_jump_entries);
2485#endif
2486#ifdef CONFIG_EVENT_TRACING
2487 mod->trace_events = section_objs(info, "_ftrace_events",
2488 sizeof(*mod->trace_events),
2489 &mod->num_trace_events);
2490 mod->trace_evals = section_objs(info, "_ftrace_eval_map",
2491 sizeof(*mod->trace_evals),
2492 &mod->num_trace_evals);
2493#endif
2494#ifdef CONFIG_TRACING
2495 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2496 sizeof(*mod->trace_bprintk_fmt_start),
2497 &mod->num_trace_bprintk_fmt);
2498#endif
2499#ifdef CONFIG_FTRACE_MCOUNT_RECORD
2500 /* sechdrs[0].sh_size is always zero */
2501 mod->ftrace_callsites = section_objs(info, FTRACE_CALLSITE_SECTION,
2502 sizeof(*mod->ftrace_callsites),
2503 &mod->num_ftrace_callsites);
2504#endif
2505#ifdef CONFIG_FUNCTION_ERROR_INJECTION
2506 mod->ei_funcs = section_objs(info, "_error_injection_whitelist",
2507 sizeof(*mod->ei_funcs),
2508 &mod->num_ei_funcs);
2509#endif
2510#ifdef CONFIG_KPROBES
2511 mod->kprobes_text_start = section_objs(info, ".kprobes.text", 1,
2512 &mod->kprobes_text_size);
2513 mod->kprobe_blacklist = section_objs(info, "_kprobe_blacklist",
2514 sizeof(unsigned long),
2515 &mod->num_kprobe_blacklist);
2516#endif
2517#ifdef CONFIG_PRINTK_INDEX
2518 mod->printk_index_start = section_objs(info, ".printk_index",
2519 sizeof(*mod->printk_index_start),
2520 &mod->printk_index_size);
2521#endif
2522#ifdef CONFIG_HAVE_STATIC_CALL_INLINE
2523 mod->static_call_sites = section_objs(info, ".static_call_sites",
2524 sizeof(*mod->static_call_sites),
2525 &mod->num_static_call_sites);
2526#endif
2527#if IS_ENABLED(CONFIG_KUNIT)
2528 mod->kunit_suites = section_objs(info, ".kunit_test_suites",
2529 sizeof(*mod->kunit_suites),
2530 &mod->num_kunit_suites);
2531 mod->kunit_init_suites = section_objs(info, ".kunit_init_test_suites",
2532 sizeof(*mod->kunit_init_suites),
2533 &mod->num_kunit_init_suites);
2534#endif
2535
2536 mod->extable = section_objs(info, "__ex_table",
2537 sizeof(*mod->extable), &mod->num_exentries);
2538
2539 if (section_addr(info, "__obsparm"))
2540 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
2541
2542#ifdef CONFIG_DYNAMIC_DEBUG_CORE
2543 mod->dyndbg_info.descs = section_objs(info, "__dyndbg",
2544 sizeof(*mod->dyndbg_info.descs),
2545 &mod->dyndbg_info.num_descs);
2546 mod->dyndbg_info.classes = section_objs(info, "__dyndbg_classes",
2547 sizeof(*mod->dyndbg_info.classes),
2548 &mod->dyndbg_info.num_classes);
2549#endif
2550
2551 return 0;
2552}
2553
2554static int move_module(struct module *mod, struct load_info *info)
2555{
2556 int i;
2557 enum mod_mem_type t = 0;
2558 int ret = -ENOMEM;
2559 bool codetag_section_found = false;
2560
2561 for_each_mod_mem_type(type) {
2562 if (!mod->mem[type].size) {
2563 mod->mem[type].base = NULL;
2564 mod->mem[type].rw_copy = NULL;
2565 continue;
2566 }
2567
2568 ret = module_memory_alloc(mod, type);
2569 if (ret) {
2570 t = type;
2571 goto out_err;
2572 }
2573 }
2574
2575 /* Transfer each section which specifies SHF_ALLOC */
2576 pr_debug("Final section addresses for %s:\n", mod->name);
2577 for (i = 0; i < info->hdr->e_shnum; i++) {
2578 void *dest;
2579 Elf_Shdr *shdr = &info->sechdrs[i];
2580 const char *sname;
2581 unsigned long addr;
2582
2583 if (!(shdr->sh_flags & SHF_ALLOC))
2584 continue;
2585
2586 sname = info->secstrings + shdr->sh_name;
2587 /*
2588 * Load codetag sections separately as they might still be used
2589 * after module unload.
2590 */
2591 if (codetag_needs_module_section(mod, sname, shdr->sh_size)) {
2592 dest = codetag_alloc_module_section(mod, sname, shdr->sh_size,
2593 arch_mod_section_prepend(mod, i), shdr->sh_addralign);
2594 if (WARN_ON(!dest)) {
2595 ret = -EINVAL;
2596 goto out_err;
2597 }
2598 if (IS_ERR(dest)) {
2599 ret = PTR_ERR(dest);
2600 goto out_err;
2601 }
2602 addr = (unsigned long)dest;
2603 codetag_section_found = true;
2604 } else {
2605 enum mod_mem_type type = shdr->sh_entsize >> SH_ENTSIZE_TYPE_SHIFT;
2606 unsigned long offset = shdr->sh_entsize & SH_ENTSIZE_OFFSET_MASK;
2607
2608 addr = (unsigned long)mod->mem[type].base + offset;
2609 dest = mod->mem[type].rw_copy + offset;
2610 }
2611
2612 if (shdr->sh_type != SHT_NOBITS) {
2613 /*
2614 * Our ELF checker already validated this, but let's
2615 * be pedantic and make the goal clearer. We actually
2616 * end up copying over all modifications made to the
2617 * userspace copy of the entire struct module.
2618 */
2619 if (i == info->index.mod &&
2620 (WARN_ON_ONCE(shdr->sh_size != sizeof(struct module)))) {
2621 ret = -ENOEXEC;
2622 goto out_err;
2623 }
2624 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2625 }
2626 /*
2627 * Update the userspace copy's ELF section address to point to
2628 * our newly allocated memory as a pure convenience so that
2629 * users of info can keep taking advantage and using the newly
2630 * minted official memory area.
2631 */
2632 shdr->sh_addr = addr;
2633 pr_debug("\t0x%lx 0x%.8lx %s\n", (long)shdr->sh_addr,
2634 (long)shdr->sh_size, info->secstrings + shdr->sh_name);
2635 }
2636
2637 return 0;
2638out_err:
2639 for (t--; t >= 0; t--)
2640 module_memory_free(mod, t);
2641 if (codetag_section_found)
2642 codetag_free_module_sections(mod);
2643
2644 return ret;
2645}
2646
2647static int check_export_symbol_versions(struct module *mod)
2648{
2649#ifdef CONFIG_MODVERSIONS
2650 if ((mod->num_syms && !mod->crcs) ||
2651 (mod->num_gpl_syms && !mod->gpl_crcs)) {
2652 return try_to_force_load(mod,
2653 "no versions for exported symbols");
2654 }
2655#endif
2656 return 0;
2657}
2658
2659static void flush_module_icache(const struct module *mod)
2660{
2661 /*
2662 * Flush the instruction cache, since we've played with text.
2663 * Do it before processing of module parameters, so the module
2664 * can provide parameter accessor functions of its own.
2665 */
2666 for_each_mod_mem_type(type) {
2667 const struct module_memory *mod_mem = &mod->mem[type];
2668
2669 if (mod_mem->size) {
2670 flush_icache_range((unsigned long)mod_mem->base,
2671 (unsigned long)mod_mem->base + mod_mem->size);
2672 }
2673 }
2674}
2675
2676bool __weak module_elf_check_arch(Elf_Ehdr *hdr)
2677{
2678 return true;
2679}
2680
2681int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
2682 Elf_Shdr *sechdrs,
2683 char *secstrings,
2684 struct module *mod)
2685{
2686 return 0;
2687}
2688
2689/* module_blacklist is a comma-separated list of module names */
2690static char *module_blacklist;
2691static bool blacklisted(const char *module_name)
2692{
2693 const char *p;
2694 size_t len;
2695
2696 if (!module_blacklist)
2697 return false;
2698
2699 for (p = module_blacklist; *p; p += len) {
2700 len = strcspn(p, ",");
2701 if (strlen(module_name) == len && !memcmp(module_name, p, len))
2702 return true;
2703 if (p[len] == ',')
2704 len++;
2705 }
2706 return false;
2707}
2708core_param(module_blacklist, module_blacklist, charp, 0400);
2709
2710static struct module *layout_and_allocate(struct load_info *info, int flags)
2711{
2712 struct module *mod;
2713 unsigned int ndx;
2714 int err;
2715
2716 /* Allow arches to frob section contents and sizes. */
2717 err = module_frob_arch_sections(info->hdr, info->sechdrs,
2718 info->secstrings, info->mod);
2719 if (err < 0)
2720 return ERR_PTR(err);
2721
2722 err = module_enforce_rwx_sections(info->hdr, info->sechdrs,
2723 info->secstrings, info->mod);
2724 if (err < 0)
2725 return ERR_PTR(err);
2726
2727 /* We will do a special allocation for per-cpu sections later. */
2728 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
2729
2730 /*
2731 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
2732 * layout_sections() can put it in the right place.
2733 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
2734 */
2735 ndx = find_sec(info, ".data..ro_after_init");
2736 if (ndx)
2737 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
2738 /*
2739 * Mark the __jump_table section as ro_after_init as well: these data
2740 * structures are never modified, with the exception of entries that
2741 * refer to code in the __init section, which are annotated as such
2742 * at module load time.
2743 */
2744 ndx = find_sec(info, "__jump_table");
2745 if (ndx)
2746 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
2747
2748 /*
2749 * Determine total sizes, and put offsets in sh_entsize. For now
2750 * this is done generically; there doesn't appear to be any
2751 * special cases for the architectures.
2752 */
2753 layout_sections(info->mod, info);
2754 layout_symtab(info->mod, info);
2755
2756 /* Allocate and move to the final place */
2757 err = move_module(info->mod, info);
2758 if (err)
2759 return ERR_PTR(err);
2760
2761 /* Module has been copied to its final place now: return it. */
2762 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2763 kmemleak_load_module(mod, info);
2764 codetag_module_replaced(info->mod, mod);
2765
2766 return mod;
2767}
2768
2769/* mod is no longer valid after this! */
2770static void module_deallocate(struct module *mod, struct load_info *info)
2771{
2772 percpu_modfree(mod);
2773 module_arch_freeing_init(mod);
2774
2775 free_mod_mem(mod);
2776}
2777
2778int __weak module_finalize(const Elf_Ehdr *hdr,
2779 const Elf_Shdr *sechdrs,
2780 struct module *me)
2781{
2782 return 0;
2783}
2784
2785int __weak module_post_finalize(const Elf_Ehdr *hdr,
2786 const Elf_Shdr *sechdrs,
2787 struct module *me)
2788{
2789 return 0;
2790}
2791
2792static int post_relocation(struct module *mod, const struct load_info *info)
2793{
2794 int ret;
2795
2796 /* Sort exception table now relocations are done. */
2797 sort_extable(mod->extable, mod->extable + mod->num_exentries);
2798
2799 /* Copy relocated percpu area over. */
2800 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
2801 info->sechdrs[info->index.pcpu].sh_size);
2802
2803 /* Setup kallsyms-specific fields. */
2804 add_kallsyms(mod, info);
2805
2806 /* Arch-specific module finalizing. */
2807 ret = module_finalize(info->hdr, info->sechdrs, mod);
2808 if (ret)
2809 return ret;
2810
2811 for_each_mod_mem_type(type) {
2812 struct module_memory *mem = &mod->mem[type];
2813
2814 if (mem->is_rox) {
2815 if (!execmem_update_copy(mem->base, mem->rw_copy,
2816 mem->size))
2817 return -ENOMEM;
2818
2819 vfree(mem->rw_copy);
2820 mem->rw_copy = NULL;
2821 }
2822 }
2823
2824 return module_post_finalize(info->hdr, info->sechdrs, mod);
2825}
2826
2827/* Call module constructors. */
2828static void do_mod_ctors(struct module *mod)
2829{
2830#ifdef CONFIG_CONSTRUCTORS
2831 unsigned long i;
2832
2833 for (i = 0; i < mod->num_ctors; i++)
2834 mod->ctors[i]();
2835#endif
2836}
2837
2838/* For freeing module_init on success, in case kallsyms traversing */
2839struct mod_initfree {
2840 struct llist_node node;
2841 void *init_text;
2842 void *init_data;
2843 void *init_rodata;
2844};
2845
2846static void do_free_init(struct work_struct *w)
2847{
2848 struct llist_node *pos, *n, *list;
2849 struct mod_initfree *initfree;
2850
2851 list = llist_del_all(&init_free_list);
2852
2853 synchronize_rcu();
2854
2855 llist_for_each_safe(pos, n, list) {
2856 initfree = container_of(pos, struct mod_initfree, node);
2857 execmem_free(initfree->init_text);
2858 execmem_free(initfree->init_data);
2859 execmem_free(initfree->init_rodata);
2860 kfree(initfree);
2861 }
2862}
2863
2864void flush_module_init_free_work(void)
2865{
2866 flush_work(&init_free_wq);
2867}
2868
2869#undef MODULE_PARAM_PREFIX
2870#define MODULE_PARAM_PREFIX "module."
2871/* Default value for module->async_probe_requested */
2872static bool async_probe;
2873module_param(async_probe, bool, 0644);
2874
2875/*
2876 * This is where the real work happens.
2877 *
2878 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
2879 * helper command 'lx-symbols'.
2880 */
2881static noinline int do_init_module(struct module *mod)
2882{
2883 int ret = 0;
2884 struct mod_initfree *freeinit;
2885#if defined(CONFIG_MODULE_STATS)
2886 unsigned int text_size = 0, total_size = 0;
2887
2888 for_each_mod_mem_type(type) {
2889 const struct module_memory *mod_mem = &mod->mem[type];
2890 if (mod_mem->size) {
2891 total_size += mod_mem->size;
2892 if (type == MOD_TEXT || type == MOD_INIT_TEXT)
2893 text_size += mod_mem->size;
2894 }
2895 }
2896#endif
2897
2898 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
2899 if (!freeinit) {
2900 ret = -ENOMEM;
2901 goto fail;
2902 }
2903 freeinit->init_text = mod->mem[MOD_INIT_TEXT].base;
2904 freeinit->init_data = mod->mem[MOD_INIT_DATA].base;
2905 freeinit->init_rodata = mod->mem[MOD_INIT_RODATA].base;
2906
2907 do_mod_ctors(mod);
2908 /* Start the module */
2909 if (mod->init != NULL)
2910 ret = do_one_initcall(mod->init);
2911 if (ret < 0) {
2912 goto fail_free_freeinit;
2913 }
2914 if (ret > 0) {
2915 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
2916 "follow 0/-E convention\n"
2917 "%s: loading module anyway...\n",
2918 __func__, mod->name, ret, __func__);
2919 dump_stack();
2920 }
2921
2922 /* Now it's a first class citizen! */
2923 mod->state = MODULE_STATE_LIVE;
2924 blocking_notifier_call_chain(&module_notify_list,
2925 MODULE_STATE_LIVE, mod);
2926
2927 /* Delay uevent until module has finished its init routine */
2928 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
2929
2930 /*
2931 * We need to finish all async code before the module init sequence
2932 * is done. This has potential to deadlock if synchronous module
2933 * loading is requested from async (which is not allowed!).
2934 *
2935 * See commit 0fdff3ec6d87 ("async, kmod: warn on synchronous
2936 * request_module() from async workers") for more details.
2937 */
2938 if (!mod->async_probe_requested)
2939 async_synchronize_full();
2940
2941 ftrace_free_mem(mod, mod->mem[MOD_INIT_TEXT].base,
2942 mod->mem[MOD_INIT_TEXT].base + mod->mem[MOD_INIT_TEXT].size);
2943 mutex_lock(&module_mutex);
2944 /* Drop initial reference. */
2945 module_put(mod);
2946 trim_init_extable(mod);
2947#ifdef CONFIG_KALLSYMS
2948 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
2949 rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
2950#endif
2951 ret = module_enable_rodata_ro(mod, true);
2952 if (ret)
2953 pr_warn("%s: module_enable_rodata_ro_after_init() returned %d, "
2954 "ro_after_init data might still be writable\n",
2955 mod->name, ret);
2956
2957 mod_tree_remove_init(mod);
2958 module_arch_freeing_init(mod);
2959 for_class_mod_mem_type(type, init) {
2960 mod->mem[type].base = NULL;
2961 mod->mem[type].size = 0;
2962 }
2963
2964#ifdef CONFIG_DEBUG_INFO_BTF_MODULES
2965 /* .BTF is not SHF_ALLOC and will get removed, so sanitize pointers */
2966 mod->btf_data = NULL;
2967 mod->btf_base_data = NULL;
2968#endif
2969 /*
2970 * We want to free module_init, but be aware that kallsyms may be
2971 * walking this with preempt disabled. In all the failure paths, we
2972 * call synchronize_rcu(), but we don't want to slow down the success
2973 * path. execmem_free() cannot be called in an interrupt, so do the
2974 * work and call synchronize_rcu() in a work queue.
2975 *
2976 * Note that execmem_alloc() on most architectures creates W+X page
2977 * mappings which won't be cleaned up until do_free_init() runs. Any
2978 * code such as mark_rodata_ro() which depends on those mappings to
2979 * be cleaned up needs to sync with the queued work by invoking
2980 * flush_module_init_free_work().
2981 */
2982 if (llist_add(&freeinit->node, &init_free_list))
2983 schedule_work(&init_free_wq);
2984
2985 mutex_unlock(&module_mutex);
2986 wake_up_all(&module_wq);
2987
2988 mod_stat_add_long(text_size, &total_text_size);
2989 mod_stat_add_long(total_size, &total_mod_size);
2990
2991 mod_stat_inc(&modcount);
2992
2993 return 0;
2994
2995fail_free_freeinit:
2996 kfree(freeinit);
2997fail:
2998 /* Try to protect us from buggy refcounters. */
2999 mod->state = MODULE_STATE_GOING;
3000 synchronize_rcu();
3001 module_put(mod);
3002 blocking_notifier_call_chain(&module_notify_list,
3003 MODULE_STATE_GOING, mod);
3004 klp_module_going(mod);
3005 ftrace_release_mod(mod);
3006 free_module(mod);
3007 wake_up_all(&module_wq);
3008
3009 return ret;
3010}
3011
3012static int may_init_module(void)
3013{
3014 if (!capable(CAP_SYS_MODULE) || modules_disabled)
3015 return -EPERM;
3016
3017 return 0;
3018}
3019
3020/* Is this module of this name done loading? No locks held. */
3021static bool finished_loading(const char *name)
3022{
3023 struct module *mod;
3024 bool ret;
3025
3026 /*
3027 * The module_mutex should not be a heavily contended lock;
3028 * if we get the occasional sleep here, we'll go an extra iteration
3029 * in the wait_event_interruptible(), which is harmless.
3030 */
3031 sched_annotate_sleep();
3032 mutex_lock(&module_mutex);
3033 mod = find_module_all(name, strlen(name), true);
3034 ret = !mod || mod->state == MODULE_STATE_LIVE
3035 || mod->state == MODULE_STATE_GOING;
3036 mutex_unlock(&module_mutex);
3037
3038 return ret;
3039}
3040
3041/* Must be called with module_mutex held */
3042static int module_patient_check_exists(const char *name,
3043 enum fail_dup_mod_reason reason)
3044{
3045 struct module *old;
3046 int err = 0;
3047
3048 old = find_module_all(name, strlen(name), true);
3049 if (old == NULL)
3050 return 0;
3051
3052 if (old->state == MODULE_STATE_COMING ||
3053 old->state == MODULE_STATE_UNFORMED) {
3054 /* Wait in case it fails to load. */
3055 mutex_unlock(&module_mutex);
3056 err = wait_event_interruptible(module_wq,
3057 finished_loading(name));
3058 mutex_lock(&module_mutex);
3059 if (err)
3060 return err;
3061
3062 /* The module might have gone in the meantime. */
3063 old = find_module_all(name, strlen(name), true);
3064 }
3065
3066 if (try_add_failed_module(name, reason))
3067 pr_warn("Could not add fail-tracking for module: %s\n", name);
3068
3069 /*
3070 * We are here only when the same module was being loaded. Do
3071 * not try to load it again right now. It prevents long delays
3072 * caused by serialized module load failures. It might happen
3073 * when more devices of the same type trigger load of
3074 * a particular module.
3075 */
3076 if (old && old->state == MODULE_STATE_LIVE)
3077 return -EEXIST;
3078 return -EBUSY;
3079}
3080
3081/*
3082 * We try to place it in the list now to make sure it's unique before
3083 * we dedicate too many resources. In particular, temporary percpu
3084 * memory exhaustion.
3085 */
3086static int add_unformed_module(struct module *mod)
3087{
3088 int err;
3089
3090 mod->state = MODULE_STATE_UNFORMED;
3091
3092 mutex_lock(&module_mutex);
3093 err = module_patient_check_exists(mod->name, FAIL_DUP_MOD_LOAD);
3094 if (err)
3095 goto out;
3096
3097 mod_update_bounds(mod);
3098 list_add_rcu(&mod->list, &modules);
3099 mod_tree_insert(mod);
3100 err = 0;
3101
3102out:
3103 mutex_unlock(&module_mutex);
3104 return err;
3105}
3106
3107static int complete_formation(struct module *mod, struct load_info *info)
3108{
3109 int err;
3110
3111 mutex_lock(&module_mutex);
3112
3113 /* Find duplicate symbols (must be called under lock). */
3114 err = verify_exported_symbols(mod);
3115 if (err < 0)
3116 goto out;
3117
3118 /* These rely on module_mutex for list integrity. */
3119 module_bug_finalize(info->hdr, info->sechdrs, mod);
3120 module_cfi_finalize(info->hdr, info->sechdrs, mod);
3121
3122 err = module_enable_rodata_ro(mod, false);
3123 if (err)
3124 goto out_strict_rwx;
3125 err = module_enable_data_nx(mod);
3126 if (err)
3127 goto out_strict_rwx;
3128 err = module_enable_text_rox(mod);
3129 if (err)
3130 goto out_strict_rwx;
3131
3132 /*
3133 * Mark state as coming so strong_try_module_get() ignores us,
3134 * but kallsyms etc. can see us.
3135 */
3136 mod->state = MODULE_STATE_COMING;
3137 mutex_unlock(&module_mutex);
3138
3139 return 0;
3140
3141out_strict_rwx:
3142 module_bug_cleanup(mod);
3143out:
3144 mutex_unlock(&module_mutex);
3145 return err;
3146}
3147
3148static int prepare_coming_module(struct module *mod)
3149{
3150 int err;
3151
3152 ftrace_module_enable(mod);
3153 err = klp_module_coming(mod);
3154 if (err)
3155 return err;
3156
3157 err = blocking_notifier_call_chain_robust(&module_notify_list,
3158 MODULE_STATE_COMING, MODULE_STATE_GOING, mod);
3159 err = notifier_to_errno(err);
3160 if (err)
3161 klp_module_going(mod);
3162
3163 return err;
3164}
3165
3166static int unknown_module_param_cb(char *param, char *val, const char *modname,
3167 void *arg)
3168{
3169 struct module *mod = arg;
3170 int ret;
3171
3172 if (strcmp(param, "async_probe") == 0) {
3173 if (kstrtobool(val, &mod->async_probe_requested))
3174 mod->async_probe_requested = true;
3175 return 0;
3176 }
3177
3178 /* Check for magic 'dyndbg' arg */
3179 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3180 if (ret != 0)
3181 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3182 return 0;
3183}
3184
3185/* Module within temporary copy, this doesn't do any allocation */
3186static int early_mod_check(struct load_info *info, int flags)
3187{
3188 int err;
3189
3190 /*
3191 * Now that we know we have the correct module name, check
3192 * if it's blacklisted.
3193 */
3194 if (blacklisted(info->name)) {
3195 pr_err("Module %s is blacklisted\n", info->name);
3196 return -EPERM;
3197 }
3198
3199 err = rewrite_section_headers(info, flags);
3200 if (err)
3201 return err;
3202
3203 /* Check module struct version now, before we try to use module. */
3204 if (!check_modstruct_version(info, info->mod))
3205 return -ENOEXEC;
3206
3207 err = check_modinfo(info->mod, info, flags);
3208 if (err)
3209 return err;
3210
3211 mutex_lock(&module_mutex);
3212 err = module_patient_check_exists(info->mod->name, FAIL_DUP_MOD_BECOMING);
3213 mutex_unlock(&module_mutex);
3214
3215 return err;
3216}
3217
3218/*
3219 * Allocate and load the module: note that size of section 0 is always
3220 * zero, and we rely on this for optional sections.
3221 */
3222static int load_module(struct load_info *info, const char __user *uargs,
3223 int flags)
3224{
3225 struct module *mod;
3226 bool module_allocated = false;
3227 long err = 0;
3228 char *after_dashes;
3229
3230 /*
3231 * Do the signature check (if any) first. All that
3232 * the signature check needs is info->len, it does
3233 * not need any of the section info. That can be
3234 * set up later. This will minimize the chances
3235 * of a corrupt module causing problems before
3236 * we even get to the signature check.
3237 *
3238 * The check will also adjust info->len by stripping
3239 * off the sig length at the end of the module, making
3240 * checks against info->len more correct.
3241 */
3242 err = module_sig_check(info, flags);
3243 if (err)
3244 goto free_copy;
3245
3246 /*
3247 * Do basic sanity checks against the ELF header and
3248 * sections. Cache useful sections and set the
3249 * info->mod to the userspace passed struct module.
3250 */
3251 err = elf_validity_cache_copy(info, flags);
3252 if (err)
3253 goto free_copy;
3254
3255 err = early_mod_check(info, flags);
3256 if (err)
3257 goto free_copy;
3258
3259 /* Figure out module layout, and allocate all the memory. */
3260 mod = layout_and_allocate(info, flags);
3261 if (IS_ERR(mod)) {
3262 err = PTR_ERR(mod);
3263 goto free_copy;
3264 }
3265
3266 module_allocated = true;
3267
3268 audit_log_kern_module(mod->name);
3269
3270 /* Reserve our place in the list. */
3271 err = add_unformed_module(mod);
3272 if (err)
3273 goto free_module;
3274
3275 /*
3276 * We are tainting your kernel if your module gets into
3277 * the modules linked list somehow.
3278 */
3279 module_augment_kernel_taints(mod, info);
3280
3281 /* To avoid stressing percpu allocator, do this once we're unique. */
3282 err = percpu_modalloc(mod, info);
3283 if (err)
3284 goto unlink_mod;
3285
3286 /* Now module is in final location, initialize linked lists, etc. */
3287 err = module_unload_init(mod);
3288 if (err)
3289 goto unlink_mod;
3290
3291 init_param_lock(mod);
3292
3293 /*
3294 * Now we've got everything in the final locations, we can
3295 * find optional sections.
3296 */
3297 err = find_module_sections(mod, info);
3298 if (err)
3299 goto free_unload;
3300
3301 err = check_export_symbol_versions(mod);
3302 if (err)
3303 goto free_unload;
3304
3305 /* Set up MODINFO_ATTR fields */
3306 setup_modinfo(mod, info);
3307
3308 /* Fix up syms, so that st_value is a pointer to location. */
3309 err = simplify_symbols(mod, info);
3310 if (err < 0)
3311 goto free_modinfo;
3312
3313 err = apply_relocations(mod, info);
3314 if (err < 0)
3315 goto free_modinfo;
3316
3317 err = post_relocation(mod, info);
3318 if (err < 0)
3319 goto free_modinfo;
3320
3321 flush_module_icache(mod);
3322
3323 /* Now copy in args */
3324 mod->args = strndup_user(uargs, ~0UL >> 1);
3325 if (IS_ERR(mod->args)) {
3326 err = PTR_ERR(mod->args);
3327 goto free_arch_cleanup;
3328 }
3329
3330 init_build_id(mod, info);
3331
3332 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3333 ftrace_module_init(mod);
3334
3335 /* Finally it's fully formed, ready to start executing. */
3336 err = complete_formation(mod, info);
3337 if (err)
3338 goto ddebug_cleanup;
3339
3340 err = prepare_coming_module(mod);
3341 if (err)
3342 goto bug_cleanup;
3343
3344 mod->async_probe_requested = async_probe;
3345
3346 /* Module is ready to execute: parsing args may do that. */
3347 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3348 -32768, 32767, mod,
3349 unknown_module_param_cb);
3350 if (IS_ERR(after_dashes)) {
3351 err = PTR_ERR(after_dashes);
3352 goto coming_cleanup;
3353 } else if (after_dashes) {
3354 pr_warn("%s: parameters '%s' after `--' ignored\n",
3355 mod->name, after_dashes);
3356 }
3357
3358 /* Link in to sysfs. */
3359 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3360 if (err < 0)
3361 goto coming_cleanup;
3362
3363 if (is_livepatch_module(mod)) {
3364 err = copy_module_elf(mod, info);
3365 if (err < 0)
3366 goto sysfs_cleanup;
3367 }
3368
3369 /* Get rid of temporary copy. */
3370 free_copy(info, flags);
3371
3372 codetag_load_module(mod);
3373
3374 /* Done! */
3375 trace_module_load(mod);
3376
3377 return do_init_module(mod);
3378
3379 sysfs_cleanup:
3380 mod_sysfs_teardown(mod);
3381 coming_cleanup:
3382 mod->state = MODULE_STATE_GOING;
3383 destroy_params(mod->kp, mod->num_kp);
3384 blocking_notifier_call_chain(&module_notify_list,
3385 MODULE_STATE_GOING, mod);
3386 klp_module_going(mod);
3387 bug_cleanup:
3388 mod->state = MODULE_STATE_GOING;
3389 /* module_bug_cleanup needs module_mutex protection */
3390 mutex_lock(&module_mutex);
3391 module_bug_cleanup(mod);
3392 mutex_unlock(&module_mutex);
3393
3394 ddebug_cleanup:
3395 ftrace_release_mod(mod);
3396 synchronize_rcu();
3397 kfree(mod->args);
3398 free_arch_cleanup:
3399 module_arch_cleanup(mod);
3400 free_modinfo:
3401 free_modinfo(mod);
3402 free_unload:
3403 module_unload_free(mod);
3404 unlink_mod:
3405 mutex_lock(&module_mutex);
3406 /* Unlink carefully: kallsyms could be walking list. */
3407 list_del_rcu(&mod->list);
3408 mod_tree_remove(mod);
3409 wake_up_all(&module_wq);
3410 /* Wait for RCU-sched synchronizing before releasing mod->list. */
3411 synchronize_rcu();
3412 mutex_unlock(&module_mutex);
3413 free_module:
3414 mod_stat_bump_invalid(info, flags);
3415 /* Free lock-classes; relies on the preceding sync_rcu() */
3416 for_class_mod_mem_type(type, core_data) {
3417 lockdep_free_key_range(mod->mem[type].base,
3418 mod->mem[type].size);
3419 }
3420
3421 module_deallocate(mod, info);
3422 free_copy:
3423 /*
3424 * The info->len is always set. We distinguish between
3425 * failures once the proper module was allocated and
3426 * before that.
3427 */
3428 if (!module_allocated)
3429 mod_stat_bump_becoming(info, flags);
3430 free_copy(info, flags);
3431 return err;
3432}
3433
3434SYSCALL_DEFINE3(init_module, void __user *, umod,
3435 unsigned long, len, const char __user *, uargs)
3436{
3437 int err;
3438 struct load_info info = { };
3439
3440 err = may_init_module();
3441 if (err)
3442 return err;
3443
3444 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3445 umod, len, uargs);
3446
3447 err = copy_module_from_user(umod, len, &info);
3448 if (err) {
3449 mod_stat_inc(&failed_kreads);
3450 mod_stat_add_long(len, &invalid_kread_bytes);
3451 return err;
3452 }
3453
3454 return load_module(&info, uargs, 0);
3455}
3456
3457struct idempotent {
3458 const void *cookie;
3459 struct hlist_node entry;
3460 struct completion complete;
3461 int ret;
3462};
3463
3464#define IDEM_HASH_BITS 8
3465static struct hlist_head idem_hash[1 << IDEM_HASH_BITS];
3466static DEFINE_SPINLOCK(idem_lock);
3467
3468static bool idempotent(struct idempotent *u, const void *cookie)
3469{
3470 int hash = hash_ptr(cookie, IDEM_HASH_BITS);
3471 struct hlist_head *head = idem_hash + hash;
3472 struct idempotent *existing;
3473 bool first;
3474
3475 u->ret = -EINTR;
3476 u->cookie = cookie;
3477 init_completion(&u->complete);
3478
3479 spin_lock(&idem_lock);
3480 first = true;
3481 hlist_for_each_entry(existing, head, entry) {
3482 if (existing->cookie != cookie)
3483 continue;
3484 first = false;
3485 break;
3486 }
3487 hlist_add_head(&u->entry, idem_hash + hash);
3488 spin_unlock(&idem_lock);
3489
3490 return !first;
3491}
3492
3493/*
3494 * We were the first one with 'cookie' on the list, and we ended
3495 * up completing the operation. We now need to walk the list,
3496 * remove everybody - which includes ourselves - fill in the return
3497 * value, and then complete the operation.
3498 */
3499static int idempotent_complete(struct idempotent *u, int ret)
3500{
3501 const void *cookie = u->cookie;
3502 int hash = hash_ptr(cookie, IDEM_HASH_BITS);
3503 struct hlist_head *head = idem_hash + hash;
3504 struct hlist_node *next;
3505 struct idempotent *pos;
3506
3507 spin_lock(&idem_lock);
3508 hlist_for_each_entry_safe(pos, next, head, entry) {
3509 if (pos->cookie != cookie)
3510 continue;
3511 hlist_del_init(&pos->entry);
3512 pos->ret = ret;
3513 complete(&pos->complete);
3514 }
3515 spin_unlock(&idem_lock);
3516 return ret;
3517}
3518
3519/*
3520 * Wait for the idempotent worker.
3521 *
3522 * If we get interrupted, we need to remove ourselves from the
3523 * the idempotent list, and the completion may still come in.
3524 *
3525 * The 'idem_lock' protects against the race, and 'idem.ret' was
3526 * initialized to -EINTR and is thus always the right return
3527 * value even if the idempotent work then completes between
3528 * the wait_for_completion and the cleanup.
3529 */
3530static int idempotent_wait_for_completion(struct idempotent *u)
3531{
3532 if (wait_for_completion_interruptible(&u->complete)) {
3533 spin_lock(&idem_lock);
3534 if (!hlist_unhashed(&u->entry))
3535 hlist_del(&u->entry);
3536 spin_unlock(&idem_lock);
3537 }
3538 return u->ret;
3539}
3540
3541static int init_module_from_file(struct file *f, const char __user * uargs, int flags)
3542{
3543 struct load_info info = { };
3544 void *buf = NULL;
3545 int len;
3546
3547 len = kernel_read_file(f, 0, &buf, INT_MAX, NULL, READING_MODULE);
3548 if (len < 0) {
3549 mod_stat_inc(&failed_kreads);
3550 return len;
3551 }
3552
3553 if (flags & MODULE_INIT_COMPRESSED_FILE) {
3554 int err = module_decompress(&info, buf, len);
3555 vfree(buf); /* compressed data is no longer needed */
3556 if (err) {
3557 mod_stat_inc(&failed_decompress);
3558 mod_stat_add_long(len, &invalid_decompress_bytes);
3559 return err;
3560 }
3561 } else {
3562 info.hdr = buf;
3563 info.len = len;
3564 }
3565
3566 return load_module(&info, uargs, flags);
3567}
3568
3569static int idempotent_init_module(struct file *f, const char __user * uargs, int flags)
3570{
3571 struct idempotent idem;
3572
3573 if (!(f->f_mode & FMODE_READ))
3574 return -EBADF;
3575
3576 /* Are we the winners of the race and get to do this? */
3577 if (!idempotent(&idem, file_inode(f))) {
3578 int ret = init_module_from_file(f, uargs, flags);
3579 return idempotent_complete(&idem, ret);
3580 }
3581
3582 /*
3583 * Somebody else won the race and is loading the module.
3584 */
3585 return idempotent_wait_for_completion(&idem);
3586}
3587
3588SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3589{
3590 int err = may_init_module();
3591 if (err)
3592 return err;
3593
3594 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3595
3596 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3597 |MODULE_INIT_IGNORE_VERMAGIC
3598 |MODULE_INIT_COMPRESSED_FILE))
3599 return -EINVAL;
3600
3601 CLASS(fd, f)(fd);
3602 if (fd_empty(f))
3603 return -EBADF;
3604 return idempotent_init_module(fd_file(f), uargs, flags);
3605}
3606
3607/* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
3608char *module_flags(struct module *mod, char *buf, bool show_state)
3609{
3610 int bx = 0;
3611
3612 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
3613 if (!mod->taints && !show_state)
3614 goto out;
3615 if (mod->taints ||
3616 mod->state == MODULE_STATE_GOING ||
3617 mod->state == MODULE_STATE_COMING) {
3618 buf[bx++] = '(';
3619 bx += module_flags_taint(mod->taints, buf + bx);
3620 /* Show a - for module-is-being-unloaded */
3621 if (mod->state == MODULE_STATE_GOING && show_state)
3622 buf[bx++] = '-';
3623 /* Show a + for module-is-being-loaded */
3624 if (mod->state == MODULE_STATE_COMING && show_state)
3625 buf[bx++] = '+';
3626 buf[bx++] = ')';
3627 }
3628out:
3629 buf[bx] = '\0';
3630
3631 return buf;
3632}
3633
3634/* Given an address, look for it in the module exception tables. */
3635const struct exception_table_entry *search_module_extables(unsigned long addr)
3636{
3637 const struct exception_table_entry *e = NULL;
3638 struct module *mod;
3639
3640 preempt_disable();
3641 mod = __module_address(addr);
3642 if (!mod)
3643 goto out;
3644
3645 if (!mod->num_exentries)
3646 goto out;
3647
3648 e = search_extable(mod->extable,
3649 mod->num_exentries,
3650 addr);
3651out:
3652 preempt_enable();
3653
3654 /*
3655 * Now, if we found one, we are running inside it now, hence
3656 * we cannot unload the module, hence no refcnt needed.
3657 */
3658 return e;
3659}
3660
3661/**
3662 * is_module_address() - is this address inside a module?
3663 * @addr: the address to check.
3664 *
3665 * See is_module_text_address() if you simply want to see if the address
3666 * is code (not data).
3667 */
3668bool is_module_address(unsigned long addr)
3669{
3670 bool ret;
3671
3672 preempt_disable();
3673 ret = __module_address(addr) != NULL;
3674 preempt_enable();
3675
3676 return ret;
3677}
3678
3679/**
3680 * __module_address() - get the module which contains an address.
3681 * @addr: the address.
3682 *
3683 * Must be called with preempt disabled or module mutex held so that
3684 * module doesn't get freed during this.
3685 */
3686struct module *__module_address(unsigned long addr)
3687{
3688 struct module *mod;
3689
3690 if (addr >= mod_tree.addr_min && addr <= mod_tree.addr_max)
3691 goto lookup;
3692
3693#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
3694 if (addr >= mod_tree.data_addr_min && addr <= mod_tree.data_addr_max)
3695 goto lookup;
3696#endif
3697
3698 return NULL;
3699
3700lookup:
3701 module_assert_mutex_or_preempt();
3702
3703 mod = mod_find(addr, &mod_tree);
3704 if (mod) {
3705 BUG_ON(!within_module(addr, mod));
3706 if (mod->state == MODULE_STATE_UNFORMED)
3707 mod = NULL;
3708 }
3709 return mod;
3710}
3711
3712/**
3713 * is_module_text_address() - is this address inside module code?
3714 * @addr: the address to check.
3715 *
3716 * See is_module_address() if you simply want to see if the address is
3717 * anywhere in a module. See kernel_text_address() for testing if an
3718 * address corresponds to kernel or module code.
3719 */
3720bool is_module_text_address(unsigned long addr)
3721{
3722 bool ret;
3723
3724 preempt_disable();
3725 ret = __module_text_address(addr) != NULL;
3726 preempt_enable();
3727
3728 return ret;
3729}
3730
3731/**
3732 * __module_text_address() - get the module whose code contains an address.
3733 * @addr: the address.
3734 *
3735 * Must be called with preempt disabled or module mutex held so that
3736 * module doesn't get freed during this.
3737 */
3738struct module *__module_text_address(unsigned long addr)
3739{
3740 struct module *mod = __module_address(addr);
3741 if (mod) {
3742 /* Make sure it's within the text section. */
3743 if (!within_module_mem_type(addr, mod, MOD_TEXT) &&
3744 !within_module_mem_type(addr, mod, MOD_INIT_TEXT))
3745 mod = NULL;
3746 }
3747 return mod;
3748}
3749
3750/* Don't grab lock, we're oopsing. */
3751void print_modules(void)
3752{
3753 struct module *mod;
3754 char buf[MODULE_FLAGS_BUF_SIZE];
3755
3756 printk(KERN_DEFAULT "Modules linked in:");
3757 /* Most callers should already have preempt disabled, but make sure */
3758 preempt_disable();
3759 list_for_each_entry_rcu(mod, &modules, list) {
3760 if (mod->state == MODULE_STATE_UNFORMED)
3761 continue;
3762 pr_cont(" %s%s", mod->name, module_flags(mod, buf, true));
3763 }
3764
3765 print_unloaded_tainted_modules();
3766 preempt_enable();
3767 if (last_unloaded_module.name[0])
3768 pr_cont(" [last unloaded: %s%s]", last_unloaded_module.name,
3769 last_unloaded_module.taints);
3770 pr_cont("\n");
3771}
3772
3773#ifdef CONFIG_MODULE_DEBUGFS
3774struct dentry *mod_debugfs_root;
3775
3776static int module_debugfs_init(void)
3777{
3778 mod_debugfs_root = debugfs_create_dir("modules", NULL);
3779 return 0;
3780}
3781module_init(module_debugfs_init);
3782#endif