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