linux - kernel/module/main.c

3277 lines · 83.4 KiB

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