linux - kernel/module/main.c

3924 lines · 99.9 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/codetag.h>
60	#include <linux/debugfs.h>
61	#include <linux/execmem.h>
62	#include <uapi/linux/module.h>
63	#include "internal.h"
64
65	#define CREATE_TRACE_POINTS
66	#include <trace/events/module.h>
67
68	/*
69	* Mutex protects:
70	* 1) List of modules (also safely readable within RCU read section),
71	* 2) module_use links,
72	* 3) mod_tree.addr_min/mod_tree.addr_max.
73	* (delete and add uses RCU list operations).
74	*/
75	DEFINE_MUTEX(module_mutex);
76	LIST_HEAD(modules);
77
78	/* Work queue for freeing init sections in success case */
79	static void do_free_init(struct work_struct *w);
80	static DECLARE_WORK(init_free_wq, do_free_init);
81	static LLIST_HEAD(init_free_list);
82
83	struct mod_tree_root mod_tree __cacheline_aligned = {
84	.addr_min = -1UL,
85	};
86
87	struct symsearch {
88	const struct kernel_symbol start, stop;
89	const u32 *crcs;
90	enum mod_license license;
91	};
92
93	/*
94	* Bounds of module memory, for speeding up __module_address.
95	* Protected by module_mutex.
96	*/
97	static void __mod_update_bounds(enum mod_mem_type type __maybe_unused, void *base,
98	unsigned int size, struct mod_tree_root *tree)
99	{
100	unsigned long min = (unsigned long)base;
101	unsigned long max = min + size;
102
103	#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
104	if (mod_mem_type_is_core_data(type)) {
105	if (min < tree->data_addr_min)
106	tree->data_addr_min = min;
107	if (max > tree->data_addr_max)
108	tree->data_addr_max = max;
109	return;
110	}
111	#endif
112	if (min < tree->addr_min)
113	tree->addr_min = min;
114	if (max > tree->addr_max)
115	tree->addr_max = max;
116	}
117
118	static void mod_update_bounds(struct module *mod)
119	{
120	for_each_mod_mem_type(type) {
121	struct module_memory *mod_mem = &mod->mem[type];
122
123	if (mod_mem->size)
124	__mod_update_bounds(type, mod_mem->base, mod_mem->size, &mod_tree);
125	}
126	}
127
128	/* Block module loading/unloading? */
129	static int modules_disabled;
130	core_param(nomodule, modules_disabled, bint, 0);
131
132	static const struct ctl_table module_sysctl_table[] = {
133	{
134	.procname = "modprobe",
135	.data = &modprobe_path,
136	.maxlen = KMOD_PATH_LEN,
137	.mode = 0644,
138	.proc_handler = proc_dostring,
139	},
140	{
141	.procname = "modules_disabled",
142	.data = &modules_disabled,
143	.maxlen = sizeof(int),
144	.mode = 0644,
145	/* only handle a transition from default "0" to "1" */
146	.proc_handler = proc_dointvec_minmax,
147	.extra1 = SYSCTL_ONE,
148	.extra2 = SYSCTL_ONE,
149	},
150	};
151
152	static int __init init_module_sysctl(void)
153	{
154	register_sysctl_init("kernel", module_sysctl_table);
155	return 0;
156	}
157
158	subsys_initcall(init_module_sysctl);
159
160	/* Waiting for a module to finish initializing? */
161	static DECLARE_WAIT_QUEUE_HEAD(module_wq);
162
163	static BLOCKING_NOTIFIER_HEAD(module_notify_list);
164
165	int register_module_notifier(struct notifier_block *nb)
166	{
167	return blocking_notifier_chain_register(&module_notify_list, nb);
168	}
169	EXPORT_SYMBOL(register_module_notifier);
170
171	int unregister_module_notifier(struct notifier_block *nb)
172	{
173	return blocking_notifier_chain_unregister(&module_notify_list, nb);
174	}
175	EXPORT_SYMBOL(unregister_module_notifier);
176
177	/*
178	* We require a truly strong try_module_get(): 0 means success.
179	* Otherwise an error is returned due to ongoing or failed
180	* initialization etc.
181	*/
182	static inline int strong_try_module_get(struct module *mod)
183	{
184	BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
185	if (mod && mod->state == MODULE_STATE_COMING)
186	return -EBUSY;
187	if (try_module_get(mod))
188	return 0;
189	else
190	return -ENOENT;
191	}
192
193	static inline void add_taint_module(struct module *mod, unsigned flag,
194	enum lockdep_ok lockdep_ok)
195	{
196	add_taint(flag, lockdep_ok);
197	set_bit(flag, &mod->taints);
198	}
199
200	/*
201	* Like strncmp(), except s/-/_/g as per scripts/Makefile.lib:name-fix-token rule.
202	*/
203	static int mod_strncmp(const char str_a, const char str_b, size_t n)
204	{
205	for (int i = 0; i < n; i++) {
206	char a = str_a[i];
207	char b = str_b[i];
208	int d;
209
210	if (a == '-') a = '_';
211	if (b == '-') b = '_';
212
213	d = a - b;
214	if (d)
215	return d;
216
217	if (!a)
218	break;
219	}
220
221	return 0;
222	}
223
224	/*
225	* A thread that wants to hold a reference to a module only while it
226	* is running can call this to safely exit.
227	*/
228	void __noreturn __module_put_and_kthread_exit(struct module *mod, long code)
229	{
230	module_put(mod);
231	kthread_exit(code);
232	}
233	EXPORT_SYMBOL(__module_put_and_kthread_exit);
234
235	/* Find a module section: 0 means not found. */
236	static unsigned int find_sec(const struct load_info info, const char name)
237	{
238	unsigned int i;
239
240	for (i = 1; i < info->hdr->e_shnum; i++) {
241	Elf_Shdr *shdr = &info->sechdrs[i];
242	/* Alloc bit cleared means "ignore it." */
243	if ((shdr->sh_flags & SHF_ALLOC)
244	&& strcmp(info->secstrings + shdr->sh_name, name) == 0)
245	return i;
246	}
247	return 0;
248	}
249
250	/**
251	* find_any_unique_sec() - Find a unique section index by name
252	* @info: Load info for the module to scan
253	* @name: Name of the section we're looking for
254	*
255	* Locates a unique section by name. Ignores SHF_ALLOC.
256	*
257	* Return: Section index if found uniquely, zero if absent, negative count
258	* of total instances if multiple were found.
259	*/
260	static int find_any_unique_sec(const struct load_info info, const char name)
261	{
262	unsigned int idx;
263	unsigned int count = 0;
264	int i;
265
266	for (i = 1; i < info->hdr->e_shnum; i++) {
267	if (strcmp(info->secstrings + info->sechdrs[i].sh_name,
268	name) == 0) {
269	count++;
270	idx = i;
271	}
272	}
273	if (count == 1) {
274	return idx;
275	} else if (count == 0) {
276	return 0;
277	} else {
278	return -count;
279	}
280	}
281
282	/* Find a module section, or NULL. */
283	static void section_addr(const struct load_info info, const char *name)
284	{
285	/* Section 0 has sh_addr 0. */
286	return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
287	}
288
289	/* Find a module section, or NULL. Fill in number of "objects" in section. */
290	static void section_objs(const struct load_info info,
291	const char *name,
292	size_t object_size,
293	unsigned int *num)
294	{
295	unsigned int sec = find_sec(info, name);
296
297	/* Section 0 has sh_addr 0 and sh_size 0. */
298	*num = info->sechdrs[sec].sh_size / object_size;
299	return (void *)info->sechdrs[sec].sh_addr;
300	}
301
302	/* Find a module section: 0 means not found. Ignores SHF_ALLOC flag. */
303	static unsigned int find_any_sec(const struct load_info info, const char name)
304	{
305	unsigned int i;
306
307	for (i = 1; i < info->hdr->e_shnum; i++) {
308	Elf_Shdr *shdr = &info->sechdrs[i];
309	if (strcmp(info->secstrings + shdr->sh_name, name) == 0)
310	return i;
311	}
312	return 0;
313	}
314
315	/*
316	* Find a module section, or NULL. Fill in number of "objects" in section.
317	* Ignores SHF_ALLOC flag.
318	*/
319	static __maybe_unused void any_section_objs(const struct load_info info,
320	const char *name,
321	size_t object_size,
322	unsigned int *num)
323	{
324	unsigned int sec = find_any_sec(info, name);
325
326	/* Section 0 has sh_addr 0 and sh_size 0. */
327	*num = info->sechdrs[sec].sh_size / object_size;
328	return (void *)info->sechdrs[sec].sh_addr;
329	}
330
331	#ifndef CONFIG_MODVERSIONS
332	#define symversion(base, idx) NULL
333	#else
334	#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
335	#endif
336
337	static const char kernel_symbol_name(const struct kernel_symbol sym)
338	{
339	#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
340	return offset_to_ptr(&sym->name_offset);
341	#else
342	return sym->name;
343	#endif
344	}
345
346	static const char kernel_symbol_namespace(const struct kernel_symbol sym)
347	{
348	#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
349	if (!sym->namespace_offset)
350	return NULL;
351	return offset_to_ptr(&sym->namespace_offset);
352	#else
353	return sym->namespace;
354	#endif
355	}
356
357	int cmp_name(const void name, const void sym)
358	{
359	return strcmp(name, kernel_symbol_name(sym));
360	}
361
362	static bool find_exported_symbol_in_section(const struct symsearch *syms,
363	struct module *owner,
364	struct find_symbol_arg *fsa)
365	{
366	struct kernel_symbol *sym;
367
368	if (!fsa->gplok && syms->license == GPL_ONLY)
369	return false;
370
371	sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
372	sizeof(struct kernel_symbol), cmp_name);
373	if (!sym)
374	return false;
375
376	fsa->owner = owner;
377	fsa->crc = symversion(syms->crcs, sym - syms->start);
378	fsa->sym = sym;
379	fsa->license = syms->license;
380
381	return true;
382	}
383
384	/*
385	* Find an exported symbol and return it, along with, (optional) crc and
386	* (optional) module which owns it. Needs RCU or module_mutex.
387	*/
388	bool find_symbol(struct find_symbol_arg *fsa)
389	{
390	static const struct symsearch arr[] = {
391	{ __start___ksymtab, __stop___ksymtab, __start___kcrctab,
392	NOT_GPL_ONLY },
393	{ __start___ksymtab_gpl, __stop___ksymtab_gpl,
394	__start___kcrctab_gpl,
395	GPL_ONLY },
396	};
397	struct module *mod;
398	unsigned int i;
399
400	for (i = 0; i < ARRAY_SIZE(arr); i++)
401	if (find_exported_symbol_in_section(&arr[i], NULL, fsa))
402	return true;
403
404	list_for_each_entry_rcu(mod, &modules, list,
405	lockdep_is_held(&module_mutex)) {
406	struct symsearch arr[] = {
407	{ mod->syms, mod->syms + mod->num_syms, mod->crcs,
408	NOT_GPL_ONLY },
409	{ mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
410	mod->gpl_crcs,
411	GPL_ONLY },
412	};
413
414	if (mod->state == MODULE_STATE_UNFORMED)
415	continue;
416
417	for (i = 0; i < ARRAY_SIZE(arr); i++)
418	if (find_exported_symbol_in_section(&arr[i], mod, fsa))
419	return true;
420	}
421
422	pr_debug("Failed to find symbol %s\n", fsa->name);
423	return false;
424	}
425
426	/*
427	* Search for module by name: must hold module_mutex (or RCU for read-only
428	* access).
429	*/
430	struct module find_module_all(const char name, size_t len,
431	bool even_unformed)
432	{
433	struct module *mod;
434
435	list_for_each_entry_rcu(mod, &modules, list,
436	lockdep_is_held(&module_mutex)) {
437	if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
438	continue;
439	if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
440	return mod;
441	}
442	return NULL;
443	}
444
445	struct module find_module(const char name)
446	{
447	return find_module_all(name, strlen(name), false);
448	}
449
450	#ifdef CONFIG_SMP
451
452	static inline void __percpu mod_percpu(struct module mod)
453	{
454	return mod->percpu;
455	}
456
457	static int percpu_modalloc(struct module mod, struct load_info info)
458	{
459	Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
460	unsigned long align = pcpusec->sh_addralign;
461
462	if (!pcpusec->sh_size)
463	return 0;
464
465	if (align > PAGE_SIZE) {
466	pr_warn("%s: per-cpu alignment %li > %li\n",
467	mod->name, align, PAGE_SIZE);
468	align = PAGE_SIZE;
469	}
470
471	mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
472	if (!mod->percpu) {
473	pr_warn("%s: Could not allocate %lu bytes percpu data\n",
474	mod->name, (unsigned long)pcpusec->sh_size);
475	return -ENOMEM;
476	}
477	mod->percpu_size = pcpusec->sh_size;
478	return 0;
479	}
480
481	static void percpu_modfree(struct module *mod)
482	{
483	free_percpu(mod->percpu);
484	}
485
486	static unsigned int find_pcpusec(struct load_info *info)
487	{
488	return find_sec(info, ".data..percpu");
489	}
490
491	static void percpu_modcopy(struct module *mod,
492	const void *from, unsigned long size)
493	{
494	int cpu;
495
496	for_each_possible_cpu(cpu)
497	memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
498	}
499
500	bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
501	{
502	struct module *mod;
503	unsigned int cpu;
504
505	guard(rcu)();
506	list_for_each_entry_rcu(mod, &modules, list) {
507	if (mod->state == MODULE_STATE_UNFORMED)
508	continue;
509	if (!mod->percpu_size)
510	continue;
511	for_each_possible_cpu(cpu) {
512	void *start = per_cpu_ptr(mod->percpu, cpu);
513	void va = (void )addr;
514
515	if (va >= start && va < start + mod->percpu_size) {
516	if (can_addr) {
517	*can_addr = (unsigned long) (va - start);
518	*can_addr += (unsigned long)
519	per_cpu_ptr(mod->percpu,
520	get_boot_cpu_id());
521	}
522	return true;
523	}
524	}
525	}
526	return false;
527	}
528
529	/**
530	* is_module_percpu_address() - test whether address is from module static percpu
531	* @addr: address to test
532	*
533	* Test whether @addr belongs to module static percpu area.
534	*
535	* Return: %true if @addr is from module static percpu area
536	*/
537	bool is_module_percpu_address(unsigned long addr)
538	{
539	return __is_module_percpu_address(addr, NULL);
540	}
541
542	#else /* ... !CONFIG_SMP */
543
544	static inline void __percpu mod_percpu(struct module mod)
545	{
546	return NULL;
547	}
548	static int percpu_modalloc(struct module mod, struct load_info info)
549	{
550	/* UP modules shouldn't have this section: ENOMEM isn't quite right */
551	if (info->sechdrs[info->index.pcpu].sh_size != 0)
552	return -ENOMEM;
553	return 0;
554	}
555	static inline void percpu_modfree(struct module *mod)
556	{
557	}
558	static unsigned int find_pcpusec(struct load_info *info)
559	{
560	return 0;
561	}
562	static inline void percpu_modcopy(struct module *mod,
563	const void *from, unsigned long size)
564	{
565	/* pcpusec should be 0, and size of that section should be 0. */
566	BUG_ON(size != 0);
567	}
568	bool is_module_percpu_address(unsigned long addr)
569	{
570	return false;
571	}
572
573	bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
574	{
575	return false;
576	}
577
578	#endif /* CONFIG_SMP */
579
580	#define MODINFO_ATTR(field) \
581	static void setup_modinfo_##field(struct module mod, const char s) \
582	{ \
583	mod->field = kstrdup(s, GFP_KERNEL); \
584	} \
585	static ssize_t show_modinfo_##field(const struct module_attribute *mattr, \
586	struct module_kobject mk, char buffer) \
587	{ \
588	return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
589	} \
590	static int modinfo_##field##_exists(struct module *mod) \
591	{ \
592	return mod->field != NULL; \
593	} \
594	static void free_modinfo_##field(struct module *mod) \
595	{ \
596	kfree(mod->field); \
597	mod->field = NULL; \
598	} \
599	static const struct module_attribute modinfo_##field = { \
600	.attr = { .name = __stringify(field), .mode = 0444 }, \
601	.show = show_modinfo_##field, \
602	.setup = setup_modinfo_##field, \
603	.test = modinfo_##field##_exists, \
604	.free = free_modinfo_##field, \
605	};
606
607	MODINFO_ATTR(version);
608	MODINFO_ATTR(srcversion);
609
610	static struct {
611	char name[MODULE_NAME_LEN];
612	char taints[MODULE_FLAGS_BUF_SIZE];
613	} last_unloaded_module;
614
615	#ifdef CONFIG_MODULE_UNLOAD
616
617	EXPORT_TRACEPOINT_SYMBOL(module_get);
618
619	/* MODULE_REF_BASE is the base reference count by kmodule loader. */
620	#define MODULE_REF_BASE 1
621
622	/* Init the unload section of the module. */
623	static int module_unload_init(struct module *mod)
624	{
625	/*
626	* Initialize reference counter to MODULE_REF_BASE.
627	* refcnt == 0 means module is going.
628	*/
629	atomic_set(&mod->refcnt, MODULE_REF_BASE);
630
631	INIT_LIST_HEAD(&mod->source_list);
632	INIT_LIST_HEAD(&mod->target_list);
633
634	/* Hold reference count during initialization. */
635	atomic_inc(&mod->refcnt);
636
637	return 0;
638	}
639
640	/* Does a already use b? */
641	static int already_uses(struct module a, struct module b)
642	{
643	struct module_use *use;
644
645	list_for_each_entry(use, &b->source_list, source_list) {
646	if (use->source == a)
647	return 1;
648	}
649	pr_debug("%s does not use %s!\n", a->name, b->name);
650	return 0;
651	}
652
653	/*
654	* Module a uses b
655	* - we add 'a' as a "source", 'b' as a "target" of module use
656	* - the module_use is added to the list of 'b' sources (so
657	* 'b' can walk the list to see who sourced them), and of 'a'
658	* targets (so 'a' can see what modules it targets).
659	*/
660	static int add_module_usage(struct module a, struct module b)
661	{
662	struct module_use *use;
663
664	pr_debug("Allocating new usage for %s.\n", a->name);
665	use = kmalloc_obj(*use, GFP_ATOMIC);
666	if (!use)
667	return -ENOMEM;
668
669	use->source = a;
670	use->target = b;
671	list_add(&use->source_list, &b->source_list);
672	list_add(&use->target_list, &a->target_list);
673	return 0;
674	}
675
676	/* Module a uses b: caller needs module_mutex() */
677	static int ref_module(struct module a, struct module b)
678	{
679	int err;
680
681	if (b == NULL \|\| already_uses(a, b))
682	return 0;
683
684	/* If module isn't available, we fail. */
685	err = strong_try_module_get(b);
686	if (err)
687	return err;
688
689	err = add_module_usage(a, b);
690	if (err) {
691	module_put(b);
692	return err;
693	}
694	return 0;
695	}
696
697	/* Clear the unload stuff of the module. */
698	static void module_unload_free(struct module *mod)
699	{
700	struct module_use use, tmp;
701
702	mutex_lock(&module_mutex);
703	list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
704	struct module *i = use->target;
705	pr_debug("%s unusing %s\n", mod->name, i->name);
706	module_put(i);
707	list_del(&use->source_list);
708	list_del(&use->target_list);
709	kfree(use);
710	}
711	mutex_unlock(&module_mutex);
712	}
713
714	#ifdef CONFIG_MODULE_FORCE_UNLOAD
715	static inline int try_force_unload(unsigned int flags)
716	{
717	int ret = (flags & O_TRUNC);
718	if (ret)
719	add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
720	return ret;
721	}
722	#else
723	static inline int try_force_unload(unsigned int flags)
724	{
725	return 0;
726	}
727	#endif /* CONFIG_MODULE_FORCE_UNLOAD */
728
729	/* Try to release refcount of module, 0 means success. */
730	static int try_release_module_ref(struct module *mod)
731	{
732	int ret;
733
734	/* Try to decrement refcnt which we set at loading */
735	ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
736	BUG_ON(ret < 0);
737	if (ret)
738	/* Someone can put this right now, recover with checking */
739	ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
740
741	return ret;
742	}
743
744	static int try_stop_module(struct module mod, int flags, int forced)
745	{
746	/* If it's not unused, quit unless we're forcing. */
747	if (try_release_module_ref(mod) != 0) {
748	*forced = try_force_unload(flags);
749	if (!(*forced))
750	return -EWOULDBLOCK;
751	}
752
753	/* Mark it as dying. */
754	mod->state = MODULE_STATE_GOING;
755
756	return 0;
757	}
758
759	/**
760	* module_refcount() - return the refcount or -1 if unloading
761	* @mod: the module we're checking
762	*
763	* Return:
764	* -1 if the module is in the process of unloading
765	* otherwise the number of references in the kernel to the module
766	*/
767	int module_refcount(struct module *mod)
768	{
769	return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
770	}
771	EXPORT_SYMBOL(module_refcount);
772
773	/* This exists whether we can unload or not */
774	static void free_module(struct module *mod);
775
776	SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
777	unsigned int, flags)
778	{
779	struct module *mod;
780	char name[MODULE_NAME_LEN];
781	char buf[MODULE_FLAGS_BUF_SIZE];
782	int ret, len, forced = 0;
783
784	if (!capable(CAP_SYS_MODULE) \|\| modules_disabled)
785	return -EPERM;
786
787	len = strncpy_from_user(name, name_user, MODULE_NAME_LEN);
788	if (len == 0 \|\| len == MODULE_NAME_LEN)
789	return -ENOENT;
790	if (len < 0)
791	return len;
792
793	audit_log_kern_module(name);
794
795	if (mutex_lock_interruptible(&module_mutex) != 0)
796	return -EINTR;
797
798	mod = find_module(name);
799	if (!mod) {
800	ret = -ENOENT;
801	goto out;
802	}
803
804	if (!list_empty(&mod->source_list)) {
805	/* Other modules depend on us: get rid of them first. */
806	ret = -EWOULDBLOCK;
807	goto out;
808	}
809
810	/* Doing init or already dying? */
811	if (mod->state != MODULE_STATE_LIVE) {
812	/* FIXME: if (force), slam module count damn the torpedoes */
813	pr_debug("%s already dying\n", mod->name);
814	ret = -EBUSY;
815	goto out;
816	}
817
818	/* If it has an init func, it must have an exit func to unload */
819	if (mod->init && !mod->exit) {
820	forced = try_force_unload(flags);
821	if (!forced) {
822	/* This module can't be removed */
823	ret = -EBUSY;
824	goto out;
825	}
826	}
827
828	ret = try_stop_module(mod, flags, &forced);
829	if (ret != 0)
830	goto out;
831
832	mutex_unlock(&module_mutex);
833	/* Final destruction now no one is using it. */
834	if (mod->exit != NULL)
835	mod->exit();
836	blocking_notifier_call_chain(&module_notify_list,
837	MODULE_STATE_GOING, mod);
838	klp_module_going(mod);
839	ftrace_release_mod(mod);
840
841	async_synchronize_full();
842
843	/* Store the name and taints of the last unloaded module for diagnostic purposes */
844	strscpy(last_unloaded_module.name, mod->name);
845	strscpy(last_unloaded_module.taints, module_flags(mod, buf, false));
846
847	free_module(mod);
848	/* someone could wait for the module in add_unformed_module() */
849	wake_up_all(&module_wq);
850	return 0;
851	out:
852	mutex_unlock(&module_mutex);
853	return ret;
854	}
855
856	void __symbol_put(const char *symbol)
857	{
858	struct find_symbol_arg fsa = {
859	.name = symbol,
860	.gplok = true,
861	};
862
863	guard(rcu)();
864	BUG_ON(!find_symbol(&fsa));
865	module_put(fsa.owner);
866	}
867	EXPORT_SYMBOL(__symbol_put);
868
869	/* Note this assumes addr is a function, which it currently always is. */
870	void symbol_put_addr(void *addr)
871	{
872	struct module *modaddr;
873	unsigned long a = (unsigned long)dereference_function_descriptor(addr);
874
875	if (core_kernel_text(a))
876	return;
877
878	/*
879	* Even though we hold a reference on the module; we still need to
880	* RCU read section in order to safely traverse the data structure.
881	*/
882	guard(rcu)();
883	modaddr = __module_text_address(a);
884	BUG_ON(!modaddr);
885	module_put(modaddr);
886	}
887	EXPORT_SYMBOL_GPL(symbol_put_addr);
888
889	static ssize_t show_refcnt(const struct module_attribute *mattr,
890	struct module_kobject mk, char buffer)
891	{
892	return sprintf(buffer, "%i\n", module_refcount(mk->mod));
893	}
894
895	static const struct module_attribute modinfo_refcnt =
896	__ATTR(refcnt, 0444, show_refcnt, NULL);
897
898	void __module_get(struct module *module)
899	{
900	if (module) {
901	atomic_inc(&module->refcnt);
902	trace_module_get(module, _RET_IP_);
903	}
904	}
905	EXPORT_SYMBOL(__module_get);
906
907	bool try_module_get(struct module *module)
908	{
909	bool ret = true;
910
911	if (module) {
912	/* Note: here, we can fail to get a reference */
913	if (likely(module_is_live(module) &&
914	atomic_inc_not_zero(&module->refcnt) != 0))
915	trace_module_get(module, _RET_IP_);
916	else
917	ret = false;
918	}
919	return ret;
920	}
921	EXPORT_SYMBOL(try_module_get);
922
923	void module_put(struct module *module)
924	{
925	int ret;
926
927	if (module) {
928	ret = atomic_dec_if_positive(&module->refcnt);
929	WARN_ON(ret < 0); /* Failed to put refcount */
930	trace_module_put(module, _RET_IP_);
931	}
932	}
933	EXPORT_SYMBOL(module_put);
934
935	#else /* !CONFIG_MODULE_UNLOAD */
936	static inline void module_unload_free(struct module *mod)
937	{
938	}
939
940	static int ref_module(struct module a, struct module b)
941	{
942	return strong_try_module_get(b);
943	}
944
945	static inline int module_unload_init(struct module *mod)
946	{
947	return 0;
948	}
949	#endif /* CONFIG_MODULE_UNLOAD */
950
951	size_t module_flags_taint(unsigned long taints, char *buf)
952	{
953	size_t l = 0;
954	int i;
955
956	for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
957	if (test_bit(i, &taints))
958	buf[l++] = taint_flags[i].c_true;
959	}
960
961	return l;
962	}
963
964	static ssize_t show_initstate(const struct module_attribute *mattr,
965	struct module_kobject mk, char buffer)
966	{
967	const char *state = "unknown";
968
969	switch (mk->mod->state) {
970	case MODULE_STATE_LIVE:
971	state = "live";
972	break;
973	case MODULE_STATE_COMING:
974	state = "coming";
975	break;
976	case MODULE_STATE_GOING:
977	state = "going";
978	break;
979	default:
980	BUG();
981	}
982	return sprintf(buffer, "%s\n", state);
983	}
984
985	static const struct module_attribute modinfo_initstate =
986	__ATTR(initstate, 0444, show_initstate, NULL);
987
988	static ssize_t store_uevent(const struct module_attribute *mattr,
989	struct module_kobject *mk,
990	const char *buffer, size_t count)
991	{
992	int rc;
993
994	rc = kobject_synth_uevent(&mk->kobj, buffer, count);
995	return rc ? rc : count;
996	}
997
998	const struct module_attribute module_uevent =
999	__ATTR(uevent, 0200, NULL, store_uevent);
1000
1001	static ssize_t show_coresize(const struct module_attribute *mattr,
1002	struct module_kobject mk, char buffer)
1003	{
1004	unsigned int size = mk->mod->mem[MOD_TEXT].size;
1005
1006	if (!IS_ENABLED(CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC)) {
1007	for_class_mod_mem_type(type, core_data)
1008	size += mk->mod->mem[type].size;
1009	}
1010	return sprintf(buffer, "%u\n", size);
1011	}
1012
1013	static const struct module_attribute modinfo_coresize =
1014	__ATTR(coresize, 0444, show_coresize, NULL);
1015
1016	#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
1017	static ssize_t show_datasize(const struct module_attribute *mattr,
1018	struct module_kobject mk, char buffer)
1019	{
1020	unsigned int size = 0;
1021
1022	for_class_mod_mem_type(type, core_data)
1023	size += mk->mod->mem[type].size;
1024	return sprintf(buffer, "%u\n", size);
1025	}
1026
1027	static const struct module_attribute modinfo_datasize =
1028	__ATTR(datasize, 0444, show_datasize, NULL);
1029	#endif
1030
1031	static ssize_t show_initsize(const struct module_attribute *mattr,
1032	struct module_kobject mk, char buffer)
1033	{
1034	unsigned int size = 0;
1035
1036	for_class_mod_mem_type(type, init)
1037	size += mk->mod->mem[type].size;
1038	return sprintf(buffer, "%u\n", size);
1039	}
1040
1041	static const struct module_attribute modinfo_initsize =
1042	__ATTR(initsize, 0444, show_initsize, NULL);
1043
1044	static ssize_t show_taint(const struct module_attribute *mattr,
1045	struct module_kobject mk, char buffer)
1046	{
1047	size_t l;
1048
1049	l = module_flags_taint(mk->mod->taints, buffer);
1050	buffer[l++] = '\n';
1051	return l;
1052	}
1053
1054	static const struct module_attribute modinfo_taint =
1055	__ATTR(taint, 0444, show_taint, NULL);
1056
1057	const struct module_attribute *const modinfo_attrs[] = {
1058	&module_uevent,
1059	&modinfo_version,
1060	&modinfo_srcversion,
1061	&modinfo_initstate,
1062	&modinfo_coresize,
1063	#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
1064	&modinfo_datasize,
1065	#endif
1066	&modinfo_initsize,
1067	&modinfo_taint,
1068	#ifdef CONFIG_MODULE_UNLOAD
1069	&modinfo_refcnt,
1070	#endif
1071	NULL,
1072	};
1073
1074	const size_t modinfo_attrs_count = ARRAY_SIZE(modinfo_attrs);
1075
1076	static const char vermagic[] = VERMAGIC_STRING;
1077
1078	int try_to_force_load(struct module mod, const char reason)
1079	{
1080	#ifdef CONFIG_MODULE_FORCE_LOAD
1081	if (!test_taint(TAINT_FORCED_MODULE))
1082	pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1083	add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1084	return 0;
1085	#else
1086	return -ENOEXEC;
1087	#endif
1088	}
1089
1090	/* Parse tag=value strings from .modinfo section */
1091	char module_next_tag_pair(char string, unsigned long *secsize)
1092	{
1093	/* Skip non-zero chars */
1094	while (string[0]) {
1095	string++;
1096	if ((*secsize)-- <= 1)
1097	return NULL;
1098	}
1099
1100	/* Skip any zero padding. */
1101	while (!string[0]) {
1102	string++;
1103	if ((*secsize)-- <= 1)
1104	return NULL;
1105	}
1106	return string;
1107	}
1108
1109	static char get_next_modinfo(const struct load_info info, const char *tag,
1110	char *prev)
1111	{
1112	char *p;
1113	unsigned int taglen = strlen(tag);
1114	Elf_Shdr *infosec = &info->sechdrs[info->index.info];
1115	unsigned long size = infosec->sh_size;
1116
1117	/*
1118	* get_modinfo() calls made before rewrite_section_headers()
1119	* must use sh_offset, as sh_addr isn't set!
1120	*/
1121	char modinfo = (char )info->hdr + infosec->sh_offset;
1122
1123	if (prev) {
1124	size -= prev - modinfo;
1125	modinfo = module_next_tag_pair(prev, &size);
1126	}
1127
1128	for (p = modinfo; p; p = module_next_tag_pair(p, &size)) {
1129	if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
1130	return p + taglen + 1;
1131	}
1132	return NULL;
1133	}
1134
1135	static char get_modinfo(const struct load_info info, const char *tag)
1136	{
1137	return get_next_modinfo(info, tag, NULL);
1138	}
1139
1140	/**
1141	* verify_module_namespace() - does @modname have access to this symbol's @namespace
1142	* @namespace: export symbol namespace
1143	* @modname: module name
1144	*
1145	* If @namespace is prefixed with "module:" to indicate it is a module namespace
1146	* then test if @modname matches any of the comma separated patterns.
1147	*
1148	* The patterns only support tail-glob.
1149	*/
1150	static bool verify_module_namespace(const char namespace, const char modname)
1151	{
1152	size_t len, modlen = strlen(modname);
1153	const char *prefix = "module:";
1154	const char *sep;
1155	bool glob;
1156
1157	if (!strstarts(namespace, prefix))
1158	return false;
1159
1160	for (namespace += strlen(prefix); *namespace; namespace = sep) {
1161	sep = strchrnul(namespace, ',');
1162	len = sep - namespace;
1163
1164	glob = false;
1165	if (sep[-1] == '*') {
1166	len--;
1167	glob = true;
1168	}
1169
1170	if (*sep)
1171	sep++;
1172
1173	if (mod_strncmp(namespace, modname, len) == 0 && (glob \|\| len == modlen))
1174	return true;
1175	}
1176
1177	return false;
1178	}
1179
1180	static int verify_namespace_is_imported(const struct load_info *info,
1181	const struct kernel_symbol *sym,
1182	struct module *mod)
1183	{
1184	const char *namespace;
1185	char *imported_namespace;
1186
1187	namespace = kernel_symbol_namespace(sym);
1188	if (namespace && namespace[0]) {
1189
1190	if (verify_module_namespace(namespace, mod->name))
1191	return 0;
1192
1193	for_each_modinfo_entry(imported_namespace, info, "import_ns") {
1194	if (strcmp(namespace, imported_namespace) == 0)
1195	return 0;
1196	}
1197	#ifdef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1198	pr_warn(
1199	#else
1200	pr_err(
1201	#endif
1202	"%s: module uses symbol (%s) from namespace %s, but does not import it.\n",
1203	mod->name, kernel_symbol_name(sym), namespace);
1204	#ifndef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1205	return -EINVAL;
1206	#endif
1207	}
1208	return 0;
1209	}
1210
1211	static bool inherit_taint(struct module mod, struct module owner, const char *name)
1212	{
1213	if (!owner \|\| !test_bit(TAINT_PROPRIETARY_MODULE, &owner->taints))
1214	return true;
1215
1216	if (mod->using_gplonly_symbols) {
1217	pr_err("%s: module using GPL-only symbols uses symbols %s from proprietary module %s.\n",
1218	mod->name, name, owner->name);
1219	return false;
1220	}
1221
1222	if (!test_bit(TAINT_PROPRIETARY_MODULE, &mod->taints)) {
1223	pr_warn("%s: module uses symbols %s from proprietary module %s, inheriting taint.\n",
1224	mod->name, name, owner->name);
1225	set_bit(TAINT_PROPRIETARY_MODULE, &mod->taints);
1226	}
1227	return true;
1228	}
1229
1230	/* Resolve a symbol for this module. I.e. if we find one, record usage. */
1231	static const struct kernel_symbol resolve_symbol(struct module mod,
1232	const struct load_info *info,
1233	const char *name,
1234	char ownername[])
1235	{
1236	struct find_symbol_arg fsa = {
1237	.name = name,
1238	.gplok = !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)),
1239	.warn = true,
1240	};
1241	int err;
1242
1243	/*
1244	* The module_mutex should not be a heavily contended lock;
1245	* if we get the occasional sleep here, we'll go an extra iteration
1246	* in the wait_event_interruptible(), which is harmless.
1247	*/
1248	sched_annotate_sleep();
1249	mutex_lock(&module_mutex);
1250	if (!find_symbol(&fsa))
1251	goto unlock;
1252
1253	if (fsa.license == GPL_ONLY)
1254	mod->using_gplonly_symbols = true;
1255
1256	if (!inherit_taint(mod, fsa.owner, name)) {
1257	fsa.sym = NULL;
1258	goto getname;
1259	}
1260
1261	if (!check_version(info, name, mod, fsa.crc)) {
1262	fsa.sym = ERR_PTR(-EINVAL);
1263	goto getname;
1264	}
1265
1266	err = verify_namespace_is_imported(info, fsa.sym, mod);
1267	if (err) {
1268	fsa.sym = ERR_PTR(err);
1269	goto getname;
1270	}
1271
1272	err = ref_module(mod, fsa.owner);
1273	if (err) {
1274	fsa.sym = ERR_PTR(err);
1275	goto getname;
1276	}
1277
1278	getname:
1279	/* We must make copy under the lock if we failed to get ref. */
1280	strscpy(ownername, module_name(fsa.owner), MODULE_NAME_LEN);
1281	unlock:
1282	mutex_unlock(&module_mutex);
1283	return fsa.sym;
1284	}
1285
1286	static const struct kernel_symbol *
1287	resolve_symbol_wait(struct module *mod,
1288	const struct load_info *info,
1289	const char *name)
1290	{
1291	const struct kernel_symbol *ksym;
1292	char owner[MODULE_NAME_LEN];
1293
1294	if (wait_event_interruptible_timeout(module_wq,
1295	!IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1296	\|\| PTR_ERR(ksym) != -EBUSY,
1297	30 * HZ) <= 0) {
1298	pr_warn("%s: gave up waiting for init of module %s.\n",
1299	mod->name, owner);
1300	}
1301	return ksym;
1302	}
1303
1304	void __weak module_arch_cleanup(struct module *mod)
1305	{
1306	}
1307
1308	void __weak module_arch_freeing_init(struct module *mod)
1309	{
1310	}
1311
1312	static int module_memory_alloc(struct module *mod, enum mod_mem_type type)
1313	{
1314	unsigned int size = PAGE_ALIGN(mod->mem[type].size);
1315	enum execmem_type execmem_type;
1316	void *ptr;
1317
1318	mod->mem[type].size = size;
1319
1320	if (mod_mem_type_is_data(type))
1321	execmem_type = EXECMEM_MODULE_DATA;
1322	else
1323	execmem_type = EXECMEM_MODULE_TEXT;
1324
1325	ptr = execmem_alloc_rw(execmem_type, size);
1326	if (!ptr)
1327	return -ENOMEM;
1328
1329	mod->mem[type].is_rox = execmem_is_rox(execmem_type);
1330
1331	/*
1332	* The pointer to these blocks of memory are stored on the module
1333	* structure and we keep that around so long as the module is
1334	* around. We only free that memory when we unload the module.
1335	* Just mark them as not being a leak then. The .init* ELF
1336	* sections do get freed after boot so we could treat them
1337	* slightly differently with kmemleak_ignore() and only grey
1338	* them out as they work as typical memory allocations which
1339	* do eventually get freed, but let's just keep things simple
1340	* and avoid any false positives.
1341	*/
1342	if (!mod->mem[type].is_rox)
1343	kmemleak_not_leak(ptr);
1344
1345	memset(ptr, 0, size);
1346	mod->mem[type].base = ptr;
1347
1348	return 0;
1349	}
1350
1351	static void module_memory_restore_rox(struct module *mod)
1352	{
1353	for_class_mod_mem_type(type, text) {
1354	struct module_memory *mem = &mod->mem[type];
1355
1356	if (mem->is_rox)
1357	execmem_restore_rox(mem->base, mem->size);
1358	}
1359	}
1360
1361	static void module_memory_free(struct module *mod, enum mod_mem_type type)
1362	{
1363	struct module_memory *mem = &mod->mem[type];
1364
1365	execmem_free(mem->base);
1366	}
1367
1368	static void free_mod_mem(struct module *mod)
1369	{
1370	for_each_mod_mem_type(type) {
1371	struct module_memory *mod_mem = &mod->mem[type];
1372
1373	if (type == MOD_DATA)
1374	continue;
1375
1376	/* Free lock-classes; relies on the preceding sync_rcu(). */
1377	lockdep_free_key_range(mod_mem->base, mod_mem->size);
1378	if (mod_mem->size)
1379	module_memory_free(mod, type);
1380	}
1381
1382	/* MOD_DATA hosts mod, so free it at last */
1383	lockdep_free_key_range(mod->mem[MOD_DATA].base, mod->mem[MOD_DATA].size);
1384	module_memory_free(mod, MOD_DATA);
1385	}
1386
1387	/* Free a module, remove from lists, etc. */
1388	static void free_module(struct module *mod)
1389	{
1390	trace_module_free(mod);
1391
1392	codetag_unload_module(mod);
1393
1394	mod_sysfs_teardown(mod);
1395
1396	/*
1397	* We leave it in list to prevent duplicate loads, but make sure
1398	* that noone uses it while it's being deconstructed.
1399	*/
1400	mutex_lock(&module_mutex);
1401	mod->state = MODULE_STATE_UNFORMED;
1402	mutex_unlock(&module_mutex);
1403
1404	/* Arch-specific cleanup. */
1405	module_arch_cleanup(mod);
1406
1407	/* Module unload stuff */
1408	module_unload_free(mod);
1409
1410	/* Free any allocated parameters. */
1411	destroy_params(mod->kp, mod->num_kp);
1412
1413	if (is_livepatch_module(mod))
1414	free_module_elf(mod);
1415
1416	/* Now we can delete it from the lists */
1417	mutex_lock(&module_mutex);
1418	/* Unlink carefully: kallsyms could be walking list. */
1419	list_del_rcu(&mod->list);
1420	mod_tree_remove(mod);
1421	/* Remove this module from bug list, this uses list_del_rcu */
1422	module_bug_cleanup(mod);
1423	/* Wait for RCU synchronizing before releasing mod->list and buglist. */
1424	synchronize_rcu();
1425	if (try_add_tainted_module(mod))
1426	pr_err("%s: adding tainted module to the unloaded tainted modules list failed.\n",
1427	mod->name);
1428	mutex_unlock(&module_mutex);
1429
1430	/* This may be empty, but that's OK */
1431	module_arch_freeing_init(mod);
1432	kfree(mod->args);
1433	percpu_modfree(mod);
1434
1435	free_mod_mem(mod);
1436	}
1437
1438	void __symbol_get(const char symbol)
1439	{
1440	struct find_symbol_arg fsa = {
1441	.name = symbol,
1442	.gplok = true,
1443	.warn = true,
1444	};
1445
1446	scoped_guard(rcu) {
1447	if (!find_symbol(&fsa))
1448	return NULL;
1449	if (fsa.license != GPL_ONLY) {
1450	pr_warn("failing symbol_get of non-GPLONLY symbol %s.\n",
1451	symbol);
1452	return NULL;
1453	}
1454	if (strong_try_module_get(fsa.owner))
1455	return NULL;
1456	}
1457	return (void *)kernel_symbol_value(fsa.sym);
1458	}
1459	EXPORT_SYMBOL_GPL(__symbol_get);
1460
1461	/*
1462	* Ensure that an exported symbol [global namespace] does not already exist
1463	* in the kernel or in some other module's exported symbol table.
1464	*
1465	* You must hold the module_mutex.
1466	*/
1467	static int verify_exported_symbols(struct module *mod)
1468	{
1469	unsigned int i;
1470	const struct kernel_symbol *s;
1471	struct {
1472	const struct kernel_symbol *sym;
1473	unsigned int num;
1474	} arr[] = {
1475	{ mod->syms, mod->num_syms },
1476	{ mod->gpl_syms, mod->num_gpl_syms },
1477	};
1478
1479	for (i = 0; i < ARRAY_SIZE(arr); i++) {
1480	for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1481	struct find_symbol_arg fsa = {
1482	.name = kernel_symbol_name(s),
1483	.gplok = true,
1484	};
1485	if (find_symbol(&fsa)) {
1486	pr_err("%s: exports duplicate symbol %s"
1487	" (owned by %s)\n",
1488	mod->name, kernel_symbol_name(s),
1489	module_name(fsa.owner));
1490	return -ENOEXEC;
1491	}
1492	}
1493	}
1494	return 0;
1495	}
1496
1497	static bool ignore_undef_symbol(Elf_Half emachine, const char *name)
1498	{
1499	/*
1500	* On x86, PIC code and Clang non-PIC code may have call foo@PLT. GNU as
1501	* before 2.37 produces an unreferenced _GLOBAL_OFFSET_TABLE_ on x86-64.
1502	* i386 has a similar problem but may not deserve a fix.
1503	*
1504	* If we ever have to ignore many symbols, consider refactoring the code to
1505	* only warn if referenced by a relocation.
1506	*/
1507	if (emachine == EM_386 \|\| emachine == EM_X86_64)
1508	return !strcmp(name, "_GLOBAL_OFFSET_TABLE_");
1509	return false;
1510	}
1511
1512	/* Change all symbols so that st_value encodes the pointer directly. */
1513	static int simplify_symbols(struct module mod, const struct load_info info)
1514	{
1515	Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
1516	Elf_Sym sym = (void )symsec->sh_addr;
1517	unsigned long secbase;
1518	unsigned int i;
1519	int ret = 0;
1520	const struct kernel_symbol *ksym;
1521
1522	for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
1523	const char *name = info->strtab + sym[i].st_name;
1524
1525	switch (sym[i].st_shndx) {
1526	case SHN_COMMON:
1527	/* Ignore common symbols */
1528	if (!strncmp(name, "__gnu_lto", 9))
1529	break;
1530
1531	/*
1532	* We compiled with -fno-common. These are not
1533	* supposed to happen.
1534	*/
1535	pr_debug("Common symbol: %s\n", name);
1536	pr_warn("%s: please compile with -fno-common\n",
1537	mod->name);
1538	ret = -ENOEXEC;
1539	break;
1540
1541	case SHN_ABS:
1542	/* Don't need to do anything */
1543	pr_debug("Absolute symbol: 0x%08lx %s\n",
1544	(long)sym[i].st_value, name);
1545	break;
1546
1547	case SHN_LIVEPATCH:
1548	/* Livepatch symbols are resolved by livepatch */
1549	break;
1550
1551	case SHN_UNDEF:
1552	ksym = resolve_symbol_wait(mod, info, name);
1553	/* Ok if resolved. */
1554	if (ksym && !IS_ERR(ksym)) {
1555	sym[i].st_value = kernel_symbol_value(ksym);
1556	break;
1557	}
1558
1559	/* Ok if weak or ignored. */
1560	if (!ksym &&
1561	(ELF_ST_BIND(sym[i].st_info) == STB_WEAK \|\|
1562	ignore_undef_symbol(info->hdr->e_machine, name)))
1563	break;
1564
1565	ret = PTR_ERR(ksym) ?: -ENOENT;
1566	pr_warn("%s: Unknown symbol %s (err %d)\n",
1567	mod->name, name, ret);
1568	break;
1569
1570	default:
1571	if (sym[i].st_shndx >= info->hdr->e_shnum) {
1572	pr_err("%s: Symbol %s has an invalid section index %u (max %u)\n",
1573	mod->name, name, sym[i].st_shndx, info->hdr->e_shnum - 1);
1574	ret = -ENOEXEC;
1575	break;
1576	}
1577
1578	/* Divert to percpu allocation if a percpu var. */
1579	if (sym[i].st_shndx == info->index.pcpu)
1580	secbase = (unsigned long)mod_percpu(mod);
1581	else
1582	secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
1583	sym[i].st_value += secbase;
1584	break;
1585	}
1586	}
1587
1588	return ret;
1589	}
1590
1591	static int apply_relocations(struct module mod, const struct load_info info)
1592	{
1593	unsigned int i;
1594	int err = 0;
1595
1596	/* Now do relocations. */
1597	for (i = 1; i < info->hdr->e_shnum; i++) {
1598	unsigned int infosec = info->sechdrs[i].sh_info;
1599
1600	/* Not a valid relocation section? */
1601	if (infosec >= info->hdr->e_shnum)
1602	continue;
1603
1604	/*
1605	* Don't bother with non-allocated sections.
1606	* An exception is the percpu section, which has separate allocations
1607	* for individual CPUs. We relocate the percpu section in the initial
1608	* ELF template and subsequently copy it to the per-CPU destinations.
1609	*/
1610	if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC) &&
1611	(!infosec \|\| infosec != info->index.pcpu))
1612	continue;
1613
1614	if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
1615	err = klp_apply_section_relocs(mod, info->sechdrs,
1616	info->secstrings,
1617	info->strtab,
1618	info->index.sym, i,
1619	NULL);
1620	else if (info->sechdrs[i].sh_type == SHT_REL)
1621	err = apply_relocate(info->sechdrs, info->strtab,
1622	info->index.sym, i, mod);
1623	else if (info->sechdrs[i].sh_type == SHT_RELA)
1624	err = apply_relocate_add(info->sechdrs, info->strtab,
1625	info->index.sym, i, mod);
1626	if (err < 0)
1627	break;
1628	}
1629	return err;
1630	}
1631
1632	/* Additional bytes needed by arch in front of individual sections */
1633	unsigned int __weak arch_mod_section_prepend(struct module *mod,
1634	unsigned int section)
1635	{
1636	/* default implementation just returns zero */
1637	return 0;
1638	}
1639
1640	long module_get_offset_and_type(struct module *mod, enum mod_mem_type type,
1641	Elf_Shdr *sechdr, unsigned int section)
1642	{
1643	long offset;
1644	long mask = ((unsigned long)(type) & SH_ENTSIZE_TYPE_MASK) << SH_ENTSIZE_TYPE_SHIFT;
1645
1646	mod->mem[type].size += arch_mod_section_prepend(mod, section);
1647	offset = ALIGN(mod->mem[type].size, sechdr->sh_addralign ?: 1);
1648	mod->mem[type].size = offset + sechdr->sh_size;
1649
1650	WARN_ON_ONCE(offset & mask);
1651	return offset \| mask;
1652	}
1653
1654	bool module_init_layout_section(const char *sname)
1655	{
1656	#ifndef CONFIG_MODULE_UNLOAD
1657	if (module_exit_section(sname))
1658	return true;
1659	#endif
1660	return module_init_section(sname);
1661	}
1662
1663	static void __layout_sections(struct module mod, struct load_info info, bool is_init)
1664	{
1665	unsigned int m, i;
1666
1667	/*
1668	* { Mask of required section header flags,
1669	* Mask of excluded section header flags }
1670	*/
1671	static const unsigned long masks[][2] = {
1672	{ SHF_EXECINSTR \| SHF_ALLOC, ARCH_SHF_SMALL },
1673	{ SHF_ALLOC, SHF_WRITE \| ARCH_SHF_SMALL },
1674	{ SHF_RO_AFTER_INIT \| SHF_ALLOC, ARCH_SHF_SMALL },
1675	{ SHF_WRITE \| SHF_ALLOC, ARCH_SHF_SMALL },
1676	{ ARCH_SHF_SMALL \| SHF_ALLOC, 0 }
1677	};
1678	static const int core_m_to_mem_type[] = {
1679	MOD_TEXT,
1680	MOD_RODATA,
1681	MOD_RO_AFTER_INIT,
1682	MOD_DATA,
1683	MOD_DATA,
1684	};
1685	static const int init_m_to_mem_type[] = {
1686	MOD_INIT_TEXT,
1687	MOD_INIT_RODATA,
1688	MOD_INVALID,
1689	MOD_INIT_DATA,
1690	MOD_INIT_DATA,
1691	};
1692
1693	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1694	enum mod_mem_type type = is_init ? init_m_to_mem_type[m] : core_m_to_mem_type[m];
1695
1696	for (i = 0; i < info->hdr->e_shnum; ++i) {
1697	Elf_Shdr *s = &info->sechdrs[i];
1698	const char *sname = info->secstrings + s->sh_name;
1699
1700	if ((s->sh_flags & masks[m][0]) != masks[m][0]
1701	\|\| (s->sh_flags & masks[m][1])
1702	\|\| s->sh_entsize != ~0UL
1703	\|\| is_init != module_init_layout_section(sname))
1704	continue;
1705
1706	if (WARN_ON_ONCE(type == MOD_INVALID))
1707	continue;
1708
1709	/*
1710	* Do not allocate codetag memory as we load it into
1711	* preallocated contiguous memory.
1712	*/
1713	if (codetag_needs_module_section(mod, sname, s->sh_size)) {
1714	/*
1715	* s->sh_entsize won't be used but populate the
1716	* type field to avoid confusion.
1717	*/
1718	s->sh_entsize = ((unsigned long)(type) & SH_ENTSIZE_TYPE_MASK)
1719	<< SH_ENTSIZE_TYPE_SHIFT;
1720	continue;
1721	}
1722
1723	s->sh_entsize = module_get_offset_and_type(mod, type, s, i);
1724	pr_debug("\t%s\n", sname);
1725	}
1726	}
1727	}
1728
1729	/*
1730	* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
1731	* might -- code, read-only data, read-write data, small data. Tally
1732	* sizes, and place the offsets into sh_entsize fields: high bit means it
1733	* belongs in init.
1734	*/
1735	static void layout_sections(struct module mod, struct load_info info)
1736	{
1737	unsigned int i;
1738
1739	for (i = 0; i < info->hdr->e_shnum; i++)
1740	info->sechdrs[i].sh_entsize = ~0UL;
1741
1742	pr_debug("Core section allocation order for %s:\n", mod->name);
1743	__layout_sections(mod, info, false);
1744
1745	pr_debug("Init section allocation order for %s:\n", mod->name);
1746	__layout_sections(mod, info, true);
1747	}
1748
1749	static void module_license_taint_check(struct module mod, const char license)
1750	{
1751	if (!license)
1752	license = "unspecified";
1753
1754	if (!license_is_gpl_compatible(license)) {
1755	if (!test_taint(TAINT_PROPRIETARY_MODULE))
1756	pr_warn("%s: module license '%s' taints kernel.\n",
1757	mod->name, license);
1758	add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
1759	LOCKDEP_NOW_UNRELIABLE);
1760	}
1761	}
1762
1763	static int setup_modinfo(struct module mod, struct load_info info)
1764	{
1765	const struct module_attribute *attr;
1766	char *imported_namespace;
1767	int i;
1768
1769	for (i = 0; (attr = modinfo_attrs[i]); i++) {
1770	if (attr->setup)
1771	attr->setup(mod, get_modinfo(info, attr->attr.name));
1772	}
1773
1774	for_each_modinfo_entry(imported_namespace, info, "import_ns") {
1775	/*
1776	* 'module:' prefixed namespaces are implicit, disallow
1777	* explicit imports.
1778	*/
1779	if (strstarts(imported_namespace, "module:")) {
1780	pr_err("%s: module tries to import module namespace: %s\n",
1781	mod->name, imported_namespace);
1782	return -EPERM;
1783	}
1784	}
1785
1786	return 0;
1787	}
1788
1789	static void free_modinfo(struct module *mod)
1790	{
1791	const struct module_attribute *attr;
1792	int i;
1793
1794	for (i = 0; (attr = modinfo_attrs[i]); i++) {
1795	if (attr->free)
1796	attr->free(mod);
1797	}
1798	}
1799
1800	bool __weak module_init_section(const char *name)
1801	{
1802	return strstarts(name, ".init");
1803	}
1804
1805	bool __weak module_exit_section(const char *name)
1806	{
1807	return strstarts(name, ".exit");
1808	}
1809
1810	static int validate_section_offset(const struct load_info info, Elf_Shdr shdr)
1811	{
1812	#if defined(CONFIG_64BIT)
1813	unsigned long long secend;
1814	#else
1815	unsigned long secend;
1816	#endif
1817
1818	/*
1819	* Check for both overflow and offset/size being
1820	* too large.
1821	*/
1822	secend = shdr->sh_offset + shdr->sh_size;
1823	if (secend < shdr->sh_offset \|\| secend > info->len)
1824	return -ENOEXEC;
1825
1826	return 0;
1827	}
1828
1829	/**
1830	* elf_validity_ehdr() - Checks an ELF header for module validity
1831	* @info: Load info containing the ELF header to check
1832	*
1833	* Checks whether an ELF header could belong to a valid module. Checks:
1834	*
1835	* * ELF header is within the data the user provided
1836	* * ELF magic is present
1837	* * It is relocatable (not final linked, not core file, etc.)
1838	* * The header's machine type matches what the architecture expects.
1839	* * Optional arch-specific hook for other properties
1840	* - module_elf_check_arch() is currently only used by PPC to check
1841	* ELF ABI version, but may be used by others in the future.
1842	*
1843	* Return: %0 if valid, %-ENOEXEC on failure.
1844	*/
1845	static int elf_validity_ehdr(const struct load_info *info)
1846	{
1847	if (info->len < sizeof(*(info->hdr))) {
1848	pr_err("Invalid ELF header len %lu\n", info->len);
1849	return -ENOEXEC;
1850	}
1851	if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0) {
1852	pr_err("Invalid ELF header magic: != %s\n", ELFMAG);
1853	return -ENOEXEC;
1854	}
1855	if (info->hdr->e_type != ET_REL) {
1856	pr_err("Invalid ELF header type: %u != %u\n",
1857	info->hdr->e_type, ET_REL);
1858	return -ENOEXEC;
1859	}
1860	if (!elf_check_arch(info->hdr)) {
1861	pr_err("Invalid architecture in ELF header: %u\n",
1862	info->hdr->e_machine);
1863	return -ENOEXEC;
1864	}
1865	if (!module_elf_check_arch(info->hdr)) {
1866	pr_err("Invalid module architecture in ELF header: %u\n",
1867	info->hdr->e_machine);
1868	return -ENOEXEC;
1869	}
1870	return 0;
1871	}
1872
1873	/**
1874	* elf_validity_cache_sechdrs() - Cache section headers if valid
1875	* @info: Load info to compute section headers from
1876	*
1877	* Checks:
1878	*
1879	* * ELF header is valid (see elf_validity_ehdr())
1880	* * Section headers are the size we expect
1881	* * Section array fits in the user provided data
1882	* * Section index 0 is NULL
1883	* * Section contents are inbounds
1884	*
1885	* Then updates @info with a &load_info->sechdrs pointer if valid.
1886	*
1887	* Return: %0 if valid, negative error code if validation failed.
1888	*/
1889	static int elf_validity_cache_sechdrs(struct load_info *info)
1890	{
1891	Elf_Shdr *sechdrs;
1892	Elf_Shdr *shdr;
1893	int i;
1894	int err;
1895
1896	err = elf_validity_ehdr(info);
1897	if (err < 0)
1898	return err;
1899
1900	if (info->hdr->e_shentsize != sizeof(Elf_Shdr)) {
1901	pr_err("Invalid ELF section header size\n");
1902	return -ENOEXEC;
1903	}
1904
1905	/*
1906	* e_shnum is 16 bits, and sizeof(Elf_Shdr) is
1907	* known and small. So e_shnum * sizeof(Elf_Shdr)
1908	* will not overflow unsigned long on any platform.
1909	*/
1910	if (info->hdr->e_shoff >= info->len
1911	\|\| (info->hdr->e_shnum * sizeof(Elf_Shdr) >
1912	info->len - info->hdr->e_shoff)) {
1913	pr_err("Invalid ELF section header overflow\n");
1914	return -ENOEXEC;
1915	}
1916
1917	sechdrs = (void *)info->hdr + info->hdr->e_shoff;
1918
1919	/*
1920	* The code assumes that section 0 has a length of zero and
1921	* an addr of zero, so check for it.
1922	*/
1923	if (sechdrs[0].sh_type != SHT_NULL
1924	\|\| sechdrs[0].sh_size != 0
1925	\|\| sechdrs[0].sh_addr != 0) {
1926	pr_err("ELF Spec violation: section 0 type(%d)!=SH_NULL or non-zero len or addr\n",
1927	sechdrs[0].sh_type);
1928	return -ENOEXEC;
1929	}
1930
1931	/* Validate contents are inbounds */
1932	for (i = 1; i < info->hdr->e_shnum; i++) {
1933	shdr = &sechdrs[i];
1934	switch (shdr->sh_type) {
1935	case SHT_NULL:
1936	case SHT_NOBITS:
1937	/* No contents, offset/size don't mean anything */
1938	continue;
1939	default:
1940	err = validate_section_offset(info, shdr);
1941	if (err < 0) {
1942	pr_err("Invalid ELF section in module (section %u type %u)\n",
1943	i, shdr->sh_type);
1944	return err;
1945	}
1946	}
1947	}
1948
1949	info->sechdrs = sechdrs;
1950
1951	return 0;
1952	}
1953
1954	/**
1955	* elf_validity_cache_secstrings() - Caches section names if valid
1956	* @info: Load info to cache section names from. Must have valid sechdrs.
1957	*
1958	* Specifically checks:
1959	*
1960	* * Section name table index is inbounds of section headers
1961	* * Section name table is not empty
1962	* * Section name table is NUL terminated
1963	* * All section name offsets are inbounds of the section
1964	*
1965	* Then updates @info with a &load_info->secstrings pointer if valid.
1966	*
1967	* Return: %0 if valid, negative error code if validation failed.
1968	*/
1969	static int elf_validity_cache_secstrings(struct load_info *info)
1970	{
1971	Elf_Shdr strhdr, shdr;
1972	char *secstrings;
1973	int i;
1974
1975	/*
1976	* Verify if the section name table index is valid.
1977	*/
1978	if (info->hdr->e_shstrndx == SHN_UNDEF
1979	\|\| info->hdr->e_shstrndx >= info->hdr->e_shnum) {
1980	pr_err("Invalid ELF section name index: %d \|\| e_shstrndx (%d) >= e_shnum (%d)\n",
1981	info->hdr->e_shstrndx, info->hdr->e_shstrndx,
1982	info->hdr->e_shnum);
1983	return -ENOEXEC;
1984	}
1985
1986	strhdr = &info->sechdrs[info->hdr->e_shstrndx];
1987
1988	/*
1989	* The section name table must be NUL-terminated, as required
1990	* by the spec. This makes strcmp and pr_* calls that access
1991	* strings in the section safe.
1992	*/
1993	secstrings = (void *)info->hdr + strhdr->sh_offset;
1994	if (strhdr->sh_size == 0) {
1995	pr_err("empty section name table\n");
1996	return -ENOEXEC;
1997	}
1998	if (secstrings[strhdr->sh_size - 1] != '\0') {
1999	pr_err("ELF Spec violation: section name table isn't null terminated\n");
2000	return -ENOEXEC;
2001	}
2002
2003	for (i = 0; i < info->hdr->e_shnum; i++) {
2004	shdr = &info->sechdrs[i];
2005	/* SHT_NULL means sh_name has an undefined value */
2006	if (shdr->sh_type == SHT_NULL)
2007	continue;
2008	if (shdr->sh_name >= strhdr->sh_size) {
2009	pr_err("Invalid ELF section name in module (section %u type %u)\n",
2010	i, shdr->sh_type);
2011	return -ENOEXEC;
2012	}
2013	}
2014
2015	info->secstrings = secstrings;
2016	return 0;
2017	}
2018
2019	/**
2020	* elf_validity_cache_index_info() - Validate and cache modinfo section
2021	* @info: Load info to populate the modinfo index on.
2022	* Must have &load_info->sechdrs and &load_info->secstrings populated
2023	*
2024	* Checks that if there is a .modinfo section, it is unique.
2025	* Then, it caches its index in &load_info->index.info.
2026	* Finally, it tries to populate the name to improve error messages.
2027	*
2028	* Return: %0 if valid, %-ENOEXEC if multiple modinfo sections were found.
2029	*/
2030	static int elf_validity_cache_index_info(struct load_info *info)
2031	{
2032	int info_idx;
2033
2034	info_idx = find_any_unique_sec(info, ".modinfo");
2035
2036	if (info_idx == 0)
2037	/* Early return, no .modinfo */
2038	return 0;
2039
2040	if (info_idx < 0) {
2041	pr_err("Only one .modinfo section must exist.\n");
2042	return -ENOEXEC;
2043	}
2044
2045	info->index.info = info_idx;
2046	/* Try to find a name early so we can log errors with a module name */
2047	info->name = get_modinfo(info, "name");
2048
2049	return 0;
2050	}
2051
2052	/**
2053	* elf_validity_cache_index_mod() - Validates and caches this_module section
2054	* @info: Load info to cache this_module on.
2055	* Must have &load_info->sechdrs and &load_info->secstrings populated
2056	*
2057	* The ".gnu.linkonce.this_module" ELF section is special. It is what modpost
2058	* uses to refer to __this_module and let's use rely on THIS_MODULE to point
2059	* to &__this_module properly. The kernel's modpost declares it on each
2060	* modules's *.mod.c file. If the struct module of the kernel changes a full
2061	* kernel rebuild is required.
2062	*
2063	* We have a few expectations for this special section, this function
2064	* validates all this for us:
2065	*
2066	* * The section has contents
2067	* * The section is unique
2068	* * We expect the kernel to always have to allocate it: SHF_ALLOC
2069	* * The section size must match the kernel's run time's struct module
2070	* size
2071	*
2072	* If all checks pass, the index will be cached in &load_info->index.mod
2073	*
2074	* Return: %0 on validation success, %-ENOEXEC on failure
2075	*/
2076	static int elf_validity_cache_index_mod(struct load_info *info)
2077	{
2078	Elf_Shdr *shdr;
2079	int mod_idx;
2080
2081	mod_idx = find_any_unique_sec(info, ".gnu.linkonce.this_module");
2082	if (mod_idx <= 0) {
2083	pr_err("module %s: Exactly one .gnu.linkonce.this_module section must exist.\n",
2084	info->name ?: "(missing .modinfo section or name field)");
2085	return -ENOEXEC;
2086	}
2087
2088	shdr = &info->sechdrs[mod_idx];
2089
2090	if (shdr->sh_type == SHT_NOBITS) {
2091	pr_err("module %s: .gnu.linkonce.this_module section must have a size set\n",
2092	info->name ?: "(missing .modinfo section or name field)");
2093	return -ENOEXEC;
2094	}
2095
2096	if (!(shdr->sh_flags & SHF_ALLOC)) {
2097	pr_err("module %s: .gnu.linkonce.this_module must occupy memory during process execution\n",
2098	info->name ?: "(missing .modinfo section or name field)");
2099	return -ENOEXEC;
2100	}
2101
2102	if (shdr->sh_size != sizeof(struct module)) {
2103	pr_err("module %s: .gnu.linkonce.this_module section size must match the kernel's built struct module size at run time\n",
2104	info->name ?: "(missing .modinfo section or name field)");
2105	return -ENOEXEC;
2106	}
2107
2108	info->index.mod = mod_idx;
2109
2110	return 0;
2111	}
2112
2113	/**
2114	* elf_validity_cache_index_sym() - Validate and cache symtab index
2115	* @info: Load info to cache symtab index in.
2116	* Must have &load_info->sechdrs and &load_info->secstrings populated.
2117	*
2118	* Checks that there is exactly one symbol table, then caches its index in
2119	* &load_info->index.sym.
2120	*
2121	* Return: %0 if valid, %-ENOEXEC on failure.
2122	*/
2123	static int elf_validity_cache_index_sym(struct load_info *info)
2124	{
2125	unsigned int sym_idx;
2126	unsigned int num_sym_secs = 0;
2127	int i;
2128
2129	for (i = 1; i < info->hdr->e_shnum; i++) {
2130	if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2131	num_sym_secs++;
2132	sym_idx = i;
2133	}
2134	}
2135
2136	if (num_sym_secs != 1) {
2137	pr_warn("%s: module has no symbols (stripped?)\n",
2138	info->name ?: "(missing .modinfo section or name field)");
2139	return -ENOEXEC;
2140	}
2141
2142	info->index.sym = sym_idx;
2143
2144	return 0;
2145	}
2146
2147	/**
2148	* elf_validity_cache_index_str() - Validate and cache strtab index
2149	* @info: Load info to cache strtab index in.
2150	* Must have &load_info->sechdrs and &load_info->secstrings populated.
2151	* Must have &load_info->index.sym populated.
2152	*
2153	* Looks at the symbol table's associated string table, makes sure it is
2154	* in-bounds, and caches it.
2155	*
2156	* Return: %0 if valid, %-ENOEXEC on failure.
2157	*/
2158	static int elf_validity_cache_index_str(struct load_info *info)
2159	{
2160	unsigned int str_idx = info->sechdrs[info->index.sym].sh_link;
2161
2162	if (str_idx == SHN_UNDEF \|\| str_idx >= info->hdr->e_shnum) {
2163	pr_err("Invalid ELF sh_link!=SHN_UNDEF(%d) or (sh_link(%d) >= hdr->e_shnum(%d)\n",
2164	str_idx, str_idx, info->hdr->e_shnum);
2165	return -ENOEXEC;
2166	}
2167
2168	info->index.str = str_idx;
2169	return 0;
2170	}
2171
2172	/**
2173	* elf_validity_cache_index_versions() - Validate and cache version indices
2174	* @info: Load info to cache version indices in.
2175	* Must have &load_info->sechdrs and &load_info->secstrings populated.
2176	* @flags: Load flags, relevant to suppress version loading, see
2177	* uapi/linux/module.h
2178	*
2179	* If we're ignoring modversions based on @flags, zero all version indices
2180	* and return validity. Othewrise check:
2181	*
2182	* * If "__version_ext_crcs" is present, "__version_ext_names" is present
2183	* * There is a name present for every crc
2184	*
2185	* Then populate:
2186	*
2187	* * &load_info->index.vers
2188	* * &load_info->index.vers_ext_crc
2189	* * &load_info->index.vers_ext_names
2190	*
2191	* if present.
2192	*
2193	* Return: %0 if valid, %-ENOEXEC on failure.
2194	*/
2195	static int elf_validity_cache_index_versions(struct load_info *info, int flags)
2196	{
2197	unsigned int vers_ext_crc;
2198	unsigned int vers_ext_name;
2199	size_t crc_count;
2200	size_t remaining_len;
2201	size_t name_size;
2202	char *name;
2203
2204	/* If modversions were suppressed, pretend we didn't find any */
2205	if (flags & MODULE_INIT_IGNORE_MODVERSIONS) {
2206	info->index.vers = 0;
2207	info->index.vers_ext_crc = 0;
2208	info->index.vers_ext_name = 0;
2209	return 0;
2210	}
2211
2212	vers_ext_crc = find_sec(info, "__version_ext_crcs");
2213	vers_ext_name = find_sec(info, "__version_ext_names");
2214
2215	/* If we have one field, we must have the other */
2216	if (!!vers_ext_crc != !!vers_ext_name) {
2217	pr_err("extended version crc+name presence does not match");
2218	return -ENOEXEC;
2219	}
2220
2221	/*
2222	* If we have extended version information, we should have the same
2223	* number of entries in every section.
2224	*/
2225	if (vers_ext_crc) {
2226	crc_count = info->sechdrs[vers_ext_crc].sh_size / sizeof(u32);
2227	name = (void *)info->hdr +
2228	info->sechdrs[vers_ext_name].sh_offset;
2229	remaining_len = info->sechdrs[vers_ext_name].sh_size;
2230
2231	while (crc_count--) {
2232	name_size = strnlen(name, remaining_len) + 1;
2233	if (name_size > remaining_len) {
2234	pr_err("more extended version crcs than names");
2235	return -ENOEXEC;
2236	}
2237	remaining_len -= name_size;
2238	name += name_size;
2239	}
2240	}
2241
2242	info->index.vers = find_sec(info, "__versions");
2243	info->index.vers_ext_crc = vers_ext_crc;
2244	info->index.vers_ext_name = vers_ext_name;
2245	return 0;
2246	}
2247
2248	/**
2249	* elf_validity_cache_index() - Resolve, validate, cache section indices
2250	* @info: Load info to read from and update.
2251	* &load_info->sechdrs and &load_info->secstrings must be populated.
2252	* @flags: Load flags, relevant to suppress version loading, see
2253	* uapi/linux/module.h
2254	*
2255	* Populates &load_info->index, validating as it goes.
2256	* See child functions for per-field validation:
2257	*
2258	* * elf_validity_cache_index_info()
2259	* * elf_validity_cache_index_mod()
2260	* * elf_validity_cache_index_sym()
2261	* * elf_validity_cache_index_str()
2262	* * elf_validity_cache_index_versions()
2263	*
2264	* If CONFIG_SMP is enabled, load the percpu section by name with no
2265	* validation.
2266	*
2267	* Return: 0 on success, negative error code if an index failed validation.
2268	*/
2269	static int elf_validity_cache_index(struct load_info *info, int flags)
2270	{
2271	int err;
2272
2273	err = elf_validity_cache_index_info(info);
2274	if (err < 0)
2275	return err;
2276	err = elf_validity_cache_index_mod(info);
2277	if (err < 0)
2278	return err;
2279	err = elf_validity_cache_index_sym(info);
2280	if (err < 0)
2281	return err;
2282	err = elf_validity_cache_index_str(info);
2283	if (err < 0)
2284	return err;
2285	err = elf_validity_cache_index_versions(info, flags);
2286	if (err < 0)
2287	return err;
2288
2289	info->index.pcpu = find_pcpusec(info);
2290
2291	return 0;
2292	}
2293
2294	/**
2295	* elf_validity_cache_strtab() - Validate and cache symbol string table
2296	* @info: Load info to read from and update.
2297	* Must have &load_info->sechdrs and &load_info->secstrings populated.
2298	* Must have &load_info->index populated.
2299	*
2300	* Checks:
2301	*
2302	* * The string table is not empty.
2303	* * The string table starts and ends with NUL (required by ELF spec).
2304	* * Every &Elf_Sym->st_name offset in the symbol table is inbounds of the
2305	* string table.
2306	*
2307	* And caches the pointer as &load_info->strtab in @info.
2308	*
2309	* Return: 0 on success, negative error code if a check failed.
2310	*/
2311	static int elf_validity_cache_strtab(struct load_info *info)
2312	{
2313	Elf_Shdr *str_shdr = &info->sechdrs[info->index.str];
2314	Elf_Shdr *sym_shdr = &info->sechdrs[info->index.sym];
2315	char strtab = (char )info->hdr + str_shdr->sh_offset;
2316	Elf_Sym syms = (void )info->hdr + sym_shdr->sh_offset;
2317	int i;
2318
2319	if (str_shdr->sh_size == 0) {
2320	pr_err("empty symbol string table\n");
2321	return -ENOEXEC;
2322	}
2323	if (strtab[0] != '\0') {
2324	pr_err("symbol string table missing leading NUL\n");
2325	return -ENOEXEC;
2326	}
2327	if (strtab[str_shdr->sh_size - 1] != '\0') {
2328	pr_err("symbol string table isn't NUL terminated\n");
2329	return -ENOEXEC;
2330	}
2331
2332	/*
2333	* Now that we know strtab is correctly structured, check symbol
2334	* starts are inbounds before they're used later.
2335	*/
2336	for (i = 0; i < sym_shdr->sh_size / sizeof(*syms); i++) {
2337	if (syms[i].st_name >= str_shdr->sh_size) {
2338	pr_err("symbol name out of bounds in string table");
2339	return -ENOEXEC;
2340	}
2341	}
2342
2343	info->strtab = strtab;
2344	return 0;
2345	}
2346
2347	/*
2348	* Check userspace passed ELF module against our expectations, and cache
2349	* useful variables for further processing as we go.
2350	*
2351	* This does basic validity checks against section offsets and sizes, the
2352	* section name string table, and the indices used for it (sh_name).
2353	*
2354	* As a last step, since we're already checking the ELF sections we cache
2355	* useful variables which will be used later for our convenience:
2356	*
2357	* o pointers to section headers
2358	* o cache the modinfo symbol section
2359	* o cache the string symbol section
2360	* o cache the module section
2361	*
2362	* As a last step we set info->mod to the temporary copy of the module in
2363	* info->hdr. The final one will be allocated in move_module(). Any
2364	* modifications we make to our copy of the module will be carried over
2365	* to the final minted module.
2366	*/
2367	static int elf_validity_cache_copy(struct load_info *info, int flags)
2368	{
2369	int err;
2370
2371	err = elf_validity_cache_sechdrs(info);
2372	if (err < 0)
2373	return err;
2374	err = elf_validity_cache_secstrings(info);
2375	if (err < 0)
2376	return err;
2377	err = elf_validity_cache_index(info, flags);
2378	if (err < 0)
2379	return err;
2380	err = elf_validity_cache_strtab(info);
2381	if (err < 0)
2382	return err;
2383
2384	/* This is temporary: point mod into copy of data. */
2385	info->mod = (void *)info->hdr + info->sechdrs[info->index.mod].sh_offset;
2386
2387	/*
2388	* If we didn't load the .modinfo 'name' field earlier, fall back to
2389	* on-disk struct mod 'name' field.
2390	*/
2391	if (!info->name)
2392	info->name = info->mod->name;
2393
2394	return 0;
2395	}
2396
2397	#define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2398
2399	static int copy_chunked_from_user(void dst, const void __user usrc, unsigned long len)
2400	{
2401	do {
2402	unsigned long n = min(len, COPY_CHUNK_SIZE);
2403
2404	if (copy_from_user(dst, usrc, n) != 0)
2405	return -EFAULT;
2406	cond_resched();
2407	dst += n;
2408	usrc += n;
2409	len -= n;
2410	} while (len);
2411	return 0;
2412	}
2413
2414	static int check_modinfo_livepatch(struct module mod, struct load_info info)
2415	{
2416	if (!get_modinfo(info, "livepatch"))
2417	/* Nothing more to do */
2418	return 0;
2419
2420	if (set_livepatch_module(mod))
2421	return 0;
2422
2423	pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
2424	mod->name);
2425	return -ENOEXEC;
2426	}
2427
2428	static void check_modinfo_retpoline(struct module mod, struct load_info info)
2429	{
2430	if (retpoline_module_ok(get_modinfo(info, "retpoline")))
2431	return;
2432
2433	pr_warn("%s: loading module not compiled with retpoline compiler.\n",
2434	mod->name);
2435	}
2436
2437	/* Sets info->hdr and info->len. */
2438	static int copy_module_from_user(const void __user *umod, unsigned long len,
2439	struct load_info *info)
2440	{
2441	int err;
2442
2443	info->len = len;
2444	if (info->len < sizeof(*(info->hdr)))
2445	return -ENOEXEC;
2446
2447	err = security_kernel_load_data(LOADING_MODULE, true);
2448	if (err)
2449	return err;
2450
2451	/* Suck in entire file: we'll want most of it. */
2452	info->hdr = __vmalloc(info->len, GFP_KERNEL \| __GFP_NOWARN);
2453	if (!info->hdr)
2454	return -ENOMEM;
2455
2456	if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2457	err = -EFAULT;
2458	goto out;
2459	}
2460
2461	err = security_kernel_post_load_data((char *)info->hdr, info->len,
2462	LOADING_MODULE, "init_module");
2463	out:
2464	if (err)
2465	vfree(info->hdr);
2466
2467	return err;
2468	}
2469
2470	static void free_copy(struct load_info *info, int flags)
2471	{
2472	if (flags & MODULE_INIT_COMPRESSED_FILE)
2473	module_decompress_cleanup(info);
2474	else
2475	vfree(info->hdr);
2476	}
2477
2478	static int rewrite_section_headers(struct load_info *info, int flags)
2479	{
2480	unsigned int i;
2481
2482	/* This should always be true, but let's be sure. */
2483	info->sechdrs[0].sh_addr = 0;
2484
2485	for (i = 1; i < info->hdr->e_shnum; i++) {
2486	Elf_Shdr *shdr = &info->sechdrs[i];
2487
2488	/*
2489	* Mark all sections sh_addr with their address in the
2490	* temporary image.
2491	*/
2492	shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2493
2494	}
2495
2496	/* Track but don't keep modinfo and version sections. */
2497	info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2498	info->sechdrs[info->index.vers_ext_crc].sh_flags &=
2499	~(unsigned long)SHF_ALLOC;
2500	info->sechdrs[info->index.vers_ext_name].sh_flags &=
2501	~(unsigned long)SHF_ALLOC;
2502	info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2503
2504	return 0;
2505	}
2506
2507	static const char *const module_license_offenders[] = {
2508	/* driverloader was caught wrongly pretending to be under GPL */
2509	"driverloader",
2510
2511	/* lve claims to be GPL but upstream won't provide source */
2512	"lve",
2513	};
2514
2515	/*
2516	* These calls taint the kernel depending certain module circumstances */
2517	static void module_augment_kernel_taints(struct module mod, struct load_info info)
2518	{
2519	int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
2520	size_t i;
2521
2522	if (!get_modinfo(info, "intree")) {
2523	if (!test_taint(TAINT_OOT_MODULE))
2524	pr_warn("%s: loading out-of-tree module taints kernel.\n",
2525	mod->name);
2526	add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2527	}
2528
2529	check_modinfo_retpoline(mod, info);
2530
2531	if (get_modinfo(info, "staging")) {
2532	add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
2533	pr_warn("%s: module is from the staging directory, the quality "
2534	"is unknown, you have been warned.\n", mod->name);
2535	}
2536
2537	if (is_livepatch_module(mod)) {
2538	add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
2539	pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
2540	mod->name);
2541	}
2542
2543	module_license_taint_check(mod, get_modinfo(info, "license"));
2544
2545	if (get_modinfo(info, "test")) {
2546	if (!test_taint(TAINT_TEST))
2547	pr_warn("%s: loading test module taints kernel.\n",
2548	mod->name);
2549	add_taint_module(mod, TAINT_TEST, LOCKDEP_STILL_OK);
2550	}
2551	#ifdef CONFIG_MODULE_SIG
2552	mod->sig_ok = info->sig_ok;
2553	if (!mod->sig_ok) {
2554	pr_notice_once("%s: module verification failed: signature "
2555	"and/or required key missing - tainting "
2556	"kernel\n", mod->name);
2557	add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
2558	}
2559	#endif
2560
2561	/*
2562	* ndiswrapper is under GPL by itself, but loads proprietary modules.
2563	* Don't use add_taint_module(), as it would prevent ndiswrapper from
2564	* using GPL-only symbols it needs.
2565	*/
2566	if (strcmp(mod->name, "ndiswrapper") == 0)
2567	add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
2568
2569	for (i = 0; i < ARRAY_SIZE(module_license_offenders); ++i) {
2570	if (strcmp(mod->name, module_license_offenders[i]) == 0)
2571	add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2572	LOCKDEP_NOW_UNRELIABLE);
2573	}
2574
2575	if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
2576	pr_warn("%s: module license taints kernel.\n", mod->name);
2577
2578	}
2579
2580	static int check_modinfo(struct module mod, struct load_info info, int flags)
2581	{
2582	const char *modmagic = get_modinfo(info, "vermagic");
2583	int err;
2584
2585	if (flags & MODULE_INIT_IGNORE_VERMAGIC)
2586	modmagic = NULL;
2587
2588	/* This is allowed: modprobe --force will invalidate it. */
2589	if (!modmagic) {
2590	err = try_to_force_load(mod, "bad vermagic");
2591	if (err)
2592	return err;
2593	} else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2594	pr_err("%s: version magic '%s' should be '%s'\n",
2595	info->name, modmagic, vermagic);
2596	return -ENOEXEC;
2597	}
2598
2599	err = check_modinfo_livepatch(mod, info);
2600	if (err)
2601	return err;
2602
2603	return 0;
2604	}
2605
2606	static int find_module_sections(struct module mod, struct load_info info)
2607	{
2608	mod->kp = section_objs(info, "__param",
2609	sizeof(*mod->kp), &mod->num_kp);
2610	mod->syms = section_objs(info, "__ksymtab",
2611	sizeof(*mod->syms), &mod->num_syms);
2612	mod->crcs = section_addr(info, "__kcrctab");
2613	mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2614	sizeof(*mod->gpl_syms),
2615	&mod->num_gpl_syms);
2616	mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2617
2618	#ifdef CONFIG_CONSTRUCTORS
2619	mod->ctors = section_objs(info, ".ctors",
2620	sizeof(*mod->ctors), &mod->num_ctors);
2621	if (!mod->ctors)
2622	mod->ctors = section_objs(info, ".init_array",
2623	sizeof(*mod->ctors), &mod->num_ctors);
2624	else if (find_sec(info, ".init_array")) {
2625	/*
2626	* This shouldn't happen with same compiler and binutils
2627	* building all parts of the module.
2628	*/
2629	pr_warn("%s: has both .ctors and .init_array.\n",
2630	mod->name);
2631	return -EINVAL;
2632	}
2633	#endif
2634
2635	mod->noinstr_text_start = section_objs(info, ".noinstr.text", 1,
2636	&mod->noinstr_text_size);
2637
2638	#ifdef CONFIG_TRACEPOINTS
2639	mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2640	sizeof(*mod->tracepoints_ptrs),
2641	&mod->num_tracepoints);
2642	#endif
2643	#ifdef CONFIG_TREE_SRCU
2644	mod->srcu_struct_ptrs = section_objs(info, "___srcu_struct_ptrs",
2645	sizeof(*mod->srcu_struct_ptrs),
2646	&mod->num_srcu_structs);
2647	#endif
2648	#ifdef CONFIG_BPF_EVENTS
2649	mod->bpf_raw_events = section_objs(info, "__bpf_raw_tp_map",
2650	sizeof(*mod->bpf_raw_events),
2651	&mod->num_bpf_raw_events);
2652	#endif
2653	#ifdef CONFIG_DEBUG_INFO_BTF_MODULES
2654	mod->btf_data = any_section_objs(info, ".BTF", 1, &mod->btf_data_size);
2655	mod->btf_base_data = any_section_objs(info, ".BTF.base", 1,
2656	&mod->btf_base_data_size);
2657	#endif
2658	#ifdef CONFIG_JUMP_LABEL
2659	mod->jump_entries = section_objs(info, "__jump_table",
2660	sizeof(*mod->jump_entries),
2661	&mod->num_jump_entries);
2662	#endif
2663	#ifdef CONFIG_EVENT_TRACING
2664	mod->trace_events = section_objs(info, "_ftrace_events",
2665	sizeof(*mod->trace_events),
2666	&mod->num_trace_events);
2667	mod->trace_evals = section_objs(info, "_ftrace_eval_map",
2668	sizeof(*mod->trace_evals),
2669	&mod->num_trace_evals);
2670	#endif
2671	#ifdef CONFIG_TRACING
2672	mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2673	sizeof(*mod->trace_bprintk_fmt_start),
2674	&mod->num_trace_bprintk_fmt);
2675	#endif
2676	#ifdef CONFIG_DYNAMIC_FTRACE
2677	/* sechdrs[0].sh_size is always zero */
2678	mod->ftrace_callsites = section_objs(info, FTRACE_CALLSITE_SECTION,
2679	sizeof(*mod->ftrace_callsites),
2680	&mod->num_ftrace_callsites);
2681	#endif
2682	#ifdef CONFIG_FUNCTION_ERROR_INJECTION
2683	mod->ei_funcs = section_objs(info, "_error_injection_whitelist",
2684	sizeof(*mod->ei_funcs),
2685	&mod->num_ei_funcs);
2686	#endif
2687	#ifdef CONFIG_KPROBES
2688	mod->kprobes_text_start = section_objs(info, ".kprobes.text", 1,
2689	&mod->kprobes_text_size);
2690	mod->kprobe_blacklist = section_objs(info, "_kprobe_blacklist",
2691	sizeof(unsigned long),
2692	&mod->num_kprobe_blacklist);
2693	#endif
2694	#ifdef CONFIG_PRINTK_INDEX
2695	mod->printk_index_start = section_objs(info, ".printk_index",
2696	sizeof(*mod->printk_index_start),
2697	&mod->printk_index_size);
2698	#endif
2699	#ifdef CONFIG_HAVE_STATIC_CALL_INLINE
2700	mod->static_call_sites = section_objs(info, ".static_call_sites",
2701	sizeof(*mod->static_call_sites),
2702	&mod->num_static_call_sites);
2703	#endif
2704	#if IS_ENABLED(CONFIG_KUNIT)
2705	mod->kunit_suites = section_objs(info, ".kunit_test_suites",
2706	sizeof(*mod->kunit_suites),
2707	&mod->num_kunit_suites);
2708	mod->kunit_init_suites = section_objs(info, ".kunit_init_test_suites",
2709	sizeof(*mod->kunit_init_suites),
2710	&mod->num_kunit_init_suites);
2711	#endif
2712
2713	mod->extable = section_objs(info, "__ex_table",
2714	sizeof(*mod->extable), &mod->num_exentries);
2715
2716	if (section_addr(info, "__obsparm"))
2717	pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
2718
2719	#ifdef CONFIG_DYNAMIC_DEBUG_CORE
2720	mod->dyndbg_info.descs = section_objs(info, "__dyndbg",
2721	sizeof(*mod->dyndbg_info.descs),
2722	&mod->dyndbg_info.num_descs);
2723	mod->dyndbg_info.classes = section_objs(info, "__dyndbg_classes",
2724	sizeof(*mod->dyndbg_info.classes),
2725	&mod->dyndbg_info.num_classes);
2726	#endif
2727
2728	return 0;
2729	}
2730
2731	static int move_module(struct module mod, struct load_info info)
2732	{
2733	int i, ret;
2734	enum mod_mem_type t = MOD_MEM_NUM_TYPES;
2735	bool codetag_section_found = false;
2736
2737	for_each_mod_mem_type(type) {
2738	if (!mod->mem[type].size) {
2739	mod->mem[type].base = NULL;
2740	continue;
2741	}
2742
2743	ret = module_memory_alloc(mod, type);
2744	if (ret) {
2745	t = type;
2746	goto out_err;
2747	}
2748	}
2749
2750	/* Transfer each section which specifies SHF_ALLOC */
2751	pr_debug("Final section addresses for %s:\n", mod->name);
2752	for (i = 0; i < info->hdr->e_shnum; i++) {
2753	void *dest;
2754	Elf_Shdr *shdr = &info->sechdrs[i];
2755	const char *sname;
2756
2757	if (!(shdr->sh_flags & SHF_ALLOC))
2758	continue;
2759
2760	sname = info->secstrings + shdr->sh_name;
2761	/*
2762	* Load codetag sections separately as they might still be used
2763	* after module unload.
2764	*/
2765	if (codetag_needs_module_section(mod, sname, shdr->sh_size)) {
2766	dest = codetag_alloc_module_section(mod, sname, shdr->sh_size,
2767	arch_mod_section_prepend(mod, i), shdr->sh_addralign);
2768	if (WARN_ON(!dest)) {
2769	ret = -EINVAL;
2770	goto out_err;
2771	}
2772	if (IS_ERR(dest)) {
2773	ret = PTR_ERR(dest);
2774	goto out_err;
2775	}
2776	codetag_section_found = true;
2777	} else {
2778	enum mod_mem_type type = shdr->sh_entsize >> SH_ENTSIZE_TYPE_SHIFT;
2779	unsigned long offset = shdr->sh_entsize & SH_ENTSIZE_OFFSET_MASK;
2780
2781	dest = mod->mem[type].base + offset;
2782	}
2783
2784	if (shdr->sh_type != SHT_NOBITS) {
2785	/*
2786	* Our ELF checker already validated this, but let's
2787	* be pedantic and make the goal clearer. We actually
2788	* end up copying over all modifications made to the
2789	* userspace copy of the entire struct module.
2790	*/
2791	if (i == info->index.mod &&
2792	(WARN_ON_ONCE(shdr->sh_size != sizeof(struct module)))) {
2793	ret = -ENOEXEC;
2794	goto out_err;
2795	}
2796	memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2797	}
2798	/*
2799	* Update the userspace copy's ELF section address to point to
2800	* our newly allocated memory as a pure convenience so that
2801	* users of info can keep taking advantage and using the newly
2802	* minted official memory area.
2803	*/
2804	shdr->sh_addr = (unsigned long)dest;
2805	pr_debug("\t0x%lx 0x%.8lx %s\n", (long)shdr->sh_addr,
2806	(long)shdr->sh_size, info->secstrings + shdr->sh_name);
2807	}
2808
2809	return 0;
2810	out_err:
2811	module_memory_restore_rox(mod);
2812	while (t--)
2813	module_memory_free(mod, t);
2814	if (codetag_section_found)
2815	codetag_free_module_sections(mod);
2816
2817	return ret;
2818	}
2819
2820	static int check_export_symbol_versions(struct module *mod)
2821	{
2822	#ifdef CONFIG_MODVERSIONS
2823	if ((mod->num_syms && !mod->crcs) \|\|
2824	(mod->num_gpl_syms && !mod->gpl_crcs)) {
2825	return try_to_force_load(mod,
2826	"no versions for exported symbols");
2827	}
2828	#endif
2829	return 0;
2830	}
2831
2832	static void flush_module_icache(const struct module *mod)
2833	{
2834	/*
2835	* Flush the instruction cache, since we've played with text.
2836	* Do it before processing of module parameters, so the module
2837	* can provide parameter accessor functions of its own.
2838	*/
2839	for_each_mod_mem_type(type) {
2840	const struct module_memory *mod_mem = &mod->mem[type];
2841
2842	if (mod_mem->size) {
2843	flush_icache_range((unsigned long)mod_mem->base,
2844	(unsigned long)mod_mem->base + mod_mem->size);
2845	}
2846	}
2847	}
2848
2849	bool __weak module_elf_check_arch(Elf_Ehdr *hdr)
2850	{
2851	return true;
2852	}
2853
2854	int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
2855	Elf_Shdr *sechdrs,
2856	char *secstrings,
2857	struct module *mod)
2858	{
2859	return 0;
2860	}
2861
2862	/* module_blacklist is a comma-separated list of module names */
2863	static char *module_blacklist;
2864	static bool blacklisted(const char *module_name)
2865	{
2866	const char *p;
2867	size_t len;
2868
2869	if (!module_blacklist)
2870	return false;
2871
2872	for (p = module_blacklist; *p; p += len) {
2873	len = strcspn(p, ",");
2874	if (strlen(module_name) == len && !memcmp(module_name, p, len))
2875	return true;
2876	if (p[len] == ',')
2877	len++;
2878	}
2879	return false;
2880	}
2881	core_param(module_blacklist, module_blacklist, charp, 0400);
2882
2883	static struct module layout_and_allocate(struct load_info info, int flags)
2884	{
2885	struct module *mod;
2886	int err;
2887
2888	/* Allow arches to frob section contents and sizes. */
2889	err = module_frob_arch_sections(info->hdr, info->sechdrs,
2890	info->secstrings, info->mod);
2891	if (err < 0)
2892	return ERR_PTR(err);
2893
2894	err = module_enforce_rwx_sections(info->hdr, info->sechdrs,
2895	info->secstrings, info->mod);
2896	if (err < 0)
2897	return ERR_PTR(err);
2898
2899	/* We will do a special allocation for per-cpu sections later. */
2900	info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
2901
2902	/*
2903	* Mark relevant sections as SHF_RO_AFTER_INIT so layout_sections() can
2904	* put them in the right place.
2905	* Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
2906	*/
2907	module_mark_ro_after_init(info->hdr, info->sechdrs, info->secstrings);
2908
2909	/*
2910	* Determine total sizes, and put offsets in sh_entsize. For now
2911	* this is done generically; there doesn't appear to be any
2912	* special cases for the architectures.
2913	*/
2914	layout_sections(info->mod, info);
2915	layout_symtab(info->mod, info);
2916
2917	/* Allocate and move to the final place */
2918	err = move_module(info->mod, info);
2919	if (err)
2920	return ERR_PTR(err);
2921
2922	/* Module has been copied to its final place now: return it. */
2923	mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2924	kmemleak_load_module(mod, info);
2925	codetag_module_replaced(info->mod, mod);
2926
2927	return mod;
2928	}
2929
2930	/* mod is no longer valid after this! */
2931	static void module_deallocate(struct module mod, struct load_info info)
2932	{
2933	percpu_modfree(mod);
2934	module_arch_freeing_init(mod);
2935	codetag_free_module_sections(mod);
2936
2937	free_mod_mem(mod);
2938	}
2939
2940	int __weak module_finalize(const Elf_Ehdr *hdr,
2941	const Elf_Shdr *sechdrs,
2942	struct module *me)
2943	{
2944	return 0;
2945	}
2946
2947	static int post_relocation(struct module mod, const struct load_info info)
2948	{
2949	/* Sort exception table now relocations are done. */
2950	sort_extable(mod->extable, mod->extable + mod->num_exentries);
2951
2952	/* Copy relocated percpu area over. */
2953	percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
2954	info->sechdrs[info->index.pcpu].sh_size);
2955
2956	/* Setup kallsyms-specific fields. */
2957	add_kallsyms(mod, info);
2958
2959	/* Arch-specific module finalizing. */
2960	return module_finalize(info->hdr, info->sechdrs, mod);
2961	}
2962
2963	/* Call module constructors. */
2964	static void do_mod_ctors(struct module *mod)
2965	{
2966	#ifdef CONFIG_CONSTRUCTORS
2967	unsigned long i;
2968
2969	for (i = 0; i < mod->num_ctors; i++)
2970	mod->ctors[i]();
2971	#endif
2972	}
2973
2974	/* For freeing module_init on success, in case kallsyms traversing */
2975	struct mod_initfree {
2976	struct llist_node node;
2977	void *init_text;
2978	void *init_data;
2979	void *init_rodata;
2980	};
2981
2982	static void do_free_init(struct work_struct *w)
2983	{
2984	struct llist_node pos, n, *list;
2985	struct mod_initfree *initfree;
2986
2987	list = llist_del_all(&init_free_list);
2988
2989	synchronize_rcu();
2990
2991	llist_for_each_safe(pos, n, list) {
2992	initfree = container_of(pos, struct mod_initfree, node);
2993	execmem_free(initfree->init_text);
2994	execmem_free(initfree->init_data);
2995	execmem_free(initfree->init_rodata);
2996	kfree(initfree);
2997	}
2998	}
2999
3000	void flush_module_init_free_work(void)
3001	{
3002	flush_work(&init_free_wq);
3003	}
3004
3005	#undef MODULE_PARAM_PREFIX
3006	#define MODULE_PARAM_PREFIX "module."
3007	/* Default value for module->async_probe_requested */
3008	static bool async_probe;
3009	module_param(async_probe, bool, 0644);
3010
3011	/*
3012	* This is where the real work happens.
3013	*
3014	* Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3015	* helper command 'lx-symbols'.
3016	*/
3017	static noinline int do_init_module(struct module *mod)
3018	{
3019	int ret = 0;
3020	struct mod_initfree *freeinit;
3021	#if defined(CONFIG_MODULE_STATS)
3022	unsigned int text_size = 0, total_size = 0;
3023
3024	for_each_mod_mem_type(type) {
3025	const struct module_memory *mod_mem = &mod->mem[type];
3026	if (mod_mem->size) {
3027	total_size += mod_mem->size;
3028	if (type == MOD_TEXT \|\| type == MOD_INIT_TEXT)
3029	text_size += mod_mem->size;
3030	}
3031	}
3032	#endif
3033
3034	freeinit = kmalloc_obj(*freeinit);
3035	if (!freeinit) {
3036	ret = -ENOMEM;
3037	goto fail;
3038	}
3039	freeinit->init_text = mod->mem[MOD_INIT_TEXT].base;
3040	freeinit->init_data = mod->mem[MOD_INIT_DATA].base;
3041	freeinit->init_rodata = mod->mem[MOD_INIT_RODATA].base;
3042
3043	do_mod_ctors(mod);
3044	/* Start the module */
3045	if (mod->init != NULL)
3046	ret = do_one_initcall(mod->init);
3047	if (ret < 0) {
3048	goto fail_free_freeinit;
3049	}
3050	if (ret > 0) {
3051	pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3052	"follow 0/-E convention\n"
3053	"%s: loading module anyway...\n",
3054	__func__, mod->name, ret, __func__);
3055	dump_stack();
3056	}
3057
3058	/* Now it's a first class citizen! */
3059	mod->state = MODULE_STATE_LIVE;
3060	blocking_notifier_call_chain(&module_notify_list,
3061	MODULE_STATE_LIVE, mod);
3062
3063	/* Delay uevent until module has finished its init routine */
3064	kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
3065
3066	/*
3067	* We need to finish all async code before the module init sequence
3068	* is done. This has potential to deadlock if synchronous module
3069	* loading is requested from async (which is not allowed!).
3070	*
3071	* See commit 0fdff3ec6d87 ("async, kmod: warn on synchronous
3072	* request_module() from async workers") for more details.
3073	*/
3074	if (!mod->async_probe_requested)
3075	async_synchronize_full();
3076
3077	ftrace_free_mem(mod, mod->mem[MOD_INIT_TEXT].base,
3078	mod->mem[MOD_INIT_TEXT].base + mod->mem[MOD_INIT_TEXT].size);
3079	mutex_lock(&module_mutex);
3080	/* Drop initial reference. */
3081	module_put(mod);
3082	trim_init_extable(mod);
3083	#ifdef CONFIG_KALLSYMS
3084	/* Switch to core kallsyms now init is done: kallsyms may be walking! */
3085	rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3086	#endif
3087	ret = module_enable_rodata_ro_after_init(mod);
3088	if (ret)
3089	pr_warn("%s: module_enable_rodata_ro_after_init() returned %d, "
3090	"ro_after_init data might still be writable\n",
3091	mod->name, ret);
3092
3093	mod_tree_remove_init(mod);
3094	module_arch_freeing_init(mod);
3095	for_class_mod_mem_type(type, init) {
3096	mod->mem[type].base = NULL;
3097	mod->mem[type].size = 0;
3098	}
3099
3100	#ifdef CONFIG_DEBUG_INFO_BTF_MODULES
3101	/* .BTF is not SHF_ALLOC and will get removed, so sanitize pointers */
3102	mod->btf_data = NULL;
3103	mod->btf_base_data = NULL;
3104	#endif
3105	/*
3106	* We want to free module_init, but be aware that kallsyms may be
3107	* walking this within an RCU read section. In all the failure paths, we
3108	* call synchronize_rcu(), but we don't want to slow down the success
3109	* path. execmem_free() cannot be called in an interrupt, so do the
3110	* work and call synchronize_rcu() in a work queue.
3111	*
3112	* Note that execmem_alloc() on most architectures creates W+X page
3113	* mappings which won't be cleaned up until do_free_init() runs. Any
3114	* code such as mark_rodata_ro() which depends on those mappings to
3115	* be cleaned up needs to sync with the queued work by invoking
3116	* flush_module_init_free_work().
3117	*/
3118	if (llist_add(&freeinit->node, &init_free_list))
3119	schedule_work(&init_free_wq);
3120
3121	mutex_unlock(&module_mutex);
3122	wake_up_all(&module_wq);
3123
3124	mod_stat_add_long(text_size, &total_text_size);
3125	mod_stat_add_long(total_size, &total_mod_size);
3126
3127	mod_stat_inc(&modcount);
3128
3129	return 0;
3130
3131	fail_free_freeinit:
3132	kfree(freeinit);
3133	fail:
3134	/* Try to protect us from buggy refcounters. */
3135	mod->state = MODULE_STATE_GOING;
3136	synchronize_rcu();
3137	module_put(mod);
3138	blocking_notifier_call_chain(&module_notify_list,
3139	MODULE_STATE_GOING, mod);
3140	klp_module_going(mod);
3141	ftrace_release_mod(mod);
3142	free_module(mod);
3143	wake_up_all(&module_wq);
3144
3145	return ret;
3146	}
3147
3148	static int may_init_module(void)
3149	{
3150	if (!capable(CAP_SYS_MODULE) \|\| modules_disabled)
3151	return -EPERM;
3152
3153	return 0;
3154	}
3155
3156	/* Is this module of this name done loading? No locks held. */
3157	static bool finished_loading(const char *name)
3158	{
3159	struct module *mod;
3160	bool ret;
3161
3162	/*
3163	* The module_mutex should not be a heavily contended lock;
3164	* if we get the occasional sleep here, we'll go an extra iteration
3165	* in the wait_event_interruptible(), which is harmless.
3166	*/
3167	sched_annotate_sleep();
3168	mutex_lock(&module_mutex);
3169	mod = find_module_all(name, strlen(name), true);
3170	ret = !mod \|\| mod->state == MODULE_STATE_LIVE
3171	\|\| mod->state == MODULE_STATE_GOING;
3172	mutex_unlock(&module_mutex);
3173
3174	return ret;
3175	}
3176
3177	/* Must be called with module_mutex held */
3178	static int module_patient_check_exists(const char *name,
3179	enum fail_dup_mod_reason reason)
3180	{
3181	struct module *old;
3182	int err = 0;
3183
3184	old = find_module_all(name, strlen(name), true);
3185	if (old == NULL)
3186	return 0;
3187
3188	if (old->state == MODULE_STATE_COMING \|\|
3189	old->state == MODULE_STATE_UNFORMED) {
3190	/* Wait in case it fails to load. */
3191	mutex_unlock(&module_mutex);
3192	err = wait_event_interruptible(module_wq,
3193	finished_loading(name));
3194	mutex_lock(&module_mutex);
3195	if (err)
3196	return err;
3197
3198	/* The module might have gone in the meantime. */
3199	old = find_module_all(name, strlen(name), true);
3200	}
3201
3202	if (try_add_failed_module(name, reason))
3203	pr_warn("Could not add fail-tracking for module: %s\n", name);
3204
3205	/*
3206	* We are here only when the same module was being loaded. Do
3207	* not try to load it again right now. It prevents long delays
3208	* caused by serialized module load failures. It might happen
3209	* when more devices of the same type trigger load of
3210	* a particular module.
3211	*/
3212	if (old && old->state == MODULE_STATE_LIVE)
3213	return -EEXIST;
3214	return -EBUSY;
3215	}
3216
3217	/*
3218	* We try to place it in the list now to make sure it's unique before
3219	* we dedicate too many resources. In particular, temporary percpu
3220	* memory exhaustion.
3221	*/
3222	static int add_unformed_module(struct module *mod)
3223	{
3224	int err;
3225
3226	mod->state = MODULE_STATE_UNFORMED;
3227
3228	mutex_lock(&module_mutex);
3229	err = module_patient_check_exists(mod->name, FAIL_DUP_MOD_LOAD);
3230	if (err)
3231	goto out;
3232
3233	mod_update_bounds(mod);
3234	list_add_rcu(&mod->list, &modules);
3235	mod_tree_insert(mod);
3236	err = 0;
3237
3238	out:
3239	mutex_unlock(&module_mutex);
3240	return err;
3241	}
3242
3243	static int complete_formation(struct module mod, struct load_info info)
3244	{
3245	int err;
3246
3247	mutex_lock(&module_mutex);
3248
3249	/* Find duplicate symbols (must be called under lock). */
3250	err = verify_exported_symbols(mod);
3251	if (err < 0)
3252	goto out;
3253
3254	/* These rely on module_mutex for list integrity. */
3255	module_bug_finalize(info->hdr, info->sechdrs, mod);
3256	module_cfi_finalize(info->hdr, info->sechdrs, mod);
3257
3258	err = module_enable_rodata_ro(mod);
3259	if (err)
3260	goto out_strict_rwx;
3261	err = module_enable_data_nx(mod);
3262	if (err)
3263	goto out_strict_rwx;
3264	err = module_enable_text_rox(mod);
3265	if (err)
3266	goto out_strict_rwx;
3267
3268	/*
3269	* Mark state as coming so strong_try_module_get() ignores us,
3270	* but kallsyms etc. can see us.
3271	*/
3272	mod->state = MODULE_STATE_COMING;
3273	mutex_unlock(&module_mutex);
3274
3275	return 0;
3276
3277	out_strict_rwx:
3278	module_bug_cleanup(mod);
3279	out:
3280	mutex_unlock(&module_mutex);
3281	return err;
3282	}
3283
3284	static int prepare_coming_module(struct module *mod)
3285	{
3286	int err;
3287
3288	ftrace_module_enable(mod);
3289	err = klp_module_coming(mod);
3290	if (err)
3291	return err;
3292
3293	err = blocking_notifier_call_chain_robust(&module_notify_list,
3294	MODULE_STATE_COMING, MODULE_STATE_GOING, mod);
3295	err = notifier_to_errno(err);
3296	if (err)
3297	klp_module_going(mod);
3298
3299	return err;
3300	}
3301
3302	static int unknown_module_param_cb(char param, char val, const char *modname,
3303	void *arg)
3304	{
3305	struct module *mod = arg;
3306	int ret;
3307
3308	if (strcmp(param, "async_probe") == 0) {
3309	if (kstrtobool(val, &mod->async_probe_requested))
3310	mod->async_probe_requested = true;
3311	return 0;
3312	}
3313
3314	/* Check for magic 'dyndbg' arg */
3315	ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3316	if (ret != 0)
3317	pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3318	return 0;
3319	}
3320
3321	/* Module within temporary copy, this doesn't do any allocation */
3322	static int early_mod_check(struct load_info *info, int flags)
3323	{
3324	int err;
3325
3326	/*
3327	* Now that we know we have the correct module name, check
3328	* if it's blacklisted.
3329	*/
3330	if (blacklisted(info->name)) {
3331	pr_err("Module %s is blacklisted\n", info->name);
3332	return -EPERM;
3333	}
3334
3335	err = rewrite_section_headers(info, flags);
3336	if (err)
3337	return err;
3338
3339	/* Check module struct version now, before we try to use module. */
3340	if (!check_modstruct_version(info, info->mod))
3341	return -ENOEXEC;
3342
3343	err = check_modinfo(info->mod, info, flags);
3344	if (err)
3345	return err;
3346
3347	mutex_lock(&module_mutex);
3348	err = module_patient_check_exists(info->mod->name, FAIL_DUP_MOD_BECOMING);
3349	mutex_unlock(&module_mutex);
3350
3351	return err;
3352	}
3353
3354	/*
3355	* Allocate and load the module: note that size of section 0 is always
3356	* zero, and we rely on this for optional sections.
3357	*/
3358	static int load_module(struct load_info info, const char __user uargs,
3359	int flags)
3360	{
3361	struct module *mod;
3362	bool module_allocated = false;
3363	long err = 0;
3364	char *after_dashes;
3365
3366	/*
3367	* Do the signature check (if any) first. All that
3368	* the signature check needs is info->len, it does
3369	* not need any of the section info. That can be
3370	* set up later. This will minimize the chances
3371	* of a corrupt module causing problems before
3372	* we even get to the signature check.
3373	*
3374	* The check will also adjust info->len by stripping
3375	* off the sig length at the end of the module, making
3376	* checks against info->len more correct.
3377	*/
3378	err = module_sig_check(info, flags);
3379	if (err)
3380	goto free_copy;
3381
3382	/*
3383	* Do basic sanity checks against the ELF header and
3384	* sections. Cache useful sections and set the
3385	* info->mod to the userspace passed struct module.
3386	*/
3387	err = elf_validity_cache_copy(info, flags);
3388	if (err)
3389	goto free_copy;
3390
3391	err = early_mod_check(info, flags);
3392	if (err)
3393	goto free_copy;
3394
3395	/* Figure out module layout, and allocate all the memory. */
3396	mod = layout_and_allocate(info, flags);
3397	if (IS_ERR(mod)) {
3398	err = PTR_ERR(mod);
3399	goto free_copy;
3400	}
3401
3402	module_allocated = true;
3403
3404	audit_log_kern_module(info->name);
3405
3406	/* Reserve our place in the list. */
3407	err = add_unformed_module(mod);
3408	if (err)
3409	goto free_module;
3410
3411	/*
3412	* We are tainting your kernel if your module gets into
3413	* the modules linked list somehow.
3414	*/
3415	module_augment_kernel_taints(mod, info);
3416
3417	/* To avoid stressing percpu allocator, do this once we're unique. */
3418	err = percpu_modalloc(mod, info);
3419	if (err)
3420	goto unlink_mod;
3421
3422	/* Now module is in final location, initialize linked lists, etc. */
3423	err = module_unload_init(mod);
3424	if (err)
3425	goto unlink_mod;
3426
3427	init_param_lock(mod);
3428
3429	/*
3430	* Now we've got everything in the final locations, we can
3431	* find optional sections.
3432	*/
3433	err = find_module_sections(mod, info);
3434	if (err)
3435	goto free_unload;
3436
3437	err = check_export_symbol_versions(mod);
3438	if (err)
3439	goto free_unload;
3440
3441	/* Set up MODINFO_ATTR fields */
3442	err = setup_modinfo(mod, info);
3443	if (err)
3444	goto free_modinfo;
3445
3446	/* Fix up syms, so that st_value is a pointer to location. */
3447	err = simplify_symbols(mod, info);
3448	if (err < 0)
3449	goto free_modinfo;
3450
3451	err = apply_relocations(mod, info);
3452	if (err < 0)
3453	goto free_modinfo;
3454
3455	err = post_relocation(mod, info);
3456	if (err < 0)
3457	goto free_modinfo;
3458
3459	flush_module_icache(mod);
3460
3461	/* Now copy in args */
3462	mod->args = strndup_user(uargs, ~0UL >> 1);
3463	if (IS_ERR(mod->args)) {
3464	err = PTR_ERR(mod->args);
3465	goto free_arch_cleanup;
3466	}
3467
3468	init_build_id(mod, info);
3469
3470	/* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3471	ftrace_module_init(mod);
3472
3473	/* Finally it's fully formed, ready to start executing. */
3474	err = complete_formation(mod, info);
3475	if (err)
3476	goto ddebug_cleanup;
3477
3478	err = prepare_coming_module(mod);
3479	if (err)
3480	goto bug_cleanup;
3481
3482	mod->async_probe_requested = async_probe;
3483
3484	/* Module is ready to execute: parsing args may do that. */
3485	after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3486	-32768, 32767, mod,
3487	unknown_module_param_cb);
3488	if (IS_ERR(after_dashes)) {
3489	err = PTR_ERR(after_dashes);
3490	goto coming_cleanup;
3491	} else if (after_dashes) {
3492	pr_warn("%s: parameters '%s' after `--' ignored\n",
3493	mod->name, after_dashes);
3494	}
3495
3496	/* Link in to sysfs. */
3497	err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3498	if (err < 0)
3499	goto coming_cleanup;
3500
3501	if (is_livepatch_module(mod)) {
3502	err = copy_module_elf(mod, info);
3503	if (err < 0)
3504	goto sysfs_cleanup;
3505	}
3506
3507	if (codetag_load_module(mod))
3508	goto sysfs_cleanup;
3509
3510	/* Get rid of temporary copy. */
3511	free_copy(info, flags);
3512
3513	/* Done! */
3514	trace_module_load(mod);
3515
3516	return do_init_module(mod);
3517
3518	sysfs_cleanup:
3519	mod_sysfs_teardown(mod);
3520	coming_cleanup:
3521	mod->state = MODULE_STATE_GOING;
3522	destroy_params(mod->kp, mod->num_kp);
3523	blocking_notifier_call_chain(&module_notify_list,
3524	MODULE_STATE_GOING, mod);
3525	klp_module_going(mod);
3526	bug_cleanup:
3527	mod->state = MODULE_STATE_GOING;
3528	/* module_bug_cleanup needs module_mutex protection */
3529	mutex_lock(&module_mutex);
3530	module_bug_cleanup(mod);
3531	mutex_unlock(&module_mutex);
3532
3533	ddebug_cleanup:
3534	ftrace_release_mod(mod);
3535	synchronize_rcu();
3536	kfree(mod->args);
3537	free_arch_cleanup:
3538	module_arch_cleanup(mod);
3539	free_modinfo:
3540	free_modinfo(mod);
3541	free_unload:
3542	module_unload_free(mod);
3543	unlink_mod:
3544	mutex_lock(&module_mutex);
3545	/* Unlink carefully: kallsyms could be walking list. */
3546	list_del_rcu(&mod->list);
3547	mod_tree_remove(mod);
3548	wake_up_all(&module_wq);
3549	/* Wait for RCU-sched synchronizing before releasing mod->list. */
3550	synchronize_rcu();
3551	mutex_unlock(&module_mutex);
3552	free_module:
3553	mod_stat_bump_invalid(info, flags);
3554	module_memory_restore_rox(mod);
3555	module_deallocate(mod, info);
3556	free_copy:
3557	/*
3558	* The info->len is always set. We distinguish between
3559	* failures once the proper module was allocated and
3560	* before that.
3561	*/
3562	if (!module_allocated) {
3563	audit_log_kern_module(info->name ? info->name : "?");
3564	mod_stat_bump_becoming(info, flags);
3565	}
3566	free_copy(info, flags);
3567	return err;
3568	}
3569
3570	SYSCALL_DEFINE3(init_module, void __user *, umod,
3571	unsigned long, len, const char __user *, uargs)
3572	{
3573	int err;
3574	struct load_info info = { };
3575
3576	err = may_init_module();
3577	if (err)
3578	return err;
3579
3580	pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3581	umod, len, uargs);
3582
3583	err = copy_module_from_user(umod, len, &info);
3584	if (err) {
3585	mod_stat_inc(&failed_kreads);
3586	mod_stat_add_long(len, &invalid_kread_bytes);
3587	return err;
3588	}
3589
3590	return load_module(&info, uargs, 0);
3591	}
3592
3593	struct idempotent {
3594	const void *cookie;
3595	struct hlist_node entry;
3596	struct completion complete;
3597	int ret;
3598	};
3599
3600	#define IDEM_HASH_BITS 8
3601	static struct hlist_head idem_hash[1 << IDEM_HASH_BITS];
3602	static DEFINE_SPINLOCK(idem_lock);
3603
3604	static bool idempotent(struct idempotent u, const void cookie)
3605	{
3606	int hash = hash_ptr(cookie, IDEM_HASH_BITS);
3607	struct hlist_head *head = idem_hash + hash;
3608	struct idempotent *existing;
3609	bool first;
3610
3611	u->ret = -EINTR;
3612	u->cookie = cookie;
3613	init_completion(&u->complete);
3614
3615	spin_lock(&idem_lock);
3616	first = true;
3617	hlist_for_each_entry(existing, head, entry) {
3618	if (existing->cookie != cookie)
3619	continue;
3620	first = false;
3621	break;
3622	}
3623	hlist_add_head(&u->entry, idem_hash + hash);
3624	spin_unlock(&idem_lock);
3625
3626	return !first;
3627	}
3628
3629	/*
3630	* We were the first one with 'cookie' on the list, and we ended
3631	* up completing the operation. We now need to walk the list,
3632	* remove everybody - which includes ourselves - fill in the return
3633	* value, and then complete the operation.
3634	*/
3635	static int idempotent_complete(struct idempotent *u, int ret)
3636	{
3637	const void *cookie = u->cookie;
3638	int hash = hash_ptr(cookie, IDEM_HASH_BITS);
3639	struct hlist_head *head = idem_hash + hash;
3640	struct hlist_node *next;
3641	struct idempotent *pos;
3642
3643	spin_lock(&idem_lock);
3644	hlist_for_each_entry_safe(pos, next, head, entry) {
3645	if (pos->cookie != cookie)
3646	continue;
3647	hlist_del_init(&pos->entry);
3648	pos->ret = ret;
3649	complete(&pos->complete);
3650	}
3651	spin_unlock(&idem_lock);
3652	return ret;
3653	}
3654
3655	/*
3656	* Wait for the idempotent worker.
3657	*
3658	* If we get interrupted, we need to remove ourselves from the
3659	* the idempotent list, and the completion may still come in.
3660	*
3661	* The 'idem_lock' protects against the race, and 'idem.ret' was
3662	* initialized to -EINTR and is thus always the right return
3663	* value even if the idempotent work then completes between
3664	* the wait_for_completion and the cleanup.
3665	*/
3666	static int idempotent_wait_for_completion(struct idempotent *u)
3667	{
3668	if (wait_for_completion_interruptible(&u->complete)) {
3669	spin_lock(&idem_lock);
3670	if (!hlist_unhashed(&u->entry))
3671	hlist_del(&u->entry);
3672	spin_unlock(&idem_lock);
3673	}
3674	return u->ret;
3675	}
3676
3677	static int init_module_from_file(struct file f, const char __user uargs, int flags)
3678	{
3679	bool compressed = !!(flags & MODULE_INIT_COMPRESSED_FILE);
3680	struct load_info info = { };
3681	void *buf = NULL;
3682	int len;
3683	int err;
3684
3685	len = kernel_read_file(f, 0, &buf, INT_MAX, NULL,
3686	compressed ? READING_MODULE_COMPRESSED :
3687	READING_MODULE);
3688	if (len < 0) {
3689	mod_stat_inc(&failed_kreads);
3690	return len;
3691	}
3692
3693	if (compressed) {
3694	err = module_decompress(&info, buf, len);
3695	vfree(buf); /* compressed data is no longer needed */
3696	if (err) {
3697	mod_stat_inc(&failed_decompress);
3698	mod_stat_add_long(len, &invalid_decompress_bytes);
3699	return err;
3700	}
3701	err = security_kernel_post_read_file(f, (char *)info.hdr, info.len,
3702	READING_MODULE);
3703	if (err) {
3704	mod_stat_inc(&failed_kreads);
3705	free_copy(&info, flags);
3706	return err;
3707	}
3708	} else {
3709	info.hdr = buf;
3710	info.len = len;
3711	}
3712
3713	return load_module(&info, uargs, flags);
3714	}
3715
3716	static int idempotent_init_module(struct file f, const char __user uargs, int flags)
3717	{
3718	struct idempotent idem;
3719
3720	if (!(f->f_mode & FMODE_READ))
3721	return -EBADF;
3722
3723	/* Are we the winners of the race and get to do this? */
3724	if (!idempotent(&idem, file_inode(f))) {
3725	int ret = init_module_from_file(f, uargs, flags);
3726	return idempotent_complete(&idem, ret);
3727	}
3728
3729	/*
3730	* Somebody else won the race and is loading the module.
3731	*/
3732	return idempotent_wait_for_completion(&idem);
3733	}
3734
3735	SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3736	{
3737	int err = may_init_module();
3738	if (err)
3739	return err;
3740
3741	pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3742
3743	if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3744	\|MODULE_INIT_IGNORE_VERMAGIC
3745	\|MODULE_INIT_COMPRESSED_FILE))
3746	return -EINVAL;
3747
3748	CLASS(fd, f)(fd);
3749	if (fd_empty(f))
3750	return -EBADF;
3751	return idempotent_init_module(fd_file(f), uargs, flags);
3752	}
3753
3754	/* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
3755	char module_flags(struct module mod, char *buf, bool show_state)
3756	{
3757	int bx = 0;
3758
3759	BUG_ON(mod->state == MODULE_STATE_UNFORMED);
3760	if (!mod->taints && !show_state)
3761	goto out;
3762	if (mod->taints \|\|
3763	mod->state == MODULE_STATE_GOING \|\|
3764	mod->state == MODULE_STATE_COMING) {
3765	buf[bx++] = '(';
3766	bx += module_flags_taint(mod->taints, buf + bx);
3767	/* Show a - for module-is-being-unloaded */
3768	if (mod->state == MODULE_STATE_GOING && show_state)
3769	buf[bx++] = '-';
3770	/* Show a + for module-is-being-loaded */
3771	if (mod->state == MODULE_STATE_COMING && show_state)
3772	buf[bx++] = '+';
3773	buf[bx++] = ')';
3774	}
3775	out:
3776	buf[bx] = '\0';
3777
3778	return buf;
3779	}
3780
3781	/* Given an address, look for it in the module exception tables. */
3782	const struct exception_table_entry *search_module_extables(unsigned long addr)
3783	{
3784	struct module *mod;
3785
3786	guard(rcu)();
3787	mod = __module_address(addr);
3788	if (!mod)
3789	return NULL;
3790
3791	if (!mod->num_exentries)
3792	return NULL;
3793	/*
3794	* The address passed here belongs to a module that is currently
3795	* invoked (we are running inside it). Therefore its module::refcnt
3796	* needs already be >0 to ensure that it is not removed at this stage.
3797	* All other user need to invoke this function within a RCU read
3798	* section.
3799	*/
3800	return search_extable(mod->extable, mod->num_exentries, addr);
3801	}
3802
3803	/**
3804	* is_module_address() - is this address inside a module?
3805	* @addr: the address to check.
3806	*
3807	* See is_module_text_address() if you simply want to see if the address
3808	* is code (not data).
3809	*/
3810	bool is_module_address(unsigned long addr)
3811	{
3812	guard(rcu)();
3813	return __module_address(addr) != NULL;
3814	}
3815
3816	/**
3817	* __module_address() - get the module which contains an address.
3818	* @addr: the address.
3819	*
3820	* Must be called within RCU read section or module mutex held so that
3821	* module doesn't get freed during this.
3822	*/
3823	struct module *__module_address(unsigned long addr)
3824	{
3825	struct module *mod;
3826
3827	if (addr >= mod_tree.addr_min && addr <= mod_tree.addr_max)
3828	goto lookup;
3829
3830	#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
3831	if (addr >= mod_tree.data_addr_min && addr <= mod_tree.data_addr_max)
3832	goto lookup;
3833	#endif
3834
3835	return NULL;
3836
3837	lookup:
3838	mod = mod_find(addr, &mod_tree);
3839	if (mod) {
3840	BUG_ON(!within_module(addr, mod));
3841	if (mod->state == MODULE_STATE_UNFORMED)
3842	mod = NULL;
3843	}
3844	return mod;
3845	}
3846
3847	/**
3848	* is_module_text_address() - is this address inside module code?
3849	* @addr: the address to check.
3850	*
3851	* See is_module_address() if you simply want to see if the address is
3852	* anywhere in a module. See kernel_text_address() for testing if an
3853	* address corresponds to kernel or module code.
3854	*/
3855	bool is_module_text_address(unsigned long addr)
3856	{
3857	guard(rcu)();
3858	return __module_text_address(addr) != NULL;
3859	}
3860
3861	void module_for_each_mod(int(func)(struct module mod, void data), void data)
3862	{
3863	struct module *mod;
3864
3865	guard(rcu)();
3866	list_for_each_entry_rcu(mod, &modules, list) {
3867	if (mod->state == MODULE_STATE_UNFORMED)
3868	continue;
3869	if (func(mod, data))
3870	break;
3871	}
3872	}
3873
3874	/**
3875	* __module_text_address() - get the module whose code contains an address.
3876	* @addr: the address.
3877	*
3878	* Must be called within RCU read section or module mutex held so that
3879	* module doesn't get freed during this.
3880	*/
3881	struct module *__module_text_address(unsigned long addr)
3882	{
3883	struct module *mod = __module_address(addr);
3884	if (mod) {
3885	/* Make sure it's within the text section. */
3886	if (!within_module_mem_type(addr, mod, MOD_TEXT) &&
3887	!within_module_mem_type(addr, mod, MOD_INIT_TEXT))
3888	mod = NULL;
3889	}
3890	return mod;
3891	}
3892
3893	/* Don't grab lock, we're oopsing. */
3894	void print_modules(void)
3895	{
3896	struct module *mod;
3897	char buf[MODULE_FLAGS_BUF_SIZE];
3898
3899	printk(KERN_DEFAULT "Modules linked in:");
3900	/* Most callers should already have preempt disabled, but make sure */
3901	guard(rcu)();
3902	list_for_each_entry_rcu(mod, &modules, list) {
3903	if (mod->state == MODULE_STATE_UNFORMED)
3904	continue;
3905	pr_cont(" %s%s", mod->name, module_flags(mod, buf, true));
3906	}
3907
3908	print_unloaded_tainted_modules();
3909	if (last_unloaded_module.name[0])
3910	pr_cont(" [last unloaded: %s%s]", last_unloaded_module.name,
3911	last_unloaded_module.taints);
3912	pr_cont("\n");
3913	}
3914
3915	#ifdef CONFIG_MODULE_DEBUGFS
3916	struct dentry *mod_debugfs_root;
3917
3918	static int module_debugfs_init(void)
3919	{
3920	mod_debugfs_root = debugfs_create_dir("modules", NULL);
3921	return 0;
3922	}
3923	module_init(module_debugfs_init);
3924	#endif