linux - kernel/module.c

4825 lines · 121.8 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	*/
6
7	#define INCLUDE_VERMAGIC
8
9	#include <linux/export.h>
10	#include <linux/extable.h>
11	#include <linux/moduleloader.h>
12	#include <linux/module_signature.h>
13	#include <linux/trace_events.h>
14	#include <linux/init.h>
15	#include <linux/kallsyms.h>
16	#include <linux/buildid.h>
17	#include <linux/file.h>
18	#include <linux/fs.h>
19	#include <linux/sysfs.h>
20	#include <linux/kernel.h>
21	#include <linux/kernel_read_file.h>
22	#include <linux/slab.h>
23	#include <linux/vmalloc.h>
24	#include <linux/elf.h>
25	#include <linux/proc_fs.h>
26	#include <linux/security.h>
27	#include <linux/seq_file.h>
28	#include <linux/syscalls.h>
29	#include <linux/fcntl.h>
30	#include <linux/rcupdate.h>
31	#include <linux/capability.h>
32	#include <linux/cpu.h>
33	#include <linux/moduleparam.h>
34	#include <linux/errno.h>
35	#include <linux/err.h>
36	#include <linux/vermagic.h>
37	#include <linux/notifier.h>
38	#include <linux/sched.h>
39	#include <linux/device.h>
40	#include <linux/string.h>
41	#include <linux/mutex.h>
42	#include <linux/rculist.h>
43	#include <linux/uaccess.h>
44	#include <asm/cacheflush.h>
45	#include <linux/set_memory.h>
46	#include <asm/mmu_context.h>
47	#include <linux/license.h>
48	#include <asm/sections.h>
49	#include <linux/tracepoint.h>
50	#include <linux/ftrace.h>
51	#include <linux/livepatch.h>
52	#include <linux/async.h>
53	#include <linux/percpu.h>
54	#include <linux/kmemleak.h>
55	#include <linux/jump_label.h>
56	#include <linux/pfn.h>
57	#include <linux/bsearch.h>
58	#include <linux/dynamic_debug.h>
59	#include <linux/audit.h>
60	#include <uapi/linux/module.h>
61	#include "module-internal.h"
62
63	#define CREATE_TRACE_POINTS
64	#include <trace/events/module.h>
65
66	#ifndef ARCH_SHF_SMALL
67	#define ARCH_SHF_SMALL 0
68	#endif
69
70	/*
71	* Modules' sections will be aligned on page boundaries
72	* to ensure complete separation of code and data, but
73	* only when CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y
74	*/
75	#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
76	# define debug_align(X) ALIGN(X, PAGE_SIZE)
77	#else
78	# define debug_align(X) (X)
79	#endif
80
81	/* If this is set, the section belongs in the init part of the module */
82	#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
83
84	/*
85	* Mutex protects:
86	* 1) List of modules (also safely readable with preempt_disable),
87	* 2) module_use links,
88	* 3) module_addr_min/module_addr_max.
89	* (delete and add uses RCU list operations).
90	*/
91	static DEFINE_MUTEX(module_mutex);
92	static LIST_HEAD(modules);
93
94	/* Work queue for freeing init sections in success case */
95	static void do_free_init(struct work_struct *w);
96	static DECLARE_WORK(init_free_wq, do_free_init);
97	static LLIST_HEAD(init_free_list);
98
99	#ifdef CONFIG_MODULES_TREE_LOOKUP
100
101	/*
102	* Use a latched RB-tree for __module_address(); this allows us to use
103	* RCU-sched lookups of the address from any context.
104	*
105	* This is conditional on PERF_EVENTS \|\| TRACING because those can really hit
106	* __module_address() hard by doing a lot of stack unwinding; potentially from
107	* NMI context.
108	*/
109
110	static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
111	{
112	struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
113
114	return (unsigned long)layout->base;
115	}
116
117	static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
118	{
119	struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
120
121	return (unsigned long)layout->size;
122	}
123
124	static __always_inline bool
125	mod_tree_less(struct latch_tree_node a, struct latch_tree_node b)
126	{
127	return __mod_tree_val(a) < __mod_tree_val(b);
128	}
129
130	static __always_inline int
131	mod_tree_comp(void key, struct latch_tree_node n)
132	{
133	unsigned long val = (unsigned long)key;
134	unsigned long start, end;
135
136	start = __mod_tree_val(n);
137	if (val < start)
138	return -1;
139
140	end = start + __mod_tree_size(n);
141	if (val >= end)
142	return 1;
143
144	return 0;
145	}
146
147	static const struct latch_tree_ops mod_tree_ops = {
148	.less = mod_tree_less,
149	.comp = mod_tree_comp,
150	};
151
152	static struct mod_tree_root {
153	struct latch_tree_root root;
154	unsigned long addr_min;
155	unsigned long addr_max;
156	} mod_tree __cacheline_aligned = {
157	.addr_min = -1UL,
158	};
159
160	#define module_addr_min mod_tree.addr_min
161	#define module_addr_max mod_tree.addr_max
162
163	static noinline void __mod_tree_insert(struct mod_tree_node *node)
164	{
165	latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
166	}
167
168	static void __mod_tree_remove(struct mod_tree_node *node)
169	{
170	latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
171	}
172
173	/*
174	* These modifications: insert, remove_init and remove; are serialized by the
175	* module_mutex.
176	*/
177	static void mod_tree_insert(struct module *mod)
178	{
179	mod->core_layout.mtn.mod = mod;
180	mod->init_layout.mtn.mod = mod;
181
182	__mod_tree_insert(&mod->core_layout.mtn);
183	if (mod->init_layout.size)
184	__mod_tree_insert(&mod->init_layout.mtn);
185	}
186
187	static void mod_tree_remove_init(struct module *mod)
188	{
189	if (mod->init_layout.size)
190	__mod_tree_remove(&mod->init_layout.mtn);
191	}
192
193	static void mod_tree_remove(struct module *mod)
194	{
195	__mod_tree_remove(&mod->core_layout.mtn);
196	mod_tree_remove_init(mod);
197	}
198
199	static struct module *mod_find(unsigned long addr)
200	{
201	struct latch_tree_node *ltn;
202
203	ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
204	if (!ltn)
205	return NULL;
206
207	return container_of(ltn, struct mod_tree_node, node)->mod;
208	}
209
210	#else /* MODULES_TREE_LOOKUP */
211
212	static unsigned long module_addr_min = -1UL, module_addr_max = 0;
213
214	static void mod_tree_insert(struct module *mod) { }
215	static void mod_tree_remove_init(struct module *mod) { }
216	static void mod_tree_remove(struct module *mod) { }
217
218	static struct module *mod_find(unsigned long addr)
219	{
220	struct module *mod;
221
222	list_for_each_entry_rcu(mod, &modules, list,
223	lockdep_is_held(&module_mutex)) {
224	if (within_module(addr, mod))
225	return mod;
226	}
227
228	return NULL;
229	}
230
231	#endif /* MODULES_TREE_LOOKUP */
232
233	/*
234	* Bounds of module text, for speeding up __module_address.
235	* Protected by module_mutex.
236	*/
237	static void __mod_update_bounds(void *base, unsigned int size)
238	{
239	unsigned long min = (unsigned long)base;
240	unsigned long max = min + size;
241
242	if (min < module_addr_min)
243	module_addr_min = min;
244	if (max > module_addr_max)
245	module_addr_max = max;
246	}
247
248	static void mod_update_bounds(struct module *mod)
249	{
250	__mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
251	if (mod->init_layout.size)
252	__mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
253	}
254
255	#ifdef CONFIG_KGDB_KDB
256	struct list_head kdb_modules = &modules; / kdb needs the list of modules */
257	#endif /* CONFIG_KGDB_KDB */
258
259	static void module_assert_mutex_or_preempt(void)
260	{
261	#ifdef CONFIG_LOCKDEP
262	if (unlikely(!debug_locks))
263	return;
264
265	WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
266	!lockdep_is_held(&module_mutex));
267	#endif
268	}
269
270	#ifdef CONFIG_MODULE_SIG
271	static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
272	module_param(sig_enforce, bool_enable_only, 0644);
273
274	void set_module_sig_enforced(void)
275	{
276	sig_enforce = true;
277	}
278	#else
279	#define sig_enforce false
280	#endif
281
282	/*
283	* Export sig_enforce kernel cmdline parameter to allow other subsystems rely
284	* on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
285	*/
286	bool is_module_sig_enforced(void)
287	{
288	return sig_enforce;
289	}
290	EXPORT_SYMBOL(is_module_sig_enforced);
291
292	/* Block module loading/unloading? */
293	int modules_disabled = 0;
294	core_param(nomodule, modules_disabled, bint, 0);
295
296	/* Waiting for a module to finish initializing? */
297	static DECLARE_WAIT_QUEUE_HEAD(module_wq);
298
299	static BLOCKING_NOTIFIER_HEAD(module_notify_list);
300
301	int register_module_notifier(struct notifier_block *nb)
302	{
303	return blocking_notifier_chain_register(&module_notify_list, nb);
304	}
305	EXPORT_SYMBOL(register_module_notifier);
306
307	int unregister_module_notifier(struct notifier_block *nb)
308	{
309	return blocking_notifier_chain_unregister(&module_notify_list, nb);
310	}
311	EXPORT_SYMBOL(unregister_module_notifier);
312
313	/*
314	* We require a truly strong try_module_get(): 0 means success.
315	* Otherwise an error is returned due to ongoing or failed
316	* initialization etc.
317	*/
318	static inline int strong_try_module_get(struct module *mod)
319	{
320	BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
321	if (mod && mod->state == MODULE_STATE_COMING)
322	return -EBUSY;
323	if (try_module_get(mod))
324	return 0;
325	else
326	return -ENOENT;
327	}
328
329	static inline void add_taint_module(struct module *mod, unsigned flag,
330	enum lockdep_ok lockdep_ok)
331	{
332	add_taint(flag, lockdep_ok);
333	set_bit(flag, &mod->taints);
334	}
335
336	/*
337	* A thread that wants to hold a reference to a module only while it
338	* is running can call this to safely exit. nfsd and lockd use this.
339	*/
340	void __noreturn __module_put_and_kthread_exit(struct module *mod, long code)
341	{
342	module_put(mod);
343	kthread_exit(code);
344	}
345	EXPORT_SYMBOL(__module_put_and_kthread_exit);
346
347	/* Find a module section: 0 means not found. */
348	static unsigned int find_sec(const struct load_info info, const char name)
349	{
350	unsigned int i;
351
352	for (i = 1; i < info->hdr->e_shnum; i++) {
353	Elf_Shdr *shdr = &info->sechdrs[i];
354	/* Alloc bit cleared means "ignore it." */
355	if ((shdr->sh_flags & SHF_ALLOC)
356	&& strcmp(info->secstrings + shdr->sh_name, name) == 0)
357	return i;
358	}
359	return 0;
360	}
361
362	/* Find a module section, or NULL. */
363	static void section_addr(const struct load_info info, const char *name)
364	{
365	/* Section 0 has sh_addr 0. */
366	return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
367	}
368
369	/* Find a module section, or NULL. Fill in number of "objects" in section. */
370	static void section_objs(const struct load_info info,
371	const char *name,
372	size_t object_size,
373	unsigned int *num)
374	{
375	unsigned int sec = find_sec(info, name);
376
377	/* Section 0 has sh_addr 0 and sh_size 0. */
378	*num = info->sechdrs[sec].sh_size / object_size;
379	return (void *)info->sechdrs[sec].sh_addr;
380	}
381
382	/* Find a module section: 0 means not found. Ignores SHF_ALLOC flag. */
383	static unsigned int find_any_sec(const struct load_info info, const char name)
384	{
385	unsigned int i;
386
387	for (i = 1; i < info->hdr->e_shnum; i++) {
388	Elf_Shdr *shdr = &info->sechdrs[i];
389	if (strcmp(info->secstrings + shdr->sh_name, name) == 0)
390	return i;
391	}
392	return 0;
393	}
394
395	/*
396	* Find a module section, or NULL. Fill in number of "objects" in section.
397	* Ignores SHF_ALLOC flag.
398	*/
399	static __maybe_unused void any_section_objs(const struct load_info info,
400	const char *name,
401	size_t object_size,
402	unsigned int *num)
403	{
404	unsigned int sec = find_any_sec(info, name);
405
406	/* Section 0 has sh_addr 0 and sh_size 0. */
407	*num = info->sechdrs[sec].sh_size / object_size;
408	return (void *)info->sechdrs[sec].sh_addr;
409	}
410
411	/* Provided by the linker */
412	extern const struct kernel_symbol __start___ksymtab[];
413	extern const struct kernel_symbol __stop___ksymtab[];
414	extern const struct kernel_symbol __start___ksymtab_gpl[];
415	extern const struct kernel_symbol __stop___ksymtab_gpl[];
416	extern const s32 __start___kcrctab[];
417	extern const s32 __start___kcrctab_gpl[];
418
419	#ifndef CONFIG_MODVERSIONS
420	#define symversion(base, idx) NULL
421	#else
422	#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
423	#endif
424
425	struct symsearch {
426	const struct kernel_symbol start, stop;
427	const s32 *crcs;
428	enum mod_license {
429	NOT_GPL_ONLY,
430	GPL_ONLY,
431	} license;
432	};
433
434	struct find_symbol_arg {
435	/* Input */
436	const char *name;
437	bool gplok;
438	bool warn;
439
440	/* Output */
441	struct module *owner;
442	const s32 *crc;
443	const struct kernel_symbol *sym;
444	enum mod_license license;
445	};
446
447	static bool check_exported_symbol(const struct symsearch *syms,
448	struct module *owner,
449	unsigned int symnum, void *data)
450	{
451	struct find_symbol_arg *fsa = data;
452
453	if (!fsa->gplok && syms->license == GPL_ONLY)
454	return false;
455	fsa->owner = owner;
456	fsa->crc = symversion(syms->crcs, symnum);
457	fsa->sym = &syms->start[symnum];
458	fsa->license = syms->license;
459	return true;
460	}
461
462	static unsigned long kernel_symbol_value(const struct kernel_symbol *sym)
463	{
464	#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
465	return (unsigned long)offset_to_ptr(&sym->value_offset);
466	#else
467	return sym->value;
468	#endif
469	}
470
471	static const char kernel_symbol_name(const struct kernel_symbol sym)
472	{
473	#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
474	return offset_to_ptr(&sym->name_offset);
475	#else
476	return sym->name;
477	#endif
478	}
479
480	static const char kernel_symbol_namespace(const struct kernel_symbol sym)
481	{
482	#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
483	if (!sym->namespace_offset)
484	return NULL;
485	return offset_to_ptr(&sym->namespace_offset);
486	#else
487	return sym->namespace;
488	#endif
489	}
490
491	static int cmp_name(const void name, const void sym)
492	{
493	return strcmp(name, kernel_symbol_name(sym));
494	}
495
496	static bool find_exported_symbol_in_section(const struct symsearch *syms,
497	struct module *owner,
498	void *data)
499	{
500	struct find_symbol_arg *fsa = data;
501	struct kernel_symbol *sym;
502
503	sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
504	sizeof(struct kernel_symbol), cmp_name);
505
506	if (sym != NULL && check_exported_symbol(syms, owner,
507	sym - syms->start, data))
508	return true;
509
510	return false;
511	}
512
513	/*
514	* Find an exported symbol and return it, along with, (optional) crc and
515	* (optional) module which owns it. Needs preempt disabled or module_mutex.
516	*/
517	static bool find_symbol(struct find_symbol_arg *fsa)
518	{
519	static const struct symsearch arr[] = {
520	{ __start___ksymtab, __stop___ksymtab, __start___kcrctab,
521	NOT_GPL_ONLY },
522	{ __start___ksymtab_gpl, __stop___ksymtab_gpl,
523	__start___kcrctab_gpl,
524	GPL_ONLY },
525	};
526	struct module *mod;
527	unsigned int i;
528
529	module_assert_mutex_or_preempt();
530
531	for (i = 0; i < ARRAY_SIZE(arr); i++)
532	if (find_exported_symbol_in_section(&arr[i], NULL, fsa))
533	return true;
534
535	list_for_each_entry_rcu(mod, &modules, list,
536	lockdep_is_held(&module_mutex)) {
537	struct symsearch arr[] = {
538	{ mod->syms, mod->syms + mod->num_syms, mod->crcs,
539	NOT_GPL_ONLY },
540	{ mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
541	mod->gpl_crcs,
542	GPL_ONLY },
543	};
544
545	if (mod->state == MODULE_STATE_UNFORMED)
546	continue;
547
548	for (i = 0; i < ARRAY_SIZE(arr); i++)
549	if (find_exported_symbol_in_section(&arr[i], mod, fsa))
550	return true;
551	}
552
553	pr_debug("Failed to find symbol %s\n", fsa->name);
554	return false;
555	}
556
557	/*
558	* Search for module by name: must hold module_mutex (or preempt disabled
559	* for read-only access).
560	*/
561	static struct module find_module_all(const char name, size_t len,
562	bool even_unformed)
563	{
564	struct module *mod;
565
566	module_assert_mutex_or_preempt();
567
568	list_for_each_entry_rcu(mod, &modules, list,
569	lockdep_is_held(&module_mutex)) {
570	if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
571	continue;
572	if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
573	return mod;
574	}
575	return NULL;
576	}
577
578	struct module find_module(const char name)
579	{
580	return find_module_all(name, strlen(name), false);
581	}
582
583	#ifdef CONFIG_SMP
584
585	static inline void __percpu mod_percpu(struct module mod)
586	{
587	return mod->percpu;
588	}
589
590	static int percpu_modalloc(struct module mod, struct load_info info)
591	{
592	Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
593	unsigned long align = pcpusec->sh_addralign;
594
595	if (!pcpusec->sh_size)
596	return 0;
597
598	if (align > PAGE_SIZE) {
599	pr_warn("%s: per-cpu alignment %li > %li\n",
600	mod->name, align, PAGE_SIZE);
601	align = PAGE_SIZE;
602	}
603
604	mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
605	if (!mod->percpu) {
606	pr_warn("%s: Could not allocate %lu bytes percpu data\n",
607	mod->name, (unsigned long)pcpusec->sh_size);
608	return -ENOMEM;
609	}
610	mod->percpu_size = pcpusec->sh_size;
611	return 0;
612	}
613
614	static void percpu_modfree(struct module *mod)
615	{
616	free_percpu(mod->percpu);
617	}
618
619	static unsigned int find_pcpusec(struct load_info *info)
620	{
621	return find_sec(info, ".data..percpu");
622	}
623
624	static void percpu_modcopy(struct module *mod,
625	const void *from, unsigned long size)
626	{
627	int cpu;
628
629	for_each_possible_cpu(cpu)
630	memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
631	}
632
633	bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
634	{
635	struct module *mod;
636	unsigned int cpu;
637
638	preempt_disable();
639
640	list_for_each_entry_rcu(mod, &modules, list) {
641	if (mod->state == MODULE_STATE_UNFORMED)
642	continue;
643	if (!mod->percpu_size)
644	continue;
645	for_each_possible_cpu(cpu) {
646	void *start = per_cpu_ptr(mod->percpu, cpu);
647	void va = (void )addr;
648
649	if (va >= start && va < start + mod->percpu_size) {
650	if (can_addr) {
651	*can_addr = (unsigned long) (va - start);
652	*can_addr += (unsigned long)
653	per_cpu_ptr(mod->percpu,
654	get_boot_cpu_id());
655	}
656	preempt_enable();
657	return true;
658	}
659	}
660	}
661
662	preempt_enable();
663	return false;
664	}
665
666	/**
667	* is_module_percpu_address() - test whether address is from module static percpu
668	* @addr: address to test
669	*
670	* Test whether @addr belongs to module static percpu area.
671	*
672	* Return: %true if @addr is from module static percpu area
673	*/
674	bool is_module_percpu_address(unsigned long addr)
675	{
676	return __is_module_percpu_address(addr, NULL);
677	}
678
679	#else /* ... !CONFIG_SMP */
680
681	static inline void __percpu mod_percpu(struct module mod)
682	{
683	return NULL;
684	}
685	static int percpu_modalloc(struct module mod, struct load_info info)
686	{
687	/* UP modules shouldn't have this section: ENOMEM isn't quite right */
688	if (info->sechdrs[info->index.pcpu].sh_size != 0)
689	return -ENOMEM;
690	return 0;
691	}
692	static inline void percpu_modfree(struct module *mod)
693	{
694	}
695	static unsigned int find_pcpusec(struct load_info *info)
696	{
697	return 0;
698	}
699	static inline void percpu_modcopy(struct module *mod,
700	const void *from, unsigned long size)
701	{
702	/* pcpusec should be 0, and size of that section should be 0. */
703	BUG_ON(size != 0);
704	}
705	bool is_module_percpu_address(unsigned long addr)
706	{
707	return false;
708	}
709
710	bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
711	{
712	return false;
713	}
714
715	#endif /* CONFIG_SMP */
716
717	#define MODINFO_ATTR(field) \
718	static void setup_modinfo_##field(struct module mod, const char s) \
719	{ \
720	mod->field = kstrdup(s, GFP_KERNEL); \
721	} \
722	static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
723	struct module_kobject mk, char buffer) \
724	{ \
725	return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
726	} \
727	static int modinfo_##field##_exists(struct module *mod) \
728	{ \
729	return mod->field != NULL; \
730	} \
731	static void free_modinfo_##field(struct module *mod) \
732	{ \
733	kfree(mod->field); \
734	mod->field = NULL; \
735	} \
736	static struct module_attribute modinfo_##field = { \
737	.attr = { .name = __stringify(field), .mode = 0444 }, \
738	.show = show_modinfo_##field, \
739	.setup = setup_modinfo_##field, \
740	.test = modinfo_##field##_exists, \
741	.free = free_modinfo_##field, \
742	};
743
744	MODINFO_ATTR(version);
745	MODINFO_ATTR(srcversion);
746
747	static char last_unloaded_module[MODULE_NAME_LEN+1];
748
749	#ifdef CONFIG_MODULE_UNLOAD
750
751	EXPORT_TRACEPOINT_SYMBOL(module_get);
752
753	/* MODULE_REF_BASE is the base reference count by kmodule loader. */
754	#define MODULE_REF_BASE 1
755
756	/* Init the unload section of the module. */
757	static int module_unload_init(struct module *mod)
758	{
759	/*
760	* Initialize reference counter to MODULE_REF_BASE.
761	* refcnt == 0 means module is going.
762	*/
763	atomic_set(&mod->refcnt, MODULE_REF_BASE);
764
765	INIT_LIST_HEAD(&mod->source_list);
766	INIT_LIST_HEAD(&mod->target_list);
767
768	/* Hold reference count during initialization. */
769	atomic_inc(&mod->refcnt);
770
771	return 0;
772	}
773
774	/* Does a already use b? */
775	static int already_uses(struct module a, struct module b)
776	{
777	struct module_use *use;
778
779	list_for_each_entry(use, &b->source_list, source_list) {
780	if (use->source == a) {
781	pr_debug("%s uses %s!\n", a->name, b->name);
782	return 1;
783	}
784	}
785	pr_debug("%s does not use %s!\n", a->name, b->name);
786	return 0;
787	}
788
789	/*
790	* Module a uses b
791	* - we add 'a' as a "source", 'b' as a "target" of module use
792	* - the module_use is added to the list of 'b' sources (so
793	* 'b' can walk the list to see who sourced them), and of 'a'
794	* targets (so 'a' can see what modules it targets).
795	*/
796	static int add_module_usage(struct module a, struct module b)
797	{
798	struct module_use *use;
799
800	pr_debug("Allocating new usage for %s.\n", a->name);
801	use = kmalloc(sizeof(*use), GFP_ATOMIC);
802	if (!use)
803	return -ENOMEM;
804
805	use->source = a;
806	use->target = b;
807	list_add(&use->source_list, &b->source_list);
808	list_add(&use->target_list, &a->target_list);
809	return 0;
810	}
811
812	/* Module a uses b: caller needs module_mutex() */
813	static int ref_module(struct module a, struct module b)
814	{
815	int err;
816
817	if (b == NULL \|\| already_uses(a, b))
818	return 0;
819
820	/* If module isn't available, we fail. */
821	err = strong_try_module_get(b);
822	if (err)
823	return err;
824
825	err = add_module_usage(a, b);
826	if (err) {
827	module_put(b);
828	return err;
829	}
830	return 0;
831	}
832
833	/* Clear the unload stuff of the module. */
834	static void module_unload_free(struct module *mod)
835	{
836	struct module_use use, tmp;
837
838	mutex_lock(&module_mutex);
839	list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
840	struct module *i = use->target;
841	pr_debug("%s unusing %s\n", mod->name, i->name);
842	module_put(i);
843	list_del(&use->source_list);
844	list_del(&use->target_list);
845	kfree(use);
846	}
847	mutex_unlock(&module_mutex);
848	}
849
850	#ifdef CONFIG_MODULE_FORCE_UNLOAD
851	static inline int try_force_unload(unsigned int flags)
852	{
853	int ret = (flags & O_TRUNC);
854	if (ret)
855	add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
856	return ret;
857	}
858	#else
859	static inline int try_force_unload(unsigned int flags)
860	{
861	return 0;
862	}
863	#endif /* CONFIG_MODULE_FORCE_UNLOAD */
864
865	/* Try to release refcount of module, 0 means success. */
866	static int try_release_module_ref(struct module *mod)
867	{
868	int ret;
869
870	/* Try to decrement refcnt which we set at loading */
871	ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
872	BUG_ON(ret < 0);
873	if (ret)
874	/* Someone can put this right now, recover with checking */
875	ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
876
877	return ret;
878	}
879
880	static int try_stop_module(struct module mod, int flags, int forced)
881	{
882	/* If it's not unused, quit unless we're forcing. */
883	if (try_release_module_ref(mod) != 0) {
884	*forced = try_force_unload(flags);
885	if (!(*forced))
886	return -EWOULDBLOCK;
887	}
888
889	/* Mark it as dying. */
890	mod->state = MODULE_STATE_GOING;
891
892	return 0;
893	}
894
895	/**
896	* module_refcount() - return the refcount or -1 if unloading
897	* @mod: the module we're checking
898	*
899	* Return:
900	* -1 if the module is in the process of unloading
901	* otherwise the number of references in the kernel to the module
902	*/
903	int module_refcount(struct module *mod)
904	{
905	return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
906	}
907	EXPORT_SYMBOL(module_refcount);
908
909	/* This exists whether we can unload or not */
910	static void free_module(struct module *mod);
911
912	SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
913	unsigned int, flags)
914	{
915	struct module *mod;
916	char name[MODULE_NAME_LEN];
917	int ret, forced = 0;
918
919	if (!capable(CAP_SYS_MODULE) \|\| modules_disabled)
920	return -EPERM;
921
922	if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
923	return -EFAULT;
924	name[MODULE_NAME_LEN-1] = '\0';
925
926	audit_log_kern_module(name);
927
928	if (mutex_lock_interruptible(&module_mutex) != 0)
929	return -EINTR;
930
931	mod = find_module(name);
932	if (!mod) {
933	ret = -ENOENT;
934	goto out;
935	}
936
937	if (!list_empty(&mod->source_list)) {
938	/* Other modules depend on us: get rid of them first. */
939	ret = -EWOULDBLOCK;
940	goto out;
941	}
942
943	/* Doing init or already dying? */
944	if (mod->state != MODULE_STATE_LIVE) {
945	/* FIXME: if (force), slam module count damn the torpedoes */
946	pr_debug("%s already dying\n", mod->name);
947	ret = -EBUSY;
948	goto out;
949	}
950
951	/* If it has an init func, it must have an exit func to unload */
952	if (mod->init && !mod->exit) {
953	forced = try_force_unload(flags);
954	if (!forced) {
955	/* This module can't be removed */
956	ret = -EBUSY;
957	goto out;
958	}
959	}
960
961	ret = try_stop_module(mod, flags, &forced);
962	if (ret != 0)
963	goto out;
964
965	mutex_unlock(&module_mutex);
966	/* Final destruction now no one is using it. */
967	if (mod->exit != NULL)
968	mod->exit();
969	blocking_notifier_call_chain(&module_notify_list,
970	MODULE_STATE_GOING, mod);
971	klp_module_going(mod);
972	ftrace_release_mod(mod);
973
974	async_synchronize_full();
975
976	/* Store the name of the last unloaded module for diagnostic purposes */
977	strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
978
979	free_module(mod);
980	/* someone could wait for the module in add_unformed_module() */
981	wake_up_all(&module_wq);
982	return 0;
983	out:
984	mutex_unlock(&module_mutex);
985	return ret;
986	}
987
988	static inline void print_unload_info(struct seq_file m, struct module mod)
989	{
990	struct module_use *use;
991	int printed_something = 0;
992
993	seq_printf(m, " %i ", module_refcount(mod));
994
995	/*
996	* Always include a trailing , so userspace can differentiate
997	* between this and the old multi-field proc format.
998	*/
999	list_for_each_entry(use, &mod->source_list, source_list) {
1000	printed_something = 1;
1001	seq_printf(m, "%s,", use->source->name);
1002	}
1003
1004	if (mod->init != NULL && mod->exit == NULL) {
1005	printed_something = 1;
1006	seq_puts(m, "[permanent],");
1007	}
1008
1009	if (!printed_something)
1010	seq_puts(m, "-");
1011	}
1012
1013	void __symbol_put(const char *symbol)
1014	{
1015	struct find_symbol_arg fsa = {
1016	.name = symbol,
1017	.gplok = true,
1018	};
1019
1020	preempt_disable();
1021	BUG_ON(!find_symbol(&fsa));
1022	module_put(fsa.owner);
1023	preempt_enable();
1024	}
1025	EXPORT_SYMBOL(__symbol_put);
1026
1027	/* Note this assumes addr is a function, which it currently always is. */
1028	void symbol_put_addr(void *addr)
1029	{
1030	struct module *modaddr;
1031	unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1032
1033	if (core_kernel_text(a))
1034	return;
1035
1036	/*
1037	* Even though we hold a reference on the module; we still need to
1038	* disable preemption in order to safely traverse the data structure.
1039	*/
1040	preempt_disable();
1041	modaddr = __module_text_address(a);
1042	BUG_ON(!modaddr);
1043	module_put(modaddr);
1044	preempt_enable();
1045	}
1046	EXPORT_SYMBOL_GPL(symbol_put_addr);
1047
1048	static ssize_t show_refcnt(struct module_attribute *mattr,
1049	struct module_kobject mk, char buffer)
1050	{
1051	return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1052	}
1053
1054	static struct module_attribute modinfo_refcnt =
1055	__ATTR(refcnt, 0444, show_refcnt, NULL);
1056
1057	void __module_get(struct module *module)
1058	{
1059	if (module) {
1060	preempt_disable();
1061	atomic_inc(&module->refcnt);
1062	trace_module_get(module, _RET_IP_);
1063	preempt_enable();
1064	}
1065	}
1066	EXPORT_SYMBOL(__module_get);
1067
1068	bool try_module_get(struct module *module)
1069	{
1070	bool ret = true;
1071
1072	if (module) {
1073	preempt_disable();
1074	/* Note: here, we can fail to get a reference */
1075	if (likely(module_is_live(module) &&
1076	atomic_inc_not_zero(&module->refcnt) != 0))
1077	trace_module_get(module, _RET_IP_);
1078	else
1079	ret = false;
1080
1081	preempt_enable();
1082	}
1083	return ret;
1084	}
1085	EXPORT_SYMBOL(try_module_get);
1086
1087	void module_put(struct module *module)
1088	{
1089	int ret;
1090
1091	if (module) {
1092	preempt_disable();
1093	ret = atomic_dec_if_positive(&module->refcnt);
1094	WARN_ON(ret < 0); /* Failed to put refcount */
1095	trace_module_put(module, _RET_IP_);
1096	preempt_enable();
1097	}
1098	}
1099	EXPORT_SYMBOL(module_put);
1100
1101	#else /* !CONFIG_MODULE_UNLOAD */
1102	static inline void print_unload_info(struct seq_file m, struct module mod)
1103	{
1104	/* We don't know the usage count, or what modules are using. */
1105	seq_puts(m, " - -");
1106	}
1107
1108	static inline void module_unload_free(struct module *mod)
1109	{
1110	}
1111
1112	static int ref_module(struct module a, struct module b)
1113	{
1114	return strong_try_module_get(b);
1115	}
1116
1117	static inline int module_unload_init(struct module *mod)
1118	{
1119	return 0;
1120	}
1121	#endif /* CONFIG_MODULE_UNLOAD */
1122
1123	static size_t module_flags_taint(struct module mod, char buf)
1124	{
1125	size_t l = 0;
1126	int i;
1127
1128	for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
1129	if (taint_flags[i].module && test_bit(i, &mod->taints))
1130	buf[l++] = taint_flags[i].c_true;
1131	}
1132
1133	return l;
1134	}
1135
1136	static ssize_t show_initstate(struct module_attribute *mattr,
1137	struct module_kobject mk, char buffer)
1138	{
1139	const char *state = "unknown";
1140
1141	switch (mk->mod->state) {
1142	case MODULE_STATE_LIVE:
1143	state = "live";
1144	break;
1145	case MODULE_STATE_COMING:
1146	state = "coming";
1147	break;
1148	case MODULE_STATE_GOING:
1149	state = "going";
1150	break;
1151	default:
1152	BUG();
1153	}
1154	return sprintf(buffer, "%s\n", state);
1155	}
1156
1157	static struct module_attribute modinfo_initstate =
1158	__ATTR(initstate, 0444, show_initstate, NULL);
1159
1160	static ssize_t store_uevent(struct module_attribute *mattr,
1161	struct module_kobject *mk,
1162	const char *buffer, size_t count)
1163	{
1164	int rc;
1165
1166	rc = kobject_synth_uevent(&mk->kobj, buffer, count);
1167	return rc ? rc : count;
1168	}
1169
1170	struct module_attribute module_uevent =
1171	__ATTR(uevent, 0200, NULL, store_uevent);
1172
1173	static ssize_t show_coresize(struct module_attribute *mattr,
1174	struct module_kobject mk, char buffer)
1175	{
1176	return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1177	}
1178
1179	static struct module_attribute modinfo_coresize =
1180	__ATTR(coresize, 0444, show_coresize, NULL);
1181
1182	static ssize_t show_initsize(struct module_attribute *mattr,
1183	struct module_kobject mk, char buffer)
1184	{
1185	return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1186	}
1187
1188	static struct module_attribute modinfo_initsize =
1189	__ATTR(initsize, 0444, show_initsize, NULL);
1190
1191	static ssize_t show_taint(struct module_attribute *mattr,
1192	struct module_kobject mk, char buffer)
1193	{
1194	size_t l;
1195
1196	l = module_flags_taint(mk->mod, buffer);
1197	buffer[l++] = '\n';
1198	return l;
1199	}
1200
1201	static struct module_attribute modinfo_taint =
1202	__ATTR(taint, 0444, show_taint, NULL);
1203
1204	static struct module_attribute *modinfo_attrs[] = {
1205	&module_uevent,
1206	&modinfo_version,
1207	&modinfo_srcversion,
1208	&modinfo_initstate,
1209	&modinfo_coresize,
1210	&modinfo_initsize,
1211	&modinfo_taint,
1212	#ifdef CONFIG_MODULE_UNLOAD
1213	&modinfo_refcnt,
1214	#endif
1215	NULL,
1216	};
1217
1218	static const char vermagic[] = VERMAGIC_STRING;
1219
1220	static int try_to_force_load(struct module mod, const char reason)
1221	{
1222	#ifdef CONFIG_MODULE_FORCE_LOAD
1223	if (!test_taint(TAINT_FORCED_MODULE))
1224	pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1225	add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1226	return 0;
1227	#else
1228	return -ENOEXEC;
1229	#endif
1230	}
1231
1232	#ifdef CONFIG_MODVERSIONS
1233
1234	static u32 resolve_rel_crc(const s32 *crc)
1235	{
1236	return (u32 )((void )crc + crc);
1237	}
1238
1239	static int check_version(const struct load_info *info,
1240	const char *symname,
1241	struct module *mod,
1242	const s32 *crc)
1243	{
1244	Elf_Shdr *sechdrs = info->sechdrs;
1245	unsigned int versindex = info->index.vers;
1246	unsigned int i, num_versions;
1247	struct modversion_info *versions;
1248
1249	/* Exporting module didn't supply crcs? OK, we're already tainted. */
1250	if (!crc)
1251	return 1;
1252
1253	/* No versions at all? modprobe --force does this. */
1254	if (versindex == 0)
1255	return try_to_force_load(mod, symname) == 0;
1256
1257	versions = (void *) sechdrs[versindex].sh_addr;
1258	num_versions = sechdrs[versindex].sh_size
1259	/ sizeof(struct modversion_info);
1260
1261	for (i = 0; i < num_versions; i++) {
1262	u32 crcval;
1263
1264	if (strcmp(versions[i].name, symname) != 0)
1265	continue;
1266
1267	if (IS_ENABLED(CONFIG_MODULE_REL_CRCS))
1268	crcval = resolve_rel_crc(crc);
1269	else
1270	crcval = *crc;
1271	if (versions[i].crc == crcval)
1272	return 1;
1273	pr_debug("Found checksum %X vs module %lX\n",
1274	crcval, versions[i].crc);
1275	goto bad_version;
1276	}
1277
1278	/* Broken toolchain. Warn once, then let it go.. */
1279	pr_warn_once("%s: no symbol version for %s\n", info->name, symname);
1280	return 1;
1281
1282	bad_version:
1283	pr_warn("%s: disagrees about version of symbol %s\n",
1284	info->name, symname);
1285	return 0;
1286	}
1287
1288	static inline int check_modstruct_version(const struct load_info *info,
1289	struct module *mod)
1290	{
1291	struct find_symbol_arg fsa = {
1292	.name = "module_layout",
1293	.gplok = true,
1294	};
1295
1296	/*
1297	* Since this should be found in kernel (which can't be removed), no
1298	* locking is necessary -- use preempt_disable() to placate lockdep.
1299	*/
1300	preempt_disable();
1301	if (!find_symbol(&fsa)) {
1302	preempt_enable();
1303	BUG();
1304	}
1305	preempt_enable();
1306	return check_version(info, "module_layout", mod, fsa.crc);
1307	}
1308
1309	/* First part is kernel version, which we ignore if module has crcs. */
1310	static inline int same_magic(const char amagic, const char bmagic,
1311	bool has_crcs)
1312	{
1313	if (has_crcs) {
1314	amagic += strcspn(amagic, " ");
1315	bmagic += strcspn(bmagic, " ");
1316	}
1317	return strcmp(amagic, bmagic) == 0;
1318	}
1319	#else
1320	static inline int check_version(const struct load_info *info,
1321	const char *symname,
1322	struct module *mod,
1323	const s32 *crc)
1324	{
1325	return 1;
1326	}
1327
1328	static inline int check_modstruct_version(const struct load_info *info,
1329	struct module *mod)
1330	{
1331	return 1;
1332	}
1333
1334	static inline int same_magic(const char amagic, const char bmagic,
1335	bool has_crcs)
1336	{
1337	return strcmp(amagic, bmagic) == 0;
1338	}
1339	#endif /* CONFIG_MODVERSIONS */
1340
1341	static char get_modinfo(const struct load_info info, const char *tag);
1342	static char get_next_modinfo(const struct load_info info, const char *tag,
1343	char *prev);
1344
1345	static int verify_namespace_is_imported(const struct load_info *info,
1346	const struct kernel_symbol *sym,
1347	struct module *mod)
1348	{
1349	const char *namespace;
1350	char *imported_namespace;
1351
1352	namespace = kernel_symbol_namespace(sym);
1353	if (namespace && namespace[0]) {
1354	imported_namespace = get_modinfo(info, "import_ns");
1355	while (imported_namespace) {
1356	if (strcmp(namespace, imported_namespace) == 0)
1357	return 0;
1358	imported_namespace = get_next_modinfo(
1359	info, "import_ns", imported_namespace);
1360	}
1361	#ifdef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1362	pr_warn(
1363	#else
1364	pr_err(
1365	#endif
1366	"%s: module uses symbol (%s) from namespace %s, but does not import it.\n",
1367	mod->name, kernel_symbol_name(sym), namespace);
1368	#ifndef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1369	return -EINVAL;
1370	#endif
1371	}
1372	return 0;
1373	}
1374
1375	static bool inherit_taint(struct module mod, struct module owner)
1376	{
1377	if (!owner \|\| !test_bit(TAINT_PROPRIETARY_MODULE, &owner->taints))
1378	return true;
1379
1380	if (mod->using_gplonly_symbols) {
1381	pr_err("%s: module using GPL-only symbols uses symbols from proprietary module %s.\n",
1382	mod->name, owner->name);
1383	return false;
1384	}
1385
1386	if (!test_bit(TAINT_PROPRIETARY_MODULE, &mod->taints)) {
1387	pr_warn("%s: module uses symbols from proprietary module %s, inheriting taint.\n",
1388	mod->name, owner->name);
1389	set_bit(TAINT_PROPRIETARY_MODULE, &mod->taints);
1390	}
1391	return true;
1392	}
1393
1394	/* Resolve a symbol for this module. I.e. if we find one, record usage. */
1395	static const struct kernel_symbol resolve_symbol(struct module mod,
1396	const struct load_info *info,
1397	const char *name,
1398	char ownername[])
1399	{
1400	struct find_symbol_arg fsa = {
1401	.name = name,
1402	.gplok = !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)),
1403	.warn = true,
1404	};
1405	int err;
1406
1407	/*
1408	* The module_mutex should not be a heavily contended lock;
1409	* if we get the occasional sleep here, we'll go an extra iteration
1410	* in the wait_event_interruptible(), which is harmless.
1411	*/
1412	sched_annotate_sleep();
1413	mutex_lock(&module_mutex);
1414	if (!find_symbol(&fsa))
1415	goto unlock;
1416
1417	if (fsa.license == GPL_ONLY)
1418	mod->using_gplonly_symbols = true;
1419
1420	if (!inherit_taint(mod, fsa.owner)) {
1421	fsa.sym = NULL;
1422	goto getname;
1423	}
1424
1425	if (!check_version(info, name, mod, fsa.crc)) {
1426	fsa.sym = ERR_PTR(-EINVAL);
1427	goto getname;
1428	}
1429
1430	err = verify_namespace_is_imported(info, fsa.sym, mod);
1431	if (err) {
1432	fsa.sym = ERR_PTR(err);
1433	goto getname;
1434	}
1435
1436	err = ref_module(mod, fsa.owner);
1437	if (err) {
1438	fsa.sym = ERR_PTR(err);
1439	goto getname;
1440	}
1441
1442	getname:
1443	/* We must make copy under the lock if we failed to get ref. */
1444	strncpy(ownername, module_name(fsa.owner), MODULE_NAME_LEN);
1445	unlock:
1446	mutex_unlock(&module_mutex);
1447	return fsa.sym;
1448	}
1449
1450	static const struct kernel_symbol *
1451	resolve_symbol_wait(struct module *mod,
1452	const struct load_info *info,
1453	const char *name)
1454	{
1455	const struct kernel_symbol *ksym;
1456	char owner[MODULE_NAME_LEN];
1457
1458	if (wait_event_interruptible_timeout(module_wq,
1459	!IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1460	\|\| PTR_ERR(ksym) != -EBUSY,
1461	30 * HZ) <= 0) {
1462	pr_warn("%s: gave up waiting for init of module %s.\n",
1463	mod->name, owner);
1464	}
1465	return ksym;
1466	}
1467
1468	#ifdef CONFIG_KALLSYMS
1469	static inline bool sect_empty(const Elf_Shdr *sect)
1470	{
1471	return !(sect->sh_flags & SHF_ALLOC) \|\| sect->sh_size == 0;
1472	}
1473	#endif
1474
1475	/*
1476	* /sys/module/foo/sections stuff
1477	* J. Corbet <[email protected]>
1478	*/
1479	#ifdef CONFIG_SYSFS
1480
1481	#ifdef CONFIG_KALLSYMS
1482	struct module_sect_attr {
1483	struct bin_attribute battr;
1484	unsigned long address;
1485	};
1486
1487	struct module_sect_attrs {
1488	struct attribute_group grp;
1489	unsigned int nsections;
1490	struct module_sect_attr attrs[];
1491	};
1492
1493	#define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4))
1494	static ssize_t module_sect_read(struct file file, struct kobject kobj,
1495	struct bin_attribute *battr,
1496	char *buf, loff_t pos, size_t count)
1497	{
1498	struct module_sect_attr *sattr =
1499	container_of(battr, struct module_sect_attr, battr);
1500	char bounce[MODULE_SECT_READ_SIZE + 1];
1501	size_t wrote;
1502
1503	if (pos != 0)
1504	return -EINVAL;
1505
1506	/*
1507	* Since we're a binary read handler, we must account for the
1508	* trailing NUL byte that sprintf will write: if "buf" is
1509	* too small to hold the NUL, or the NUL is exactly the last
1510	* byte, the read will look like it got truncated by one byte.
1511	* Since there is no way to ask sprintf nicely to not write
1512	* the NUL, we have to use a bounce buffer.
1513	*/
1514	wrote = scnprintf(bounce, sizeof(bounce), "0x%px\n",
1515	kallsyms_show_value(file->f_cred)
1516	? (void *)sattr->address : NULL);
1517	count = min(count, wrote);
1518	memcpy(buf, bounce, count);
1519
1520	return count;
1521	}
1522
1523	static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1524	{
1525	unsigned int section;
1526
1527	for (section = 0; section < sect_attrs->nsections; section++)
1528	kfree(sect_attrs->attrs[section].battr.attr.name);
1529	kfree(sect_attrs);
1530	}
1531
1532	static void add_sect_attrs(struct module mod, const struct load_info info)
1533	{
1534	unsigned int nloaded = 0, i, size[2];
1535	struct module_sect_attrs *sect_attrs;
1536	struct module_sect_attr *sattr;
1537	struct bin_attribute **gattr;
1538
1539	/* Count loaded sections and allocate structures */
1540	for (i = 0; i < info->hdr->e_shnum; i++)
1541	if (!sect_empty(&info->sechdrs[i]))
1542	nloaded++;
1543	size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded),
1544	sizeof(sect_attrs->grp.bin_attrs[0]));
1545	size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.bin_attrs[0]);
1546	sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1547	if (sect_attrs == NULL)
1548	return;
1549
1550	/* Setup section attributes. */
1551	sect_attrs->grp.name = "sections";
1552	sect_attrs->grp.bin_attrs = (void *)sect_attrs + size[0];
1553
1554	sect_attrs->nsections = 0;
1555	sattr = &sect_attrs->attrs[0];
1556	gattr = &sect_attrs->grp.bin_attrs[0];
1557	for (i = 0; i < info->hdr->e_shnum; i++) {
1558	Elf_Shdr *sec = &info->sechdrs[i];
1559	if (sect_empty(sec))
1560	continue;
1561	sysfs_bin_attr_init(&sattr->battr);
1562	sattr->address = sec->sh_addr;
1563	sattr->battr.attr.name =
1564	kstrdup(info->secstrings + sec->sh_name, GFP_KERNEL);
1565	if (sattr->battr.attr.name == NULL)
1566	goto out;
1567	sect_attrs->nsections++;
1568	sattr->battr.read = module_sect_read;
1569	sattr->battr.size = MODULE_SECT_READ_SIZE;
1570	sattr->battr.attr.mode = 0400;
1571	*(gattr++) = &(sattr++)->battr;
1572	}
1573	*gattr = NULL;
1574
1575	if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1576	goto out;
1577
1578	mod->sect_attrs = sect_attrs;
1579	return;
1580	out:
1581	free_sect_attrs(sect_attrs);
1582	}
1583
1584	static void remove_sect_attrs(struct module *mod)
1585	{
1586	if (mod->sect_attrs) {
1587	sysfs_remove_group(&mod->mkobj.kobj,
1588	&mod->sect_attrs->grp);
1589	/*
1590	* We are positive that no one is using any sect attrs
1591	* at this point. Deallocate immediately.
1592	*/
1593	free_sect_attrs(mod->sect_attrs);
1594	mod->sect_attrs = NULL;
1595	}
1596	}
1597
1598	/*
1599	* /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1600	*/
1601
1602	struct module_notes_attrs {
1603	struct kobject *dir;
1604	unsigned int notes;
1605	struct bin_attribute attrs[];
1606	};
1607
1608	static ssize_t module_notes_read(struct file filp, struct kobject kobj,
1609	struct bin_attribute *bin_attr,
1610	char *buf, loff_t pos, size_t count)
1611	{
1612	/*
1613	* The caller checked the pos and count against our size.
1614	*/
1615	memcpy(buf, bin_attr->private + pos, count);
1616	return count;
1617	}
1618
1619	static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1620	unsigned int i)
1621	{
1622	if (notes_attrs->dir) {
1623	while (i-- > 0)
1624	sysfs_remove_bin_file(notes_attrs->dir,
1625	&notes_attrs->attrs[i]);
1626	kobject_put(notes_attrs->dir);
1627	}
1628	kfree(notes_attrs);
1629	}
1630
1631	static void add_notes_attrs(struct module mod, const struct load_info info)
1632	{
1633	unsigned int notes, loaded, i;
1634	struct module_notes_attrs *notes_attrs;
1635	struct bin_attribute *nattr;
1636
1637	/* failed to create section attributes, so can't create notes */
1638	if (!mod->sect_attrs)
1639	return;
1640
1641	/* Count notes sections and allocate structures. */
1642	notes = 0;
1643	for (i = 0; i < info->hdr->e_shnum; i++)
1644	if (!sect_empty(&info->sechdrs[i]) &&
1645	(info->sechdrs[i].sh_type == SHT_NOTE))
1646	++notes;
1647
1648	if (notes == 0)
1649	return;
1650
1651	notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes),
1652	GFP_KERNEL);
1653	if (notes_attrs == NULL)
1654	return;
1655
1656	notes_attrs->notes = notes;
1657	nattr = &notes_attrs->attrs[0];
1658	for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1659	if (sect_empty(&info->sechdrs[i]))
1660	continue;
1661	if (info->sechdrs[i].sh_type == SHT_NOTE) {
1662	sysfs_bin_attr_init(nattr);
1663	nattr->attr.name = mod->sect_attrs->attrs[loaded].battr.attr.name;
1664	nattr->attr.mode = S_IRUGO;
1665	nattr->size = info->sechdrs[i].sh_size;
1666	nattr->private = (void *) info->sechdrs[i].sh_addr;
1667	nattr->read = module_notes_read;
1668	++nattr;
1669	}
1670	++loaded;
1671	}
1672
1673	notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1674	if (!notes_attrs->dir)
1675	goto out;
1676
1677	for (i = 0; i < notes; ++i)
1678	if (sysfs_create_bin_file(notes_attrs->dir,
1679	&notes_attrs->attrs[i]))
1680	goto out;
1681
1682	mod->notes_attrs = notes_attrs;
1683	return;
1684
1685	out:
1686	free_notes_attrs(notes_attrs, i);
1687	}
1688
1689	static void remove_notes_attrs(struct module *mod)
1690	{
1691	if (mod->notes_attrs)
1692	free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1693	}
1694
1695	#else
1696
1697	static inline void add_sect_attrs(struct module *mod,
1698	const struct load_info *info)
1699	{
1700	}
1701
1702	static inline void remove_sect_attrs(struct module *mod)
1703	{
1704	}
1705
1706	static inline void add_notes_attrs(struct module *mod,
1707	const struct load_info *info)
1708	{
1709	}
1710
1711	static inline void remove_notes_attrs(struct module *mod)
1712	{
1713	}
1714	#endif /* CONFIG_KALLSYMS */
1715
1716	static void del_usage_links(struct module *mod)
1717	{
1718	#ifdef CONFIG_MODULE_UNLOAD
1719	struct module_use *use;
1720
1721	mutex_lock(&module_mutex);
1722	list_for_each_entry(use, &mod->target_list, target_list)
1723	sysfs_remove_link(use->target->holders_dir, mod->name);
1724	mutex_unlock(&module_mutex);
1725	#endif
1726	}
1727
1728	static int add_usage_links(struct module *mod)
1729	{
1730	int ret = 0;
1731	#ifdef CONFIG_MODULE_UNLOAD
1732	struct module_use *use;
1733
1734	mutex_lock(&module_mutex);
1735	list_for_each_entry(use, &mod->target_list, target_list) {
1736	ret = sysfs_create_link(use->target->holders_dir,
1737	&mod->mkobj.kobj, mod->name);
1738	if (ret)
1739	break;
1740	}
1741	mutex_unlock(&module_mutex);
1742	if (ret)
1743	del_usage_links(mod);
1744	#endif
1745	return ret;
1746	}
1747
1748	static void module_remove_modinfo_attrs(struct module *mod, int end);
1749
1750	static int module_add_modinfo_attrs(struct module *mod)
1751	{
1752	struct module_attribute *attr;
1753	struct module_attribute *temp_attr;
1754	int error = 0;
1755	int i;
1756
1757	mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1758	(ARRAY_SIZE(modinfo_attrs) + 1)),
1759	GFP_KERNEL);
1760	if (!mod->modinfo_attrs)
1761	return -ENOMEM;
1762
1763	temp_attr = mod->modinfo_attrs;
1764	for (i = 0; (attr = modinfo_attrs[i]); i++) {
1765	if (!attr->test \|\| attr->test(mod)) {
1766	memcpy(temp_attr, attr, sizeof(*temp_attr));
1767	sysfs_attr_init(&temp_attr->attr);
1768	error = sysfs_create_file(&mod->mkobj.kobj,
1769	&temp_attr->attr);
1770	if (error)
1771	goto error_out;
1772	++temp_attr;
1773	}
1774	}
1775
1776	return 0;
1777
1778	error_out:
1779	if (i > 0)
1780	module_remove_modinfo_attrs(mod, --i);
1781	else
1782	kfree(mod->modinfo_attrs);
1783	return error;
1784	}
1785
1786	static void module_remove_modinfo_attrs(struct module *mod, int end)
1787	{
1788	struct module_attribute *attr;
1789	int i;
1790
1791	for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1792	if (end >= 0 && i > end)
1793	break;
1794	/* pick a field to test for end of list */
1795	if (!attr->attr.name)
1796	break;
1797	sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1798	if (attr->free)
1799	attr->free(mod);
1800	}
1801	kfree(mod->modinfo_attrs);
1802	}
1803
1804	static void mod_kobject_put(struct module *mod)
1805	{
1806	DECLARE_COMPLETION_ONSTACK(c);
1807	mod->mkobj.kobj_completion = &c;
1808	kobject_put(&mod->mkobj.kobj);
1809	wait_for_completion(&c);
1810	}
1811
1812	static int mod_sysfs_init(struct module *mod)
1813	{
1814	int err;
1815	struct kobject *kobj;
1816
1817	if (!module_sysfs_initialized) {
1818	pr_err("%s: module sysfs not initialized\n", mod->name);
1819	err = -EINVAL;
1820	goto out;
1821	}
1822
1823	kobj = kset_find_obj(module_kset, mod->name);
1824	if (kobj) {
1825	pr_err("%s: module is already loaded\n", mod->name);
1826	kobject_put(kobj);
1827	err = -EINVAL;
1828	goto out;
1829	}
1830
1831	mod->mkobj.mod = mod;
1832
1833	memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1834	mod->mkobj.kobj.kset = module_kset;
1835	err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1836	"%s", mod->name);
1837	if (err)
1838	mod_kobject_put(mod);
1839
1840	out:
1841	return err;
1842	}
1843
1844	static int mod_sysfs_setup(struct module *mod,
1845	const struct load_info *info,
1846	struct kernel_param *kparam,
1847	unsigned int num_params)
1848	{
1849	int err;
1850
1851	err = mod_sysfs_init(mod);
1852	if (err)
1853	goto out;
1854
1855	mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1856	if (!mod->holders_dir) {
1857	err = -ENOMEM;
1858	goto out_unreg;
1859	}
1860
1861	err = module_param_sysfs_setup(mod, kparam, num_params);
1862	if (err)
1863	goto out_unreg_holders;
1864
1865	err = module_add_modinfo_attrs(mod);
1866	if (err)
1867	goto out_unreg_param;
1868
1869	err = add_usage_links(mod);
1870	if (err)
1871	goto out_unreg_modinfo_attrs;
1872
1873	add_sect_attrs(mod, info);
1874	add_notes_attrs(mod, info);
1875
1876	return 0;
1877
1878	out_unreg_modinfo_attrs:
1879	module_remove_modinfo_attrs(mod, -1);
1880	out_unreg_param:
1881	module_param_sysfs_remove(mod);
1882	out_unreg_holders:
1883	kobject_put(mod->holders_dir);
1884	out_unreg:
1885	mod_kobject_put(mod);
1886	out:
1887	return err;
1888	}
1889
1890	static void mod_sysfs_fini(struct module *mod)
1891	{
1892	remove_notes_attrs(mod);
1893	remove_sect_attrs(mod);
1894	mod_kobject_put(mod);
1895	}
1896
1897	static void init_param_lock(struct module *mod)
1898	{
1899	mutex_init(&mod->param_lock);
1900	}
1901	#else /* !CONFIG_SYSFS */
1902
1903	static int mod_sysfs_setup(struct module *mod,
1904	const struct load_info *info,
1905	struct kernel_param *kparam,
1906	unsigned int num_params)
1907	{
1908	return 0;
1909	}
1910
1911	static void mod_sysfs_fini(struct module *mod)
1912	{
1913	}
1914
1915	static void module_remove_modinfo_attrs(struct module *mod, int end)
1916	{
1917	}
1918
1919	static void del_usage_links(struct module *mod)
1920	{
1921	}
1922
1923	static void init_param_lock(struct module *mod)
1924	{
1925	}
1926	#endif /* CONFIG_SYSFS */
1927
1928	static void mod_sysfs_teardown(struct module *mod)
1929	{
1930	del_usage_links(mod);
1931	module_remove_modinfo_attrs(mod, -1);
1932	module_param_sysfs_remove(mod);
1933	kobject_put(mod->mkobj.drivers_dir);
1934	kobject_put(mod->holders_dir);
1935	mod_sysfs_fini(mod);
1936	}
1937
1938	/*
1939	* LKM RO/NX protection: protect module's text/ro-data
1940	* from modification and any data from execution.
1941	*
1942	* General layout of module is:
1943	* [text] [read-only-data] [ro-after-init] [writable data]
1944	* text_size -----^ ^ ^ ^
1945	* ro_size ------------------------\| \| \|
1946	* ro_after_init_size -----------------------------\| \|
1947	* size -----------------------------------------------------------\|
1948	*
1949	* These values are always page-aligned (as is base)
1950	*/
1951
1952	/*
1953	* Since some arches are moving towards PAGE_KERNEL module allocations instead
1954	* of PAGE_KERNEL_EXEC, keep frob_text() and module_enable_x() outside of the
1955	* CONFIG_STRICT_MODULE_RWX block below because they are needed regardless of
1956	* whether we are strict.
1957	*/
1958	#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
1959	static void frob_text(const struct module_layout *layout,
1960	int (*set_memory)(unsigned long start, int num_pages))
1961	{
1962	BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1963	BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1964	set_memory((unsigned long)layout->base,
1965	layout->text_size >> PAGE_SHIFT);
1966	}
1967
1968	static void module_enable_x(const struct module *mod)
1969	{
1970	frob_text(&mod->core_layout, set_memory_x);
1971	frob_text(&mod->init_layout, set_memory_x);
1972	}
1973	#else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
1974	static void module_enable_x(const struct module *mod) { }
1975	#endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
1976
1977	#ifdef CONFIG_STRICT_MODULE_RWX
1978	static void frob_rodata(const struct module_layout *layout,
1979	int (*set_memory)(unsigned long start, int num_pages))
1980	{
1981	BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1982	BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1983	BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1984	set_memory((unsigned long)layout->base + layout->text_size,
1985	(layout->ro_size - layout->text_size) >> PAGE_SHIFT);
1986	}
1987
1988	static void frob_ro_after_init(const struct module_layout *layout,
1989	int (*set_memory)(unsigned long start, int num_pages))
1990	{
1991	BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1992	BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1993	BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1994	set_memory((unsigned long)layout->base + layout->ro_size,
1995	(layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
1996	}
1997
1998	static void frob_writable_data(const struct module_layout *layout,
1999	int (*set_memory)(unsigned long start, int num_pages))
2000	{
2001	BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
2002	BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
2003	BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
2004	set_memory((unsigned long)layout->base + layout->ro_after_init_size,
2005	(layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
2006	}
2007
2008	static void module_enable_ro(const struct module *mod, bool after_init)
2009	{
2010	if (!rodata_enabled)
2011	return;
2012
2013	set_vm_flush_reset_perms(mod->core_layout.base);
2014	set_vm_flush_reset_perms(mod->init_layout.base);
2015	frob_text(&mod->core_layout, set_memory_ro);
2016
2017	frob_rodata(&mod->core_layout, set_memory_ro);
2018	frob_text(&mod->init_layout, set_memory_ro);
2019	frob_rodata(&mod->init_layout, set_memory_ro);
2020
2021	if (after_init)
2022	frob_ro_after_init(&mod->core_layout, set_memory_ro);
2023	}
2024
2025	static void module_enable_nx(const struct module *mod)
2026	{
2027	frob_rodata(&mod->core_layout, set_memory_nx);
2028	frob_ro_after_init(&mod->core_layout, set_memory_nx);
2029	frob_writable_data(&mod->core_layout, set_memory_nx);
2030	frob_rodata(&mod->init_layout, set_memory_nx);
2031	frob_writable_data(&mod->init_layout, set_memory_nx);
2032	}
2033
2034	static int module_enforce_rwx_sections(Elf_Ehdr hdr, Elf_Shdr sechdrs,
2035	char secstrings, struct module mod)
2036	{
2037	const unsigned long shf_wx = SHF_WRITE\|SHF_EXECINSTR;
2038	int i;
2039
2040	for (i = 0; i < hdr->e_shnum; i++) {
2041	if ((sechdrs[i].sh_flags & shf_wx) == shf_wx) {
2042	pr_err("%s: section %s (index %d) has invalid WRITE\|EXEC flags\n",
2043	mod->name, secstrings + sechdrs[i].sh_name, i);
2044	return -ENOEXEC;
2045	}
2046	}
2047
2048	return 0;
2049	}
2050
2051	#else /* !CONFIG_STRICT_MODULE_RWX */
2052	static void module_enable_nx(const struct module *mod) { }
2053	static void module_enable_ro(const struct module *mod, bool after_init) {}
2054	static int module_enforce_rwx_sections(Elf_Ehdr hdr, Elf_Shdr sechdrs,
2055	char secstrings, struct module mod)
2056	{
2057	return 0;
2058	}
2059	#endif /* CONFIG_STRICT_MODULE_RWX */
2060
2061	#ifdef CONFIG_LIVEPATCH
2062	/*
2063	* Persist Elf information about a module. Copy the Elf header,
2064	* section header table, section string table, and symtab section
2065	* index from info to mod->klp_info.
2066	*/
2067	static int copy_module_elf(struct module mod, struct load_info info)
2068	{
2069	unsigned int size, symndx;
2070	int ret;
2071
2072	size = sizeof(*mod->klp_info);
2073	mod->klp_info = kmalloc(size, GFP_KERNEL);
2074	if (mod->klp_info == NULL)
2075	return -ENOMEM;
2076
2077	/* Elf header */
2078	size = sizeof(mod->klp_info->hdr);
2079	memcpy(&mod->klp_info->hdr, info->hdr, size);
2080
2081	/* Elf section header table */
2082	size = sizeof(info->sechdrs) info->hdr->e_shnum;
2083	mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL);
2084	if (mod->klp_info->sechdrs == NULL) {
2085	ret = -ENOMEM;
2086	goto free_info;
2087	}
2088
2089	/* Elf section name string table */
2090	size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
2091	mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL);
2092	if (mod->klp_info->secstrings == NULL) {
2093	ret = -ENOMEM;
2094	goto free_sechdrs;
2095	}
2096
2097	/* Elf symbol section index */
2098	symndx = info->index.sym;
2099	mod->klp_info->symndx = symndx;
2100
2101	/*
2102	* For livepatch modules, core_kallsyms.symtab is a complete
2103	* copy of the original symbol table. Adjust sh_addr to point
2104	* to core_kallsyms.symtab since the copy of the symtab in module
2105	* init memory is freed at the end of do_init_module().
2106	*/
2107	mod->klp_info->sechdrs[symndx].sh_addr = \
2108	(unsigned long) mod->core_kallsyms.symtab;
2109
2110	return 0;
2111
2112	free_sechdrs:
2113	kfree(mod->klp_info->sechdrs);
2114	free_info:
2115	kfree(mod->klp_info);
2116	return ret;
2117	}
2118
2119	static void free_module_elf(struct module *mod)
2120	{
2121	kfree(mod->klp_info->sechdrs);
2122	kfree(mod->klp_info->secstrings);
2123	kfree(mod->klp_info);
2124	}
2125	#else /* !CONFIG_LIVEPATCH */
2126	static int copy_module_elf(struct module mod, struct load_info info)
2127	{
2128	return 0;
2129	}
2130
2131	static void free_module_elf(struct module *mod)
2132	{
2133	}
2134	#endif /* CONFIG_LIVEPATCH */
2135
2136	void __weak module_memfree(void *module_region)
2137	{
2138	/*
2139	* This memory may be RO, and freeing RO memory in an interrupt is not
2140	* supported by vmalloc.
2141	*/
2142	WARN_ON(in_interrupt());
2143	vfree(module_region);
2144	}
2145
2146	void __weak module_arch_cleanup(struct module *mod)
2147	{
2148	}
2149
2150	void __weak module_arch_freeing_init(struct module *mod)
2151	{
2152	}
2153
2154	static void cfi_cleanup(struct module *mod);
2155
2156	/* Free a module, remove from lists, etc. */
2157	static void free_module(struct module *mod)
2158	{
2159	trace_module_free(mod);
2160
2161	mod_sysfs_teardown(mod);
2162
2163	/*
2164	* We leave it in list to prevent duplicate loads, but make sure
2165	* that noone uses it while it's being deconstructed.
2166	*/
2167	mutex_lock(&module_mutex);
2168	mod->state = MODULE_STATE_UNFORMED;
2169	mutex_unlock(&module_mutex);
2170
2171	/* Remove dynamic debug info */
2172	ddebug_remove_module(mod->name);
2173
2174	/* Arch-specific cleanup. */
2175	module_arch_cleanup(mod);
2176
2177	/* Module unload stuff */
2178	module_unload_free(mod);
2179
2180	/* Free any allocated parameters. */
2181	destroy_params(mod->kp, mod->num_kp);
2182
2183	if (is_livepatch_module(mod))
2184	free_module_elf(mod);
2185
2186	/* Now we can delete it from the lists */
2187	mutex_lock(&module_mutex);
2188	/* Unlink carefully: kallsyms could be walking list. */
2189	list_del_rcu(&mod->list);
2190	mod_tree_remove(mod);
2191	/* Remove this module from bug list, this uses list_del_rcu */
2192	module_bug_cleanup(mod);
2193	/* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2194	synchronize_rcu();
2195	mutex_unlock(&module_mutex);
2196
2197	/* Clean up CFI for the module. */
2198	cfi_cleanup(mod);
2199
2200	/* This may be empty, but that's OK */
2201	module_arch_freeing_init(mod);
2202	module_memfree(mod->init_layout.base);
2203	kfree(mod->args);
2204	percpu_modfree(mod);
2205
2206	/* Free lock-classes; relies on the preceding sync_rcu(). */
2207	lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
2208
2209	/* Finally, free the core (containing the module structure) */
2210	module_memfree(mod->core_layout.base);
2211	}
2212
2213	void __symbol_get(const char symbol)
2214	{
2215	struct find_symbol_arg fsa = {
2216	.name = symbol,
2217	.gplok = true,
2218	.warn = true,
2219	};
2220
2221	preempt_disable();
2222	if (!find_symbol(&fsa) \|\| strong_try_module_get(fsa.owner)) {
2223	preempt_enable();
2224	return NULL;
2225	}
2226	preempt_enable();
2227	return (void *)kernel_symbol_value(fsa.sym);
2228	}
2229	EXPORT_SYMBOL_GPL(__symbol_get);
2230
2231	/*
2232	* Ensure that an exported symbol [global namespace] does not already exist
2233	* in the kernel or in some other module's exported symbol table.
2234	*
2235	* You must hold the module_mutex.
2236	*/
2237	static int verify_exported_symbols(struct module *mod)
2238	{
2239	unsigned int i;
2240	const struct kernel_symbol *s;
2241	struct {
2242	const struct kernel_symbol *sym;
2243	unsigned int num;
2244	} arr[] = {
2245	{ mod->syms, mod->num_syms },
2246	{ mod->gpl_syms, mod->num_gpl_syms },
2247	};
2248
2249	for (i = 0; i < ARRAY_SIZE(arr); i++) {
2250	for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2251	struct find_symbol_arg fsa = {
2252	.name = kernel_symbol_name(s),
2253	.gplok = true,
2254	};
2255	if (find_symbol(&fsa)) {
2256	pr_err("%s: exports duplicate symbol %s"
2257	" (owned by %s)\n",
2258	mod->name, kernel_symbol_name(s),
2259	module_name(fsa.owner));
2260	return -ENOEXEC;
2261	}
2262	}
2263	}
2264	return 0;
2265	}
2266
2267	static bool ignore_undef_symbol(Elf_Half emachine, const char *name)
2268	{
2269	/*
2270	* On x86, PIC code and Clang non-PIC code may have call foo@PLT. GNU as
2271	* before 2.37 produces an unreferenced _GLOBAL_OFFSET_TABLE_ on x86-64.
2272	* i386 has a similar problem but may not deserve a fix.
2273	*
2274	* If we ever have to ignore many symbols, consider refactoring the code to
2275	* only warn if referenced by a relocation.
2276	*/
2277	if (emachine == EM_386 \|\| emachine == EM_X86_64)
2278	return !strcmp(name, "_GLOBAL_OFFSET_TABLE_");
2279	return false;
2280	}
2281
2282	/* Change all symbols so that st_value encodes the pointer directly. */
2283	static int simplify_symbols(struct module mod, const struct load_info info)
2284	{
2285	Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2286	Elf_Sym sym = (void )symsec->sh_addr;
2287	unsigned long secbase;
2288	unsigned int i;
2289	int ret = 0;
2290	const struct kernel_symbol *ksym;
2291
2292	for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2293	const char *name = info->strtab + sym[i].st_name;
2294
2295	switch (sym[i].st_shndx) {
2296	case SHN_COMMON:
2297	/* Ignore common symbols */
2298	if (!strncmp(name, "__gnu_lto", 9))
2299	break;
2300
2301	/*
2302	* We compiled with -fno-common. These are not
2303	* supposed to happen.
2304	*/
2305	pr_debug("Common symbol: %s\n", name);
2306	pr_warn("%s: please compile with -fno-common\n",
2307	mod->name);
2308	ret = -ENOEXEC;
2309	break;
2310
2311	case SHN_ABS:
2312	/* Don't need to do anything */
2313	pr_debug("Absolute symbol: 0x%08lx\n",
2314	(long)sym[i].st_value);
2315	break;
2316
2317	case SHN_LIVEPATCH:
2318	/* Livepatch symbols are resolved by livepatch */
2319	break;
2320
2321	case SHN_UNDEF:
2322	ksym = resolve_symbol_wait(mod, info, name);
2323	/* Ok if resolved. */
2324	if (ksym && !IS_ERR(ksym)) {
2325	sym[i].st_value = kernel_symbol_value(ksym);
2326	break;
2327	}
2328
2329	/* Ok if weak or ignored. */
2330	if (!ksym &&
2331	(ELF_ST_BIND(sym[i].st_info) == STB_WEAK \|\|
2332	ignore_undef_symbol(info->hdr->e_machine, name)))
2333	break;
2334
2335	ret = PTR_ERR(ksym) ?: -ENOENT;
2336	pr_warn("%s: Unknown symbol %s (err %d)\n",
2337	mod->name, name, ret);
2338	break;
2339
2340	default:
2341	/* Divert to percpu allocation if a percpu var. */
2342	if (sym[i].st_shndx == info->index.pcpu)
2343	secbase = (unsigned long)mod_percpu(mod);
2344	else
2345	secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2346	sym[i].st_value += secbase;
2347	break;
2348	}
2349	}
2350
2351	return ret;
2352	}
2353
2354	static int apply_relocations(struct module mod, const struct load_info info)
2355	{
2356	unsigned int i;
2357	int err = 0;
2358
2359	/* Now do relocations. */
2360	for (i = 1; i < info->hdr->e_shnum; i++) {
2361	unsigned int infosec = info->sechdrs[i].sh_info;
2362
2363	/* Not a valid relocation section? */
2364	if (infosec >= info->hdr->e_shnum)
2365	continue;
2366
2367	/* Don't bother with non-allocated sections */
2368	if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2369	continue;
2370
2371	if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
2372	err = klp_apply_section_relocs(mod, info->sechdrs,
2373	info->secstrings,
2374	info->strtab,
2375	info->index.sym, i,
2376	NULL);
2377	else if (info->sechdrs[i].sh_type == SHT_REL)
2378	err = apply_relocate(info->sechdrs, info->strtab,
2379	info->index.sym, i, mod);
2380	else if (info->sechdrs[i].sh_type == SHT_RELA)
2381	err = apply_relocate_add(info->sechdrs, info->strtab,
2382	info->index.sym, i, mod);
2383	if (err < 0)
2384	break;
2385	}
2386	return err;
2387	}
2388
2389	/* Additional bytes needed by arch in front of individual sections */
2390	unsigned int __weak arch_mod_section_prepend(struct module *mod,
2391	unsigned int section)
2392	{
2393	/* default implementation just returns zero */
2394	return 0;
2395	}
2396
2397	/* Update size with this section: return offset. */
2398	static long get_offset(struct module mod, unsigned int size,
2399	Elf_Shdr *sechdr, unsigned int section)
2400	{
2401	long ret;
2402
2403	*size += arch_mod_section_prepend(mod, section);
2404	ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2405	*size = ret + sechdr->sh_size;
2406	return ret;
2407	}
2408
2409	static bool module_init_layout_section(const char *sname)
2410	{
2411	#ifndef CONFIG_MODULE_UNLOAD
2412	if (module_exit_section(sname))
2413	return true;
2414	#endif
2415	return module_init_section(sname);
2416	}
2417
2418	/*
2419	* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2420	* might -- code, read-only data, read-write data, small data. Tally
2421	* sizes, and place the offsets into sh_entsize fields: high bit means it
2422	* belongs in init.
2423	*/
2424	static void layout_sections(struct module mod, struct load_info info)
2425	{
2426	static unsigned long const masks[][2] = {
2427	/*
2428	* NOTE: all executable code must be the first section
2429	* in this array; otherwise modify the text_size
2430	* finder in the two loops below
2431	*/
2432	{ SHF_EXECINSTR \| SHF_ALLOC, ARCH_SHF_SMALL },
2433	{ SHF_ALLOC, SHF_WRITE \| ARCH_SHF_SMALL },
2434	{ SHF_RO_AFTER_INIT \| SHF_ALLOC, ARCH_SHF_SMALL },
2435	{ SHF_WRITE \| SHF_ALLOC, ARCH_SHF_SMALL },
2436	{ ARCH_SHF_SMALL \| SHF_ALLOC, 0 }
2437	};
2438	unsigned int m, i;
2439
2440	for (i = 0; i < info->hdr->e_shnum; i++)
2441	info->sechdrs[i].sh_entsize = ~0UL;
2442
2443	pr_debug("Core section allocation order:\n");
2444	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2445	for (i = 0; i < info->hdr->e_shnum; ++i) {
2446	Elf_Shdr *s = &info->sechdrs[i];
2447	const char *sname = info->secstrings + s->sh_name;
2448
2449	if ((s->sh_flags & masks[m][0]) != masks[m][0]
2450	\|\| (s->sh_flags & masks[m][1])
2451	\|\| s->sh_entsize != ~0UL
2452	\|\| module_init_layout_section(sname))
2453	continue;
2454	s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2455	pr_debug("\t%s\n", sname);
2456	}
2457	switch (m) {
2458	case 0: /* executable */
2459	mod->core_layout.size = debug_align(mod->core_layout.size);
2460	mod->core_layout.text_size = mod->core_layout.size;
2461	break;
2462	case 1: /* RO: text and ro-data */
2463	mod->core_layout.size = debug_align(mod->core_layout.size);
2464	mod->core_layout.ro_size = mod->core_layout.size;
2465	break;
2466	case 2: /* RO after init */
2467	mod->core_layout.size = debug_align(mod->core_layout.size);
2468	mod->core_layout.ro_after_init_size = mod->core_layout.size;
2469	break;
2470	case 4: /* whole core */
2471	mod->core_layout.size = debug_align(mod->core_layout.size);
2472	break;
2473	}
2474	}
2475
2476	pr_debug("Init section allocation order:\n");
2477	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2478	for (i = 0; i < info->hdr->e_shnum; ++i) {
2479	Elf_Shdr *s = &info->sechdrs[i];
2480	const char *sname = info->secstrings + s->sh_name;
2481
2482	if ((s->sh_flags & masks[m][0]) != masks[m][0]
2483	\|\| (s->sh_flags & masks[m][1])
2484	\|\| s->sh_entsize != ~0UL
2485	\|\| !module_init_layout_section(sname))
2486	continue;
2487	s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
2488	\| INIT_OFFSET_MASK);
2489	pr_debug("\t%s\n", sname);
2490	}
2491	switch (m) {
2492	case 0: /* executable */
2493	mod->init_layout.size = debug_align(mod->init_layout.size);
2494	mod->init_layout.text_size = mod->init_layout.size;
2495	break;
2496	case 1: /* RO: text and ro-data */
2497	mod->init_layout.size = debug_align(mod->init_layout.size);
2498	mod->init_layout.ro_size = mod->init_layout.size;
2499	break;
2500	case 2:
2501	/*
2502	* RO after init doesn't apply to init_layout (only
2503	* core_layout), so it just takes the value of ro_size.
2504	*/
2505	mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
2506	break;
2507	case 4: /* whole init */
2508	mod->init_layout.size = debug_align(mod->init_layout.size);
2509	break;
2510	}
2511	}
2512	}
2513
2514	static void set_license(struct module mod, const char license)
2515	{
2516	if (!license)
2517	license = "unspecified";
2518
2519	if (!license_is_gpl_compatible(license)) {
2520	if (!test_taint(TAINT_PROPRIETARY_MODULE))
2521	pr_warn("%s: module license '%s' taints kernel.\n",
2522	mod->name, license);
2523	add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2524	LOCKDEP_NOW_UNRELIABLE);
2525	}
2526	}
2527
2528	/* Parse tag=value strings from .modinfo section */
2529	static char next_string(char string, unsigned long *secsize)
2530	{
2531	/* Skip non-zero chars */
2532	while (string[0]) {
2533	string++;
2534	if ((*secsize)-- <= 1)
2535	return NULL;
2536	}
2537
2538	/* Skip any zero padding. */
2539	while (!string[0]) {
2540	string++;
2541	if ((*secsize)-- <= 1)
2542	return NULL;
2543	}
2544	return string;
2545	}
2546
2547	static char get_next_modinfo(const struct load_info info, const char *tag,
2548	char *prev)
2549	{
2550	char *p;
2551	unsigned int taglen = strlen(tag);
2552	Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2553	unsigned long size = infosec->sh_size;
2554
2555	/*
2556	* get_modinfo() calls made before rewrite_section_headers()
2557	* must use sh_offset, as sh_addr isn't set!
2558	*/
2559	char modinfo = (char )info->hdr + infosec->sh_offset;
2560
2561	if (prev) {
2562	size -= prev - modinfo;
2563	modinfo = next_string(prev, &size);
2564	}
2565
2566	for (p = modinfo; p; p = next_string(p, &size)) {
2567	if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2568	return p + taglen + 1;
2569	}
2570	return NULL;
2571	}
2572
2573	static char get_modinfo(const struct load_info info, const char *tag)
2574	{
2575	return get_next_modinfo(info, tag, NULL);
2576	}
2577
2578	static void setup_modinfo(struct module mod, struct load_info info)
2579	{
2580	struct module_attribute *attr;
2581	int i;
2582
2583	for (i = 0; (attr = modinfo_attrs[i]); i++) {
2584	if (attr->setup)
2585	attr->setup(mod, get_modinfo(info, attr->attr.name));
2586	}
2587	}
2588
2589	static void free_modinfo(struct module *mod)
2590	{
2591	struct module_attribute *attr;
2592	int i;
2593
2594	for (i = 0; (attr = modinfo_attrs[i]); i++) {
2595	if (attr->free)
2596	attr->free(mod);
2597	}
2598	}
2599
2600	#ifdef CONFIG_KALLSYMS
2601
2602	/* Lookup exported symbol in given range of kernel_symbols */
2603	static const struct kernel_symbol lookup_exported_symbol(const char name,
2604	const struct kernel_symbol *start,
2605	const struct kernel_symbol *stop)
2606	{
2607	return bsearch(name, start, stop - start,
2608	sizeof(struct kernel_symbol), cmp_name);
2609	}
2610
2611	static int is_exported(const char *name, unsigned long value,
2612	const struct module *mod)
2613	{
2614	const struct kernel_symbol *ks;
2615	if (!mod)
2616	ks = lookup_exported_symbol(name, __start___ksymtab, __stop___ksymtab);
2617	else
2618	ks = lookup_exported_symbol(name, mod->syms, mod->syms + mod->num_syms);
2619
2620	return ks != NULL && kernel_symbol_value(ks) == value;
2621	}
2622
2623	/* As per nm */
2624	static char elf_type(const Elf_Sym sym, const struct load_info info)
2625	{
2626	const Elf_Shdr *sechdrs = info->sechdrs;
2627
2628	if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2629	if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2630	return 'v';
2631	else
2632	return 'w';
2633	}
2634	if (sym->st_shndx == SHN_UNDEF)
2635	return 'U';
2636	if (sym->st_shndx == SHN_ABS \|\| sym->st_shndx == info->index.pcpu)
2637	return 'a';
2638	if (sym->st_shndx >= SHN_LORESERVE)
2639	return '?';
2640	if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2641	return 't';
2642	if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2643	&& sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2644	if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2645	return 'r';
2646	else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2647	return 'g';
2648	else
2649	return 'd';
2650	}
2651	if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2652	if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2653	return 's';
2654	else
2655	return 'b';
2656	}
2657	if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2658	".debug")) {
2659	return 'n';
2660	}
2661	return '?';
2662	}
2663
2664	static bool is_core_symbol(const Elf_Sym src, const Elf_Shdr sechdrs,
2665	unsigned int shnum, unsigned int pcpundx)
2666	{
2667	const Elf_Shdr *sec;
2668
2669	if (src->st_shndx == SHN_UNDEF
2670	\|\| src->st_shndx >= shnum
2671	\|\| !src->st_name)
2672	return false;
2673
2674	#ifdef CONFIG_KALLSYMS_ALL
2675	if (src->st_shndx == pcpundx)
2676	return true;
2677	#endif
2678
2679	sec = sechdrs + src->st_shndx;
2680	if (!(sec->sh_flags & SHF_ALLOC)
2681	#ifndef CONFIG_KALLSYMS_ALL
2682	\|\| !(sec->sh_flags & SHF_EXECINSTR)
2683	#endif
2684	\|\| (sec->sh_entsize & INIT_OFFSET_MASK))
2685	return false;
2686
2687	return true;
2688	}
2689
2690	/*
2691	* We only allocate and copy the strings needed by the parts of symtab
2692	* we keep. This is simple, but has the effect of making multiple
2693	* copies of duplicates. We could be more sophisticated, see
2694	* linux-kernel thread starting with
2695	* <73defb5e4bca04a6431392cc341112b1@localhost>.
2696	*/
2697	static void layout_symtab(struct module mod, struct load_info info)
2698	{
2699	Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2700	Elf_Shdr *strsect = info->sechdrs + info->index.str;
2701	const Elf_Sym *src;
2702	unsigned int i, nsrc, ndst, strtab_size = 0;
2703
2704	/* Put symbol section at end of init part of module. */
2705	symsect->sh_flags \|= SHF_ALLOC;
2706	symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2707	info->index.sym) \| INIT_OFFSET_MASK;
2708	pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2709
2710	src = (void *)info->hdr + symsect->sh_offset;
2711	nsrc = symsect->sh_size / sizeof(*src);
2712
2713	/* Compute total space required for the core symbols' strtab. */
2714	for (ndst = i = 0; i < nsrc; i++) {
2715	if (i == 0 \|\| is_livepatch_module(mod) \|\|
2716	is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2717	info->index.pcpu)) {
2718	strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2719	ndst++;
2720	}
2721	}
2722
2723	/* Append room for core symbols at end of core part. */
2724	info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
2725	info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
2726	mod->core_layout.size += strtab_size;
2727	info->core_typeoffs = mod->core_layout.size;
2728	mod->core_layout.size += ndst * sizeof(char);
2729	mod->core_layout.size = debug_align(mod->core_layout.size);
2730
2731	/* Put string table section at end of init part of module. */
2732	strsect->sh_flags \|= SHF_ALLOC;
2733	strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2734	info->index.str) \| INIT_OFFSET_MASK;
2735	pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2736
2737	/* We'll tack temporary mod_kallsyms on the end. */
2738	mod->init_layout.size = ALIGN(mod->init_layout.size,
2739	__alignof__(struct mod_kallsyms));
2740	info->mod_kallsyms_init_off = mod->init_layout.size;
2741	mod->init_layout.size += sizeof(struct mod_kallsyms);
2742	info->init_typeoffs = mod->init_layout.size;
2743	mod->init_layout.size += nsrc * sizeof(char);
2744	mod->init_layout.size = debug_align(mod->init_layout.size);
2745	}
2746
2747	/*
2748	* We use the full symtab and strtab which layout_symtab arranged to
2749	* be appended to the init section. Later we switch to the cut-down
2750	* core-only ones.
2751	*/
2752	static void add_kallsyms(struct module mod, const struct load_info info)
2753	{
2754	unsigned int i, ndst;
2755	const Elf_Sym *src;
2756	Elf_Sym *dst;
2757	char *s;
2758	Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2759
2760	/* Set up to point into init section. */
2761	mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
2762
2763	mod->kallsyms->symtab = (void *)symsec->sh_addr;
2764	mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2765	/* Make sure we get permanent strtab: don't use info->strtab. */
2766	mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2767	mod->kallsyms->typetab = mod->init_layout.base + info->init_typeoffs;
2768
2769	/*
2770	* Now populate the cut down core kallsyms for after init
2771	* and set types up while we still have access to sections.
2772	*/
2773	mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
2774	mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
2775	mod->core_kallsyms.typetab = mod->core_layout.base + info->core_typeoffs;
2776	src = mod->kallsyms->symtab;
2777	for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2778	mod->kallsyms->typetab[i] = elf_type(src + i, info);
2779	if (i == 0 \|\| is_livepatch_module(mod) \|\|
2780	is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2781	info->index.pcpu)) {
2782	mod->core_kallsyms.typetab[ndst] =
2783	mod->kallsyms->typetab[i];
2784	dst[ndst] = src[i];
2785	dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
2786	s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2787	KSYM_NAME_LEN) + 1;
2788	}
2789	}
2790	mod->core_kallsyms.num_symtab = ndst;
2791	}
2792	#else
2793	static inline void layout_symtab(struct module mod, struct load_info info)
2794	{
2795	}
2796
2797	static void add_kallsyms(struct module mod, const struct load_info info)
2798	{
2799	}
2800	#endif /* CONFIG_KALLSYMS */
2801
2802	#if IS_ENABLED(CONFIG_KALLSYMS) && IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
2803	static void init_build_id(struct module mod, const struct load_info info)
2804	{
2805	const Elf_Shdr *sechdr;
2806	unsigned int i;
2807
2808	for (i = 0; i < info->hdr->e_shnum; i++) {
2809	sechdr = &info->sechdrs[i];
2810	if (!sect_empty(sechdr) && sechdr->sh_type == SHT_NOTE &&
2811	!build_id_parse_buf((void *)sechdr->sh_addr, mod->build_id,
2812	sechdr->sh_size))
2813	break;
2814	}
2815	}
2816	#else
2817	static void init_build_id(struct module mod, const struct load_info info)
2818	{
2819	}
2820	#endif
2821
2822	static void dynamic_debug_setup(struct module mod, struct _ddebug debug, unsigned int num)
2823	{
2824	if (!debug)
2825	return;
2826	ddebug_add_module(debug, num, mod->name);
2827	}
2828
2829	static void dynamic_debug_remove(struct module mod, struct _ddebug debug)
2830	{
2831	if (debug)
2832	ddebug_remove_module(mod->name);
2833	}
2834
2835	void * __weak module_alloc(unsigned long size)
2836	{
2837	return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
2838	GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS,
2839	NUMA_NO_NODE, __builtin_return_address(0));
2840	}
2841
2842	bool __weak module_init_section(const char *name)
2843	{
2844	return strstarts(name, ".init");
2845	}
2846
2847	bool __weak module_exit_section(const char *name)
2848	{
2849	return strstarts(name, ".exit");
2850	}
2851
2852	#ifdef CONFIG_DEBUG_KMEMLEAK
2853	static void kmemleak_load_module(const struct module *mod,
2854	const struct load_info *info)
2855	{
2856	unsigned int i;
2857
2858	/* only scan the sections containing data */
2859	kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2860
2861	for (i = 1; i < info->hdr->e_shnum; i++) {
2862	/* Scan all writable sections that's not executable */
2863	if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) \|\|
2864	!(info->sechdrs[i].sh_flags & SHF_WRITE) \|\|
2865	(info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2866	continue;
2867
2868	kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2869	info->sechdrs[i].sh_size, GFP_KERNEL);
2870	}
2871	}
2872	#else
2873	static inline void kmemleak_load_module(const struct module *mod,
2874	const struct load_info *info)
2875	{
2876	}
2877	#endif
2878
2879	#ifdef CONFIG_MODULE_SIG
2880	static int module_sig_check(struct load_info *info, int flags)
2881	{
2882	int err = -ENODATA;
2883	const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2884	const char *reason;
2885	const void *mod = info->hdr;
2886	bool mangled_module = flags & (MODULE_INIT_IGNORE_MODVERSIONS \|
2887	MODULE_INIT_IGNORE_VERMAGIC);
2888	/*
2889	* Do not allow mangled modules as a module with version information
2890	* removed is no longer the module that was signed.
2891	*/
2892	if (!mangled_module &&
2893	info->len > markerlen &&
2894	memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2895	/* We truncate the module to discard the signature */
2896	info->len -= markerlen;
2897	err = mod_verify_sig(mod, info);
2898	if (!err) {
2899	info->sig_ok = true;
2900	return 0;
2901	}
2902	}
2903
2904	/*
2905	* We don't permit modules to be loaded into the trusted kernels
2906	* without a valid signature on them, but if we're not enforcing,
2907	* certain errors are non-fatal.
2908	*/
2909	switch (err) {
2910	case -ENODATA:
2911	reason = "unsigned module";
2912	break;
2913	case -ENOPKG:
2914	reason = "module with unsupported crypto";
2915	break;
2916	case -ENOKEY:
2917	reason = "module with unavailable key";
2918	break;
2919
2920	default:
2921	/*
2922	* All other errors are fatal, including lack of memory,
2923	* unparseable signatures, and signature check failures --
2924	* even if signatures aren't required.
2925	*/
2926	return err;
2927	}
2928
2929	if (is_module_sig_enforced()) {
2930	pr_notice("Loading of %s is rejected\n", reason);
2931	return -EKEYREJECTED;
2932	}
2933
2934	return security_locked_down(LOCKDOWN_MODULE_SIGNATURE);
2935	}
2936	#else /* !CONFIG_MODULE_SIG */
2937	static int module_sig_check(struct load_info *info, int flags)
2938	{
2939	return 0;
2940	}
2941	#endif /* !CONFIG_MODULE_SIG */
2942
2943	static int validate_section_offset(struct load_info info, Elf_Shdr shdr)
2944	{
2945	#if defined(CONFIG_64BIT)
2946	unsigned long long secend;
2947	#else
2948	unsigned long secend;
2949	#endif
2950
2951	/*
2952	* Check for both overflow and offset/size being
2953	* too large.
2954	*/
2955	secend = shdr->sh_offset + shdr->sh_size;
2956	if (secend < shdr->sh_offset \|\| secend > info->len)
2957	return -ENOEXEC;
2958
2959	return 0;
2960	}
2961
2962	/*
2963	* Sanity checks against invalid binaries, wrong arch, weird elf version.
2964	*
2965	* Also do basic validity checks against section offsets and sizes, the
2966	* section name string table, and the indices used for it (sh_name).
2967	*/
2968	static int elf_validity_check(struct load_info *info)
2969	{
2970	unsigned int i;
2971	Elf_Shdr shdr, strhdr;
2972	int err;
2973
2974	if (info->len < sizeof(*(info->hdr))) {
2975	pr_err("Invalid ELF header len %lu\n", info->len);
2976	goto no_exec;
2977	}
2978
2979	if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0) {
2980	pr_err("Invalid ELF header magic: != %s\n", ELFMAG);
2981	goto no_exec;
2982	}
2983	if (info->hdr->e_type != ET_REL) {
2984	pr_err("Invalid ELF header type: %u != %u\n",
2985	info->hdr->e_type, ET_REL);
2986	goto no_exec;
2987	}
2988	if (!elf_check_arch(info->hdr)) {
2989	pr_err("Invalid architecture in ELF header: %u\n",
2990	info->hdr->e_machine);
2991	goto no_exec;
2992	}
2993	if (info->hdr->e_shentsize != sizeof(Elf_Shdr)) {
2994	pr_err("Invalid ELF section header size\n");
2995	goto no_exec;
2996	}
2997
2998	/*
2999	* e_shnum is 16 bits, and sizeof(Elf_Shdr) is
3000	* known and small. So e_shnum * sizeof(Elf_Shdr)
3001	* will not overflow unsigned long on any platform.
3002	*/
3003	if (info->hdr->e_shoff >= info->len
3004	\|\| (info->hdr->e_shnum * sizeof(Elf_Shdr) >
3005	info->len - info->hdr->e_shoff)) {
3006	pr_err("Invalid ELF section header overflow\n");
3007	goto no_exec;
3008	}
3009
3010	info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
3011
3012	/*
3013	* Verify if the section name table index is valid.
3014	*/
3015	if (info->hdr->e_shstrndx == SHN_UNDEF
3016	\|\| info->hdr->e_shstrndx >= info->hdr->e_shnum) {
3017	pr_err("Invalid ELF section name index: %d \|\| e_shstrndx (%d) >= e_shnum (%d)\n",
3018	info->hdr->e_shstrndx, info->hdr->e_shstrndx,
3019	info->hdr->e_shnum);
3020	goto no_exec;
3021	}
3022
3023	strhdr = &info->sechdrs[info->hdr->e_shstrndx];
3024	err = validate_section_offset(info, strhdr);
3025	if (err < 0) {
3026	pr_err("Invalid ELF section hdr(type %u)\n", strhdr->sh_type);
3027	return err;
3028	}
3029
3030	/*
3031	* The section name table must be NUL-terminated, as required
3032	* by the spec. This makes strcmp and pr_* calls that access
3033	* strings in the section safe.
3034	*/
3035	info->secstrings = (void *)info->hdr + strhdr->sh_offset;
3036	if (info->secstrings[strhdr->sh_size - 1] != '\0') {
3037	pr_err("ELF Spec violation: section name table isn't null terminated\n");
3038	goto no_exec;
3039	}
3040
3041	/*
3042	* The code assumes that section 0 has a length of zero and
3043	* an addr of zero, so check for it.
3044	*/
3045	if (info->sechdrs[0].sh_type != SHT_NULL
3046	\|\| info->sechdrs[0].sh_size != 0
3047	\|\| info->sechdrs[0].sh_addr != 0) {
3048	pr_err("ELF Spec violation: section 0 type(%d)!=SH_NULL or non-zero len or addr\n",
3049	info->sechdrs[0].sh_type);
3050	goto no_exec;
3051	}
3052
3053	for (i = 1; i < info->hdr->e_shnum; i++) {
3054	shdr = &info->sechdrs[i];
3055	switch (shdr->sh_type) {
3056	case SHT_NULL:
3057	case SHT_NOBITS:
3058	continue;
3059	case SHT_SYMTAB:
3060	if (shdr->sh_link == SHN_UNDEF
3061	\|\| shdr->sh_link >= info->hdr->e_shnum) {
3062	pr_err("Invalid ELF sh_link!=SHN_UNDEF(%d) or (sh_link(%d) >= hdr->e_shnum(%d)\n",
3063	shdr->sh_link, shdr->sh_link,
3064	info->hdr->e_shnum);
3065	goto no_exec;
3066	}
3067	fallthrough;
3068	default:
3069	err = validate_section_offset(info, shdr);
3070	if (err < 0) {
3071	pr_err("Invalid ELF section in module (section %u type %u)\n",
3072	i, shdr->sh_type);
3073	return err;
3074	}
3075
3076	if (shdr->sh_flags & SHF_ALLOC) {
3077	if (shdr->sh_name >= strhdr->sh_size) {
3078	pr_err("Invalid ELF section name in module (section %u type %u)\n",
3079	i, shdr->sh_type);
3080	return -ENOEXEC;
3081	}
3082	}
3083	break;
3084	}
3085	}
3086
3087	return 0;
3088
3089	no_exec:
3090	return -ENOEXEC;
3091	}
3092
3093	#define COPY_CHUNK_SIZE (16*PAGE_SIZE)
3094
3095	static int copy_chunked_from_user(void dst, const void __user usrc, unsigned long len)
3096	{
3097	do {
3098	unsigned long n = min(len, COPY_CHUNK_SIZE);
3099
3100	if (copy_from_user(dst, usrc, n) != 0)
3101	return -EFAULT;
3102	cond_resched();
3103	dst += n;
3104	usrc += n;
3105	len -= n;
3106	} while (len);
3107	return 0;
3108	}
3109
3110	#ifdef CONFIG_LIVEPATCH
3111	static int check_modinfo_livepatch(struct module mod, struct load_info info)
3112	{
3113	if (get_modinfo(info, "livepatch")) {
3114	mod->klp = true;
3115	add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
3116	pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
3117	mod->name);
3118	}
3119
3120	return 0;
3121	}
3122	#else /* !CONFIG_LIVEPATCH */
3123	static int check_modinfo_livepatch(struct module mod, struct load_info info)
3124	{
3125	if (get_modinfo(info, "livepatch")) {
3126	pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
3127	mod->name);
3128	return -ENOEXEC;
3129	}
3130
3131	return 0;
3132	}
3133	#endif /* CONFIG_LIVEPATCH */
3134
3135	static void check_modinfo_retpoline(struct module mod, struct load_info info)
3136	{
3137	if (retpoline_module_ok(get_modinfo(info, "retpoline")))
3138	return;
3139
3140	pr_warn("%s: loading module not compiled with retpoline compiler.\n",
3141	mod->name);
3142	}
3143
3144	/* Sets info->hdr and info->len. */
3145	static int copy_module_from_user(const void __user *umod, unsigned long len,
3146	struct load_info *info)
3147	{
3148	int err;
3149
3150	info->len = len;
3151	if (info->len < sizeof(*(info->hdr)))
3152	return -ENOEXEC;
3153
3154	err = security_kernel_load_data(LOADING_MODULE, true);
3155	if (err)
3156	return err;
3157
3158	/* Suck in entire file: we'll want most of it. */
3159	info->hdr = __vmalloc(info->len, GFP_KERNEL \| __GFP_NOWARN);
3160	if (!info->hdr)
3161	return -ENOMEM;
3162
3163	if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
3164	err = -EFAULT;
3165	goto out;
3166	}
3167
3168	err = security_kernel_post_load_data((char *)info->hdr, info->len,
3169	LOADING_MODULE, "init_module");
3170	out:
3171	if (err)
3172	vfree(info->hdr);
3173
3174	return err;
3175	}
3176
3177	static void free_copy(struct load_info *info, int flags)
3178	{
3179	if (flags & MODULE_INIT_COMPRESSED_FILE)
3180	module_decompress_cleanup(info);
3181	else
3182	vfree(info->hdr);
3183	}
3184
3185	static int rewrite_section_headers(struct load_info *info, int flags)
3186	{
3187	unsigned int i;
3188
3189	/* This should always be true, but let's be sure. */
3190	info->sechdrs[0].sh_addr = 0;
3191
3192	for (i = 1; i < info->hdr->e_shnum; i++) {
3193	Elf_Shdr *shdr = &info->sechdrs[i];
3194
3195	/*
3196	* Mark all sections sh_addr with their address in the
3197	* temporary image.
3198	*/
3199	shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
3200
3201	}
3202
3203	/* Track but don't keep modinfo and version sections. */
3204	info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
3205	info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
3206
3207	return 0;
3208	}
3209
3210	/*
3211	* Set up our basic convenience variables (pointers to section headers,
3212	* search for module section index etc), and do some basic section
3213	* verification.
3214	*
3215	* Set info->mod to the temporary copy of the module in info->hdr. The final one
3216	* will be allocated in move_module().
3217	*/
3218	static int setup_load_info(struct load_info *info, int flags)
3219	{
3220	unsigned int i;
3221
3222	/* Try to find a name early so we can log errors with a module name */
3223	info->index.info = find_sec(info, ".modinfo");
3224	if (info->index.info)
3225	info->name = get_modinfo(info, "name");
3226
3227	/* Find internal symbols and strings. */
3228	for (i = 1; i < info->hdr->e_shnum; i++) {
3229	if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
3230	info->index.sym = i;
3231	info->index.str = info->sechdrs[i].sh_link;
3232	info->strtab = (char *)info->hdr
3233	+ info->sechdrs[info->index.str].sh_offset;
3234	break;
3235	}
3236	}
3237
3238	if (info->index.sym == 0) {
3239	pr_warn("%s: module has no symbols (stripped?)\n",
3240	info->name ?: "(missing .modinfo section or name field)");
3241	return -ENOEXEC;
3242	}
3243
3244	info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
3245	if (!info->index.mod) {
3246	pr_warn("%s: No module found in object\n",
3247	info->name ?: "(missing .modinfo section or name field)");
3248	return -ENOEXEC;
3249	}
3250	/* This is temporary: point mod into copy of data. */
3251	info->mod = (void *)info->hdr + info->sechdrs[info->index.mod].sh_offset;
3252
3253	/*
3254	* If we didn't load the .modinfo 'name' field earlier, fall back to
3255	* on-disk struct mod 'name' field.
3256	*/
3257	if (!info->name)
3258	info->name = info->mod->name;
3259
3260	if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
3261	info->index.vers = 0; /* Pretend no __versions section! */
3262	else
3263	info->index.vers = find_sec(info, "__versions");
3264
3265	info->index.pcpu = find_pcpusec(info);
3266
3267	return 0;
3268	}
3269
3270	static int check_modinfo(struct module mod, struct load_info info, int flags)
3271	{
3272	const char *modmagic = get_modinfo(info, "vermagic");
3273	int err;
3274
3275	if (flags & MODULE_INIT_IGNORE_VERMAGIC)
3276	modmagic = NULL;
3277
3278	/* This is allowed: modprobe --force will invalidate it. */
3279	if (!modmagic) {
3280	err = try_to_force_load(mod, "bad vermagic");
3281	if (err)
3282	return err;
3283	} else if (!same_magic(modmagic, vermagic, info->index.vers)) {
3284	pr_err("%s: version magic '%s' should be '%s'\n",
3285	info->name, modmagic, vermagic);
3286	return -ENOEXEC;
3287	}
3288
3289	if (!get_modinfo(info, "intree")) {
3290	if (!test_taint(TAINT_OOT_MODULE))
3291	pr_warn("%s: loading out-of-tree module taints kernel.\n",
3292	mod->name);
3293	add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
3294	}
3295
3296	check_modinfo_retpoline(mod, info);
3297
3298	if (get_modinfo(info, "staging")) {
3299	add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
3300	pr_warn("%s: module is from the staging directory, the quality "
3301	"is unknown, you have been warned.\n", mod->name);
3302	}
3303
3304	err = check_modinfo_livepatch(mod, info);
3305	if (err)
3306	return err;
3307
3308	/* Set up license info based on the info section */
3309	set_license(mod, get_modinfo(info, "license"));
3310
3311	return 0;
3312	}
3313
3314	static int find_module_sections(struct module mod, struct load_info info)
3315	{
3316	mod->kp = section_objs(info, "__param",
3317	sizeof(*mod->kp), &mod->num_kp);
3318	mod->syms = section_objs(info, "__ksymtab",
3319	sizeof(*mod->syms), &mod->num_syms);
3320	mod->crcs = section_addr(info, "__kcrctab");
3321	mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
3322	sizeof(*mod->gpl_syms),
3323	&mod->num_gpl_syms);
3324	mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
3325
3326	#ifdef CONFIG_CONSTRUCTORS
3327	mod->ctors = section_objs(info, ".ctors",
3328	sizeof(*mod->ctors), &mod->num_ctors);
3329	if (!mod->ctors)
3330	mod->ctors = section_objs(info, ".init_array",
3331	sizeof(*mod->ctors), &mod->num_ctors);
3332	else if (find_sec(info, ".init_array")) {
3333	/*
3334	* This shouldn't happen with same compiler and binutils
3335	* building all parts of the module.
3336	*/
3337	pr_warn("%s: has both .ctors and .init_array.\n",
3338	mod->name);
3339	return -EINVAL;
3340	}
3341	#endif
3342
3343	mod->noinstr_text_start = section_objs(info, ".noinstr.text", 1,
3344	&mod->noinstr_text_size);
3345
3346	#ifdef CONFIG_TRACEPOINTS
3347	mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
3348	sizeof(*mod->tracepoints_ptrs),
3349	&mod->num_tracepoints);
3350	#endif
3351	#ifdef CONFIG_TREE_SRCU
3352	mod->srcu_struct_ptrs = section_objs(info, "___srcu_struct_ptrs",
3353	sizeof(*mod->srcu_struct_ptrs),
3354	&mod->num_srcu_structs);
3355	#endif
3356	#ifdef CONFIG_BPF_EVENTS
3357	mod->bpf_raw_events = section_objs(info, "__bpf_raw_tp_map",
3358	sizeof(*mod->bpf_raw_events),
3359	&mod->num_bpf_raw_events);
3360	#endif
3361	#ifdef CONFIG_DEBUG_INFO_BTF_MODULES
3362	mod->btf_data = any_section_objs(info, ".BTF", 1, &mod->btf_data_size);
3363	#endif
3364	#ifdef CONFIG_JUMP_LABEL
3365	mod->jump_entries = section_objs(info, "__jump_table",
3366	sizeof(*mod->jump_entries),
3367	&mod->num_jump_entries);
3368	#endif
3369	#ifdef CONFIG_EVENT_TRACING
3370	mod->trace_events = section_objs(info, "_ftrace_events",
3371	sizeof(*mod->trace_events),
3372	&mod->num_trace_events);
3373	mod->trace_evals = section_objs(info, "_ftrace_eval_map",
3374	sizeof(*mod->trace_evals),
3375	&mod->num_trace_evals);
3376	#endif
3377	#ifdef CONFIG_TRACING
3378	mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
3379	sizeof(*mod->trace_bprintk_fmt_start),
3380	&mod->num_trace_bprintk_fmt);
3381	#endif
3382	#ifdef CONFIG_FTRACE_MCOUNT_RECORD
3383	/* sechdrs[0].sh_size is always zero */
3384	mod->ftrace_callsites = section_objs(info, FTRACE_CALLSITE_SECTION,
3385	sizeof(*mod->ftrace_callsites),
3386	&mod->num_ftrace_callsites);
3387	#endif
3388	#ifdef CONFIG_FUNCTION_ERROR_INJECTION
3389	mod->ei_funcs = section_objs(info, "_error_injection_whitelist",
3390	sizeof(*mod->ei_funcs),
3391	&mod->num_ei_funcs);
3392	#endif
3393	#ifdef CONFIG_KPROBES
3394	mod->kprobes_text_start = section_objs(info, ".kprobes.text", 1,
3395	&mod->kprobes_text_size);
3396	mod->kprobe_blacklist = section_objs(info, "_kprobe_blacklist",
3397	sizeof(unsigned long),
3398	&mod->num_kprobe_blacklist);
3399	#endif
3400	#ifdef CONFIG_PRINTK_INDEX
3401	mod->printk_index_start = section_objs(info, ".printk_index",
3402	sizeof(*mod->printk_index_start),
3403	&mod->printk_index_size);
3404	#endif
3405	#ifdef CONFIG_HAVE_STATIC_CALL_INLINE
3406	mod->static_call_sites = section_objs(info, ".static_call_sites",
3407	sizeof(*mod->static_call_sites),
3408	&mod->num_static_call_sites);
3409	#endif
3410	mod->extable = section_objs(info, "__ex_table",
3411	sizeof(*mod->extable), &mod->num_exentries);
3412
3413	if (section_addr(info, "__obsparm"))
3414	pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
3415
3416	info->debug = section_objs(info, "__dyndbg",
3417	sizeof(*info->debug), &info->num_debug);
3418
3419	return 0;
3420	}
3421
3422	static int move_module(struct module mod, struct load_info info)
3423	{
3424	int i;
3425	void *ptr;
3426
3427	/* Do the allocs. */
3428	ptr = module_alloc(mod->core_layout.size);
3429	/*
3430	* The pointer to this block is stored in the module structure
3431	* which is inside the block. Just mark it as not being a
3432	* leak.
3433	*/
3434	kmemleak_not_leak(ptr);
3435	if (!ptr)
3436	return -ENOMEM;
3437
3438	memset(ptr, 0, mod->core_layout.size);
3439	mod->core_layout.base = ptr;
3440
3441	if (mod->init_layout.size) {
3442	ptr = module_alloc(mod->init_layout.size);
3443	/*
3444	* The pointer to this block is stored in the module structure
3445	* which is inside the block. This block doesn't need to be
3446	* scanned as it contains data and code that will be freed
3447	* after the module is initialized.
3448	*/
3449	kmemleak_ignore(ptr);
3450	if (!ptr) {
3451	module_memfree(mod->core_layout.base);
3452	return -ENOMEM;
3453	}
3454	memset(ptr, 0, mod->init_layout.size);
3455	mod->init_layout.base = ptr;
3456	} else
3457	mod->init_layout.base = NULL;
3458
3459	/* Transfer each section which specifies SHF_ALLOC */
3460	pr_debug("final section addresses:\n");
3461	for (i = 0; i < info->hdr->e_shnum; i++) {
3462	void *dest;
3463	Elf_Shdr *shdr = &info->sechdrs[i];
3464
3465	if (!(shdr->sh_flags & SHF_ALLOC))
3466	continue;
3467
3468	if (shdr->sh_entsize & INIT_OFFSET_MASK)
3469	dest = mod->init_layout.base
3470	+ (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3471	else
3472	dest = mod->core_layout.base + shdr->sh_entsize;
3473
3474	if (shdr->sh_type != SHT_NOBITS)
3475	memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3476	/* Update sh_addr to point to copy in image. */
3477	shdr->sh_addr = (unsigned long)dest;
3478	pr_debug("\t0x%lx %s\n",
3479	(long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3480	}
3481
3482	return 0;
3483	}
3484
3485	static int check_module_license_and_versions(struct module *mod)
3486	{
3487	int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
3488
3489	/*
3490	* ndiswrapper is under GPL by itself, but loads proprietary modules.
3491	* Don't use add_taint_module(), as it would prevent ndiswrapper from
3492	* using GPL-only symbols it needs.
3493	*/
3494	if (strcmp(mod->name, "ndiswrapper") == 0)
3495	add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3496
3497	/* driverloader was caught wrongly pretending to be under GPL */
3498	if (strcmp(mod->name, "driverloader") == 0)
3499	add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3500	LOCKDEP_NOW_UNRELIABLE);
3501
3502	/* lve claims to be GPL but upstream won't provide source */
3503	if (strcmp(mod->name, "lve") == 0)
3504	add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3505	LOCKDEP_NOW_UNRELIABLE);
3506
3507	if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
3508	pr_warn("%s: module license taints kernel.\n", mod->name);
3509
3510	#ifdef CONFIG_MODVERSIONS
3511	if ((mod->num_syms && !mod->crcs) \|\|
3512	(mod->num_gpl_syms && !mod->gpl_crcs)) {
3513	return try_to_force_load(mod,
3514	"no versions for exported symbols");
3515	}
3516	#endif
3517	return 0;
3518	}
3519
3520	static void flush_module_icache(const struct module *mod)
3521	{
3522	/*
3523	* Flush the instruction cache, since we've played with text.
3524	* Do it before processing of module parameters, so the module
3525	* can provide parameter accessor functions of its own.
3526	*/
3527	if (mod->init_layout.base)
3528	flush_icache_range((unsigned long)mod->init_layout.base,
3529	(unsigned long)mod->init_layout.base
3530	+ mod->init_layout.size);
3531	flush_icache_range((unsigned long)mod->core_layout.base,
3532	(unsigned long)mod->core_layout.base + mod->core_layout.size);
3533	}
3534
3535	int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3536	Elf_Shdr *sechdrs,
3537	char *secstrings,
3538	struct module *mod)
3539	{
3540	return 0;
3541	}
3542
3543	/* module_blacklist is a comma-separated list of module names */
3544	static char *module_blacklist;
3545	static bool blacklisted(const char *module_name)
3546	{
3547	const char *p;
3548	size_t len;
3549
3550	if (!module_blacklist)
3551	return false;
3552
3553	for (p = module_blacklist; *p; p += len) {
3554	len = strcspn(p, ",");
3555	if (strlen(module_name) == len && !memcmp(module_name, p, len))
3556	return true;
3557	if (p[len] == ',')
3558	len++;
3559	}
3560	return false;
3561	}
3562	core_param(module_blacklist, module_blacklist, charp, 0400);
3563
3564	static struct module layout_and_allocate(struct load_info info, int flags)
3565	{
3566	struct module *mod;
3567	unsigned int ndx;
3568	int err;
3569
3570	err = check_modinfo(info->mod, info, flags);
3571	if (err)
3572	return ERR_PTR(err);
3573
3574	/* Allow arches to frob section contents and sizes. */
3575	err = module_frob_arch_sections(info->hdr, info->sechdrs,
3576	info->secstrings, info->mod);
3577	if (err < 0)
3578	return ERR_PTR(err);
3579
3580	err = module_enforce_rwx_sections(info->hdr, info->sechdrs,
3581	info->secstrings, info->mod);
3582	if (err < 0)
3583	return ERR_PTR(err);
3584
3585	/* We will do a special allocation for per-cpu sections later. */
3586	info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3587
3588	/*
3589	* Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3590	* layout_sections() can put it in the right place.
3591	* Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3592	*/
3593	ndx = find_sec(info, ".data..ro_after_init");
3594	if (ndx)
3595	info->sechdrs[ndx].sh_flags \|= SHF_RO_AFTER_INIT;
3596	/*
3597	* Mark the __jump_table section as ro_after_init as well: these data
3598	* structures are never modified, with the exception of entries that
3599	* refer to code in the __init section, which are annotated as such
3600	* at module load time.
3601	*/
3602	ndx = find_sec(info, "__jump_table");
3603	if (ndx)
3604	info->sechdrs[ndx].sh_flags \|= SHF_RO_AFTER_INIT;
3605
3606	/*
3607	* Determine total sizes, and put offsets in sh_entsize. For now
3608	* this is done generically; there doesn't appear to be any
3609	* special cases for the architectures.
3610	*/
3611	layout_sections(info->mod, info);
3612	layout_symtab(info->mod, info);
3613
3614	/* Allocate and move to the final place */
3615	err = move_module(info->mod, info);
3616	if (err)
3617	return ERR_PTR(err);
3618
3619	/* Module has been copied to its final place now: return it. */
3620	mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3621	kmemleak_load_module(mod, info);
3622	return mod;
3623	}
3624
3625	/* mod is no longer valid after this! */
3626	static void module_deallocate(struct module mod, struct load_info info)
3627	{
3628	percpu_modfree(mod);
3629	module_arch_freeing_init(mod);
3630	module_memfree(mod->init_layout.base);
3631	module_memfree(mod->core_layout.base);
3632	}
3633
3634	int __weak module_finalize(const Elf_Ehdr *hdr,
3635	const Elf_Shdr *sechdrs,
3636	struct module *me)
3637	{
3638	return 0;
3639	}
3640
3641	static int post_relocation(struct module mod, const struct load_info info)
3642	{
3643	/* Sort exception table now relocations are done. */
3644	sort_extable(mod->extable, mod->extable + mod->num_exentries);
3645
3646	/* Copy relocated percpu area over. */
3647	percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3648	info->sechdrs[info->index.pcpu].sh_size);
3649
3650	/* Setup kallsyms-specific fields. */
3651	add_kallsyms(mod, info);
3652
3653	/* Arch-specific module finalizing. */
3654	return module_finalize(info->hdr, info->sechdrs, mod);
3655	}
3656
3657	/* Is this module of this name done loading? No locks held. */
3658	static bool finished_loading(const char *name)
3659	{
3660	struct module *mod;
3661	bool ret;
3662
3663	/*
3664	* The module_mutex should not be a heavily contended lock;
3665	* if we get the occasional sleep here, we'll go an extra iteration
3666	* in the wait_event_interruptible(), which is harmless.
3667	*/
3668	sched_annotate_sleep();
3669	mutex_lock(&module_mutex);
3670	mod = find_module_all(name, strlen(name), true);
3671	ret = !mod \|\| mod->state == MODULE_STATE_LIVE;
3672	mutex_unlock(&module_mutex);
3673
3674	return ret;
3675	}
3676
3677	/* Call module constructors. */
3678	static void do_mod_ctors(struct module *mod)
3679	{
3680	#ifdef CONFIG_CONSTRUCTORS
3681	unsigned long i;
3682
3683	for (i = 0; i < mod->num_ctors; i++)
3684	mod->ctors[i]();
3685	#endif
3686	}
3687
3688	/* For freeing module_init on success, in case kallsyms traversing */
3689	struct mod_initfree {
3690	struct llist_node node;
3691	void *module_init;
3692	};
3693
3694	static void do_free_init(struct work_struct *w)
3695	{
3696	struct llist_node pos, n, *list;
3697	struct mod_initfree *initfree;
3698
3699	list = llist_del_all(&init_free_list);
3700
3701	synchronize_rcu();
3702
3703	llist_for_each_safe(pos, n, list) {
3704	initfree = container_of(pos, struct mod_initfree, node);
3705	module_memfree(initfree->module_init);
3706	kfree(initfree);
3707	}
3708	}
3709
3710	/*
3711	* This is where the real work happens.
3712	*
3713	* Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3714	* helper command 'lx-symbols'.
3715	*/
3716	static noinline int do_init_module(struct module *mod)
3717	{
3718	int ret = 0;
3719	struct mod_initfree *freeinit;
3720
3721	freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3722	if (!freeinit) {
3723	ret = -ENOMEM;
3724	goto fail;
3725	}
3726	freeinit->module_init = mod->init_layout.base;
3727
3728	/*
3729	* We want to find out whether @mod uses async during init. Clear
3730	* PF_USED_ASYNC. async_schedule*() will set it.
3731	*/
3732	current->flags &= ~PF_USED_ASYNC;
3733
3734	do_mod_ctors(mod);
3735	/* Start the module */
3736	if (mod->init != NULL)
3737	ret = do_one_initcall(mod->init);
3738	if (ret < 0) {
3739	goto fail_free_freeinit;
3740	}
3741	if (ret > 0) {
3742	pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3743	"follow 0/-E convention\n"
3744	"%s: loading module anyway...\n",
3745	__func__, mod->name, ret, __func__);
3746	dump_stack();
3747	}
3748
3749	/* Now it's a first class citizen! */
3750	mod->state = MODULE_STATE_LIVE;
3751	blocking_notifier_call_chain(&module_notify_list,
3752	MODULE_STATE_LIVE, mod);
3753
3754	/* Delay uevent until module has finished its init routine */
3755	kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
3756
3757	/*
3758	* We need to finish all async code before the module init sequence
3759	* is done. This has potential to deadlock. For example, a newly
3760	* detected block device can trigger request_module() of the
3761	* default iosched from async probing task. Once userland helper
3762	* reaches here, async_synchronize_full() will wait on the async
3763	* task waiting on request_module() and deadlock.
3764	*
3765	* This deadlock is avoided by perfomring async_synchronize_full()
3766	* iff module init queued any async jobs. This isn't a full
3767	* solution as it will deadlock the same if module loading from
3768	* async jobs nests more than once; however, due to the various
3769	* constraints, this hack seems to be the best option for now.
3770	* Please refer to the following thread for details.
3771	*
3772	* http://thread.gmane.org/gmane.linux.kernel/1420814
3773	*/
3774	if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3775	async_synchronize_full();
3776
3777	ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base +
3778	mod->init_layout.size);
3779	mutex_lock(&module_mutex);
3780	/* Drop initial reference. */
3781	module_put(mod);
3782	trim_init_extable(mod);
3783	#ifdef CONFIG_KALLSYMS
3784	/* Switch to core kallsyms now init is done: kallsyms may be walking! */
3785	rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3786	#endif
3787	module_enable_ro(mod, true);
3788	mod_tree_remove_init(mod);
3789	module_arch_freeing_init(mod);
3790	mod->init_layout.base = NULL;
3791	mod->init_layout.size = 0;
3792	mod->init_layout.ro_size = 0;
3793	mod->init_layout.ro_after_init_size = 0;
3794	mod->init_layout.text_size = 0;
3795	#ifdef CONFIG_DEBUG_INFO_BTF_MODULES
3796	/* .BTF is not SHF_ALLOC and will get removed, so sanitize pointer */
3797	mod->btf_data = NULL;
3798	#endif
3799	/*
3800	* We want to free module_init, but be aware that kallsyms may be
3801	* walking this with preempt disabled. In all the failure paths, we
3802	* call synchronize_rcu(), but we don't want to slow down the success
3803	* path. module_memfree() cannot be called in an interrupt, so do the
3804	* work and call synchronize_rcu() in a work queue.
3805	*
3806	* Note that module_alloc() on most architectures creates W+X page
3807	* mappings which won't be cleaned up until do_free_init() runs. Any
3808	* code such as mark_rodata_ro() which depends on those mappings to
3809	* be cleaned up needs to sync with the queued work - ie
3810	* rcu_barrier()
3811	*/
3812	if (llist_add(&freeinit->node, &init_free_list))
3813	schedule_work(&init_free_wq);
3814
3815	mutex_unlock(&module_mutex);
3816	wake_up_all(&module_wq);
3817
3818	return 0;
3819
3820	fail_free_freeinit:
3821	kfree(freeinit);
3822	fail:
3823	/* Try to protect us from buggy refcounters. */
3824	mod->state = MODULE_STATE_GOING;
3825	synchronize_rcu();
3826	module_put(mod);
3827	blocking_notifier_call_chain(&module_notify_list,
3828	MODULE_STATE_GOING, mod);
3829	klp_module_going(mod);
3830	ftrace_release_mod(mod);
3831	free_module(mod);
3832	wake_up_all(&module_wq);
3833	return ret;
3834	}
3835
3836	static int may_init_module(void)
3837	{
3838	if (!capable(CAP_SYS_MODULE) \|\| modules_disabled)
3839	return -EPERM;
3840
3841	return 0;
3842	}
3843
3844	/*
3845	* We try to place it in the list now to make sure it's unique before
3846	* we dedicate too many resources. In particular, temporary percpu
3847	* memory exhaustion.
3848	*/
3849	static int add_unformed_module(struct module *mod)
3850	{
3851	int err;
3852	struct module *old;
3853
3854	mod->state = MODULE_STATE_UNFORMED;
3855
3856	again:
3857	mutex_lock(&module_mutex);
3858	old = find_module_all(mod->name, strlen(mod->name), true);
3859	if (old != NULL) {
3860	if (old->state != MODULE_STATE_LIVE) {
3861	/* Wait in case it fails to load. */
3862	mutex_unlock(&module_mutex);
3863	err = wait_event_interruptible(module_wq,
3864	finished_loading(mod->name));
3865	if (err)
3866	goto out_unlocked;
3867	goto again;
3868	}
3869	err = -EEXIST;
3870	goto out;
3871	}
3872	mod_update_bounds(mod);
3873	list_add_rcu(&mod->list, &modules);
3874	mod_tree_insert(mod);
3875	err = 0;
3876
3877	out:
3878	mutex_unlock(&module_mutex);
3879	out_unlocked:
3880	return err;
3881	}
3882
3883	static int complete_formation(struct module mod, struct load_info info)
3884	{
3885	int err;
3886
3887	mutex_lock(&module_mutex);
3888
3889	/* Find duplicate symbols (must be called under lock). */
3890	err = verify_exported_symbols(mod);
3891	if (err < 0)
3892	goto out;
3893
3894	/* This relies on module_mutex for list integrity. */
3895	module_bug_finalize(info->hdr, info->sechdrs, mod);
3896
3897	module_enable_ro(mod, false);
3898	module_enable_nx(mod);
3899	module_enable_x(mod);
3900
3901	/*
3902	* Mark state as coming so strong_try_module_get() ignores us,
3903	* but kallsyms etc. can see us.
3904	*/
3905	mod->state = MODULE_STATE_COMING;
3906	mutex_unlock(&module_mutex);
3907
3908	return 0;
3909
3910	out:
3911	mutex_unlock(&module_mutex);
3912	return err;
3913	}
3914
3915	static int prepare_coming_module(struct module *mod)
3916	{
3917	int err;
3918
3919	ftrace_module_enable(mod);
3920	err = klp_module_coming(mod);
3921	if (err)
3922	return err;
3923
3924	err = blocking_notifier_call_chain_robust(&module_notify_list,
3925	MODULE_STATE_COMING, MODULE_STATE_GOING, mod);
3926	err = notifier_to_errno(err);
3927	if (err)
3928	klp_module_going(mod);
3929
3930	return err;
3931	}
3932
3933	static int unknown_module_param_cb(char param, char val, const char *modname,
3934	void *arg)
3935	{
3936	struct module *mod = arg;
3937	int ret;
3938
3939	if (strcmp(param, "async_probe") == 0) {
3940	mod->async_probe_requested = true;
3941	return 0;
3942	}
3943
3944	/* Check for magic 'dyndbg' arg */
3945	ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3946	if (ret != 0)
3947	pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3948	return 0;
3949	}
3950
3951	static void cfi_init(struct module *mod);
3952
3953	/*
3954	* Allocate and load the module: note that size of section 0 is always
3955	* zero, and we rely on this for optional sections.
3956	*/
3957	static int load_module(struct load_info info, const char __user uargs,
3958	int flags)
3959	{
3960	struct module *mod;
3961	long err = 0;
3962	char *after_dashes;
3963
3964	/*
3965	* Do the signature check (if any) first. All that
3966	* the signature check needs is info->len, it does
3967	* not need any of the section info. That can be
3968	* set up later. This will minimize the chances
3969	* of a corrupt module causing problems before
3970	* we even get to the signature check.
3971	*
3972	* The check will also adjust info->len by stripping
3973	* off the sig length at the end of the module, making
3974	* checks against info->len more correct.
3975	*/
3976	err = module_sig_check(info, flags);
3977	if (err)
3978	goto free_copy;
3979
3980	/*
3981	* Do basic sanity checks against the ELF header and
3982	* sections.
3983	*/
3984	err = elf_validity_check(info);
3985	if (err)
3986	goto free_copy;
3987
3988	/*
3989	* Everything checks out, so set up the section info
3990	* in the info structure.
3991	*/
3992	err = setup_load_info(info, flags);
3993	if (err)
3994	goto free_copy;
3995
3996	/*
3997	* Now that we know we have the correct module name, check
3998	* if it's blacklisted.
3999	*/
4000	if (blacklisted(info->name)) {
4001	err = -EPERM;
4002	pr_err("Module %s is blacklisted\n", info->name);
4003	goto free_copy;
4004	}
4005
4006	err = rewrite_section_headers(info, flags);
4007	if (err)
4008	goto free_copy;
4009
4010	/* Check module struct version now, before we try to use module. */
4011	if (!check_modstruct_version(info, info->mod)) {
4012	err = -ENOEXEC;
4013	goto free_copy;
4014	}
4015
4016	/* Figure out module layout, and allocate all the memory. */
4017	mod = layout_and_allocate(info, flags);
4018	if (IS_ERR(mod)) {
4019	err = PTR_ERR(mod);
4020	goto free_copy;
4021	}
4022
4023	audit_log_kern_module(mod->name);
4024
4025	/* Reserve our place in the list. */
4026	err = add_unformed_module(mod);
4027	if (err)
4028	goto free_module;
4029
4030	#ifdef CONFIG_MODULE_SIG
4031	mod->sig_ok = info->sig_ok;
4032	if (!mod->sig_ok) {
4033	pr_notice_once("%s: module verification failed: signature "
4034	"and/or required key missing - tainting "
4035	"kernel\n", mod->name);
4036	add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
4037	}
4038	#endif
4039
4040	/* To avoid stressing percpu allocator, do this once we're unique. */
4041	err = percpu_modalloc(mod, info);
4042	if (err)
4043	goto unlink_mod;
4044
4045	/* Now module is in final location, initialize linked lists, etc. */
4046	err = module_unload_init(mod);
4047	if (err)
4048	goto unlink_mod;
4049
4050	init_param_lock(mod);
4051
4052	/*
4053	* Now we've got everything in the final locations, we can
4054	* find optional sections.
4055	*/
4056	err = find_module_sections(mod, info);
4057	if (err)
4058	goto free_unload;
4059
4060	err = check_module_license_and_versions(mod);
4061	if (err)
4062	goto free_unload;
4063
4064	/* Set up MODINFO_ATTR fields */
4065	setup_modinfo(mod, info);
4066
4067	/* Fix up syms, so that st_value is a pointer to location. */
4068	err = simplify_symbols(mod, info);
4069	if (err < 0)
4070	goto free_modinfo;
4071
4072	err = apply_relocations(mod, info);
4073	if (err < 0)
4074	goto free_modinfo;
4075
4076	err = post_relocation(mod, info);
4077	if (err < 0)
4078	goto free_modinfo;
4079
4080	flush_module_icache(mod);
4081
4082	/* Setup CFI for the module. */
4083	cfi_init(mod);
4084
4085	/* Now copy in args */
4086	mod->args = strndup_user(uargs, ~0UL >> 1);
4087	if (IS_ERR(mod->args)) {
4088	err = PTR_ERR(mod->args);
4089	goto free_arch_cleanup;
4090	}
4091
4092	init_build_id(mod, info);
4093	dynamic_debug_setup(mod, info->debug, info->num_debug);
4094
4095	/* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
4096	ftrace_module_init(mod);
4097
4098	/* Finally it's fully formed, ready to start executing. */
4099	err = complete_formation(mod, info);
4100	if (err)
4101	goto ddebug_cleanup;
4102
4103	err = prepare_coming_module(mod);
4104	if (err)
4105	goto bug_cleanup;
4106
4107	/* Module is ready to execute: parsing args may do that. */
4108	after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
4109	-32768, 32767, mod,
4110	unknown_module_param_cb);
4111	if (IS_ERR(after_dashes)) {
4112	err = PTR_ERR(after_dashes);
4113	goto coming_cleanup;
4114	} else if (after_dashes) {
4115	pr_warn("%s: parameters '%s' after `--' ignored\n",
4116	mod->name, after_dashes);
4117	}
4118
4119	/* Link in to sysfs. */
4120	err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
4121	if (err < 0)
4122	goto coming_cleanup;
4123
4124	if (is_livepatch_module(mod)) {
4125	err = copy_module_elf(mod, info);
4126	if (err < 0)
4127	goto sysfs_cleanup;
4128	}
4129
4130	/* Get rid of temporary copy. */
4131	free_copy(info, flags);
4132
4133	/* Done! */
4134	trace_module_load(mod);
4135
4136	return do_init_module(mod);
4137
4138	sysfs_cleanup:
4139	mod_sysfs_teardown(mod);
4140	coming_cleanup:
4141	mod->state = MODULE_STATE_GOING;
4142	destroy_params(mod->kp, mod->num_kp);
4143	blocking_notifier_call_chain(&module_notify_list,
4144	MODULE_STATE_GOING, mod);
4145	klp_module_going(mod);
4146	bug_cleanup:
4147	mod->state = MODULE_STATE_GOING;
4148	/* module_bug_cleanup needs module_mutex protection */
4149	mutex_lock(&module_mutex);
4150	module_bug_cleanup(mod);
4151	mutex_unlock(&module_mutex);
4152
4153	ddebug_cleanup:
4154	ftrace_release_mod(mod);
4155	dynamic_debug_remove(mod, info->debug);
4156	synchronize_rcu();
4157	kfree(mod->args);
4158	free_arch_cleanup:
4159	cfi_cleanup(mod);
4160	module_arch_cleanup(mod);
4161	free_modinfo:
4162	free_modinfo(mod);
4163	free_unload:
4164	module_unload_free(mod);
4165	unlink_mod:
4166	mutex_lock(&module_mutex);
4167	/* Unlink carefully: kallsyms could be walking list. */
4168	list_del_rcu(&mod->list);
4169	mod_tree_remove(mod);
4170	wake_up_all(&module_wq);
4171	/* Wait for RCU-sched synchronizing before releasing mod->list. */
4172	synchronize_rcu();
4173	mutex_unlock(&module_mutex);
4174	free_module:
4175	/* Free lock-classes; relies on the preceding sync_rcu() */
4176	lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
4177
4178	module_deallocate(mod, info);
4179	free_copy:
4180	free_copy(info, flags);
4181	return err;
4182	}
4183
4184	SYSCALL_DEFINE3(init_module, void __user *, umod,
4185	unsigned long, len, const char __user *, uargs)
4186	{
4187	int err;
4188	struct load_info info = { };
4189
4190	err = may_init_module();
4191	if (err)
4192	return err;
4193
4194	pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
4195	umod, len, uargs);
4196
4197	err = copy_module_from_user(umod, len, &info);
4198	if (err)
4199	return err;
4200
4201	return load_module(&info, uargs, 0);
4202	}
4203
4204	SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
4205	{
4206	struct load_info info = { };
4207	void *buf = NULL;
4208	int len;
4209	int err;
4210
4211	err = may_init_module();
4212	if (err)
4213	return err;
4214
4215	pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
4216
4217	if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
4218	\|MODULE_INIT_IGNORE_VERMAGIC
4219	\|MODULE_INIT_COMPRESSED_FILE))
4220	return -EINVAL;
4221
4222	len = kernel_read_file_from_fd(fd, 0, &buf, INT_MAX, NULL,
4223	READING_MODULE);
4224	if (len < 0)
4225	return len;
4226
4227	if (flags & MODULE_INIT_COMPRESSED_FILE) {
4228	err = module_decompress(&info, buf, len);
4229	vfree(buf); /* compressed data is no longer needed */
4230	if (err)
4231	return err;
4232	} else {
4233	info.hdr = buf;
4234	info.len = len;
4235	}
4236
4237	return load_module(&info, uargs, flags);
4238	}
4239
4240	static inline int within(unsigned long addr, void *start, unsigned long size)
4241	{
4242	return ((void )addr >= start && (void )addr < start + size);
4243	}
4244
4245	#ifdef CONFIG_KALLSYMS
4246	/*
4247	* This ignores the intensely annoying "mapping symbols" found
4248	* in ARM ELF files: $a, $t and $d.
4249	*/
4250	static inline int is_arm_mapping_symbol(const char *str)
4251	{
4252	if (str[0] == '.' && str[1] == 'L')
4253	return true;
4254	return str[0] == '$' && strchr("axtd", str[1])
4255	&& (str[2] == '\0' \|\| str[2] == '.');
4256	}
4257
4258	static const char kallsyms_symbol_name(struct mod_kallsyms kallsyms, unsigned int symnum)
4259	{
4260	return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
4261	}
4262
4263	/*
4264	* Given a module and address, find the corresponding symbol and return its name
4265	* while providing its size and offset if needed.
4266	*/
4267	static const char find_kallsyms_symbol(struct module mod,
4268	unsigned long addr,
4269	unsigned long *size,
4270	unsigned long *offset)
4271	{
4272	unsigned int i, best = 0;
4273	unsigned long nextval, bestval;
4274	struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4275
4276	/* At worse, next value is at end of module */
4277	if (within_module_init(addr, mod))
4278	nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
4279	else
4280	nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
4281
4282	bestval = kallsyms_symbol_value(&kallsyms->symtab[best]);
4283
4284	/*
4285	* Scan for closest preceding symbol, and next symbol. (ELF
4286	* starts real symbols at 1).
4287	*/
4288	for (i = 1; i < kallsyms->num_symtab; i++) {
4289	const Elf_Sym *sym = &kallsyms->symtab[i];
4290	unsigned long thisval = kallsyms_symbol_value(sym);
4291
4292	if (sym->st_shndx == SHN_UNDEF)
4293	continue;
4294
4295	/*
4296	* We ignore unnamed symbols: they're uninformative
4297	* and inserted at a whim.
4298	*/
4299	if (*kallsyms_symbol_name(kallsyms, i) == '\0'
4300	\|\| is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms, i)))
4301	continue;
4302
4303	if (thisval <= addr && thisval > bestval) {
4304	best = i;
4305	bestval = thisval;
4306	}
4307	if (thisval > addr && thisval < nextval)
4308	nextval = thisval;
4309	}
4310
4311	if (!best)
4312	return NULL;
4313
4314	if (size)
4315	*size = nextval - bestval;
4316	if (offset)
4317	*offset = addr - bestval;
4318
4319	return kallsyms_symbol_name(kallsyms, best);
4320	}
4321
4322	void * __weak dereference_module_function_descriptor(struct module *mod,
4323	void *ptr)
4324	{
4325	return ptr;
4326	}
4327
4328	/*
4329	* For kallsyms to ask for address resolution. NULL means not found. Careful
4330	* not to lock to avoid deadlock on oopses, simply disable preemption.
4331	*/
4332	const char *module_address_lookup(unsigned long addr,
4333	unsigned long *size,
4334	unsigned long *offset,
4335	char **modname,
4336	const unsigned char **modbuildid,
4337	char *namebuf)
4338	{
4339	const char *ret = NULL;
4340	struct module *mod;
4341
4342	preempt_disable();
4343	mod = __module_address(addr);
4344	if (mod) {
4345	if (modname)
4346	*modname = mod->name;
4347	if (modbuildid) {
4348	#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
4349	*modbuildid = mod->build_id;
4350	#else
4351	*modbuildid = NULL;
4352	#endif
4353	}
4354
4355	ret = find_kallsyms_symbol(mod, addr, size, offset);
4356	}
4357	/* Make a copy in here where it's safe */
4358	if (ret) {
4359	strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
4360	ret = namebuf;
4361	}
4362	preempt_enable();
4363
4364	return ret;
4365	}
4366
4367	int lookup_module_symbol_name(unsigned long addr, char *symname)
4368	{
4369	struct module *mod;
4370
4371	preempt_disable();
4372	list_for_each_entry_rcu(mod, &modules, list) {
4373	if (mod->state == MODULE_STATE_UNFORMED)
4374	continue;
4375	if (within_module(addr, mod)) {
4376	const char *sym;
4377
4378	sym = find_kallsyms_symbol(mod, addr, NULL, NULL);
4379	if (!sym)
4380	goto out;
4381
4382	strlcpy(symname, sym, KSYM_NAME_LEN);
4383	preempt_enable();
4384	return 0;
4385	}
4386	}
4387	out:
4388	preempt_enable();
4389	return -ERANGE;
4390	}
4391
4392	int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
4393	unsigned long offset, char modname, char *name)
4394	{
4395	struct module *mod;
4396
4397	preempt_disable();
4398	list_for_each_entry_rcu(mod, &modules, list) {
4399	if (mod->state == MODULE_STATE_UNFORMED)
4400	continue;
4401	if (within_module(addr, mod)) {
4402	const char *sym;
4403
4404	sym = find_kallsyms_symbol(mod, addr, size, offset);
4405	if (!sym)
4406	goto out;
4407	if (modname)
4408	strlcpy(modname, mod->name, MODULE_NAME_LEN);
4409	if (name)
4410	strlcpy(name, sym, KSYM_NAME_LEN);
4411	preempt_enable();
4412	return 0;
4413	}
4414	}
4415	out:
4416	preempt_enable();
4417	return -ERANGE;
4418	}
4419
4420	int module_get_kallsym(unsigned int symnum, unsigned long value, char type,
4421	char name, char module_name, int *exported)
4422	{
4423	struct module *mod;
4424
4425	preempt_disable();
4426	list_for_each_entry_rcu(mod, &modules, list) {
4427	struct mod_kallsyms *kallsyms;
4428
4429	if (mod->state == MODULE_STATE_UNFORMED)
4430	continue;
4431	kallsyms = rcu_dereference_sched(mod->kallsyms);
4432	if (symnum < kallsyms->num_symtab) {
4433	const Elf_Sym *sym = &kallsyms->symtab[symnum];
4434
4435	*value = kallsyms_symbol_value(sym);
4436	*type = kallsyms->typetab[symnum];
4437	strlcpy(name, kallsyms_symbol_name(kallsyms, symnum), KSYM_NAME_LEN);
4438	strlcpy(module_name, mod->name, MODULE_NAME_LEN);
4439	exported = is_exported(name, value, mod);
4440	preempt_enable();
4441	return 0;
4442	}
4443	symnum -= kallsyms->num_symtab;
4444	}
4445	preempt_enable();
4446	return -ERANGE;
4447	}
4448
4449	/* Given a module and name of symbol, find and return the symbol's value */
4450	static unsigned long find_kallsyms_symbol_value(struct module mod, const char name)
4451	{
4452	unsigned int i;
4453	struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4454
4455	for (i = 0; i < kallsyms->num_symtab; i++) {
4456	const Elf_Sym *sym = &kallsyms->symtab[i];
4457
4458	if (strcmp(name, kallsyms_symbol_name(kallsyms, i)) == 0 &&
4459	sym->st_shndx != SHN_UNDEF)
4460	return kallsyms_symbol_value(sym);
4461	}
4462	return 0;
4463	}
4464
4465	/* Look for this name: can be of form module:name. */
4466	unsigned long module_kallsyms_lookup_name(const char *name)
4467	{
4468	struct module *mod;
4469	char *colon;
4470	unsigned long ret = 0;
4471
4472	/* Don't lock: we're in enough trouble already. */
4473	preempt_disable();
4474	if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
4475	if ((mod = find_module_all(name, colon - name, false)) != NULL)
4476	ret = find_kallsyms_symbol_value(mod, colon+1);
4477	} else {
4478	list_for_each_entry_rcu(mod, &modules, list) {
4479	if (mod->state == MODULE_STATE_UNFORMED)
4480	continue;
4481	if ((ret = find_kallsyms_symbol_value(mod, name)) != 0)
4482	break;
4483	}
4484	}
4485	preempt_enable();
4486	return ret;
4487	}
4488
4489	#ifdef CONFIG_LIVEPATCH
4490	int module_kallsyms_on_each_symbol(int (fn)(void , const char *,
4491	struct module *, unsigned long),
4492	void *data)
4493	{
4494	struct module *mod;
4495	unsigned int i;
4496	int ret = 0;
4497
4498	mutex_lock(&module_mutex);
4499	list_for_each_entry(mod, &modules, list) {
4500	/* We hold module_mutex: no need for rcu_dereference_sched */
4501	struct mod_kallsyms *kallsyms = mod->kallsyms;
4502
4503	if (mod->state == MODULE_STATE_UNFORMED)
4504	continue;
4505	for (i = 0; i < kallsyms->num_symtab; i++) {
4506	const Elf_Sym *sym = &kallsyms->symtab[i];
4507
4508	if (sym->st_shndx == SHN_UNDEF)
4509	continue;
4510
4511	ret = fn(data, kallsyms_symbol_name(kallsyms, i),
4512	mod, kallsyms_symbol_value(sym));
4513	if (ret != 0)
4514	goto out;
4515
4516	cond_resched();
4517	}
4518	}
4519	out:
4520	mutex_unlock(&module_mutex);
4521	return ret;
4522	}
4523	#endif /* CONFIG_LIVEPATCH */
4524	#endif /* CONFIG_KALLSYMS */
4525
4526	static void cfi_init(struct module *mod)
4527	{
4528	#ifdef CONFIG_CFI_CLANG
4529	initcall_t *init;
4530	exitcall_t *exit;
4531
4532	rcu_read_lock_sched();
4533	mod->cfi_check = (cfi_check_fn)
4534	find_kallsyms_symbol_value(mod, "__cfi_check");
4535	init = (initcall_t *)
4536	find_kallsyms_symbol_value(mod, "__cfi_jt_init_module");
4537	exit = (exitcall_t *)
4538	find_kallsyms_symbol_value(mod, "__cfi_jt_cleanup_module");
4539	rcu_read_unlock_sched();
4540
4541	/* Fix init/exit functions to point to the CFI jump table */
4542	if (init)
4543	mod->init = *init;
4544	#ifdef CONFIG_MODULE_UNLOAD
4545	if (exit)
4546	mod->exit = *exit;
4547	#endif
4548
4549	cfi_module_add(mod, module_addr_min);
4550	#endif
4551	}
4552
4553	static void cfi_cleanup(struct module *mod)
4554	{
4555	#ifdef CONFIG_CFI_CLANG
4556	cfi_module_remove(mod, module_addr_min);
4557	#endif
4558	}
4559
4560	/* Maximum number of characters written by module_flags() */
4561	#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
4562
4563	/* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
4564	static char module_flags(struct module mod, char *buf)
4565	{
4566	int bx = 0;
4567
4568	BUG_ON(mod->state == MODULE_STATE_UNFORMED);
4569	if (mod->taints \|\|
4570	mod->state == MODULE_STATE_GOING \|\|
4571	mod->state == MODULE_STATE_COMING) {
4572	buf[bx++] = '(';
4573	bx += module_flags_taint(mod, buf + bx);
4574	/* Show a - for module-is-being-unloaded */
4575	if (mod->state == MODULE_STATE_GOING)
4576	buf[bx++] = '-';
4577	/* Show a + for module-is-being-loaded */
4578	if (mod->state == MODULE_STATE_COMING)
4579	buf[bx++] = '+';
4580	buf[bx++] = ')';
4581	}
4582	buf[bx] = '\0';
4583
4584	return buf;
4585	}
4586
4587	#ifdef CONFIG_PROC_FS
4588	/* Called by the /proc file system to return a list of modules. */
4589	static void m_start(struct seq_file m, loff_t *pos)
4590	{
4591	mutex_lock(&module_mutex);
4592	return seq_list_start(&modules, *pos);
4593	}
4594
4595	static void m_next(struct seq_file m, void p, loff_t pos)
4596	{
4597	return seq_list_next(p, &modules, pos);
4598	}
4599
4600	static void m_stop(struct seq_file m, void p)
4601	{
4602	mutex_unlock(&module_mutex);
4603	}
4604
4605	static int m_show(struct seq_file m, void p)
4606	{
4607	struct module *mod = list_entry(p, struct module, list);
4608	char buf[MODULE_FLAGS_BUF_SIZE];
4609	void *value;
4610
4611	/* We always ignore unformed modules. */
4612	if (mod->state == MODULE_STATE_UNFORMED)
4613	return 0;
4614
4615	seq_printf(m, "%s %u",
4616	mod->name, mod->init_layout.size + mod->core_layout.size);
4617	print_unload_info(m, mod);
4618
4619	/* Informative for users. */
4620	seq_printf(m, " %s",
4621	mod->state == MODULE_STATE_GOING ? "Unloading" :
4622	mod->state == MODULE_STATE_COMING ? "Loading" :
4623	"Live");
4624	/* Used by oprofile and other similar tools. */
4625	value = m->private ? NULL : mod->core_layout.base;
4626	seq_printf(m, " 0x%px", value);
4627
4628	/* Taints info */
4629	if (mod->taints)
4630	seq_printf(m, " %s", module_flags(mod, buf));
4631
4632	seq_puts(m, "\n");
4633	return 0;
4634	}
4635
4636	/*
4637	* Format: modulename size refcount deps address
4638	*
4639	* Where refcount is a number or -, and deps is a comma-separated list
4640	* of depends or -.
4641	*/
4642	static const struct seq_operations modules_op = {
4643	.start = m_start,
4644	.next = m_next,
4645	.stop = m_stop,
4646	.show = m_show
4647	};
4648
4649	/*
4650	* This also sets the "private" pointer to non-NULL if the
4651	* kernel pointers should be hidden (so you can just test
4652	* "m->private" to see if you should keep the values private).
4653	*
4654	* We use the same logic as for /proc/kallsyms.
4655	*/
4656	static int modules_open(struct inode inode, struct file file)
4657	{
4658	int err = seq_open(file, &modules_op);
4659
4660	if (!err) {
4661	struct seq_file *m = file->private_data;
4662	m->private = kallsyms_show_value(file->f_cred) ? NULL : (void *)8ul;
4663	}
4664
4665	return err;
4666	}
4667
4668	static const struct proc_ops modules_proc_ops = {
4669	.proc_flags = PROC_ENTRY_PERMANENT,
4670	.proc_open = modules_open,
4671	.proc_read = seq_read,
4672	.proc_lseek = seq_lseek,
4673	.proc_release = seq_release,
4674	};
4675
4676	static int __init proc_modules_init(void)
4677	{
4678	proc_create("modules", 0, NULL, &modules_proc_ops);
4679	return 0;
4680	}
4681	module_init(proc_modules_init);
4682	#endif
4683
4684	/* Given an address, look for it in the module exception tables. */
4685	const struct exception_table_entry *search_module_extables(unsigned long addr)
4686	{
4687	const struct exception_table_entry *e = NULL;
4688	struct module *mod;
4689
4690	preempt_disable();
4691	mod = __module_address(addr);
4692	if (!mod)
4693	goto out;
4694
4695	if (!mod->num_exentries)
4696	goto out;
4697
4698	e = search_extable(mod->extable,
4699	mod->num_exentries,
4700	addr);
4701	out:
4702	preempt_enable();
4703
4704	/*
4705	* Now, if we found one, we are running inside it now, hence
4706	* we cannot unload the module, hence no refcnt needed.
4707	*/
4708	return e;
4709	}
4710
4711	/**
4712	* is_module_address() - is this address inside a module?
4713	* @addr: the address to check.
4714	*
4715	* See is_module_text_address() if you simply want to see if the address
4716	* is code (not data).
4717	*/
4718	bool is_module_address(unsigned long addr)
4719	{
4720	bool ret;
4721
4722	preempt_disable();
4723	ret = __module_address(addr) != NULL;
4724	preempt_enable();
4725
4726	return ret;
4727	}
4728
4729	/**
4730	* __module_address() - get the module which contains an address.
4731	* @addr: the address.
4732	*
4733	* Must be called with preempt disabled or module mutex held so that
4734	* module doesn't get freed during this.
4735	*/
4736	struct module *__module_address(unsigned long addr)
4737	{
4738	struct module *mod;
4739
4740	if (addr < module_addr_min \|\| addr > module_addr_max)
4741	return NULL;
4742
4743	module_assert_mutex_or_preempt();
4744
4745	mod = mod_find(addr);
4746	if (mod) {
4747	BUG_ON(!within_module(addr, mod));
4748	if (mod->state == MODULE_STATE_UNFORMED)
4749	mod = NULL;
4750	}
4751	return mod;
4752	}
4753
4754	/**
4755	* is_module_text_address() - is this address inside module code?
4756	* @addr: the address to check.
4757	*
4758	* See is_module_address() if you simply want to see if the address is
4759	* anywhere in a module. See kernel_text_address() for testing if an
4760	* address corresponds to kernel or module code.
4761	*/
4762	bool is_module_text_address(unsigned long addr)
4763	{
4764	bool ret;
4765
4766	preempt_disable();
4767	ret = __module_text_address(addr) != NULL;
4768	preempt_enable();
4769
4770	return ret;
4771	}
4772
4773	/**
4774	* __module_text_address() - get the module whose code contains an address.
4775	* @addr: the address.
4776	*
4777	* Must be called with preempt disabled or module mutex held so that
4778	* module doesn't get freed during this.
4779	*/
4780	struct module *__module_text_address(unsigned long addr)
4781	{
4782	struct module *mod = __module_address(addr);
4783	if (mod) {
4784	/* Make sure it's within the text section. */
4785	if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
4786	&& !within(addr, mod->core_layout.base, mod->core_layout.text_size))
4787	mod = NULL;
4788	}
4789	return mod;
4790	}
4791
4792	/* Don't grab lock, we're oopsing. */
4793	void print_modules(void)
4794	{
4795	struct module *mod;
4796	char buf[MODULE_FLAGS_BUF_SIZE];
4797
4798	printk(KERN_DEFAULT "Modules linked in:");
4799	/* Most callers should already have preempt disabled, but make sure */
4800	preempt_disable();
4801	list_for_each_entry_rcu(mod, &modules, list) {
4802	if (mod->state == MODULE_STATE_UNFORMED)
4803	continue;
4804	pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4805	}
4806	preempt_enable();
4807	if (last_unloaded_module[0])
4808	pr_cont(" [last unloaded: %s]", last_unloaded_module);
4809	pr_cont("\n");
4810	}
4811
4812	#ifdef CONFIG_MODVERSIONS
4813	/*
4814	* Generate the signature for all relevant module structures here.
4815	* If these change, we don't want to try to parse the module.
4816	*/
4817	void module_layout(struct module *mod,
4818	struct modversion_info *ver,
4819	struct kernel_param *kp,
4820	struct kernel_symbol *ks,
4821	struct tracepoint * const *tp)
4822	{
4823	}
4824	EXPORT_SYMBOL(module_layout);
4825	#endif