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