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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2002 Richard Henderson
4 * Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
5 */
6
7#define INCLUDE_VERMAGIC
8
9#include <linux/export.h>
10#include <linux/extable.h>
11#include <linux/moduleloader.h>
12#include <linux/module_signature.h>
13#include <linux/trace_events.h>
14#include <linux/init.h>
15#include <linux/kallsyms.h>
16#include <linux/buildid.h>
17#include <linux/file.h>
18#include <linux/fs.h>
19#include <linux/sysfs.h>
20#include <linux/kernel.h>
21#include <linux/kernel_read_file.h>
22#include <linux/slab.h>
23#include <linux/vmalloc.h>
24#include <linux/elf.h>
25#include <linux/proc_fs.h>
26#include <linux/security.h>
27#include <linux/seq_file.h>
28#include <linux/syscalls.h>
29#include <linux/fcntl.h>
30#include <linux/rcupdate.h>
31#include <linux/capability.h>
32#include <linux/cpu.h>
33#include <linux/moduleparam.h>
34#include <linux/errno.h>
35#include <linux/err.h>
36#include <linux/vermagic.h>
37#include <linux/notifier.h>
38#include <linux/sched.h>
39#include <linux/device.h>
40#include <linux/string.h>
41#include <linux/mutex.h>
42#include <linux/rculist.h>
43#include <linux/uaccess.h>
44#include <asm/cacheflush.h>
45#include <linux/set_memory.h>
46#include <asm/mmu_context.h>
47#include <linux/license.h>
48#include <asm/sections.h>
49#include <linux/tracepoint.h>
50#include <linux/ftrace.h>
51#include <linux/livepatch.h>
52#include <linux/async.h>
53#include <linux/percpu.h>
54#include <linux/kmemleak.h>
55#include <linux/jump_label.h>
56#include <linux/pfn.h>
57#include <linux/bsearch.h>
58#include <linux/dynamic_debug.h>
59#include <linux/audit.h>
60#include <uapi/linux/module.h>
61#include "module-internal.h"
62
63#define CREATE_TRACE_POINTS
64#include <trace/events/module.h>
65
66#ifndef ARCH_SHF_SMALL
67#define ARCH_SHF_SMALL 0
68#endif
69
70/*
71 * Modules' sections will be aligned on page boundaries
72 * to ensure complete separation of code and data, but
73 * only when CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y
74 */
75#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
76# define debug_align(X) ALIGN(X, PAGE_SIZE)
77#else
78# define debug_align(X) (X)
79#endif
80
81/* If this is set, the section belongs in the init part of the module */
82#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
83
84/*
85 * Mutex protects:
86 * 1) List of modules (also safely readable with preempt_disable),
87 * 2) module_use links,
88 * 3) module_addr_min/module_addr_max.
89 * (delete and add uses RCU list operations).
90 */
91static DEFINE_MUTEX(module_mutex);
92static LIST_HEAD(modules);
93
94/* Work queue for freeing init sections in success case */
95static void do_free_init(struct work_struct *w);
96static DECLARE_WORK(init_free_wq, do_free_init);
97static LLIST_HEAD(init_free_list);
98
99#ifdef CONFIG_MODULES_TREE_LOOKUP
100
101/*
102 * Use a latched RB-tree for __module_address(); this allows us to use
103 * RCU-sched lookups of the address from any context.
104 *
105 * This is conditional on PERF_EVENTS || TRACING because those can really hit
106 * __module_address() hard by doing a lot of stack unwinding; potentially from
107 * NMI context.
108 */
109
110static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
111{
112 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
113
114 return (unsigned long)layout->base;
115}
116
117static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
118{
119 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
120
121 return (unsigned long)layout->size;
122}
123
124static __always_inline bool
125mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
126{
127 return __mod_tree_val(a) < __mod_tree_val(b);
128}
129
130static __always_inline int
131mod_tree_comp(void *key, struct latch_tree_node *n)
132{
133 unsigned long val = (unsigned long)key;
134 unsigned long start, end;
135
136 start = __mod_tree_val(n);
137 if (val < start)
138 return -1;
139
140 end = start + __mod_tree_size(n);
141 if (val >= end)
142 return 1;
143
144 return 0;
145}
146
147static const struct latch_tree_ops mod_tree_ops = {
148 .less = mod_tree_less,
149 .comp = mod_tree_comp,
150};
151
152static struct mod_tree_root {
153 struct latch_tree_root root;
154 unsigned long addr_min;
155 unsigned long addr_max;
156} mod_tree __cacheline_aligned = {
157 .addr_min = -1UL,
158};
159
160#define module_addr_min mod_tree.addr_min
161#define module_addr_max mod_tree.addr_max
162
163static noinline void __mod_tree_insert(struct mod_tree_node *node)
164{
165 latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
166}
167
168static void __mod_tree_remove(struct mod_tree_node *node)
169{
170 latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
171}
172
173/*
174 * These modifications: insert, remove_init and remove; are serialized by the
175 * module_mutex.
176 */
177static void mod_tree_insert(struct module *mod)
178{
179 mod->core_layout.mtn.mod = mod;
180 mod->init_layout.mtn.mod = mod;
181
182 __mod_tree_insert(&mod->core_layout.mtn);
183 if (mod->init_layout.size)
184 __mod_tree_insert(&mod->init_layout.mtn);
185}
186
187static void mod_tree_remove_init(struct module *mod)
188{
189 if (mod->init_layout.size)
190 __mod_tree_remove(&mod->init_layout.mtn);
191}
192
193static void mod_tree_remove(struct module *mod)
194{
195 __mod_tree_remove(&mod->core_layout.mtn);
196 mod_tree_remove_init(mod);
197}
198
199static struct module *mod_find(unsigned long addr)
200{
201 struct latch_tree_node *ltn;
202
203 ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
204 if (!ltn)
205 return NULL;
206
207 return container_of(ltn, struct mod_tree_node, node)->mod;
208}
209
210#else /* MODULES_TREE_LOOKUP */
211
212static unsigned long module_addr_min = -1UL, module_addr_max = 0;
213
214static void mod_tree_insert(struct module *mod) { }
215static void mod_tree_remove_init(struct module *mod) { }
216static void mod_tree_remove(struct module *mod) { }
217
218static struct module *mod_find(unsigned long addr)
219{
220 struct module *mod;
221
222 list_for_each_entry_rcu(mod, &modules, list,
223 lockdep_is_held(&module_mutex)) {
224 if (within_module(addr, mod))
225 return mod;
226 }
227
228 return NULL;
229}
230
231#endif /* MODULES_TREE_LOOKUP */
232
233/*
234 * Bounds of module text, for speeding up __module_address.
235 * Protected by module_mutex.
236 */
237static void __mod_update_bounds(void *base, unsigned int size)
238{
239 unsigned long min = (unsigned long)base;
240 unsigned long max = min + size;
241
242 if (min < module_addr_min)
243 module_addr_min = min;
244 if (max > module_addr_max)
245 module_addr_max = max;
246}
247
248static void mod_update_bounds(struct module *mod)
249{
250 __mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
251 if (mod->init_layout.size)
252 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
253}
254
255#ifdef CONFIG_KGDB_KDB
256struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
257#endif /* CONFIG_KGDB_KDB */
258
259static void module_assert_mutex_or_preempt(void)
260{
261#ifdef CONFIG_LOCKDEP
262 if (unlikely(!debug_locks))
263 return;
264
265 WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
266 !lockdep_is_held(&module_mutex));
267#endif
268}
269
270#ifdef CONFIG_MODULE_SIG
271static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
272module_param(sig_enforce, bool_enable_only, 0644);
273
274void set_module_sig_enforced(void)
275{
276 sig_enforce = true;
277}
278#else
279#define sig_enforce false
280#endif
281
282/*
283 * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
284 * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
285 */
286bool is_module_sig_enforced(void)
287{
288 return sig_enforce;
289}
290EXPORT_SYMBOL(is_module_sig_enforced);
291
292/* Block module loading/unloading? */
293int modules_disabled = 0;
294core_param(nomodule, modules_disabled, bint, 0);
295
296/* Waiting for a module to finish initializing? */
297static DECLARE_WAIT_QUEUE_HEAD(module_wq);
298
299static BLOCKING_NOTIFIER_HEAD(module_notify_list);
300
301int register_module_notifier(struct notifier_block *nb)
302{
303 return blocking_notifier_chain_register(&module_notify_list, nb);
304}
305EXPORT_SYMBOL(register_module_notifier);
306
307int unregister_module_notifier(struct notifier_block *nb)
308{
309 return blocking_notifier_chain_unregister(&module_notify_list, nb);
310}
311EXPORT_SYMBOL(unregister_module_notifier);
312
313/*
314 * We require a truly strong try_module_get(): 0 means success.
315 * Otherwise an error is returned due to ongoing or failed
316 * initialization etc.
317 */
318static inline int strong_try_module_get(struct module *mod)
319{
320 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
321 if (mod && mod->state == MODULE_STATE_COMING)
322 return -EBUSY;
323 if (try_module_get(mod))
324 return 0;
325 else
326 return -ENOENT;
327}
328
329static inline void add_taint_module(struct module *mod, unsigned flag,
330 enum lockdep_ok lockdep_ok)
331{
332 add_taint(flag, lockdep_ok);
333 set_bit(flag, &mod->taints);
334}
335
336/*
337 * A thread that wants to hold a reference to a module only while it
338 * is running can call this to safely exit. nfsd and lockd use this.
339 */
340void __noreturn __module_put_and_exit(struct module *mod, long code)
341{
342 module_put(mod);
343 do_exit(code);
344}
345EXPORT_SYMBOL(__module_put_and_exit);
346
347/* Find a module section: 0 means not found. */
348static unsigned int find_sec(const struct load_info *info, const char *name)
349{
350 unsigned int i;
351
352 for (i = 1; i < info->hdr->e_shnum; i++) {
353 Elf_Shdr *shdr = &info->sechdrs[i];
354 /* Alloc bit cleared means "ignore it." */
355 if ((shdr->sh_flags & SHF_ALLOC)
356 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
357 return i;
358 }
359 return 0;
360}
361
362/* Find a module section, or NULL. */
363static void *section_addr(const struct load_info *info, const char *name)
364{
365 /* Section 0 has sh_addr 0. */
366 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
367}
368
369/* Find a module section, or NULL. Fill in number of "objects" in section. */
370static void *section_objs(const struct load_info *info,
371 const char *name,
372 size_t object_size,
373 unsigned int *num)
374{
375 unsigned int sec = find_sec(info, name);
376
377 /* Section 0 has sh_addr 0 and sh_size 0. */
378 *num = info->sechdrs[sec].sh_size / object_size;
379 return (void *)info->sechdrs[sec].sh_addr;
380}
381
382/* Find a module section: 0 means not found. Ignores SHF_ALLOC flag. */
383static unsigned int find_any_sec(const struct load_info *info, const char *name)
384{
385 unsigned int i;
386
387 for (i = 1; i < info->hdr->e_shnum; i++) {
388 Elf_Shdr *shdr = &info->sechdrs[i];
389 if (strcmp(info->secstrings + shdr->sh_name, name) == 0)
390 return i;
391 }
392 return 0;
393}
394
395/*
396 * Find a module section, or NULL. Fill in number of "objects" in section.
397 * Ignores SHF_ALLOC flag.
398 */
399static __maybe_unused void *any_section_objs(const struct load_info *info,
400 const char *name,
401 size_t object_size,
402 unsigned int *num)
403{
404 unsigned int sec = find_any_sec(info, name);
405
406 /* Section 0 has sh_addr 0 and sh_size 0. */
407 *num = info->sechdrs[sec].sh_size / object_size;
408 return (void *)info->sechdrs[sec].sh_addr;
409}
410
411/* Provided by the linker */
412extern const struct kernel_symbol __start___ksymtab[];
413extern const struct kernel_symbol __stop___ksymtab[];
414extern const struct kernel_symbol __start___ksymtab_gpl[];
415extern const struct kernel_symbol __stop___ksymtab_gpl[];
416extern const s32 __start___kcrctab[];
417extern const s32 __start___kcrctab_gpl[];
418
419#ifndef CONFIG_MODVERSIONS
420#define symversion(base, idx) NULL
421#else
422#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
423#endif
424
425struct symsearch {
426 const struct kernel_symbol *start, *stop;
427 const s32 *crcs;
428 enum mod_license {
429 NOT_GPL_ONLY,
430 GPL_ONLY,
431 } license;
432};
433
434struct find_symbol_arg {
435 /* Input */
436 const char *name;
437 bool gplok;
438 bool warn;
439
440 /* Output */
441 struct module *owner;
442 const s32 *crc;
443 const struct kernel_symbol *sym;
444 enum mod_license license;
445};
446
447static bool check_exported_symbol(const struct symsearch *syms,
448 struct module *owner,
449 unsigned int symnum, void *data)
450{
451 struct find_symbol_arg *fsa = data;
452
453 if (!fsa->gplok && syms->license == GPL_ONLY)
454 return false;
455 fsa->owner = owner;
456 fsa->crc = symversion(syms->crcs, symnum);
457 fsa->sym = &syms->start[symnum];
458 fsa->license = syms->license;
459 return true;
460}
461
462static unsigned long kernel_symbol_value(const struct kernel_symbol *sym)
463{
464#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
465 return (unsigned long)offset_to_ptr(&sym->value_offset);
466#else
467 return sym->value;
468#endif
469}
470
471static const char *kernel_symbol_name(const struct kernel_symbol *sym)
472{
473#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
474 return offset_to_ptr(&sym->name_offset);
475#else
476 return sym->name;
477#endif
478}
479
480static const char *kernel_symbol_namespace(const struct kernel_symbol *sym)
481{
482#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
483 if (!sym->namespace_offset)
484 return NULL;
485 return offset_to_ptr(&sym->namespace_offset);
486#else
487 return sym->namespace;
488#endif
489}
490
491static int cmp_name(const void *name, const void *sym)
492{
493 return strcmp(name, kernel_symbol_name(sym));
494}
495
496static bool find_exported_symbol_in_section(const struct symsearch *syms,
497 struct module *owner,
498 void *data)
499{
500 struct find_symbol_arg *fsa = data;
501 struct kernel_symbol *sym;
502
503 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
504 sizeof(struct kernel_symbol), cmp_name);
505
506 if (sym != NULL && check_exported_symbol(syms, owner,
507 sym - syms->start, data))
508 return true;
509
510 return false;
511}
512
513/*
514 * Find an exported symbol and return it, along with, (optional) crc and
515 * (optional) module which owns it. Needs preempt disabled or module_mutex.
516 */
517static bool find_symbol(struct find_symbol_arg *fsa)
518{
519 static const struct symsearch arr[] = {
520 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
521 NOT_GPL_ONLY },
522 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
523 __start___kcrctab_gpl,
524 GPL_ONLY },
525 };
526 struct module *mod;
527 unsigned int i;
528
529 module_assert_mutex_or_preempt();
530
531 for (i = 0; i < ARRAY_SIZE(arr); i++)
532 if (find_exported_symbol_in_section(&arr[i], NULL, fsa))
533 return true;
534
535 list_for_each_entry_rcu(mod, &modules, list,
536 lockdep_is_held(&module_mutex)) {
537 struct symsearch arr[] = {
538 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
539 NOT_GPL_ONLY },
540 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
541 mod->gpl_crcs,
542 GPL_ONLY },
543 };
544
545 if (mod->state == MODULE_STATE_UNFORMED)
546 continue;
547
548 for (i = 0; i < ARRAY_SIZE(arr); i++)
549 if (find_exported_symbol_in_section(&arr[i], mod, fsa))
550 return true;
551 }
552
553 pr_debug("Failed to find symbol %s\n", fsa->name);
554 return false;
555}
556
557/*
558 * Search for module by name: must hold module_mutex (or preempt disabled
559 * for read-only access).
560 */
561static struct module *find_module_all(const char *name, size_t len,
562 bool even_unformed)
563{
564 struct module *mod;
565
566 module_assert_mutex_or_preempt();
567
568 list_for_each_entry_rcu(mod, &modules, list,
569 lockdep_is_held(&module_mutex)) {
570 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
571 continue;
572 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
573 return mod;
574 }
575 return NULL;
576}
577
578struct module *find_module(const char *name)
579{
580 return find_module_all(name, strlen(name), false);
581}
582
583#ifdef CONFIG_SMP
584
585static inline void __percpu *mod_percpu(struct module *mod)
586{
587 return mod->percpu;
588}
589
590static int percpu_modalloc(struct module *mod, struct load_info *info)
591{
592 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
593 unsigned long align = pcpusec->sh_addralign;
594
595 if (!pcpusec->sh_size)
596 return 0;
597
598 if (align > PAGE_SIZE) {
599 pr_warn("%s: per-cpu alignment %li > %li\n",
600 mod->name, align, PAGE_SIZE);
601 align = PAGE_SIZE;
602 }
603
604 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
605 if (!mod->percpu) {
606 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
607 mod->name, (unsigned long)pcpusec->sh_size);
608 return -ENOMEM;
609 }
610 mod->percpu_size = pcpusec->sh_size;
611 return 0;
612}
613
614static void percpu_modfree(struct module *mod)
615{
616 free_percpu(mod->percpu);
617}
618
619static unsigned int find_pcpusec(struct load_info *info)
620{
621 return find_sec(info, ".data..percpu");
622}
623
624static void percpu_modcopy(struct module *mod,
625 const void *from, unsigned long size)
626{
627 int cpu;
628
629 for_each_possible_cpu(cpu)
630 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
631}
632
633bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
634{
635 struct module *mod;
636 unsigned int cpu;
637
638 preempt_disable();
639
640 list_for_each_entry_rcu(mod, &modules, list) {
641 if (mod->state == MODULE_STATE_UNFORMED)
642 continue;
643 if (!mod->percpu_size)
644 continue;
645 for_each_possible_cpu(cpu) {
646 void *start = per_cpu_ptr(mod->percpu, cpu);
647 void *va = (void *)addr;
648
649 if (va >= start && va < start + mod->percpu_size) {
650 if (can_addr) {
651 *can_addr = (unsigned long) (va - start);
652 *can_addr += (unsigned long)
653 per_cpu_ptr(mod->percpu,
654 get_boot_cpu_id());
655 }
656 preempt_enable();
657 return true;
658 }
659 }
660 }
661
662 preempt_enable();
663 return false;
664}
665
666/**
667 * is_module_percpu_address() - test whether address is from module static percpu
668 * @addr: address to test
669 *
670 * Test whether @addr belongs to module static percpu area.
671 *
672 * Return: %true if @addr is from module static percpu area
673 */
674bool is_module_percpu_address(unsigned long addr)
675{
676 return __is_module_percpu_address(addr, NULL);
677}
678
679#else /* ... !CONFIG_SMP */
680
681static inline void __percpu *mod_percpu(struct module *mod)
682{
683 return NULL;
684}
685static int percpu_modalloc(struct module *mod, struct load_info *info)
686{
687 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
688 if (info->sechdrs[info->index.pcpu].sh_size != 0)
689 return -ENOMEM;
690 return 0;
691}
692static inline void percpu_modfree(struct module *mod)
693{
694}
695static unsigned int find_pcpusec(struct load_info *info)
696{
697 return 0;
698}
699static inline void percpu_modcopy(struct module *mod,
700 const void *from, unsigned long size)
701{
702 /* pcpusec should be 0, and size of that section should be 0. */
703 BUG_ON(size != 0);
704}
705bool is_module_percpu_address(unsigned long addr)
706{
707 return false;
708}
709
710bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
711{
712 return false;
713}
714
715#endif /* CONFIG_SMP */
716
717#define MODINFO_ATTR(field) \
718static void setup_modinfo_##field(struct module *mod, const char *s) \
719{ \
720 mod->field = kstrdup(s, GFP_KERNEL); \
721} \
722static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
723 struct module_kobject *mk, char *buffer) \
724{ \
725 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
726} \
727static int modinfo_##field##_exists(struct module *mod) \
728{ \
729 return mod->field != NULL; \
730} \
731static void free_modinfo_##field(struct module *mod) \
732{ \
733 kfree(mod->field); \
734 mod->field = NULL; \
735} \
736static struct module_attribute modinfo_##field = { \
737 .attr = { .name = __stringify(field), .mode = 0444 }, \
738 .show = show_modinfo_##field, \
739 .setup = setup_modinfo_##field, \
740 .test = modinfo_##field##_exists, \
741 .free = free_modinfo_##field, \
742};
743
744MODINFO_ATTR(version);
745MODINFO_ATTR(srcversion);
746
747static char last_unloaded_module[MODULE_NAME_LEN+1];
748
749#ifdef CONFIG_MODULE_UNLOAD
750
751EXPORT_TRACEPOINT_SYMBOL(module_get);
752
753/* MODULE_REF_BASE is the base reference count by kmodule loader. */
754#define MODULE_REF_BASE 1
755
756/* Init the unload section of the module. */
757static int module_unload_init(struct module *mod)
758{
759 /*
760 * Initialize reference counter to MODULE_REF_BASE.
761 * refcnt == 0 means module is going.
762 */
763 atomic_set(&mod->refcnt, MODULE_REF_BASE);
764
765 INIT_LIST_HEAD(&mod->source_list);
766 INIT_LIST_HEAD(&mod->target_list);
767
768 /* Hold reference count during initialization. */
769 atomic_inc(&mod->refcnt);
770
771 return 0;
772}
773
774/* Does a already use b? */
775static int already_uses(struct module *a, struct module *b)
776{
777 struct module_use *use;
778
779 list_for_each_entry(use, &b->source_list, source_list) {
780 if (use->source == a) {
781 pr_debug("%s uses %s!\n", a->name, b->name);
782 return 1;
783 }
784 }
785 pr_debug("%s does not use %s!\n", a->name, b->name);
786 return 0;
787}
788
789/*
790 * Module a uses b
791 * - we add 'a' as a "source", 'b' as a "target" of module use
792 * - the module_use is added to the list of 'b' sources (so
793 * 'b' can walk the list to see who sourced them), and of 'a'
794 * targets (so 'a' can see what modules it targets).
795 */
796static int add_module_usage(struct module *a, struct module *b)
797{
798 struct module_use *use;
799
800 pr_debug("Allocating new usage for %s.\n", a->name);
801 use = kmalloc(sizeof(*use), GFP_ATOMIC);
802 if (!use)
803 return -ENOMEM;
804
805 use->source = a;
806 use->target = b;
807 list_add(&use->source_list, &b->source_list);
808 list_add(&use->target_list, &a->target_list);
809 return 0;
810}
811
812/* Module a uses b: caller needs module_mutex() */
813static int ref_module(struct module *a, struct module *b)
814{
815 int err;
816
817 if (b == NULL || already_uses(a, b))
818 return 0;
819
820 /* If module isn't available, we fail. */
821 err = strong_try_module_get(b);
822 if (err)
823 return err;
824
825 err = add_module_usage(a, b);
826 if (err) {
827 module_put(b);
828 return err;
829 }
830 return 0;
831}
832
833/* Clear the unload stuff of the module. */
834static void module_unload_free(struct module *mod)
835{
836 struct module_use *use, *tmp;
837
838 mutex_lock(&module_mutex);
839 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
840 struct module *i = use->target;
841 pr_debug("%s unusing %s\n", mod->name, i->name);
842 module_put(i);
843 list_del(&use->source_list);
844 list_del(&use->target_list);
845 kfree(use);
846 }
847 mutex_unlock(&module_mutex);
848}
849
850#ifdef CONFIG_MODULE_FORCE_UNLOAD
851static inline int try_force_unload(unsigned int flags)
852{
853 int ret = (flags & O_TRUNC);
854 if (ret)
855 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
856 return ret;
857}
858#else
859static inline int try_force_unload(unsigned int flags)
860{
861 return 0;
862}
863#endif /* CONFIG_MODULE_FORCE_UNLOAD */
864
865/* Try to release refcount of module, 0 means success. */
866static int try_release_module_ref(struct module *mod)
867{
868 int ret;
869
870 /* Try to decrement refcnt which we set at loading */
871 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
872 BUG_ON(ret < 0);
873 if (ret)
874 /* Someone can put this right now, recover with checking */
875 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
876
877 return ret;
878}
879
880static int try_stop_module(struct module *mod, int flags, int *forced)
881{
882 /* If it's not unused, quit unless we're forcing. */
883 if (try_release_module_ref(mod) != 0) {
884 *forced = try_force_unload(flags);
885 if (!(*forced))
886 return -EWOULDBLOCK;
887 }
888
889 /* Mark it as dying. */
890 mod->state = MODULE_STATE_GOING;
891
892 return 0;
893}
894
895/**
896 * module_refcount() - return the refcount or -1 if unloading
897 * @mod: the module we're checking
898 *
899 * Return:
900 * -1 if the module is in the process of unloading
901 * otherwise the number of references in the kernel to the module
902 */
903int module_refcount(struct module *mod)
904{
905 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
906}
907EXPORT_SYMBOL(module_refcount);
908
909/* This exists whether we can unload or not */
910static void free_module(struct module *mod);
911
912SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
913 unsigned int, flags)
914{
915 struct module *mod;
916 char name[MODULE_NAME_LEN];
917 int ret, forced = 0;
918
919 if (!capable(CAP_SYS_MODULE) || modules_disabled)
920 return -EPERM;
921
922 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
923 return -EFAULT;
924 name[MODULE_NAME_LEN-1] = '\0';
925
926 audit_log_kern_module(name);
927
928 if (mutex_lock_interruptible(&module_mutex) != 0)
929 return -EINTR;
930
931 mod = find_module(name);
932 if (!mod) {
933 ret = -ENOENT;
934 goto out;
935 }
936
937 if (!list_empty(&mod->source_list)) {
938 /* Other modules depend on us: get rid of them first. */
939 ret = -EWOULDBLOCK;
940 goto out;
941 }
942
943 /* Doing init or already dying? */
944 if (mod->state != MODULE_STATE_LIVE) {
945 /* FIXME: if (force), slam module count damn the torpedoes */
946 pr_debug("%s already dying\n", mod->name);
947 ret = -EBUSY;
948 goto out;
949 }
950
951 /* If it has an init func, it must have an exit func to unload */
952 if (mod->init && !mod->exit) {
953 forced = try_force_unload(flags);
954 if (!forced) {
955 /* This module can't be removed */
956 ret = -EBUSY;
957 goto out;
958 }
959 }
960
961 /* Stop the machine so refcounts can't move and disable module. */
962 ret = try_stop_module(mod, flags, &forced);
963 if (ret != 0)
964 goto out;
965
966 mutex_unlock(&module_mutex);
967 /* Final destruction now no one is using it. */
968 if (mod->exit != NULL)
969 mod->exit();
970 blocking_notifier_call_chain(&module_notify_list,
971 MODULE_STATE_GOING, mod);
972 klp_module_going(mod);
973 ftrace_release_mod(mod);
974
975 async_synchronize_full();
976
977 /* Store the name of the last unloaded module for diagnostic purposes */
978 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
979
980 free_module(mod);
981 /* someone could wait for the module in add_unformed_module() */
982 wake_up_all(&module_wq);
983 return 0;
984out:
985 mutex_unlock(&module_mutex);
986 return ret;
987}
988
989static inline void print_unload_info(struct seq_file *m, struct module *mod)
990{
991 struct module_use *use;
992 int printed_something = 0;
993
994 seq_printf(m, " %i ", module_refcount(mod));
995
996 /*
997 * Always include a trailing , so userspace can differentiate
998 * between this and the old multi-field proc format.
999 */
1000 list_for_each_entry(use, &mod->source_list, source_list) {
1001 printed_something = 1;
1002 seq_printf(m, "%s,", use->source->name);
1003 }
1004
1005 if (mod->init != NULL && mod->exit == NULL) {
1006 printed_something = 1;
1007 seq_puts(m, "[permanent],");
1008 }
1009
1010 if (!printed_something)
1011 seq_puts(m, "-");
1012}
1013
1014void __symbol_put(const char *symbol)
1015{
1016 struct find_symbol_arg fsa = {
1017 .name = symbol,
1018 .gplok = true,
1019 };
1020
1021 preempt_disable();
1022 BUG_ON(!find_symbol(&fsa));
1023 module_put(fsa.owner);
1024 preempt_enable();
1025}
1026EXPORT_SYMBOL(__symbol_put);
1027
1028/* Note this assumes addr is a function, which it currently always is. */
1029void symbol_put_addr(void *addr)
1030{
1031 struct module *modaddr;
1032 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1033
1034 if (core_kernel_text(a))
1035 return;
1036
1037 /*
1038 * Even though we hold a reference on the module; we still need to
1039 * disable preemption in order to safely traverse the data structure.
1040 */
1041 preempt_disable();
1042 modaddr = __module_text_address(a);
1043 BUG_ON(!modaddr);
1044 module_put(modaddr);
1045 preempt_enable();
1046}
1047EXPORT_SYMBOL_GPL(symbol_put_addr);
1048
1049static ssize_t show_refcnt(struct module_attribute *mattr,
1050 struct module_kobject *mk, char *buffer)
1051{
1052 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1053}
1054
1055static struct module_attribute modinfo_refcnt =
1056 __ATTR(refcnt, 0444, show_refcnt, NULL);
1057
1058void __module_get(struct module *module)
1059{
1060 if (module) {
1061 preempt_disable();
1062 atomic_inc(&module->refcnt);
1063 trace_module_get(module, _RET_IP_);
1064 preempt_enable();
1065 }
1066}
1067EXPORT_SYMBOL(__module_get);
1068
1069bool try_module_get(struct module *module)
1070{
1071 bool ret = true;
1072
1073 if (module) {
1074 preempt_disable();
1075 /* Note: here, we can fail to get a reference */
1076 if (likely(module_is_live(module) &&
1077 atomic_inc_not_zero(&module->refcnt) != 0))
1078 trace_module_get(module, _RET_IP_);
1079 else
1080 ret = false;
1081
1082 preempt_enable();
1083 }
1084 return ret;
1085}
1086EXPORT_SYMBOL(try_module_get);
1087
1088void module_put(struct module *module)
1089{
1090 int ret;
1091
1092 if (module) {
1093 preempt_disable();
1094 ret = atomic_dec_if_positive(&module->refcnt);
1095 WARN_ON(ret < 0); /* Failed to put refcount */
1096 trace_module_put(module, _RET_IP_);
1097 preempt_enable();
1098 }
1099}
1100EXPORT_SYMBOL(module_put);
1101
1102#else /* !CONFIG_MODULE_UNLOAD */
1103static inline void print_unload_info(struct seq_file *m, struct module *mod)
1104{
1105 /* We don't know the usage count, or what modules are using. */
1106 seq_puts(m, " - -");
1107}
1108
1109static inline void module_unload_free(struct module *mod)
1110{
1111}
1112
1113static int ref_module(struct module *a, struct module *b)
1114{
1115 return strong_try_module_get(b);
1116}
1117
1118static inline int module_unload_init(struct module *mod)
1119{
1120 return 0;
1121}
1122#endif /* CONFIG_MODULE_UNLOAD */
1123
1124static size_t module_flags_taint(struct module *mod, char *buf)
1125{
1126 size_t l = 0;
1127 int i;
1128
1129 for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
1130 if (taint_flags[i].module && test_bit(i, &mod->taints))
1131 buf[l++] = taint_flags[i].c_true;
1132 }
1133
1134 return l;
1135}
1136
1137static ssize_t show_initstate(struct module_attribute *mattr,
1138 struct module_kobject *mk, char *buffer)
1139{
1140 const char *state = "unknown";
1141
1142 switch (mk->mod->state) {
1143 case MODULE_STATE_LIVE:
1144 state = "live";
1145 break;
1146 case MODULE_STATE_COMING:
1147 state = "coming";
1148 break;
1149 case MODULE_STATE_GOING:
1150 state = "going";
1151 break;
1152 default:
1153 BUG();
1154 }
1155 return sprintf(buffer, "%s\n", state);
1156}
1157
1158static struct module_attribute modinfo_initstate =
1159 __ATTR(initstate, 0444, show_initstate, NULL);
1160
1161static ssize_t store_uevent(struct module_attribute *mattr,
1162 struct module_kobject *mk,
1163 const char *buffer, size_t count)
1164{
1165 int rc;
1166
1167 rc = kobject_synth_uevent(&mk->kobj, buffer, count);
1168 return rc ? rc : count;
1169}
1170
1171struct module_attribute module_uevent =
1172 __ATTR(uevent, 0200, NULL, store_uevent);
1173
1174static ssize_t show_coresize(struct module_attribute *mattr,
1175 struct module_kobject *mk, char *buffer)
1176{
1177 return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1178}
1179
1180static struct module_attribute modinfo_coresize =
1181 __ATTR(coresize, 0444, show_coresize, NULL);
1182
1183static ssize_t show_initsize(struct module_attribute *mattr,
1184 struct module_kobject *mk, char *buffer)
1185{
1186 return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1187}
1188
1189static struct module_attribute modinfo_initsize =
1190 __ATTR(initsize, 0444, show_initsize, NULL);
1191
1192static ssize_t show_taint(struct module_attribute *mattr,
1193 struct module_kobject *mk, char *buffer)
1194{
1195 size_t l;
1196
1197 l = module_flags_taint(mk->mod, buffer);
1198 buffer[l++] = '\n';
1199 return l;
1200}
1201
1202static struct module_attribute modinfo_taint =
1203 __ATTR(taint, 0444, show_taint, NULL);
1204
1205static struct module_attribute *modinfo_attrs[] = {
1206 &module_uevent,
1207 &modinfo_version,
1208 &modinfo_srcversion,
1209 &modinfo_initstate,
1210 &modinfo_coresize,
1211 &modinfo_initsize,
1212 &modinfo_taint,
1213#ifdef CONFIG_MODULE_UNLOAD
1214 &modinfo_refcnt,
1215#endif
1216 NULL,
1217};
1218
1219static const char vermagic[] = VERMAGIC_STRING;
1220
1221static int try_to_force_load(struct module *mod, const char *reason)
1222{
1223#ifdef CONFIG_MODULE_FORCE_LOAD
1224 if (!test_taint(TAINT_FORCED_MODULE))
1225 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1226 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1227 return 0;
1228#else
1229 return -ENOEXEC;
1230#endif
1231}
1232
1233#ifdef CONFIG_MODVERSIONS
1234
1235static u32 resolve_rel_crc(const s32 *crc)
1236{
1237 return *(u32 *)((void *)crc + *crc);
1238}
1239
1240static int check_version(const struct load_info *info,
1241 const char *symname,
1242 struct module *mod,
1243 const s32 *crc)
1244{
1245 Elf_Shdr *sechdrs = info->sechdrs;
1246 unsigned int versindex = info->index.vers;
1247 unsigned int i, num_versions;
1248 struct modversion_info *versions;
1249
1250 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1251 if (!crc)
1252 return 1;
1253
1254 /* No versions at all? modprobe --force does this. */
1255 if (versindex == 0)
1256 return try_to_force_load(mod, symname) == 0;
1257
1258 versions = (void *) sechdrs[versindex].sh_addr;
1259 num_versions = sechdrs[versindex].sh_size
1260 / sizeof(struct modversion_info);
1261
1262 for (i = 0; i < num_versions; i++) {
1263 u32 crcval;
1264
1265 if (strcmp(versions[i].name, symname) != 0)
1266 continue;
1267
1268 if (IS_ENABLED(CONFIG_MODULE_REL_CRCS))
1269 crcval = resolve_rel_crc(crc);
1270 else
1271 crcval = *crc;
1272 if (versions[i].crc == crcval)
1273 return 1;
1274 pr_debug("Found checksum %X vs module %lX\n",
1275 crcval, versions[i].crc);
1276 goto bad_version;
1277 }
1278
1279 /* Broken toolchain. Warn once, then let it go.. */
1280 pr_warn_once("%s: no symbol version for %s\n", info->name, symname);
1281 return 1;
1282
1283bad_version:
1284 pr_warn("%s: disagrees about version of symbol %s\n",
1285 info->name, symname);
1286 return 0;
1287}
1288
1289static inline int check_modstruct_version(const struct load_info *info,
1290 struct module *mod)
1291{
1292 struct find_symbol_arg fsa = {
1293 .name = "module_layout",
1294 .gplok = true,
1295 };
1296
1297 /*
1298 * Since this should be found in kernel (which can't be removed), no
1299 * locking is necessary -- use preempt_disable() to placate lockdep.
1300 */
1301 preempt_disable();
1302 if (!find_symbol(&fsa)) {
1303 preempt_enable();
1304 BUG();
1305 }
1306 preempt_enable();
1307 return check_version(info, "module_layout", mod, fsa.crc);
1308}
1309
1310/* First part is kernel version, which we ignore if module has crcs. */
1311static inline int same_magic(const char *amagic, const char *bmagic,
1312 bool has_crcs)
1313{
1314 if (has_crcs) {
1315 amagic += strcspn(amagic, " ");
1316 bmagic += strcspn(bmagic, " ");
1317 }
1318 return strcmp(amagic, bmagic) == 0;
1319}
1320#else
1321static inline int check_version(const struct load_info *info,
1322 const char *symname,
1323 struct module *mod,
1324 const s32 *crc)
1325{
1326 return 1;
1327}
1328
1329static inline int check_modstruct_version(const struct load_info *info,
1330 struct module *mod)
1331{
1332 return 1;
1333}
1334
1335static inline int same_magic(const char *amagic, const char *bmagic,
1336 bool has_crcs)
1337{
1338 return strcmp(amagic, bmagic) == 0;
1339}
1340#endif /* CONFIG_MODVERSIONS */
1341
1342static char *get_modinfo(const struct load_info *info, const char *tag);
1343static char *get_next_modinfo(const struct load_info *info, const char *tag,
1344 char *prev);
1345
1346static int verify_namespace_is_imported(const struct load_info *info,
1347 const struct kernel_symbol *sym,
1348 struct module *mod)
1349{
1350 const char *namespace;
1351 char *imported_namespace;
1352
1353 namespace = kernel_symbol_namespace(sym);
1354 if (namespace && namespace[0]) {
1355 imported_namespace = get_modinfo(info, "import_ns");
1356 while (imported_namespace) {
1357 if (strcmp(namespace, imported_namespace) == 0)
1358 return 0;
1359 imported_namespace = get_next_modinfo(
1360 info, "import_ns", imported_namespace);
1361 }
1362#ifdef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1363 pr_warn(
1364#else
1365 pr_err(
1366#endif
1367 "%s: module uses symbol (%s) from namespace %s, but does not import it.\n",
1368 mod->name, kernel_symbol_name(sym), namespace);
1369#ifndef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1370 return -EINVAL;
1371#endif
1372 }
1373 return 0;
1374}
1375
1376static bool inherit_taint(struct module *mod, struct module *owner)
1377{
1378 if (!owner || !test_bit(TAINT_PROPRIETARY_MODULE, &owner->taints))
1379 return true;
1380
1381 if (mod->using_gplonly_symbols) {
1382 pr_err("%s: module using GPL-only symbols uses symbols from proprietary module %s.\n",
1383 mod->name, owner->name);
1384 return false;
1385 }
1386
1387 if (!test_bit(TAINT_PROPRIETARY_MODULE, &mod->taints)) {
1388 pr_warn("%s: module uses symbols from proprietary module %s, inheriting taint.\n",
1389 mod->name, owner->name);
1390 set_bit(TAINT_PROPRIETARY_MODULE, &mod->taints);
1391 }
1392 return true;
1393}
1394
1395/* Resolve a symbol for this module. I.e. if we find one, record usage. */
1396static const struct kernel_symbol *resolve_symbol(struct module *mod,
1397 const struct load_info *info,
1398 const char *name,
1399 char ownername[])
1400{
1401 struct find_symbol_arg fsa = {
1402 .name = name,
1403 .gplok = !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)),
1404 .warn = true,
1405 };
1406 int err;
1407
1408 /*
1409 * The module_mutex should not be a heavily contended lock;
1410 * if we get the occasional sleep here, we'll go an extra iteration
1411 * in the wait_event_interruptible(), which is harmless.
1412 */
1413 sched_annotate_sleep();
1414 mutex_lock(&module_mutex);
1415 if (!find_symbol(&fsa))
1416 goto unlock;
1417
1418 if (fsa.license == GPL_ONLY)
1419 mod->using_gplonly_symbols = true;
1420
1421 if (!inherit_taint(mod, fsa.owner)) {
1422 fsa.sym = NULL;
1423 goto getname;
1424 }
1425
1426 if (!check_version(info, name, mod, fsa.crc)) {
1427 fsa.sym = ERR_PTR(-EINVAL);
1428 goto getname;
1429 }
1430
1431 err = verify_namespace_is_imported(info, fsa.sym, mod);
1432 if (err) {
1433 fsa.sym = ERR_PTR(err);
1434 goto getname;
1435 }
1436
1437 err = ref_module(mod, fsa.owner);
1438 if (err) {
1439 fsa.sym = ERR_PTR(err);
1440 goto getname;
1441 }
1442
1443getname:
1444 /* We must make copy under the lock if we failed to get ref. */
1445 strncpy(ownername, module_name(fsa.owner), MODULE_NAME_LEN);
1446unlock:
1447 mutex_unlock(&module_mutex);
1448 return fsa.sym;
1449}
1450
1451static const struct kernel_symbol *
1452resolve_symbol_wait(struct module *mod,
1453 const struct load_info *info,
1454 const char *name)
1455{
1456 const struct kernel_symbol *ksym;
1457 char owner[MODULE_NAME_LEN];
1458
1459 if (wait_event_interruptible_timeout(module_wq,
1460 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1461 || PTR_ERR(ksym) != -EBUSY,
1462 30 * HZ) <= 0) {
1463 pr_warn("%s: gave up waiting for init of module %s.\n",
1464 mod->name, owner);
1465 }
1466 return ksym;
1467}
1468
1469#ifdef CONFIG_KALLSYMS
1470static inline bool sect_empty(const Elf_Shdr *sect)
1471{
1472 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1473}
1474#endif
1475
1476/*
1477 * /sys/module/foo/sections stuff
1478 * J. Corbet <corbet@lwn.net>
1479 */
1480#ifdef CONFIG_SYSFS
1481
1482#ifdef CONFIG_KALLSYMS
1483struct module_sect_attr {
1484 struct bin_attribute battr;
1485 unsigned long address;
1486};
1487
1488struct module_sect_attrs {
1489 struct attribute_group grp;
1490 unsigned int nsections;
1491 struct module_sect_attr attrs[];
1492};
1493
1494#define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4))
1495static ssize_t module_sect_read(struct file *file, struct kobject *kobj,
1496 struct bin_attribute *battr,
1497 char *buf, loff_t pos, size_t count)
1498{
1499 struct module_sect_attr *sattr =
1500 container_of(battr, struct module_sect_attr, battr);
1501 char bounce[MODULE_SECT_READ_SIZE + 1];
1502 size_t wrote;
1503
1504 if (pos != 0)
1505 return -EINVAL;
1506
1507 /*
1508 * Since we're a binary read handler, we must account for the
1509 * trailing NUL byte that sprintf will write: if "buf" is
1510 * too small to hold the NUL, or the NUL is exactly the last
1511 * byte, the read will look like it got truncated by one byte.
1512 * Since there is no way to ask sprintf nicely to not write
1513 * the NUL, we have to use a bounce buffer.
1514 */
1515 wrote = scnprintf(bounce, sizeof(bounce), "0x%px\n",
1516 kallsyms_show_value(file->f_cred)
1517 ? (void *)sattr->address : NULL);
1518 count = min(count, wrote);
1519 memcpy(buf, bounce, count);
1520
1521 return count;
1522}
1523
1524static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1525{
1526 unsigned int section;
1527
1528 for (section = 0; section < sect_attrs->nsections; section++)
1529 kfree(sect_attrs->attrs[section].battr.attr.name);
1530 kfree(sect_attrs);
1531}
1532
1533static void add_sect_attrs(struct module *mod, const struct load_info *info)
1534{
1535 unsigned int nloaded = 0, i, size[2];
1536 struct module_sect_attrs *sect_attrs;
1537 struct module_sect_attr *sattr;
1538 struct bin_attribute **gattr;
1539
1540 /* Count loaded sections and allocate structures */
1541 for (i = 0; i < info->hdr->e_shnum; i++)
1542 if (!sect_empty(&info->sechdrs[i]))
1543 nloaded++;
1544 size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded),
1545 sizeof(sect_attrs->grp.bin_attrs[0]));
1546 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.bin_attrs[0]);
1547 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1548 if (sect_attrs == NULL)
1549 return;
1550
1551 /* Setup section attributes. */
1552 sect_attrs->grp.name = "sections";
1553 sect_attrs->grp.bin_attrs = (void *)sect_attrs + size[0];
1554
1555 sect_attrs->nsections = 0;
1556 sattr = §_attrs->attrs[0];
1557 gattr = §_attrs->grp.bin_attrs[0];
1558 for (i = 0; i < info->hdr->e_shnum; i++) {
1559 Elf_Shdr *sec = &info->sechdrs[i];
1560 if (sect_empty(sec))
1561 continue;
1562 sysfs_bin_attr_init(&sattr->battr);
1563 sattr->address = sec->sh_addr;
1564 sattr->battr.attr.name =
1565 kstrdup(info->secstrings + sec->sh_name, GFP_KERNEL);
1566 if (sattr->battr.attr.name == NULL)
1567 goto out;
1568 sect_attrs->nsections++;
1569 sattr->battr.read = module_sect_read;
1570 sattr->battr.size = MODULE_SECT_READ_SIZE;
1571 sattr->battr.attr.mode = 0400;
1572 *(gattr++) = &(sattr++)->battr;
1573 }
1574 *gattr = NULL;
1575
1576 if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp))
1577 goto out;
1578
1579 mod->sect_attrs = sect_attrs;
1580 return;
1581 out:
1582 free_sect_attrs(sect_attrs);
1583}
1584
1585static void remove_sect_attrs(struct module *mod)
1586{
1587 if (mod->sect_attrs) {
1588 sysfs_remove_group(&mod->mkobj.kobj,
1589 &mod->sect_attrs->grp);
1590 /*
1591 * We are positive that no one is using any sect attrs
1592 * at this point. Deallocate immediately.
1593 */
1594 free_sect_attrs(mod->sect_attrs);
1595 mod->sect_attrs = NULL;
1596 }
1597}
1598
1599/*
1600 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1601 */
1602
1603struct module_notes_attrs {
1604 struct kobject *dir;
1605 unsigned int notes;
1606 struct bin_attribute attrs[];
1607};
1608
1609static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1610 struct bin_attribute *bin_attr,
1611 char *buf, loff_t pos, size_t count)
1612{
1613 /*
1614 * The caller checked the pos and count against our size.
1615 */
1616 memcpy(buf, bin_attr->private + pos, count);
1617 return count;
1618}
1619
1620static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1621 unsigned int i)
1622{
1623 if (notes_attrs->dir) {
1624 while (i-- > 0)
1625 sysfs_remove_bin_file(notes_attrs->dir,
1626 ¬es_attrs->attrs[i]);
1627 kobject_put(notes_attrs->dir);
1628 }
1629 kfree(notes_attrs);
1630}
1631
1632static void add_notes_attrs(struct module *mod, const struct load_info *info)
1633{
1634 unsigned int notes, loaded, i;
1635 struct module_notes_attrs *notes_attrs;
1636 struct bin_attribute *nattr;
1637
1638 /* failed to create section attributes, so can't create notes */
1639 if (!mod->sect_attrs)
1640 return;
1641
1642 /* Count notes sections and allocate structures. */
1643 notes = 0;
1644 for (i = 0; i < info->hdr->e_shnum; i++)
1645 if (!sect_empty(&info->sechdrs[i]) &&
1646 (info->sechdrs[i].sh_type == SHT_NOTE))
1647 ++notes;
1648
1649 if (notes == 0)
1650 return;
1651
1652 notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes),
1653 GFP_KERNEL);
1654 if (notes_attrs == NULL)
1655 return;
1656
1657 notes_attrs->notes = notes;
1658 nattr = ¬es_attrs->attrs[0];
1659 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1660 if (sect_empty(&info->sechdrs[i]))
1661 continue;
1662 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1663 sysfs_bin_attr_init(nattr);
1664 nattr->attr.name = mod->sect_attrs->attrs[loaded].battr.attr.name;
1665 nattr->attr.mode = S_IRUGO;
1666 nattr->size = info->sechdrs[i].sh_size;
1667 nattr->private = (void *) info->sechdrs[i].sh_addr;
1668 nattr->read = module_notes_read;
1669 ++nattr;
1670 }
1671 ++loaded;
1672 }
1673
1674 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1675 if (!notes_attrs->dir)
1676 goto out;
1677
1678 for (i = 0; i < notes; ++i)
1679 if (sysfs_create_bin_file(notes_attrs->dir,
1680 ¬es_attrs->attrs[i]))
1681 goto out;
1682
1683 mod->notes_attrs = notes_attrs;
1684 return;
1685
1686 out:
1687 free_notes_attrs(notes_attrs, i);
1688}
1689
1690static void remove_notes_attrs(struct module *mod)
1691{
1692 if (mod->notes_attrs)
1693 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1694}
1695
1696#else
1697
1698static inline void add_sect_attrs(struct module *mod,
1699 const struct load_info *info)
1700{
1701}
1702
1703static inline void remove_sect_attrs(struct module *mod)
1704{
1705}
1706
1707static inline void add_notes_attrs(struct module *mod,
1708 const struct load_info *info)
1709{
1710}
1711
1712static inline void remove_notes_attrs(struct module *mod)
1713{
1714}
1715#endif /* CONFIG_KALLSYMS */
1716
1717static void del_usage_links(struct module *mod)
1718{
1719#ifdef CONFIG_MODULE_UNLOAD
1720 struct module_use *use;
1721
1722 mutex_lock(&module_mutex);
1723 list_for_each_entry(use, &mod->target_list, target_list)
1724 sysfs_remove_link(use->target->holders_dir, mod->name);
1725 mutex_unlock(&module_mutex);
1726#endif
1727}
1728
1729static int add_usage_links(struct module *mod)
1730{
1731 int ret = 0;
1732#ifdef CONFIG_MODULE_UNLOAD
1733 struct module_use *use;
1734
1735 mutex_lock(&module_mutex);
1736 list_for_each_entry(use, &mod->target_list, target_list) {
1737 ret = sysfs_create_link(use->target->holders_dir,
1738 &mod->mkobj.kobj, mod->name);
1739 if (ret)
1740 break;
1741 }
1742 mutex_unlock(&module_mutex);
1743 if (ret)
1744 del_usage_links(mod);
1745#endif
1746 return ret;
1747}
1748
1749static void module_remove_modinfo_attrs(struct module *mod, int end);
1750
1751static int module_add_modinfo_attrs(struct module *mod)
1752{
1753 struct module_attribute *attr;
1754 struct module_attribute *temp_attr;
1755 int error = 0;
1756 int i;
1757
1758 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1759 (ARRAY_SIZE(modinfo_attrs) + 1)),
1760 GFP_KERNEL);
1761 if (!mod->modinfo_attrs)
1762 return -ENOMEM;
1763
1764 temp_attr = mod->modinfo_attrs;
1765 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1766 if (!attr->test || attr->test(mod)) {
1767 memcpy(temp_attr, attr, sizeof(*temp_attr));
1768 sysfs_attr_init(&temp_attr->attr);
1769 error = sysfs_create_file(&mod->mkobj.kobj,
1770 &temp_attr->attr);
1771 if (error)
1772 goto error_out;
1773 ++temp_attr;
1774 }
1775 }
1776
1777 return 0;
1778
1779error_out:
1780 if (i > 0)
1781 module_remove_modinfo_attrs(mod, --i);
1782 else
1783 kfree(mod->modinfo_attrs);
1784 return error;
1785}
1786
1787static void module_remove_modinfo_attrs(struct module *mod, int end)
1788{
1789 struct module_attribute *attr;
1790 int i;
1791
1792 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1793 if (end >= 0 && i > end)
1794 break;
1795 /* pick a field to test for end of list */
1796 if (!attr->attr.name)
1797 break;
1798 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1799 if (attr->free)
1800 attr->free(mod);
1801 }
1802 kfree(mod->modinfo_attrs);
1803}
1804
1805static void mod_kobject_put(struct module *mod)
1806{
1807 DECLARE_COMPLETION_ONSTACK(c);
1808 mod->mkobj.kobj_completion = &c;
1809 kobject_put(&mod->mkobj.kobj);
1810 wait_for_completion(&c);
1811}
1812
1813static int mod_sysfs_init(struct module *mod)
1814{
1815 int err;
1816 struct kobject *kobj;
1817
1818 if (!module_sysfs_initialized) {
1819 pr_err("%s: module sysfs not initialized\n", mod->name);
1820 err = -EINVAL;
1821 goto out;
1822 }
1823
1824 kobj = kset_find_obj(module_kset, mod->name);
1825 if (kobj) {
1826 pr_err("%s: module is already loaded\n", mod->name);
1827 kobject_put(kobj);
1828 err = -EINVAL;
1829 goto out;
1830 }
1831
1832 mod->mkobj.mod = mod;
1833
1834 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1835 mod->mkobj.kobj.kset = module_kset;
1836 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1837 "%s", mod->name);
1838 if (err)
1839 mod_kobject_put(mod);
1840
1841out:
1842 return err;
1843}
1844
1845static int mod_sysfs_setup(struct module *mod,
1846 const struct load_info *info,
1847 struct kernel_param *kparam,
1848 unsigned int num_params)
1849{
1850 int err;
1851
1852 err = mod_sysfs_init(mod);
1853 if (err)
1854 goto out;
1855
1856 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1857 if (!mod->holders_dir) {
1858 err = -ENOMEM;
1859 goto out_unreg;
1860 }
1861
1862 err = module_param_sysfs_setup(mod, kparam, num_params);
1863 if (err)
1864 goto out_unreg_holders;
1865
1866 err = module_add_modinfo_attrs(mod);
1867 if (err)
1868 goto out_unreg_param;
1869
1870 err = add_usage_links(mod);
1871 if (err)
1872 goto out_unreg_modinfo_attrs;
1873
1874 add_sect_attrs(mod, info);
1875 add_notes_attrs(mod, info);
1876
1877 return 0;
1878
1879out_unreg_modinfo_attrs:
1880 module_remove_modinfo_attrs(mod, -1);
1881out_unreg_param:
1882 module_param_sysfs_remove(mod);
1883out_unreg_holders:
1884 kobject_put(mod->holders_dir);
1885out_unreg:
1886 mod_kobject_put(mod);
1887out:
1888 return err;
1889}
1890
1891static void mod_sysfs_fini(struct module *mod)
1892{
1893 remove_notes_attrs(mod);
1894 remove_sect_attrs(mod);
1895 mod_kobject_put(mod);
1896}
1897
1898static void init_param_lock(struct module *mod)
1899{
1900 mutex_init(&mod->param_lock);
1901}
1902#else /* !CONFIG_SYSFS */
1903
1904static int mod_sysfs_setup(struct module *mod,
1905 const struct load_info *info,
1906 struct kernel_param *kparam,
1907 unsigned int num_params)
1908{
1909 return 0;
1910}
1911
1912static void mod_sysfs_fini(struct module *mod)
1913{
1914}
1915
1916static void module_remove_modinfo_attrs(struct module *mod, int end)
1917{
1918}
1919
1920static void del_usage_links(struct module *mod)
1921{
1922}
1923
1924static void init_param_lock(struct module *mod)
1925{
1926}
1927#endif /* CONFIG_SYSFS */
1928
1929static void mod_sysfs_teardown(struct module *mod)
1930{
1931 del_usage_links(mod);
1932 module_remove_modinfo_attrs(mod, -1);
1933 module_param_sysfs_remove(mod);
1934 kobject_put(mod->mkobj.drivers_dir);
1935 kobject_put(mod->holders_dir);
1936 mod_sysfs_fini(mod);
1937}
1938
1939/*
1940 * LKM RO/NX protection: protect module's text/ro-data
1941 * from modification and any data from execution.
1942 *
1943 * General layout of module is:
1944 * [text] [read-only-data] [ro-after-init] [writable data]
1945 * text_size -----^ ^ ^ ^
1946 * ro_size ------------------------| | |
1947 * ro_after_init_size -----------------------------| |
1948 * size -----------------------------------------------------------|
1949 *
1950 * These values are always page-aligned (as is base)
1951 */
1952
1953/*
1954 * Since some arches are moving towards PAGE_KERNEL module allocations instead
1955 * of PAGE_KERNEL_EXEC, keep frob_text() and module_enable_x() outside of the
1956 * CONFIG_STRICT_MODULE_RWX block below because they are needed regardless of
1957 * whether we are strict.
1958 */
1959#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
1960static void frob_text(const struct module_layout *layout,
1961 int (*set_memory)(unsigned long start, int num_pages))
1962{
1963 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1964 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1965 set_memory((unsigned long)layout->base,
1966 layout->text_size >> PAGE_SHIFT);
1967}
1968
1969static void module_enable_x(const struct module *mod)
1970{
1971 frob_text(&mod->core_layout, set_memory_x);
1972 frob_text(&mod->init_layout, set_memory_x);
1973}
1974#else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
1975static void module_enable_x(const struct module *mod) { }
1976#endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
1977
1978#ifdef CONFIG_STRICT_MODULE_RWX
1979static void frob_rodata(const struct module_layout *layout,
1980 int (*set_memory)(unsigned long start, int num_pages))
1981{
1982 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1983 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1984 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1985 set_memory((unsigned long)layout->base + layout->text_size,
1986 (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
1987}
1988
1989static void frob_ro_after_init(const struct module_layout *layout,
1990 int (*set_memory)(unsigned long start, int num_pages))
1991{
1992 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1993 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1994 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1995 set_memory((unsigned long)layout->base + layout->ro_size,
1996 (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
1997}
1998
1999static void frob_writable_data(const struct module_layout *layout,
2000 int (*set_memory)(unsigned long start, int num_pages))
2001{
2002 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
2003 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
2004 BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
2005 set_memory((unsigned long)layout->base + layout->ro_after_init_size,
2006 (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
2007}
2008
2009static void module_enable_ro(const struct module *mod, bool after_init)
2010{
2011 if (!rodata_enabled)
2012 return;
2013
2014 set_vm_flush_reset_perms(mod->core_layout.base);
2015 set_vm_flush_reset_perms(mod->init_layout.base);
2016 frob_text(&mod->core_layout, set_memory_ro);
2017
2018 frob_rodata(&mod->core_layout, set_memory_ro);
2019 frob_text(&mod->init_layout, set_memory_ro);
2020 frob_rodata(&mod->init_layout, set_memory_ro);
2021
2022 if (after_init)
2023 frob_ro_after_init(&mod->core_layout, set_memory_ro);
2024}
2025
2026static void module_enable_nx(const struct module *mod)
2027{
2028 frob_rodata(&mod->core_layout, set_memory_nx);
2029 frob_ro_after_init(&mod->core_layout, set_memory_nx);
2030 frob_writable_data(&mod->core_layout, set_memory_nx);
2031 frob_rodata(&mod->init_layout, set_memory_nx);
2032 frob_writable_data(&mod->init_layout, set_memory_nx);
2033}
2034
2035static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
2036 char *secstrings, struct module *mod)
2037{
2038 const unsigned long shf_wx = SHF_WRITE|SHF_EXECINSTR;
2039 int i;
2040
2041 for (i = 0; i < hdr->e_shnum; i++) {
2042 if ((sechdrs[i].sh_flags & shf_wx) == shf_wx) {
2043 pr_err("%s: section %s (index %d) has invalid WRITE|EXEC flags\n",
2044 mod->name, secstrings + sechdrs[i].sh_name, i);
2045 return -ENOEXEC;
2046 }
2047 }
2048
2049 return 0;
2050}
2051
2052#else /* !CONFIG_STRICT_MODULE_RWX */
2053static void module_enable_nx(const struct module *mod) { }
2054static void module_enable_ro(const struct module *mod, bool after_init) {}
2055static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
2056 char *secstrings, struct module *mod)
2057{
2058 return 0;
2059}
2060#endif /* CONFIG_STRICT_MODULE_RWX */
2061
2062#ifdef CONFIG_LIVEPATCH
2063/*
2064 * Persist Elf information about a module. Copy the Elf header,
2065 * section header table, section string table, and symtab section
2066 * index from info to mod->klp_info.
2067 */
2068static int copy_module_elf(struct module *mod, struct load_info *info)
2069{
2070 unsigned int size, symndx;
2071 int ret;
2072
2073 size = sizeof(*mod->klp_info);
2074 mod->klp_info = kmalloc(size, GFP_KERNEL);
2075 if (mod->klp_info == NULL)
2076 return -ENOMEM;
2077
2078 /* Elf header */
2079 size = sizeof(mod->klp_info->hdr);
2080 memcpy(&mod->klp_info->hdr, info->hdr, size);
2081
2082 /* Elf section header table */
2083 size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
2084 mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL);
2085 if (mod->klp_info->sechdrs == NULL) {
2086 ret = -ENOMEM;
2087 goto free_info;
2088 }
2089
2090 /* Elf section name string table */
2091 size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
2092 mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL);
2093 if (mod->klp_info->secstrings == NULL) {
2094 ret = -ENOMEM;
2095 goto free_sechdrs;
2096 }
2097
2098 /* Elf symbol section index */
2099 symndx = info->index.sym;
2100 mod->klp_info->symndx = symndx;
2101
2102 /*
2103 * For livepatch modules, core_kallsyms.symtab is a complete
2104 * copy of the original symbol table. Adjust sh_addr to point
2105 * to core_kallsyms.symtab since the copy of the symtab in module
2106 * init memory is freed at the end of do_init_module().
2107 */
2108 mod->klp_info->sechdrs[symndx].sh_addr = \
2109 (unsigned long) mod->core_kallsyms.symtab;
2110
2111 return 0;
2112
2113free_sechdrs:
2114 kfree(mod->klp_info->sechdrs);
2115free_info:
2116 kfree(mod->klp_info);
2117 return ret;
2118}
2119
2120static void free_module_elf(struct module *mod)
2121{
2122 kfree(mod->klp_info->sechdrs);
2123 kfree(mod->klp_info->secstrings);
2124 kfree(mod->klp_info);
2125}
2126#else /* !CONFIG_LIVEPATCH */
2127static int copy_module_elf(struct module *mod, struct load_info *info)
2128{
2129 return 0;
2130}
2131
2132static void free_module_elf(struct module *mod)
2133{
2134}
2135#endif /* CONFIG_LIVEPATCH */
2136
2137void __weak module_memfree(void *module_region)
2138{
2139 /*
2140 * This memory may be RO, and freeing RO memory in an interrupt is not
2141 * supported by vmalloc.
2142 */
2143 WARN_ON(in_interrupt());
2144 vfree(module_region);
2145}
2146
2147void __weak module_arch_cleanup(struct module *mod)
2148{
2149}
2150
2151void __weak module_arch_freeing_init(struct module *mod)
2152{
2153}
2154
2155static void cfi_cleanup(struct module *mod);
2156
2157/* Free a module, remove from lists, etc. */
2158static void free_module(struct module *mod)
2159{
2160 trace_module_free(mod);
2161
2162 mod_sysfs_teardown(mod);
2163
2164 /*
2165 * We leave it in list to prevent duplicate loads, but make sure
2166 * that noone uses it while it's being deconstructed.
2167 */
2168 mutex_lock(&module_mutex);
2169 mod->state = MODULE_STATE_UNFORMED;
2170 mutex_unlock(&module_mutex);
2171
2172 /* Remove dynamic debug info */
2173 ddebug_remove_module(mod->name);
2174
2175 /* Arch-specific cleanup. */
2176 module_arch_cleanup(mod);
2177
2178 /* Module unload stuff */
2179 module_unload_free(mod);
2180
2181 /* Free any allocated parameters. */
2182 destroy_params(mod->kp, mod->num_kp);
2183
2184 if (is_livepatch_module(mod))
2185 free_module_elf(mod);
2186
2187 /* Now we can delete it from the lists */
2188 mutex_lock(&module_mutex);
2189 /* Unlink carefully: kallsyms could be walking list. */
2190 list_del_rcu(&mod->list);
2191 mod_tree_remove(mod);
2192 /* Remove this module from bug list, this uses list_del_rcu */
2193 module_bug_cleanup(mod);
2194 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2195 synchronize_rcu();
2196 mutex_unlock(&module_mutex);
2197
2198 /* Clean up CFI for the module. */
2199 cfi_cleanup(mod);
2200
2201 /* This may be empty, but that's OK */
2202 module_arch_freeing_init(mod);
2203 module_memfree(mod->init_layout.base);
2204 kfree(mod->args);
2205 percpu_modfree(mod);
2206
2207 /* Free lock-classes; relies on the preceding sync_rcu(). */
2208 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
2209
2210 /* Finally, free the core (containing the module structure) */
2211 module_memfree(mod->core_layout.base);
2212}
2213
2214void *__symbol_get(const char *symbol)
2215{
2216 struct find_symbol_arg fsa = {
2217 .name = symbol,
2218 .gplok = true,
2219 .warn = true,
2220 };
2221
2222 preempt_disable();
2223 if (!find_symbol(&fsa) || strong_try_module_get(fsa.owner)) {
2224 preempt_enable();
2225 return NULL;
2226 }
2227 preempt_enable();
2228 return (void *)kernel_symbol_value(fsa.sym);
2229}
2230EXPORT_SYMBOL_GPL(__symbol_get);
2231
2232/*
2233 * Ensure that an exported symbol [global namespace] does not already exist
2234 * in the kernel or in some other module's exported symbol table.
2235 *
2236 * You must hold the module_mutex.
2237 */
2238static int verify_exported_symbols(struct module *mod)
2239{
2240 unsigned int i;
2241 const struct kernel_symbol *s;
2242 struct {
2243 const struct kernel_symbol *sym;
2244 unsigned int num;
2245 } arr[] = {
2246 { mod->syms, mod->num_syms },
2247 { mod->gpl_syms, mod->num_gpl_syms },
2248 };
2249
2250 for (i = 0; i < ARRAY_SIZE(arr); i++) {
2251 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2252 struct find_symbol_arg fsa = {
2253 .name = kernel_symbol_name(s),
2254 .gplok = true,
2255 };
2256 if (find_symbol(&fsa)) {
2257 pr_err("%s: exports duplicate symbol %s"
2258 " (owned by %s)\n",
2259 mod->name, kernel_symbol_name(s),
2260 module_name(fsa.owner));
2261 return -ENOEXEC;
2262 }
2263 }
2264 }
2265 return 0;
2266}
2267
2268static bool ignore_undef_symbol(Elf_Half emachine, const char *name)
2269{
2270 /*
2271 * On x86, PIC code and Clang non-PIC code may have call foo@PLT. GNU as
2272 * before 2.37 produces an unreferenced _GLOBAL_OFFSET_TABLE_ on x86-64.
2273 * i386 has a similar problem but may not deserve a fix.
2274 *
2275 * If we ever have to ignore many symbols, consider refactoring the code to
2276 * only warn if referenced by a relocation.
2277 */
2278 if (emachine == EM_386 || emachine == EM_X86_64)
2279 return !strcmp(name, "_GLOBAL_OFFSET_TABLE_");
2280 return false;
2281}
2282
2283/* Change all symbols so that st_value encodes the pointer directly. */
2284static int simplify_symbols(struct module *mod, const struct load_info *info)
2285{
2286 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2287 Elf_Sym *sym = (void *)symsec->sh_addr;
2288 unsigned long secbase;
2289 unsigned int i;
2290 int ret = 0;
2291 const struct kernel_symbol *ksym;
2292
2293 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2294 const char *name = info->strtab + sym[i].st_name;
2295
2296 switch (sym[i].st_shndx) {
2297 case SHN_COMMON:
2298 /* Ignore common symbols */
2299 if (!strncmp(name, "__gnu_lto", 9))
2300 break;
2301
2302 /*
2303 * We compiled with -fno-common. These are not
2304 * supposed to happen.
2305 */
2306 pr_debug("Common symbol: %s\n", name);
2307 pr_warn("%s: please compile with -fno-common\n",
2308 mod->name);
2309 ret = -ENOEXEC;
2310 break;
2311
2312 case SHN_ABS:
2313 /* Don't need to do anything */
2314 pr_debug("Absolute symbol: 0x%08lx\n",
2315 (long)sym[i].st_value);
2316 break;
2317
2318 case SHN_LIVEPATCH:
2319 /* Livepatch symbols are resolved by livepatch */
2320 break;
2321
2322 case SHN_UNDEF:
2323 ksym = resolve_symbol_wait(mod, info, name);
2324 /* Ok if resolved. */
2325 if (ksym && !IS_ERR(ksym)) {
2326 sym[i].st_value = kernel_symbol_value(ksym);
2327 break;
2328 }
2329
2330 /* Ok if weak or ignored. */
2331 if (!ksym &&
2332 (ELF_ST_BIND(sym[i].st_info) == STB_WEAK ||
2333 ignore_undef_symbol(info->hdr->e_machine, name)))
2334 break;
2335
2336 ret = PTR_ERR(ksym) ?: -ENOENT;
2337 pr_warn("%s: Unknown symbol %s (err %d)\n",
2338 mod->name, name, ret);
2339 break;
2340
2341 default:
2342 /* Divert to percpu allocation if a percpu var. */
2343 if (sym[i].st_shndx == info->index.pcpu)
2344 secbase = (unsigned long)mod_percpu(mod);
2345 else
2346 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2347 sym[i].st_value += secbase;
2348 break;
2349 }
2350 }
2351
2352 return ret;
2353}
2354
2355static int apply_relocations(struct module *mod, const struct load_info *info)
2356{
2357 unsigned int i;
2358 int err = 0;
2359
2360 /* Now do relocations. */
2361 for (i = 1; i < info->hdr->e_shnum; i++) {
2362 unsigned int infosec = info->sechdrs[i].sh_info;
2363
2364 /* Not a valid relocation section? */
2365 if (infosec >= info->hdr->e_shnum)
2366 continue;
2367
2368 /* Don't bother with non-allocated sections */
2369 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2370 continue;
2371
2372 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
2373 err = klp_apply_section_relocs(mod, info->sechdrs,
2374 info->secstrings,
2375 info->strtab,
2376 info->index.sym, i,
2377 NULL);
2378 else if (info->sechdrs[i].sh_type == SHT_REL)
2379 err = apply_relocate(info->sechdrs, info->strtab,
2380 info->index.sym, i, mod);
2381 else if (info->sechdrs[i].sh_type == SHT_RELA)
2382 err = apply_relocate_add(info->sechdrs, info->strtab,
2383 info->index.sym, i, mod);
2384 if (err < 0)
2385 break;
2386 }
2387 return err;
2388}
2389
2390/* Additional bytes needed by arch in front of individual sections */
2391unsigned int __weak arch_mod_section_prepend(struct module *mod,
2392 unsigned int section)
2393{
2394 /* default implementation just returns zero */
2395 return 0;
2396}
2397
2398/* Update size with this section: return offset. */
2399static long get_offset(struct module *mod, unsigned int *size,
2400 Elf_Shdr *sechdr, unsigned int section)
2401{
2402 long ret;
2403
2404 *size += arch_mod_section_prepend(mod, section);
2405 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2406 *size = ret + sechdr->sh_size;
2407 return ret;
2408}
2409
2410static bool module_init_layout_section(const char *sname)
2411{
2412#ifndef CONFIG_MODULE_UNLOAD
2413 if (module_exit_section(sname))
2414 return true;
2415#endif
2416 return module_init_section(sname);
2417}
2418
2419/*
2420 * Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2421 * might -- code, read-only data, read-write data, small data. Tally
2422 * sizes, and place the offsets into sh_entsize fields: high bit means it
2423 * belongs in init.
2424 */
2425static void layout_sections(struct module *mod, struct load_info *info)
2426{
2427 static unsigned long const masks[][2] = {
2428 /*
2429 * NOTE: all executable code must be the first section
2430 * in this array; otherwise modify the text_size
2431 * finder in the two loops below
2432 */
2433 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2434 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2435 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
2436 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2437 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2438 };
2439 unsigned int m, i;
2440
2441 for (i = 0; i < info->hdr->e_shnum; i++)
2442 info->sechdrs[i].sh_entsize = ~0UL;
2443
2444 pr_debug("Core section allocation order:\n");
2445 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2446 for (i = 0; i < info->hdr->e_shnum; ++i) {
2447 Elf_Shdr *s = &info->sechdrs[i];
2448 const char *sname = info->secstrings + s->sh_name;
2449
2450 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2451 || (s->sh_flags & masks[m][1])
2452 || s->sh_entsize != ~0UL
2453 || module_init_layout_section(sname))
2454 continue;
2455 s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2456 pr_debug("\t%s\n", sname);
2457 }
2458 switch (m) {
2459 case 0: /* executable */
2460 mod->core_layout.size = debug_align(mod->core_layout.size);
2461 mod->core_layout.text_size = mod->core_layout.size;
2462 break;
2463 case 1: /* RO: text and ro-data */
2464 mod->core_layout.size = debug_align(mod->core_layout.size);
2465 mod->core_layout.ro_size = mod->core_layout.size;
2466 break;
2467 case 2: /* RO after init */
2468 mod->core_layout.size = debug_align(mod->core_layout.size);
2469 mod->core_layout.ro_after_init_size = mod->core_layout.size;
2470 break;
2471 case 4: /* whole core */
2472 mod->core_layout.size = debug_align(mod->core_layout.size);
2473 break;
2474 }
2475 }
2476
2477 pr_debug("Init section allocation order:\n");
2478 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2479 for (i = 0; i < info->hdr->e_shnum; ++i) {
2480 Elf_Shdr *s = &info->sechdrs[i];
2481 const char *sname = info->secstrings + s->sh_name;
2482
2483 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2484 || (s->sh_flags & masks[m][1])
2485 || s->sh_entsize != ~0UL
2486 || !module_init_layout_section(sname))
2487 continue;
2488 s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
2489 | INIT_OFFSET_MASK);
2490 pr_debug("\t%s\n", sname);
2491 }
2492 switch (m) {
2493 case 0: /* executable */
2494 mod->init_layout.size = debug_align(mod->init_layout.size);
2495 mod->init_layout.text_size = mod->init_layout.size;
2496 break;
2497 case 1: /* RO: text and ro-data */
2498 mod->init_layout.size = debug_align(mod->init_layout.size);
2499 mod->init_layout.ro_size = mod->init_layout.size;
2500 break;
2501 case 2:
2502 /*
2503 * RO after init doesn't apply to init_layout (only
2504 * core_layout), so it just takes the value of ro_size.
2505 */
2506 mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
2507 break;
2508 case 4: /* whole init */
2509 mod->init_layout.size = debug_align(mod->init_layout.size);
2510 break;
2511 }
2512 }
2513}
2514
2515static void set_license(struct module *mod, const char *license)
2516{
2517 if (!license)
2518 license = "unspecified";
2519
2520 if (!license_is_gpl_compatible(license)) {
2521 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2522 pr_warn("%s: module license '%s' taints kernel.\n",
2523 mod->name, license);
2524 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2525 LOCKDEP_NOW_UNRELIABLE);
2526 }
2527}
2528
2529/* Parse tag=value strings from .modinfo section */
2530static char *next_string(char *string, unsigned long *secsize)
2531{
2532 /* Skip non-zero chars */
2533 while (string[0]) {
2534 string++;
2535 if ((*secsize)-- <= 1)
2536 return NULL;
2537 }
2538
2539 /* Skip any zero padding. */
2540 while (!string[0]) {
2541 string++;
2542 if ((*secsize)-- <= 1)
2543 return NULL;
2544 }
2545 return string;
2546}
2547
2548static char *get_next_modinfo(const struct load_info *info, const char *tag,
2549 char *prev)
2550{
2551 char *p;
2552 unsigned int taglen = strlen(tag);
2553 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2554 unsigned long size = infosec->sh_size;
2555
2556 /*
2557 * get_modinfo() calls made before rewrite_section_headers()
2558 * must use sh_offset, as sh_addr isn't set!
2559 */
2560 char *modinfo = (char *)info->hdr + infosec->sh_offset;
2561
2562 if (prev) {
2563 size -= prev - modinfo;
2564 modinfo = next_string(prev, &size);
2565 }
2566
2567 for (p = modinfo; p; p = next_string(p, &size)) {
2568 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2569 return p + taglen + 1;
2570 }
2571 return NULL;
2572}
2573
2574static char *get_modinfo(const struct load_info *info, const char *tag)
2575{
2576 return get_next_modinfo(info, tag, NULL);
2577}
2578
2579static void setup_modinfo(struct module *mod, struct load_info *info)
2580{
2581 struct module_attribute *attr;
2582 int i;
2583
2584 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2585 if (attr->setup)
2586 attr->setup(mod, get_modinfo(info, attr->attr.name));
2587 }
2588}
2589
2590static void free_modinfo(struct module *mod)
2591{
2592 struct module_attribute *attr;
2593 int i;
2594
2595 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2596 if (attr->free)
2597 attr->free(mod);
2598 }
2599}
2600
2601#ifdef CONFIG_KALLSYMS
2602
2603/* Lookup exported symbol in given range of kernel_symbols */
2604static const struct kernel_symbol *lookup_exported_symbol(const char *name,
2605 const struct kernel_symbol *start,
2606 const struct kernel_symbol *stop)
2607{
2608 return bsearch(name, start, stop - start,
2609 sizeof(struct kernel_symbol), cmp_name);
2610}
2611
2612static int is_exported(const char *name, unsigned long value,
2613 const struct module *mod)
2614{
2615 const struct kernel_symbol *ks;
2616 if (!mod)
2617 ks = lookup_exported_symbol(name, __start___ksymtab, __stop___ksymtab);
2618 else
2619 ks = lookup_exported_symbol(name, mod->syms, mod->syms + mod->num_syms);
2620
2621 return ks != NULL && kernel_symbol_value(ks) == value;
2622}
2623
2624/* As per nm */
2625static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2626{
2627 const Elf_Shdr *sechdrs = info->sechdrs;
2628
2629 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2630 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2631 return 'v';
2632 else
2633 return 'w';
2634 }
2635 if (sym->st_shndx == SHN_UNDEF)
2636 return 'U';
2637 if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
2638 return 'a';
2639 if (sym->st_shndx >= SHN_LORESERVE)
2640 return '?';
2641 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2642 return 't';
2643 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2644 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2645 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2646 return 'r';
2647 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2648 return 'g';
2649 else
2650 return 'd';
2651 }
2652 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2653 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2654 return 's';
2655 else
2656 return 'b';
2657 }
2658 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2659 ".debug")) {
2660 return 'n';
2661 }
2662 return '?';
2663}
2664
2665static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2666 unsigned int shnum, unsigned int pcpundx)
2667{
2668 const Elf_Shdr *sec;
2669
2670 if (src->st_shndx == SHN_UNDEF
2671 || src->st_shndx >= shnum
2672 || !src->st_name)
2673 return false;
2674
2675#ifdef CONFIG_KALLSYMS_ALL
2676 if (src->st_shndx == pcpundx)
2677 return true;
2678#endif
2679
2680 sec = sechdrs + src->st_shndx;
2681 if (!(sec->sh_flags & SHF_ALLOC)
2682#ifndef CONFIG_KALLSYMS_ALL
2683 || !(sec->sh_flags & SHF_EXECINSTR)
2684#endif
2685 || (sec->sh_entsize & INIT_OFFSET_MASK))
2686 return false;
2687
2688 return true;
2689}
2690
2691/*
2692 * We only allocate and copy the strings needed by the parts of symtab
2693 * we keep. This is simple, but has the effect of making multiple
2694 * copies of duplicates. We could be more sophisticated, see
2695 * linux-kernel thread starting with
2696 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2697 */
2698static void layout_symtab(struct module *mod, struct load_info *info)
2699{
2700 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2701 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2702 const Elf_Sym *src;
2703 unsigned int i, nsrc, ndst, strtab_size = 0;
2704
2705 /* Put symbol section at end of init part of module. */
2706 symsect->sh_flags |= SHF_ALLOC;
2707 symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2708 info->index.sym) | INIT_OFFSET_MASK;
2709 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2710
2711 src = (void *)info->hdr + symsect->sh_offset;
2712 nsrc = symsect->sh_size / sizeof(*src);
2713
2714 /* Compute total space required for the core symbols' strtab. */
2715 for (ndst = i = 0; i < nsrc; i++) {
2716 if (i == 0 || is_livepatch_module(mod) ||
2717 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2718 info->index.pcpu)) {
2719 strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2720 ndst++;
2721 }
2722 }
2723
2724 /* Append room for core symbols at end of core part. */
2725 info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
2726 info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
2727 mod->core_layout.size += strtab_size;
2728 info->core_typeoffs = mod->core_layout.size;
2729 mod->core_layout.size += ndst * sizeof(char);
2730 mod->core_layout.size = debug_align(mod->core_layout.size);
2731
2732 /* Put string table section at end of init part of module. */
2733 strsect->sh_flags |= SHF_ALLOC;
2734 strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2735 info->index.str) | INIT_OFFSET_MASK;
2736 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2737
2738 /* We'll tack temporary mod_kallsyms on the end. */
2739 mod->init_layout.size = ALIGN(mod->init_layout.size,
2740 __alignof__(struct mod_kallsyms));
2741 info->mod_kallsyms_init_off = mod->init_layout.size;
2742 mod->init_layout.size += sizeof(struct mod_kallsyms);
2743 info->init_typeoffs = mod->init_layout.size;
2744 mod->init_layout.size += nsrc * sizeof(char);
2745 mod->init_layout.size = debug_align(mod->init_layout.size);
2746}
2747
2748/*
2749 * We use the full symtab and strtab which layout_symtab arranged to
2750 * be appended to the init section. Later we switch to the cut-down
2751 * core-only ones.
2752 */
2753static void add_kallsyms(struct module *mod, const struct load_info *info)
2754{
2755 unsigned int i, ndst;
2756 const Elf_Sym *src;
2757 Elf_Sym *dst;
2758 char *s;
2759 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2760
2761 /* Set up to point into init section. */
2762 mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
2763
2764 mod->kallsyms->symtab = (void *)symsec->sh_addr;
2765 mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2766 /* Make sure we get permanent strtab: don't use info->strtab. */
2767 mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2768 mod->kallsyms->typetab = mod->init_layout.base + info->init_typeoffs;
2769
2770 /*
2771 * Now populate the cut down core kallsyms for after init
2772 * and set types up while we still have access to sections.
2773 */
2774 mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
2775 mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
2776 mod->core_kallsyms.typetab = mod->core_layout.base + info->core_typeoffs;
2777 src = mod->kallsyms->symtab;
2778 for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2779 mod->kallsyms->typetab[i] = elf_type(src + i, info);
2780 if (i == 0 || is_livepatch_module(mod) ||
2781 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2782 info->index.pcpu)) {
2783 mod->core_kallsyms.typetab[ndst] =
2784 mod->kallsyms->typetab[i];
2785 dst[ndst] = src[i];
2786 dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
2787 s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2788 KSYM_NAME_LEN) + 1;
2789 }
2790 }
2791 mod->core_kallsyms.num_symtab = ndst;
2792}
2793#else
2794static inline void layout_symtab(struct module *mod, struct load_info *info)
2795{
2796}
2797
2798static void add_kallsyms(struct module *mod, const struct load_info *info)
2799{
2800}
2801#endif /* CONFIG_KALLSYMS */
2802
2803#if IS_ENABLED(CONFIG_KALLSYMS) && IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
2804static void init_build_id(struct module *mod, const struct load_info *info)
2805{
2806 const Elf_Shdr *sechdr;
2807 unsigned int i;
2808
2809 for (i = 0; i < info->hdr->e_shnum; i++) {
2810 sechdr = &info->sechdrs[i];
2811 if (!sect_empty(sechdr) && sechdr->sh_type == SHT_NOTE &&
2812 !build_id_parse_buf((void *)sechdr->sh_addr, mod->build_id,
2813 sechdr->sh_size))
2814 break;
2815 }
2816}
2817#else
2818static void init_build_id(struct module *mod, const struct load_info *info)
2819{
2820}
2821#endif
2822
2823static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num)
2824{
2825 if (!debug)
2826 return;
2827 ddebug_add_module(debug, num, mod->name);
2828}
2829
2830static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug)
2831{
2832 if (debug)
2833 ddebug_remove_module(mod->name);
2834}
2835
2836void * __weak module_alloc(unsigned long size)
2837{
2838 return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
2839 GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS,
2840 NUMA_NO_NODE, __builtin_return_address(0));
2841}
2842
2843bool __weak module_init_section(const char *name)
2844{
2845 return strstarts(name, ".init");
2846}
2847
2848bool __weak module_exit_section(const char *name)
2849{
2850 return strstarts(name, ".exit");
2851}
2852
2853#ifdef CONFIG_DEBUG_KMEMLEAK
2854static void kmemleak_load_module(const struct module *mod,
2855 const struct load_info *info)
2856{
2857 unsigned int i;
2858
2859 /* only scan the sections containing data */
2860 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2861
2862 for (i = 1; i < info->hdr->e_shnum; i++) {
2863 /* Scan all writable sections that's not executable */
2864 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2865 !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2866 (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2867 continue;
2868
2869 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2870 info->sechdrs[i].sh_size, GFP_KERNEL);
2871 }
2872}
2873#else
2874static inline void kmemleak_load_module(const struct module *mod,
2875 const struct load_info *info)
2876{
2877}
2878#endif
2879
2880#ifdef CONFIG_MODULE_SIG
2881static int module_sig_check(struct load_info *info, int flags)
2882{
2883 int err = -ENODATA;
2884 const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2885 const char *reason;
2886 const void *mod = info->hdr;
2887
2888 /*
2889 * Require flags == 0, as a module with version information
2890 * removed is no longer the module that was signed
2891 */
2892 if (flags == 0 &&
2893 info->len > markerlen &&
2894 memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2895 /* We truncate the module to discard the signature */
2896 info->len -= markerlen;
2897 err = mod_verify_sig(mod, info);
2898 if (!err) {
2899 info->sig_ok = true;
2900 return 0;
2901 }
2902 }
2903
2904 /*
2905 * We don't permit modules to be loaded into the trusted kernels
2906 * without a valid signature on them, but if we're not enforcing,
2907 * certain errors are non-fatal.
2908 */
2909 switch (err) {
2910 case -ENODATA:
2911 reason = "unsigned module";
2912 break;
2913 case -ENOPKG:
2914 reason = "module with unsupported crypto";
2915 break;
2916 case -ENOKEY:
2917 reason = "module with unavailable key";
2918 break;
2919
2920 default:
2921 /*
2922 * All other errors are fatal, including lack of memory,
2923 * unparseable signatures, and signature check failures --
2924 * even if signatures aren't required.
2925 */
2926 return err;
2927 }
2928
2929 if (is_module_sig_enforced()) {
2930 pr_notice("Loading of %s is rejected\n", reason);
2931 return -EKEYREJECTED;
2932 }
2933
2934 return security_locked_down(LOCKDOWN_MODULE_SIGNATURE);
2935}
2936#else /* !CONFIG_MODULE_SIG */
2937static int module_sig_check(struct load_info *info, int flags)
2938{
2939 return 0;
2940}
2941#endif /* !CONFIG_MODULE_SIG */
2942
2943static int validate_section_offset(struct load_info *info, Elf_Shdr *shdr)
2944{
2945 unsigned long secend;
2946
2947 /*
2948 * Check for both overflow and offset/size being
2949 * too large.
2950 */
2951 secend = shdr->sh_offset + shdr->sh_size;
2952 if (secend < shdr->sh_offset || secend > info->len)
2953 return -ENOEXEC;
2954
2955 return 0;
2956}
2957
2958/*
2959 * Sanity checks against invalid binaries, wrong arch, weird elf version.
2960 *
2961 * Also do basic validity checks against section offsets and sizes, the
2962 * section name string table, and the indices used for it (sh_name).
2963 */
2964static int elf_validity_check(struct load_info *info)
2965{
2966 unsigned int i;
2967 Elf_Shdr *shdr, *strhdr;
2968 int err;
2969
2970 if (info->len < sizeof(*(info->hdr)))
2971 return -ENOEXEC;
2972
2973 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2974 || info->hdr->e_type != ET_REL
2975 || !elf_check_arch(info->hdr)
2976 || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2977 return -ENOEXEC;
2978
2979 /*
2980 * e_shnum is 16 bits, and sizeof(Elf_Shdr) is
2981 * known and small. So e_shnum * sizeof(Elf_Shdr)
2982 * will not overflow unsigned long on any platform.
2983 */
2984 if (info->hdr->e_shoff >= info->len
2985 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2986 info->len - info->hdr->e_shoff))
2987 return -ENOEXEC;
2988
2989 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2990
2991 /*
2992 * Verify if the section name table index is valid.
2993 */
2994 if (info->hdr->e_shstrndx == SHN_UNDEF
2995 || info->hdr->e_shstrndx >= info->hdr->e_shnum)
2996 return -ENOEXEC;
2997
2998 strhdr = &info->sechdrs[info->hdr->e_shstrndx];
2999 err = validate_section_offset(info, strhdr);
3000 if (err < 0)
3001 return err;
3002
3003 /*
3004 * The section name table must be NUL-terminated, as required
3005 * by the spec. This makes strcmp and pr_* calls that access
3006 * strings in the section safe.
3007 */
3008 info->secstrings = (void *)info->hdr + strhdr->sh_offset;
3009 if (info->secstrings[strhdr->sh_size - 1] != '\0')
3010 return -ENOEXEC;
3011
3012 /*
3013 * The code assumes that section 0 has a length of zero and
3014 * an addr of zero, so check for it.
3015 */
3016 if (info->sechdrs[0].sh_type != SHT_NULL
3017 || info->sechdrs[0].sh_size != 0
3018 || info->sechdrs[0].sh_addr != 0)
3019 return -ENOEXEC;
3020
3021 for (i = 1; i < info->hdr->e_shnum; i++) {
3022 shdr = &info->sechdrs[i];
3023 switch (shdr->sh_type) {
3024 case SHT_NULL:
3025 case SHT_NOBITS:
3026 continue;
3027 case SHT_SYMTAB:
3028 if (shdr->sh_link == SHN_UNDEF
3029 || shdr->sh_link >= info->hdr->e_shnum)
3030 return -ENOEXEC;
3031 fallthrough;
3032 default:
3033 err = validate_section_offset(info, shdr);
3034 if (err < 0) {
3035 pr_err("Invalid ELF section in module (section %u type %u)\n",
3036 i, shdr->sh_type);
3037 return err;
3038 }
3039
3040 if (shdr->sh_flags & SHF_ALLOC) {
3041 if (shdr->sh_name >= strhdr->sh_size) {
3042 pr_err("Invalid ELF section name in module (section %u type %u)\n",
3043 i, shdr->sh_type);
3044 return -ENOEXEC;
3045 }
3046 }
3047 break;
3048 }
3049 }
3050
3051 return 0;
3052}
3053
3054#define COPY_CHUNK_SIZE (16*PAGE_SIZE)
3055
3056static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
3057{
3058 do {
3059 unsigned long n = min(len, COPY_CHUNK_SIZE);
3060
3061 if (copy_from_user(dst, usrc, n) != 0)
3062 return -EFAULT;
3063 cond_resched();
3064 dst += n;
3065 usrc += n;
3066 len -= n;
3067 } while (len);
3068 return 0;
3069}
3070
3071#ifdef CONFIG_LIVEPATCH
3072static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
3073{
3074 if (get_modinfo(info, "livepatch")) {
3075 mod->klp = true;
3076 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
3077 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
3078 mod->name);
3079 }
3080
3081 return 0;
3082}
3083#else /* !CONFIG_LIVEPATCH */
3084static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
3085{
3086 if (get_modinfo(info, "livepatch")) {
3087 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
3088 mod->name);
3089 return -ENOEXEC;
3090 }
3091
3092 return 0;
3093}
3094#endif /* CONFIG_LIVEPATCH */
3095
3096static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
3097{
3098 if (retpoline_module_ok(get_modinfo(info, "retpoline")))
3099 return;
3100
3101 pr_warn("%s: loading module not compiled with retpoline compiler.\n",
3102 mod->name);
3103}
3104
3105/* Sets info->hdr and info->len. */
3106static int copy_module_from_user(const void __user *umod, unsigned long len,
3107 struct load_info *info)
3108{
3109 int err;
3110
3111 info->len = len;
3112 if (info->len < sizeof(*(info->hdr)))
3113 return -ENOEXEC;
3114
3115 err = security_kernel_load_data(LOADING_MODULE, true);
3116 if (err)
3117 return err;
3118
3119 /* Suck in entire file: we'll want most of it. */
3120 info->hdr = __vmalloc(info->len, GFP_KERNEL | __GFP_NOWARN);
3121 if (!info->hdr)
3122 return -ENOMEM;
3123
3124 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
3125 err = -EFAULT;
3126 goto out;
3127 }
3128
3129 err = security_kernel_post_load_data((char *)info->hdr, info->len,
3130 LOADING_MODULE, "init_module");
3131out:
3132 if (err)
3133 vfree(info->hdr);
3134
3135 return err;
3136}
3137
3138static void free_copy(struct load_info *info)
3139{
3140 vfree(info->hdr);
3141}
3142
3143static int rewrite_section_headers(struct load_info *info, int flags)
3144{
3145 unsigned int i;
3146
3147 /* This should always be true, but let's be sure. */
3148 info->sechdrs[0].sh_addr = 0;
3149
3150 for (i = 1; i < info->hdr->e_shnum; i++) {
3151 Elf_Shdr *shdr = &info->sechdrs[i];
3152
3153 /*
3154 * Mark all sections sh_addr with their address in the
3155 * temporary image.
3156 */
3157 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
3158
3159 }
3160
3161 /* Track but don't keep modinfo and version sections. */
3162 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
3163 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
3164
3165 return 0;
3166}
3167
3168/*
3169 * Set up our basic convenience variables (pointers to section headers,
3170 * search for module section index etc), and do some basic section
3171 * verification.
3172 *
3173 * Set info->mod to the temporary copy of the module in info->hdr. The final one
3174 * will be allocated in move_module().
3175 */
3176static int setup_load_info(struct load_info *info, int flags)
3177{
3178 unsigned int i;
3179
3180 /* Try to find a name early so we can log errors with a module name */
3181 info->index.info = find_sec(info, ".modinfo");
3182 if (info->index.info)
3183 info->name = get_modinfo(info, "name");
3184
3185 /* Find internal symbols and strings. */
3186 for (i = 1; i < info->hdr->e_shnum; i++) {
3187 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
3188 info->index.sym = i;
3189 info->index.str = info->sechdrs[i].sh_link;
3190 info->strtab = (char *)info->hdr
3191 + info->sechdrs[info->index.str].sh_offset;
3192 break;
3193 }
3194 }
3195
3196 if (info->index.sym == 0) {
3197 pr_warn("%s: module has no symbols (stripped?)\n",
3198 info->name ?: "(missing .modinfo section or name field)");
3199 return -ENOEXEC;
3200 }
3201
3202 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
3203 if (!info->index.mod) {
3204 pr_warn("%s: No module found in object\n",
3205 info->name ?: "(missing .modinfo section or name field)");
3206 return -ENOEXEC;
3207 }
3208 /* This is temporary: point mod into copy of data. */
3209 info->mod = (void *)info->hdr + info->sechdrs[info->index.mod].sh_offset;
3210
3211 /*
3212 * If we didn't load the .modinfo 'name' field earlier, fall back to
3213 * on-disk struct mod 'name' field.
3214 */
3215 if (!info->name)
3216 info->name = info->mod->name;
3217
3218 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
3219 info->index.vers = 0; /* Pretend no __versions section! */
3220 else
3221 info->index.vers = find_sec(info, "__versions");
3222
3223 info->index.pcpu = find_pcpusec(info);
3224
3225 return 0;
3226}
3227
3228static int check_modinfo(struct module *mod, struct load_info *info, int flags)
3229{
3230 const char *modmagic = get_modinfo(info, "vermagic");
3231 int err;
3232
3233 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
3234 modmagic = NULL;
3235
3236 /* This is allowed: modprobe --force will invalidate it. */
3237 if (!modmagic) {
3238 err = try_to_force_load(mod, "bad vermagic");
3239 if (err)
3240 return err;
3241 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
3242 pr_err("%s: version magic '%s' should be '%s'\n",
3243 info->name, modmagic, vermagic);
3244 return -ENOEXEC;
3245 }
3246
3247 if (!get_modinfo(info, "intree")) {
3248 if (!test_taint(TAINT_OOT_MODULE))
3249 pr_warn("%s: loading out-of-tree module taints kernel.\n",
3250 mod->name);
3251 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
3252 }
3253
3254 check_modinfo_retpoline(mod, info);
3255
3256 if (get_modinfo(info, "staging")) {
3257 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
3258 pr_warn("%s: module is from the staging directory, the quality "
3259 "is unknown, you have been warned.\n", mod->name);
3260 }
3261
3262 err = check_modinfo_livepatch(mod, info);
3263 if (err)
3264 return err;
3265
3266 /* Set up license info based on the info section */
3267 set_license(mod, get_modinfo(info, "license"));
3268
3269 return 0;
3270}
3271
3272static int find_module_sections(struct module *mod, struct load_info *info)
3273{
3274 mod->kp = section_objs(info, "__param",
3275 sizeof(*mod->kp), &mod->num_kp);
3276 mod->syms = section_objs(info, "__ksymtab",
3277 sizeof(*mod->syms), &mod->num_syms);
3278 mod->crcs = section_addr(info, "__kcrctab");
3279 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
3280 sizeof(*mod->gpl_syms),
3281 &mod->num_gpl_syms);
3282 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
3283
3284#ifdef CONFIG_CONSTRUCTORS
3285 mod->ctors = section_objs(info, ".ctors",
3286 sizeof(*mod->ctors), &mod->num_ctors);
3287 if (!mod->ctors)
3288 mod->ctors = section_objs(info, ".init_array",
3289 sizeof(*mod->ctors), &mod->num_ctors);
3290 else if (find_sec(info, ".init_array")) {
3291 /*
3292 * This shouldn't happen with same compiler and binutils
3293 * building all parts of the module.
3294 */
3295 pr_warn("%s: has both .ctors and .init_array.\n",
3296 mod->name);
3297 return -EINVAL;
3298 }
3299#endif
3300
3301 mod->noinstr_text_start = section_objs(info, ".noinstr.text", 1,
3302 &mod->noinstr_text_size);
3303
3304#ifdef CONFIG_TRACEPOINTS
3305 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
3306 sizeof(*mod->tracepoints_ptrs),
3307 &mod->num_tracepoints);
3308#endif
3309#ifdef CONFIG_TREE_SRCU
3310 mod->srcu_struct_ptrs = section_objs(info, "___srcu_struct_ptrs",
3311 sizeof(*mod->srcu_struct_ptrs),
3312 &mod->num_srcu_structs);
3313#endif
3314#ifdef CONFIG_BPF_EVENTS
3315 mod->bpf_raw_events = section_objs(info, "__bpf_raw_tp_map",
3316 sizeof(*mod->bpf_raw_events),
3317 &mod->num_bpf_raw_events);
3318#endif
3319#ifdef CONFIG_DEBUG_INFO_BTF_MODULES
3320 mod->btf_data = any_section_objs(info, ".BTF", 1, &mod->btf_data_size);
3321#endif
3322#ifdef CONFIG_JUMP_LABEL
3323 mod->jump_entries = section_objs(info, "__jump_table",
3324 sizeof(*mod->jump_entries),
3325 &mod->num_jump_entries);
3326#endif
3327#ifdef CONFIG_EVENT_TRACING
3328 mod->trace_events = section_objs(info, "_ftrace_events",
3329 sizeof(*mod->trace_events),
3330 &mod->num_trace_events);
3331 mod->trace_evals = section_objs(info, "_ftrace_eval_map",
3332 sizeof(*mod->trace_evals),
3333 &mod->num_trace_evals);
3334#endif
3335#ifdef CONFIG_TRACING
3336 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
3337 sizeof(*mod->trace_bprintk_fmt_start),
3338 &mod->num_trace_bprintk_fmt);
3339#endif
3340#ifdef CONFIG_FTRACE_MCOUNT_RECORD
3341 /* sechdrs[0].sh_size is always zero */
3342 mod->ftrace_callsites = section_objs(info, FTRACE_CALLSITE_SECTION,
3343 sizeof(*mod->ftrace_callsites),
3344 &mod->num_ftrace_callsites);
3345#endif
3346#ifdef CONFIG_FUNCTION_ERROR_INJECTION
3347 mod->ei_funcs = section_objs(info, "_error_injection_whitelist",
3348 sizeof(*mod->ei_funcs),
3349 &mod->num_ei_funcs);
3350#endif
3351#ifdef CONFIG_KPROBES
3352 mod->kprobes_text_start = section_objs(info, ".kprobes.text", 1,
3353 &mod->kprobes_text_size);
3354 mod->kprobe_blacklist = section_objs(info, "_kprobe_blacklist",
3355 sizeof(unsigned long),
3356 &mod->num_kprobe_blacklist);
3357#endif
3358#ifdef CONFIG_HAVE_STATIC_CALL_INLINE
3359 mod->static_call_sites = section_objs(info, ".static_call_sites",
3360 sizeof(*mod->static_call_sites),
3361 &mod->num_static_call_sites);
3362#endif
3363 mod->extable = section_objs(info, "__ex_table",
3364 sizeof(*mod->extable), &mod->num_exentries);
3365
3366 if (section_addr(info, "__obsparm"))
3367 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
3368
3369 info->debug = section_objs(info, "__dyndbg",
3370 sizeof(*info->debug), &info->num_debug);
3371
3372 return 0;
3373}
3374
3375static int move_module(struct module *mod, struct load_info *info)
3376{
3377 int i;
3378 void *ptr;
3379
3380 /* Do the allocs. */
3381 ptr = module_alloc(mod->core_layout.size);
3382 /*
3383 * The pointer to this block is stored in the module structure
3384 * which is inside the block. Just mark it as not being a
3385 * leak.
3386 */
3387 kmemleak_not_leak(ptr);
3388 if (!ptr)
3389 return -ENOMEM;
3390
3391 memset(ptr, 0, mod->core_layout.size);
3392 mod->core_layout.base = ptr;
3393
3394 if (mod->init_layout.size) {
3395 ptr = module_alloc(mod->init_layout.size);
3396 /*
3397 * The pointer to this block is stored in the module structure
3398 * which is inside the block. This block doesn't need to be
3399 * scanned as it contains data and code that will be freed
3400 * after the module is initialized.
3401 */
3402 kmemleak_ignore(ptr);
3403 if (!ptr) {
3404 module_memfree(mod->core_layout.base);
3405 return -ENOMEM;
3406 }
3407 memset(ptr, 0, mod->init_layout.size);
3408 mod->init_layout.base = ptr;
3409 } else
3410 mod->init_layout.base = NULL;
3411
3412 /* Transfer each section which specifies SHF_ALLOC */
3413 pr_debug("final section addresses:\n");
3414 for (i = 0; i < info->hdr->e_shnum; i++) {
3415 void *dest;
3416 Elf_Shdr *shdr = &info->sechdrs[i];
3417
3418 if (!(shdr->sh_flags & SHF_ALLOC))
3419 continue;
3420
3421 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3422 dest = mod->init_layout.base
3423 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3424 else
3425 dest = mod->core_layout.base + shdr->sh_entsize;
3426
3427 if (shdr->sh_type != SHT_NOBITS)
3428 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3429 /* Update sh_addr to point to copy in image. */
3430 shdr->sh_addr = (unsigned long)dest;
3431 pr_debug("\t0x%lx %s\n",
3432 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3433 }
3434
3435 return 0;
3436}
3437
3438static int check_module_license_and_versions(struct module *mod)
3439{
3440 int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
3441
3442 /*
3443 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3444 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3445 * using GPL-only symbols it needs.
3446 */
3447 if (strcmp(mod->name, "ndiswrapper") == 0)
3448 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3449
3450 /* driverloader was caught wrongly pretending to be under GPL */
3451 if (strcmp(mod->name, "driverloader") == 0)
3452 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3453 LOCKDEP_NOW_UNRELIABLE);
3454
3455 /* lve claims to be GPL but upstream won't provide source */
3456 if (strcmp(mod->name, "lve") == 0)
3457 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3458 LOCKDEP_NOW_UNRELIABLE);
3459
3460 if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
3461 pr_warn("%s: module license taints kernel.\n", mod->name);
3462
3463#ifdef CONFIG_MODVERSIONS
3464 if ((mod->num_syms && !mod->crcs) ||
3465 (mod->num_gpl_syms && !mod->gpl_crcs)) {
3466 return try_to_force_load(mod,
3467 "no versions for exported symbols");
3468 }
3469#endif
3470 return 0;
3471}
3472
3473static void flush_module_icache(const struct module *mod)
3474{
3475 /*
3476 * Flush the instruction cache, since we've played with text.
3477 * Do it before processing of module parameters, so the module
3478 * can provide parameter accessor functions of its own.
3479 */
3480 if (mod->init_layout.base)
3481 flush_icache_range((unsigned long)mod->init_layout.base,
3482 (unsigned long)mod->init_layout.base
3483 + mod->init_layout.size);
3484 flush_icache_range((unsigned long)mod->core_layout.base,
3485 (unsigned long)mod->core_layout.base + mod->core_layout.size);
3486}
3487
3488int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3489 Elf_Shdr *sechdrs,
3490 char *secstrings,
3491 struct module *mod)
3492{
3493 return 0;
3494}
3495
3496/* module_blacklist is a comma-separated list of module names */
3497static char *module_blacklist;
3498static bool blacklisted(const char *module_name)
3499{
3500 const char *p;
3501 size_t len;
3502
3503 if (!module_blacklist)
3504 return false;
3505
3506 for (p = module_blacklist; *p; p += len) {
3507 len = strcspn(p, ",");
3508 if (strlen(module_name) == len && !memcmp(module_name, p, len))
3509 return true;
3510 if (p[len] == ',')
3511 len++;
3512 }
3513 return false;
3514}
3515core_param(module_blacklist, module_blacklist, charp, 0400);
3516
3517static struct module *layout_and_allocate(struct load_info *info, int flags)
3518{
3519 struct module *mod;
3520 unsigned int ndx;
3521 int err;
3522
3523 err = check_modinfo(info->mod, info, flags);
3524 if (err)
3525 return ERR_PTR(err);
3526
3527 /* Allow arches to frob section contents and sizes. */
3528 err = module_frob_arch_sections(info->hdr, info->sechdrs,
3529 info->secstrings, info->mod);
3530 if (err < 0)
3531 return ERR_PTR(err);
3532
3533 err = module_enforce_rwx_sections(info->hdr, info->sechdrs,
3534 info->secstrings, info->mod);
3535 if (err < 0)
3536 return ERR_PTR(err);
3537
3538 /* We will do a special allocation for per-cpu sections later. */
3539 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3540
3541 /*
3542 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3543 * layout_sections() can put it in the right place.
3544 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3545 */
3546 ndx = find_sec(info, ".data..ro_after_init");
3547 if (ndx)
3548 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3549 /*
3550 * Mark the __jump_table section as ro_after_init as well: these data
3551 * structures are never modified, with the exception of entries that
3552 * refer to code in the __init section, which are annotated as such
3553 * at module load time.
3554 */
3555 ndx = find_sec(info, "__jump_table");
3556 if (ndx)
3557 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3558
3559 /*
3560 * Determine total sizes, and put offsets in sh_entsize. For now
3561 * this is done generically; there doesn't appear to be any
3562 * special cases for the architectures.
3563 */
3564 layout_sections(info->mod, info);
3565 layout_symtab(info->mod, info);
3566
3567 /* Allocate and move to the final place */
3568 err = move_module(info->mod, info);
3569 if (err)
3570 return ERR_PTR(err);
3571
3572 /* Module has been copied to its final place now: return it. */
3573 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3574 kmemleak_load_module(mod, info);
3575 return mod;
3576}
3577
3578/* mod is no longer valid after this! */
3579static void module_deallocate(struct module *mod, struct load_info *info)
3580{
3581 percpu_modfree(mod);
3582 module_arch_freeing_init(mod);
3583 module_memfree(mod->init_layout.base);
3584 module_memfree(mod->core_layout.base);
3585}
3586
3587int __weak module_finalize(const Elf_Ehdr *hdr,
3588 const Elf_Shdr *sechdrs,
3589 struct module *me)
3590{
3591 return 0;
3592}
3593
3594static int post_relocation(struct module *mod, const struct load_info *info)
3595{
3596 /* Sort exception table now relocations are done. */
3597 sort_extable(mod->extable, mod->extable + mod->num_exentries);
3598
3599 /* Copy relocated percpu area over. */
3600 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3601 info->sechdrs[info->index.pcpu].sh_size);
3602
3603 /* Setup kallsyms-specific fields. */
3604 add_kallsyms(mod, info);
3605
3606 /* Arch-specific module finalizing. */
3607 return module_finalize(info->hdr, info->sechdrs, mod);
3608}
3609
3610/* Is this module of this name done loading? No locks held. */
3611static bool finished_loading(const char *name)
3612{
3613 struct module *mod;
3614 bool ret;
3615
3616 /*
3617 * The module_mutex should not be a heavily contended lock;
3618 * if we get the occasional sleep here, we'll go an extra iteration
3619 * in the wait_event_interruptible(), which is harmless.
3620 */
3621 sched_annotate_sleep();
3622 mutex_lock(&module_mutex);
3623 mod = find_module_all(name, strlen(name), true);
3624 ret = !mod || mod->state == MODULE_STATE_LIVE;
3625 mutex_unlock(&module_mutex);
3626
3627 return ret;
3628}
3629
3630/* Call module constructors. */
3631static void do_mod_ctors(struct module *mod)
3632{
3633#ifdef CONFIG_CONSTRUCTORS
3634 unsigned long i;
3635
3636 for (i = 0; i < mod->num_ctors; i++)
3637 mod->ctors[i]();
3638#endif
3639}
3640
3641/* For freeing module_init on success, in case kallsyms traversing */
3642struct mod_initfree {
3643 struct llist_node node;
3644 void *module_init;
3645};
3646
3647static void do_free_init(struct work_struct *w)
3648{
3649 struct llist_node *pos, *n, *list;
3650 struct mod_initfree *initfree;
3651
3652 list = llist_del_all(&init_free_list);
3653
3654 synchronize_rcu();
3655
3656 llist_for_each_safe(pos, n, list) {
3657 initfree = container_of(pos, struct mod_initfree, node);
3658 module_memfree(initfree->module_init);
3659 kfree(initfree);
3660 }
3661}
3662
3663/*
3664 * This is where the real work happens.
3665 *
3666 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3667 * helper command 'lx-symbols'.
3668 */
3669static noinline int do_init_module(struct module *mod)
3670{
3671 int ret = 0;
3672 struct mod_initfree *freeinit;
3673
3674 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3675 if (!freeinit) {
3676 ret = -ENOMEM;
3677 goto fail;
3678 }
3679 freeinit->module_init = mod->init_layout.base;
3680
3681 /*
3682 * We want to find out whether @mod uses async during init. Clear
3683 * PF_USED_ASYNC. async_schedule*() will set it.
3684 */
3685 current->flags &= ~PF_USED_ASYNC;
3686
3687 do_mod_ctors(mod);
3688 /* Start the module */
3689 if (mod->init != NULL)
3690 ret = do_one_initcall(mod->init);
3691 if (ret < 0) {
3692 goto fail_free_freeinit;
3693 }
3694 if (ret > 0) {
3695 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3696 "follow 0/-E convention\n"
3697 "%s: loading module anyway...\n",
3698 __func__, mod->name, ret, __func__);
3699 dump_stack();
3700 }
3701
3702 /* Now it's a first class citizen! */
3703 mod->state = MODULE_STATE_LIVE;
3704 blocking_notifier_call_chain(&module_notify_list,
3705 MODULE_STATE_LIVE, mod);
3706
3707 /* Delay uevent until module has finished its init routine */
3708 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
3709
3710 /*
3711 * We need to finish all async code before the module init sequence
3712 * is done. This has potential to deadlock. For example, a newly
3713 * detected block device can trigger request_module() of the
3714 * default iosched from async probing task. Once userland helper
3715 * reaches here, async_synchronize_full() will wait on the async
3716 * task waiting on request_module() and deadlock.
3717 *
3718 * This deadlock is avoided by perfomring async_synchronize_full()
3719 * iff module init queued any async jobs. This isn't a full
3720 * solution as it will deadlock the same if module loading from
3721 * async jobs nests more than once; however, due to the various
3722 * constraints, this hack seems to be the best option for now.
3723 * Please refer to the following thread for details.
3724 *
3725 * http://thread.gmane.org/gmane.linux.kernel/1420814
3726 */
3727 if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3728 async_synchronize_full();
3729
3730 ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base +
3731 mod->init_layout.size);
3732 mutex_lock(&module_mutex);
3733 /* Drop initial reference. */
3734 module_put(mod);
3735 trim_init_extable(mod);
3736#ifdef CONFIG_KALLSYMS
3737 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3738 rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3739#endif
3740 module_enable_ro(mod, true);
3741 mod_tree_remove_init(mod);
3742 module_arch_freeing_init(mod);
3743 mod->init_layout.base = NULL;
3744 mod->init_layout.size = 0;
3745 mod->init_layout.ro_size = 0;
3746 mod->init_layout.ro_after_init_size = 0;
3747 mod->init_layout.text_size = 0;
3748#ifdef CONFIG_DEBUG_INFO_BTF_MODULES
3749 /* .BTF is not SHF_ALLOC and will get removed, so sanitize pointer */
3750 mod->btf_data = NULL;
3751#endif
3752 /*
3753 * We want to free module_init, but be aware that kallsyms may be
3754 * walking this with preempt disabled. In all the failure paths, we
3755 * call synchronize_rcu(), but we don't want to slow down the success
3756 * path. module_memfree() cannot be called in an interrupt, so do the
3757 * work and call synchronize_rcu() in a work queue.
3758 *
3759 * Note that module_alloc() on most architectures creates W+X page
3760 * mappings which won't be cleaned up until do_free_init() runs. Any
3761 * code such as mark_rodata_ro() which depends on those mappings to
3762 * be cleaned up needs to sync with the queued work - ie
3763 * rcu_barrier()
3764 */
3765 if (llist_add(&freeinit->node, &init_free_list))
3766 schedule_work(&init_free_wq);
3767
3768 mutex_unlock(&module_mutex);
3769 wake_up_all(&module_wq);
3770
3771 return 0;
3772
3773fail_free_freeinit:
3774 kfree(freeinit);
3775fail:
3776 /* Try to protect us from buggy refcounters. */
3777 mod->state = MODULE_STATE_GOING;
3778 synchronize_rcu();
3779 module_put(mod);
3780 blocking_notifier_call_chain(&module_notify_list,
3781 MODULE_STATE_GOING, mod);
3782 klp_module_going(mod);
3783 ftrace_release_mod(mod);
3784 free_module(mod);
3785 wake_up_all(&module_wq);
3786 return ret;
3787}
3788
3789static int may_init_module(void)
3790{
3791 if (!capable(CAP_SYS_MODULE) || modules_disabled)
3792 return -EPERM;
3793
3794 return 0;
3795}
3796
3797/*
3798 * We try to place it in the list now to make sure it's unique before
3799 * we dedicate too many resources. In particular, temporary percpu
3800 * memory exhaustion.
3801 */
3802static int add_unformed_module(struct module *mod)
3803{
3804 int err;
3805 struct module *old;
3806
3807 mod->state = MODULE_STATE_UNFORMED;
3808
3809again:
3810 mutex_lock(&module_mutex);
3811 old = find_module_all(mod->name, strlen(mod->name), true);
3812 if (old != NULL) {
3813 if (old->state != MODULE_STATE_LIVE) {
3814 /* Wait in case it fails to load. */
3815 mutex_unlock(&module_mutex);
3816 err = wait_event_interruptible(module_wq,
3817 finished_loading(mod->name));
3818 if (err)
3819 goto out_unlocked;
3820 goto again;
3821 }
3822 err = -EEXIST;
3823 goto out;
3824 }
3825 mod_update_bounds(mod);
3826 list_add_rcu(&mod->list, &modules);
3827 mod_tree_insert(mod);
3828 err = 0;
3829
3830out:
3831 mutex_unlock(&module_mutex);
3832out_unlocked:
3833 return err;
3834}
3835
3836static int complete_formation(struct module *mod, struct load_info *info)
3837{
3838 int err;
3839
3840 mutex_lock(&module_mutex);
3841
3842 /* Find duplicate symbols (must be called under lock). */
3843 err = verify_exported_symbols(mod);
3844 if (err < 0)
3845 goto out;
3846
3847 /* This relies on module_mutex for list integrity. */
3848 module_bug_finalize(info->hdr, info->sechdrs, mod);
3849
3850 module_enable_ro(mod, false);
3851 module_enable_nx(mod);
3852 module_enable_x(mod);
3853
3854 /*
3855 * Mark state as coming so strong_try_module_get() ignores us,
3856 * but kallsyms etc. can see us.
3857 */
3858 mod->state = MODULE_STATE_COMING;
3859 mutex_unlock(&module_mutex);
3860
3861 return 0;
3862
3863out:
3864 mutex_unlock(&module_mutex);
3865 return err;
3866}
3867
3868static int prepare_coming_module(struct module *mod)
3869{
3870 int err;
3871
3872 ftrace_module_enable(mod);
3873 err = klp_module_coming(mod);
3874 if (err)
3875 return err;
3876
3877 err = blocking_notifier_call_chain_robust(&module_notify_list,
3878 MODULE_STATE_COMING, MODULE_STATE_GOING, mod);
3879 err = notifier_to_errno(err);
3880 if (err)
3881 klp_module_going(mod);
3882
3883 return err;
3884}
3885
3886static int unknown_module_param_cb(char *param, char *val, const char *modname,
3887 void *arg)
3888{
3889 struct module *mod = arg;
3890 int ret;
3891
3892 if (strcmp(param, "async_probe") == 0) {
3893 mod->async_probe_requested = true;
3894 return 0;
3895 }
3896
3897 /* Check for magic 'dyndbg' arg */
3898 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3899 if (ret != 0)
3900 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3901 return 0;
3902}
3903
3904static void cfi_init(struct module *mod);
3905
3906/*
3907 * Allocate and load the module: note that size of section 0 is always
3908 * zero, and we rely on this for optional sections.
3909 */
3910static int load_module(struct load_info *info, const char __user *uargs,
3911 int flags)
3912{
3913 struct module *mod;
3914 long err = 0;
3915 char *after_dashes;
3916
3917 /*
3918 * Do the signature check (if any) first. All that
3919 * the signature check needs is info->len, it does
3920 * not need any of the section info. That can be
3921 * set up later. This will minimize the chances
3922 * of a corrupt module causing problems before
3923 * we even get to the signature check.
3924 *
3925 * The check will also adjust info->len by stripping
3926 * off the sig length at the end of the module, making
3927 * checks against info->len more correct.
3928 */
3929 err = module_sig_check(info, flags);
3930 if (err)
3931 goto free_copy;
3932
3933 /*
3934 * Do basic sanity checks against the ELF header and
3935 * sections.
3936 */
3937 err = elf_validity_check(info);
3938 if (err) {
3939 pr_err("Module has invalid ELF structures\n");
3940 goto free_copy;
3941 }
3942
3943 /*
3944 * Everything checks out, so set up the section info
3945 * in the info structure.
3946 */
3947 err = setup_load_info(info, flags);
3948 if (err)
3949 goto free_copy;
3950
3951 /*
3952 * Now that we know we have the correct module name, check
3953 * if it's blacklisted.
3954 */
3955 if (blacklisted(info->name)) {
3956 err = -EPERM;
3957 pr_err("Module %s is blacklisted\n", info->name);
3958 goto free_copy;
3959 }
3960
3961 err = rewrite_section_headers(info, flags);
3962 if (err)
3963 goto free_copy;
3964
3965 /* Check module struct version now, before we try to use module. */
3966 if (!check_modstruct_version(info, info->mod)) {
3967 err = -ENOEXEC;
3968 goto free_copy;
3969 }
3970
3971 /* Figure out module layout, and allocate all the memory. */
3972 mod = layout_and_allocate(info, flags);
3973 if (IS_ERR(mod)) {
3974 err = PTR_ERR(mod);
3975 goto free_copy;
3976 }
3977
3978 audit_log_kern_module(mod->name);
3979
3980 /* Reserve our place in the list. */
3981 err = add_unformed_module(mod);
3982 if (err)
3983 goto free_module;
3984
3985#ifdef CONFIG_MODULE_SIG
3986 mod->sig_ok = info->sig_ok;
3987 if (!mod->sig_ok) {
3988 pr_notice_once("%s: module verification failed: signature "
3989 "and/or required key missing - tainting "
3990 "kernel\n", mod->name);
3991 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3992 }
3993#endif
3994
3995 /* To avoid stressing percpu allocator, do this once we're unique. */
3996 err = percpu_modalloc(mod, info);
3997 if (err)
3998 goto unlink_mod;
3999
4000 /* Now module is in final location, initialize linked lists, etc. */
4001 err = module_unload_init(mod);
4002 if (err)
4003 goto unlink_mod;
4004
4005 init_param_lock(mod);
4006
4007 /*
4008 * Now we've got everything in the final locations, we can
4009 * find optional sections.
4010 */
4011 err = find_module_sections(mod, info);
4012 if (err)
4013 goto free_unload;
4014
4015 err = check_module_license_and_versions(mod);
4016 if (err)
4017 goto free_unload;
4018
4019 /* Set up MODINFO_ATTR fields */
4020 setup_modinfo(mod, info);
4021
4022 /* Fix up syms, so that st_value is a pointer to location. */
4023 err = simplify_symbols(mod, info);
4024 if (err < 0)
4025 goto free_modinfo;
4026
4027 err = apply_relocations(mod, info);
4028 if (err < 0)
4029 goto free_modinfo;
4030
4031 err = post_relocation(mod, info);
4032 if (err < 0)
4033 goto free_modinfo;
4034
4035 flush_module_icache(mod);
4036
4037 /* Setup CFI for the module. */
4038 cfi_init(mod);
4039
4040 /* Now copy in args */
4041 mod->args = strndup_user(uargs, ~0UL >> 1);
4042 if (IS_ERR(mod->args)) {
4043 err = PTR_ERR(mod->args);
4044 goto free_arch_cleanup;
4045 }
4046
4047 init_build_id(mod, info);
4048 dynamic_debug_setup(mod, info->debug, info->num_debug);
4049
4050 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
4051 ftrace_module_init(mod);
4052
4053 /* Finally it's fully formed, ready to start executing. */
4054 err = complete_formation(mod, info);
4055 if (err)
4056 goto ddebug_cleanup;
4057
4058 err = prepare_coming_module(mod);
4059 if (err)
4060 goto bug_cleanup;
4061
4062 /* Module is ready to execute: parsing args may do that. */
4063 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
4064 -32768, 32767, mod,
4065 unknown_module_param_cb);
4066 if (IS_ERR(after_dashes)) {
4067 err = PTR_ERR(after_dashes);
4068 goto coming_cleanup;
4069 } else if (after_dashes) {
4070 pr_warn("%s: parameters '%s' after `--' ignored\n",
4071 mod->name, after_dashes);
4072 }
4073
4074 /* Link in to sysfs. */
4075 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
4076 if (err < 0)
4077 goto coming_cleanup;
4078
4079 if (is_livepatch_module(mod)) {
4080 err = copy_module_elf(mod, info);
4081 if (err < 0)
4082 goto sysfs_cleanup;
4083 }
4084
4085 /* Get rid of temporary copy. */
4086 free_copy(info);
4087
4088 /* Done! */
4089 trace_module_load(mod);
4090
4091 return do_init_module(mod);
4092
4093 sysfs_cleanup:
4094 mod_sysfs_teardown(mod);
4095 coming_cleanup:
4096 mod->state = MODULE_STATE_GOING;
4097 destroy_params(mod->kp, mod->num_kp);
4098 blocking_notifier_call_chain(&module_notify_list,
4099 MODULE_STATE_GOING, mod);
4100 klp_module_going(mod);
4101 bug_cleanup:
4102 mod->state = MODULE_STATE_GOING;
4103 /* module_bug_cleanup needs module_mutex protection */
4104 mutex_lock(&module_mutex);
4105 module_bug_cleanup(mod);
4106 mutex_unlock(&module_mutex);
4107
4108 ddebug_cleanup:
4109 ftrace_release_mod(mod);
4110 dynamic_debug_remove(mod, info->debug);
4111 synchronize_rcu();
4112 kfree(mod->args);
4113 free_arch_cleanup:
4114 cfi_cleanup(mod);
4115 module_arch_cleanup(mod);
4116 free_modinfo:
4117 free_modinfo(mod);
4118 free_unload:
4119 module_unload_free(mod);
4120 unlink_mod:
4121 mutex_lock(&module_mutex);
4122 /* Unlink carefully: kallsyms could be walking list. */
4123 list_del_rcu(&mod->list);
4124 mod_tree_remove(mod);
4125 wake_up_all(&module_wq);
4126 /* Wait for RCU-sched synchronizing before releasing mod->list. */
4127 synchronize_rcu();
4128 mutex_unlock(&module_mutex);
4129 free_module:
4130 /* Free lock-classes; relies on the preceding sync_rcu() */
4131 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
4132
4133 module_deallocate(mod, info);
4134 free_copy:
4135 free_copy(info);
4136 return err;
4137}
4138
4139SYSCALL_DEFINE3(init_module, void __user *, umod,
4140 unsigned long, len, const char __user *, uargs)
4141{
4142 int err;
4143 struct load_info info = { };
4144
4145 err = may_init_module();
4146 if (err)
4147 return err;
4148
4149 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
4150 umod, len, uargs);
4151
4152 err = copy_module_from_user(umod, len, &info);
4153 if (err)
4154 return err;
4155
4156 return load_module(&info, uargs, 0);
4157}
4158
4159SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
4160{
4161 struct load_info info = { };
4162 void *hdr = NULL;
4163 int err;
4164
4165 err = may_init_module();
4166 if (err)
4167 return err;
4168
4169 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
4170
4171 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
4172 |MODULE_INIT_IGNORE_VERMAGIC))
4173 return -EINVAL;
4174
4175 err = kernel_read_file_from_fd(fd, 0, &hdr, INT_MAX, NULL,
4176 READING_MODULE);
4177 if (err < 0)
4178 return err;
4179 info.hdr = hdr;
4180 info.len = err;
4181
4182 return load_module(&info, uargs, flags);
4183}
4184
4185static inline int within(unsigned long addr, void *start, unsigned long size)
4186{
4187 return ((void *)addr >= start && (void *)addr < start + size);
4188}
4189
4190#ifdef CONFIG_KALLSYMS
4191/*
4192 * This ignores the intensely annoying "mapping symbols" found
4193 * in ARM ELF files: $a, $t and $d.
4194 */
4195static inline int is_arm_mapping_symbol(const char *str)
4196{
4197 if (str[0] == '.' && str[1] == 'L')
4198 return true;
4199 return str[0] == '$' && strchr("axtd", str[1])
4200 && (str[2] == '\0' || str[2] == '.');
4201}
4202
4203static const char *kallsyms_symbol_name(struct mod_kallsyms *kallsyms, unsigned int symnum)
4204{
4205 return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
4206}
4207
4208/*
4209 * Given a module and address, find the corresponding symbol and return its name
4210 * while providing its size and offset if needed.
4211 */
4212static const char *find_kallsyms_symbol(struct module *mod,
4213 unsigned long addr,
4214 unsigned long *size,
4215 unsigned long *offset)
4216{
4217 unsigned int i, best = 0;
4218 unsigned long nextval, bestval;
4219 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4220
4221 /* At worse, next value is at end of module */
4222 if (within_module_init(addr, mod))
4223 nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
4224 else
4225 nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
4226
4227 bestval = kallsyms_symbol_value(&kallsyms->symtab[best]);
4228
4229 /*
4230 * Scan for closest preceding symbol, and next symbol. (ELF
4231 * starts real symbols at 1).
4232 */
4233 for (i = 1; i < kallsyms->num_symtab; i++) {
4234 const Elf_Sym *sym = &kallsyms->symtab[i];
4235 unsigned long thisval = kallsyms_symbol_value(sym);
4236
4237 if (sym->st_shndx == SHN_UNDEF)
4238 continue;
4239
4240 /*
4241 * We ignore unnamed symbols: they're uninformative
4242 * and inserted at a whim.
4243 */
4244 if (*kallsyms_symbol_name(kallsyms, i) == '\0'
4245 || is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms, i)))
4246 continue;
4247
4248 if (thisval <= addr && thisval > bestval) {
4249 best = i;
4250 bestval = thisval;
4251 }
4252 if (thisval > addr && thisval < nextval)
4253 nextval = thisval;
4254 }
4255
4256 if (!best)
4257 return NULL;
4258
4259 if (size)
4260 *size = nextval - bestval;
4261 if (offset)
4262 *offset = addr - bestval;
4263
4264 return kallsyms_symbol_name(kallsyms, best);
4265}
4266
4267void * __weak dereference_module_function_descriptor(struct module *mod,
4268 void *ptr)
4269{
4270 return ptr;
4271}
4272
4273/*
4274 * For kallsyms to ask for address resolution. NULL means not found. Careful
4275 * not to lock to avoid deadlock on oopses, simply disable preemption.
4276 */
4277const char *module_address_lookup(unsigned long addr,
4278 unsigned long *size,
4279 unsigned long *offset,
4280 char **modname,
4281 const unsigned char **modbuildid,
4282 char *namebuf)
4283{
4284 const char *ret = NULL;
4285 struct module *mod;
4286
4287 preempt_disable();
4288 mod = __module_address(addr);
4289 if (mod) {
4290 if (modname)
4291 *modname = mod->name;
4292 if (modbuildid) {
4293#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
4294 *modbuildid = mod->build_id;
4295#else
4296 *modbuildid = NULL;
4297#endif
4298 }
4299
4300 ret = find_kallsyms_symbol(mod, addr, size, offset);
4301 }
4302 /* Make a copy in here where it's safe */
4303 if (ret) {
4304 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
4305 ret = namebuf;
4306 }
4307 preempt_enable();
4308
4309 return ret;
4310}
4311
4312int lookup_module_symbol_name(unsigned long addr, char *symname)
4313{
4314 struct module *mod;
4315
4316 preempt_disable();
4317 list_for_each_entry_rcu(mod, &modules, list) {
4318 if (mod->state == MODULE_STATE_UNFORMED)
4319 continue;
4320 if (within_module(addr, mod)) {
4321 const char *sym;
4322
4323 sym = find_kallsyms_symbol(mod, addr, NULL, NULL);
4324 if (!sym)
4325 goto out;
4326
4327 strlcpy(symname, sym, KSYM_NAME_LEN);
4328 preempt_enable();
4329 return 0;
4330 }
4331 }
4332out:
4333 preempt_enable();
4334 return -ERANGE;
4335}
4336
4337int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
4338 unsigned long *offset, char *modname, char *name)
4339{
4340 struct module *mod;
4341
4342 preempt_disable();
4343 list_for_each_entry_rcu(mod, &modules, list) {
4344 if (mod->state == MODULE_STATE_UNFORMED)
4345 continue;
4346 if (within_module(addr, mod)) {
4347 const char *sym;
4348
4349 sym = find_kallsyms_symbol(mod, addr, size, offset);
4350 if (!sym)
4351 goto out;
4352 if (modname)
4353 strlcpy(modname, mod->name, MODULE_NAME_LEN);
4354 if (name)
4355 strlcpy(name, sym, KSYM_NAME_LEN);
4356 preempt_enable();
4357 return 0;
4358 }
4359 }
4360out:
4361 preempt_enable();
4362 return -ERANGE;
4363}
4364
4365int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
4366 char *name, char *module_name, int *exported)
4367{
4368 struct module *mod;
4369
4370 preempt_disable();
4371 list_for_each_entry_rcu(mod, &modules, list) {
4372 struct mod_kallsyms *kallsyms;
4373
4374 if (mod->state == MODULE_STATE_UNFORMED)
4375 continue;
4376 kallsyms = rcu_dereference_sched(mod->kallsyms);
4377 if (symnum < kallsyms->num_symtab) {
4378 const Elf_Sym *sym = &kallsyms->symtab[symnum];
4379
4380 *value = kallsyms_symbol_value(sym);
4381 *type = kallsyms->typetab[symnum];
4382 strlcpy(name, kallsyms_symbol_name(kallsyms, symnum), KSYM_NAME_LEN);
4383 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
4384 *exported = is_exported(name, *value, mod);
4385 preempt_enable();
4386 return 0;
4387 }
4388 symnum -= kallsyms->num_symtab;
4389 }
4390 preempt_enable();
4391 return -ERANGE;
4392}
4393
4394/* Given a module and name of symbol, find and return the symbol's value */
4395static unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name)
4396{
4397 unsigned int i;
4398 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4399
4400 for (i = 0; i < kallsyms->num_symtab; i++) {
4401 const Elf_Sym *sym = &kallsyms->symtab[i];
4402
4403 if (strcmp(name, kallsyms_symbol_name(kallsyms, i)) == 0 &&
4404 sym->st_shndx != SHN_UNDEF)
4405 return kallsyms_symbol_value(sym);
4406 }
4407 return 0;
4408}
4409
4410/* Look for this name: can be of form module:name. */
4411unsigned long module_kallsyms_lookup_name(const char *name)
4412{
4413 struct module *mod;
4414 char *colon;
4415 unsigned long ret = 0;
4416
4417 /* Don't lock: we're in enough trouble already. */
4418 preempt_disable();
4419 if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
4420 if ((mod = find_module_all(name, colon - name, false)) != NULL)
4421 ret = find_kallsyms_symbol_value(mod, colon+1);
4422 } else {
4423 list_for_each_entry_rcu(mod, &modules, list) {
4424 if (mod->state == MODULE_STATE_UNFORMED)
4425 continue;
4426 if ((ret = find_kallsyms_symbol_value(mod, name)) != 0)
4427 break;
4428 }
4429 }
4430 preempt_enable();
4431 return ret;
4432}
4433
4434#ifdef CONFIG_LIVEPATCH
4435int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
4436 struct module *, unsigned long),
4437 void *data)
4438{
4439 struct module *mod;
4440 unsigned int i;
4441 int ret = 0;
4442
4443 mutex_lock(&module_mutex);
4444 list_for_each_entry(mod, &modules, list) {
4445 /* We hold module_mutex: no need for rcu_dereference_sched */
4446 struct mod_kallsyms *kallsyms = mod->kallsyms;
4447
4448 if (mod->state == MODULE_STATE_UNFORMED)
4449 continue;
4450 for (i = 0; i < kallsyms->num_symtab; i++) {
4451 const Elf_Sym *sym = &kallsyms->symtab[i];
4452
4453 if (sym->st_shndx == SHN_UNDEF)
4454 continue;
4455
4456 ret = fn(data, kallsyms_symbol_name(kallsyms, i),
4457 mod, kallsyms_symbol_value(sym));
4458 if (ret != 0)
4459 goto out;
4460 }
4461 }
4462out:
4463 mutex_unlock(&module_mutex);
4464 return ret;
4465}
4466#endif /* CONFIG_LIVEPATCH */
4467#endif /* CONFIG_KALLSYMS */
4468
4469static void cfi_init(struct module *mod)
4470{
4471#ifdef CONFIG_CFI_CLANG
4472 initcall_t *init;
4473 exitcall_t *exit;
4474
4475 rcu_read_lock_sched();
4476 mod->cfi_check = (cfi_check_fn)
4477 find_kallsyms_symbol_value(mod, "__cfi_check");
4478 init = (initcall_t *)
4479 find_kallsyms_symbol_value(mod, "__cfi_jt_init_module");
4480 exit = (exitcall_t *)
4481 find_kallsyms_symbol_value(mod, "__cfi_jt_cleanup_module");
4482 rcu_read_unlock_sched();
4483
4484 /* Fix init/exit functions to point to the CFI jump table */
4485 if (init)
4486 mod->init = *init;
4487#ifdef CONFIG_MODULE_UNLOAD
4488 if (exit)
4489 mod->exit = *exit;
4490#endif
4491
4492 cfi_module_add(mod, module_addr_min);
4493#endif
4494}
4495
4496static void cfi_cleanup(struct module *mod)
4497{
4498#ifdef CONFIG_CFI_CLANG
4499 cfi_module_remove(mod, module_addr_min);
4500#endif
4501}
4502
4503/* Maximum number of characters written by module_flags() */
4504#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
4505
4506/* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
4507static char *module_flags(struct module *mod, char *buf)
4508{
4509 int bx = 0;
4510
4511 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
4512 if (mod->taints ||
4513 mod->state == MODULE_STATE_GOING ||
4514 mod->state == MODULE_STATE_COMING) {
4515 buf[bx++] = '(';
4516 bx += module_flags_taint(mod, buf + bx);
4517 /* Show a - for module-is-being-unloaded */
4518 if (mod->state == MODULE_STATE_GOING)
4519 buf[bx++] = '-';
4520 /* Show a + for module-is-being-loaded */
4521 if (mod->state == MODULE_STATE_COMING)
4522 buf[bx++] = '+';
4523 buf[bx++] = ')';
4524 }
4525 buf[bx] = '\0';
4526
4527 return buf;
4528}
4529
4530#ifdef CONFIG_PROC_FS
4531/* Called by the /proc file system to return a list of modules. */
4532static void *m_start(struct seq_file *m, loff_t *pos)
4533{
4534 mutex_lock(&module_mutex);
4535 return seq_list_start(&modules, *pos);
4536}
4537
4538static void *m_next(struct seq_file *m, void *p, loff_t *pos)
4539{
4540 return seq_list_next(p, &modules, pos);
4541}
4542
4543static void m_stop(struct seq_file *m, void *p)
4544{
4545 mutex_unlock(&module_mutex);
4546}
4547
4548static int m_show(struct seq_file *m, void *p)
4549{
4550 struct module *mod = list_entry(p, struct module, list);
4551 char buf[MODULE_FLAGS_BUF_SIZE];
4552 void *value;
4553
4554 /* We always ignore unformed modules. */
4555 if (mod->state == MODULE_STATE_UNFORMED)
4556 return 0;
4557
4558 seq_printf(m, "%s %u",
4559 mod->name, mod->init_layout.size + mod->core_layout.size);
4560 print_unload_info(m, mod);
4561
4562 /* Informative for users. */
4563 seq_printf(m, " %s",
4564 mod->state == MODULE_STATE_GOING ? "Unloading" :
4565 mod->state == MODULE_STATE_COMING ? "Loading" :
4566 "Live");
4567 /* Used by oprofile and other similar tools. */
4568 value = m->private ? NULL : mod->core_layout.base;
4569 seq_printf(m, " 0x%px", value);
4570
4571 /* Taints info */
4572 if (mod->taints)
4573 seq_printf(m, " %s", module_flags(mod, buf));
4574
4575 seq_puts(m, "\n");
4576 return 0;
4577}
4578
4579/*
4580 * Format: modulename size refcount deps address
4581 *
4582 * Where refcount is a number or -, and deps is a comma-separated list
4583 * of depends or -.
4584 */
4585static const struct seq_operations modules_op = {
4586 .start = m_start,
4587 .next = m_next,
4588 .stop = m_stop,
4589 .show = m_show
4590};
4591
4592/*
4593 * This also sets the "private" pointer to non-NULL if the
4594 * kernel pointers should be hidden (so you can just test
4595 * "m->private" to see if you should keep the values private).
4596 *
4597 * We use the same logic as for /proc/kallsyms.
4598 */
4599static int modules_open(struct inode *inode, struct file *file)
4600{
4601 int err = seq_open(file, &modules_op);
4602
4603 if (!err) {
4604 struct seq_file *m = file->private_data;
4605 m->private = kallsyms_show_value(file->f_cred) ? NULL : (void *)8ul;
4606 }
4607
4608 return err;
4609}
4610
4611static const struct proc_ops modules_proc_ops = {
4612 .proc_flags = PROC_ENTRY_PERMANENT,
4613 .proc_open = modules_open,
4614 .proc_read = seq_read,
4615 .proc_lseek = seq_lseek,
4616 .proc_release = seq_release,
4617};
4618
4619static int __init proc_modules_init(void)
4620{
4621 proc_create("modules", 0, NULL, &modules_proc_ops);
4622 return 0;
4623}
4624module_init(proc_modules_init);
4625#endif
4626
4627/* Given an address, look for it in the module exception tables. */
4628const struct exception_table_entry *search_module_extables(unsigned long addr)
4629{
4630 const struct exception_table_entry *e = NULL;
4631 struct module *mod;
4632
4633 preempt_disable();
4634 mod = __module_address(addr);
4635 if (!mod)
4636 goto out;
4637
4638 if (!mod->num_exentries)
4639 goto out;
4640
4641 e = search_extable(mod->extable,
4642 mod->num_exentries,
4643 addr);
4644out:
4645 preempt_enable();
4646
4647 /*
4648 * Now, if we found one, we are running inside it now, hence
4649 * we cannot unload the module, hence no refcnt needed.
4650 */
4651 return e;
4652}
4653
4654/**
4655 * is_module_address() - is this address inside a module?
4656 * @addr: the address to check.
4657 *
4658 * See is_module_text_address() if you simply want to see if the address
4659 * is code (not data).
4660 */
4661bool is_module_address(unsigned long addr)
4662{
4663 bool ret;
4664
4665 preempt_disable();
4666 ret = __module_address(addr) != NULL;
4667 preempt_enable();
4668
4669 return ret;
4670}
4671
4672/**
4673 * __module_address() - get the module which contains an address.
4674 * @addr: the address.
4675 *
4676 * Must be called with preempt disabled or module mutex held so that
4677 * module doesn't get freed during this.
4678 */
4679struct module *__module_address(unsigned long addr)
4680{
4681 struct module *mod;
4682
4683 if (addr < module_addr_min || addr > module_addr_max)
4684 return NULL;
4685
4686 module_assert_mutex_or_preempt();
4687
4688 mod = mod_find(addr);
4689 if (mod) {
4690 BUG_ON(!within_module(addr, mod));
4691 if (mod->state == MODULE_STATE_UNFORMED)
4692 mod = NULL;
4693 }
4694 return mod;
4695}
4696
4697/**
4698 * is_module_text_address() - is this address inside module code?
4699 * @addr: the address to check.
4700 *
4701 * See is_module_address() if you simply want to see if the address is
4702 * anywhere in a module. See kernel_text_address() for testing if an
4703 * address corresponds to kernel or module code.
4704 */
4705bool is_module_text_address(unsigned long addr)
4706{
4707 bool ret;
4708
4709 preempt_disable();
4710 ret = __module_text_address(addr) != NULL;
4711 preempt_enable();
4712
4713 return ret;
4714}
4715
4716/**
4717 * __module_text_address() - get the module whose code contains an address.
4718 * @addr: the address.
4719 *
4720 * Must be called with preempt disabled or module mutex held so that
4721 * module doesn't get freed during this.
4722 */
4723struct module *__module_text_address(unsigned long addr)
4724{
4725 struct module *mod = __module_address(addr);
4726 if (mod) {
4727 /* Make sure it's within the text section. */
4728 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
4729 && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
4730 mod = NULL;
4731 }
4732 return mod;
4733}
4734
4735/* Don't grab lock, we're oopsing. */
4736void print_modules(void)
4737{
4738 struct module *mod;
4739 char buf[MODULE_FLAGS_BUF_SIZE];
4740
4741 printk(KERN_DEFAULT "Modules linked in:");
4742 /* Most callers should already have preempt disabled, but make sure */
4743 preempt_disable();
4744 list_for_each_entry_rcu(mod, &modules, list) {
4745 if (mod->state == MODULE_STATE_UNFORMED)
4746 continue;
4747 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4748 }
4749 preempt_enable();
4750 if (last_unloaded_module[0])
4751 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4752 pr_cont("\n");
4753}
4754
4755#ifdef CONFIG_MODVERSIONS
4756/*
4757 * Generate the signature for all relevant module structures here.
4758 * If these change, we don't want to try to parse the module.
4759 */
4760void module_layout(struct module *mod,
4761 struct modversion_info *ver,
4762 struct kernel_param *kp,
4763 struct kernel_symbol *ks,
4764 struct tracepoint * const *tp)
4765{
4766}
4767EXPORT_SYMBOL(module_layout);
4768#endif
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 Copyright (C) 2002 Richard Henderson
4 Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
5
6*/
7
8#define INCLUDE_VERMAGIC
9
10#include <linux/export.h>
11#include <linux/extable.h>
12#include <linux/moduleloader.h>
13#include <linux/module_signature.h>
14#include <linux/trace_events.h>
15#include <linux/init.h>
16#include <linux/kallsyms.h>
17#include <linux/file.h>
18#include <linux/fs.h>
19#include <linux/sysfs.h>
20#include <linux/kernel.h>
21#include <linux/slab.h>
22#include <linux/vmalloc.h>
23#include <linux/elf.h>
24#include <linux/proc_fs.h>
25#include <linux/security.h>
26#include <linux/seq_file.h>
27#include <linux/syscalls.h>
28#include <linux/fcntl.h>
29#include <linux/rcupdate.h>
30#include <linux/capability.h>
31#include <linux/cpu.h>
32#include <linux/moduleparam.h>
33#include <linux/errno.h>
34#include <linux/err.h>
35#include <linux/vermagic.h>
36#include <linux/notifier.h>
37#include <linux/sched.h>
38#include <linux/device.h>
39#include <linux/string.h>
40#include <linux/mutex.h>
41#include <linux/rculist.h>
42#include <linux/uaccess.h>
43#include <asm/cacheflush.h>
44#include <linux/set_memory.h>
45#include <asm/mmu_context.h>
46#include <linux/license.h>
47#include <asm/sections.h>
48#include <linux/tracepoint.h>
49#include <linux/ftrace.h>
50#include <linux/livepatch.h>
51#include <linux/async.h>
52#include <linux/percpu.h>
53#include <linux/kmemleak.h>
54#include <linux/jump_label.h>
55#include <linux/pfn.h>
56#include <linux/bsearch.h>
57#include <linux/dynamic_debug.h>
58#include <linux/audit.h>
59#include <uapi/linux/module.h>
60#include "module-internal.h"
61
62#define CREATE_TRACE_POINTS
63#include <trace/events/module.h>
64
65#ifndef ARCH_SHF_SMALL
66#define ARCH_SHF_SMALL 0
67#endif
68
69/*
70 * Modules' sections will be aligned on page boundaries
71 * to ensure complete separation of code and data, but
72 * only when CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y
73 */
74#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
75# define debug_align(X) ALIGN(X, PAGE_SIZE)
76#else
77# define debug_align(X) (X)
78#endif
79
80/* If this is set, the section belongs in the init part of the module */
81#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
82
83/*
84 * Mutex protects:
85 * 1) List of modules (also safely readable with preempt_disable),
86 * 2) module_use links,
87 * 3) module_addr_min/module_addr_max.
88 * (delete and add uses RCU list operations). */
89DEFINE_MUTEX(module_mutex);
90EXPORT_SYMBOL_GPL(module_mutex);
91static LIST_HEAD(modules);
92
93/* Work queue for freeing init sections in success case */
94static struct work_struct init_free_wq;
95static struct llist_head init_free_list;
96
97#ifdef CONFIG_MODULES_TREE_LOOKUP
98
99/*
100 * Use a latched RB-tree for __module_address(); this allows us to use
101 * RCU-sched lookups of the address from any context.
102 *
103 * This is conditional on PERF_EVENTS || TRACING because those can really hit
104 * __module_address() hard by doing a lot of stack unwinding; potentially from
105 * NMI context.
106 */
107
108static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
109{
110 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
111
112 return (unsigned long)layout->base;
113}
114
115static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
116{
117 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
118
119 return (unsigned long)layout->size;
120}
121
122static __always_inline bool
123mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
124{
125 return __mod_tree_val(a) < __mod_tree_val(b);
126}
127
128static __always_inline int
129mod_tree_comp(void *key, struct latch_tree_node *n)
130{
131 unsigned long val = (unsigned long)key;
132 unsigned long start, end;
133
134 start = __mod_tree_val(n);
135 if (val < start)
136 return -1;
137
138 end = start + __mod_tree_size(n);
139 if (val >= end)
140 return 1;
141
142 return 0;
143}
144
145static const struct latch_tree_ops mod_tree_ops = {
146 .less = mod_tree_less,
147 .comp = mod_tree_comp,
148};
149
150static struct mod_tree_root {
151 struct latch_tree_root root;
152 unsigned long addr_min;
153 unsigned long addr_max;
154} mod_tree __cacheline_aligned = {
155 .addr_min = -1UL,
156};
157
158#define module_addr_min mod_tree.addr_min
159#define module_addr_max mod_tree.addr_max
160
161static noinline void __mod_tree_insert(struct mod_tree_node *node)
162{
163 latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
164}
165
166static void __mod_tree_remove(struct mod_tree_node *node)
167{
168 latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
169}
170
171/*
172 * These modifications: insert, remove_init and remove; are serialized by the
173 * module_mutex.
174 */
175static void mod_tree_insert(struct module *mod)
176{
177 mod->core_layout.mtn.mod = mod;
178 mod->init_layout.mtn.mod = mod;
179
180 __mod_tree_insert(&mod->core_layout.mtn);
181 if (mod->init_layout.size)
182 __mod_tree_insert(&mod->init_layout.mtn);
183}
184
185static void mod_tree_remove_init(struct module *mod)
186{
187 if (mod->init_layout.size)
188 __mod_tree_remove(&mod->init_layout.mtn);
189}
190
191static void mod_tree_remove(struct module *mod)
192{
193 __mod_tree_remove(&mod->core_layout.mtn);
194 mod_tree_remove_init(mod);
195}
196
197static struct module *mod_find(unsigned long addr)
198{
199 struct latch_tree_node *ltn;
200
201 ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
202 if (!ltn)
203 return NULL;
204
205 return container_of(ltn, struct mod_tree_node, node)->mod;
206}
207
208#else /* MODULES_TREE_LOOKUP */
209
210static unsigned long module_addr_min = -1UL, module_addr_max = 0;
211
212static void mod_tree_insert(struct module *mod) { }
213static void mod_tree_remove_init(struct module *mod) { }
214static void mod_tree_remove(struct module *mod) { }
215
216static struct module *mod_find(unsigned long addr)
217{
218 struct module *mod;
219
220 list_for_each_entry_rcu(mod, &modules, list,
221 lockdep_is_held(&module_mutex)) {
222 if (within_module(addr, mod))
223 return mod;
224 }
225
226 return NULL;
227}
228
229#endif /* MODULES_TREE_LOOKUP */
230
231/*
232 * Bounds of module text, for speeding up __module_address.
233 * Protected by module_mutex.
234 */
235static void __mod_update_bounds(void *base, unsigned int size)
236{
237 unsigned long min = (unsigned long)base;
238 unsigned long max = min + size;
239
240 if (min < module_addr_min)
241 module_addr_min = min;
242 if (max > module_addr_max)
243 module_addr_max = max;
244}
245
246static void mod_update_bounds(struct module *mod)
247{
248 __mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
249 if (mod->init_layout.size)
250 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
251}
252
253#ifdef CONFIG_KGDB_KDB
254struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
255#endif /* CONFIG_KGDB_KDB */
256
257static void module_assert_mutex(void)
258{
259 lockdep_assert_held(&module_mutex);
260}
261
262static void module_assert_mutex_or_preempt(void)
263{
264#ifdef CONFIG_LOCKDEP
265 if (unlikely(!debug_locks))
266 return;
267
268 WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
269 !lockdep_is_held(&module_mutex));
270#endif
271}
272
273static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
274module_param(sig_enforce, bool_enable_only, 0644);
275
276/*
277 * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
278 * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
279 */
280bool is_module_sig_enforced(void)
281{
282 return sig_enforce;
283}
284EXPORT_SYMBOL(is_module_sig_enforced);
285
286void set_module_sig_enforced(void)
287{
288 sig_enforce = true;
289}
290
291/* Block module loading/unloading? */
292int modules_disabled = 0;
293core_param(nomodule, modules_disabled, bint, 0);
294
295/* Waiting for a module to finish initializing? */
296static DECLARE_WAIT_QUEUE_HEAD(module_wq);
297
298static BLOCKING_NOTIFIER_HEAD(module_notify_list);
299
300int register_module_notifier(struct notifier_block *nb)
301{
302 return blocking_notifier_chain_register(&module_notify_list, nb);
303}
304EXPORT_SYMBOL(register_module_notifier);
305
306int unregister_module_notifier(struct notifier_block *nb)
307{
308 return blocking_notifier_chain_unregister(&module_notify_list, nb);
309}
310EXPORT_SYMBOL(unregister_module_notifier);
311
312/*
313 * We require a truly strong try_module_get(): 0 means success.
314 * Otherwise an error is returned due to ongoing or failed
315 * initialization etc.
316 */
317static inline int strong_try_module_get(struct module *mod)
318{
319 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
320 if (mod && mod->state == MODULE_STATE_COMING)
321 return -EBUSY;
322 if (try_module_get(mod))
323 return 0;
324 else
325 return -ENOENT;
326}
327
328static inline void add_taint_module(struct module *mod, unsigned flag,
329 enum lockdep_ok lockdep_ok)
330{
331 add_taint(flag, lockdep_ok);
332 set_bit(flag, &mod->taints);
333}
334
335/*
336 * A thread that wants to hold a reference to a module only while it
337 * is running can call this to safely exit. nfsd and lockd use this.
338 */
339void __noreturn __module_put_and_exit(struct module *mod, long code)
340{
341 module_put(mod);
342 do_exit(code);
343}
344EXPORT_SYMBOL(__module_put_and_exit);
345
346/* Find a module section: 0 means not found. */
347static unsigned int find_sec(const struct load_info *info, const char *name)
348{
349 unsigned int i;
350
351 for (i = 1; i < info->hdr->e_shnum; i++) {
352 Elf_Shdr *shdr = &info->sechdrs[i];
353 /* Alloc bit cleared means "ignore it." */
354 if ((shdr->sh_flags & SHF_ALLOC)
355 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
356 return i;
357 }
358 return 0;
359}
360
361/* Find a module section, or NULL. */
362static void *section_addr(const struct load_info *info, const char *name)
363{
364 /* Section 0 has sh_addr 0. */
365 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
366}
367
368/* Find a module section, or NULL. Fill in number of "objects" in section. */
369static void *section_objs(const struct load_info *info,
370 const char *name,
371 size_t object_size,
372 unsigned int *num)
373{
374 unsigned int sec = find_sec(info, name);
375
376 /* Section 0 has sh_addr 0 and sh_size 0. */
377 *num = info->sechdrs[sec].sh_size / object_size;
378 return (void *)info->sechdrs[sec].sh_addr;
379}
380
381/* Provided by the linker */
382extern const struct kernel_symbol __start___ksymtab[];
383extern const struct kernel_symbol __stop___ksymtab[];
384extern const struct kernel_symbol __start___ksymtab_gpl[];
385extern const struct kernel_symbol __stop___ksymtab_gpl[];
386extern const struct kernel_symbol __start___ksymtab_gpl_future[];
387extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
388extern const s32 __start___kcrctab[];
389extern const s32 __start___kcrctab_gpl[];
390extern const s32 __start___kcrctab_gpl_future[];
391#ifdef CONFIG_UNUSED_SYMBOLS
392extern const struct kernel_symbol __start___ksymtab_unused[];
393extern const struct kernel_symbol __stop___ksymtab_unused[];
394extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
395extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
396extern const s32 __start___kcrctab_unused[];
397extern const s32 __start___kcrctab_unused_gpl[];
398#endif
399
400#ifndef CONFIG_MODVERSIONS
401#define symversion(base, idx) NULL
402#else
403#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
404#endif
405
406static bool each_symbol_in_section(const struct symsearch *arr,
407 unsigned int arrsize,
408 struct module *owner,
409 bool (*fn)(const struct symsearch *syms,
410 struct module *owner,
411 void *data),
412 void *data)
413{
414 unsigned int j;
415
416 for (j = 0; j < arrsize; j++) {
417 if (fn(&arr[j], owner, data))
418 return true;
419 }
420
421 return false;
422}
423
424/* Returns true as soon as fn returns true, otherwise false. */
425static bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
426 struct module *owner,
427 void *data),
428 void *data)
429{
430 struct module *mod;
431 static const struct symsearch arr[] = {
432 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
433 NOT_GPL_ONLY, false },
434 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
435 __start___kcrctab_gpl,
436 GPL_ONLY, false },
437 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
438 __start___kcrctab_gpl_future,
439 WILL_BE_GPL_ONLY, false },
440#ifdef CONFIG_UNUSED_SYMBOLS
441 { __start___ksymtab_unused, __stop___ksymtab_unused,
442 __start___kcrctab_unused,
443 NOT_GPL_ONLY, true },
444 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
445 __start___kcrctab_unused_gpl,
446 GPL_ONLY, true },
447#endif
448 };
449
450 module_assert_mutex_or_preempt();
451
452 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
453 return true;
454
455 list_for_each_entry_rcu(mod, &modules, list,
456 lockdep_is_held(&module_mutex)) {
457 struct symsearch arr[] = {
458 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
459 NOT_GPL_ONLY, false },
460 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
461 mod->gpl_crcs,
462 GPL_ONLY, false },
463 { mod->gpl_future_syms,
464 mod->gpl_future_syms + mod->num_gpl_future_syms,
465 mod->gpl_future_crcs,
466 WILL_BE_GPL_ONLY, false },
467#ifdef CONFIG_UNUSED_SYMBOLS
468 { mod->unused_syms,
469 mod->unused_syms + mod->num_unused_syms,
470 mod->unused_crcs,
471 NOT_GPL_ONLY, true },
472 { mod->unused_gpl_syms,
473 mod->unused_gpl_syms + mod->num_unused_gpl_syms,
474 mod->unused_gpl_crcs,
475 GPL_ONLY, true },
476#endif
477 };
478
479 if (mod->state == MODULE_STATE_UNFORMED)
480 continue;
481
482 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
483 return true;
484 }
485 return false;
486}
487
488struct find_symbol_arg {
489 /* Input */
490 const char *name;
491 bool gplok;
492 bool warn;
493
494 /* Output */
495 struct module *owner;
496 const s32 *crc;
497 const struct kernel_symbol *sym;
498 enum mod_license license;
499};
500
501static bool check_exported_symbol(const struct symsearch *syms,
502 struct module *owner,
503 unsigned int symnum, void *data)
504{
505 struct find_symbol_arg *fsa = data;
506
507 if (!fsa->gplok) {
508 if (syms->license == GPL_ONLY)
509 return false;
510 if (syms->license == WILL_BE_GPL_ONLY && fsa->warn) {
511 pr_warn("Symbol %s is being used by a non-GPL module, "
512 "which will not be allowed in the future\n",
513 fsa->name);
514 }
515 }
516
517#ifdef CONFIG_UNUSED_SYMBOLS
518 if (syms->unused && fsa->warn) {
519 pr_warn("Symbol %s is marked as UNUSED, however this module is "
520 "using it.\n", fsa->name);
521 pr_warn("This symbol will go away in the future.\n");
522 pr_warn("Please evaluate if this is the right api to use and "
523 "if it really is, submit a report to the linux kernel "
524 "mailing list together with submitting your code for "
525 "inclusion.\n");
526 }
527#endif
528
529 fsa->owner = owner;
530 fsa->crc = symversion(syms->crcs, symnum);
531 fsa->sym = &syms->start[symnum];
532 fsa->license = syms->license;
533 return true;
534}
535
536static unsigned long kernel_symbol_value(const struct kernel_symbol *sym)
537{
538#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
539 return (unsigned long)offset_to_ptr(&sym->value_offset);
540#else
541 return sym->value;
542#endif
543}
544
545static const char *kernel_symbol_name(const struct kernel_symbol *sym)
546{
547#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
548 return offset_to_ptr(&sym->name_offset);
549#else
550 return sym->name;
551#endif
552}
553
554static const char *kernel_symbol_namespace(const struct kernel_symbol *sym)
555{
556#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
557 if (!sym->namespace_offset)
558 return NULL;
559 return offset_to_ptr(&sym->namespace_offset);
560#else
561 return sym->namespace;
562#endif
563}
564
565static int cmp_name(const void *name, const void *sym)
566{
567 return strcmp(name, kernel_symbol_name(sym));
568}
569
570static bool find_exported_symbol_in_section(const struct symsearch *syms,
571 struct module *owner,
572 void *data)
573{
574 struct find_symbol_arg *fsa = data;
575 struct kernel_symbol *sym;
576
577 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
578 sizeof(struct kernel_symbol), cmp_name);
579
580 if (sym != NULL && check_exported_symbol(syms, owner,
581 sym - syms->start, data))
582 return true;
583
584 return false;
585}
586
587/* Find an exported symbol and return it, along with, (optional) crc and
588 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
589static const struct kernel_symbol *find_symbol(const char *name,
590 struct module **owner,
591 const s32 **crc,
592 enum mod_license *license,
593 bool gplok,
594 bool warn)
595{
596 struct find_symbol_arg fsa;
597
598 fsa.name = name;
599 fsa.gplok = gplok;
600 fsa.warn = warn;
601
602 if (each_symbol_section(find_exported_symbol_in_section, &fsa)) {
603 if (owner)
604 *owner = fsa.owner;
605 if (crc)
606 *crc = fsa.crc;
607 if (license)
608 *license = fsa.license;
609 return fsa.sym;
610 }
611
612 pr_debug("Failed to find symbol %s\n", name);
613 return NULL;
614}
615
616/*
617 * Search for module by name: must hold module_mutex (or preempt disabled
618 * for read-only access).
619 */
620static struct module *find_module_all(const char *name, size_t len,
621 bool even_unformed)
622{
623 struct module *mod;
624
625 module_assert_mutex_or_preempt();
626
627 list_for_each_entry_rcu(mod, &modules, list,
628 lockdep_is_held(&module_mutex)) {
629 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
630 continue;
631 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
632 return mod;
633 }
634 return NULL;
635}
636
637struct module *find_module(const char *name)
638{
639 module_assert_mutex();
640 return find_module_all(name, strlen(name), false);
641}
642EXPORT_SYMBOL_GPL(find_module);
643
644#ifdef CONFIG_SMP
645
646static inline void __percpu *mod_percpu(struct module *mod)
647{
648 return mod->percpu;
649}
650
651static int percpu_modalloc(struct module *mod, struct load_info *info)
652{
653 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
654 unsigned long align = pcpusec->sh_addralign;
655
656 if (!pcpusec->sh_size)
657 return 0;
658
659 if (align > PAGE_SIZE) {
660 pr_warn("%s: per-cpu alignment %li > %li\n",
661 mod->name, align, PAGE_SIZE);
662 align = PAGE_SIZE;
663 }
664
665 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
666 if (!mod->percpu) {
667 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
668 mod->name, (unsigned long)pcpusec->sh_size);
669 return -ENOMEM;
670 }
671 mod->percpu_size = pcpusec->sh_size;
672 return 0;
673}
674
675static void percpu_modfree(struct module *mod)
676{
677 free_percpu(mod->percpu);
678}
679
680static unsigned int find_pcpusec(struct load_info *info)
681{
682 return find_sec(info, ".data..percpu");
683}
684
685static void percpu_modcopy(struct module *mod,
686 const void *from, unsigned long size)
687{
688 int cpu;
689
690 for_each_possible_cpu(cpu)
691 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
692}
693
694bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
695{
696 struct module *mod;
697 unsigned int cpu;
698
699 preempt_disable();
700
701 list_for_each_entry_rcu(mod, &modules, list) {
702 if (mod->state == MODULE_STATE_UNFORMED)
703 continue;
704 if (!mod->percpu_size)
705 continue;
706 for_each_possible_cpu(cpu) {
707 void *start = per_cpu_ptr(mod->percpu, cpu);
708 void *va = (void *)addr;
709
710 if (va >= start && va < start + mod->percpu_size) {
711 if (can_addr) {
712 *can_addr = (unsigned long) (va - start);
713 *can_addr += (unsigned long)
714 per_cpu_ptr(mod->percpu,
715 get_boot_cpu_id());
716 }
717 preempt_enable();
718 return true;
719 }
720 }
721 }
722
723 preempt_enable();
724 return false;
725}
726
727/**
728 * is_module_percpu_address - test whether address is from module static percpu
729 * @addr: address to test
730 *
731 * Test whether @addr belongs to module static percpu area.
732 *
733 * RETURNS:
734 * %true if @addr is from module static percpu area
735 */
736bool is_module_percpu_address(unsigned long addr)
737{
738 return __is_module_percpu_address(addr, NULL);
739}
740
741#else /* ... !CONFIG_SMP */
742
743static inline void __percpu *mod_percpu(struct module *mod)
744{
745 return NULL;
746}
747static int percpu_modalloc(struct module *mod, struct load_info *info)
748{
749 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
750 if (info->sechdrs[info->index.pcpu].sh_size != 0)
751 return -ENOMEM;
752 return 0;
753}
754static inline void percpu_modfree(struct module *mod)
755{
756}
757static unsigned int find_pcpusec(struct load_info *info)
758{
759 return 0;
760}
761static inline void percpu_modcopy(struct module *mod,
762 const void *from, unsigned long size)
763{
764 /* pcpusec should be 0, and size of that section should be 0. */
765 BUG_ON(size != 0);
766}
767bool is_module_percpu_address(unsigned long addr)
768{
769 return false;
770}
771
772bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
773{
774 return false;
775}
776
777#endif /* CONFIG_SMP */
778
779#define MODINFO_ATTR(field) \
780static void setup_modinfo_##field(struct module *mod, const char *s) \
781{ \
782 mod->field = kstrdup(s, GFP_KERNEL); \
783} \
784static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
785 struct module_kobject *mk, char *buffer) \
786{ \
787 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
788} \
789static int modinfo_##field##_exists(struct module *mod) \
790{ \
791 return mod->field != NULL; \
792} \
793static void free_modinfo_##field(struct module *mod) \
794{ \
795 kfree(mod->field); \
796 mod->field = NULL; \
797} \
798static struct module_attribute modinfo_##field = { \
799 .attr = { .name = __stringify(field), .mode = 0444 }, \
800 .show = show_modinfo_##field, \
801 .setup = setup_modinfo_##field, \
802 .test = modinfo_##field##_exists, \
803 .free = free_modinfo_##field, \
804};
805
806MODINFO_ATTR(version);
807MODINFO_ATTR(srcversion);
808
809static char last_unloaded_module[MODULE_NAME_LEN+1];
810
811#ifdef CONFIG_MODULE_UNLOAD
812
813EXPORT_TRACEPOINT_SYMBOL(module_get);
814
815/* MODULE_REF_BASE is the base reference count by kmodule loader. */
816#define MODULE_REF_BASE 1
817
818/* Init the unload section of the module. */
819static int module_unload_init(struct module *mod)
820{
821 /*
822 * Initialize reference counter to MODULE_REF_BASE.
823 * refcnt == 0 means module is going.
824 */
825 atomic_set(&mod->refcnt, MODULE_REF_BASE);
826
827 INIT_LIST_HEAD(&mod->source_list);
828 INIT_LIST_HEAD(&mod->target_list);
829
830 /* Hold reference count during initialization. */
831 atomic_inc(&mod->refcnt);
832
833 return 0;
834}
835
836/* Does a already use b? */
837static int already_uses(struct module *a, struct module *b)
838{
839 struct module_use *use;
840
841 list_for_each_entry(use, &b->source_list, source_list) {
842 if (use->source == a) {
843 pr_debug("%s uses %s!\n", a->name, b->name);
844 return 1;
845 }
846 }
847 pr_debug("%s does not use %s!\n", a->name, b->name);
848 return 0;
849}
850
851/*
852 * Module a uses b
853 * - we add 'a' as a "source", 'b' as a "target" of module use
854 * - the module_use is added to the list of 'b' sources (so
855 * 'b' can walk the list to see who sourced them), and of 'a'
856 * targets (so 'a' can see what modules it targets).
857 */
858static int add_module_usage(struct module *a, struct module *b)
859{
860 struct module_use *use;
861
862 pr_debug("Allocating new usage for %s.\n", a->name);
863 use = kmalloc(sizeof(*use), GFP_ATOMIC);
864 if (!use)
865 return -ENOMEM;
866
867 use->source = a;
868 use->target = b;
869 list_add(&use->source_list, &b->source_list);
870 list_add(&use->target_list, &a->target_list);
871 return 0;
872}
873
874/* Module a uses b: caller needs module_mutex() */
875static int ref_module(struct module *a, struct module *b)
876{
877 int err;
878
879 if (b == NULL || already_uses(a, b))
880 return 0;
881
882 /* If module isn't available, we fail. */
883 err = strong_try_module_get(b);
884 if (err)
885 return err;
886
887 err = add_module_usage(a, b);
888 if (err) {
889 module_put(b);
890 return err;
891 }
892 return 0;
893}
894
895/* Clear the unload stuff of the module. */
896static void module_unload_free(struct module *mod)
897{
898 struct module_use *use, *tmp;
899
900 mutex_lock(&module_mutex);
901 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
902 struct module *i = use->target;
903 pr_debug("%s unusing %s\n", mod->name, i->name);
904 module_put(i);
905 list_del(&use->source_list);
906 list_del(&use->target_list);
907 kfree(use);
908 }
909 mutex_unlock(&module_mutex);
910}
911
912#ifdef CONFIG_MODULE_FORCE_UNLOAD
913static inline int try_force_unload(unsigned int flags)
914{
915 int ret = (flags & O_TRUNC);
916 if (ret)
917 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
918 return ret;
919}
920#else
921static inline int try_force_unload(unsigned int flags)
922{
923 return 0;
924}
925#endif /* CONFIG_MODULE_FORCE_UNLOAD */
926
927/* Try to release refcount of module, 0 means success. */
928static int try_release_module_ref(struct module *mod)
929{
930 int ret;
931
932 /* Try to decrement refcnt which we set at loading */
933 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
934 BUG_ON(ret < 0);
935 if (ret)
936 /* Someone can put this right now, recover with checking */
937 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
938
939 return ret;
940}
941
942static int try_stop_module(struct module *mod, int flags, int *forced)
943{
944 /* If it's not unused, quit unless we're forcing. */
945 if (try_release_module_ref(mod) != 0) {
946 *forced = try_force_unload(flags);
947 if (!(*forced))
948 return -EWOULDBLOCK;
949 }
950
951 /* Mark it as dying. */
952 mod->state = MODULE_STATE_GOING;
953
954 return 0;
955}
956
957/**
958 * module_refcount - return the refcount or -1 if unloading
959 *
960 * @mod: the module we're checking
961 *
962 * Returns:
963 * -1 if the module is in the process of unloading
964 * otherwise the number of references in the kernel to the module
965 */
966int module_refcount(struct module *mod)
967{
968 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
969}
970EXPORT_SYMBOL(module_refcount);
971
972/* This exists whether we can unload or not */
973static void free_module(struct module *mod);
974
975SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
976 unsigned int, flags)
977{
978 struct module *mod;
979 char name[MODULE_NAME_LEN];
980 int ret, forced = 0;
981
982 if (!capable(CAP_SYS_MODULE) || modules_disabled)
983 return -EPERM;
984
985 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
986 return -EFAULT;
987 name[MODULE_NAME_LEN-1] = '\0';
988
989 audit_log_kern_module(name);
990
991 if (mutex_lock_interruptible(&module_mutex) != 0)
992 return -EINTR;
993
994 mod = find_module(name);
995 if (!mod) {
996 ret = -ENOENT;
997 goto out;
998 }
999
1000 if (!list_empty(&mod->source_list)) {
1001 /* Other modules depend on us: get rid of them first. */
1002 ret = -EWOULDBLOCK;
1003 goto out;
1004 }
1005
1006 /* Doing init or already dying? */
1007 if (mod->state != MODULE_STATE_LIVE) {
1008 /* FIXME: if (force), slam module count damn the torpedoes */
1009 pr_debug("%s already dying\n", mod->name);
1010 ret = -EBUSY;
1011 goto out;
1012 }
1013
1014 /* If it has an init func, it must have an exit func to unload */
1015 if (mod->init && !mod->exit) {
1016 forced = try_force_unload(flags);
1017 if (!forced) {
1018 /* This module can't be removed */
1019 ret = -EBUSY;
1020 goto out;
1021 }
1022 }
1023
1024 /* Stop the machine so refcounts can't move and disable module. */
1025 ret = try_stop_module(mod, flags, &forced);
1026 if (ret != 0)
1027 goto out;
1028
1029 mutex_unlock(&module_mutex);
1030 /* Final destruction now no one is using it. */
1031 if (mod->exit != NULL)
1032 mod->exit();
1033 blocking_notifier_call_chain(&module_notify_list,
1034 MODULE_STATE_GOING, mod);
1035 klp_module_going(mod);
1036 ftrace_release_mod(mod);
1037
1038 async_synchronize_full();
1039
1040 /* Store the name of the last unloaded module for diagnostic purposes */
1041 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
1042
1043 free_module(mod);
1044 /* someone could wait for the module in add_unformed_module() */
1045 wake_up_all(&module_wq);
1046 return 0;
1047out:
1048 mutex_unlock(&module_mutex);
1049 return ret;
1050}
1051
1052static inline void print_unload_info(struct seq_file *m, struct module *mod)
1053{
1054 struct module_use *use;
1055 int printed_something = 0;
1056
1057 seq_printf(m, " %i ", module_refcount(mod));
1058
1059 /*
1060 * Always include a trailing , so userspace can differentiate
1061 * between this and the old multi-field proc format.
1062 */
1063 list_for_each_entry(use, &mod->source_list, source_list) {
1064 printed_something = 1;
1065 seq_printf(m, "%s,", use->source->name);
1066 }
1067
1068 if (mod->init != NULL && mod->exit == NULL) {
1069 printed_something = 1;
1070 seq_puts(m, "[permanent],");
1071 }
1072
1073 if (!printed_something)
1074 seq_puts(m, "-");
1075}
1076
1077void __symbol_put(const char *symbol)
1078{
1079 struct module *owner;
1080
1081 preempt_disable();
1082 if (!find_symbol(symbol, &owner, NULL, NULL, true, false))
1083 BUG();
1084 module_put(owner);
1085 preempt_enable();
1086}
1087EXPORT_SYMBOL(__symbol_put);
1088
1089/* Note this assumes addr is a function, which it currently always is. */
1090void symbol_put_addr(void *addr)
1091{
1092 struct module *modaddr;
1093 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1094
1095 if (core_kernel_text(a))
1096 return;
1097
1098 /*
1099 * Even though we hold a reference on the module; we still need to
1100 * disable preemption in order to safely traverse the data structure.
1101 */
1102 preempt_disable();
1103 modaddr = __module_text_address(a);
1104 BUG_ON(!modaddr);
1105 module_put(modaddr);
1106 preempt_enable();
1107}
1108EXPORT_SYMBOL_GPL(symbol_put_addr);
1109
1110static ssize_t show_refcnt(struct module_attribute *mattr,
1111 struct module_kobject *mk, char *buffer)
1112{
1113 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1114}
1115
1116static struct module_attribute modinfo_refcnt =
1117 __ATTR(refcnt, 0444, show_refcnt, NULL);
1118
1119void __module_get(struct module *module)
1120{
1121 if (module) {
1122 preempt_disable();
1123 atomic_inc(&module->refcnt);
1124 trace_module_get(module, _RET_IP_);
1125 preempt_enable();
1126 }
1127}
1128EXPORT_SYMBOL(__module_get);
1129
1130bool try_module_get(struct module *module)
1131{
1132 bool ret = true;
1133
1134 if (module) {
1135 preempt_disable();
1136 /* Note: here, we can fail to get a reference */
1137 if (likely(module_is_live(module) &&
1138 atomic_inc_not_zero(&module->refcnt) != 0))
1139 trace_module_get(module, _RET_IP_);
1140 else
1141 ret = false;
1142
1143 preempt_enable();
1144 }
1145 return ret;
1146}
1147EXPORT_SYMBOL(try_module_get);
1148
1149void module_put(struct module *module)
1150{
1151 int ret;
1152
1153 if (module) {
1154 preempt_disable();
1155 ret = atomic_dec_if_positive(&module->refcnt);
1156 WARN_ON(ret < 0); /* Failed to put refcount */
1157 trace_module_put(module, _RET_IP_);
1158 preempt_enable();
1159 }
1160}
1161EXPORT_SYMBOL(module_put);
1162
1163#else /* !CONFIG_MODULE_UNLOAD */
1164static inline void print_unload_info(struct seq_file *m, struct module *mod)
1165{
1166 /* We don't know the usage count, or what modules are using. */
1167 seq_puts(m, " - -");
1168}
1169
1170static inline void module_unload_free(struct module *mod)
1171{
1172}
1173
1174static int ref_module(struct module *a, struct module *b)
1175{
1176 return strong_try_module_get(b);
1177}
1178
1179static inline int module_unload_init(struct module *mod)
1180{
1181 return 0;
1182}
1183#endif /* CONFIG_MODULE_UNLOAD */
1184
1185static size_t module_flags_taint(struct module *mod, char *buf)
1186{
1187 size_t l = 0;
1188 int i;
1189
1190 for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
1191 if (taint_flags[i].module && test_bit(i, &mod->taints))
1192 buf[l++] = taint_flags[i].c_true;
1193 }
1194
1195 return l;
1196}
1197
1198static ssize_t show_initstate(struct module_attribute *mattr,
1199 struct module_kobject *mk, char *buffer)
1200{
1201 const char *state = "unknown";
1202
1203 switch (mk->mod->state) {
1204 case MODULE_STATE_LIVE:
1205 state = "live";
1206 break;
1207 case MODULE_STATE_COMING:
1208 state = "coming";
1209 break;
1210 case MODULE_STATE_GOING:
1211 state = "going";
1212 break;
1213 default:
1214 BUG();
1215 }
1216 return sprintf(buffer, "%s\n", state);
1217}
1218
1219static struct module_attribute modinfo_initstate =
1220 __ATTR(initstate, 0444, show_initstate, NULL);
1221
1222static ssize_t store_uevent(struct module_attribute *mattr,
1223 struct module_kobject *mk,
1224 const char *buffer, size_t count)
1225{
1226 int rc;
1227
1228 rc = kobject_synth_uevent(&mk->kobj, buffer, count);
1229 return rc ? rc : count;
1230}
1231
1232struct module_attribute module_uevent =
1233 __ATTR(uevent, 0200, NULL, store_uevent);
1234
1235static ssize_t show_coresize(struct module_attribute *mattr,
1236 struct module_kobject *mk, char *buffer)
1237{
1238 return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1239}
1240
1241static struct module_attribute modinfo_coresize =
1242 __ATTR(coresize, 0444, show_coresize, NULL);
1243
1244static ssize_t show_initsize(struct module_attribute *mattr,
1245 struct module_kobject *mk, char *buffer)
1246{
1247 return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1248}
1249
1250static struct module_attribute modinfo_initsize =
1251 __ATTR(initsize, 0444, show_initsize, NULL);
1252
1253static ssize_t show_taint(struct module_attribute *mattr,
1254 struct module_kobject *mk, char *buffer)
1255{
1256 size_t l;
1257
1258 l = module_flags_taint(mk->mod, buffer);
1259 buffer[l++] = '\n';
1260 return l;
1261}
1262
1263static struct module_attribute modinfo_taint =
1264 __ATTR(taint, 0444, show_taint, NULL);
1265
1266static struct module_attribute *modinfo_attrs[] = {
1267 &module_uevent,
1268 &modinfo_version,
1269 &modinfo_srcversion,
1270 &modinfo_initstate,
1271 &modinfo_coresize,
1272 &modinfo_initsize,
1273 &modinfo_taint,
1274#ifdef CONFIG_MODULE_UNLOAD
1275 &modinfo_refcnt,
1276#endif
1277 NULL,
1278};
1279
1280static const char vermagic[] = VERMAGIC_STRING;
1281
1282static int try_to_force_load(struct module *mod, const char *reason)
1283{
1284#ifdef CONFIG_MODULE_FORCE_LOAD
1285 if (!test_taint(TAINT_FORCED_MODULE))
1286 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1287 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1288 return 0;
1289#else
1290 return -ENOEXEC;
1291#endif
1292}
1293
1294#ifdef CONFIG_MODVERSIONS
1295
1296static u32 resolve_rel_crc(const s32 *crc)
1297{
1298 return *(u32 *)((void *)crc + *crc);
1299}
1300
1301static int check_version(const struct load_info *info,
1302 const char *symname,
1303 struct module *mod,
1304 const s32 *crc)
1305{
1306 Elf_Shdr *sechdrs = info->sechdrs;
1307 unsigned int versindex = info->index.vers;
1308 unsigned int i, num_versions;
1309 struct modversion_info *versions;
1310
1311 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1312 if (!crc)
1313 return 1;
1314
1315 /* No versions at all? modprobe --force does this. */
1316 if (versindex == 0)
1317 return try_to_force_load(mod, symname) == 0;
1318
1319 versions = (void *) sechdrs[versindex].sh_addr;
1320 num_versions = sechdrs[versindex].sh_size
1321 / sizeof(struct modversion_info);
1322
1323 for (i = 0; i < num_versions; i++) {
1324 u32 crcval;
1325
1326 if (strcmp(versions[i].name, symname) != 0)
1327 continue;
1328
1329 if (IS_ENABLED(CONFIG_MODULE_REL_CRCS))
1330 crcval = resolve_rel_crc(crc);
1331 else
1332 crcval = *crc;
1333 if (versions[i].crc == crcval)
1334 return 1;
1335 pr_debug("Found checksum %X vs module %lX\n",
1336 crcval, versions[i].crc);
1337 goto bad_version;
1338 }
1339
1340 /* Broken toolchain. Warn once, then let it go.. */
1341 pr_warn_once("%s: no symbol version for %s\n", info->name, symname);
1342 return 1;
1343
1344bad_version:
1345 pr_warn("%s: disagrees about version of symbol %s\n",
1346 info->name, symname);
1347 return 0;
1348}
1349
1350static inline int check_modstruct_version(const struct load_info *info,
1351 struct module *mod)
1352{
1353 const s32 *crc;
1354
1355 /*
1356 * Since this should be found in kernel (which can't be removed), no
1357 * locking is necessary -- use preempt_disable() to placate lockdep.
1358 */
1359 preempt_disable();
1360 if (!find_symbol("module_layout", NULL, &crc, NULL, true, false)) {
1361 preempt_enable();
1362 BUG();
1363 }
1364 preempt_enable();
1365 return check_version(info, "module_layout", mod, crc);
1366}
1367
1368/* First part is kernel version, which we ignore if module has crcs. */
1369static inline int same_magic(const char *amagic, const char *bmagic,
1370 bool has_crcs)
1371{
1372 if (has_crcs) {
1373 amagic += strcspn(amagic, " ");
1374 bmagic += strcspn(bmagic, " ");
1375 }
1376 return strcmp(amagic, bmagic) == 0;
1377}
1378#else
1379static inline int check_version(const struct load_info *info,
1380 const char *symname,
1381 struct module *mod,
1382 const s32 *crc)
1383{
1384 return 1;
1385}
1386
1387static inline int check_modstruct_version(const struct load_info *info,
1388 struct module *mod)
1389{
1390 return 1;
1391}
1392
1393static inline int same_magic(const char *amagic, const char *bmagic,
1394 bool has_crcs)
1395{
1396 return strcmp(amagic, bmagic) == 0;
1397}
1398#endif /* CONFIG_MODVERSIONS */
1399
1400static char *get_modinfo(const struct load_info *info, const char *tag);
1401static char *get_next_modinfo(const struct load_info *info, const char *tag,
1402 char *prev);
1403
1404static int verify_namespace_is_imported(const struct load_info *info,
1405 const struct kernel_symbol *sym,
1406 struct module *mod)
1407{
1408 const char *namespace;
1409 char *imported_namespace;
1410
1411 namespace = kernel_symbol_namespace(sym);
1412 if (namespace && namespace[0]) {
1413 imported_namespace = get_modinfo(info, "import_ns");
1414 while (imported_namespace) {
1415 if (strcmp(namespace, imported_namespace) == 0)
1416 return 0;
1417 imported_namespace = get_next_modinfo(
1418 info, "import_ns", imported_namespace);
1419 }
1420#ifdef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1421 pr_warn(
1422#else
1423 pr_err(
1424#endif
1425 "%s: module uses symbol (%s) from namespace %s, but does not import it.\n",
1426 mod->name, kernel_symbol_name(sym), namespace);
1427#ifndef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1428 return -EINVAL;
1429#endif
1430 }
1431 return 0;
1432}
1433
1434static bool inherit_taint(struct module *mod, struct module *owner)
1435{
1436 if (!owner || !test_bit(TAINT_PROPRIETARY_MODULE, &owner->taints))
1437 return true;
1438
1439 if (mod->using_gplonly_symbols) {
1440 pr_err("%s: module using GPL-only symbols uses symbols from proprietary module %s.\n",
1441 mod->name, owner->name);
1442 return false;
1443 }
1444
1445 if (!test_bit(TAINT_PROPRIETARY_MODULE, &mod->taints)) {
1446 pr_warn("%s: module uses symbols from proprietary module %s, inheriting taint.\n",
1447 mod->name, owner->name);
1448 set_bit(TAINT_PROPRIETARY_MODULE, &mod->taints);
1449 }
1450 return true;
1451}
1452
1453/* Resolve a symbol for this module. I.e. if we find one, record usage. */
1454static const struct kernel_symbol *resolve_symbol(struct module *mod,
1455 const struct load_info *info,
1456 const char *name,
1457 char ownername[])
1458{
1459 struct module *owner;
1460 const struct kernel_symbol *sym;
1461 const s32 *crc;
1462 enum mod_license license;
1463 int err;
1464
1465 /*
1466 * The module_mutex should not be a heavily contended lock;
1467 * if we get the occasional sleep here, we'll go an extra iteration
1468 * in the wait_event_interruptible(), which is harmless.
1469 */
1470 sched_annotate_sleep();
1471 mutex_lock(&module_mutex);
1472 sym = find_symbol(name, &owner, &crc, &license,
1473 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1474 if (!sym)
1475 goto unlock;
1476
1477 if (license == GPL_ONLY)
1478 mod->using_gplonly_symbols = true;
1479
1480 if (!inherit_taint(mod, owner)) {
1481 sym = NULL;
1482 goto getname;
1483 }
1484
1485 if (!check_version(info, name, mod, crc)) {
1486 sym = ERR_PTR(-EINVAL);
1487 goto getname;
1488 }
1489
1490 err = verify_namespace_is_imported(info, sym, mod);
1491 if (err) {
1492 sym = ERR_PTR(err);
1493 goto getname;
1494 }
1495
1496 err = ref_module(mod, owner);
1497 if (err) {
1498 sym = ERR_PTR(err);
1499 goto getname;
1500 }
1501
1502getname:
1503 /* We must make copy under the lock if we failed to get ref. */
1504 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1505unlock:
1506 mutex_unlock(&module_mutex);
1507 return sym;
1508}
1509
1510static const struct kernel_symbol *
1511resolve_symbol_wait(struct module *mod,
1512 const struct load_info *info,
1513 const char *name)
1514{
1515 const struct kernel_symbol *ksym;
1516 char owner[MODULE_NAME_LEN];
1517
1518 if (wait_event_interruptible_timeout(module_wq,
1519 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1520 || PTR_ERR(ksym) != -EBUSY,
1521 30 * HZ) <= 0) {
1522 pr_warn("%s: gave up waiting for init of module %s.\n",
1523 mod->name, owner);
1524 }
1525 return ksym;
1526}
1527
1528/*
1529 * /sys/module/foo/sections stuff
1530 * J. Corbet <corbet@lwn.net>
1531 */
1532#ifdef CONFIG_SYSFS
1533
1534#ifdef CONFIG_KALLSYMS
1535static inline bool sect_empty(const Elf_Shdr *sect)
1536{
1537 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1538}
1539
1540struct module_sect_attr {
1541 struct bin_attribute battr;
1542 unsigned long address;
1543};
1544
1545struct module_sect_attrs {
1546 struct attribute_group grp;
1547 unsigned int nsections;
1548 struct module_sect_attr attrs[];
1549};
1550
1551#define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4))
1552static ssize_t module_sect_read(struct file *file, struct kobject *kobj,
1553 struct bin_attribute *battr,
1554 char *buf, loff_t pos, size_t count)
1555{
1556 struct module_sect_attr *sattr =
1557 container_of(battr, struct module_sect_attr, battr);
1558 char bounce[MODULE_SECT_READ_SIZE + 1];
1559 size_t wrote;
1560
1561 if (pos != 0)
1562 return -EINVAL;
1563
1564 /*
1565 * Since we're a binary read handler, we must account for the
1566 * trailing NUL byte that sprintf will write: if "buf" is
1567 * too small to hold the NUL, or the NUL is exactly the last
1568 * byte, the read will look like it got truncated by one byte.
1569 * Since there is no way to ask sprintf nicely to not write
1570 * the NUL, we have to use a bounce buffer.
1571 */
1572 wrote = scnprintf(bounce, sizeof(bounce), "0x%px\n",
1573 kallsyms_show_value(file->f_cred)
1574 ? (void *)sattr->address : NULL);
1575 count = min(count, wrote);
1576 memcpy(buf, bounce, count);
1577
1578 return count;
1579}
1580
1581static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1582{
1583 unsigned int section;
1584
1585 for (section = 0; section < sect_attrs->nsections; section++)
1586 kfree(sect_attrs->attrs[section].battr.attr.name);
1587 kfree(sect_attrs);
1588}
1589
1590static void add_sect_attrs(struct module *mod, const struct load_info *info)
1591{
1592 unsigned int nloaded = 0, i, size[2];
1593 struct module_sect_attrs *sect_attrs;
1594 struct module_sect_attr *sattr;
1595 struct bin_attribute **gattr;
1596
1597 /* Count loaded sections and allocate structures */
1598 for (i = 0; i < info->hdr->e_shnum; i++)
1599 if (!sect_empty(&info->sechdrs[i]))
1600 nloaded++;
1601 size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded),
1602 sizeof(sect_attrs->grp.bin_attrs[0]));
1603 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.bin_attrs[0]);
1604 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1605 if (sect_attrs == NULL)
1606 return;
1607
1608 /* Setup section attributes. */
1609 sect_attrs->grp.name = "sections";
1610 sect_attrs->grp.bin_attrs = (void *)sect_attrs + size[0];
1611
1612 sect_attrs->nsections = 0;
1613 sattr = §_attrs->attrs[0];
1614 gattr = §_attrs->grp.bin_attrs[0];
1615 for (i = 0; i < info->hdr->e_shnum; i++) {
1616 Elf_Shdr *sec = &info->sechdrs[i];
1617 if (sect_empty(sec))
1618 continue;
1619 sysfs_bin_attr_init(&sattr->battr);
1620 sattr->address = sec->sh_addr;
1621 sattr->battr.attr.name =
1622 kstrdup(info->secstrings + sec->sh_name, GFP_KERNEL);
1623 if (sattr->battr.attr.name == NULL)
1624 goto out;
1625 sect_attrs->nsections++;
1626 sattr->battr.read = module_sect_read;
1627 sattr->battr.size = MODULE_SECT_READ_SIZE;
1628 sattr->battr.attr.mode = 0400;
1629 *(gattr++) = &(sattr++)->battr;
1630 }
1631 *gattr = NULL;
1632
1633 if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp))
1634 goto out;
1635
1636 mod->sect_attrs = sect_attrs;
1637 return;
1638 out:
1639 free_sect_attrs(sect_attrs);
1640}
1641
1642static void remove_sect_attrs(struct module *mod)
1643{
1644 if (mod->sect_attrs) {
1645 sysfs_remove_group(&mod->mkobj.kobj,
1646 &mod->sect_attrs->grp);
1647 /* We are positive that no one is using any sect attrs
1648 * at this point. Deallocate immediately. */
1649 free_sect_attrs(mod->sect_attrs);
1650 mod->sect_attrs = NULL;
1651 }
1652}
1653
1654/*
1655 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1656 */
1657
1658struct module_notes_attrs {
1659 struct kobject *dir;
1660 unsigned int notes;
1661 struct bin_attribute attrs[];
1662};
1663
1664static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1665 struct bin_attribute *bin_attr,
1666 char *buf, loff_t pos, size_t count)
1667{
1668 /*
1669 * The caller checked the pos and count against our size.
1670 */
1671 memcpy(buf, bin_attr->private + pos, count);
1672 return count;
1673}
1674
1675static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1676 unsigned int i)
1677{
1678 if (notes_attrs->dir) {
1679 while (i-- > 0)
1680 sysfs_remove_bin_file(notes_attrs->dir,
1681 ¬es_attrs->attrs[i]);
1682 kobject_put(notes_attrs->dir);
1683 }
1684 kfree(notes_attrs);
1685}
1686
1687static void add_notes_attrs(struct module *mod, const struct load_info *info)
1688{
1689 unsigned int notes, loaded, i;
1690 struct module_notes_attrs *notes_attrs;
1691 struct bin_attribute *nattr;
1692
1693 /* failed to create section attributes, so can't create notes */
1694 if (!mod->sect_attrs)
1695 return;
1696
1697 /* Count notes sections and allocate structures. */
1698 notes = 0;
1699 for (i = 0; i < info->hdr->e_shnum; i++)
1700 if (!sect_empty(&info->sechdrs[i]) &&
1701 (info->sechdrs[i].sh_type == SHT_NOTE))
1702 ++notes;
1703
1704 if (notes == 0)
1705 return;
1706
1707 notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes),
1708 GFP_KERNEL);
1709 if (notes_attrs == NULL)
1710 return;
1711
1712 notes_attrs->notes = notes;
1713 nattr = ¬es_attrs->attrs[0];
1714 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1715 if (sect_empty(&info->sechdrs[i]))
1716 continue;
1717 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1718 sysfs_bin_attr_init(nattr);
1719 nattr->attr.name = mod->sect_attrs->attrs[loaded].battr.attr.name;
1720 nattr->attr.mode = S_IRUGO;
1721 nattr->size = info->sechdrs[i].sh_size;
1722 nattr->private = (void *) info->sechdrs[i].sh_addr;
1723 nattr->read = module_notes_read;
1724 ++nattr;
1725 }
1726 ++loaded;
1727 }
1728
1729 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1730 if (!notes_attrs->dir)
1731 goto out;
1732
1733 for (i = 0; i < notes; ++i)
1734 if (sysfs_create_bin_file(notes_attrs->dir,
1735 ¬es_attrs->attrs[i]))
1736 goto out;
1737
1738 mod->notes_attrs = notes_attrs;
1739 return;
1740
1741 out:
1742 free_notes_attrs(notes_attrs, i);
1743}
1744
1745static void remove_notes_attrs(struct module *mod)
1746{
1747 if (mod->notes_attrs)
1748 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1749}
1750
1751#else
1752
1753static inline void add_sect_attrs(struct module *mod,
1754 const struct load_info *info)
1755{
1756}
1757
1758static inline void remove_sect_attrs(struct module *mod)
1759{
1760}
1761
1762static inline void add_notes_attrs(struct module *mod,
1763 const struct load_info *info)
1764{
1765}
1766
1767static inline void remove_notes_attrs(struct module *mod)
1768{
1769}
1770#endif /* CONFIG_KALLSYMS */
1771
1772static void del_usage_links(struct module *mod)
1773{
1774#ifdef CONFIG_MODULE_UNLOAD
1775 struct module_use *use;
1776
1777 mutex_lock(&module_mutex);
1778 list_for_each_entry(use, &mod->target_list, target_list)
1779 sysfs_remove_link(use->target->holders_dir, mod->name);
1780 mutex_unlock(&module_mutex);
1781#endif
1782}
1783
1784static int add_usage_links(struct module *mod)
1785{
1786 int ret = 0;
1787#ifdef CONFIG_MODULE_UNLOAD
1788 struct module_use *use;
1789
1790 mutex_lock(&module_mutex);
1791 list_for_each_entry(use, &mod->target_list, target_list) {
1792 ret = sysfs_create_link(use->target->holders_dir,
1793 &mod->mkobj.kobj, mod->name);
1794 if (ret)
1795 break;
1796 }
1797 mutex_unlock(&module_mutex);
1798 if (ret)
1799 del_usage_links(mod);
1800#endif
1801 return ret;
1802}
1803
1804static void module_remove_modinfo_attrs(struct module *mod, int end);
1805
1806static int module_add_modinfo_attrs(struct module *mod)
1807{
1808 struct module_attribute *attr;
1809 struct module_attribute *temp_attr;
1810 int error = 0;
1811 int i;
1812
1813 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1814 (ARRAY_SIZE(modinfo_attrs) + 1)),
1815 GFP_KERNEL);
1816 if (!mod->modinfo_attrs)
1817 return -ENOMEM;
1818
1819 temp_attr = mod->modinfo_attrs;
1820 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1821 if (!attr->test || attr->test(mod)) {
1822 memcpy(temp_attr, attr, sizeof(*temp_attr));
1823 sysfs_attr_init(&temp_attr->attr);
1824 error = sysfs_create_file(&mod->mkobj.kobj,
1825 &temp_attr->attr);
1826 if (error)
1827 goto error_out;
1828 ++temp_attr;
1829 }
1830 }
1831
1832 return 0;
1833
1834error_out:
1835 if (i > 0)
1836 module_remove_modinfo_attrs(mod, --i);
1837 else
1838 kfree(mod->modinfo_attrs);
1839 return error;
1840}
1841
1842static void module_remove_modinfo_attrs(struct module *mod, int end)
1843{
1844 struct module_attribute *attr;
1845 int i;
1846
1847 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1848 if (end >= 0 && i > end)
1849 break;
1850 /* pick a field to test for end of list */
1851 if (!attr->attr.name)
1852 break;
1853 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1854 if (attr->free)
1855 attr->free(mod);
1856 }
1857 kfree(mod->modinfo_attrs);
1858}
1859
1860static void mod_kobject_put(struct module *mod)
1861{
1862 DECLARE_COMPLETION_ONSTACK(c);
1863 mod->mkobj.kobj_completion = &c;
1864 kobject_put(&mod->mkobj.kobj);
1865 wait_for_completion(&c);
1866}
1867
1868static int mod_sysfs_init(struct module *mod)
1869{
1870 int err;
1871 struct kobject *kobj;
1872
1873 if (!module_sysfs_initialized) {
1874 pr_err("%s: module sysfs not initialized\n", mod->name);
1875 err = -EINVAL;
1876 goto out;
1877 }
1878
1879 kobj = kset_find_obj(module_kset, mod->name);
1880 if (kobj) {
1881 pr_err("%s: module is already loaded\n", mod->name);
1882 kobject_put(kobj);
1883 err = -EINVAL;
1884 goto out;
1885 }
1886
1887 mod->mkobj.mod = mod;
1888
1889 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1890 mod->mkobj.kobj.kset = module_kset;
1891 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1892 "%s", mod->name);
1893 if (err)
1894 mod_kobject_put(mod);
1895
1896 /* delay uevent until full sysfs population */
1897out:
1898 return err;
1899}
1900
1901static int mod_sysfs_setup(struct module *mod,
1902 const struct load_info *info,
1903 struct kernel_param *kparam,
1904 unsigned int num_params)
1905{
1906 int err;
1907
1908 err = mod_sysfs_init(mod);
1909 if (err)
1910 goto out;
1911
1912 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1913 if (!mod->holders_dir) {
1914 err = -ENOMEM;
1915 goto out_unreg;
1916 }
1917
1918 err = module_param_sysfs_setup(mod, kparam, num_params);
1919 if (err)
1920 goto out_unreg_holders;
1921
1922 err = module_add_modinfo_attrs(mod);
1923 if (err)
1924 goto out_unreg_param;
1925
1926 err = add_usage_links(mod);
1927 if (err)
1928 goto out_unreg_modinfo_attrs;
1929
1930 add_sect_attrs(mod, info);
1931 add_notes_attrs(mod, info);
1932
1933 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1934 return 0;
1935
1936out_unreg_modinfo_attrs:
1937 module_remove_modinfo_attrs(mod, -1);
1938out_unreg_param:
1939 module_param_sysfs_remove(mod);
1940out_unreg_holders:
1941 kobject_put(mod->holders_dir);
1942out_unreg:
1943 mod_kobject_put(mod);
1944out:
1945 return err;
1946}
1947
1948static void mod_sysfs_fini(struct module *mod)
1949{
1950 remove_notes_attrs(mod);
1951 remove_sect_attrs(mod);
1952 mod_kobject_put(mod);
1953}
1954
1955static void init_param_lock(struct module *mod)
1956{
1957 mutex_init(&mod->param_lock);
1958}
1959#else /* !CONFIG_SYSFS */
1960
1961static int mod_sysfs_setup(struct module *mod,
1962 const struct load_info *info,
1963 struct kernel_param *kparam,
1964 unsigned int num_params)
1965{
1966 return 0;
1967}
1968
1969static void mod_sysfs_fini(struct module *mod)
1970{
1971}
1972
1973static void module_remove_modinfo_attrs(struct module *mod, int end)
1974{
1975}
1976
1977static void del_usage_links(struct module *mod)
1978{
1979}
1980
1981static void init_param_lock(struct module *mod)
1982{
1983}
1984#endif /* CONFIG_SYSFS */
1985
1986static void mod_sysfs_teardown(struct module *mod)
1987{
1988 del_usage_links(mod);
1989 module_remove_modinfo_attrs(mod, -1);
1990 module_param_sysfs_remove(mod);
1991 kobject_put(mod->mkobj.drivers_dir);
1992 kobject_put(mod->holders_dir);
1993 mod_sysfs_fini(mod);
1994}
1995
1996/*
1997 * LKM RO/NX protection: protect module's text/ro-data
1998 * from modification and any data from execution.
1999 *
2000 * General layout of module is:
2001 * [text] [read-only-data] [ro-after-init] [writable data]
2002 * text_size -----^ ^ ^ ^
2003 * ro_size ------------------------| | |
2004 * ro_after_init_size -----------------------------| |
2005 * size -----------------------------------------------------------|
2006 *
2007 * These values are always page-aligned (as is base)
2008 */
2009
2010/*
2011 * Since some arches are moving towards PAGE_KERNEL module allocations instead
2012 * of PAGE_KERNEL_EXEC, keep frob_text() and module_enable_x() outside of the
2013 * CONFIG_STRICT_MODULE_RWX block below because they are needed regardless of
2014 * whether we are strict.
2015 */
2016#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
2017static void frob_text(const struct module_layout *layout,
2018 int (*set_memory)(unsigned long start, int num_pages))
2019{
2020 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
2021 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
2022 set_memory((unsigned long)layout->base,
2023 layout->text_size >> PAGE_SHIFT);
2024}
2025
2026static void module_enable_x(const struct module *mod)
2027{
2028 frob_text(&mod->core_layout, set_memory_x);
2029 frob_text(&mod->init_layout, set_memory_x);
2030}
2031#else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
2032static void module_enable_x(const struct module *mod) { }
2033#endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
2034
2035#ifdef CONFIG_STRICT_MODULE_RWX
2036static void frob_rodata(const struct module_layout *layout,
2037 int (*set_memory)(unsigned long start, int num_pages))
2038{
2039 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
2040 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
2041 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
2042 set_memory((unsigned long)layout->base + layout->text_size,
2043 (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
2044}
2045
2046static void frob_ro_after_init(const struct module_layout *layout,
2047 int (*set_memory)(unsigned long start, int num_pages))
2048{
2049 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
2050 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
2051 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
2052 set_memory((unsigned long)layout->base + layout->ro_size,
2053 (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
2054}
2055
2056static void frob_writable_data(const struct module_layout *layout,
2057 int (*set_memory)(unsigned long start, int num_pages))
2058{
2059 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
2060 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
2061 BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
2062 set_memory((unsigned long)layout->base + layout->ro_after_init_size,
2063 (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
2064}
2065
2066static void module_enable_ro(const struct module *mod, bool after_init)
2067{
2068 if (!rodata_enabled)
2069 return;
2070
2071 set_vm_flush_reset_perms(mod->core_layout.base);
2072 set_vm_flush_reset_perms(mod->init_layout.base);
2073 frob_text(&mod->core_layout, set_memory_ro);
2074
2075 frob_rodata(&mod->core_layout, set_memory_ro);
2076 frob_text(&mod->init_layout, set_memory_ro);
2077 frob_rodata(&mod->init_layout, set_memory_ro);
2078
2079 if (after_init)
2080 frob_ro_after_init(&mod->core_layout, set_memory_ro);
2081}
2082
2083static void module_enable_nx(const struct module *mod)
2084{
2085 frob_rodata(&mod->core_layout, set_memory_nx);
2086 frob_ro_after_init(&mod->core_layout, set_memory_nx);
2087 frob_writable_data(&mod->core_layout, set_memory_nx);
2088 frob_rodata(&mod->init_layout, set_memory_nx);
2089 frob_writable_data(&mod->init_layout, set_memory_nx);
2090}
2091
2092static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
2093 char *secstrings, struct module *mod)
2094{
2095 const unsigned long shf_wx = SHF_WRITE|SHF_EXECINSTR;
2096 int i;
2097
2098 for (i = 0; i < hdr->e_shnum; i++) {
2099 if ((sechdrs[i].sh_flags & shf_wx) == shf_wx)
2100 return -ENOEXEC;
2101 }
2102
2103 return 0;
2104}
2105
2106#else /* !CONFIG_STRICT_MODULE_RWX */
2107static void module_enable_nx(const struct module *mod) { }
2108static void module_enable_ro(const struct module *mod, bool after_init) {}
2109static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
2110 char *secstrings, struct module *mod)
2111{
2112 return 0;
2113}
2114#endif /* CONFIG_STRICT_MODULE_RWX */
2115
2116#ifdef CONFIG_LIVEPATCH
2117/*
2118 * Persist Elf information about a module. Copy the Elf header,
2119 * section header table, section string table, and symtab section
2120 * index from info to mod->klp_info.
2121 */
2122static int copy_module_elf(struct module *mod, struct load_info *info)
2123{
2124 unsigned int size, symndx;
2125 int ret;
2126
2127 size = sizeof(*mod->klp_info);
2128 mod->klp_info = kmalloc(size, GFP_KERNEL);
2129 if (mod->klp_info == NULL)
2130 return -ENOMEM;
2131
2132 /* Elf header */
2133 size = sizeof(mod->klp_info->hdr);
2134 memcpy(&mod->klp_info->hdr, info->hdr, size);
2135
2136 /* Elf section header table */
2137 size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
2138 mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL);
2139 if (mod->klp_info->sechdrs == NULL) {
2140 ret = -ENOMEM;
2141 goto free_info;
2142 }
2143
2144 /* Elf section name string table */
2145 size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
2146 mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL);
2147 if (mod->klp_info->secstrings == NULL) {
2148 ret = -ENOMEM;
2149 goto free_sechdrs;
2150 }
2151
2152 /* Elf symbol section index */
2153 symndx = info->index.sym;
2154 mod->klp_info->symndx = symndx;
2155
2156 /*
2157 * For livepatch modules, core_kallsyms.symtab is a complete
2158 * copy of the original symbol table. Adjust sh_addr to point
2159 * to core_kallsyms.symtab since the copy of the symtab in module
2160 * init memory is freed at the end of do_init_module().
2161 */
2162 mod->klp_info->sechdrs[symndx].sh_addr = \
2163 (unsigned long) mod->core_kallsyms.symtab;
2164
2165 return 0;
2166
2167free_sechdrs:
2168 kfree(mod->klp_info->sechdrs);
2169free_info:
2170 kfree(mod->klp_info);
2171 return ret;
2172}
2173
2174static void free_module_elf(struct module *mod)
2175{
2176 kfree(mod->klp_info->sechdrs);
2177 kfree(mod->klp_info->secstrings);
2178 kfree(mod->klp_info);
2179}
2180#else /* !CONFIG_LIVEPATCH */
2181static int copy_module_elf(struct module *mod, struct load_info *info)
2182{
2183 return 0;
2184}
2185
2186static void free_module_elf(struct module *mod)
2187{
2188}
2189#endif /* CONFIG_LIVEPATCH */
2190
2191void __weak module_memfree(void *module_region)
2192{
2193 /*
2194 * This memory may be RO, and freeing RO memory in an interrupt is not
2195 * supported by vmalloc.
2196 */
2197 WARN_ON(in_interrupt());
2198 vfree(module_region);
2199}
2200
2201void __weak module_arch_cleanup(struct module *mod)
2202{
2203}
2204
2205void __weak module_arch_freeing_init(struct module *mod)
2206{
2207}
2208
2209/* Free a module, remove from lists, etc. */
2210static void free_module(struct module *mod)
2211{
2212 trace_module_free(mod);
2213
2214 mod_sysfs_teardown(mod);
2215
2216 /* We leave it in list to prevent duplicate loads, but make sure
2217 * that noone uses it while it's being deconstructed. */
2218 mutex_lock(&module_mutex);
2219 mod->state = MODULE_STATE_UNFORMED;
2220 mutex_unlock(&module_mutex);
2221
2222 /* Remove dynamic debug info */
2223 ddebug_remove_module(mod->name);
2224
2225 /* Arch-specific cleanup. */
2226 module_arch_cleanup(mod);
2227
2228 /* Module unload stuff */
2229 module_unload_free(mod);
2230
2231 /* Free any allocated parameters. */
2232 destroy_params(mod->kp, mod->num_kp);
2233
2234 if (is_livepatch_module(mod))
2235 free_module_elf(mod);
2236
2237 /* Now we can delete it from the lists */
2238 mutex_lock(&module_mutex);
2239 /* Unlink carefully: kallsyms could be walking list. */
2240 list_del_rcu(&mod->list);
2241 mod_tree_remove(mod);
2242 /* Remove this module from bug list, this uses list_del_rcu */
2243 module_bug_cleanup(mod);
2244 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2245 synchronize_rcu();
2246 mutex_unlock(&module_mutex);
2247
2248 /* This may be empty, but that's OK */
2249 module_arch_freeing_init(mod);
2250 module_memfree(mod->init_layout.base);
2251 kfree(mod->args);
2252 percpu_modfree(mod);
2253
2254 /* Free lock-classes; relies on the preceding sync_rcu(). */
2255 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
2256
2257 /* Finally, free the core (containing the module structure) */
2258 module_memfree(mod->core_layout.base);
2259}
2260
2261void *__symbol_get(const char *symbol)
2262{
2263 struct module *owner;
2264 const struct kernel_symbol *sym;
2265
2266 preempt_disable();
2267 sym = find_symbol(symbol, &owner, NULL, NULL, true, true);
2268 if (sym && strong_try_module_get(owner))
2269 sym = NULL;
2270 preempt_enable();
2271
2272 return sym ? (void *)kernel_symbol_value(sym) : NULL;
2273}
2274EXPORT_SYMBOL_GPL(__symbol_get);
2275
2276/*
2277 * Ensure that an exported symbol [global namespace] does not already exist
2278 * in the kernel or in some other module's exported symbol table.
2279 *
2280 * You must hold the module_mutex.
2281 */
2282static int verify_exported_symbols(struct module *mod)
2283{
2284 unsigned int i;
2285 struct module *owner;
2286 const struct kernel_symbol *s;
2287 struct {
2288 const struct kernel_symbol *sym;
2289 unsigned int num;
2290 } arr[] = {
2291 { mod->syms, mod->num_syms },
2292 { mod->gpl_syms, mod->num_gpl_syms },
2293 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2294#ifdef CONFIG_UNUSED_SYMBOLS
2295 { mod->unused_syms, mod->num_unused_syms },
2296 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2297#endif
2298 };
2299
2300 for (i = 0; i < ARRAY_SIZE(arr); i++) {
2301 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2302 if (find_symbol(kernel_symbol_name(s), &owner, NULL,
2303 NULL, true, false)) {
2304 pr_err("%s: exports duplicate symbol %s"
2305 " (owned by %s)\n",
2306 mod->name, kernel_symbol_name(s),
2307 module_name(owner));
2308 return -ENOEXEC;
2309 }
2310 }
2311 }
2312 return 0;
2313}
2314
2315/* Change all symbols so that st_value encodes the pointer directly. */
2316static int simplify_symbols(struct module *mod, const struct load_info *info)
2317{
2318 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2319 Elf_Sym *sym = (void *)symsec->sh_addr;
2320 unsigned long secbase;
2321 unsigned int i;
2322 int ret = 0;
2323 const struct kernel_symbol *ksym;
2324
2325 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2326 const char *name = info->strtab + sym[i].st_name;
2327
2328 switch (sym[i].st_shndx) {
2329 case SHN_COMMON:
2330 /* Ignore common symbols */
2331 if (!strncmp(name, "__gnu_lto", 9))
2332 break;
2333
2334 /* We compiled with -fno-common. These are not
2335 supposed to happen. */
2336 pr_debug("Common symbol: %s\n", name);
2337 pr_warn("%s: please compile with -fno-common\n",
2338 mod->name);
2339 ret = -ENOEXEC;
2340 break;
2341
2342 case SHN_ABS:
2343 /* Don't need to do anything */
2344 pr_debug("Absolute symbol: 0x%08lx\n",
2345 (long)sym[i].st_value);
2346 break;
2347
2348 case SHN_LIVEPATCH:
2349 /* Livepatch symbols are resolved by livepatch */
2350 break;
2351
2352 case SHN_UNDEF:
2353 ksym = resolve_symbol_wait(mod, info, name);
2354 /* Ok if resolved. */
2355 if (ksym && !IS_ERR(ksym)) {
2356 sym[i].st_value = kernel_symbol_value(ksym);
2357 break;
2358 }
2359
2360 /* Ok if weak. */
2361 if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
2362 break;
2363
2364 ret = PTR_ERR(ksym) ?: -ENOENT;
2365 pr_warn("%s: Unknown symbol %s (err %d)\n",
2366 mod->name, name, ret);
2367 break;
2368
2369 default:
2370 /* Divert to percpu allocation if a percpu var. */
2371 if (sym[i].st_shndx == info->index.pcpu)
2372 secbase = (unsigned long)mod_percpu(mod);
2373 else
2374 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2375 sym[i].st_value += secbase;
2376 break;
2377 }
2378 }
2379
2380 return ret;
2381}
2382
2383static int apply_relocations(struct module *mod, const struct load_info *info)
2384{
2385 unsigned int i;
2386 int err = 0;
2387
2388 /* Now do relocations. */
2389 for (i = 1; i < info->hdr->e_shnum; i++) {
2390 unsigned int infosec = info->sechdrs[i].sh_info;
2391
2392 /* Not a valid relocation section? */
2393 if (infosec >= info->hdr->e_shnum)
2394 continue;
2395
2396 /* Don't bother with non-allocated sections */
2397 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2398 continue;
2399
2400 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
2401 err = klp_apply_section_relocs(mod, info->sechdrs,
2402 info->secstrings,
2403 info->strtab,
2404 info->index.sym, i,
2405 NULL);
2406 else if (info->sechdrs[i].sh_type == SHT_REL)
2407 err = apply_relocate(info->sechdrs, info->strtab,
2408 info->index.sym, i, mod);
2409 else if (info->sechdrs[i].sh_type == SHT_RELA)
2410 err = apply_relocate_add(info->sechdrs, info->strtab,
2411 info->index.sym, i, mod);
2412 if (err < 0)
2413 break;
2414 }
2415 return err;
2416}
2417
2418/* Additional bytes needed by arch in front of individual sections */
2419unsigned int __weak arch_mod_section_prepend(struct module *mod,
2420 unsigned int section)
2421{
2422 /* default implementation just returns zero */
2423 return 0;
2424}
2425
2426/* Update size with this section: return offset. */
2427static long get_offset(struct module *mod, unsigned int *size,
2428 Elf_Shdr *sechdr, unsigned int section)
2429{
2430 long ret;
2431
2432 *size += arch_mod_section_prepend(mod, section);
2433 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2434 *size = ret + sechdr->sh_size;
2435 return ret;
2436}
2437
2438/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2439 might -- code, read-only data, read-write data, small data. Tally
2440 sizes, and place the offsets into sh_entsize fields: high bit means it
2441 belongs in init. */
2442static void layout_sections(struct module *mod, struct load_info *info)
2443{
2444 static unsigned long const masks[][2] = {
2445 /* NOTE: all executable code must be the first section
2446 * in this array; otherwise modify the text_size
2447 * finder in the two loops below */
2448 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2449 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2450 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
2451 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2452 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2453 };
2454 unsigned int m, i;
2455
2456 for (i = 0; i < info->hdr->e_shnum; i++)
2457 info->sechdrs[i].sh_entsize = ~0UL;
2458
2459 pr_debug("Core section allocation order:\n");
2460 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2461 for (i = 0; i < info->hdr->e_shnum; ++i) {
2462 Elf_Shdr *s = &info->sechdrs[i];
2463 const char *sname = info->secstrings + s->sh_name;
2464
2465 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2466 || (s->sh_flags & masks[m][1])
2467 || s->sh_entsize != ~0UL
2468 || module_init_section(sname))
2469 continue;
2470 s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2471 pr_debug("\t%s\n", sname);
2472 }
2473 switch (m) {
2474 case 0: /* executable */
2475 mod->core_layout.size = debug_align(mod->core_layout.size);
2476 mod->core_layout.text_size = mod->core_layout.size;
2477 break;
2478 case 1: /* RO: text and ro-data */
2479 mod->core_layout.size = debug_align(mod->core_layout.size);
2480 mod->core_layout.ro_size = mod->core_layout.size;
2481 break;
2482 case 2: /* RO after init */
2483 mod->core_layout.size = debug_align(mod->core_layout.size);
2484 mod->core_layout.ro_after_init_size = mod->core_layout.size;
2485 break;
2486 case 4: /* whole core */
2487 mod->core_layout.size = debug_align(mod->core_layout.size);
2488 break;
2489 }
2490 }
2491
2492 pr_debug("Init section allocation order:\n");
2493 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2494 for (i = 0; i < info->hdr->e_shnum; ++i) {
2495 Elf_Shdr *s = &info->sechdrs[i];
2496 const char *sname = info->secstrings + s->sh_name;
2497
2498 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2499 || (s->sh_flags & masks[m][1])
2500 || s->sh_entsize != ~0UL
2501 || !module_init_section(sname))
2502 continue;
2503 s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
2504 | INIT_OFFSET_MASK);
2505 pr_debug("\t%s\n", sname);
2506 }
2507 switch (m) {
2508 case 0: /* executable */
2509 mod->init_layout.size = debug_align(mod->init_layout.size);
2510 mod->init_layout.text_size = mod->init_layout.size;
2511 break;
2512 case 1: /* RO: text and ro-data */
2513 mod->init_layout.size = debug_align(mod->init_layout.size);
2514 mod->init_layout.ro_size = mod->init_layout.size;
2515 break;
2516 case 2:
2517 /*
2518 * RO after init doesn't apply to init_layout (only
2519 * core_layout), so it just takes the value of ro_size.
2520 */
2521 mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
2522 break;
2523 case 4: /* whole init */
2524 mod->init_layout.size = debug_align(mod->init_layout.size);
2525 break;
2526 }
2527 }
2528}
2529
2530static void set_license(struct module *mod, const char *license)
2531{
2532 if (!license)
2533 license = "unspecified";
2534
2535 if (!license_is_gpl_compatible(license)) {
2536 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2537 pr_warn("%s: module license '%s' taints kernel.\n",
2538 mod->name, license);
2539 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2540 LOCKDEP_NOW_UNRELIABLE);
2541 }
2542}
2543
2544/* Parse tag=value strings from .modinfo section */
2545static char *next_string(char *string, unsigned long *secsize)
2546{
2547 /* Skip non-zero chars */
2548 while (string[0]) {
2549 string++;
2550 if ((*secsize)-- <= 1)
2551 return NULL;
2552 }
2553
2554 /* Skip any zero padding. */
2555 while (!string[0]) {
2556 string++;
2557 if ((*secsize)-- <= 1)
2558 return NULL;
2559 }
2560 return string;
2561}
2562
2563static char *get_next_modinfo(const struct load_info *info, const char *tag,
2564 char *prev)
2565{
2566 char *p;
2567 unsigned int taglen = strlen(tag);
2568 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2569 unsigned long size = infosec->sh_size;
2570
2571 /*
2572 * get_modinfo() calls made before rewrite_section_headers()
2573 * must use sh_offset, as sh_addr isn't set!
2574 */
2575 char *modinfo = (char *)info->hdr + infosec->sh_offset;
2576
2577 if (prev) {
2578 size -= prev - modinfo;
2579 modinfo = next_string(prev, &size);
2580 }
2581
2582 for (p = modinfo; p; p = next_string(p, &size)) {
2583 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2584 return p + taglen + 1;
2585 }
2586 return NULL;
2587}
2588
2589static char *get_modinfo(const struct load_info *info, const char *tag)
2590{
2591 return get_next_modinfo(info, tag, NULL);
2592}
2593
2594static void setup_modinfo(struct module *mod, struct load_info *info)
2595{
2596 struct module_attribute *attr;
2597 int i;
2598
2599 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2600 if (attr->setup)
2601 attr->setup(mod, get_modinfo(info, attr->attr.name));
2602 }
2603}
2604
2605static void free_modinfo(struct module *mod)
2606{
2607 struct module_attribute *attr;
2608 int i;
2609
2610 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2611 if (attr->free)
2612 attr->free(mod);
2613 }
2614}
2615
2616#ifdef CONFIG_KALLSYMS
2617
2618/* Lookup exported symbol in given range of kernel_symbols */
2619static const struct kernel_symbol *lookup_exported_symbol(const char *name,
2620 const struct kernel_symbol *start,
2621 const struct kernel_symbol *stop)
2622{
2623 return bsearch(name, start, stop - start,
2624 sizeof(struct kernel_symbol), cmp_name);
2625}
2626
2627static int is_exported(const char *name, unsigned long value,
2628 const struct module *mod)
2629{
2630 const struct kernel_symbol *ks;
2631 if (!mod)
2632 ks = lookup_exported_symbol(name, __start___ksymtab, __stop___ksymtab);
2633 else
2634 ks = lookup_exported_symbol(name, mod->syms, mod->syms + mod->num_syms);
2635
2636 return ks != NULL && kernel_symbol_value(ks) == value;
2637}
2638
2639/* As per nm */
2640static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2641{
2642 const Elf_Shdr *sechdrs = info->sechdrs;
2643
2644 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2645 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2646 return 'v';
2647 else
2648 return 'w';
2649 }
2650 if (sym->st_shndx == SHN_UNDEF)
2651 return 'U';
2652 if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
2653 return 'a';
2654 if (sym->st_shndx >= SHN_LORESERVE)
2655 return '?';
2656 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2657 return 't';
2658 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2659 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2660 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2661 return 'r';
2662 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2663 return 'g';
2664 else
2665 return 'd';
2666 }
2667 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2668 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2669 return 's';
2670 else
2671 return 'b';
2672 }
2673 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2674 ".debug")) {
2675 return 'n';
2676 }
2677 return '?';
2678}
2679
2680static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2681 unsigned int shnum, unsigned int pcpundx)
2682{
2683 const Elf_Shdr *sec;
2684
2685 if (src->st_shndx == SHN_UNDEF
2686 || src->st_shndx >= shnum
2687 || !src->st_name)
2688 return false;
2689
2690#ifdef CONFIG_KALLSYMS_ALL
2691 if (src->st_shndx == pcpundx)
2692 return true;
2693#endif
2694
2695 sec = sechdrs + src->st_shndx;
2696 if (!(sec->sh_flags & SHF_ALLOC)
2697#ifndef CONFIG_KALLSYMS_ALL
2698 || !(sec->sh_flags & SHF_EXECINSTR)
2699#endif
2700 || (sec->sh_entsize & INIT_OFFSET_MASK))
2701 return false;
2702
2703 return true;
2704}
2705
2706/*
2707 * We only allocate and copy the strings needed by the parts of symtab
2708 * we keep. This is simple, but has the effect of making multiple
2709 * copies of duplicates. We could be more sophisticated, see
2710 * linux-kernel thread starting with
2711 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2712 */
2713static void layout_symtab(struct module *mod, struct load_info *info)
2714{
2715 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2716 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2717 const Elf_Sym *src;
2718 unsigned int i, nsrc, ndst, strtab_size = 0;
2719
2720 /* Put symbol section at end of init part of module. */
2721 symsect->sh_flags |= SHF_ALLOC;
2722 symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2723 info->index.sym) | INIT_OFFSET_MASK;
2724 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2725
2726 src = (void *)info->hdr + symsect->sh_offset;
2727 nsrc = symsect->sh_size / sizeof(*src);
2728
2729 /* Compute total space required for the core symbols' strtab. */
2730 for (ndst = i = 0; i < nsrc; i++) {
2731 if (i == 0 || is_livepatch_module(mod) ||
2732 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2733 info->index.pcpu)) {
2734 strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2735 ndst++;
2736 }
2737 }
2738
2739 /* Append room for core symbols at end of core part. */
2740 info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
2741 info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
2742 mod->core_layout.size += strtab_size;
2743 info->core_typeoffs = mod->core_layout.size;
2744 mod->core_layout.size += ndst * sizeof(char);
2745 mod->core_layout.size = debug_align(mod->core_layout.size);
2746
2747 /* Put string table section at end of init part of module. */
2748 strsect->sh_flags |= SHF_ALLOC;
2749 strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2750 info->index.str) | INIT_OFFSET_MASK;
2751 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2752
2753 /* We'll tack temporary mod_kallsyms on the end. */
2754 mod->init_layout.size = ALIGN(mod->init_layout.size,
2755 __alignof__(struct mod_kallsyms));
2756 info->mod_kallsyms_init_off = mod->init_layout.size;
2757 mod->init_layout.size += sizeof(struct mod_kallsyms);
2758 info->init_typeoffs = mod->init_layout.size;
2759 mod->init_layout.size += nsrc * sizeof(char);
2760 mod->init_layout.size = debug_align(mod->init_layout.size);
2761}
2762
2763/*
2764 * We use the full symtab and strtab which layout_symtab arranged to
2765 * be appended to the init section. Later we switch to the cut-down
2766 * core-only ones.
2767 */
2768static void add_kallsyms(struct module *mod, const struct load_info *info)
2769{
2770 unsigned int i, ndst;
2771 const Elf_Sym *src;
2772 Elf_Sym *dst;
2773 char *s;
2774 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2775
2776 /* Set up to point into init section. */
2777 mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
2778
2779 mod->kallsyms->symtab = (void *)symsec->sh_addr;
2780 mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2781 /* Make sure we get permanent strtab: don't use info->strtab. */
2782 mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2783 mod->kallsyms->typetab = mod->init_layout.base + info->init_typeoffs;
2784
2785 /*
2786 * Now populate the cut down core kallsyms for after init
2787 * and set types up while we still have access to sections.
2788 */
2789 mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
2790 mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
2791 mod->core_kallsyms.typetab = mod->core_layout.base + info->core_typeoffs;
2792 src = mod->kallsyms->symtab;
2793 for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2794 mod->kallsyms->typetab[i] = elf_type(src + i, info);
2795 if (i == 0 || is_livepatch_module(mod) ||
2796 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2797 info->index.pcpu)) {
2798 mod->core_kallsyms.typetab[ndst] =
2799 mod->kallsyms->typetab[i];
2800 dst[ndst] = src[i];
2801 dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
2802 s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2803 KSYM_NAME_LEN) + 1;
2804 }
2805 }
2806 mod->core_kallsyms.num_symtab = ndst;
2807}
2808#else
2809static inline void layout_symtab(struct module *mod, struct load_info *info)
2810{
2811}
2812
2813static void add_kallsyms(struct module *mod, const struct load_info *info)
2814{
2815}
2816#endif /* CONFIG_KALLSYMS */
2817
2818static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num)
2819{
2820 if (!debug)
2821 return;
2822 ddebug_add_module(debug, num, mod->name);
2823}
2824
2825static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug)
2826{
2827 if (debug)
2828 ddebug_remove_module(mod->name);
2829}
2830
2831void * __weak module_alloc(unsigned long size)
2832{
2833 return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
2834 GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS,
2835 NUMA_NO_NODE, __builtin_return_address(0));
2836}
2837
2838bool __weak module_init_section(const char *name)
2839{
2840 return strstarts(name, ".init");
2841}
2842
2843bool __weak module_exit_section(const char *name)
2844{
2845 return strstarts(name, ".exit");
2846}
2847
2848#ifdef CONFIG_DEBUG_KMEMLEAK
2849static void kmemleak_load_module(const struct module *mod,
2850 const struct load_info *info)
2851{
2852 unsigned int i;
2853
2854 /* only scan the sections containing data */
2855 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2856
2857 for (i = 1; i < info->hdr->e_shnum; i++) {
2858 /* Scan all writable sections that's not executable */
2859 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2860 !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2861 (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2862 continue;
2863
2864 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2865 info->sechdrs[i].sh_size, GFP_KERNEL);
2866 }
2867}
2868#else
2869static inline void kmemleak_load_module(const struct module *mod,
2870 const struct load_info *info)
2871{
2872}
2873#endif
2874
2875#ifdef CONFIG_MODULE_SIG
2876static int module_sig_check(struct load_info *info, int flags)
2877{
2878 int err = -ENODATA;
2879 const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2880 const char *reason;
2881 const void *mod = info->hdr;
2882
2883 /*
2884 * Require flags == 0, as a module with version information
2885 * removed is no longer the module that was signed
2886 */
2887 if (flags == 0 &&
2888 info->len > markerlen &&
2889 memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2890 /* We truncate the module to discard the signature */
2891 info->len -= markerlen;
2892 err = mod_verify_sig(mod, info);
2893 }
2894
2895 switch (err) {
2896 case 0:
2897 info->sig_ok = true;
2898 return 0;
2899
2900 /* We don't permit modules to be loaded into trusted kernels
2901 * without a valid signature on them, but if we're not
2902 * enforcing, certain errors are non-fatal.
2903 */
2904 case -ENODATA:
2905 reason = "Loading of unsigned module";
2906 goto decide;
2907 case -ENOPKG:
2908 reason = "Loading of module with unsupported crypto";
2909 goto decide;
2910 case -ENOKEY:
2911 reason = "Loading of module with unavailable key";
2912 decide:
2913 if (is_module_sig_enforced()) {
2914 pr_notice("%s: %s is rejected\n", info->name, reason);
2915 return -EKEYREJECTED;
2916 }
2917
2918 return security_locked_down(LOCKDOWN_MODULE_SIGNATURE);
2919
2920 /* All other errors are fatal, including nomem, unparseable
2921 * signatures and signature check failures - even if signatures
2922 * aren't required.
2923 */
2924 default:
2925 return err;
2926 }
2927}
2928#else /* !CONFIG_MODULE_SIG */
2929static int module_sig_check(struct load_info *info, int flags)
2930{
2931 return 0;
2932}
2933#endif /* !CONFIG_MODULE_SIG */
2934
2935/* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2936static int elf_header_check(struct load_info *info)
2937{
2938 if (info->len < sizeof(*(info->hdr)))
2939 return -ENOEXEC;
2940
2941 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2942 || info->hdr->e_type != ET_REL
2943 || !elf_check_arch(info->hdr)
2944 || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2945 return -ENOEXEC;
2946
2947 if (info->hdr->e_shoff >= info->len
2948 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2949 info->len - info->hdr->e_shoff))
2950 return -ENOEXEC;
2951
2952 return 0;
2953}
2954
2955#define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2956
2957static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
2958{
2959 do {
2960 unsigned long n = min(len, COPY_CHUNK_SIZE);
2961
2962 if (copy_from_user(dst, usrc, n) != 0)
2963 return -EFAULT;
2964 cond_resched();
2965 dst += n;
2966 usrc += n;
2967 len -= n;
2968 } while (len);
2969 return 0;
2970}
2971
2972#ifdef CONFIG_LIVEPATCH
2973static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2974{
2975 if (get_modinfo(info, "livepatch")) {
2976 mod->klp = true;
2977 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
2978 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
2979 mod->name);
2980 }
2981
2982 return 0;
2983}
2984#else /* !CONFIG_LIVEPATCH */
2985static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2986{
2987 if (get_modinfo(info, "livepatch")) {
2988 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
2989 mod->name);
2990 return -ENOEXEC;
2991 }
2992
2993 return 0;
2994}
2995#endif /* CONFIG_LIVEPATCH */
2996
2997static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
2998{
2999 if (retpoline_module_ok(get_modinfo(info, "retpoline")))
3000 return;
3001
3002 pr_warn("%s: loading module not compiled with retpoline compiler.\n",
3003 mod->name);
3004}
3005
3006/* Sets info->hdr and info->len. */
3007static int copy_module_from_user(const void __user *umod, unsigned long len,
3008 struct load_info *info)
3009{
3010 int err;
3011
3012 info->len = len;
3013 if (info->len < sizeof(*(info->hdr)))
3014 return -ENOEXEC;
3015
3016 err = security_kernel_load_data(LOADING_MODULE);
3017 if (err)
3018 return err;
3019
3020 /* Suck in entire file: we'll want most of it. */
3021 info->hdr = __vmalloc(info->len, GFP_KERNEL | __GFP_NOWARN);
3022 if (!info->hdr)
3023 return -ENOMEM;
3024
3025 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
3026 vfree(info->hdr);
3027 return -EFAULT;
3028 }
3029
3030 return 0;
3031}
3032
3033static void free_copy(struct load_info *info)
3034{
3035 vfree(info->hdr);
3036}
3037
3038static int rewrite_section_headers(struct load_info *info, int flags)
3039{
3040 unsigned int i;
3041
3042 /* This should always be true, but let's be sure. */
3043 info->sechdrs[0].sh_addr = 0;
3044
3045 for (i = 1; i < info->hdr->e_shnum; i++) {
3046 Elf_Shdr *shdr = &info->sechdrs[i];
3047 if (shdr->sh_type != SHT_NOBITS
3048 && info->len < shdr->sh_offset + shdr->sh_size) {
3049 pr_err("Module len %lu truncated\n", info->len);
3050 return -ENOEXEC;
3051 }
3052
3053 /* Mark all sections sh_addr with their address in the
3054 temporary image. */
3055 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
3056
3057#ifndef CONFIG_MODULE_UNLOAD
3058 /* Don't load .exit sections */
3059 if (module_exit_section(info->secstrings+shdr->sh_name))
3060 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
3061#endif
3062 }
3063
3064 /* Track but don't keep modinfo and version sections. */
3065 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
3066 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
3067
3068 return 0;
3069}
3070
3071/*
3072 * Set up our basic convenience variables (pointers to section headers,
3073 * search for module section index etc), and do some basic section
3074 * verification.
3075 *
3076 * Set info->mod to the temporary copy of the module in info->hdr. The final one
3077 * will be allocated in move_module().
3078 */
3079static int setup_load_info(struct load_info *info, int flags)
3080{
3081 unsigned int i;
3082
3083 /* Set up the convenience variables */
3084 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
3085 info->secstrings = (void *)info->hdr
3086 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
3087
3088 /* Try to find a name early so we can log errors with a module name */
3089 info->index.info = find_sec(info, ".modinfo");
3090 if (info->index.info)
3091 info->name = get_modinfo(info, "name");
3092
3093 /* Find internal symbols and strings. */
3094 for (i = 1; i < info->hdr->e_shnum; i++) {
3095 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
3096 info->index.sym = i;
3097 info->index.str = info->sechdrs[i].sh_link;
3098 info->strtab = (char *)info->hdr
3099 + info->sechdrs[info->index.str].sh_offset;
3100 break;
3101 }
3102 }
3103
3104 if (info->index.sym == 0) {
3105 pr_warn("%s: module has no symbols (stripped?)\n",
3106 info->name ?: "(missing .modinfo section or name field)");
3107 return -ENOEXEC;
3108 }
3109
3110 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
3111 if (!info->index.mod) {
3112 pr_warn("%s: No module found in object\n",
3113 info->name ?: "(missing .modinfo section or name field)");
3114 return -ENOEXEC;
3115 }
3116 /* This is temporary: point mod into copy of data. */
3117 info->mod = (void *)info->hdr + info->sechdrs[info->index.mod].sh_offset;
3118
3119 /*
3120 * If we didn't load the .modinfo 'name' field earlier, fall back to
3121 * on-disk struct mod 'name' field.
3122 */
3123 if (!info->name)
3124 info->name = info->mod->name;
3125
3126 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
3127 info->index.vers = 0; /* Pretend no __versions section! */
3128 else
3129 info->index.vers = find_sec(info, "__versions");
3130
3131 info->index.pcpu = find_pcpusec(info);
3132
3133 return 0;
3134}
3135
3136static int check_modinfo(struct module *mod, struct load_info *info, int flags)
3137{
3138 const char *modmagic = get_modinfo(info, "vermagic");
3139 int err;
3140
3141 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
3142 modmagic = NULL;
3143
3144 /* This is allowed: modprobe --force will invalidate it. */
3145 if (!modmagic) {
3146 err = try_to_force_load(mod, "bad vermagic");
3147 if (err)
3148 return err;
3149 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
3150 pr_err("%s: version magic '%s' should be '%s'\n",
3151 info->name, modmagic, vermagic);
3152 return -ENOEXEC;
3153 }
3154
3155 if (!get_modinfo(info, "intree")) {
3156 if (!test_taint(TAINT_OOT_MODULE))
3157 pr_warn("%s: loading out-of-tree module taints kernel.\n",
3158 mod->name);
3159 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
3160 }
3161
3162 check_modinfo_retpoline(mod, info);
3163
3164 if (get_modinfo(info, "staging")) {
3165 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
3166 pr_warn("%s: module is from the staging directory, the quality "
3167 "is unknown, you have been warned.\n", mod->name);
3168 }
3169
3170 err = check_modinfo_livepatch(mod, info);
3171 if (err)
3172 return err;
3173
3174 /* Set up license info based on the info section */
3175 set_license(mod, get_modinfo(info, "license"));
3176
3177 return 0;
3178}
3179
3180static int find_module_sections(struct module *mod, struct load_info *info)
3181{
3182 mod->kp = section_objs(info, "__param",
3183 sizeof(*mod->kp), &mod->num_kp);
3184 mod->syms = section_objs(info, "__ksymtab",
3185 sizeof(*mod->syms), &mod->num_syms);
3186 mod->crcs = section_addr(info, "__kcrctab");
3187 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
3188 sizeof(*mod->gpl_syms),
3189 &mod->num_gpl_syms);
3190 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
3191 mod->gpl_future_syms = section_objs(info,
3192 "__ksymtab_gpl_future",
3193 sizeof(*mod->gpl_future_syms),
3194 &mod->num_gpl_future_syms);
3195 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
3196
3197#ifdef CONFIG_UNUSED_SYMBOLS
3198 mod->unused_syms = section_objs(info, "__ksymtab_unused",
3199 sizeof(*mod->unused_syms),
3200 &mod->num_unused_syms);
3201 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
3202 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
3203 sizeof(*mod->unused_gpl_syms),
3204 &mod->num_unused_gpl_syms);
3205 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
3206#endif
3207#ifdef CONFIG_CONSTRUCTORS
3208 mod->ctors = section_objs(info, ".ctors",
3209 sizeof(*mod->ctors), &mod->num_ctors);
3210 if (!mod->ctors)
3211 mod->ctors = section_objs(info, ".init_array",
3212 sizeof(*mod->ctors), &mod->num_ctors);
3213 else if (find_sec(info, ".init_array")) {
3214 /*
3215 * This shouldn't happen with same compiler and binutils
3216 * building all parts of the module.
3217 */
3218 pr_warn("%s: has both .ctors and .init_array.\n",
3219 mod->name);
3220 return -EINVAL;
3221 }
3222#endif
3223
3224 mod->noinstr_text_start = section_objs(info, ".noinstr.text", 1,
3225 &mod->noinstr_text_size);
3226
3227#ifdef CONFIG_TRACEPOINTS
3228 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
3229 sizeof(*mod->tracepoints_ptrs),
3230 &mod->num_tracepoints);
3231#endif
3232#ifdef CONFIG_TREE_SRCU
3233 mod->srcu_struct_ptrs = section_objs(info, "___srcu_struct_ptrs",
3234 sizeof(*mod->srcu_struct_ptrs),
3235 &mod->num_srcu_structs);
3236#endif
3237#ifdef CONFIG_BPF_EVENTS
3238 mod->bpf_raw_events = section_objs(info, "__bpf_raw_tp_map",
3239 sizeof(*mod->bpf_raw_events),
3240 &mod->num_bpf_raw_events);
3241#endif
3242#ifdef CONFIG_JUMP_LABEL
3243 mod->jump_entries = section_objs(info, "__jump_table",
3244 sizeof(*mod->jump_entries),
3245 &mod->num_jump_entries);
3246#endif
3247#ifdef CONFIG_EVENT_TRACING
3248 mod->trace_events = section_objs(info, "_ftrace_events",
3249 sizeof(*mod->trace_events),
3250 &mod->num_trace_events);
3251 mod->trace_evals = section_objs(info, "_ftrace_eval_map",
3252 sizeof(*mod->trace_evals),
3253 &mod->num_trace_evals);
3254#endif
3255#ifdef CONFIG_TRACING
3256 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
3257 sizeof(*mod->trace_bprintk_fmt_start),
3258 &mod->num_trace_bprintk_fmt);
3259#endif
3260#ifdef CONFIG_FTRACE_MCOUNT_RECORD
3261 /* sechdrs[0].sh_size is always zero */
3262 mod->ftrace_callsites = section_objs(info, FTRACE_CALLSITE_SECTION,
3263 sizeof(*mod->ftrace_callsites),
3264 &mod->num_ftrace_callsites);
3265#endif
3266#ifdef CONFIG_FUNCTION_ERROR_INJECTION
3267 mod->ei_funcs = section_objs(info, "_error_injection_whitelist",
3268 sizeof(*mod->ei_funcs),
3269 &mod->num_ei_funcs);
3270#endif
3271#ifdef CONFIG_KPROBES
3272 mod->kprobes_text_start = section_objs(info, ".kprobes.text", 1,
3273 &mod->kprobes_text_size);
3274 mod->kprobe_blacklist = section_objs(info, "_kprobe_blacklist",
3275 sizeof(unsigned long),
3276 &mod->num_kprobe_blacklist);
3277#endif
3278 mod->extable = section_objs(info, "__ex_table",
3279 sizeof(*mod->extable), &mod->num_exentries);
3280
3281 if (section_addr(info, "__obsparm"))
3282 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
3283
3284 info->debug = section_objs(info, "__dyndbg",
3285 sizeof(*info->debug), &info->num_debug);
3286
3287 return 0;
3288}
3289
3290static int move_module(struct module *mod, struct load_info *info)
3291{
3292 int i;
3293 void *ptr;
3294
3295 /* Do the allocs. */
3296 ptr = module_alloc(mod->core_layout.size);
3297 /*
3298 * The pointer to this block is stored in the module structure
3299 * which is inside the block. Just mark it as not being a
3300 * leak.
3301 */
3302 kmemleak_not_leak(ptr);
3303 if (!ptr)
3304 return -ENOMEM;
3305
3306 memset(ptr, 0, mod->core_layout.size);
3307 mod->core_layout.base = ptr;
3308
3309 if (mod->init_layout.size) {
3310 ptr = module_alloc(mod->init_layout.size);
3311 /*
3312 * The pointer to this block is stored in the module structure
3313 * which is inside the block. This block doesn't need to be
3314 * scanned as it contains data and code that will be freed
3315 * after the module is initialized.
3316 */
3317 kmemleak_ignore(ptr);
3318 if (!ptr) {
3319 module_memfree(mod->core_layout.base);
3320 return -ENOMEM;
3321 }
3322 memset(ptr, 0, mod->init_layout.size);
3323 mod->init_layout.base = ptr;
3324 } else
3325 mod->init_layout.base = NULL;
3326
3327 /* Transfer each section which specifies SHF_ALLOC */
3328 pr_debug("final section addresses:\n");
3329 for (i = 0; i < info->hdr->e_shnum; i++) {
3330 void *dest;
3331 Elf_Shdr *shdr = &info->sechdrs[i];
3332
3333 if (!(shdr->sh_flags & SHF_ALLOC))
3334 continue;
3335
3336 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3337 dest = mod->init_layout.base
3338 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3339 else
3340 dest = mod->core_layout.base + shdr->sh_entsize;
3341
3342 if (shdr->sh_type != SHT_NOBITS)
3343 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3344 /* Update sh_addr to point to copy in image. */
3345 shdr->sh_addr = (unsigned long)dest;
3346 pr_debug("\t0x%lx %s\n",
3347 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3348 }
3349
3350 return 0;
3351}
3352
3353static int check_module_license_and_versions(struct module *mod)
3354{
3355 int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
3356
3357 /*
3358 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3359 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3360 * using GPL-only symbols it needs.
3361 */
3362 if (strcmp(mod->name, "ndiswrapper") == 0)
3363 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3364
3365 /* driverloader was caught wrongly pretending to be under GPL */
3366 if (strcmp(mod->name, "driverloader") == 0)
3367 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3368 LOCKDEP_NOW_UNRELIABLE);
3369
3370 /* lve claims to be GPL but upstream won't provide source */
3371 if (strcmp(mod->name, "lve") == 0)
3372 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3373 LOCKDEP_NOW_UNRELIABLE);
3374
3375 if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
3376 pr_warn("%s: module license taints kernel.\n", mod->name);
3377
3378#ifdef CONFIG_MODVERSIONS
3379 if ((mod->num_syms && !mod->crcs)
3380 || (mod->num_gpl_syms && !mod->gpl_crcs)
3381 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3382#ifdef CONFIG_UNUSED_SYMBOLS
3383 || (mod->num_unused_syms && !mod->unused_crcs)
3384 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3385#endif
3386 ) {
3387 return try_to_force_load(mod,
3388 "no versions for exported symbols");
3389 }
3390#endif
3391 return 0;
3392}
3393
3394static void flush_module_icache(const struct module *mod)
3395{
3396 /*
3397 * Flush the instruction cache, since we've played with text.
3398 * Do it before processing of module parameters, so the module
3399 * can provide parameter accessor functions of its own.
3400 */
3401 if (mod->init_layout.base)
3402 flush_icache_range((unsigned long)mod->init_layout.base,
3403 (unsigned long)mod->init_layout.base
3404 + mod->init_layout.size);
3405 flush_icache_range((unsigned long)mod->core_layout.base,
3406 (unsigned long)mod->core_layout.base + mod->core_layout.size);
3407}
3408
3409int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3410 Elf_Shdr *sechdrs,
3411 char *secstrings,
3412 struct module *mod)
3413{
3414 return 0;
3415}
3416
3417/* module_blacklist is a comma-separated list of module names */
3418static char *module_blacklist;
3419static bool blacklisted(const char *module_name)
3420{
3421 const char *p;
3422 size_t len;
3423
3424 if (!module_blacklist)
3425 return false;
3426
3427 for (p = module_blacklist; *p; p += len) {
3428 len = strcspn(p, ",");
3429 if (strlen(module_name) == len && !memcmp(module_name, p, len))
3430 return true;
3431 if (p[len] == ',')
3432 len++;
3433 }
3434 return false;
3435}
3436core_param(module_blacklist, module_blacklist, charp, 0400);
3437
3438static struct module *layout_and_allocate(struct load_info *info, int flags)
3439{
3440 struct module *mod;
3441 unsigned int ndx;
3442 int err;
3443
3444 err = check_modinfo(info->mod, info, flags);
3445 if (err)
3446 return ERR_PTR(err);
3447
3448 /* Allow arches to frob section contents and sizes. */
3449 err = module_frob_arch_sections(info->hdr, info->sechdrs,
3450 info->secstrings, info->mod);
3451 if (err < 0)
3452 return ERR_PTR(err);
3453
3454 err = module_enforce_rwx_sections(info->hdr, info->sechdrs,
3455 info->secstrings, info->mod);
3456 if (err < 0)
3457 return ERR_PTR(err);
3458
3459 /* We will do a special allocation for per-cpu sections later. */
3460 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3461
3462 /*
3463 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3464 * layout_sections() can put it in the right place.
3465 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3466 */
3467 ndx = find_sec(info, ".data..ro_after_init");
3468 if (ndx)
3469 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3470 /*
3471 * Mark the __jump_table section as ro_after_init as well: these data
3472 * structures are never modified, with the exception of entries that
3473 * refer to code in the __init section, which are annotated as such
3474 * at module load time.
3475 */
3476 ndx = find_sec(info, "__jump_table");
3477 if (ndx)
3478 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3479
3480 /* Determine total sizes, and put offsets in sh_entsize. For now
3481 this is done generically; there doesn't appear to be any
3482 special cases for the architectures. */
3483 layout_sections(info->mod, info);
3484 layout_symtab(info->mod, info);
3485
3486 /* Allocate and move to the final place */
3487 err = move_module(info->mod, info);
3488 if (err)
3489 return ERR_PTR(err);
3490
3491 /* Module has been copied to its final place now: return it. */
3492 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3493 kmemleak_load_module(mod, info);
3494 return mod;
3495}
3496
3497/* mod is no longer valid after this! */
3498static void module_deallocate(struct module *mod, struct load_info *info)
3499{
3500 percpu_modfree(mod);
3501 module_arch_freeing_init(mod);
3502 module_memfree(mod->init_layout.base);
3503 module_memfree(mod->core_layout.base);
3504}
3505
3506int __weak module_finalize(const Elf_Ehdr *hdr,
3507 const Elf_Shdr *sechdrs,
3508 struct module *me)
3509{
3510 return 0;
3511}
3512
3513static int post_relocation(struct module *mod, const struct load_info *info)
3514{
3515 /* Sort exception table now relocations are done. */
3516 sort_extable(mod->extable, mod->extable + mod->num_exentries);
3517
3518 /* Copy relocated percpu area over. */
3519 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3520 info->sechdrs[info->index.pcpu].sh_size);
3521
3522 /* Setup kallsyms-specific fields. */
3523 add_kallsyms(mod, info);
3524
3525 /* Arch-specific module finalizing. */
3526 return module_finalize(info->hdr, info->sechdrs, mod);
3527}
3528
3529/* Is this module of this name done loading? No locks held. */
3530static bool finished_loading(const char *name)
3531{
3532 struct module *mod;
3533 bool ret;
3534
3535 /*
3536 * The module_mutex should not be a heavily contended lock;
3537 * if we get the occasional sleep here, we'll go an extra iteration
3538 * in the wait_event_interruptible(), which is harmless.
3539 */
3540 sched_annotate_sleep();
3541 mutex_lock(&module_mutex);
3542 mod = find_module_all(name, strlen(name), true);
3543 ret = !mod || mod->state == MODULE_STATE_LIVE;
3544 mutex_unlock(&module_mutex);
3545
3546 return ret;
3547}
3548
3549/* Call module constructors. */
3550static void do_mod_ctors(struct module *mod)
3551{
3552#ifdef CONFIG_CONSTRUCTORS
3553 unsigned long i;
3554
3555 for (i = 0; i < mod->num_ctors; i++)
3556 mod->ctors[i]();
3557#endif
3558}
3559
3560/* For freeing module_init on success, in case kallsyms traversing */
3561struct mod_initfree {
3562 struct llist_node node;
3563 void *module_init;
3564};
3565
3566static void do_free_init(struct work_struct *w)
3567{
3568 struct llist_node *pos, *n, *list;
3569 struct mod_initfree *initfree;
3570
3571 list = llist_del_all(&init_free_list);
3572
3573 synchronize_rcu();
3574
3575 llist_for_each_safe(pos, n, list) {
3576 initfree = container_of(pos, struct mod_initfree, node);
3577 module_memfree(initfree->module_init);
3578 kfree(initfree);
3579 }
3580}
3581
3582static int __init modules_wq_init(void)
3583{
3584 INIT_WORK(&init_free_wq, do_free_init);
3585 init_llist_head(&init_free_list);
3586 return 0;
3587}
3588module_init(modules_wq_init);
3589
3590/*
3591 * This is where the real work happens.
3592 *
3593 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3594 * helper command 'lx-symbols'.
3595 */
3596static noinline int do_init_module(struct module *mod)
3597{
3598 int ret = 0;
3599 struct mod_initfree *freeinit;
3600
3601 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3602 if (!freeinit) {
3603 ret = -ENOMEM;
3604 goto fail;
3605 }
3606 freeinit->module_init = mod->init_layout.base;
3607
3608 /*
3609 * We want to find out whether @mod uses async during init. Clear
3610 * PF_USED_ASYNC. async_schedule*() will set it.
3611 */
3612 current->flags &= ~PF_USED_ASYNC;
3613
3614 do_mod_ctors(mod);
3615 /* Start the module */
3616 if (mod->init != NULL)
3617 ret = do_one_initcall(mod->init);
3618 if (ret < 0) {
3619 goto fail_free_freeinit;
3620 }
3621 if (ret > 0) {
3622 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3623 "follow 0/-E convention\n"
3624 "%s: loading module anyway...\n",
3625 __func__, mod->name, ret, __func__);
3626 dump_stack();
3627 }
3628
3629 /* Now it's a first class citizen! */
3630 mod->state = MODULE_STATE_LIVE;
3631 blocking_notifier_call_chain(&module_notify_list,
3632 MODULE_STATE_LIVE, mod);
3633
3634 /*
3635 * We need to finish all async code before the module init sequence
3636 * is done. This has potential to deadlock. For example, a newly
3637 * detected block device can trigger request_module() of the
3638 * default iosched from async probing task. Once userland helper
3639 * reaches here, async_synchronize_full() will wait on the async
3640 * task waiting on request_module() and deadlock.
3641 *
3642 * This deadlock is avoided by perfomring async_synchronize_full()
3643 * iff module init queued any async jobs. This isn't a full
3644 * solution as it will deadlock the same if module loading from
3645 * async jobs nests more than once; however, due to the various
3646 * constraints, this hack seems to be the best option for now.
3647 * Please refer to the following thread for details.
3648 *
3649 * http://thread.gmane.org/gmane.linux.kernel/1420814
3650 */
3651 if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3652 async_synchronize_full();
3653
3654 ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base +
3655 mod->init_layout.size);
3656 mutex_lock(&module_mutex);
3657 /* Drop initial reference. */
3658 module_put(mod);
3659 trim_init_extable(mod);
3660#ifdef CONFIG_KALLSYMS
3661 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3662 rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3663#endif
3664 module_enable_ro(mod, true);
3665 mod_tree_remove_init(mod);
3666 module_arch_freeing_init(mod);
3667 mod->init_layout.base = NULL;
3668 mod->init_layout.size = 0;
3669 mod->init_layout.ro_size = 0;
3670 mod->init_layout.ro_after_init_size = 0;
3671 mod->init_layout.text_size = 0;
3672 /*
3673 * We want to free module_init, but be aware that kallsyms may be
3674 * walking this with preempt disabled. In all the failure paths, we
3675 * call synchronize_rcu(), but we don't want to slow down the success
3676 * path. module_memfree() cannot be called in an interrupt, so do the
3677 * work and call synchronize_rcu() in a work queue.
3678 *
3679 * Note that module_alloc() on most architectures creates W+X page
3680 * mappings which won't be cleaned up until do_free_init() runs. Any
3681 * code such as mark_rodata_ro() which depends on those mappings to
3682 * be cleaned up needs to sync with the queued work - ie
3683 * rcu_barrier()
3684 */
3685 if (llist_add(&freeinit->node, &init_free_list))
3686 schedule_work(&init_free_wq);
3687
3688 mutex_unlock(&module_mutex);
3689 wake_up_all(&module_wq);
3690
3691 return 0;
3692
3693fail_free_freeinit:
3694 kfree(freeinit);
3695fail:
3696 /* Try to protect us from buggy refcounters. */
3697 mod->state = MODULE_STATE_GOING;
3698 synchronize_rcu();
3699 module_put(mod);
3700 blocking_notifier_call_chain(&module_notify_list,
3701 MODULE_STATE_GOING, mod);
3702 klp_module_going(mod);
3703 ftrace_release_mod(mod);
3704 free_module(mod);
3705 wake_up_all(&module_wq);
3706 return ret;
3707}
3708
3709static int may_init_module(void)
3710{
3711 if (!capable(CAP_SYS_MODULE) || modules_disabled)
3712 return -EPERM;
3713
3714 return 0;
3715}
3716
3717/*
3718 * We try to place it in the list now to make sure it's unique before
3719 * we dedicate too many resources. In particular, temporary percpu
3720 * memory exhaustion.
3721 */
3722static int add_unformed_module(struct module *mod)
3723{
3724 int err;
3725 struct module *old;
3726
3727 mod->state = MODULE_STATE_UNFORMED;
3728
3729again:
3730 mutex_lock(&module_mutex);
3731 old = find_module_all(mod->name, strlen(mod->name), true);
3732 if (old != NULL) {
3733 if (old->state != MODULE_STATE_LIVE) {
3734 /* Wait in case it fails to load. */
3735 mutex_unlock(&module_mutex);
3736 err = wait_event_interruptible(module_wq,
3737 finished_loading(mod->name));
3738 if (err)
3739 goto out_unlocked;
3740 goto again;
3741 }
3742 err = -EEXIST;
3743 goto out;
3744 }
3745 mod_update_bounds(mod);
3746 list_add_rcu(&mod->list, &modules);
3747 mod_tree_insert(mod);
3748 err = 0;
3749
3750out:
3751 mutex_unlock(&module_mutex);
3752out_unlocked:
3753 return err;
3754}
3755
3756static int complete_formation(struct module *mod, struct load_info *info)
3757{
3758 int err;
3759
3760 mutex_lock(&module_mutex);
3761
3762 /* Find duplicate symbols (must be called under lock). */
3763 err = verify_exported_symbols(mod);
3764 if (err < 0)
3765 goto out;
3766
3767 /* This relies on module_mutex for list integrity. */
3768 module_bug_finalize(info->hdr, info->sechdrs, mod);
3769
3770 module_enable_ro(mod, false);
3771 module_enable_nx(mod);
3772 module_enable_x(mod);
3773
3774 /* Mark state as coming so strong_try_module_get() ignores us,
3775 * but kallsyms etc. can see us. */
3776 mod->state = MODULE_STATE_COMING;
3777 mutex_unlock(&module_mutex);
3778
3779 return 0;
3780
3781out:
3782 mutex_unlock(&module_mutex);
3783 return err;
3784}
3785
3786static int prepare_coming_module(struct module *mod)
3787{
3788 int err;
3789
3790 ftrace_module_enable(mod);
3791 err = klp_module_coming(mod);
3792 if (err)
3793 return err;
3794
3795 blocking_notifier_call_chain(&module_notify_list,
3796 MODULE_STATE_COMING, mod);
3797 return 0;
3798}
3799
3800static int unknown_module_param_cb(char *param, char *val, const char *modname,
3801 void *arg)
3802{
3803 struct module *mod = arg;
3804 int ret;
3805
3806 if (strcmp(param, "async_probe") == 0) {
3807 mod->async_probe_requested = true;
3808 return 0;
3809 }
3810
3811 /* Check for magic 'dyndbg' arg */
3812 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3813 if (ret != 0)
3814 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3815 return 0;
3816}
3817
3818/* Allocate and load the module: note that size of section 0 is always
3819 zero, and we rely on this for optional sections. */
3820static int load_module(struct load_info *info, const char __user *uargs,
3821 int flags)
3822{
3823 struct module *mod;
3824 long err = 0;
3825 char *after_dashes;
3826
3827 err = elf_header_check(info);
3828 if (err)
3829 goto free_copy;
3830
3831 err = setup_load_info(info, flags);
3832 if (err)
3833 goto free_copy;
3834
3835 if (blacklisted(info->name)) {
3836 err = -EPERM;
3837 goto free_copy;
3838 }
3839
3840 err = module_sig_check(info, flags);
3841 if (err)
3842 goto free_copy;
3843
3844 err = rewrite_section_headers(info, flags);
3845 if (err)
3846 goto free_copy;
3847
3848 /* Check module struct version now, before we try to use module. */
3849 if (!check_modstruct_version(info, info->mod)) {
3850 err = -ENOEXEC;
3851 goto free_copy;
3852 }
3853
3854 /* Figure out module layout, and allocate all the memory. */
3855 mod = layout_and_allocate(info, flags);
3856 if (IS_ERR(mod)) {
3857 err = PTR_ERR(mod);
3858 goto free_copy;
3859 }
3860
3861 audit_log_kern_module(mod->name);
3862
3863 /* Reserve our place in the list. */
3864 err = add_unformed_module(mod);
3865 if (err)
3866 goto free_module;
3867
3868#ifdef CONFIG_MODULE_SIG
3869 mod->sig_ok = info->sig_ok;
3870 if (!mod->sig_ok) {
3871 pr_notice_once("%s: module verification failed: signature "
3872 "and/or required key missing - tainting "
3873 "kernel\n", mod->name);
3874 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3875 }
3876#endif
3877
3878 /* To avoid stressing percpu allocator, do this once we're unique. */
3879 err = percpu_modalloc(mod, info);
3880 if (err)
3881 goto unlink_mod;
3882
3883 /* Now module is in final location, initialize linked lists, etc. */
3884 err = module_unload_init(mod);
3885 if (err)
3886 goto unlink_mod;
3887
3888 init_param_lock(mod);
3889
3890 /* Now we've got everything in the final locations, we can
3891 * find optional sections. */
3892 err = find_module_sections(mod, info);
3893 if (err)
3894 goto free_unload;
3895
3896 err = check_module_license_and_versions(mod);
3897 if (err)
3898 goto free_unload;
3899
3900 /* Set up MODINFO_ATTR fields */
3901 setup_modinfo(mod, info);
3902
3903 /* Fix up syms, so that st_value is a pointer to location. */
3904 err = simplify_symbols(mod, info);
3905 if (err < 0)
3906 goto free_modinfo;
3907
3908 err = apply_relocations(mod, info);
3909 if (err < 0)
3910 goto free_modinfo;
3911
3912 err = post_relocation(mod, info);
3913 if (err < 0)
3914 goto free_modinfo;
3915
3916 flush_module_icache(mod);
3917
3918 /* Now copy in args */
3919 mod->args = strndup_user(uargs, ~0UL >> 1);
3920 if (IS_ERR(mod->args)) {
3921 err = PTR_ERR(mod->args);
3922 goto free_arch_cleanup;
3923 }
3924
3925 dynamic_debug_setup(mod, info->debug, info->num_debug);
3926
3927 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3928 ftrace_module_init(mod);
3929
3930 /* Finally it's fully formed, ready to start executing. */
3931 err = complete_formation(mod, info);
3932 if (err)
3933 goto ddebug_cleanup;
3934
3935 err = prepare_coming_module(mod);
3936 if (err)
3937 goto bug_cleanup;
3938
3939 /* Module is ready to execute: parsing args may do that. */
3940 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3941 -32768, 32767, mod,
3942 unknown_module_param_cb);
3943 if (IS_ERR(after_dashes)) {
3944 err = PTR_ERR(after_dashes);
3945 goto coming_cleanup;
3946 } else if (after_dashes) {
3947 pr_warn("%s: parameters '%s' after `--' ignored\n",
3948 mod->name, after_dashes);
3949 }
3950
3951 /* Link in to sysfs. */
3952 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3953 if (err < 0)
3954 goto coming_cleanup;
3955
3956 if (is_livepatch_module(mod)) {
3957 err = copy_module_elf(mod, info);
3958 if (err < 0)
3959 goto sysfs_cleanup;
3960 }
3961
3962 /* Get rid of temporary copy. */
3963 free_copy(info);
3964
3965 /* Done! */
3966 trace_module_load(mod);
3967
3968 return do_init_module(mod);
3969
3970 sysfs_cleanup:
3971 mod_sysfs_teardown(mod);
3972 coming_cleanup:
3973 mod->state = MODULE_STATE_GOING;
3974 destroy_params(mod->kp, mod->num_kp);
3975 blocking_notifier_call_chain(&module_notify_list,
3976 MODULE_STATE_GOING, mod);
3977 klp_module_going(mod);
3978 bug_cleanup:
3979 /* module_bug_cleanup needs module_mutex protection */
3980 mutex_lock(&module_mutex);
3981 module_bug_cleanup(mod);
3982 mutex_unlock(&module_mutex);
3983
3984 ddebug_cleanup:
3985 ftrace_release_mod(mod);
3986 dynamic_debug_remove(mod, info->debug);
3987 synchronize_rcu();
3988 kfree(mod->args);
3989 free_arch_cleanup:
3990 module_arch_cleanup(mod);
3991 free_modinfo:
3992 free_modinfo(mod);
3993 free_unload:
3994 module_unload_free(mod);
3995 unlink_mod:
3996 mutex_lock(&module_mutex);
3997 /* Unlink carefully: kallsyms could be walking list. */
3998 list_del_rcu(&mod->list);
3999 mod_tree_remove(mod);
4000 wake_up_all(&module_wq);
4001 /* Wait for RCU-sched synchronizing before releasing mod->list. */
4002 synchronize_rcu();
4003 mutex_unlock(&module_mutex);
4004 free_module:
4005 /* Free lock-classes; relies on the preceding sync_rcu() */
4006 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
4007
4008 module_deallocate(mod, info);
4009 free_copy:
4010 free_copy(info);
4011 return err;
4012}
4013
4014SYSCALL_DEFINE3(init_module, void __user *, umod,
4015 unsigned long, len, const char __user *, uargs)
4016{
4017 int err;
4018 struct load_info info = { };
4019
4020 err = may_init_module();
4021 if (err)
4022 return err;
4023
4024 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
4025 umod, len, uargs);
4026
4027 err = copy_module_from_user(umod, len, &info);
4028 if (err)
4029 return err;
4030
4031 return load_module(&info, uargs, 0);
4032}
4033
4034SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
4035{
4036 struct load_info info = { };
4037 loff_t size;
4038 void *hdr;
4039 int err;
4040
4041 err = may_init_module();
4042 if (err)
4043 return err;
4044
4045 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
4046
4047 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
4048 |MODULE_INIT_IGNORE_VERMAGIC))
4049 return -EINVAL;
4050
4051 err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX,
4052 READING_MODULE);
4053 if (err)
4054 return err;
4055 info.hdr = hdr;
4056 info.len = size;
4057
4058 return load_module(&info, uargs, flags);
4059}
4060
4061static inline int within(unsigned long addr, void *start, unsigned long size)
4062{
4063 return ((void *)addr >= start && (void *)addr < start + size);
4064}
4065
4066#ifdef CONFIG_KALLSYMS
4067/*
4068 * This ignores the intensely annoying "mapping symbols" found
4069 * in ARM ELF files: $a, $t and $d.
4070 */
4071static inline int is_arm_mapping_symbol(const char *str)
4072{
4073 if (str[0] == '.' && str[1] == 'L')
4074 return true;
4075 return str[0] == '$' && strchr("axtd", str[1])
4076 && (str[2] == '\0' || str[2] == '.');
4077}
4078
4079static const char *kallsyms_symbol_name(struct mod_kallsyms *kallsyms, unsigned int symnum)
4080{
4081 return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
4082}
4083
4084/*
4085 * Given a module and address, find the corresponding symbol and return its name
4086 * while providing its size and offset if needed.
4087 */
4088static const char *find_kallsyms_symbol(struct module *mod,
4089 unsigned long addr,
4090 unsigned long *size,
4091 unsigned long *offset)
4092{
4093 unsigned int i, best = 0;
4094 unsigned long nextval, bestval;
4095 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4096
4097 /* At worse, next value is at end of module */
4098 if (within_module_init(addr, mod))
4099 nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
4100 else
4101 nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
4102
4103 bestval = kallsyms_symbol_value(&kallsyms->symtab[best]);
4104
4105 /* Scan for closest preceding symbol, and next symbol. (ELF
4106 starts real symbols at 1). */
4107 for (i = 1; i < kallsyms->num_symtab; i++) {
4108 const Elf_Sym *sym = &kallsyms->symtab[i];
4109 unsigned long thisval = kallsyms_symbol_value(sym);
4110
4111 if (sym->st_shndx == SHN_UNDEF)
4112 continue;
4113
4114 /* We ignore unnamed symbols: they're uninformative
4115 * and inserted at a whim. */
4116 if (*kallsyms_symbol_name(kallsyms, i) == '\0'
4117 || is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms, i)))
4118 continue;
4119
4120 if (thisval <= addr && thisval > bestval) {
4121 best = i;
4122 bestval = thisval;
4123 }
4124 if (thisval > addr && thisval < nextval)
4125 nextval = thisval;
4126 }
4127
4128 if (!best)
4129 return NULL;
4130
4131 if (size)
4132 *size = nextval - bestval;
4133 if (offset)
4134 *offset = addr - bestval;
4135
4136 return kallsyms_symbol_name(kallsyms, best);
4137}
4138
4139void * __weak dereference_module_function_descriptor(struct module *mod,
4140 void *ptr)
4141{
4142 return ptr;
4143}
4144
4145/* For kallsyms to ask for address resolution. NULL means not found. Careful
4146 * not to lock to avoid deadlock on oopses, simply disable preemption. */
4147const char *module_address_lookup(unsigned long addr,
4148 unsigned long *size,
4149 unsigned long *offset,
4150 char **modname,
4151 char *namebuf)
4152{
4153 const char *ret = NULL;
4154 struct module *mod;
4155
4156 preempt_disable();
4157 mod = __module_address(addr);
4158 if (mod) {
4159 if (modname)
4160 *modname = mod->name;
4161
4162 ret = find_kallsyms_symbol(mod, addr, size, offset);
4163 }
4164 /* Make a copy in here where it's safe */
4165 if (ret) {
4166 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
4167 ret = namebuf;
4168 }
4169 preempt_enable();
4170
4171 return ret;
4172}
4173
4174int lookup_module_symbol_name(unsigned long addr, char *symname)
4175{
4176 struct module *mod;
4177
4178 preempt_disable();
4179 list_for_each_entry_rcu(mod, &modules, list) {
4180 if (mod->state == MODULE_STATE_UNFORMED)
4181 continue;
4182 if (within_module(addr, mod)) {
4183 const char *sym;
4184
4185 sym = find_kallsyms_symbol(mod, addr, NULL, NULL);
4186 if (!sym)
4187 goto out;
4188
4189 strlcpy(symname, sym, KSYM_NAME_LEN);
4190 preempt_enable();
4191 return 0;
4192 }
4193 }
4194out:
4195 preempt_enable();
4196 return -ERANGE;
4197}
4198
4199int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
4200 unsigned long *offset, char *modname, char *name)
4201{
4202 struct module *mod;
4203
4204 preempt_disable();
4205 list_for_each_entry_rcu(mod, &modules, list) {
4206 if (mod->state == MODULE_STATE_UNFORMED)
4207 continue;
4208 if (within_module(addr, mod)) {
4209 const char *sym;
4210
4211 sym = find_kallsyms_symbol(mod, addr, size, offset);
4212 if (!sym)
4213 goto out;
4214 if (modname)
4215 strlcpy(modname, mod->name, MODULE_NAME_LEN);
4216 if (name)
4217 strlcpy(name, sym, KSYM_NAME_LEN);
4218 preempt_enable();
4219 return 0;
4220 }
4221 }
4222out:
4223 preempt_enable();
4224 return -ERANGE;
4225}
4226
4227int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
4228 char *name, char *module_name, int *exported)
4229{
4230 struct module *mod;
4231
4232 preempt_disable();
4233 list_for_each_entry_rcu(mod, &modules, list) {
4234 struct mod_kallsyms *kallsyms;
4235
4236 if (mod->state == MODULE_STATE_UNFORMED)
4237 continue;
4238 kallsyms = rcu_dereference_sched(mod->kallsyms);
4239 if (symnum < kallsyms->num_symtab) {
4240 const Elf_Sym *sym = &kallsyms->symtab[symnum];
4241
4242 *value = kallsyms_symbol_value(sym);
4243 *type = kallsyms->typetab[symnum];
4244 strlcpy(name, kallsyms_symbol_name(kallsyms, symnum), KSYM_NAME_LEN);
4245 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
4246 *exported = is_exported(name, *value, mod);
4247 preempt_enable();
4248 return 0;
4249 }
4250 symnum -= kallsyms->num_symtab;
4251 }
4252 preempt_enable();
4253 return -ERANGE;
4254}
4255
4256/* Given a module and name of symbol, find and return the symbol's value */
4257static unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name)
4258{
4259 unsigned int i;
4260 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4261
4262 for (i = 0; i < kallsyms->num_symtab; i++) {
4263 const Elf_Sym *sym = &kallsyms->symtab[i];
4264
4265 if (strcmp(name, kallsyms_symbol_name(kallsyms, i)) == 0 &&
4266 sym->st_shndx != SHN_UNDEF)
4267 return kallsyms_symbol_value(sym);
4268 }
4269 return 0;
4270}
4271
4272/* Look for this name: can be of form module:name. */
4273unsigned long module_kallsyms_lookup_name(const char *name)
4274{
4275 struct module *mod;
4276 char *colon;
4277 unsigned long ret = 0;
4278
4279 /* Don't lock: we're in enough trouble already. */
4280 preempt_disable();
4281 if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
4282 if ((mod = find_module_all(name, colon - name, false)) != NULL)
4283 ret = find_kallsyms_symbol_value(mod, colon+1);
4284 } else {
4285 list_for_each_entry_rcu(mod, &modules, list) {
4286 if (mod->state == MODULE_STATE_UNFORMED)
4287 continue;
4288 if ((ret = find_kallsyms_symbol_value(mod, name)) != 0)
4289 break;
4290 }
4291 }
4292 preempt_enable();
4293 return ret;
4294}
4295
4296int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
4297 struct module *, unsigned long),
4298 void *data)
4299{
4300 struct module *mod;
4301 unsigned int i;
4302 int ret;
4303
4304 module_assert_mutex();
4305
4306 list_for_each_entry(mod, &modules, list) {
4307 /* We hold module_mutex: no need for rcu_dereference_sched */
4308 struct mod_kallsyms *kallsyms = mod->kallsyms;
4309
4310 if (mod->state == MODULE_STATE_UNFORMED)
4311 continue;
4312 for (i = 0; i < kallsyms->num_symtab; i++) {
4313 const Elf_Sym *sym = &kallsyms->symtab[i];
4314
4315 if (sym->st_shndx == SHN_UNDEF)
4316 continue;
4317
4318 ret = fn(data, kallsyms_symbol_name(kallsyms, i),
4319 mod, kallsyms_symbol_value(sym));
4320 if (ret != 0)
4321 return ret;
4322 }
4323 }
4324 return 0;
4325}
4326#endif /* CONFIG_KALLSYMS */
4327
4328/* Maximum number of characters written by module_flags() */
4329#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
4330
4331/* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
4332static char *module_flags(struct module *mod, char *buf)
4333{
4334 int bx = 0;
4335
4336 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
4337 if (mod->taints ||
4338 mod->state == MODULE_STATE_GOING ||
4339 mod->state == MODULE_STATE_COMING) {
4340 buf[bx++] = '(';
4341 bx += module_flags_taint(mod, buf + bx);
4342 /* Show a - for module-is-being-unloaded */
4343 if (mod->state == MODULE_STATE_GOING)
4344 buf[bx++] = '-';
4345 /* Show a + for module-is-being-loaded */
4346 if (mod->state == MODULE_STATE_COMING)
4347 buf[bx++] = '+';
4348 buf[bx++] = ')';
4349 }
4350 buf[bx] = '\0';
4351
4352 return buf;
4353}
4354
4355#ifdef CONFIG_PROC_FS
4356/* Called by the /proc file system to return a list of modules. */
4357static void *m_start(struct seq_file *m, loff_t *pos)
4358{
4359 mutex_lock(&module_mutex);
4360 return seq_list_start(&modules, *pos);
4361}
4362
4363static void *m_next(struct seq_file *m, void *p, loff_t *pos)
4364{
4365 return seq_list_next(p, &modules, pos);
4366}
4367
4368static void m_stop(struct seq_file *m, void *p)
4369{
4370 mutex_unlock(&module_mutex);
4371}
4372
4373static int m_show(struct seq_file *m, void *p)
4374{
4375 struct module *mod = list_entry(p, struct module, list);
4376 char buf[MODULE_FLAGS_BUF_SIZE];
4377 void *value;
4378
4379 /* We always ignore unformed modules. */
4380 if (mod->state == MODULE_STATE_UNFORMED)
4381 return 0;
4382
4383 seq_printf(m, "%s %u",
4384 mod->name, mod->init_layout.size + mod->core_layout.size);
4385 print_unload_info(m, mod);
4386
4387 /* Informative for users. */
4388 seq_printf(m, " %s",
4389 mod->state == MODULE_STATE_GOING ? "Unloading" :
4390 mod->state == MODULE_STATE_COMING ? "Loading" :
4391 "Live");
4392 /* Used by oprofile and other similar tools. */
4393 value = m->private ? NULL : mod->core_layout.base;
4394 seq_printf(m, " 0x%px", value);
4395
4396 /* Taints info */
4397 if (mod->taints)
4398 seq_printf(m, " %s", module_flags(mod, buf));
4399
4400 seq_puts(m, "\n");
4401 return 0;
4402}
4403
4404/* Format: modulename size refcount deps address
4405
4406 Where refcount is a number or -, and deps is a comma-separated list
4407 of depends or -.
4408*/
4409static const struct seq_operations modules_op = {
4410 .start = m_start,
4411 .next = m_next,
4412 .stop = m_stop,
4413 .show = m_show
4414};
4415
4416/*
4417 * This also sets the "private" pointer to non-NULL if the
4418 * kernel pointers should be hidden (so you can just test
4419 * "m->private" to see if you should keep the values private).
4420 *
4421 * We use the same logic as for /proc/kallsyms.
4422 */
4423static int modules_open(struct inode *inode, struct file *file)
4424{
4425 int err = seq_open(file, &modules_op);
4426
4427 if (!err) {
4428 struct seq_file *m = file->private_data;
4429 m->private = kallsyms_show_value(file->f_cred) ? NULL : (void *)8ul;
4430 }
4431
4432 return err;
4433}
4434
4435static const struct proc_ops modules_proc_ops = {
4436 .proc_flags = PROC_ENTRY_PERMANENT,
4437 .proc_open = modules_open,
4438 .proc_read = seq_read,
4439 .proc_lseek = seq_lseek,
4440 .proc_release = seq_release,
4441};
4442
4443static int __init proc_modules_init(void)
4444{
4445 proc_create("modules", 0, NULL, &modules_proc_ops);
4446 return 0;
4447}
4448module_init(proc_modules_init);
4449#endif
4450
4451/* Given an address, look for it in the module exception tables. */
4452const struct exception_table_entry *search_module_extables(unsigned long addr)
4453{
4454 const struct exception_table_entry *e = NULL;
4455 struct module *mod;
4456
4457 preempt_disable();
4458 mod = __module_address(addr);
4459 if (!mod)
4460 goto out;
4461
4462 if (!mod->num_exentries)
4463 goto out;
4464
4465 e = search_extable(mod->extable,
4466 mod->num_exentries,
4467 addr);
4468out:
4469 preempt_enable();
4470
4471 /*
4472 * Now, if we found one, we are running inside it now, hence
4473 * we cannot unload the module, hence no refcnt needed.
4474 */
4475 return e;
4476}
4477
4478/*
4479 * is_module_address - is this address inside a module?
4480 * @addr: the address to check.
4481 *
4482 * See is_module_text_address() if you simply want to see if the address
4483 * is code (not data).
4484 */
4485bool is_module_address(unsigned long addr)
4486{
4487 bool ret;
4488
4489 preempt_disable();
4490 ret = __module_address(addr) != NULL;
4491 preempt_enable();
4492
4493 return ret;
4494}
4495
4496/*
4497 * __module_address - get the module which contains an address.
4498 * @addr: the address.
4499 *
4500 * Must be called with preempt disabled or module mutex held so that
4501 * module doesn't get freed during this.
4502 */
4503struct module *__module_address(unsigned long addr)
4504{
4505 struct module *mod;
4506
4507 if (addr < module_addr_min || addr > module_addr_max)
4508 return NULL;
4509
4510 module_assert_mutex_or_preempt();
4511
4512 mod = mod_find(addr);
4513 if (mod) {
4514 BUG_ON(!within_module(addr, mod));
4515 if (mod->state == MODULE_STATE_UNFORMED)
4516 mod = NULL;
4517 }
4518 return mod;
4519}
4520
4521/*
4522 * is_module_text_address - is this address inside module code?
4523 * @addr: the address to check.
4524 *
4525 * See is_module_address() if you simply want to see if the address is
4526 * anywhere in a module. See kernel_text_address() for testing if an
4527 * address corresponds to kernel or module code.
4528 */
4529bool is_module_text_address(unsigned long addr)
4530{
4531 bool ret;
4532
4533 preempt_disable();
4534 ret = __module_text_address(addr) != NULL;
4535 preempt_enable();
4536
4537 return ret;
4538}
4539
4540/*
4541 * __module_text_address - get the module whose code contains an address.
4542 * @addr: the address.
4543 *
4544 * Must be called with preempt disabled or module mutex held so that
4545 * module doesn't get freed during this.
4546 */
4547struct module *__module_text_address(unsigned long addr)
4548{
4549 struct module *mod = __module_address(addr);
4550 if (mod) {
4551 /* Make sure it's within the text section. */
4552 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
4553 && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
4554 mod = NULL;
4555 }
4556 return mod;
4557}
4558
4559/* Don't grab lock, we're oopsing. */
4560void print_modules(void)
4561{
4562 struct module *mod;
4563 char buf[MODULE_FLAGS_BUF_SIZE];
4564
4565 printk(KERN_DEFAULT "Modules linked in:");
4566 /* Most callers should already have preempt disabled, but make sure */
4567 preempt_disable();
4568 list_for_each_entry_rcu(mod, &modules, list) {
4569 if (mod->state == MODULE_STATE_UNFORMED)
4570 continue;
4571 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4572 }
4573 preempt_enable();
4574 if (last_unloaded_module[0])
4575 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4576 pr_cont("\n");
4577}
4578
4579#ifdef CONFIG_MODVERSIONS
4580/* Generate the signature for all relevant module structures here.
4581 * If these change, we don't want to try to parse the module. */
4582void module_layout(struct module *mod,
4583 struct modversion_info *ver,
4584 struct kernel_param *kp,
4585 struct kernel_symbol *ks,
4586 struct tracepoint * const *tp)
4587{
4588}
4589EXPORT_SYMBOL(module_layout);
4590#endif