projects/linux·blob v5.5-rc4 · refs

4552 lines · 115.6 KiB

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