projects/linux·blob v5.6-rc6 · refs

4513 lines · 114.7 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 lockdep_is_held(&module_mutex)) {
219 if (within_module(addr, mod))
220 return mod;
221 }
222
223 return NULL;
224}
225
226#endif /* MODULES_TREE_LOOKUP */
227
228/*
229 * Bounds of module text, for speeding up __module_address.
230 * Protected by module_mutex.
231 */
232static void __mod_update_bounds(void *base, unsigned int size)
233{
234 unsigned long min = (unsigned long)base;
235 unsigned long max = min + size;
236
237 if (min < module_addr_min)
238 module_addr_min = min;
239 if (max > module_addr_max)
240 module_addr_max = max;
241}
242
243static void mod_update_bounds(struct module *mod)
244{
245 __mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
246 if (mod->init_layout.size)
247 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
248}
249
250#ifdef CONFIG_KGDB_KDB
251struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
252#endif /* CONFIG_KGDB_KDB */
253
254static void module_assert_mutex(void)
255{
256 lockdep_assert_held(&module_mutex);
257}
258
259static void module_assert_mutex_or_preempt(void)
260{
261#ifdef CONFIG_LOCKDEP
262 if (unlikely(!debug_locks))
263 return;
264
265 WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
266 !lockdep_is_held(&module_mutex));
267#endif
268}
269
270static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
271module_param(sig_enforce, bool_enable_only, 0644);
272
273/*
274 * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
275 * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
276 */
277bool is_module_sig_enforced(void)
278{
279 return sig_enforce;
280}
281EXPORT_SYMBOL(is_module_sig_enforced);
282
283void set_module_sig_enforced(void)
284{
285 sig_enforce = true;
286}
287
288/* Block module loading/unloading? */
289int modules_disabled = 0;
290core_param(nomodule, modules_disabled, bint, 0);
291
292/* Waiting for a module to finish initializing? */
293static DECLARE_WAIT_QUEUE_HEAD(module_wq);
294
295static BLOCKING_NOTIFIER_HEAD(module_notify_list);
296
297int register_module_notifier(struct notifier_block *nb)
298{
299 return blocking_notifier_chain_register(&module_notify_list, nb);
300}
301EXPORT_SYMBOL(register_module_notifier);
302
303int unregister_module_notifier(struct notifier_block *nb)
304{
305 return blocking_notifier_chain_unregister(&module_notify_list, nb);
306}
307EXPORT_SYMBOL(unregister_module_notifier);
308
309/*
310 * We require a truly strong try_module_get(): 0 means success.
311 * Otherwise an error is returned due to ongoing or failed
312 * initialization etc.
313 */
314static inline int strong_try_module_get(struct module *mod)
315{
316 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
317 if (mod && mod->state == MODULE_STATE_COMING)
318 return -EBUSY;
319 if (try_module_get(mod))
320 return 0;
321 else
322 return -ENOENT;
323}
324
325static inline void add_taint_module(struct module *mod, unsigned flag,
326 enum lockdep_ok lockdep_ok)
327{
328 add_taint(flag, lockdep_ok);
329 set_bit(flag, &mod->taints);
330}
331
332/*
333 * A thread that wants to hold a reference to a module only while it
334 * is running can call this to safely exit. nfsd and lockd use this.
335 */
336void __noreturn __module_put_and_exit(struct module *mod, long code)
337{
338 module_put(mod);
339 do_exit(code);
340}
341EXPORT_SYMBOL(__module_put_and_exit);
342
343/* Find a module section: 0 means not found. */
344static unsigned int find_sec(const struct load_info *info, const char *name)
345{
346 unsigned int i;
347
348 for (i = 1; i < info->hdr->e_shnum; i++) {
349 Elf_Shdr *shdr = &info->sechdrs[i];
350 /* Alloc bit cleared means "ignore it." */
351 if ((shdr->sh_flags & SHF_ALLOC)
352 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
353 return i;
354 }
355 return 0;
356}
357
358/* Find a module section, or NULL. */
359static void *section_addr(const struct load_info *info, const char *name)
360{
361 /* Section 0 has sh_addr 0. */
362 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
363}
364
365/* Find a module section, or NULL. Fill in number of "objects" in section. */
366static void *section_objs(const struct load_info *info,
367 const char *name,
368 size_t object_size,
369 unsigned int *num)
370{
371 unsigned int sec = find_sec(info, name);
372
373 /* Section 0 has sh_addr 0 and sh_size 0. */
374 *num = info->sechdrs[sec].sh_size / object_size;
375 return (void *)info->sechdrs[sec].sh_addr;
376}
377
378/* Provided by the linker */
379extern const struct kernel_symbol __start___ksymtab[];
380extern const struct kernel_symbol __stop___ksymtab[];
381extern const struct kernel_symbol __start___ksymtab_gpl[];
382extern const struct kernel_symbol __stop___ksymtab_gpl[];
383extern const struct kernel_symbol __start___ksymtab_gpl_future[];
384extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
385extern const s32 __start___kcrctab[];
386extern const s32 __start___kcrctab_gpl[];
387extern const s32 __start___kcrctab_gpl_future[];
388#ifdef CONFIG_UNUSED_SYMBOLS
389extern const struct kernel_symbol __start___ksymtab_unused[];
390extern const struct kernel_symbol __stop___ksymtab_unused[];
391extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
392extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
393extern const s32 __start___kcrctab_unused[];
394extern const s32 __start___kcrctab_unused_gpl[];
395#endif
396
397#ifndef CONFIG_MODVERSIONS
398#define symversion(base, idx) NULL
399#else
400#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
401#endif
402
403static bool each_symbol_in_section(const struct symsearch *arr,
404 unsigned int arrsize,
405 struct module *owner,
406 bool (*fn)(const struct symsearch *syms,
407 struct module *owner,
408 void *data),
409 void *data)
410{
411 unsigned int j;
412
413 for (j = 0; j < arrsize; j++) {
414 if (fn(&arr[j], owner, data))
415 return true;
416 }
417
418 return false;
419}
420
421/* Returns true as soon as fn returns true, otherwise false. */
422bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
423 struct module *owner,
424 void *data),
425 void *data)
426{
427 struct module *mod;
428 static const struct symsearch arr[] = {
429 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
430 NOT_GPL_ONLY, false },
431 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
432 __start___kcrctab_gpl,
433 GPL_ONLY, false },
434 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
435 __start___kcrctab_gpl_future,
436 WILL_BE_GPL_ONLY, false },
437#ifdef CONFIG_UNUSED_SYMBOLS
438 { __start___ksymtab_unused, __stop___ksymtab_unused,
439 __start___kcrctab_unused,
440 NOT_GPL_ONLY, true },
441 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
442 __start___kcrctab_unused_gpl,
443 GPL_ONLY, true },
444#endif
445 };
446
447 module_assert_mutex_or_preempt();
448
449 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
450 return true;
451
452 list_for_each_entry_rcu(mod, &modules, list,
453 lockdep_is_held(&module_mutex)) {
454 struct symsearch arr[] = {
455 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
456 NOT_GPL_ONLY, false },
457 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
458 mod->gpl_crcs,
459 GPL_ONLY, false },
460 { mod->gpl_future_syms,
461 mod->gpl_future_syms + mod->num_gpl_future_syms,
462 mod->gpl_future_crcs,
463 WILL_BE_GPL_ONLY, false },
464#ifdef CONFIG_UNUSED_SYMBOLS
465 { mod->unused_syms,
466 mod->unused_syms + mod->num_unused_syms,
467 mod->unused_crcs,
468 NOT_GPL_ONLY, true },
469 { mod->unused_gpl_syms,
470 mod->unused_gpl_syms + mod->num_unused_gpl_syms,
471 mod->unused_gpl_crcs,
472 GPL_ONLY, true },
473#endif
474 };
475
476 if (mod->state == MODULE_STATE_UNFORMED)
477 continue;
478
479 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
480 return true;
481 }
482 return false;
483}
484EXPORT_SYMBOL_GPL(each_symbol_section);
485
486struct find_symbol_arg {
487 /* Input */
488 const char *name;
489 bool gplok;
490 bool warn;
491
492 /* Output */
493 struct module *owner;
494 const s32 *crc;
495 const struct kernel_symbol *sym;
496};
497
498static bool check_exported_symbol(const struct symsearch *syms,
499 struct module *owner,
500 unsigned int symnum, void *data)
501{
502 struct find_symbol_arg *fsa = data;
503
504 if (!fsa->gplok) {
505 if (syms->licence == GPL_ONLY)
506 return false;
507 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
508 pr_warn("Symbol %s is being used by a non-GPL module, "
509 "which will not be allowed in the future\n",
510 fsa->name);
511 }
512 }
513
514#ifdef CONFIG_UNUSED_SYMBOLS
515 if (syms->unused && fsa->warn) {
516 pr_warn("Symbol %s is marked as UNUSED, however this module is "
517 "using it.\n", fsa->name);
518 pr_warn("This symbol will go away in the future.\n");
519 pr_warn("Please evaluate if this is the right api to use and "
520 "if it really is, submit a report to the linux kernel "
521 "mailing list together with submitting your code for "
522 "inclusion.\n");
523 }
524#endif
525
526 fsa->owner = owner;
527 fsa->crc = symversion(syms->crcs, symnum);
528 fsa->sym = &syms->start[symnum];
529 return true;
530}
531
532static unsigned long kernel_symbol_value(const struct kernel_symbol *sym)
533{
534#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
535 return (unsigned long)offset_to_ptr(&sym->value_offset);
536#else
537 return sym->value;
538#endif
539}
540
541static const char *kernel_symbol_name(const struct kernel_symbol *sym)
542{
543#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
544 return offset_to_ptr(&sym->name_offset);
545#else
546 return sym->name;
547#endif
548}
549
550static const char *kernel_symbol_namespace(const struct kernel_symbol *sym)
551{
552#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
553 if (!sym->namespace_offset)
554 return NULL;
555 return offset_to_ptr(&sym->namespace_offset);
556#else
557 return sym->namespace;
558#endif
559}
560
561static int cmp_name(const void *name, const void *sym)
562{
563 return strcmp(name, kernel_symbol_name(sym));
564}
565
566static bool find_exported_symbol_in_section(const struct symsearch *syms,
567 struct module *owner,
568 void *data)
569{
570 struct find_symbol_arg *fsa = data;
571 struct kernel_symbol *sym;
572
573 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
574 sizeof(struct kernel_symbol), cmp_name);
575
576 if (sym != NULL && check_exported_symbol(syms, owner,
577 sym - syms->start, data))
578 return true;
579
580 return false;
581}
582
583/* Find an exported symbol and return it, along with, (optional) crc and
584 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
585const struct kernel_symbol *find_symbol(const char *name,
586 struct module **owner,
587 const s32 **crc,
588 bool gplok,
589 bool warn)
590{
591 struct find_symbol_arg fsa;
592
593 fsa.name = name;
594 fsa.gplok = gplok;
595 fsa.warn = warn;
596
597 if (each_symbol_section(find_exported_symbol_in_section, &fsa)) {
598 if (owner)
599 *owner = fsa.owner;
600 if (crc)
601 *crc = fsa.crc;
602 return fsa.sym;
603 }
604
605 pr_debug("Failed to find symbol %s\n", name);
606 return NULL;
607}
608EXPORT_SYMBOL_GPL(find_symbol);
609
610/*
611 * Search for module by name: must hold module_mutex (or preempt disabled
612 * for read-only access).
613 */
614static struct module *find_module_all(const char *name, size_t len,
615 bool even_unformed)
616{
617 struct module *mod;
618
619 module_assert_mutex_or_preempt();
620
621 list_for_each_entry_rcu(mod, &modules, list,
622 lockdep_is_held(&module_mutex)) {
623 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
624 continue;
625 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
626 return mod;
627 }
628 return NULL;
629}
630
631struct module *find_module(const char *name)
632{
633 module_assert_mutex();
634 return find_module_all(name, strlen(name), false);
635}
636EXPORT_SYMBOL_GPL(find_module);
637
638#ifdef CONFIG_SMP
639
640static inline void __percpu *mod_percpu(struct module *mod)
641{
642 return mod->percpu;
643}
644
645static int percpu_modalloc(struct module *mod, struct load_info *info)
646{
647 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
648 unsigned long align = pcpusec->sh_addralign;
649
650 if (!pcpusec->sh_size)
651 return 0;
652
653 if (align > PAGE_SIZE) {
654 pr_warn("%s: per-cpu alignment %li > %li\n",
655 mod->name, align, PAGE_SIZE);
656 align = PAGE_SIZE;
657 }
658
659 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
660 if (!mod->percpu) {
661 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
662 mod->name, (unsigned long)pcpusec->sh_size);
663 return -ENOMEM;
664 }
665 mod->percpu_size = pcpusec->sh_size;
666 return 0;
667}
668
669static void percpu_modfree(struct module *mod)
670{
671 free_percpu(mod->percpu);
672}
673
674static unsigned int find_pcpusec(struct load_info *info)
675{
676 return find_sec(info, ".data..percpu");
677}
678
679static void percpu_modcopy(struct module *mod,
680 const void *from, unsigned long size)
681{
682 int cpu;
683
684 for_each_possible_cpu(cpu)
685 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
686}
687
688bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
689{
690 struct module *mod;
691 unsigned int cpu;
692
693 preempt_disable();
694
695 list_for_each_entry_rcu(mod, &modules, list) {
696 if (mod->state == MODULE_STATE_UNFORMED)
697 continue;
698 if (!mod->percpu_size)
699 continue;
700 for_each_possible_cpu(cpu) {
701 void *start = per_cpu_ptr(mod->percpu, cpu);
702 void *va = (void *)addr;
703
704 if (va >= start && va < start + mod->percpu_size) {
705 if (can_addr) {
706 *can_addr = (unsigned long) (va - start);
707 *can_addr += (unsigned long)
708 per_cpu_ptr(mod->percpu,
709 get_boot_cpu_id());
710 }
711 preempt_enable();
712 return true;
713 }
714 }
715 }
716
717 preempt_enable();
718 return false;
719}
720
721/**
722 * is_module_percpu_address - test whether address is from module static percpu
723 * @addr: address to test
724 *
725 * Test whether @addr belongs to module static percpu area.
726 *
727 * RETURNS:
728 * %true if @addr is from module static percpu area
729 */
730bool is_module_percpu_address(unsigned long addr)
731{
732 return __is_module_percpu_address(addr, NULL);
733}
734
735#else /* ... !CONFIG_SMP */
736
737static inline void __percpu *mod_percpu(struct module *mod)
738{
739 return NULL;
740}
741static int percpu_modalloc(struct module *mod, struct load_info *info)
742{
743 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
744 if (info->sechdrs[info->index.pcpu].sh_size != 0)
745 return -ENOMEM;
746 return 0;
747}
748static inline void percpu_modfree(struct module *mod)
749{
750}
751static unsigned int find_pcpusec(struct load_info *info)
752{
753 return 0;
754}
755static inline void percpu_modcopy(struct module *mod,
756 const void *from, unsigned long size)
757{
758 /* pcpusec should be 0, and size of that section should be 0. */
759 BUG_ON(size != 0);
760}
761bool is_module_percpu_address(unsigned long addr)
762{
763 return false;
764}
765
766bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
767{
768 return false;
769}
770
771#endif /* CONFIG_SMP */
772
773#define MODINFO_ATTR(field) \
774static void setup_modinfo_##field(struct module *mod, const char *s) \
775{ \
776 mod->field = kstrdup(s, GFP_KERNEL); \
777} \
778static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
779 struct module_kobject *mk, char *buffer) \
780{ \
781 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
782} \
783static int modinfo_##field##_exists(struct module *mod) \
784{ \
785 return mod->field != NULL; \
786} \
787static void free_modinfo_##field(struct module *mod) \
788{ \
789 kfree(mod->field); \
790 mod->field = NULL; \
791} \
792static struct module_attribute modinfo_##field = { \
793 .attr = { .name = __stringify(field), .mode = 0444 }, \
794 .show = show_modinfo_##field, \
795 .setup = setup_modinfo_##field, \
796 .test = modinfo_##field##_exists, \
797 .free = free_modinfo_##field, \
798};
799
800MODINFO_ATTR(version);
801MODINFO_ATTR(srcversion);
802
803static char last_unloaded_module[MODULE_NAME_LEN+1];
804
805#ifdef CONFIG_MODULE_UNLOAD
806
807EXPORT_TRACEPOINT_SYMBOL(module_get);
808
809/* MODULE_REF_BASE is the base reference count by kmodule loader. */
810#define MODULE_REF_BASE 1
811
812/* Init the unload section of the module. */
813static int module_unload_init(struct module *mod)
814{
815 /*
816 * Initialize reference counter to MODULE_REF_BASE.
817 * refcnt == 0 means module is going.
818 */
819 atomic_set(&mod->refcnt, MODULE_REF_BASE);
820
821 INIT_LIST_HEAD(&mod->source_list);
822 INIT_LIST_HEAD(&mod->target_list);
823
824 /* Hold reference count during initialization. */
825 atomic_inc(&mod->refcnt);
826
827 return 0;
828}
829
830/* Does a already use b? */
831static int already_uses(struct module *a, struct module *b)
832{
833 struct module_use *use;
834
835 list_for_each_entry(use, &b->source_list, source_list) {
836 if (use->source == a) {
837 pr_debug("%s uses %s!\n", a->name, b->name);
838 return 1;
839 }
840 }
841 pr_debug("%s does not use %s!\n", a->name, b->name);
842 return 0;
843}
844
845/*
846 * Module a uses b
847 * - we add 'a' as a "source", 'b' as a "target" of module use
848 * - the module_use is added to the list of 'b' sources (so
849 * 'b' can walk the list to see who sourced them), and of 'a'
850 * targets (so 'a' can see what modules it targets).
851 */
852static int add_module_usage(struct module *a, struct module *b)
853{
854 struct module_use *use;
855
856 pr_debug("Allocating new usage for %s.\n", a->name);
857 use = kmalloc(sizeof(*use), GFP_ATOMIC);
858 if (!use)
859 return -ENOMEM;
860
861 use->source = a;
862 use->target = b;
863 list_add(&use->source_list, &b->source_list);
864 list_add(&use->target_list, &a->target_list);
865 return 0;
866}
867
868/* Module a uses b: caller needs module_mutex() */
869int ref_module(struct module *a, struct module *b)
870{
871 int err;
872
873 if (b == NULL || already_uses(a, b))
874 return 0;
875
876 /* If module isn't available, we fail. */
877 err = strong_try_module_get(b);
878 if (err)
879 return err;
880
881 err = add_module_usage(a, b);
882 if (err) {
883 module_put(b);
884 return err;
885 }
886 return 0;
887}
888EXPORT_SYMBOL_GPL(ref_module);
889
890/* Clear the unload stuff of the module. */
891static void module_unload_free(struct module *mod)
892{
893 struct module_use *use, *tmp;
894
895 mutex_lock(&module_mutex);
896 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
897 struct module *i = use->target;
898 pr_debug("%s unusing %s\n", mod->name, i->name);
899 module_put(i);
900 list_del(&use->source_list);
901 list_del(&use->target_list);
902 kfree(use);
903 }
904 mutex_unlock(&module_mutex);
905}
906
907#ifdef CONFIG_MODULE_FORCE_UNLOAD
908static inline int try_force_unload(unsigned int flags)
909{
910 int ret = (flags & O_TRUNC);
911 if (ret)
912 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
913 return ret;
914}
915#else
916static inline int try_force_unload(unsigned int flags)
917{
918 return 0;
919}
920#endif /* CONFIG_MODULE_FORCE_UNLOAD */
921
922/* Try to release refcount of module, 0 means success. */
923static int try_release_module_ref(struct module *mod)
924{
925 int ret;
926
927 /* Try to decrement refcnt which we set at loading */
928 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
929 BUG_ON(ret < 0);
930 if (ret)
931 /* Someone can put this right now, recover with checking */
932 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
933
934 return ret;
935}
936
937static int try_stop_module(struct module *mod, int flags, int *forced)
938{
939 /* If it's not unused, quit unless we're forcing. */
940 if (try_release_module_ref(mod) != 0) {
941 *forced = try_force_unload(flags);
942 if (!(*forced))
943 return -EWOULDBLOCK;
944 }
945
946 /* Mark it as dying. */
947 mod->state = MODULE_STATE_GOING;
948
949 return 0;
950}
951
952/**
953 * module_refcount - return the refcount or -1 if unloading
954 *
955 * @mod: the module we're checking
956 *
957 * Returns:
958 * -1 if the module is in the process of unloading
959 * otherwise the number of references in the kernel to the module
960 */
961int module_refcount(struct module *mod)
962{
963 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
964}
965EXPORT_SYMBOL(module_refcount);
966
967/* This exists whether we can unload or not */
968static void free_module(struct module *mod);
969
970SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
971 unsigned int, flags)
972{
973 struct module *mod;
974 char name[MODULE_NAME_LEN];
975 int ret, forced = 0;
976
977 if (!capable(CAP_SYS_MODULE) || modules_disabled)
978 return -EPERM;
979
980 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
981 return -EFAULT;
982 name[MODULE_NAME_LEN-1] = '\0';
983
984 audit_log_kern_module(name);
985
986 if (mutex_lock_interruptible(&module_mutex) != 0)
987 return -EINTR;
988
989 mod = find_module(name);
990 if (!mod) {
991 ret = -ENOENT;
992 goto out;
993 }
994
995 if (!list_empty(&mod->source_list)) {
996 /* Other modules depend on us: get rid of them first. */
997 ret = -EWOULDBLOCK;
998 goto out;
999 }
1000
1001 /* Doing init or already dying? */
1002 if (mod->state != MODULE_STATE_LIVE) {
1003 /* FIXME: if (force), slam module count damn the torpedoes */
1004 pr_debug("%s already dying\n", mod->name);
1005 ret = -EBUSY;
1006 goto out;
1007 }
1008
1009 /* If it has an init func, it must have an exit func to unload */
1010 if (mod->init && !mod->exit) {
1011 forced = try_force_unload(flags);
1012 if (!forced) {
1013 /* This module can't be removed */
1014 ret = -EBUSY;
1015 goto out;
1016 }
1017 }
1018
1019 /* Stop the machine so refcounts can't move and disable module. */
1020 ret = try_stop_module(mod, flags, &forced);
1021 if (ret != 0)
1022 goto out;
1023
1024 mutex_unlock(&module_mutex);
1025 /* Final destruction now no one is using it. */
1026 if (mod->exit != NULL)
1027 mod->exit();
1028 blocking_notifier_call_chain(&module_notify_list,
1029 MODULE_STATE_GOING, mod);
1030 klp_module_going(mod);
1031 ftrace_release_mod(mod);
1032
1033 async_synchronize_full();
1034
1035 /* Store the name of the last unloaded module for diagnostic purposes */
1036 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
1037
1038 free_module(mod);
1039 /* someone could wait for the module in add_unformed_module() */
1040 wake_up_all(&module_wq);
1041 return 0;
1042out:
1043 mutex_unlock(&module_mutex);
1044 return ret;
1045}
1046
1047static inline void print_unload_info(struct seq_file *m, struct module *mod)
1048{
1049 struct module_use *use;
1050 int printed_something = 0;
1051
1052 seq_printf(m, " %i ", module_refcount(mod));
1053
1054 /*
1055 * Always include a trailing , so userspace can differentiate
1056 * between this and the old multi-field proc format.
1057 */
1058 list_for_each_entry(use, &mod->source_list, source_list) {
1059 printed_something = 1;
1060 seq_printf(m, "%s,", use->source->name);
1061 }
1062
1063 if (mod->init != NULL && mod->exit == NULL) {
1064 printed_something = 1;
1065 seq_puts(m, "[permanent],");
1066 }
1067
1068 if (!printed_something)
1069 seq_puts(m, "-");
1070}
1071
1072void __symbol_put(const char *symbol)
1073{
1074 struct module *owner;
1075
1076 preempt_disable();
1077 if (!find_symbol(symbol, &owner, NULL, true, false))
1078 BUG();
1079 module_put(owner);
1080 preempt_enable();
1081}
1082EXPORT_SYMBOL(__symbol_put);
1083
1084/* Note this assumes addr is a function, which it currently always is. */
1085void symbol_put_addr(void *addr)
1086{
1087 struct module *modaddr;
1088 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1089
1090 if (core_kernel_text(a))
1091 return;
1092
1093 /*
1094 * Even though we hold a reference on the module; we still need to
1095 * disable preemption in order to safely traverse the data structure.
1096 */
1097 preempt_disable();
1098 modaddr = __module_text_address(a);
1099 BUG_ON(!modaddr);
1100 module_put(modaddr);
1101 preempt_enable();
1102}
1103EXPORT_SYMBOL_GPL(symbol_put_addr);
1104
1105static ssize_t show_refcnt(struct module_attribute *mattr,
1106 struct module_kobject *mk, char *buffer)
1107{
1108 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1109}
1110
1111static struct module_attribute modinfo_refcnt =
1112 __ATTR(refcnt, 0444, show_refcnt, NULL);
1113
1114void __module_get(struct module *module)
1115{
1116 if (module) {
1117 preempt_disable();
1118 atomic_inc(&module->refcnt);
1119 trace_module_get(module, _RET_IP_);
1120 preempt_enable();
1121 }
1122}
1123EXPORT_SYMBOL(__module_get);
1124
1125bool try_module_get(struct module *module)
1126{
1127 bool ret = true;
1128
1129 if (module) {
1130 preempt_disable();
1131 /* Note: here, we can fail to get a reference */
1132 if (likely(module_is_live(module) &&
1133 atomic_inc_not_zero(&module->refcnt) != 0))
1134 trace_module_get(module, _RET_IP_);
1135 else
1136 ret = false;
1137
1138 preempt_enable();
1139 }
1140 return ret;
1141}
1142EXPORT_SYMBOL(try_module_get);
1143
1144void module_put(struct module *module)
1145{
1146 int ret;
1147
1148 if (module) {
1149 preempt_disable();
1150 ret = atomic_dec_if_positive(&module->refcnt);
1151 WARN_ON(ret < 0); /* Failed to put refcount */
1152 trace_module_put(module, _RET_IP_);
1153 preempt_enable();
1154 }
1155}
1156EXPORT_SYMBOL(module_put);
1157
1158#else /* !CONFIG_MODULE_UNLOAD */
1159static inline void print_unload_info(struct seq_file *m, struct module *mod)
1160{
1161 /* We don't know the usage count, or what modules are using. */
1162 seq_puts(m, " - -");
1163}
1164
1165static inline void module_unload_free(struct module *mod)
1166{
1167}
1168
1169int ref_module(struct module *a, struct module *b)
1170{
1171 return strong_try_module_get(b);
1172}
1173EXPORT_SYMBOL_GPL(ref_module);
1174
1175static inline int module_unload_init(struct module *mod)
1176{
1177 return 0;
1178}
1179#endif /* CONFIG_MODULE_UNLOAD */
1180
1181static size_t module_flags_taint(struct module *mod, char *buf)
1182{
1183 size_t l = 0;
1184 int i;
1185
1186 for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
1187 if (taint_flags[i].module && test_bit(i, &mod->taints))
1188 buf[l++] = taint_flags[i].c_true;
1189 }
1190
1191 return l;
1192}
1193
1194static ssize_t show_initstate(struct module_attribute *mattr,
1195 struct module_kobject *mk, char *buffer)
1196{
1197 const char *state = "unknown";
1198
1199 switch (mk->mod->state) {
1200 case MODULE_STATE_LIVE:
1201 state = "live";
1202 break;
1203 case MODULE_STATE_COMING:
1204 state = "coming";
1205 break;
1206 case MODULE_STATE_GOING:
1207 state = "going";
1208 break;
1209 default:
1210 BUG();
1211 }
1212 return sprintf(buffer, "%s\n", state);
1213}
1214
1215static struct module_attribute modinfo_initstate =
1216 __ATTR(initstate, 0444, show_initstate, NULL);
1217
1218static ssize_t store_uevent(struct module_attribute *mattr,
1219 struct module_kobject *mk,
1220 const char *buffer, size_t count)
1221{
1222 int rc;
1223
1224 rc = kobject_synth_uevent(&mk->kobj, buffer, count);
1225 return rc ? rc : count;
1226}
1227
1228struct module_attribute module_uevent =
1229 __ATTR(uevent, 0200, NULL, store_uevent);
1230
1231static ssize_t show_coresize(struct module_attribute *mattr,
1232 struct module_kobject *mk, char *buffer)
1233{
1234 return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1235}
1236
1237static struct module_attribute modinfo_coresize =
1238 __ATTR(coresize, 0444, show_coresize, NULL);
1239
1240static ssize_t show_initsize(struct module_attribute *mattr,
1241 struct module_kobject *mk, char *buffer)
1242{
1243 return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1244}
1245
1246static struct module_attribute modinfo_initsize =
1247 __ATTR(initsize, 0444, show_initsize, NULL);
1248
1249static ssize_t show_taint(struct module_attribute *mattr,
1250 struct module_kobject *mk, char *buffer)
1251{
1252 size_t l;
1253
1254 l = module_flags_taint(mk->mod, buffer);
1255 buffer[l++] = '\n';
1256 return l;
1257}
1258
1259static struct module_attribute modinfo_taint =
1260 __ATTR(taint, 0444, show_taint, NULL);
1261
1262static struct module_attribute *modinfo_attrs[] = {
1263 &module_uevent,
1264 &modinfo_version,
1265 &modinfo_srcversion,
1266 &modinfo_initstate,
1267 &modinfo_coresize,
1268 &modinfo_initsize,
1269 &modinfo_taint,
1270#ifdef CONFIG_MODULE_UNLOAD
1271 &modinfo_refcnt,
1272#endif
1273 NULL,
1274};
1275
1276static const char vermagic[] = VERMAGIC_STRING;
1277
1278static int try_to_force_load(struct module *mod, const char *reason)
1279{
1280#ifdef CONFIG_MODULE_FORCE_LOAD
1281 if (!test_taint(TAINT_FORCED_MODULE))
1282 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1283 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1284 return 0;
1285#else
1286 return -ENOEXEC;
1287#endif
1288}
1289
1290#ifdef CONFIG_MODVERSIONS
1291
1292static u32 resolve_rel_crc(const s32 *crc)
1293{
1294 return *(u32 *)((void *)crc + *crc);
1295}
1296
1297static int check_version(const struct load_info *info,
1298 const char *symname,
1299 struct module *mod,
1300 const s32 *crc)
1301{
1302 Elf_Shdr *sechdrs = info->sechdrs;
1303 unsigned int versindex = info->index.vers;
1304 unsigned int i, num_versions;
1305 struct modversion_info *versions;
1306
1307 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1308 if (!crc)
1309 return 1;
1310
1311 /* No versions at all? modprobe --force does this. */
1312 if (versindex == 0)
1313 return try_to_force_load(mod, symname) == 0;
1314
1315 versions = (void *) sechdrs[versindex].sh_addr;
1316 num_versions = sechdrs[versindex].sh_size
1317 / sizeof(struct modversion_info);
1318
1319 for (i = 0; i < num_versions; i++) {
1320 u32 crcval;
1321
1322 if (strcmp(versions[i].name, symname) != 0)
1323 continue;
1324
1325 if (IS_ENABLED(CONFIG_MODULE_REL_CRCS))
1326 crcval = resolve_rel_crc(crc);
1327 else
1328 crcval = *crc;
1329 if (versions[i].crc == crcval)
1330 return 1;
1331 pr_debug("Found checksum %X vs module %lX\n",
1332 crcval, versions[i].crc);
1333 goto bad_version;
1334 }
1335
1336 /* Broken toolchain. Warn once, then let it go.. */
1337 pr_warn_once("%s: no symbol version for %s\n", info->name, symname);
1338 return 1;
1339
1340bad_version:
1341 pr_warn("%s: disagrees about version of symbol %s\n",
1342 info->name, symname);
1343 return 0;
1344}
1345
1346static inline int check_modstruct_version(const struct load_info *info,
1347 struct module *mod)
1348{
1349 const s32 *crc;
1350
1351 /*
1352 * Since this should be found in kernel (which can't be removed), no
1353 * locking is necessary -- use preempt_disable() to placate lockdep.
1354 */
1355 preempt_disable();
1356 if (!find_symbol("module_layout", NULL, &crc, true, false)) {
1357 preempt_enable();
1358 BUG();
1359 }
1360 preempt_enable();
1361 return check_version(info, "module_layout", mod, crc);
1362}
1363
1364/* First part is kernel version, which we ignore if module has crcs. */
1365static inline int same_magic(const char *amagic, const char *bmagic,
1366 bool has_crcs)
1367{
1368 if (has_crcs) {
1369 amagic += strcspn(amagic, " ");
1370 bmagic += strcspn(bmagic, " ");
1371 }
1372 return strcmp(amagic, bmagic) == 0;
1373}
1374#else
1375static inline int check_version(const struct load_info *info,
1376 const char *symname,
1377 struct module *mod,
1378 const s32 *crc)
1379{
1380 return 1;
1381}
1382
1383static inline int check_modstruct_version(const struct load_info *info,
1384 struct module *mod)
1385{
1386 return 1;
1387}
1388
1389static inline int same_magic(const char *amagic, const char *bmagic,
1390 bool has_crcs)
1391{
1392 return strcmp(amagic, bmagic) == 0;
1393}
1394#endif /* CONFIG_MODVERSIONS */
1395
1396static char *get_modinfo(const struct load_info *info, const char *tag);
1397static char *get_next_modinfo(const struct load_info *info, const char *tag,
1398 char *prev);
1399
1400static int verify_namespace_is_imported(const struct load_info *info,
1401 const struct kernel_symbol *sym,
1402 struct module *mod)
1403{
1404 const char *namespace;
1405 char *imported_namespace;
1406
1407 namespace = kernel_symbol_namespace(sym);
1408 if (namespace && namespace[0]) {
1409 imported_namespace = get_modinfo(info, "import_ns");
1410 while (imported_namespace) {
1411 if (strcmp(namespace, imported_namespace) == 0)
1412 return 0;
1413 imported_namespace = get_next_modinfo(
1414 info, "import_ns", imported_namespace);
1415 }
1416#ifdef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1417 pr_warn(
1418#else
1419 pr_err(
1420#endif
1421 "%s: module uses symbol (%s) from namespace %s, but does not import it.\n",
1422 mod->name, kernel_symbol_name(sym), namespace);
1423#ifndef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1424 return -EINVAL;
1425#endif
1426 }
1427 return 0;
1428}
1429
1430
1431/* Resolve a symbol for this module. I.e. if we find one, record usage. */
1432static const struct kernel_symbol *resolve_symbol(struct module *mod,
1433 const struct load_info *info,
1434 const char *name,
1435 char ownername[])
1436{
1437 struct module *owner;
1438 const struct kernel_symbol *sym;
1439 const s32 *crc;
1440 int err;
1441
1442 /*
1443 * The module_mutex should not be a heavily contended lock;
1444 * if we get the occasional sleep here, we'll go an extra iteration
1445 * in the wait_event_interruptible(), which is harmless.
1446 */
1447 sched_annotate_sleep();
1448 mutex_lock(&module_mutex);
1449 sym = find_symbol(name, &owner, &crc,
1450 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1451 if (!sym)
1452 goto unlock;
1453
1454 if (!check_version(info, name, mod, crc)) {
1455 sym = ERR_PTR(-EINVAL);
1456 goto getname;
1457 }
1458
1459 err = verify_namespace_is_imported(info, sym, mod);
1460 if (err) {
1461 sym = ERR_PTR(err);
1462 goto getname;
1463 }
1464
1465 err = ref_module(mod, owner);
1466 if (err) {
1467 sym = ERR_PTR(err);
1468 goto getname;
1469 }
1470
1471getname:
1472 /* We must make copy under the lock if we failed to get ref. */
1473 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1474unlock:
1475 mutex_unlock(&module_mutex);
1476 return sym;
1477}
1478
1479static const struct kernel_symbol *
1480resolve_symbol_wait(struct module *mod,
1481 const struct load_info *info,
1482 const char *name)
1483{
1484 const struct kernel_symbol *ksym;
1485 char owner[MODULE_NAME_LEN];
1486
1487 if (wait_event_interruptible_timeout(module_wq,
1488 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1489 || PTR_ERR(ksym) != -EBUSY,
1490 30 * HZ) <= 0) {
1491 pr_warn("%s: gave up waiting for init of module %s.\n",
1492 mod->name, owner);
1493 }
1494 return ksym;
1495}
1496
1497/*
1498 * /sys/module/foo/sections stuff
1499 * J. Corbet <[email protected]>
1500 */
1501#ifdef CONFIG_SYSFS
1502
1503#ifdef CONFIG_KALLSYMS
1504static inline bool sect_empty(const Elf_Shdr *sect)
1505{
1506 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1507}
1508
1509struct module_sect_attr {
1510 struct module_attribute mattr;
1511 char *name;
1512 unsigned long address;
1513};
1514
1515struct module_sect_attrs {
1516 struct attribute_group grp;
1517 unsigned int nsections;
1518 struct module_sect_attr attrs[0];
1519};
1520
1521static ssize_t module_sect_show(struct module_attribute *mattr,
1522 struct module_kobject *mk, char *buf)
1523{
1524 struct module_sect_attr *sattr =
1525 container_of(mattr, struct module_sect_attr, mattr);
1526 return sprintf(buf, "0x%px\n", kptr_restrict < 2 ?
1527 (void *)sattr->address : NULL);
1528}
1529
1530static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1531{
1532 unsigned int section;
1533
1534 for (section = 0; section < sect_attrs->nsections; section++)
1535 kfree(sect_attrs->attrs[section].name);
1536 kfree(sect_attrs);
1537}
1538
1539static void add_sect_attrs(struct module *mod, const struct load_info *info)
1540{
1541 unsigned int nloaded = 0, i, size[2];
1542 struct module_sect_attrs *sect_attrs;
1543 struct module_sect_attr *sattr;
1544 struct attribute **gattr;
1545
1546 /* Count loaded sections and allocate structures */
1547 for (i = 0; i < info->hdr->e_shnum; i++)
1548 if (!sect_empty(&info->sechdrs[i]))
1549 nloaded++;
1550 size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded),
1551 sizeof(sect_attrs->grp.attrs[0]));
1552 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1553 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1554 if (sect_attrs == NULL)
1555 return;
1556
1557 /* Setup section attributes. */
1558 sect_attrs->grp.name = "sections";
1559 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1560
1561 sect_attrs->nsections = 0;
1562 sattr = &sect_attrs->attrs[0];
1563 gattr = &sect_attrs->grp.attrs[0];
1564 for (i = 0; i < info->hdr->e_shnum; i++) {
1565 Elf_Shdr *sec = &info->sechdrs[i];
1566 if (sect_empty(sec))
1567 continue;
1568 sattr->address = sec->sh_addr;
1569 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1570 GFP_KERNEL);
1571 if (sattr->name == NULL)
1572 goto out;
1573 sect_attrs->nsections++;
1574 sysfs_attr_init(&sattr->mattr.attr);
1575 sattr->mattr.show = module_sect_show;
1576 sattr->mattr.store = NULL;
1577 sattr->mattr.attr.name = sattr->name;
1578 sattr->mattr.attr.mode = S_IRUSR;
1579 *(gattr++) = &(sattr++)->mattr.attr;
1580 }
1581 *gattr = NULL;
1582
1583 if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1584 goto out;
1585
1586 mod->sect_attrs = sect_attrs;
1587 return;
1588 out:
1589 free_sect_attrs(sect_attrs);
1590}
1591
1592static void remove_sect_attrs(struct module *mod)
1593{
1594 if (mod->sect_attrs) {
1595 sysfs_remove_group(&mod->mkobj.kobj,
1596 &mod->sect_attrs->grp);
1597 /* We are positive that no one is using any sect attrs
1598 * at this point. Deallocate immediately. */
1599 free_sect_attrs(mod->sect_attrs);
1600 mod->sect_attrs = NULL;
1601 }
1602}
1603
1604/*
1605 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1606 */
1607
1608struct module_notes_attrs {
1609 struct kobject *dir;
1610 unsigned int notes;
1611 struct bin_attribute attrs[0];
1612};
1613
1614static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1615 struct bin_attribute *bin_attr,
1616 char *buf, loff_t pos, size_t count)
1617{
1618 /*
1619 * The caller checked the pos and count against our size.
1620 */
1621 memcpy(buf, bin_attr->private + pos, count);
1622 return count;
1623}
1624
1625static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1626 unsigned int i)
1627{
1628 if (notes_attrs->dir) {
1629 while (i-- > 0)
1630 sysfs_remove_bin_file(notes_attrs->dir,
1631 &notes_attrs->attrs[i]);
1632 kobject_put(notes_attrs->dir);
1633 }
1634 kfree(notes_attrs);
1635}
1636
1637static void add_notes_attrs(struct module *mod, const struct load_info *info)
1638{
1639 unsigned int notes, loaded, i;
1640 struct module_notes_attrs *notes_attrs;
1641 struct bin_attribute *nattr;
1642
1643 /* failed to create section attributes, so can't create notes */
1644 if (!mod->sect_attrs)
1645 return;
1646
1647 /* Count notes sections and allocate structures. */
1648 notes = 0;
1649 for (i = 0; i < info->hdr->e_shnum; i++)
1650 if (!sect_empty(&info->sechdrs[i]) &&
1651 (info->sechdrs[i].sh_type == SHT_NOTE))
1652 ++notes;
1653
1654 if (notes == 0)
1655 return;
1656
1657 notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes),
1658 GFP_KERNEL);
1659 if (notes_attrs == NULL)
1660 return;
1661
1662 notes_attrs->notes = notes;
1663 nattr = &notes_attrs->attrs[0];
1664 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1665 if (sect_empty(&info->sechdrs[i]))
1666 continue;
1667 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1668 sysfs_bin_attr_init(nattr);
1669 nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1670 nattr->attr.mode = S_IRUGO;
1671 nattr->size = info->sechdrs[i].sh_size;
1672 nattr->private = (void *) info->sechdrs[i].sh_addr;
1673 nattr->read = module_notes_read;
1674 ++nattr;
1675 }
1676 ++loaded;
1677 }
1678
1679 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1680 if (!notes_attrs->dir)
1681 goto out;
1682
1683 for (i = 0; i < notes; ++i)
1684 if (sysfs_create_bin_file(notes_attrs->dir,
1685 &notes_attrs->attrs[i]))
1686 goto out;
1687
1688 mod->notes_attrs = notes_attrs;
1689 return;
1690
1691 out:
1692 free_notes_attrs(notes_attrs, i);
1693}
1694
1695static void remove_notes_attrs(struct module *mod)
1696{
1697 if (mod->notes_attrs)
1698 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1699}
1700
1701#else
1702
1703static inline void add_sect_attrs(struct module *mod,
1704 const struct load_info *info)
1705{
1706}
1707
1708static inline void remove_sect_attrs(struct module *mod)
1709{
1710}
1711
1712static inline void add_notes_attrs(struct module *mod,
1713 const struct load_info *info)
1714{
1715}
1716
1717static inline void remove_notes_attrs(struct module *mod)
1718{
1719}
1720#endif /* CONFIG_KALLSYMS */
1721
1722static void del_usage_links(struct module *mod)
1723{
1724#ifdef CONFIG_MODULE_UNLOAD
1725 struct module_use *use;
1726
1727 mutex_lock(&module_mutex);
1728 list_for_each_entry(use, &mod->target_list, target_list)
1729 sysfs_remove_link(use->target->holders_dir, mod->name);
1730 mutex_unlock(&module_mutex);
1731#endif
1732}
1733
1734static int add_usage_links(struct module *mod)
1735{
1736 int ret = 0;
1737#ifdef CONFIG_MODULE_UNLOAD
1738 struct module_use *use;
1739
1740 mutex_lock(&module_mutex);
1741 list_for_each_entry(use, &mod->target_list, target_list) {
1742 ret = sysfs_create_link(use->target->holders_dir,
1743 &mod->mkobj.kobj, mod->name);
1744 if (ret)
1745 break;
1746 }
1747 mutex_unlock(&module_mutex);
1748 if (ret)
1749 del_usage_links(mod);
1750#endif
1751 return ret;
1752}
1753
1754static void module_remove_modinfo_attrs(struct module *mod, int end);
1755
1756static int module_add_modinfo_attrs(struct module *mod)
1757{
1758 struct module_attribute *attr;
1759 struct module_attribute *temp_attr;
1760 int error = 0;
1761 int i;
1762
1763 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1764 (ARRAY_SIZE(modinfo_attrs) + 1)),
1765 GFP_KERNEL);
1766 if (!mod->modinfo_attrs)
1767 return -ENOMEM;
1768
1769 temp_attr = mod->modinfo_attrs;
1770 for (i = 0; (attr = modinfo_attrs[i]); i++) {
1771 if (!attr->test || attr->test(mod)) {
1772 memcpy(temp_attr, attr, sizeof(*temp_attr));
1773 sysfs_attr_init(&temp_attr->attr);
1774 error = sysfs_create_file(&mod->mkobj.kobj,
1775 &temp_attr->attr);
1776 if (error)
1777 goto error_out;
1778 ++temp_attr;
1779 }
1780 }
1781
1782 return 0;
1783
1784error_out:
1785 if (i > 0)
1786 module_remove_modinfo_attrs(mod, --i);
1787 else
1788 kfree(mod->modinfo_attrs);
1789 return error;
1790}
1791
1792static void module_remove_modinfo_attrs(struct module *mod, int end)
1793{
1794 struct module_attribute *attr;
1795 int i;
1796
1797 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1798 if (end >= 0 && i > end)
1799 break;
1800 /* pick a field to test for end of list */
1801 if (!attr->attr.name)
1802 break;
1803 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1804 if (attr->free)
1805 attr->free(mod);
1806 }
1807 kfree(mod->modinfo_attrs);
1808}
1809
1810static void mod_kobject_put(struct module *mod)
1811{
1812 DECLARE_COMPLETION_ONSTACK(c);
1813 mod->mkobj.kobj_completion = &c;
1814 kobject_put(&mod->mkobj.kobj);
1815 wait_for_completion(&c);
1816}
1817
1818static int mod_sysfs_init(struct module *mod)
1819{
1820 int err;
1821 struct kobject *kobj;
1822
1823 if (!module_sysfs_initialized) {
1824 pr_err("%s: module sysfs not initialized\n", mod->name);
1825 err = -EINVAL;
1826 goto out;
1827 }
1828
1829 kobj = kset_find_obj(module_kset, mod->name);
1830 if (kobj) {
1831 pr_err("%s: module is already loaded\n", mod->name);
1832 kobject_put(kobj);
1833 err = -EINVAL;
1834 goto out;
1835 }
1836
1837 mod->mkobj.mod = mod;
1838
1839 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1840 mod->mkobj.kobj.kset = module_kset;
1841 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1842 "%s", mod->name);
1843 if (err)
1844 mod_kobject_put(mod);
1845
1846 /* delay uevent until full sysfs population */
1847out:
1848 return err;
1849}
1850
1851static int mod_sysfs_setup(struct module *mod,
1852 const struct load_info *info,
1853 struct kernel_param *kparam,
1854 unsigned int num_params)
1855{
1856 int err;
1857
1858 err = mod_sysfs_init(mod);
1859 if (err)
1860 goto out;
1861
1862 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1863 if (!mod->holders_dir) {
1864 err = -ENOMEM;
1865 goto out_unreg;
1866 }
1867
1868 err = module_param_sysfs_setup(mod, kparam, num_params);
1869 if (err)
1870 goto out_unreg_holders;
1871
1872 err = module_add_modinfo_attrs(mod);
1873 if (err)
1874 goto out_unreg_param;
1875
1876 err = add_usage_links(mod);
1877 if (err)
1878 goto out_unreg_modinfo_attrs;
1879
1880 add_sect_attrs(mod, info);
1881 add_notes_attrs(mod, info);
1882
1883 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1884 return 0;
1885
1886out_unreg_modinfo_attrs:
1887 module_remove_modinfo_attrs(mod, -1);
1888out_unreg_param:
1889 module_param_sysfs_remove(mod);
1890out_unreg_holders:
1891 kobject_put(mod->holders_dir);
1892out_unreg:
1893 mod_kobject_put(mod);
1894out:
1895 return err;
1896}
1897
1898static void mod_sysfs_fini(struct module *mod)
1899{
1900 remove_notes_attrs(mod);
1901 remove_sect_attrs(mod);
1902 mod_kobject_put(mod);
1903}
1904
1905static void init_param_lock(struct module *mod)
1906{
1907 mutex_init(&mod->param_lock);
1908}
1909#else /* !CONFIG_SYSFS */
1910
1911static int mod_sysfs_setup(struct module *mod,
1912 const struct load_info *info,
1913 struct kernel_param *kparam,
1914 unsigned int num_params)
1915{
1916 return 0;
1917}
1918
1919static void mod_sysfs_fini(struct module *mod)
1920{
1921}
1922
1923static void module_remove_modinfo_attrs(struct module *mod, int end)
1924{
1925}
1926
1927static void del_usage_links(struct module *mod)
1928{
1929}
1930
1931static void init_param_lock(struct module *mod)
1932{
1933}
1934#endif /* CONFIG_SYSFS */
1935
1936static void mod_sysfs_teardown(struct module *mod)
1937{
1938 del_usage_links(mod);
1939 module_remove_modinfo_attrs(mod, -1);
1940 module_param_sysfs_remove(mod);
1941 kobject_put(mod->mkobj.drivers_dir);
1942 kobject_put(mod->holders_dir);
1943 mod_sysfs_fini(mod);
1944}
1945
1946#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
1947/*
1948 * LKM RO/NX protection: protect module's text/ro-data
1949 * from modification and any data from execution.
1950 *
1951 * General layout of module is:
1952 * [text] [read-only-data] [ro-after-init] [writable data]
1953 * text_size -----^ ^ ^ ^
1954 * ro_size ------------------------| | |
1955 * ro_after_init_size -----------------------------| |
1956 * size -----------------------------------------------------------|
1957 *
1958 * These values are always page-aligned (as is base)
1959 */
1960static void frob_text(const struct module_layout *layout,
1961 int (*set_memory)(unsigned long start, int num_pages))
1962{
1963 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1964 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1965 set_memory((unsigned long)layout->base,
1966 layout->text_size >> PAGE_SHIFT);
1967}
1968
1969#ifdef CONFIG_STRICT_MODULE_RWX
1970static void frob_rodata(const struct module_layout *layout,
1971 int (*set_memory)(unsigned long start, int num_pages))
1972{
1973 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1974 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1975 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1976 set_memory((unsigned long)layout->base + layout->text_size,
1977 (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
1978}
1979
1980static void frob_ro_after_init(const struct module_layout *layout,
1981 int (*set_memory)(unsigned long start, int num_pages))
1982{
1983 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1984 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1985 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1986 set_memory((unsigned long)layout->base + layout->ro_size,
1987 (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
1988}
1989
1990static void frob_writable_data(const struct module_layout *layout,
1991 int (*set_memory)(unsigned long start, int num_pages))
1992{
1993 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1994 BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1995 BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
1996 set_memory((unsigned long)layout->base + layout->ro_after_init_size,
1997 (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
1998}
1999
2000/* livepatching wants to disable read-only so it can frob module. */
2001void module_disable_ro(const struct module *mod)
2002{
2003 if (!rodata_enabled)
2004 return;
2005
2006 frob_text(&mod->core_layout, set_memory_rw);
2007 frob_rodata(&mod->core_layout, set_memory_rw);
2008 frob_ro_after_init(&mod->core_layout, set_memory_rw);
2009 frob_text(&mod->init_layout, set_memory_rw);
2010 frob_rodata(&mod->init_layout, set_memory_rw);
2011}
2012
2013void module_enable_ro(const struct module *mod, bool after_init)
2014{
2015 if (!rodata_enabled)
2016 return;
2017
2018 set_vm_flush_reset_perms(mod->core_layout.base);
2019 set_vm_flush_reset_perms(mod->init_layout.base);
2020 frob_text(&mod->core_layout, set_memory_ro);
2021
2022 frob_rodata(&mod->core_layout, set_memory_ro);
2023 frob_text(&mod->init_layout, set_memory_ro);
2024 frob_rodata(&mod->init_layout, set_memory_ro);
2025
2026 if (after_init)
2027 frob_ro_after_init(&mod->core_layout, set_memory_ro);
2028}
2029
2030static void module_enable_nx(const struct module *mod)
2031{
2032 frob_rodata(&mod->core_layout, set_memory_nx);
2033 frob_ro_after_init(&mod->core_layout, set_memory_nx);
2034 frob_writable_data(&mod->core_layout, set_memory_nx);
2035 frob_rodata(&mod->init_layout, set_memory_nx);
2036 frob_writable_data(&mod->init_layout, set_memory_nx);
2037}
2038
2039#else /* !CONFIG_STRICT_MODULE_RWX */
2040static void module_enable_nx(const struct module *mod) { }
2041#endif /* CONFIG_STRICT_MODULE_RWX */
2042static void module_enable_x(const struct module *mod)
2043{
2044 frob_text(&mod->core_layout, set_memory_x);
2045 frob_text(&mod->init_layout, set_memory_x);
2046}
2047#else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
2048static void module_enable_nx(const struct module *mod) { }
2049static void module_enable_x(const struct module *mod) { }
2050#endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
2051
2052
2053#ifdef CONFIG_LIVEPATCH
2054/*
2055 * Persist Elf information about a module. Copy the Elf header,
2056 * section header table, section string table, and symtab section
2057 * index from info to mod->klp_info.
2058 */
2059static int copy_module_elf(struct module *mod, struct load_info *info)
2060{
2061 unsigned int size, symndx;
2062 int ret;
2063
2064 size = sizeof(*mod->klp_info);
2065 mod->klp_info = kmalloc(size, GFP_KERNEL);
2066 if (mod->klp_info == NULL)
2067 return -ENOMEM;
2068
2069 /* Elf header */
2070 size = sizeof(mod->klp_info->hdr);
2071 memcpy(&mod->klp_info->hdr, info->hdr, size);
2072
2073 /* Elf section header table */
2074 size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
2075 mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL);
2076 if (mod->klp_info->sechdrs == NULL) {
2077 ret = -ENOMEM;
2078 goto free_info;
2079 }
2080
2081 /* Elf section name string table */
2082 size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
2083 mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL);
2084 if (mod->klp_info->secstrings == NULL) {
2085 ret = -ENOMEM;
2086 goto free_sechdrs;
2087 }
2088
2089 /* Elf symbol section index */
2090 symndx = info->index.sym;
2091 mod->klp_info->symndx = symndx;
2092
2093 /*
2094 * For livepatch modules, core_kallsyms.symtab is a complete
2095 * copy of the original symbol table. Adjust sh_addr to point
2096 * to core_kallsyms.symtab since the copy of the symtab in module
2097 * init memory is freed at the end of do_init_module().
2098 */
2099 mod->klp_info->sechdrs[symndx].sh_addr = \
2100 (unsigned long) mod->core_kallsyms.symtab;
2101
2102 return 0;
2103
2104free_sechdrs:
2105 kfree(mod->klp_info->sechdrs);
2106free_info:
2107 kfree(mod->klp_info);
2108 return ret;
2109}
2110
2111static void free_module_elf(struct module *mod)
2112{
2113 kfree(mod->klp_info->sechdrs);
2114 kfree(mod->klp_info->secstrings);
2115 kfree(mod->klp_info);
2116}
2117#else /* !CONFIG_LIVEPATCH */
2118static int copy_module_elf(struct module *mod, struct load_info *info)
2119{
2120 return 0;
2121}
2122
2123static void free_module_elf(struct module *mod)
2124{
2125}
2126#endif /* CONFIG_LIVEPATCH */
2127
2128void __weak module_memfree(void *module_region)
2129{
2130 /*
2131 * This memory may be RO, and freeing RO memory in an interrupt is not
2132 * supported by vmalloc.
2133 */
2134 WARN_ON(in_interrupt());
2135 vfree(module_region);
2136}
2137
2138void __weak module_arch_cleanup(struct module *mod)
2139{
2140}
2141
2142void __weak module_arch_freeing_init(struct module *mod)
2143{
2144}
2145
2146/* Free a module, remove from lists, etc. */
2147static void free_module(struct module *mod)
2148{
2149 trace_module_free(mod);
2150
2151 mod_sysfs_teardown(mod);
2152
2153 /* We leave it in list to prevent duplicate loads, but make sure
2154 * that noone uses it while it's being deconstructed. */
2155 mutex_lock(&module_mutex);
2156 mod->state = MODULE_STATE_UNFORMED;
2157 mutex_unlock(&module_mutex);
2158
2159 /* Remove dynamic debug info */
2160 ddebug_remove_module(mod->name);
2161
2162 /* Arch-specific cleanup. */
2163 module_arch_cleanup(mod);
2164
2165 /* Module unload stuff */
2166 module_unload_free(mod);
2167
2168 /* Free any allocated parameters. */
2169 destroy_params(mod->kp, mod->num_kp);
2170
2171 if (is_livepatch_module(mod))
2172 free_module_elf(mod);
2173
2174 /* Now we can delete it from the lists */
2175 mutex_lock(&module_mutex);
2176 /* Unlink carefully: kallsyms could be walking list. */
2177 list_del_rcu(&mod->list);
2178 mod_tree_remove(mod);
2179 /* Remove this module from bug list, this uses list_del_rcu */
2180 module_bug_cleanup(mod);
2181 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2182 synchronize_rcu();
2183 mutex_unlock(&module_mutex);
2184
2185 /* This may be empty, but that's OK */
2186 module_arch_freeing_init(mod);
2187 module_memfree(mod->init_layout.base);
2188 kfree(mod->args);
2189 percpu_modfree(mod);
2190
2191 /* Free lock-classes; relies on the preceding sync_rcu(). */
2192 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
2193
2194 /* Finally, free the core (containing the module structure) */
2195 module_memfree(mod->core_layout.base);
2196}
2197
2198void *__symbol_get(const char *symbol)
2199{
2200 struct module *owner;
2201 const struct kernel_symbol *sym;
2202
2203 preempt_disable();
2204 sym = find_symbol(symbol, &owner, NULL, true, true);
2205 if (sym && strong_try_module_get(owner))
2206 sym = NULL;
2207 preempt_enable();
2208
2209 return sym ? (void *)kernel_symbol_value(sym) : NULL;
2210}
2211EXPORT_SYMBOL_GPL(__symbol_get);
2212
2213/*
2214 * Ensure that an exported symbol [global namespace] does not already exist
2215 * in the kernel or in some other module's exported symbol table.
2216 *
2217 * You must hold the module_mutex.
2218 */
2219static int verify_exported_symbols(struct module *mod)
2220{
2221 unsigned int i;
2222 struct module *owner;
2223 const struct kernel_symbol *s;
2224 struct {
2225 const struct kernel_symbol *sym;
2226 unsigned int num;
2227 } arr[] = {
2228 { mod->syms, mod->num_syms },
2229 { mod->gpl_syms, mod->num_gpl_syms },
2230 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2231#ifdef CONFIG_UNUSED_SYMBOLS
2232 { mod->unused_syms, mod->num_unused_syms },
2233 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2234#endif
2235 };
2236
2237 for (i = 0; i < ARRAY_SIZE(arr); i++) {
2238 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2239 if (find_symbol(kernel_symbol_name(s), &owner, NULL,
2240 true, false)) {
2241 pr_err("%s: exports duplicate symbol %s"
2242 " (owned by %s)\n",
2243 mod->name, kernel_symbol_name(s),
2244 module_name(owner));
2245 return -ENOEXEC;
2246 }
2247 }
2248 }
2249 return 0;
2250}
2251
2252/* Change all symbols so that st_value encodes the pointer directly. */
2253static int simplify_symbols(struct module *mod, const struct load_info *info)
2254{
2255 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2256 Elf_Sym *sym = (void *)symsec->sh_addr;
2257 unsigned long secbase;
2258 unsigned int i;
2259 int ret = 0;
2260 const struct kernel_symbol *ksym;
2261
2262 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2263 const char *name = info->strtab + sym[i].st_name;
2264
2265 switch (sym[i].st_shndx) {
2266 case SHN_COMMON:
2267 /* Ignore common symbols */
2268 if (!strncmp(name, "__gnu_lto", 9))
2269 break;
2270
2271 /* We compiled with -fno-common. These are not
2272 supposed to happen. */
2273 pr_debug("Common symbol: %s\n", name);
2274 pr_warn("%s: please compile with -fno-common\n",
2275 mod->name);
2276 ret = -ENOEXEC;
2277 break;
2278
2279 case SHN_ABS:
2280 /* Don't need to do anything */
2281 pr_debug("Absolute symbol: 0x%08lx\n",
2282 (long)sym[i].st_value);
2283 break;
2284
2285 case SHN_LIVEPATCH:
2286 /* Livepatch symbols are resolved by livepatch */
2287 break;
2288
2289 case SHN_UNDEF:
2290 ksym = resolve_symbol_wait(mod, info, name);
2291 /* Ok if resolved. */
2292 if (ksym && !IS_ERR(ksym)) {
2293 sym[i].st_value = kernel_symbol_value(ksym);
2294 break;
2295 }
2296
2297 /* Ok if weak. */
2298 if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
2299 break;
2300
2301 ret = PTR_ERR(ksym) ?: -ENOENT;
2302 pr_warn("%s: Unknown symbol %s (err %d)\n",
2303 mod->name, name, ret);
2304 break;
2305
2306 default:
2307 /* Divert to percpu allocation if a percpu var. */
2308 if (sym[i].st_shndx == info->index.pcpu)
2309 secbase = (unsigned long)mod_percpu(mod);
2310 else
2311 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2312 sym[i].st_value += secbase;
2313 break;
2314 }
2315 }
2316
2317 return ret;
2318}
2319
2320static int apply_relocations(struct module *mod, const struct load_info *info)
2321{
2322 unsigned int i;
2323 int err = 0;
2324
2325 /* Now do relocations. */
2326 for (i = 1; i < info->hdr->e_shnum; i++) {
2327 unsigned int infosec = info->sechdrs[i].sh_info;
2328
2329 /* Not a valid relocation section? */
2330 if (infosec >= info->hdr->e_shnum)
2331 continue;
2332
2333 /* Don't bother with non-allocated sections */
2334 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2335 continue;
2336
2337 /* Livepatch relocation sections are applied by livepatch */
2338 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
2339 continue;
2340
2341 if (info->sechdrs[i].sh_type == SHT_REL)
2342 err = apply_relocate(info->sechdrs, info->strtab,
2343 info->index.sym, i, mod);
2344 else if (info->sechdrs[i].sh_type == SHT_RELA)
2345 err = apply_relocate_add(info->sechdrs, info->strtab,
2346 info->index.sym, i, mod);
2347 if (err < 0)
2348 break;
2349 }
2350 return err;
2351}
2352
2353/* Additional bytes needed by arch in front of individual sections */
2354unsigned int __weak arch_mod_section_prepend(struct module *mod,
2355 unsigned int section)
2356{
2357 /* default implementation just returns zero */
2358 return 0;
2359}
2360
2361/* Update size with this section: return offset. */
2362static long get_offset(struct module *mod, unsigned int *size,
2363 Elf_Shdr *sechdr, unsigned int section)
2364{
2365 long ret;
2366
2367 *size += arch_mod_section_prepend(mod, section);
2368 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2369 *size = ret + sechdr->sh_size;
2370 return ret;
2371}
2372
2373/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2374 might -- code, read-only data, read-write data, small data. Tally
2375 sizes, and place the offsets into sh_entsize fields: high bit means it
2376 belongs in init. */
2377static void layout_sections(struct module *mod, struct load_info *info)
2378{
2379 static unsigned long const masks[][2] = {
2380 /* NOTE: all executable code must be the first section
2381 * in this array; otherwise modify the text_size
2382 * finder in the two loops below */
2383 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2384 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2385 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
2386 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2387 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2388 };
2389 unsigned int m, i;
2390
2391 for (i = 0; i < info->hdr->e_shnum; i++)
2392 info->sechdrs[i].sh_entsize = ~0UL;
2393
2394 pr_debug("Core section allocation order:\n");
2395 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2396 for (i = 0; i < info->hdr->e_shnum; ++i) {
2397 Elf_Shdr *s = &info->sechdrs[i];
2398 const char *sname = info->secstrings + s->sh_name;
2399
2400 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2401 || (s->sh_flags & masks[m][1])
2402 || s->sh_entsize != ~0UL
2403 || strstarts(sname, ".init"))
2404 continue;
2405 s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2406 pr_debug("\t%s\n", sname);
2407 }
2408 switch (m) {
2409 case 0: /* executable */
2410 mod->core_layout.size = debug_align(mod->core_layout.size);
2411 mod->core_layout.text_size = mod->core_layout.size;
2412 break;
2413 case 1: /* RO: text and ro-data */
2414 mod->core_layout.size = debug_align(mod->core_layout.size);
2415 mod->core_layout.ro_size = mod->core_layout.size;
2416 break;
2417 case 2: /* RO after init */
2418 mod->core_layout.size = debug_align(mod->core_layout.size);
2419 mod->core_layout.ro_after_init_size = mod->core_layout.size;
2420 break;
2421 case 4: /* whole core */
2422 mod->core_layout.size = debug_align(mod->core_layout.size);
2423 break;
2424 }
2425 }
2426
2427 pr_debug("Init section allocation order:\n");
2428 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2429 for (i = 0; i < info->hdr->e_shnum; ++i) {
2430 Elf_Shdr *s = &info->sechdrs[i];
2431 const char *sname = info->secstrings + s->sh_name;
2432
2433 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2434 || (s->sh_flags & masks[m][1])
2435 || s->sh_entsize != ~0UL
2436 || !strstarts(sname, ".init"))
2437 continue;
2438 s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
2439 | INIT_OFFSET_MASK);
2440 pr_debug("\t%s\n", sname);
2441 }
2442 switch (m) {
2443 case 0: /* executable */
2444 mod->init_layout.size = debug_align(mod->init_layout.size);
2445 mod->init_layout.text_size = mod->init_layout.size;
2446 break;
2447 case 1: /* RO: text and ro-data */
2448 mod->init_layout.size = debug_align(mod->init_layout.size);
2449 mod->init_layout.ro_size = mod->init_layout.size;
2450 break;
2451 case 2:
2452 /*
2453 * RO after init doesn't apply to init_layout (only
2454 * core_layout), so it just takes the value of ro_size.
2455 */
2456 mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
2457 break;
2458 case 4: /* whole init */
2459 mod->init_layout.size = debug_align(mod->init_layout.size);
2460 break;
2461 }
2462 }
2463}
2464
2465static void set_license(struct module *mod, const char *license)
2466{
2467 if (!license)
2468 license = "unspecified";
2469
2470 if (!license_is_gpl_compatible(license)) {
2471 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2472 pr_warn("%s: module license '%s' taints kernel.\n",
2473 mod->name, license);
2474 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2475 LOCKDEP_NOW_UNRELIABLE);
2476 }
2477}
2478
2479/* Parse tag=value strings from .modinfo section */
2480static char *next_string(char *string, unsigned long *secsize)
2481{
2482 /* Skip non-zero chars */
2483 while (string[0]) {
2484 string++;
2485 if ((*secsize)-- <= 1)
2486 return NULL;
2487 }
2488
2489 /* Skip any zero padding. */
2490 while (!string[0]) {
2491 string++;
2492 if ((*secsize)-- <= 1)
2493 return NULL;
2494 }
2495 return string;
2496}
2497
2498static char *get_next_modinfo(const struct load_info *info, const char *tag,
2499 char *prev)
2500{
2501 char *p;
2502 unsigned int taglen = strlen(tag);
2503 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2504 unsigned long size = infosec->sh_size;
2505
2506 /*
2507 * get_modinfo() calls made before rewrite_section_headers()
2508 * must use sh_offset, as sh_addr isn't set!
2509 */
2510 char *modinfo = (char *)info->hdr + infosec->sh_offset;
2511
2512 if (prev) {
2513 size -= prev - modinfo;
2514 modinfo = next_string(prev, &size);
2515 }
2516
2517 for (p = modinfo; p; p = next_string(p, &size)) {
2518 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2519 return p + taglen + 1;
2520 }
2521 return NULL;
2522}
2523
2524static char *get_modinfo(const struct load_info *info, const char *tag)
2525{
2526 return get_next_modinfo(info, tag, NULL);
2527}
2528
2529static void setup_modinfo(struct module *mod, struct load_info *info)
2530{
2531 struct module_attribute *attr;
2532 int i;
2533
2534 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2535 if (attr->setup)
2536 attr->setup(mod, get_modinfo(info, attr->attr.name));
2537 }
2538}
2539
2540static void free_modinfo(struct module *mod)
2541{
2542 struct module_attribute *attr;
2543 int i;
2544
2545 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2546 if (attr->free)
2547 attr->free(mod);
2548 }
2549}
2550
2551#ifdef CONFIG_KALLSYMS
2552
2553/* Lookup exported symbol in given range of kernel_symbols */
2554static const struct kernel_symbol *lookup_exported_symbol(const char *name,
2555 const struct kernel_symbol *start,
2556 const struct kernel_symbol *stop)
2557{
2558 return bsearch(name, start, stop - start,
2559 sizeof(struct kernel_symbol), cmp_name);
2560}
2561
2562static int is_exported(const char *name, unsigned long value,
2563 const struct module *mod)
2564{
2565 const struct kernel_symbol *ks;
2566 if (!mod)
2567 ks = lookup_exported_symbol(name, __start___ksymtab, __stop___ksymtab);
2568 else
2569 ks = lookup_exported_symbol(name, mod->syms, mod->syms + mod->num_syms);
2570
2571 return ks != NULL && kernel_symbol_value(ks) == value;
2572}
2573
2574/* As per nm */
2575static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2576{
2577 const Elf_Shdr *sechdrs = info->sechdrs;
2578
2579 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2580 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2581 return 'v';
2582 else
2583 return 'w';
2584 }
2585 if (sym->st_shndx == SHN_UNDEF)
2586 return 'U';
2587 if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
2588 return 'a';
2589 if (sym->st_shndx >= SHN_LORESERVE)
2590 return '?';
2591 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2592 return 't';
2593 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2594 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2595 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2596 return 'r';
2597 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2598 return 'g';
2599 else
2600 return 'd';
2601 }
2602 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2603 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2604 return 's';
2605 else
2606 return 'b';
2607 }
2608 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2609 ".debug")) {
2610 return 'n';
2611 }
2612 return '?';
2613}
2614
2615static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2616 unsigned int shnum, unsigned int pcpundx)
2617{
2618 const Elf_Shdr *sec;
2619
2620 if (src->st_shndx == SHN_UNDEF
2621 || src->st_shndx >= shnum
2622 || !src->st_name)
2623 return false;
2624
2625#ifdef CONFIG_KALLSYMS_ALL
2626 if (src->st_shndx == pcpundx)
2627 return true;
2628#endif
2629
2630 sec = sechdrs + src->st_shndx;
2631 if (!(sec->sh_flags & SHF_ALLOC)
2632#ifndef CONFIG_KALLSYMS_ALL
2633 || !(sec->sh_flags & SHF_EXECINSTR)
2634#endif
2635 || (sec->sh_entsize & INIT_OFFSET_MASK))
2636 return false;
2637
2638 return true;
2639}
2640
2641/*
2642 * We only allocate and copy the strings needed by the parts of symtab
2643 * we keep. This is simple, but has the effect of making multiple
2644 * copies of duplicates. We could be more sophisticated, see
2645 * linux-kernel thread starting with
2646 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2647 */
2648static void layout_symtab(struct module *mod, struct load_info *info)
2649{
2650 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2651 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2652 const Elf_Sym *src;
2653 unsigned int i, nsrc, ndst, strtab_size = 0;
2654
2655 /* Put symbol section at end of init part of module. */
2656 symsect->sh_flags |= SHF_ALLOC;
2657 symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2658 info->index.sym) | INIT_OFFSET_MASK;
2659 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2660
2661 src = (void *)info->hdr + symsect->sh_offset;
2662 nsrc = symsect->sh_size / sizeof(*src);
2663
2664 /* Compute total space required for the core symbols' strtab. */
2665 for (ndst = i = 0; i < nsrc; i++) {
2666 if (i == 0 || is_livepatch_module(mod) ||
2667 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2668 info->index.pcpu)) {
2669 strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2670 ndst++;
2671 }
2672 }
2673
2674 /* Append room for core symbols at end of core part. */
2675 info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
2676 info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
2677 mod->core_layout.size += strtab_size;
2678 info->core_typeoffs = mod->core_layout.size;
2679 mod->core_layout.size += ndst * sizeof(char);
2680 mod->core_layout.size = debug_align(mod->core_layout.size);
2681
2682 /* Put string table section at end of init part of module. */
2683 strsect->sh_flags |= SHF_ALLOC;
2684 strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2685 info->index.str) | INIT_OFFSET_MASK;
2686 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2687
2688 /* We'll tack temporary mod_kallsyms on the end. */
2689 mod->init_layout.size = ALIGN(mod->init_layout.size,
2690 __alignof__(struct mod_kallsyms));
2691 info->mod_kallsyms_init_off = mod->init_layout.size;
2692 mod->init_layout.size += sizeof(struct mod_kallsyms);
2693 info->init_typeoffs = mod->init_layout.size;
2694 mod->init_layout.size += nsrc * sizeof(char);
2695 mod->init_layout.size = debug_align(mod->init_layout.size);
2696}
2697
2698/*
2699 * We use the full symtab and strtab which layout_symtab arranged to
2700 * be appended to the init section. Later we switch to the cut-down
2701 * core-only ones.
2702 */
2703static void add_kallsyms(struct module *mod, const struct load_info *info)
2704{
2705 unsigned int i, ndst;
2706 const Elf_Sym *src;
2707 Elf_Sym *dst;
2708 char *s;
2709 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2710
2711 /* Set up to point into init section. */
2712 mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
2713
2714 mod->kallsyms->symtab = (void *)symsec->sh_addr;
2715 mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2716 /* Make sure we get permanent strtab: don't use info->strtab. */
2717 mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2718 mod->kallsyms->typetab = mod->init_layout.base + info->init_typeoffs;
2719
2720 /*
2721 * Now populate the cut down core kallsyms for after init
2722 * and set types up while we still have access to sections.
2723 */
2724 mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
2725 mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
2726 mod->core_kallsyms.typetab = mod->core_layout.base + info->core_typeoffs;
2727 src = mod->kallsyms->symtab;
2728 for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2729 mod->kallsyms->typetab[i] = elf_type(src + i, info);
2730 if (i == 0 || is_livepatch_module(mod) ||
2731 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2732 info->index.pcpu)) {
2733 mod->core_kallsyms.typetab[ndst] =
2734 mod->kallsyms->typetab[i];
2735 dst[ndst] = src[i];
2736 dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
2737 s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2738 KSYM_NAME_LEN) + 1;
2739 }
2740 }
2741 mod->core_kallsyms.num_symtab = ndst;
2742}
2743#else
2744static inline void layout_symtab(struct module *mod, struct load_info *info)
2745{
2746}
2747
2748static void add_kallsyms(struct module *mod, const struct load_info *info)
2749{
2750}
2751#endif /* CONFIG_KALLSYMS */
2752
2753static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num)
2754{
2755 if (!debug)
2756 return;
2757 ddebug_add_module(debug, num, mod->name);
2758}
2759
2760static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug)
2761{
2762 if (debug)
2763 ddebug_remove_module(mod->name);
2764}
2765
2766void * __weak module_alloc(unsigned long size)
2767{
2768 return vmalloc_exec(size);
2769}
2770
2771bool __weak module_exit_section(const char *name)
2772{
2773 return strstarts(name, ".exit");
2774}
2775
2776#ifdef CONFIG_DEBUG_KMEMLEAK
2777static void kmemleak_load_module(const struct module *mod,
2778 const struct load_info *info)
2779{
2780 unsigned int i;
2781
2782 /* only scan the sections containing data */
2783 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2784
2785 for (i = 1; i < info->hdr->e_shnum; i++) {
2786 /* Scan all writable sections that's not executable */
2787 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2788 !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2789 (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2790 continue;
2791
2792 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2793 info->sechdrs[i].sh_size, GFP_KERNEL);
2794 }
2795}
2796#else
2797static inline void kmemleak_load_module(const struct module *mod,
2798 const struct load_info *info)
2799{
2800}
2801#endif
2802
2803#ifdef CONFIG_MODULE_SIG
2804static int module_sig_check(struct load_info *info, int flags)
2805{
2806 int err = -ENODATA;
2807 const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2808 const char *reason;
2809 const void *mod = info->hdr;
2810
2811 /*
2812 * Require flags == 0, as a module with version information
2813 * removed is no longer the module that was signed
2814 */
2815 if (flags == 0 &&
2816 info->len > markerlen &&
2817 memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2818 /* We truncate the module to discard the signature */
2819 info->len -= markerlen;
2820 err = mod_verify_sig(mod, info);
2821 }
2822
2823 switch (err) {
2824 case 0:
2825 info->sig_ok = true;
2826 return 0;
2827
2828 /* We don't permit modules to be loaded into trusted kernels
2829 * without a valid signature on them, but if we're not
2830 * enforcing, certain errors are non-fatal.
2831 */
2832 case -ENODATA:
2833 reason = "Loading of unsigned module";
2834 goto decide;
2835 case -ENOPKG:
2836 reason = "Loading of module with unsupported crypto";
2837 goto decide;
2838 case -ENOKEY:
2839 reason = "Loading of module with unavailable key";
2840 decide:
2841 if (is_module_sig_enforced()) {
2842 pr_notice("%s: %s is rejected\n", info->name, reason);
2843 return -EKEYREJECTED;
2844 }
2845
2846 return security_locked_down(LOCKDOWN_MODULE_SIGNATURE);
2847
2848 /* All other errors are fatal, including nomem, unparseable
2849 * signatures and signature check failures - even if signatures
2850 * aren't required.
2851 */
2852 default:
2853 return err;
2854 }
2855}
2856#else /* !CONFIG_MODULE_SIG */
2857static int module_sig_check(struct load_info *info, int flags)
2858{
2859 return 0;
2860}
2861#endif /* !CONFIG_MODULE_SIG */
2862
2863/* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2864static int elf_header_check(struct load_info *info)
2865{
2866 if (info->len < sizeof(*(info->hdr)))
2867 return -ENOEXEC;
2868
2869 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2870 || info->hdr->e_type != ET_REL
2871 || !elf_check_arch(info->hdr)
2872 || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2873 return -ENOEXEC;
2874
2875 if (info->hdr->e_shoff >= info->len
2876 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2877 info->len - info->hdr->e_shoff))
2878 return -ENOEXEC;
2879
2880 return 0;
2881}
2882
2883#define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2884
2885static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
2886{
2887 do {
2888 unsigned long n = min(len, COPY_CHUNK_SIZE);
2889
2890 if (copy_from_user(dst, usrc, n) != 0)
2891 return -EFAULT;
2892 cond_resched();
2893 dst += n;
2894 usrc += n;
2895 len -= n;
2896 } while (len);
2897 return 0;
2898}
2899
2900#ifdef CONFIG_LIVEPATCH
2901static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2902{
2903 if (get_modinfo(info, "livepatch")) {
2904 mod->klp = true;
2905 add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
2906 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
2907 mod->name);
2908 }
2909
2910 return 0;
2911}
2912#else /* !CONFIG_LIVEPATCH */
2913static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
2914{
2915 if (get_modinfo(info, "livepatch")) {
2916 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
2917 mod->name);
2918 return -ENOEXEC;
2919 }
2920
2921 return 0;
2922}
2923#endif /* CONFIG_LIVEPATCH */
2924
2925static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
2926{
2927 if (retpoline_module_ok(get_modinfo(info, "retpoline")))
2928 return;
2929
2930 pr_warn("%s: loading module not compiled with retpoline compiler.\n",
2931 mod->name);
2932}
2933
2934/* Sets info->hdr and info->len. */
2935static int copy_module_from_user(const void __user *umod, unsigned long len,
2936 struct load_info *info)
2937{
2938 int err;
2939
2940 info->len = len;
2941 if (info->len < sizeof(*(info->hdr)))
2942 return -ENOEXEC;
2943
2944 err = security_kernel_load_data(LOADING_MODULE);
2945 if (err)
2946 return err;
2947
2948 /* Suck in entire file: we'll want most of it. */
2949 info->hdr = __vmalloc(info->len,
2950 GFP_KERNEL | __GFP_NOWARN, PAGE_KERNEL);
2951 if (!info->hdr)
2952 return -ENOMEM;
2953
2954 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2955 vfree(info->hdr);
2956 return -EFAULT;
2957 }
2958
2959 return 0;
2960}
2961
2962static void free_copy(struct load_info *info)
2963{
2964 vfree(info->hdr);
2965}
2966
2967static int rewrite_section_headers(struct load_info *info, int flags)
2968{
2969 unsigned int i;
2970
2971 /* This should always be true, but let's be sure. */
2972 info->sechdrs[0].sh_addr = 0;
2973
2974 for (i = 1; i < info->hdr->e_shnum; i++) {
2975 Elf_Shdr *shdr = &info->sechdrs[i];
2976 if (shdr->sh_type != SHT_NOBITS
2977 && info->len < shdr->sh_offset + shdr->sh_size) {
2978 pr_err("Module len %lu truncated\n", info->len);
2979 return -ENOEXEC;
2980 }
2981
2982 /* Mark all sections sh_addr with their address in the
2983 temporary image. */
2984 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2985
2986#ifndef CONFIG_MODULE_UNLOAD
2987 /* Don't load .exit sections */
2988 if (module_exit_section(info->secstrings+shdr->sh_name))
2989 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2990#endif
2991 }
2992
2993 /* Track but don't keep modinfo and version sections. */
2994 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2995 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2996
2997 return 0;
2998}
2999
3000/*
3001 * Set up our basic convenience variables (pointers to section headers,
3002 * search for module section index etc), and do some basic section
3003 * verification.
3004 *
3005 * Set info->mod to the temporary copy of the module in info->hdr. The final one
3006 * will be allocated in move_module().
3007 */
3008static int setup_load_info(struct load_info *info, int flags)
3009{
3010 unsigned int i;
3011
3012 /* Set up the convenience variables */
3013 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
3014 info->secstrings = (void *)info->hdr
3015 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
3016
3017 /* Try to find a name early so we can log errors with a module name */
3018 info->index.info = find_sec(info, ".modinfo");
3019 if (info->index.info)
3020 info->name = get_modinfo(info, "name");
3021
3022 /* Find internal symbols and strings. */
3023 for (i = 1; i < info->hdr->e_shnum; i++) {
3024 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
3025 info->index.sym = i;
3026 info->index.str = info->sechdrs[i].sh_link;
3027 info->strtab = (char *)info->hdr
3028 + info->sechdrs[info->index.str].sh_offset;
3029 break;
3030 }
3031 }
3032
3033 if (info->index.sym == 0) {
3034 pr_warn("%s: module has no symbols (stripped?)\n",
3035 info->name ?: "(missing .modinfo section or name field)");
3036 return -ENOEXEC;
3037 }
3038
3039 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
3040 if (!info->index.mod) {
3041 pr_warn("%s: No module found in object\n",
3042 info->name ?: "(missing .modinfo section or name field)");
3043 return -ENOEXEC;
3044 }
3045 /* This is temporary: point mod into copy of data. */
3046 info->mod = (void *)info->hdr + info->sechdrs[info->index.mod].sh_offset;
3047
3048 /*
3049 * If we didn't load the .modinfo 'name' field earlier, fall back to
3050 * on-disk struct mod 'name' field.
3051 */
3052 if (!info->name)
3053 info->name = info->mod->name;
3054
3055 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
3056 info->index.vers = 0; /* Pretend no __versions section! */
3057 else
3058 info->index.vers = find_sec(info, "__versions");
3059
3060 info->index.pcpu = find_pcpusec(info);
3061
3062 return 0;
3063}
3064
3065static int check_modinfo(struct module *mod, struct load_info *info, int flags)
3066{
3067 const char *modmagic = get_modinfo(info, "vermagic");
3068 int err;
3069
3070 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
3071 modmagic = NULL;
3072
3073 /* This is allowed: modprobe --force will invalidate it. */
3074 if (!modmagic) {
3075 err = try_to_force_load(mod, "bad vermagic");
3076 if (err)
3077 return err;
3078 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
3079 pr_err("%s: version magic '%s' should be '%s'\n",
3080 info->name, modmagic, vermagic);
3081 return -ENOEXEC;
3082 }
3083
3084 if (!get_modinfo(info, "intree")) {
3085 if (!test_taint(TAINT_OOT_MODULE))
3086 pr_warn("%s: loading out-of-tree module taints kernel.\n",
3087 mod->name);
3088 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
3089 }
3090
3091 check_modinfo_retpoline(mod, info);
3092
3093 if (get_modinfo(info, "staging")) {
3094 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
3095 pr_warn("%s: module is from the staging directory, the quality "
3096 "is unknown, you have been warned.\n", mod->name);
3097 }
3098
3099 err = check_modinfo_livepatch(mod, info);
3100 if (err)
3101 return err;
3102
3103 /* Set up license info based on the info section */
3104 set_license(mod, get_modinfo(info, "license"));
3105
3106 return 0;
3107}
3108
3109static int find_module_sections(struct module *mod, struct load_info *info)
3110{
3111 mod->kp = section_objs(info, "__param",
3112 sizeof(*mod->kp), &mod->num_kp);
3113 mod->syms = section_objs(info, "__ksymtab",
3114 sizeof(*mod->syms), &mod->num_syms);
3115 mod->crcs = section_addr(info, "__kcrctab");
3116 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
3117 sizeof(*mod->gpl_syms),
3118 &mod->num_gpl_syms);
3119 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
3120 mod->gpl_future_syms = section_objs(info,
3121 "__ksymtab_gpl_future",
3122 sizeof(*mod->gpl_future_syms),
3123 &mod->num_gpl_future_syms);
3124 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
3125
3126#ifdef CONFIG_UNUSED_SYMBOLS
3127 mod->unused_syms = section_objs(info, "__ksymtab_unused",
3128 sizeof(*mod->unused_syms),
3129 &mod->num_unused_syms);
3130 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
3131 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
3132 sizeof(*mod->unused_gpl_syms),
3133 &mod->num_unused_gpl_syms);
3134 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
3135#endif
3136#ifdef CONFIG_CONSTRUCTORS
3137 mod->ctors = section_objs(info, ".ctors",
3138 sizeof(*mod->ctors), &mod->num_ctors);
3139 if (!mod->ctors)
3140 mod->ctors = section_objs(info, ".init_array",
3141 sizeof(*mod->ctors), &mod->num_ctors);
3142 else if (find_sec(info, ".init_array")) {
3143 /*
3144 * This shouldn't happen with same compiler and binutils
3145 * building all parts of the module.
3146 */
3147 pr_warn("%s: has both .ctors and .init_array.\n",
3148 mod->name);
3149 return -EINVAL;
3150 }
3151#endif
3152
3153#ifdef CONFIG_TRACEPOINTS
3154 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
3155 sizeof(*mod->tracepoints_ptrs),
3156 &mod->num_tracepoints);
3157#endif
3158#ifdef CONFIG_TREE_SRCU
3159 mod->srcu_struct_ptrs = section_objs(info, "___srcu_struct_ptrs",
3160 sizeof(*mod->srcu_struct_ptrs),
3161 &mod->num_srcu_structs);
3162#endif
3163#ifdef CONFIG_BPF_EVENTS
3164 mod->bpf_raw_events = section_objs(info, "__bpf_raw_tp_map",
3165 sizeof(*mod->bpf_raw_events),
3166 &mod->num_bpf_raw_events);
3167#endif
3168#ifdef CONFIG_JUMP_LABEL
3169 mod->jump_entries = section_objs(info, "__jump_table",
3170 sizeof(*mod->jump_entries),
3171 &mod->num_jump_entries);
3172#endif
3173#ifdef CONFIG_EVENT_TRACING
3174 mod->trace_events = section_objs(info, "_ftrace_events",
3175 sizeof(*mod->trace_events),
3176 &mod->num_trace_events);
3177 mod->trace_evals = section_objs(info, "_ftrace_eval_map",
3178 sizeof(*mod->trace_evals),
3179 &mod->num_trace_evals);
3180#endif
3181#ifdef CONFIG_TRACING
3182 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
3183 sizeof(*mod->trace_bprintk_fmt_start),
3184 &mod->num_trace_bprintk_fmt);
3185#endif
3186#ifdef CONFIG_FTRACE_MCOUNT_RECORD
3187 /* sechdrs[0].sh_size is always zero */
3188 mod->ftrace_callsites = section_objs(info, FTRACE_CALLSITE_SECTION,
3189 sizeof(*mod->ftrace_callsites),
3190 &mod->num_ftrace_callsites);
3191#endif
3192#ifdef CONFIG_FUNCTION_ERROR_INJECTION
3193 mod->ei_funcs = section_objs(info, "_error_injection_whitelist",
3194 sizeof(*mod->ei_funcs),
3195 &mod->num_ei_funcs);
3196#endif
3197 mod->extable = section_objs(info, "__ex_table",
3198 sizeof(*mod->extable), &mod->num_exentries);
3199
3200 if (section_addr(info, "__obsparm"))
3201 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
3202
3203 info->debug = section_objs(info, "__verbose",
3204 sizeof(*info->debug), &info->num_debug);
3205
3206 return 0;
3207}
3208
3209static int move_module(struct module *mod, struct load_info *info)
3210{
3211 int i;
3212 void *ptr;
3213
3214 /* Do the allocs. */
3215 ptr = module_alloc(mod->core_layout.size);
3216 /*
3217 * The pointer to this block is stored in the module structure
3218 * which is inside the block. Just mark it as not being a
3219 * leak.
3220 */
3221 kmemleak_not_leak(ptr);
3222 if (!ptr)
3223 return -ENOMEM;
3224
3225 memset(ptr, 0, mod->core_layout.size);
3226 mod->core_layout.base = ptr;
3227
3228 if (mod->init_layout.size) {
3229 ptr = module_alloc(mod->init_layout.size);
3230 /*
3231 * The pointer to this block is stored in the module structure
3232 * which is inside the block. This block doesn't need to be
3233 * scanned as it contains data and code that will be freed
3234 * after the module is initialized.
3235 */
3236 kmemleak_ignore(ptr);
3237 if (!ptr) {
3238 module_memfree(mod->core_layout.base);
3239 return -ENOMEM;
3240 }
3241 memset(ptr, 0, mod->init_layout.size);
3242 mod->init_layout.base = ptr;
3243 } else
3244 mod->init_layout.base = NULL;
3245
3246 /* Transfer each section which specifies SHF_ALLOC */
3247 pr_debug("final section addresses:\n");
3248 for (i = 0; i < info->hdr->e_shnum; i++) {
3249 void *dest;
3250 Elf_Shdr *shdr = &info->sechdrs[i];
3251
3252 if (!(shdr->sh_flags & SHF_ALLOC))
3253 continue;
3254
3255 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3256 dest = mod->init_layout.base
3257 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3258 else
3259 dest = mod->core_layout.base + shdr->sh_entsize;
3260
3261 if (shdr->sh_type != SHT_NOBITS)
3262 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3263 /* Update sh_addr to point to copy in image. */
3264 shdr->sh_addr = (unsigned long)dest;
3265 pr_debug("\t0x%lx %s\n",
3266 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3267 }
3268
3269 return 0;
3270}
3271
3272static int check_module_license_and_versions(struct module *mod)
3273{
3274 int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
3275
3276 /*
3277 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3278 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3279 * using GPL-only symbols it needs.
3280 */
3281 if (strcmp(mod->name, "ndiswrapper") == 0)
3282 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3283
3284 /* driverloader was caught wrongly pretending to be under GPL */
3285 if (strcmp(mod->name, "driverloader") == 0)
3286 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3287 LOCKDEP_NOW_UNRELIABLE);
3288
3289 /* lve claims to be GPL but upstream won't provide source */
3290 if (strcmp(mod->name, "lve") == 0)
3291 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3292 LOCKDEP_NOW_UNRELIABLE);
3293
3294 if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
3295 pr_warn("%s: module license taints kernel.\n", mod->name);
3296
3297#ifdef CONFIG_MODVERSIONS
3298 if ((mod->num_syms && !mod->crcs)
3299 || (mod->num_gpl_syms && !mod->gpl_crcs)
3300 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3301#ifdef CONFIG_UNUSED_SYMBOLS
3302 || (mod->num_unused_syms && !mod->unused_crcs)
3303 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3304#endif
3305 ) {
3306 return try_to_force_load(mod,
3307 "no versions for exported symbols");
3308 }
3309#endif
3310 return 0;
3311}
3312
3313static void flush_module_icache(const struct module *mod)
3314{
3315 mm_segment_t old_fs;
3316
3317 /* flush the icache in correct context */
3318 old_fs = get_fs();
3319 set_fs(KERNEL_DS);
3320
3321 /*
3322 * Flush the instruction cache, since we've played with text.
3323 * Do it before processing of module parameters, so the module
3324 * can provide parameter accessor functions of its own.
3325 */
3326 if (mod->init_layout.base)
3327 flush_icache_range((unsigned long)mod->init_layout.base,
3328 (unsigned long)mod->init_layout.base
3329 + mod->init_layout.size);
3330 flush_icache_range((unsigned long)mod->core_layout.base,
3331 (unsigned long)mod->core_layout.base + mod->core_layout.size);
3332
3333 set_fs(old_fs);
3334}
3335
3336int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3337 Elf_Shdr *sechdrs,
3338 char *secstrings,
3339 struct module *mod)
3340{
3341 return 0;
3342}
3343
3344/* module_blacklist is a comma-separated list of module names */
3345static char *module_blacklist;
3346static bool blacklisted(const char *module_name)
3347{
3348 const char *p;
3349 size_t len;
3350
3351 if (!module_blacklist)
3352 return false;
3353
3354 for (p = module_blacklist; *p; p += len) {
3355 len = strcspn(p, ",");
3356 if (strlen(module_name) == len && !memcmp(module_name, p, len))
3357 return true;
3358 if (p[len] == ',')
3359 len++;
3360 }
3361 return false;
3362}
3363core_param(module_blacklist, module_blacklist, charp, 0400);
3364
3365static struct module *layout_and_allocate(struct load_info *info, int flags)
3366{
3367 struct module *mod;
3368 unsigned int ndx;
3369 int err;
3370
3371 err = check_modinfo(info->mod, info, flags);
3372 if (err)
3373 return ERR_PTR(err);
3374
3375 /* Allow arches to frob section contents and sizes. */
3376 err = module_frob_arch_sections(info->hdr, info->sechdrs,
3377 info->secstrings, info->mod);
3378 if (err < 0)
3379 return ERR_PTR(err);
3380
3381 /* We will do a special allocation for per-cpu sections later. */
3382 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3383
3384 /*
3385 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3386 * layout_sections() can put it in the right place.
3387 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3388 */
3389 ndx = find_sec(info, ".data..ro_after_init");
3390 if (ndx)
3391 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3392 /*
3393 * Mark the __jump_table section as ro_after_init as well: these data
3394 * structures are never modified, with the exception of entries that
3395 * refer to code in the __init section, which are annotated as such
3396 * at module load time.
3397 */
3398 ndx = find_sec(info, "__jump_table");
3399 if (ndx)
3400 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3401
3402 /* Determine total sizes, and put offsets in sh_entsize. For now
3403 this is done generically; there doesn't appear to be any
3404 special cases for the architectures. */
3405 layout_sections(info->mod, info);
3406 layout_symtab(info->mod, info);
3407
3408 /* Allocate and move to the final place */
3409 err = move_module(info->mod, info);
3410 if (err)
3411 return ERR_PTR(err);
3412
3413 /* Module has been copied to its final place now: return it. */
3414 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3415 kmemleak_load_module(mod, info);
3416 return mod;
3417}
3418
3419/* mod is no longer valid after this! */
3420static void module_deallocate(struct module *mod, struct load_info *info)
3421{
3422 percpu_modfree(mod);
3423 module_arch_freeing_init(mod);
3424 module_memfree(mod->init_layout.base);
3425 module_memfree(mod->core_layout.base);
3426}
3427
3428int __weak module_finalize(const Elf_Ehdr *hdr,
3429 const Elf_Shdr *sechdrs,
3430 struct module *me)
3431{
3432 return 0;
3433}
3434
3435static int post_relocation(struct module *mod, const struct load_info *info)
3436{
3437 /* Sort exception table now relocations are done. */
3438 sort_extable(mod->extable, mod->extable + mod->num_exentries);
3439
3440 /* Copy relocated percpu area over. */
3441 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3442 info->sechdrs[info->index.pcpu].sh_size);
3443
3444 /* Setup kallsyms-specific fields. */
3445 add_kallsyms(mod, info);
3446
3447 /* Arch-specific module finalizing. */
3448 return module_finalize(info->hdr, info->sechdrs, mod);
3449}
3450
3451/* Is this module of this name done loading? No locks held. */
3452static bool finished_loading(const char *name)
3453{
3454 struct module *mod;
3455 bool ret;
3456
3457 /*
3458 * The module_mutex should not be a heavily contended lock;
3459 * if we get the occasional sleep here, we'll go an extra iteration
3460 * in the wait_event_interruptible(), which is harmless.
3461 */
3462 sched_annotate_sleep();
3463 mutex_lock(&module_mutex);
3464 mod = find_module_all(name, strlen(name), true);
3465 ret = !mod || mod->state == MODULE_STATE_LIVE;
3466 mutex_unlock(&module_mutex);
3467
3468 return ret;
3469}
3470
3471/* Call module constructors. */
3472static void do_mod_ctors(struct module *mod)
3473{
3474#ifdef CONFIG_CONSTRUCTORS
3475 unsigned long i;
3476
3477 for (i = 0; i < mod->num_ctors; i++)
3478 mod->ctors[i]();
3479#endif
3480}
3481
3482/* For freeing module_init on success, in case kallsyms traversing */
3483struct mod_initfree {
3484 struct llist_node node;
3485 void *module_init;
3486};
3487
3488static void do_free_init(struct work_struct *w)
3489{
3490 struct llist_node *pos, *n, *list;
3491 struct mod_initfree *initfree;
3492
3493 list = llist_del_all(&init_free_list);
3494
3495 synchronize_rcu();
3496
3497 llist_for_each_safe(pos, n, list) {
3498 initfree = container_of(pos, struct mod_initfree, node);
3499 module_memfree(initfree->module_init);
3500 kfree(initfree);
3501 }
3502}
3503
3504static int __init modules_wq_init(void)
3505{
3506 INIT_WORK(&init_free_wq, do_free_init);
3507 init_llist_head(&init_free_list);
3508 return 0;
3509}
3510module_init(modules_wq_init);
3511
3512/*
3513 * This is where the real work happens.
3514 *
3515 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3516 * helper command 'lx-symbols'.
3517 */
3518static noinline int do_init_module(struct module *mod)
3519{
3520 int ret = 0;
3521 struct mod_initfree *freeinit;
3522
3523 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3524 if (!freeinit) {
3525 ret = -ENOMEM;
3526 goto fail;
3527 }
3528 freeinit->module_init = mod->init_layout.base;
3529
3530 /*
3531 * We want to find out whether @mod uses async during init. Clear
3532 * PF_USED_ASYNC. async_schedule*() will set it.
3533 */
3534 current->flags &= ~PF_USED_ASYNC;
3535
3536 do_mod_ctors(mod);
3537 /* Start the module */
3538 if (mod->init != NULL)
3539 ret = do_one_initcall(mod->init);
3540 if (ret < 0) {
3541 goto fail_free_freeinit;
3542 }
3543 if (ret > 0) {
3544 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3545 "follow 0/-E convention\n"
3546 "%s: loading module anyway...\n",
3547 __func__, mod->name, ret, __func__);
3548 dump_stack();
3549 }
3550
3551 /* Now it's a first class citizen! */
3552 mod->state = MODULE_STATE_LIVE;
3553 blocking_notifier_call_chain(&module_notify_list,
3554 MODULE_STATE_LIVE, mod);
3555
3556 /*
3557 * We need to finish all async code before the module init sequence
3558 * is done. This has potential to deadlock. For example, a newly
3559 * detected block device can trigger request_module() of the
3560 * default iosched from async probing task. Once userland helper
3561 * reaches here, async_synchronize_full() will wait on the async
3562 * task waiting on request_module() and deadlock.
3563 *
3564 * This deadlock is avoided by perfomring async_synchronize_full()
3565 * iff module init queued any async jobs. This isn't a full
3566 * solution as it will deadlock the same if module loading from
3567 * async jobs nests more than once; however, due to the various
3568 * constraints, this hack seems to be the best option for now.
3569 * Please refer to the following thread for details.
3570 *
3571 * http://thread.gmane.org/gmane.linux.kernel/1420814
3572 */
3573 if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3574 async_synchronize_full();
3575
3576 ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base +
3577 mod->init_layout.size);
3578 mutex_lock(&module_mutex);
3579 /* Drop initial reference. */
3580 module_put(mod);
3581 trim_init_extable(mod);
3582#ifdef CONFIG_KALLSYMS
3583 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3584 rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3585#endif
3586 module_enable_ro(mod, true);
3587 mod_tree_remove_init(mod);
3588 module_arch_freeing_init(mod);
3589 mod->init_layout.base = NULL;
3590 mod->init_layout.size = 0;
3591 mod->init_layout.ro_size = 0;
3592 mod->init_layout.ro_after_init_size = 0;
3593 mod->init_layout.text_size = 0;
3594 /*
3595 * We want to free module_init, but be aware that kallsyms may be
3596 * walking this with preempt disabled. In all the failure paths, we
3597 * call synchronize_rcu(), but we don't want to slow down the success
3598 * path. module_memfree() cannot be called in an interrupt, so do the
3599 * work and call synchronize_rcu() in a work queue.
3600 *
3601 * Note that module_alloc() on most architectures creates W+X page
3602 * mappings which won't be cleaned up until do_free_init() runs. Any
3603 * code such as mark_rodata_ro() which depends on those mappings to
3604 * be cleaned up needs to sync with the queued work - ie
3605 * rcu_barrier()
3606 */
3607 if (llist_add(&freeinit->node, &init_free_list))
3608 schedule_work(&init_free_wq);
3609
3610 mutex_unlock(&module_mutex);
3611 wake_up_all(&module_wq);
3612
3613 return 0;
3614
3615fail_free_freeinit:
3616 kfree(freeinit);
3617fail:
3618 /* Try to protect us from buggy refcounters. */
3619 mod->state = MODULE_STATE_GOING;
3620 synchronize_rcu();
3621 module_put(mod);
3622 blocking_notifier_call_chain(&module_notify_list,
3623 MODULE_STATE_GOING, mod);
3624 klp_module_going(mod);
3625 ftrace_release_mod(mod);
3626 free_module(mod);
3627 wake_up_all(&module_wq);
3628 return ret;
3629}
3630
3631static int may_init_module(void)
3632{
3633 if (!capable(CAP_SYS_MODULE) || modules_disabled)
3634 return -EPERM;
3635
3636 return 0;
3637}
3638
3639/*
3640 * We try to place it in the list now to make sure it's unique before
3641 * we dedicate too many resources. In particular, temporary percpu
3642 * memory exhaustion.
3643 */
3644static int add_unformed_module(struct module *mod)
3645{
3646 int err;
3647 struct module *old;
3648
3649 mod->state = MODULE_STATE_UNFORMED;
3650
3651again:
3652 mutex_lock(&module_mutex);
3653 old = find_module_all(mod->name, strlen(mod->name), true);
3654 if (old != NULL) {
3655 if (old->state != MODULE_STATE_LIVE) {
3656 /* Wait in case it fails to load. */
3657 mutex_unlock(&module_mutex);
3658 err = wait_event_interruptible(module_wq,
3659 finished_loading(mod->name));
3660 if (err)
3661 goto out_unlocked;
3662 goto again;
3663 }
3664 err = -EEXIST;
3665 goto out;
3666 }
3667 mod_update_bounds(mod);
3668 list_add_rcu(&mod->list, &modules);
3669 mod_tree_insert(mod);
3670 err = 0;
3671
3672out:
3673 mutex_unlock(&module_mutex);
3674out_unlocked:
3675 return err;
3676}
3677
3678static int complete_formation(struct module *mod, struct load_info *info)
3679{
3680 int err;
3681
3682 mutex_lock(&module_mutex);
3683
3684 /* Find duplicate symbols (must be called under lock). */
3685 err = verify_exported_symbols(mod);
3686 if (err < 0)
3687 goto out;
3688
3689 /* This relies on module_mutex for list integrity. */
3690 module_bug_finalize(info->hdr, info->sechdrs, mod);
3691
3692 module_enable_ro(mod, false);
3693 module_enable_nx(mod);
3694 module_enable_x(mod);
3695
3696 /* Mark state as coming so strong_try_module_get() ignores us,
3697 * but kallsyms etc. can see us. */
3698 mod->state = MODULE_STATE_COMING;
3699 mutex_unlock(&module_mutex);
3700
3701 return 0;
3702
3703out:
3704 mutex_unlock(&module_mutex);
3705 return err;
3706}
3707
3708static int prepare_coming_module(struct module *mod)
3709{
3710 int err;
3711
3712 ftrace_module_enable(mod);
3713 err = klp_module_coming(mod);
3714 if (err)
3715 return err;
3716
3717 blocking_notifier_call_chain(&module_notify_list,
3718 MODULE_STATE_COMING, mod);
3719 return 0;
3720}
3721
3722static int unknown_module_param_cb(char *param, char *val, const char *modname,
3723 void *arg)
3724{
3725 struct module *mod = arg;
3726 int ret;
3727
3728 if (strcmp(param, "async_probe") == 0) {
3729 mod->async_probe_requested = true;
3730 return 0;
3731 }
3732
3733 /* Check for magic 'dyndbg' arg */
3734 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3735 if (ret != 0)
3736 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3737 return 0;
3738}
3739
3740/* Allocate and load the module: note that size of section 0 is always
3741 zero, and we rely on this for optional sections. */
3742static int load_module(struct load_info *info, const char __user *uargs,
3743 int flags)
3744{
3745 struct module *mod;
3746 long err = 0;
3747 char *after_dashes;
3748
3749 err = elf_header_check(info);
3750 if (err)
3751 goto free_copy;
3752
3753 err = setup_load_info(info, flags);
3754 if (err)
3755 goto free_copy;
3756
3757 if (blacklisted(info->name)) {
3758 err = -EPERM;
3759 goto free_copy;
3760 }
3761
3762 err = module_sig_check(info, flags);
3763 if (err)
3764 goto free_copy;
3765
3766 err = rewrite_section_headers(info, flags);
3767 if (err)
3768 goto free_copy;
3769
3770 /* Check module struct version now, before we try to use module. */
3771 if (!check_modstruct_version(info, info->mod)) {
3772 err = -ENOEXEC;
3773 goto free_copy;
3774 }
3775
3776 /* Figure out module layout, and allocate all the memory. */
3777 mod = layout_and_allocate(info, flags);
3778 if (IS_ERR(mod)) {
3779 err = PTR_ERR(mod);
3780 goto free_copy;
3781 }
3782
3783 audit_log_kern_module(mod->name);
3784
3785 /* Reserve our place in the list. */
3786 err = add_unformed_module(mod);
3787 if (err)
3788 goto free_module;
3789
3790#ifdef CONFIG_MODULE_SIG
3791 mod->sig_ok = info->sig_ok;
3792 if (!mod->sig_ok) {
3793 pr_notice_once("%s: module verification failed: signature "
3794 "and/or required key missing - tainting "
3795 "kernel\n", mod->name);
3796 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3797 }
3798#endif
3799
3800 /* To avoid stressing percpu allocator, do this once we're unique. */
3801 err = percpu_modalloc(mod, info);
3802 if (err)
3803 goto unlink_mod;
3804
3805 /* Now module is in final location, initialize linked lists, etc. */
3806 err = module_unload_init(mod);
3807 if (err)
3808 goto unlink_mod;
3809
3810 init_param_lock(mod);
3811
3812 /* Now we've got everything in the final locations, we can
3813 * find optional sections. */
3814 err = find_module_sections(mod, info);
3815 if (err)
3816 goto free_unload;
3817
3818 err = check_module_license_and_versions(mod);
3819 if (err)
3820 goto free_unload;
3821
3822 /* Set up MODINFO_ATTR fields */
3823 setup_modinfo(mod, info);
3824
3825 /* Fix up syms, so that st_value is a pointer to location. */
3826 err = simplify_symbols(mod, info);
3827 if (err < 0)
3828 goto free_modinfo;
3829
3830 err = apply_relocations(mod, info);
3831 if (err < 0)
3832 goto free_modinfo;
3833
3834 err = post_relocation(mod, info);
3835 if (err < 0)
3836 goto free_modinfo;
3837
3838 flush_module_icache(mod);
3839
3840 /* Now copy in args */
3841 mod->args = strndup_user(uargs, ~0UL >> 1);
3842 if (IS_ERR(mod->args)) {
3843 err = PTR_ERR(mod->args);
3844 goto free_arch_cleanup;
3845 }
3846
3847 dynamic_debug_setup(mod, info->debug, info->num_debug);
3848
3849 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3850 ftrace_module_init(mod);
3851
3852 /* Finally it's fully formed, ready to start executing. */
3853 err = complete_formation(mod, info);
3854 if (err)
3855 goto ddebug_cleanup;
3856
3857 err = prepare_coming_module(mod);
3858 if (err)
3859 goto bug_cleanup;
3860
3861 /* Module is ready to execute: parsing args may do that. */
3862 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3863 -32768, 32767, mod,
3864 unknown_module_param_cb);
3865 if (IS_ERR(after_dashes)) {
3866 err = PTR_ERR(after_dashes);
3867 goto coming_cleanup;
3868 } else if (after_dashes) {
3869 pr_warn("%s: parameters '%s' after `--' ignored\n",
3870 mod->name, after_dashes);
3871 }
3872
3873 /* Link in to sysfs. */
3874 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3875 if (err < 0)
3876 goto coming_cleanup;
3877
3878 if (is_livepatch_module(mod)) {
3879 err = copy_module_elf(mod, info);
3880 if (err < 0)
3881 goto sysfs_cleanup;
3882 }
3883
3884 /* Get rid of temporary copy. */
3885 free_copy(info);
3886
3887 /* Done! */
3888 trace_module_load(mod);
3889
3890 return do_init_module(mod);
3891
3892 sysfs_cleanup:
3893 mod_sysfs_teardown(mod);
3894 coming_cleanup:
3895 mod->state = MODULE_STATE_GOING;
3896 destroy_params(mod->kp, mod->num_kp);
3897 blocking_notifier_call_chain(&module_notify_list,
3898 MODULE_STATE_GOING, mod);
3899 klp_module_going(mod);
3900 bug_cleanup:
3901 /* module_bug_cleanup needs module_mutex protection */
3902 mutex_lock(&module_mutex);
3903 module_bug_cleanup(mod);
3904 mutex_unlock(&module_mutex);
3905
3906 ddebug_cleanup:
3907 ftrace_release_mod(mod);
3908 dynamic_debug_remove(mod, info->debug);
3909 synchronize_rcu();
3910 kfree(mod->args);
3911 free_arch_cleanup:
3912 module_arch_cleanup(mod);
3913 free_modinfo:
3914 free_modinfo(mod);
3915 free_unload:
3916 module_unload_free(mod);
3917 unlink_mod:
3918 mutex_lock(&module_mutex);
3919 /* Unlink carefully: kallsyms could be walking list. */
3920 list_del_rcu(&mod->list);
3921 mod_tree_remove(mod);
3922 wake_up_all(&module_wq);
3923 /* Wait for RCU-sched synchronizing before releasing mod->list. */
3924 synchronize_rcu();
3925 mutex_unlock(&module_mutex);
3926 free_module:
3927 /* Free lock-classes; relies on the preceding sync_rcu() */
3928 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
3929
3930 module_deallocate(mod, info);
3931 free_copy:
3932 free_copy(info);
3933 return err;
3934}
3935
3936SYSCALL_DEFINE3(init_module, void __user *, umod,
3937 unsigned long, len, const char __user *, uargs)
3938{
3939 int err;
3940 struct load_info info = { };
3941
3942 err = may_init_module();
3943 if (err)
3944 return err;
3945
3946 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3947 umod, len, uargs);
3948
3949 err = copy_module_from_user(umod, len, &info);
3950 if (err)
3951 return err;
3952
3953 return load_module(&info, uargs, 0);
3954}
3955
3956SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3957{
3958 struct load_info info = { };
3959 loff_t size;
3960 void *hdr;
3961 int err;
3962
3963 err = may_init_module();
3964 if (err)
3965 return err;
3966
3967 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3968
3969 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3970 |MODULE_INIT_IGNORE_VERMAGIC))
3971 return -EINVAL;
3972
3973 err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX,
3974 READING_MODULE);
3975 if (err)
3976 return err;
3977 info.hdr = hdr;
3978 info.len = size;
3979
3980 return load_module(&info, uargs, flags);
3981}
3982
3983static inline int within(unsigned long addr, void *start, unsigned long size)
3984{
3985 return ((void *)addr >= start && (void *)addr < start + size);
3986}
3987
3988#ifdef CONFIG_KALLSYMS
3989/*
3990 * This ignores the intensely annoying "mapping symbols" found
3991 * in ARM ELF files: $a, $t and $d.
3992 */
3993static inline int is_arm_mapping_symbol(const char *str)
3994{
3995 if (str[0] == '.' && str[1] == 'L')
3996 return true;
3997 return str[0] == '$' && strchr("axtd", str[1])
3998 && (str[2] == '\0' || str[2] == '.');
3999}
4000
4001static const char *kallsyms_symbol_name(struct mod_kallsyms *kallsyms, unsigned int symnum)
4002{
4003 return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
4004}
4005
4006/*
4007 * Given a module and address, find the corresponding symbol and return its name
4008 * while providing its size and offset if needed.
4009 */
4010static const char *find_kallsyms_symbol(struct module *mod,
4011 unsigned long addr,
4012 unsigned long *size,
4013 unsigned long *offset)
4014{
4015 unsigned int i, best = 0;
4016 unsigned long nextval, bestval;
4017 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4018
4019 /* At worse, next value is at end of module */
4020 if (within_module_init(addr, mod))
4021 nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
4022 else
4023 nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
4024
4025 bestval = kallsyms_symbol_value(&kallsyms->symtab[best]);
4026
4027 /* Scan for closest preceding symbol, and next symbol. (ELF
4028 starts real symbols at 1). */
4029 for (i = 1; i < kallsyms->num_symtab; i++) {
4030 const Elf_Sym *sym = &kallsyms->symtab[i];
4031 unsigned long thisval = kallsyms_symbol_value(sym);
4032
4033 if (sym->st_shndx == SHN_UNDEF)
4034 continue;
4035
4036 /* We ignore unnamed symbols: they're uninformative
4037 * and inserted at a whim. */
4038 if (*kallsyms_symbol_name(kallsyms, i) == '\0'
4039 || is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms, i)))
4040 continue;
4041
4042 if (thisval <= addr && thisval > bestval) {
4043 best = i;
4044 bestval = thisval;
4045 }
4046 if (thisval > addr && thisval < nextval)
4047 nextval = thisval;
4048 }
4049
4050 if (!best)
4051 return NULL;
4052
4053 if (size)
4054 *size = nextval - bestval;
4055 if (offset)
4056 *offset = addr - bestval;
4057
4058 return kallsyms_symbol_name(kallsyms, best);
4059}
4060
4061void * __weak dereference_module_function_descriptor(struct module *mod,
4062 void *ptr)
4063{
4064 return ptr;
4065}
4066
4067/* For kallsyms to ask for address resolution. NULL means not found. Careful
4068 * not to lock to avoid deadlock on oopses, simply disable preemption. */
4069const char *module_address_lookup(unsigned long addr,
4070 unsigned long *size,
4071 unsigned long *offset,
4072 char **modname,
4073 char *namebuf)
4074{
4075 const char *ret = NULL;
4076 struct module *mod;
4077
4078 preempt_disable();
4079 mod = __module_address(addr);
4080 if (mod) {
4081 if (modname)
4082 *modname = mod->name;
4083
4084 ret = find_kallsyms_symbol(mod, addr, size, offset);
4085 }
4086 /* Make a copy in here where it's safe */
4087 if (ret) {
4088 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
4089 ret = namebuf;
4090 }
4091 preempt_enable();
4092
4093 return ret;
4094}
4095
4096int lookup_module_symbol_name(unsigned long addr, char *symname)
4097{
4098 struct module *mod;
4099
4100 preempt_disable();
4101 list_for_each_entry_rcu(mod, &modules, list) {
4102 if (mod->state == MODULE_STATE_UNFORMED)
4103 continue;
4104 if (within_module(addr, mod)) {
4105 const char *sym;
4106
4107 sym = find_kallsyms_symbol(mod, addr, NULL, NULL);
4108 if (!sym)
4109 goto out;
4110
4111 strlcpy(symname, sym, KSYM_NAME_LEN);
4112 preempt_enable();
4113 return 0;
4114 }
4115 }
4116out:
4117 preempt_enable();
4118 return -ERANGE;
4119}
4120
4121int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
4122 unsigned long *offset, char *modname, char *name)
4123{
4124 struct module *mod;
4125
4126 preempt_disable();
4127 list_for_each_entry_rcu(mod, &modules, list) {
4128 if (mod->state == MODULE_STATE_UNFORMED)
4129 continue;
4130 if (within_module(addr, mod)) {
4131 const char *sym;
4132
4133 sym = find_kallsyms_symbol(mod, addr, size, offset);
4134 if (!sym)
4135 goto out;
4136 if (modname)
4137 strlcpy(modname, mod->name, MODULE_NAME_LEN);
4138 if (name)
4139 strlcpy(name, sym, KSYM_NAME_LEN);
4140 preempt_enable();
4141 return 0;
4142 }
4143 }
4144out:
4145 preempt_enable();
4146 return -ERANGE;
4147}
4148
4149int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
4150 char *name, char *module_name, int *exported)
4151{
4152 struct module *mod;
4153
4154 preempt_disable();
4155 list_for_each_entry_rcu(mod, &modules, list) {
4156 struct mod_kallsyms *kallsyms;
4157
4158 if (mod->state == MODULE_STATE_UNFORMED)
4159 continue;
4160 kallsyms = rcu_dereference_sched(mod->kallsyms);
4161 if (symnum < kallsyms->num_symtab) {
4162 const Elf_Sym *sym = &kallsyms->symtab[symnum];
4163
4164 *value = kallsyms_symbol_value(sym);
4165 *type = kallsyms->typetab[symnum];
4166 strlcpy(name, kallsyms_symbol_name(kallsyms, symnum), KSYM_NAME_LEN);
4167 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
4168 *exported = is_exported(name, *value, mod);
4169 preempt_enable();
4170 return 0;
4171 }
4172 symnum -= kallsyms->num_symtab;
4173 }
4174 preempt_enable();
4175 return -ERANGE;
4176}
4177
4178/* Given a module and name of symbol, find and return the symbol's value */
4179static unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name)
4180{
4181 unsigned int i;
4182 struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
4183
4184 for (i = 0; i < kallsyms->num_symtab; i++) {
4185 const Elf_Sym *sym = &kallsyms->symtab[i];
4186
4187 if (strcmp(name, kallsyms_symbol_name(kallsyms, i)) == 0 &&
4188 sym->st_shndx != SHN_UNDEF)
4189 return kallsyms_symbol_value(sym);
4190 }
4191 return 0;
4192}
4193
4194/* Look for this name: can be of form module:name. */
4195unsigned long module_kallsyms_lookup_name(const char *name)
4196{
4197 struct module *mod;
4198 char *colon;
4199 unsigned long ret = 0;
4200
4201 /* Don't lock: we're in enough trouble already. */
4202 preempt_disable();
4203 if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
4204 if ((mod = find_module_all(name, colon - name, false)) != NULL)
4205 ret = find_kallsyms_symbol_value(mod, colon+1);
4206 } else {
4207 list_for_each_entry_rcu(mod, &modules, list) {
4208 if (mod->state == MODULE_STATE_UNFORMED)
4209 continue;
4210 if ((ret = find_kallsyms_symbol_value(mod, name)) != 0)
4211 break;
4212 }
4213 }
4214 preempt_enable();
4215 return ret;
4216}
4217
4218int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
4219 struct module *, unsigned long),
4220 void *data)
4221{
4222 struct module *mod;
4223 unsigned int i;
4224 int ret;
4225
4226 module_assert_mutex();
4227
4228 list_for_each_entry(mod, &modules, list) {
4229 /* We hold module_mutex: no need for rcu_dereference_sched */
4230 struct mod_kallsyms *kallsyms = mod->kallsyms;
4231
4232 if (mod->state == MODULE_STATE_UNFORMED)
4233 continue;
4234 for (i = 0; i < kallsyms->num_symtab; i++) {
4235 const Elf_Sym *sym = &kallsyms->symtab[i];
4236
4237 if (sym->st_shndx == SHN_UNDEF)
4238 continue;
4239
4240 ret = fn(data, kallsyms_symbol_name(kallsyms, i),
4241 mod, kallsyms_symbol_value(sym));
4242 if (ret != 0)
4243 return ret;
4244 }
4245 }
4246 return 0;
4247}
4248#endif /* CONFIG_KALLSYMS */
4249
4250/* Maximum number of characters written by module_flags() */
4251#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
4252
4253/* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
4254static char *module_flags(struct module *mod, char *buf)
4255{
4256 int bx = 0;
4257
4258 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
4259 if (mod->taints ||
4260 mod->state == MODULE_STATE_GOING ||
4261 mod->state == MODULE_STATE_COMING) {
4262 buf[bx++] = '(';
4263 bx += module_flags_taint(mod, buf + bx);
4264 /* Show a - for module-is-being-unloaded */
4265 if (mod->state == MODULE_STATE_GOING)
4266 buf[bx++] = '-';
4267 /* Show a + for module-is-being-loaded */
4268 if (mod->state == MODULE_STATE_COMING)
4269 buf[bx++] = '+';
4270 buf[bx++] = ')';
4271 }
4272 buf[bx] = '\0';
4273
4274 return buf;
4275}
4276
4277#ifdef CONFIG_PROC_FS
4278/* Called by the /proc file system to return a list of modules. */
4279static void *m_start(struct seq_file *m, loff_t *pos)
4280{
4281 mutex_lock(&module_mutex);
4282 return seq_list_start(&modules, *pos);
4283}
4284
4285static void *m_next(struct seq_file *m, void *p, loff_t *pos)
4286{
4287 return seq_list_next(p, &modules, pos);
4288}
4289
4290static void m_stop(struct seq_file *m, void *p)
4291{
4292 mutex_unlock(&module_mutex);
4293}
4294
4295static int m_show(struct seq_file *m, void *p)
4296{
4297 struct module *mod = list_entry(p, struct module, list);
4298 char buf[MODULE_FLAGS_BUF_SIZE];
4299 void *value;
4300
4301 /* We always ignore unformed modules. */
4302 if (mod->state == MODULE_STATE_UNFORMED)
4303 return 0;
4304
4305 seq_printf(m, "%s %u",
4306 mod->name, mod->init_layout.size + mod->core_layout.size);
4307 print_unload_info(m, mod);
4308
4309 /* Informative for users. */
4310 seq_printf(m, " %s",
4311 mod->state == MODULE_STATE_GOING ? "Unloading" :
4312 mod->state == MODULE_STATE_COMING ? "Loading" :
4313 "Live");
4314 /* Used by oprofile and other similar tools. */
4315 value = m->private ? NULL : mod->core_layout.base;
4316 seq_printf(m, " 0x%px", value);
4317
4318 /* Taints info */
4319 if (mod->taints)
4320 seq_printf(m, " %s", module_flags(mod, buf));
4321
4322 seq_puts(m, "\n");
4323 return 0;
4324}
4325
4326/* Format: modulename size refcount deps address
4327
4328 Where refcount is a number or -, and deps is a comma-separated list
4329 of depends or -.
4330*/
4331static const struct seq_operations modules_op = {
4332 .start = m_start,
4333 .next = m_next,
4334 .stop = m_stop,
4335 .show = m_show
4336};
4337
4338/*
4339 * This also sets the "private" pointer to non-NULL if the
4340 * kernel pointers should be hidden (so you can just test
4341 * "m->private" to see if you should keep the values private).
4342 *
4343 * We use the same logic as for /proc/kallsyms.
4344 */
4345static int modules_open(struct inode *inode, struct file *file)
4346{
4347 int err = seq_open(file, &modules_op);
4348
4349 if (!err) {
4350 struct seq_file *m = file->private_data;
4351 m->private = kallsyms_show_value() ? NULL : (void *)8ul;
4352 }
4353
4354 return err;
4355}
4356
4357static const struct proc_ops modules_proc_ops = {
4358 .proc_open = modules_open,
4359 .proc_read = seq_read,
4360 .proc_lseek = seq_lseek,
4361 .proc_release = seq_release,
4362};
4363
4364static int __init proc_modules_init(void)
4365{
4366 proc_create("modules", 0, NULL, &modules_proc_ops);
4367 return 0;
4368}
4369module_init(proc_modules_init);
4370#endif
4371
4372/* Given an address, look for it in the module exception tables. */
4373const struct exception_table_entry *search_module_extables(unsigned long addr)
4374{
4375 const struct exception_table_entry *e = NULL;
4376 struct module *mod;
4377
4378 preempt_disable();
4379 mod = __module_address(addr);
4380 if (!mod)
4381 goto out;
4382
4383 if (!mod->num_exentries)
4384 goto out;
4385
4386 e = search_extable(mod->extable,
4387 mod->num_exentries,
4388 addr);
4389out:
4390 preempt_enable();
4391
4392 /*
4393 * Now, if we found one, we are running inside it now, hence
4394 * we cannot unload the module, hence no refcnt needed.
4395 */
4396 return e;
4397}
4398
4399/*
4400 * is_module_address - is this address inside a module?
4401 * @addr: the address to check.
4402 *
4403 * See is_module_text_address() if you simply want to see if the address
4404 * is code (not data).
4405 */
4406bool is_module_address(unsigned long addr)
4407{
4408 bool ret;
4409
4410 preempt_disable();
4411 ret = __module_address(addr) != NULL;
4412 preempt_enable();
4413
4414 return ret;
4415}
4416
4417/*
4418 * __module_address - get the module which contains an address.
4419 * @addr: the address.
4420 *
4421 * Must be called with preempt disabled or module mutex held so that
4422 * module doesn't get freed during this.
4423 */
4424struct module *__module_address(unsigned long addr)
4425{
4426 struct module *mod;
4427
4428 if (addr < module_addr_min || addr > module_addr_max)
4429 return NULL;
4430
4431 module_assert_mutex_or_preempt();
4432
4433 mod = mod_find(addr);
4434 if (mod) {
4435 BUG_ON(!within_module(addr, mod));
4436 if (mod->state == MODULE_STATE_UNFORMED)
4437 mod = NULL;
4438 }
4439 return mod;
4440}
4441EXPORT_SYMBOL_GPL(__module_address);
4442
4443/*
4444 * is_module_text_address - is this address inside module code?
4445 * @addr: the address to check.
4446 *
4447 * See is_module_address() if you simply want to see if the address is
4448 * anywhere in a module. See kernel_text_address() for testing if an
4449 * address corresponds to kernel or module code.
4450 */
4451bool is_module_text_address(unsigned long addr)
4452{
4453 bool ret;
4454
4455 preempt_disable();
4456 ret = __module_text_address(addr) != NULL;
4457 preempt_enable();
4458
4459 return ret;
4460}
4461
4462/*
4463 * __module_text_address - get the module whose code contains an address.
4464 * @addr: the address.
4465 *
4466 * Must be called with preempt disabled or module mutex held so that
4467 * module doesn't get freed during this.
4468 */
4469struct module *__module_text_address(unsigned long addr)
4470{
4471 struct module *mod = __module_address(addr);
4472 if (mod) {
4473 /* Make sure it's within the text section. */
4474 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
4475 && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
4476 mod = NULL;
4477 }
4478 return mod;
4479}
4480EXPORT_SYMBOL_GPL(__module_text_address);
4481
4482/* Don't grab lock, we're oopsing. */
4483void print_modules(void)
4484{
4485 struct module *mod;
4486 char buf[MODULE_FLAGS_BUF_SIZE];
4487
4488 printk(KERN_DEFAULT "Modules linked in:");
4489 /* Most callers should already have preempt disabled, but make sure */
4490 preempt_disable();
4491 list_for_each_entry_rcu(mod, &modules, list) {
4492 if (mod->state == MODULE_STATE_UNFORMED)
4493 continue;
4494 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4495 }
4496 preempt_enable();
4497 if (last_unloaded_module[0])
4498 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4499 pr_cont("\n");
4500}
4501
4502#ifdef CONFIG_MODVERSIONS
4503/* Generate the signature for all relevant module structures here.
4504 * If these change, we don't want to try to parse the module. */
4505void module_layout(struct module *mod,
4506 struct modversion_info *ver,
4507 struct kernel_param *kp,
4508 struct kernel_symbol *ks,
4509 struct tracepoint * const *tp)
4510{
4511}
4512EXPORT_SYMBOL(module_layout);
4513#endif